阿托伐他汀对脂多糖诱导人脐静脉内皮细胞Toll样受体4及其下游信号转导通路的影响

Effect of atorvastatin on the expression of lipopolysaccharide-induced Toll like receptor 4 and downstream signal transduction pathway in human umbilical vein endothelial cells

背景:研究表明Toll样受体4参与了动脉粥样硬化的发生和发展,目前Toll样受体4与MyD88依赖性或MyD88非依赖性信号转导通路在动脉粥样硬化发生和发展中的机制尚不明确。目的:观察阿托伐他汀对脂多糖诱导的人脐静脉内皮细胞Toll样受体4及其下游信号转导通路主要元件MyD88、TRAF-6、TRAM及TRIF表达的影响,分析阿托伐他汀防治动脉粥样硬化的机制。方法:体外培养人脐静脉内皮细胞,用脂多糖刺激并加入阿托伐他汀干预24h,收集细胞,用荧光定量PCR方法测定TLR4、MyD88、TRAF-6、TRAM及TRIFmRNA表达;用Westernblotting法测定TLR4、MyD88及TRAF-6蛋白表达。结果与结论:用脂多糖刺激人脐静脉内皮细胞后,引起TLR4、MyD88、TRAF-6、TRAM和TRIF的高表达(P<0.01),用阿托伐他汀干预后可显著抑制TLR4、MyD88及TRAF-6的表达(P<0.01)。提示阿托伐他汀可阻断Toll样受体4高表达,同时阻断Toll样受体4胞内信号转导的MyD88依赖性途径,这可能是阿托伐他汀抗动脉粥样硬化的作用机制之一。

BACKGROUND： Recent research shows that Toll like receptor 4 （TLR4） is involved in the occurrence and development of atherosderosis. The mechanisms of TLR4, MyD88 dependent or MyD88 independent signal transduction during the process of AS occurrence and development is not clear yet. OBJECTIVE： To investigate the influence of atorvastatin on expression of lipopolysaccharide-induced （LPS） TLR4 and its downstream signal transduction pathway, such as MyD88, TRAF-6, TRAM and TRIF in human umbilical vein endothelial cells （HUVECs）, and to study its possible anti-atherosclerotic mechanism. METHODS： HUVECs was cultured in vitro and stimulated with lipopolysaccharide （LPS）, then treated with atorvastatin for 24 hours and collected the cells, finally the expression of TLR4, MyD88, TRAF-6, TRAM and TRIF mRNA was measured with real-time PCR, the expression of TLR4, MyD88 and TRAF-6 protein was analyzed by Western blotting method. RESULTS AND CONCLUSION： LPS enhanced the expression of TLR4, MyD88, TRAF-6, TRAM and TRIF （vs. normal control group, P 0.01）, atorvastatin decreased the high expression of TLR4, MyD88 and TRAF-6 （vs. model group, P 0.01） which were stimulated by LPS. Atorvastatin can block the high expression of TLR4, and also influence the MyD88-dependent signaling pathway of TLR4. Atorvastatin may exert the function of anti-artherosclerosis by blocking the MyD88-dependent signaling pathway of TLR4.