C2C12 myoblast differentiation stimulated by octacalcium phosphate material

To know about whether a bone substitute material octacalcium phosphate (OCP) is associated with bone formation by acting on surrounding tissue-derived cells, such as muscle cells, the effect of OCP was investigated on muscle-derived myoblast C2C12 cells in vitro. C2C12 cells were cultured with or without OCP granules. The diameter of the myotube formed from C2C12 cells with OCP was larger than that without OCP. mRNA expressions of myoblast differentiation markers (MyHC, MCK) and myokine (FGF-2) were increased by OCP, while Fndc5 and osteoglycin (myokine) were decreased. The alkaline phosphatase activity of mesenchymal stem cells was increased by adding the extract of media cultured with C2C12 cells and OCP up to 14 days. The chemical and spectroscopic analyses indicated that OCP hydrolysis progressed towards Ca-deficient hydroxyapatite in the media. The results suggest that OCP promotes myoblast differentiation and assists osteoblast differentiation through the myokines secretion under the environment induced by OCP hydrolysis.