Cardiomyocyte Differentiation From Rat Bone Marrow Mesenchymal Stem Cell In Vitro

Bone marrow (BM) stromal cells have many of the characteristics of stem cells for differentiation into mesenchymal tissues. We have isolated mescenchymal stem cells (MSC) from BM mononuclear cells (BMNC). The cells showed a fibroblast-like morphology, but the morphology changed after 12μmol/L 5-azacytidine (5-aza). The cells gradually increased in size, lengthened in one direction and formed a stick-like morphology at one week. They connected with adjoining cells after two weeks and formed myotube-like structures at three weeks through phase-contrast microscope. RT-PCR result showed that these cells expressed α-skeletal actin,desmin and MEF-2D before 5-aza treatment and expressed β-MHC and GATA4 after the treatment. They expressed α-actin before and after the treatment, and expressed myosin only after the treatment by western blot. The cells expressed α-actin in the whole cells before and after the treatment and myosin in the cytoplasm only after the treatment by immunofluoresence. These results indicated that the stage of differentiation of the cells was between cadiomyocyte progenitor and differentiated cardiomyocytes and could represent a useful source of cardiomyocyte progenitor for the cell transplantation therapy for heart failure.