[Experimental study of differentiation of mouse bone marrow stromal stem cells into progenitor cardiomyocyte in vitro].

OBJECTIVE

To investigate the possibility of inducing mouse bone marrow stromal stem cells (MSCs) into progenitor cardiomyocytes in vitro.

METHODS

The MSCs were isolated by adhesion culture in vitro and flow cytometery was employed to identify the phenotypes of the cell passages. 5-azacytidine was used to induce the stem cells to differentiate into cardiomyotes in the experimental group, which were then detected by RT-PCR, semi-quantitative RT-PCR, Western-blot analysis, electron microscopy and immunofluorescence technique.

RESULTS

The isolated subcultured MSCs displayed a fusiform cell-like morphology. The MSCs were uniformly positive for CD29 and CD44 but negative for CD34 and CD45, and after induction, they expressed cardiomyocyte-specific transcription factors (NKx2-5/Csx and GATA4) and fetal ventricular cardiomyocyte-specific gene beta-myosin heavy chain, but not adult ventricular cardiomyocyte-specific gene alpha-myosin heavy chain as detected by RT-PCR. Western blotting identified the expressions of alpha-sarcomeric actin and desmin in the induced MSCs, with myofilament formation observed under electron microscope. Compared with the control group, the expression level of DNA methyltransferase mRNA was significantly lowered in the experimental group as observed by semi-quantitative RT-PCR (P<0.05).

CONCLUSION

MSCs are capable of differentiating into progenitor cardiomyocytes.