INF-γ对体外培养的系膜细胞HMGB1和MMP-2表达的影响

Effect of INF-γ on expressions of HMGB1 and MMP-2 protein in mesangial cells

目的:探讨INF-γ对体外培养的人肾小球系膜细胞高迁移率族蛋白1(HMGB1)和基质金属蛋白酶2(MMP-2)表达的影响及可能机制,为系统性红斑狼疮(SLE)肾脏损害的治疗提供依据。方法:将常规培养的人肾小球系膜细胞分为正常对照组和INF-γ刺激组,于6、12和24 h收集细胞和上清,RT-PCR和免疫细胞化学法检测HMGB1 mRNA和蛋白表达;双抗夹心ELISA法检测细胞培养上清中HMGB1和MMP-2表达;免疫细胞化学法检测细胞中增殖细胞核抗原(PCNA)和MMP-2表达。结果:与对照组比较,INF-γ刺激组系膜细胞PCNA蛋白表达强度增加,INF-γ刺激12和24 h时系膜细胞中HMGB1 mRNA水平明显增加(P<0.01),HMGB1蛋白表达强度增加;培养上清中HMGB1浓度明显增加(P<0.01);与对照组比较,INF-γ刺激组系膜细胞中MMP-2表达强度增加,培养上清中MMP-2蛋白水平升高(P<0.01);培养上清中HMGB1浓度与MMP-2蛋白表达量呈正相关关系(r=0.915,P<0.01)。结论:INF-γ通过促进系膜细胞合成和分泌HMGB1而上调MMP-2的表达,可能与SLE肾脏损伤有关联。

Objective To investigate the effect of INF-γ on the expression of high mobility group box 1 （HMGB1） and MMP-2 protein in mesangial cells （MC） and its possible mechanism in order to provide basis for treatment of renal injury in systemic lupus erythematosus （SLE） . Methods Human MC induced by 5 ng · L^-1 INF-γwere collected in 6, 12 and 24 h respectively, as well as cells in normal control group in vitro. The expressions of HMGB1 mRNA and protein were detected by reverse transcription polymerase chain reaction （RT-PCR） and immunocytoehemistry. The expressions of proliferation cell nuclear antigen （PCNA） and MMP-2 protein were detected by immunocytochemistry. ELISA was used to determine the levels of HMGB1 and MMP-2 in supernatant. Results Compared with control group, the PCNA protein expression was up-regulated in INF-γgroup, the HMGB1 mRNA and protein expressions in MC obviously increased, the HMGB1 content in supernatant increased significantly. Compared with control group, MMP-2 protein in MC and supernatant in INF-γ group increased; there was positive correlation between HMGB1 and MMP-2 protein in supernatant （r = 0. 915, P 〈0.01）. Conclusion INF-7 can up-regulate the expression of MMP-2 by promoting synthesis of MC and secretion of HMGB1, it might play an important role in renal injury of SLE.