Fig. 2: Skeletal muscle-specific ablation of LONP1 impairs muscle growth and causes muscle weakness and precocious aging.
a Representative hindlimbs and GC muscles from indicated mice at the age of 6 weeks. b, c GC and TA muscles weight in WT and LONP1 mKO mice in basal conditions (Basal) and after 15 days of denervation (Den). n = 5 mice per group. d WGA (green) staining of GC muscle from indicated mice. Scale bar: 50 μm. n = 5 mice per group. (e) Cross-sectional areas of GC myofibers. n = 5 mice per group. f LONP1 mKO mice showed decreased muscle-grip strength compared to WT controls. n = 8–12 mice per group. g Measurement of muscle tetanic contraction reveals a reduced contraction force in LONP1 mKO EDL muscle. n = 3–4 mice per group. h Bars represent mean running time and distance for 10-week-old male LONP1 mKO mice and WT controls on a motorized treadmill. n = 7 mice per group. i (Left) Schematic depicts the increments of speed over time. (Right) Respiratory exchange ratio (RER) during the course of the high-intensity exercise in indicated mice. n = 8 mice per group. j Peak ΔVO2 (increase in oxygen consumption during exercise) is graphed. n = 8 mice per group. k Bars represent mean blood lactate levels for indicated mice following a 25-min run on a motorized treadmill. n = 9–13 mice per group. (l) GSEA of genes upregulated in LONP1-deficient muscle in relation to normal aging in WT mice. m Representative lateral X-ray images of WT and LONP1 mKO mice at indicated age. n = 3–9 mice per group. Values represent mean ± SEM; for (b) and (e), *P < 0.05, **P < 0.01, ***P < 0.001 versus corresponding WT controls, ‡P < 0.05, ‡‡P < 0.01, ‡‡‡P < 0.001 versus Basal, determined by one-way ANOVA coupled to a Fisher’s LSD post-hoc test; for (c) and (f–k), *P < 0.05, **P < 0.01, ***P < 0.001 versus corresponding WT controls determined by two-tailed unpaired Student’s t test. Source data are provided as a Source Data file.
