Fig 7.

Analysis of P2X7 expression and activation in mdx and C57 muscles at 4 month. (A) Immunoblots of dystrophin (Dp427 muscle isoform), P2X7 receptor, ERK and phospho-ERK1/2 in protein extracts from hind limb muscles [tibialis anterior (TA), gastrocnemius (GC), soleus] and (B) in diaphragms of 4 month old wild-type and mdx mice. β-Actin represents a control for equal protein loading. Images are representative of at least three independent experiments. (C, D) Densitometric analyses of immunoblot results. Two-way ANOVA revealed that for P2X7 protein expression levels, the main effect of genotype was significant (*P < 0.0001, F = 59.91) whereas the effect of muscle type was not significant (P > 0.05). Moreover, for phospho-ERK1/2 protein expressed as a percentage of ERK1/2, the main effects of muscle type and genotype were significant (*P = 0.0010, F = 12.88 and P = 0.0007, F = 20.15, respectively). (E) Representative immunoblot analysis of the same set of leg muscle samples with the F4/80 macrophage marker to evaluate the abundance of macrophages in dystrophic muscles at 4 months of age.