Abstract: Background　The pathogenesis of rheumatoid arthritis（RA） is complicated.Previous studies have proved that toll-like receptor（TLR） plays a key role in the development of RA，which is expressed on the surface of cells such as dendritic cells，macrophages，T cells，B cells，identifies different molecular structures of pathogens，and then raises the inflammatory cytokines and chemokines，activates intracellular signal transduction pathways，causes an autoinflammatory response in the host cell，playing an important role in autoimmune diseases.Objective　To observe the effect of dihydroartemisinin （DHA） on TLR-mediated MyD88-dependent signaling pathway of peripheral blood mononuclear cells（PBMCs） and the express of protein.Methods　From the Second Affiliated Hospital of Baotou Medical College，Inner Mongolia University of Science & Technology from October 2017 to December 2018，10 active RA patients and 10 randomly selected physical examinees from the medical examination center were enrolled.PBMCs of two groups were isolated，cultured and divided into 5 groups with 5 multiple pores in each group.（1）control group：the PBMCs of the healthy volunteers were not interfered with TLR-mediated signaling pathway.（2）RA group：the PBMCs of RA patients were not interfered with TLR-mediated signal pathway.（3）TLR2 inhibitors group：the PBMCs of RA patients were treated with TLR2 inhibitors（100 μg/L） to interfere with TLR-mediated signaling pathway.（4）Low-dose DHA group：the PBMCs of RA patients were treated with DHA（200 μmol/L） to interfere with TLR-mediated signaling pathway.（5）High-dose DHA group：the PBMCs of RA patients were treated with DHA（1 000 μmol/L） to interfere with TLR-mediated signaling pathway.The positive expression rate of TLR2，and levels of TLR2 mRNA，MyD88 mRNA，TLR2，MyD88，TNF-α and IL-6 were detected and compared among the five groups.Results　（1）The positive expression rate of TLR2 in RA group was higher than that in control or TLR2 inhibitors group （P<0.05）.The positive expression rate of TLR2 in low-dose DHA group was higher than that in high-dose DHA group （P<0.05）.（2）RA group had higher average levels of TLR2 mRNA and MyD88 mRNA than control group or TLR2 inhibitors group（P<0.05）.Low-dose DHA group had higher average levels of TLR2 mRNA and MyD88 mRNA than high-dose DHA group （P<0.05）.（3） The control group had lower average levels of TLR2 and MyD88 than each of other groups（P<0.05）.The average levels of TLR2 and MyD88 in RA group were higher than those of TLR2 inhibitors group（P<0.05）.The average levels of TLR2 and MyD88 in low-dose DHA group were higher than those of high-dose DHA group（P<0.05）.（4） The control group had lower average levels of TNF-α and IL-6 than each of other groups（P<0.05） .The average levels of TNF-α and IL-6 in RA group were higher than those of TLR2 inhibitors group（P<0.05）.The average levels of TNF-α and IL-6 in low-dose DHA group were higher than those of high-dose DHA group（P<0.05）.Conclusion　DHA may inhibit the expression of TLR2 and MyD88 in mononuclear cells of RA patients，and the levels of TNF-αand IL-6 in the supernatant，which may be related to the inhibition of the inflammatory response by the TLR4-mediated MyD88-dependent signaling pathway.

Key words: Arthritis, rheumatoid；Dihydroartemisinin；Toll-Like Receptors；MyD88；Tumor Necrosis Factor-alpha；Interleukin-6

摘要： 背景　类风湿关节炎（RA）的发病机制复杂，已有研究证实Toll样受体（TLR）在RA的发病中起关键作用，其表达于树突状细胞、巨噬细胞、T细胞、B细胞等细胞表面，识别病原体不同的分子结构，进而上调炎性细胞因子和趋化因子，激活细胞内的信号转导通路，引起宿主细胞发生自身炎性反应，在自身免疫性疾病中发挥重要作用。目的　观察双氢青蒿素（DHA）对RA患者外周血单个核细胞（PBMCs）TLR4/MyD88信号通路及蛋白表达的影响。方法　选取2017年10月—2018年12月于内蒙古科技大学包头医学院第二附属医院就诊的活动期RA患者10例为观察组，同时随机选取本院体检中心健康体检者10例为对照组。取两组外周血PBMCs分离培养，将PBMCs分为5组，每组设5个复孔。（1）对照组：健康志愿者外周血PBMCs，不给予干预TLR介导的信号通路；（2）RA组：RA患者外周血PBMCs，不给予干预TLR介导的信号通路；（3）TLR2抑制剂组：RA患者外周血PBMCs，给予100 μg/L的TLR2抑制剂干预TLR介导的信号通路；（4）DHA低剂量组：RA患者外周血PBMCs，给予200 μmol/L的DHA干预TLR介导的信号通路；（5）DHA高剂量组：RA患者外周血PBMCs，给予1 000 μmol/L的DHA干预TLR介导的信号通路。检测并比较5组TLR2阳性率、TLR2 mRNA、MyD88 mRNA、TLR2、MyD88、肿瘤坏死因子α（TNF-α）及白介素6（IL-6）水平。结果　RA组TLR2阳性率高于对照组、TLR2抑制剂组（P<0.05）；DHA低剂量组TLR2阳性率高于DHA高剂量组（P<0.05）。RA组TLR2 mRNA、MyD88 mRNA高于对照组、TLR2抑制剂组（P<0.05）；DHA低剂量组TLR2 mRNA、MyD88 mRNA高于DHA高剂量组（P<0.05）。TLR2抑制剂组、RA组、DHA低剂量组、DHA高剂量组TLR2、MyD88高于对照组（P<0.05）。RA组TLR2、MyD88高于TLR2抑制剂组（P<0.05）；DHA低剂量组TLR2、MyD88高于DHA高剂量组（P<0.05）。TLR2抑制剂组、RA组、DHA低剂量组、DHA高剂量组TNF-α、IL-6水平高于对照组（P<0.05）。RA组TNF-α、IL-6水平高于TLR2抑制剂组（P<0.05）；DHA低剂量组TNF-α、IL-6水平高于DHA高剂量组（P<0.05）。结论　DHA可抑制RA患者的PBMCs中TLR2、MyD88表达和上清液中TNF-α及IL-6水平，可能与其可抑制TLR4/MyD88信号通路介导的炎性反应有关。

关键词: 关节炎, 类风湿；双氢青蒿素；Toll样受体；MyD88；肿瘤坏死因子α；白细胞介素6