Nicotinamide promotes human pluripotent stem cells differentiation into cardiomyocytes [2]

Nicotinamide, the amide form of vitamin B3, is essential to maintain the human fetal development. It benefits the ectoderm and endoderm development, but its influence in mesoderm differentiation is elusive. In this study, we reported that nicotinamide regulated the gene expression of cardiovascular system, and it induced functional cardiomyocytes which was independent of canonical WNT signaling. Through a kinase screening, we found that nicotinamide inhibited the activity of P38δ to promote cardiomyocyte differentiation. Furthermore, we compared the gene expression of cardiomyocytes induced by WNT inhibitor IWP-2, nicotinamide or P38 inhibitor SB202190. The results showed that the cardiomyocytes induced by nicotinamide had similar gene expression profile compared with P38 inhibitor, which indicated nicotinamide promoted cardiac differentiation via the inhibition of P38. Total RNA was harvested from the differentiated cells induced by IWP-2 (3 μM), SB202190 (10 μM), nicotinamide (10 mM) or none treated control at day 10 of cardiac differentiation.