NF- kappa B independent suppression of endothelial vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 gene expression by inhibition of flavin binding proteins and superoxide production.
Oxidation-reduction (redox) coupled mechanisms play an important role in the regulation of cell surface adhesion molecule expression. In endothelial cells membrane-bound NADH/NADPH oxidase is a significant source of intracellular superoxide (O(2)(-)) production. We explored the role of flavin containing proteins such as NADH/NADPH oxidase in the induction of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) gene expression in human aortic endothelial cells (HAECs) and human dermal microvascular endothelial cells (HMECs). Treatment of HAECs by tumor necrosis factor- alpha (TNF- alpha, 100 U/ml) for 1 h induced a 31% increase in O(2)(-)production within 5 min as determined by lucigenin chemiluminescence analysis of whole cells (n=4, P<0.05). Pretreatment with the NADH/NADPH oxidase inhibitor diphenylene iodonium (DPI, 40 microm) for 1 h inhibited O(2)(-)production. DPI also inhibited TNF and LPS-induced VCAM-1 and ICAM-1 cell surface expression and TNF- alpha, LPS, or IL-1 beta induced VCAM-1 and ICAM-1 mRNA accumulation. However, DPI did not inhibit TNF- alpha -induced activation of nuclear NF- kappa B-like binding activity in HAECs and HMECs. Furthermore, DPI did not inhibit TNF- alpha induced transactivation of NF- kappa B-driven VCAM-1 and HIV-LTR promoter gene constructs in transiently transfected HMECs. These data suggest that flavin binding proteins such as NADH/NADPH oxidase can regulate VCAM-1 gene expression independent of NF- kappa B. Furthermore, intracellular O(2)(-)generation is not necessary for NF- kappa B activation or for transactivation of NF- kappa B driven promoters.
Tummala
P E
PE
Division of Cardiology, Emory University School of Medicine, Atlanta, GA 30322, USA.
Chen
X L
XL
Medford
R M
RM
D001011:Aorta / Q000378:metabolism; D015152:Blotting, Northern; D002448:Cell Adhesion; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000166:cytology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D005415:Flavins / Q000378:metabolism*; D015870:Gene Expression / Q000187:drug effects*; D016325:HIV Long Terminal Repeat / Q000235:genetics; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism*; D009861:Onium Compounds / Q000494:pharmacology; D010084:Oxidation-Reduction; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012333:RNA, Messenger / Q000378:metabolism; D013481:Superoxides / Q000037:antagonists & inhibitors*; D013997:Time Factors; D015533:Transcriptional Activation; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism*
D004791:Enzyme Inhibitors; D005415:Flavins; D016328:NF-kappa B; D009861:Onium Compounds; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D019010:Vascular Cell Adhesion Molecule-1; D013481:Superoxides; D018799:Intercellular Adhesion Molecule-1; C007517:diphenyleneiodonium