Figure 4

Fasudil administration inhibits ROCK in skeletal muscle and restores normal myogenin expression levels. Tibialis anterior (TA) muscles were isolated from post-natal (P) day 21 untreated wild type (WT) (n = 4), vehicle-treated Smn ^2B/- (n = 4) and fasudil-treated Smn ^2B/- (n = 4) mice. (A) Immunoblot analysis of p-cofilin 2, a muscle-specific downstream substrate of ROCK, shows that its levels are increased in the TA muscles of Smn ^2B/- mice compared with wild type. Furthermore, this experiment shows that fasudil inhibits ROCK in the TA muscle of Smn ^2B/- mice, and reduces the p-cofilin 2 levels to wild type levels. (B) Quantification shows that wild type TA muscles have significantly less p-cofilin 2 than vehicle-treated Smn ^2B/- TA muscles, and that fasudil is active in skeletal muscle and restores p-cofilin 2 to normal levels. (*P < 0.05; NS = not significant; data are mean +/- s.d.). (C) Immunoblot analysis shows that fasudil does not increase Smn protein levels in the TA muscles of Smn ^2B/- mice. (D) Immunoblot analysis shows that fasudil results in a decrease in myogenin protein levels in fasudil-treated Smn ^2B/- TA muscles when compared to vehicle-treated Smn ^2B/- mice. (E) Wild type muscle has significantly less myogenin than vehicle-treated Smn ^2B/- TA muscles. Fasudil administration to Smn ^2B/- mice restores myogenin to normal levels (*P < 0.05; NS = not significant; data are mean +/- s.d.).