邻苯二甲酸单乙基己基酯暴露对肝脏脂质代谢的影响及调控机制

Effects of mono-(2-ethylhexyl)phthalate exposure on liver lipid metabolism and its regulatory mechanism

邻苯二甲酸二(2-乙基己基)酯(Di(2-ethylhexyl)phthalate,DEHP)是一种重要的内分泌干扰物,对神经系统、生殖系统、内分泌系统等都具有特定的损伤作用.DEHP被机体摄入后,在肝脏和肠道中被消化酶代谢为邻苯二甲酸单(2-乙基己基)酯(mono-(2-ethylhexyl)phthalate,MEHP)以发挥毒性作用.本研究采用体外HepG2暴露结合mRNA芯片以及生信分析的方法,探讨MEHP暴露对HepG2细胞脂质代谢的影响.首先,采用油红O染色法观察细胞内脂滴蓄积情况,发现MEHP暴露能够以浓度依赖性的方式增加HepG2细胞内脂质蓄积.为了探究其可能的机制,采用Agilent(人)表达谱芯片分析并筛选差异基因,共筛选出93个差异表达基因,其中上调基因57个,下调基因36个.在此基础上,通过DAVID在线数据库对差异表达基因进行基因功能富集分析,发现其主要参与细胞脂质代谢过程(cellular lipid metabolic process)、跨膜运输(transmembrane transport)、跨膜转运的调控(regulation of transmembrane transport)等生物学过程.随后,通过qRT-PCR法对关键基因的mRNA表达水平进行验证.最后,通过GEPIA在线验证上述基因在肝细胞癌(LIHC)中的表达.综上,MEHP暴露能够影响细胞脂质代谢通路中的基因FADS6、MVD、SC5D、PLA2G4E在HepG2细胞中的表达,在一定程度上促进了肝脏细胞中的脂肪蓄积,从而使肝细胞内脂质代谢紊乱.

Di(2-ethylhexyl)phthalate(DEHP)is an important endocrine disruptor,which has specific damage to nervous system,reproductive system and endocrine system.DEHP is metabolized by digestive enzymes into mono-(2-ethylhexyl)phthalate(MEHP)in liver and intestine,so as to produce toxic effects on human health.HepG2 was exposed to MEHP and then mRNA microarray and bioassay was used to investigate the effects of MEHP exposure on lipid metabolism of HepG2.First,oil red O staining was used to observe the accumulation of lipid droplets in HepG2 cells.It was found that MEHP exposure could increase the accumulation of lipid droplets in HepG2 cells.In order to explore the possible mechanism,Agilent(human)expression microarray was used to analyze and screen differentially expressed genes.A total of 93 differentially expressed genes were screened,including 57 up-regulated genes and 36 down-regulated genes.In addition,gene function enrichment analysis of differentially expressed genes was conducted through DAVID online database.It was found that these differentially expressed genes were mainly involved in the regulation of cellular lipid metabolic process,transmembrane transport and transmembrane transport Transport and other biological processes.Then,the mRNA expression levels of key genes were verified by qRT-PCR.Finally,GEPIA was used to verify the expression of these genes in Liver hepatocellular carcinoma(LIHC).In conclusion,MEHP exposure can affect the expression of FADS6、MVD、SC5D and PLA2G4E genes in cellular lipid metabolism pathway in liver,and promote the accumulation of fat in HepG2 cells,thus leading to the disorder of lipid metabolism in liver cells.