Try a new search

Format these results:

Searched for:

school:SOM

Department/Unit:Cell Biology

Total Results:

14178


Studies in Fat Grafting: Part I. Effects of Injection Technique on in vitro Fat Viability and in vivo Volume Retention

Chung, Michael T; Paik, Kevin J; Atashroo, David A; Hyun, Jeong S; McArdle, Adrian; Senarath-Yapa, Kshemendra; Zielins, Elizabeth R; Tevlin, Ruth; Duldulao, Chris; Hu, Michael S; Walmsley, Graham G; Parisi-Amon, Andreina; Momeni, Arash; Rimsa, Joe R; Commons, George W; Gurtner, Geoffrey C; Wan, Derrick C; Longaker, Michael T
BACKGROUND:: Fat grafting has become increasingly popular for the correction of soft tissue deficits at many sites throughout the body. Long-term outcomes, however, depend on delivery of fat in the least traumatic fashion to optimize viability of the transplanted tissue. In this study, we compare the biologic properties of fat following injection using two methods. METHODS:: Lipoaspiration samples were obtained from five female donors and cellular viability, proliferation, and lipolysis were evaluated following injection using either a modified Coleman technique or an automated, low shear device. Comparisons were made to minimally processed, uninjected fat. Volume retention was also measured over twelve weeks following injection of fat under the scalp of immunodeficient mice using either the modified Coleman technique or the Adipose Tissue Injector. Finally, fat grafts were analyzed histologically. RESULTS:: Fat viability and cellular proliferation were both significantly greater with the Adipose Tissue Injector relative to injection with the modified Coleman technique. In contrast, significantly less lipolysis was noted using the automated device. In vivo fat volume retention was significantly greater than with the modified Coleman technique at 4, 6, 8, and 12 week time points. This corresponded with significantly greater histological scores for healthy fat and lower scores for injury following injection with the device. CONCLUSIONS:: Biological properties of injected tissues reflect how disruptive and harmful techniques for placement of fat may be, and our in vitro and in vivo data both support the use of the automated, low shear devices compared to the modified Coleman technique.
PMCID:4102616
PMID: 24622574
ISSN: 1529-4242
CID: 901162

FGFR3 induces degradation of BMP type I receptor to regulate skeletal development

Qi, Huabing; Jin, Min; Duan, Yaqi; Du, Xiaolan; Zhang, Yuanquan; Ren, Fangli; Wang, Yinyin; Tian, Qingyun; Wang, Xiaofeng; Wang, Quan; Zhu, Ying; Xie, Yangli; Liu, Chuanju; Cao, Xu; Mishina, Yuji; Chen, Di; Deng, Chu-Xia; Chang, Zhijie; Chen, Lin
Fibroblast growth factors (FGFs) and their receptors (FGFRs) play significant roles in vertebrate organogenesis and morphogenesis. FGFR3 is a negative regulator of chondrogenesis and multiple mutations with constitutive activity of FGFR3 result in achondroplasia, one of the most common dwarfisms in humans, but the molecular mechanism remains elusive. In this study, we found that chondrocyte-specific deletion of BMP type I receptor a (Bmpr1a) rescued the bone overgrowth phenotype observed in Fgfr3 deficient mice by reducing chondrocyte differentiation. Consistently, using in vitro chondrogenic differentiation assay system, we demonstrated that FGFR3 inhibited BMPR1a-mediated chondrogenic differentiation. Furthermore, we showed that FGFR3 hyper-activation resulted in impaired BMP signaling in chondrocytes of mouse growth plates. We also found that FGFR3 inhibited BMP-2- or constitutively activated BMPR1-induced phosphorylation of Smads through a mechanism independent of its tyrosine kinase activity. We found that FGFR3 facilitates BMPR1a to degradation through Smurf1-mediated ubiquitination pathway. We demonstrated that down-regulation of BMP signaling by BMPR1 inhibitor dorsomorphin led to the retardation of chondrogenic differentiation, which mimics the effect of FGF-2 on chondrocytes and BMP-2 treatment partially rescued the retarded growth of cultured bone rudiments from thanatophoric dysplasia type II mice. Our findings reveal that FGFR3 promotes the degradation of BMPR1a, which plays an important role in the pathogenesis of FGFR3-related skeletal dysplasia.
PMCID:4111238
PMID: 24657641
ISSN: 0006-3002
CID: 863262

A novel genome-wide in vivo screen for metastatic suppressors in human colon cancer identifies the positive WNT-TCF pathway modulators TMED3 and SOX12

Duquet, Arnaud; Melotti, Alice; Mishra, Sonakshi; Malerba, Monica; Seth, Chandan; Conod, Arwen; Ruiz I Altaba, Ariel
The progression of tumors to the metastatic state involves the loss of metastatic suppressor functions. Finding these, however, is difficult as in vitro assays do not fully predict metastatic behavior, and the majority of studies have used cloned cell lines, which do not reflect primary tumor heterogeneity. Here, we have designed a novel genome-wide screen to identify metastatic suppressors using primary human tumor cells in mice, which allows saturation screens. Using this unbiased approach, we have tested the hypothesis that endogenous colon cancer metastatic suppressors affect WNT-TCF signaling. Our screen has identified two novel metastatic suppressors: TMED3 and SOX12, the knockdown of which increases metastatic growth after direct seeding. Moreover, both modify the type of self-renewing spheroids, but only knockdown of TMED3 also induces spheroid cell spreading and lung metastases from a subcutaneous xenograft. Importantly, whereas TMED3 and SOX12 belong to different families involved in protein secretion and transcriptional regulation, both promote endogenous WNT-TCF activity. Treatments for advanced or metastatic colon cancer may thus not benefit from WNT blockers, and these may promote a worse outcome.
PMCID:4119353
PMID: 24920608
ISSN: 1757-4676
CID: 1033752

Developing Core Outcome Measurement Sets for Clinical Trials: OMERACT Filter 2.0

Boers, Maarten; Kirwan, John R; Wells, George; Beaton, Dorcas; Gossec, Laure; d'Agostino, Maria-Antonietta; Conaghan, Philip G; Bingham, Clifton O 3rd; Brooks, Peter; Landewe, Robert; March, Lyn; Simon, Lee S; Singh, Jasvinder A; Strand, Vibeke; Tugwell, Peter
BACKGROUND: Lack of standardization of outcome measures limits the usefulness of clinical trial evidence to inform health care decisions. This can be addressed by agreeing on a minimum core set of outcome measures per health condition, containing measures relevant to patients and decision makers. Since 1992, the Outcome Measures in Rheumatology (OMERACT) consensus initiative has successfully developed core sets for many rheumatologic conditions, actively involving patients since 2002. Its expanding scope required an explicit formulation of its underlying conceptual framework and process. METHODS: Literature searches and iterative consensus process (surveys and group meetings) of stakeholders including patients, health professionals, and methodologists within and outside rheumatology. RESULTS: To comprehensively sample patient-centered and intervention-specific outcomes, a framework emerged that comprises three core "Areas," namely Death, Life Impact, and Pathophysiological Manifestations; and one strongly recommended Resource Use. Through literature review and consensus process, core set development for any specific health condition starts by identifying at least one core "Domain" within each of the Areas to formulate the "Core Domain Set." Next, at least one applicable measurement instrument for each core Domain is identified to formulate a "Core Outcome Measurement Set." Each instrument must prove to be truthful (valid), discriminative, and feasible. In 2012, 96% of the voting participants (n=125) at the OMERACT 11 consensus conference endorsed this model and process. CONCLUSION: The OMERACT Filter 2.0 explicitly describes a comprehensive conceptual framework and a recommended process to develop core outcome measurement sets for rheumatology likely to be useful as a template in other areas of health care.
PMID: 24582946
ISSN: 0895-4356
CID: 910242

Telomere length, family history, and paternal age in schizophrenia

Malaspina, Dolores; Dracxler, Roberta; Walsh-Messinger, Julie; Harlap, Susan; Goetz, Raymond R; Keefe, David; Perrin, Mary C
Leukocyte telomere length (LTL) is longer in association with advanced paternal age, but this association has not been examined along with family history (FH) in schizophrenia. LTL was measured by PCR and compared across cases and controls as part of a study to examine the characteristics of paternal age related schizophrenia. The 53 schizophrenia cases had similar mean LTL as 20 controls, although cases were significantly older than controls and overwhelmingly smoked cigarettes. Multivariate analyses showed that a FH of schizophrenia was associated with longer LTL in both male and female cases. Later paternal age was also related to longer LTL in male cases, but with shorter LTL in female cases. Male cases with older fathers and a FH had the longest LTL. The genetic architecture associated with a familial risk for schizophrenia may include pathways that lengthen LTL. Paternal aging conferred an additional increase in LTL lengthening in male cases, but reduced LTL in female cases. The gender difference in LTL for paternal aging is consistent with the severe illness features reported for female cases with older fathers and could implicate epigenetic alterations in the paternal X chromosomal region with advanced paternal age in association with the risk for schizophrenia.
PMCID:4113273
PMID: 25077175
ISSN: 2324-9269
CID: 1090242

Metabolism and function of mitochondrial cardiolipin

Ren, Mindong; Phoon, Colin K L; Schlame, Michael
Since it has been recognized that mitochondria are crucial not only for energy metabolism but also for other cellular functions, there has been a growing interest in cardiolipin, the specific phospholipid of mitochondrial membranes. Indeed, cardiolipin is a universal component of mitochondria in all eukaryotes. It has a unique dimeric structure comprised of two phosphatidic acid residues linked by a glycerol bridge, which gives rise to unique physicochemical properties. Cardiolipin plays an important role in the structural organization and the function of mitochondrial membranes. In this article, we review the literature on cardiolipin biology, focusing on the most important discoveries of the past decade. Specifically, we describe the formation, the migration, and the degradation of cardiolipin and we discuss how cardiolipin affects mitochondrial function. We also give an overview of the various phenotypes of cardiolipin deficiency in different organisms.
PMID: 24769127
ISSN: 0163-7827
CID: 932362

Studies in Fat Grafting: Part II. Effects of Injection Mechanics on Material Properties of Fat

Atashroo, David; Raphel, Jordan; Chung, Michael T; Paik, Kevin J; Parisi-Amon, Andreina; McArdle, Adrian; Senarath-Yapa, Kshemendra; Zielins, Elizabeth R; Tevlin, Ruth; Duldulao, Chris; Walmsley, Graham G; Hu, Michael S; Momeni, Arash; Domecus, Brian; Rimsa, Joe R; Greenberg, Lauren; Gurtner, Geoffrey C; Longaker, Michael T; Wan, Derrick C
BACKGROUND: Although fat grafting can address many soft-tissue deficits, results remain inconsistent. In this study, the authors compared physical properties of fat following injection using an automated, low-shear device or the modified Coleman technique. METHODS: Lipoaspirate was obtained from nine patients and processed for injection using either a modified Coleman technique or an automated, low-shear device. Fat was passed through a 2-mm cannula and compared with minimally processed fat. A rheometer was used to measure the storage modulus and shear rate at which tissues began to lose their solid-like properties. Viscosity was also measured, and gross properties of treatment groups were evaluated qualitatively with a glass slide test. RESULTS: Fat injected through an automated, low-shear device closely matched physical properties of minimally processed fat. The storage modulus (G') of fat for the device group was greater than for the modified Coleman group, and the onset of breakdown was delayed. Similarly, viscosity measurement of fat from the automated device closely matched minimally processed fat and was greater than that of othe modified Coleman group. CONCLUSIONS: The physical properties of lipoaspirate processed using an automated, low-shear device with a 2-mm cannula preserved the intactness of fat more than the modified Coleman technique. The authors' rheologic data demonstrate less damage using an automated device compared with the modified Coleman technique and potentially support its use for improved fat graft integrity.
PMCID:4101917
PMID: 25028817
ISSN: 1529-4242
CID: 1075162

Desmosomes and the sodium channel complex: Implications for arrhythmogenic cardiomyopathy and Brugada syndrome

Cerrone, Marina; Delmar, Mario
Mutations in proteins of the desmosome are associated with arrhythmogenic cardiomyopathy (AC; also referred to as "ARVC" or "ARVD"). Life-threatening ventricular arrhythmias often occur in the concealed phase of the disease before the onset of structural changes. Among the various potential mechanisms for arrhythmogenesis in AC, in this article, we concentrate on the relation between desmosomes and sodium channel function. We review evidence indicating that (1) loss of desmosomal integrity (including mutations or loss of expression of plakophilin-2; PKP2) leads to reduced sodium current (INa), (2) the PKP2-INa relation could be partly consequent to the fact that PKP2 facilitates proper trafficking of proteins to the intercalated disc, and (3) PKP2 mutations can be present in patients diagnosed with Brugada syndrome (BrS), thus supporting the previously proposed notion that AC and BrS are not two completely separate entities, but "bookends" in a continuum of variable sodium current deficiency and structural disease.
PMCID:4099253
PMID: 24656989
ISSN: 1050-1738
CID: 877442

Mechanotransduction and fibrosis

Duscher, Dominik; Maan, Zeshaan N; Wong, Victor W; Rennert, Robert C; Januszyk, Michael; Rodrigues, Melanie; Hu, Michael; Whitmore, Arnetha J; Whittam, Alexander J; Longaker, Michael T; Gurtner, Geoffrey C
Scarring and tissue fibrosis represent a significant source of morbidity in the United States. Despite considerable research focused on elucidating the mechanisms underlying cutaneous scar formation, effective clinical therapies are still in the early stages of development. A thorough understanding of the various signaling pathways involved is essential to formulate strategies to combat fibrosis and scarring. While initial efforts focused primarily on the biochemical mechanisms involved in scar formation, more recent research has revealed a central role for mechanical forces in modulating these pathways. Mechanotransduction, which refers to the mechanisms by which mechanical forces are converted to biochemical stimuli, has been closely linked to inflammation and fibrosis and is believed to play a critical role in scarring. This review provides an overview of our current understanding of the mechanisms underlying scar formation, with an emphasis on the relationship between mechanotransduction pathways and their therapeutic implications.
PMCID:4425300
PMID: 24709567
ISSN: 0021-9290
CID: 901192

Best practices for data sharing in phylogenetic research

Cranston, Karen; Harmon, Luke J; O'Leary, Maureen A; Lisle, Curtis
As phylogenetic data becomes increasingly available, along with associated data on species' genomes, traits, and geographic distributions, the need to ensure data availability and reuse become more and more acute. In this paper, we provide ten "simple rules" that we view as best practices for data sharing in phylogenetic research. These rules will help lead towards a future phylogenetics where data can easily be archived, shared, reused, and repurposed across a wide variety of projects.
PMCID:4073804
PMID: 24987572
ISSN: 2157-3999
CID: 1455902