Figure 2.

A single session of moderate intensity exercise increases pro-fission phosphorylation of Drp1 in a time dependent manner and alters the mitochondrial proteome. (A) Quadriceps mRNA expression (presented in a heat map), representing mitochondrial fission, fusion, and autophagy signaling, in SED, EX45, EX90, and EX90+3 h Rest (N = 6/group; one-way ANOVA with Tukey post hoc analysis). (B–E) Immunoblot densitometry of quadriceps protein and phospho-protein abundance of mitochondrial fission, fusion, and autophagy signaling, in SED (open bars), EX45 (light gray bars), EX90 (dark gray bars), and EX90+3 h Rest (closed black bars) for C57BL/6J (N = 6/group; additional representative immunoblots presented in Supplemental Figure 1; one-way ANOVA with Tukey's post hoc analysis). Muscle Drp1^Ser616 phosphorylation in (A) male and female C57BL/6J (N = 6 mice/time point), and (C) female A/J, BALB/CJ, and C3H/HeJ mice (N = 6 mice/group). (F) Transmission electron micrograph (TEM) images of mouse soleus muscle from SED and EX90 groups. (G) Frequency of mitochondrial area (nm²) determined from the TEMs obtained from SED and EX90 muscle (494 mitochondria visualized/group; Kolmogorov–Smirnov test for cumulative distribution comparison, P = 0.52). (H) Mitochondrial proteomics of gastrocnemius muscle represented in a volcano plot for EX90 vs. SED groups. Dashed line indicates significance threshold and blue dots indicate significance SED vs. EX90 (two-tailed unpaired t-test with Bonferroni correction). (I) Mitochondrial proteomics pathway analysis. (J) Mitochondrial proteomics functional annotation of significantly impacted protein clusters. Data are means ± SEM (N = 6/group). *, P < 0.05 vs. SED.