Increased ERK1/2 activity in skeletal muscle of LmnaH222P/H222Pmice at 16 weeks of age. Immunoblot showing phosphorylated ERK1/2 (p-ERK1/2) and total ERK1/2 in protein extracts from quadriceps of 16-week-old male wild-type (Lmna WT) and LmnaH222P/H222P (Lmna H222P) mice. Each lane contains protein extracts from a different mouse. The bar graph shows means ± SEM values of pERK1/2 normalized to total ERK1/2 from scanned band densities of three immunoblots from n = 3 different mice per group. *P <0.05.