Duodenal-Jejunal Bypass Ameliorates Type 2 Diabetes Mellitus by Activating Insulin Signaling and Improving Glucose Utilization in the Brain

Abstract

Background: Duodenal-jejunal bypass (DJB) can dramatically improve type 2 diabetes independent of weight loss and food restriction. Increasing evidence has demonstrated that brain insulin signaling plays an important role in the pathophysiology of type 2 diabetes. This study explores whether the antidiabetic effect of DJB is involved in brain insulin signaling activation and brain glucose utilization.

Methods: A diabetic rat model was established by high-fat and high-glucose diet. DJB or sham surgery was performed in diabetic rats. 18F-FDG PET scanning was used to detect glucose uptake in different organs, particularly in the brain. The levels of glucose transporters, glucose utilization-related proteins (HK1 and PFK2), insulin, and insulin signaling pathway-related proteins (InsR, IRS1/2, PI3K, and p-Akt) in the brain tissues were evaluated and analyzed.

Results: The results showed that DJB significantly improved basal glycemic parameters and reversed the decreasing glucose uptake in the brains of type 2 diabetic rats. DJB significantly increased not only the expression levels of brain insulin, IRS1/2, PI3K, and p-Akt but also the levels of the glucose utilization enzymes HK1 and PFK2 in the brain.

Conclusion: These results indicate that enhanced brain insulin signaling transduction and brain glucose utilization play important roles in the antidiabetic effect of DJB.

Keywords: Brain glucose metabolism; Brain insulin signaling; Diabetic neuropathy; Metabolic surgery.