G.P.32: Enhancement of myosin heavy chain class I (MyHC I) mRNA expression in C2C12 myocyte by chlorogenic acid

Abstract

Chlorogenic acid is a physiologically functional compound in coffee beans and has been reported as a calcineurin activator, but the effect to muscle cell hypertrophy still remain elusive. We previously reported that IL-6-and/or calcineurin-dependent increment of mRNA expression of myosin heavy chain class I (MyHC_@I) and skeletal muscle modulators including IL-6 and HSP70. In the present study, we examined the effects of chlorogenic acid as calcineurin activator and cyclosporine A as calcineurin inhibitor on expression of MyHC I, IL-6 and HSP70 mRNAs in C2C12 cells. C2C12 cells were induced to differentiate to myotubes by medium exchange to D-MEM containing 2% FBS. C2C12 cells were incubated in D-MEM containing 2% FBS with or without chlorogenic acid, or cyclosporine A at the beginning of differenton and removed after 24 h, and were maintained in differentiation medium for 3 days. Then our results are as follows: (1) The MyHC I mRNA expression was significantly increased by chlorogenic acid, but was decreased by cyclosporine A with or without chlorogenic acid. (2) The HSP70 mRNA expression was significantly upregulated by cyclosporine A with or without chlorogenic acid. These results suggested that the chlorogenic acid upregulates MyHC I mRNA in calcineurin-dependent manner.