Protective roles of liraglutide against brain injury of streptozotocin induced diabetic rats.

Our study aimed to explore the impacts of liraglutide on brain dysfunction of type 2 diabetes mellitus. Rats in liraglutide treatment group were diabetic rats further received daily intraperitoneal administration of liraglutide for continuous 6 weeks. Body weight and blood glucose were measured weekly. Vascular structure changes in brain tissues were evaluated by Periodic acid-Schiff (PAS) staining. Angiopoietin-2 (ANG-2), high-mobility group box 1 (HMGB-1), CD105, NeuN, Oligo-2 in brain tissues were measured by immunohistochemistry staining and ANG-2, HMGB-1, and matrix metalloproteinase-9 (MMP-9) were detected by western blotting. Blood glucose levels of rats in diabetic model group were significantly elevated and blood glucose levels of rats in liraglutide treatment group were reduced to comparable levels with control group. PAS staining showed vascular basement membrane of rats in the diabetic model group was thicker than that of the control group. ANG-2, HMGB1 and MMP-9 were up-regulated in the diabetic model group comparing the control group, while down-regulated after treated with liraglutide (p<0.05). NeuN expressions were significantly higher in liraglutide treatment group. Liraglutide may have protective roles against brain injury of streptozotocin induced diabetic rats by inhibiting HMGB1, which further suppressing the MMP-9 and ANG-2.