Fig. 3.

Myoblast-released TNF-α is critical to the activation of myogenesis in C2C12 myoblasts. Differentiation of C2C12 myoblasts was induced as described in Fig. 1. Myoblasts were collected at the indicated times and processed for Western blot analysis using antibodies against phosphorylated myocyte enhancer factor (MEF)-2C and myogenin, p21, and myosin heavy chain (MHC). Levels of these proteins were normalized against MEF2C or β-actin. Representative blots from 3 independent experiments are shown. Data were expressed and analyzed as described in Fig. 2.