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Updated: Jun 1, 2026
11:17
Sensing of Barrier Tissue Disruption with an Organic Electrochemical Transistor
Published on: February 10, 2014
Acidic bile salts modulate the squamous epithelial barrier function by modulating tight junction proteins.
Xin Chen1, Tadayuki Oshima, Toshihiko Tomita
1Division of Upper Gastroenterology, Department of Internal Medicine, Hyogo College of Medicine, Nishinomiya, Japan.
Summary
Acidic bile salts, like taurocholic acid (TCA) and glycocholic acid (GCA), disrupt the esophageal epithelial barrier by affecting tight junction proteins. This study reveals how these conditions impact barrier integrity and offers insights into esophagitis.
Area of Science:
- Gastroenterology
- Cell Biology
- Epithelial Biology
Background:
- Developing accurate in vitro models for esophageal epithelium is challenging due to poor differentiation or complex culture systems.
- An air-liquid interface model using human bronchial epithelial cells mimics esophageal squamous epithelial layers.
- Understanding the impact of bile acids on esophageal barrier function is crucial for studying conditions like esophagitis.
Purpose of the Study:
- To investigate the effects of bile acids on esophageal epithelial barrier function and tight junction (TJ) proteins.
- To determine how different pH levels and pepsin influence bile acid-induced barrier disruption.
- To elucidate the role of specific TJ proteins, claudin-1 and claudin-4, in esophageal barrier integrity.
Main Methods:
- Utilized an air-liquid interface culture system of human bronchial epithelial cells.
- Treated cells with taurocholic acid (TCA), glycocholic acid (GCA), deoxycholic acid (DCA), or pepsin at various pH conditions.
- Assessed barrier function via transepithelial electrical resistance (TEER) and paracellular permeability assays.
- Examined TJ protein expression (claudin-1, claudin-4) using Western blotting on soluble and insoluble cell fractions.
Main Results:
- Acidic conditions (pH 3) significantly impaired barrier function when cells were exposed to TCA or GCA, indicated by decreased TEER and increased permeability.
- Deoxycholic acid (DCA) disrupted the barrier at pH 6.
- TCA and GCA at pH 3 reduced the insoluble fractions of claudin-1 and claudin-4, suggesting modulation of TJ protein localization.
- Pepsin had no significant effect on barrier function under the tested conditions.
Conclusions:
- Acidic bile salts disrupt esophageal squamous epithelial barrier function.
- The disruption is partly mediated by alterations in claudin-1 and claudin-4 protein levels.
- These findings provide valuable insights into the mechanisms underlying esophagitis and the role of TJ proteins.
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