白细胞介素1β通过植物血凝素样氧化低密度脂蛋白受体1途径促进人肾小球系膜细胞摄取氧化低密度脂蛋白

Enhanced uptake of human mesangial cell line to oxidized low density lipoprotein stimulated by interleukin-1β partly through the lectin-like oxidized low-density lipoprotein receptor pathway

目的研究白细胞介素（IL）1β是否促进人肾小球系膜细胞（HMC）摄取氧化低密度脂蛋白（Ox—LDL）以及对其植物血凝素样受体（LOX-1）表达的作用，探讨IL-1β影响脂质摄取的可能作用途径。方法脂质化学染色、流式细胞计数观察IL—1β对HMC脂质摄取的影响，分析LOX-1受体的功能及IL-1β影响脂质摄取的可能作用途径。实时定量PCR和Western印迹方法检测IL-1β对LOX-1表达的影响。结果油红“O”染色发现IL-1β增强HMC对Ox—LDL的摄取；流式细胞仪计数发现IL-1β呈剂量和时间依赖性促进HMC摄取荧光Dil标记的Ox-LDL（Dil—Ox—LDL），抗LOX-1抗体部分阻断IL-1β诱导的HMC对Ox—LDL的摄取，约为单纯IL-1β组的89．8％（P〈0．05）。5μg／L IL-1β刺激HMC，LOX-1 mRNA于6h达高峰，为对照的6．87倍，IL-1β剂量依赖性促进LOX-1mRNA的表达，当刺激HMC12h，LOX-1 mRNA于10μg/L组达高峰，为对照的6．57倍。IL-1β剂量和时间依赖性促进LOX．1蛋白的表达。5μg／LIL-1β刺激HMC，LOX-1蛋白表达于24h达高峰，为对照的1．88倍。10μg／L组刺激细胞24h达高峰，LOX-1蛋白为对照的2．57倍。结论HMC基础状态下摄取Ox-LDL，IL-1β可能通过LOX-1途径增强对Ox-LDL摄取，促进细胞内脂质的摄取，加重细胞内脂质失调。

Objective To analysis if intedeukin-1β （IL-1β） can regulate human mesangial cells （HMC） to uptake oxidized low density lipoprotein （Ox-LDL） and if the effect of IL-1β be changed through the leetin-like oxidized low-density lipoprotein receptor 1 （LOX-1） pathway. Methods The uptake of HMC to Ox-LDL stimulated by IL-1β was observed using Oil Red ＂0＂ and flow cytometry. The level of LOX-1 in HMC induced by IL-1β and Ox-LDL was examined using real-time PCR and Western blotting. Results Uptake of Ox-LDL and Dil-Ox- LDL by HMC was up-regulated upon stimulation with IL-1β in a dose- and time-dependent manner. Intracellular mean fluorescence density of Dil-Ox-LDL with LOX-1 blocker in IL-1β stimulation group was decreased compared to that without blocker. The peak level of LOX-1 mRNA reached after 6 h of stimulation and was as high as 6.87-fold of control. IL-1β could induce LOX- 1 mRNA expression in a dose-dependent manner. Treated with 10 μg/L IL-1β for 12 h, the up- regulation effect on LOX-1 mRNA was as high as 6.57-fold of control. IL-1β could induce LOX-1 protein expression in a time- and dose-dependent manner. The peak level of LOX-1 protein reached after 24 h of stimulation of 5 μg/L IL-1β and was as high as 1.88-fold of control. Treated with 10 μg/L IL-113 for 24 h, the up-regulation effect on LOX-1 protein reached peak and was as high as 2.57-fold of control. IL-1β could induce LOX-1 mRNA and protein expression in a dose- dependent manner. Conclusion The expression of LOX-1 can be up-regulated by IL-1β in a dose-dependent manner and the enhanced uptake of HMC to Ox-LDL stimulated by IL-1β partly through the LOX-1 pathway, which means the dyslipidemia of HMC can be enhanced by inflammatory cytokines.