Fig. 4.

STAT3 activity was necessary for muscle atrophy. A: infection of adenovirus expressing dominant negative STAT3 (Ad-dnSTAT3-GFP) resulted in increased fiber diameter in control and IL-6-treated C₂C₁₂ myotubes (n = 200–300 fibers from 3 independent wells/condition). B: Ad-shSTAT3-GFP also increased baseline myofiber size and inhibited IL-6-dependent fiber atrophy (n = 200–300 fibers from 3 independent wells/condition). Data represent several independent experiments in which adenovirus was applied for 24 h and then washed out, and IL-6 was applied for 48 h and cells were fixed and measured. ***P < 0.001.