基于嘌呤能受体P2X7R的痛风性关节炎病理研究

Pathology of gouty arthritis based on purinergic receptor P2X7R

目的 观察冰水泳浴对痛风大鼠模型病理变化的影响并探究其中P2X7R的调控机制。方法 雄性SD大鼠分为正常(NORM)组和实验组,实验组包括痛风对照(GC)组、冰水泳浴(IWS)组和亮蓝G(BBG,P2X7R拮抗剂)组。实验组大鼠通过尿酸酶抑制法联合Coderre法塑造高尿酸血症合并痛风性关节炎模型。冰水泳浴组大鼠在Coderre法造模后的0 h和12 h,分别于深约0.5 m的冰水混合物中进行5 min的耐力游泳,BBG组则在造模后立即腹腔注射BBG溶液1次。公式计算踝关节肿胀指数;尿酸酶法检测大鼠血清尿酸水平;ELISA法检测血清IL-1β、IL-6和TNF-α含量;HE染色观察踝关节和滑膜组织的病理变化;Western blot和免疫组化分别检测滑膜组织中P2X7R和NLRP3蛋白表达。结果 与正常组相比,实验组大鼠血清尿酸水平及踝关节肿胀指数均显著升高(P<0.05或P<0.01),且滑膜组织均存在不同程度的炎性浸润。与痛风对照组相比,冰水泳浴组踝关节肿胀指数在12 h显著升高(P<0.05),血清IL-1β、IL-6和TNF-α含量(P<0.01)及滑膜组织中P2X7R、NLRP3蛋白量均有显著表达(P<0.05);病理结果显示软骨表面破损,滑膜组织出现严重增生与糜烂,并伴有大量炎性细胞聚集。BBG组大鼠滑膜组织的P2X7R、NLRP3蛋白表达与病理损伤较痛风对照组无显著变化(P>0.05),而血清IL-1β、IL-6和TNF-α的表达均有显著改善(P<0.01)。结论 冰水泳浴模拟的寒冷刺激和剧烈运动可加重痛风性关节炎的病理损伤,其机制可能与关节局部P2X7R的高表达有关。

Objective To observe the effects of ice-water swimming on pathological changes in model gouty rats,and investigate the relevant regulatory mechanism of the purinergic P2X7R receptor.Methods Male Sprague Dawley rats were divided into normal(NORM)and experimental groups including gouty control(GC),ice-water swimming(IWS),and Brilliant Blue G(BBG,a P2X7R inhibitor)groups.Rats in the experimental groups were modeled to simulate hyperuricemia and gouty arthritis by inhibiting uric acid metabolism combined with the Coderre method.Rats in the ice-water swimming group were treated with 5 min of endurance swimming in an ice-water mixture at a depth of about 0.5 m for 0 h and 12 h after modeling by the Coderre method,while rats in the BBG group were injected intraperitoneally with BBG solution once after modeling.Ankle swelling index was calculated using a formula.Serum uric acid levels were detected by uricase assay,and serum levels of the inflammatory factors interleukin(IL)-1β,IL-6,and tumor necrosis factor(TNF)-αwere detected by enzyme-linked immunosorbent assay.The pathological status of the ankle joints was examined by hematoxylin and eosin staining.P2X7R and NLRP3 protein expression levels in synovial tissue were detected by Western blot and immunohistochemistry,respectively.Results Serum uric acid levels and the ankle joint swelling index were significantly higher in the experimental groups compared with the normal group(P<0.05 or P<0.01),and the synovial tissues showed different degrees of inflammatory infiltration.The ankle swelling index was significantly higher in the ice-water swimming group compared with the gouty control group at 12 h(P<0.05).Serum IL-1β,IL-6,and TNF-αlevels(P<0.01)and P2X7R and NLRP3 protein levels in synovial tissues were all significantly elevated(P<0.05).Histopathology showed that the cartilage surface was broken and the synovial tissue showed severe hyperplasia and erosion,accompanied by numerous inflammatory cell aggregates.There were no significant changes in P2X7R or NLRP3 protein expression or pathology in synovial tissues in the BBG group compared with the gouty control group(P>0.05),but serum IL-1β,IL-6,and TNF-αlevels were all significantly suppressed(P<0.01).Conclusions Cold stimulation and strenuous exercise simulated by ice-water swimming may exacerbate pathological damage in gouty arthritis via a mechanism related to high P2X7R expression in the joints.