Effects of MG53 knock-out on skeletal muscle damage of mice during delayed onset muscle damage / 中国康复医学杂志

ABSTRACT

Objective:To discuss the effect of knock-out MG53 on skeletal muscle,and to determine whether MG53 can protect skeletal muscle from injury during delayed onset muscle damage(DOMS).Method:Eighty-four eight-week old C57 mice were divided into two groups due to their gene (WT and KO),and each group were divided into 7 subgroups again.14 groups,6 mice in each.They were WC,WE0,WE2,WE12,WE24,WE48,WE72 and KC,KE0,KE2,KE12,KE24,KE48,KE72.At each time point after 3 days eccentric exercise,the mice were decapitated after drawing blood.The rectus femoris of left leg was used to detect the level of MG53 with Western blot,the other side were used to do electron microscope analysis.Blood CK were measured also.Result:The CK of K0 raised remarkably and decreased gradually until W 12.But the second peak appear at W24 and decreased again gradually since then.Ultrastructural changes of skeletal muscle after eccentric exercise at different time points is obvious.The injury is worsen gradually from Wo to W24,and improved gradually from W48 to W72.Comparing with W groups,the injury in K group were even worsen an each time point.The MG53 of W0 and W24 were 16％ and 11％ higher than those before exercise (p＜0.05)and restored to normal in 72 hours after exercise.Conclusion:The injury after severe exercise is more severity in MG53 knock-out mouse than those in wild mouse.and the MG53 protein increased significantly.It suggests that MG53 may significantly relieve the skeleton muscle injury in delayed muscle sore period.