烟酸通过下调PCSK9的表达促进HepG2细胞摄取LDL-C

发布时间：2019-04-26 19:41

【摘要】：目的探讨烟酸对HepG2细胞摄取及代谢LDL-C的影响,寻找烟酸改善血脂异常,减缓动脉粥样硬化进程的相关分子机制,为其临床用药提供指导。方法采用油红O染色观察细胞内脂质蓄积;酶法检测细胞内胆固醇含量;荧光流式检测细胞表面LDLR丰度分布;qPCR及Western blot检测LDLR、SREBP2以及PCSK9的mRNA及蛋白含量变化。结果经烟酸处理的HepG2细胞,油红O阳性细胞数及细胞内红染脂滴增多,细胞内TC、FC水平明显增高(P0.05);LDLR mRNA含量无差异(P0.05),而细胞膜表面LDLR分布丰度及细胞内LDLR的含量明显增加(P0.05);烟酸对SREBP2的表达无影响,却能明显下调PCSK9的表达。结论烟酸可能通过下调PCSK9的表达,减少PCSK9成熟体蛋白含量,使得LDLR降解减少,进而增加LDLR含量,促进HepG2细胞摄取LDL-C。
[Abstract]:Aim to investigate the effect of nicotinic acid on the uptake and metabolism of LDL-C in HepG2 cells, and to find out the molecular mechanism of nicotinic acid in improving dyslipidemia and slowing down the process of atherosclerosis, so as to provide guidance for its clinical use. Methods Lipid accumulation was observed by oil red O staining, cholesterol content was measured by enzyme method, LDLR abundance distribution on cell surface was measured by fluorescence flow cytometry, mRNA and protein contents of LDLR,SREBP2 and PCSK9 were detected by qPCR and Western blot. Results in the HepG2 cells treated with nicotinic acid, the number of oil red O positive cells and the red staining lipid droplets in the cells were increased, and the intracellular TC,FC level was significantly increased (P0.05). There was no difference in the content of LDLR mRNA (P0.05), but the distribution abundance of LDLR on the surface of cell membrane and the content of LDLR in the cell increased significantly (P0.05), while nicotinic acid had no effect on the expression of SREBP2, but could significantly down-regulate the expression of PCSK9. Conclusion nicotinic acid may decrease the content of PCSK9 mature body protein by down-regulating the expression of PCSK9 and decrease the degradation of LDLR, then increase the content of LDLR and promote the uptake of LDL-C. by HepG2 cells.
【作者单位】：常德市妇幼保健院遗传科;南华大学生物技术系;常德市职业技术学院医学系;
【基金】：湖南省科技厅项目(No2015SK2038) 湖南省卫生计生委项目(NoB2015-49) 湖南省高层次卫生人才“225”工程项目基金辽宁中医药大学重点实验室开放基金(2015) 湖南省教育厅项目(No15C1217) 湖南省自然科学基金资助项目(No2014JJ3104) 湖南省大学生研究性学习和创新性实验计划项目(No2015-230) 衡阳市科技局项目(No2015KJ15) 南华大学“十二五”科技创新团队基金;南华大学留学回国人员启动基金(No2013XQD52);南华大学大学生研究性学习和创新性实验计划项目(2014,2015) 国家自然科学基金资助项目(No81600291) 湖南省研究生科研创新项目(NoCX2016B474)
【分类号】：R96

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