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Rowena McBeath

Bio: Rowena McBeath is an academic researcher from Thomas Jefferson University. The author has contributed to research in topics: Medicine & Tendon. The author has an hindex of 5, co-authored 11 publications receiving 4125 citations. Previous affiliations of Rowena McBeath include Thomas Jefferson University Hospital & Johns Hopkins University.
Topics: Medicine, Tendon, Mesenchymal stem cell, RHOA, Wrist

Papers
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Journal ArticleDOI
TL;DR: It is demonstrated that cell shape regulates commitment of human mesenchymal stem cells to adipocyte or osteoblast fate and mechanical cues experienced in developmental and adult contexts, embodied by cell shape, cytoskeletal tension, and RhoA signaling, are integral to the commitment of stem cell fate.

3,995 citations

Journal ArticleDOI
TL;DR: A chondrogenic‐SMC fate decision is demonstrated mediated by cell shape, Rac1, and N‐cadherin, and is highlighted to highlight the tight coupling between lineage commitment and the many changes incell shape, cell‐matrix adhesion, and cell‐cell adhesion that occur during morphogenesis.
Abstract: Human mesenchymal stem cells (hMSCs) are multipotent cells that can differentiate into many cell types. Chondrogenesis is induced in hMSCs cultured as a micromass pellet to mimic cellular condensation during cartilage development, and exposed to transforming growth factor beta (TGFbeta). Interestingly, TGFbeta can also induce hMSC differentiation to smooth-muscle-like cell types, but it remains unclear what directs commitment between these two lineages. Our previous work revealed that cell shape regulates hMSC commitment between osteoblasts and adipocytes through RhoA signaling. Here we show that cell shape also confers a switch between chondrogenic and smooth muscle cell (SMC) fates. Adherent and well-spread hMSCs stimulated with TGF beta 3 upregulated SMC genes, whereas cells allowed to attach onto micropatterned substrates, but prevented from spreading and flattening, upregulated chondrogenic genes. Interestingly, cells undergoing SMC differentiation exhibited little change in RhoA, but significantly higher Rac1 activity than chondrogenic cells. Rac1 activation inhibited chondrogenesis and was necessary and sufficient for inducing SMC differentiation. Furthermore, TGF beta 3 and Rac1 signaling upregulated N-cadherin, which was required for SMC differentiation. These results demonstrate a chondrogenic-SMC fate decision mediated by cell shape, Rac1, and N-cadherin, and highlight the tight coupling between lineage commitment and the many changes in cell shape, cell-matrix adhesion, and cell-cell adhesion that occur during morphogenesis.

375 citations

Journal ArticleDOI
TL;DR: A 46-year-old right hand-dominant woman presents with left ulnar-sided wrist pain following a fall from a standing height onto her outstretched hand 6 months before.
Abstract: THE PATIENT A 46-year-old right hand–dominant woman presents with left ulnar-sided wrist pain following a fall from a standing height onto her outstretched hand 6 months before. The examination is normal except for pain with ulnar deviation and axial loading of the wrist. A posteroanterior radiograph of the wrist taken with the forearm in full pronation demonstrates ulnar-positive variance measuring 4 mm. Magnetic resonance imaging reveals increased signal intensity over the proximal ulnar aspect of the lunate and distal ulna along with a central defect of the triangular fibrocartilage complex.

27 citations

Journal ArticleDOI
TL;DR: With careful patient selection, soft tissue considerations, and novel implant designs, TWA may become a viable treatment staple for patients with functional wrist disability.

20 citations

Journal ArticleDOI
TL;DR: It is demonstrated that hypoxia drives tenocyte phenotypic changes, and molecular insight is provided into the development of human tendinosis that occurs with aging.
Abstract: Age-related tendon degeneration (tendinosis) is characterized by a phenotypic change in which tenocytes display characteristics of fibrochondrocytes and mineralized fibrochondrocytes. As tendon degeneration has been noted in vivo in areas of decreased tendon vascularity, we hypothesized that hypoxia is responsible for the development of the tendinosis phenotype, and that these effects are more pronounced in aged tenocytes. Hypoxic (1% O2 ) culture of aged, tendinotic, and young human tenocytes resulted in a mineralized fibrochondrocyte phenotype in aged tenocytes, and a fibrochondrocyte phenotype in young and tendinotic tenocytes. Investigation of the molecular mechanism responsible for this phenotype change revealed that the fibrochondrocyte phenotype in aged tenocytes occurs with decreased Rac1 activity in response to hypoxia. In young hypoxic tenocytes, however, the fibrochondrocyte phenotype occurs with concomitant decreased Rac1 activity coupled with increased RhoA activity. Using pharmacologic and adenoviral manipulation, we confirmed that these hypoxic effects on the tenocyte phenotype are linked directly to the activity of RhoA/Rac1 GTPase in in vitro human cell culture and tendon explants. These results demonstrate that hypoxia drives tenocyte phenotypic changes, and provide a molecular insight into the development of human tendinosis that occurs with aging.

13 citations


Cited by
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Journal ArticleDOI
25 Aug 2006-Cell
TL;DR: Naive mesenchymal stem cells are shown here to specify lineage and commit to phenotypes with extreme sensitivity to tissue-level elasticity, consistent with the elasticity-insensitive commitment of differentiated cell types.

12,204 citations

Journal ArticleDOI
09 Jun 2011-Nature
TL;DR: YAP/TAZ are identified as sensors and mediators of mechanical cues instructed by the cellular microenvironment and are functionally required for differentiation of mesenchymal stem cells induced by ECM stiffness and for survival of endothelial cells regulated by cell geometry.
Abstract: Cells perceive their microenvironment not only through soluble signals but also through physical and mechanical cues, such as extracellular matrix (ECM) stiffness or confined adhesiveness. By mechanotransduction systems, cells translate these stimuli into biochemical signals controlling multiple aspects of cell behaviour, including growth, differentiation and cancer malignant progression, but how rigidity mechanosensing is ultimately linked to activity of nuclear transcription factors remains poorly understood. Here we report the identification of the Yorkie-homologues YAP (Yes-associated protein) and TAZ (transcriptional coactivator with PDZ-binding motif, also known as WWTR1) as nuclear relays of mechanical signals exerted by ECM rigidity and cell shape. This regulation requires Rho GTPase activity and tension of the actomyosin cytoskeleton, but is independent of the Hippo/LATS cascade. Crucially, YAP/TAZ are functionally required for differentiation of mesenchymal stem cells induced by ECM stiffness and for survival of endothelial cells regulated by cell geometry; conversely, expression of activated YAP overrules physical constraints in dictating cell behaviour. These findings identify YAP/TAZ as sensors and mediators of mechanical cues instructed by the cellular microenvironment.

4,120 citations

Journal ArticleDOI
26 Jun 2009-Science
TL;DR: Multifaceted technologies are increasingly required to produce and interrogate cells ex vivo, to build predictive models, and, ultimately, to enhance stem cell integration in vivo for therapeutic benefit.
Abstract: Stem cell fate is influenced by a number of factors and interactions that require robust control for safe and effective regeneration of functional tissue. Coordinated interactions with soluble factors, other cells, and extracellular matrices define a local biochemical and mechanical niche with complex and dynamic regulation that stem cells sense. Decellularized tissue matrices and synthetic polymer niches are being used in the clinic, and they are also beginning to clarify fundamental aspects of how stem cells contribute to homeostasis and repair, for example, at sites of fibrosis. Multifaceted technologies are increasingly required to produce and interrogate cells ex vivo, to build predictive models, and, ultimately, to enhance stem cell integration in vivo for therapeutic benefit.

2,446 citations

Journal ArticleDOI
TL;DR: Interest in adipogenesis has increased markedly over the past few years with emphasis on the intersection between extracellular signals and the transcriptional cascade that regulates adipocyte differentiation.
Abstract: Improved knowledge of all aspects of adipose biology will be required to counter the burgeoning epidemic of obesity. Interest in adipogenesis has increased markedly over the past few years with emphasis on the intersection between extracellular signals and the transcriptional cascade that regulates adipocyte differentiation. Many different events contribute to the commitment of a mesenchymal stem cell to the adipocyte lineage including the coordination of a complex network of transcription factors, cofactors and signalling intermediates from numerous pathways.

2,363 citations

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TL;DR: The extracellular matrix (ECM), a complex network of macromolecules with distinctive physical, biochemical, and biomechanical properties, is commonly deregulated and becomes disorganized in diseases such as cancer.
Abstract: The local microenvironment, or niche, of a cancer cell plays important roles in cancer development. A major component of the niche is the extracellular matrix (ECM), a complex network of macromolecules with distinctive physical, biochemical, and biomechanical properties. Although tightly controlled during embryonic development and organ homeostasis, the ECM is commonly deregulated and becomes disorganized in diseases such as cancer. Abnormal ECM affects cancer progression by directly promoting cellular transformation and metastasis. Importantly, however, ECM anomalies also deregulate behavior of stromal cells, facilitate tumor-associated angiogenesis and inflammation, and thus lead to generation of a tumorigenic microenvironment. Understanding how ECM composition and topography are maintained and how their deregulation influences cancer progression may help develop new therapeutic interventions by targeting the tumor niche.

2,353 citations