Anti-inflammatory Effect And Mechanism Of Electroacupuncture On MSU-induced Acute Gouty Arthritis In Rats

ObjectiveTo explore the effect of electroacupuncture?EA?on the expression of synovial AMP-activated protein kinase?AMPK?protein,Arginse-1 mRNA,nitric oxide synthase 2?NOS2?mRNA,NOD-like receptor protein 3?NLRP3?mRNA,and interleukin-1??1L-1??in acute gouty arthritis?AGA?rats,so as to explore its mechanisms underlying improvement of AGA via M1/M2 macrophage polarization.MethodsA total of 60 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 7days.EA?2 Hz/10 Hz,1.0mA,?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 AMPK??p-AMPK??protein,and Arginase-1?a maker of M2 macrophages?mRNA,NOS2?a maker of M1 macrophages?mRNA,NLRP3 mRNA and IL-1?mRNA in the knee joint synovial tissue were detected by Western blot and quantitative real-time PCR,respectively.ResultsCompared with the normal group,the inflammatory cell infiltration of the synovial tissue was more severe,the expressions of p-AMPK?protein was significantly decreased?P<0.01?,and the expressions levels of Arginase-1,NOS2,IL-1?and NLRP3 mRNAs were considerably increased in the model group?P<0.01?.the expressions levels of p-AMPK?protein and Arginase-1 mRNA were significantly up-regulated,and those of NOS2,IL-1?and NLRP3 mRNAs obviously down-regulated in both EA and medication groups relevant to the model group?P<0.05,P<0.01?,suggesting an increase of M1 macrophage and a decrease of M2macrophage activity after EA.No significant differences were found between the EA and medication groups in up-regulated of Arginase-1mRNA in the medication group?P<0.05?.ConclusionEA intervention can up-regulate the expression of Arginase-1 mRNA and p-AMPK?protein,and down-regulate the expression of NOS2 mRNA to promote conversion of macrophages from M1 pro-inflammatory phenotype to M2 anti-inflammatory phenotype in synovial in AGA rats,while down-regulating 1L-1?,NLRP 3 to control the inflammatory which induced by MSU crystals.