Expression levels of myosin heavy chain and AMPK-PGC-1α pathway in the skeletal muscles.

The mRNA expression levels of MYH1 (encoding MHC type IIx), MYH2 (encoding MHC type IIa), and MYH7 (encoding MHC type I) normalized to β2-microglobulin levels in the intercostal muscles of SBMA (n = 5) and ALS (n = 5) subjects (A–C). The expression levels of MYH1 (A) and MYH2 (B) were significantly decreased in subjects with SBMA compared with subjects with ALS. The mRNA expression levels of MYH1, MYH2, and MYH7 normalized to β2-microglobulin levels in the iliopsoas muscles of SBMA (n = 5), ALS (n = 6), and DC (n = 4) subjects (D–F). The mRNA levels of MYH1 and MYH2 in the iliopsoas muscle were significantly decreased in subjects with SBMA compared with ALS subjects, as observed in the intercostal muscles (D, E). The expression levels of MYH7 were significantly higher in subjects with SBMA than in subjects with ALS (F). Expression levels of the genes known to regulate muscle fiber type switching in SBMA (n = 5), ALS (n = 6), and DC (n = 4) samples. The mRNA levels of PGC-1α and PPAR-δ, which regulate the oxidative fiber type profile, were significantly increased in SBMA compared with ALS and DC. The Mann-Whitney U test was performed to assess significant differences for each target gene between SBMA and ALS. ANOVA with Tukey’s post-hoc test was performed to compare the significance of differences in each target gene among SBMA, ALS, and DC. **p < 0.01. *p < 0.05. Data are presented as the mean ± SE. SBMA, spinal and bulbar muscular atrophy; ALS, amyotrophic lateral sclerosis; DC, disease control; PGC-1α, proliferator-activated receptor gamma coactivator 1-alpha; PPAR, peroxisome proliferator-activated receptor.