Abstract
Oxidative signals play an important role in the regulation of endothelial cell adhesion molecule expression. Small GTP-binding protein Rac1 is activated by various proinflammatory substances and regulates superoxide generation in endothelial cells. In the present study, we demonstrate that adenoviral-mediated expression of dominant negative N17Rac1 (Ad.N17Rac1) suppresses tumor necrosis factor-alpha (TNF-alpha)-induced vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and E-selectin gene expression in a dose-dependent manner. Ad.N17Rac1 did not inhibit TNF-alpha-induced activation of nuclear factor-kappaB (NF-kappaB) binding activity or inhibitor of NF-kappaB-alpha degradation. In contrast, Ad.N17Rac1 inhibited TNF-alpha-induced NF-kappaB-driven HIV(kappaB)(4)-CAT and p288VCAM-Luc promoter activity, suggesting that N17Rac1 inhibits TNF-alpha-induced VCAM-1, E-selectin, and ICAM-1 through suppressing NF-kappaB-mediated transactivation. In addition, expression of superoxide dismutase by adenovirus suppressed TNF-alpha-induced VCAM-1, E-selectin, and ICAM-1 mRNA accumulation. However, adenoviral-mediated expression of catalase only partially inhibited TNF-alpha-induced E-selectin gene expression and had no effect on VCAM-1 and ICAM-1 gene expression. These data suggest that Rac1 and superoxide play crucial roles in the regulation of expression of cell adhesion molecules in endothelial cells.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Adenoviridae / genetics
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Blotting, Northern
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Catalase / biosynthesis
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Cell Adhesion Molecules / biosynthesis*
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Cell Adhesion Molecules / genetics
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Cell Nucleus / metabolism
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Cells, Cultured
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Cytokines / biosynthesis
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E-Selectin / biosynthesis
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E-Selectin / genetics
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Electrophoretic Mobility Shift Assay
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Endothelium, Vascular / cytology
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Endothelium, Vascular / drug effects
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Endothelium, Vascular / metabolism*
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Enzyme-Linked Immunosorbent Assay
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Genes, Reporter / genetics
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Humans
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Hydrogen Peroxide / metabolism
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Intercellular Adhesion Molecule-1 / biosynthesis
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Intercellular Adhesion Molecule-1 / genetics
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NF-kappa B / metabolism
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Plasmids / genetics
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RNA, Messenger / biosynthesis
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Reactive Oxygen Species / metabolism
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Signal Transduction / drug effects
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Stimulation, Chemical
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Superoxide Dismutase / biosynthesis
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Superoxides / metabolism*
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Transfection
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Tumor Necrosis Factor-alpha / pharmacology*
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Up-Regulation / drug effects
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Vascular Cell Adhesion Molecule-1 / biosynthesis
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Vascular Cell Adhesion Molecule-1 / genetics
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rac1 GTP-Binding Protein / genetics
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rac1 GTP-Binding Protein / metabolism*
Substances
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Cell Adhesion Molecules
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Cytokines
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E-Selectin
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NF-kappa B
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RNA, Messenger
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Reactive Oxygen Species
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Tumor Necrosis Factor-alpha
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Vascular Cell Adhesion Molecule-1
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Superoxides
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Intercellular Adhesion Molecule-1
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Hydrogen Peroxide
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Catalase
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Superoxide Dismutase
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rac1 GTP-Binding Protein