不同时间一次有氧运动对小鼠骨骼肌Nrf2与Keap1结合作用的影响

Effects of an Aerobic Exercise of Different Durations on Nrf2/Keap1 Binding Capacity in Skeletal Muscles of Mice

目的:探讨不同时间一次有氧运动对小鼠骨骼肌NF-E2相关因子(NF-E2-related factor 2,Nrf2)与Kelch样环氧氯丙烷相关蛋白-1(Kelch-like ECH-associated protein-1,Keapl)结合作用的影响。方法:C57BL/6J小鼠30只,按体重随机分为安静对照组(0 h组)和一次有氧运动3小时组(3 h组)、一次有氧运动6小时组(6 h组),每组10只。0 h组安静饲养,3 h组和6 h组小鼠分别进行3小时和6小时的一次有氧跑台训练,跑速为15 m/min,坡度为0。运动后即刻取后腿骨骼肌。高质荧光测定法检测小鼠骨骼肌活性氧(ROS)水平;免疫共沉淀法测Nrf2/Keap1结合量;Western Blot法测定骨骼肌总Nrf2、Keap1蛋白表达量和细胞核Nrf2蛋白表达量。结果:与0 h组相比,6 h组ROS水平显著高于0 h组(P<0.05);3h、6 h组小鼠骨骼肌中Nrf2/Keap1结合量显著降低(P<0.05);3 h、6 h组小鼠骨骼肌总Nrf2蛋白表达显著升高(P<0.05),6 h组小鼠骨骼肌细胞核Nrf2蛋白表达显著增加且与3h组相比也显著增加(P<0.05);小鼠骨骼肌总Keap1蛋白表达基本无变化。结论:一次有氧运动对小鼠骨骼肌Nrf2与Keap1解绑和Nrf2转位入核的影响与运动时间的长短有关。

Objective To explore the effects of an aerobic exercise of different durations on the bind-ing capacity of NF-E2-related factor 2（Nrf2）/Kelch-like ECH-associated protein-1（Keap1） in skeletalmuscle of mice. Methods Thirty C57 BL/6 J mice were divided into a control（0 h） group,an acute exer-cise for 3 hours（3 h） group and an acute exercise for 6 hours（6 h） group. The mice ran on treadmillat the speed of 15 m/min for different durations. The mice were sacrificed immediately after exerciseand collected skeletal muscles of legs. The high quality fluorescence assay was done to detect the reac-tive oxygen species（ROS） level in the skeletal muscles of mice. The binding capacity of Nrf2/Keap1 was detected using co-immunoprecipitation. The expression of Nrf2 and Keap1 was analyzed using theWestern blotting. Result Compared with grouP〈0 h,the Nrf2/Keap1 binding capacity in skeletal musclesof group 3 h and 6 h decreased significantly（P〈0.05）,but the total Nrf2 in skeletal muscles increasedsignificantly（P〈0.05）. No significant differences were observed in the expression of total Keap1. The ex-pression of Nrf2 protein of group 3 h and 6 h increased significantly compared with 0 h,with that ofgroup 6 h significantly higher than group 3 h（P〈0.05）.The ROS level in skeletal muscles of group 6 h increased significantly compared with grouP〈0 h（P〈0.05）. Conclusion The effect of acute aerobic exerciseon Nrf2/Keap1 binding capacity in skeletal muscle of mice depends on its duration.