氧化低密度脂蛋白刺激人肾小球系膜细胞产生单核细胞趋化蛋白-1由核因子-κB活化调控

Expression of MCP-1 in human mesangial cells induced by Ox-LDL is mediated by the activition of nuclear factor-KB

目的 研究核因子ＫＢ（ＮＦ－ＫＢ）在氧化低密度脂蛋白（Ｏｘ- ＬＤＬ）诱导的体外培养的人肾小球系膜细胞表达单核／巨噬细胞趋化蛋白－１（ＭＣＰ－１）中的作用。方法 采用凝胶迁移率变动分析检测ＮＦ－ＫＢ的ＤＮＡ结合活性变化，以免疫组织化学观测细胞内ｐ６５的核转位，用细胞ＥＬＩＳＡ法检测细胞内 ＭＣＰ－１及ＩＫＢα蛋白含量变化。结果 不同浓度（１０、２５、５０、１００μｇ／ｍｌ）Ｏｘ－ＬＤＬ刺激肾小球系膜细胞均可引起细胞ＮＦ-ＫＢ的ＤＮＡ结合活性增强、ＩＫＢα蛋白表达下降以及ＭＣＰ－１蛋白表达增强，以５０μｇ／ｍｌ刺激１ｈ ＮＦ－ＫＢ活化及ＩＫＢα表达减弱最明显，作用２４ｈＭＣＰ-１表达水平最高。ＮＦ－ＫＢ俯活化的同时伴有ｐ６５核转位。上述效应可被ＮＦ－ＫＢ特异性抑制剂吡咯二硫氨基甲酸酯（ＰＤＴＣ）所抑制。结论Ｏｘ－ＬＤＬ刺激人肾小球系膜细胞产生ＭＣＰ－１是由ＮＦ－ＫＢ调控，ＮＦ－ＫＢ参与了脂质肾损害的发病过程。

Objective To investigate the role of nuclear factor-KB( NF-KB) in the expression of monocyte chemoattractant protein-i (MCP-1) in human mesangial cells induced by oxidized low density lipoprotein(Ox-LDL) . Methods Human mesangial cells were used as target cells. Levels of inhibitory KBK (IKBα) and MCP-1 protein were measured by ELISA. Activity of transcriptional factors NF-KB was determined by electrophoresis mobility shift assay ( EMSA) . Immunohistochemistry was used to detect the translocation of p65. Results Ox-LDL increased the DNA-binding activition of NF-KB and decreased the expression of IKBα. These effects were most obvious when the mesangial cells were cultured with Ox-LDL in 50 μg/ml for 1 hour( P <0.01). The expression of MCP-1 protein in mesangial cells increased at 24 hours when incubated with 10 μg/m1 to 100 μg/ml Ox-LDL and 50 μg/mI Ox-LDL caused the highest expression level. The translocation of p65 from cytoplasm to nucleus was found with the activation of NF-KB too. NF-KB inhibitor pyrrolidithiocabonate( PDTC) could inhibit these effects of Ox-LDL. Conclusion Activition of NF-KB regulates the expression of MCP-1 in human mesangial cells induced by Ox-LDL