Role Of ATF6-DAPK-1 Pathway In Exercise-induced Autophagy Of Skeletal Muscle Cell After Once Eccentric Exercise

Objective: Observing the influence of autophagy levels in rat skeletal muscle cells after once eccentric exercise,as well as ATF6,p50ATF6,DAPK-1 pathway related protein expression changes,to investigate the role of proteins associated with ATF6-DAPK-1 pathway in the process of autophagy.Methods: 8-week-old SD rats were randomly divided into the quiet group(group C,n=8)and the exercise group(group E).The exercise group(group E)was randomly divided into five groups immediately after exercise,12 h,24h,48 h and 72 h according to the required time points,with 8 animals in each group.The intervention plan adopted by the exercise group was a high-load downhill running intervention,with a running platform slope of-16°and a duration of 90 minutes.According to the groups,the rectus femoris muscle was taken at different time points after exercise intervention.Using Western Blot method to detect protein expression of GRP78、ATF6、p50ATF6、DAPK-1、Beclin1 and LC3(Ⅱ/Ⅰ)in rectus femoris muscle.Image Lab software was used to analyze the gray value of the corresponding strips,and SPSS One Way ANOVA was used to process the data.Results:1.After once eccentric exercise GRP78 protein in skeletal muscle of rats increased significantly at all selected time periods compared with that of the quiet group(P<0.05).The expression of protein shows a trend of going up first and then goes down.It peaks at 12 h after exercise(P<0.05);2.Protein expressions of ATF6,p50ATF6,and DAPK-1 were increased significantly at all selected time periods compared with that of the quiet group(P<0.05).The expression of protein shows a trend of going up first and then goes down.It peaks at 12 h after exercise(P<0.05);3.Protein expressions of Beclin1 and LC3(Ⅱ/Ⅰ)were increased at all selected time periods compare with that of the quiet group(P < 0.05),peak at 12 h and 24 h after exercise.Conclusions: One-time eccentric exercise can induce autophagy enhancement in skeletal muscle cells,which may cause endoplasmic reticulum stress through exercise,activating the involvement of atf6-DAPK-1-Beclin1 pathway.