An Experimental Study Of The Protective Effect Of Human Amniotic Membrane Extract Against Hypoxic Injury Of Pancreatic Islet In Mice And Its Molecular Mechanism

Objective: To explore the protective effect of human amniotic membrane extract against islet hypoxic injury using the islet transplantation model.Methods: Mouse models of primary pancreatic islet hypoxia were established,and were divided into hypoxia incubation group,hypoxia +human amniotic membrane extract treatment group and normal oxygen incubation group.After 12 hours of in vitro incubation before transplantation,acridine orange(AO)and ethidium bromide(EB)staining were used to evaluate the activity of islets;Glucose stimulated insulin secretion was used to monitor islet insulin secretion;To explore the mechanism of human amniotic membrane extract to protect islets,Western blot method was used to detect the expression of related proteins Nrf2 and HO-1.The model of type 1 diabetes was induced by an intraperitoneal injection of streptozotocin(STZ),the islets cultured in vitro were transplanted to observe the recipient’s blood glucose,body weight,glucose tolerance and pathology of the graft after transplantation.Software Graph-Pad Prism 6 was used to analyze the experimental data.P<0.05 indicated that the difference was statistically significant.All experiments were performed at least 3 times.Results: Hypoxia significantly reduced the activity of pancreatic islets and insulin secretion function,while human amniotic membrane extract could significantly improve the activity of pancreatic islets and insulin secretion function under hypoxic stress,the difference was statistically significant(P<0.05).Compared with the hypoxia culture group,the expression level of Nrf2/HO-1 in the islet cells in the hypoxia + human amniotic membrane extract treatment group was significantly increased(P<0.05).At the same time,in the normal oxygen culture group with human amniotic membrane extract,the islets The expression level of Nrf2/HO-1 in the cell also increased.The addition of human amniotic membrane extract(hAME)to culture hypoxic pancreatic islets and transplantation has a better regulatory effect on abnormal blood sugar in diabetic mice,while increasing the weight of the recipient and improving the glucose tolerance of the recipient.The difference was statistically significant(P<0.05)).Conclusion: Human amniotic membrane extract can protect the activity and secretory function of mouse islets under hypoxic conditions,and up-regulate the expression level of Nrf2/HO-1 in islet cells to resist oxidative stress caused by hypoxia and improve the effect of islet transplantation.