Figure 4.

Dystrophin Restoration Increases Sub-sarcolemmal Mitochondria Pool Density in mdx Mice Treated with PMO-GF for 1 Year

(A) Transmission electron microscopy micrographs of the SSM pool in tibialis anterior skeletal muscles from wild-type C57BL6, age-matched untreated mdx controls, and PMO-GF-treated mdx mice (scale bars, 1 μm). Arrowheads point to SSMs. (B) Quantitative analysis of SSM densities. Number of mitochondria per micron length of sarcolemma was determined from transmission electron micrographs. In both wild-type C57BL6 and PMO-GF-treated mdx mice skeletal muscle, SSMs were heavily concentrated along the subsarcolemmal space and averaged around three SSMs per micron of sarcolemma. SSM density in PMO-GF-treated mdx mice was significantly increased compared with aged-matched untreated mdx controls (two-tailed t test, n = 5, *p < 0.05). (C) Measurement of basal and maximal oxygen consumption rate (OCR) in skeletal muscles from mdx mice treated with PMO-GF for 1 year. Data show a significant reduction at the maximal OCR in mdx mice treated with PMO-GF compared with untreated mdx controls (two-tailed t test, n = 5, **p < 0.01).