The Effect Of Rho Gtpase/Cofilin Signaling Pathway On Eccentric Exercise-induce Depolymerization And Acupuncture Intervention To Rat Skeletal Muscle

Objective:The aim of the study is to investigate the effect of Rho GTPase/cofilin signaling pathway on the rat skeletal muscle depolymerization induced by eccentric exercise and the acupuncture intervention, to discuss the mechanisms of skeletal muscle ultrastructure changes induced by exercise, and for providing important theoretical basis of how acupuncture restore skeletal muscle micro-damage.Methods:Divide8weeks old SD rats into four groups:control(C), exercise (E), acupuncture (CA), exercise and acupuncture (EA). E and EA groups were carried out running on a treadmill down a16°decline at16m·min-1for90min. CA and EA groups were carried out acupuncture in rats'lower limb soleus muscle, keeping2minutes. Difference between CA and EA is giving acupuncture on EA groups after they finished the exercise. Rats were killed at0,12,24,48,72,120h after the termination of an acute bout of exercise or acupuncture except C group, which was killed at48h. Histologic features of F-actin, cofilin and cofilin's position were assessed by immuno-histochemistry and immunofluorescence staining. The7key protein expression of Rho GTPase/cofilin signaling pathway were assessed by western blot.Results:(1) An acute bout of exercise decreased phosphorylation of LIM and cofilin2(P<0.01), for Rho activity declining (P<0.01).Although activity of Cdc42and Racl increased, it can't provent this declining trend. This lead to skeletal muscle F-actin depolymerization after post-exercise24h clearly, at peak of depolymerization at post-exercise72h.(2) Needling can increase protein expression of Rho and Racl from post-exercise12h to24h (P<0.01),which improved phosphorylation of LIM and cofilin2(P<0.01), it kept F-actin structure.Cdc42activity declining (P<0.01) can't provent LIM and cofilin increasing (P<0.01).(3) Needling can increase protein expression of Rho and Raclobviously (P<0.01), kept the structure of F-actin. Acupuncture can provent reduction of cofilin2phosphorylation, and maintain F-actin structure stability, which is easy change induce by eccentric exercise. Conclusions:Acute eccentric exercise lead to cofilin2increase by down-regulating Rho protein, and this is main factor made the promotion of F-actin depolymerization. Acupuncture is mainly through the increase of Rho, Racl, then promote cofilin2phosphorylation, inhibition of F-actin depolymerization for it, restore the ultrastructural changes caused by eccentric exercise.