Objectives To test the hypothesis that over-expressing miR-499 in rat bone marrow-derived mesenchymal stem cells (BM-MSCs) induces them to differentiate into cardiomyocyte-like cells.
Methods The fourth passage of rat BM-MSCs were infected with lentiviral vectors bearing miR-499 or empty lentiviral vectors as control. The expression of cardiac-specific markers, NKx2.5, GATA4, MEF2C, and cTnI in these cells were examined by real time PCR or western blot analysis, respectively, 0, 1, 3, 5, 7 days.
Results The fourth passage of the cultured rat BM-MSCs express significant markers of MSCs. After transfection of microRNA 499 in MSCs, the expression level of microRNA 499 was markedly enhanced. The mRNA expression of GATA4, NK×2.5 and MEF2C gradually increased from day 3 to day 7. The cTnI expression was detected at the same time. These cannot be detected in MSCs infected with empty lentiviral vectors.
Conclusions Over-expression of miR-499 rat BM-MSCs can induce rat BM-MSCs toward cardiac differentiation.