Pang Minhui, Yang Jianwei, Rao Jiaming, Wang Haiqing, Zhang Jiayi, Wang Shengyong, Chen Xiongfei, Dong Xiaomei
Department of Epidemiology and Health Statistics, Basic Medical College of Jinan University.
Guangzhou Center for Disease Control and Prevention.
Tohoku J Exp Med. 2018 Feb;244(2):93-103. doi: 10.1620/tjem.244.93.
Exercise induces the expression of peroxisome proliferator-activated receptor gamma co-activator 1-α (PGC-1α) in skeletal muscle, which promotes the cleavage of fibronectin type III domain-containing protein 5 (FNDC5) to irisin. To explore the relationship between irisin and its regulators, we analyzed the plasma irisin levels and the muscle levels of FNDC5 and PGC-1α after exercise. Male C57BL/6J mice underwent a treadmill exercise (60% of VO) for 30 min or one hour (h), and blood and gastrocnemius samples were collected before exercise (pre-exercise), immediately after exercise, and during 24-h recovery after 1-h exercise. We found that plasma irisin levels were significantly increased during exercise (P < 0.05), while FNDC5 protein levels were not significantly increased. Moreover, PGC-1α mRNA and protein levels were significantly increased during 30-min exercise, but were decreased during 1-h exercise. After 1-h exercise, the irisin levels peaked at 6 h (20.71 ± 0.25 ng/ml) and decreased to pre-exercise levels by 24 h (15.45 ± 0.27 ng/ml). Likewise, PGC-1α mRNA and protein levels were increased at 1 h and maintained at elevated levels for 6 h; thereafter, the expression levels of PGC1-α protein were decreased to pre-exercise levels at 12 h. Thus, the restoration of PGC-1α expression to the pre-exercise levels was followed by the decrease in plasma irisin levels. By contrast, during 24-h recovery, the expression levels of FNDC5 mRNA and protein were maintained at elevated levels. These results suggest that the coordinated expression of FNDC5 and PGC-1α may contribute to the increased levels of plasma irisin after exercise.
运动可诱导骨骼肌中过氧化物酶体增殖物激活受体γ共激活因子1-α（PGC-1α）的表达，该因子可促进含III型纤连蛋白结构域蛋白5（FNDC5）裂解为鸢尾素。为探究鸢尾素与其调节因子之间的关系，我们分析了运动后血浆鸢尾素水平以及FNDC5和PGC-1α的肌肉水平。雄性C57BL/6J小鼠进行30分钟或1小时的跑步机运动（最大摄氧量的60%），并在运动前（运动前）、运动后即刻以及1小时运动后的24小时恢复期间采集血液和腓肠肌样本。我们发现，运动期间血浆鸢尾素水平显著升高（P < 0.05），而FNDC5蛋白水平未显著升高。此外，PGC-1α mRNA和蛋白水平在30分钟运动期间显著升高，但在1小时运动期间下降。1小时运动后，鸢尾素水平在6小时达到峰值（20.71±0.25 ng/ml），并在24小时降至运动前水平（15.45±0.27 ng/ml）。同样，PGC-1α mRNA和蛋白水平在1小时升高，并在6小时维持在较高水平；此后，PGC1-α蛋白表达水平在12小时降至运动前水平。因此，PGC-1α表达恢复到运动前水平后，血浆鸢尾素水平随之下降。相比之下，在24小时恢复期间，FNDC5 mRNA和蛋白表达水平维持在较高水平。这些结果表明，FNDC5和PGC-1α的协同表达可能有助于运动后血浆鸢尾素水平的升高。
