SRC kinase family inhibitor PP2 promotes DMSO-induced cardiac differentiation of P19 cells and inhibits proliferation

Abstract Background It has been reported recently that PP2, a Src family kinase inhibitor, promotes selective cardiogenesis in embryonic stem cells. However, there is no other research proved pro-cardiogenic characteristic of PP2 so far. In this study, we explored the potential cardiogenic effect of PP2 on P19 cells differentiation. Methods P19-αMHC-EGFP cell line was established by transfecting P19 cells with αMHC-EGFP vector in order to evaluate cardiogenesis with EGFP. P19-αMHC-EGFP cells and P19 cells were induced to differentiate into cardiomyocytes with 1%DMSO, 5 μmol/L PP2, or both 1%DMSO and 5 μmol/L PP2. Differentiated cells from P19-αMHC-EGFP cells were then assessed under confocal microscope. Western-blot and RT-PCR were also performed to detect expression of cardiac troponin I and cardiac transcription factors respectively. In addition, the effects of PP2 on proliferation of P19 cells were further examined using Cell Counting Kit-8. Results EGFP positive cells were firstly detected on day 7 and PP2 alone cannot induce efficient cardiac differentiation of P19-αMHC-EGFP cells. However PP2 supplementation dramatically increases DMSO induced cardiac differentiation than DMSO alone. It was also found that PP2 inhibit proliferation of P19 cells in both a dose-dependent manner and a time-dependent manner. Conclusion PP2 alone cannot substitute DMSO to induce cardiac differentiation, however, PP2 supplementation drastically promotes DMSO-induced cardiac differentiation of P19 cells. The increased percentages of differentiated cardiac myocytes is partly resulting from cell proliferative inhibit effect of PP2 in undifferentiated P19 cells. P19-αMHC-EGFP cell line has the potential to be used for regenerative therapies in experimental models of heart repair.