Regulation of Histone Acetylation on Expression Profiles of Potassium Channels During Cardiomyocyte Differentiation...

The cardiomyocyte differentiation from mouse embryonic stem cells (mESCs) is a dynamic and complex process that involved in the precision regulation of histone acetylation. The formation of action potential (AP) in mature cardiomyocytes is based on the expression pattern of Na⁺ , Ca²⁺ , and K⁺ ion channels, in which the slow delayed rectifier potassium current (I_Ks ), the rapid delayed rectifier potassium current (I_Kr ) and the inwardly rectifying Kir current (I_K1 ) mainly contribute to repolarization for AP in different species. However, the expression status of potassium channels conducted I_Ks , I_Kr , and I_K1 in cardiomyocyte differentiation are not fully defined. Here, we investigated the expression pattern of the slow delayed rectifier potassium channel and the rapid delayed rectifier potassium channel using a model of mouse cardiomyocyte differentiation under different conditions of histone acetylation. We found that expression levels of both the delayed rectifier potassium channel and the inwardly rectifying potassium channel were more sensitive to histone hyperacetylation during differentiation from mESCs into cardiomyocytes. Especially, histone H4 hyperacetylation induced by Class I HDACs inhibitors promoted the expression profiles of potassium channels (Kcnj2, Kcnj3, Kcnj5, Kcnj11, and Kcnh2) in the process. Our results provide a clue for expression status of potassium channels which may be essential to forming functional cardiomyocyte in the cardiac lineage commitment of mESC. J. Cell. Biochem. 118: 4460-4467, 2017. © 2017 Wiley Periodicals, Inc.