Aerobic Exercise Recovers Disuse-induced Atrophy Through the Stimulus of the LRP130/PGC-1α Complex in Aged Rats

Physical training has been shown to be important to the control of muscle mass during aging, through the activation of several pathways including, IGF1-AKT and PGC-1 alpha. Also, it was demonstrated that LRP130, a component of the PGC-1 alpha complex, is important for the PGC-1 alpha-dependent transcription of several mitochondrial genes in vivo. To explore the role of physical training during aging, we investigated the effects on muscle recovery after short-term immobilization followed by 3 or 7 days with aerobic or resistance training. Using morphological (myofibrillar adenosine triphosphatase activity, to assess the total muscle fiber cross-sectional area (CSA) and the frequency of specific fiber types), biochemical (myosin heavy chain), and molecular analyses (quantitative real-time PCR, functional pathways analyses, and Western blot), our results indicated that after an atrophic stimulus, only animals subjected to aerobic training showed entire recovery of cross-sectional area; aerobic training reduced the ubiquitin-proteasome system components involved in muscle atrophy after 3 days of recovery, and the upregulation in PGC-1 alpha expression enhanced the process of muscle recovery by inhibiting the FoxO pathway, with the possible involvement of LRP130. These results suggest that aerobic training enhanced the muscle regeneration process after disuse-induced atrophy in aged rats possibly through of the LRP130/PGC-1 alpha complex by inhibiting the ubiquitin-proteasome system.