Effect of integrin β1 on Vc-induced cardiomyocyte differentiation of mouse induced pluripotent stem cells

AIM:To explore the effect of integrin β1 on Vc-induced cardiomyocyte (CM) differentiation of mouse induced pluripotent stem cells (iPSCs). METHODS: Hearts were acquired, respectively, from embryonic BALB/c fetal mice (12.5 days, 14.5 days, 16.5 days), newborn mice (birth 1 day, P1) and adult BALB/c mice under stereomicroscopy, and total RNA was extracted and then analyzed by semiquantitative and real-time quantitative PCR to observe the expressions of integrin β1 during different periods of heart development. Embryoid bodies (EBs) formed from iPSCs via the hanging drop method in vitro were cultured in three groups: control group (without addition), Vc group, and Vc combined with HM β1-1 (inhibition of integrin β1) group. On the third, fifth and seventh day of differentiation, Oct4, integrin β1 and cardiac-specific factors (α-MHC, MLC2a) were evaluated by semiquantitative RT-PCR and quantitative real-time PCR and the expression of cTnI was evaluated by immunocytochemistry. RESULTS: Integrin β1 expressed increasingly during the embryonic development period of the heart (E12.5, E14.5, E16.5, P1) (P<0.01), but the expression of integrin β1 decreased during the adult stage (P<0.01). Semiquantitative RT-PCR and quantitative RT-PCR, the number of beating EB, and immunocytochemistry staining all suggested that the differentiation efficiency in the Vc group was much higher than in control group (P<0.01). Inhibition of integrin β1 (HMβ1-1) decreased this effect (P<0.01). CONCLUSION: Vc improves the differentiation efficiency of iPSC-derived CMs (iPSCMs). Integrin β1 plays an important role in this process.