Fig. 4. Depletion of CD206⁺ M2-like MΦ reduces TGF-β signaling and improves muscle recovery.

a Representative images of paraffin sections of muscle from Tg mice and their littermate control WT mice following acute injury (7 dpi). Scale bar, 200 μm, 20×. Quantification of TGF-β1⁺, and p27⁺cells/field is given in right panel (n = 5 mice per group). b Histological sections of gastrocnemius muscle from CD206⁺ M2-like MΦ-derived TGF-β1 KO and TGF-β1^f/f mice, harvested at 7 dpi, stained with H&E (upper) or WGA and DAPI (lower) (n = 4 mice per group). Scale bar, 200 μm (H&E) and 100 μm (WGA). c Quantification of CN myofibers of the gastrocnemius muscle (n = 4 mice per group). d Relative mRNA expression of myogenesis-related marker genes in the muscle of TGF-β1 KO mice compared to TGF-β1^f/f littermate control mice (n = 6 mice per group). e Relative mRNA expression of activated FAP-related marker genes in FACS-isolated FAPs of TGF-β1 KO mice compared to TGF-β1^f/f littermate control mice (n = 3 mice per group). f Representative images of sirius red-stained sections of TA from tamoxifen-treated TGF-β1 KO mice compared to tamoxifen-treated TGF-β1^f/f control mice. Quantification is given in right panel (n = 3 mice per group). Scale bars, 200 μm. Fibrotic area (red) was analyzed by ImageJ software. Data are representative of at least two independent experiments. g Relative mRNA expression of fibrosis-related marker genes in the muscle of TGF-β1 KO mice, compared with their littermate TGF-β1^f/f control mice (n = 3 mice per group). The data are shown as the means ± SEM. *p < 0.05, and **p < 0.01 were considered significant as determined using the two-tailed Student t-test. Source data are provided as a Source Data file. CN centrally nucleated, and TGF-β transforming growth factor-beta.