title: Zyxin modulates the transmigration of Haemophilus influenzae to the central nervous system.
abstract: The mechanism by which Haemophilus influenzae causes meningitis is unclear. Previously, we established murine meningitis by intranasal instillation of H. influenzae as a cell-bound organism (CBO). In this study, we aimed to identify the molecules associated with inhibiting the transmigration of cells across the blood-brain barrier (BBB). Two-dimensional difference gel electrophoresis and protein identification by mass spectrometry were used for proteomic analysis. Analysis of the membranous extract from a tumor necrosis factor (TNF)-α-treated human brain microvascular endothelial cell (HBMEC) monolayer revealed 41 differentially expressed proteins. Zyxin, which is thought to be essential for tight cell-to-cell junctions, decreased 1.8-fold in TNF-α-treated HBMECs. In addition, zyxin transcript levels decreased 1.5-fold in cells derived from TNF-α-treated HBMECs. Intranasal instillation of CBOs in zyxin-deficient mice resulted in a significant higher mortality rate than in wild-type mice. Transmigration of CBOs across a HBMEC monolayer pretreated with TNF-α (1 ng/mL), interleukin (IL)-1β (10 ng/mL), or lipopolysaccharide (LPS; 10 ng/mL) was assayed by counting CBOs that migrated from an upper chamber into a lower chamber. HBMEC pretreated with TNF-α exhibited significantly greater migration (P<0.01) than did control cells or cells treated with IL-1β or LPS. Our findings highlight that zyxin is an important protein protecting the tight junction of the BBB against cell transmigration across the BBB. Finally, TNF-α produced in respiratory infection when the primary infection reached the BBB caused decreased zyxin levels in BBB cell membranes. Furthermore, H. influenzae reaching the BBB as CBOs could transmigrate into cerebrospinal fluid across the zyxin-decreased BBB.
authors.affiliation: Department of Endocrinology and Metabolism; Yokohama City University School of Medicine; Yokohama, Kanagawa, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Miyazaki
authors.affiliation: Division of Microbiology and Immunology; Center for Advanced Research; Graduate School of Medical Sciences; Toho University; Ota, Tokyo, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Yusa
authors.affiliation: Laboratory of Toxicology; Course of Veterinary Science; Graduate School of Life and Environmental Biosciences; Osaka Prefecture University; Izumisano, Osaka, Japan.
authors.forename: Saburo
authors.initials: S
authors.lastname: Matsuo
authors.affiliation: Department of Endocrinology and Metabolism; Yokohama City University School of Medicine; Yokohama, Kanagawa, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Terauchi
authors.affiliation: Division of Microbiology and Immunology; Center for Advanced Research; Graduate School of Medical Sciences; Toho University; Ota, Tokyo, Japan.
authors.forename: Shuichi
authors.initials: S
authors.lastname: Miyazaki
mesh_terms: D000818:Animals; D001812:Blood-Brain Barrier / Q000382:microbiology*; D002478:Cells, Cultured; D002490:Central Nervous System / Q000382:microbiology*; D004195:Disease Models, Animal; D015180:Electrophoresis, Gel, Two-Dimensional; D042783:Endothelial Cells / Q000737:chemistry / Q000187:drug effects; D020869:Gene Expression Profiling; D006193:Haemophilus influenzae / Q000502:physiology*; D054884:Host-Pathogen Interactions; D006801:Humans; D013058:Mass Spectrometry; D008583:Meningitis, Haemophilus / Q000382:microbiology*; D018345:Mice, Knockout; D020543:Proteome / Q000032:analysis; D016019:Survival Analysis; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology; D060589:Zyxin / Q000378:metabolism*
chemical_list: D020543:Proteome; D014409:Tumor Necrosis Factor-alpha; C498285:Zyx protein, mouse; D060589:Zyxin
keywords: TNF-α; blood-brain barrier; cell-bound organism; intracellular parasite; meningitis; secondary infection; zyxin