Correlation And Function Between SIRT3 And NAFLD

In recent years,the global incidence of non-alcoholic fatty liver diseases(NAFLD)rising year by year,and has a tendency to gradually younger patients.It is reported that the world is about 20% ~ 30% of adults may be suffering from NAFLD,most of them in the stage of SFL and won’t appear serious symptoms or liver damage early,therefore has not received enough attention.1/5 of SFL patients may progression to NASH and even cirrhosis and liver cancer within a few years.NAFLD,therefore,has become a kind of to cause serious public health hazard of common diseases and frequently-occurring disease of body and mind,with the increasing investment by the government and the whole society to the scientific research and diagnosis and treatment of the disease.But there is no effective measure for prevention and control of NAFLD,which depends on deep explora tion of the disease mechanism.Previous study suggests SIRT3 is an important molecular for fat metabolism regulation of liver,and can base on a series of the substrate to acetylated modification reaction to participate in regulating the biological processes of liver cells,such as fatty acid oxidation,oxidative stress,mitochondrial function change and inflammation factor expression.These processes are likely to closely associate with onset and progress of NAFLD.This group engaged in nutrition intervention plan research of chronic metabolic diseases such as diabetes,fatty liver,found that SIRT3 is the core molecule to the nutrition,exercise intervention scheme such as sports,energy limit and plant compounds.In order to find the evidence of whether the SIRT3 gene is occurred with fatty liver disease in the crowd,we select SIRT3 as objective target gene,first by using bioinformatics methods to analyze SIRT3 gene linkage disequilibrium relationships and single nucleotide polymorphisms(SNP)site.Then establish population-based cohort research in 384 patients with NAFLD and 384 normal controls,extract genomic DNA respectively,and 13 of SIRT3 gene SNP locus for genotyping and correlation analysis,found the SNP locus rs11246020,rs3782118 and rs73392700 are associated with disease risk.For further study how SIRT3 gain-of-function to affect the disease process of NAFLD,we successfully built long-range high-fat feeding method NAFLD mice model,constructed SIRT3 eukaryotic expression plasmid vector,using intermittent tail intravenous injection method after transfection reagent packaging induced the model mice with high expression of genes SIRT3 in liver successfully,monitoring and analyzing the relationship of animal dietary intake and weight gain,corresponding kits are used for testing biochemical indexes such as lipid metabolism related triglycerides(TG),total cholesterol(CHO)and free fatty acid(FFA)in mice liver and blood.At the same time,using the liver HE staining,oil red O staini ng to observe hepatocyte pathological changes such as adipose accumulate,extract the protein and RNA,respectively using proteins molecularly imprinted and Real-time PCR detection to test Ppar alpha,cpt1 a,cpt1b and Acox1 gene expression which belong to the related protein and fatty acid metabolism related signaling pathway.Main results:(1)SIRT3 gene encoding area SNP rs11246020 genotype distribution in NAFLD and with significant differences of the distribution in contrast groups.Individual with genotype GG relative AG + AA genotype have an increased risk of effect(OR = 1.4,P = 1.4).Different allele of rs3782118 and rs73392700 associated with the risk of the occurrence of NAFLD(ORT/C-rs3782118 = 1.27,P = 0.0361;ORC/G-rs73392700 = 1.45,P = 0.0361).(2)Long-term high fat diet feeding could be successfully built NAFLD model in mice,SIRT3 gene plasmid vector transfection methods are used successfully to put anthropogenic sex SIRT3 genes to the liver of model mice,and lead to the high expression of SIRT3 protein in liver;after 25 days,the weight of SIRT3 high expression group of NAFLD model mice was significantly lower than blank group,and effectively control in lower level;While the weight of blank group mice showed a trend of rising,and stability at a higher level.(3)The accumulation of fat tissue,cell vacuole degeneration,and the degree of fatty change in model mice liver tissue with SIRT3 gene therapy were significantly lower than blank group.The generation of TG,CHO and FFA in liver and FFA l evels in serum are significantly lower than blank group as well.With high gene expression of SIRT3,transcription of genes Ppar alpha and downstream target genes Acox1 that closely related to lipid metabolism in liver is dropped significantly.Conclusion:(1)SIRT3 genetic polymorphism can affect the crowd NAFLD risk.(2)The gain-of-function of SIRT3 shows a significant improvement NAFLD model mice liver fat accumulation.NAFLD dietary nutrition plan that based on up-regulated SIRT3 as targets can directly improve NAFLD by regulating mitochondrial metabolism.