Related Experiment Video
Updated: Aug 24, 2026

Sensing of Barrier Tissue Disruption with an Organic Electrochemical Transistor
Published on: February 10, 2014
Glutamine regulates Caco-2 cell tight junction proteins
Nan Li1, Patricia Lewis, Don Samuelson
1Division of Neonatology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida 32610, USA.
Abstract:
Intestinal epithelial tight junction (TJ) barrier dysfunction may lead to inflammation and mucosal injury. Glutamine (GLN) plays a role in maintenance of intestinal barrier function in various animal models and critically ill humans. Recent evidence from intestinal cell monolayers indicates that GLN maintains transepithelial resistance and decreases permeability. The mechanisms of these effects remain undefined. We hypothesized that GLN affects proteins involved in the intercellular junctional complex. GLN availability was controlled in Caco-2 monolayers by addition to the medium and treatment with methionine sulfoximine (MSO) to inhibit glutamine synthetase (GS). Expression of TJ proteins, claudin-1, occludin, and zonula occluden (ZO)-1 was measured by immunoblotting. Localization of TJ proteins was evaluated by immunofluorescence light microscopy. Structure of TJ was determined by transmission electron microscopy (TEM). Deprivation of GLN decreased claudin-1, occludin, and ZO-1 protein expression and caused a disappearance of perijunctional claudin-1 and a reduction of occludin but had no effect on ZO-1. TEM revealed that MSO-treated cells in the absence of GLN formed irregular junctional complexes between the apical lateral margins of adjoining cells. These findings indicate that TJ protein expression and cellular localization in Caco-2 cell monolayers rely on GLN. This mechanism may similarly relate to GLN-mediated modulation of intestinal barrier function in stressed animals and humans.
More Related Videos
09:22The Cell-based L-Glutathione Protection Assays to Study Endocytosis and Recycling of Plasma Membrane Proteins
Published on: December 13, 2013
06:43Functional Assessment of Intestinal Tight Junction Barrier and Ion Permeability in Native Tissue by Ussing Chamber Technique
Published on: May 26, 2021
Related Concept Videos
Tight Junctions
Overview of Cell-Cell Junctions
Occluding or Tight Junctions
Tight...
Glucose Absorption Into the Small Intestine
Transcellular Transport of Solutes
Ligand-Gated Ion Channel Receptor: Gating Mechanism
Adherens Junctions
Adherens Junctions are Dynamic
The endothelial cells...