The Changes Of MiR-128 During The Injury And Regeneration Of Skeletal Muscle Induced By Exercise In Rats

ObjectiveSkeletal muscle injury and repair is a complex process involving many factors.In recent years,it has been found that miRNAs plays an important role in the repair of muscle damage.MiR-128 can regulate the expression of Sp1 and then influence the expression of CDKN1 A.It can play a regulatory role in the proliferation and differentiation of skeletal muscle satellite cells,which provides a new reference for the study of skeletal muscle damage repair.In this paper,the rat skeletal muscle damage model was established to detect the expression of miR-128 during the repair of skeletal muscle injury in rats,so as to provide a better understanding of the regulation mechanism of the repair of skeletal muscle injury by miRNAs,and provide a new reference for the injury and repair of skeletal muscle.Method2 month old healthy male SD rats were selected,and 72 rats were randomly divided into 9 groups,8 rats in each group.There were 8 rats in each group.The specific group situation: quiet control group,post exercise 0h group,post exercise 6h group,post exercise 12 h group,post exercise 24 h group,48 h group after exercise,72 h group after exercise,1W group after exercise and 2W group after exercise.The specific parameters of the experimental animals are running slope-16 degree,speed 16m/min and movement time 120 min.In the control group,the control group did not take exercise directly,and the exercise group took 0h,6h,12 h,24h,48 h,72h,1W and 2W after exercise,and the following experiments were carried out by the bilateral gastrocnemius muscle.1)paraffin sections of gastrocnemius muscle were stained with HE for histological observation.2)the expression levels of miR-128,Sp1 and CDKN1 A mRNA were detected by RT-PCR.3)Western Blot was used to detect the expression level of Sp1 and CDKN1 A protein.Results:1)HE staining: the muscle fibers in the quiet control group were polygons and arranged more closely.After exercise,the interstitial space of group 0h increased.After exercise,the muscle fibers in group 6h,12 h,24h and 48 h were swollen and the gap became larger,and the muscle fiber swelling of group 72 h was slowly restored,and the muscle fiber morphology of group 1W and 2W group was close to the control group after exercise.The cell gap was small and the boundaries were clear,arranged closely,and basically returned to normal.2)mRNA level expression: after downhill running,compared with the control group,the overall expression of miR-128 showed a rising trend,and the results of 72 h and 1W in the group of 72 h and 1W were significant(p<0.05)after the exercise.The expression of mRNA in Sp1 was slightly up and no significant difference.CDKN1 A mRNA expression was significant in 24 h,72h,1W,and group.05).3)protein level expression: after downhill running,there was no significant difference in Sp1 protein expression and no significant difference compared with the control group.There was no significant difference in the expression of CDKN1 A protein,but the overall fluctuation was larger.Conclusion1)miR-128 may be involved in the regeneration process of exercise-induced skeletal muscle injury.2)miR-128 may promote the repair of skeletal muscle injury by regulating the expression of CDKN1A.