Figure 2. Thbs4 overexpression in skeletal muscle mitigates MD in mice.
(A) Masson’s trichrome stained sections of quadriceps (Quad.) and diaphragm (Diaph.) from WT, Thbs4-Tg, Sgcd-/- and Sgcd-/- Thbs4-Tg mice at 3 mo of age (Scale bar = 100 μm). Blue staining is fibrosis. (B) Quantitation of serum CK levels (units/liter) in indicated genotypes at 3 mo of age. *p<0.05 vs WT; #p<0.05 vs Sgcd-/- by one-way ANOVA with post hoc Tukey’s test. N = 8 mice for WT, Thbs4 Tg and Sgcd-/-Thbs4 Tg and n = 7 mice for Sgcd-/-. The legend in this panel also refers to panels C–F. (C) Percentage of myofibers with centrally located nuclei in Quad and Diaph from H&E-stained histological sections at 3 mo of age. Representative images are shown in Figure 2—figure supplement 3. *p<0.05 vs WT; #p<0.05 vs Sgcd-/- by one-way ANOVA with post hoc Tukey’s test. (D) Interstitial fibrosis analyzed in trichrome stained histological sections from Quad, gastrocnemius (Gas) and Diaph at three months of age. *p<0.05 vs WT; #p<0.05 vs Sgcd-/- by one-way ANOVA with post hoc Tukey’s test. N = 6 mice for WT and Thbs4 Tg and n = 8 mice for Sgcd-/-and Sgcd-/-Thbs4 Tg in panel A, C and D. (E) Time to fatigue in seconds with forced downhill treadmill running at 3 mo of age in the indicated genotypes of mice. *p<0.05 vs WT; #p<0.05 vs Sgcd-/- by one-way ANOVA with post hoc Tukey’s test. N = 6 mice per genotype. (F,G) Quantitation of total Evan’s blue dye (EBD) positive fibers and representative immunofluorescent images of EBD uptake (red) in Quad of three month-old mice. Membranes of myofibers are shown in green. *p<0.05 vs WT; #p<0.05 vs Sgcd-/- by one-way ANOVA with post hoc Tukey’s test. N = 5 mice per genotype in panel F. Scale bar = 100 μm. (H) Transmission electron microscopy of quadriceps muscle in Sgcd-/-Thbs4 Tg mice compared to Sgcd-/- mice at 3 mo of age. The arrowheads show subsarcolemmal vesicular expansion due to the Thbs4 Tg. Representative images of 2 mice per genotype are shown. Scale bar = 500 nm. All data are represented as mean ± SEM.
Figure 2—figure supplement 1. Thbs4 overexpression mitigates muscular dystrophy in Sgcd-/- and mdx mice with aging to one year.
Figure 2—figure supplement 2. Thbs4 overexpression mitigates MD in mdx mice at three months of age.
Figure 2—figure supplement 3. In depth imaging of H&E sections showing how Thbs4 overexpression reduces myofiber degeneration-regeneration (central nucleation) in both Sgcd-/-and mdx dystrophic quadriceps.
Figure 2—figure supplement 4. Intramuscular AAV9-mediated overexpression of Thbs4 mitigates MD in Sgcd-/- mice.
