The Effect Of Eccentric Exercise On Myogenic Regulatory Factors In Skeletal Muscle And Intervention Study Of Acupuncture

Objective:The aim of this study is to observe the effect of eccentric exercise and acupuncture on the myogenic regulatory factors and Wnt/β-catenin signaling, then investigate the characteristics of the MRFs and the possible mechanism as well as its effect on repairment during skeletal muscle damage.Methods:Experiment 1:For this, rats were divided into three groups: control (C), exercise (E), exercise and acupuncture(EA). E and EA groups were submitted to four weeks of eccentric exercise on a treadmill down a 16°decline. Protein expression of MRFs were detected by western blot. Experiment 2:Rats were divided into four groups:C, control and acupuncture (CA), E and EA groups. E and EA group were submitted to a single bout of eccentric exercise on a treadmill down a 16°decline. mRNA expression of Wntl and Wnt3a were detected by RT-PCR, phosphorylation ofβ-catenin and GSK-3βas well as protein expression of MyoD and Myogenin were detected by western blot.Results:(1) The protein expression of MyoD and MRF4 elevated significantly in EA group relative to E group in 1,3,4 weeks(P<0.05). In 1 and 3weeks, EA group Myf-5 protein expression was greater compared with E group (P<0.05);the protein expression of Myogenin elevated significantly in EA group relative to E group in 1,2 weeks(P<0.05), it was the opposite position in week 3 and 4(P<0.05). (2) CA group Wnt1 mRNA expression were lower than C group, Wnt 3a were significantly higher than C group in 12h,72h and 120h (P<0.05). GSK-3βactivity decreased significantly compared with C group in 72h (P<0.05), phosphorylation ofβ-catenin decreased significantly compared with C group in 120h (P<0.05); MyoD protein expression elevated significantly in 24h and 48h (P<0.05), Myogenin protein expression elevated significantly after 48h (P<0.05). (3) EA group wntl and wnt3a mRNA expression were lower than E group. GSK-313 activity and phosphorylation ofβ-catenin of EA group decreased significantly compared with E group in 72h (P<0.05), and phosphorylation ofβ-catenin in E group decreased significantly than EA group (P<0.05). MyoD protein expression of EA group elevated significantly in 12h and 24h compared with E and C group (P<0.05); E group Myogenin protein expression had two crest values in 24h and 72h (P<0.05); EA group Myogenin protein expression was significantly higher than E group in 12h,72h and 120h(P<0.05).Conclusion:Four weeks eccentric exercise may up-regulate Myf-5 and Myogenin protein expression, down-regulate MyoD and MRF4 protein expression. Acupuncture can maintain MRFs in normal levels. Needling normal skeletal muscle has effect on Wnt/β-catenin signal. An eccentric exercise and needling after exercise can up-regulate Wntl and Wnt3a mRNA expression, decrease activity of GSK-3βand phosphorylation ofβ-catenin, needling has the effect on up-regulating phosphorylation ofβ-catenin.