Articles by Michael A. Trembley in JoVE
Épicardique Excroissance Culture Assay et Michael A. Trembley1,3, Lissette S. Velasquez1, Eric M. Small1,2,3 1Aab Cardiovascular Research Institute, University of Rochester School of Medicine and Dentistry, 2Department of Medicine, University of Rochester School of Medicine and Dentistry, 3Department of Pharmacology and Physiology, University of Rochester School of Medicine and Dentistry
Other articles by Michael A. Trembley on PubMed
The Yeast 14-3-3 Proteins Bmh1 and Bmh2 Differentially Regulate Rapamycin-mediated Transcription Bioscience Reports. Jan, 2014 | Pubmed ID: 24438204 14-3-3 proteins are highly conserved and have been found in all eukaryotic organisms investigated. They are involved in many varied cellular processes, and interact with hundreds of other proteins. Among many other roles in cells, yeast 14-3-3 proteins have been implicated in rapamycin-mediated cell signaling. We determined the transcription profiles of bmh1 and bmh2 yeast after treatment with rapamycin. We found that, under these conditions, BMH1 and BMH2 are required for rapamycin-induced regulation of distinct, but overlapping sets of genes. Both Bmh1 and Bmh2 associate with the promoters of at least some of these genes. BMH2, but not BMH1, attenuates the repression of genes involved in some functions required for ribosome biogenesis. BMH2 also attenuates the activation of genes sensitive to nitrogen catabolite repression.
Myocardin-related Transcription Factors Control the Motility of Epicardium-derived Cells and the Maturation of Coronary Vessels Development (Cambridge, England). Jan, 2015 | Pubmed ID: 25516967 An important pool of cardiovascular progenitor cells arises from the epicardium, a single layer of mesothelium lining the heart. Epicardium-derived progenitor cell (EPDC) formation requires epithelial-to-mesenchymal transition (EMT) and the subsequent migration of these cells into the sub-epicardial space. Although some of the physiological signals that promote EMT are understood, the functional mediators of EPDC motility and differentiation are not known. Here, we identify a novel regulatory mechanism of EPDC mobilization. Myocardin-related transcription factor (MRTF)-A and MRTF-B (MKL1 and MKL2, respectively) are enriched in the perinuclear space of epicardial cells during development. Transforming growth factor (TGF)-β signaling and disassembly of cell contacts leads to nuclear accumulation of MRTFs and the activation of the motile gene expression program. Conditional ablation of Mrtfa and Mrtfb specifically in the epicardium disrupts cell migration and leads to sub-epicardial hemorrhage, partially stemming from the depletion of coronary pericytes. Using lineage-tracing analyses, we demonstrate that sub-epicardial pericytes arise from EPDCs in a process that requires the MRTF-dependent motile gene expression program. These findings provide novel mechanisms linking EPDC motility and differentiation, shed light on the transcriptional control of coronary microvascular maturation and suggest novel therapeutic strategies to manipulate epicardium-derived progenitor cells for cardiac repair.