RESUMEN
AIM: To set up a method of inducing mouse embryonic stem cells (mESC) to differentiate into cardiomyocyte after treatment with 5-azacytidine. METHODS: Cytotoxicity of 5-azacytidine was measured by MTT assay. Treatment of mESC with conditioned culture mediums, which were composed of 5-azacytidine alone or combined with retinoic acid, induced the cell differentiation to cardiomyocytes. The cells induced were identified by detecting the expression of cardiac proteins (myosin, desmin, ?-actin and ?-actinin). Gene MLC-2v, a specific gene of ventricular-like cardiomyocyte, was also detected by RT-PCR. RESULTS: The non-cytotoxic dose of 5-azacytidine was 8 ?mol/L, which was able to induce mESC to differentiate into cardiac syncytiums. Cells induced expressed many cardiac proteins and MLC-2v mRNA. However, combined with retinoic acid inhibited mESC differentiation into cardiomyocyte. CONCLUSION: 5-azacytidine is able to promote mESC differentiation into cardiomyocytes. A method of inducing mESC to differentiate into cardiomyocytes in vitro has been established.