Figure 7.
PV controls muscle fiber size by modulating mitochondrial Ca2+ and PGC-1α4 expression
(A) Representative images of muscle cross-sections of TA muscles electroporated with shMCU and shPV for 7 days. shMCU-positive fibers are in red, shPV-positive fibers in green, and α-laminin in green; Hoechst staining marks the nuclei. Scale bars, 100 μm.
(B) CSA measurements of non-transfected fibers, shMCU-transfected fibers, shPV-transfected fibers, and shMCU- and shPV-co-transfected fibers. More than 100 fibers per muscle; n = 8.
(C) Size-frequency distribution of CSA of the experiment as in (A) and (B).
(D) Representative WB of indicated antibodies on denervated (Den) and contralateral (Con) TA muscle from WT and PV−/− mice. n = 3.
(E) Quantification of the levels of p-Akt protein levels obtained as in (D) and normalized to total Akt.
(F) Expression levels of PGC-1α4 and Pik3r1 in WT and PV−/− TA muscles. Data were normalized to WT. Expression levels were normalized to POL2. n = 3.
(G) CSA measurements of non-transfected and shPV- and shPGC-1α4-double-positive fibers from the same TA muscle transfected for 7 days. More than 100 fibers per muscle; n = 8.
(H) Size-frequency distribution of CSA of the experiment as in (G).
Data are shown as mean ± SEM. For data analysis, one-way ANOVA with Tukey’s post hoc (B and E) or two-tailed, unpaired Student’s t tests (F and G) were used. ∗p ≤ 0.05; ∗∗p ≤ 0.01; ∗∗∗p < 0.001. See also Figure S7.