title: NADPH oxidase NOX2 mediates TLR2/6-dependent release of GM-CSF from endothelial cells.
abstract: NADPH oxidase-generated reactive oxygen species (ROS) from immune cells are well known to be important for pathogen killing in response to TLR ligands. Here, we investigated a new aspect of NADPH oxidase in the TLR2/6-induced release of the immunologically relevant GM-CSF by endothelial cells. Stimulation of human endothelial cells with TLR2/6 agonist, MALP-2 (macrophage-activating lipopeptide of 2 kDa), induced NADPH oxidase activation and ROS formation. Inhibition by ROS scavengers and NADPH oxidase inhibitors blocked MALP-2-induced GM-CSF release. NADPH oxidase activators or ROS donors alone did not result in GM-CSF secretion; however, additional superoxide supply augmented MALP-2-induced GM-CSF secretion and restored GM-CSF levels after NADPH oxidase inhibition. MALP-2-dependent NF-ĸB activation was suppressed by NADPH oxidase inhibition, and inhibition of NF-κB completely blunted MALP-2-induced GM-CSF release. Vascular explants from mice that were deficient for the NADPH oxidase subunit p47phoxshowed diminished intimal superoxide production and GM-CSF release afterex vivostimulation with MALP-2. Moreover, an increase in circulating progenitor cells after MALP-2 injection was completely abolished in p47phox-knockout mice. Finally, MALP-2 stimulation increased mRNA expression of the major subunit NADPH oxidase, (Nox)2, in endothelial cells, and Nox2 inhibition prevented MALP-2-induced GM-CSF release. Our findings identify a Nox2-containing NADPH oxidase as a crucial regulator of the immunologic important growth factor GM-CSF after TLR2/6 stimulation in endothelial cells.-Schuett, J., Schuett, H., Oberoi, R., Koch, A.-K., Pretzer, S., Luchtefeld, M., Schieffer, B., Grote, K. NADPH oxidase NOX2 mediates TLR2/6-dependent release of GM-CSF from endothelial cells.
authors.affiliation: Department of Cardiology and Angiology, Philipps-University, Marburg, Germany.
authors.forename: Jutta
authors.initials: J
authors.lastname: Schuett
authors.affiliation: Department of Cardiology and Angiology, Philipps-University, Marburg, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Schuett
authors.affiliation: Department of Cardiology and Angiology, Philipps-University, Marburg, Germany.
authors.forename: Raghav
authors.initials: R
authors.lastname: Oberoi
authors.affiliation: Department of Cardiology and Angiology, Philipps-University, Marburg, Germany.
authors.forename: Ann-Kathrin
authors.initials: AK
authors.lastname: Koch
authors.affiliation: Department of Cardiology and Angiology, Hannover Medical School, Hannover, Germany.
authors.forename: Silke
authors.initials: S
authors.lastname: Pretzer
authors.affiliation: Department of Cardiology and Angiology, Philipps-University, Marburg, Germany.
authors.forename: Maren
authors.initials: M
authors.lastname: Luchtefeld
authors.affiliation: Department of Cardiology and Angiology, Philipps-University, Marburg, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Schieffer
authors.affiliation: Department of Cardiology and Angiology, Philipps-University, Marburg, Germany; karsten.grote@staff.uni-marburg.de.
authors.forename: Karsten
authors.initials: K
authors.lastname: Grote
mesh_terms: D000074183:ATPases Associated with Diverse Cellular Activities; D000818:Animals; D002470:Cell Survival; D002478:Cells, Cultured; D004265:DNA Helicases; D005786:Gene Expression Regulation; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000235:genetics / Q000378:metabolism*; D055666:Lipopeptides / Q000494:pharmacology; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000235:genetics / Q000378:metabolism*; D016328:NF-kappa B; D010766:Phosphorylation; D051195:Toll-Like Receptor 2 / Q000235:genetics / Q000378:metabolism*; D051216:Toll-Like Receptor 6 / Q000235:genetics / Q000378:metabolism*
chemical_list: D055666:Lipopeptides; D008562:Membrane Glycoproteins; D016328:NF-kappa B; C495342:TLR2 protein, human; C495368:TLR6 protein, human; C493486:Tlr2 protein, mouse; C495369:Tlr6 protein, mouse; D051195:Toll-Like Receptor 2; D051216:Toll-Like Receptor 6; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; C106335:macrophage stimulatory lipopeptide 2; C056558:CYBB protein, human; C488842:Cybb protein, mouse; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases; D000074183:ATPases Associated with Diverse Cellular Activities; D004265:DNA Helicases; C518330:RUVBL2 protein, mouse
keywords: endothelial cell biology; immune factors; innate immunity; pattern recognition receptors; reactive oxygen species