title: Cloning and characterization of the murine claudin-5 promoter.
abstract: Claudin-5, an integral tight junction protein component, plays a critical role in permeability of the endothelial cell barrier. Recently, we have shown that claudin-5 protein is down-regulated by the proinflammatory cytokine TNF alpha and its levels restored by dexamethasone treatment. In order to investigate the regulation of claudin-5 at the transcriptional level, we have cloned the murine claudin-5 promoter. The claudin-5 promoter sequence (1131 bp) showed no consensus TATA-box. We identified putative transcription factor binding sites, including six full and two half sites degenerated glucocorticoid-response elements (GREs), two NFkappaB, three Sp1, one Sp2, one Ap2, as well as three E-boxes. Serially deleted promoter constructs showed high basal activity. TNF alpha significantly reduced the promoter activity and mRNA levels of claudin-5 in brain cEND and myocardial MyEND endothelial cells. Dexamethasone treatment led to a significant increase of the murine claudin-5 promoter activity and mRNA levels in cEND cells. However, no claudin-5 induction could be observed in MyEND cells in response to dexamethasone. Our studies suggest tissue-specific regulation of the claudin-5 gene via glucocorticoids and a high vulnerability of claudin-5 to TNF alpha. This could be an important mechanism in diseases accompanied by the release of proinflammatory cytokines, for example in patients with chronic heart failure or multiple sclerosis.
authors.affiliation: University of Würzburg, Institute of Anatomy and Cell Biology, Würzburg, Germany.
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Burek
authors.forename: Carola Y
authors.initials: CY
authors.lastname: Förster
mesh_terms: D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D062507:Claudin-5; D003001:Cloning, Molecular; D003907:Dexamethasone / Q000494:pharmacology; D017353:Gene Deletion; D017930:Genes, Reporter / Q000187:drug effects; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics*; D051379:Mice / Q000235:genetics*; D008969:Molecular Sequence Data; D009928:Organ Specificity / Q000187:drug effects / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000187:drug effects / Q000502:physiology; D014018:Tissue Distribution / Q000187:drug effects; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D062507:Claudin-5; C491511:Cldn5 protein, mouse; D008565:Membrane Proteins; D014409:Tumor Necrosis Factor-alpha; D003907:Dexamethasone