Fig 5.

Map4k4 silencing does not promote skeletal muscle differentiation through canonical MAPK signaling pathways. C2C12 myoblasts were transfected with scrambled siRNA or siRNA against Map4k4, p38α, JNK1, JNK2, JNK1 and JNK2, Erk1, Erk2, or Erk1 and Erk2. Cells were transferred to DM 24 h after differentiation and then incubated for 72 h. (A) (Left) Myoblast differentiation was observed by immunostaining for MyHC expression. Magnification, ×50. (Right) Efficiency of MAP kinase knockdown as determined by Western blotting. (B) C2C12 myoblasts were transfected with scrambled or Map4k4 siRNA. Cells were transferred to DM 24 h after transfection and then incubated for the indicated times. Lysates were immunoblotted with the indicated antibodies. Densitometric analysis data represent means ± SEM for three independent experiments.