狼疮肾炎患者外周血单个核细胞IL-17信号转导途径的初步研究

目的:了解IL-17及其信号转导成分JNK活化状态在狼疮肾炎(LN)发病机制中作用。方法:活动期LN病人15例,分离、培养外周血单个核细胞(PBMC);ELISA法检测上清液IL-6蛋白水平;逆转录多聚酶链反应法检测IL-6mRNA水平;蛋白印迹法检测JNK活性。结果:IL-17刺激下,LN患者PBMC反应性明显增强,各浓度点IL-6蛋白水平明显高于正常对照(均P<0.05)。LN患者PBMCIL-6mRNA表达水平明显高于对照组(无刺激培养:1.80±0.11vs0.36±0.07,P<0.01;刺激培养:3.21±0.24vs1.30±0.14,P<0.05);正常对照或LN患者刺激培养组PBMCIL-6mRNA表达水平均明显高于其无刺激培养组(对照:1.30±0.14vs0.36±0.07,P<0.05;LN患者:3.21±0.24vs1.80±0.11,P<0.01)。LN患者PBMCJNK活性水平明显高于对照组(无刺激培养:3.21±0.32vs1.00,P<0.01;刺激培养:4.82±0.39vs1.21±0.35,P<0.01);LN患者的刺激培养组PBMCJNK活性水平明显高于LN对照培养组(4.82±0.39vs3.21±0.32,P<0.01)。活动性LN病人PBMCJNK活性高低与其SLEDAI和IL-6mRNA水平均呈显著正相关。结论:IL-17介导LN患者PBMC过度表达、分泌IL-6可能是其参与LN的发病机制之一,JNK的活化在IL-17信号转导中具有重要作用。

Preliminary study of IL-17 signal transduction pathway in peripheral blood mononuclear cells from lupus nephritis patients

AIM: To investigate the role of IL-17 and its signal conduction component-JNK activity in the pathogenesis of LN. METHODS: Peripheral blood mononuclear cells (PBMC) were separated and cultured from 15 cases of active lupus nephritis (LN) patients. IL-6 level was detected by ELISA, IL-6 mRNA was checked with RT-PCR, and JNK activity was measured by Western blot. RESULTS: At same IL-17 end concentrations, there was a much higher level of IL-6 in LN group than in control group (all P<0.05). IL-17 induced a significant elevation of IL-6 mRNA expression and JNK activity in PBMC from LN patients in a time- and dose-dependent manner, which could be blocked markedly by IL-17 monoclonal antibody, mIgG₂₈, and dexamethasone. Much higher IL-6 mRNA expression was observed in LN group than in control group under medium culture or IL-17-conditioned culture (all P<0.01). Under medium culture or IL-17-conditioned culture, there was much higher JNK activity of PBMC in active LN group than that in control group. There was a positive linear correlation between PBMC JNK activity and their SLEDAI or IL-6 mRNA expression level in LN patients (r₁=0.638, P<0.01; r₂=0.644, P<0.01).