TLR/STAT通路在HMGB1诱导的系膜细胞增殖中的作用

Effects of TLR/STAT pathway on the proliferation of mesangial cell induced by HMGB1

目的:探讨TLR/STAT通路在HMGB1诱导的系膜细胞增殖中的作用。方法:将体外培养的人系膜细胞分为正常对照组和HMGB1刺激组,培养6、12和24小时后收集细胞,免疫细胞化学检测PCNA表达的变化;免疫细胞化学和流式细胞术检测TLR2蛋白表达的变化;PCR技术检测STAT1/STAT3mRNA表达的变化。结果:人重组HMGB1刺激系膜细胞后,能够促使其增殖;与正常对照组相比,HMGB1刺激组中TLR2蛋白表达增强;与正常对照组相比,HMGB1刺激组中STAT1和STAT3mRNA表达增强;TLR2蛋白与STAT1、STAT3mRNA表达均呈显著正相关(r=0.830,P<0.001;r=0.926,P<0.001);PC-NA阳性表达率与STAT1、STAT3mRNA表达亦呈显著正相关(r=0.817,P<0.001;r=0.863,P<0.001)。结论:HMGB1可能通过与其受体蛋白TLR2结合,进而激活STAT1/STAT3,促进系膜细胞增生,从而导致肾脏损害。

Objective： To investigate the effects of TLR/STAT pathway in the proliferation of mesangial cell induced by HMGB1. Methods： Human mesangial cells were inoculated in the dose of 1 × 10^4 ml^-1. After 24 h, cells were cultured with standard medium as control group or with medium supplement with 10 μg/L human recombinant protein HMGB1 as trial group in vitro.Then the cells were collected in 6, 12 and 24 h respectively, as well as control group cells, lmmunocytochemical staining was adopted to examine the expressions of PCNA proteins on mesangial cells in different groups. Immunocytochemical staining and FCM were performed to detect the changes of TLR2 protein expression. STAT1 and STAT3 mRNA were examined by RT-PCR technique. Results： Immunocytochemical staining indicated that the mesangial cells could multiply after they were induced by human recombinant protein HMGB1. Immunocytochemical staining showed that the level of TLR2 protein in trial groups were higher than those in control groups. FCM indicated that HMGB1 could significantly up-regulate the expression of TLR2 protein time-dependently. The STAT1 and STAT3 mRNA in HMGB1 groups were higher than those in control groups. The expression of TLR2 protein was positively correlated with those of STAT1 and STAT mRNA respectively. The positive rate of PCNA was remarkably correlated with the expression of STAT1 and STAT3 mRNA. Conclusion： HMGBI could activate STAT1/STAT3 through combining with its cell-surface receptor TLR2, which may play an important role in promoting the proliferation of mesangial cells and then damaging the renal of lupus nephritis.