Abstract: Objective To investigate the effects of Oncostatin M (OSM) on differentiation of murine induced pluripotent stem cells (miPSCs) into cardiomyocytes in vitro. Methods using the embryoid bodies differentiation method, OSM was added during early-phase and midphase (day 0-6) of miPSCs differentiation to induced for 15 days. Semi-quantitative RT-PCR, Western blot and immunofluorescence staining were used to detect the expression levels of myocardial cells -specific markers. Results The best concentration of OSM to induce the cardiac differentiation of miPSCs was 20 pmol/L and revealed that cardiac troponin-T (cTnT) were expressed 7-fold higher in OSM-treated compared with vehicle control-treated embryoid bodies at day 15 post-differentiation. Cardiac-specific gene and protein expression of cTnT and Gata4 demonstrated that the OSM-treated embryoid bodies expressed cardiac-specific gene (Tnnt2、Nkx2.5、MLC2a、MLC2v、GATA4 and GATA6) and protein (cTnI、Gata4) at levels that were higher than those of the vehicle-control group after induced for 15 days. Furthermore, Immunostaining of the cardiac-specific protein markers cTnT showed that the miPSCs expressed cTnT across all groups, and exhibited a markedly increased of cTnT-positive cells in OSM-treated cells. Conclusions OSM promote the differentiation of murine induced pluripotent stem cells into cardiomyocytes, and it could serve as a valuable strategy for myocardiac differentiation of miPSCs in vitro.

Key words: Oncostatin M, miPSC, myocardial cell, differentiation