摘要
本研究通过对衰老大鼠进行运动训练,探究不同运动方式对神经肌肉接头(neuromuscular junction,NMJ)和骨骼肌相关蛋白代谢的影响及机制。从38只3月龄SPF级Sprague-Dawley(SD)雄性大鼠中随机选出10只作为青年对照组(Y组),其余养至21月龄后随机分为老年对照组(O组、8只)、耐力运动组(EN组、10只)、抗阻运动组(R组、10只)。经过相对应的8周训练后,取大鼠腓肠肌,用免疫荧光染色法检测S100B在施旺细胞上的表达水平。用Western blot检测凝集蛋白(Agrin)、低密度脂蛋白受体相关蛋白4(low-density lipoprotein receptor-related protein 4,Lrp4)、肌肉特异性激酶(muscle-specific kinase protein,MuSK)、酪氨酸激酶下游分子7(downstream of tyrosine kinase 7,Dok7)与磷酸化蛋白激酶B(phosphorylated protein kinase B,p-Akt)、磷酸化哺乳动物雷帕霉素靶蛋白(phosphorylated mammalian target of rapamycin,p-mTOR)、磷酸化叉头转录因子1(phosphorylated forkhead box O1,p-FoxO1)蛋白表达水平。结果显示,耐力和抗阻运动均提高衰老大鼠腓肠肌湿重比。R组S100B蛋白表达显著高于O组和EN组;与Y组比较,O组大鼠腓肠肌NMJ功能相关蛋白Agrin、Lrp4、MuSK、Dok7蛋白表达水平显著下调;衰老大鼠经过抗阻运动后,腓肠肌Agrin、Lrp4、MuSK、Dok7蛋白表达水平均显著上调,而衰老大鼠经耐力运动后仅Agrin蛋白表达水平显著上调,而Lrp4、MuSK、Dok7蛋白表达未得到改善。在骨骼肌相关蛋白代谢相关通路中,与Y组比较,O组大鼠腓肠肌p-Akt、p-mTOR蛋白表达水平下调,p-FoxO1蛋白表达水平上升;抗阻和耐力运动可逆转衰老大鼠p-mTOR和p-FoxO1蛋白表达的变化。以上结果表明,两种运动方式均可改善衰老大鼠NMJ功能,并增加骨骼肌蛋白质合成,降低骨骼肌蛋白质分解代谢,且抗阻运动效果更加显著。
The present study aimed to explore the effects of different exercise modes on neuromuscular junction(NMJ)and metabolism of skeletal muscle-related proteins in aging rats.Ten from 38 male Sprague-Dawley(SD)rats(3-month-old)were randomly selected into young(Y)group,while the rest were raised to 21 months old and randomly divided into elderly control(O),endurance exercise(EN)and resistance exercise(R)groups.After 8 weeks of corresponding exercises training,the gastrocnemius muscles of rats werecollected,and the expression of S100B in Schwann cells was detected by immunofluorescence staining.Western blot was used to detect the protein expression levels of agglutinate protein(Agrin),low-density lipoprotein receptor-related protein 4(Lrp4),musclespecific kinase protein(MuSK),downstream tyrosine kinase 7(Dok7),phosphorylated protein kinase B(p-Akt),phosphorylated mammalian target rapamycin(p-mTOR),and phosphorylated forkhead box O1(p-FoxO1)in rat gastrocnemius muscles.The results showed that,endurance and resistance exercises increased the wet weight ratio of gastrocnemius muscle in the aging rats.The protein expression of S100B in the R group was significantly higher than those in the O and EN groups.Proteins related to NMJ function,including Agrin,Lrp4,MuSK,and Dok7 were significantly decreased in the O group compared with those in the Y group.Resistance exercise up-regulated these four proteins in the aging rats,whereas endurance exercise could not reverse the protein expression levels of Lrp4,MuSK and Dok7.Regarding skeletal muscle-related proteins,the O group showed down-regulated p-Akt,and p-mTOR protein expression levels and up-regulated p-FoxO1 protein expression level,compared to the Y group.Resistance and endurance exercises reversed the changes in p-mTOR and p-FoxO1 protein expression in the aging rats.These findings demonstrate that both exercise modes can enhance NMJ function,increase protein synthesis and reduce the catabolism of skeletal muscle-related proteins in aging rats,with resistance exercise showi
作者
苏艳红
程翌
李婷婷
张熠晨
杜泽宇
陈娟
王福清
刘忠浩
龚文翰
SU Yan-Hong;CHENG Yi;LI Ting-Ting;ZHANG Yi-Chen;DU Ze-Yu;CHEN Juan;WANG Fu-Qing;LIU Zhong-Hao;GONG Wen-Han(School of Physical Education,Liaoning Normal University,Dalian 116029,China;Qilu Medical University,Zibo 255300,China;School of Life Science,Liaoning Normal University,Dalian 116029,China;Dalian Bay Middle School,Dalian 116033,China;School of Physical Education,Minnan University of Science and Technology,Quanzhou 362799,China)
出处
《生理学报》
CAS
CSCD
北大核心
2024年第3期376-384,共9页
Acta Physiologica Sinica
基金
supported by the Scientific Research Project from the Education Department of Liaoning Province,China(No.WZ2020001)
the High-end Scientific Research Achievement Cultivation Project of Liaoning Normal University(No.203070142207).
关键词
骨骼肌
肌肉萎缩
神经肌肉接头
运动
skeletal muscle
atrophy of muscles
neuromuscular junction
exercise
