Figure 1.

Muscle Extracts Accelerate Satellite Cell Activation

(A) A schematic illustrating the experimental procedure. TA muscle homogenates were filtered and used as muscle extracts.

(B–G) Individual myofibers associated with satellite cells were freshly isolated from EDL and cultured in DMEM with or without muscle extracts for 24 h and then immunostained for (B) PAX7 and MYOD (quantified in C), (D) PAX7 and Ki67 (quantified in E), or (F) PAX7 and EdU (quantified in G). Data represent means ± SEM. (C) Control n = 3 mice, extract n = 5 mice; (E) n = 3 mice per condition; (G) control n = 3 mice, extract n = 4 mice; >15 individual myofibers per mouse were counted. ^∗p < 0.05. Scale bars, 50 μm.