肝脏X受体α对肝细胞HepG2胆固醇代谢基因表达的调控  

Effect of liver X receptor α on modulation of cholesterol metabolism gene expression in HepG2 hepatic cells

作　　者：王蕾[1] 蔡劬[2] 蒋兆彦[2] 施敏敏[2] 崔巍[2] 韩天权[2] 袁耀宗[1] 吴卫泽[2] 张圣道[2] 

机构地区：[1]上海交通大学医学院附属瑞金医院消化内科,上海200025 [2]上海交通大学医学院附属瑞金医院外科上海消化外科研究所,上海200025

出　　处：《内科理论与实践》2010年第2期165-169,共5页Journal of Internal Medicine Concepts & Practice

基　　金：国家自然科学基金资助课题(项目编号:30672042;30700310)

摘　　要：目的:研究肝细胞X受体α(liver X receptorα,LXRα)基因对HepG2肝细胞胆固醇代谢相关基因表达的调控作用。方法:将特异性LXRα小片段干扰RNA(siRNA)经脂质体Lipofectamine 2000介导转染人HepG2肝细胞,同时行HepG2肝细胞LXRα的激动(T0901317)实验,采用实时定量PCR方法分别测定干扰和激动前后的LXRα以及胆固醇代谢相关基因ATP结合盒(ABC)G5、ABCG8、ABCA1 mRNA的表达。结果:LXRαsiRNA干扰24h后,HepG2实验组LXRα mRNA相对表达量显著低于阴性对照组(P<0.01),LXRα mRNA表达抑制率为86.06%。实验组ABCG5、ABCG8和ABCA1 mRNA表达水平均较阴性对照组有下降趋势(P>0.05)。HepG2加入激动剂(T0901317)48h后,实验组ABCG8和ABCA1基因表达均显著升高(P<0.05),但ABCG5基因表达仅有升高趋势(P>0.05)。结论:RNA干扰使HepG2肝细胞LXRα表达受抑制,继而有使靶基因ABCG5、ABCG8、ABCA1表达降低趋势;人工合成配体T0901317与LXRα结合,使其活性增加,上调了ABCG8、ABCA1和ABCG5 mRNA的表达。提示LXRα可调控HepG2肝细胞的胆固醇代谢基因。Objective To investigate the modulation of cholesterol metabolism gene expression by liver X receptor α（LXRα） in HepG2 hepatic cells.Methods Human hepatoma cell line HepG2 was transfected with LXRα small interfering RNA（siRNA） by Lipofectamine 2000.Expressions of LXRα mRNA before and after transfection were determined by real-time polymerase chain reaction（PCR）.The mRNA expression levels of ABCG5,ABCG8,ABCA1 were assayed by real-time PCR.In another experiment,HepG2 cells were treated with LXRα agonist T0901317 and the mRNA expression levels of ABCG5,ABCG8,ABCA1 were assessed by real-time PCR.Results Level of LXRα mRNA in HepG2 cells was significantly lower in siRNA transfected group than in control group（P〈0.01） 24 h after transfection,the inhibition ratio of LXRα mRNA was 86.06%.Expressions of ABCG5,ABCG8 and ABCA1 had a trend to decrease when compared with the control group（P〉0.05）.In the agonist experiment,expression levels of ABCG8 and ABCA1 increased significantly 48 h after treated with T0901317（P〈0.05）,yet ABCG5 only had a trend to increase（P〉0.05）.Conclusions siRNA interference could efficiently down-regulate the expression of LXRα mRNA in HepG2 cells,and the mRNA expressions of target genes ABCG5,ABCG8 and ABCA1 had a trend to decrease.On the other hand,LXRα agonist T0901317 could enhance the activity of LXRα and up-regulate the mRNA expressions of ABCG5,ABCG8,ABCA1.This suggested that LXRα could modulate the expression of cholesterol metabolism gene.

关 键 词：肝X受体Α 胆固醇代谢 RNA干扰 激动剂 胆石病 

分 类 号：R575.62[医药卫生—消化系统]