Fig. 2: Deletion of Sirt6 reduces persistent activation of MuSC in skeletal muscles of mdx mice.

a Immunofluorescence staining of MYOD⁺/PAX7⁺ double positive MuSCs in TA muscles of control (n = 4), mdx (n = 6) and Sirt6^mKO/mdx (n = 7) mice. Scale bar: 20 µm. The ratios of MYOD⁺/PAX7 double positive MuSCs are shown in the right panel (one-way ANOVA with Bonferroni multiple comparisons test: ***p = 0.002, ****p < 0.0001). b EM images of increased heterochromatin content and decreased nuclei size in MuSCs of Sirt6^mKO/mdx mice. Scale bar: 2 μm. Recordings were quantified with ImageJ software and are shown in the lower panels (one-way ANOVA with Bonferroni multiple comparisons test: heterochromatin content ****p < 0.0001, ***p = 0.0004; *p = 0.0379; nuclei size: *p = 0.0374, *p = 0.0361, control: n = 23; mdx: n = 35; Sirt6^mKO/mdx: n = 31). c Venn diagram of upregulated genes in mdx MuSCs compared with control MuSCs and downregulated genes in Sirt6^mKO/mdx MuSCs compared to mdx MuSCs (upper panel) based on RNA-seq analysis. GO term analysis of WikiPathways enriched in overlapping set of 173 genes based on p values (lower panel) using Enrichr. d Immunofluorescence staining of EdU⁺/PAX7⁺ MuSCs in TA muscles of control, mdx and Sirt6^mKO/mdx mice. Scale bar: 20 μm. A schematic outline of the experimental design is shown in the upper panel. Quantification of EdU⁺/PAX7⁺ MuSCs is shown on the right (one-way ANOVA with Bonferroni multiple comparisons test: ****p < 0.0001, n = 6). Twelve to 16 weeks old male mice were used. Data are presented as mean ± SEM (a, b, d). Source data are provided in the Source Data file.