Protective paracrine effect of mesenchymal stem cells on cardiomyocytes.
OBJECTIVE
The aim of this study was to test the protective effect of mesenchymal stem cells (MSCs) on cardiomyocytes in vitro and to investigate the anti-apoptotic signaling pathway.


METHODS
MSCs from Sprague-Dawley (SD) rats were separated and cultured. MSC medium was collected from MSCs cultured in serum-free Dulbecco's modified eagle medium (DMEM) under hypoxia. Cultured cardiomyocytes from neonatal SD rats were exposed to hypoxia/reoxygenation (H/R) and treated with MSC medium. The apoptotic cardiomyocytes were stained with Annexin-V-fluorescein isothiocyanate (FITC), Hoechst 33342 and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL). The mitochondrial transmembrane potential of cardiomyocytes was assessed using a fluorescence microscope. The expression of Bcl-2, Bax, cytochrome C, apoptosis-induced factor (AIF), and caspase-3 was tested by Western blot analysis.


RESULTS
Our data demonstrated that MSC medium reduced H/R-induced cardiomyocyte apoptosis, increased the Bcl-2/Bax ratio, and reduced the release of cytochrome C and AIF from mitochondria into the cytosol.


CONCLUSIONS
MSCs protected the cardiomyocytes from H/R-induced apoptosis through a mitochondrial pathway in a paracrine manner.
Xiang
Mei-xiang
MX
Department of Cardiology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, China.
He
Ai-na
AN
Wang
Jian-an
JA
Gui
Chun
C
D000818:Animals; D017209:Apoptosis; D051033:Apoptosis Inducing Factor / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism; D002478:Cells, Cultured; D045304:Cytochromes c / Q000378:metabolism; D019610:Cytoprotection; D053078:Membrane Potential, Mitochondrial; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000502:physiology*; D032383:Myocytes, Cardiac / Q000166:cytology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D051028:bcl-2-Associated X Protein / Q000032:analysis
C494831:Aifm1 protein, rat; D051033:Apoptosis Inducing Factor; C494828:Bax protein, rat; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D045304:Cytochromes c; D053148:Caspase 3