基于P2X7R探讨冰水泳浴条件下高尿酸血症致痛风性关节炎发作的机制研究OA

Objective To explore the mechanism of gout attacks in hyperuricemic rats under ice-water swimming conditions based on the purinergic P2X7 receptor(P2X7R).Methods Male Sprague-Dawley rats were divided randomly into Control group(n=6),HPD+IWS group(n=12),HPD group(n=6),and IWS group(n=6).Hyperuricemia was induced by gavage with potassium oxonate combined with yeast extract.Ice-water swimming was performed by 5-minute endurance swimming in an ice-water mixture.The experiment lasted for 21 days.Serum uric acid levels were detected by the uricase method,serum and liver xanthine oxidase(XOD)levels were detected by colorimetry,and serum ATP levels were detected by phosphomolybdic acid colorimetry.Uric acid crystals in joint fluid were observed by polarized light microscopy.During the experiment,the right ankle joint diameter and foot thickness were measured every 2 days,and the swelling index was calculated.The pathological changes of ankle joint and synovial tissue were observed by hematoxylin-eosin(HE)staining.The serum levels of interleukin(IL)-1β,IL-6,and tumor necrosis factor(TNF)-α were detected by ELISA.Neutrophil count in venous blood was detected by full self-help blood cell analyzer.The expression level of P2X7R protein in synovial tissue was detected by Western blot.The expression level of nucleotide-binding oligomerization domain-like receptor 3(NLRP3)protein in synovial tissue was detected by immunohistochemistry.Results Compared with Control group,on the 7th,14 th and 21 st days of the experiment,the serum uric acid levels of HPD+IWS group and HPD group were significantly increased(P＜0.01 or P＜0.05).Compared with HPD+IWS group,the serum uric acid level of HPD group was significantly decreased on the 7th and 21st days of the experiment(P＜0.01).And the serum uric acid level of IWS group was significantly decreased on the 7th,14th and 21st days of the experiment(P＜0.01).Compared with Control group,the serum and liver XOD levels in HPD+IWS group were significantly increased(P＜0.01).Compared with HPD+IWS group,the serum XOD levels of HPD group and IWS group were significantly reduced(P＜0.01).And the liver XOD level of HPD group was significantly reduced(P＜0.05).Compared with HPD+IWS group,the serum ATP of HPD group was significantly increased on the 7th,14th and 21st days(P＜0.01 or P＜0.05).And the serum ATP level of IWS group was significantly increased on the 14th day(P＜0.01).Urate crystals were observed in HPD+IWS group.Compared with Control group,the swelling index of the right ankle joint in HPD+IWS group increased significantly on the 5th,7th,9th,11th and 13th days(P＜0.01 or P＜0.05).Compared with Control group,the foot thickness swelling index of HPD+IWS group was significantly increased on the 5th,7th,9th,11th,13th,15th,17th,19th and 21st days(P＜0.01 or P＜0.05).The result of HE staining showed that synovial hyperplasia and inflammatory cell infiltration appeared in the ankle joint cavity of HPD+IWS group.Compared with Control group,the levels of serum IL-1β,IL-6 and TNF-α in HPD+IWS group were significantly increased(P＜0.01).Compared with HPD+IWS group,the levels of serum IL-1β,IL-6 and TNF-α in HPD group and IWS group were significantly decreased(P＜0.01).Compared with Control group,the neutrophil count in HPD+IWS group was significantly increased(P＜0.01).Compared with HPD+IWS group,the neutrophil count in IWS group was significantly reduced(P＜0.01).Compared with Control group,the expression of P2X7R and NLRP3 protein in the synovial tissue of HPD+IWS group was significantly increased(P＜0.01 or P＜0.05).Conclusions Ice-water swimming under hyperuricemic conditions can lead to ATP metabolic imbalance,increase uric acid levels and urate deposition,and activate P2X7R,leading to gouty arthritis attacks via the ATP-P2X7R-NLRP3 pathway.