title: TNF-alpha induced NFκB signaling and p65 (RelA) overexpression repress Cldn5 promoter in mouse brain endothelial cells.
abstract: Inflammatory cytokine TNFα enhances permeability of brain capillaries constituting blood brain barrier (BBB). In the monoculture endothelial models of BBB TNFα alters tight junction (TJ) structure and protein content. Claudin-5 (Cldn5) is a key TJ protein whose expression in the brain endothelial cells is critical to the function of BBB. TNFα reduces Cldn5 promoter activity and mRNA expression in mouse brain derived endothelial cells but the regulatory elements and signaling mechanism involved are not defined. Here we report that TNFα acts through NFκB signaling and requires a conserved promoter region for the down-regulation of Cldn5 expression. Overexpression of the NFκB subunit p65 (RelA) alone repressed Cldn5 promoter activity in mouse brain endothelial cells. We observed partial loss of Cldn5 protein expression after prolonged TNFα treatment in primary endothelial culture isolated from C56BL/6 mice brain. Taken together, our results confirm and extend previous observations of TNFα induced down-regulation of Cldn5 expression in mouse brain endothelial cells.
authors.affiliation: Department of Neurology, Klinikum rechts der Isar, Technische Universität München, 81675 München, Germany.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Aslam
authors.forename: Nafees
authors.initials: N
authors.lastname: Ahmad
authors.forename: Rajneesh
authors.initials: R
authors.lastname: Srivastava
authors.forename: Bernhard
authors.initials: B
authors.lastname: Hemmer
mesh_terms: D024506:5' Flanking Region / Q000235:genetics; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000166:cytology*; D062507:Claudin-5; D057167:Claudins / Q000235:genetics*; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects; D051379:Mice; D008810:Mice, Inbred C57BL; D055806:Microvessels / Q000166:cytology; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects* / Q000235:genetics; D051996:Transcription Factor RelA / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D062507:Claudin-5; D057167:Claudins; C491511:Cldn5 protein, mouse; D012333:RNA, Messenger; D051996:Transcription Factor RelA; D014409:Tumor Necrosis Factor-alpha