Vitamin B₁₂ Promotes Cx40 and HCN4 Gene Expression at an Early Stage of Cardiomyocyte Differentiation

Abstract

Vitamin B₁₂ (VB₁₂) was investigated for its ability to influence the expression of genes required for cardiac cell differentiation from mouse embryonic stem cells. When VB₁₂ (0.5 mM) was added to the medium on day 3 of culture, the levels of Cx40 and HCN4 expression increased over those in the control, 2 to 3 days before the start of cardiomyocyte beating. In contrast, the expression levels of α-MHC, MLC-2a, and MLC-2v were almost the same as those of the control throughout the culture period. Our results suggest that VB₁₂ is involved in the promotion of the intercellular conducting system rather than the generation of contractile proteins.