NYU Health Sciences Libraries Faculty Bibliography

Ann Marie Schmidt

School of Medicine. Medicine. Endocrinology; Pathology; Biochemistry and Molecular Pharmacology. Dr. Iven Young Professor of Endocrinology and Professor of Pathology and Professor of Biochemistry and Molecular Pharmacology, 1984-
  1. Tsukiji, Jun; Cho, Soo Jung; Echevarria, Ghislaine C; Kwon, Sophia; Joseph, Phillip; Schenck, Edward J; Naveed, Bushra; Prezant, David J; Rom, William N; Schmidt, Ann Marie; Weiden, Michael D; Nolan, Anna. "Lysophosphatidic acid and apolipoprotein A1 predict increased risk of developing World Trade Center-lung injury: a nested case-control study". Biomarkers. 2014 Mar;19(2):159-165 (MEDL:24548082 #820982)       

    Abstract Rationale: Metabolic syndrome, inflammatory and vascular injury markers measured in serum after World Trade Center (WTC) exposures predict abnormal FEV1. We hypothesized that elevated LPA levels predict FEV1 < LLN. Methods: Nested case-control study of WTC-exposed firefighters. Cases had FEV1 < LLN. Controls derived from the baseline cohort. Demographics, pulmonary function, serum lipids, LPA and ApoA1 were measured. Results: LPA and ApoA1 levels were higher in cases than controls and predictive of case status. LPA increased the odds by 13% while ApoA1 increased the odds by 29% of an FEV1 < LLN in a multivariable model. Conclusions: Elevated LPA and ApoA1 are predictive of a significantly increased risk of developing an FEV1 < LLN.
  2. Vedantham, Srinivasan; Thiagarajan, Devi; Ananthakrishnan, Radha; Wang, Lingjie; Rosario, Rosa; Zou, Yu Shan; Goldberg, Ira; Yan, Shi Fang; Schmidt, Ann Marie; Ramasamy, Ravichandran. "Aldose reductase drives hyperacetylation of egr-1 in hyperglycemia and consequent upregulation of proinflammatory and prothrombotic signals". Diabetes. 2014 Feb;63(2):761-774 (MEDL:24186862 #777962)       

    Sustained increases in glucose flux via the aldose reductase (AR) pathway have been linked to diabetic vascular complications. Previous studies revealed that glucose flux via AR mediates endothelial dysfunction and leads to lesional hemorrhage in diabetic human AR (hAR) expressing mice in an apoE(-/-) background. Our studies revealed sustained activation of Egr-1 with subsequent induction of its downstream target genes tissue factor (TF) and vascular cell adhesion molecule-1 (VCAM-1) in diabetic apoE(-/-)hAR mice aortas and in high glucose-treated primary murine aortic endothelial cells expressing hAR. Furthermore, we observed that flux via AR impaired NAD(+) homeostasis and reduced activity of NAD(+)-dependent deacetylase Sirt-1 leading to acetylation and prolonged expression of Egr-1 in hyperglycemic conditions. In conclusion, our data demonstrate a novel mechanism by which glucose flux via AR triggers activation, acetylation, and prolonged expression of Egr-1 leading to proinflammatory and prothrombotic responses in diabetic atherosclerosis.
  3. Abedini, Andisheh; Schmidt, Ann Marie. "Mechanisms of islet amyloidosis toxicity in type 2 diabetes". FEBS letters. 2013 Apr;587(8):1119-1127 (MEDL:23337872 #287162)       

    Amyloid formation by the neuropancreatic hormone, islet amyloid polypeptide (IAPP or amylin), one of the most amyloidogenic sequences known, leads to islet amyloidosis in type 2 diabetes and to islet transplant failure. Under normal conditions, IAPP plays a role in the maintenance of energy homeostasis by regulating several metabolic parameters, such as satiety, blood glucose levels, adiposity and body weight. The mechanisms of IAPP amyloid formation, the nature of IAPP toxic species and the cellular pathways that lead to pancreatic beta-cell toxicity are not well characterized. Several mechanisms of toxicity, including receptor and non-receptor-mediated events, have been proposed. Analogs of IAPP have been approved for the treatment of diabetes and are under investigation for the treatment of obesity.
  4. Ananthakrishnan, Radha; Li, Qing; O'Shea, Karen M; Quadri, Nosirudeen; Wang, Lingjie; Abuchowski, Abraham; Schmidt, Ann Marie; Ramasamy, Ravichandran. "Carbon monoxide form of PEGylated hemoglobin protects myocardium against ischemia/reperfusion injury in diabetic and normal mice". Artificial cells, nanomedicine, & biotechnology. 2013 Dec;41(6):428-436 (MEDL:23342967 #665972)       

    Abstract We investigated the pre-clinical utility of carbon monoxide form of PEGylated hemoglobin (PEG-Hb also named SANGUINATE()) in myocardial infarction (MI) and in particular the response of diabetic tissues to superimposed ischemia/reperfusion injury. SANGUINATE() was evaluated in diabetic and normal mice subjected to 30 min of coronary artery ligation followed by either 48 h or 28 days of reperfusion. Our results demonstrate that SANGUINATE() was effective in reducing infarct size when administered either prior to left anterior descending coronary artery (LAD) occlusion or during reperfusion. This finding is an important step in exploring the efficacy of a pharmacoinvasive strategy using SANGUINATE() in patients with acute coronary syndromes.
  5. Bao, Li; Taskin, Eylem; Foster, Monique; Ray, Beevash; Rosario, Rosa; Ananthakrishnan, Radha; Howlett, Susan E; Schmidt, Ann M; Ramasamy, Ravichandran; Coetzee, William A. "Alterations in ventricular K(ATP) channel properties during aging". Aging Cell. 2013 Feb;12(1):167-176 (MEDL:23173756 #213602)       

    Coronary heart disease remains the principle cause of mortality in the United States. During aging, the efficiency of the cardiovascular system is decreased and the aged heart is less tolerant to ischemic injury. ATP-sensitive K(+) (K(ATP) ) channels protect the myocardium against ischemic damage. We investigated how aging affects cardiac K(ATP) channels in the Fischer 344 rat model. Expression of K(ATP) channel subunit mRNA and protein levels was unchanged in hearts from 26-month-old vs. 4-month-old rats. Interestingly, the mRNA expression of several other ion channels (> 80) was also largely unchanged, suggesting that posttranscriptional regulatory mechanisms occur during aging. The whole-cell K(ATP) channel current density was strongly diminished in ventricular myocytes from aged male rat hearts (also observed in aged C57BL/6 mouse myocytes). Experiments with isolated patches (inside-out configuration) demonstrated that the K(ATP) channel unitary conductance was unchanged, but that the inhibitory effect of cytosolic ATP on channel activity was enhanced in the aged heart. The mean patch current was diminished, consistent with the whole-cell data. We incorporated these findings into an empirical model of the K(ATP) channel and numerically simulated the effects of decreased cytosolic ATP levels on the human action potential. This analysis predicts lesser activation of K(ATP) channels by metabolic impairment in the aged heart and a diminished action potential shortening. This study provides insights into the changes in K(ATP) channels during aging and suggests that the protective role of these channels during ischemia is significantly compromised in the aged individual.
  6. Bowman, Marion A Hofmann; Schmidt, Ann Marie. "The next generation of RAGE modulators: implications for soluble RAGE therapies in vascular inflammation". Journal of Molecular Medicine (Berlin). 2013 Dec;91(12):1329-1331 (MEDL:24196572 #746702)       
  7. Cao, Ping; Abedini, Andisheh; Wang, Hui; Tu, Ling-Hsien; Zhang, Xiaoxue; Schmidt, Ann Marie; Raleigh, Daniel P. "Islet amyloid polypeptide toxicity and membrane interactions". Proceedings of the National Academy of Sciences of the United States of America. 2013 Nov;110(48):19279-19284 (MEDL:24218607 #688142)       

    Islet amyloid polypeptide (IAPP) is responsible for amyloid formation in type 2 diabetes and contributes to the failure of islet cell transplants, however the mechanisms of IAPP-induced cytotoxicity are not known. Interactions with model anionic membranes are known to catalyze IAPP amyloid formation in vitro. Human IAPP damages anionic membranes, promoting vesicle leakage, but the features that control IAPP-membrane interactions and the connection with cellular toxicity are not clear. Kinetic studies with wild-type IAPP and IAPP mutants demonstrate that membrane leakage is induced by prefibrillar IAPP species and continues over the course of amyloid formation, correlating additional membrane disruption with fibril growth. Analyses of a set of designed mutants reveal that membrane leakage does not require the formation of beta-sheet or alpha-helical structures. A His-18 to Arg substitution enhances leakage, whereas replacement of all of the aromatic residues via a triple leucine mutant has no effect. Biophysical measurements in conjunction with cytotoxicity studies show that nonamyloidogenic rat IAPP is as effective as human IAPP at disrupting standard anionic model membranes under conditions where rat IAPP does not induce cellular toxicity. Similar results are obtained with more complex model membranes, including ternary systems that contain cholesterol and are capable of forming lipid rafts. A designed point mutant, I26P-IAPP; a designed double mutant, G24P, I26P-IAPP; a double N-methylated variant; and pramlintide, a US Food and Drug Administration-approved IAPP variant all induce membrane leakage, but are not cytotoxic, showing that there is no one-to-one relationship between disruption of model membranes and induction of cellular toxicity.
  8. Cho, SJ; Kwon, S; Naveed, B; Schenck, E; Tsukiji, J; Schmidt, AM; Prezant, DJ; Rom, WN; Weiden, M; Nolan, A. "RAGE Mediates LPA Induced Pulmonary Inflammation [Meeting Abstract]". American journal of respiratory & critical care medicine. 2013;187:A3787-A3787 (ORIGINAL:0008098 #291382)    
  9. Colombo, Paolo C; Onat, Duygu; Harxhi, Ante; Demmer, Ryan T; Hayashi, Yacki; Jelic, Sanja; Lejemtel, Thierry H; Bucciarelli, Loredana; Kebschull, Moritz; Papapanou, Panos; Uriel, Nir; Schmidt, Ann Marie; Sabbah, Hani N; Jorde, Ulrich P. "Peripheral venous congestion causes inflammation, neurohormonal, and endothelial cell activation". European heart journal. 2013 Nov;:19279-19284 (MEDL:24265434 #778762)       

    AIMS: Volume overload and venous congestion are typically viewed as a consequence of advanced and of acute heart failure (HF) and renal failure (RF) although it is possible that hypervolaemia itself might be a critical intermediate in the pathophysiology of these diseases. This study aimed at elucidating whether peripheral venous congestion is sufficient to promote changes in inflammatory, neurohormonal, and endothelial phenotype similar to those observed in HF and RF. METHODS: To experimentally model peripheral venous congestion, we developed a new method (so-called venous stress test) and applied the methodology on 24 healthy subjects (14 men, age 35 +/- 2 years). Venous arm pressure was increased to approximately 30 mmHg above the baseline level by inflating a tourniquet cuff around the dominant arm (test arm). Blood and endothelial cells (ECs) were sampled from test and control arm (lacking an inflated cuff) before and after 75 min of venous congestion, using angiocatheters and endovascular wires. Magnetic beads coated with EC-specific antibodies were used for EC separation; amplified mRNA was analysed by Affymetrix HG-U133 Plus 2.0 Microarray. RESULTS: Plasma interleukin-6 (IL-6), endothelin-1 (ET-1), angiotensin II (AII), vascular cell adhesion molecule-1 (VCAM-1), and chemokine (C-X-C motif) ligand 2 (CXCL2) were significantly increased in the congested arm. A total of 3437 mRNA probe sets were differentially expressed (P < 0.05) in venous ECs before vs. after testing, including ET-1, VCAM-1, and CXCL2. CONCLUSION: Peripheral venous congestion causes release of inflammatory mediators, neurohormones, and activation of ECs. Overall, venous congestion mimicked, notable aspects of the phenotype typical of advanced and of acute HF and RF.
  10. Daffu, Gurdip; Del Pozo, Carmen Hurtado; O'Shea, Karen M; Ananthakrishnan, Radha; Ramasamy, Ravichandran; Schmidt, Ann Marie. "Radical Roles for RAGE in the Pathogenesis of Oxidative Stress in Cardiovascular Diseases and Beyond". International journal of molecular sciences. 2013;14(10):19891-19910 (MEDL:24084731 #574032)       

    Oxidative stress is a central mechanism by which the receptor for advanced glycation endproducts (RAGE) mediates its pathological effects. Multiple experimental inquiries in RAGE-expressing cultured cells have demonstrated that ligand-RAGE interaction mediates generation of reactive oxygen species (ROS) and consequent downstream signal transduction and regulation of gene expression. The primary mechanism by which RAGE generates oxidative stress is via activation of NADPH oxidase; amplification mechanisms in the mitochondria may further drive ROS production. Recent studies indicating that the cytoplasmic domain of RAGE binds to the formin mDia1 provide further support for the critical roles of this pathway in oxidative stress; mDia1 was required for activation of rac1 and NADPH oxidase in primary murine aortic smooth muscle cells treated with RAGE ligand S100B. In vivo, in multiple distinct disease models in animals, RAGE action generates oxidative stress and modulates cellular/tissue fate in range of disorders, such as in myocardial ischemia, atherosclerosis, and aneurysm formation. Blockade or genetic deletion of RAGE was shown to be protective in these settings. Indeed, beyond cardiovascular disease, evidence is accruing in human subjects linking levels of RAGE ligands and soluble RAGE to oxidative stress in disorders such as doxorubicin toxicity, acetaminophen toxicity, neurodegeneration, hyperlipidemia, diabetes, preeclampsia, rheumatoid arthritis and pulmonary fibrosis. Blockade of RAGE signal transduction may be a key strategy for the prevention of the deleterious consequences of oxidative stress, particularly in chronic disease.
  11. Juranek, Judyta K; Geddis, Matthew S; Kothary, Pratik; Hays, Arthur; Schmidt, Ann Marie; Brannagan, Thomas H 3rd. "Reduced expression of Munc13-1 in human and porcine diabetic peripheral nerve". Acta histochemica. 2013 Jul;:106-111 (MEDL:23830992 #528202)       

    Peripheral neuropathy (PN) involves widespread peripheral nerve disorders affecting a large human population worldwide. In Europe and the United States, the first single most prominent cause of peripheral neuropathy is diabetes, affecting 60-70% patients with long-term diabetes followed by idiopathic neuropathy, peripheral nerve damage of unknown etiology, diagnosed in 10-40% of all patients admitted to hospitals with symptoms of peripheral nerve damage. The molecular mechanisms underlying the pathogenesis of this disorder are not yet fully understood, however a few potential molecular contributors, such as Munc13-1, have been recently suggested. Munc13-1 is a diacylglycerol (DAG) receptor and a multifunction active zone protein essential for synaptic vesicle priming and crucial for insulin release from pancreatic beta cells. Here, for the first time, we focused on the comparative expression of Munc13-1 in human and porcine peripheral nerves. Our results revealed significantly reduced number of Munc13-1 in human (64.26%+/-6.68%) and porcine (84.09%+/-2.21%) diabetic nerve fibers and lower number of the double stained, neuronal marker, Neurofilament (NF) and Munc13-1 positive, human (56.83%+/-3.77%) and porcine (65.87%+/-4.86%) nerve fibers. Optical density quantification of Western blots showed similar results. Our study indicates that Munc13-1, on account of its role in both insulin and neurotransmitter exocytosis and through its binding properties, may be an important factor contributing to the development or progression of diabetic neuropathy.
  12. Juranek, Judyta K; Geddis, Matthew S; Rosario, Rosa; Schmidt, Ann Marie. "Impaired slow axonal transport in diabetic peripheral nerve is independent of RAGE". European journal of neuroscience. 2013 Aug;:3159-3168 (MEDL:23941591 #528192)       

    Diabetic peripheral nerve dysfunction is a common complication occurring in 30-50% of long-term diabetic patients. The pathogenesis of this dysfunction remains unclear but growing evidence suggests that it might be attributed, in part, to alteration in axonal transport. Our previous studies demonstrated that RAGE (Receptor for Advanced Glycation Endproducts) contributes to the pathogenesis of diabetic peripheral neuropathy and impairs nerve regeneration consequent to sciatic nerve crush, particularly in diabetes. We hypothesize that RAGE plays a role in axonal transport impairment via the interaction of its cytoplasmic domain with mammalian Diaphanous 1 (mDia1) - actin interacting molecule. Studies showed that mDia1-RAGE interaction is necessary for RAGE-ligand-dependent cellular migration, AKT phosphorylation, macrophage inflammatory response and smooth muscle migration. Here, we studied RAGE, mDia1 and markers of axonal transport rates in the peripheral nerves of wild-type C57BL/6 and RAGE null control and streptozotocin-injected diabetic mice at 1, 3 and 6 h after sciatic nerve crush. The results show that in both control and diabetic nerves, the amount of RAGE accumulated at the proximal and distal side of the crush area is similar, indicating that the recycling rate for RAGE is very high and that it is evenly transported from and towards the neuronal cell body. Furthermore, we show that slow axonal transport of proteins such as Neurofilament is affected by diabetes in a RAGE-independent manner. Finally, our study demonstrates that mDia1 axonal transport is impaired in diabetes, suggesting that diabetes-related changes affecting actin binding proteins occur early in the course of the disease.
  13. Juranek, Judyta K; Geddis, Matthew S; Song, Fei; Zhang, Jinghua; Garcia, Jose; Rosario, Rosa; Yan, Shi Fang; Brannagan, Thomas H; Schmidt, Ann Marie. "RAGE Deficiency Improves Postinjury Sciatic Nerve Regeneration in Type 1 Diabetic Mice". Diabetes. 2013 Mar;62(3):931-943 (MEDL:23172920 #250702)       

    Peripheral neuropathy and insensate limbs and digits cause significant morbidity in diabetic individuals. Previous studies showed that deletion of the receptor for advanced end-glycation products (RAGE) in mice was protective in long-term diabetic neuropathy. Here, we tested the hypothesis that RAGE suppresses effective axonal regeneration in superimposed acute peripheral nerve injury attributable to tissue-damaging inflammatory responses. We report that deletion of RAGE, particularly in diabetic mice, resulted in significantly higher myelinated fiber densities and conduction velocities consequent to acute sciatic nerve crush compared with wild-type control animals. Consistent with key roles for RAGE-dependent inflammation, reconstitution of diabetic wild-type mice with RAGE-null versus wild-type bone marrow resulted in significantly improved axonal regeneration and restoration of function. Diabetic RAGE-null mice displayed higher numbers of invading macrophages in the nerve segments postcrush compared with wild-type animals, and these macrophages in diabetic RAGE-null mice displayed greater M2 polarization. In vitro, treatment of wild-type bone marrow-derived macrophages with advanced glycation end products (AGEs), which accumulate in diabetic nerve tissue, increased M1 and decreased M2 gene expression in a RAGE-dependent manner. Blockade of RAGE may be beneficial in the acute complications of diabetic neuropathy, at least in part, via upregulation of regeneration signals.
  14. Juranek, Judyta K; Kothary, Pratik; Mehra, Alka; Hays, Arthur; Brannagan, Thomas H 3rd; Schmidt, Ann Marie. "Increased expression of the receptor for advanced glycation end-products in human peripheral neuropathies". Brain & Behavior. 2013 Nov;3(6):701-709 (MEDL:24363972 #778772)       

    BACKGROUND: Diabetic neuropathy and idiopathic neuropathy are among the most prevalent neuropathies in human patients. The molecular mechanism underlying pathological changes observed in the affected nerve remains unclear but one candidate molecule, the receptor for advanced glycation end-products (RAGE), has recently gained attention as a potential contributor to neuropathy. Our previous studies revealed that RAGE expression is higher in porcine and murine diabetic nerve, contributing to the inflammatory mechanisms leading to diabetic neuropathy. Here, for the first time, we focused on the expression of RAGE in human peripheral nerve. METHODS: Our study utilized de-identified human sural nerve surplus obtained from 5 non-neuropathic patients (control group), 6 patients with long-term mild-to-moderate diabetic neuropathy (diabetic group) and 5 patients with mild-to-moderate peripheral neuropathy of unknown etiology (idiopathic group). By using immunofluorescent staining and protein immunoblotting we studied the expression and colocalization patterns of RAGE and its ligands: carboxymethyllysine (CML), high mobility group box 1 (HMBG1) and mammalian Diaphanous 1 (mDia1) in control and neuropathic nerves. RESULTS: We found that in a normal, healthy human nerve, RAGE is expressed in almost 30% of all nerve fibers and that number is higher in pathological states such as peripheral neuropathy. We established that the levels of RAGE and its pro-inflammatory ligands, CML and HMBG1, are higher in both idiopathic and diabetic nerve, while the expression of the RAGE cytoplasmic domain-binding partner, mDia1 is similar among control, diabetic, and idiopathic nerve. The highest number of double stained nerve fibers was noted for RAGE and CML: approximately 76% (control), approximately 91% (idiopathic) and approximately 82% (diabetic) respectively. CONCLUSIONS: Our data suggest roles for RAGE and its inflammatory ligands in human peripheral neuropathies and lay the foundation for further, more detailed and clinically oriented investigation involving these proteins and their roles in disorders of the human peripheral nerve.
  15. Mangalmurti, Nilam S; Friedman, Jessica L; Wang, Liang-Chuan; Stolz, Donna; Muthukumaran, Geetha; Siegel, Don L; Schmidt, Ann Marie; Lee, Janet S; Albelda, Steven M. "The receptor for advanced glycation end products mediates lung endothelial activation by RBCs". American journal of physiology. Lung cellular & molecular physiology. 2013 Feb;304(4):L250-L263 (MEDL:23275625 #778792)       

    The receptor for advanced glycation end products (RAGE) is a multiligand pattern recognition receptor implicated in multiple disease states. Although RAGE is expressed on systemic vascular endothelium, the expression and function of RAGE on lung endothelium has not been studied. Utilizing in vitro (human) and in vivo (mouse) models, we established the presence of RAGE on lung endothelium. Because RAGE ligands can induce the expression of RAGE and stored red blood cells express the RAGE ligand N(epsilon)-carboxymethyl lysine, we investigated whether red blood cell (RBC) transfusion would augment RAGE expression on endothelium utilizing a syngeneic model of RBC transfusion. RBC transfusion not only increased lung endothelial RAGE expression but enhanced lung inflammation and endothelial activation, since lung high mobility group box 1 and vascular cell adhesion molecule 1 expression was elevated following transfusion. These effects were mediated by RAGE, since endothelial activation was absent in RBC-transfused RAGE knockout mice. Thus, RAGE is inducibly expressed on lung endothelium, and one functional consequence of RBC transfusion is increased RAGE expression and endothelial activation.
  16. Manigrasso, Michaele B; Juranek, Judyta; Ramasamy, Ravichandran; Schmidt, Ann Marie. "Unlocking the biology of RAGE in diabetic microvascular complications". Trends in endocrinology & metabolism. 2013 Sep;:15-22 (MEDL:24011512 #528182)       

    The discovery of the receptor for advanced glycation end-products (RAGE) set the stage for the elucidation of important mechanisms underpinning diabetic complications. RAGE transduces the signals of advanced glycation end-products (AGEs), proinflammatory S100/calgranulins, and high mobility group box 1 (HMGB1), and is a one of a family of receptors for lysophosphatidic acid (LPA). These ligand tales weave a theme of vascular perturbation and inflammation linked to the pathogenesis of the chronic complications of diabetes. Once deemed implausible, this concept of inflammatory cues participating in diabetic complications is now supported by a plethora of experimental evidence in the macro- and microvasculature. We review the biology of ligand-RAGE signal transduction and its roles in diabetic microvascular complications, from animal models to human subjects.
  17. Nagareddy, Prabhakara R; Murphy, Andrew J; Stirzaker, Roslynn A; Hu, Yunying; Yu, Shiquing; Miller, Rachel G; Ramkhelawon, Bhama; Distel, Emilie; Westerterp, Marit; Huang, Li-Shin; Schmidt, Ann Marie; Orchard, Trevor J; Fisher, Edward A; Tall, Alan R; Goldberg, Ira J. "Hyperglycemia promotes myelopoiesis and impairs the resolution of atherosclerosis". Cell metabolism. 2013 May;17(5):695-708 (MEDL:23663738 #426002)       

    Diabetes is a major risk factor for atherosclerosis. Although atherosclerosis is initiated by deposition of cholesterol-rich lipoproteins in the artery wall, the entry of inflammatory leukocytes into lesions fuels disease progression and impairs resolution. We show that diabetic mice have increased numbers of circulating neutrophils and Ly6-C(hi) monocytes, reflecting hyperglycemia-induced proliferation and expansion of bone marrow myeloid progenitors and release of monocytes into the circulation. Increased neutrophil production of S100A8/S100A9, and its subsequent interaction with the receptor for advanced glycation end products on common myeloid progenitor cells, leads to enhanced myelopoiesis. Treatment of hyperglycemia reduces monocytosis, entry of monocytes into atherosclerotic lesions, and promotes regression. In patients with type 1 diabetes, plasma S100A8/S100A9 levels correlate with leukocyte counts and coronary artery disease. Thus, hyperglycemia drives myelopoiesis and promotes atherogenesis in diabetes.
  18. Reverdatto, Sergey; Rai, Vivek; Xue, Jing; Burz, David S; Schmidt, Ann Marie; Shekhtman, Alexander. "Combinatorial library of improved peptide aptamers, CLIPs to inhibit RAGE signal transduction in mammalian cells". PLoS ONE. 2013;8(6):e65180-e65180 (e65180) (MEDL:23785412 #778782)       

    Peptide aptamers are small proteins containing a randomized peptide sequence embedded into a stable protein scaffold, such as Thioredoxin. We developed a robust method for building a Combinatorial Library of Improved Peptide aptamers (CLIPs) of high complexity, containing >/=3x10(10) independent clones, to be used as a molecular tool in the study of biological pathways. The Thioredoxin scaffold was modified to increase solubility and eliminate aggregation of the peptide aptamers. The CLIPs was used in a yeast two-hybrid screen to identify peptide aptamers that bind to various domains of the Receptor for Advanced Glycation End products (RAGE). NMR spectroscopy was used to identify interaction surfaces between the peptide aptamers and RAGE domains. Cellular functional assays revealed that in addition to directly interfering with known binding sites, peptide aptamer binding distal to ligand sites also inhibits RAGE ligand-induced signal transduction. This finding underscores the potential of using CLIPs to select allosteric inhibitors of biological targets.
  19. Schmidt, Ann Marie. "Macrophages: much more than big eaters!". Arteriosclerosis, thrombosis, & vascular biology. 2013 Jun;33(6):1118-1119 (MEDL:23640489 #346522)       
  20. Schmidt, Ann Marie; Moore, Kathryn J. "The Semaphorin 3E/PlexinD1 Axis Regulates Macrophage Inflammation in Obesity". Cell metabolism. 2013 Oct;18(4):461-462 (MEDL:24093672 #574092)       

    Increased accumulation of adipose tissue macrophages in obesity propagates chronic inflammation that is closely associated with insulin resistance and type 2 diabetes. Semaphorin 3E, a guidance molecule for neurons, takes on a new role in obesity by directing the recruitment of macrophages in visceral adipose tissue (Shimizu et al., 2013).
  21. Tekabe, Yared; Kollaros, Maria; Li, Chong; Zhang, Geping; Schmidt, Ann Marie; Johnson, Lynne. "Imaging receptor for advanced glycation end product expression in mouse model of hind limb ischemia". EJNMMI Research. 2013;3(1):37-37 (MEDL:23663412 #422282)       

    BACKGROUND: The purpose of this study is to image the effect of diabetes on expression of receptor for advanced glycation endproducts (RAGE) in limb ischemia in live animals. METHODS: Male wild-type C57BL/6 mice were either made diabetic or left as control. Two months later, diabetic and non-diabetic mice underwent left femoral artery ligation. The right leg served as lesion control. Five days later, mice were injected with 15.1 +/- 4.4 MBq 99mTc-anti-RAGE F(ab')2 and 4 to 5 h later (blood pool clearance) underwent SPECT/CT imaging. At the completion of imaging, mice were euthanized, hind limbs counted and sectioned, and scans reconstructed. Regions of interest were drawn on serial transverse sections comprising the hind limbs and activity in millicuries summed and divided by the injected dose (ID). Quantitative histology was performed for RAGE staining and angiogenesis. RESULTS: Uptake of 99mTc-anti-RAGE F(ab')2 as %ID x 10-3 was higher in the left (ischemic) limbs for the diabetic mice (n = 8) compared to non-diabetic mice (n = 8) (1.20 +/- 0.44% vs. 0.49 +/- 0.40%; P = 0.0007) and corresponded to less angiogenesis in the diabetic mice. Uptake was also higher in the right limbs of diabetic compared to non-diabetic animals (0.82 +/- 0.33% vs. 0.40 +/- 0.14%; P = 0.0004). CONCLUSIONS: These data show the feasibility of imaging and quantifying the effect of diabetes on RAGE expression in limb ischemia.
  22. Abedini, Andisheh; Plesner, Annette; Cao, Ping; Zhang, Jinghua; Meng, Fanling Meng; Middleton, Chris; Song, Fei; Zanni, Martin; Verchere, C. Bruce; Raleigh, Daniel; Schmidt, Ann Marie. "The molecular basis of islet amyloid induced cell death [Meeting Abstract]". Protein science. 2012 AUG;21 1 1(SI):204-204 (ISI:000307019800378 #175797)    
  23. Akirav, Eitan M; Preston-Hurlburt, Paula; Garyu, Justin; Henegariu, Octavian; Clynes, Raphael; Schmidt, Ann Marie; Herold, Kevan C. "RAGE expression in human T cells: a link between environmental factors and adaptive immune responses". PLoS ONE. 2012;7(4):e34698-e34698 (e34698) (MEDL:22509345 #778812)       

    The Receptor for Advanced Glycation Endproducts (RAGE) is a scavenger ligand that binds glycated endproducts as well as molecules released during cell death such as S100b and HMGB1. RAGE is expressed on antigen presenting cells where it may participate in activation of innate immune responses but its role in adaptive human immune responses has not been described. We have found that RAGE is expressed intracellularly in human T cells following TCR activation but constitutively on T cells from patients with diabetes. The levels of RAGE on T cells from patients with diabetes are not related to the level of glucose control. It co-localizes to the endosomes. Its expression increases in activated T cells from healthy control subjects but bystander cells also express RAGE after stimulation of the antigen specific T cells. RAGE ligands enhance RAGE expression. In patients with T1D, the level of RAGE expression decreases with T cell activation. RAGE+ T cells express higher levels of IL-17A, CD107a, and IL-5 than RAGE- cells from the same individual with T1D. Our studies have identified the expression of RAGE on adaptive immune cells and a role for this receptor and its ligands in modulating human immune responses.
  24. Albert, DA; Ward, A; Allweiss, P; Graves, DT; Knowler, WC; Kunzel, C; Leibel, RL; Novak, KF; Oates, TW; Papapanou, PN; Schmidt, AM; Taylor, GW; Lamster, IB; Lalla, E. "Diabetes and oral disease: implications for health professionals". Annals of the New York Academy of Sciences. 2012 Mar;:1-15 (MEDL:22409777 #161191)       

    "Diabetes and Oral Disease: Implications for Health Professionals" was a one-day conference convened by the Columbia University College of Dental Medicine, the Columbia University College of Physicians and Surgeons, and the New York Academy of Sciences on May 4, 2011 in New York City. The program included an examination of the bidirectional relationship between oral disease and diabetes and the interprofessional working relationships for the care of people who have diabetes. The overall goal of the conference was to promote discussion among the healthcare professions who treat people with diabetes, encourage improved communication and collaboration among them, and, ultimately, improve patient management of the oral and overall effects of diabetes. Attracting over 150 members of the medical and dental professions from eight different countries, the conference included speakers from academia and government and was divided into four sessions. This report summarizes the scientific presentations of the event.(a).
  25. Arumugam, Thiruvengadam; Ramachandran, Vijaya; Gomez, Sobeyda B; Schmidt, Ann M; Logsdon, Craig D. "S100P-Derived RAGE Antagonistic Peptide Reduces Tumor Growth and Metastasis". Clinical cancer research. 2012 Aug;18(16):4356-4364 (MEDL:22718861 #174390)       

    PURPOSE: The receptor for advanced glycation end products (RAGE) contributes to multiple pathologies, including diabetes, arthritis, neurodegenerative diseases, and cancer. Despite the obvious need, no RAGE inhibitors are in common clinical use. Therefore, we developed a novel small RAGE antagonist peptide (RAP) that blocks activation by multiple ligands. EXPERIMENTAL DESIGN: RAGE and its ligands were visualized by immunohistochemical analysis of human pancreatic tissues, and siRNA was used to analyze their functions. Interactions between RAGE and S100P, S100A4, and HMGB-1 were measured by ELISA. Three S100P-derived small antagonistic peptides were designed, synthesized, and tested for inhibition of RAGE binding. The effects of the peptide blockers on NFkappaB-luciferase reporter activity was used to assess effects on RAGE-mediated signaling. The most effective peptide was tested on glioma and pancreatic ductal adenocarcinoma (PDAC) models. RESULTS: Immunohistochemical analysis confirmed the expression of RAGE and its ligands S100P, S100A4, and HMGB-1 in human PDAC. siRNA silencing of RAGE or its ligands reduced the growth and migration of PDAC cells in vitro. The most effective RAP inhibited the interaction of S100P, S100A4, and HMGB-1 with RAGE at micromolar concentrations. RAP also reduced the ability of the ligands to stimulate RAGE activation of NFkappaB in cancer cells in vitro and in vivo. Importantly, systemic in vivo administration of RAP reduced the growth and metastasis of pancreatic tumors and also inhibited glioma tumor growth. CONCLUSION: RAP shows promise as a tool for the investigation of RAGE function and as an in vivo treatment for RAGE-related disorders. Clin Cancer Res; 18(16); 4356-64. (c)2012 AACR.
  26. Cao, Ping; Abedini, Andisheh; Plesner, Annette; Schmidt, Ann Marie; Raleigh, Daniel. "Toxic intermediates in islet amyloid formation: Analysis of IAPP mutants reveals a correlation between lag time and toxicity [Meeting Abstract]". Protein science. 2012 AUG;21 1 1(SI):104-105 (ISI:000307019800134 #175801)    
  27. Cao, Ping; Tu, Ling-Hsien; Abedini, Andisheh; Levsh, Olesya; Akter, Rehana; Patsalo, Vadim; Schmidt, Ann Marie; Raleigh, Daniel P. "Sensitivity of amyloid formation by human islet amyloid polypeptide to mutations at residue 20". Journal of molecular biology. 2012 Aug;421(2-3):282-295 (MEDL:22206987 #174534)       

    Islet amyloid polypeptide (IAPP, amylin) is responsible for amyloid formation in type 2 diabetes and in islet cell transplants. The only known natural mutation found in mature human IAPP is a Ser20-to-Gly missense mutation, found with small frequency in Chinese and Japanese populations. The mutation appears to be associated with increased risk of early-onset type 2 diabetes. Early measurements in the presence of organic co-solvents showed that S20G-IAPP formed amyloid more quickly than the wild type. We confirm that the mutant accelerates amyloid formation under a range of conditions including in the absence of co-solvents. Ser20 adopts a normal backbone geometry, and the side chain makes no steric clashes in models of IAPP amyloid fibers, suggesting that the increased rate of amyloid formation by the mutant does not result from the relief of steric incompatibility in the fiber state. Transmission electronic microscopy, circular dichroism, and seeding studies were used to probe the structure of the resulting fibers. The S20G-IAPP peptide is toxic to cultured rat INS-1 (transformed rat insulinoma-1) beta-cells. The sensitivity of amyloid formation to the identity of residue 20 was exploited to design a variant that is much slower to aggregate and that inhibits amyloid formation by wild-type IAPP. An S20K mutant forms amyloid with an 18-fold longer lag phase in homogeneous solution. Thioflavin T binding assays, together with experiments using a p-cyanophenylalanine (p-cyanoPhe) variant of human IAPP, show that the designed S20K mutant inhibits amyloid formation by human IAPP. The experiments illustrate how p-cyanoPhe can be exploited to monitor amyloid formation even in the presence of other amyloidogenic proteins.
  28. Dinorcia J; Lee MK; Moroziewicz DN; Winner M; Suman P; Bao F; Remotti HE; Zou YS; Yan SF; Qiu W; Su GH; Schmidt AM; Allendorf JD. "RAGE Gene Deletion Inhibits the Development and Progression of Ductal Neoplasia and Prolongs Survival in a Murine Model of Pancreatic Cancer". Journal of gastrointestinal surgery. 2012 Jan;16(1):104-12; discussion 112 (MEDL:22052106 #140586)       

    BACKGROUND: The receptor for advanced glycation end-products (RAGE) is implicated in pancreatic tumorigenesis. Activating Kras mutations and p16 inactivation are genetic abnormalities most commonly detected as pancreatic ductal epithelium progresses from intraepithelial neoplasia (PanIN) to adenocarcinoma (PDAC). OBJECTIVE: The aim of this study was to evaluate the effect of RAGE (or AGER) deletion on the development of PanIN and PDAC in conditional Kras ( G12D ) mice. MATERIALS AND METHODS: Pdx1-Cre; LSL-Kras ( G12D/+) mice were crossed with RAGE (-/-) mice to generate Pdx1-Cre; LSL-Kras ( G12D/+) ; RAGE (-/-) mice. Pdx1-Cre; LSL-Kras ( G12D/+); p16 ( Ink4a-/-) mice were crossed with RAGE (-/-) mice to generate Pdx1-Cre; LSL-Kras ( G12D/+); p16 ( Ink4a-/-); RAGE (-/-) mice. Pancreatic ducts were scored and compared to the relevant RAGE (+/+) controls. RESULTS: At 16 weeks of age, Pdx1-Cre; LSL-Kras ( G12D/+); RAGE (-/-) mice had significantly fewer high-grade PanIN lesions than Pdx1-Cre; LSL-Kras ( G12D/+); RAGE (+/+) controls. At 12 weeks of age, none of the Pdx1-Cre; LSL-Kras ( G12D/+); p16 ( Ink4a-/-); RAGE (-/-) mice had PDAC compared to a 45.5% incidence of PDAC in Pdx1-Cre; LSL-Kras ( G12D/+); p16 ( Ink4a-/-); RAGE (+/+) controls. Finally, Pdx1-Cre; LSL-Kras ( G12D/+); p16 ( Ink4a-/-); RAGE (-/-) mice also displayed markedly longer median survival. CONCLUSION: Loss of RAGE function inhibited the development of PanIN and progression to PDAC and significantly prolonged survival in these mouse models. Further work is needed to target the ligand-RAGE axis for possible early intervention and prophylaxis in patients at risk for developing pancreatic cancer
  29. Kamide, Tomoya; Kitao, Yasuko; Takeichi, Toshiaki; Okada, Akiko; Mohri, Hiromi; Schmidt, Ann Marie; Kawano, Takayuki; Munesue, Seiichi; Yamamoto, Yasuhiko; Yamamoto, Hiroshi; Hamada, Jun-ichiro; Hori, Osamu. "RAGE mediates vascular injury and inflammation after global cerebral ischemia". Neurochemistry international. 2012 Feb;60(3):220-228 (MEDL:22202666 #164277)       

    The receptor for advanced glycation end products (RAGE) is a multi-ligand receptor involved in a diverse range of pathological conditions. To analyze the roles of RAGE and its decoy receptor, endogenous secretory RAGE (esRAGE), in the global cerebral ischemia, three different mouse cohorts, wild-type, RAGE/, and esRAGE transgenic (Tg) mice were subjected to bilateral common carotid artery occlusion (BCCAO). RT-PCR and immunohistochemical analysis revealed that expression of RAGE was induced in the vascular cells at 12 h, and then in the neurons and glia from 3 to 7 days in the hippocampus after BCCAO. The numbers of surviving neurons in the hippocampal CA1 region were significantly higher in RAGE/ and esRAGE Tg mice than those in wild-type mice in the periods between 24 h and 7 days after BCCAO. Lower levels of 3-nitrotyrosine (3-NT) and higher levels of endothelial nitric oxide synthase (eNOS), together with enlarged vascular areas were observed in RAGE/ and esRAGE Tg mice at 12 h after BCCAO. In the later periods, expressions of glia-derived inflammatory mediators TNFalpha and inducible nitric oxide synthase (iNOS) were reduced in RAGE/ and esRAGE Tg mice. These results suggest that RAGE may contribute to delayed neuronal death after global cerebral ischemia by enhancing vascular injury and deleterious glia-mediated inflammation.
  30. Ladiwala, Ali Reza A; Bhattacharya, Moumita; Perchiacca, Joseph M; Cao, Ping; Raleigh, Daniel P; Abedini, Andisheh; Schmidt, Ann Marie; Varkey, Jobin; Langen, Ralf; Tessier, Peter M. "Rational design of potent domain antibody inhibitors of amyloid fibril assembly". Proceedings of the National Academy of Sciences of the United States of America. 2012 Dec;109(49):19965-19970 (MEDL:23161913 #205512)       

    Antibodies hold significant potential for inhibiting toxic protein aggregation associated with conformational disorders such as Alzheimer's and Huntington's diseases. However, near-stoichiometric antibody concentrations are typically required to completely inhibit protein aggregation. We posited that the molecular interactions mediating amyloid fibril formation could be harnessed to generate antibodies with potent antiaggregation. Here we report that grafting small amyloidogenic peptides (6-10 residues) into the complementarity-determining regions of a single-domain (V(H)) antibody yields potent domain antibody inhibitors of amyloid formation. Grafted AMyloid-Motif AntiBODIES (gammabodies) presenting hydrophobic peptides from Abeta (Alzheimer's disease), alpha-Synuclein (Parkinson's disease), and islet amyloid polypeptide (type 2 diabetes) inhibit fibril assembly of each corresponding polypeptide at low substoichiometric concentrations (1:10 gammabody:monomer molar ratio). In contrast, sequence- and conformation-specific antibodies that were obtained via immunization are unable to prevent fibrillization at the same substoichiometric concentrations. Gammabodies prevent amyloid formation by converting monomers and/or fibrillar intermediates into small complexes that are unstructured and benign. We expect that our antibody design approach-which eliminates the need for immunization or screening to identify sequence-specific domain antibody inhibitors-can be readily extended to generate potent aggregation inhibitors of other amyloidogenic polypeptides linked to human disease.
  31. Ma, Wanchao; Rai, Vivek; Hudson, Barry I; Song, Fei; Schmidt, Ann Marie; Barile, Gaetano R. "RAGE binds C1q and enhances C1q-mediated phagocytosis". Cellular immunology. 2012;274(1-2):72-82 (MEDL:22386596 #778802)       

    RAGE, the multiligand receptor of the immunoglobulin superfamily of cell surface molecules, is implicated in innate and adaptive immunity. Complement component C1q serves roles in complement activation and antibody-independent opsonization. Using soluble forms of RAGE (sRAGE) and RAGE-expressing cells, we determined that RAGE is a native C1q globular domain receptor. Direct C1q-sRAGE interaction was demonstrated with surface plasmon resonance (SPR), with minimum K(d) 5.6 muM, and stronger binding affinity seen in ELISA-like experiments involving multivalent binding. Pull-down experiments suggested formation of a receptor complex of RAGE and Mac-1 to further enhance affinity for C1q. C1q induced U937 cell adhesion and phagocytosis was inhibited by antibodies to RAGE or Mac-1. These data link C1q and RAGE to the recruitment of leukocytes and phagocytosis of C1q-coated material.
  32. Rai, Vivek; Maldonado, Andres Y.; Burz, David S.; Reverdatto, Sergey; Yan, Shi Fang; Schmidt, Ann Marie; Shekhtman, Alexander. "Signal transduction in receptor for advanced glycation end products (RAGE). SOLUTION STRUCTURE OF C-TERMINAL RAGE (ctRAGE) AND ITS BINDING TO mDia1 (vol 287, pg 5133, 2012)". Journal of biological chemistry. 2012 MAR 30;287(14):11283-11283 (ISI:000302780100057 #166672)       
  33. Rai, Vivek; Maldonado, Andres Y; Burz, David S; Reverdatto, Sergey; Schmidt, Ann Marie; Shekhtman, Alexander. "Signal Transduction in Receptor for Advanced Glycation End Products (RAGE): SOLUTION STRUCTURE OF C-TERMINAL RAGE (ctRAGE) AND ITS BINDING TO mDia1". Journal of biological chemistry. 2012 Feb;287(7):5133-5144 (MEDL:22194616 #157474)       

    The receptor for advanced glycation end products (RAGE) is a multiligand cell surface macromolecule that plays a central role in the etiology of diabetes complications, inflammation, and neurodegeneration. The cytoplasmic domain of RAGE (C-terminal RAGE; ctRAGE) is critical for RAGE-dependent signal transduction. As the most membrane-proximal event, mDia1 binds to ctRAGE, and it is essential for RAGE ligand-stimulated phosphorylation of AKT and cell proliferation/migration. We show that ctRAGE contains an unusual alpha-turn that mediates the mDia1-ctRAGE interaction and is required for RAGE-dependent signaling. The results establish a novel mechanism through which an extracellular signal initiated by RAGE ligands regulates RAGE signaling in a manner requiring mDia1.
  34. Rai, Vivek; Toure, Fatouma; Chitayat, Seth; Pei, Renjun; Song, Fei; Li, Qing; Zhang, Jinghua; Rosario, Rosa; Ramasamy, Ravichandran; Chazin, Walter J; Schmidt, Ann Marie. "Lysophosphatidic acid targets vascular and oncogenic pathways via RAGE signaling". Journal of experimental medicine. 2012 Dec;209(13):2339-2350 (MEDL:23209312 #203922)       

    The endogenous phospholipid lysophosphatidic acid (LPA) regulates fundamental cellular processes such as proliferation, survival, motility, and invasion implicated in homeostatic and pathological conditions. Hence, delineation of the full range of molecular mechanisms by which LPA exerts its broad effects is essential. We report avid binding of LPA to the receptor for advanced glycation end products (RAGE), a member of the immunoglobulin superfamily, and mapping of the LPA binding site on this receptor. In vitro, RAGE was required for LPA-mediated signal transduction in vascular smooth muscle cells and C6 glioma cells, as well as proliferation and migration. In vivo, the administration of soluble RAGE or genetic deletion of RAGE mitigated LPA-stimulated vascular Akt signaling, autotaxin/LPA-driven phosphorylation of Akt and cyclin D1 in the mammary tissue of transgenic mice vulnerable to carcinogenesis, and ovarian tumor implantation and development. These findings identify novel roles for RAGE as a conduit for LPA signaling and suggest targeting LPA-RAGE interaction as a therapeutic strategy to modify the pathological actions of LPA.
  35. Raleigh, Daniel; Abedini, Andisheh; Cao, Ping; Marek, Peter; Meng, Fanling; Middleton, Chris; Patsalo, Vadim; Plesner, Annette; Schmidt, Ann Marie; Tu, Ling-Hsien; Verchere, C. Bruce; Wang, Hui; Zanni, Marty. "Islet amyloid: From fundamental biophysics to mechanisms of cytotoxicity [Meeting Abstract]". Protein science. 2012 AUG;21 1 1(SI):66-66 (ISI:000307019800042 #175798)    
  36. Ramasamy R; Yan SF; Schmidt AM. "Advanced glycation endproducts: from precursors to RAGE: round and round we go". Amino acids. 2012 Apr;42(4):1151-1161 (MEDL:20957395 #138340)       

    The formation of advanced glycation endproducts (AGEs) occurs in diverse settings such as diabetes, aging, renal failure, inflammation and hypoxia. The chief cellular receptor for AGEs, RAGE, transduces the effects of AGEs via signal transduction, at least in part via processes requiring the RAGE cytoplasmic domain binding partner, diaphanous-1 or mDia1. Data suggest that RAGE perpetuates the inflammatory signals initiated by AGEs via multiple mechanisms. AGE-RAGE interaction stimulates generation of reactive oxygen species and inflammation-mechanisms which enhance AGE formation. Further, recent data in type 1 diabetic kidney reveal that deletion of RAGE prevents methylglyoxal accumulation, at least in part via RAGE-dependent regulation of glyoxalase-1, a major enzyme involved in methylglyoxal detoxification. Taken together, these considerations place RAGE in the center of biochemical and molecular stresses that characterize the complications of diabetes and chronic disease. Stopping RAGE-dependent signaling may hold the key to interrupting cycles of cellular perturbation and tissue damage in these disorders
  37. Ramasamy, Ravichandran; Schmidt, Ann Marie. "Receptor for Advanced Glycation End Products (RAGE) and Implications for the Pathophysiology of Heart Failure". Current heart failure reports. 2012 Jun;9(2):107-116 (MEDL:22457230 #166791)       

    The receptor for advanced glycation end products (RAGE) is expressed in the heart in cardiomyocytes, vascular cells, fibroblasts, and in infiltrating inflammatory cells. Experiments in murine, rat, and swine models of injury suggest that RAGE and the ligands of RAGE are upregulated in key injuries to the heart, including ischemia/reperfusion injury, diabetes, and inflammation. Pharmacological antagonism of RAGE or genetic deletion of the receptor in mice is strikingly protective in models of these stresses. Data emerging from human studies suggest that measurement of levels of RAGE ligands or soluble RAGEs in plasma or serum may correlate with the degree of heart failure. Taken together, the ligand-RAGE axis is implicated in heart failure and we predict that therapeutic antagonism of RAGE might be a unique target for therapeutic intervention in this disorder.
  38. Ramasamy, Ravichandran; Yan, Shi Fang; Schmidt, Ann Marie. "The diverse ligand repertoire of the receptor for advanced glycation endproducts and pathways to the complications of diabetes". Vascular pharmacology. 2012 Nov;57(5-6):160-167 (MEDL:22750165 #178279)       

    The multi-ligand receptor RAGE was discovered on account of its ability to bind and transduce the cell stress-provoking signals of advanced glycation endproducts (AGEs). The finding that RAGE also bound pro-inflammatory molecules set the stage for linking RAGE and inflammation to the pathogenesis of diabetic macro- and microvascular complications. In this review, we focus on the roles of RAGE and its ligands in diabetes complications. We recount the findings from mice, rats, swine and human subjects suggesting that RAGE action potently contributes to vascular, inflammatory and end-organ stress and damage in types 1 and 2 diabetes. We detail the efforts to track ligands and RAGE in human subjects with diabetes to address if this axis may be a biomarker reflective of the state of the diabetic complications. Lastly, we suggest specific strategies to tackle AGE-ligand-RAGE interactions as potential therapeutic targets for diabetes and its complications.
  39. Schmidt, Ann Marie. "Insulin resistance and metabolic syndrome: mechanisms and consequences". Arteriosclerosis, thrombosis, & vascular biology. 2012 Aug;32(8):1753-1753 (MEDL:22815339 #174080)       
  40. Song, Fei; Schmidt, Ann Marie. "Glycation and insulin resistance: novel mechanisms and unique targets?". Arteriosclerosis, thrombosis, & vascular biology. 2012 Aug;32(8):1760-1765 (MEDL:22815341 #174081)       

    Multiple biochemical, metabolic, and signal transduction pathways contribute to insulin resistance. In this review, we present evidence that the posttranslational process of protein glycation may play a role in insulin resistance. The posttranslational modifications, the advanced glycation end products (AGEs), are formed and accumulated by endogenous and exogenous mechanisms. AGEs may contribute to insulin resistance by a variety of mechanisms, including generation of tumor necrosis factor-alpha direct modification of the insulin molecule, thereby leading to its impaired action, generation of oxidative stress, and impairment of mitochondrial function, as examples. AGEs may stimulate signal transduction via engagement of cellular receptors, such as receptor for AGEs. AGE-receptor for AGE interaction perpetuates AGE formation and cellular stress via induction of inflammation, oxidative stress, and reduction in the expression and activity of the enzyme glyoxalase I that detoxifies the AGE precursor, methylglyoxal. Once set in motion, glycation-promoting mechanisms may stimulate ongoing AGE production and target tissue stresses that reduce insulin responsiveness. Strategies to limit AGE accumulation and action may contribute to the prevention of insulin resistance and its consequences.
  41. Tekabe, Y; Luma, J; Li, Q; Ramasamy, R; Schmidt, A M; Johnson, L. "Quantifying course of RAGE expression after myocardial reperfusion injury [Meeting Abstract]". Molecular Imaging & Biology. 2012 February 2012;14:S825-S825 (EMBASE:70789505 #171163)    

    Background: RAGE and its ligands have been implicated in the pathogenesis of I/R injury through pathways of inflammation and apoptosis. We hypothesized that RAGE-directed quantitative imaging of myocardial uptake of 99mTc-anti-RAGE F(ab')2 in a mouse model of I/R can detect RAGE expression in the myocardium and show quantitative differences between early (18-20 h) and later times (48 h) after reperfusion. Methods: Twenty-four wild-type (WT) mice underwent left anterior descending coronary artery (LAD) occlusion for 30 min followed by reperfusion for 18-20 h (n = 8) or 48 h (n = 12) and 3 WT mice underwent sham operation without coronary intervention. Twenty-seven mice (including shams) were injected with 19.98 +/- 1.78 MBq 99mTc anti-RAGE F(ab')2 and 5 h later, mice were injected with 6.14 +/- 2.0 MBq 201Tl and immediately underwent dual isotope SPECT/CT imaging. Four WT mice were injected with control nonspecific F(ab')2 and similarly imaged at 18-20 h. At the completion of imaging, hearts were removed, radioactivity counted, and sectioned for histology. Results: The uptake of 99mTc-anti-RAGE F(ab')2 in the ischemic zone from the scans as mean percentage injected dose (%ID) was significantly greater at 18-20 h (5.7 +/- 2.1 x 10-3%) compared to 48 h (1.4 +/- 1.1 x 10-3%; p < 0.001) following reperfusion. Disease and antibody controls showed no focal uptake in the infarct. Gamma well counting of the myocardium from experiments performed at 18-20 h and 48 h post reperfusion supported the quantitative scan data. Immunohistochemical staining of the myocardium showed greater caspase-3 and RAGE staining at 18-20 h vs. 48 h (p = 0.04 and p = 0.01, respectively). On dual immunofluorescence, RAGE colocalized mainly with injured cardiomyocytes undergoing apoptosis. Conclusion: RAGE expression in reperfusion injury can be imaged in-vivo using a novel 99mTc-anti-RAGE F(ab')2. This imaging approach may be useful in evaluating contribution of RAGE to myocardial ischemic injury in diseases with increased expression such as diabetes
  42. Tekabe, Yared; Luma, Joane; Li, Qing; Schmidt, Ann Marie; Ramasamy, Ravichandran; Johnson, Lynne L. "Imaging of receptors for advanced glycation end products in experimental myocardial ischemia and reperfusion injury". JACC: Cardiovascular Imaging. 2012 Jan;5(1):59-67 (MEDL:22239894 #155936)       

    OBJECTIVES: The aim of this study was to image expression of receptor for advanced glycation end products (RAGE) in a mouse model of myocardial reperfusion injury. BACKGROUND: RAGE and its ligands are implicated in the pathogenesis of ischemia/reperfusion injury and infarction. We hypothesized that RAGE-directed quantitative imaging of myocardial uptake of technetium-99m ((99m)Tc)-anti-RAGE F(ab')(2) in a mouse model of myocardial ischemic injury can detect RAGE expression and show quantitative differences between early (18 to 20 h) and later times (48 h) after reperfusion. METHODS: Twenty-five wild-type (WT) mice underwent left anterior descending coronary artery occlusion for 30 min. Mice were injected with 19.98 +/- 1.78 MBq of (99m)Tc anti-RAGE F(ab')(2) at 2 time points after reperfusion (at 18 to 20 h [n = 8] and at 48 h [n = 12]) and 5 h later with 6.14 +/- 2.0 MBq of thallium-201 ((201)Tl). Five WT mice were injected with nonspecific F(ab')(2) and (201)Tl 18 to 20 h after reperfusion. Six WT mice underwent sham operation without coronary intervention. After injection with (201)Tl, all mice immediately underwent dual isotope single-photon emission computed tomography/computed tomography. At completion of imaging, hearts were counted and sectioned. RESULTS: The uptake of (99m)Tc-anti-RAGE F(ab')(2) in the ischemic zone from the scans as mean percentage injected dose was significantly greater at 18 to 20 h (5.7 +/- 2.1 x 10(-3)%) as compared with at 48 h (1.4 +/- 1.1 x 10(-3)%; p < 0.001) after reperfusion. Disease and antibody controls showed no focal uptake in the infarct. Gamma well counting of the myocardium supported the quantitative scan data. By immunohistochemical staining there was greater caspase-3 and RAGE staining at 18 to 20 h versus at 48 h (p = 0.04 and p = 0.01, respectively). On dual immunofluorescence, RAGE colocalized mainly with injured cardiomyocytes undergoing apoptosis. CONCLUSIONS: RAGE expression in myocardial ischemic injury can be imaged in vivo using a novel (99m)Tc-anti-RAGE F(ab')(2). RAGE plays a role in several cardiovascular diseases and is a potential target for clinical imaging.
  43. Toure, Fatouma; Fritz, Gunter; Li, Qing; Rai, Vivek; Daffu, Gurdip; Zou, Yu Shan; Rosario, Rosa; Ramasamy, Ravichandran; Alberts, Arthur S; Yan, Shi Fang; Schmidt, Ann Marie. "Formin mDia1 Mediates Vascular Remodeling via Integration of Oxidative and Signal Transduction Pathways". Circulation research. 2012 May;110(10):1279-1293 (MEDL:22511750 #166826)       

    Rationale: The mammalian diaphanous-related formin (mDia1), governs microtubule and microfilament dynamics while functioning as an effector for Rho small GTP-binding proteins during key cellular processes such as adhesion, cytokinesis, cell polarity, and morphogenesis. The cytoplasmic domain of the receptor for advanced glycation endproducts binds to the formin homology 1 domain of mDia1; mDia1 is required for receptor for advanced glycation endproducts ligand-induced cellular migration in transformed cells. Objective: Because a key mechanism in vascular remodeling is the induction of smooth muscle cell migration, we tested the role of mDia1 in this process. Methods and Results: We report that endothelial denudation injury to the murine femoral artery significantly upregulates mDia1 mRNA transcripts and protein in the injured vessel, particularly in vascular smooth muscle cells within the expanding neointima. Loss of mDia1 expression significantly reduces pathological neointimal expansion consequent to injury. In primary murine aortic smooth muscle cells, mDia1 is required for receptor for advanced glycation endproducts ligand-induced membrane translocation of c-Src, which leads to Rac1 activation, redox phosphorylation of AKT/glycogen synthase kinase 3beta, and consequent smooth muscle cell migration. Conclusions: We conclude that mDia1 integrates oxidative and signal transduction pathways triggered, at least in part, by receptor for advanced glycation endproducts ligands, thereby regulating pathological neointimal expansion.
  44. Vedantham, Srinivasan; Ananthakrishnan, Radha; Schmidt, Ann Marie; Ramasamy, Ravichandran. "Aldose reductase, oxidative stress and diabetic cardiovascular complications". Cardiovascular & hematological agents in medicinal chemistry. 2012 Sep;10(3):234-240 (MEDL:22632267 #174070)    

    Cardiovascular disease represents the major cause of morbidity and mortality in patients with diabetes mellitus. Studies by us and others have implicated increased flux via aldose reductase (AR) as a key player in mediating diabetic complications, including cardiovascular complications. Data suggest that increased flux via AR in diabetics perpetuates increased injury after myocardial infarction, accelerates atherosclerotic lesion formation, and promotes restenosis via multiple mechanisms. Most importantly, studies have shown that increased generation of reactive oxygen species due to flux via AR has been a common feature in animal models of diabetic cardiovascular disease. Taken together, these considerations place AR in the center of biochemical and molecular stresses that characterize the cardiovascular complications of diabetes. Stopping AR-dependent signaling may hold the key to interrupting cycles of cellular perturbation and tissue damage in diabetic cardiovascular complications.
  45. Zeng S; Zhang QY; Huang J; Vedantham S; Rosario R; Ananthakrishnan R; Yan SF; Ramasamy R; Dematteo RP; Emond JC; Friedman RA; Schmidt AM. "Opposing roles of RAGE and Myd88 signaling in extensive liver resection". FASEB journal. 2012 Feb;26(2):882-893 (MEDL:22075646 #141686)       

    In extensive liver resection secondary to primary or metastatic liver tumors, or in living donor liver transplantation, strategies to quell deleterious inflammatory responses and facilitate regeneration are essential. The receptor for advanced glycation endproducts (RAGE) and myeloid differentiating factor 88 (Myd88) are implicated in the inflammatory response. To establish the contributions of RAGE vs. Myd88 signaling in extensive liver resection, we probed the effect of RAGE and/or Myd88, the latter primarily a key transducer of major toll-like receptors and also implicated in interleukin-1 (Il1) signaling, in a murine model of extensive (85%) hepatectomy. We report that, although Myd88 is thoroughly essential for survival via regulation of NF-kappaB and TNF-alpha, deletion of RAGE significantly improved survival compared to wild-type, Myd88-null, or RAGE-null/Myd88-null mice. RAGE opposes Myd88 signaling at multiple levels: by suppression of p65 levels, thereby reducing activation of NF-kappaB and consequent production of cyclin D1, and by suppression of Il6-mediated phosphorylation of Stat3, thereby down-regulating Pim1 and suppressing the hyperplastic response. Further, RAGE-dependent suppression of glyoxalase1, a detoxification pathway for pre-AGEs, enhances AGE levels and suppresses Il6 action. We conclude that blockade of RAGE may rescue liver remnants from the multiple signals that preclude adaptive proliferation triggered primarily by Myd88 signaling pathways.-Zeng, S., Zhang, Q. Y., Huang, J., Vedantham, S., Rosario, R., Ananthakrishnan, R., Yan, S. F., Ramasamy, R., DeMatteo, R. P., Emond, J. C., Friedman, R. A., Schmidt, A. M. Opposing roles of RAGE and Myd88 signaling in extensive liver resection
  46. Ananthakrishnan, Radha; Li, Qing; Gomes, Teodoro; Schmidt, Ann Marie; Ramasamy, Ravichandran. "Aldose reductase pathway contributes to vulnerability of aging myocardium to ischemic injury". Experimental gerontology. 2011 Sep;46(9):762-767 (MEDL:21600277 #137436)       

    Aging men and women display both increased incidence of cardiovascular disease and complications of myocardial infarction and heart failure. We hypothesized that altered glucose metabolism, in particular, flux of glucose via the polyol pathway (PP) may be responsible, in part, for the enhanced vulnerability of aging myocardium to ischemic injury, even in the absence of superimposed disease processes linked to PP flux, such as diabetes. To test our hypothesis, we determined the expression and products of PP enzymes aldose reductase (AR) and sorbitol dehydrogenase (SDH) in hearts from Fischer 344 aged (26 months) and young (4 months) rats subjected to global ischemia followed by reperfusion in the presence or absence of blockers of PP and the measures of ischemic injury and functional recovery were determined. Expression and activities of AR and SDH were significantly higher in aged vs. young hearts, and induction of ischemia further increased AR and SDH activity in the aged hearts. Myocardial ischemic injury was significantly greater in aged vs. young hearts, and blockade of AR reduced ischemic injury and improved cardiac functional recovery on reperfusion in aged hearts. These data indicate that innate increases in activity of the PP enzymes augment myocardial vulnerability to I/R injury in aging, and that blockers of PP protect the vulnerable aging hearts
  47. Devisser, Adriena; Yang, Christina; Herring, Amanda; Martinez, Jose A; Rosales-Hernandez, Alma; Poliakov, Ilia; Ayer, Amit; Garven, Alexandra; Zaver, Shaila; Rincon, Natalia; Xu, Kevin; Tuor, Ursula I; Schmidt, Ann Marie; Toth, Cory. "Differential impact of diabetes and hypertension in the brain: adverse effects in grey matter". Neurobiology of disease. 2011 Nov;44(2):161-173 (MEDL:21742034 #778822)       

    Diabetes mellitus types 1 and 2 (DM1 and DM2) and/or hypertension (HTN) can contribute to cognitive decline, cerebral atrophy and white matter abnormalities in humans. Adult rat models of streptozotocin-induced DM1 and genetic strains of DM2 and HTN were used to investigate relative contributions of DM and HTN for alterations in cerebral structure and function as well as insulin receptor biology using cognitive testing, magnetic resonance imaging (MRI), and histological and molecular methods. The effects of DM1 or DM2 were generally similar. DM was associated with earlier onset of cognitive impairment than with HTN alone. DM was independently correlated with brain atrophy, whereas HTN had minimal effects on brain volume. The combination of DM and HTN led to identifiable mild hippocampal neuronal loss while either DM or HTN led to synaptic loss. Only DM led to downregulation of the insulin receptor pathways' activation. In contrast, only HTN was associated with vascular luminal reduction and restricted cerebral perfusion on MRI. The impacts of DM and HTN in the brain differ, while their separate contributions can lead to some additive adverse effects within rodent brain grey matter.
  48. Hofmann Bowman, Marion A; Fedson, Savitri; Schmidt, Ann Marie. "Advanced glycation end products in diabetic cardiomyopathy: an alternative hypothesis [Letter]". Journal of heart & lung transplantation. 2011 Nov;30(11):1303; discussion 1303-1303; discussion 1304 (MEDL:21723747 #146223)       
  49. Hofmann Bowman, Marion A; Schmidt, Ann Marie. "S100/calgranulins EN-RAGEing the blood vessels: implications for inflammatory responses and atherosclerosis". American journal of cardiovascular disease. 2011;1(1):92-100 (MEDL:22200033 #778862)    

    Atherosclerosis remains the leading cause of death in the western countries and represents a complex chronic inflammatory process whose regulation is dependent on a network of cytokine and chemokine signaling between key cells such as endothelial cells, monocytes, dendritic cells, lymphocytes and smooth muscle cells. This review focuses on the biology and function of S100 proteins and their receptor RAGE with respect to the multifactorial process leading to atherosclerosis, plaque rupture, and aortic wall remodeling.
  50. Hudson, Barry I; Moon, Yeseon Park; Kalea, Anastasia Z; Khatri, Minesh; Marquez, Chensy; Schmidt, Ann Marie; Paik, Myunghee C; Yoshita, Mitsuhiro; Sacco, Ralph L; DeCarli, Charles; Wright, Clinton B; Elkind, Mitchell S V. "Association of serum soluble receptor for advanced glycation end-products with subclinical cerebrovascular disease: the Northern Manhattan Study (NOMAS)". Atherosclerosis. 2011 May;216(1):192-198 (MEDL:21316677 #778852)       

    OBJECTIVE: Serum levels of the soluble receptor for advanced glycation end-products (sRAGE) have been associated with risk of cardiovascular disease. We hypothesized that sRAGE levels are associated with subclinical cerebrovascular disease in an ethnically diverse population. METHODS: Clinically stroke-free participants in the multi-ethnic Northern Manhattan Study (NOMAS) underwent brain MRI to quantify subclinical brain infarcts (SBI) and white matter hyperintensity volume (WMHV) (n = 1102). Serum levels of sRAGE were measured by ELISA. Logistic and multiple linear regression were employed to estimate associations of sRAGE with SBI and WMHV, after adjusting for demographics and vascular risk factors. RESULTS: Median sRAGE levels were significantly lower in Hispanics (891.9 pg/ml; n = 708) and non-Hispanic blacks (757.4 pg/ml; n = 197) than in non-Hispanic whites (1120.5 pg/ml; n = 170), and these differences remained after adjusting for other risk factors. Interactions were observed by race-ethnicity between sRAGE levels and MRI measurements, including for SBI in Hispanics (p = 0.04) and WMHV among blacks (p = 0.03). In Hispanics, increasing sRAGE levels were associated with a lower odds of SBI, with those in the upper sRAGE quartile displaying a 50% lower odds of SBI after adjusting for sociodemographic and vascular risk factors (p = 0.05). Among blacks, those in the upper quartile of sRAGE had a similarly reduced increased risk of SBI (p = 0.06) and greater WMHV (p = 0.04). CONCLUSION: Compared to whites, Hispanics and blacks have significantly lower sRAGE levels, and these levels were associated with more subclinical brain disease. Taken together, these findings suggest sRAGE levels may be significantly influence by ethnicity. Further studies of sRAGE and stroke risk, particularly in minorities, are warranted.
  51. Kalea, Anastasia Z; Schmidt, Ann Marie; Hudson, Barry I. "Alternative splicing of RAGE: roles in biology and disease". Frontiers in biosciences. 2011;17:2756-2770 (MEDL:21622207 #141665)       

    The Receptor for Advanced Glycation End-products (RAGE) is a complex, multi-ligand signaling system implicated in the pathogenesis of diabetes, cardiovascular disease and various cancers. RAGE undergoes extensive alternative splicing to produce a variety of transcripts with diverse functions, including soluble antagonists and variants with altered ligand binding domains. Studies focused on the major soluble variant (RAGEv1/esRAGE) have revealed this to function by binding RAGE-ligands and preventing activation of RAGE signaling in vascular and tumor cells. Furthermore, measurement of this variant in human serum has revealed that RAGEv1/esRAGE levels may represent a novel biomarker for RAGE-ligand related pathogenic states. Understanding the full plethora of RAGE alternative splicing and its regulation is central to elucidating the role of RAGE in biology and disease
  52. Onat, Duygu; Brillon, David; Colombo, Paolo C; Schmidt, Ann Marie. "Human vascular endothelial cells: a model system for studying vascular inflammation in diabetes and atherosclerosis". Current diabetes reports. 2011 Jun;11(3):193-202 (MEDL:21337131 #134273)       

    The vascular endothelium is the inner lining of blood vessels serving as autocrine and paracrine organ that regulates vascular wall function. Endothelial dysfunction is recognized as initial step in the atherosclerotic process and is well advanced in diabetes, even before the manifestation of end-organ damage. Strategies capable of assessing changes in vascular endothelium at the preclinical stage hold potential to refine cardiovascular risk. In vitro cell culture is useful in understanding the interaction of endothelial cells with various mediators; however, it is often criticized due to the uncertain relevance of results to humans. Although circulating endothelial cells, endothelial microparticles, and progenitor cells opened the way for ex vivo studies, a recently described method for obtaining primary endothelial cells through endovascular biopsy allows direct characterization of endothelial phenotype in humans. In this article, we appraise the use of endothelial cell-based methodologies to study vascular inflammation in diabetes and atherosclerosis
  53. Ramasamy, Ravichandran; Yan, Shi Fang; Schmidt, Ann Marie. "Receptor for AGE (RAGE): signaling mechanisms in the pathogenesis of diabetes and its complications". Annals of the New York Academy of Sciences. 2011 Dec;1243(1):88-102 (MEDL:22211895 #148734)       

    The receptor for advanced glycation endproducts (RAGE) was first described as a signal transduction receptor for advanced glycation endproducts (AGEs), the products of nonenzymatic glycation and oxidation of proteins and lipids that accumulate in diabetes and in inflammatory foci. The discovery that RAGE was a receptor for inflammatory S100/calgranulins and high mobility group box 1 (HMGB1) set the stage for linking RAGE to both the consequences and causes of types 1 and 2 diabetes. Recent discoveries regarding the structure of RAGE as well as novel intracellular binding partner interactions advance our understanding of the mechanisms by which RAGE evokes pathological consequences and underscore strategies by which antagonism of RAGE in the clinic may be realized. Finally, recent data tracking RAGE in the clinic suggest that levels of soluble RAGEs and polymorphisms in the gene encoding RAGE may hold promise for the identification of patients who are vulnerable to the complications of diabetes and/or are receptive to therapeutic interventions designed to prevent and reverse the damage inflicted by chronic hyperglycemia, irrespective of its etiology
  54. Tekabe, Yared; Shen, Xiaoping; Luma, Joane; Weisenberger, Drew; Yan, Shi Fang; Haubner, Roland; Schmidt, Ann Marie; Johnson, Lynne. "Imaging the effect of receptor for advanced glycation endproducts on angiogenic response to hindlimb ischemia in diabetes". EJNMMI Research. 2011;1(1):3-3 (MEDL:22214528 #778832)       

    BACKGROUND: Receptor for advanced glycation endproducts (RAGE) expression contributes to the impaired angiogenic response to limb ischemia in diabetes. The aim of this study was to detect the effect of increased expression of RAGE on the angiogenic response to limb ischemia in diabetes by targeting alphavbeta3 integrin with 99mTc-labeled Arg-Gly-Asp (RGD). METHODS: Male wild-type (WT) C57BL/6 mice were either made diabetic or left as control for 2 months when they underwent femoral artery ligation. Four groups were studied at days 3 to 7 after ligation: WT without diabetes (NDM) (n = 14), WT with diabetes (DM) (n = 14), RAGE-/- NDM (n = 16), and RAGE-/- DM (n = 14). Mice were injected with 99mTc-HYNIC-RGD and imaged. Count ratios for ischemic/non-ischemic limbs were measured. Muscle was stained for RAGE, alphavbeta3, and lectins. RESULTS: There was no difference in count ratio between RAGE-/- and WT NDM groups. Mean count ratio was lower for WT DM (1.38 +/- 0.26) vs. WT NDM (1.91 +/- 0.34) (P<0.001). Mean count ratio was lower for the RAGE-/- DM group than for RAGE-/- NDM group (1.75 +/- 0.22 vs. 2.02 +/- 0.29) (P<0.001) and higher than for the WT DM group (P<0.001). Immunohistopathology supported the scan findings. CONCLUSIONS: In vivo imaging of alphavbeta3 integrin can detect the effect of RAGE on the angiogenic response to limb ischemia in diabetes.
  55. Vedantham, Srinivasan; Noh, Hyelim; Ananthakrishnan, Radha; Son, Ni; Hallam, Kellie; Hu, Yunying; Yu, Shuiquing; Shen, Xiaoping; Rosario, Rosa; Lu, Yan; Ravindranath, Thyyar; Drosatos, Konstantinos; Huggins, Lesley Ann; Schmidt, Ann Marie; Goldberg, Ira J; Ramasamy, Ravichandran. "Human aldose reductase expression accelerates atherosclerosis in diabetic apolipoprotein e-/- mice". Arteriosclerosis, thrombosis, & vascular biology. 2011 Aug;31(8):1805-1813 (MEDL:21636809 #135542)       

    OBJECTIVE: There are several pathways that mediate the aberrant metabolism of glucose and that might induce greater vascular damage in the setting of diabetes. The polyol pathway mediated by aldose reductase (AR) has been postulated to be one such pathway. However, it has been reported that AR reduces toxic lipid aldehydes and, under some circumstances, might be antiatherogenic. METHODS AND RESULTS: Atherosclerosis development was quantified in 2 lines of transgenic mice expressing human AR (hAR) crossed on the apolipoprotein E knockout background. The transgenes were used to increase the normally low levels of this enzyme in wild-type mice. Both generalized hAR overexpression and hAR expression via the Tie 2 promoter increased lesion size in streptozotocin diabetic mice. In addition, pharmacological inhibition of AR reduced lesion size. CONCLUSIONS: Although in some settings AR expression might reduce levels of toxic aldehydes, transgenic expression of this enzyme within the artery wall leads to greater atherosclerosis
  56. Xue, Jing; Rai, Vivek; Singer, David; Chabierski, Stefan; Xie, Jingjing; Reverdatto, Sergey; Burz, David S; Schmidt, Ann Marie; Hoffmann, Ralf; Shekhtman, Alexander. "Advanced Glycation End Product Recognition by the Receptor for AGEs". Structure. 2011 May 11;19(5):722-732 (MEDL:21565706 #134164)       

    Nonenzymatic protein glycation results in the formation of advanced glycation end products (AGEs) that are implicated in the pathology of diabetes, chronic inflammation, Alzheimer's disease, and cancer. AGEs mediate their effects primarily through a receptor-dependent pathway in which AGEs bind to a specific cell surface associated receptor, the Receptor for AGEs (RAGE). N(varepsilon)-carboxy-methyl-lysine (CML) and N(varepsilon)-carboxy-ethyl-lysine (CEL), constitute two of the major AGE structures found in tissue and blood plasma, and are physiological ligands of RAGE. The solution structure of a CEL-containing peptide-RAGE V domain complex reveals that the carboxyethyl moiety fits inside a positively charged cavity of the V domain. Peptide backbone atoms make specific contacts with the V domain. The geometry of the bound CEL peptide is compatible with many CML (CEL)-modified sites found in plasma proteins. The structure explains how such patterned ligands as CML (CEL)-proteins bind to RAGE and contribute to RAGE signaling
  57. Yang, Christina; DeVisser, Adriena; Martinez, Jose A; Poliakov, Ilia; Rosales-Hernandez, Alma; Ayer, Amit; Garven, Alexandra; Zaver, Shaila; Rincon, Natalia; Xu, Kevin; Tuor, Ursula I; Schmidt, Ann Marie; Toth, Cory. "Differential impact of diabetes and hypertension in the brain: adverse effects in white matter". Neurobiology of disease. 2011 Jun;42(3):446-458 (MEDL:21324363 #778842)       

    Humans subjected to diabetes mellitus (DM) and/or hypertension (HTN) develop cognitive decline, cerebral atrophy and white matter abnormalities, but the relative effects of DM and HTN upon myelin and axonal integrity is unknown. We studied models of Type 1 (streptozotocin-induced) and Type 2 DM (ZDF) +/- HTN (ZSF-1, SHR) in adult rats using magnetic resonance imaging (MRI) and structural and molecular techniques. Type 1 or 2 DM independently led to loss of myelin associated with changes with MRI T2 and magnetization tensor ratios throughout white matter regions. HTN's effect on myelin loss was minimal. Loss of oligodendroglia and myelin proteins was only identified in either Type 1 or Type 2 DM. Activation of the signal transduction pathways initiated by the receptor for advanced glycation end products (AGEs), RAGE, including upregulation of the signal transducer nuclear factor (NF) kappaB only occurred with DM. Diabetes is a greater contributor to white matter loss than hypertension in the rat brain, while hypertension only plays a mild additive effect upon neurodegeneration in the presence of diabetes.
  58. Bu, De-xiu; Rai, Vivek; Shen, Xiaoping; Rosario, Rosa; Lu, Yan; D'Agati, Vivette; Yan, Shi Fang; Friedman, Richard A; Nuglozeh, Edem; Schmidt, Ann Marie. "Activation of the ROCK1 branch of the transforming growth factor-beta pathway contributes to RAGE-dependent acceleration of atherosclerosis in diabetic ApoE-null mice". Circulation research. 2010 Apr 2;106(6):1040-1051 (MEDL:20133903 #140590)       

    RATIONALE: The multiligand RAGE (receptor for advanced glycation end products) contributes to atherosclerosis in apolipoprotein (Apo)E-null mice. OBJECTIVE: To delineate the specific mechanisms by which RAGE accelerated atherosclerosis, we performed Affymetrix gene expression arrays on aortas of nondiabetic and diabetic ApoE-null mice expressing RAGE or devoid of RAGE at nine weeks of age, as this reflected a time point at which frank atherosclerotic lesions were not yet present, but that we would be able to identify the genes likely involved in diabetes- and RAGE-dependent atherogenesis. METHODS AND RESULTS: We report that there is very little overlap of the genes that are differentially expressed both in the onset of diabetes in ApoE-null mice, and in the effect of RAGE deletion in diabetic ApoE-null mice. Pathway-Express analysis revealed that the transforming growth factor-beta pathway and focal adhesion pathways might be expected to play a significant role in both the mechanism by which diabetes facilitates the formation of atherosclerotic plaques in ApoE-null mice, and the mechanism by which deletion of RAGE ameliorates this effect. Quantitative polymerase chain reaction studies, Western blotting, and confocal microscopy in aortic tissue and in primary cultures of murine aortic smooth muscle cells supported these findings. CONCLUSIONS: Taken together, our work suggests that RAGE-dependent acceleration of atherosclerosis in ApoE-null mice is dependent, at least in part, on the action of the ROCK1 (rho-associated protein kinase 1) branch of the transforming growth factor-beta pathway
  59. D'Agati, Vivette; Schmidt, Ann Marie. "RAGE and the pathogenesis of chronic kidney disease". Nature reviews. Nephrology. 2010 Jun;6(6):352-360 (MEDL:20421886 #778922)       

    The multiligand receptor of the immunoglobulin superfamily, receptor for advanced glycation endproducts (RAGE), is a signal transduction receptor that binds advanced glycation endproducts, certain members of the S100/calgranulin family of proteins, high mobility group box 1 (HMGB1), advanced oxidation protein products, and amyloid (beta-sheet fibrils). Initial studies investigating the role of RAGE in renal dysfunction focused on diabetes. However, RAGE also has roles in the pathogenesis of renal disorders that are not associated with diabetes, such as obesity-related glomerulopathy, doxorubicin-induced nephropathy, hypertensive nephropathy, lupus nephritis, renal amyloidosis, and ischemic renal injuries. Experiments that have employed transgenic mouse models, pharmacological blockade of RAGE, or genetic deletion or modification of RAGE indicate that modulation of RAGE expression or function affects the functional and pathological properties of these nephropathies. Accumulating evidence links RAGE to the pathogenesis of nephropathies, indicating that antagonism of RAGE might be a strategy for the treatment of chronic kidney disease.
  60. D'Agati, Vivette; Yan, Shi Fang; Ramasamy, Ravichandran; Schmidt, Ann Marie. "RAGE, glomerulosclerosis and proteinuria: roles in podocytes and endothelial cells". Trends in endocrinology & metabolism. 2010 Jan;21(1):50-56 (MEDL:19783154 #130808)       

    The multi-ligand Receptor for Advanced Glycation Endproducts (RAGE) is expressed in podocytes and endothelial cells in the human and murine glomerulus. Although present at low levels in homeostasis, RAGE expression is increased during disease. Pharmacological antagonism of RAGE or its genetic deletion imparts marked protection from podocyte effacement, albuminuria and glomerular sclerosis in disease models. In human subjects, associations between specific genetic polymorphisms of RAGE and levels of soluble forms of RAGE are linked to disease states in the kidney. In this review, we summarize the evidence from mouse to man, linking RAGE to the pathogenesis of nephropathy
  61. DiNorcia, Joseph; Moroziewicz, Dorota N; Ippagunta, Nikalesh; Lee, Minna K; Foster, Mark; Rotterdam, Heidrun Z; Bao, Fei; Zhou, Yu Shan; Yan, Shi Fang; Emond, Jean; Schmidt, Ann Marie; Allendorf, John D. "RAGE signaling significantly impacts tumorigenesis and hepatic tumor growth in murine models of colorectal carcinoma". Journal of gastrointestinal surgery. 2010 Nov;14(11):1680-1690 (MEDL:20824364 #140587)       

    BACKGROUND: The receptor for advanced glycation end-products (RAGE) is a cell surface receptor implicated in tumor cell proliferation and migration. We hypothesized that RAGE signaling impacts tumorigenesis and metastatic tumor growth in murine models of colorectal carcinoma. MATERIALS AND METHODS: Tumorigenesis: Apc (1638N/+) mice were crossed with Rage (-/-) mice in the C57BL/6 background to generate Apc (1638N/+)/Rage (-/-) mice. Metastasis: BALB/c mice underwent portal vein injection with CT26 cells (syngeneic) and received daily soluble (s)RAGE or vehicle. Rage (-/-) mice and Rage (+/+) controls underwent portal vein injection with MC38 cells (syngeneic). Rage (+/+) mice underwent portal vein injection with MC38 cells after stable transfection with full-length RAGE or mock transfection control. RESULTS: Tumorigenesis: Apc (1638N/+)/Rage (-/-) mice had reduced tumor incidence, size, and histopathologic grade. Metastasis: Pharmacological blockade of RAGE with sRAGE or genetic deletion of Rage reduced hepatic tumor incidence, nodules, and burden. Gain of function by transfection with full-length RAGE increased hepatic tumor burden compared to vector control MC38 cells. CONCLUSION: RAGE signaling plays an important role in tumorigenesis and hepatic tumor growth in murine models of colorectal carcinoma. Further work is needed to target the ligand-RAGE axis for possible prophylaxis and treatment of primary and metastatic colorectal carcinoma
  62. Fang, Fang; Lue, Lih-Fen; Yan, Shiqiang; Xu, Hongwei; Luddy, John S; Chen, Doris; Walker, Douglas G; Stern, David M; Yan, Shifang; Schmidt, Ann Marie; Chen, John X; Yan, Shirley ShiDu. "RAGE-dependent signaling in microglia contributes to neuroinflammation, Abeta accumulation, and impaired learning/memory in a mouse model of Alzheimer's disease". FASEB journal. 2010 Apr;24(4):1043-1055 (MEDL:19906677 #140647)       

    Microglia are critical for amyloid-beta peptide (Abeta)-mediated neuronal perturbation relevant to Alzheimer's disease (AD) pathogenesis. We demonstrate that overexpression of receptor for advanced glycation end products (RAGE) in imbroglio exaggerates neuroinflammation, as evidenced by increased proinflammatory mediator production, Abeta accumulation, impaired learning/memory, and neurotoxicity in an Abeta-rich environment. Transgenic (Tg) mice expressing human mutant APP (mAPP) in neurons and RAGE in microglia displayed enhanced IL-1beta and TNF-alpha production, increased infiltration of microglia and astrocytes, accumulation of Abeta, reduced acetylcholine esterase (AChE) activity, and accelerated deterioration of spatial learning/memory. Notably, introduction of a signal transduction-defective mutant RAGE (DN-RAGE) to microglia attenuates deterioration induced by Abeta. These findings indicate that RAGE signaling in microglia contributes to the pathogenesis of an inflammatory response that ultimately impairs neuronal function and directly affects amyloid accumulation. We conclude that blockade of microglial RAGE may have a beneficial effect on Abeta-mediated neuronal perturbation relevant to AD pathogenesis.-Fang, F., Lue, L.-F., Yan, S., Xu, H., Luddy, J. S., Chen, D., Walker, D. G., Stern, D. M., Yan, S., Schmidt, A. M., Chen, J. X., Yan, S. S. RAGE-dependent signaling in microglia contributes to neuroinflammation, Abeta accumulation, and impaired learning/memory in a mouse model of Alzheimer's disease
  63. Hallam, Kellie McCormick; Li, Qing; Ananthakrishnan, Radha; Kalea, Anastasia; Zou, Yu S; Vedantham, Srinivasan; Schmidt, Ann Marie; Yan, Shi Fang; Ramasamy, Ravichandran. "Aldose reductase and AGE-RAGE pathways: central roles in the pathogenesis of vascular dysfunction in aging rats". Aging Cell. 2010 Oct;9(5):776-784 (MEDL:20670350 #130803)       

    Aging is inevitably accompanied by gradual and irreversible innate endothelial dysfunction. In this study, we tested the hypothesis that accentuation of glucose metabolism via the aldose reductase (AR) pathway contributes to age-related vascular dysfunction. AR protein and activity levels were significantly increased in aged vs. young aortic homogenates from Fischer 344 rats. Immunostaining revealed that the principal site of increased AR protein was the aortic endothelium as well as smooth muscle cells. Studies revealed that endothelial-dependent relaxation (EDR) in response to acetylcholine was impaired in aged rats compared to young rats and that treatment with the AR inhibitor (ARI) zopolrestat significantly improved EDR in aged rats. Methylglyoxal (MG), a key precursor of advanced glycation endproducts (AGEs), was significantly increased in the aortas of aged rats vs. young rats. Consistent with central roles for AR in generation of MG in aging, ARI treatment significantly reduced MG levels in aged rat aorta to those in young rats. Treatment of aged rats with soluble(s) RAGE, a soluble form of the chief signal transduction receptor for AGEs, RAGE, significantly improved EDR in aged rats, thus establishing the contribution of age-related increases in AGEs to endothelial dysfunction. These findings reveal that significant increases in AR expression and activity in aged rat vasculature linked to endothelial dysfunction may be mitigated, at least in part, via ARI and that aging-linked increased flux via AR generates AGEs; species which transduce endothelial injury consequent to their interaction with RAGE. These data demonstrate for the first time that AR mediates aging-related vascular dysfunction, at least in part, via RAGE
  64. Juranek, Judyta K; Aleshin, Alexey; Rattigan, Eileen M; Johnson, Lynne; Qu, Wu; Song, Fei; Ananthakrishnan, Radha; Quadri, Nosirudeen; Yan, Shi Du; Ramasamy, Ravichandran; Schmidt, Ann Marie; Geddis, Matthew S. "Morphological Changes and Immunohistochemical Expression of RAGE and its Ligands in the Sciatic Nerve of Hyperglycemic Pig (Sus Scrofa)". Biochemistry Insights. 2010 Sep;2010(3):47-59 (MEDL:21852897 #528222)       

    The aim of our project was to study the effect of streptozotocin (STZ)-induced hyperglycemia on sciatic nerve morphology, blood plasma markers and immunohistochemical expression of RAGE (the Receptor for Advanced Glycation End-products), and its ligands-S100B and Carboxymethyl Lysine (CML)-advanced glycation endproduct (AGE) in the laboratory pig. Six months after STZ-injections, blood plasma measurements, morphometric analysis of sciatic nerve fiber density, immunofluorescent distribution of potential molecular neuropathy contributors, ELISA measurement of plasma AGE level and HPLC analysis of sciatic nerve levels of one of the pre-AGE and the glycolysis intermediate products-methyl-glyoxal (MG) were performed. The results of our study revealed that STZ-injected animals displayed elevated levels of plasma glucose, gamma glutamyl transferase (GGT) and triglycerides. The sciatic nerve of STZ-injected pigs revealed significantly lower numbers of small-diameter myelinated fibers, higher immunoreactivity for RAGE and S100B and increased levels of MG as compared to control animals. Our results correspond to clinical findings in human patients with hyperglycemia/diabetes-evoked peripheral neuropathy and suggest that the domestic pig may be a suitable large animal model for the study of mechanisms underlying hyperglycemia-induced neurological complications in the peripheral nerve and may serve as a relevant model for the pre-clinical assessment of candidate drugs in neuropathy.
  65. Kalea, Anastasia Z; See, Fiona; Harja, Evis; Arriero, Maria; Schmidt, Ann Marie; Hudson, Barry I. "Alternatively spliced RAGEv1 inhibits tumorigenesis through suppression of JNK signaling". Cancer research. 2010 Jul;70(13):5628-5638 (MEDL:20570900 #778902)       

    Receptor for advanced glycation end products (RAGE) and its ligands are overexpressed in multiple cancers. RAGE has been implicated in tumorigenesis and metastasis, but little is known of the mechanisms involved. In this study, we define a specific functional role for an alternate splice variant termed RAGE splice variant 1 (RAGEv1), which encodes a soluble endogenous form of the receptor that inhibits tumorigenesis. RAGEv1 was downregulated in lung, prostate, and brain tumors relative to control matched tissues. Overexpressing RAGEv1 in tumor cells altered RAGE ligand stimulation of several novel classes of genes that are critical in tumorigenesis and metastasis. Additionally, RAGEv1 inhibited tumor formation, cell invasion, and angiogenesis induced by RAGE ligand signaling. Analysis of signal transduction pathways underlying these effects revealed marked suppression of c-jun-NH(2)-kinase (JNK) pathway signaling, and JNK inhibition suppressed signaling through the RAGE pathway. Tumors expressing RAGEv1 were significantly smaller than wild-type tumors and displayed prominently reduced activation of JNK. Our results identify RAGEv1 as a novel suppressor, the study of which may offer new cancer therapeutic directions.
  66. Lee, Song Eun; Ma, Wanchao; Rattigan, Eileen M; Aleshin, Alexey; Chen, Liqun; Johnson, Lynne L; D'Agati, Vivette D; Schmidt, Ann Marie; Barile, Gaetano R. "Ultrastructural features of retinal capillary basement membrane thickening in diabetic swine". Ultrastructural pathology. 2010 Feb;34(1):35-41 (MEDL:20070152 #778942)       

    PURPOSE: To assess retinal capillary basement membrane thickening (BMT) in a swine model of type 1 diabetes. MATERIALS AND METHODS: Yorkshire pigs were rendered diabetic with streptozotocin and dyslipidemic with a high fat and cholesterol diet. At 18, 26, and 32 weeks of diabetes, the retina sections within 3 disc diameters from the optic disc were examined under transmission electron microscopy to evaluate the ultrastructural features of the capillary BM. Digital morphometric analysis was performed to measure BMT. RESULTS: Diabetic swine had significantly thicker retinal capillary BMs compared to controls. Pigs that sustained diabetes for longer periods or experienced severe diabetes tended to have more BMT. Those pigs that did not sustain glucose levels above 200 mg/dL did not demonstrate thicker retinal capillary BMs. Characteristic ultrastructural features of diabetic vasculopathy observed included rarefaction as an early stage of Swiss cheese cavitation, lamellation with multiplication of electron dense layers, and fibrillar materials within capillary BM. CONCLUSIONS: Diabetic Yorkshire pigs develop characteristic features of an early retinal microvasculopathy fairly rapidly and may serve as a higher-order animal model for studies of type 1 diabetes.
  67. Lu, Lin; Zhang, Qi; Xu, Yan; Zhu, Zheng-bin; Geng, Liang; Wang, Ling-jie; Jin, Cao; Chen, Qiu-jing; Schmidt, Ann Marie; Shen, Wei-feng. "Intra-coronary administration of soluble receptor for advanced glycation end-products attenuates cardiac remodeling with decreased myocardial transforming growth factor-beta1 expression and fibrosis in minipigs with ischemia-reperfusion injury". Chinese medical journal. 2010 Mar;123(5):594-598 (MEDL:20367988 #778932)       

    BACKGROUND: The cardioprotective effects of soluble receptor for advanced glycation end-products (sRAGE) have not been evaluated in large animals and the underlying mechanisms are not fully understood. This study aimed to evaluate the effects of intra-coronary administration of sRAGE on left ventricular function and myocardial remodeling in a porcine model of ischemia-reperfusion (I/R) injury. METHODS: Ten male minipigs with I/R injury were randomly allocated to receive intra-coronary administration of sRAGE (sRAGE group, n = 5) or saline (control group, n = 5). Echocardiography was performed before and 2 months after infarction. Myocardial expression of transforming growth factor (TGF)-beta1 was determined by immunohistochemistry and fibrosis was evaluated by Sirius red staining. RESULTS: As compared with the baseline values in the control animals, left ventricular end-diastolic volume (from (19.5 +/- 5.1) to (32.3 +/- 5.6) ml, P < 0.05) and end-systolic volume (from (8.3 +/- 3.2) to (15.2 +/- 4.1) ml, P< 0.05) were significantly increased, whereas ejection fraction was decreased (from (61.6 +/- 13.3)% to (50.2 +/- 11.9)%, P < 0.05). No obvious change in these parameters was observed in the sRAGE group. Myocardial expression of TGF-beta1 was significantly elevated in the infarct and non-infarct regions in the control group, as compared with sRAGE group (both P< 0.01). Fibrotic lesions were consistently more prominent in the infarct region of the myocardium in the control animals (P < 0.05). CONCLUSION: Intra-coronary sRAGE administration attenuates RAGE-mediated myocardial fibrosis and I/R injury through a TGF-beta1-dependent mechanism, suggesting a clinical potential in treating RAGE/ligand-associated cardiovascular diseases.
  68. Mangalmurti, Nilam S; Chatterjee, Shampa; Cheng, Guanjun; Andersen, Emily; Mohammed, Aishat; Siegel, Donald L; Schmidt, Ann Marie; Albelda, Steven M; Lee, Janet S. "Advanced glycation end products on stored red blood cells increase endothelial reactive oxygen species generation through interaction with receptor for advanced glycation end products". Transfusion. 2010 Nov;50(11):2353-2361 (MEDL:20492604 #778872)       

    BACKGROUND: Recent evidence suggests that storage-induced alterations of the red blood cell (RBC) are associated with adverse consequences in susceptible hosts. As RBCs have been shown to form advanced glycation end products (AGEs) after increased oxidative stress and under pathologic conditions, we examined whether stored RBCs undergo modification with the specific AGE N-(carboxymethyl)lysine (N(epsilon) -CML) during standard blood banking conditions. STUDY DESIGN AND METHODS: Purified, fresh RBCs from volunteers were compared to stored RBCs (35-42 days old) obtained from the blood bank. N(epsilon) -CML formation was quantified using a competitive enzyme-linked immunosorbent assay. The receptor for advanced glycation end products (RAGE) was detected in human pulmonary microvascular endothelial cells (HMVEC-L) by real-time polymerase chain reaction, Western blotting, and flow cytometry. Intracellular reactive oxygen species (ROS) generation was measured by the use of 5-(and 6-)chloromethyl-2',7'-dichlorodihydrofluorescein diacetate, acetyl ester-based assays. RESULTS: Stored RBCs showed increased surface N(epsilon) -CML formation when compared with fresh RBCs. HMVEC-L showed detectable surface RAGE expression constitutively. When compared to fresh RBCs, stored RBCs triggered increased intracellular ROS generation in both human umbilical vein endothelial cells and HMVEC-L. RBC-induced endothelial ROS generation was attenuated in the presence of soluble RAGE or RAGE blocking antibody. CONCLUSIONS: The formation of the AGE N(epsilon) -CML on the surface of stored RBCs is one functional consequence of the storage lesion. AGE-RAGE interactions may be one mechanism by which transfused RBCs cause endothelial cell damage.
  69. Pollreisz, Andreas; Hudson, Barry I; Chang, Jong S; Qu, Wu; Cheng, Bin; Papapanou, Panos N; Schmidt, Ann Marie; Lalla, Evanthia. "Receptor for advanced glycation endproducts mediates pro-atherogenic responses to periodontal infection in vascular endothelial cells". Atherosclerosis. 2010 Oct;212(2):451-456 (MEDL:20701913 #778882)       

    OBJECTIVE: A link between periodontal infections and an increased risk for vascular disease has been demonstrated. Porphyromonas gingivalis, a major periodontal pathogen, localizes in human atherosclerotic plaques, accelerates atherosclerosis in animal models and modulates vascular cell function. The receptor for advanced glycation endproducts (RAGE) regulates vascular inflammation and atherogenesis. We hypothesized that RAGE is involved in P. gingivalis's contribution to pro-atherogenic responses in vascular endothelial cells. METHODS AND RESULTS: Murine aortic endothelial cells (MAEC) were isolated from wild-type C57BL/6 or RAGE-/- mice and were infected with P. gingivalis strain 381. P. gingivalis 381 infection significantly enhanced expression of RAGE in wild-type MAEC. Levels of pro-atherogenic advanced glycation endproducts (AGEs) and monocyte chemoattractant protein 1 (MCP-1) were significantly increased in wild-type MAEC following P. gingivalis 381 infection, but were unaffected in MAEC from RAGE-/- mice or in MAEC infected with DPG3, a fimbriae-deficient mutant of P. gingivalis 381. Consistent with a role for oxidative stress and an AGE-dependent activation of RAGE in this setting, both antioxidant treatment and AGE blockade significantly suppressed RAGE gene expression and RAGE and MCP-1 protein levels in P. gingivalis 381-infected human aortic endothelial cells (HAEC). CONCLUSION: The present findings implicate for the first time the AGE-RAGE axis in the amplification of pro-atherogenic responses triggered by P. gingivalis in vascular endothelial cells.
  70. Reiniger, Nina; Lau, Kai; McCalla, Daren; Eby, Bonnie; Cheng, Bin; Lu, Yan; Qu, Wu; Quadri, Nosirudeen; Ananthakrishnan, Radha; Furmansky, Maryana; Rosario, Rosa; Song, Fei; Rai, Vivek; Weinberg, Alan; Friedman, Richard; Ramasamy, Ravichandran; D'Agati, Vivette; Schmidt, Ann Marie. "Deletion of the receptor for advanced glycation end products reduces glomerulosclerosis and preserves renal function in the diabetic OVE26 mouse". Diabetes. 2010 Aug;59(8):2043-2054 (MEDL:20627935 #130804)       

    OBJECTIVE: Previous studies showed that genetic deletion or pharmacological blockade of the receptor for advanced glycation end products (RAGE) prevents the early structural changes in the glomerulus associated with diabetic nephropathy. To overcome limitations of mouse models that lack the progressive glomerulosclerosis observed in humans, we studied the contribution of RAGE to diabetic nephropathy in the OVE26 type 1 mouse, a model of progressive glomerulosclerosis and decline of renal function. RESEARCH DESIGN AND METHODS: We bred OVE26 mice with homozygous RAGE knockout (RKO) mice and examined structural changes associated with diabetic nephropathy and used inulin clearance studies and albumin:creatinine measurements to assess renal function. Transcriptional changes in the Tgf-beta1 and plasminogen activator inhibitor 1 gene products were measured to investigate mechanisms underlying accumulation of mesangial matrix in OVE26 mice. RESULTS: Deletion of RAGE in OVE26 mice reduced nephromegaly, mesangial sclerosis, cast formation, glomerular basement membrane thickening, podocyte effacement, and albuminuria. The significant 29% reduction in glomerular filtration rate observed in OVE26 mice was completely prevented by deletion of RAGE. Increased transcription of the genes for plasminogen activator inhibitor 1, Tgf-beta1, Tgf-beta-induced, and alpha1-(IV) collagen observed in OVE26 renal cortex was significantly reduced in OVE26 RKO kidney cortex. ROCK1 activity was significantly lower in OVE26 RKO compared with OVE26 kidney cortex. CONCLUSIONS: These data provide compelling evidence for critical roles for RAGE in the pathogenesis of diabetic nephropathy and suggest that strategies targeting RAGE in long-term diabetes may prevent loss of renal function
  71. Shang, Linshan; Ananthakrishnan, Radha; Li, Qing; Quadri, Nosirudeen; Abdillahi, Mariane; Zhu, Zhengbin; Qu, Wu; Rosario, Rosa; Toure, Fatouma; Yan, Shi Fang; Schmidt, Ann Marie; Ramasamy, Ravichandran. "RAGE modulates hypoxia/reoxygenation injury in adult murine cardiomyocytes via JNK and GSK-3beta signaling pathways". PLoS ONE. 2010;5(4):e10092-e10092 (MEDL:20404919 #130806)       

    BACKGROUND: Advanced glycation end-products (AGEs) have been implicated in diverse pathological settings including diabetes, inflammation and acute ischemia/reperfusion injury in the heart. AGEs interact with the receptor for AGEs (RAGE) and transduce signals through activation of MAPKs and proapoptotic pathways. In the current study, adult cardiomyocytes were studied in an in vitro ischemia/reperfusion (I/R) injury model to delineate the molecular mechanisms underlying RAGE-mediated injury due to hypoxia/reoxygenation (H/R). METHODOLOGY/PRINCIPAL FINDINGS: Cardiomyocytes isolated from adult wild-type (WT), homozygous RAGE-null (RKO), and WT mice treated with soluble RAGE (sRAGE) were subjected to hypoxia for 30 minutes alone or followed by reoxygenation for 1 hour. In specific experiments, RAGE ligand carboxymethyllysine (CML)-AGE (termed 'CML' in this manuscript) was evaluated in vitro. LDH, a marker of cellular injury, was assayed in the supernatant in the presence or absence of signaling inhibitor-treated cardiomyocytes. Cardiomyocyte levels of heterogeneous AGEs were measured using ELISA. A pronounced increase in RAGE expression along with AGEs was observed in H/R vs. normoxia in WT cardiomyocytes. WT cardiomyocytes after H/R displayed increased LDH release compared to RKO or sRAGE-treated cardiomyocytes. Our results revealed significant increases in phospho-JNK in WT cardiomyocytes after H/R. In contrast, neither RKO nor sRAGE-treated cardiomyocytes exhibited increased phosphorylation of JNK after H/R stress. The impact of RAGE deletion on GSK-3beta phosphorylation in the cardiomyocytes subjected to H/R revealed significantly higher levels of phospho-GSK-3beta/total GSK-3beta in RKO, as well as in sRAGE-treated cardiomyocytes versus WT cardiomyocytes after H/R. Further investigation established a key role for Akt, which functions upstream of GSK-3beta, in modulating H/R injury in adult cardiomyocytes. CONCLUSIONS/SIGNIFICANCE: These data illustrate key roles for RAGE-ligand interaction in the pathogenesis of cardiomyocyte injury induced by hypoxia/reoxygenation and indicate that the effects of RAGE are mediated by JNK activation and dephosphorylation of GSK-3beta. The outcome in this study lends further support to the potential use of RAGE blockade as an adjunctive therapy for protection of the ischemic heart
  72. Tekabe, Yared; Luma, Joane; Einstein, Andrew J; Sedlar, Marija; Li, Qing; Schmidt, Ann Marie; Johnson, Lynne L. "A novel monoclonal antibody for RAGE-directed imaging identifies accelerated atherosclerosis in diabetes". Journal of nuclear medicine. 2010 Jan;51(1):92-97 (MEDL:20008983 #778952)       

    Receptor for advanced glycation end products (RAGE) binds advanced glycation end products and other inflammatory ligands and is expressed in atherosclerotic plaques in diabetic and nondiabetic subjects. The higher expression in diabetes mellitus corresponds to the accelerated course of the atherosclerosis. This study was designed to test the hypothesis that the level of RAGE expression in atherosclerosis can be detected by quantitative in vivo SPECT and that counts in the target will correlate with the strength of the biologic signal. METHODS: A monoclonal murine antibody was developed against the V-domain of RAGE, fragmented into F(ab')(2) and labeled with (99m)Tc, and injected at a dose of 15.14 +/- 1.23 MBq into 24-wk-old male apolipoprotein E null (ApoE(-/-)) mice (n = 22), including mice with streptozotocin-induced diabetes mellitus (n = 8), nondiabetic mice (n = 8), and control ApoE(-/-)/RAGE(-/-) double-knock-out mice (n = 6). Four hours later (allowing for blood-pool clearance), the mice were imaged and sacrificed, and the proximal aorta was removed and counted to calculate the percentage injected dose of RAGE per gram of tissue, followed by histologic and immunohistochemical characterization. RESULTS: Radiotracer uptake in the aortic lesions was clearly visualized noninvasively by SPECT. RAGE uptake as percentage injected dose in diabetic ApoE(-/-) mice (1.39 +/- 0.16 x 10(-2)) was significantly higher than that in nondiabetic ApoE(-/-) mice (0.48 +/- 0.27 x 10(-2)) (P < 0.0001). The radiotracer uptake was highly correlated with RAGE expression by quantitative immunohistomorphometry (r = 0.82, P = 0.002) and with percentage of macrophages (r = 0.86, P < 0.0001). CONCLUSION: In this study, (99m)Tc-labeled anti-RAGE F(ab')(2) SPECT successfully identified early accelerated disease in diabetes mellitus for age-matched ApoE(-/-) mice and quantified RAGE expression over a range of lesion severities.
  73. van Zoelen, Marieke A D; Achouiti, Ahmed; Schmidt, Ann-Marie; Yang, Huan; Florquin, Sandrine; Tracey, Kevin J; van der Poll, Tom. "Ligands of the receptor for advanced glycation end products, including high-mobility group box 1, limit bacterial dissemination during Escherichia coli peritonitis". Critical care medicine. 2010 Jun;38(6):1414-1422 (MEDL:20386310 #778912)       

    OBJECTIVE: The receptor for advanced glycation end products mediates a variety of inflammatory responses. Soluble receptor for advanced glycation end products has been suggested to function as a decoy abrogating cellular activation. High-mobility group box 1 is a high-affinity binding ligand for the receptor for advanced glycation end products with cytokine activities and plays a role in sepsis. DESIGN: Controlled, in vivo laboratory study. SETTING: Research laboratory of a health sciences university. SUBJECTS: C57BL/6 mice. INTERVENTIONS: Peritonitis was induced by intraperitoneal injection of Escherichia coli. Mice received soluble receptor for advanced glycation end products or anti-high-mobility group box 1 immunoglobulin G, or the appropriate control treatment. MEASUREMENTS AND MAIN RESULTS: Soluble receptor for advanced glycation end products-treated mice demonstrated an enhanced bacterial dissemination to liver and lungs, accompanied by increased hepatocellular injury and exaggerated systemic cytokine release, 20 hrs after intraperitoneal administration of Escherichia coli. Soluble receptor for advanced glycation end products administration in healthy, uninfected mice did not induce an immune response. Remarkably, lung inflammation was unaffected. Furthermore, high-mobility group box 1 release was enhanced during peritonitis and anti-high-mobility group box 1 treatment was associated with higher bacterial loads in liver and lungs. CONCLUSIONS: These data are the first to suggest that receptor for advanced glycation end products ligands, including high-mobility group box 1, limit bacterial dissemination during Gram-negative sepsis.
  74. Wang, Yijie; Wang, Hongmei; Piper, Melissa G; McMaken, Sara; Mo, Xiaokui; Opalek, Judy; Schmidt, Ann Marie; Marsh, Clay B. "sRAGE induces human monocyte survival and differentiation". Journal of immunology. 2010 Aug;185(3):1822-1835 (MEDL:20574008 #778892)       

    The receptor for advanced glycation end products (RAGE) is produced either as a transmembrane or soluble form (sRAGE). Substantial evidence supports a role for RAGE and its ligands in disease. sRAGE is reported to be a competitive, negative regulator of membrane RAGE activation, inhibiting ligand binding. However, some reports indicate that sRAGE is associated with inflammatory disease. We sought to define the biological function of sRAGE on inflammatory cell recruitment, survival, and differentiation in vivo and in vitro. To test the in vivo impact of sRAGE, the recombinant protein was intratracheally administered to mice, which demonstrated monocyte- and neutrophil-mediated lung inflammation. We also observed that sRAGE induced human monocyte and neutrophil migration in vitro. Human monocytes treated with sRAGE produced proinflammatory cytokines and chemokines. Our data demonstrated that sRAGE directly bound human monocytes and monocyte-derived macrophages. Binding of sRAGE to monocytes promoted their survival and differentiation to macrophages. Furthermore, sRAGE binding to cells increased during maturation, which was similar in freshly isolated mouse monocytes compared with mature tissue macrophages. Because sRAGE activated cell survival and differentiation, we examined intracellular pathways that were activated by sRAGE. In primary human monocytes and macrophages, sRAGE treatment activated Akt, Erk, and NF-kappaB, and their activation appeared to be critical for cell survival and differentiation. Our data suggest a novel role for sRAGE in monocyte- and neutrophil-mediated inflammation and mononuclear phagocyte survival and differentiation.
  75. Xu, Yunlu; Toure, Fatouma; Qu, Wu; Lin, Lili; Song, Fei; Shen, Xiaoping; Rosario, Rosa; Garcia, Joel; Schmidt, Ann Marie; Yan, Shi-Fang. "Advanced glycation end product (AGE)-receptor for AGE (RAGE) signaling and up-regulation of Egr-1 in hypoxic macrophages". Journal of biological chemistry. 2010 Jul 23;285(30):23233-23240 (MEDL:20507991 #140589)       

    Receptor for advanced glycation end product (RAGE)-dependent signaling has been implicated in ischemia/reperfusion injury in the heart, lung, liver, and brain. Because macrophages contribute to vascular perturbation and tissue injury in hypoxic settings, we tested the hypothesis that RAGE regulates early growth response-1 (Egr-1) expression in hypoxia-exposed macrophages. Molecular analysis, including silencing of RAGE, or blockade of RAGE with sRAGE (the extracellular ligand-binding domain of RAGE), anti-RAGE IgG, or anti-AGE IgG in THP-1 cells, and genetic deletion of RAGE in peritoneal macrophages, revealed that hypoxia-induced up-regulation of Egr-1 is mediated by RAGE signaling. In addition, the observation of increased cellular release of RAGE ligand AGEs in hypoxic THP-1 cells suggests that recruitment of RAGE in hypoxia is stimulated by rapid production of RAGE ligands in this setting. Finally, we show that mDia-1, previously shown to interact with the RAGE cytoplasmic domain, is essential for hypoxia-stimulated regulation of Egr-1, at least in part through protein kinase C betaII, ERK1/2, and c-Jun NH(2)-terminal kinase signaling triggered by RAGE ligands. Our findings highlight a novel mechanism by which an extracellular signal initiated by RAGE ligand AGEs regulates Egr-1 in a manner requiring mDia-1
  76. Yan, Shi Fang; Ramasamy, Ravichandran; Schmidt, Ann Marie. "Soluble RAGE: therapy and biomarker in unraveling the RAGE axis in chronic disease and aging". Biochemical pharmacology. 2010 May 15;79(10):1379-1386 (MEDL:20096667 #130805)       

    The multi-ligand Receptor for Advanced Glycation Endproducts (RAGE) is implicated in the pathogenesis and progression of chronic diseases such as diabetes and immune/inflammatory disorders. Recent studies are uncovering the precise mechanisms by which distinct RAGE ligands bind the extracellular (soluble) domain of the receptor at the V-, C1- and/or C2-immunoglobulin like domains. Experiments using soluble RAGE in animals as a ligand decoy have illustrated largely beneficial effects in reducing vascular and inflammatory stress and, thereby, preventing long-term tissue damage in models of diabetes and immune/inflammatory disorders. Measurement of soluble RAGE levels in the human, both 'total' soluble RAGE and a splice variant-derived product known as endogenous secretory or esRAGE, holds promise for the identification of potential therapeutic targets and/or biomarkers of RAGE activity in disease. In this article, we review the evidence from the rodent to the human implicating RAGE in the diverse disease states in which its ligands accumulate
  77. Yan, Shi Fang; Ramasamy, Ravichandran; Schmidt, Ann Marie. "The RAGE axis: a fundamental mechanism signaling danger to the vulnerable vasculature". Circulation research. 2010 Mar 19;106(5):842-853 (MEDL:20299674 #130807)       

    The immunoglobulin superfamily molecule RAGE (receptor for advanced glycation end product) transduces the effects of multiple ligands, including AGEs (advanced glycation end products), advanced oxidation protein products, S100/calgranulins, high-mobility group box-1, amyloid-beta peptide, and beta-sheet fibrils. In diabetes, hyperglycemia likely stimulates the initial burst of production of ligands that interact with RAGE and activate signaling mechanisms. Consequently, increased generation of proinflammatory and prothrombotic molecules and reactive oxygen species trigger further cycles of oxidative stress via RAGE, thus setting the stage for augmented damage to diabetic tissues in the face of further insults. Many of the ligand families of RAGE have been identified in atherosclerotic plaques and in the infarcted heart. Together with increased expression of RAGE in diabetic settings, we propose that release and accumulation of RAGE ligands contribute to exaggerated cellular damage. Stopping the vicious cycle of AGE-RAGE and RAGE axis signaling in the vulnerable heart and great vessels may be essential in controlling and preventing the consequences of diabetes
  78. Bucciarelli, Loredana G; Pollreisz, Andreas; Kebschull, Moritz; Ganda, Anjali; Kalea, Anastasia Z; Hudson, Barry I; Zou, Yu Shan; Lalla, Evanthia; Ramasamy, Ravichandran; Colombo, Paolo C; Schmidt, Ann Marie; Yan, Shi Fang. "Inflammatory stress in primary venous and aortic endothelial cells of type 1 diabetic mice". Diabetes & vascular disease research. 2009 Oct;6(4):249-261 (MEDL:20368219 #130799)       

    OBJECTIVE: The progression of diabetes is associated with profound endothelial dysfunction. We tested the hypothesis that cellular stress would be detectable in ECs retrieved from arterial and venous vessels of diabetic mice. METHOD: We describe a method for direct isolation of well-characterised aortic and venous ECs from mice in which cells are not subjected to propagation in culture. RESULTS: Gene expression profiling, confirmed by real-time PCR, revealed a progressive increase in markers of injury within two main gene families, EC activation and EC apoptosis, in aortic and venous ECs recovered from diabetic versus non-diabetic mice. In short-term diabetes, Il1b mRNA transcripts were higher in aortic and venous ECs of diabetic mice versus controls. In long-term diabetes, casp-1 mRNA transcripts were higher in aortic and venous ECs of diabetic mice versus controls. CONCLUSION: These data suggest that diabetes imparts diffuse endothelial perturbation in the arterial and venous endothelium
  79. Calcutt, Nigel A; Cooper, Mark E; Kern, Tim S; Schmidt, Ann Marie. "Therapies for hyperglycaemia-induced diabetic complications: from animal models to clinical trials". Nature reviews. Drug discovery. 2009 May;8(5):417-429 (MEDL:19404313 #779022)       

    Long-term diabetes increases the likelihood of developing secondary damage to numerous systems, and these complications represent a substantial cause of morbidity and mortality. Establishing the causes of diabetes remains the key step towards eradicating the disease, but the prevention and amelioration of diabetic complications is equally important for the millions of individuals who already have the disease or are likely to develop it before prophylaxis or a cure become routinely available. In this Review, we focus on four common complications of diabetes, discuss the range of pathologies that are precipitated by hyperglycaemia and highlight emerging targets for therapeutic intervention.
  80. Cecil, Denise L; Appleton, C Thomas G; Polewski, Monika D; Mort, John S; Schmidt, Ann Marie; Bendele, Alison; Beier, Frank; Terkeltaub, Robert. "The pattern recognition receptor CD36 is a chondrocyte hypertrophy marker associated with suppression of catabolic responses and promotion of repair responses to inflammatory stimuli". Journal of immunology. 2009 Apr 15;182(8):5024-5031 (MEDL:19342682 #133754)       

    Multiple inflammatory mediators in osteoarthritis (OA) cartilage, including S100/calgranulin ligands of receptor for advanced glycation end products (RAGE), promote chondrocyte hypertrophy, a differentiation state associated with matrix catabolism. In this study, we observed that RAGE knockout was not chondroprotective in instability-induced knee OA in 8-wk-old mice. Hence, we tested the hypothesis that expression of the alternative S100/calgranulin and patterning receptor CD36, identified here as a marker of growth plate chondrocyte hypertrophy, mediates chondrocyte inflammatory and differentiation responses that promote OA. In rat knee joint destabilization-induced OA, RAGE expression was initially sparse throughout cartilage but increased diffusely by 4 wk after surgery. In contrast, CD36 expression focally increased at sites of cartilage injury and colocalized with developing chondrocyte hypertrophy and aggrecan cleavage NITEGE neoepitope formation. However, CD36 transfection in normal human knee-immortalized chondrocytes (CH-8 cells) was associated with decreased capacity of S100A11 and TNF-alpha to induce chondrocyte hypertrophy and ADAMTS-4 and matrix metalloproteinase 13 expression. S100A11 lost the capacity to inhibit proteoglycans synthesis and gained the capacity to induce proteoglycan synthesis in CD36-transfected CH-8 cells. Moreover, S100A11 required the p38 MAPK pathway kinase MKK3 to induce NITEGE development in mouse articular cartilage explants. However, CH-8 cells transfected with CD36 demonstrated decreased S100A11-induced MKK3 and p38 phosphorylation. Therefore, RAGE and CD36 patterning receptor expression were linked with opposing effects on inflammatory, procatabolic responses to S100A11 and TNF-alpha in chondrocytes
  81. Harja, Evis; Chang, Jong Sun; Lu, Yan; Leitges, Michael; Zou, Yu Shan; Schmidt, Ann Marie; Yan, Shi-Fang. "Mice deficient in PKCbeta and apolipoprotein E display decreased atherosclerosis". FASEB journal. 2009 Apr;23(4):1081-1091 (MEDL:19036858 #140591)       

    Endothelial activation is a central initiating event in atheroma formation. Evidence from our laboratory and others has demonstrated links between activation of early growth response-1 (Egr-1) and atherosclerosis and also has demonstrated that activated protein kinase C (PKC) betaII is a critical upstream regulator of Egr-1 in response to vascular stress. We tested the role of PKCbeta in regulating key events linked to atherosclerosis and show that the aortas of apoE(-/-) mice display an age-dependent increase in PKCbetaII antigen in membranous fractions vs. C57BL/6 animals with a approximately 2-fold increase at age 6 wk and a approximately 4.5-fold increase at age 24 wk. Consistent with important roles for PKCbeta in atherosclerosis, a significant decrease in atherosclerotic lesion area was evident in PKCbeta(-/-)/apoE(-/-) vs. apoE(-/-) mice by approximately 5-fold, in parallel with significantly reduced vascular transcripts for Egr-1 and matrix metalloproteinase (MMP)-2 antigen and activity vs. apoE(-/-) mice. Significant reduction in atherosclerosis of approximately 2-fold was observed in apoE(-/-) mice fed ruboxistaurin chow (PKCbeta inhibitor) vs. vehicle. In primary murine and human aortic endothelial cells, the PKCbeta-JNK mitogen-activated protein kinase pathway importantly contributes to oxLDL-mediated induction of MMP2 expression. Blockade of PKCbeta may be beneficial in mitigating endothelial perturbation and atherosclerosis
  82. Hassid, Benjamin G; Nair, M Nathan; Ducruet, Andrew F; Otten, Marc L; Komotar, Ricardo J; Pinsky, David J; Schmidt, Ann Marie; Yan, Shi Fang; Connolly, E Sander. "Neuronal RAGE expression modulates severity of injury following transient focal cerebral ischemia". Journal of clinical neuroscience. 2009 Feb;16(2):302-306 (MEDL:19071026 #140592)       

    Inflammation has a significant role in the neurological injury that follows stroke. The receptor for advanced-glycation end products (RAGE) is a multiligand member of the immunoglobulin superfamily that has been implicated in multiple neuronal and inflammatory stress processes. To directly test the role of neuronal RAGE in stroke, we employed two cohorts of transgenic mice, one over-expressing full-length functional human RAGE in neurons, and the other a human RAGE transgene in which deletion of the cytoplasmic domain of the receptor in neurons suppresses signal transduction stimulated by ligands (referred to as dominant negative or DN-RAGE). We found a statistically significant increase in stroke volume in the RAGE over-expressing cohort compared to normal controls, and a trend towards decreased stroke volume in the DN RAGE cohort. These results indicate that RAGE signaling directly contributes to pathology in cerebral ischemia
  83. Kalea, Anastasia Z; Reiniger, Nina; Yang, Hojin; Arriero, Maria; Schmidt, Ann Marie; Hudson, Barry I. "Alternative splicing of the murine receptor for advanced glycation end-products (RAGE) gene". FASEB journal. 2009 Jun;23(6):1766-1774 (MEDL:19164451 #779012)       

    The alternative splicing of pre-mRNAs is a critical mechanism in genomic complexity, disease, and development. Studies of the receptor for advanced glycation end-products (RAGE) indicate that this gene undergoes a variety of splice events in humans. However, no studies have extensively analyzed the tissue distribution in other species or compared evolutionary differences of RAGE isoforms. Because the majority of studies probing RAGE function have been performed in murine models, we therefore performed studies to identify and characterize the splice variants of the murine RAGE gene, and we compared these to human isoforms. Here, using mouse tissues, we identified numerous splice variants including changes in the extracellular domain or the removal of the transmembrane and cytoplasmic domains, which produce soluble splice isoforms. Comparison of splice variants between humans and mice revealed homologous regions in the RAGE gene that undergo splicing as well as key species-specific mechanisms of splicing. Further analysis of tissue splice variant distribution in mice revealed major differences between lung, kidney, heart, and brain. To probe the potential impact of disease-like pathological states, we studied diabetic mice and report that RAGE splice variation changed dramatically, resulting in an increase in production of soluble RAGE (sRAGE) splice variants, which were not associated with detectable levels of sRAGE in murine plasma. In conclusion, we have determined that the murine RAGE gene undergoes extensive splicing with distinct splice isoforms being uniquely distributed in different tissues. These differences in RAGE splicing in both physiological and pathogenic states further expand our understanding of the biological repertoire of this receptor in health and disease.
  84. Kalea, Anastasia Z; Schmidt, Ann Marie; Hudson, Barry I. "RAGE: a novel biological and genetic marker for vascular disease". Clinical science (London, 1979). 2009 Apr;116(8):621-637 (MEDL:19275767 #779032)       

    RAGE [receptor for AGEs (advanced glycation end-products)] plays an important role in the development and progression of vascular disease. Studies in cultured cells and small animal models of disease have clearly demonstrated that RAGE is central to the pathogenesis of vascular disease of the macro- and micro-vessels in both the diabetic and non-diabetic state. Emerging results from human clinical studies have revealed that levels of circulating soluble RAGE in the plasma may reflect the presence and/or extent of vascular disease state. Additionally, genetic variants of the RAGE gene (AGER in HUGO nomenclature) have been associated with vascular disease risk. Combining RAGE circulating protein levels and the presence of particular RAGE polymorphisms may be a useful clinical tool for the prediction of individuals at risk for vascular disease. Therapeutic intervention targeted at the RAGE gene may therefore be a useful means of treating pathologies of the vasculature.
  85. Ramasamy, Ravichandran; Yan, Shi Fang; Schmidt, Ann Marie. "RAGE: therapeutic target and biomarker of the inflammatory response--the evidence mounts". Journal of leukocyte biology. 2009 Sep;86(3):505-512 (MEDL:19477910 #130810)       

    The RAGE binds multiple ligand families linked to hyperglycemia, aging, inflammation, neurodegeneration, and cancer. Activation of RAGE by its ligands stimulates diverse signaling cascades. The recent observation that the cytoplasmic domain of RAGE interacts with diaphanous or mDia-1 links RAGE signal transduction to cellular migration and activation of the Rho GTPases, cdc42 and rac-1. Pharmacological blockade of RAGE or genetic deletion of RAGE imparts significant protection in murine models of diabetes, inflammatory conditions, Alzheimer's disease, and tumors. Intriguingly, soluble forms of RAGE, including the splice variant-derived esRAGE, circulate in human plasma. Studies in human subjects suggest that sRAGE levels may be modulated by the diseases impacted by RAGE and its ligands. Thus, in addition to being a potential therapeutic target in chronic disease, monitoring of plasma sRAGE levels may provide a novel biomarker platform for tracking chronic inflammatory diseases, their severity, and response to therapeutic intervention
  86. Ravindranath, Thyyar M; Mong, Phyllus Y; Ananthakrishnan, Radha; Li, Qing; Quadri, Nosirudeen; Schmidt, Ann Marie; Ramasamy, Ravichandran; Wang, Qin. "Novel role for aldose reductase in mediating acute inflammatory responses in the lung". Journal of immunology. 2009 Dec 15;183(12):8128-8137 (MEDL:20007578 #130809)       

    Exaggerated inflammatory responses and the resultant increases in alveolar-capillary permeability underlie the pathogenesis of acute lung injury during sepsis. This study examined the functions of aldose reductase (AR) in mediating acute lung inflammation. Transgenic mice expressing human AR (ARTg) were used to study the functions of AR since mice have low intrinsic AR activity. In a mild cecal ligation and puncture model, ARTg mice demonstrated an enhanced AR activity and a greater inflammatory response as evaluated by circulating cytokine levels, neutrophil accumulation in the lungs, and activation of Rho kinase in lung endothelial cells (ECs). Compared with WT lung cells, ARTg lung cells produced more IL-6 and showed augmented JNK activation in response to LPS stimulation ex vivo. In human neutrophils, AR activity was required for fMLP-included CD11b activation and up-regulation, respiratory burst, and shape changes. In human pulmonary microvascular ECs, AR activity was required for TNF-alpha-induced activation of the Rho kinase/MKK4/JNK pathway and IL-6 production, but not p38 activation or ICAM-1 expression. Importantly, AR activity in both human neutrophils and ECs was required for neutrophil adhesion to TNF-alpha-stimulated ECs. These data demonstrate a novel role for AR in regulating the signaling pathways leading to neutrophil-EC adhesion during acute lung inflammation
  87. Roth, Georg A; Aumayr, Klaus; Giacona, Mary Beth; Papapanou, Panos N; Schmidt, Ann Marie; Lalla, Evanthia. "Porphyromonas gingivalis infection and prothrombotic effects in human aortic smooth muscle cells". Thrombosis research. 2009 Mar;123(5):780-784 (MEDL:18789816 #779042)       

    INTRODUCTION: Accumulating evidence has demonstrated an association between periodontal infectious agents, such as Porphyromonas gingivalis, and vascular disease. Tissue factor (TF) and its specific tissue factor pathway inhibitor (TFPI) are produced by vascular cells and are important regulators of the coagulation cascade. MATERIALS AND METHODS: To assess the role of P. gingivalis in atherothrombosis, we infected primary human aortic smooth muscle cells (HASMC) with either P. gingivalis 381, its non-invasive mutant DPG3, or heat-killed P. gingivalis 381. Levels and activity of TF and TFPI were measured 8 and 24 hours after infection in cell extracts and cell culture supernatants. RESULTS: P. gingivalis 381 did not affect total TF antigen or TF activity in HASMC, but it significantly suppressed TFPI levels and activity compared to uninfected control cells, and those infected with the non-invasive mutant strain or the heat-killed bacteria. Further, P. gingivalis' LPS (up to a concentration of 5 microg/ml) failed to induce prothrombotic effects in HASMC, suggesting a significant role for the ability of whole viable bacteria to invade this cell type. CONCLUSION: These data demonstrate for the first time that infection with a periodontal pathogen induces a prothrombotic response in HASMC.
  88. Schmidt, Ann Marie; Sahagan, Barbara; Nelson, Robert B; Selmer, Johan; Rothlein, Robert; Bell, Joanne M. "The role of RAGE in amyloid-beta peptide-mediated pathology in Alzheimer's disease". Current opinion in investigational drugs. 2009 Jul;10(7):672-680 (MEDL:19579173 #779002)    

    This review discusses current knowledge of the complex interactions between amyloid-beta (A beta) peptide, the receptor for advanced glycation endproducts (RAGE), and inflammatory mediators, focusing on the roles of such interactions in the pathogenesis of Alzheimer's disease. As a ubiquitous cell-surface receptor, RAGE demonstrates enhanced expression in an A beta-rich environment; the effects of RAGE on microglia, the blood-brain barrier and neurons are mediated through various signaling pathways. Relevant preclinical models illustrate that the A beta-RAGE interaction amplifies neuronal stress and the accumulation of A beta, impairs memory and learning, and exaggerates neuroinflammation. These findings suggest that RAGE may mediate a common proinflammatory pathway in neurodegenerative disorders.
  89. Spiekerkoetter, Edda; Guignabert, Christophe; de Jesus Perez, Vinicio; Alastalo, Tero-Pekka; Powers, Janine M; Wang, Lingli; Lawrie, Allan; Ambartsumian, Noona; Schmidt, Ann-Marie; Berryman, Mark; Ashley, Richard H; Rabinovitch, Marlene. "S100A4 and bone morphogenetic protein-2 codependently induce vascular smooth muscle cell migration via phospho-extracellular signal-regulated kinase and chloride intracellular channel 4". Circulation research. 2009 Sep;105(7):639-47, 13 p following 647 (MEDL:19713532 #778972)       

    RATIONALE: S100A4/Mts1 is implicated in motility of human pulmonary artery smooth muscle cells (hPASMCs), through an interaction with the RAGE (receptor for advanced glycation end products). OBJECTIVE: We hypothesized that S100A4/Mts1-mediated hPASMC motility might be enhanced by loss of function of bone morphogenetic protein (BMP) receptor (BMPR)II, observed in pulmonary arterial hypertension. METHODS AND RESULTS: Both S100A4/Mts1 (500 ng/mL) and BMP-2 (10 ng/mL) induce migration of hPASMCs in a novel codependent manner, in that the response to either ligand is lost with anti-RAGE or BMPRII short interference (si)RNA. Phosphorylation of extracellular signal-regulated kinase is induced by both ligands and is required for motility by inducing matrix metalloproteinase 2 activity, but phospho-extracellular signal-regulated kinase 1/2 is blocked by anti-RAGE and not by BMPRII short interference RNA. In contrast, BMPRII short interference RNA, but not anti-RAGE, reduces expression of intracellular chloride channel (CLIC)4, a scaffolding molecule necessary for motility in response to S100A4/Mts1 or BMP-2. Reduced CLIC4 expression does not interfere with S100A4/Mts1 internalization or its interaction with myosin heavy chain IIA, but does alter alignment of myosin heavy chain IIA and actin filaments creating the appearance of vacuoles. This abnormality is associated with reduced peripheral distribution and/or delayed activation of RhoA and Rac1, small GTPases required for retraction and extension of lamellipodia in motile cells. CONCLUSIONS: Our studies demonstrate how a single ligand (BMP-2 or S100A4/Mts1) can recruit multiple cell surface receptors to relay signals that coordinate events culminating in a functional response, ie, cell motility. We speculate that this carefully controlled process limits signals from multiple ligands, but could be subverted in disease.
  90. van Zoelen, Marieke A D; Schmidt, Ann-Marie; Florquin, Sandrine; Meijers, Joost C; de Beer, Regina; de Vos, Alex F; Nawroth, Peter P; Bierhaus, Angelika; van der Poll, Tom. "Receptor for advanced glycation end products facilitates host defense during Escherichia coli-induced abdominal sepsis in mice". Journal of infectious diseases. 2009 Sep;200(5):765-773 (MEDL:19627249 #778992)       

    BACKGROUND: The receptor for advanced glycation end products (RAGE) mediates a variety of inflammatory responses. METHODS: To determine the role of RAGE in the innate immune response to abdominal sepsis caused by Escherichia coli, RAGE-deficient (RAGE(-/-)) and normal wild-type mice were intraperitoneally injected with E. coli. In a separate experiment, wild-type mice received either anti-RAGE immunoglobulin (Ig) G or control IgG. RESULTS: E. coli sepsis resulted in an up-regulation of RAGE in the liver but not in the lungs. RAGE-deficient mice demonstrated an enhanced bacterial outgrowth in their peritoneal cavity and increased dissemination of the infection, accompanied by increased hepatocellular injury and exaggerated systemic cytokine release and coagulation activation, 20 h after intraperitoneal administration of E. coli. Wild-type mice treated with anti-RAGE IgG also displayed a diminished defense against the growth and/or dissemination of E. coli. RAGE was important for the initiation of the host response, as reflected by a reduced immune and procoagulant response early after intraperitoneal injection of E. coli lipopolysaccharide. CONCLUSION: These data are the first to suggest that intact RAGE signaling contributes to an effective antibacterial defense during E. coli sepsis, thereby limiting the accompanying inflammatory and procoagulant response.
  91. Yan, Shi Fang; Ramasamy, Ravichandran; Schmidt, Ann Marie. "Receptor for AGE (RAGE) and its ligands-cast into leading roles in diabetes and the inflammatory response". Journal of Molecular Medicine (Berlin). 2009 Mar;87(3):235-247 (MEDL:19189073 #130812)       

    The actors in the pathogenesis of diabetes and its complications are many and multifaceted. The effects of elevated levels of glucose are myriad; among these is the generation of advanced glycation end products (AGEs), the products of nonenzymatic glycoxidation of proteins and lipids. The finding that AGEs stimulate signal transduction cascades through the multiligand receptor RAGE unveiled novel insights into diabetes and its complications. Inextricably woven into AGE-RAGE interactions in diabetes is the engagement of the innate and adaptive immune responses. Although glucose may be the triggering stimulus to draw RAGE into diabetes pathology, consequent cellular stress results in release of proinflammatory RAGE ligands S100/calgranulins and HMGB1. We predict that once RAGE is engaged in the diabetic tissue, a vicious cycle of ligand-RAGE perturbation ensues, leading to chronic tissue injury and suppression of repair mechanisms. Targeting RAGE may be a beneficial strategy in diabetes, its complications, and untoward inflammatory responses
  92. Yan, Shi Fang; Ramasamy, Ravichandran; Schmidt, Ann Marie. "The receptor for advanced glycation endproducts (RAGE) and cardiovascular disease". Expert reviews in molecular medicine. 2009;11:e9-e9 (MEDL:19278572 #130811)       

    Recent and compelling investigation has expanded our view of the biological settings in which the products of nonenzymatic glycation and oxidation of proteins and lipids - the advanced glycation endproducts (AGEs) - form and accumulate. Beyond diabetes, natural ageing and renal failure, AGEs form in inflammation, oxidative stress and in ischaemia-reperfusion. The chief signal transduction receptor for AGEs - the receptor for AGEs (RAGE) - is a multiligand-binding member of the immunoglobulin superfamily. In addition to AGEs, RAGE binds certain members of the S100/calgranulin family, high-mobility group box 1 (HMGB1), and beta-amyloid peptide and beta-sheet fibrils. Recent studies demonstrate beneficial effects of RAGE antagonism and genetic deletion in rodent models of atherosclerosis and ischaemia-reperfusion injury in the heart and great vessels. Experimental evidence is accruing that RAGE ligand generation and release during ischaemia-reperfusion may signal through RAGE, thus suggesting that antagonism of this receptor might provide a novel form of therapeutic intervention in heart disease. However, it is plausible that innate, tissue-regenerative roles for these RAGE ligands may also impact the failing heart - perhaps through RAGE and/or distinct receptors. In this review, we focus on RAGE and the consequences of its activation in the cardiovasculature
  93. Yan, Shi Fang; Yan, Shi Du; Ramasamy, Ravichandran; Schmidt, Ann Marie. "Tempering the wrath of RAGE: an emerging therapeutic strategy against diabetic complications, neurodegeneration, and inflammation". Annals of medicine (Helsinki). 2009;41(6):408-422 (MEDL:19322705 #130813)       

    The multiligand receptor RAGE (receptor for advanced glycation end-products) is emerging as a central mediator in the immune/inflammatory response. Epidemiological evidence accruing in the human suggests upregulation of RAGE's ligands (AGEs, S100/calgranulins, high mobility group box-1 (HMGB1), and amyloid beta-peptide and beta-sheet fibrils) and the receptor itself at sites of inflammation and in chronic diseases such as diabetes and neurodegeneration. The consequences of ligand-RAGE interaction include upregulation of molecules implicated in inflammatory responses and tissue damage, such as cytokines, adhesion molecules, and matrix metalloproteinases. In this review, we discuss the localization of RAGE and its ligand families and the biological impact of this axis in multiple cell types implicated in chronic diseases. Lastly, we consider findings from animal model studies suggesting that although tissue-damaging effects ensue from recruitment of the ligand-RAGE interaction, in distinct settings, adaptive and repair/regeneration outcomes appear to override detrimental effects of RAGE. As RAGE blockade moves further into clinical development, clarifying the biology of RAGE garners ever-increasing importance
  94. Zeng, Shan; Dun, Hao; Ippagunta, Nikalesh; Rosario, Rosa; Zhang, Qing Y; Lefkowitch, Jay; Yan, Shi F; Schmidt, Ann Marie; Emond, Jean C. "Receptor for advanced glycation end product (RAGE)-dependent modulation of early growth response-1 in hepatic ischemia/reperfusion injury". Journal of hepatology. 2009 May;50(5):929-936 (MEDL:19303658 #140646)       

    BACKGROUND/AIMS: We previously showed that blockade of RAGE significantly attenuates hepatic ischemia/reperfusion (I/R) injury in mice. Here, we identify that early growth response-1 (Egr-1) is a downstream target of RAGE in hepatic I/R injury. METHODS: Hepatic I/R was induced in male mice. Liver remnants were analyzed for induction of Egr-1 and cytokines, as well as regulation of apoptotic pathways after reperfusion. RESULTS: Egr-1 was upregulated in the liver remnants after hepatic I/R injury and was suppressed by administration of soluble RAGE or deletion of the RAGE gene. RAGE-mediated increased expression of Egr-1 upregulates a central downstream gene, MIP2. In contrast, RAGE-stimulated Egr-1-independent pathways regulate TNF-alpha production and apoptosis in response to I/R. Consistent with these findings, phospho-p44/42 and phospho-JNK MAPK and c-Jun were strikingly suppressed in RAGE(-/-) versus WT mice, but not in Egr-1(-/-) mice. RAGE ligand HMGB1 was upregulated after I/R in the liver remnants. In vitro, incubation of RAGE-expressing liver dendritic cells (DCs) with recombinant HMGB-1 resulted in increased Egr-1 transcripts, in a manner suppressed by RAGE gene deletion, soluble RAGE and inhibitors of p44/p42 or JNK MAP kinase. CONCLUSIONS: Suppression of Egr-1 may contribute to the protective mechanisms underlying the beneficial impact of RAGE blockade or deletion
  95. Zhang, Fan; Kent, K Craig; Yamanouchi, Dai; Zhang, Yan; Kato, Kaori; Tsai, Shirling; Nowygrod, Roman; Schmidt, Ann Marie; Liu, Bo. "Anti-receptor for advanced glycation end products therapies as novel treatment for abdominal aortic aneurysm". Annals of surgery. 2009 Sep;250(3):416-423 (MEDL:19652591 #778982)       

    OBJECTIVE: Rupture of abdominal aortic aneurysms (AAA) is a devastating event potentially preventable by therapies that inhibit growth of small aneurysms. Receptor of advanced glycation end products (RAGE) has been implicated in age related diseases including atherosclerosis and Alzheimer. Consequently, we explored whether RAGE may also contribute to the formation of AAAs. RESULTS: Implicating a role for RAGE in AAA, we found the expression of RAGE and its ligand AGE were highly elevated in human aneurysm specimens as compared with normal aortic tissue. In a mouse model of AAA, RAGE gene deletion (knockout) dramatically reduced the incidence of AAA to 1/3 of control (AAAs in 75.0% of controls vs. 25.0% knockouts). Moreover, aortic diameter was markedly reduced in RAGE knockout animals versus controls. As to mechanism, we found that RAGE was coexpressed in AAA macrophages with MMP-9, a promoter of matrix degradation, which is known to induce AAA. In vitro, AGE induced the production of MMP-9 in macrophages in a dose-dependent manner while blocking RAGE signaling with a soluble AGE inhibitor prevented MMP-9 expression. In vivo, RAGE gene deficiency eliminated MMP-9 activity that was prevalent in aneurismal wall of the wild-type mice. CONCLUSIONS: RAGE promotes the development of AAA by inducing MMP-9 expression. Blocking RAGE in a mouse aneurysm model has a dramatic inhibitory effect on the formation of aneurysms. These data suggest that larger animal and eventually human trials should be designed to test oral RAGE inhibitors and their potential to prevent progression of small aneurysms.
  96. Zhang, Yue; Nuglozeh, Edem; Toure, Fatouma; Schmidt, Ann Marie; Vunjak-Novakovic, Gordana. "Controllable expansion of primary cardiomyocytes by reversible immortalization". Human gene therapy. 2009 Dec;20(12):1687-1696 (MEDL:19708763 #778962)       

    Cardiac tissue engineering will remain only a prospect unless large numbers of therapeutic cells can be provided, either from small samples of cardiac cells or from stem cell sources. In contrast to most adult cells, cardiomyocytes are terminally differentiated and cannot be expanded in culture. We explored the feasibility of enabling the in vitro expansion of primary neonatal rat cardiomyocytes by lentivector-mediated cell immortalization, and then reverting the phenotype of the expanded cells back to the cardiomyocyte state. Primary rat cardiomyocytes were transduced with simian virus 40 large T antigen (TAg), or with Bmi-1 followed by the human telomerase reverse transcriptase (hTERT) gene; the cells were expanded; and the transduced genes were removed by adenoviral vector expressing Cre recombinase. The TAg gene was more efficient in cell transduction than the Bmi-1/hTERT gene, based on the rate of cell proliferation. Immortalized cells exhibited the morphological features of dedifferentiation (increased vimentin expression, and reduced expression of troponin I and Nkx2.5) along with the continued expression of cardiac markers (alpha-actin, connexin-43, and calcium transients). After the immortalization was reversed, cells returned to their differentiated state. This strategy for controlled expansion of primary cardiomyocytes by gene transfer has potential for providing large amounts of a patient's own cardiomyocytes for cell therapy, and the cardiomyocytes derived by this method could be a useful cellular model by which to study cardiogenesis.
  97. Aleshin, Alexey; Ananthakrishnan, Radha; Li, Qing; Rosario, Rosa; Lu, Yan; Qu, Wu; Song, Fei; Bakr, Soliman; Szabolcs, Matthias; D'Agati, Vivette; Liu, Rui; Homma, Shunichi; Schmidt, Ann Marie; Yan, Shi Fang; Ramasamy, Ravichandran. "RAGE modulates myocardial injury consequent to LAD infarction via impact on JNK and STAT signaling in a murine model". American journal of physiology. Heart & circulatory physiology. 2008 Apr;294(4):H1823-H1832 (MEDL:18245563 #130818)       

    The receptor for advanced glycation end-products (RAGE) has been implicated in the pathogenesis of ischemia-reperfusion (I/R) injury in the isolated perfused heart. To test the hypothesis that RAGE-dependent mechanisms modulated responses to I/R in a murine model of transient occlusion and reperfusion of the left anterior descending coronary artery (LAD), we subjected male homozygous RAGE(-/-) mice and their wild-type age-matched littermates to 30 min of occlusion of the LAD followed by reperfusion. At 48 h of reperfusion, hematoxylin and eosin staining revealed significantly larger infarct size in wild-type versus RAGE(-/-) mice. Contractile function, as evaluated by echocardiography 48 h after reperfusion, revealed that fractional shortening was significantly higher in RAGE(-/-) versus wild-type mice. Plasma levels of creatine kinase were markedly decreased in RAGE(-/-) versus wild-type animals. Integral to the impact of RAGE deletion on diminished myocardial damage after infarction was significantly decreased apoptosis in the heart, as assessed by TUNEL staining, release of cytochrome c, and caspase-3 activity. Experiments investigating the impact of RAGE on early signaling pathways influencing myocardial ischemic injury revealed attenuation of JNK and STAT5 phosphorylation in RAGE(-/-) mouse hearts versus robust activation observed in wild-type mice upon ischemia and reperfusion. Solidifying the link to RAGE, these experiments revealed that infarction stimulated the rapid production of advanced glycation end-products in the heart. Thus, we tested the effect of ligand decoy soluble RAGE (sRAGE). Administration of sRAGE protected the myocardium from ischemic damage, similar to the effects observed in RAGE(-/-) mouse hearts. Taken together, these data implicate RAGE and its ligands in the pathogenesis of I/R injury and identify JNK and STAT signal transduction as central downstream effector pathways of the ligand-RAGE axis in the heart subjected to I/R injury
  98. Bucciarelli, Loredana G; Ananthakrishnan, Radha; Hwang, Yuying C; Kaneko, Michiyo; Song, Fei; Sell, David R; Strauch, Christopher; Monnier, Vincent M; Yan, Shi Fang; Schmidt, Ann Marie; Ramasamy, Ravichandran. "RAGE and modulation of ischemic injury in the diabetic myocardium". Diabetes. 2008 Jul;57(7):1941-1951 (MEDL:18420491 #130800)       

    OBJECTIVE: Subjects with diabetes experience an increased risk of myocardial infarction and cardiac failure compared with nondiabetic age-matched individuals. The receptor for advanced glycation end products (RAGE) is upregulated in diabetic tissues. In this study, we tested the hypothesis that RAGE affected ischemia/reperfusion (I/R) injury in the diabetic myocardium. In diabetic rat hearts, expression of RAGE and its ligands was enhanced and localized particularly to both endothelial cells and mononuclear phagocytes. RESEARCH DESIGN AND METHODS: To specifically dissect the impact of RAGE, homozygous RAGE-null mice and transgenic (Tg) mice expressing cytoplasmic domain-deleted RAGE (DN RAGE), in which RAGE-dependent signal transduction was deficient in endothelial cells or mononuclear phagocytes, were rendered diabetic with streptozotocin. Isolated perfused hearts were subjected to I/R. RESULTS: Diabetic RAGE-null mice were significantly protected from the adverse impact of I/R injury in the heart, as indicated by decreased release of LDH and lower glycoxidation products carboxymethyl-lysine (CML) and pentosidine, improved functional recovery, and increased ATP. In diabetic Tg mice expressing DN RAGE in endothelial cells or mononuclear phagocytes, markers of ischemic injury and CML were significantly reduced, and levels of ATP were increased in heart tissue compared with littermate diabetic controls. Furthermore, key markers of apoptosis, caspase-3 activity and cytochrome c release, were reduced in the hearts of diabetic RAGE-modified mice compared with wild-type diabetic littermates in I/R. CONCLUSIONS: These findings demonstrate novel and key roles for RAGE in I/R injury in the diabetic heart
  99. Chang, Jong Sun; Wendt, Thoralf; Qu, Wu; Kong, Linghua; Zou, Yu Shan; Schmidt, Ann Marie; Yan, Shi-Fang. "Oxygen deprivation triggers upregulation of early growth response-1 by the receptor for advanced glycation end products". Circulation research. 2008 Apr 25;102(8):905-913 (MEDL:18323529 #140593)       

    Myocardial infarction, stroke, and venous thromboembolism are characterized by oxygen deprivation. In hypoxia, biological responses are activated that evoke tissue damage. Rapid activation of early growth response-1 in hypoxia upregulates fundamental inflammatory and prothrombotic stress genes. We probed the mechanisms mediating regulation of early growth response-1 and demonstrate that hypoxia stimulates brisk generation of advanced glycation end products (AGEs) by endothelial cells. Via AGE interaction with their chief signaling receptor, RAGE, membrane translocation of protein kinase C-betaII occurs, provoking phosphorylation of c-Jun NH(2)-terminal kinase and increased transcription of early growth response-1 and its downstream target genes. These findings identify RAGE as a master regulator of tissue stress elicited by hypoxia and highlight this receptor as a central therapeutic target to suppress the tissue injury-provoking effects of oxygen deprivation
  100. Chen, Yali; Akirav, Eitan M; Chen, Wei; Henegariu, Octavian; Moser, Bernhard; Desai, Dharmesh; Shen, Jane M; Webster, Jeffery C; Andrews, Robert C; Mjalli, Adnan M; Rothlein, Robert; Schmidt, Ann Marie; Clynes, Raphael; Herold, Kevan C. "RAGE ligation affects T cell activation and controls T cell differentiation". Journal of immunology. 2008 Sep;181(6):4272-4278 (MEDL:18768885 #779082)    

    The pattern recognition receptor, RAGE, has been shown to be involved in adaptive immune responses but its role on the components of these responses is not well understood. We have studied the effects of a small molecule inhibitor of RAGE and the deletion of the receptor (RAGE-/- mice) on T cell responses involved in autoimmunity and allograft rejection. Syngeneic islet graft and islet allograft rejection was reduced in NOD and B6 mice treated with TTP488, a small molecule RAGE inhibitor (p < 0.001). RAGE-/- mice with streptozotocin-induced diabetes showed delayed rejection of islet allografts compared with wild type (WT) mice (p < 0.02). This response in vivo correlated with reduced proliferative responses of RAGE-/- T cells in MLRs and in WT T cells cultured with TTP488. Overall T cell proliferation following activation with anti-CD3 and anti-CD28 mAbs were similar in RAGE-/- and WT cells, but RAGE-/- T cells did not respond to costimulation with anti-CD28 mAb. Furthermore, culture supernatants from cultures with anti-CD3 and anti-CD28 mAbs showed higher levels of IL-10, IL-5, and TNF-alpha with RAGE-/- compared with WT T cells, and WT T cells showed reduced production of IFN-gamma in the presence of TTP488, suggesting that RAGE may be important in the differentiation of T cell subjects. Indeed, by real-time PCR, we found higher levels of RAGE mRNA expression on clonal T cells activated under Th1 differentiating conditions. We conclude that activation of RAGE on T cells is involved in early events that lead to differentiation of Th1(+) T cells.
  101. Gao, Xue; Zhang, Hanrui; Schmidt, Ann Marie; Zhang, Cuihua. "AGE/RAGE produces endothelial dysfunction in coronary arterioles in type 2 diabetic mice". American journal of physiology. Heart & circulatory physiology. 2008 Aug;295(2):H491-H498 (MEDL:18539754 #779092)       

    We hypothesized that impaired nitric oxide (NO)-dependent dilation (endothelial dysfunction) in type 2 diabetes results, in part, from elevated production of superoxide (O(2)(*-)) induced by the interaction of advanced glycation end products (AGE)/receptor for AGE (RAGE) and TNF-alpha signaling. We assessed the role of AGE/RAGE and TNF-alpha signaling in endothelial dysfunction in type 2 diabetic (Lepr(db)) mice by evaluation of endothelial function in isolated coronary resistance vessels of normal control (nondiabetic, m Lepr(db)) and diabetic mice. Although dilation of vessels to the endothelium-independent vasodilator sodium nitroprusside (SNP) was not different between diabetic and control mice, dilation to the endothelium-dependent agonist acetylcholine (ACh) was reduced in diabetic vs. control mice. The activation of RAGE with RAGE agonist S100b eliminated SNP-potentiated dilation to ACh in Lepr(db) mice. Administration of a soluble form of RAGE (sRAGE) partially restored dilation in diabetic mice but did not affect dilation in control mice. The expression of RAGE in coronary arterioles was markedly increased in diabetic vs. control mice. We also observed in diabetic mice that augmented RAGE signaling augmented expression of TNF-alpha, because this increase was attenuated by sRAGE or NF-kappaB inhibitor MG132. Protein and mRNA expression of NAD(P)H oxidase subunits including NOX-2, p22(phox), and p40(phox) increased in diabetic compared with control mice. sRAGE significantly inhibited the expression of NAD(P)H oxidase in diabetic mice. These results indicate that AGE/RAGE signaling plays a pivotal role in regulating the production/expression of TNF-alpha, oxidative stress, and endothelial dysfunction in type 2 diabetes.
  102. Guo, Jiancheng; Ananthakrishnan, Radha; Qu, Wu; Lu, Yan; Reiniger, Nina; Zeng, Shan; Ma, Wanchao; Rosario, Rosa; Yan, Shi Fang; Ramasamy, Ravichandran; D'Agati, Vivette; Schmidt, Ann Marie. "RAGE mediates podocyte injury in adriamycin-induced glomerulosclerosis". Journal of the American Society of Nephrology. 2008 May;19(5):961-972 (MEDL:18256352 #130816)       

    In the kidney, the receptor for advanced glycation end products (RAGE) is principally expressed in the podocyte at low levels, but is upregulated in both human and mouse glomerular diseases. Because podocyte injury is central to proteinuric states, such as the nephrotic syndrome, the murine adriamycin nephrosis model was used to explore the role of RAGE in podocyte damage. In this model, administration of the anthracycline antibiotic adriamycin provokes severe podocyte stress and glomerulosclerosis. In contrast to wild-type animals, adriamycin-treated RAGE-null mice were significantly protected from effacement of the podocyte foot processes, albuminuria, and glomerulosclerosis. Administration of adriamycin induced rapid generation of RAGE ligands, and treatment with soluble RAGE protected against podocyte injury and glomerulosclerosis. In vitro, incubation of RAGE-expressing murine podocytes with adriamycin stimulated AGE formation, and treatment with RAGE ligands rapidly activated nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase, via p44/p42 MAP kinase signaling, and upregulated pro-fibrotic growth factors. These data suggest that RAGE may contribute to the pathogenesis of podocyte injury in sclerosing glomerulopathies such as focal segmental glomerulosclerosis
  103. Harja, Evis; Bu, De-xiu; Hudson, Barry I; Chang, Jong Sun; Shen, Xiaoping; Hallam, Kellie; Kalea, Anastasia Z; Lu, Yan; Rosario, Rosa H; Oruganti, Sai; Nikolla, Zana; Belov, Dmitri; Lalla, Evanthia; Ramasamy, Ravichandran; Yan, Shi Fang; Schmidt, Ann Marie. "Vascular and inflammatory stresses mediate atherosclerosis via RAGE and its ligands in apoE-/- mice". Journal of clinical investigation. 2008 Jan;118(1):183-194 (MEDL:18079965 #130821)       

    Endothelial dysfunction is a key triggering event in atherosclerosis. Following the entry of lipoproteins into the vessel wall, their rapid modification results in the generation of advanced glycation endproduct epitopes and subsequent infiltration of inflammatory cells. These inflammatory cells release receptor for advanced glycation endproduct (RAGE) ligands, specifically S100/calgranulins and high-mobility group box 1, which sustain vascular injury. Here, we demonstrate critical roles for RAGE and its ligands in vascular inflammation, endothelial dysfunction, and atherosclerotic plaque development in a mouse model of atherosclerosis, apoE-/- mice. Experiments in primary aortic endothelial cells isolated from mice and in cultured human aortic endothelial cells revealed the central role of JNK signaling in transducing the impact of RAGE ligands on inflammation. These data highlight unifying mechanisms whereby endothelial RAGE and its ligands mediate vascular and inflammatory stresses that culminate in atherosclerosis in the vulnerable vessel wall
  104. Hudson, Barry I; Carter, Angela M; Harja, Evis; Kalea, Anastasia Z; Arriero, Maria; Yang, Hojin; Grant, Peter J; Schmidt, Ann Marie. "Identification, classification, and expression of RAGE gene splice variants". FASEB journal. 2008 May;22(5):1572-1580 (MEDL:18089847 #779102)       

    The receptor for advanced glycation end-products (RAGE) is a single-transmembrane, multiligand receptor of the immunoglobulin superfamily. RAGE up-regulation is implicated in numerous pathological states including vascular disease, diabetes, cancer, and neurodegeneration. The understanding of the regulation of RAGE is important in both disease pathogenesis and normal homeostasis. Here, we demonstrate the characterization and identification of human RAGE splice variants by analysis of RAGE cDNA from tissue and cells. We identified a vast range of splice forms that lead to changes in the protein coding region of RAGE, which we have classified according to the Human Gene Nomenclature Committee (HGNC). These resulted in protein changes in the ligand-binding domain of RAGE or the removal of the transmembrane domain and cytosolic tail. Analysis of splice variants for premature termination codons reveals approximately 50% of identified variants are targeted to the nonsense-mediated mRNA decay pathway. Expression analysis revealed the RAGE_v1 variant to be the primary secreted soluble isoform of RAGE. Taken together, identification of functional splice variants of RAGE underscores the biological diversity of the RAGE gene and will aid in the understanding of the gene in the normal and pathological state.
  105. Hudson, Barry I; Kalea, Anastasia Z; Del Mar Arriero, Maria; Harja, Evis; Boulanger, Eric; D'Agati, Vivette; Schmidt, Ann Marie. "Interaction of the RAGE cytoplasmic domain with diaphanous-1 is required for ligand-stimulated cellular migration through activation of Rac1 and Cdc42". Journal of biological chemistry. 2008 Dec;283(49):34457-34468 (MEDL:18922799 #779052)       

    Cellular migration is a fundamental process linked to diverse pathological states such as diabetes and its complications, atherosclerosis, inflammation, and cancer. The receptor for advanced glycation end products (RAGE) is a multiligand cell surface macromolecule which binds distinct ligands that accumulate in these settings. RAGE-ligand interaction evokes central changes in key biological properties of cells, including proliferation, generation of inflammatory mediators, and migration. Although RAGE-dependent signal transduction is critically dependent on its short cytoplasmic domain, to date the proximate mechanism by which this RAGE domain engages and stimulates cytoplasmic signaling pathways has yet to be identified. Here we show that the RAGE cytoplasmic domain interacts with Diaphanous-1 (Dia-1) both in vitro and in vivo. We employed the human RAGE cytoplasmic domain as "bait" in the yeast two-hybrid assay and identified the formin homology (FH1) domain of Dia-1 as a potential binding partner of this RAGE domain. Immunoprecipitation studies revealed that the RAGE cytoplasmic domain interacts with the FH1 domain of Dia-1. Down-regulation of Dia-1 expression by RNA interference blocks RAGE-mediated activation of Rac-1 and Cdc42 and, in parallel, RAGE ligand-stimulated cellular migration. Taken together, these findings indicate that the interaction of the RAGE cytoplasmic domain with Dia-1 is required to transduce extracellular environmental cues evoked by binding of RAGE ligands to their cell surface receptor, a chief consequence of which is Rac-1 and Cdc42 activation and cellular migration. Because RAGE and Dia-1 are implicated in the regulation of inflammatory, vascular, and transformed cell migration, these findings highlight this interaction as a novel target for therapeutic intervention in inflammation, atherosclerosis, diabetes, and cancer.
  106. Kong, Linghua; Andrassy, Martin; Chang, Jong Sun; Huang, Chun; Asai, Tomohiro; Szabolcs, Matthias J; Homma, Shunichi; Liu, Rui; Zou, Yu Shan; Leitges, Michael; Yan, Shi Du; Ramasamy, Ravichandran; Schmidt, Ann Marie; Yan, Shi-Fang. "PKCbeta modulates ischemia-reperfusion injury in the heart". American journal of physiology. Heart & circulatory physiology. 2008 Apr;294(4):H1862-H1870 (MEDL:18245560 #130819)       

    Protein kinase C-betaII (PKCbetaII) is an important modulator of cellular stress responses. To test the hypothesis that PKCbetaII modulates the response to myocardial ischemia-reperfusion (I/R) injury, we subjected mice to occlusion and reperfusion of the left anterior descending coronary artery. Homozygous PKCbeta-null (PKCbeta(-/-)) and wild-type mice fed the PKCbeta inhibitor ruboxistaurin displayed significantly decreased infarct size and enhanced recovery of left ventricular (LV) function and reduced markers of cellular necrosis and serum creatine phosphokinase and lactate dehydrogenase levels compared with wild-type or vehicle-treated animals after 30 min of ischemia followed by 48 h of reperfusion. Our studies revealed that membrane translocation of PKCbetaII in LV tissue was sustained after I/R and that gene deletion or pharmacological blockade of PKCbeta protected ischemic myocardium. Homozygous deletion of PKCbeta significantly diminished phosphorylation of c-Jun NH(2)-terminal mitogen-activated protein kinase and expression of activated caspase-3 in LV tissue of mice subjected to I/R. These data implicate PKCbeta in I/R-mediated myocardial injury, at least in part via phosphorylation of JNK, and suggest that blockade of PKCbeta may represent a potent strategy to protect the vulnerable myocardium
  107. Landesberg, Regina; Woo, Victoria; Huang, Linda; Cozin, Matthew; Lu, Yan; Bailey, Cory; Qu, Wu; Pulse, Carla; Schmidt, Ann Marie. "The expression of the receptor for glycation endproducts (RAGE) in oral squamous cell carcinomas". Oral surgery, oral medicine, oral pathology, oral radiology, & endodontics. 2008 May;105(5):617-624 (MEDL:18206396 #779112)       

    Advanced glycation endproducts (AGEs) and their receptors, receptor for advanced glycation endproducts (RAGE), are novel groups of molecules with roles in inflammation, cytokine activation, and promotion of cell growth. Recently, RAGE has been implicated in the progression and metastasis of several epithelial tumors. The expression of RAGE was examined in 38 oral squamous cell carcinoma (OSCC) cases by immunohistochemistry. In the OSCCs, RAGE positivity, interpreted as more than 25% positive cells, was detected in 10 of 10 well-differentiated, 3 of 4 well-to-moderately differentiated, 3 of 9 moderately differentiated, 1 of 7 moderate-to-poorly differentiated, and 0 of 8 poorly differentiated tumors. The staining percentage was significantly higher in well-differentiated tumors compared to moderately (P < .05) and poorly differentiated (P < .05) tumors. All normal mucosa samples were RAGE-positive. Western blot analysis for RAGE was performed on 2 OSCCs and 2 normal oral mucosa samples. Higher expression was observed in the normal tissues compared to the OSCCs. Our results show that RAGE immunoreactivity correlates with histologic differentiation in OSCC.
  108. Origlia, Nicola; Righi, Massimo; Capsoni, Simona; Cattaneo, Antonino; Fang, Fang; Stern, David M; Chen, John Xi; Schmidt, Ann Marie; Arancio, Ottavio; Yan, Shi Du; Domenici, Luciano. "Receptor for advanced glycation end product-dependent activation of p38 mitogen-activated protein kinase contributes to amyloid-beta-mediated cortical synaptic dysfunction". Journal of neuroscience. 2008 Mar 26;28(13):3521-3530 (MEDL:18367618 #140645)       

    Soluble amyloid-beta (Abeta) peptide is likely to play a key role during early stages of Alzheimer's disease (AD) by perturbing synaptic function and cognitive processes. Receptor for advanced glycation end products (RAGE) has been identified as a receptor involved in Abeta-induced neuronal dysfunction. We investigated the role of neuronal RAGE in Abeta-induced synaptic dysfunction in the entorhinal cortex, an area of the brain important in memory processes that is affected early in AD. We found that soluble oligomeric Abeta peptide (Abeta42) blocked long-term potentiation (LTP), but did not affect long-term depression, paired-pulse facilitation, or basal synaptic transmission. In contrast, Abeta did not inhibit LTP in slices from RAGE-null mutant mice or in slices from wild-type mice treated with anti-RAGE IgG. Similarly, transgenic mice expressing a dominant-negative form of RAGE targeted to neurons showed normal LTP in the presence of Abeta, suggesting that neuronal RAGE functions as a signal transducer for Abeta-mediated LTP impairment. To investigate intracellular pathway transducing RAGE activation by Abeta, we used inhibitors of stress activated kinases. We found that inhibiting p38 mitogen-activated protein kinase (p38 MAPK), but not blocking c-Jun N-terminal kinase activation, was capable of maintaining LTP in Abeta-treated slices. Moreover, Abeta-mediated enhancement of p38 MAPK phosphorylation in cortical neurons was reduced by blocking antibodies to RAGE. Together, our results indicate that Abeta impairs LTP in the entorhinal cortex through neuronal RAGE-mediated activation of p38 MAPK
  109. Ramasamy, Ravichandran; Yan, Shi Fang; Herold, Kevan; Clynes, Raphael; Schmidt, Ann Marie. "Receptor for advanced glycation end products: fundamental roles in the inflammatory response: winding the way to the pathogenesis of endothelial dysfunction and atherosclerosis". Annals of the New York Academy of Sciences. 2008 Apr;1126:7-13 (MEDL:18448789 #130820)       

    The multiligand receptor for advanced glycation end products (RAGE) of the immunoglobulin superfamily is expressed on multiple cell types implicated in the immune-inflammatory response and in atherosclerosis. Multiple studies have elucidated that ligand-RAGE interaction on cells, such as monocytes, macrophages, and endothelial cells, mediates cellular migration and upregulation of proinflammatory and prothrombotic molecules. In addition, recent studies reveal definitive rules for RAGE in effective T lymphocyte priming in vivo. RAGE ligand AGEs may be formed in diverse settings; although AGEs are especially generated in hyperglycemia, their production in settings characterized by oxidative stress and inflammation suggests that these species, in part via RAGE, may contribute to the pathogenesis of atherosclerosis. In murine models of atherosclerosis, vascular inflammation is a key factor and one which is augmented, in parallel with even further increases in RAGE ligands, in diabetic macrovessels. The findings that antagonism and genetic disruption of RAGE in atherosclerosis-susceptible mice strikingly reduces vascular inflammation and atherosclerotic lesion area and complexity link RAGE intimately to these processes and suggest that RAGE is a logical target for therapeutic intervention in aberrant inflammatory mechanisms and in atherosclerosis
  110. Ramasamy, Ravichandran; Yan, Shi Fang; Schmidt, Ann Marie. "Stopping the primal RAGE reaction in myocardial infarction: capturing adaptive responses to heal the heart? [Editorial]". Circulation. 2008 Jun 24;117(25):3165-3167 (MEDL:18574057 #130815)       
  111. Romero, Roberto; Espinoza, Jimmy; Hassan, Sonia; Gotsch, Francesca; Kusanovic, Juan Pedro; Avila, Cecilia; Erez, Offer; Edwin, Sam; Schmidt, Ann Marie. "Soluble receptor for advanced glycation end products (sRAGE) and endogenous secretory RAGE (esRAGE) in amniotic fluid: modulation by infection and inflammation". Journal of perinatal medicine. 2008;36(5):388-398 (MEDL:18593373 #779132)       

    OBJECTIVE: The receptor for advanced glycation end products (RAGE) has been proposed to participate in the innate and adaptive immune responses. RAGE can induce production of pro-inflammatory cytokines and chemokines, as well as neutrophil chemotaxis in a manner that may be suppressed or stimulated by soluble, truncated forms of RAGE including the soluble form of RAGE (sRAGE) and endogenous secretory RAGE (esRAGE). The objective of this study was to determine whether intra-amniotic infection/inflammation (IAI) is associated with changes in the amniotic fluid concentration of sRAGE and esRAGE. STUDY DESIGN: Amniotic fluid (AF) was retrieved from patients in the following groups: 1) mid-trimester (14-18 weeks of gestation; n=68); 2) term not in labor (n=24); 3) term in labor (n=51); 4) preterm labor and intact membranes (n=124); and 5) preterm PROM (n=80). Intra-amniotic infection and inflammation were defined as the presence of a positive amniotic fluid culture for microorganisms and an AF interleukin-6 concentration >or=2.6 ng/mL, respectively. The AF concentration of sRAGE and esRAGE were determined using specific and sensitive ELISAs which measured total immunoreactive sRAGE and esRAGE, respectively. Patients were matched for gestational age at amniocentesis to compare the AF concentration of sRAGE and esRAGE in patients with and without IAI. Non-parametric statistics were used for analysis and a P<0.05 was considered significant. RESULTS: 1) Patients at term not in labor had higher median AF concentrations of sRAGE and esRAGE than those in the mid-trimester (P<0.001 for both comparisons) and those at term in labor (P=0.03 and P=0.04, respectively); 2) patients with preterm labor and intact membranes with intra-amniotic infection/inflammation (IAI) had higher median AF concentrations of sRAGE and esRAGE than those without IAI (P=0.02 and P=0.005, respectively); 3) similarly, patients with preterm PROM with IAI had higher median AF concentrations of sRAGE and esRAGE than those without IAI (P=0.03 and P=0.02, respectively). CONCLUSION: Intra-amniotic infection/inflammation is associated with increased amniotic fluid concentrations of sRAGE and esRAGE. Changes in the amniotic fluid concentration of sRAGE and esRAGE may represent part of the immune response to intra-amniotic infection/inflammation.
  112. Sternberg, David I; Gowda, Ram; Mehra, Divya; Qu, Wu; Weinberg, Alan; Twaddell, William; Sarkar, Joydeep; Wallace, Allison; Hudson, Barry; D'Ovidio, Frank; Arcasoy, Selim; Ramasamy, Ravichandran; D'Armiento, Jeanine; Schmidt, Ann Marie; Sonett, Joshua R. "Blockade of receptor for advanced glycation end product attenuates pulmonary reperfusion injury in mice". Journal of thoracic & cardiovascular surgery. 2008 Dec;136(6):1576-1585 (MEDL:19114209 #130814)       

    OBJECTIVE: The receptor for advanced glycation end products (RAGE) is expressed at high levels in the lung, particularly in type 1 alveolar cells, and has been shown to amplify injury triggered by acute stress. Previous studies suggest serum concentrations of soluble RAGE increase during pulmonary reperfusion injury after transplantation. RAGE blockade has been shown to suppress hepatic and cardiac ischemia and reperfusion injury in mice. Thus we tested the hypothesis that RAGE mediates tissue-injury mechanisms in ischemia and reperfusion injury in the lung. METHODS: C57BL/6 mice were subjected to 30 minutes of pulmonary ischemia by clamping the left hilum, followed by 60 minutes of reperfusion. Lung function was assessed by means of blood gas analysis, and capillary leak was assessed by injecting fluorescein isothiocyanate-labeled albumin and comparing fluorescence in bronchial lavage fluid with that in serum. Histologic analysis of the lung was performed by a pathologist naive to the experimental conditions. RESULTS: In animals subjected to RAGE blockade, significant increases in Po(2) (108 vs 73 mm Hg, P = .0094) and more than 3-fold decrease in capillary leak Relative Fluorescent Units (RFU, 6.12 vs 1.75; P = .001) were observed. Histologic examination revealed significant injury reduction in soluble RAGE-treated animals versus control animals. RAGE knockout mice exhibited a protected phenotype when exposed to pulmonary ischemia and reperfusion. Additionally, interleukin 8 production and nuclear factor kappaB activation were increased in control mice. CONCLUSION: Abrogation of RAGE signaling attenuates pulmonary ischemia and reperfusion injury. This study suggests that RAGE might play a central role in pulmonary reperfusion injury and in transplantation and that blockade of RAGE might offer a potential target to abrogate pulmonary reperfusion injury in clinical transplantation
  113. Tekabe, Yared; Li, Qing; Rosario, Rosa; Sedlar, Marija; Majewski, Stan; Hudson, Barry I; Einstein, Andrew J; Schmidt, Ann Marie; Johnson, Lynne L. "Development of receptor for advanced glycation end products-directed imaging of atherosclerotic plaque in a murine model of spontaneous atherosclerosis". Circulation. Cardiovascular imaging. 2008 Nov;1(3):212-219 (MEDL:19808545 #779072)       

    BACKGROUND: The receptor for advanced glycation end products (RAGE) is implicated in the development and progression of atherosclerosis. We tested the hypothesis that (99m)Tc-labeled anti-RAGE F(ab')(2) can be used as a noninvasive tool to image atherosclerotic lesions in apolipoprotein E-deficient (apoE(-/-)) mice. METHODS AND RESULTS: A sequence in the V-type Ig extracellular domain of RAGE was used to develop a peptide injected into rabbits; serum was retrieved, IgG prepared and affinity-purified, and pepsin-digested into F(ab')(2). Thirteen 6-week apoE(-/-) mice were fed a Western diet. At 20 weeks, 6 were injected with 15.2+/-1.9 MBq (350 to 411 microCi) (99m)Tc-labeled anti-RAGE F(ab')(2), 6 were injected with (99m)Tc-labeled control nonspecific IgG F(ab')(2), and 1 was injected with dual-labeled (99m)Tc and rhodamine anti-RAGE F(ab')(2). Four 20-week C57BL/6 mice were injected with (99m)Tc-labeled anti-RAGE F(ab')(2). All mice were imaged on a high resolution mini-gamma camera 4 hours after injection and euthanized. The aortic tree was dissected and photographed, and the proximal aorta was sectioned for staining after gamma scintillation counting. All 6 apoE(-/-) mice injected with (99m)Tc-labeled anti-RAGE F(ab')(2) fragments showed focal tracer uptake in the proximal aorta (mean %ID/g, 1.98%). Disease and antibody controls showed no focal tracer uptake in the thorax (%ID/g, <1.0%). Histological sections of the proximal aorta showed American Heart Association class III lesions with lipid laden macrophages, smooth muscle cells, and positive staining for RAGE. On immunofluorescence, RAGE colocalized with macrophages. CONCLUSIONS: These data show the feasibility of noninvasively imaging RAGE in atherosclerotic lesions in a murine model and confirm levels of RAGE expression sufficient to allow detection on in vivo imaging.
  114. Toth, Cory; Rong, Ling Ling; Yang, Christina; Martinez, Jose; Song, Fei; Ramji, Noor; Brussee, Valentine; Liu, Wei; Durand, Jeff; Nguyen, Minh Dang; Schmidt, Ann Marie; Zochodne, Douglas W. "Receptor for advanced glycation end products (RAGEs) and experimental diabetic neuropathy". Diabetes. 2008 Apr;57(4):1002-1017 (MEDL:18039814 #779122)       

    OBJECTIVE: Heightened expression of the receptor for advanced glycation end products (RAGE) contributes to development of systemic diabetic complications, but its contribution to diabetic neuropathy is uncertain. We studied experimental diabetic neuropathy and its relationship with RAGE expression using streptozotocin-induced diabetic mice including a RAGE(-/-) cohort exposed to long-term diabetes compared with littermates without diabetes. RESEARCH DESIGN AND METHODS: Structural indexes of neuropathy were addressed with serial (1, 3, 5, and 9 months of experimental diabetes) electrophysiological and quantitative morphometric analysis of dorsal root ganglia (DRG), peripheral nerve, and epidermal innervation. RAGE protein and mRNA levels in DRG, peripheral nerve, and epidermal terminals were assessed in WT and RAGE(-/-) mice, with and without diabetes. The correlation of RAGE activation with nuclear factor (NF)-kappaB and protein kinase C beta II (PKC beta II) protein and mRNA expression was also determined. RESULTS: Diabetic peripheral epidermal axons, sural axons, Schwann cells, and sensory neurons within ganglia developed dramatic and cumulative rises in RAGE mRNA and protein along with progressive electrophysiological and structural abnormalities. RAGE(-/-) mice had attenuated structural features of neuropathy after 5 months of diabetes. RAGE-mediated signaling pathway activation for NF-kappaB and PKC beta II pathways was most evident among Schwann cells in the DRG and peripheral nerve. CONCLUSIONS: In a long-term model of experimental diabetes resembling human diabetic peripheral neuropathy, RAGE expression in the peripheral nervous system rises cumulatively and relates to progressive pathological changes. Mice lacking RAGE have attenuated features of neuropathy and limited activation of potentially detrimental signaling pathways.
  115. Toure, Fatouma; Zahm, Jean-Marie; Garnotel, Roselyne; Lambert, Elise; Bonnet, Noel; Schmidt, Ann Marie; Vitry, Fabien; Chanard, Jacques; Gillery, Philippe; Rieu, Philippe. "Receptor for advanced glycation end-products (RAGE) modulates neutrophil adhesion and migration on glycoxidated extracellular matrix". Biochemical journal. 2008 Dec;416(2):255-261 (MEDL:18643777 #779062)       

    AGEs (advanced glycation end-products) accumulate in collagen molecules during uraemia and diabetes, two diseases associated with high susceptibility to bacterial infection. Because neutrophils bind to collagen during their locomotion in extravascular tissue towards the infected area we investigated whether glycoxidation of collagen (AGE-collagen) alters neutrophil migration. Type I collagen extracted from rat tail tendons was used for in vitro glycoxidation (AGE-collagen). Neutrophils were obtained from peripheral blood of healthy adult volunteers and were used for the in vitro study of adhesion and migration on AGE- or control collagen. Glycoxidation of collagen increased adhesion of neutrophils to collagen surfaces. Neutrophil adhesion to AGE-collagen was inhibited by a rabbit anti-RAGE (receptor for AGEs) antibody and by PI3K (phosphoinositide 3-kinase) inhibitors. No effect was observed with ERK (extracellular-signal-regulated kinase) or p38 MAPK (mitogen-activated protein kinase) inhibitors. AGE-collagen was able to: (i) induce PI3K activation in neutrophils, and (ii) inhibit chemotaxis and chemokinesis of chemoattractant-stimulated neutrophils. Finally, we found that blocking RAGE with anti-RAGE antibodies or inhibiting PI3K with PI3K inhibitors restored fMLP (N-formylmethionyl-leucyl-phenylalanine)-induced neutrophil migration on AGE-collagen. These results show that RAGE and PI3K modulate adhesion and migration rate of neutrophils on AGE-collagen. Modulation of adhesiveness may account for the change in neutrophil migration rate on AGE-collagen. As neutrophils rely on their ability to move to perform their function as the first line of defence against bacterial invasion, glycoxidation of collagen may participate in the suppression of normal host defence in patients with diabetes and uraemia.
  116. Yan, Shi Fang; Ramasamy, Ravichandran; Schmidt, Ann Marie. "Mechanisms of disease: advanced glycation end-products and their receptor in inflammation and diabetes complications". Nature clinical practice. Endocrinology & metabolism. 2008 May;4(5):285-293 (MEDL:18332897 #130817)       

    Many important biochemical mechanisms are activated in the presence of high levels of glucose, which occur in diabetes. Elevated levels of glucose accelerate the formation of advanced glycation end-products (AGEs). Via their chief signaling receptor-the AGE-specific receptor (commonly abbreviated as RAGE)-AGEs generate reactive oxygen species and activate inflammatory signaling cascades. Consequently, AGEs have key roles in the pathogenesis of diabetic complications. Two discoveries have advanced our knowledge of the roles of RAGE in inflammation. First, this receptor has multiple ligands and binds not only AGEs but also proinflammatory, calcium-binding S100 proteins (also known as calgranulins) and nuclear high mobility group protein box-1. Second, RAGE is expressed on T lymphocytes, monocytes and macrophages; RAGE expression on T lymphocytes is essential for effective priming of immune responses in vivo. In this Review, we chronicle roles for RAGE in the pathogenesis of diabetic complications and develop the hypothesis that, in addition to RAGE's central role in the inflammatory response, it is critically linked to the pathogenesis of types 1 and 2 diabetes
  117. Chen, Xi; Walker, Douglas G; Schmidt, Ann Marie; Arancio, Ottavio; Lue, Lih-Fen; Yan, Shi Du. "RAGE: a potential target for Abeta-mediated cellular perturbation in Alzheimer's disease". Current molecular medicine. 2007 Dec;7(8):735-742 (MEDL:18331231 #779152)    

    This review focuses on the current findings regarding interaction between amyloid beta peptide (Abeta) and receptor for advanced glycation endproducts (RAGE) and its roles in the pathogenesis of Alzheimer's disease (AD). As a ubiquitously expressed cell surface receptor, RAGE mediates the effects of Abeta on microglia, blood-brain barrier (BBB) and neurons through activating different signaling pathways. Data from autopsy brain tissues, in vitro cell cultures and transgenic mouse models suggest that Abeta-RAGE interaction exaggerates neuronal stress, accumulation of Abeta, impaired learning memory, and neuroinflammation. Blockade of RAGE protects against Abeta-mediated cellular perturbation. These findings may have an important therapeutic implication for neurodegenerative disorders relevant to AD.
  118. Clynes, Raphael; Herold, Kevan; Schmidt, Ann Marie. "RAGE: exacting a toll on the host in response to polymicrobial sepsis and Listeria monocytogenes [Comment]". Critical care. 2007;11(6):183-183 (MEDL:18190725 #779222)       

    The receptor for advanced glycation endproducts (RAGE) has complex roles in the immune/inflammatory response. RAGE is expressed on monocytes/macrophages, T and B lymphocytes, and dendritic cells. Previous studies illustrated that homozygous RAGE-/- mice subjected to overwhelming bacterial sepsis displayed normal clearance of pathogenic bacteria and significantly increased survival. In this issue of Critical Care, Lutterloh and colleagues confirm these findings and provide evidence that blocking antibodies to RAGE afford similar protection in mice, even when administration of anti-RAGE is delayed by 24 hours. Furthermore, these authors illustrate that deletion of RAGE is remarkably protective in mice infected with the intracellular pathogen Listeria monocytogenes. In this Commentary, we consider these findings and propose possible mechanisms by which RAGE exacts a heavy toll on the host in response to polymicrobial sepsis and L. monocytogenes.
  119. Clynes, Raphael; Moser, Bernhard; Yan, Shi Fang; Ramasamy, Ravichandran; Herold, Kevan; Schmidt, Ann Marie. "Receptor for AGE (RAGE): weaving tangled webs within the inflammatory response". Current molecular medicine. 2007 Dec;7(8):743-751 (MEDL:18331232 #130822)    

    The family of RAGE ligands, including Advanced Glycation Endproducts (AGEs), S100/calgranulins, High Mobility Group Box-1 (HMGB1) and amyloid beta peptide (Abeta) and beta-sheet fibrils are highly enriched in immune and inflammatory foci. In parallel, upregulation of Receptor for AGE (RAGE) is noted in diverse forms of inflammation and autoimmunity, based on experiments examining human tissues as well as animal models. Indeed, prior to the demonstration that S100/calgranulins were signal transduction ligands of RAGE, these molecules were considered 'biomarkers' of disease and disease activity in disorders such as colitis and arthritis. Premiere roles for RAGE in advancing cellular migration implicate this receptor in targeting immune cells to vulnerable foci. Once engaged, ligand-RAGE interaction in inflammatory and vascular cells amplifies upregulation of inflammatory cytokines, adhesion molecules and matrix metalloproteinases (MMPs). Discerning the primal versus chronic injury-provoking roles for this ligand-receptor interaction is a challenge in delineating the functions of the ligand/RAGE axis. As RAGE is expressed by many of the key cell types linked integrally to the immune response, we propose that the sites and time course of ligand-RAGE stimulation determine the phenotype produced by this axis. Ultimately, drawing the fine line between antagonism versus stimulation of the receptor in health and disease will depend on the full characterization of RAGE in repair versus injury
  120. Fuentes, Maren K; Nigavekar, Shraddha S; Arumugam, Thiruvengadam; Logsdon, Craig D; Schmidt, Ann Marie; Park, Juliet C; Huang, Emina H. "RAGE activation by S100P in colon cancer stimulates growth, migration, and cell signaling pathways". Diseases of the colon & rectum. 2007 Aug;50(8):1230-1240 (MEDL:17587138 #779182)       

    PURPOSE: Colon cancer is the third most prevalent cancer in the United States. However, the molecular mechanisms involved in the development and progression of colon cancer are incompletely understood. This study was initiated to explore the potential role of the receptor for advanced glycation end-products and S100P in modulation of key properties of human colon cancer cells. METHODS: Western blot, reverse transcription-polymerase chain reaction, and quantitative polymerase chain reaction were performed for detection of the receptor for advanced glycation end-products and S100P in colon cancer and matched normal colon. The influence of exogenously added S100P was analyzed on SW480 colon cancer cell line proliferation, migration, phosphorylation of mitogen activated protein kinases, and NFkappaB activation. To identify the mechanisms involved in these responses, coimmunoprecipitation examining the S100P/Receptor for advanced glycation end-products interaction and the effects of receptor for advanced glycation end-products inhibition in this interaction were analyzed. RESULTS: Although the receptor for advanced glycation end-products was present in normal and malignant colon specimens, only the malignant specimens expressed S100P. Treatment of SW480 cells with S100P increased proliferation and cell migration. Addition of exogenous S100P stimulated both ERK1/2 phosphorylation and NFkappaB activity. The interaction between S100P and the receptor for advanced glycation end-products was demonstrated by coimmunoprecipitation of these molecules from SW480 cells. Antagonism of the receptor for advanced glycation end-products blocked this interaction and the biologic effects of S100P on these cells. CONCLUSIONS: These data indicate that S100P is expressed at greater levels in colon cancer than matched normal tissue and that S100P stimulates colon cancer cell growth, migration, Erk phosphorylation, and NFkappaB activation in vitro, suggesting that this ligand/receptor pair may be targeted for the development of new therapies.
  121. Herold, Kevan; Moser, Bernhard; Chen, Yali; Zeng, Shan; Yan, Shi Fang; Ramasamy, Ravichandran; Emond, Jean; Clynes, Raphael; Schmidt, Ann Marie. "Receptor for advanced glycation end products (RAGE) in a dash to the rescue: inflammatory signals gone awry in the primal response to stress". Journal of leukocyte biology. 2007 Aug;82(2):204-212 (MEDL:17513693 #130825)       

    The multiligand receptor for advanced glycation end products (RAGE) of the Ig superfamily transduces the biological impact of discrete families of ligands, including advanced glycation end products, certain members of the S100/calgranulin family, high mobility group box-1, Mac-1 (alpha(M)beta(2), CD11b/CD18), and amyloid-beta peptide and beta-sheet fibrils. Although structurally dissimilar, at least at the monomeric level, recent evidence suggests that oligomeric forms of these RAGE ligands may be especially apt to activate the receptor and up-regulate a program of inflammatory and tissue injury-provoking genes. The challenge in probing the biology of RAGE and its impact in acute responses to stress and the potential development of chronic disease is to draw the line between mechanisms that evoke repair versus those that sustain inflammation and tissue damage. In this review, we suggest the concept that the ligands of RAGE comprise a primal program in the acute response to stress. When up-regulated in environments laden with oxidative stress, inflammation, innate aging, or high glucose, as examples, the function of these ligand families may be transformed from ones linked to rapid repair to those that drive chronic disease. Identification of the threshold beyond which ligands of RAGE mediate repair versus injury is a central component in delineating optimal strategies to target RAGE in the clinic
  122. Ma, Wanchao; Lee, Song Eun; Guo, Jiancheng; Qu, Wu; Hudson, Barry I; Schmidt, Ann Marie; Barile, Gaetano R. "RAGE ligand upregulation of VEGF secretion in ARPE-19 cells". Investigative ophthalmology & visual science. IOVS. 2007 Mar;48(3):1355-1361 (MEDL:17325184 #779202)       

    PURPOSE: The importance of VEGF in stimulating neovascular age-related macular degeneration (AMD) is well-recognized, but the initiating factors that induce local upregulation of VEGF remain unclear. The current study was conducted to test the hypothesis that activation of RAGE (receptor for advanced glycation end products [AGEs]) by its ligands, including AGEs, amyloid-beta peptide (Abeta), and S100B/calgranulins, some of which are known components of drusen and Bruch's membrane deposits, modulate secretion of VEGF by retinal pigment epithelial (RPE) cells. METHODS: ARPE-19 cells were used for all experiments. The cells were transfected with constructs encoding a signal transduction mutant of human RAGE to assess the RAGE-dependence of intracellular signaling. VEGF secretion and gene expression were assessed by ELISA and quantitative real-time PCR. SDS-PAGE and size exclusion chromatography were performed to analyze the structural changes of S100B after oxidation of its thiol groups under denaturing and nondenaturing conditions, respectively. NF-kappaB activation was assessed via electrophoretic mobility shift assay (EMSA). The impact of the NF-kappaB inhibition was assessed by using parthenolide. RESULTS: ARPE-19 cells basally secreted VEGF under normal cell culture conditions. Immobilized ligands of RAGE increased VEGF secretion in a RAGE-dependent manner. In contrast, soluble AGE-BSA, fresh Abeta, and S100B were less effective in increasing VEGF secretion. Studies with Abeta demonstrated that oligomeric and surface-immobilized forms of Abeta, but not soluble monomeric forms of Abeta, were effective upregulators of VEGF secretion via RAGE. Oxidation of S100B's thiol groups resulted in the formation of oligomers that displayed distinct RAGE biological activity compared with the simple dimeric form. RAGE-mediated upregulation of VEGF secretion by ARPE-19 cells was largely dependent on NF-kappaB, as indicated by studies with parthenolide. CONCLUSIONS: Immobilized or oligomerized ligands for RAGE induce RPE cells to increase VEGF secretion. NF-kappaB plays a central role in RAGE-dependent RPE secretion of VEGF. In AMD, activation of the RAGE axis in RPE cells may contribute to upregulation of VEGF, potentially inciting or propagating neovascular macular disease.
  123. Moser, Bernhard; Desai, Dharmesh D; Downie, Matthew P; Chen, Yali; Yan, Shi Fang; Herold, Kevan; Schmidt, Ann Marie; Clynes, Raphael. "Receptor for advanced glycation end products expression on T cells contributes to antigen-specific cellular expansion in vivo". Journal of immunology. 2007 Dec 15;179(12):8051-8058 (MEDL:18056345 #140594)    

    Receptor for advanced glycation end products (RAGE) is an activation receptor triggered by inflammatory S100/calgranulins and high mobility group box-1 ligands. We have investigated the importance of RAGE on Ag priming of T cells in murine models in vivo. RAGE is inducibly up-regulated during T cell activation. Transfer of RAGE-deficient OT II T cells into OVA-immunized hosts resulted in reduced proliferative responses that were further diminished in RAGE-deficient recipients. Examination of RAGE-deficient dendritic cells did not reveal functional impairment in Ag presentation, maturation, or migratory capacities. However, RAGE-deficient T cells showed markedly impaired proliferative responses in vitro to nominal and alloantigens, in parallel with decreased production of IFN-gamma and IL-2. These data indicate that RAGE expressed on T cells is required for efficient priming of T cells and elucidate critical roles for RAGE engagement during cognate dendritic cell-T cell interactions
  124. Onat, Duygu; Jelic, Sanja; Schmidt, Ann Marie; Pile-Spellman, John; Homma, Shunichi; Padeletti, Margherita; Jin, Zhezhen; Le Jemtel, Thierry H; Colombo, Paolo C; Feng, Lei. "Vascular endothelial sampling and analysis of gene transcripts: a new quantitative approach to monitor vascular inflammation". Journal of applied physiology. Respiratory, environmental & exercise physiology. 2007 Nov;103(5):1873-1878 (MEDL:17717122 #779172)       

    BACKGROUND: Limited access to endothelial tissue is a major constraint when investigating the cellular mechanisms of vascular inflammation in patients with cardiovascular and metabolic diseases. We introduce venous endothelial sampling coupled to quantitative analysis of gene transcripts by real-time PCR, as a novel approach to study endothelial gene expression in human subjects. METHODS: Endothelial cells were collected from a superficial forearm vein using five guide wires sequentially inserted through a 20-gauge angiocatheter in seven patients with history of cardiovascular events related to advanced vascular disease and in 17 healthy subjects. Endothelial cells were purified using magnetic beads coated with endothelial specific antibodies. Endothelial mRNA was amplified using RiboAmp HS RNA Amplification kit (Molecular Devices, Sunnyvale, CA). Amplified RNA was analyzed by real-time PCR. RESULTS: Linearity of RNA amplification was validated by real-time PCR using RNA from 1,000 human umbilical endothelial cells (HUVECs) before and after amplification. In human subjects, vascular disease was associated with significant induction of proatherosclerotic genes: early growth response gene product (Egr-1) and monocyte chemoattractant protein-1 (MCP-1). CONCLUSION: Venous endothelial sampling coupled to real-time PCR analysis is a minimally invasive, safe, and reliable technique to monitor vascular inflammation in human subjects. Expression of genes implicated in the atherosclerotic process is increased in the venous endothelium of patients with arterial vascular disease. Venous endothelial sampling and quantitative analysis of gene expression may help develop new vascular-targeted biomarkers to identify and track the impact of disease states and therapeutic interventions in vascular diseases.
  125. Pichiule, Paola; Chavez, Juan Carlos; Schmidt, Ann Marie; Vannucci, Susan J. "Hypoxia-inducible factor-1 mediates neuronal expression of the receptor for advanced glycation end products following hypoxia/ischemia". Journal of biological chemistry. 2007 Dec;282(50):36330-36340 (MEDL:17942394 #779142)       

    Activation of the receptor for advanced glycation endproducts (RAGE) by its multiple ligands can trigger diverse signaling pathways with injurious or pro-survival consequences. In this study, we show that Rage mRNA and protein levels were stimulated in the mouse brain after experimental stroke and systemic hypoxia. In both cases, RAGE expression was primarily associated with neurons. Activation of RAGE-dependent pathway(s) post-ischemia appears to have a neuroprotective role because mice genetically deficient for RAGE exhibited increased infarct size 24 h after injury. Up-regulation of RAGE expression was also observed in primary neurons subjected to hypoxia or oxygen-glucose deprivation, an in vitro model of ischemia. Treatment of neurons with low concentrations of S100B decreased neuronal death after oxygen-glucose deprivation, and this effect was abolished by a neutralizing antibody against RAGE. Conversely, high concentrations of exogenous S100B had a cytotoxic effect that seems to be RAGE-independent. As an important novel finding, we demonstrate that hypoxic stimulation of RAGE expression is mediated by the transcription factor hypoxia-inducible factor-1. This conclusion is supported by the finding that HIF-1alpha down-regulation by Cre-mediated excision drastically decreased RAGE induction by hypoxia or desferrioxamine. In addition, we showed that the mouse RAGE promoter region contains at least one functional HIF-1 binding site, located upstream of the proposed transcription start site. A luciferase reporter construct containing this RAGE promoter fragment was activated by hypoxia, and mutation at the potential HIF-1 binding site decreased hypoxia-dependent promoter activation. Specific binding of HIF-1 to this putative HRE in hypoxic cells was detected by chromatin immunoprecipitation assay.
  126. Ramasamy, Ravichandran; Yan, Shi Fang; Schmidt, Ann Marie. "Arguing for the motion: yes, RAGE is a receptor for advanced glycation endproducts [Comment]". Molecular nutrition & food research. 2007 Sep;51(9):1111-1115 (MEDL:17854009 #130824)       

    Advanced glycation endproducts (AGEs) are an heterogenous class of compounds formed by diverse stimuli, including hyperglycemia, oxidative stress, inflammation, renal failure, and innate aging. Recent evidence suggests that dietary sources of AGE may contribute to pathology. AGEs impart diverse effects in cells; evidence strongly suggests that crosslinking of proteins by AGEs may irrevocably alter basement membrane integrity and function. In addition, the ability of AGEs to bind to cells and activate signal transduction, thereby affecting broad properties in the cellular milieu, indicates that AGEs are not innocent bystanders in the diseases of AGEing. Here, we present evidence that receptor for AGE (RAGE) is a receptor for AGEs
  127. Roth, Georg A; Ankersmit, Hendrik J; Brown, Vinette B; Papapanou, Panos N; Schmidt, Ann Marie; Lalla, Evanthia. "Porphyromonas gingivalis infection and cell death in human aortic endothelial cells". FEMS microbiology letters. 2007 Jul;272(1):106-113 (MEDL:17459112 #779192)       

    Porphyromonas gingivalis is a periodontal pathogen that promotes a proatherogenic response in endothelial cells. Cell death responses of human aortic endothelial cells to P. gingivalis at various multiplicities of infection (MOI) were investigated by assessment of cell detachment, histone-associated DNA fragmentation, lactate dehydrogenase release and ADP:ATP ratio. Porphyromonas gingivalis at MOI 1:10-1:100 did not have a cytotoxic effect, but induced apoptotic cell death at MOI 1:500 and 1:1000. Monocyte chemoattractant protein-1 production was significantly enhanced by P. gingivalis at MOI 1:100. At higher MOI, at least in vitro, P. gingivalis mediates endothelial apoptosis, thereby potentially amplifying proatherogenic mechanisms in the perturbed vasculature.
  128. Roth, Georg A; Moser, Bernhard; Roth-Walter, Franziska; Giacona, Mary Beth; Harja, Evis; Papapanou, Panos N; Schmidt, Ann Marie; Lalla, Evanthia. "Infection with a periodontal pathogen increases mononuclear cell adhesion to human aortic endothelial cells". Atherosclerosis. 2007 Feb;190(2):271-281 (MEDL:16620832 #779212)       

    BACKGROUND: As a link between periodontal infections and an increased risk for vascular disease has been demonstrated, we assessed the ability of the Gram-negative periodontal pathogen Porphyromonas gingivalis to modulate properties of endothelial cells linked to inflammation and proatherogenic pathways. METHODS AND RESULTS: Primary human aortic endothelial cells (HAEC) were infected with either P. gingivalis strain 381 or its non-invasive fimbriae-deficient mutant, DPG3, and incubated with U-937 monocytes, or Jurkat T cells. P. gingivalis-infected HAEC demonstrated significantly increased adhesion of immune cells compared to non-infected cells or those infected with DPG3. Heat-killed bacteria had no effect on mononuclear cell adhesion and P. gingivalis LPS had only a minimal effect. P. gingivalis infection significantly increased HAEC expression of VCAM-1, ICAM-1 and E-selectin, and enhanced production of IL-6, IL-8 and MCP-1. CONCLUSION: These data demonstrate that live invasive P. gingivalis 381 elicits a pro-atherogenic response in HAEC.
  129. Schmidt, Ann Marie. "Editorial [Editorial]". Current molecular medicine. 2007 Dec;7(8):697-698 (MEDL:18331227 #779162)       
  130. Yan, Shi Fang; Barile, Gaetano R; D'Agati, Vivette; Du Yan, Shi; Ramasamy, Ravichandran; Schmidt, Ann Marie. "The biology of RAGE and its ligands: uncovering mechanisms at the heart of diabetes and its complications". Current diabetes reports. 2007 Apr;7(2):146-153 (MEDL:17425919 #130826)    

    The interaction of glucose-modified and inflammation-promoting ligands with the receptor for advanced glycation end products (RAGE) is emerging as a central mechanism contributing to the diverse complications of diabetes. These ligands, particularly in oligomeric form, bind to RAGE and transduce intracellular signals. The consequences of this interaction, as elucidated in cultured cells and animal models, include upregulation of inflammatory and tissue-degradative pathways. Pharmacologic antagonism of RAGE may hold promise for the treatment of diabetic complications
  131. Yan, Shi Fang; D'Agati, Vivette; Schmidt, Ann Marie; Ramasamy, Ravichandran. "Receptor for Advanced Glycation Endproducts (RAGE): a formidable force in the pathogenesis of the cardiovascular complications of diabetes & aging". Current molecular medicine. 2007 Dec;7(8):699-710 (MEDL:18331228 #130823)    

    Unifying mechanisms for the consequences of aging and chronic diabetes are coming to light with the identification that common to both settings is the production and accumulation of the largely irreversible Advanced Glycation Endproducts (AGEs). AGEs impart multiple consequences in the tissues; a key means by which they exert maladaptive effects is via their interaction with and activation of their chief cell surface receptor, Receptor for AGE or RAGE. Although the time course, rate and extent of AGE generation and accumulation in diabetes and aging may be distinct, unifying outcomes of the ligand-RAGE interaction in the vasculature and heart are linked to upregulation of inflammatory and tissue-destructive mechanisms. Consistent with these concepts, administration of the ligand-binding decoy of RAGE, soluble or sRAGE, suppresses early initiation and progression of atherosclerosis in diabetic mice; suppresses exaggerated neointimal expansion consequent to arterial injury; and mitigates the adverse impact of ischemia/reperfusion injury in the heart. Importantly, the RAGE ligand repertoire upregulated in these settings is not limited to AGEs. The key finding that RAGE was a multi-ligand receptor unified the concept that in diabetes and aging, innate and adaptive inflammatory mechanisms contribute to the pathogenesis of tissue injury. We conclude that antagonism of RAGE may reflect a novel and therapeutically logical and safe target in cardiovascular stress induced by aging and chronic diabetes
  132. Andrassy, Martin; Igwe, John; Autschbach, Frank; Volz, Christian; Remppis, Andrew; Neurath, Markus F; Schleicher, Erwin; Humpert, Per M; Wendt, Thoralf; Liliensiek, Birgit; Morcos, Michael; Schiekofer, Stephan; Thiele, Kirsten; Chen, Jiang; Kientsch-Engel, Rose; Schmidt, Ann-Marie; Stremmel, Wolfgang; Stern, David M; Katus, Hugo A; Nawroth, Peter P; Bierhaus, Angelika. "Posttranslationally modified proteins as mediators of sustained intestinal inflammation". American journal of pathology. 2006 Oct;169(4):1223-1237 (MEDL:17003481 #779242)       

    Oxidative and carbonyl stress leads to generation of N(epsilon)-carboxymethyllysine-modified proteins (CML-mps), which are known to bind the receptor for advanced glycation end products (RAGE) and induce nuclear factor (NF)-kappaB-dependent proinflammatory gene expression. To determine the impact of CML-mps in vivo, RAGE-dependent sustained NF-kappaB activation was studied in resection gut specimens from patients with inflammatory bowel disease. Inflamed gut biopsy tissue demonstrated a significant up-regulation of RAGE and increased NF-kappaB activation. Protein extracts from the inflamed zones, but not from noninflamed resection borders, caused perpetuated NF-kappaB activation in cultured endothelial cells, which was mediated by CML-mps including CML-modified S100 proteins. The resulting NF-kappaB activation, lasting 5 days, was primarily inhibited by either depletion of CML-mps or by the addition of sRAGE, p44/42 and p38 MAPKinase-specific inhibitors. Consistently, CML-mps isolated from inflamed gut areas and rectally applied into mice caused NF-kappaB activation, increased proinflammatory gene expression, and histologically detectable inflammation in wild-type mice, but not in RAGE-/- mice. A comparable up-regulation of NF-kappaB and inflammation on rectal application of CML-mps was observed in IL-10-/- mice. Thus, CML-mps generated in inflammatory lesions have the capacity to elicit a RAGE-dependent intestinal inflammatory response.
  133. Bucciarelli, Loredana G; Kaneko, Michiyo; Ananthakrishnan, Radha; Harja, Evis; Lee, Larisse K; Hwang, Yuying C; Lerner, Shulamit; Bakr, Soliman; Li, Qing; Lu, Yan; Song, Fei; Qu, Wu; Gomez, Teodoro; Zou, Yu Shan; Yan, Shi Fang; Schmidt, Ann Marie; Ramasamy, Ravichandran. "Receptor for advanced-glycation end products: key modulator of myocardial ischemic injury". Circulation. 2006 Mar 7;113(9):1226-1234 (MEDL:16505177 #130801)       

    BACKGROUND: The beneficial effects of reperfusion therapies have been limited by the amount of ischemic damage that occurs before reperfusion. To enable development of interventions to reduce cell injury, our research has focused on understanding mechanisms involved in cardiac cell death after ischemia/reperfusion (I/R) injury. In this context, our laboratory has been investigating the role of the receptor for advanced-glycation end products (RAGE) in myocardial I/R injury. METHODS AND RESULTS: In this study we tested the hypothesis that RAGE is a key modulator of I/R injury in the myocardium. In ischemic rat hearts, expression of RAGE and its ligands was significantly enhanced. Pretreatment of rats with sRAGE, a decoy soluble part of RAGE receptor, reduced ischemic injury and improved functional recovery of myocardium. To specifically dissect the impact of RAGE, hearts from homozygous RAGE-null mice were isolated, perfused, and subjected to I/R. RAGE-null mice were strikingly protected from the adverse impact of I/R injury in the heart, as indicated by decreased release of LDH, improved functional recovery, and increased adenosine triphosphate (ATP). In rats and mice, activation of the RAGE axis was associated with increases in inducible nitric oxide synthase expression and levels of nitric oxide, cyclic guanosine monophosphate (cGMP), and nitrotyrosine. CONCLUSIONS: These findings demonstrate novel and key roles for RAGE in I/R injury in the heart. The findings also demonstrate that the interaction of RAGE with advanced-glycation end products affects myocardial energy metabolism and function during I/R
  134. Cuccurullo, Chiara; Iezzi, Annalisa; Fazia, Maria Luigia; De Cesare, Domenico; Di Francesco, Andrea; Muraro, Raffaella; Bei, Roberto; Ucchino, Sante; Spigonardo, Francesco; Chiarelli, Francesco; Schmidt, Ann Marie; Cuccurullo, Franco; Mezzetti, Andrea; Cipollone, Francesco. "Suppression of RAGE as a basis of simvastatin-dependent plaque stabilization in type 2 diabetes". Arteriosclerosis, thrombosis, & vascular biology. 2006 Dec;26(12):2716-2723 (MEDL:17038636 #779232)       

    OBJECTIVE: Receptor for advanced glycation end products (AGEs) (RAGE) plays a central role in the process of plaque rupture in diabetic patients. Recently, it has been reported that RAGE may be downregulated by improving glycemic control. In contrast, despite being well known that RAGE may be induced in human vessels in a glucose-independent fashion, also by myeloperoxidase (MPO)-dependent AGE generation, no data exist regarding the possibility of a pharmacological modulation of glucose-independent RAGE generation. Thus, the aim of this study was to characterize the effect of simvastatin on the expression of RAGE and RAGE-dependent plaque-destabilizing genes in human atherosclerotic plaques. METHODS AND RESULTS: Seventy type 2 diabetic patients with asymptomatic carotid artery stenosis (>70%) were randomized to American Heart Association (AHA) step 1 diet plus simvastatin (40 mg/d) or AHA step 1 diet alone for 4 months before endarterectomy. Plaque expression of MPO, AGEs, RAGE, NF-kappaB, COX-2, mPGES-1, matrix metalloproteinase (MMP)-2 and MMP-9, lipid and oxidized LDL (oxLDL) content, procollagen 1, and interstitial collagen was analyzed by immunohistochemistry and Western blot; zymography was used to detect MMP activity. Plaques from the simvastatin group had less (P<0.0001) immunoreactivity for MPO, AGEs, RAGE, p65, COX-2, mPGES-1, MMP-2, and MMP-9, lipids and oxLDL; reduced (P<0.0001) gelatinolytic activity; increased (P<0.0001) procollagen 1 and collagen content; and fewer (P<0.0001) macrophages, T-lymphocytes, and HLA-DR+ cells. Of interest, RAGE inhibition by simvastatin, observed not only in plaque sections but also in plaque-derived macrophages, was reverted by addition of AGEs in vitro. CONCLUSIONS: This study supports the hypothesis that simvastatin inhibits plaque RAGE expression by decreasing MPO-dependent AGE generation. This effect in turn might contribute to plaque stabilization by inhibiting the biosynthesis of PGE2-dependent MMPs, responsible for plaque rupture.
  135. Ekong, Udeme; Zeng, Shan; Dun, Hao; Feirt, Nikki; Guo, Jiancheng; Ippagunta, Nikalesh; Guarrera, James V; Lu, Yan; Weinberg, Alan; Qu, Wu; Ramasamy, Ravichandran; Schmidt, Ann Marie; Emond, Jean C. "Blockade of the receptor for advanced glycation end products attenuates acetaminophen-induced hepatotoxicity in mice". Journal of gastroenterology & hepatology. 2006 Apr;21(4):682-688 (MEDL:16677153 #130829)       

    BACKGROUND AND AIM: Severe injury to the liver, such as that induced by toxic doses of acetaminophen, triggers a cascade of events leading to hepatocyte death. It is hypothesized that activation of the receptor for advanced glycation end products (RAGE) might contribute to acetaminophen-induced liver toxicity by virtue of its ability to generate reactive oxygen species, at least in part via nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, and thereby activate downstream signaling pathways leading to cellular injury. METHODS: A model was employed in which toxic doses of acetaminophen (1125 mg/kg) were administered to C57BL/6 mice. To block RAGE, mice received murine soluble (s) RAGE, the extracellular ligand binding domain of the receptor that acts as a decoy to interrupt ligand-RAGE signaling. RESULTS: Animals treated with sRAGE displayed increased survival compared with vehicle treatment, and markedly decreased hepatic necrosis. Consistent with an important role for RAGE-triggered oxidant stress in acetaminophen-induced injury, a significant reduction of nitrotyrosine protein adducts was observed in hepatic tissue in sRAGE-treated versus vehicle-treated mice receiving acetaminophen, in parallel with significantly increased levels of glutathione. In addition, pro-regenerative cytokines tumor necrosis factor-alpha and interleukin-6 were increased in sRAGE-treated versus vehicle-treated mice. CONCLUSION: These findings implicate RAGE-dependent mechanisms in acetaminophen-induced liver damage and suggest that blockade of this pathway may impart beneficial effects in toxin-induced liver injury
  136. Goldin, Alison; Beckman, Joshua A; Schmidt, Ann Marie; Creager, Mark A. "Advanced glycation end products: sparking the development of diabetic vascular injury". Circulation. 2006 Aug;114(6):597-605 (MEDL:16894049 #779262)       

    Advanced glycation end products (AGEs) are proteins or lipids that become glycated after exposure to sugars. AGEs are prevalent in the diabetic vasculature and contribute to the development of atherosclerosis. The presence and accumulation of AGEs in many different cell types affect extracellular and intracellular structure and function. AGEs contribute to a variety of microvascular and macrovascular complications through the formation of cross-links between molecules in the basement membrane of the extracellular matrix and by engaging the receptor for advanced glycation end products (RAGE). Activation of RAGE by AGEs causes upregulation of the transcription factor nuclear factor-kappaB and its target genes. Soluble AGEs activate monocytes, and AGEs in the basement membrane inhibit monocyte migration. AGE-bound RAGE increases endothelial permeability to macromolecules. AGEs block nitric oxide activity in the endothelium and cause the production of reactive oxygen species. Because of the emerging evidence about the adverse effects of AGEs on the vasculature of patients with diabetes, a number of different therapies to inhibit AGEs are under investigation.
  137. Huang, Emina H; Park, Juliet C; Appelman, Henry; Weinberg, Alan D; Banerjee, Mousumi; Logsdon, Craig D; Schmidt, Ann Marie. "Induction of inflammatory bowel disease accelerates adenoma formation in Min +/- mice". Surgery. 2006 Jun;139(6):782-788 (MEDL:16782435 #779272)       

    BACKGROUND: The accelerated incidence of colorectal carcinoma in individuals with inflammatory bowel disease suggests that cellular perturbation triggered by chronic inflammation is linked to the development of dysplasia and neoplastic transformation. To test the mechanistic links between these processes, we employed the following murine strains: (1) multiple intestinal neoplasia (Min) +/- mice, bearing a mutation in the adenomatous polyposis coli (APC) gene; (2) mice deficient in interleukin 10 (IL-10), which normally develop enterocolitis; and (3) Min +/-/IL-10 null mice, first developed in our laboratory. METHODS: Mice with either parental strain or the cross were sacrificed at time points ranging from 10 to 30 weeks of age. The small bowel and colon of 170 IL-10 null mice, 31 Min +/- mice, and 120 Min +/-/IL-10 null mice were examined microscopically. RESULTS: The number of flat adenomas was increased in the colons of the Min +/-/IL-10-/- mice, compared with the Min +/- mice (P = .0005). Neither colitis-type dysplasia nor carcinoma was increased in the Min +/-/IL-10 -/-, compared with the IL-10 null mice (P = .18). Mice deficient in IL-10 developed colitic-type dysplasia (P = .0001) or carcinoma (P = .0001) correlated with increasing inflammation. CONCLUSIONS: Breeding the Min +/- genotype into the IL-10 -/- background increased the incidence of colonic adenomas. Our studies demonstrate that acceleration of dysplasia and progression to invasion were associated with the degree of the inflammatory response in mice deficient in IL-10. These findings provide a novel system to dissect the pathways by which inflammatory mechanisms accelerate adenoma formation.
  138. Moser, Bernhard; Herold, Kevan C; Schmidt, Ann Marie. "Receptor for advanced glycation end products and its ligands: initiators or amplifiers of joint inflammation--a bit of both? [Comment]". Arthritis & rheumatism. 2006 Jan;54(1):14-18 (MEDL:16385492 #779292)       
  139. Pachydaki, Sophia I; Tari, Samir R; Lee, Song Eun; Ma, Wanchao; Tseng, Joseph J; Sosunov, Alexander A; Cataldergirmen, Guellue; Scarmeas, Nikolaos; Caspersen, Casper; Chang, Stanley; Schiff, William M; Schmidt, Ann Marie; Barile, Gaetano R. "Upregulation of RAGE and its ligands in proliferative retinal disease". Experimental eye research. 2006 May;82(5):807-815 (MEDL:16364297 #161164)       

    We sought to study the presence of the receptor for advanced glycation endproducts (RAGE) and its ligands, advanced glycation endproducts (AGEs), S100/calgranulins and amphoterin (high mobility group box 1 protein; HMGB1), in the vitreous cavity and epiretinal membranes (ERMs) of eyes of patients with proliferative diabetic retinopathy (PDR) and proliferative vitreoretinopathy (PVR). Undiluted vitreous specimens were collected from 30 eyes of 30 patients undergoing pars plana vitrectomy for repair of retinal detachment (RD) secondary to PDR (n = 15) or PVR (n = 15). The vitreous samples obtained from 10 eyes undergoing macular hole repair were used as controls. Epiretinal membranes were obtained from eight eyes with PDR and from 10 eyes with PVR. The levels of AGEs in the vitreous were measured using ELISA. The vitreous levels of soluble RAGE (sRAGE), S100/calgranulins and amphoterin were measured using Western blot analyses. The localization of RAGE and its ligands in ERMs was determined with immunohistochemistry. The vitreous levels of sRAGE were significantly increased in both PDR and PVR (p < or = 0.05) compared to control vitreous. In both PDR and PVR, the vitreous levels of AGEs (p < or = 0.01), S100/calgranulins (p < or = 0.05), and amphoterin (p < or = 0.01) were also elevated compared to control eyes. Expression of RAGE was detected in six of eight ERMs from eyes with PDR and eight of 10 ERMs from eyes with PVR. Many cells expressing RAGE also expressed vimentin, suggesting a glial cell origin. Ligands for RAGE were also detected in ERMs, with AGEs detected in five eyes with PDR and eight eyes with PVR. Similarly, S100 and amphoterin ERM expression was observed in six eyes with PDR; these ligands were also expressed in ERMs from eyes with PVR (8 and 7 cases, respectively). We conclude that RAGE and its ligands are increased in the vitreous cavity of eyes with PDR and PVR and are present in ERMs of eyes with these proliferative retinal disorders. These findings suggest a role for the proinflammatory RAGE axis in the pathogenesis of proliferative retinal diseases.
  140. Raman, Kathleen G; Sappington, Penny L; Yang, Runkuan; Levy, Ryan M; Prince, Jose M; Liu, Shiguang; Watkins, Simon K; Schmidt, Ann Marie; Billiar, Timothy R; Fink, Mitchell P. "The role of RAGE in the pathogenesis of intestinal barrier dysfunction after hemorrhagic shock". American journal of physiology. Gastrointestinal & liver physiology. 2006 Oct;291(4):G556-G565 (MEDL:16751175 #779252)       

    The receptor for advanced glycation end products (RAGE) has been implicated in the pathogenesis of numerous conditions associated with excessive inflammation. To determine whether RAGE-dependent signaling is important in the development of intestinal barrier dysfunction after hemorrhagic shock and resuscitation (HS/R), C57Bl/6, rage(-/-), or congenic rage(+/+) mice were subjected to HS/R (mean arterial pressure of 25 mmHg for 3 h) or a sham procedure. Twenty-four hours later, bacterial translocation to mesenteric lymph nodes and ileal mucosal permeability to FITC-labeled dextran were assessed. Additionally, samples of ileum were obtained for immunofluorescence microscopy, and plasma was collected for measuring IL-6 and IL-10 levels. HS/R in C57Bl/6 mice was associated with increased bacterial translocation, ileal mucosal hyperpermeability, and high circulating levels of IL-6. All of these effects were prevented when C57Bl/6 mice were treated with recombinant human soluble RAGE (sRAGE; the extracellular ligand-binding domain of RAGE). HS/R induced bacterial translocation, ileal mucosal hyperpermeability, and high plasma IL-6 levels in rage(+/+) but not rage(-/-) mice. Circulating IL-10 levels were higher in rage(-/-) compared with rage(+/+) mice. These results suggest that activation of RAGE-dependent signaling is a key factor leading to gut mucosal barrier dysfunction after HS/R.
  141. Ramasamy, Ravichandran; Yan, Shi Fang; Schmidt, Ann Marie. "Methylglyoxal comes of AGE [Comment]". Cell. 2006 Jan 27;124(2):258-260 (MEDL:16439200 #130830)       

    The posttranslational modification of proteins by methylglyoxal, a highly reactive compound derived from glycolysis, may contribute to aging, diabetes, and other disorders. In this issue of Cell, Brownlee and colleagues (Yao et al., 2006) demonstrate a specific mechanism by which methylglyoxal modifies a transcriptional corepressor to enhance gene expression
  142. Ramasamy, Ravichandran; Yan, Shi Fang; Schmidt, Ann Marie. "Sphingosine-1-phosphate: waging a battle in the diabetic blood vessel [Editorial]". Circulation research. 2006 Sep 29;99(7):669-671 (MEDL:17008596 #130827)       
  143. Toth, Cory; Schmidt, Ann Marie; Tuor, Ursula I; Francis, George; Foniok, Tadeusz; Brussee, Valentine; Kaur, Jaspreet; Yan, Shi Fang; Martinez, Jose A; Barber, Philip A; Buchan, Alastair; Zochodne, Douglas W. "Diabetes, leukoencephalopathy and rage". Neurobiology of disease. 2006 Aug;23(2):445-461 (MEDL:16815028 #140598)       

    Longstanding diabetes mellitus damages kidney, retina, peripheral nerve and blood vessels, but brain is not usually considered a primary target. We describe direct involvement of the brain, particularly white matter, in long-term (9 months) experimental diabetes of mice, not previously modeled, correlating magnetic resonance (MR) imaging with quantitative histological assessment. Leukoencephalopathy and cerebral atrophy, resembling that encountered in diabetic humans, developed in diabetic mice and was accompanied by time-related development of cognitive changes in behavioural testing. Increased RAGE (receptor for advanced glycation end products) expression, a mediator of widespread diabetic complications, increased dramatically at sites of white matter damage in regions of myelination. RAGE expression was also elevated within neurons, astrocytes and microglia in grey matter and within oligodendrocytes in white matter. RAGE null diabetic mice had significantly less neurodegenerative changes when compared to wild-type diabetic mice. Our findings identify a robust and novel model of cerebral, particularly white matter, involvement with diabetes associated with abnormal RAGE signaling
  144. Wang, Kai; Zhou, Zhongmin; Zhang, Ming; Fan, Liming; Forudi, Farhad; Zhou, Xiaorong; Qu, Wu; Lincoff, A Michael; Schmidt, Ann Marie; Topol, Eric J; Penn, Marc S. "Peroxisome proliferator-activated receptor gamma down-regulates receptor for advanced glycation end products and inhibits smooth muscle cell proliferation in a diabetic and nondiabetic rat carotid artery injury model". Journal of pharmacology & experimental therapeutics. 2006 Apr;317(1):37-43 (MEDL:16368901 #779282)       

    Diabetes is associated with an increase in circulating advanced glycosylation end products (AGEs) and the increased expression of the receptor for AGEs (RAGE). Inhibition of AGE/RAGE binding through the administration of soluble RAGE (sRAGE) has been shown to decrease neointimal hyperplasia. Peroxisome proliferator-activated receptor gamma (PPARgamma), which inhibits neointimal hyperplasia, has been shown to decrease RAGE expression in cultured endothelial cells. We hypothesized that PPARgamma agonists inhibit neointimal hyperplasia via down-regulation of RAGE in vivo. Pretreatment of rat aortic smooth muscle cells (SMCs) with PPARgamma agonist rosiglitazone significantly down-regulated RAGE expression and inhibited SMC proliferation in response to the RAGE agonist S100/calgranulins. In vivo studies showed that rosiglitazone decreased RAGE expression and SMC proliferation at 7 days following carotid arterial injury in both diabetic and nondiabetic rats. At 21 days following injury, neointimal formation was significantly decreased in both diabetic and nondiabetic animals that received rosiglitazone. To determine whether inhibition of neointimal formation by PPARgamma activation could fully be accounted for by its down-regulation of RAGE, we compared the results obtained in animals treated with sRAGE, PPARgamma activator, and sRAGE + PPARgamma activator. Consistent with PPARgamma working through its effects on RAGE, we found that the addition of PPARgamma activator to sRAGE did not result in any further decrease in neointimal formation. These data demonstrate for the first time that PPARgamma agonists inhibit RAGE expression at sites of arterial injury and suggest that down-regulation of RAGE by the PPARgamma activation inhibits neointimal formation in response to arterial injury.
  145. Wendt, Thoralf; Harja, Evis; Bucciarelli, Loredana; Qu, Wu; Lu, Yan; Rong, Ling Ling; Jenkins, Daniel G; Stein, Guenther; Schmidt, Ann Marie; Yan, Shi Fang. "RAGE modulates vascular inflammation and atherosclerosis in a murine model of type 2 diabetes". Atherosclerosis. 2006 Mar;185(1):70-77 (MEDL:16076470 #140599)       

    Previous studies demonstrated that induction of diabetes with streptozotocin (stz) accelerated atherosclerosis in hyperlipidemic apo E null (-/-) mice. Blockade of the Receptor for Advanced Glycation Endproducts (RAGE) in those animals suppressed acceleration of atherosclerotic lesion area, in a manner independent of changes in levels of glucose, insulin or lipids. In the present studies, we extended these concepts to a murine model of type 2 diabetes, and bred apo E -/- mice into the db/db background. Db/db mice are a model of obesity and insulin resistance-mediated hyperglycemia. Compared to apo E -/- m/db (non-diabetic) mice, apo E -/- db/db (diabetic) mice displayed accelerated atherosclerosis at the aortic sinus. Consistent with an important role for RAGE in this process, administration of soluble (s) RAGE, the extracellular ligand-binding domain of RAGE, resulted in significantly reduced atherosclerotic lesion area in a glycemia- and lipid-independent manner. In parallel, apo E -/- db/db mice displayed RAGE-dependent enhanced expression of Vascular Cell Adhesion Molecule-1, tissue factor and matrix metalloproteinase (MMP)-9 antigen/activity in aortae compared to non-diabetic animals. In addition, consistent with the premise that upregulation of RAGE ligands and RAGE occurs even in the non-diabetic, hyperlipidemic state, albeit to lesser degrees than in diabetes, administration of sRAGE to apo E -/- m/db mice resulted in decreased atherosclerotic lesion area at the aortic sinus. Taken together, these findings establish a new murine model for the study of atherosclerosis in type 2 diabetes and highlight important roles for RAGE in proatherogenic mechanisms in hyperglycemia triggered by insulin resistance
  146. Yan, Shi Fang; Naka, Yoshifumi; Hudson, Barry I; Herold, Kevan; Yan, Shi Du; Ramasamy, Ravichandran; Schmidt, Ann Marie. "The ligand/RAGE axis: lighting the fuse and igniting vascular stress". Current atherosclerosis reports. 2006 May;8(3):232-239 (MEDL:16640960 #130828)    

    Vascular inflammation contributes critically to the initiation and progression of atherosclerosis. These processes are accelerated in hyperglycemia and play key roles in the increased incidence and severity of myocardial infarction and stroke observed in diabetes. Evidence suggests that the ligands of the receptor for advanced glycation endproducts (RAGE), a multiligand member of the immunoglobulin superfamily, interact with this receptor to play important roles in both early development and progression of atherosclerosis and vascular inflammation. Studies in animal models of vascular injury underscored the potent impact of RAGE blockade; administration of ligand-binding decoys of RAGE or antibodies to the receptor reduced the consequences of diabetes, hyperlipidemia, and physical injury to the vessel wall. This review focuses on the ligand repertoire of RAGE, the impact of ligand-RAGE interaction, and the potent effect of RAGE blockade in rodent models of vascular injury
  147. Yan, Shi Fang; Yan, Shi Du; Herold, Kevan; Ramsamy, Ravichandran; Schmidt, Ann Marie. "Receptor for advanced glycation end products and the cardiovascular complications of diabetes and beyond: lessons from AGEing". Endocrinology & metabolism clinics of North America. 2006 Sep;35(3):4565-4573 (MEDL:16959583 #140597)       

    The presence of elevated blood glucose levels characterizes the diabetic state. Hyperglycemia may be caused by a number of underlying factors; however, the consequences of chronically elevated glucose are similar. Both the macrovasculature and microvasculature are exquisitely sensitive to the long-term effects of elevated blood glucose. Cardiovascular disease remains the leading cause of morbidity and mortality in diabetes, regardless of the underlying cause of hyperglycemia. Although other substrates, such as DNA, are susceptible to glycation, this article addresses the impact of nonenzymatic glycation on the proteome. The impact of Advanced Glycation End products (AGEs) on alteration of protein function and signal transduction mechanisms contributes to the pathogenesis of diabetes complications. This suggests that blocking the generation or molecular impact of AGEs may modulate the complications of diabetes
  148. Yan, Shi-Fang; Harja, Evis; Andrassy, Martin; Fujita, Tomoyuki; Schmidt, Ann Marie. "Protein kinase C beta/early growth response-1 pathway: a key player in ischemia, atherosclerosis, and restenosis". Journal of the American College of Cardiology. 2006 Nov 7;48(9 Suppl 1):A47-A55 (MEDL:17084284 #140595)       

    Atherosclerosis, restenosis, and the consequences of ischemia are the major causes of morbidity and mortality worldwide. Elucidation of key contributing pathways in animal models of ischemia-reperfusion injury, atherosclerosis, and restenosis consequent to vascular injury may lead to great interest in determining if blocking these pathways could prevent vascular disease in human subjects. This review details the evidence that the protein kinase C (PKC) beta/early growth response-1 axis plays a central role in the response to both acute and chronic vascular stresses in animal models and also indicates the clinical implications of a specific inhibitor of PKCbeta, ruboxistaurin (LY333531)
  149. Andrassy, Martin; Belov, Dmitry; Harja, Evis; Zou, Yu Shan; Leitges, Michael; Katus, Hugo A; Nawroth, Peter P; Yan, Shi Du; Schmidt, Ann Marie; Yan, Shi-Fang. "Central role of PKCbeta in neointimal expansion triggered by acute arterial injury". Circulation research. 2005 Mar 4;96(4):476-483 (MEDL:15662033 #140602)       

    We tested the hypothesis that PKCbeta contributes to vascular smooth muscle cell (SMC) migration and proliferation; processes central to the pathogenesis of restenosis consequent to vascular injury. Homozygous PKCbeta null (-/-) mice or wild-type mice fed the PKCbeta inhibitor, ruboxistaurin, displayed significantly decreased neointimal expansion in response to acute femoral artery endothelial denudation injury compared with controls. In vivo and in vitro analyses demonstrated that PKCbetaII is critically linked to SMC activation, at least in part via regulation of ERK1/2 MAP kinase and early growth response-1. These data highlight novel roles for PKCbeta in the SMC response to acute arterial injury and suggest that blockade of PKCbeta may represent a therapeutic strategy to limit restenosis
  150. Barile, Gaetano R; Pachydaki, Sophia I; Tari, Samir R; Lee, Song E; Donmoyer, Christine M; Ma, Wanchao; Rong, Ling Ling; Buciarelli, Loredana G; Wendt, Thoralf; Horig, Heidi; Hudson, Barry I; Qu, Wu; Weinberg, Alan D; Yan, Shi Fang; Schmidt, Ann Marie. "The RAGE axis in early diabetic retinopathy". Investigative ophthalmology & visual science. IOVS. 2005 Aug;46(8):2916-2924 (MEDL:16043866 #140601)       

    PURPOSE: The receptor for advanced glycation end products (AGEs) has been implicated in the pathogenesis of diabetic complications. This study was conducted to characterize the role of the RAGE axis in a murine model of nonproliferative diabetic retinopathy (NPDR). METHODS: The retinas of hyperglycemic, hyperlipidemic (HGHL, apolipoprotein E(-/-) db/db) mice were examined for the development of early retinal vascular lesions of NPDR and compared to littermates at 6 months of age. Neural function was assessed with electroretinography. Immunohistochemistry, real-time RT-PCR, autofluorescence, and ELISA studies were used to localize and quantify the AGE/RAGE axis. Soluble RAGE, a competitor of cellular RAGE for its ligands, was administered to assess the impact of RAGE blockade. RESULTS: Early inner retinal neuronal dysfunction, manifested by prolonged latencies of the oscillatory potentials and b-wave, was detected in hyperglycemic mice. HGHL mice exhibited accelerated development of acellular capillaries and pericyte ghosts compared with littermate control animals. AGEs were localized primarily to the vitreous cavity and internal limiting membrane (ILM) of the retina, where they were intimately associated with the footplates of RAGE-expressing Muller cells. AGE accumulation measured by ELISA was increased within the retinal extracellular matrix of hyperglycemic mice. AGE fluorescence and upregulation of RAGE transcripts was highest in the retinas of HGHL mice, and attenuation of the RAGE axis with soluble RAGE ameliorated neuronal dysfunction and reduced the development of capillary lesions in these mice. CONCLUSIONS: In early diabetic retinopathy, the RAGE axis, comprising the cellular receptor and its AGE ligands, is amplified within the retina and is accentuated along the vitreoretinal interface. Antagonism of the RAGE axis in NPDR reduces neurovascular perturbations, providing an important therapeutic target for intervention
  151. Basta, Giuseppina; Lazzerini, Guido; Del Turco, Serena; Ratto, Gian Michele; Schmidt, Ann Marie; De Caterina, Raffaele. "At least 2 distinct pathways generating reactive oxygen species mediate vascular cell adhesion molecule-1 induction by advanced glycation end products". Arteriosclerosis, thrombosis, & vascular biology. 2005 Jul;25(7):1401-1407 (MEDL:15845907 #779332)       

    OBJECTIVE: The interaction of advanced glycation end products (AGEs) with their main receptor RAGE in endothelial cells induces intracellular generation of reactive oxygen species (ROS) and the expression of vascular cell adhesion molecule (VCAM)-1. We investigated the role of distinct sources of ROS, including the mitochondrial electron transport chain, NAD(P)H oxidase, xanthine oxidase, and arachidonic acid metabolism, in AGE-induced VCAM-1 expression. METHODS AND RESULTS: The induction of ROS and VCAM-1 by AGEs in cultured human umbilical vein endothelial cells was specifically blocked by an anti-RAGE antibody. The inhibition of NAD(P)H oxidase by apocynin and diphenylene iodonium, and of the mitochondrial electron transport system at complex II by thenoyltrifluoroacetone (TTFA), significantly inhibited both AGE-induced ROS production and VCAM-1 expression, whereas these effects were potentiated by rotenone and antimycin A, specific inhibitors of mitochondrial complex I and III, respectively. The inhibition of Cu/Zn superoxide dismutase inhibited both ROS and VCAM-1 induction, indicating that H2O2 by this source is involved as a mediator of VCAM-1 expression by AGEs. CONCLUSIONS: Altogether, these results demonstrate that ROS generated by both NAD(P)H-oxidase and the mitochondrial electron transport system are involved in AGE signaling through RAGE, and indicate potential targets for the inhibition of the atherogenic signals triggered by AGE-RAGE interaction.
  152. Cataldegirmen, Guellue; Zeng, Shan; Feirt, Nikki; Ippagunta, Nikalesh; Dun, Hao; Qu, Wu; Lu, Yan; Rong, Ling Ling; Hofmann, Marion A; Kislinger, Thomas; Pachydaki, Sophia I; Jenkins, Daniel G; Weinberg, Alan; Lefkowitch, Jay; Rogiers, Xavier; Yan, Shi Fang; Schmidt, Ann Marie; Emond, Jean C. "RAGE limits regeneration after massive liver injury by coordinated suppression of TNF-alpha and NF-kappaB". Journal of experimental medicine. 2005 Feb 7;201(3):473-484 (MEDL:15699076 #140603)       

    The exquisite ability of the liver to regenerate is finite. Identification of mechanisms that limit regeneration after massive injury holds the key to expanding the limits of liver transplantation and salvaging livers and hosts overwhelmed by carcinoma and toxic insults. Receptor for advanced glycation endproducts (RAGE) is up-regulated in liver remnants selectively after massive (85%) versus partial (70%) hepatectomy, principally in mononuclear phagocyte-derived dendritic cells (MPDDCs). Blockade of RAGE, using pharmacological antagonists or transgenic mice in which a signaling-deficient RAGE mutant is expressed in cells of mononuclear phagocyte lineage, significantly increases survival after massive liver resection. In the first hours after massive resection, remnants retrieved from RAGE-blocked mice displayed increased activated NF-kappaB, principally in hepatocytes, and enhanced expression of regeneration-promoting cytokines, TNF-alpha and IL-6, and the antiinflammatory cytokine, IL-10. Hepatocyte proliferation was increased by RAGE blockade, in parallel with significantly reduced apoptosis. These data highlight central roles for RAGE and MPDDCs in modulation of cell death-promoting mechanisms in massive hepatectomy and suggest that RAGE blockade is a novel strategy to promote regeneration in the massively injured liver
  153. Cecil, Denise L; Johnson, Kristen; Rediske, John; Lotz, Martin; Schmidt, Ann Marie; Terkeltaub, Robert. "Inflammation-induced chondrocyte hypertrophy is driven by receptor for advanced glycation end products". Journal of immunology. 2005 Dec;175(12):8296-8302 (MEDL:16339570 #779302)    

    The multiligand receptor for advanced glycation end products (RAGE) mediates certain chronic vascular and neurologic degenerative diseases accompanied by low-grade inflammation. RAGE ligands include S100/calgranulins, a class of low-molecular-mass, calcium-binding polypeptides, several of which are chondrocyte expressed. Here, we tested the hypothesis that S100A11 and RAGE signaling modulate osteoarthritis (OA) pathogenesis by regulating a shift in chondrocyte differentiation to hypertrophy. We analyzed human cartilages and cultured human articular chondrocytes, and used recombinant human S100A11, soluble RAGE, and previously characterized RAGE-specific blocking Abs. Normal human knee cartilages demonstrated constitutive RAGE and S100A11 expression, and RAGE and S100A11 expression were up-regulated in OA cartilages studied by immunohistochemistry. CXCL8 and TNF-alpha induced S100A11 expression and release in cultured chondrocytes. Moreover, S100A11 induced cell size increase and expression of type X collagen consistent with chondrocyte hypertrophy in vitro. CXCL8-induced, IL-8-induced, and TNF-alpha-induced but not retinoic acid-induced chondrocyte hypertrophy were suppressed by treatment with soluble RAGE or RAGE-specific blocking Abs. Last, via transfection of dominant-negative RAGE and dominant-negative MAPK kinase 3, we demonstrated that S100A11-induced chondrocyte type X collagen expression was dependent on RAGE-mediated p38 MAPK pathway activation. We conclude that up-regulated chondrocyte expression of the RAGE ligand S100A11 in OA cartilage, and RAGE signaling through the p38 MAPK pathway, promote inflammation-associated chondrocyte hypertrophy. RAGE signaling thereby has the potential to contribute to the progression of OA.
  154. Chaney, Michael O; Stine, W Blaine; Kokjohn, Tyler A; Kuo, Yu-Min; Esh, Chera; Rahman, Afroza; Luehrs, Dean C; Schmidt, Ann Marie; Stern, David; Yan, Shi Du; Roher, Alex E. "RAGE and amyloid beta interactions: atomic force microscopy and molecular modeling". Biochimica & biophysica acta. 2005 Jun 30;1741(1-2):199-205 (MEDL:15882940 #140644)       

    In the AD brain, there are elevated amounts of soluble and insoluble Abeta peptides which enhance the expression of membrane bound and soluble receptor for advanced glycation end products (RAGE). The binding of soluble Abeta to soluble RAGE inhibits further aggregation of Abeta peptides, while membrane bound RAGE-Abeta interactions elicit activation of the NF-kappaB transcription factor promoting sustained chronic neuroinflammation. Atomic force microscopy observations demonstrated that the N-terminal domain of RAGE, by interacting with Abeta, is a powerful inhibitor of Abeta polymerization even at prolonged periods of incubation. Hence, the potential RAGE-Abeta structural interactions were further explored utilizing a series of computational chemistry algorithms. Our modeling suggests that a soluble dimeric RAGE assembly creates a positively charged well into which the negative charges of the N-terminal domain of dimeric Abeta dock
  155. Feng, Lei; Matsumoto, Carolyn; Schwartz, Allan; Schmidt, Ann Marie; Stern, David M; Pile-Spellman, John. "Chronic vascular inflammation in patients with type 2 diabetes: endothelial biopsy and RT-PCR analysis". Diabetes care. 2005 Feb;28(2):379-384 (MEDL:15677796 #779362)       

    OBJECTIVE: Chronic vascular inflammation may play a role in the development of macrovascular complications in diabetic patients. In this study, we examine the association of endothelial expression of two inflammatory mediators, receptor for advanced glycation end product (RAGE) and monocyte chemoattractant protein-1 (MCP-1), with type 2 diabetes using novel endothelial biopsy and RT-PCR techniques. RESEARCH DESIGN AND METHODS: Endothelial samples are obtained from the aorta of 12 patients with type 2 diabetes and 23 control subjects who underwent cardiac catheterization for chest pain syndrome or heart transplant follow-up. Endothelial cells are purified using magnetic beads with adsorbed CD146 antibody and subjected to RT-PCR analysis of RAGE and MCP-1 transcripts. The association of RAGE and MCP-1 expression with type 2 diabetes is assessed with chi(2) test and confirmed with in vitro experiments on human aorta endothelial cells. RESULTS: RT-PCR reveals gene expression patterns in patient-derived endothelial cells. Strong associations are observed between induction of RAGE mRNA and diabetes (P < 0.01) and between induction of RAGE and MCP-1 transcripts (P < 0.05). Treatment of cultured human aortic endothelial cells with S100b induces the expression of MCP-1 and RAGE transcripts. CONCLUSIONS: Endothelial cells can be harvested during cardiac catheterization and can be characterized with respect to molecular phenotypes under the influence of both genetic and environmental factors. Induction of RAGE and MCP-1 transcripts in patients with diabetes supports a role of chronic vascular inflammation in macrovascular complications.
  156. Hofmann, Marion A; Yang, Qiong; Harja, Evis; Kedia, Prashant; Gregersen, Peter K; Cupples, L Adrienne; Schmidt, Ann Marie; Hudson, Barry I. "The RAGE Gly82Ser polymorphism is not associated with cardiovascular disease in the Framingham offspring study". Atherosclerosis. 2005 Oct;182(2):301-305 (MEDL:16159602 #93133)       

    The receptor for advanced glycation end-products (RAGE) is expressed to enhance degrees in human atherosclerotic plaques and co-localizes with inflammatory and pro-oxidant mediators in the vulnerable regions of the plaque. Previous studies highlighted a number of variants in the gene encoding the receptor, including a Gly to Ser substitution at amino acid 82 within the ligand-binding domain of RAGE. The Ser82 allele enhanced ligand-binding affinity and increased ligand-stimulated generation of inflammatory mediators in transfected cells and human monocytes compared to the common RAGE Gly82 allele. Thus it was logical to test the hypothesis that increased prevalence of the Gly82Ser polymorphism was associated with cardiovascular events in the Framingham offspring study (n=1632). Our analyses revealed that the Gly82Ser RAGE polymorphism did not demonstrate any association with the incidence of cardiovascular disease in diabetic or non-diabetic subjects (Gly82 96%, Ser82 4%). Analysis of specific manifestations of cardiovascular disease, including coronary heart disease (CHD), cardiovascular disease (CVD), myocardial infarction (MI) and ischemic disease (ISD) revealed no association with RAGE genotype. Further studies are required on other more prevalent genetic variants of RAGE and cardiovascular disease
  157. Hudson, Barry I; Harja, Evis; Moser, Bernhard; Schmidt, Ann Marie. "Soluble levels of receptor for advanced glycation endproducts (sRAGE) and coronary artery disease: the next C-reactive protein? [Comment]". Arteriosclerosis, thrombosis, & vascular biology. 2005 May;25(5):879-882 (MEDL:15863717 #779342)       
  158. Hudson, Barry I; Wendt, Thoralf; Bucciarelli, Loredana G; Rong, Ling Ling; Naka, Yoshifumi; Yan, Shi Fang; Schmidt, Ann Marie. "Diabetic vascular disease: it's all the RAGE". Antioxidants & Redox Signaling. 2005 Nov-Dec;7(11-12):1588-1600 (MEDL:16356122 #140600)       

    The major consequence of long-term diabetes is the increased incidence of disease of the vasculature. Of the underlying mechanisms leading to disease, the accumulation of advanced glycation end products (AGEs), resulting from the associated hyperglycemia, is the most convincing. Interaction of AGEs with their receptor, RAGE, activates numerous signaling pathways leading to activation of proinflammatory and procoagulatory genes. Studies in rodent models of macro- and microvascular disease have demonstrated that blockade of RAGE can prevent development of disease. These observations highlight RAGE as a therapeutic target for treatment of diabetic vascular disease
  159. Kaneko, Michiyo; Bucciarelli, Loredana; Hwang, Yuying C; Lee, Larisee; Yan, Shi Fang; Schmidt, Ann Marie; Ramasamy, Ravichandran. "Aldose reductase and AGE-RAGE pathways: key players in myocardial ischemic injury". Annals of the New York Academy of Sciences. 2005 Jun;1043:702-709 (MEDL:16037296 #130802)       

    Cardiovascular disease represents the major cause of morbidity and mortality in patients with diabetes mellitus. The impact of cardiac disease includes increased sensitivity of diabetic myocardium to ischemic episodes and diabetic cardiomyopathy, manifested as a subnormal functional response of the diabetic heart independent of coronary artery disease. In this context, we were to our knowledge the first to demonstrate that diabetes increases glucose flux via the first and key enzyme, aldose reductase, of the polyol pathway, resulting in impaired glycolysis under normoxic and ischemic conditions in diabetic myocardium. Our laboratory has been investigating the role of the polyol pathway in mediating myocardial ischemic injury in diabetics. Furthermore, the influence of the aldose reductase pathway in facilitating generation of key potent glycating compounds has led us to investigate the impact of advanced glycation end products (AGEs) in myocardial ischemic injury in diabetics. The potent impact of increased flux via the aldose reductase pathway and the increased AGE interactions with its receptor (RAGE) resulting in cardiac dysfunction will be discussed in this chapter
  160. Kim, William; Hudson, Barry I; Moser, Bernhard; Guo, Jiancheng; Rong, Ling Ling; Lu, Yan; Qu, Wu; Lalla, Evanthia; Lerner, Shulamit; Chen, Yali; Yan, Shirley Shi Du; D'Agati, Vivette; Naka, Yoshifumi; Ramasamy, Ravichandran; Herold, Kevan; Yan, Shi Fang; Schmidt, Ann Marie. "Receptor for advanced glycation end products and its ligands: a journey from the complications of diabetes to its pathogenesis". Annals of the New York Academy of Sciences. 2005 Jun;1043:553-561 (MEDL:16037278 #130833)       

    Many studies have suggested that the expression of RAGE (receptor for advanced glycation end products) is upregulated in human tissues susceptible to the long-term complications of diabetes. From the kidneys to the macrovessels of the aorta, RAGE expression is upregulated in a diverse array of cell types, from glomerular epithelial cells (podocytes) to endothelial cells, vascular smooth muscle cells, and inflammatory mononuclear phagocytes and lymphocytes. Although RAGE was first described as a receptor for advanced glycation end products (AGEs), the key finding that RAGE was also a signaling receptor for proinflammatory S100/calgranulins and amphoterin, led to the premise that even in euglycemia, ligand-RAGE interaction propagated inflammatory mechanisms linked to chronic cellular perturbation and tissue injury. Indeed, such considerations suggested that RAGE might even participate in the pathogenesis of type 1 diabetes. Our studies have shown that pharmacological and/or genetic deletion/mutation of the receptor attenuates the development of hyperglycemia in NOD mice; in mice with myriad complications of diabetes, interruption of ligand-RAGE interaction prevents or delays the chronic complications of the disease in both macro- and microvessel structures. Taken together, these findings suggest that RAGE is 'at the right place and time' to contribute to the pathogenesis of diabetes and it complications. Studies are in progress to test the premise that antagonism of this interaction is a logical strategy for the prevention and treatment of diabetes
  161. Klein, Ophir D; Cotter, Philip D; Schmidt, Ann M; Bick, David P; Tidyman, William E; Albertson, Donna G; Pinkel, Daniel; Rauen, Katherine A. "Interstitial deletion of chromosome 12q: genotype-phenotype correlation of two patients utilizing array comparative genomic hybridization [Case Report]". American journal of medical genetics. Pt A. 2005 Nov;138(4):349-354 (MEDL:16200635 #372792)       

    Interstitial deletions of chromosome 12q are rare, with only 11 reported cases in the literature. We recently described two cases with cytogenetically identical interstitial deletions of the long arm of chromosome 12. Here, we report on a third patient, a 26-month-old male with a cytogenetically-identical interstitial deletion: 46,XY,del(12)(q21.2q22). Phenotypic features of this male proband included craniofacial and ectodermal anomalies, genitourinary anomalies, minor cardiac abnormalities, mild ventriculomegaly on brain MRI, hyperopia, and developmental delay. To further define the extent of the chromosomal aberration, microarray-based comparative genomic hybridization (array CGH) analysis was performed and the array data was compared to one of our previously reported cases. Although cytogenetic analysis of the two patients was concordant, molecular analysis by array CGH revealed that the patients had discordant distal breakpoints. The determination of molecular breakpoints and phenotypic analyses in these two patients, in conjunction with previously reported cases, leads us to propose a 12q deletion phenotype and a possible genetic locus for hyperkeratosis pilaris/ulerythema ophryogenes.
  162. Lawrie, Allan; Spiekerkoetter, Edda; Martinez, Eliana C; Ambartsumian, Noona; Sheward, W John; MacLean, Margaret R; Harmar, Anthony J; Schmidt, Ann-Marie; Lukanidin, Eugene; Rabinovitch, Marlene. "Interdependent serotonin transporter and receptor pathways regulate S100A4/Mts1, a gene associated with pulmonary vascular disease". Circulation research. 2005 Aug;97(3):227-235 (MEDL:16002749 #779322)       

    Heightened expression of the S100 calcium-binding protein, S100A4/Mts1, is observed in pulmonary vascular disease. Loss of serotonin (5-hydroxytryptamine [5-HT]) receptors or of the serotonin transporter (SERT) attenuates pulmonary hypertension in animals, and polymorphisms causing gain of SERT function are linked to clinical pulmonary vascular disease. Because 5-HT induces release of S100beta, we investigated the codependence of 5-HT receptors and SERT in regulating S100A4/Mts1 in human pulmonary artery smooth muscle cells (hPA-SMC). 5-HT elevated S100A4/Mts1 mRNA levels and increased S100A4/Mts1 protein in hPA-SMC lysates and culture media. S100A4/Mts1 in the culture media stimulated proliferation and migration of hPA-SMC in a manner dependent on the receptor for advanced glycation end products. Treatment with SB224289 (selective antagonist of 5-HT1B), fluoxetine (SERT inhibitor), SERT RNA-interference, and iproniazid (monoamine oxidase-A inhibitor), blocked 5-HT-induced S100A4/Mts1. 5-HT signaling mediated phosphorylation (p) of extracellular signal-regulated kinase 1/2 (pERK1/2), but pERK1/2 nuclear translocation depended on SERT, monoamine oxidase activity, and reactive oxygen species. Nuclear translocation of pERK1/2 was required for pGATA-4-mediated transcription of S100A4/Mts1. These data provide evidence for a mechanistic link between the 5-HT pathway and S100A4/Mts1 in pulmonary hypertension and explain how the 5-HT1B receptor and SERT are codependent in regulating S100A4/Mts1.
  163. Moser, Bernhard; Hudson, Barry I; Schmidt, Ann Marie. "Soluble RAGE: a hot new biomarker for the hot joint? [Comment]". Arthritis research & therapy. 2005;7(4):142-144 (MEDL:15987496 #779372)       

    The receptor for advanced glycation endproducts (RAGE) interacts with distinct ligand families linked to the inflammatory response. Studies in animal models suggest that RAGE is upregulated in the inflamed joint and that blockade of the receptor, using a ligand decoy soluble form of RAGE (sRAGE), attenuates joint inflammation and expression of inflammatory and tissue-destructive mediators. In this issue of Arthritis Research & Therapy, Rille Pullerits and colleagues reported that plasma levels of sRAGE were reduced in subjects with rheumatoid arthritis compared with healthy controls or subjects with non-inflammatory joint disease. These findings suggest the possibility that levels of sRAGE might be a biomarker of inflammation. Not resolved by these studies, however, is the intriguing possibility that endogenously higher levels of sRAGE might be linked to a lower incidence of arthritis or to the extent of inflammation. Nevertheless, although 'cause or effect' relationships may not be established in this report, fascinating insights into RAGE, inflammation and human arthritis emerge from these studies.
  164. Ramasamy, Ravichandran; Vannucci, Susan J; Yan, Shirley Shi Du; Herold, Kevan; Yan, Shi Fang; Schmidt, Ann Marie. "Advanced glycation end products and RAGE: a common thread in aging, diabetes, neurodegeneration, and inflammation". Glycobiology. 2005 Jul;15(7):16R-28R (MEDL:15764591 #130832)       

    The products of nonenzymatic glycation and oxidation of proteins and lipids, the advanced glycation end products (AGEs), accumulate in a wide variety of environments. AGEs may be generated rapidly or over long times stimulated by a range of distinct triggering mechanisms, thereby accounting for their roles in multiple settings and disease states. A critical property of AGEs is their ability to activate receptor for advanced glycation end products (RAGE), a signal transduction receptor of the immunoglobulin superfamily. It is our hypothesis that due to such interaction, AGEs impart a potent impact in tissues, stimulating processes linked to inflammation and its consequences. We hypothesize that AGEs cause perturbation in a diverse group of diseases, such as diabetes, inflammation, neurodegeneration, and aging. Thus, we propose that targeting this pathway may represent a logical step in the prevention/treatment of the sequelae of these disorders
  165. Ramasamy, Ravichandran; Yan, Shi Fang; Schmidt, Ann Marie. "The RAGE axis and endothelial dysfunction: maladaptive roles in the diabetic vasculature and beyond". Trends in cardiovascular medicine. 2005 Oct;15(7):237-243 (MEDL:16226677 #130831)       

    Receptor for advanced glycation end product (RAGE) is a member of the immunoglobulin superfamily of cell surface molecules. The ligand-RAGE axis is emerging as a central mechanism linked to vascular injury and atherosclerosis in diabetes and in euglycemia. The repertoire of RAGE ligands, including advanced glycation end products, S100/calgranulins, high-mobility group box 1, amyloid-beta peptide, and Mac-1, transcends RAGE biology from specifically the science of diabetic complications to central aspects of the inflammatory response and oxidative stress. Experiments in cell culture and in vivo support the notion that interaction of RAGE ligands with RAGE activates key signal transduction pathways that modulate fundamental cellular properties, thereby leading to vascular and inflammatory cell perturbation. These considerations support the premise that the ligand-RAGE axis may be an important target for therapeutic intervention in cardiovascular disease and, fundamentally, in initiation and amplification of inflammatory responses
  166. Rong, Ling Ling; Gooch, Clifton; Szabolcs, Mattias; Herold, Kevan C; Lalla, Evanthia; Hays, Arthur P; Yan, Shi Fang; Yan, Shirley Shi Du; Schmidt, Ann Marie. "RAGE: a journey from the complications of diabetes to disorders of the nervous system - striking a fine balance between injury and repair". Restorative neurology & neuroscience. 2005;23(5-6):355-365 (MEDL:16477098 #140604)    

    The Receptor for Advanced Glycation End Products (RAGE) is a multiligand member of the immunoglobulin superfamily. RAGE interacts with AGEs, the products of nonenzymatic glycation/oxidation of proteins and lipids that accumulate in diverse settings, such as diabetes, inflammation, renal failure, pro-oxidant states and natural aging. In addition, RAGE is also a receptor for amyloid-beta peptide and beta-sheet fibril species. Recent studies underscore the premise that RAGE interacts with pro-inflammatory molecules, including S100/calgranulins and amphoterin, the latter also known as high mobility group box 1 (HMGB1). In chronic neurodegenerative disorders as well as in nerve tissue upon acute injury, evidence points to upregulation of both RAGE and these ligand families. In this review, we will discuss the implications of transient/self-limited upregulation of RAGE and its ligands, vs sustained/chronic upregulation of this axis in neurodegeneration vs repair in both the central and peripheral nervous systems. Experimental evidence supports the premise that RAGE bears both homeostatic and injurious properties in the nervous system, thereby highlighting 'yin/yang' features of this receptor and its ligand families
  167. Sakaguchi, Taichi; Asai, Tomohiro; Belov, Dmitri; Okada, Morihito; Pinsky, David J; Schmidt, Ann Marie; Naka, Yoshifumi. "Influence of ischemic injury on vein graft remodeling: role of cyclic adenosine monophosphate second messenger pathway in enhanced vein graft preservation". Journal of thoracic & cardiovascular surgery. 2005 Jan;129(1):129-137 (MEDL:15632834 #779382)       

    OBJECTIVE: Endothelial injury during the harvest of saphenous vein grafts might play an important role in the development of vein graft disease after coronary artery bypass grafting. Using a murine autologous arterialized vein patch model, we tested whether the initial ischemic insult of vein grafts was linked to the later development of graft neointimal hyperplasia and whether the restoration of the cyclic adenosine monophosphate second messenger pathway would attenuate the development of neointimal hyperplasia. METHODS: A segment of the external jugular vein of a mouse was grafted onto its abdominal aorta. Three weeks after the operation, the degree of neointimal hyperplasia of the implanted graft was compared among (1) grafts without preservation, (2) grafts with 2 hours of preservation (25 degrees C) in heparinized saline, and (3) grafts with 2 hours of preservation in heparinized saline in the presence of a cyclic adenosine monophosphate analog. In addition, cyclic adenosine monophosphate contents of vein grafts and leukocyte adherence to the graft endothelium were assessed. RESULTS: Cyclic adenosine monophosphate contents were significantly decreased after 2 hours of preservation (212 +/- 8 vs 156 +/- 5 pmol/L, P < .01). The grafts preserved for 2 hours showed greater neointimal hyperplasia compared with the grafts without preservation (neointimal expansion, 68.7% +/- 9.6% vs 46.1% +/- 4.8%; P < .01). The addition of a cyclic adenosine monophosphate analog to the preservation solution significantly suppressed neointimal hyperplasia of grafts preserved for 2 hours (44.3% +/- 5.0%). Inhibiting the cyclic adenosine monophosphate-dependent protein kinase by adding Rp-cAMPS abrogated the beneficial effects. Furthermore, grafts preserved for 2 hours had significantly more leukocytes adhering to the graft endothelium 24 hours after the operation compared with nonpreserved grafts, which was significantly reduced by the cyclic adenosine monophosphate treatment. CONCLUSIONS: Ischemic insult during vein graft harvest and preservation is a key factor in the development of vein graft neointimal hyperplasia at least in part caused by the depletion of cyclic adenosine monophosphate. We conclude that stimulation of the cyclic adenosine monophosphate second messenger pathway might be a potential strategy for the prevention of vein graft disease.
  168. Spiekerkoetter, Edda; Lawrie, Allan; Merklinger, Sandra; Ambartsumian, Noona; Lukanidin, Eugene; Schmidt, Ann-Marie; Rabinovitch, Marlene. "Mts1/S100A4 stimulates human pulmonary artery smooth muscle cell migration through multiple signaling pathways". Chest. 2005 Dec;128(6 Suppl):577S-577S (577S) (MEDL:16373840 #779312)       
  169. Zhou, Jilin; Cai, Bolin; Jang, Young P; Pachydaki, Sophia; Schmidt, Ann Marie; Sparrow, Janet R. "Mechanisms for the induction of HNE- MDA- and AGE-adducts, RAGE and VEGF in retinal pigment epithelial cells". Experimental eye research. 2005 Apr;80(4):567-580 (MEDL:15781285 #779352)       

    Pathological features of age-related macular degeneration such as the formation of extracellular deposits and neovascularization are frequently viewed as outcomes of compromising processes within retinal pigment epithelial cells, but the initiating circumstances are poorly understood. Here we tested the hypothesis that photooxidation events initiated by A2E, a blue light-excitable aging fluorophore of the retinal pigment epithelium, can set the stage for altered cellular signaling and changes in the expression of genes that can impact the extracellular milieu. Proteins modified by lipid peroxidation products (4-hydroxynonenal; malondialdhyde) and advanced glycation end products were detected at sites of blue light irradiation both in association with the cultured A2E-laden retinal pigment epithelial cells and within the fibronectin substrate on which the cells were grown. RAGE, the cell surface receptor that transduces the effects of advanced glycation end products, was also upregulated, and RAGE expression co-localized with the deposition of advanced glycation end products. Blue light triggered alterations in gene expression was also evidenced by elevations in both transcripts and protein for vascular endothelial growth factor, a potent angiogenic and permeability-enhancing factor. These findings indicate that cell associated and extracellular modification of proteins by lipid peroxidation products and advanced glycation end products together with increased expression of RAGE and vascular endothelial growth factor may be induced consequent to blue light illumination of A2E-burdened retinal pigment epithelial cells. Thus, photooxidative events that are not an immediate threat to retinal pigment epithelial cell viability may nevertheless elicit sustained perturbation that could ultimately alter neighboring tissues and impact retinal pigment epithelial cell function.
  170. Arancio, Ottavio; Zhang, Hui Ping; Chen, Xi; Lin, Chang; Trinchese, Fabrizio; Puzzo, Daniela; Liu, Shumin; Hegde, Ashok; Yan, Shi Fang; Stern, Alan; Luddy, John S; Lue, Lih-Fen; Walker, Douglas G; Roher, Alex; Buttini, Manuel; Mucke, Lennart; Li, Weiying; Schmidt, Ann Marie; Kindy, Mark; Hyslop, Paul A; Stern, David M; Du Yan, Shirley Shi. "RAGE potentiates Abeta-induced perturbation of neuronal function in transgenic mice". EMBO journal. 2004 Oct 13;23(20):4096-4105 (MEDL:15457210 #47799)       

    Receptor for Advanced Glycation Endproducts (RAGE), a multiligand receptor in the immunoglobulin superfamily, functions as a signal-transducing cell surface acceptor for amyloid-beta peptide (Abeta). In view of increased neuronal expression of RAGE in Alzheimer's disease, a murine model was developed to assess the impact of RAGE in an Abeta-rich environment, employing transgenics (Tgs) with targeted neuronal overexpression of RAGE and mutant amyloid precursor protein (APP). Double Tgs (mutant APP (mAPP)/RAGE) displayed early abnormalities in spatial learning/memory, accompanied by altered activation of markers of synaptic plasticity and exaggerated neuropathologic findings, before such changes were found in mAPP mice. In contrast, Tg mice bearing a dominant-negative RAGE construct targeted to neurons crossed with mAPP animals displayed preservation of spatial learning/memory and diminished neuropathologic changes. These data indicate that RAGE is a cofactor for Abeta-induced neuronal perturbation in a model of Alzheimer's-type pathology, and suggest its potential as a therapeutic target to ameliorate cellular dysfunction
  171. Arumugam, Thiruvengadam; Simeone, Diane M; Schmidt, Ann Marie; Logsdon, Craig D. "S100P stimulates cell proliferation and survival via receptor for activated glycation end products (RAGE)". Journal of biological chemistry. 2004 Feb;279(7):5059-5065 (MEDL:14617629 #779462)       

    S100P is a member of the S100 protein family that is expressed in several malignant neoplasms. Currently the effects of this molecule on cell function are unknown. In the present study we investigated the biological effects and mechanisms of action of S100P using NIH3T3 cells. Expression of S100P in NIH3T3 cells led to the presence of S100P in the culture medium, increased cellular proliferation, and enhanced survival after detachment from the culture substrate or after exposure to the chemotherapeutic agent 5-flurouracil. The proliferation and survival effects of S100P expression were duplicated in a time- and concentration-dependent manner by the extracellular addition of purified S100P to wild-type NIH3T3 cells and correlated with the activation of extracellular-regulated kinases (Erks) and NF-kappaB. To determine the mechanisms involved in these effects, we tested the hypothesis that S100P activated RAGE (receptor for activated glycation end products). We found that S100P co-immunoprecipitated with RAGE. Furthermore, the effects of S100P on cell signaling, proliferation, and survival were blocked by agents that interfere with RAGE including administration of an amphoterin-derived peptide known to antagonize RAGE activation, anti-RAGE antibodies, and by expression of a dominant negative RAGE. These data suggest that S100P can act in an autocrine manner via RAGE to stimulate cell proliferation and survival.
  172. Basta, Giuseppina; Schmidt, Ann Marie; De Caterina, Raffaele. "Advanced glycation end products and vascular inflammation: implications for accelerated atherosclerosis in diabetes". Cardiovascular research. 2004 Sep;63(4):582-592 (MEDL:15306213 #779422)       

    The formation of advanced glycation end products (AGEs) is an important biochemical abnormality that accompanies diabetes mellitus and, likely, inflammation in general. Here we summarize and discuss recent studies indicating that the effects of AGEs on vessel wall homeostasis may account for the rapidly progressive atherosclerosis associated with diabetes mellitus. Driven by hyperglycemia and oxidant stress, AGEs form to a greatly accelerated degree in diabetes. Within the vessel wall, collagen-linked AGEs may "trap" plasma proteins, quench nitric oxide (NO) activity and interact with specific receptors to modulate a large number of cellular properties. On plasma low density lipoproteins (LDL), AGEs initiate oxidative reactions that promote the formation of oxidized LDL. Interaction of AGEs with endothelial cells as well as with other cells accumulating within the atherosclerotic plaque, such as mononuclear phagocytes and smooth muscle cells (SMCs), provides a mechanism to augment vascular dysfunction. Specifically, the interaction of AGEs with vessel wall components increases vascular permeability, the expression of procoagulant activity and the generation of reactive oxygen species (ROS), resulting in increased endothelial expression of endothelial leukocyte adhesion molecules. AGEs potently modulate initiating steps in atherogenesis involving blood-vessel wall interactions, triggering an inflammatory-proliferative process and, furthermore, critically contribute to propagation of inflammation and vascular perturbation in established disease. Thus, a better understanding of the biochemical mechanisms by which AGEs contribute to such processes in the vessel wall could be relevant to devise preventive and therapeutic strategies for diabetic atherosclerosis.
  173. Bierhaus, Angelika; Haslbeck, Karl-Matthias; Humpert, Per M; Liliensiek, Birgit; Dehmer, Thomas; Morcos, Michael; Sayed, Ahmed A R; Andrassy, Martin; Schiekofer, Stephan; Schneider, Jochen G; Schulz, Jorg B; Heuss, Dieter; Neundorfer, Bernhard; Dierl, Stefan; Huber, Jochen; Tritschler, Hans; Schmidt, Ann-Marie; Schwaninger, Markus; Haering, Hans-Ulrich; Schleicher, Erwin; Kasper, Michael; Stern, David M; Arnold, Bernd; Nawroth, Peter P. "Loss of pain perception in diabetes is dependent on a receptor of the immunoglobulin superfamily". Journal of clinical investigation. 2004 Dec;114(12):1741-1751 (MEDL:15599399 #779412)       

    Molecular events that result in loss of pain perception are poorly understood in diabetic neuropathy. Our results show that the receptor for advanced glycation end products (RAGE), a receptor associated with sustained NF-kappaB activation in the diabetic microenvironment, has a central role in sensory neuronal dysfunction. In sural nerve biopsies, ligands of RAGE, the receptor itself, activated NF-kappaBp65, and IL-6 colocalized in the microvasculature of patients with diabetic neuropathy. Activation of NF-kappaB and NF-kappaB-dependent gene expression was upregulated in peripheral nerves of diabetic mice, induced by advanced glycation end products, and prevented by RAGE blockade. NF-kappaB activation was blunted in RAGE-null (RAGE(-/-)) mice compared with robust enhancement in strain-matched controls, even 6 months after diabetes induction. Loss of pain perception, indicative of long-standing diabetic neuropathy, was reversed in WT mice treated with soluble RAGE. Most importantly, loss of pain perception was largely prevented in RAGE(-/-) mice, although they were not protected from diabetes-induced loss of PGP9.5-positive plantar nerve fibers. These data demonstrate, for the first time to our knowledge, that the RAGE-NF-kappaB axis operates in diabetic neuropathy, by mediating functional sensory deficits, and that its inhibition may provide new therapeutic approaches.
  174. Chen, Yali; Yan, Shirley ShiDu; Colgan, John; Zhang, Hui-Ping; Luban, Jeremy; Schmidt, Ann Marie; Stern, David; Herold, Kevan C. "Blockade of late stages of autoimmune diabetes by inhibition of the receptor for advanced glycation end products". Journal of immunology. 2004 Jul 15;173(2):1399-1405 (MEDL:15240736 #140643)    

    Ligation of the receptor for advanced glycation end products (RAGE) occurs during inflammation. Engagement of RAGE results in enhanced expression of addressins and it is therefore, not surprising that previous studies have shown a role of RAGE/ligand interactions in immune responses including cell/cell contact but the role of RAGE in spontaneous autoimmunity has not been clearly defined. To study the role of RAGE/ligand interactions in autoimmune diabetes, we tested the ability of soluble RAGE, a scavenger of RAGE ligands, in late stages of diabetes development in the NOD mouse-disease transferred with diabetogenic T cells and recurrent disease in NOD/scid recipients of syngeneic islet transplants. RAGE expression was detected on CD4(+), CD8(+), and B cells from diabetic mice and transferred to NOD/scid recipients. RAGE and its ligand, S100B, were found in the islets of NOD/scid mice that developed diabetes. Treatment of recipient NOD/scid mice with soluble RAGE prevented transfer of diabetes and delayed recurrent disease in syngeneic islet transplants. RAGE blockade was associated with increased expression of IL-10 and TGF-beta in the islets from protected mice. RAGE blockade reduced the transfer of disease with enriched T cells, but had no effect when diabetes was transferred with the activated CD4(+) T cell clone, BDC2.5. We conclude that RAGE/ligand interactions are involved in the differentiation of T cells to a mature pathogenic phenotype during the late stages of the development of diabetes
  175. Fujita, Tomoyuki; Asai, Tomohiro; Andrassy, Martin; Stern, David M; Pinsky, David J; Zou, Yu Shan; Okada, Morihito; Naka, Yoshifumi; Schmidt, Ann Marie; Yan, Shi-Fang. "PKCbeta regulates ischemia/reperfusion injury in the lung". Journal of clinical investigation. 2004 Jun;113(11):1615-1623 (MEDL:15173888 #140606)       

    Activation of PKCbetaII is associated with the response to ischemia/reperfusion (I/R), though its role, either pathogenic or protective, has not been determined. In a murine model of single-lung I/R, evidence linking PKCbeta to maladaptive responses is shown in the following studies. Homozygous PKCbeta-null mice and WT mice fed the PKCbeta inhibitor ruboxistaurin subjected to I/R displayed increased survival compared with controls. In PKCbeta-null mice, phosphorylation of extracellular signal-regulated protein kinase-1 and -2 (ERK1/2), JNK, and p38 MAPK was suppressed in I/R. Expression of the immediate early gene, early growth response-1 (Egr-1), and its downstream target genes was significantly increased in WT mice in I/R, particularly in mononuclear phagocytes (MPs), whereas this expression was attenuated in PKCbeta-null mice or WT mice fed ruboxistaurin. In vitro, hypoxia/reoxygenation-mediated induction of Egr-1 in MPs was suppressed by inhibition of PKCbeta, ERK1/2, and JNK, but not by inhibition of p38 MAPK. These findings elucidate key roles for PKCbetaII activation in I/R by coordinated activation of MAPKs (ERK1/2, JNK) and Egr-1
  176. Giacona, Mary Beth; Papapanou, Panos N; Lamster, Ira B; Rong, Ling Ling; D'Agati, Vivette D; Schmidt, Ann Marie; Lalla, Evanthia. "Porphyromonas gingivalis induces its uptake by human macrophages and promotes foam cell formation in vitro". FEMS microbiology letters. 2004 Dec;241(1):95-101 (MEDL:15556715 #779402)       

    Porphyromonas gingivalis is an etiologic agent of periodontal disease in humans, which has been linked to an increased risk for atherosclerosis-related events. In this study, we examined the effect of P. gingivalis infection on human macrophages with respect to foam cell formation, the hallmark of early atherogenesis, and the potential of P. gingivalis to induce its uptake by these cells. Human monocyte-derived macrophages were incubated with low density lipoprotein and infected with P. gingivalis FDC381 or its fimbriae deficient mutant, DPG3. Consistent with a role for fimbriae in this process, strain 381 significantly increased foam cell formation as compared to DPG3. Recovery of viable P. gingivalis in antibiotic protection experiments was significantly higher for strain 381 than for DPG3. By transmission electron microscopy, the wild-type strain was shown to adhere to and enter THP-1 cells. These results suggest that properties of P. gingivalis which render it capable of adhering to/invading other cell types may also be operative in macrophages and play an important role in its atherogenic potential.
  177. Harja, Evis; Bucciarelli, Loredana G; Lu, Yan; Stern, David M; Zou, Yu Shan; Schmidt, Ann Marie; Yan, Shi-Fang. "Early growth response-1 promotes atherogenesis: mice deficient in early growth response-1 and apolipoprotein E display decreased atherosclerosis and vascular inflammation". Circulation research. 2004 Feb 20;94(3):333-339 (MEDL:14670837 #140607)       

    Early growth response-1 (Egr-1) regulates expression of proinflammatory and procoagulant genes in acute cell stress. Experimental evidence suggested that Egr-1 transcripts were upregulated in human atherosclerotic plaques versus adjacent unaffected tissue. To test the impact of Egr-1 in chronic vascular stress, we examined its role in a murine model of atherosclerosis. Real-time PCR analysis of aortae retrieved from apoE-/- mice demonstrated increased Egr-1 transcripts in an age-dependent manner, compared with aortae retrieved from C57BL/6 control animals. Therefore, homozygous Egr-1-/- mice were bred into the apoE-/- background. Homozygous double-knockout mice (Egr-1-/-/apoE-/-) in the C57BL/6 background were maintained on normal chow diet. At age 14 and 24 weeks, atherosclerotic lesion area and complexity at the aortic root were strikingly decreased in mice deficient in both Egr-1 and apoE compared with mice deficient in apoE alone. In parallel, transcripts for genes regulating the inflammatory/prothrombotic response were diminished in Egr-1-/-/apoE-/- aortae versus apoE-/-. In vitro, oxidized low-density lipoprotein (OxLDL), a key factor inciting atherogenic mechanisms in the vasculature, upregulated Egr-1 expression in monocytes via the MEK-ERK1/2 pathway. We conclude that Egr-1 broadly regulates expression of molecules critically linked to atherogenesis and lesion progression
  178. Hou, Fan Fan; Ren, Hao; Owen, William F Jr; Guo, Zhi Jian; Chen, Ping Yan; Schmidt, Ann Marie; Miyata, Toshio; Zhang, Xun. "Enhanced expression of receptor for advanced glycation end products in chronic kidney disease". Journal of the American Society of Nephrology. 2004 Jul;15(7):1889-1896 (MEDL:15213278 #779442)       

    Inappropriate chronic inflammation associated with progressive, chronic kidney disease (CKD) reflects sustained activation of immunocompetent cells, like monocytes/macrophages. Advanced glycation end products (AGE) accumulate in CKD, but it is unclear if they stimulate monocytes by binding with the receptor for AGE (RAGE). Posited was the notion that RAGE plays a contributory role to monocyte-mediated systemic inflammation of progressive CKD. Peripheral blood monocytes were isolated from 102 patients without diabetes with varying severity of CKD. RAGE expression on peripheral blood monocytes increased with worsening CKD (r2 = 0.73) and was strongly correlated with plasma levels of pentosidine, a marker for AGE (r = 0.71). Strongly positive statistical correlations were observed in patients with CKD between monocyte RAGE and plasma levels of tumor necrosis factor alpha (TNF-alpha) (r = 0.61), the monocyte activation marker, neopterin (r = 0.65), and the systemic acute phase reactant, C-reactive protein (r = 0.44). Monocytes obtained from patients with CKD showed a monotonic increase in the number and affinity of specific AGE binding sites and increased production of TNF-alpha under stimulation of AGE. All these upregulatory responses in uremic monocytes could be largely blocked by an anti-RAGE antibody. It was concluded that RAGE expression was upregulated on monocytes from patients with CKD. Enhanced RAGE may amplify AGE-induced monocytes perturbation and contribute to monocyte-mediated systemic inflammation in progressive CKD.
  179. Hudson, Barry I; Schmidt, Ann Marie. "RAGE: a novel target for drug intervention in diabetic vascular disease". Pharmacheutical research. 2004 Jul;21(7):1079-1086 (MEDL:15290845 #779452)       

    At high levels as seen in diabetes, glucose reacts with and forms adducts (advanced glycation end products; AGEs) on macromolecules including proteins and DNA, eliciting cellular dysfunction and leading to vascular disease. The major means is through cellular receptors; the best characterized is the receptor for advanced glycation end products (RAGE). Accumulation of both AGE/RAGE in addition to other identified ligands of RAGE, including S100/calgranulins, is the hallmark of this receptor in disease pathogenesis. Blockade of ligand-receptor interaction directly at the protein level, or transgenetically, prevents development of micro vascular (nephropathy) and macro vascular (atherosclerosis/restenosis) disease in small animal models. Furthermore, allelic variants of RAGE exist that alter the protein function and gene expression, which may further affect disease outcome. In conclusion, RAGE is a target for drug development to prevent vascular disease in diabetic and nondiabetic subjects.
  180. Hwang, Yuying C; Kaneko, Michiyo; Bakr, Soliman; Liao, Hui; Lu, Yan; Lewis, Erin R; Yan, Shidu; Ii, Setsuko; Itakura, Mitsuo; Rui, Liu; Skopicki, Hal; Homma, Shunichi; Schmidt, Ann Marie; Oates, Peter J; Szabolcs, Matthias; Ramasamy, Ravichandran. "Central role for aldose reductase pathway in myocardial ischemic injury". FASEB journal. 2004 Aug;18(11):1192-1199 (MEDL:15284219 #130792)       

    Aldose reductase (AR), a member of the aldo-keto reductase family, has been implicated in the development of vascular and neurological complications of diabetes. Recently, we demonstrated that aldose reductase is a component of myocardial ischemic injury and that inhibitors of this enzyme protect rat hearts from ischemia-reperfusion injury. To rigorously test the effect of aldose reductase on myocardial ischemia-reperfusion injury, we used transgenic mice broadly overexpressing human aldose reductase (ARTg) driven by the major histocompatibility complex I promoter. Hearts from these ARTg or littermate mice (WT) (n=6 in each group) were isolated, perfused under normoxic conditions, then subjected to 50 min of severe low flow ischemia followed by 60 min of reperfusion. Creatine kinase (CK) release (a marker of ischemic injury) was measured during reperfusion; left ventricular developed pressure (LVDP), end diastolic pressure (EDP), and ATP were measured throughout the protocol. CK release was significantly greater in ARTg mice compared with the WT mice. LVDP recovery was significantly reduced in ARTg mice compared with the WT mice. Furthermore, ATP content was higher in WT mice compared with ARTg mice during ischemia and reperfusion. Infarct size measured by staining techniques and myocardial damage evaluated histologically were also significantly worse in ARTg mice hearts than in controls. Pharmacological inhibition of aldose reductase significantly reduced ischemic injury and improved functional recovery in ARTg mice. These data strongly support key roles for AR in ischemic injury and impairment of functional and metabolic recovery after ischemia. We propose that interventions targeting AR may provide a novel adjunctive approach to protect ischemic myocardium
  181. Liliensiek, Birgit; Weigand, Markus A; Bierhaus, Angelika; Nicklas, Werner; Kasper, Michael; Hofer, Stefan; Plachky, Jens; Grone, Herman-Josef; Kurschus, Florian C; Schmidt, Ann Marie; Yan, Shi Du; Martin, Eike; Schleicher, Erwin; Stern, David M; Hammerling G, G unterJ; Nawroth, Peter P; Arnold, Bernd. "Receptor for advanced glycation end products (RAGE) regulates sepsis but not the adaptive immune response". Journal of clinical investigation. 2004 Jun;113(11):1641-1650 (MEDL:15173891 #140642)       

    While the initiation of the adaptive and innate immune response is well understood, less is known about cellular mechanisms propagating inflammation. The receptor for advanced glycation end products (RAGE), a transmembrane receptor of the immunoglobulin superfamily, leads to perpetuated cell activation. Using novel animal models with defective or tissue-specific RAGE expression, we show that in these animal models RAGE does not play a role in the adaptive immune response. However, deletion of RAGE provides protection from the lethal effects of septic shock caused by cecal ligation and puncture. Such protection is reversed by reconstitution of RAGE in endothelial and hematopoietic cells. These results indicate that the innate immune response is controlled by pattern-recognition receptors not only at the initiating steps but also at the phase of perpetuation
  182. Naka, Yoshifumi; Bucciarelli, Loredana G; Wendt, Thoralf; Lee, Larisse K; Rong, Ling Ling; Ramasamy, Ravichandran; Yan, Shi Fang; Schmidt, Ann Marie. "RAGE axis: Animal models and novel insights into the vascular complications of diabetes". Arteriosclerosis, thrombosis, & vascular biology. 2004 Aug;24(8):1342-1349 (MEDL:15155381 #130795)       

    Receptor for AGE (RAGE) is a multi-ligand member of the immunoglobulin superfamily of cell surface molecules. Engagement of RAGE by its signal transduction ligands evokes inflammatory cell infiltration and activation in the vessel wall. In diabetes, when fueled by oxidant stress, hyperglycemia, and superimposed stresses such as hyperlipidemia or acute balloon/endothelial denuding arterial injury, the ligand-RAGE axis amplifies vascular stress and accelerates atherosclerosis and neointimal expansion. In this brief synopsis, we review the use of rodent models to test these concepts. Taken together, our findings support the premise that RAGE is an amplification step in vascular inflammation and acceleration of atherosclerosis. Future studies must rigorously test the potential impact of RAGE blockade in human subjects; such trials are on the horizon
  183. Rong, Ling Ling; Trojaborg, Werner; Qu, Wu; Kostov, Konstantin; Yan, Shi Du; Gooch, Clifton; Szabolcs, Matthias; Hays, Arthur P; Schmidt, Ann Marie. "Antagonism of RAGE suppresses peripheral nerve regeneration". FASEB journal. 2004 Dec;18(15):1812-1817 (MEDL:15576484 #779392)       

    Axotomy of peripheral nerve triggers events that coordinate a limited inflammatory response to axonal degeneration and initiation of neurite outgrowth. Inflammatory and neurite outgrowth-promoting roles for the receptor for advanced glycation end products (RAGE) have been suggested, so we tested its role in peripheral nerve regeneration. Analysis of immunohistochemical localization of RAGE by confocal microscopy revealed that RAGE was expressed in axons and infiltrating mononuclear phagocytes upon unilateral sciatic nerve crush in mice. Administration of soluble RAGE, the extracellular ligand binding domain of RAGE, or blocking F(ab')2 fragments of antibodies raised to either RAGE or its ligands, S100/calgranulins or amphoterin, reduced functional recovery as assessed by motor and sensory nerve conduction velocities and sciatic functional index and reduced regeneration, as assessed by myelinated fiber density after acute crush of the sciatic nerve. In parallel, in mice subjected to RAGE blockade, decreased numbers of mononuclear phagocytes infiltrated the distal nerve segments after crush. These findings provide the first evidence of an innate function of the ligand/RAGE axis and suggest that RAGE plays an important role in regeneration of the peripheral nervous system.
  184. Rong, Ling Ling; Yan, Shi-Fang; Wendt, Thoralf; Hans, Diana; Pachydaki, Sophia; Bucciarelli, Loredana G; Adebayo, Adebukola; Qu, Wu; Lu, Yan; Kostov, Konstantin; Lalla, Evanthia; Yan, Shi Du; Gooch, Clifton; Szabolcs, Matthias; Trojaborg, Werner; Hays, Arthur P; Schmidt, Ann Marie. "RAGE modulates peripheral nerve regeneration via recruitment of both inflammatory and axonal outgrowth pathways". FASEB journal. 2004 Dec;18(15):1818-1825 (MEDL:15576485 #140605)       

    Axotomy of peripheral nerve stimulates events in multiple cell types that initiate a limited inflammatory response to axonal degeneration and simultaneous outgrowth of neurites into the distal segments after injury. We found that pharmacological blockade of RAGE impaired peripheral nerve regeneration in mice subjected to RAGE blockade and acute crush of the sciatic nerve. As our studies revealed that RAGE was expressed in axons and in infiltrating mononuclear phagocytes upon injury, we tested the role of RAGE in these distinct cell types on nerve regeneration. Transgenic mice expressing signal transduction-deficient RAGE in mononuclear phagocytes or peripheral neurons were generated and subjected to unilateral crush injury to the sciatic nerve. Transgenic mice displayed decreased functional and morphological recovery compared with littermate controls, as assessed by motor and sensory conduction velocities; and myelinated fiber density. In double transgenic mice expressing signal transduction deficient RAGE in both mononuclear phagocytes and peripheral neurons, regeneration was even further impaired, suggesting the critical interplay between RAGE-modulated inflammation and neurite outgrowth in nerve repair. These findings suggest that RAGE signaling in inflammatory cells and peripheral neurons plays an important role in plasticity of the peripheral nervous system
  185. Schmidt AM; Hudson BI; Yan SF; Stern DM. "Receptor-dependent vascular stress in diabetes" IN: Diabetes and cardiovascular disease : integrating science and clinical medicine. Philadelphia : Lippincott Williams and Wilkins, 2004. . p.?-?.  (OCLC:52418025 #5834)    
  186. Wautier, Jean-Luc; Schmidt, Ann Marie. "Protein glycation: a firm link to endothelial cell dysfunction". Circulation research. 2004 Aug;95(3):233-238 (MEDL:15297385 #779432)       

    The advanced glycation end products (AGEs) are a heterogeneous class of molecules, including the following main subgroups: bis(lysyl)imidazolium cross-links, hydroimidazolones, 3-deoxyglucosone derivatives, and monolysyl adducts. AGEs are increased in diabetes, renal failure, and aging. Microvascular lesions correlate with the accumulation of AGEs, as demonstrated in diabetic retinopathy or renal glomerulosclerosis. On endothelial cells, ligation of receptor for AGE (RAGE) by AGEs induces the expression of cell adhesion molecules, tissue factor, cytokines such as interleukin-6, and monocyte chemoattractant protein-1. A chief means by which AGEs via RAGE exert their effects is by generation of reactive oxygen species, at least in part via stimulation of NADPH oxidase. Diabetes-associated vascular dysfunction in vivo can be prevented by blockade of RAGE. Thus, agents that limit AGE formation, increase the catabolism of these species, or antagonize their binding to RAGE may provide new targets for vascular protection in diabetes.
  187. Yan, Shi-Fang; Ramasamy, Ravichandran; Bucciarelli, Loredana G; Wendt, Thoralf; Lee, Larisse K; Hudson, Barry I; Stern, David M; Lalla, Evanthia; DU Yan, Shi; Rong, Ling Ling; Naka, Yoshifumi; Schmidt, Ann Marie. "RAGE and its ligands: a lasting memory in diabetic complications?". Diabetes & vascular disease research. 2004 May;1(1):10-20 (MEDL:16305050 #130796)       

    The complications of diabetes are myriad and represent a rising cause of morbidity and mortality, particularly in the Western world. The update of the Diabetes Control and Clinical Trials Group/Epidemiology of Diabetes Interventions and Complications Research Group (DCCT/EDIC) suggested that previous strict control of hyperglycaemia was associated with reduced carotid atherosclerosis compared to conventional treatment, even after levels of glycosylated haemoglobin between the two treatment groups became indistinguishable. These intriguing findings prompt the key question, why does the blood vessel 'remember'? This review focuses on the hypothesis that the ligand/RAGE axis contributes importantly to glycaemic 'memory'. Studies in rodent models of diabetes suggest that blockade or genetic modification of RAGE suppress diabetes-associated progression of atherosclerosis, exaggerated neointimal expansion consequent to acute arterial injury, and cardiac dysfunction. We propose that therapeutic RAGE blockade will intercept maladaptive diabetes-associated memory in the vessel wall and provide cardiovascular protection in diabetes
  188. Zeng, Shan; Feirt, Nikki; Goldstein, Michael; Guarrera, James; Ippagunta, Nikalesh; Ekong, Udeme; Dun, Hao; Lu, Yan; Qu, Wu; Schmidt, Ann Marie; Emond, Jean C. "Blockade of receptor for advanced glycation end product (RAGE) attenuates ischemia and reperfusion injury to the liver in mice". Hepatology. 2004 Feb;39(2):422-432 (MEDL:14767995 #779472)       

    Hepatic ischemia/reperfusion (I/R) injury associated with liver transplantation and hepatic resection is characterized by hepatocellular damage and a deleterious inflammatory response. In this study, we examined whether receptor for advanced glycation end product (RAGE) activation is linked to mechanisms accentuating inflammation on I/R in a murine model of total hepatic ischemia. Animals treated with soluble RAGE (sRAGE), the extracellular ligand-binding domain of RAGE, displayed increased survival after total hepatic I/R compared with vehicle treatment. TUNEL assay and histologic analysis revealed that blockade of RAGE was highly protective against hepatocellular death and necrosis on I/R; in parallel, proliferating cell nuclear antigen was enhanced in livers of mice treated with sRAGE. Rapid activation of p38, p44/42, stress-activated protein kinase and c-Jun N-terminal kinase mitogen-activated protein kinases, signal transducer and activator of transcription-3, and nuclear translocation of activator protein-1 was evident at early times on I/R. In the remnants of sRAGE-treated livers, however, activation of each of these signaling and transcription factor pathways was strikingly decreased. sRAGE-treated remnants displayed enhanced activation of nuclear factor kappaB, in parallel with increased transcripts for the proregenerative cytokine, tumor necrosis factor-alpha. In conclusion, these data suggest that RAGE modulates hepatic I/R injury, at least in part by activation of key signaling pathways linked to proinflammatory and cell death-promoting responses. We propose that blockade of this pathway may represent a novel strategy to attenuate injury in hepatic I/R and to facilitate regeneration.
  189. Cipollone, Francesco; Iezzi, Annalisa; Fazia, Maria; Zucchelli, Mirco; Pini, Barbara; Cuccurullo, Chiara; De Cesare, Domenico; De Blasis, Giovanni; Muraro, Raffaella; Bei, Roberto; Chiarelli, Francesco; Schmidt, Ann Marie; Cuccurullo, Franco; Mezzetti, Andrea. "The receptor RAGE as a progression factor amplifying arachidonate-dependent inflammatory and proteolytic response in human atherosclerotic plaques: role of glycemic control". Circulation. 2003 Sep;108(9):1070-1077 (MEDL:12912808 #779482)       

    BACKGROUND: RAGE (receptor for advanced glycation end products [AGEs]) plays a role in diabetic atherosclerosis. Recently, we have demonstrated enhanced expression of cyclooxygenase-2 and PGE synthase-1 (COX-2/mPGES-1) in human symptomatic plaques, and provided evidence that it is associated with metalloproteinase (MMP)-induced plaque rupture. However, the specific transmembrane signaling pathway(s) influencing plaque COX-2/mPGES-1 expression is unknown. The aim of this study was to characterize RAGE expression in human plaques and to correlate it with the inflammatory infiltration, COX-2/mPGES-1 and MMP expression, and with clinical evidence of diabetes. METHODS AND RESULTS: Plaques obtained from 60 patients undergoing carotid endarterectomy were divided into diabetic and nondiabetic according to clinical evidence of type 2 diabetes. Plaques were subjected to analysis of RAGE, NF-kappaB, COX-2/mPGES-1, MMP-2 and MMP-9, lipid and oxidized LDL (oxLDL) content, and collagen content by immunohistochemistry and Western blot, whereas zymography was used to detect MMP activity. Immunohistochemistry was used to identify CD68+ macrophages, CD3+ T-lymphocytes, smooth muscle cells (SMCs), and HLA-DR+ inflammatory cells. Diabetic plaques had more (P<0.0001) macrophages, T-lymphocytes, and HLA-DR+ cells, more (P<0.0001) immunoreactivity for RAGE, activated NF-kappaB, COX-2/mPGES-1, and MMPs, increased (P<0.0001) gelatinolytic activity, reduced (P<0.0001) collagen content, and increased (P<0.0001) lipid and oxLDL content. Interestingly, RAGE, COX-2/mPGES-1, and MMP expression was linearly correlated with plasma level of HbA1c. CONCLUSIONS: In conclusion, this study demonstrates in humans that RAGE overexpression is associated with enhanced inflammatory reaction and COX-2/mPGES-1 expression in diabetic plaque macrophages, and this effect may contribute to plaque destabilization by inducing culprit metalloproteinase expression.
  190. Deane, Rashid; Du Yan, Shi; Submamaryan, Ram Kumar; LaRue, Barbara; Jovanovic, Suzana; Hogg, Elizabeth; Welch, Deborah; Manness, Lawrence; Lin, Chang; Yu, Jin; Zhu, Hong; Ghiso, Jorge; Frangione, Blas; Stern, Alan; Schmidt, Ann Marie; Armstrong, Don L; Arnold, Bernd; Liliensiek, Birgit; Nawroth, Peter; Hofman, Florence; Kindy, Mark; Stern, David; Zlokovic, Berislav. "RAGE mediates amyloid-beta peptide transport across the blood-brain barrier and accumulation in brain". Nature medicine. 2003 Jul;9(7):907-913 (MEDL:12808450 #42003)       

    Amyloid-beta peptide (Abeta) interacts with the vasculature to influence Abeta levels in the brain and cerebral blood flow, providing a means of amplifying the Abeta-induced cellular stress underlying neuronal dysfunction and dementia. Systemic Abeta infusion and studies in genetically manipulated mice show that Abeta interaction with receptor for advanced glycation end products (RAGE)-bearing cells in the vessel wall results in transport of Abeta across the blood-brain barrier (BBB) and expression of proinflammatory cytokines and endothelin-1 (ET-1), the latter mediating Abeta-induced vasoconstriction. Inhibition of RAGE-ligand interaction suppresses accumulation of Abeta in brain parenchyma in a mouse transgenic model. These findings suggest that vascular RAGE is a target for inhibiting pathogenic consequences of Abeta-vascular interactions, including development of cerebral amyloidosis
  191. Hudson, Barry I; Bucciarelli, Loredana G; Wendt, Thoralf; Sakaguchi, Taichi; Lalla, Evanthia; Qu, Wu; Lu, Yan; Lee, Larisse; Stern, David M; Naka, Yoshifumi; Ramasamy, Ravichandran; Yan, Shi Du; Yan, Shi Fang; D'Agati, Vivette; Schmidt, Ann Marie. "Blockade of receptor for advanced glycation endproducts: a new target for therapeutic intervention in diabetic complications and inflammatory disorders". Archives of biochemistry & biophysics. ABB. 2003 Nov 1;419(1):80-88 (MEDL:14568011 #130797)       

    The glycation and oxidation of proteins/lipids leads to the generation of a new class of biologically active moieties, the advanced glycation endproducts (AGEs). Recent studies have elucidated that carboxymethyllysine (CML) adducts of proteins/lipids are a highly prevalent AGE in vivo. CML-modified adducts are signal transduction ligands of the receptor for AGE (RAGE), a member of the immunoglobulin superfamily. Importantly, CML-modified adducts accumulate in diverse settings. In addition to enhanced formation in settings of high glucose, these adducts form in inflammatory milieu. Studies performed both in vitro and in vivo have suggested that the proinflammatory/tissue destructive consequences of RAGE activation in the diabetic/inflamed environment may be markedly attenuated by blockade of the ligand-RAGE axis. Here, we will summarize the known consequences of RAGE activation in the tissues and highlight novel areas for therapeutic intervention in these disease states
  192. Lalla, Evanthia; Lamster, Ira B; Hofmann, Marion A; Bucciarelli, Loredana; Jerud, Adrienne P; Tucker, Sid; Lu, Yan; Papapanou, Panos N; Schmidt, Ann Marie. "Oral infection with a periodontal pathogen accelerates early atherosclerosis in apolipoprotein E-null mice". Arteriosclerosis, thrombosis, & vascular biology. 2003 Aug;23(8):1405-1411 (MEDL:12816879 #779502)       

    OBJECTIVE: Because recent epidemiologic evidence suggests that periodontal infections may increase the risk of atherosclerosis and related events in humans, we assessed the impact of oral inoculation with the periodontal pathogen Porphyromonas gingivalis on atherogenesis in hypercholesterolemic apolipoprotein E-null mice. METHODS AND RESULTS: In the absence of alterations in distinct risk factors, P gingivalis infection exacerbated the early stages of atherogenesis in this model. Infected animals displayed evidence of local periodontal infection, as the severity of alveolar bone loss, the hallmark of periodontitis, was increased. Generalized activation of host inflammatory responses was evident in infected mice, as demonstrated by serum IgG response to P gingivalis and elevated levels of interleukin-6. P gingivalis DNA was localized in the aortic tissue from a limited number of infected mice but not in any noninfected controls. Infected mice displayed enhanced vascular activation, as suggested by increased aortic expression of vascular cell adhesion molecule-1 and tissue factor. CONCLUSIONS: Oral infection with P gingivalis accelerates early atherosclerosis. Thus, uncovering the underlying mechanisms is critical for the design of preventive and therapeutic strategies targeting atherosclerotic vascular disease and its sequelae.
  193. Sakaguchi, Taichi; Yan, Shi Fang; Yan, Shi Du; Belov, Dmitri; Rong, Ling Ling; Sousa, Monica; Andrassy, Martin; Marso, Steven P; Duda, Stephan; Arnold, Bernd; Liliensiek, Birgit; Nawroth, Peter P; Stern, David M; Schmidt, Ann Marie; Naka, Yoshifumi. "Central role of RAGE-dependent neointimal expansion in arterial restenosis". Journal of clinical investigation. 2003 Apr;111(7):959-972 (MEDL:12671045 #140608)       

    Cellular proliferation, migration, and expression of extracellular matrix proteins and MMPs contribute to neointimal formation upon vascular injury. Wild-type mice undergoing arterial endothelial denudation displayed striking upregulation of receptor for advanced glycation end products (RAGE) in the injured vessel, particularly in activated smooth muscle cells of the expanding neointima. In parallel, two of RAGE's signal transducing ligands, advanced glycation end products (AGEs) and S100/calgranulins, demonstrated increased deposition/expression in the injured vessel wall. Blockade of RAGE, employing soluble truncated receptor or antibodies, or in homozygous RAGE null mice, resulted in significantly decreased neointimal expansion after arterial injury and decreased smooth muscle cell proliferation, migration, and expression of extracellular matrix proteins. A critical role for smooth muscle cell RAGE signaling was demonstrated in mice bearing a transgene encoding a RAGE cytosolic tail-deletion mutant, specifically in smooth muscle cells, driven by the SM22alpha promoter. Upon arterial injury, neointimal expansion was strikingly suppressed compared with that observed in wild-type littermates. Taken together, these data highlight key roles for RAGE in modulating smooth muscle cell properties after injury and suggest that RAGE is a logical target for suppression of untoward neointimal expansion consequent to arterial injury
  194. Shaw, Sean S; Schmidt, Ann Marie; Banes, Amy K; Wang, Xiaodan; Stern, David M; Marrero, Mario B. "S100B-RAGE-mediated augmentation of angiotensin II-induced activation of JAK2 in vascular smooth muscle cells is dependent on PLD2". Diabetes. 2003 Sep;52(9):2381-2388 (MEDL:12941779 #779492)       

    Angiotensin II (Ang II), a vasoactive peptide that is also considered a growth factor, has been implicated in both normal and diabetic cellular proliferation. We recently found that activation of janus kinase 2 (JAK2) is essential for the Ang II-induced proliferation of vascular smooth muscle cells (VSMCs) and that high glucose augments Ang II-induced proliferation of VSMCs by increasing signal transduction through activation of JAK2. Here, we demonstrate that S100B, a ligand for the receptor of advanced glycation end products (RAGEs), augmented both Ang II-induced tyrosine phosphorylation of JAK2 and cell proliferation in VSMCs in a receptor-dependent manner. We also found that S100B-RAGE interaction triggered intracellular generation of reactive oxygen species (ROS), VSMC proliferation, and JAK2 tyrosine phosphorylation via activation of phospholipase D (PLD)2. These results provide direct evidence for linkages between PLD2, ROS production, and S100B-RAGE-induced enhancement of Ang II-induced cell proliferation and activation of JAK2 in VSMCs.
  195. Wendt, Thoralf M; Tanji, Nozomu; Guo, Jiancheng; Kislinger, Thomas R; Qu, Wu; Lu, Yan; Bucciarelli, Loredana G; Rong, Ling Ling; Moser, Bernhard; Markowitz, Glen S; Stein, Gunther; Bierhaus, Angelika; Liliensiek, Birgit; Arnold, Bernd; Nawroth, Peter P; Stern, David M; D'Agati, Vivette D; Schmidt, Ann Marie. "RAGE drives the development of glomerulosclerosis and implicates podocyte activation in the pathogenesis of diabetic nephropathy". American journal of pathology. 2003 Apr;162(4):1123-1137 (MEDL:12651605 #779522)       

    Diabetic nephropathy ensues from events involving earliest changes in the glomeruli and podocytes, followed by accumulation of extracellular matrix in the mesangium. Postulated mechanisms include roles for vascular endothelial growth factor (VEGF), produced by podocytes and contributing to enhanced excretion of urinary albumin and recruitment/activation of inflammatory cells, and transforming growth factor-beta (TGF-beta), elicited largely from mesangial cells and driving production of extracellular matrix. RAGE, a receptor for advanced glycation endproducts (AGEs) and S100/calgranulins, displays enhanced expression in podocytes of genetically diabetic db/db mice by age 13 weeks. RAGE-bearing podocytes express high levels of VEGF by this time, in parallel with enhanced recruitment of mononuclear phagocytes to the glomeruli; events prevented by blockade of RAGE. By age 27 weeks, soluble RAGE-treated db/db mice displayed diminished albuminuria and glomerulosclerosis, and improved renal function. Diabetic homozygous RAGE null mice failed to develop significantly increased mesangial matrix expansion or thickening of the glomerular basement membrane. We propose that activation of RAGE contributes to expression of VEGF and enhanced attraction/activation of inflammatory cells in the diabetic glomerulus, thereby setting the stage for mesangial activation and TGF-beta production; processes which converge to cause albuminuria and glomerulosclerosis.
  196. Wendt, Thoralf; Tanji, Nozomu; Guo, Jiancheng; Hudson, Barry I; Bierhaus, Angelika; Ramasamy, Ravichandran; Arnold, Bernd; Nawroth, Peter P; Yan, Shi Fang; D'Agati, Vivette; Schmidt, Ann Marie. "Glucose, glycation, and RAGE: implications for amplification of cellular dysfunction in diabetic nephropathy". Journal of the American Society of Nephrology. 2003 May;14(5):1383-1395 (MEDL:12707408 #130798)       

    Receptor for advanced glycation endproducts (RAGE) is a multi-ligand member of the immunoglobulin superfamily of cell surface molecules. Driven by rapid accumulation and expression of key ligands such as advanced glycation endproducts (AGE) and S100/calgranulins in diabetic tissues, upregulation and activation of RAGE magnifies cellular perturbation in tissues affected by hyperglycemia, such as the large blood vessels and the kidney. In the diabetic glomerulus, RAGE is expressed principally by glomerular visceral epithelial cells (podocytes). Blockade of RAGE in the hyperglycemic db/db mouse suppresses functional and structural alterations in the kidney, in the absence of alterations in blood glucose. Recent studies in homozygous RAGE null mice support a key role for RAGE in glomerular perturbation in diabetes. Importantly, beyond diabetes, studies in other settings of glomerulopathies support a critical RAGE-dependent pathway in podocytes linked to albuminuria, mesangial expansion, and glomerular sclerosis. A new paradigm is proposed in glomerular injury, and it is suggested that blockade of the RAGE axis may provide a novel means to prevent irreparable glomerular injury in diabetes and other sclerosing glomerulopathies
  197. Yan, Shi Fang; Ramasamy, Ravichandran; Naka, Yoshifumi; Schmidt, Ann Marie. "Glycation, inflammation, and RAGE: a scaffold for the macrovascular complications of diabetes and beyond". Circulation research. 2003 Dec 12;93(12):1159-1169 (MEDL:14670831 #130834)       

    The cardiovascular complications of diabetes represent the leading cause of morbidity and mortality in affected subjects. The impact of hyperglycemia may be both direct and indirect: indirect consequences of elevated blood glucose lead to generation of advanced glycation endproducts, the products of nonenzymatic glycation/oxidation of proteins/lipids that accumulate in the vessel wall, and are signal transduction ligands for Receptor for AGE (RAGE). Although enhanced in diabetes, AGE accumulation also occurs in euglycemia and aging, albeit to lower degrees, driven by oxidant stress and inflammation. In hyperglycemia, production of 3-deoxyglucosone, at least in part via the polyol pathway, provides an amplification loop to sustain AGE generation, oxidant stress, and vascular activation. Furthermore, recruitment of inflammatory cells bearing S100/calgranulins, also ligands for RAGE, augments vascular dysfunction. We hypothesize that activation of RAGE is a final common pathway that transduces signals from these diverse biochemical and molecular species, leading to cardiovascular perturbation. Ultimately, these pathways synergize to construct a scaffold on which the complications of diabetes in the vasculature and heart may be built. We propose that antagonism of RAGE will provide a unique means to dismantle this scaffold and, thereby, suppress initiation/progression of vascular disease and cardiac dysfunction that accompany diabetes and aging
  198. Yan, Shirley ShiDu; Wu, Zhi-Ying; Zhang, Hui Ping; Furtado, Glaucia; Chen, Xi; Yan, Shi Fang; Schmidt, Ann Marie; Brown, Chris; Stern, Alan; LaFaille, Juan; Chess, Leonard; Stern, David M; Jiang, Hong. "Suppression of experimental autoimmune encephalomyelitis by selective blockade of encephalitogenic T-cell infiltration of the central nervous system". Nature medicine. 2003 Mar;9(3):287-293 (MEDL:12598893 #44897)       

    Multiple sclerosis (MS) is a devastating neuroinflammatory disorder of the central nervous system (CNS) in which T cells that are reactive with major components of myelin sheaths have a central role. The receptor for advanced glycation end products (RAGE) is present on T cells, mononuclear phagocytes and endothelium. Its pro-inflammatory ligands, S100-calgranulins, are upregulated in MS and in the related rodent model, experimental autoimmune encephalomyelitis (EAE). Blockade of RAGE suppressed EAE when disease was induced by myelin basic protein (MBP) peptide or encephalitogenic T cells, or when EAE occurred spontaneously in T-cell receptor (TCR)-transgenic mice devoid of endogenous TCR-alpha and TCR-beta chains. Inhibition of RAGE markedly decreased infiltration of the CNS by immune and inflammatory cells. Transgenic mice with targeted overexpression of dominant-negative RAGE in CD4+ T cells were resistant to MBP-induced EAE. These data reinforce the importance of RAGE-ligand interactions in modulating properties of CD4+ T cells that infiltrate the CNS
  199. Zhou, Zhongmin; Wang, Kai; Penn, Marc S; Marso, Steven P; Lauer, Michael A; Forudi, Farhad; Zhou, Xiaorong; Qu, Wu; Lu, Yan; Stern, David M; Schmidt, Ann Marie; Lincoff, A Michael; Topol, Eric J. "Receptor for AGE (RAGE) mediates neointimal formation in response to arterial injury". Circulation. 2003 May;107(17):2238-2243 (MEDL:12719284 #779512)       

    BACKGROUND: Receptor for advanced-glycation end products (RAGE) and its ligands AGEs and S100/calgranulins have been implicated in a range of disorders. However, the role of RAGE/ligand interaction in neointimal hyperplasia after vascular injury remains unclear. METHODS AND RESULTS: We examined the expression of RAGE and its ligands after balloon injury of the carotid artery in both Zucker diabetic and nondiabetic rats. Using a soluble portion of the extracellular domain of RAGE, we determined the effects of suppressing RAGE/ligand interaction on vascular smooth muscle cell (VSMC) proliferation and neointimal formation after arterial injury. We demonstrate a significantly increased accumulation of AGE and immunoreactivities of RAGE and S100/calgranulins in response to balloon injury in diabetic compared with nondiabetic rats. Blockade of RAGE/ligand interaction significantly decreased S100-stimulated VSMC proliferation in vitro and bromodeoxyuridine (BrdU)-labeled proliferating VSMC in vivo, and suppressed neointimal formation and increased luminal area in both Zucker diabetic and nondiabetic rats. CONCLUSIONS: These findings indicate that RAGE/ligand interaction plays a key role in neointimal formation after vascular injury irrespective of diabetes status and suggest a novel target to minimize neointimal hyperplasia.
  200. Basta, Giuseppina; Lazzerini, Guido; Massaro, Marika; Simoncini, Tommaso; Tanganelli, Piero; Fu, Caifeng; Kislinger, Thomas; Stern, David M; Schmidt, Ann Marie; De Caterina, Raffaele. "Advanced glycation end products activate endothelium through signal-transduction receptor RAGE: a mechanism for amplification of inflammatory responses". Circulation. 2002 Feb;105(7):816-822 (MEDL:11854121 #779562)       

    BACKGROUND: The products of nonenzymatic glycation and oxidation of proteins, the advanced glycation end products (AGEs), form under diverse circumstances such as aging, diabetes, and kidney failure. Recent studies suggested that AGEs may form in inflamed foci, driven by oxidation or the myeloperoxidase pathway. A principal means by which AGEs alter cellular properties is through interaction with their signal-transduction receptor RAGE. We tested the hypothesis that interaction of AGEs with RAGE on endothelial cells enhances vascular activation. METHODS AND RESULTS: AGEs, RAGE, vascular cell adhesion molecule-1, intercellular adhesion molecule-1, and E-selectin are expressed in an overlapping manner in human inflamed rheumatoid synovia, especially within the endothelium. In primary cultures of human saphenous vein endothelial cells, engagement of RAGE by heterogeneous AGEs or Nepsilon(carboxymethyl)lysine-modified adducts enhanced levels of mRNA and antigen for vascular cell adhesion molecule-1, intercellular adhesion molecule-1, and E-selectin. AGEs increased adhesion of polymorphonuclear leukocytes to stimulated endothelial cells in a manner reduced on blockade of RAGE. CONCLUSIONS: AGEs, through RAGE, may prime proinflammatory mechanisms in endothelial cells, thereby amplifying proinflammatory mechanisms in atherogenesis and chronic inflammatory disorders.
  201. Birkett, A; Lyons, K; Schmidt, A; Boyd, D; Oliveira, G A; Siddique, A; Nussenzweig, R; Calvo-Calle, J M; Nardin, E. "A modified hepatitis B virus core particle containing multiple epitopes of the Plasmodium falciparum circumsporozoite protein provides a highly immunogenic malaria vaccine in preclinical analyses in rodent and primate hosts". Infection & immunity. 2002 Dec;70(12):6860-6870 (MEDL:12438363 #165571)       

    Despite extensive public health efforts, there are presently 200 to 400 million malaria infections and 1 to 2 million deaths each year due to the Plasmodium parasite. A prime target for malaria vaccine development is the circumsporozoite (CS) protein, which is expressed on the extracellular sporozoite and the intracellular hepatic stages of the parasite. Previous studies in rodent malaria models have shown that CS repeat B-cell epitopes expressed in a recombinant hepatitis B virus core (HBc) protein can elicit protective immunity. To design a vaccine for human use, a series of recombinant HBc proteins containing epitopes of Plasmodium falciparum CS protein were assayed for immunogenicity in mice [A. Birkett, B. Thornton, D. Milich, G. A. Oliveira, A. Siddique, R. Nussenzweig, J. M. Calvo-Calle, and E. H. Nardin, abstract from the 50th Annual Meeting of the American Society of Tropical Medicine and Hygiene 2001, Am. J. Trop. Med. Hyg. 65(Suppl. 3):258, 2001; D. R. Milich, J. Hughes, J. Jones, M. Sallberg, and T. R. Phillips, Vaccine 20:771-788, 2001]. The present paper summarizes preclinical analyses of the optimal P. falciparum HBc vaccine candidate, termed ICC-1132, which contains T- and B-cell epitopes from the repeat region and a universal T-cell epitope from the C terminus of the CS protein. The vaccine was highly immunogenic in mice and in Macaca fascicularis (cynomolgus) monkeys. When formulated in adjuvants suitable for human use, the vaccine elicited antisporozoite antibody titers that were logs higher than those obtained in previous studies. Human malaria-specific CD4(+)-T-cell clones and T cells of ICC-1132-immunized mice specifically recognized malaria T-cell epitopes contained in the vaccine. In addition to inducing strong malaria-specific immune responses in naive hosts, ICC-1132 elicited potent anamnestic antibody responses in mice primed with P. falciparum sporozoites, suggesting potential efficacy in enhancing the sporozoite-primed immune responses of individuals living in areas where malaria is endemic.
  202. Bucciarelli, L G; Wendt, T; Rong, L; Lalla, E; Hofmann, M A; Goova, M T; Taguchi, A; Yan, S F; Yan, S D; Stern, D M; Schmidt, A M. "RAGE is a multiligand receptor of the immunoglobulin superfamily: implications for homeostasis and chronic disease". Cellular & molecular life sciences: CMLS. 2002 Jul;59(7):1117-1128 (MEDL:12222959 #140640)       

    Receptor for AGE (RAGE) is a member of the immunoglobulin superfamily that engages distinct classes of ligands. The biology of RAGE is driven by the settings in which these ligands accumulate, such as diabetes, inflammation, neurodegenerative disorders and tumors. In this review, we discuss the context of each of these classes of ligands, including advance glycation end-products, amyloid beta peptide and the family of beta sheet fibrils, S100/calgranulins and amphoterin. Implications for the role of these ligands interacting with RAGE in homeostasis and disease will be considered
  203. Bucciarelli, Loredana G; Wendt, Thoralf; Qu, Wu; Lu, Yan; Lalla, Evanthia; Rong, Ling Ling; Goova, Mouza T; Moser, Bernhard; Kislinger, Thomas; Lee, Daniel C; Kashyap, Yogita; Stern, David M; Schmidt, Ann Marie. "RAGE blockade stabilizes established atherosclerosis in diabetic apolipoprotein E-null mice". Circulation. 2002 Nov;106(22):2827-2835 (MEDL:12451010 #779532)       

    BACKGROUND: Previous studies suggested that blockade of RAGE in diabetic apolipoprotein (apo) E-null mice suppressed early acceleration of atherosclerosis. A critical test of the potential applicability of RAGE blockade to clinical settings was its ability to impact established vascular disease. In this study, we tested the hypothesis that RAGE contributed to lesion progression in established atherosclerosis in diabetic apoE-null mice. METHODS AND RESULTS: Male apoE-null mice, age 6 weeks, were rendered diabetic with streptozotocin or treated with citrate buffer. At age 14 weeks, certain mice were killed or treated with once-daily murine soluble RAGE or albumin; all mice were killed at age 20 weeks. Compared with diabetic mice at age 14 weeks, albumin-treated animals displayed increased atherosclerotic lesion area and complexity. In diabetic mice treated with sRAGE from age 14 to 20 weeks, lesion area and complexity were significantly reduced and not statistically different from those observed in diabetic mice at age 14 weeks. In parallel, decreased parameters of inflammation and mononuclear phagocyte and smooth muscle cell activation were observed. CONCLUSIONS: RAGE contributes not only to accelerated lesion formation in diabetic apoE-null mice but also to lesion progression. Blockade of RAGE may be a novel strategy to stabilize atherosclerosis and vascular inflammation in established diabetes.
  204. Collison, Kate S; Parhar, Ranjit S; Saleh, Soad S; Meyer, Brian F; Kwaasi, Aaron A; Hammami, Muhammad M; Schmidt, Ann Marie; Stern, David M; Al-Mohanna, Futwan A. "RAGE-mediated neutrophil dysfunction is evoked by advanced glycation end products (AGEs)". Journal of leukocyte biology. 2002 Mar;71(3):433-444 (MEDL:11867681 #779552)    

    The accumulation of advanced glycation end products (AGEs) in the tissue and serum of subjects with diabetes has been linked to the pathogenesis of vascular complications. Because diabetes may be also complicated by increased susceptibility to recurrent infection, we investigated the effects of AGEs on human neutrophils, because their burst of activity immediately upon engagement of pathogens or other inflammatory triggers is critical to host response. We demonstrate the presence of receptor for advanced glycation end products (RAGE) at the message and protein levels. We also demonstrate that AGE albumin (but not control albumin) binds with high affinity to human neutrophils (K(d) of 3.7 +/- 0.4 nM). The binding was blocked almost completely by excess soluble RAGE, anti-RAGE antibodies, or antibodies to CML-modified albumin. AGE albumin induced a dose-dependent increase in intracellular-free calcium as well as actin polymerization. Further, AGE albumin inhibited transendothelial migration and Staphylococcus aureus-induced but not fMLP-induced production of reactive oxygen metabolite. Moreover, although AGE albumin enhanced neutrophil phagocytosis of S. aureus, it inhibited bacterial killing. We conclude that functional RAGE is present on the plasma membrane of human neutrophils and is linked to Ca(2)(+) and actin polymerization, and engagement of RAGE impairs neutrophil functions.
  205. Hofmann, M A; Drury, S; Hudson, B I; Gleason, M R; Qu, W; Lu, Y; Lalla, E; Chitnis, S; Monteiro, J; Stickland, M H; Bucciarelli, L G; Moser, B; Moxley, G; Itescu, S; Grant, P J; Gregersen, P K; Stern, D M; Schmidt, A M. "RAGE and arthritis: the G82S polymorphism amplifies the inflammatory response". Genes & immunity. 2002 May;3(3):123-135 (MEDL:12070776 #93153)       

    The receptor for advanced glycation end products (RAGE) and its proinflammatory S100/calgranulin ligands are enriched in joints of subjects with rheumatoid arthritis (RA) and amplify the immune/inflammatory response. In a model of inflammatory arthritis, blockade of RAGE in mice immunized and challenged with bovine type II collagen suppressed clinical and histologic evidence of arthritis, in parallel with diminished levels of TNF-alpha, IL-6, and matrix metalloproteinases (MMP) 3, 9 and 13 in affected tissues. Allelic variation within key domains of RAGE may influence these proinflammatory mechanisms, thereby predisposing individuals to heightened inflammatory responses. A polymorphism of the RAGE gene within the ligand-binding domain of the receptor has been identified, consisting of a glycine to serine change at position 82. Cells bearing the RAGE 82S allele displayed enhanced binding and cytokine/MMP generation following ligation by a prototypic S100/calgranulin compared with cells expressing the RAGE 82G allele. In human subjects, a case-control study demonstrated an increased prevalence of the 82S allele in patients with RA compared with control subjects. These data suggest that RAGE 82S upregulates the inflammatory response upon engagement of S100/calgranulins, and, thereby, may contribute to enhanced proinflammatory mechanisms in immune/inflammatory diseases
  206. Hou, Fan Fan; Jiang, Jian Ping; Guo, Jun Qi; Wang, Guo Bao; Zhang, Xun; Stern, David M; Schmidt, Ann Marie; Owen, William F Jr. "Receptor for advanced glycation end products on human synovial fibroblasts: role in the pathogenesis of dialysis-related amyloidosis". Journal of the American Society of Nephrology. 2002 May;13(5):1296-1306 (MEDL:11961018 #779542)    

    An important component of amyloid fibrils in dialysis-related amyloidosis (DRA) is beta(2)-microglobulin (beta(2)m) modified with advanced glycation end products (AGE). The amyloid deposits are located principally in joint structures, with adjacent chronic inflammatory reaction characterized by monocyte infiltration. This study examined the interaction of AGE-beta(2)m with human synovial fibroblasts and investigated the proinflammatory effects of that interaction. It was demonstrated that human synovial fibroblasts constitutively expressed the receptor for AGE (RAGE). RAGE expression was detected mainly in synovial intima and was upregulated in DRA synovium. (125)I-AGE-beta(2)m bound to immobilized human synovial fibroblasts in a specific, dose-dependent manner (K(d) of approximately 138.0 nM), and binding was inhibited by anti-RAGE IgG. Incubation of human synovial fibroblasts with AGE-beta(2)m induced degradation of this AGE-modified protein, as well as increased monocyte chemoattractant protein-1 (MCP-1) mRNA and protein expression. The amount of MCP-1 produced by AGE-beta(2)m-stimulated human synovial fibroblasts was sufficient to induce the chemotaxis of monocytes. MCP-1 synthesis resulted from engagement of RAGE, because the increase in MCP-1 synthesis was attenuated by preincubation of human synovial fibroblasts with anti-RAGE IgG. These data provide evidence of RAGE-mediated perturbation of human synoviocytes, which may be involved in the pathogenesis of inflammatory processes associated with DRA.
  207. Hudson BI; Hofmann MA; Bucciarelli L; Wendt T; Moser B; Lu Y; Qu W; Stern DM; D'Agati VD; Yan SD; Yan SF; Grant PJ; Schmidt Am. "Glycation and diabetes : the RAGE connection". Current science. 2002;83:1515-1521 (ORIGINAL:0006939 #140673)    
  208. Stern, David M; Yan, Shi Du; Yan, Shi Fang; Schmidt, Ann Marie. "Receptor for advanced glycation endproducts (RAGE) and the complications of diabetes". Ageing research reviews. 2002 Feb;1(1):1-15 (MEDL:12039445 #140613)       

    Receptor for Advanced Glycation Endproducts (RAGE) is a multiligand member of the immunoglobulin superfamily of cell surface molecules with a diverse repertoire of ligands. These ligands include products of nonenzymatic glycation, the Advanced Glycation Endproducts (AGEs, enriched in the diabetic milieu), members of the S100/calgranulin family of proinflammatory mediators, beta-sheet fibrillar structures (characteristic of amyloid) and amphoterin (present at high levels in the tumor bed). Ligation of RAGE by its ligands upregulates expression of the receptor and triggers an ascending spiral of cellular perturbation due to sustained RAGE-mediated cellular activation. For example, in the setting of diabetes, a vascular environment rich in AGEs and S100/calgranulins accelerates atherogenesis in murine models, and this can be blocked by intercepting the interaction of ligands with RAGE. While RAGE is certainly not the cause of diabetes, it functions as a progression factor driving cellular dysfunction underlying the development of diabetic complications as the microenvironment becomes enriched in its ligands. Though further studies will be required to determine the importance of RAGE-mediated cellular activation to human chronic diseases, it represents a novel receptor-ligand system potentially impacting on a range of pathophysiologic conditions
  209. Stern, David; Yan, Shi Du; Yan, Shi Fang; Schmidt, Ann Marie. "Receptor for advanced glycation endproducts: a multiligand receptor magnifying cell stress in diverse pathologic settings". Advanced drug delivery reviews. 2002 Dec 7;54(12):1615-1625 (MEDL:12453678 #140609)       

    Receptor for Advanced Glycation Endproducts (RAGE) is a member of the immunoglobulin superfamily of cell surface molecules capable of interacting with a broad spectrum of ligands, including advanced glycation endproducts (AGEs), amyloid fibrils, S100/calgranulins and amphoterin. The biology of RAGE is dictated by the accumulation of these ligands at pathologic sites, leading to upregulation of the receptor and sustained RAGE-dependent cell activation eventuating in cellular dysfunction. Although RAGE is not central to the initial pathogenesis of disorders in which it ultimately appears to be involved, such as diabetes, amyloidoses, inflammatory conditions and tumors (each of these conditions leading to accumulation of RAGE ligands), the receptor functions as a progression factor driving cellular dysfunction and exaggerating the host response towards tissue destruction, rather than restitution of homeostasis. These observations suggest that RAGE might represent a therapeutic target in a diverse group of seemingly unrelated disorders linked only by a multiligand receptor with an unusually wide and diverse repertoire of ligands, namely, RAGE
  210. Wendt, Thoralf; Bucciarelli, Loredana; Qu, Wu; Lu, Yan; Yan, Shi Fang; Stern, David M; Schmidt, Ann Marie. "Receptor for advanced glycation endproducts (RAGE) and vascular inflammation: insights into the pathogenesis of macrovascular complications in diabetes". Current atherosclerosis reports. 2002 May;4(3):228-237 (MEDL:11931721 #140612)    

    The incidence and severity of atherosclerosis is increased in patients with diabetes. Indeed, accelerated macrovascular disease in diabetic patients has emerged as a leading cause of morbidity and mortality in the United States and worldwide. Multiple investigations have suggested that there are numerous potential contributory factors that underlie these observations. Our laboratory has focused on the contribution of receptor for advanced glycation endproducts (RAGE) and its proinflammatory ligands, advanced glycation endproducts (AGEs) and S100/calgranulins in vascular perturbation, manifested as enhanced atherogenesis or accelerated restenosis after angioplasty. In rodent models of diabetic complications, blockade of RAGE suppressed vascular hyperpermeability, accelerated atherosclerotic lesion area and complexity in diabetic apolipoprotein E-deficient mice, and prevented exaggerated neointimal formation in hyperglycemic fatty Zucker rats subjected to injury of the carotid artery. In this review, we summarize these findings and provide an overview of distinct mechanisms that contribute to the development of accelerated diabetic macrovascular disease. Insights into therapeutic strategies to prevent or interrupt these processes are presented
  211. Goova, M T; Li, J; Kislinger, T; Qu, W; Lu, Y; Bucciarelli, L G; Nowygrod, S; Wolf, B M; Caliste, X; Yan, S F; Stern, D M; Schmidt, A M. "Blockade of receptor for advanced glycation end-products restores effective wound healing in diabetic mice". American journal of pathology. 2001 Aug;159(2):513-525 (MEDL:11485910 #140634)       

    Receptor for advanced glycation end-products (RAGE), and two of its ligands, AGE and EN-RAGEs (members of the S100/calgranulin family of pro-inflammatory cytokines), display enhanced expression in slowly resolving full-thickness excisional wounds developed in genetically diabetic db+/db+ mice. We tested the concept that blockade of RAGE, using soluble(s) RAGE, the extracellular ligand-binding domain of the receptor, would enhance wound closure in these animals. Administration of sRAGE accelerated the development of appropriately limited inflammatory cell infiltration and activation in wound foci. In parallel with accelerated wound closure at later times, blockade of RAGE suppressed levels of cytokines; tumor necrosis factor-alpha; interleukin-6; and matrix metalloproteinases-2, -3, and -9. In addition, generation of thick, well-vascularized granulation tissue was enhanced, in parallel with increased levels of platelet-derived growth factor-B and vascular endothelial growth factor. These findings identify a central role for RAGE in disordered wound healing associated with diabetes, and suggest that blockade of this receptor might represent a targeted strategy to restore effective wound repair in this disorder
  212. Lue, L F; Walker, D G; Brachova, L; Beach, T G; Rogers, J; Schmidt, A M; Stern, D M; Yan, S D. "Involvement of microglial receptor for advanced glycation endproducts (RAGE) in Alzheimer's disease: identification of a cellular activation mechanism". Experimental neurology. 2001 Sep;171(1):29-45 (MEDL:11520119 #140635)       

    Receptor-mediated interactions with amyloid beta-peptide (Abeta) could be important in the evolution of the inflammatory processes and cellular dysfunction that are prominent in Alzheimer's disease (AD) pathology. One candidate receptor is the receptor for advanced glycation endproducts (RAGE), which can bind Abeta and transduce signals leading to cellular activation. Data are presented showing a potential mechanism for Abeta activation of microglia that could be mediated by RAGE and macrophage colony-stimulating factor (M-CSF). Using brain tissue from AD and nondemented (ND) individuals, RAGE expression was shown to be present on microglia and neurons of the hippocampus, entorhinal cortex, and superior frontal gyrus. The presence of increased numbers of RAGE-immunoreactive microglia in AD led us to further analyze RAGE-related properties of these cells cultured from AD and ND brains. Direct addition of Abeta(1-42) to the microglia increased their expression of M-CSF. This effect was significantly greater in microglia derived from AD brains compared to those from ND brains. Increased M-CSF secretion was also demonstrated using a cell culture model of plaques whereby microglia were cultured in wells containing focal deposits of immobilized Abeta(1-42). In each case, the Abeta stimulation of M-CSF secretion was significantly blocked by treatment of cultures with anti-RAGE F(ab')2. Treatment of microglia with anti-RAGE F(ab')2 also inhibited the chemotactic response of microglia toward Abeta(1-42). Finally, incubation of microglia with M-CSF and Abeta increased expression of RAGE mRNA. These microglia also expressed M-CSF receptor mRNA. These data suggest a positive feedback loop in which Abeta-RAGE-mediated microglial activation enhances expression of M-CSF and RAGE, possibly initiating an ascending spiral of cellular activation
  213. Schmidt, A M; Yan, S D; Yan, S F; Stern, D M. "The multiligand receptor RAGE as a progression factor amplifying immune and inflammatory responses". Journal of clinical investigation. 2001 Oct;108(7):949-955 (MEDL:11581294 #140637)       
  214. Wyss-Coray, T; McConlogue, L; Kindy, M; Schmidt, A M; Du Yan, S; Stern, D M. "Key signaling pathways regulate the biological activities and accumulation of amyloid-beta". Neurobiology of aging. 2001 Nov-Dec;22(6):967-973 (MEDL:11755005 #140639)       
  215. Yan, S D; Schmidt, A M; Stern, D. "Alzheimer's disease: inside, outside, upside down". Biochemical Society symposia. 2001;(67):15-22 (MEDL:11447831 #140633)    

    Neurotoxicity of beta-amyloid peptide (A beta) in Alzheimer's disease (AD) is usually thought to arise from the nonspecific effects of high concentrations of A beta on vulnerable neurons, resulting in membrane destabilization and increasing intracellular calcium concentration. This review advances the hypothesis that at early stages of AD, when A beta is present in lower amounts, its ability to perturb the function of cellular targets is mediated by specific cofactors present on the cell surface and intracellularly. Receptor for advanced glycation endproducts (RAGE) is a cell-surface receptor which binds A beta and amplifies its effects on cells in the nanomolar range. The intracellular enzyme A beta-binding alcohol dehydrogenase (ABAD) is likely to engage nascent A beta formed in the endoplasmic reticulum, and to mediate cell stress from this site. The analysis of A beta interaction with RAGE and ABAD, as well as other cofactors, provides insight into new mechanisms and, potentially, identifies therapeutic targets relevant to neuronal dysfunction in AD
  216. Giri, R; Shen, Y; Stins, M; Du Yan, S; Schmidt, A M; Stern, D; Kim, K S; Zlokovic, B; Kalra, V K. "beta-amyloid-induced migration of monocytes across human brain endothelial cells involves RAGE and PECAM-1". American journal of physiology. Cell physiology. 2000 Dec;279(6):C1772-C1781 (MEDL:11078691 #140627)    

    In patients with amyloid beta-related cerebrovascular disorders, e.g. , Alzheimer's disease, one finds increased deposition of amyloid peptide (Abeta) and increased presence of monocyte/microglia cells in the brain. However, relatively little is known of the role of Abeta in the trafficking of monocytes across the blood-brain barrier (BBB). Our studies show that interaction of Abeta(1-40) with monolayer of human brain endothelial cells results in augmented adhesion and transendothelial migration of monocytic cells (THP-1 and HL-60) and peripheral blood monocytes. The Abeta-mediated migration of monocytes was inhibited by antibody to Abeta receptor (RAGE) and platelet endothelial cell adhesion molecule (PECAM-1). Additionally, Abeta-induced transendothelial migration of monocytes were inhibited by protein kinase C inhibitor and augmented by phosphatase inhibitor. We conclude that interaction of Abeta with RAGE expressed on brain endothelial cells initiates cellular signaling leading to the transendothelial migration of monocytes. We suggest that increased diapedesis of monocytes across the BBB in response to Abeta present either in the peripheral circulation or in the brain parenchyma may play a role in the pathophysiology of Abeta-related vascular disorder
  217. Schmidt, A M; Hofmann, M; Taguchi, A; Yan, S D; Stern, D M. "RAGE: a multiligand receptor contributing to the cellular response in diabetic vasculopathy and inflammation". Seminars in thrombosis & hemostasis. 2000;26(5):485-493 (MEDL:11129404 #140631)       

    RAGE is a multiligand member of the immunoglobulin superfamily of cell surface molecules whose properties extend the paradigm of ligand-receptor interactions. The receptor recognizes families of ligands with diverse structural features, such as advanced glycation endproducts (AGEs), amyloidogenic peptides/polypeptides, amphoterins, and S100/calgranulins rather than individual species. Engagement of RAGE by its ligands upregulates the receptor and initiates a cycle of sustained cellular perturbation; increased levels of RAGE on the cell surface make it an ideal target for subsequent ligand interactions and for propagating cellular dysfunction. At this time, the only means known to break this apparently vicious cycle appears to be blocking access to RAGE or removing the ligands. Taken together, these data suggest that RAGE has the potential to function as a progression factor in a range of disorders (AGEs are relevant to diabetes and other settings of oxidant stress, amyloidogenic peptides are relevant to amyloidoses, S100/calgranulins are relevant to inflammatory disorders, etc.) in which its ligands accumulate. The chronic juxtaposition of ligand and receptor triggers sustained cellular perturbation favoring mechanisms eventuating in tissue injury rather than those that would restore homeostasis
  218. Schmidt, A M; Yan, S D; Yan, S F; Stern, D M. "The biology of the receptor for advanced glycation end products and its ligands". Biochimica & biophysica acta. 2000 Dec 20;1498(2-3):99-111 (MEDL:11108954 #140629)       

    Receptor for advanced glycation end products (RAGE) is a multiligand member of the immunoglobulin superfamily of cell surface molecules whose repertoire of ligands includes advanced glycation end products (AGEs), amyloid fibrils, amphoterins and S100/calgranulins. The overlapping distribution of these ligands and cells overexpressing RAGE results in sustained receptor expression which is magnified via the apparent capacity of ligands to upregulate the receptor. We hypothesize that RAGE-ligand interaction is a propagation factor in a range of chronic disorders, based on the enhanced accumulation of the ligands in diseased tissues. For example, increased levels of AGEs in diabetes and renal insufficiency, amyloid fibrils in Alzheimer's disease brain, amphoterin in tumors and S100/calgranulins at sites of inflammation have been identified. The engagement of RAGE by its ligands can be considered the 'first hit' in a two-stage model, in which the second phase of cellular perturbation is mediated by superimposed accumulation of modified lipoproteins (in atherosclerosis), invading bacterial pathogens, ischemic stress and other factors. Taken together, these 'two hits' eventuate in a cellular response with a propensity towards tissue destruction rather than resolution of the offending pathogenic stimulus. Experimental data are cited regarding this hypothesis, though further studies will be required, especially with selective low molecular weight inhibitors of RAGE and RAGE knockout mice, to obtain additional proof in support of our concept
  219. Yan, S D; Roher, A; Chaney, M; Zlokovic, B; Schmidt, A M; Stern, D. "Cellular cofactors potentiating induction of stress and cytotoxicity by amyloid beta-peptide". Biochimica & biophysica acta. 2000 Jul 26;1502(1):145-157 (MEDL:10899440 #140625)       

    Insights into factors underlying causes of familial Alzheimer's disease (AD), such as mutant forms of beta-amyloid precursor protein and presenilins, and those conferring increased risk of sporadic AD, such as isoforms of apolipoprotein E and polymorphisms of alpha2-macroglobulin, have been rapidly emerging. However, mechanisms through which amyloid beta-peptide (Abeta), the fibrillogenic peptide most closely associated with neurotoxicity in AD, exerts its effects on cellular targets have only been more generally outlined. Late in the course of AD, when Abeta fibrils are abundant, non-specific interactions of amyloid with cellular elements are likely to induce broad cytotoxicity. However, early in AD, when concentrations of Abeta are much lower and extracellular deposits are infrequent, mechanisms underlying cellular dysfunction have not been clearly defined. The key issue in elucidating the means through which Abeta perturbs cellular properties early in AD is the possibility that protective therapy at such times may prevent cytotoxicity at a point when damage is still reversible. This brief review focusses on two cellular cofactors for Abeta-induced cellular perturbation: the cell surface immunoglobulin superfamily molecule RAGE (receptor for advanced glycation endproducts) and ABAD (Abeta binding alcohol dehydrogenase). Although final proof for the involvement of these cofactors in cellular dysfunction in AD must await the results of further in vivo experiments, their increased expression in AD brain, as well as other evidence described below, suggests the possibility of specific pathways for Abeta-induced cellular perturbation which could provide future therapeutic targets
  220. Yan, S D; Zhu, H; Zhu, A; Golabek, A; Du, H; Roher, A; Yu, J; Soto, C; Schmidt, A M; Stern, D; Kindy, M. "Receptor-dependent cell stress and amyloid accumulation in systemic amyloidosis". Nature medicine. 2000 Jun;6(6):643-651 (MEDL:10835680 #140623)       

    Accumulation of fibrils composed of amyloid A in tissues resulting in displacement of normal structures and cellular dysfunction is the characteristic feature of systemic amyloidoses. Here we show that RAGE, a multiligand immunoglobulin superfamily cell surface molecule, is a receptor for the amyloidogenic form of serum amyloid A. Interactions between RAGE and amyloid A induced cellular perturbation. In a mouse model, amyloid A accumulation, evidence of cell stress and expression of RAGE were closely linked. Antagonizing RAGE suppressed cell stress and amyloid deposition in mouse spleens. These data indicate that RAGE is a potential target for inhibiting accumulation of amyloid A and for limiting cellular dysfunction induced by amyloid A
  221. Barile GR; Chang SS; Park LS; Reppucci VS; Schiff WM; Schmidt AM. "Soluble cellular adhesion molecules in proliferative vitreoretinopathy and proliferative diabetic retinopathy". Current eye research. 1999 Sep;19(3):219-227 (MEDL:10487959 #59362)       

    PURPOSE. To measure vitreous levels of soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cellular adhesion molecule-1 (sVCAM-1) in the eyes of patients with retinal detachment (RD) due to proliferative diabetic retinopathy (PDR) or proliferative vitreoretinopathy (PVR) and to determine whether the levels of these mediators correlated with clinical parameters of disease. METHODS. Undiluted vitreous specimens were collected from 50 eyes of 48 patients undergoing vitrectomy for traction RD due to PDR (21 specimens) and recurrent RD due to PVR (19 specimens). Control vitreous specimens were obtained from patients undergoing macular hole repair (10 specimens). The levels of sICAM-1 and sVCAM-1 were measured in each sample by specific enzyme-linked immunoadsorbent assays. RESULTS. Vitreous levels of sICAM-1 were significantly increased in vitreous specimens from both PVR (median +/- SD; 12.0 +/- 76.3 ng/ml; P < 0.01) and PDR (8.4 +/- 24.0 ng/ml; P < 0.01) when compared to vitreous from eyes with macular holes (0. 3 +/- 4.2 ng/ml). Vitreous levels of sVCAM-1 were significantly increased in both PVR (36.5 +/- 255.2 ng/ml; P < 0.001) and PDR (26. 2 +/- 93.5 ng/ml; P < 0.01) when compared to control vitreous (17.7 +/- 7.8 ng/ml). The vitreous levels of sICAM-1 were higher in cases of PDR which developed recurrent proliferative disease (P < 0.01) and recurrent RD (P = 0.01), whereas the levels of sICAM-1 in PVR and sVCAM-1 in PDR and PVR did not significantly correlate with these clinical parameters. CONCLUSIONS. Soluble forms of ICAM-1 and VCAM-1 are increased in the vitreous cavity of patients with RD due to PDR or PVR, reflecting the inflammatory nature of these conditions and suggesting a possible role for these mediators in the pathogenesis of proliferative retinal disease. The vitreous levels of these sCAMs at the time of surgery may serve as a marker of inflammation, but their specific levels do not predict the likelihood of recurrent proliferation or surgical anatomic success in most cases of PVR and PDR
  222. Kislinger, T; Fu, C; Huber, B; Qu, W; Taguchi, A; Du Yan, S; Hofmann, M; Yan, S F; Pischetsrieder, M; Stern, D; Schmidt, A M. "N(epsilon)-(carboxymethyl)lysine adducts of proteins are ligands for receptor for advanced glycation end products that activate cell signaling pathways and modulate gene expression". Journal of biological chemistry. 1999 Oct 29;274(44):31740-31749 (MEDL:10531386 #140619)       

    Recent studies suggested that interruption of the interaction of advanced glycation end products (AGEs), with the signal-transducing receptor receptor for AGE (RAGE), by administration of the soluble, extracellular ligand-binding domain of RAGE, reversed vascular hyperpermeability and suppressed accelerated atherosclerosis in diabetic rodents. Since the precise molecular target of soluble RAGE in those settings was not elucidated, we tested the hypothesis that predominant specific AGEs within the tissues in disorders such as diabetes and renal failure, N(epsilon)-(carboxymethyl)lysine (CML) adducts, are ligands of RAGE. We demonstrate here that physiologically relevant CML modifications of proteins engage cellular RAGE, thereby activating key cell signaling pathways such as NF-kappaB and modulating gene expression. Thus, CML-RAGE interaction triggers processes intimately linked to accelerated vascular and inflammatory complications that typify disorders in which inflammation is an established component
  223. Schmidt, A M; Yan, S D; Wautier, J L; Stern, D. "Activation of receptor for advanced glycation end products: a mechanism for chronic vascular dysfunction in diabetic vasculopathy and atherosclerosis". Circulation research. 1999 Mar 19;84(5):489-497 (MEDL:10082470 #140615)    

    Receptor for advanced glycation end products (RAGE) is a member of the immunoglobulin superfamily of cell surface molecules and engages diverse ligands relevant to distinct pathological processes. One class of RAGE ligands includes glycoxidation products, termed advanced glycation end products, which occur in diabetes, at sites of oxidant stress in tissues, and in renal failure and amyloidoses. RAGE also functions as a signal transduction receptor for amyloid beta peptide, known to accumulate in Alzheimer disease in both affected brain parenchyma and cerebral vasculature. Interaction of RAGE with these ligands enhances receptor expression and initiates a positive feedback loop whereby receptor occupancy triggers increased RAGE expression, thereby perpetuating another wave of cellular activation. Sustained expression of RAGE by critical target cells, including endothelium, smooth muscle cells, mononuclear phagocytes, and neurons, in proximity to these ligands, sets the stage for chronic cellular activation and tissue damage. In a model of accelerated atherosclerosis associated with diabetes in genetically manipulated mice, blockade of cell surface RAGE by infusion of a soluble, truncated form of the receptor completely suppressed enhanced formation of vascular lesions. Amelioration of atherosclerosis in these diabetic/atherosclerotic animals by soluble RAGE occurred in the absence of changes in plasma lipids or glycemia, emphasizing the contribution of a lipid- and glycemia-independent mechanism(s) to atherogenesis, which we postulate to be interaction of RAGE with its ligands. Future studies using mice in which RAGE expression has been genetically manipulated and with selective low molecular weight RAGE inhibitors will be required to definitively assign a critical role for RAGE activation in diabetic vasculopathy. However, sustained receptor expression in a microenvironment with a plethora of ligand makes possible prolonged receptor stimulation, suggesting that interaction of cellular RAGE with its ligands could be a factor contributing to a range of important chronic disorders
  224. Yan, S D; Roher, A; Schmidt, A M; Stern, D M. "Cellular cofactors for amyloid beta-peptide-induced cell stress. Moving from cell culture to in vivo". American journal of pathology. 1999 Nov;155(5):1403-1411 (MEDL:10550293 #140620)       
  225. Mackic JB; Stins M; McComb JG; Calero M; Ghiso J; Kim KS; Yan SD; Stern D; Schmidt AM; Frangione B; Zlokovic BV. "Human blood-brain barrier receptors for Alzheimer's amyloid-beta 1- 40. Asymmetrical binding, endocytosis, and transcytosis at the apical side of brain microvascular endothelial cell monolayer". Journal of clinical investigation. 1998 Aug 15;102(4):734-743 (MEDL:9710442 #7669)       

    A soluble monomeric form of Alzheimer's amyloid-beta (1-40) peptide (sAbeta1-40) is present in the circulation and could contribute to neurotoxicity if it crosses the brain capillary endothelium, which comprises the blood-brain barrier (BBB) in vivo. This study characterizes endothelial binding and transcytosis of a synthetic peptide homologous to human sAbeta1-40 using an in vitro model of human BBB. 125I-sAbeta1-40 binding to the brain microvascular endothelial cell monolayer was time dependent, polarized to the apical side, and saturable with high- and low-affinity dissociation constants of 7.8+/-1.2 and 52.8+/-6.2 nM, respectively. Binding of 125I-sAbeta1-40 was inhibited by anti-RAGE (receptor for advanced glycation end products) antibody (63%) and by acetylated low density lipoproteins (33%). Consistent with these data, transfected cultured cells overexpressing RAGE or macrophage scavenger receptor (SR), type A, displayed binding and internalization of 125I-sAbeta1-40. The internalized peptide remains intact > 94%. Transcytosis of 125I-sAbeta1-40 was time and temperature dependent, asymmetrical from the apical to basolateral side, saturable with a Michaelis constant of 45+/-9 nM, and partially sensitive to RAGE blockade (36%) but not to SR blockade. We conclude that RAGE and SR mediate binding of sAbeta1-40 at the apical side of human BBB, and that RAGE is also involved in sAbeta1-40 transcytosis
  226. Park L; Raman KG; Lee KJ; Lu Y; Ferran LJ Jr; Chow WS; Stern D; Schmidt AM. "Suppression of accelerated diabetic atherosclerosis by the soluble receptor for advanced glycation endproducts". Nature medicine. 1998 Sep;4(9):1025-1031 (MEDL:9734395 #59364)       

    Accelerated atherosclerosis in patients with diabetes is a major cause of their morbidity and mortality, and it is unresponsive to therapy aimed at restoring relative euglycemia. In hyperglycemia, nonenzymatic glycation and oxidation of proteins and lipids results in the accumulation of irreversibly formed advanced glycation endproducts. These advanced glycation endproducts engage their receptor in cells of the blood vessel wall, thereby activating mechanisms linked to the development of vascular lesions. We report here a model of accelerated and advanced atherosclerosis in diabetic mice deficient for apolipoprotein E. Treatment of these mice with the soluble extracellular domain of the receptor for advanced glycation endproducts completely suppressed diabetic atherosclerosis in a glycemia- and lipid-independent manner. These findings indicate interaction between the advanced glycation endproducts and their receptor is involved in the development of accelerated atherosclerosis in diabetes, and identify this receptor as a new therapeutic target in diabetic macrovascular disease
  227. Du Yan, S; Zhu, H; Fu, J; Yan, S F; Roher, A; Tourtellotte, W W; Rajavashisth, T; Chen, X; Godman, G C; Stern, D; Schmidt, A M. "Amyloid-beta peptide-receptor for advanced glycation endproduct interaction elicits neuronal expression of macrophage-colony stimulating factor: a proinflammatory pathway in Alzheimer disease". Proceedings of the National Academy of Sciences of the United States of America. 1997 May 13;94(10):5296-5301 (MEDL:9144231 #140665)    

    In Alzheimer disease (AD), neurons are thought to be subjected to the deleterious cytotoxic effects of activated microglia. We demonstrate that binding of amyloid-beta peptide (Abeta) to neuronal Receptor for Advanced Glycation Endproduct (RAGE), a cell surface receptor for Abeta, induces macrophage-colony stimulating factor (M-CSF) by an oxidant sensitive, nuclear factor kappaB-dependent pathway. AD brain shows increased neuronal expression of M-CSF in proximity to Abeta deposits, and in cerebrospinal fluid from AD patients there was approximately 5-fold increased M-CSF antigen (P < 0.01), compared with age-matched controls. M-CSF released by Abeta-stimulated neurons interacts with its cognate receptor, c-fms, on microglia, thereby triggering chemotaxis, cell proliferation, increased expression of the macrophage scavenger receptor and apolipoprotein E, and enhanced survival of microglia exposed to Abeta, consistent with pathologic findings in AD. These data delineate an inflammatory pathway triggered by engagement of Abeta on neuronal RAGE. We suggest that M-CSF, thus generated, contributes to the pathogenesis of AD, and that M-CSF in cerebrospinal fluid might provide a means for monitoring neuronal perturbation at an early stage in AD
  228. Park L; Raman KG; Lee KJ; Lu Y; Ginsberg MD; Ferran L Jr; Stern DM; Schmidt AM. "A murine model of accelerated diabetic atherosclerosis: supression by soluble receptor for advanced glycation endproducts". Circulation. 1997 Oct 21;96(8 Suppl):550-550 (abstract #3079) (ORIGINAL:0005448 #59371)    
  229. Yan, S D; Stern, D; Schmidt, A M. "What's the RAGE? The receptor for advanced glycation end products (RAGE) and the dark side of glucose". European journal of clinical investigation. 1997 Mar;27(3):179-181 (MEDL:9088851 #140663)       
  230. Hori, O; Yan, S D; Ogawa, S; Kuwabara, K; Matsumoto, M; Stern, D; Schmidt, A M. "The receptor for advanced glycation end-products has a central role in mediating the effects of advanced glycation end-products on the development of vascular disease in diabetes mellitus". Nephrology, dialysis, transplantation. 1996;11 Suppl 5:13-16 (MEDL:9044300 #140662)    

    Proteins or lipids exposed to aldose sugars undergo initial and ultimately irreversible modification resulting in the formation of so-called advanced glycation end-products (AGEs). AGEs are postulated to be especially important in the setting of diabetes mellitus due to hyperglycaemia characteristic of this disorder. Our work has demonstrated that one of the principal means by which AGEs interact with the vascular wall is by interaction with their cellular receptor, the receptor for advanced glycation end-products (RAGE), which is present on the surface of endothelial cells, smooth muscle cells, mesangial cells, mononuclear phagocytes and certain neurons. AGEs interact with RAGE, resulting in the induction of monocyte chemotaxis as well as oxidant stress. One of the consequences of AGE-RAGE-induced cellular oxidant stress is the enhanced expression of vascular cell adhesion molecule-1 on the endothelial surface, a critical consequence of which is the attraction of mononuclear phagocytes into the vessel wall. In both cases, the pro-inflammatory effects of AGEs may be inhibited in the presence of RAGE blockade, using either anti-RAGE F(ab')2 or soluble RAGE, the extracellular domain of the molecule. These data suggest that inhibition of RAGE may interfere with monocyte chemotaxis and attraction into the vessel wall where AGEs deposit/form, suggesting the potential of this intervention to interfere with a critical step in the development of vascular disease, especially in patients with diabetes
  231. Park L; Hori O; Yan SD; Zou YS; Verstuyft J; Rubin EM; Liu JK; Yeo HC; Ames BN; Andaz S; Stern D; Schmidt AM. "An accelerated atherosclerosis model in diabetic apolipoprotein E knockout mice: vascular accumulation of advanced glycation". Circulation. 1996 Oct 15;94(8 Suppl):36-36 (abstract #0200) (ORIGINAL:0005449 #59372)    
  232. Schmidt, A M; Hori, O; Cao, R; Yan, S D; Brett, J; Wautier, J L; Ogawa, S; Kuwabara, K; Matsumoto, M; Stern, D. "RAGE: a novel cellular receptor for advanced glycation end products". Diabetes. 1996 Jul;45 Suppl 3:S77-S80 (MEDL:8674899 #140658)    

    Exposure of proteins to reducing sugars results in nonenzymatic glycation with the ultimate formation of advanced glycation end products (AGEs). One means through which AGEs modulate cellular functions is through binding to specific cell surface acceptor molecules. The receptor for AGEs (RAGE) is such a receptor and is a newly identified member of the immunoglobulin superfamily expressed on endothelial cells (ECs), mononuclear phagocytes (MPs), and vascular smooth muscle cells (SMCs) in both vivo and in vitro. Binding of AGEs to RAGE results in induction of cellular oxidant stress, as exemplified by the generation of thiobarbituric acid-reactive substances, expression of heme oxygenase type I, and activation of the transcription factor NF-kB, with consequences for a range of cellular functions. AGEs on the surface of diabetic red cells enhance binding to endothelial RAGE and result in enhanced oxidant stress in the vessel wall. By using reagents to selectively block access to RAGE, the role of this receptor in AGE-mediated perturbation of cellular properties can be dissected in detail
  233. Yan, S D; Chen, X; Fu, J; Chen, M; Zhu, H; Roher, A; Slattery, T; Zhao, L; Nagashima, M; Morser, J; Migheli, A; Nawroth, P; Stern, D; Schmidt, A M. "RAGE and amyloid-beta peptide neurotoxicity in Alzheimer's disease". Nature. 1996 Aug 22;382(6593):685-691 (MEDL:8751438 #140659)       

    Amyloid-beta peptide is central to the pathology of Alzheimer's disease, because it is neurotoxic--directly by inducing oxidant stress, and indirectly by activating microglia. A specific cell-surface acceptor site that could focus its effects on target cells has been postulated but not identified. Here we present evidence that the 'receptor for advanced glycation end products' (RAGE) is such a receptor, and that it mediates effects of the peptide on neurons and microglia. Increased expressing of RAGE in Alzheimer's disease brain indicates that it is relevant to the pathogenesis of neuronal dysfunction and death
  234. Schmidt, A M; Hori, O; Chen, J X; Li, J F; Crandall, J; Zhang, J; Cao, R; Yan, S D; Brett, J; Stern, D. "Advanced glycation endproducts interacting with their endothelial receptor induce expression of vascular cell adhesion molecule-1 (VCAM-1) in cultured human endothelial cells and in mice. A potential mechanism for the accelerated vasculopathy of diabetes". Journal of clinical investigation. 1995 Sep;96(3):1395-1403 (MEDL:7544803 #140649)       

    Vascular cell adhesion molecule-1 (VCAM-1), an inducible cell-cell recognition protein on the endothelial cell surface (EC), has been associated with early stages of atherosclerosis. In view of the accelerated vascular disease observed in patients with diabetes, and the enhanced expression of VCAM-1 in diabetic rabbits, we examined whether irreversible advanced glycation endproducts (AGEs), could mediate VCAM-1 expression by interacting with their endothelial cell receptor (receptor for AGE, RAGE). Exposure of cultured human ECs to AGEs induced expression of VCAM-1, increased adhesivity of the monolayer for Molt-4 cells, and was associated with increased levels of VCAM-1 transcripts. The inhibitory effect of anti-RAGE IgG, a truncated form of the receptor (soluble RAGE) or N-acetylcysteine on VCAM-1 expression indicated that AGE-RAGE-induced oxidant stress was central to VCAM-1 induction. Electrophoretic mobility shift assays on nuclear extracts from AGE-treated ECs showed induction of specific DNA binding activity for NF-kB in the VCAM-1 promoter, which was blocked by anti-RAGE IgG or N-acetylcysteine. Soluble VCAM-1 antigen was elevated in human diabetic plasma. These data are consistent with the hypothesis that AGE-RAGE interaction induces expression of VCAM-1 which can prime diabetic vasculature for enhanced interaction with circulating monocytes
  235. Schmidt, A M; Yan, S D; Stern, D M. "The dark side of glucose [Comment]". Nature medicine. 1995 Oct;1(10):1002-1004 (MEDL:7489352 #140648)       
  236. Schmidt, A M; Hori, O; Brett, J; Yan, S D; Wautier, J L; Stern, D. "Cellular receptors for advanced glycation end products. Implications for induction of oxidant stress and cellular dysfunction in the pathogenesis of vascular lesions". Arteriosclerosis & thrombosis. 1994 Oct;14(10):1521-1528 (MEDL:7918300 #140651)       

    Advanced glycation end products (AGEs) form by the interaction of aldoses with proteins and the subsequent molecular rearrangements of the covalently linked sugars, eventuating in a diverse group of fluorescent compounds of yellow-brown color. This heterogeneous class of nonenzymatically glycated proteins or lipids is found in the plasma and accumulates in the vessel wall and tissues even in normal aging. As a consequence of hyperglycemia, AGE formation and deposition are much enhanced in diabetes, in which their presence has been linked to secondary complications, especially microvascular disease. This review summarizes the cellular interactions of AGEs and describes the central role of a novel receptor for AGE (RAGE). RAGE, an immunoglobulin superfamily member, mediates the binding of AGEs to endothelial cells and mononuclear phagocytes, interacts with a lactoferrin-like polypeptide that also binds AGEs, and appears to activate intracellular signal transduction mechanisms consequent to its interaction with the glycated ligand. RAGE is expressed by ECs, mononuclear phagocytes, smooth muscle cells, mesangial cells, and neurons, indicating a potential role in the regulation of their properties in homeostasis and/or their dysfunction in the development of diabetic complications. Since AGEs have been shown to generate reactive oxygen intermediates, tethering of AGEs to the cell surface by their receptors focuses oxidant stress on cellular targets, resulting in changes in gene expression and the cellular phenotype. The discovery of RAGE and development of reagents to block its interaction with AGEs should provide insights into the role of this ligand-receptor interaction in the pathogenesis of diabetic complications and, potentially, atherosclerosis
  237. Schmidt, A M; Mora, R; Cao, R; Yan, S D; Brett, J; Ramakrishnan, R; Tsang, T C; Simionescu, M; Stern, D. "The endothelial cell binding site for advanced glycation end products consists of a complex: an integral membrane protein and a lactoferrin-like polypeptide". Journal of biological chemistry. 1994 Apr 1;269(13):9882-9888 (MEDL:8144581 #140652)    

    Advanced glycation end products (AGEs), formed as the result of the extended interaction of proteins with ketoses, modulate central properties of endothelial cells and mononuclear phagocytes by interacting with a cell surface binding site comprised of a novel integral membrane protein (receptor for AGE = RAGE) and a lactoferrin-like polypeptide (LF-L), the latter having sequence identity to lactoferrin (LF). To further understand this cellular binding site, the interaction of RAGE with LF-L and LF was characterized. By ligand blotting and a solid state competitive binding assay, 125I-LF-L and 125I-LF bound to RAGE immobilized on nitrocellulose membranes or polypropylene tubes in a time-dependent and reversible manner, demonstrating a high affinity component with Kd approximately 100 pM. The interaction of 125I-LF-L and 125I-LF with RAGE was independent of iron in LF and was competed by addition of an excess of unlabeled carboxyl-terminal portion of LF. Cross-linking studies with purified 125I-LF-L and RAGE, in the presence of disuccinimidyl suberate, showed a new, slowly migrating band, corresponding to a complex of RAGE and LF-L, and cross-linking on mouse aortic endothelial cells showed two new slowly migrating bands on immunoblotting visualized with both anti-RAGE IgG and anti-LF-L IgG. These data lead us to propose that the endothelial cell surface binding site for AGEs consists of LF-L bound noncovalently to RAGE anchored in the cell membrane
  238. Yan, S D; Schmidt, A M; Anderson, G M; Zhang, J; Brett, J; Zou, Y S; Pinsky, D; Stern, D. "Enhanced cellular oxidant stress by the interaction of advanced glycation end products with their receptors/binding proteins". Journal of biological chemistry. 1994 Apr 1;269(13):9889-9897 (MEDL:8144582 #140653)    

    Attack by reactive oxygen intermediates, common to many kinds of cell/tissue injury, has been implicated in the development of diabetic and other vascular diseases. Such oxygen-free radicals can be generated by advanced glycation end products (AGEs), which are nonenzymatically glycated and oxidized proteins. Since cellular interactions of AGEs are mediated by specific cellular binding proteins, receptor for AGE (RAGE) and the lactoferrin-like polypeptide (LF-L), we tested the hypothesis that AGE ligands tethered to the complex of RAGE and LF-L could induce oxidant stress. AGE albumin or AGEs immunoisolated from diabetic plasma resulted in induction of endothelial cell (EC) oxidant stress, including the generation of thiobarbituric acid reactive substances (TBARS) and resulted in the activation of NF-kappa B, each of which was blocked by antibodies to AGE receptor polypeptides and by antioxidants. Infusion of AGE albumin into normal animals led to the appearance of malondialdehyde determinants in the vessel wall and increased TBARS in the tissues, activation of NF-kappa B, and induction of heme oxygenase mRNA. AGE-induced oxidant stress was inhibited by pretreatment of animals with either antibodies to the AGE receptor/binding proteins or antioxidants. These data indicate that interaction of AGEs with cellular targets, such as ECs, leads to oxidant stress resulting in changes in gene expression and other cellular properties, potentially contributing to the development of vascular lesions. Further studies will be required to dissect whether oxidant stress occurs on the cell surface or at an intracellular locus
  239. Brett, J; Schmidt, A M; Yan, S D; Zou, Y S; Weidman, E; Pinsky, D; Nowygrod, R; Neeper, M; Przysiecki, C; Shaw, A. "Survey of the distribution of a newly characterized receptor for advanced glycation end products in tissues". American journal of pathology. 1993 Dec;143(6):1699-1712 (MEDL:8256857 #140655)    

    Advanced glycation end products (AGEs), the final products of nonenzymatic glycation and oxidation of proteins, are found in the plasma and accumulate in the tissues during aging and at an accelerated rate in diabetes. A novel integral membrane protein, termed receptor for AGE (RAGE), forms a central part of the cell surface binding site for AGEs. Using monospecific, polyclonal antibody raised to human recombinant and bovine RAGE, immunostaining of bovine tissues showed RAGE in the vasculature, endothelium, and smooth muscle cells and in mononuclear cells in the tissues. Consistent with these data, RAGE antigen and mRNA were identified in cultured bovine endothelium, vascular smooth muscle, and monocyte-derived macrophages. RAGE antigen was also visualized in bovine cardiac myocytes as well as in cultures of neonatal rat cardiac myocytes and in neural tissue where motor neurons, peripheral nerves, and a population of cortical neurons were positive. In situ hybridization confirmed the presence of RAGE mRNA in the tissues, and studies with rat PC12 pheochromocytes indicated that they provide a neuronal-related cell culture model for examining RAGE expression. Pathological studies of human atherosclerotic plaques showed infiltration of RAGE-expressing cells in the expanded intima. These results indicate that RAGE is present in multiple tissues and suggest the potential relevance of AGE-RAGE interactions for modulating properties of the vasculature as well as neural and cardiac function, prominent areas of involvement in diabetes and in the normal aging process
  240. Schmidt, A M; Yan, S D; Brett, J; Mora, R; Nowygrod, R; Stern, D. "Regulation of human mononuclear phagocyte migration by cell surface-binding proteins for advanced glycation end products". Journal of clinical investigation. 1993 May;91(5):2155-2168 (MEDL:8387541 #140656)       

    Nonenzymatic glycation of proteins occurs at an accelerated rate in diabetes and can lead to the formation of advanced glycation end products of proteins (AGEs), which bind to mononuclear phagocytes (MPs) and induce chemotaxis. We have isolated two cell surface-associated binding proteins that mediate the interaction of AGEs with bovine endothelial cells. One of these proteins is a new member of the immunoglobulin superfamily of receptors (termed receptor for AGEs or RAGE); and the second is a lactoferrin-like polypeptide (LF-L). Using monospecific antibodies to these two AGE-binding proteins, we detected immunoreactive material on Western blots of detergent extracts from human MPs. Radioligand-binding studies demonstrated that antibody to the binding proteins blocked 125I-AGE-albumin binding and endocytosis by MPs. Chemotaxis of human MPs induced by soluble AGE-albumin was prevented in a dose-dependent manner by intact antibodies raised to the AGE-binding proteins, F(ab')2 fragments of these antibodies and by soluble RAGE. When MP migration in response to N-formyl-Met-Leu-Phe was studied in a chemotaxis chamber with AGE-albumin adsorbed to the upper surface of the chamber membrane, movement of MPs to the lower compartment was decreased because of interaction of the glycated proteins with RAGE and LF-L on the cell surface. The capacity of AGEs to attract and retain MPs was shown by implanting polytetrafluoroethylene (PTFE) mesh impregnated with AGE-albumin into rats: within 4 d a florid mononuclear cell infiltrate was evident in contrast to the lack of a significant cellular response to PTFE with adsorbed native albumin. These data indicate that RAGE and LF-L have a central role in the interaction of AGEs with human mononuclear cells and that AGEs can serve as a nidus to attract MPs in vivo
  241. Neeper, M; Schmidt, A M; Brett, J; Yan, S D; Wang, F; Pan, Y C; Elliston, K; Stern, D; Shaw, A. "Cloning and expression of a cell surface receptor for advanced glycosylation end products of proteins". Journal of biological chemistry. 1992 Jul 25;267(21):14998-15004 (MEDL:1378843 #140641)    

    Advanced glycosylation end products of proteins (AGEs) are nonenzymatically glycosylated proteins which accumulate in vascular tissue in aging and at an accelerated rate in diabetes. A approximately 35-kDa polypeptide with a unique NH2-terminal sequence has been isolated from bovine lung and found to be present on the surface of endothelial cells where it mediates the binding of AGEs (receptor for advanced glycosylation end product or RAGE). Using an oligonucleotide probe based on the amino-terminal sequence of RAGE, an apparently full-length cDNA of 1.5 kilobases was isolated from a bovine lung cDNA library. This cDNA encoded a 394 amino acid mature protein comprised of the following putative domains: an extracellular domain of 332 amino acids, a single hydrophobic membrane spanning domain of 19 amino acids, and a carboxyl-terminal domain of 43 amino acids. A partial clone encoding the human counterpart of RAGE, isolated from a human lung library, was found to be approximately 90% homologous to the bovine molecule. Based on computer analysis of the amino acid sequence of RAGE and comparison with databases, RAGE is a new member of the immunoglobulin superfamily of cell surface molecules and shares significant homology with MUC 18, NCAM, and the cytoplasmic domain of CD20. Expression of the RAGE cDNA in 293 cells allowed them to bind 125I-AGE-albumin in a saturable and dose-dependent manner (Kd approximately 100 nM), blocked by antibody to RAGE. Western blots of 293 cells transfected with RAGE cDNA probed with anti-RAGE IgG demonstrated expression of immunoreactive protein compared to its absence in mock-transfected cells. These results suggest that RAGE functions as a cell surface receptor for AGEs, which could potentially mediate cellular effects of this class of glycosylated proteins
  242. Honegger, A M; Schmidt, A; Ullrich, A; Schlessinger, J. "Evidence for epidermal growth factor (EGF)-induced intermolecular autophosphorylation of the EGF receptors in living cells". Molecular & cellular biology. 1990 Aug;10(8):4035-4044 (MEDL:2164634 #388482)    

    In response to epidermal growth factor (EGF) stimulation, the intrinsic protein tyrosine kinase of EGF receptor is activated, leading to tyrosine phosphorylation of several cellular substrate proteins, including the EGF receptor molecule itself. To test the mechanism of EGF receptor autophosphorylation in living cells, we established transfected cell lines coexpressing a kinase-negative point mutant of EGF receptor (K721A) with an active EGF receptor mutant lacking 63 amino acids from its carboxy terminus. The addition of EGF to these cells caused tyrosine phosphorylation of the kinase-negative mutant by the active receptor molecule, demonstrating EGF receptor cross-phosphorylation in living cells. After internalization the kinase-negative mutant and CD63 have separate trafficking pathways. This limits their association and the extent of cross-phosphorylation of K721A by CD63. The coexpression of the kinase-negative mutant together with active EGF receptors in the same cells suppressed the mitogenic response toward EGF as compared with that in cells that express active receptors alone. The presence of the kinase-negative mutant functions as a negative dominant mutation suppressing the response of active EGF receptors, probably by interfering with EGF-induced signal transduction. It appears, therefore, that crucial events of signal transduction occur before K721A and active EGF receptors are separated by their different endocytic itineraries.
  243. Honegger, A M; Schmidt, A; Ullrich, A; Schlessinger, J. "Separate endocytic pathways of kinase-defective and -active EGF receptor mutants expressed in same cells". Journal of cell biology. 1990 May;110(5):1541-1548 (MEDL:2335562 #388492)       

    Ligand binding to the membrane receptor for EGF induces its clustering and internalization. Both receptor and ligand are then degraded by lysosomal enzymes. A kinase defective point mutant (K721A) of EGF receptor undergoes internalization similarly to the wild-type receptor. However, while internalized EGF molecules bound to either the wild-type or mutant receptors are degraded, the K721A mutant receptor molecules recycle to the cell surface for reutilization. To investigate the mechanism of receptor trafficking, we have established transfected NIH-3T3 cells coexpressing the kinase-negative mutant (K721A) together with a mutant EGF receptor (CD63) with active kinase. CD63 was chosen because it behaves like wild-type EGF receptor with respect to biological responsiveness and cellular routing but afforded immunological distinction between kinase active and inactive mutants. Although expressed in the same cells, the two receptor mutants followed their separate endocytic itineraries. Like wild-type receptor, the CD63 mutant was downregulated and degraded in response to EFG while the kinase-negative mutant K721A returned to the cell surface for reutilization. Intracellular trafficking of EGF receptor must be determined by a sorting mechanism that specifically recognizes EGF receptor molecules according to their intrinsic kinase activity.
  244. Lax, I; Bellot, F; Honegger, A M; Schmidt, A; Ullrich, A; Givol, D; Schlessinger, J. "Domain deletion in the extracellular portion of the EGF-receptor reduces ligand binding and impairs cell surface expression". Cell regulation. 1990 Jan;1(2):173-188 (MEDL:2100196 #388512)    

    Cultured NIH-3T3 cells were transfected with cDNA constructs encoding human epidermal growth factor-receptor (EGF-R)* and two deletion mutants in the extracellular portion of the receptor molecule. One mutant is devoid of 124 amino-terminal amino acids, and the other lacks 76 residues. Mutant receptors were not delivered to the cell surface unless the transfected cells contained also endogenous EGF-Rs, suggesting that receptor interaction complements the mutation and allows surface display of mutant receptors. Immunoprecipitation experiments revealed an association between mutant and endogenous EGF-Rs when both proteins were expressed in the same cell. Hence, receptor-oligomers may exist in the plane of the membrane even in the absence of ligand binding, and oligomerization may play a role in normal trafficking of EGF-Rs to the cell surface. Mutant receptors retained partial ligand binding activity as 125I-labeled EGF was covalently cross-linked to both mutant receptors, and EGF stimulated, albeit weakly, their protein tyrosine kinase activity. Both mutant EGF-Rs bind EGF with a 10-fold lower affinity than that of the solubilized wild type EGF-R. These results provide further evidence that the region flanked by the two cysteine-rich domains plays a crucial role in defining ligand-binding specificity of EGF-R.
  245. Honegger, A; Dull, T J; Bellot, F; Van Obberghen, E; Szapary, D; Schmidt, A; Ullrich, A; Schlessinger, J. "Biological activities of EGF-receptor mutants with individually altered autophosphorylation sites". EMBO journal. 1988 Oct;7(10):3045-3052 (MEDL:3263271 #388602)    

    In vitro site-directed mutagenesis was used to replace individually the three known autophosphorylation sites of the epidermal growth factor (EGF)-receptor (i.e. Tyr1173, Tyr1148 and Tyr1068) by phenylalanine, a residue which cannot serve as a phosphate acceptor site. In another mutant, Tyr1173 was substituted by a serine residue. The cDNA constructs encoding either mutant or wild-type EGF-receptors were transfected into NIH-3T3 cells devoid of endogenous EGF-receptors. The mutant receptors were expressed on the cell surface and displayed typical high- and low-affinity binding sites for [125I]EGF. Phorbol ester (PMA) modulated the binding affinity of wild-type and mutant receptors in a similar manner. Mutant EGF-receptors exhibited EGF-dependent tyrosine kinase activity leading to self-phosphorylation and phosphorylation of exogenous substrates both in vitro and in living cells. The internalization and degradation of EGF-receptors were not affected by the mutations. Cells expressing mutant EGF-receptors became mitogenically responsive to EGF, indicating that none of the vital functions of the EGF-receptor were critically impaired by the loss of individual autophosphorylation sites. Maximal mitogenic stimulation correlated with the number of wild-type or mutant receptors per cell, highly expressing cells showing higher maximal stimulation. However, the dose-response curves of cells expressing mutant receptors were slightly shifted to lower concentrations of EGF, rendering the cells mitogenically responsive to lower doses of EGF than cells expressing normal EGF-receptor at similar expression levels. Basal [3H]thymidine incorporation in the presence of 0.5% calf serum was consistently higher for cells expressing mutant receptors, while the response to stimulation with 10% calf serum was not affected.
  246. Honegger, A M; Dull, T J; Felder, S; Van Obberghen, E; Bellot, F; Szapary, D; Schmidt, A; Ullrich, A; Schlessinger, J. "Point mutation at the ATP binding site of EGF receptor abolishes protein-tyrosine kinase activity and alters cellular routing". Cell. 1987 Oct;51(2):199-209 (MEDL:3499230 #170455)       

    Cultured NIH 3T3 cells devoid of endogenous EGF receptors were transfected with cDNA constructs encoding either the human EGF receptor or an EGF receptor mutant in which Lys721, a key residue in the ATP binding site, was replaced with an alanine residue. The mutant receptor was properly processed, and it displayed both high- and low-affinity surface binding sites. Unlike the wild-type receptor, the mutant receptor did not possess intrinsic protein-tyrosine kinase activity. The initial rate of EGF internalization was similar for wild-type and mutant EGF receptors. Surprisingly, the mutant receptors were not down regulated, but appeared to recycle in transfected cells. These data suggest that degradation of normal EGF receptors after endocytosis is due to the kinase activity endogenous to this receptor. A single amino acid substitution rendered a "down-regulated" receptor into a receptor that can recycle from cytoplasmic compartment back to the cell surface.
  247. Honegger, A M; Szapary, D; Schmidt, A; Lyall, R; Van Obberghen, E; Dull, T J; Ullrich, A; Schlessinger, J. "A mutant epidermal growth factor receptor with defective protein tyrosine kinase is unable to stimulate proto-oncogene expression and DNA synthesis". Molecular & cellular biology. 1987 Dec;7(12):4568-4571 (MEDL:3501826 #388572)    

    Cultured NIH-3T3 cells devoid of endogenous epidermal growth factor (EGF) receptors were transfected with cDNA expression constructs encoding either normal human EGF receptor or a receptor mutated in vitro at Lys-721, a residue that is thought to function as part of the ATP-binding site of the kinase domain. Unlike the wild-type EGF-receptor expressed in these cells, which exhibited EGF-dependent protein tyrosine kinase activity, the mutant receptor lacked protein tyrosine kinase activity and was unable to undergo autophosphorylation and to phosphorylate exogenous substrates. Despite this deficiency, the mutant receptor was normally expressed on the cell surface, and it exhibited both high- and low-affinity binding sites. The addition of EGF to cells expressing wild-type receptors caused the stimulation of various responses, including enhanced expression of proto-oncogenes c-fos and c-myc, morphological changes, and stimulation of DNA synthesis. However, in cells expressing mutant receptors, EGF was unable to stimulate these responses, suggesting that the tyrosine kinase activity is essential for EGF receptor signal transduction.
  248. Blum RH; Cooper J; Schmidt AM; Ashinoff R; Collins A; Wernz JC; Speyer JL; Boyd A; Muggia FM. "Cisplatin and vinblastine chemotherapy for metastatic non-small cell carcinoma followed by irradiation in patients with regional disease". Cancer treatment reports. 1986 Mar;70(3):333-337 (MEDL:3955544 #15695)    

    Forty-four patients with non-small cell carcinoma of the lung were treated every 3 weeks with vinblastine (4 mg/m2/day iv X 2) and cisplatin (20 mg/m2/day iv X 3). Of the 28 patients with metastatic disease, eight (29%; 90% confidence interval of true response, 17%-47%) achieved objective response, for a median duration of 27 weeks. Median survival in this group was 47 and 28 weeks for responders and nonresponders, respectively. Of the 16 patients with advanced regional disease, 11 (69%; 90% confidence interval of true response, 49%-86%) achieved objective response. Thirteen of these patients received consolidation radiotherapy (4500 cGy/25 fractions/5 weeks), with a boost of 1000 cGy/5 fractions/1 week in those patients who achieved response. In the three patients who did not receive radiotherapy, two died during the induction phase, one from grade 4 leukopenia and sepsis and the second from unrelated factors. The third patient had systemic progression of disease during induction chemotherapy. Six patients experienced overall improvement in their chemotherapy response from the radiotherapy. Two patients who did not respond to the chemotherapy achieved partial response with irradiation. Four patients who had partial response to the chemotherapy achieved complete response with irradiation, and seven patients had no further change in their degree of response to irradiation. The overall median survival of this group was 81 weeks. Maintenance chemotherapy was not given. After radiotherapy, the site of first failure was outside the radiation field in nine of 13 patients (69%). Hematologic toxicity was dose-limiting. Other toxic effects that were not dose-limiting included nephrotoxicity, neurotoxicity, and acute nausea and vomiting. In the patients with advanced regional disease, there was no increase in the radiation toxicity attributable to the chemotherapy. We conclude that: (a) this dose schedule of vinblastine and cisplatin has reproducible activity in non-small cell carcinoma of the lung; (b) the response and median survival of patients with advanced regional disease are superior to those of patients with metastatic disease; and (c) in patients with advanced regional disease, treatment with chemotherapy followed by radiotherapy yielded an overall response rate of 81% (90% confidence interval of true response, 60%-93%) and improved survival compared to a similar group of patients studied by others receiving radiotherapy alone. We recommend further testing of this concept
  249. Schmidt AM; Blum RH; Clayton M; Speyer JL; Bottino J; Muggia FM. "Phase II trial of cyclophosphamide and cis-platinum for non-small cell bronchogenic carcinoma". American journal of clinical oncology. 1984 Dec;7(6):725-727 (MEDL:6543291 #35105)       

    We hypothesized that cyclophosphamide and cis-platinum, without adriamycin, which had been used in previous studies, may be equally efficacious, but less toxic. We treated 27 patients with non-small cell bronchogenic carcinoma with the combination of cyclophosphamide and cis-platinum. We report six responses (25% response rate), with median survival of 79 weeks as compared to 28 weeks in nonresponders (p less than 0.01). Our regimen had acceptable hematologic toxicity and tolerable gastrointestinal toxicity. However, cumulative nephrotoxicity and neurotoxicity were observed. We conclude that cyclophosphamide and cis-platinum may compare favorably to the cyclophosphamide, adriamycin and cis-platinum combination, with respect to response and toxicity

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