Effects Of High Intensity Intermittent Training On Cardiac Autophagy Signaling Pathway And Mitochondrial Function In Middle-aged Mice

The aim of study:To observe the effects of HIIT on autophagic signaling pathway and mitochondrial function in middle-aged mice,a model of 8-week High-intensity Interval Training(HIIT)was established,which could provide theoretical and experimental basis for delaying cardiac aging and improving the health level of middle-aged population.Methods:Thirteen middle-aged(12-month-old)healthy male C57BL/6 mice were randomly divided into quiet control group(CON)and High-intensity Interval Training group(HIIT).Mice in HIIT group received 8 weeks of High-intensity Interval Training.Western Blot was used to detect microtubule-associated protein 1 light chain 3(LC3),autophagy-related gene 5(ATG5),Lysosomal Associated Membrane Protein 2(LAMP2)and mitochondrial autophagy-related protein Parkinson's disease protein in mice.Parkin,BCL2/adenovirus E1B-19 kDa interacting protein 3(BCL2/adenovirus EIB 19kDa interacting protein 3-like,Bnip3L)expression,cytochrome C oxidase ?(cytochrome C oxidase subunit IV,COXIV)expression and respiratory chain enzyme complex ?-?protein expression.Results:1.Effect of high-intensity interval training on expression of autophagy-related protein in myocardium of middle-aged miceCompared with the control group,the ratio of LC3-?/LC3-? in myocardium of HIIT group increased significantly(P<0.05),LC3-? increased significantly(P<0.01),ATG5 protein expression increased significantly(P<0.05),LAMP2 protein expression increased significantly(P<0.01),Parkin protein expression had no significant difference,The expression of Bnip3L protein increased significantly(P<0.05).2.Effects of high-intensity interval training on myocardial mitochondrial function in middle-aged miceCompared with CON group,the expression of COXIV protein in myocardium of HIIT group increased significantly(P<0.05).The expression of Complex ? protein in mitochondrial complex was significantly increased(P<0.05),and there was no significant difference between Complex ?-?.Conclusions:1.High-intensity interval training significantly increased the expression levels of autophagy-related proteins LC3,ATG5,LAMP2 and Bnip3L in middle-aged mice.2.High-intensity interval training increased the content of mitochondria in myocardial tissue of middle-aged mice and improved the respiratory function of mitochondria.