Relationship between apoptosis and differentiation from ESCs into cardiomyocytes induced by TGF-β_1 and co-culture with visceral endoderm like END-2 cells

AIM: To provide the reference for optimizing the seed cells for tissue engineering,the relationship between apoptosis and differentiation in the process of induction on embryonic stem cells(ESCs) was investigated.METHODS: Day 2-3 embryoid bodys(EBs) were derived from ESCs,and then tissue growth factor-β1(TGF-β1) was added,and co-cultured with visceral endoderm like END-2 cell conditioned medium.The induced cells were evaluated by using immunofluoresence and transmission electron micrography.Cell apoptosis was analyzed using flow cytometry.RESULTS: The total percentage of beating EBs treated with TGF-β1 was 43%.All the beating cardiomyocytes derived from ESCs expressed cardiacspecific proteins for TnT,and were observed the cardiac-specific ultrastructure.Interestingly,the total percentage of beating EBs treated with TGF-β1 combined with END-2 cell conditioned medium was 88%(P0.01),and the beating areas were bigger.After 3 days of induction with different conditions,the apoptotic levels were(5.58%±0.65% and 9.60%±0.75%,P0.05),respectively.CONCLUSION: combination of TGF-β1 with co-cultured visceral endoderm like END-2 cell conditioned medium could get a higher induction efficiency on the differentiation of ESCs into the cardiomyocytes.The partly inducible effect mechanisms may induce EDCs differentiation toward a cardiac phenotype and enhance apoptosis in cells not committed to cardiac differentiation.