title: Activation of NAD(P)H oxidase by lipid hydroperoxides: mechanism of oxidant-mediated smooth muscle cytotoxicity.
abstract: Oxidized lipids, such as 13-hydroperoxyoctadecadienoic acid (13-HPODE), have been implicated in the pathogenesis of atherosclerosis. 13-HPODE, a constituent of oxidized low-density lipoproteins, can induce cytotoxicity of vascular smooth muscle cells (SMC), which may facilitate plaque destabilization and/or rupture. 13-HPODE-induced cytotoxicity has been linked to oxidative stress, although the mechanisms by which this occurs are unknown. In the present study, we show that 13-HPODE and 9-HPODE (10-30 microM) increased superoxide (O2*-) production and induced cytotoxicity in SMC. The 13-HPODE-induced increase in O2*- was blocked by transfecting the cells with antisense oligonucleotides against p22phox, suggesting that the O2*- was produced by NAD(P)H oxidase. Similar concentrations of the corresponding HPODE reduction products, 13-hydroxyoctadecadienoic acid (13-HODE) and 9-HODE, neither increased O2*- production nor induced cytotoxicity, while 4-hydroxy nonenal (4-HNE), an unsaturated aldehyde lipid peroxidation product, induced cytotoxicity without increasing O2*- production. Treatment with superoxide dismutase or Tiron to scavenge O2*-, or transfection with p22phox antisense oligonucleotides to inhibit O2*- production, attenuated 13-HPODE-induced cytotoxicity, but not that induced by 4-HNE. These findings suggest that activation of NAD(P)H oxidase, and production of O2*-, play an important role in lipid hydroperoxide-induced smooth muscle cytotoxicity.
authors.affiliation: Department of Internal Medicine, University of Iowa College of Medicine, Iowa City, IA 52242, USA.
authors.forename: Wei-Gen
authors.initials: WG
authors.lastname: Li
authors.forename: Lynn L
authors.initials: LL
authors.lastname: Stoll
authors.forename: James B
authors.initials: JB
authors.lastname: Rice
authors.forename: Shao-Ping
authors.initials: SP
authors.lastname: Xu
authors.forename: Francis J
authors.initials: FJ
authors.lastname: Miller
authors.forename: Papri
authors.initials: P
authors.lastname: Chatterjee
authors.forename: Ling
authors.initials: L
authors.lastname: Hu
authors.forename: Larry W
authors.initials: LW
authors.lastname: Oberley
authors.forename: Arthur A
authors.initials: AA
authors.lastname: Spector
authors.forename: Neal L
authors.initials: NL
authors.lastname: Weintraub
mesh_terms: D000818:Animals; D001161:Arteriosclerosis; D002470:Cell Survival; D002478:Cells, Cultured; D004789:Enzyme Activation; D005609:Free Radicals; D007093:Imidazoles; D008041:Linoleic Acids / Q000494:pharmacology; D008054:Lipid Peroxides / Q000378:metabolism* / Q000494:pharmacology; D008297:Male; D026901:Membrane Transport Proteins; D018613:Microscopy, Confocal; D009130:Muscle, Smooth / Q000166:cytology / Q000378:metabolism; D009252:NADPH Dehydrogenase / Q000378:metabolism; D019255:NADPH Oxidases / Q000378:metabolism*; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D016877:Oxidants / Q000378:metabolism; D018384:Oxidative Stress; D010100:Oxygen / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D011719:Pyrazines / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013481:Superoxides / Q000378:metabolism; D014162:Transfection
chemical_list: D005609:Free Radicals; D007093:Imidazoles; D008041:Linoleic Acids; D008054:Lipid Peroxides; D026901:Membrane Transport Proteins; D016376:Oligonucleotides, Antisense; D016877:Oxidants; D010750:Phosphoproteins; D011719:Pyrazines; D012333:RNA, Messenger; D013481:Superoxides; C038649:13-hydroperoxy-9,11-octadecadienoic acid; C017144:coelenterazine; C049606:9-hydroperoxy-11,12-octadecadienoic acid; D019255:NADPH Oxidases; C086986:CYBA protein, human; D009252:NADPH Dehydrogenase; D010100:Oxygen