The Expression And CpG Island Methylation Of PNPLA3in Experimental Nonalcoholic Fatty Liver Disease

Background:In recent years,the prevalence of Nonalcoholic fatty liverdisease(NAFLD) is increasing not only in the developed contries but also thedeveloping contries,and it has becoming the second liver disease which affecthuman's health.It affects estimated20–40%of adults in Western countries and15%ofadults in our contry.NAFLD is currently considered ahepatic manifestation of the metabolic syndrome and the pathogenesis is not clear.Recently, genomewide association studies identified that the SNPs inPNPLA3(rs738409? rs6006460? rs2294918? rs2281135) are connected withNAFLD.Some studies indicate that the loss of PNPLA3doesn't cause fatty liver.Kumashiro, N., et al. treated high-fat-fed rats with specific antisence oligonucleotidesto decrease hepatic pnpla3expression,and it can prevented fatty liver.So the PNPLA3may plays primarily in a lipogenic capacity. With the development of epigenetics,therole of DNA methylation in NAFLD is becoming more and more important,especiallysome key enzymes of lipid and carbohydrate metabolism.Whether the expression ofPNPLA3is higer in fatty liver group than control group is not reported.In thisstudy,we investigate the expression and CpG island methylation of PNPLA3toexpore the role in NAFLD because there are not studies reported.Objective:To investigate the expression and CpG island methylation of PNPLA3inexperimental nonalcoholic fatty liver disease,and explore the role of gene PNPLA3indevelopment of NAFLD.Methods:The normal L02hepatocytes were treated with10ug/ml oleic acid to establish nonalcoholic fatty liver disease(NAFLD) cell models. Quantitative real-timePCR was used to analyze PNPLA3gene expression in control group, NAFLD groupand curcumin group (treated with10.0uM curcumin). The DNA methylation level wasanalyzed by pyrosequencing.Results: The expression level of PNPLA3mRNA in NAFLD group was much higherthan the control group.After curcumin treatment,PNPLA3mRNA expressiondecreased when compared with the NAFLD group.The methylation level at point2ofthe PNPLA3gene promoter region was lower than the normal group.Conclusion:1?After oil red O staining,much more red lipid droplets accumulate incytoplasm of NAFLD group than control group,indicating that10ug/ml oleic acid cansuccessfully induce nonalcoholic hepatocellular steatosis.2.The lever of expressionand methylation of PNPLA3were correlation with NAFLD,PNPLA3may plays animportant role in the occurrence and development of NAFLD.3.Inhibition of thePNPLA3activity and decreasing the expression ofPNPLA3may represent a novel therapeutic approach for the treatment of NAFLD.