游泳运动对细胞自噬轴诱导生理性心肌肥大形成的影响  

Effect of Swimming on Autophagy Axis Induced Physiological Hypertrophy

作　　者：齐洁[1] 张波 蒋丽 张钧[1] QI Jie;ZHANG Bo;JIANG Li;ZHANG Jun(School of PE,Shanghai Normal University,Shanghai 200234,China;School of PE,Yili Normal University,Yining 835000,China)

机构地区：[1]上海师范大学体育学院,上海200234 [2]伊利师范大学体育学院,新疆835000

出　　处：《天津体育学院学报》2021年第3期347-353,共7页Journal of Tianjin University of Sport

基　　金：国家自然科学基金项目(项目编号:31571223)。

摘　　要：目的:检测和观察心肌自噬轴在10周游泳运动诱导的心肌肥大中的变化,探讨游泳训练通过心肌miRNA致自噬水平改变影响运动性心肌肥大形成的机制。方法:6周龄雌性SD大鼠随机分为对照组(CON组)和运动组(EX组)。CON组大鼠安静饲养10周,EX组大鼠进行10周游泳运动。10周训练后,采用心脏超声检测以及用RT-qPCR法检测心肌病理性指标mRNA的表达量,综合评价运动性心肌肥大动物模型的建立;用透射电镜观察心肌组织自噬体,免疫荧光检测LC3B在心肌组织的表达,RT-qPCR检测心肌组织自噬标记物LC3、Beclin1的mRNA表达水平及通过生物信息学软件预测的与自噬基因相关的miRNAs表达水平,Western Blot检测心肌自噬相关基因的蛋白表达水平。结果:(1)EX组大鼠左心室自噬轴发生显著变化,具体表现为:与CON组相比,EX组大鼠心肌出现双层膜结构自噬小体,LC3B免疫荧光信号阳性颗粒显著增加;LC3Ⅱ/LC3Ⅰ比值显著升高,Beclin1 mRNA和蛋白表达水平均显著上调,心肌自噬相关基因ULK1、Atg4B、Atg5、Atg7、Atg12蛋白表达水平均显著增加,SQSTM1蛋白表达水平显著下降,提示EX组大鼠心肌自噬水平显著提高;(2)RT-qPCR结果表明:与CON组相比,EX组大鼠左心室miR-26b-5p、miR-204-5p、miR-497-3p和let-7a-5p表达水平均显著下调,miR-181a-5p表达量发生显著上调。结论:心肌自噬轴参与了运动诱导的生理性心肌肥大的过程,其作用机制可能是通过miRNA对自噬相关基因的靶向调控作用实现。Objective:Swimming exercise leads to a nonpathological,physiological left ventricular hypertrophy.However,the potential molecular mechanisms are unknown.We investigated the role of autophagy regulating the cardiac signal cascades were studied in exercised rats.Methods:Female Sprague-Dawley rats were assigned into two groups:(1)sedentary control(CON),(2)swimming exercise(EX).The rats in the EX group completed a 10-week swimming exercise without load.The autophagosome were observed by transmission electron microscope.Moreover,we assessed cardiac protein expression of LC3,Beclin1,ULK1,Atg5,Atg7,Atg4B and SQSTM1.The gene expression analysis of LC3,Beclin1,miRNAs were performed by real-time PCR in heart muscle.Results:1)As compared with the group CON,the LC3B fluorescence intensity was increased markedly,the gene expression of LC3 and Beclin1 were increased significantly,the cardiac autophagy was increased in the EX group when compared with CON group,the mRNA and protein expression of LC3 and Beclin1 were increased in the group EX;The swimming exercise increased the protein levels of ULK1,Atg4B,Atg5,Atg7,Atg12,while it decreased the protein expression of SQSTM1.2)The expression of miR-26b-5p,Let-7a-5p,miR-204-5p and miR-497-3p were down-regulated significantly in EX group,but miR181-a-5p was obviously increased.Conclusions:These findings are consistent with a model in which exercise may induce left ventricular hypertrophy,at least in part,autophagy play important role in physical cardiac hypertrophy,which regulated by the specific miRNAs.

关 键 词：自噬 运动 心脏肥大 微小RNA 

分 类 号：G804.2[文化科学—运动人体科学]