Fig. 4

IL-33-ST2 signaling suppresses immobilization-induced muscle atrophy. A H&E staining of TA muscle cryosections at the day 14 after immobilization of negative-control, IL-33-treated and sST2-treated young (upper) and aged (lower) mice. Bar, 100 μm. B Frequency distribution of CSA of muscle fibers of TA muscles collected from IL-33- and sST2-treated young (upper) and aged (lower) mice. Accumulated data from four mice are shown in each group. C Expression levels of Fbxo32 (upper) and Trim63 (lower) transcripts in the TA muscles from young and aged mice on days 14 of immobilization (n = 4). NC, vehicle-treated negative control. *P < 0.05; **P < 0.01