[Effect of electrical stimulation on the differentiation of induced pluripotent stem cells into cardiomyocytes induced by vitamin C in vitro].

To investigate the effect of electrical stimulation on the differentiation of induced pluripotent stem cells (iPSCs) into cardiomyocytes in vitro. Classical hanging-drop method was used to induce iPSCs from mice to form embryoid bodies (EBs) and vitamin C was contained in the medium through the induction period. According to whether or not electrical stimulation was used in the whole induction period, iPSCs were divided to electrical stimulation group and non-stimulation group. During the induction, dynamic morphological changes of the EBs were observed and photographed, the time point when beating EBs in each group appeared was recorded and the number of them was counted. The percentage of beating ones in all EBs was calculated as the differentiation rate of cardiomyocytes induced from iPSCs. Furthermore, expression of cardiac troponin T (cTnT) was observed by immunofluorescent staining under a confocal laser scanning microscope (CLSM), and mRNA expression levels of the related genes Oct-4, GATA-4 and α-MHC were analyzed by RT-PCR. Compared with the non-stimulation group, beating cells in electrical stimulation group appeared in a shorter time, and the differentiation rate of cardiomyocytes was higher [(68.89 ± 5.09)% vs (52.22 ± 3.85)%, P<0.05]. c-TnT was expressed in the beating area of both groups, but the cells in the electrical stimulation group showed a more clear cytoskeleton. The mRNA level of Oct-4 decreased in a time-dependent manner in the whole period of induction and in the electrical stimulated group it decreased faster than the non-stimulation group (P<0.05). In addition, more GATA4 and α-MHC mRNA in electrical stimulation group were expressed than the non-stimulated group at the same point-in-time (P<0.05). The electrical stimulation which simulates cardiac electrical microenvironment to some extent improved the differentiation of iPSCs into functional cardiomyocytes induced by vitamin C in vitro.