Cathepsin-B involved in effect of electroacupuncture by inhibiting the activation of NLRP3 inflammasome in rats with acute gouty arthritis

Abstract

To observe the effect of electroacupuncture (EA) on Cathepsin-B in the synovium of the knee joint of acute gouty arthritis(AGA) rats, so as to explore the mechanism of EA in the treatment of AGA. A total of 60 male Wistar rats were randomly divided into normal control,model, medication and EA groups, with 15 rats in each group. Rat model of AGA was established by injection of 0.2 mL sodium urate crystal suspension into the left knee joint cavity. The rats in the medication group were treated with colchicine by gavage(0.3 mg·kg-1·d-1), and the rats in the EA group were treated with EA at the left "Sanyinjiao" (SP6) and "Zusanli"(ST36) for 10 min each time, once a day for a week. The Coderre gait grading standard was used to score the gait of rats. The pathological morphology of synovial tissue of the left knee joint was observed by H.E. staining. The expression levels of Cathepsin-B protein and Nod-like receptor pyrin domain 3(NLRP3), apoptosis-associated speck-like protein containing CARD (ASC),Caspase-1, interleukin-1β(IL-1β) and IL-18 mRNAs were detected by Western blot and real-time fluorescence quantitative PCR, respectively. Compared with the normal control group, the degree of synovitis infiltration in the model group was more serious. And the gait score，the protein expression level of Cathepsin-B and the mRNA expression levels of NLRP3,ASC,Caspase-1, IL-1β,IL-18 were significantly increased (P<0.01).After the interventions, the degree of inflammatory infiltration was mild, The gait score, the protein expression level of Cathepsin-B and the mRNA expression levels of NLRP3 and ASC,Caspase-1，IL-1β,IL-18 were significantly decreased in both medication and EA groups in contrast to the model group (P<0.01, P<0.05). Compared with medication group, the mRNA expression levels of Caspase-1 and IL-18 in the EA group were increased (P<0.05). EA may inhibit the activation of NLRP3 inflammasome by reducing the activity of Cathepsin-B in the synovium of the knee joint, so as to treat AGA.