title: 20-HETE increases superoxide production and activates NAPDH oxidase in pulmonary artery endothelial cells.
abstract: Reactive oxygen species (ROS) signal vital physiological processes including cell growth, angiogenesis, contraction, and relaxation of vascular smooth muscle. Because cytochrome P-450 family 4 (CYP4)/20-hydroxyeicosatetraenoic acid (20-HETE) has been reported to enhance angiogenesis, pulmonary vascular tone, and endothelial nitric oxide synthase function, we explored the potential of this system to stimulate bovine pulmonary artery endothelial cell (BPAEC) ROS production. Our data are the first to demonstrate that 20-HETE increases ROS in BPAECs in a time- and concentration-dependent manner as detected by enhanced fluorescence of oxidation products of dihydroethidium (DHE) and dichlorofluorescein diacetate. An analog of 20-HETE elicits no increase in ROS and blocks 20-HETE-evoked increments in DHE fluorescence, supporting its function as an antagonist. Endothelial cells derived from bovine aortas exhibit enhanced ROS production to 20-HETE quantitatively similar to that of BPAECs. 20-HETE-induced ROS production in BPAECs is blunted by pretreatment with polyethylene-glycolated SOD, apocynin, inhibition of Rac1, and a peptide-based inhibitor of NADPH oxidase subunit p47(phox) association with gp91. These data support 20-HETE-stimulated, NADPH oxidase-derived, and Rac1/2-dependent ROS production in BPAECs. 20-HETE promotes translocation of p47(phox) and tyrosine phosphorylation of p47(phox) in a time-dependent manner as well as increased activated Rac1/2, providing at least three mechanisms through which 20-HETE activates NADPH oxidase. These observations suggest that 20-HETE stimulates ROS production in BPAECs at least in part through activation of NADPH oxidase within minutes of application of the lipid.
authors.affiliation: Pulmonary and Critical Care Medicine and Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
authors.forename: Meetha
authors.initials: M
authors.lastname: Medhora
authors.forename: Yuenmu
authors.initials: Y
authors.lastname: Chen
authors.forename: Stephanie
authors.initials: S
authors.lastname: Gruenloh
authors.forename: Daniel
authors.initials: D
authors.lastname: Harland
authors.forename: Sreedhar
authors.initials: S
authors.lastname: Bodiga
authors.forename: Jacek
authors.initials: J
authors.lastname: Zielonka
authors.forename: Debebe
authors.initials: D
authors.lastname: Gebremedhin
authors.forename: Ying
authors.initials: Y
authors.lastname: Gao
authors.forename: John R
authors.initials: JR
authors.lastname: Falck
authors.forename: Siddam
authors.initials: S
authors.lastname: Anjaiah
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Jacobs
mesh_terms: D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism; D006893:Hydroxyeicosatetraenoic Acids / Q000494:pharmacology*; D019255:NADPH Oxidases / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D011651:Pulmonary Artery / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism*; D020744:rac GTP-Binding Proteins / Q000378:metabolism; D020830:rac1 GTP-Binding Protein / Q000378:metabolism; D000097766:RAC2 GTP-Binding Protein
chemical_list: D006861:Hydrogen Peroxide; D006893:Hydroxyeicosatetraenoic Acids; D019255:NADPH Oxidases; D017382:Reactive Oxygen Species; D013481:Superoxides; D020744:rac GTP-Binding Proteins; D020830:rac1 GTP-Binding Protein; D000097766:RAC2 GTP-Binding Protein; C494667:20-hydroxyeicosa-6(Z),15(Z)-dienoic acid; C055987:20-hydroxy-5,8,11,14-eicosatetraenoic acid