Fig. 4
From: AAV-NRIP gene therapy ameliorates motor neuron degeneration and muscle atrophy in ALS model mice
AAV-NRIP treated SOD1 G93A mice increase myofiber size and slow myosin expression. A Myofiber size in SOD1 G93A mice treated with AAV-NRIP. Soleus muscles were stained with anti-laminin (red) to define the muscle fiber borders. DAPI was used for nuclear staining. Scale bars: 50 μm. B The average myofiber cross-sectional area (CSA) was measured from WT and SOD1 G93A mice treated with AAV-GFP or AAV-NRIP. The CSA of all myofibers circumscribed by laminin was measured using ImageJ software (N = 4 for each group). Data are presented as mean ± SEM. *P = 0.0214 (WT vs. SOD1 G93A + AAV-GFP); **P = 0.0093 (SOD1 G93A + AAV-GFP vs. SOD1 G93A + AAV-NRIP); one-way ANOVA with Tukey’s post hoc test. C Distribution of different myofiber sizes in soleus muscles from WT and SOD1 G93A mice treated with AAV-GFP and AAV-NRIP. The CSA of myofibers was categorized into three groups based on size (< 1000 μm2, 1000–1500 μm2, or > 1500 μm2). The percentage of each categorized myofiber size relative to the total myofibers was calculated to assess the effect of AAV-NRIP on myofiber CSA (N = 4 for each group). Data are presented as mean ± SEM. *P = 0.0146 (< 1000 μm2, WT vs. SOD1 G93A + AAV-GFP); *P = 0.0168 (< 1000 μm2, SOD1 G93A + AAV-GFP vs. SOD1 G93A + AAV-NRIP); *P = 0.0390 (> 1500 μm2, WT vs. SOD1 G93A + AAV-GFP); *P = 0.0137 (> 1500 μm2, SOD1 G93A + AAV-GFP vs. SOD1 G93A + AAV-NRIP); one-way ANOVA with Tukey’s post hoc test. D AAV-NRIP increases slow myosin expression in the soleus muscle of SOD1 G93A mice. The soleus muscles were co-stained with anti-slow myosin and anti-Flag antibodies to visualize oxidative fibers (green) and Flag-NRIP expression (red). DAPI was used for nuclear staining. Scale bars: 50 μm. E Proportion of slow myosin-positive myofibers relative to the total myofibers (N = 3 for each group). Data are presented as mean ± SEM. **P = 0.0053 (WT vs. SOD1 G93A + AAV-GFP); **P = 0.0012 (SOD1 G93A + AAV-GFP vs. SOD1 G93A + AAV-NRIP); one-way ANOVA with Tukey’s post hoc test. F Fluorescence intensity of slow myosin in myotubes with or without Flag-NRIP expression in AAV-NRIP treated SOD1 G93A mice (N = 3 mice). Data are presented as mean ± SEM. Statistical analysis was conducted using Student t-test for panel F. *P < 0.05