Figure 1.

PV expression level decreases after denervation and the modulation of its expression affects muscle trophism

(A) mRNA expression levels of PV normalized to contralateral muscles in TA muscles at 3 and 14 days after denervation. Data are normalized to POL2. n = 3.

(B) Representative WB of denervated and contralateral muscles. α-Actin was used as loading control. n = 3.

(C) Quantification of the levels of PV protein obtained as in (B) and normalized to actin. n = 3.

(D) Mean fiber CSA at 3, 7, and 14 days after denervation compared to contralateral muscles of TA muscles from WT and PV^−/− mice. At least 1,500 fibers per muscle; n = 3.

(E) Size-frequency distribution of CSA of the experiment as in (D) at 14 days after denervation.

(F) Representative images of muscle cross-sections of TA muscles electroporated with shPV for 7 days. shPV-positive fibers are displayed in red and α-laminin in green. Scale bar, 100 μm.

(G) CSA of shPV-positive fibers compared to non-transfected fibers in the same muscle. More than 200 fibers per muscle; n = 3.

(H) Size-frequency distribution of CSA of the experiment as in (F) and (G).

(I) Representative images of muscle cross-sections of mCherry-transfected muscles (upper panel) and PV-overexpressing muscles (lower panel) for 7 days. α-Laminin is visualized in green. Scale bar, 100 μm.

(J) CSA measurements of control and PV-overexpressing fibers. More than 200 fibers per muscle; n = 3.

(K) Size-frequency distribution of CSA of the experiment as in (J) and (K).

Data are expressed as mean ± SEM. For data analysis, a two-tailed, unpaired Student’s t test (A and C); two-way ANOVA with Bonferroni post hoc (D); or two-tailed, paired Student’s t test (G and J) were performed. ^∗p < 0.05; ^∗∗p < 0.01; ^∗∗∗p < 0.001; n.s., not statistically significant. Con, contralateral muscle; Den, denervated muscle.