1. SOX-18 controls endothelial-specific claudin-5 gene expression and barrier function
- Author
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Ruud D. Fontijn, Joost O. Fledderus, Anton J.G. Horrevoets, Arie Reijerkerk, Helga E. de Vries, Oscar L. Volger, Medical Biochemistry, ACS - Amsterdam Cardiovascular Sciences, Molecular cell biology and Immunology, Neuroscience Campus Amsterdam 2008, and ICaR - Ischemia and repair
- Subjects
endocrine system ,Umbilical Veins ,SOXF Transcription Factors ,Transcription, Genetic ,Physiology ,Blotting, Western ,Fluorescent Antibody Technique ,Gene Expression ,Biology ,Genes, Reporter ,Physiology (medical) ,Gene expression ,Transcriptional regulation ,Gene silencing ,Humans ,Claudin-5 ,Claudin ,Promoter Regions, Genetic ,Barrier function ,Cells, Cultured ,Oligonucleotide Array Sequence Analysis ,urogenital system ,Reverse Transcriptase Polymerase Chain Reaction ,Lentivirus ,High Mobility Group Proteins ,Endothelial Cells ,Membrane Proteins ,Nucleic Acid Hybridization ,Promoter ,Molecular biology ,Gene expression profiling ,embryonic structures ,RNA ,Electrophoresis, Polyacrylamide Gel ,Endothelium, Vascular ,Cardiology and Cardiovascular Medicine ,Transcription Factors - Abstract
Members of the claudin family constitute tight junction strands and are major determinants in specificity and selectivity of paracellular barriers. Transcriptional control of claudin gene expression is essential to establish individual claudin expression patterns and barrier properties. Using full genome expression profiling, we now identify sex-determining region Y-box (SOX)-18, a member of the SOX family of high-mobility group box transcription factors, as one of the most differentially induced genes during establishment of the endothelial barrier. We show that overexpression of SOX-18 and a dominant-negative mutant thereof, as well as SOX-18 silencing, greatly affect levels of claudin-5 (CLDN5). The relevance of an evolutionary conserved SOX-binding site in the CLDN5 promoter is shown using sequential promoter deletions, as well as point mutations. Furthermore, SOX-18 silencing abrogates endothelial barrier function, as measured by electric cell-substrate impedance sensing. Thus an obligatory role for SOX-18 in the regulation of CLDN5 gene expression in an endothelial-specific and cell density-dependent manner is established, as well as a crucial, nonredundant role for specifically SOX-18 in the formation of the endothelial barrier.
- Published
- 2007
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