title: Nitrite and nitrate-dependent generation of anti-inflammatory fatty acid nitroalkenes.
abstract: A gap in our understanding of the beneficial systemic responses to dietary constituents nitrate (NO3(-)), nitrite (NO2(-)) and conjugated linoleic acid (cLA) is the identification of the downstream metabolites that mediate their actions. To examine these reactions in a clinical context, investigational drug preparations of (15)N-labeled NO3(-) and NO2(-) were orally administered to healthy humans with and without cLA. Mass spectrometry analysis of plasma and urine indicated that the nitrating species nitrogen dioxide was formed and reacted with the olefinic carbons of unsaturated fatty acids to yield the electrophilic fatty acid, nitro-cLA (NO2-cLA). These species mediate the post-translational modification (PTM) of proteins via reversible Michael addition with nucleophilic amino acids. The PTM of critical target proteins by electrophilic lipids has been described as a sensing mechanism that regulates adaptive cellular responses, but little is known about the endogenous generation of fatty acid nitroalkenes and their metabolites. We report that healthy humans consuming (15)N-labeled NO3(-) or NO2(-), with and without cLA supplementation, produce (15)NO2-cLA and corresponding metabolites that are detected in plasma and urine. These data support that the dietary constituents NO3(-), NO2(-) and cLA promote the further generation of secondary electrophilic lipid products that are absorbed into the circulation at concentrations sufficient to exert systemic effects before being catabolized or excreted.
authors.affiliation: Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA.
authors.forename: Meghan
authors.initials: M
authors.lastname: Delmastro-Greenwood
authors.affiliation: Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh PA, 15261, USA.
authors.forename: Kara S
authors.initials: KS
authors.lastname: Hughan
authors.affiliation: Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA.
authors.forename: Dario A
authors.initials: DA
authors.lastname: Vitturi
authors.affiliation: Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA.
authors.forename: Sonia R
authors.initials: SR
authors.lastname: Salvatore
authors.affiliation: Pharmaceutical Development Section, Pharmacy Department, Clinical Center, National Institutes of Health, Bethesda, MD, 20892, USA.
authors.forename: George
authors.initials: G
authors.lastname: Grimes
authors.affiliation: Pharmaceutical Development Section, Pharmacy Department, Clinical Center, National Institutes of Health, Bethesda, MD, 20892, USA.
authors.forename: Gopal
authors.initials: G
authors.lastname: Potti
authors.affiliation: Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA; Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh PA, 15261, USA.
authors.forename: Sruti
authors.initials: S
authors.lastname: Shiva
authors.affiliation: Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA; Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh PA, 15261, USA.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Schopfer
authors.affiliation: Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh PA, 15261, USA.
authors.forename: Mark T
authors.initials: MT
authors.lastname: Gladwin
authors.affiliation: Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA; Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh PA, 15261, USA. Electronic address: freerad@pitt.edu.
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Freeman
authors.affiliation: Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA; Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh PA, 15261, USA. Electronic address: gstacy@pitt.edu.
authors.forename: Stacy
authors.initials: S
authors.lastname: Gelhaus Wendell
mesh_terms: D000328:Adult; D000475:Alkenes / Q000378:metabolism*; D000893:Anti-Inflammatory Agents / Q000378:metabolism*; D002853:Chromatography, Liquid; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D019787:Linoleic Acid / Q000378:metabolism*; D008297:Male; D009566:Nitrates / Q000008:administration & dosage* / Q000378:metabolism; D009573:Nitrites / Q000008:administration & dosage* / Q000378:metabolism; D009574:Nitro Compounds / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D000475:Alkenes; D000893:Anti-Inflammatory Agents; D009566:Nitrates; D009573:Nitrites; D009574:Nitro Compounds; D019787:Linoleic Acid
keywords: Conjugated linoleic acid; Diet; Nitrate; Nitrite; Nitro-fatty acid; Nitrogen metabolism; Redox signaling