PROTEOMIC CHANGES INDUCED BY LOW-INTENSITY ENDURANCE EXERCISE IN MDX MOUSE QUADRICEPS: CORRELATION WITH REDUCTION OF MUSCLE DEGENERATION.

Previous study showed that low-intensity endurance exercise induced a significant recovery of damaged skeletal muscle in mdx mice, probably by reducing the degeneration of dystrophic muscle1. In order to explore the molecular basis of this observation, we perfomed a proteomic analysis to evaluate changes in proteins profiling of quadriceps dystrophic muscles of exercised versus sedentary mdx mice. Four protein spots were found significantly changed and were identified as three isoforms of Carbonic anhydrase 3 (CA3) and as superoxide dismutase [Cu-Zn] (SODC). Protein levels of CA3 isoforms were found significantly up-regulated in quadriceps of sedentary mdx mice (MDX-Sed) and were completely restored to wild type values in quadriceps of exercised mdx mice (MDX-Ex). Protein levels of SODC were found down-regulated in quadriceps of sedentary mdx mice and were significantly restored to wild type values in quadriceps of exercised mdx mice. These proteomic data, validated by Western blot analysis, indicate that low-intensity endurance exercise, by modulating some proteins involved in oxidative stress defense, may in part contribute to reduce the reported cell degeneration in mdx muscles1. Further investigations are needed to better define the extension of proteins change in MDX-Ex versus MDX-Sed mice and its correlation with the recovery of damaged fibers in MDX-Ex mice.