Fig. 5

IL-33 does not affect muscle fibers in the non-immobilized state, but acts on FAPs. A Frequency distribution of CSA of muscle fibers of TA muscles collected from normal and IL-33-treated young (upper) and aged (lower) mice without hindlimb immobilization. Accumulated data from four mice are shown in each group. NC, vehicle-treated negative control; non-IM IL-33, non-immobilization IL-33-treated. B Expression levels of Fbxo32 (left) and Trim63 (right) transcripts in TA muscles from young and aged mice on day 14 of IL-33 administration without immobilization (n = 4). C FAPs and muscle fibers stained for NF-κB and with DAPI. Cells were treated with vehicle (Ctrl) or IL-33 for 1 h. Bar, 20 μm