基于NLRP3/Caspase-1/IL-1β信号通路探讨艾灸改善佐剂性关节炎大鼠滑膜炎的机制

Moxibustion intervention improves synovitis by dow n-regulating NLRP3/Caspase-1/IL-1β signaling of synovial tissue in rats with adjuvant arthritis

目的:观察艾灸对佐剂性关节炎(AA)大鼠NOD样受体家族蛋白3(NLRP3)/半胱氨酸蛋白酶-1(Caspase-1)/白细胞介素1β(IL-1β)信号通路的影响,探讨艾灸对类风湿关节炎的部分作用机制。方法:Wistar雄性大鼠随机分为正常组、模型组和艾灸组,每组10只。采用风、寒、湿环境因素加注射弗氏完全佐剂复制AA大鼠模型。艾灸组艾灸双侧“肾俞”“足三里”,20 min/次,1次/d,连续治疗21 d。观察并比较各组大鼠关节肿胀度(JSD)、关节炎指数(AI);透射电镜观察各组大鼠膝关节滑膜细胞超微结构;Western blot法检测各组大鼠膝关节滑膜组织中NLRP3、凋亡相关斑点样蛋白(ASC)、Caspase-1、肿瘤坏死因子-α(TNF-α)和IL-1β的蛋白表达水平。结果:与正常组比较,模型组大鼠JSD、AI升高(P<0.01),滑膜组织中NLRP3、ASC、Caspase-1、TNF-α和IL-1β的蛋白表达量均升高(P<0.01);与模型组比较,艾灸组大鼠JSD、AI降低(P<0.01),滑膜组织中NLRP3、ASC、Caspase-1、TNF-α和IL-1β的蛋白表达量降低(P<0.01)。与正常组比较,模型组大鼠关节滑膜细胞形态不规则,线粒体膜边界不清,明显肿胀,嵴稀疏;与模型组比较,艾灸组滑膜病理损伤程度减轻。结论:艾灸能够明显改善AA大鼠滑膜炎性反应,其机制可能与艾灸抑制NLRP3/Caspase-1/IL-1β炎性小体信号通路有关。

Objective To observe the effect of moxibustion on activities of NOD-like receptor family protein 3(NLRP3)/cysteine aspartic acid specific protease-1(Caspase-1)/interleukin-1β(IL-1β)signaling pathway in rats with adjuvant arthritis(AA),so as to explore its mechanisms underlying improvement of rheumatoid arthritis(RA).Methods Thirty male Wistar rats were randomly divided into normal control,AA model and moxibustion groups,with 10 rats in each group.The AA model was replicated by raising in wind,cold and damp environment combined with complete Freund's adjuvant injection.In the moxibustion group,moxibustion was applied to bilateral“Shenshu"(BL23)and"Zusanli"(ST36)for 20 min each time,once daily for 21 days.Changes of joint swelling degree((JSD)and arthritis index(Al)in each group were observed.The ultrastructural changes of synovial cells in each group were observed by transmission electron microscopy.The protein expression levels of NLRP3,apoptosis-associated speck-like protein(AsC),Caspase-1,tumor necrosis factor-α(TNF-α)and IL-1βin the synovial tissues of the knee joint were measured by Western blot.Results Compared with the normal control group,JSD,Al and the protein expressions of NLRP3,ASC,Caspase-1,TNF-αand IL-1βin the synovial tissues were significantly increased(P<0.01)in the model group.In comparison with themodel group,JSD,Aland the protein expression levels ofNLRP3,ASC,Caspase-1,TNF-αand IL-1βwere significantly decreased(P<0.01)in the moxibustion group.Results of transmission electron microscope showed an irregular and vague nuclear membrane of synovial cells,and unclear mitochondrial membrane boundary with sparse,swelling crests in the model group,which was relatively milder in the damage degree in the moxibustion group.Conclusion Moxibustion can relieve the inflammatory response in the synovial membrane of AA rats,which may be related to its function in down-regulating synovial NLRP3/Caspase-1/lIL-1β inflammatory signaling.