Figure 4. Aged AMPK-MKO Mice Develop Exacerbated Myopathy and Mitochondrial Disease.
(A) Percent of fibers with centrally located nuclei (n = 4–10) and (B) collagen accumulation (n = 3–10) in TA muscle.
(C–K) Aged AMPK-MKO and WT mice. (C) Photomicrograph (scale bar, 100 μm) showing large rounded fibers (closed arrow), small angular fibers (open arrow), and necrotic fibers (asterisk) in TA. (D) Maximum isometric and (E) specific force production of TA muscle (n = 4–6). (F) Percent adiposity with representative CT images (n = 4–7). Mitochondrial size in the (G) IMF and (H) SS regions of the myofiber (n = 3 per group). Number of mitochondria in the (I) IMF and (J) SS myofiber regions (n = 3 per group). (K) Representative electronmicrograph showing enlarged mitochondria (closed arrow) (scale bar, 4 μm).
(L and M) Number of mtDNA copies (L, n = 6–9) and mtDNA deletions (M, n = 5–10) in quadriceps muscle.
(N and O) p62 (N) and Parkin (O, n = 7–11) expression in extensor digitorum longus muscle in fed state.
Data are means ± SEM. * WT versus AMPK-MKO p < 0.05, **p < 0.01, ***p < 0.001, # fed versus fasted p < 0.05, ## p < 0.01, ### p < 0.001.