title: Oxidative stress induces gastric epithelial permeability through claudin-3.
abstract: Although reactive oxygen species have been implicated as mediators of gastrointestinal injury, their influence on the function of gastric epithelial tight junctions (TJs), which create a paracellular permeability barrier, needs to be fully investigated. H2O2 exposure to MKN28 gastric epithelial monolayers caused a significant decrease in trans-epithelial electrical resistance (TEER) and a significant increase in dextran permeability. Oxidant-mediated gastric epithelial permeability was significantly attenuated by a radical scavenger, rebamipide. H2O2 decreased the amount of claudin-3 protein but not claudin-4, -7, and JAM-A. Rebamipide significantly attenuated H2O2-induced decrease in claudin-3 protein. Small interfering RNA (siRNA) against claudin-3 treatment specifically decreased claudin-3 as seen by immunoblotting and immunofluorescent staining. Gastric TEER was significantly decreased with the treatment of siRNA against claudin-3. This is the first study to demonstrate that claudin-3 is involved in the barrier function of gastric epithelial cells and that rebamipide abolishes the H2O2-induced decrease in claudin-3 protein.
authors.affiliation: Division of Upper Gastroenterology, Department of Internal Medicine, Hyogo College of Medicine, 1-1 Mukogawa, Nishinomiya, Hyogo 663-8501, Japan.
authors.forename: Kayo
authors.initials: K
authors.lastname: Hashimoto
authors.forename: Tadayuki
authors.initials: T
authors.lastname: Oshima
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Tomita
authors.forename: Yongmin
authors.initials: Y
authors.lastname: Kim
authors.forename: Takayuki
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Takashi
authors.initials: T
authors.lastname: Joh
authors.forename: Hiroto
authors.initials: H
authors.lastname: Miwa
mesh_terms: D000409:Alanine / Q000031:analogs & derivatives / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology; D045744:Cell Line, Tumor; D062465:Claudin-3; D062506:Claudin-4; D005753:Gastric Mucosa / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D018384:Oxidative Stress; D010539:Permeability / Q000187:drug effects; D015363:Quinolones / Q000494:pharmacology; D034741:RNA, Small Interfering / Q000235:genetics; D019108:Tight Junctions / Q000187:drug effects / Q000378:metabolism*
chemical_list: D000975:Antioxidants; C568122:CLDN3 protein, human; C568157:CLDN4 protein, human; D062465:Claudin-3; D062506:Claudin-4; D008565:Membrane Proteins; D015363:Quinolones; D034741:RNA, Small Interfering; D006861:Hydrogen Peroxide; C052785:rebamipide; D000409:Alanine