title: Coenzyme A thioester formation of 11- and 15-oxo-eicosatetraenoic acid.
abstract: Release of arachidonic acid (AA) by cytoplasmic phospholipase A2 (cPLA2), followed by metabolism through cyclooxygenase-2 (COX-2) and 15-hydroxyprostaglandin dehydrogenase (15-PGDH), results in the formation of the eicosanoids 11-oxo- and 15-oxo-eicosatetraenoic acid (oxo-ETE). Both 11-oxo- and 15-oxo-ETE have been identified in human biospecimens but their function and further metabolism is poorly described. The oxo-ETEs contain an α,β-unsaturated ketone and a free carboxyclic acid, and thus may form Michael adducts with a nucleophile or a thioester with the free thiol of Coenzyme A (CoA). To examine the potential for eicosanoid-CoA formation, which has not previously been a metabolic route examined for this class of lipids, we applied a semi-targeted neutral loss scanning approach following arachidonic acid treatment in cell culture and detected inducible long-chain acyl-CoAs including a predominant AA-CoA peak. Interestingly, a series of AA-inducible acyl-CoAs at lower abundance but higher mass, likely corresponding to eicosanoid metabolites, was detected. Using a targeted LC-MS/MS approach we detected the formation of CoA thioesters of both 11-oxo- and 15-oxo-ETE and monitored the kinetics of their formation. Subsequently, we demonstrated that these acyl-CoA species undergo up to four double bond reductions. We confirmed the generation of 15-oxo-ETE-CoA in human platelets via LC-high resolution MS. Acyl-CoA thioesters of eicosanoids may provide a route to generate reducing equivalents, substrates for fatty acid oxidation, and substrates for acyl-transferases through cPLA2-dependent eicosanoid metabolism outside of the signaling contexts traditionally ascribed to eicosanoid metabolites.
authors.affiliation: Penn SRP and Center for Excellence in Environmental Toxicology, Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania, Philadelphia, PA 19104, United States.
authors.forename: Clementina
authors.initials: C
authors.lastname: Mesaros
authors.affiliation: Penn SRP and Center for Excellence in Environmental Toxicology, Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania, Philadelphia, PA 19104, United States.
authors.forename: Alejandro D
authors.initials: AD
authors.lastname: Arroyo
authors.affiliation: Penn SRP and Center for Excellence in Environmental Toxicology, Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania, Philadelphia, PA 19104, United States.
authors.forename: Ian A
authors.initials: IA
authors.lastname: Blair
authors.affiliation: A.J. Drexel Autism Institute, Drexel University, Philadelphia, PA 19104, United States. Electronic address: nws28@drexel.edu.
authors.forename: Nathaniel W
authors.initials: NW
authors.lastname: Snyder
mesh_terms: D000214:Acyl Coenzyme A / Q000378:metabolism*; D001095:Arachidonic Acids / Q000737:chemistry* / Q000378:metabolism*; D001792:Blood Platelets / Q000378:metabolism; D004952:Esters / Q000737:chemistry*; D006801:Humans
chemical_list: C571448:11-oxoeicosatetraenoic acid; C000625904:15-oxo-5,8,11,13-eicosatetraenoic acid; D000214:Acyl Coenzyme A; D001095:Arachidonic Acids; D004952:Esters
keywords: Coenzyme A; Eicosanoids; KETE; LC–MS; LoVo; Metabolism; PGDH