Objective: To explore the effect of moxibustion at "Zusanli"(ST36) and "Shenshu"(BL23) on synovitis, and expressions of miR-155, Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), interlukine（IL-1） receptor-associated kinase (IRAK1), tumor necrosis factor receptor-associated factor 6 (TRAF6), nuclear factor κB (NF-κB), IL-1β, tumor necrosis factor receptor (TNF)-α and IL-6 mRNA and protein of synovial membrane in rheumatoid arthritis (RA) rats, so as to explore its mechanism underlying improvement of RA.
Methods: A total of 48 male Wistar rats were randomly divided into normal control, model, moxibustion and antagonist groups (n=12 rats in each group). The RA model was replicated by placing the rats in a wind, cold and wet environment and injection of Freund's complete adjuvant (CFA, 0.5 mL) into the right hindlimb foot plantar. Moxibustion was applied to bilateral ST36 and BL23 for 30 min, once daily for 21 consecutive days. Rats of the antagonist group was treated by injection of TLR4 antagonist (TAK-242, 1 mg/mL, 0.1 mg/kg) via tail vein, once per day for consecutive 21 d. The joint swelling degree (JSD) and arthritis index (AI, red swelling scale) were determined, and the expression levels of various indicators of miR-155, and TLR4, myeloid MyD88, IRAK1, TRAF6, NF-κB, IL-1β, TNF-α and IL-6 mRNA and protein were assayed by quantitative real time-PCR and Western blot, separately.
Results: Compared with the normal control group, the JSD and AI, and the expression levels of synovial miR-155, TLR4, MyD88, IRAK1, TRAF6, NF-κB, IL-1β, TNF-α and IL-6 mRNA and protein were significantly increased in the model group (P<0.01). Compared with the model group, the increased levels of JSD and AI, and the expression levels of synovial miR-155, TLR4, MyD88, IRAK1, TRAF6, NF-κB, IL-1β, TNF-α and IL-6 mRNA and protein were notably down-regulated in both moxibustion and antagonist groups (P<0.01). The effects of moxibustion were evidently superior to the antagonist in down-regulating the abovementioned indexes (P<0.01), except TLR4 mRNA and protein.
Conclusion: Moxibustion at ST36 and BL23 can reduce the synovitis of RA rats, which is related to its effects in suppressing the expressions of miR-155, TLR4, MyD88, IRAK1, TRAF6, NF-κB, IL-1β, TNF-α and IL-6 mRNA and protein (i.e., inhibition of miR-155/TLR4/NF-κB signaling).
目的：观察艾灸“足三里”“肾俞”对佐剂性关节炎(AA)大鼠miR-155/ Toll样受体4 (TLR4) /核因子-κB（NF-κB）信号通路的影响，探讨艾灸治疗类风湿性关节炎的可能机制。方法：Wistar大鼠随机分为正常组、模型组、拮抗剂组、艾灸组，每组12只。采用风、寒、湿环境因素+弗氏完全佐剂复合造模方法复制AA模型。艾灸组于大鼠“足三里”“肾俞”给予艾灸治疗，30 min/次，1次/d，连续治疗21 d；拮抗剂组经尾静脉注射TLR4拮抗剂，1次/d，连续注射21 d；正常组和模型组不做任何处理。观察各组大鼠关节肿胀度(JSD)、关节炎指数(AI)，荧光定量PCR法及Western blot法检测大鼠滑膜组织中miR-155/TLR4/NF-κB信号通路相关指标miR-155及TLR4、NF-κB、髓样分化因子88(MyD88)、白细胞介素（IL）1受体相关酶(IRAK1)、肿瘤坏死因子受体相关因子6(TRAF6)、IL-1β、肿瘤坏死因子α(TNF-α)、IL-6的mRNA和蛋白表达。结果：与正常组比较，模型组、艾灸组及拮抗剂组大鼠JSD、AI明显升高(P<0.01)，滑膜组织中miR-155及TLR4、NF-κB、MyD88、IRAK1、TRAF6、IL-1β、TNF-α、IL-6的mRNA和蛋白表达均明显升高(P<0.01)；与模型组比较，艾灸组和拮抗剂组大鼠JSD、AI明显降低(P<0.01)，滑膜组织中miR-155及TLR4、NF-κB、MyD88、IRAK1、TRAF6、IL-1β、TNF-α、IL-6的mRNA和蛋白表达明显减少(P<0.01)。艾灸组大鼠JSD、AI及滑膜组织中miR-155 mRNA及NF-κB、MyD88、IRAK1、TRAF6、IL-1β、TNF-α、IL-6的mRNA和蛋白表达明显低于拮抗剂组(P<0.01)，滑膜组织中TLR4 mRNA及蛋白表达明显高于拮抗剂组(P<0.01)。结论：艾灸“足三里”“肾俞”能够明显改善AA大鼠滑膜炎性反应，可能与艾灸抑制miR-155/TLR4/NF-κB信号通路有关。.
Keywords: Adjuvant arthritis; MiR-155; Moxibustion; TLR4/NF-κB signaling pathway.