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

Abstract

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-1α. Also, it was demonstrated that LRP130, a component of the PGC-1α complex, is important for the PGC-1α-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-1α 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-1α complex by inhibiting the ubiquitin-proteasome system.

The effect of acute and chronic sprint-interval training on LRP130, SIRT3, and PGC-1α expression in human skeletal muscle

“…The discrepancy between the findings of this study and those of Vechetti‐Junior et al. () may be partly explained by species differences, and/or differences in basal levels of LRP130 expression due to the immobilization protocol implemented prior to training. However, given that LRP130 and PGC‐1 α control each other's expression in cellular models (Cooper et al.…”

“…Although LRP130 protein expression is elevated in response to 7 days of swim training following hindlimb immobilization in rat skeletal muscle (Vechetti‐Junior et al. ), we observed no change in LRP130 protein expression following 3 and 6 weeks of SIT. The discrepancy between the findings of this study and those of Vechetti‐Junior et al.…”

“…Although swim training prevents reductions in lrp130 mRNA expression caused by hindlimb immobilization in rats (Vechetti‐Junior et al. ), we found no change in lrp130 mRNA expression 3 h after an acute bout of SIT in human skeletal muscle. Not surprisingly, we observed an increase in pgc‐1α mRNA expression, which increases in response to various types of acute aerobic exercise (Hellsten et al.…”

“…In rat skeletal muscle, LRP130 gene and protein expression are elevated in response to swimming for 7 days (Vechetti‐Junior et al. ); however, to date, no studies have investigated the effect of exercise on LRP130 in human skeletal muscle. Thus, while PGC‐1 α , SIRT3, and mitochondrial gene and/or protein expression increase following acute and chronic aerobic exercise (Perry et al.…”

Exercise, fasting, and mimetics: toward beneficial combinations?

“…In apparent contrast to this conclusion, endurance training, but not resistance training, caused recovery from disuse‐ induced muscle atrophy in old (18 mo) male rats. Muscle regeneration was accompanied by an up‐regulation of PGC‐1α and inactivation of the FoxO pathway (166).…”