Nicotinamide adenine dinucleotide phosphate (reduced form) oxidase is important for LPS-induced endothelial cell activation.
Activation of the endothelium plays an important role in the innate immune response. This process is associated with an increase in the production of superoxide (O2-) by nicotinamide adenine dinucleotide phosphate (reduced form; NADPH) oxidase. Our objective was to determine if O2- from NADPH oxidase contributes to activation of human umbilical vein endothelial cells by LPS as it does for TNF-alpha. We used the adhesion molecule intracellular adhesion molecule 1 and cytokine IL-8 as indicators of human umbilical vein endothelial cell activation and measured O2- production with chemiluminescence. LPS increased baseline and NADPH-stimulated O2- production. The increase was reduced by tiron, a protein kinase C inhibitor (bisindolylmaleimide I hydrochloride), the flavin inhibitor (diphenylene iodonium), and by a short interfering RNA against the p22phox component of NADPH oxidase. Inhibition of NADPH oxidase with the short interfering RNA reduced the induction by LPS of intracellular adhesion molecule 1 mRNA, protein, and IL-8 release (by enzyme-linked immunosorbent assay). The production of O2- by NADPH oxidase contributes to intracellular signaling by LPS in endothelial cells as it does for TNF-alpha and helps turn on the innate immune response in these cells.
Al Ghouleh
Imad
I
McGill University Health Centre, Montreal, Quebec, Canada.
Magder
Sheldon
S
D014013:1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium Salt / Q000737:chemistry; D042783:Endothelial Cells / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology; D004731:Endotoxins / Q000378:metabolism; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D008070:Lipopolysaccharides / Q000378:metabolism*; D008954:Models, Biological; D019255:NADPH Oxidases / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism; D017382:Reactive Oxygen Species; D013481:Superoxides / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D004731:Endotoxins; D016209:Interleukin-8; D008070:Lipopolysaccharides; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D014409:Tumor Necrosis Factor-alpha; D013481:Superoxides; D018799:Intercellular Adhesion Molecule-1; D014013:1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium Salt; D019255:NADPH Oxidases; C086986:CYBA protein, human