| Objective: autophagy and mitochondrial autophagy are important mechanisms to ensure the stability of intracellular environment.Appropriate level of autophagy and mitochondrial autophagy can be conducive to cell survival.Excessive autophagy or insufficient autophagy level will lead to cell physiological dysfunction and induce various diseases.Studies have shown that exercise can induce autophagy of cells and mitochondria,but excessive exercise may lead to excessive autophagy and induce apoptosis.Therefore,this study used 504-week-old SPF clean grade rats as the experimental objects to observe the effects of different forms of exercise preconditioning training on the autophagy,mitochondrial autophagy and mitochondrial function of skeletal muscle cells in rats,so as to identify the best exercise preconditioning scheme that can resist the level of autophagy and mitochondrial dysfunction caused by excessive stimulation,and further determine and further explore the mechanism Objective to investigate the molecular mechanism of mitochondrial autophagy and its relationship with mitochondrial function.Methods: Fifty 4-week-old SPF clean grade rats were randomly divided into control group(Group C),one-time exhaustive exercise group(Group E),medium intensity continuous training + one-time exhaustive exercise group(group M + e),high intensity intermittent training + one-time exhaustive exercise group(Group H + e)and resistance training + one-time exhaustive exercise group(Group R + e).After a week of adaptability training,formal training was carried out.Middle intensity continuous training and high intensity intermittent training are in the form of treadmill exercise,and resistance exercise is in the form of load-bearing ladder.One time exhaustive exercise is treadmill exercise with increasing load.The rats were killed 24 hours after exhaustive exercise.Western blot was used to detect the expression of LC3 protein and fkbp8 protein in skeletal muscle cells and mitochondria.Enzyme linked immunosorbent assay(ELISA)was used to detect the activities of mitochondrial respiratory chain complex II and IV in soleus muscle.Results: 1)compared with group C,the expression of mitochondrial lc3 ii in all exercise groups was significantly increased(P < 0.01);compared with group E,the expression of mitochondrial lc3 ii in M + E and H + e groups was significantly lower(P < 0.01);compared with each exercise preconditioning group,the expression of mitochondrial lc3 ii in M + E and H + e groups was significantly lower(P < 0.05).2)Compared with group C,the expression of lc3 ii protein in gastrocnemius muscle cells of all exercise groups was increased,and there were significant differences between M + E and H + e(P < 0.05);compared with group E,the expression of lc3 ii protein in gastrocnemius muscle cells of all exercise groups was lower,but there was no statistical significance(P > 0.05),and there was no statistical significance between exercise preconditioning groups(P > 0.05).3)Compared with group C,the activity of mitochondrial respiratory chain complex IV in group M + e,R + E and H + e decreased significantly(P < 0.05),and the activity of mitochondrial respiratory chain complex IV in Group E decreased significantly(P < 0.01);compared with group E,the activity of mitochondrial respiratory chain complex IV in group M + E and R + e was higher than that in Group E(P < 0.05),There was no statistical significance in the comparison among the exercise preconditioning groups(P > 0.05).4)The activity of mitochondrial respiratory chain complex II in M + e,H + e,R + E and e groups was lower than that in C group,but there was only significant difference between H + e group and E group(P < 0.05);compared with E group,the expression of M + e,H + E and R + e was higher,but there was no significant difference(P > 0.05),and there was no significant difference among exercise preconditioning groups(P > 0.05).5)The expression of fkbp8 protein in M + e,H + e,R + E and e groups was higher than that in C group,and the increase of protein expression in H + e,R + E and e groups showed significant difference(P < 0.05);compared with E group,the expression of fkbp8 protein in M + e,H + E and R + e groups was lower,but only m + e group showed statistical significance(P < 0.05).Conclusion:(1)autophagy and mitochondrial autophagy increased significantly after exhaustive exercise.Compared with 8 weeks of resistance training,high intensity intermittent training and medium intensity continuous training can make mitochondrial autophagy adapt to exercise and reduce the harm of excessive autophagy.However,the effect of exercise preconditioning on autophagy was not obvious.(2)Compared with high-intensity intermittent training,8 weeks of medium intensity continuous training and resistance training can make the mitochondrial function change more adaptively,which can help mitochondria cope with the energy metabolism dysfunction caused by one-time exhaustive exercise to a certain extent.(3)Exercise can increase the expression of mitochondrial autophagy pathway protein fkbp8,and the change trend of fkbp8 protein expression is consistent with the trend of mitochondrial autophagy. |
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