Related Experiment Video

Updated: Dec 5, 2025

Functional Assessment of Intestinal Tight Junction Barrier and Ion Permeability in Native Tissue by Ussing Chamber Technique

Functional Assessment of Intestinal Tight Junction Barrier and Ion Permeability in Native Tissue by Ussing Chamber Technique

Published on: May 26, 2021

Claudin-18 Loss Alters Transcellular Chloride Flux but not Tight Junction Ion Selectivity in Gastric Epithelial Cells

Tyler J Caron¹, Kathleen E Scott¹, Nishita Sinha²

¹Department of Surgery/Division of General Surgery, Beth Israel Deaconess Medical Center, Boston, Massachusetts; Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts.

Cellular and Molecular Gastroenterology and Hepatology

|October 18, 2020

Abstract

Background & Aims:

Tight junctions form a barrier to the paracellular passage of luminal antigens. Although most tight junction proteins reside within the apical tight junction complex, claudin-18 localizes mainly to the basolateral membrane where its contribution to paracellular ion transport is undefined. Claudin-18 loss in mice results in gastric neoplasia development and tumorigenesis that may or may not be due to tight junction dysfunction. The aim here was to investigate paracellular permeability defects in stomach mucosa from claudin-18 knockout (Cldn18-KO) mice.

Methods:

Stomach tissue from wild-type, heterozygous, or Cldn18-KO mice were stripped of the external muscle layer and mounted in Ussing chambers. Transepithelial resistance, dextran 4 kDa flux, and potential difference (PD) were calculated from the chambered tissues after identifying differences in tissue histopathology that were used to normalize these measurements. Marker expression for claudins and ion transporters were investigated by transcriptomic and immunostaining analysis.

Results:

No paracellular permeability defects were evident in stomach mucosa from Cldn18-KO mice. RNAseq identified changes in 4 claudins from Cldn18-KO mice, particularly the up-regulation of claudin-2. Although claudin-2 localized to tight junctions in cells at the base of gastric glands, its presence did not contribute overall to mucosal permeability. Stomach tissue from Cldn18-KO mice also had no PD versus a lumen-negative PD in tissues from wild-type mice. This difference resulted from changes in transcellular Cl^- permeability with the down-regulation of Cl^- loading and Cl^- secreting anion transporters.

Conclusions:

Our findings suggest that Cldn18-KO has no effect on tight junction permeability in the stomach from adult mice but rather affects anion permeability. The phenotype in these mice may thus be secondary to transcellular anion transporter expression/function in the absence of claudin-18.

Keywords:

Claudin-2 Gastric Cancer Genomic Profile Paracellular Permeability RNAseq Ussing Chambers

More Related Videos

Sensing of Barrier Tissue Disruption with an Organic Electrochemical Transistor

Sensing of Barrier Tissue Disruption with an Organic Electrochemical Transistor

Published on: February 10, 2014

A Fluorescence-Based Assay of Membrane Potential for High-Throughput Functional Study of Two Endogenous Ion Channels in Two Epithelial Cell Lines

A Fluorescence-Based Assay of Membrane Potential for High-Throughput Functional Study of Two Endogenous Ion Channels in Two Epithelial Cell Lines

Published on: June 22, 2022

Related Concept Videos

Tight Junctions

Tight Junctions

Tight junctions are molecular seals between cells that prevent the leaking of fluids, ions, and other small solutes across cavities and compartments in multicellular organisms. They are mainly composed of claudin and occludin transmembrane proteins, and other proteins such as tricellulin and JAM (junctional adhesion molecule). All these proteins are 4-pass transmembrane proteins, except JAM, which is a single-pass transmembrane protein belonging to the immunoglobulin superfamily. The...

Mucosal Barrier of the Stomach

Mucosal Barrier of the Stomach

The gastric glands contain parietal cells that secrete hydrochloric acid (HCl) for digestion. The cells secrete HCl because it is highly corrosive and essential for breaking down food. To achieve this, they secrete hydrogen and chloride ions into the lumen of the gastric glands, which combine to form HCl.
Within parietal cells, carbonic acid is first formed through the reaction of water and carbon dioxide. The dissociation of carbonic acid releases bicarbonate and hydrogen ions. The bicarbonate...

Transcellular Transport of Solutes

Transcellular Transport of Solutes

Transcellular transport of solutes is the movement of substances like monosaccharides and amino acids through polarized cells. This transport mechanism is primarily seen in epithelial and endothelial cells aided by membrane transport proteins such as channels and transporters. The tight junctions between these cells confine the membrane proteins to the two sides of the cell. The epithelial cells have distinct apical and basolateral domains. In contrast, the endothelial cells show the luminal...

Glucose Absorption Into the Small Intestine

Glucose Absorption Into the Small Intestine

Complex carbohydrates consumed cannot be absorbed into the small intestine in their original form. First, they must be hydrolyzed to a monosaccharide form such as glucose or galactose. These monosaccharides are then transported across the intestinal membrane and into the blood via transcellular transport. The intestinal epithelial cells allow the movement of these monosaccharides with a defined 'entry' through membrane transporter proteins present on their apical membrane and...

Stomach pH Regulation

Stomach pH Regulation

The human body carefully regulates the internal pH of different organs to maintain homeostasis. For example, while the blood plasma maintains a neutral pH of 7, the stomach lumen has an acidic pH of 1.5 - 3.5. The low pH of stomach lumen helps kill pathogens in the food and break down complex food molecules.
The acid-secreting gastric mucosal epithelial cells (parietal cells) lining the stomach lumen maintain the low pH in the lumen. Numerous ion transporters and channels on these parietal...

Patch Clamp

Patch Clamp

Many fundamental cell functions such as muscle contraction and nerve transmission rely on the electrical signals produced by the movement of positively and negatively charged ions across the cell membrane. One competent method to record current flowing across the whole cell or single ion channel is the patch-clamp technique.
In this method, a glass micropipette containing electrolyte solution is tightly sealed against a small portion of the cell membrane. As a result, a patch of the cell...

Articles linked to this work by shared authors, journal, and citation graph.

TagR, a newly identified member of the MarR family of transcriptional regulators, represses the NRPS operon in Klebsiella oxytoca.

Microbiology spectrum·2026

Microbial induction of MHC-II expression in colon cancer cells overcomes immunotherapy resistance and limits metastasis.

bioRxiv : the preprint server for biology·2026

Clinical Management of Helicobacter Infection in Captive Baboons (Papio anubis and Papio hamadryas), and Isolation and Molecular Characterization of Three Novel Helicobacter Species.

Journal of medical primatology·2026

The Quorum-Sensing Regulator SdiA Activates npsA Expression and Modulates Cytotoxicity in Klebsiella oxytoca.

Microorganisms·2026

Whole genome sequences of novel Staphylococcus epidermidis, Streptococcus salivarius, and Streptococcus anginosus strains isolated from human gastric biopsy tissue.

Microbiology resource announcements·2026

Implementation of a hybrid lung health program for Northeast Texas: study protocol.

Implementation science communications·2026

See all related articles