The role of whey protein in myogenic differentiation

Whey protein has been shown to prevent exercise-induced protein degradation and muscle damage. We hypothesized that whey protein would regulate muscle cell differentiation. Adding various concentrations of whey protein to C2C12 myoblasts induced cell differentiation and MyoD (myogenic differentiation protein) expression as well as the phosphorylation of AKT (protein kinase B). Whey protein-induced differentiation-specific markers increased the enzymatic activities of creatine kinase and citrate synthase and the expression of muscle-specific microRNA. Whey protein elevated AKT phosphorylation on Thr308 and Ser473, which was inhibited by LY294002 (a non-selective phosphoinositide 3-kinases inhibitor), suggesting that whey protein acts via PI3K (phosphatidylinositol 3-kinase). Blocking of the PI3K/AKT pathway with specific inhibitors revealed its requirement in mediating the promotive effects of whey protein on C2C12 cell differentiation. These effects of whey protein on myoblast differentiation suggest its positive influence in preventing muscle atrophy.