Fig. 2
From: Premature skeletal muscle aging in VPS13A deficiency relates to impaired autophagy
Vps13a−/− mouse skeletal muscle displays increased mitochondrial area with less but wider cristae, and signs of alteration autophagy-lysosome system associated with increased intracellular protein/ lipid oxidation. (a) EM analysis of WT (left) and Vps13a-/- skeletal muscle (right). Upper panels: Vps13a-/- muscle show the presence of altered myofiber structure and autophagic figures adjacent to mitochondria (asterisks), not detectable in WT muscles. Mitochondrial morphometry in WT and Vps13a-/- 8-month-old quadriceps. Lower panels: higher magnification image highlighting mitochondrial ultrastructure. Scale bars: 2 μm for the upper panel, 200 nm for the lower panel. (b) Quantitative analysis of mitochondrial ultrastructure. Mitochondria show increased area and cristae number, but cristae appear wider. Unpaired Student’s t tests. (c) OxyBlot analysis of quadriceps from 8-month-old WT and Vps13a-/- female mice. GAPDH, loading control. Representative of 4 similar experiments. (d) Malondialdehyde (MDA) content of WT and Vps13a-/- quadriceps. Means ± SEM (n = 6), *p < 0.002 by unpaired Student’s t test. (e) Acid phosphatase staining of skeletal muscle samples from WT (top) and Vps13a-/- mice. In Vps13a-/- mice a few muscle fibers show multiple small foci of acid phosphatase reactivity (appearing red). Scale bar is 40 μm.