Thrombin-induced autoinhibitory factor, Down syndrome critical region-1, attenuates NFAT-dependent vascular cell adhesion molecule-1 expression and inflammation in the endothelium.
Activation and dysfunction of the endothelium underlie many vascular disorders including atherosclerosis, tumor growth, and inflammation. We recently reported that thrombin and vascular endothelial growth factor, but not tumor necrosis factor-alpha, results in dramatic up-regulation of Down syndrome critical region (DSCR)-1 gene in endothelial cells, a negative feedback regulator of calcineurin-NFAT signaling. Constitutive expression of DSCR-1 in activated endothelial cells markedly impaired NFAT nuclear localization, proliferation, tube formation, and tumor growth. The goal of the present study was to elucidate the relative roles of NFAT/DSCR-1 and NF-kappaB/I-kappaB in mediating thrombin-responsive gene expression in endothelial cells. DNA microarrays of thrombin-treated human umbilical vein endothelial cells overexpressing DSCR-1 or constitutive active IkappaBalpha revealed genes that were dependent on NFAT and/or NF-kappaB activity. Vascular cell adhesion molecule-1 was inhibited both by DSCR-1 and I-kappaB at the level of mRNA, protein, promoter activity, and function (monocyte adhesion). Using a combination of transient transfections, electrophoretic mobility shift assays, and chromatin immunoprecipitation, thrombin was shown to induce time-dependent coordinate binding of RelA and NFATc to a tandem NF-kappaB element in the upstream promoter region of vascular cell adhesion molecule-1. Together, these findings suggest that thrombin-mediated activation of endothelial cells involves an interplay between NFAT and NF-kappaB signaling pathways and their negative feedback inhibitors, DSCR-1 and I-kappaB, respectively. As natural brakes in the inflammatory process, DSCR-1 and I-kappaB may lend themselves to therapeutic manipulation in vasculopathic disease states.
Minami
Takashi
T
Research Center for Advanced Science and Technology, University of Tokyo, Tokyo 153-8904, Japan. minami@med.rcast.u-tokyo.ac.jp
Miura
Mai
M
Aird
William C
WC
Kodama
Tatsuhiko
T
D002448:Cell Adhesion / Q000502:physiology; D002460:Cell Line; D002478:Cells, Cultured; D004247:DNA / Q000235:genetics; D004268:DNA-Binding Proteins; D004314:Down Syndrome / Q000235:genetics; D004730:Endothelium, Vascular / Q000503:physiopathology*; D006801:Humans; D020672:I-kappa B Proteins / Q000235:genetics / Q000502:physiology; D007249:Inflammation / Q000503:physiopathology*; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics*; D009000:Monocytes / Q000502:physiology; D009124:Muscle Proteins / Q000235:genetics*; D000072000:NF-KappaB Inhibitor alpha; D050778:NFATC Transcription Factors / Q000502:physiology*; D020411:Oligonucleotide Array Sequence Analysis; D010957:Plasmids; D012313:RNA / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D013917:Thrombin / Q000502:physiology*; D051996:Transcription Factor RelA / Q000378:metabolism; D014471:Umbilical Veins; D019010:Vascular Cell Adhesion Molecule-1 / Q000235:genetics*
D004268:DNA-Binding Proteins; D020672:I-kappa B Proteins; D047908:Intracellular Signaling Peptides and Proteins; D009124:Muscle Proteins; D050778:NFATC Transcription Factors; C000606204:NFKBIA protein, human; C108612:RCAN1 protein, human; C498143:RELA protein, human; D012333:RNA, Messenger; D051996:Transcription Factor RelA; D019010:Vascular Cell Adhesion Molecule-1; D000072000:NF-KappaB Inhibitor alpha; D012313:RNA; D004247:DNA; D013917:Thrombin