泡沫细胞胆固醇逆向转运机制及药物干预研究

Effect of lovastatin and rosiglitazone on cholesterol reverse transportation in foam cell

目的 人THP-1单核/巨噬细胞源性泡沫细胞为研究对象,探讨罗格列酮、洛伐他汀对三磷酸腺苷结合盒转运蛋白（ABC）A1表达和细胞内胆固醇含量的影响.方法 低密度脂蛋白（LDL）提取,Cu^2＋氧化法获得氧化型LDL（ox-LDL）.建立泡沫细胞模型.Western blot检测洛伐他汀、罗格列酮对THP-1单核/巨噬细胞ABCA1蛋白表达的影响.泡沫细胞分9组,分别给予相应的干预因子,培养24 h,检测各组细胞内胆固醇含量.结果 与对照组比较,洛伐他汀组、罗格列酮组、各ABCA1单克隆抗体预处理组细胞内胆固醇含量无明显变化（P〉0.05）;而载脂蛋白（Apo）A-I组、洛伐他汀＋ApoA-I组、罗格列酮＋ApoA-I组显著降低（P〈0.05）.结论 胆固醇逆向转运需在ApoA-I和ABCA1蛋白共同参与下完成,并能降低细胞内胆固醇含量.罗格列酮能通过促进ABCA1蛋白表达介导胆固醇向胞外转运,使细胞内胆固醇含量进一步降低.

Objectives This study was designed to explore the function of ATP binding cassette transporter 1 （ ABCA1） and ApolipoproteinA-I （ApoA-I） in cholesterol reverse transportation （ RCT） , the influence of lovastatin and rosiglitazone on the concentration of cholesterol （ CHO） in THP-1 （ human monocytic leukemia cell line） derived foam cells.Methods LDL from healthy volunteers was obtained by density-gradient ultracentrifugation and was oxidized by incubation with Cu2＋ and ox-LDL was identified.Macrophages were induced from THP-1 cell by phorbol ester （PMA）.Models of foam cells were built by incubating macrophages with oxLDL.The effect of lovastatin and rosiglitazone on ABCA1 protein expression in THP-1 cell line derived macrophage were detected by western blot Foam cells were divided into 9 groups： control, ApoA-I, lovastatin, rosiglitazone lovastatin ＋ ApoA-I, rosiglitazone ＋ ApoA-I, ABCA1 monoclonal antibody pretreatment ＋ ApoA-I, ABCA1 monoclonal antibody pretreatment ＋ lovastatin ＋ ApoA-I, ABCA1 monoclonal antibody pretreatment ＋ rosiglitazone ＋ ApoA-I.The concentration of intracellular CHO in each group was detected by using cholesterol kit Results As compared with control group, there are no big differences of CHO concentration within the cell of group lovastatin, rosiglitazone, and each ABCA1 monoclonal antibody pretreatment group （P 〉0.05）, but the CHO concentration within the cells of group ApoA-I, lovastatin ＋ ApoA-I, rosiglitazone ＋ ApoA-I decreased obviously as compared with the control （P 〈0.05）, and CHO concentration in group rosiglitazone ＋ ApoA-I have a further decrease than the former two groups （ P 〈 0.05 ）.Conclusions CHO concentration can be descreased in foam cells by cooperation of ABCA1 and ApoA-I mediate cholesterol efflux.Rosiglitazone can enhance this procedure in THP-1 macrophages derived foam cells which means that they can promote ABCA1 mediated cholesterol reverse transportation through improve ABCA1 protein expression.