Effects of lifelong exercise on age-related body composition, oxidative stress, inflammatory cytokines, and skeletal muscle proteome in rats.

PURPOSE:This study aims to evaluate whether regular lifelong exercise has effects on age-related inflammatory cytokines, oxidative stress, and the skeletal muscle proteome. METHODS:Four groups of adult-aged (8-month-old) female Sprague Dawley rats were used: rats for which training was initiated at either 8 (8 M-MICT, moderate-intensity continuous training) or 18 months (18 M-MICT) and sedentary rats aged either 26 (26 M-SED) or 8 months (8M-SED), who served as aging and adult sedentary controls, respectively. Aged skeletal muscles were subjected to proteomic and Kyoto Encyclopedia of Genes and Genomes (KEGG) and immunoblotting analyses. RESULTS:Age-related loss of physical performance and anti-inflammatory steroid levels were lowest in the 8 M-MICT group, while the anti-oxidative activities remained unchanged compared to 18 M-MICT rats. The proteomic analysis demonstrated an amelioration of age-related changes to muscle contraction, focal adhesion signaling, mitochondrial function, apoptosis and regeneration, anti-oxidation, and protein processing in the endoplasmic reticulum in the 8 M-MICT. Additionally, neurotrophin (BDNF) and AKT/FOXO signaling pathways were upregulated in 8 M-MICT rats compared to 26 M-SED. CONCLUSION:8 M-MICT exhibited greater beneficial effects in ameliorating age-related inflammation and physical performance loss, compared to 18 M-MICT. The amelioration is potentially related to the upregulation of autophagy activities via BDNF/AKT signaling.