有氧运动干预父系C57BL/6J小鼠对雄性子代骨骼肌mTOR信号通路的影响

Paternal Aerobic Exercise Affects Skeletal Muscle m TOR Signaling Pathway in Male Offsprings of C57BL/6J Mice

目的:探究运动干预父系小鼠对雄性子代骨骼肌mTOR信号通路的影响。方法:同窝C57BL/6J雄性小鼠(F0),自出生21天断乳后随机分为运动组(E)和安静组(C),正常饮食,运动组进行6周跑台训练,6周后两组分别与同窝安静雌性小鼠1︰1交配。运动组F1代雄性小鼠为EM组;安静组F1代雄性小鼠为CM组。F1代小鼠出生21天断乳后,分别检测其表型及骨骼肌mTOR信号通路分子的表达变化。结果:(1) EM组小鼠体重、抓力、股四头肌湿重及股四头肌湿重/体重比值较CM组均显著增加(P<0.05);(2)EM组小鼠股四头肌细胞的横截面积较对照组增加30.26%(P<0.05);(3) EM组小鼠股四头肌PI3K、Akt、mTOR以及S6K1总蛋白表达水平较CM组略有增加(P>0.05);而pAkt,pmTOR,pS6K1以及p4E-BP1蛋白表达水平较对照组显著增加(P<0.05)。结论:(1) 6周跑台运动干预父系小鼠可显著增加雄性子代小鼠的体重、抓力、股四头肌湿重及股四头肌细胞横截面积。(2) 6周跑台运动干预父系小鼠后,其雄性子代小鼠骨骼肌组织mTOR信号通路活性显著高于对照组。提示,运动干预父系小鼠促进子代雄性小鼠骨骼肌发育可能与mTOR信号通路激活密切相关。

Objective To explore the effect of paternal aerobic exercise oil the skeletal muscle mTOR signaling pathway in male offsprings of C57BL/6 mice. Methods Sibling males were divided into the control (C) and exercise (E) groups. All mice stopped breast feeding 21 days after their birth and was fed in the same way. The control group and sibling females were kept sedentary, while group E underwent treadmill running for 6 weeks. Then one male and one female were mated. The male newborns (Fl) of fathers from group E belonged to group EM, while those of fathers from group C were members of group CE. Twenty-one day after their birth, the skeletal muscle phenotype and the activity of mTOR signaling pathway were assessed. Results Compared to group CM, a significant increase was observed in the body weight, grip, quadriceps femoris muscle wet weight and the ratio of quadriceps femoris muscle wet weight/body weight in group EM (P<0.05). The mean cross sectional area of the quadriceps femoris muscle increased by 30.26% in group EM (P<0.05). The total protein expression of PI3K, Akt, mTOR and S6K1 of group EM increased compared with group CM, but not signifi-cantly, while the protein expression of pAkt, pniTOR,pS6K 1 and p4E- BP1 levels increased significantlv compcirrd with group EM group (P<0.05). Conclusions In our present study, we have found that paternal Ireadmill exercise can significantly enhances increase the body weight, grip,(jiiadriceps fenioris muscle wet weight and cross sectional area of nude offsprings. The positive effect of paternal treadmill exercise on skeletal muscle growth of male offsprings might be partially mediated by exerciseinduced activcilion of mTOR signaling piithway in quadriceps femoris muscle.