Myocardial CXCR4 expression is required for mesenchymal stem cell mediated repair following acute myocardial infarction.
Animals; Apoptosis/physiology; Cardiac/cytology/physiology; Cell Movement/physiology; Chemokine CXCL12/*metabolism; Coronary Circulation/physiology; CXCR4/*genetics/metabolism; Gene Expression/physiology; Green Fluorescent Proteins/genetics; Inbred C57BL; Knockout; Mesenchymal Stem Cell Transplantation/*methods; Mesenchymal Stem Cells/*metabolism; Mice; Myocardial Infarction/genetics/pathology/*therapy; Myocardium/cytology; Myocytes; Paracrine Communication/physiology; Receptors; Ventricular Remodeling/physiology
BACKGROUND: Overexpression of stromal cell-derived factor-1 in injured tissue leads to improved end-organ function. In this study, we quantify the local trophic effects of mesenchymal stem cell (MSC) stromal cell-derived factor-1 release on the effects of MSC engraftment in the myocardium after acute myocardial infarction. METHODS AND RESULTS: Conditional cardiac myocyte CXCR4 (CM-CXCR4) null mice were generated by use of tamoxifen-inducible cardiac-specific cre by crossing CXCR4 floxed with MCM-cre mouse. Studies were performed in littermates with (CM-CXCR4 null) or without (control) tamoxifen injection 3 weeks before acute myocardial infarction. One day after acute myocardial infarction, mice received 100,000 MSC or saline via tail vein. We show alpha-myosin heavy chain MerCreMer and the MLC-2v promoters are active in cardiac progenitor cells. MSC engraftment in wild-type mice decreased terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling positive CM (-44%, P\textless0.01), increased cardiac progenitor cell recruitment (100.9%, P\textless0.01), and increased cardiac myosin-positive area (39%, P\textless0.05) at 4, 7, and 21 days after acute myocardial infarction, respectively. MSC in wild-type mice resulted in 107.4% (P\textless0.05) increase in ejection fraction in comparison with 25.9% (P=NS) increase in CM-CXCR4 null mice. These differences occurred despite equivalent increases (16%) in vascular density in response to MSC infusion in wild-type and
Dong Feng; Harvey James; Finan Amanda; Weber Kristal; Agarwal Udit; Penn Marc S
Circulation
2012
2012-07
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1161/CIRCULATIONAHA.111.082453" target="_blank" rel="noreferrer noopener">10.1161/CIRCULATIONAHA.111.082453</a>
TRPV4 channels mediate cardiac fibroblast differentiation by integrating mechanical and soluble signals.
*Calcium Signaling; *Cell Differentiation; *Mechanotransduction; Animals; Cellular; Extracellular Matrix/metabolism/physiology; Fibroblasts/*physiology; Gene Knockdown Techniques; Male; Monoterpenes/pharmacology; Myocardium/cytology; Myofibroblasts/metabolism; Rats; RNA; Small Interfering/genetics; Sprague-Dawley; Transforming Growth Factor beta1/physiology; TRPM Cation Channels/antagonists & inhibitors/metabolism; TRPV Cation Channels/genetics/*metabolism
The phenotypic switch underlying the differentiation of cardiac fibroblasts into hypersecretory myofibroblasts is critical for cardiac remodeling following myocardial infarction. Myofibroblasts facilitate wound repair in the myocardium by secreting and organizing extracellular matrix (ECM) during the wound healing process. However, the molecular mechanisms involved in myofibroblast differentiation are not well known. TGF-beta has been shown to promote differentiation and this, combined with the robust mechanical environment in the heart, lead us to hypothesize that the mechanotransduction and TGF-beta signaling pathways play active roles in the differentiation of cardiac fibroblasts to myofibroblasts. Here, we show that the mechanosensitve ion channel TRPV4 is required for TGF-beta1-induced differentiation of cardiac fibroblasts into myofibroblasts. We found that the TRPV4-specific antagonist AB159908 and siRNA knockdown of TRPV4 significantly inhibited TGFbeta1-induced differentiation as measured by incorporation of alpha-SMA into stress fibers. Further, we found that
Adapala Ravi K; Thoppil Roslin J; Luther Daniel J; Paruchuri Sailaja; Meszaros J Gary; Chilian William M; Thodeti Charles K
Journal of molecular and cellular cardiology
2013
2013-01
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1016/j.yjmcc.2012.10.016" target="_blank" rel="noreferrer noopener">10.1016/j.yjmcc.2012.10.016</a>