Diseases and disorders Abstract Pivotal to brain development and function is an intact blood-brain barrier BBBwhich acts as a gatekeeper to control the passage and exchange of molecules and nutrients between the circulatory system and the brain parenchyma. We report that germ-free micebeginning with intrauterine life, displayed increased BBB permeability compared to pathogen-free mice with a normal gut flora. The increased BBB permeability was maintained in germ-free mice after birth and during adulthood and was associated with reduced expression of the tight junction proteins occludin and claudin-5, which are known to regulate barrier function in endothelial tissues.
Bile salts disrupt human esophageal squamous epithelial barrier function by modulating tight junction proteins Reflux of acid and bile acids contributes to epithelial tissue injury in gastro-esophageal reflux disease.
However, the influence of refluxed material on human esophageal stratified epithelial barrier function and tight junction TJ However, the influence of refluxed material on human esophageal stratified epithelial barrier function and tight junction TJ proteins has not been fully elucidated. Here, we investigated the influence of acid and bile acids on barrier function and TJ protein distribution using a newly developed air-liquid interface ALI in vitro culture model of stratified squamous epithelium based on primary human esophageal epithelial cells HEECs.
The epithelial layers formed TJ, and the presence of claudin-1, claudin-4, and occludin were detected by immunofluorescent staining. We found that deoxycholic acid pH 7. Based on these findings, ALI-cultured HEECs represent a new in vitro model of human esophageal stratified epithelium and are suitable for studying esophageal epithelial barrier functions.
Using this model, we demonstrated that acid, bile acids, and pepsin disrupt squamous epithelial barrier function partly by modulating TJ proteins. These results provide new insights into understanding the role of TJ proteins in esophagitis.Occludin is a tetraspan integral membrane protein in epithelial and endothelial tight junction (TJ) structures that is projected to have two extracellular loops.
Molecular Regulation of Endothelial Cell Tight Junctions Fig. 1. Proposed interactions between claudins at the tight junction. The claudin proteins. In conclusion, the interaction between pericytes and endothelial cells can regulate the formation of tight junctions in hyaloid vessels devoid of astrocytes.
We demonstrate the expression of tight junction proteins, ZO-1 and occludin, in hyaloid vessels during the early postnatal periods. A Transmembrane Tight Junction Protein Selectively Expressed on Endothelial Cells and Platelets* Received for publication, December 17, , and in revised form, January 24, Here we demonstrate that progressive inflammatory demyelination in cerebral adrenoleukodystrophy coincides with blood–brain barrier dysfunction, increased MMP9 expression, and changes in endothelial tight junction proteins as well as adhesion molecules.
The tight junctions between endothelial cells are responsible for the barrier function.
Occludin was the first integral membrane protein found to be exclusively localized within the tight junctions.