Fig. 3

The GDF11 is involved in myotube atrophy induced by CM from PAEC. A Schematic drawing depicting the generation of CM by hypoxia-culture of PAEC, then myotube was stimulated with CM for 48 h. B Concentrations of GDF11 (pg/mL) in 50% Norm-CM, 20% or 50% Hypo-CM. C Bright-field images of C2C12-derived myotubes treated with either 50% Norm-CM, 20% or 50% Hypo-CM from PAEC, and myotube diameter for conditions represented in the panel. Scale bar is 50 μm. D Myotubes were transfected with GDF11 siRNA or NC siRNA and 50% Norm-CM or 50% Hypo-CM. Protein levels were examined by immunoblotting. E Bright-field images of myotubes treated with 50% Hypo-CM with GDF11 antibody or isotype control, and myotube diameter for conditions represented in the panel. Scale bar is 50μm. F Immunoblots of trim63, fbx32, and foxo1 using lysates from myotubes treated with 50% Norm-CM or 50% Hypo-CM with GDF11 antibody or isotype control; and protein expression levels were quantified by densitometry. Values are presented as average ± SEM. Versus vehicle control, *P < 0.05, **P < 0.01, ***P < 0.001; versus Hypo-CM control, ^#P < 0.05, ^##P < 0.01, ^###P < 0.001; n=3