In vitro modulation of epithelial barrier mediated by tight junctions in cell lines: effect of exposure to glucose, palmitic acid, insulin and gut microbiota of prediabetic animals

• Grant number: 13/16662-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2013
• End date: September 30, 2015
• Field of knowledge: Biological Sciences - Morphology - Histology
• Principal Investigator: Carla Beatriz Collares Buzato
• Grantee: Leandro Pereira Canuto
• Host Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

Tight Junction (TJ) plays an essential role as a diffusion barrier through the paracellular pathway in intestinal epithelia, limiting the entry of toxins and harmful bacteria into the organism. Recent evidence has pointed out a possible link between intestinal barrier disruption and the pathogenesis of obesity-associated type 2 diabetes mellitus (T2DM). Nevertheless, the mechanisms underlying this process are unknown. The general objectives of the present project are 1) to investigate the direct effect of components found at high concentrations within a high fat-containing diet (glucose and palmitic acid) or those that can be increased/altered in the prediabetic state (glucose, palmitic acid, insulin, and gut microbiota) on the epithelial barrier function of epithelial cell lines; and 2) to study the intracellular mechanisms involved in the putative tight junction disruption at these experimental conditions. For that, we will use two established epithelial cell lines, namely Caco-2 (human colon adenocarcinoma cells) and MDCK (canine renal tubular cells). To assess the epithelial barrier function, we will employ electrophysiological and biochemical methods (measurement of transepithelial electrical resistance and transepithelial flux of extracellular markers) as well as immunocytochemistry (to see the cellular distribution of some TJ-associated proteins, such as claudins, occludin, and ZO-1) and Western Blot (to analyze the cellular content of TJ proteins). (AU)