title: Interendothelial claudin-5 expression depends on cerebral endothelial cell-matrix adhesion by β(1)-integrins.
abstract: The hypothesis tested by these studies states that in addition to interendothelial cell tight junction proteins, matrix adhesion by β(1)-integrin receptors expressed by endothelial cells have an important role in maintaining the cerebral microvessel permeability barrier. Primary brain endothelial cells from C57 BL/6 mice were incubated with β(1)-integrin function-blocking antibody (Ha2/5) or isotype control and the impacts on claudin-5 expression and microvessel permeability were quantified. Both flow cytometry and immunofluorescence studies demonstrated that the interendothelial claudin-5 expression by confluent endothelial cells was significantly decreased in a time-dependent manner by Ha2/5 exposure relative to isotype. Furthermore, to assess the barrier properties, transendothelial electrical resistance and permeability measurements of the monolayer, and stereotaxic injection into the striatum of mice were performed. Ha2/5 incubation reduced the resistance of endothelial cell monolayers significantly, and significantly increased permeability to 40 and 150  kDa dextrans. Ha2/5 injection into mouse striatum produced significantly greater IgG extravasation than the isotype or the control injections. This study demonstrates that blockade of β(1)-integrin function changes interendothelial claudin-5 expression and increases microvessel permeability. Hence, endothelial cell-matrix interactions via β(1)-integrin directly affect interendothelial cell tight junction claudin-5 expression and brain microvascular permeability.
authors.affiliation: Division of Hematology, Department of Medicine, University of Washington School of Medicine, Seattle, Washington 98104, USA.
authors.forename: Takashi
authors.initials: T
authors.lastname: Osada
authors.forename: Yu-Huan
authors.initials: YH
authors.lastname: Gu
authors.forename: Masato
authors.initials: M
authors.lastname: Kanazawa
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Tsubota
authors.forename: Brian T
authors.initials: BT
authors.lastname: Hawkins
authors.forename: Maria
authors.initials: M
authors.lastname: Spatz
authors.forename: Richard
authors.initials: R
authors.lastname: Milner
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: del Zoppo
mesh_terms: D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D002199:Capillary Permeability / Q000187:drug effects / Q000502:physiology; D002448:Cell Adhesion / Q000502:physiology; D002478:Cells, Cultured; D062507:Claudin-5; D003342:Corpus Striatum / Q000098:blood supply / Q000378:metabolism; D004727:Endothelium / Q000166:cytology / Q000378:metabolism*; D005109:Extracellular Matrix / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D019012:Integrin beta1 / Q000378:metabolism*; D008565:Membrane Proteins / Q000096:biosynthesis*; D051379:Mice; D019108:Tight Junctions / Q000378:metabolism*
chemical_list: D000906:Antibodies; D062507:Claudin-5; C491511:Cldn5 protein, mouse; D019012:Integrin beta1; D008565:Membrane Proteins