Fig. 6: Adult dystrophic thymus transplantation determines dystrophic muscle features and skeletal muscle regression.

Representative immune fluorescence staining with DYS-2 (C-terminal-domain) antibody. Overall, confocal microscope images of TAs from nu^PBS, Tnu^MDX and Tnu^C57Bl showed weak dystrophin intensity around the myofibers in TA of Tnu^MDX mice (a). Overview and higher magnification of ATPase (pH 4.3) muscle sections of TAs from nu^PBS, Tnu^MDX and Tnu^C57Bl mice (a). Densitometric analysis of WB images of dystrophin protein expression showed downregulation of Dp427 dystrophin isoform in TA muscles of Tnu^MDX and Tnu^C57Bl mice (b). RT-PCR analysis of TA of nu^PBS, Tnu^MDX and Tnu^C57Bl mice determined the expression of Dp427 dystrophin isoform (c). Representative images of skeletal muscle showed the distribution and composition of the myosin heavy chain (MyHC) isoforms (Type IIa, Type IIx and Type IIb). Graph portrays the percentage of myofibers expressing different MyHC isoforms in TAs of nu^PBS, Tnu^MDX and Tnu^C57Bl mice. n = 10 images were analysed for each mouse (d). RT-qPCR experiments on TA muscles demonstrated the over-expression of MyHC-sl2 gene together with the downregulation of fast atp2a1 in TA of Tnu^MDX mice related to TAs of other mice (e). Tnu^MDX mice showed a dramatic weight loss (f), which correlated with the over-expression of the atrophy-related MuRF-1 gene (g). Cropped image of a representative WB showing the expression of the Akt and vinculin proteins in TA muscles of nu^PBS, Tnu^MDX and Tnu^C57Bl mice. Densitometric analyses are shown as Akt/vinculin ratio (h). Scale bar: 50 μm for Dys-2 (a); upper images: 500 µm and higher magnification in bottom images: 200 µm for ATPase (a). The comparisons among the averages of the groups were evaluated using one-way ANOVA (b, d–g) and two-sided Student’s t-test (e, g). b *p = 0.0218 (nu^PBS vs Tnu^MDX), *p = 0.0260 (nu^PBS vs Tnu^C57Bl). d **p = 0.0098 Tnu^MDX vs Tnu^C57Bl and **p = 0.0024 Tnu^MDX vs nu^PBS mice for MyHC type IIx; **p = 0.0071 Tnu^MDX vs nu^PBS mice for MyHC type IIb. e *p = 0.0299 Tnu^MDX vs Tnu^C57Bl and *p = 0.0324 Tnu^MDX vs nu^PBS mice for MyHC-SL2. f ****p < 0.0001 Tnu^C57Bl and nu^PBS vs Tnu^MDX. g ***p = 0.0005 Tnu^MDX vs Tnu^C57Bl and **p = 0.003 Tnu^MDX vs nu^PBS mice; *p = 0.0189 (mdx vs C57Bl). Data are presented as mean ± SD of three independent experiments with n = 4 mice Tnu^MDX, Tnu^C57Bl and nu^PBS (a–d); n = 8 mice Tnu^C57Bl, n = 9 mice Tnu^MDX and n = 7 mice nu^PBS, n = 6 C57Bl and n = 6 mdx mice (e); n = 4 mice/group (f); n = 8 mice TnuC57Bl, n = 9 mice Tnu^MDX and n = 7 mice nu^PBS, n = 6 C57Bl and n = 6 mdx mice (g); n = 4 mice/group (h). Source data are provided as a Source Data file.