Identification of novel F2-isoprostane metabolites by specific UDP-glucuronosyltransferases

• Published in: Redox biology Vol. 70; p. 103020
• Main Authors: Milne, Ginger L., Nogueira, Marina S., Gao, Benlian, Sanchez, Stephanie C., Amin, Warda, Thomas, Sarah, Oger, Camille, Galano, Jean-Marie, Murff, Harvey J., Yang, Gong, Durand, Thierry
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.04.2024; Elsevier
• Subjects: Biochemistry, Molecular Biology; Fish oil; Geriatry and gerontology; Glucuronidation; Human health and pathology; Isoprostanes; Life Sciences; Mass spectrometry; Metabolism; Pharmaceutical sciences; Isoprostanes; Glucuronidation; Metabolism; Mass spectrometry; Fish oil
• ISSN: 2213-2317; 2213-2317
• DOI: 10.1016/j.redox.2023.103020

UDP-glucuronosyltransferases (UGTs) catalyze the conjugation of glucuronic acid with endogenous and exogenous lipophilic small molecules to facilitate their inactivation and excretion from the body. This represents approximately 35 % of all phase II metabolic transformations. Fatty acids and their oxidized eicosanoid derivatives can be metabolized by UGTs. F2-isoprostanes (F2-IsoPs) are eicosanoids formed from the free radical oxidation of arachidonic acid. These molecules are potent vasoconstrictors and are widely used as biomarkers of endogenous oxidative damage. An increasing body of evidence demonstrates the efficacy of measuring the β-oxidation metabolites of F2-IsoPs rather than the unmetabolized F2-IsoPs to quantify oxidative damage in certain settings. Yet, the metabolism of F2-IsoPs is incompletely understood. This study sought to identify and characterize novel phase II metabolites of 15-F2t-IsoP and 5-epi-5-F2t-IsoP, two abundantly produced F2-IsoPs, in human liver microsomes (HLM). Utilizing liquid chromatography-mass spectrometry, we demonstrated that glucuronide conjugates are the major metabolites of these F2-IsoPs in HLM. Further, we showed that these molecules are metabolized by specific UGT isoforms. 15-F2t-IsoP is metabolized by UGT1A3, 1A9, and 2B7, while 5-epi-5-F2t-IsoP is metabolized by UGT1A7, 1A9, and 2B7. We identified, for the first time, the formation of intact glucuronide F2-IsoPs in human urine and showed that F2-IsoP glucuronidation is reduced in people supplemented with eicosapentaenoic and docosahexaenoic acids for 12 weeks. These studies demonstrate that endogenous F2-IsoP levels can be modified by factors other than redox mechanisms. [Display omitted] •F2-Isoprostanes (F2-IsoPs) are metabolized to glucuronide conjugates by human liver microsomes.•Individual F2-IsoP isomers are metabolized by specific UDP-glucuronosyltransferases (UGTs).•Intact F2-IsoP glucuronide conjugates were identified in human urine.•Supplementation with eicosapentaenoic acid and docosahexaenoic acid decreases F2-IsoP glucuronidation.