Fig. 1.

Lsd1 ablation or inhibition delays skeletal muscle regeneration. a Immunofluorescence assay using antibodies directed against paired box 7 (Pax7, green) and lysine-specific demethylase 1 (Lsd1, red) on tibialis muscle sections of control mice (Ctrl) or mice with selective Lsd1 ablation in Pax7-positive satellite cells (Lsd1^iKO) 5 days after cardiotoxin (Ctx) treatment. Nuclei were stained with DAPI (blue). Arrows indicate that Lsd1 is expressed in Pax7-positive satellite cells of control mice, whereas it is ablated from Lsd1^iKO Pax7-positive satellite cells. b Gomori staining of representative tibialis muscle sections from Ctrl, Lsd1^iKO mice, and wild-type mice treated with vehicle or Lsd1 inhibitor [Lsd1(i)], 0, 5, and 7 days after cardiotoxin (Ctx) injection. c, d Analyses of regenerating centronuclear fibers in Ctrl and Lsd1^iKO mice 5 or 7 days after Ctx treatment. c Number of fibers per area (mm²). Significance was calculated by two-tailed Student’s t-test. d Cross-sectional area (CSA) measurement of fibers. Significance was calculated by two-way analysis of variance (ANOVA) test. (c, d: n = 5; mean + SEM, *p < 0.05, **p < 0.01, ***p < 0.001; scale bars: a 50 µm, b 100 µm)