Tceal5 and Tceal7 Function in C2C12 Myogenic Differentiation via Exosomes in Fetal Bovine Serum

The proliferation and differentiation of skeletal muscle cells are usually controlled by serum components. Myogenic differentiation is induced by a reduction of serum components in vitro. It has been recently reported that serum contains not only various growth factors with specific actions on the proliferation and differentiation of myogenic cells, but also exogenous exosomes, the function of which is poorly understood in myogenesis. We have found that exosomes in fetal bovine serum are capable of exerting an inhibitive effect on the differentiation of C2C12 myogenic cells in vitro. In this process of inhibition, the downregulation of Tceal5 and Tceal7 genes was observed. Expression of these genes is specifically increased in direct proportion to myogenic differentiation. Loss-or gain-of function studies with Tceal5 and Tceal7 indicated that they have the potential to regulate myogenic differentiation via exosomes in fetal bovine serum.