运动预处理通过上调Aplein/APJ改善脑卒中小鼠心肌萎缩和心功能降低

Myocardial atrophy and cardiac function in stroke mice improved by exercise preconditioning through upregulating Aplein/APJ

目的:探讨运动预处理对脑卒中后心肌萎缩和心脏功能紊乱的预防作用。方法:采用大脑中动脉闭塞方式制造缺血性脑卒中小鼠模型,观察表型。30 d游泳运动或静养小鼠,再分别制造脑卒中模型。应用qRT-PCR检测心肌中萎缩标志物Atrogin-1、Mu RF-1和Apelin/APJ mRNA的表达。应用小动物超声仪检测小鼠心脏功能,包括分析收缩功能指标射血分数(EF)、短暂缩短率(FS)和心脏舒张功能指标E/A比值。采用蛋白免疫印迹(Western blot)检测APJ蛋白表达。结果:脑卒中后发生心肌萎缩和心脏功能降低;脑卒中小鼠心肌中萎缩基因Atrogin-1、Mu RF-1表达增加,而Apelin/APJ表达降低(P<0.05);运动能够降低萎缩基因表达,减少心肌萎缩并改善脑卒中心脏功能,且运动预处理上调了脑卒中小鼠心肌中Apelin/APJ表达,差异均有统计学意义(P<0.05)。结论:运动预处理可能通过上调Apelin/APJ缓解脑卒中心肌萎缩和心功能降低。

Objective:To explore the effect of exercise preconditioning on myocardial atrophy and cardiac function after stroke.Methods:The stroke mouse model was made by occlusion of middle cerebral artery,and the phenotype was observed.After 30 days of swimming exercise or resting,stroke mice models were created respectively.The expression of Atrogin-1,MuRF-1 and Apelin/APJ mRNA in myocardium was detected by qRTPCR.Small animal ultrasonic instrument was used to detect the cardiac function of mice,including an analysis of ejection fraction(EF),transient shortening rate(FS)and E/A ratio of diastolic function.The expression of APJ protein was detected by western blot.Results:Myocardial atrophy and decreased cardiac function occurred after stroke;The expression of Atrogin-1 and MuRF-1 in myocardium of stroke mice increased,while the expression of Apelin/APJ decreased(P<0.05).Exercise could reduce the expression of atrophy gene and myocardial atrophy but improve cardiac function after stroke.Exercise up-regulated the expression of Apelin/APJ in myocardium of stroke mice(P<0.05).Conclusion:Exercise preconditioning alleviated central muscle atrophy and decreased cardiac function in stroke.Exercise may prevent muscle atrophy in stroke center by up-regulating Apelin/APJ.