title: Hydrogen peroxide-induced alterations of tight junction proteins in bovine brain microvascular endothelial cells.
abstract: Occludin and zonular occludens (ZO)-1 in tight junctions (TJs) and actin play an important role in maintaining blood-brain barrier (BBB) endothelial ion and solute barriers. Malfunction of BBB by reactive oxygen species (ROS) has been attributed to the disruption of TJs. This study examined H2O2 effects on changes of paracellular permeability, actin, and TJ proteins (occludin and ZO-1) using primary culture of bovine brain microvessel endothelial cells. The BBB permeability, measured as transendothelial electrical resistance (TER), decreased in a dose- and time-dependent manner when treated with H2O2. Cytotoxicity test revealed that H2O2 did not cause cell death at 0.01, 0.1, and 1.0 mM H2O2. H2O2 caused increased protein expression of occludin (1.17- to 1.29-fold) and actin (1.2- to 1.3-fold). ZO-1 maintained steady state levels of expression. H2O2 caused rearrangement of occludin and ZO-1 at tight junctions and formation of actin stress fiber. Although ZO-1 did not show significant change in protein expression, permeability changes shown in the current study correlate with alterations in expression and localization of occludin, actin, and ZO-1. These data suggest that H2O2 induces increased paracellular permeability of BBB that is accompanied with redistribution of occludin and ZO-1 and increased protein expression of occludin and actin.
authors.affiliation: Department of Anatomy, College of Medicine, Chung-Ang University, South Korea.
authors.forename: Hee-Sang
authors.initials: HS
authors.lastname: Lee
authors.forename: Kee
authors.initials: K
authors.lastname: Namkoong
authors.forename: Dong-Hwa
authors.initials: DH
authors.lastname: Kim
authors.forename: Ki-Jeong
authors.initials: KJ
authors.lastname: Kim
authors.forename: Yoon-Hee
authors.initials: YH
authors.lastname: Cheong
authors.forename: Sung-Su
authors.initials: SS
authors.lastname: Kim
authors.forename: Won-Bok
authors.initials: WB
authors.lastname: Lee
authors.forename: Kyung-Yong
authors.initials: KY
authors.lastname: Kim
mesh_terms: D000818:Animals; D001812:Blood-Brain Barrier; D015153:Blotting, Western; D001921:Brain / Q000166:cytology*; D002417:Cattle; D002470:Cell Survival; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000166:cytology; D004730:Endothelium, Vascular / Q000166:cytology*; D006861:Hydrogen Peroxide / Q000737:chemistry / Q000494:pharmacology*; D008565:Membrane Proteins / Q000737:chemistry; D008833:Microcirculation; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D062793:Occludin; D017382:Reactive Oxygen Species; D019108:Tight Junctions; D013997:Time Factors
chemical_list: D008565:Membrane Proteins; D062793:Occludin; D017382:Reactive Oxygen Species; D006861:Hydrogen Peroxide