Faculty Bibliography

Background/UNASSIGNED:Multiple studies demonstrate the benefit of a vegan diet on cardiovascular risk factors when compared to no intervention or usual dietary patterns. The aim of this study is to evaluate the effect of a vegan diet versus the American Heart Association (AHA)-recommended diet on inflammatory and glucometabolic profiles in patients with angiographically defined coronary artery disease (CAD). Study Design/UNASSIGNED:This study is a randomized, open label, blinded end-point trial of 100 patients with CAD as defined by ≥50% diameter stenosis in a coronary artery ≥2 mm in diameter on invasive angiography. Participants are randomized to 8 weeks of either a vegan or AHA-recommended diet (March 2014 and February 2017). Participants are provided weekly groceries that adhere to the guidelines of their diet. The primary endpoint is high sensitivity C-reactive concentrations. Secondary endpoints include anthropometric data, other markers of inflammation, lipid parameters, glycemic markers, endothelial function, quality of life data, and assessment of physical activity. Endpoints are measured at each visit (baseline, 4 weeks, and 8 weeks). Dietary adherence is measured by two weekly 24-hour dietary recalls, a 4-day food record during the week prior to each visit, and both plasma and urine levels of trimethylamine-N-oxide at each visit. Conclusion/UNASSIGNED:This study is the first to comprehensively assess multiple indices of inflammation and glucometabolic profile in a rigorously conducted randomized trial of patients with CAD on a vegan versus AHA-recommended diet.

High throughput technologies opened a new era in biomedicine by enabling massive analysis of gene expression at both RNA and protein levels. Unfortunately, expression data obtained in different experiments are often poorly compatible, even for the same biologic samples. Here, using experimental and bioinformatic investigation of major experimental platforms, we show that aggregation of gene expression data at the level of molecular pathways helps to diminish cross- and intra-platform bias otherwise clearly seen at the level of individual genes. We created a mathematical model of cumulative suppression of data variation that predicts the ideal parameters and the optimal size of a molecular pathway. We compared the abilities to aggregate experimental molecular data for the 5 alternative methods, also evaluated by their capacity to retain meaningful features of biologic samples. The bioinformatic method OncoFinder showed optimal performance in both tests and should be very useful for future cross-platform data analyses.

BACKGROUND:Atsttrin, an engineered protein composed of three tumor necrosis factor receptor (TNFR)-binding fragments of progranulin (PGRN), shows therapeutic effect in multiple murine models of inflammatory arthritis . Additionally, intra-articular delivery of PGRN protects against osteoarthritis (OA) progression. The purpose of this study is to determine whether Atsttrin also has therapeutic effects in OA and the molecular mechanisms involved. METHODS:Surgically induced and noninvasive rupture OA models were established in mouse and rat, respectively. Cartilage degradation and OA were evaluated using Safranin O staining, immunohistochemistry, and ELISA. Additionally, expressions of pain-related markers, degenerative factors, and anabolic and catabolic markers known to be involved in OA were analyzed. Furthermore, the anabolic and anti-catabolic effects and underlying mechanisms of Atsttrin were determined using in-vitro assays with primary chondrocytes. RESULTS:Herein, we found Atsttrin effectively prevented the accelerated OA phenotype associated with PGRN deficiency. Additionally, Atsttrin exhibited a preventative effect in OA by protecting articular cartilage and reducing OA-associated pain in both nonsurgically induced rat and surgically induced murine OA models. Mechanistic studies revealed that Atsttrin stimulated TNFR2-Akt-Erk1/2-dependent chondrocyte anabolism, while inhibiting TNFα/TNFR1-mediated inflammatory catabolism. CONCLUSIONS:These findings not only provide new insights into the role of PGRN and its derived engineered protein Atsttrin in cartilage homeostasis as well as OA in vivo, but may also lead to new therapeutic alternatives for OA as well as other relative degenerative joint diseases.

Purpose: The intrawound application of lyophilized vancomycin has been reported to significantly decrease the rates of perioperative infection in arthroplasty and spine procedures. The local effect of clinically used supra-therapeutic concentration of intra wound vancomycin on surrounding healing tissue has been a topic of continued investigation. The purpose of this study was to examine the in vitro cytotoxicity profile of vancomycin hydrochloride on osteoblasts, fibroblast, and myoblasts. Methods: Human primary osteoblasts (Lonza), fibroblasts (Lonza), and myoblasts (DV Biologics) were expanded and passaged in sterile polystyrene tissue culture flasks and plated at a density of 10,000 cells/cm2. Cells were exposed to vancomycin hydrochloride (Sigma-Aldrich) at concentrations of 1, 3, 6, or 12 mg/cm2. To assess the effect of vancomycin on cell migration, a scratch assay was performed, in which a "scratch" was made in a cell monolayer following vancomycin exposure, and images were subsequently captured at regular intervals until cellular closure of the scratch. Cell survival was measured 48 hours post-vancomycin exposure using a cell cytotoxicity assay (Cell Counting Kit-8, Dojindo). Results: Vancomycin concentrations greater than or equal to 1 mg/cm2 decreased survival of myoblasts and osteoblasts to less than 11% relative to control. Vancomycin greater than or equal to 3 mg/ cm2 decreased fibroblast survival to less than 8% relative to control (Fig. 1). Vancomycin concentrations of 1 mg/cm2 did not significantly affect the survival of fibroblasts. Closure of the scratch defect was observed in less than 24 hours for all control conditions. In myoblasts and osteoblasts, the scratch defect remained open indefinitely following exposure to vancomycin concentrations greater than or equal to 1 mg/cm2. Closure of the scratch defect in fibroblasts was observed in less than 36 hours following exposure to vancomycin of 1 mg/cm2, and remained opened indefinitely following exposure to vancomycin greater than or equal to 3 mg/cm2. Conclusions: Vancomycin has a significant cytotoxic effect on proliferating osteoblasts and myoblasts at concentrations greater than (Figure Presented) or equal to 1 mg/cm2.Vancomycin has a pronounced cytotoxic effect on fibroblasts at concentrations greater than or equal to 3 mg/cm2. Further in vivo studies are warranted to investigate the effect of high local concentrations of vancomycin on infection, bony fusion, and wound healing

Transposable elements can drive genome evolution, but their enhanced activity is detrimental to the host and therefore must be tightly regulated. The Piwi-interacting small RNA (piRNA) pathway is vital for the regulation of transposable elements, by inducing transcriptional silencing or post-transcriptional decay of mRNAs. Here we show that piRNAs and piRNA biogenesis components regulate precursor mRNA splicing of P-transposable element transcripts in vivo, leading to the production of the non-transposase-encoding mature mRNA isoform in Drosophila germ cells. Unexpectedly, we show that the piRNA pathway components do not act to reduce transcript levels of the P-element transposon during P-M hybrid dysgenesis, a syndrome that affects germline development in Drosophila. Instead, splicing regulation is mechanistically achieved together with piRNA-mediated changes to repressive chromatin states, and relies on the function of the Piwi-piRNA complex proteins Asterix (also known as Gtsf1) and Panoramix (Silencio), as well as Heterochromatin protein 1a (HP1a; encoded by Su(var)205). Furthermore, we show that this machinery, together with the piRNA Flamenco cluster, not only controls the accumulation of Gypsy retrotransposon transcripts but also regulates the splicing of Gypsy mRNAs in cultured ovarian somatic cells, a process required for the production of infectious particles that can lead to heritable transposition events. Our findings identify splicing regulation as a new role and essential function for the Piwi pathway in protecting the genome against transposon mobility, and provide a model system for studying the role of chromatin structure in modulating alternative splicing during development.

Effective anti-rat sarcoma viral oncogene (RAS) therapies have remained the holy grail of cancer treatment. Mutant Kirsten rat sarcoma viral oncogene homolog (KRAS) sustains tumorigenesis when linked to the plasma membrane (PM). The G protein-coupled receptor 31 (GPR31) is now identified to mediate KRAS membrane association and is crucial for proliferation, survival and macropinocytosis of KRAS-dependent cancer cells, suggesting that GPR31 is a druggable target for anti-RAS therapy.

Muscle fiber length is nearly uniform within a muscle but widely different among different muscles. We show that Abelson tyrosine-protein kinase 2 (Abl2) has a key role in regulating myofiber length, as a loss of Abl2 leads to excessively long myofibers in the diaphragm, intercostal and levator auris muscles but not limb muscles. Increased myofiber length is caused by enhanced myoblast proliferation, expanding the pool of myoblasts and leading to increased myoblast fusion. Abl2 acts in myoblasts, but as a consequence of expansion of the diaphragm muscle, the diaphragm central tendon is reduced in size, likely contributing to reduced stamina of Abl2 mutant mice. Ectopic muscle islands, each composed of myofibers of uniform length and orientation, form within the central tendon of Abl2+/- mice. Specialized tendon cells, resembling tendon cells at myotendinous junctions, form at the ends of these muscle islands, suggesting that myofibers induce differentiation of tendon cells, which reciprocally regulate myofiber length and orientation.

BACKGROUND/BACKGROUND:Cardiac sodium channel (NaV1.5) dysfunction contributes to arrhythmogenesis during pathophysiological conditions. Nav1.5 localizes to distinct subcellular microdomains within the cardiomyocyte, where it associates with region-specific proteins, yielding complexes whose function is location specific. We herein investigated sodium channel remodeling within distinct cardiomyocyte microdomains during heart failure. METHODS AND RESULTS/RESULTS:Mice were subjected to 6 weeks of transverse aortic constriction (TAC; n=32) to induce heart failure. Sham-operated on mice were used as controls (n=20). TAC led to reduced left ventricular ejection fraction, QRS prolongation, increased heart mass, and upregulation of prohypertrophic genes. Whole-cell sodium current (INa) density was decreased by 30% in TAC versus sham-operated on cardiomyocytes. On macropatch analysis, INa in TAC cardiomyocytes was reduced by 50% at the lateral membrane (LM) and by 40% at the intercalated disc. Electron microscopy and scanning ion conductance microscopy revealed remodeling of the intercalated disc (replacement of [inter-]plicate regions by large foldings) and LM (less identifiable T tubules and reduced Z-groove ratios). Using scanning ion conductance microscopy, cell-attached recordings in LM subdomains revealed decreased INa and increased late openings specifically at the crest of TAC cardiomyocytes, but not in groove/T tubules. Failing cardiomyocytes displayed a denser, but more stable, microtubule network (demonstrated by increased α-tubulin and Glu-tubulin expression). Superresolution microscopy showed reduced average NaV1.5 cluster size at the LM of TAC cells, in line with reduced INa. CONCLUSIONS/CONCLUSIONS:Heart failure induces structural remodeling of the intercalated disc, LM, and microtubule network in cardiomyocytes. These adaptations are accompanied by alterations in NaV1.5 clustering and INa within distinct subcellular microdomains of failing cardiomyocytes.