Fibro-adipogenic progenitors prevent skeletal muscle degeneration at acute phase upon tendon rupture in a murine tibialis anterior tenotomy model

Figure 4 The progression of muscle fibrotic degeneration after tendon rupture vs sham surgery in C57BL/6 mice. A: The modified Masson trichrome staining results of the tibialis anterior muscle at 0 day, 1 week, 2 weeks, 4 weeks, and 6 weeks after tibialis anterior tenotomy (TAT) or sham surgery (SS) in C57BL/6 mice; B: The statistical analysis of area fraction of collagen which represents the severity of fibrosis (^aP < 0.05, ^bP < 0.001, TAT compared to SS side at 4 weeks and 6 weeks, respectively); C: The alpha-smooth muscle actin immunohistochemistry staining results of the muscle at 0 day, 1 week, 2 weeks, 4 weeks, and 6 weeks after TAT or SS in C57BL/6 mice; D: The statistical analysis of the area fraction of positive stained area. Area fraction of collagen (%) = area of collagen staining of the entire sample area which represents the tendency of fibrosis (^aP < 0.001, ^bP < 0.001, ^cP < 0.001, ^dP < 0.001, TAT compared to SS side at 1 week, 2 weeks, 4 weeks, and 6 weeks, respectively). Scale bar = 100 μm. TAT: Tibialis anterior tenotomy; SS: Sham surgery.