IL-38 抑制LPS / TLR4 诱导炎症减轻类风湿关节炎的机制研究

目的:探讨IL-38 和TLR4 在类风湿关节炎中的潜在关联及其在类风湿性关节炎中致病的机制。方法:选取2013 年1 月至2016 年2 月间本院收治的41 例类风湿关节炎患者(观察组)及45 例本院实施创伤后滑膜切除术的患者(对照组)为研究对象。收集观察组和对照组的外周血单个核细胞(PBMCs)、滑膜组织及血清。荧光定量PCR 检测PBMCs 及滑膜组织中IL-38 及TLR4 的mRNA 水平。ELISA 检测滑膜液及血清中IL-38 的表达,Western blot 检测滑膜组织中IL-38 及TLR4的表达。LPS 和/ 或IL-38 刺激RAW264.7 细胞,ELISA 检测RAW264.7 细胞上清中IL-6、IL-8 及TNF-α的含量,荧光定量PCR检测RAW264.7 细胞TLR4、IL-6、IL-8 及TNF-α的表达。NF-κB 激活-核转运试剂盒及Western blot 检测NF-κB 信号的激活水平。结果:与对照组相比,类风湿关节炎患者PBMCs、血清及滑膜组织和滑膜液中IL-38 水平显著升高,而TLR4 水平也显著升高,Pearson 相关分析显示二者呈负相关。LPS 和/ 或IL-38 刺激RAW264.7 细胞后,IL-38 能够抑制LPS 诱导的TLR4、IL-6、IL-8 及TNF-α表达,进一步的分析显示,IL-38 能抑制NF-κB 信号途径激活,因此推测IL-38 可能是通过抑制NF-κB 信号途径激活从而抑制LPS/ TLR4 信号诱导的炎症因子表达。结论:IL-38 能抑制LPS/ TLR4 诱导炎症减轻类风湿关节炎,其机制可能是通过抑制NF-κB 信号途径的激活。

Mechanism of IL-38 inhibits LPS / TLR4 induced inflammation in patients with rheumatoid arthritis

Objective:To investigate the proteins association of IL-38 and TLR4 in rheumatoid arthritis ( RA) and its mechanism in RA pathogenesis.Methods: Forty-one rheumatoid arthritis patients (observation group) and forty-five patients with post-traumatic synovial membrane resection ( control group) in our hospital from Jan 2013 to Feb 2016 were selected as study subjects.Peripheral blood mononuclear cells ( PBMCs), synovial tissues and serum from patients with RA and controls were collected.The expression of IL-38 and TLR4 in PBMCs and synovial tissues were detected by real-time polymerase chain reaction(realtime-PCR).The protiens of IL-38 and TLR4 in synovial tissues and fluid from RA patients and controls were detected by enzyme-linked immunosorbent assay (ELISA) or Western blot assay,respectively.RAW264.7 cells were stimulated by lipopolysaccharide(LPS) and/ or IL-38.The production of inflammatory cytokines including IL-6,IL-8 as well as TNF-αwere detected by real-time-PCR and ELISA,respectively.The activation of nuclear factor-κB (NF-κB) signaling were determined by nuclear transfer reagent kit for NF-κB and Western blot.Results: Compared with control group,the expression of IL-38 in PBMCs,synovial tissue,serum and synovial fluid of patients with RA increased significantly, meanwhile, TLR4 was significantly increased in PBMCs and synovium of RA patients.Moreover,IL-38 was negatively associated with TLR4 in RA,suggested by Pearson’s correlation analysis.When RAW264.7 cells were stimulated by LPS with or without IL-38 in vitro,IL-38 could suppress LPS-mediated expression of TLR4 and the production of IL-6,IL-8 and TNF-αin RAW264.7 cells.IL-38 can inhibit the activation of NF-κB signaling pathway,so we hypothesized that IL-38 may inhibit the expression of inflammatory factor which induced by LPS/ TLR4 signaling via inhibiting the activation of NF-κB signaling pathway.Conclusion: IL-38 can attenuates rheumatoid arthritis through inhibiting LPS/ TLR4 induced inflammation in rheumatoid arthritis,and the mechanism may be through inhibiting the activation of NF-κB signaling pathway.