Research Of NLRP3 Inflammasome And Adiponectin In Non-alcoholic Fatty Liver Disease

Background and Objectives:Non-alcoholic fatty liver disease(NAFLD)is a clinical pathological syndrome characterized by excessive accumulation of fatty in hepatocytes and excluding alcohol or other defined factors of liver damage.The spectrum of disease includes non-alcoholic simple fatty liver,non-alcoholic steatohepatitis(NASH)and non-alcoholic fatty cirrhosis.In recent years,NAFLD has become one of the most common chronic liver diseases that affecting a quarter of the world's population.According to statistics,the prevalence of NAFLD in the world is about 25.24%,and the prevalence of NASH is estimated to be 3%to 5%.NAFLD is the leading cause of chronic liver disease in Western countries.With the rapid development of China's economy and society and changes in diet structure and lifestyle,NAFLD has become the most common chronic liver disease except for viral hepatitis in China.Most NAFLD patients with have no obvious clinical symptoms or signs,which leads to a lower diagnosis rate of early stage disease,and 20%-25%of simple nonalcoholic fatty liver disease will progress to NASH without any intervention.Simple fatty liver is associated with a higher risk of progression to cirrhosis with NASH,and approximately 20%of NASH patients can progress to cirrhosis and liver cancer.In addition to adversely affecting the liver itself,NAFLD has also been shown to be associated with a variety of extrahepatic diseases,such as cardiovascular and cerebrovascular diseases,malignant tumors,chronic kidney disease,and thyroid disease.It can be seen that NAFLD,especially NASH,seriously harms the health of the population,greatly increases the medical economic burden,and becomes a public health problem that urgently needs to be solved.However,the pathogenesis of NAFLD is not completely clear,and there is no effective drug.treatment.Up to now,,multiple strikes theory,has become the mainstream theory of the occurrence and development of NAFLD.In the field of pathogenesis of NAFLD,inflammatory reaction and lipid metabolism disorder are considered to be important components of the occurrence and development of NAFLD.As an important component of innate immunity,inflammasome can be activated by various types of pathogens or dangerous signals,and play a key role in various diseases.The NLRP3 inflammasome is the most structural and functional significance inflammasome and is involved in various inflammatory reactions.Adiponectin(APN)is an endogenous biologically active polypeptide or protein secreted by adipocytes and is an important regulator of the bodyVs lipid metabolism regulation network.Therefore,this study intends to explore the mechanism of NLRP3 inflammasome and adiponectin in NAFLD by constructing mouse NAFLD model and clinical research,aiming to provide experimental basis for the development of therapeutic drugs for this disease.Methods and Meterials1.Animal experiment study:24 male C57 mice of 6-8 weeks were adaptively fed for 1 week,and then randomly divided into 2 groups,12 mice ie each group:control group and high-fat diet group,respectively,fed with normal diet and high-fat diet.The mice were weighed weekly and the growth of the mice was observed(hair,activity,state of mind).The mice were sacrificed 8 weeks later.The weight gain,liver weight and liver index of the two groups were compared.Serum were colleted to detect indicators including transaminase,blood glucose,blood lipidsand and liver tissue samples were collected to detect liver pathological changes by HE staining and oil red 0 staining.western-blot was used to detect the expression levels of NLRP3 inflammasome and adiponectin metabolic pathway proteins in the liver.2.Clinical sample study:According to inclusion criteria and exclusion criteria serum samples of NAFLD patients and non-NAFLD patients(respectively 30 cases)who diagnosed by abdominal ultrasound in the Department of Gastroenterology,Nanfang Hospital from October 2018 to December 2018 were collected.Serum IL-1?,IL-18,APN levels was detected by ELISA.routine blood count,liver and kidney function,blood lipids,blood glucose and other clinical data were gathered.Comparnng the levels of IL-1?,IL-18 and adiponectin between the two groups.3.Statistical method:Statistical analysis was performed using SPSS22.0.The measurement data were expressed as mean±standard error.The count data was expressed as a percentage.The data between the two groups that met the approximate normal distribution were analyzed by independent sample t-test.The comparnson between non-normal distribution data groups Wilcoxon rank sum test analysis was used.The percentage comparison was analyzed by chi-square test.Regression equation analysis and covariance analysis were used to remove the influence of confounding factors.The difference was statistically significant at P<0.05.Results1.After 2 weeks of feeding,the mice in the HFD group showed impotence,decreased activity,sluggish eyes,dull hair,disordered and shedding.After 8 weeks of modeling,the mice in the high-fat group were heavier than the control group(33.09±0.51;30.18±0.23),liver wet weight(1.32±0.01;1.16±0.02)increased significantly(P<0.05);liver index(0.43±0.004;0.42±0.004)averaged was also higher,but the difference was not statistically significant(P>0.05).2.There were significant differences in serum ALT(32.19d±0.65;24.01±1.05)?AST(55.22±1.04;43.00±1.06)?GLU(10.08±0.41.5,91±0.24)?CHOL(8.25±0.15;5.52±0.18)?TG(2.27±0.23;2.13±0,20)betweenthetwogroups.3.The mice in the HFD group had large liver,darker color and tough texture compared with the control group.HE staining showed obvious vacuolar-like fatty changes in liver cells,and oil red O staining showed obvious deposition of liver fat,demonstrating that the NAFLD model was successful established.4.Western-Blot showed that the expression of NLRP3 and downstream IL-1?in the HFD group was up-regulated,and the expression of APN and downstream PPAR-a were down-regulated compared with the control group.5.Patients with NAFLD had elevated BMI(24.7±0.55;22.5±0.62),ALT(25.3±3.04;16.4±1.96),and GLU(5.44±0.29;4.56±0.10)compared with non-NAFLD patients diagnosed by abdominal unltrosound.After removing the confounding factors of BMI,GLU and ALT,the serum IL-1?(8.69±1.39;7.98±0.40)and IL-18(59.88±1.30;56.19±1.07)were elevated in the NAFLD group,while APN(12.79±0.93;15.61±0.89)level decreased,the difference was statistically significant(P<0.05).ConclusionsIn this study,a model of NAFLD in C57 mice was successfcully established by continuous HFD feeding for 8 weeks.The up-regulation of NLRP3 inflammasome and the down-regulation of adiponectin expression may be related to the occurrence and development of NAFLD,which provides a basis for further exploration of the relationship between NLPR3 inflammasome and adiponectin.