[Therapeutic effect of massage on denervated skeletal muscle atrophy in rats and its mechanism].

OBJECTIVE: To investigate the therapeutic effects of massage on denervated skeletal muscle atrophy in rats and its mechanism. METHODS: Forty-eight male SD rats were randomly divided into model group (n=24) and massage group (n=24). Gastrocnemius muscle atrophy model was established by transecting the right tibial nerve of rat. On the second day after operation, the gastrocnemius muscle of the rats in the massage group was given manual intervention and the model group was not intervened. Six rats were sacrificed at the four time points of 0 d, 7 d, 14 d and 21 d. The gastrocnemius of the rats were obtained and measured the wet mass ratio after weighing. Cross-sectional area and diameter of the muscle fiber were measured after HE staining. The relative expressions of miR-23a, Akt, MuRF1 and MAFbx mRNA were tested with qPCR. RESULTS: Compared with 0 d, the wet weight ratio, cross-sectional area and diameter of gastrocnemius muscle showed a progressive decline in the model group and massage group. The wet weight ratio, cross-sectional area and diameter of gastrocnemius muscle in the massage group were higher than those in the model group on 7 d, 14 d and 21 d (P＜0.05, P＜0.01). Compared with 0 d, the expressions of MuRF1, MAFbx and Akt mRNA were increased first and then were decreased in the model group and massage group. The expression of MuRF1 mRNA in massage group was lower than that in model group on 7 d and 21 d (P＜0.05, P＜0.01). The expression of MAFbx mRNA in massage group was lower than that in model group on 7 d, 14 d and 21 d (P＜0.01, P＜0.05, P＜0.01). The expression of Akt mRNA in massage group was higher than that in model group on 7 d, 14 d and 21 d (P＜0.05, P＜0.01). Compared with 0 d, the expression of miR-23a mRNA was increased in the model group and massage group on 21 d, and the expression of miR-23a mRNA in massage group was higher than that in model group (P＜ 0.05). CONCLUSION: Massage can delay the atrophy of denervated skeletal muscle. The mechanism may be related to up-regulation of the expression of miR-23a and Akt mRNA, down-regulation of the expressions of MuRF1 and MAFbx mRNA, inhibition of protein degradation rate, and reduction of skeletal muscle protein degradation.

[Electroacupuncture improves denervated gastrocnemius atrophy by regulating expression of fork-head protein 3A，muscle atrophy F-box and myogenic differentiation antigen proteins in sciatic nerve injury rats].

OBJECTIVE: To observe the effect of electroacupuncture (EA) on morphological changes of denervated gastrocnemius(GS) and the expression of fork-head protein(FOXO3A), muscle atrophy F-box(MAFbx)and myogenic differentiation antigen (Myod1) in sciatic nerve injury rats, so as to reveal its mechanism underlying improvement of myoatrophy. METHODS: Eighteen male Sprague-Dawley rats were randomly divided into sham operation, model and EA groups (n＝6 per group). The model of gastrocnemius atrophy was established by crushing the right sciatic nerve. Then, EA (2 Hz) was applied to the right "Zusanli" (ST36) and "Huantiao" (GB30) for 10 min, once a day for 14 successive days. The wet weight of the GS on both sides was weighted to calculate the wet weight ratio (the injured side /the healthy side), and the cross-sectional area (CSA) and diameter of GS fibers were measured after H．E. staining. The expressions of FOXO3A, MAFbx and Myod1 protein and mRNA in the GS tissue were tested using Western blot and fluorescence quantitative PCR, separately. RESULTS: Following modeling, the GS wet weight ratio, CSA and fiber diameter were smaller in the model group than those in the sham group (P<0.01), and were significantly higher in the EA group than in the model group (P<0.01). H．E. staining showed that the GS fibers became smaller and the myocyte got round in the model group, while the GS fibers were bigger and the myocyte was relatively regular in morphology in the EA group. After modeling, the expression levels of FOXO3A, MAFbx and Myod1 mRNA and protein were evidently higher in the model group (P<0.01); Moreover, after EA treatment, modeling-induced increasing of expression levels of FOXO3A and MAFbx mRNA and protein were revised (P<0.01), while the increased expression level of Myod1 was further up-regulated relavant to that in the model group (P<0.01)．. CONCLUSION: EA of ST36 and GB30 can suppress the up-regulated expression of FOXO3A and MAFbx mRNA and protein and further promote the expression of Myod1 mRNA and protein in the GS tissue in rats with denervated GS atrophy, which may contribute to its function in relieving the myoatrophy, promoting the skeletal muscle protein hydrolysis and differentiation of satellite cells.

[Effect of Electroacupuncture on Synovial M 1/M 2 Macrophage Polarization in Rats with Acute Gouty Arthritis].

OBJECTIVE: To explore the effect of electroacupuncture (EA) on the expression of synovial AMP-activated protein kinase (AMPK) protein α， arginase-1 mRNA, nitric oxide synthase 2 (NOS 2) mRNA, NOD-like receptor protein 3 (NLRP 3) mRNA, and interleukin-1 ß (IL-1 ß) mRNA in acute gouty arthritis (AGA) rats, so as to explore its mechanisms underlying improvement of AGA via M 1/M 2 macrophage polarization. METHODS: Male Wistar rats were randomly divided into normal control, model, medication (colchicine) and EA groups (n＝15 rats in each group). The AGA model was established by injection of sodium urate crystal (MSU) suspension (0.2 mL) into the articular cavity of the left knee. The rats of the normal control group received articular injection of normal saline (0.2 mL) of the left knee, and those of the medication group were treated by gavage of the colchicine (0.3 mg•kg－1•d－1) once daily for 7 days. EA (2 Hz/10 Hz, 1.0 mA) was applied to "Zusanli"(ST 36) and "Sanyinjiao" (SP 6) of the left hind limb for 10 min, once daily for 7 days. The inflammatory conditions of the synovial membrane tissue of the left knee joint were observed by H．E. staining. The expression levels of phosphorylated AMPKα (p-AMPKα) protein, and arginase-1 (a maker of M 2 macrophages) mRNA, NOS 2 (a maker of M 1 macrophages) mRNA, NLRP 3 mRNA, and IL-1 ß mRNA in the knee joint synovial tissue were detected by Western blot and quantitative real-time PCR, respectively. RESULTS: Compared with the normal group, the inflammatory cell infiltration of the synovial tissue was more severe, the expression of p-AMPKα protein was significantly decreased (P<0.01), and the expression levels of arginase-1, NOS 2, IL-1 ß and NLRP 3 mRNAs were considerably increased in the model group (P<0.01). The expression levels of p-AMPKα protein and arginase-1 mRNA were significantly up-regulated, and those of NOS 2, IL-1 ß and NLRP 3 mRNAs obviously down-regulated in both EA and medication groups relevant to the model group (P<0.01, P<0.05), suggesting an increase of M 2 macrophage and a decrease of M 1 macrophage activity after EA. No significant differences were found between the EA and medication groups in up-regulating p-AMPKα expression and in down-regulating NOS 2, IL-1 ß and NLRP 3 mRNA expression (P>0.05), except higher up-regulation of arginase-1 mRNA in the medication group (P<0.05)．. CONCLUSION: EA intervention can up-regulate the expression of arginase-1 mRNA and p-AMPKα protein, and down-regulate the expression of NOS 2, IL-1 ß and NLRP 3 mRNAs in synovial tissues in AGA rats, which may contribute to its anti-inflammatory effect by promoting conversion of macrophages from M 1 pro-inflammatory phenotype to M 2 anti-inflammatory phenotype.