论文部分内容阅读
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 study the regulatory effect of liver X receptor α (LXRα) gene on the gene expression of cholesterol metabolism in HepG2 hepatocytes. Methods: The specific LXRα small interfering RNA (siRNA) was transfected into human HepG2 hepatocytes by Lipofectamine 2000. At the same time, the activation of LXRα in HepG2 hepatocytes (T0901317) was measured. The real-time quantitative PCR LXRα before and after excitement and expression of ATP binding cassette (ABC) G5, ABCG8, ABCA1 mRNA of cholesterol metabolism related genes. Results: The relative expression level of LXRα mRNA in HepG2 experimental group was significantly lower than that in the negative control group (P <0.01) after LXRα siRNA interference for 24 h, and the inhibition rate of LXRα mRNA expression was 86.06%. The expression of ABCG5, ABCG8 and ABCA1 mRNA in the experimental group decreased compared with the negative control group (P> 0.05). The expression of ABCG8 and ABCA1 gene in HepG2 group was significantly increased (P <0.05) 48 h after addition of agonist (T0901317), but the expression of ABCG5 gene only increased (P> 0.05). CONCLUSIONS: RNA interference inhibited the expression of LXRα in HepG2 hepatocytes, and then decreased the expression of ABCG5, ABCG8 and ABCA1. The synthetic ligand T0901317 combined with LXRα increased the activity of ABCG8, ABCA1 and ABCG5 mRNA expression. It is suggested that LXRα regulates cholesterol metabolism genes in HepG2 hepatocytes.