动物实验,RNA,胰岛素 z-bo 2020-08-22 576

　　OBJECTIVE: To observe the changes in the first-phase insulin secretion of pancreatic islets in db/db mice after blocking the expression of local angiotensin II type 1 receptor (AT1R) by RNA interference technology and explore its underlying mechanism.

　　Methods: Isolate islets from db/db and db/m mice and detect the expression of AT1R mRNA and protein. Construction of RNA interference recombinant adenovirus (Ad-siAT1R) targeting mouse AT1R gene and recombinant adenovirus containing control sequence (Ad-siControl). The isolated and cultured db/db mouse pancreatic islet cells were divided into three groups: Ad-siAT1R infection group, Ad-siControl infection group, and blank control group. After adenovirus infection, pancreatic islet cells were cultured for 72 h. The expression of AT1R, GLUT-2 and glucokinase (GCK) in each group was detected, and the dynamic secretion of insulin was detected by the islet perfusion system.

　　Results: The expression levels of AT1R mRNA and protein in the pancreatic islets of db/db mice were about 2 times higher than those of the pancreatic islets of db/m mice (P<0.05). After adenovirus infection, compared with Ad-siControl group, the expression level of pancreatic islet AT1R mRNA in the Ad-siAT1R group decreased by 75%, and the protein expression level decreased by 65%, while the expression levels of GLUT-2 and GCK increased by 190% and 121% respectively (both P< 0.05). Islet perfusion showed that the first phase of insulin secretion in the blank control group and the Ad-siControl group decreased significantly, which was only 1.8 times the basal level; while the Ad-siAT1R group reached the highest peak 1~2 min after high glucose load. mU/L, which is 2.8 times the basal level, indicates that the first phase insulin secretion is significantly improved.

　　Conclusion: RNA interference can specifically block the local AT1R expression of pancreatic islets can up-regulate the expression of GLUT-2 and GCK, and restore the first-phase insulin secretion. This may be one of the mechanisms by which AT1R blockers improve the secretion of pancreatic islets.