Effects Of Exenatide On The Regulation Of Hepatocyte Glucose Metabolism In Different Parts Of Human Adipose Tissue

Objectives: The adipose tissue in different locations plays a role in glucose metabolism in hepatocytes.Exenatide(EXE)is a GLP-1 receptor agonist used in the treatment of type 2 diabetes.The purpose of this study is to explore whether EXE has an effect on glucose metabolism in hepatocytesregulated adipose tissue in different locations.Methods:1.HepG2 cells were cultured in six groups:(1)HepG2;(2)HepG2+SAT;(3)HepG2+VAT;(4)HepG2+SAT+EXE;(5)HepG2+VAT+EXE;(6)HepG2+0.4% Triton X-100.group(2)to group(5)were co-cultured by transwell,the co-culture system was constructed using transwell chambers,with human HepG2 cells seeded in the lower chamber and adipose tissue seeded with the upper chamber.The lower chambers of groups(4)to group(5)were added with EXE.2.After the co-culture time,the transwell and adipose tissue were removed,and the supernatants of all experimental groups were collected,and the(lactate dehydrogenase)LDH content was detected by ELISA to determine the survival of HepG2 cells and to ensure that the next experiment could be performed.3.Groups(1)-(5)were treated with insulin-containing medium or without insulin for 10 minutes,then reclassified into the following 10 groups:(1)HepG2+insulin;(2)HepG2;(3)HepG2+SAT+insulin;(4)HepG2+SAT;(5)HepG2+VAT+insulin;(6)HepG2+VAT;(7)He p G2+SAT+EXE+insulin;(8)HepG2+SAT+EXE.(9)HepG2+VAT+EXE+insulin;(10)H ep G2+VAT+EXE.HepG2 from each experimental group was collected and the percentage of fluorescently labeled cells was observed using flow cytometry after staining with the fluorescent glucose analog 2-DBDG.We can evaluate the glucose uptake rate of HepG2 cells.The glycogen content of HepG2 cells was measured by anthrone assay,and the glycogen distribution was observed by periodic acid Schiff reaction(PAS)staining.Results:1.Based on the pictures of HepG2 cells and the determination results of LDH activity,the cells in each group still maintained certain activity and could be subjected to the next experiment.2.The glucose uptake rate: In the basic state and insulin-stimulated state,compared with HepG2 cells,the glucose uptake rate of HepG2 cells co-cultureed of adipose tissue was significantly decreased(P<0.01).and the decrease of VAT was more pronounced than that of SAT(P<0.01).EXE improved the glucose uptake rate of HepG2 cells co-cultured with adipose tissue(P<0.05).3.The glycogen content: In the basic stateand insulin-stimulated state,the glycogen content of HepG2 cells co-cultured with adipose tissue decreased compared with HepG2 cells,and the decrease of VAT was more pronounced than that of SAT(P<0.05).EXE was able to improve the glycogen content of HepG2 cells co-cultured with adipose tissue.4.In each group,The changes in the glucose rate and the glycogen synthesis in insulin-stimulated state were consistent with the trends in the groups without insulin.Conclusions: 1.Adipose tissue in different locations inhibited the glucose uptake rate and the glycogen synthesis in hepatocytes,and VAT was more pronounced than SAT;2.Exenatide could positively regulatesthe glucose uptake rate and the glycogen synthesis inhibited by adipose tissue,providing a theoretical basis for exenatide treatment of T2 DM.3.Insulin could improve the glucose uptake rate and the glycogen synthesis in hepatocytes induced by adipose tissue in different locations.