Study Of Let-7 In Nonalcoholic Fatty Liver Disease

[Objective]Nonalcoholic fatty liver disease is defined as a person with little or no alcohol consumption who has no other liver disease leading to steatosis(such as the use of pathogenic drugs,or viral hepatitis),at least 5%in imaging or liver histology Hepatocytes have fatty degeneration.Nonalcoholic fatty liver disease is histologically divided into simple liver steatosis and steatohepatitis.Currently,liver biopsy is the gold standard for the diagnosis of alcoholic fatty liver disease and steatohepatitis and fibrosis stage.However,it is invasive,variability,and has a range of adverse effects,including pain,infection,and rare deaths.With the increase in the number of patients with nonalcoholic fatty liver disease,the operability is not strong,and non-invasive means for the diagnosis of nonalcoholic fatty liver disease and the severity of thedisease are urgently needed.More and more research is concerned with the use of microRNAs,inflammatory factors,and metabolic indicators as biomarkers for the diagnosis and treatment of nonalcoholic fatty liver disease.In this study,differentially expressed microRNAs(let-7)were screened by microarray microarray in the previous research group to detect the expression of let-7,inflammatory factors(TNFa,IL-6)and the expression of homocysteine in the metabolic index.The relationship between let-7 and inflammatory factors,homocysteine and steatosis in nonalcoholic fatty liver disease was analyzed,and the risk factors related to the development of nonalcoholic fatty liver disease were further analyzed.[Methods]1.Establishment of a mouse model of nonalcoholic fatty liver disease induced by high-fat diet:30 SPF male SD mouses were fed for 1 week,and 20 of them with similar body weight were randomly divided into modeling group and control group.,each group of 10 each.The HFD modeling group and the control group were fed with high fat diet and normal feed for 14 weeks.At the end of 13w,3 mouses were randomly selected from the model,and the liver tissue sections were stained with oil red O and HE stained(haematoxylin-eosin staining)to observe and evaluate hepatic steatosis and inflammation.After successful modeling,the materials were taken for pathological examination and subsequent experiments.2.From April to June of 2018,600 physical examination populations were taken at the Health Examination Center of the First Affiliated Hospital of Kunming Medical University.According to the selection criteria and exclusion criteria,a total of 227 volunteers(168 non-alcoholic fatty liver disease and 59 normal control group)were included,including 140 males and 87 females,aged(44±12)years old.All volunteers were tested for Fibrotouch and B-ultrasound and related biochemical indicators.3,qPCR detection of let-7 expression in mouse liver and human serum,double antibody sandwich ELISA detection of inflammatory factors(TNFa,IL-6),automatic biochemical analyzer for measuring homocysteine and liver and kidney Biochemical indicators such as work.[Results]1.The expression of let-7 was detected by qPCR:the expression of let-7a,let-7b and let-7d in liver of mouses and human serum with nonalcoholic fatty liver disease was up-regulated compared with the normal control group;2.ELISA method for detecting inflammatory factors(TNF?,IL-6):Compared with the normal control group,the expression of TNFa and IL-6 in serum of patients with nonalcoholic fatty liver disease were significantly up-regulated;3.we found that in patients with nonalcoholic fatty liver,serum homocysteine has an increasing trend,but also found that obesity and blood lipids,liver function have an effect on liver fat content;4.Correlation analysis showed that let-7b was associated with IL-6 and liver fat content.[Conclusions]1.The up-regulation of let-7 and inflammatory factors in liver of mouses and serum of patients with nonalcoholic fatty liver disease indicates that let-7 and inflammatory factors may be further studied as novel biomarkers for the diagnosis and treatment of nonalcoholic fatty liver disease;2.Homocysteine may be a new important risk factor for nonalcoholic fatty liver disease,which may provide a new way for the prevention and treatment of nonalcoholic fatty liver disease;3.let-7b was positively correlated with IL-6 and CAP,and the difference was statistically significant.Let-7b was positively correlated with TNFa and HCY,and the difference was not statistically significant.There was a low positive correlation between let-7a and let-7d and TNFa,IL-6,HCY and CAP.The difference was not statistically significant.It may be due to the lack of correlation between the two,or the lack of sample size.4.obesity and blood lipids,liver dysfunction is a risk factor for nonalcoholic fatty liver disease,so the treatment and prognosis of nonalcoholic fatty liver disease,mainly in the improvement of lifestyle,weight loss,low-fat diet,regular monitoring of weight,Liver function and blood lipids.