Fig. 4

FGF21 reduces atrophic marker expression via AMPK pathway in TNFα–treated myotubes. (a) The levels of p-AMPK/AMPK protein in skeletal muscle from WT and FGF21-deficient mice fed an HFD. Results are means ± SEM (n = 4 mice per group). ***P < 0.001 compared with WT mice fed an HFD. (b) The levels of p-AMPK/AMPK protein in C2C12 myotubes were measured at the indicated concentrations (0, 0.5, 1 μg/mL) of FGF21 for 24 h. Results are means ± SEM *P < 0.05,**P < 0.01, ***P < 0.001 compared with TNFα-treated myotubes. (c) The levels of Atrogin-1 protein in TNFα-treated C2C12 myotubes with or without 0.5 μg/mL FGF21. Compound C added for 1 h before FGF21 treatment. Results are means ± SEM *P < 0.05 compared with TNFα plus FGF21-treated myotubes