title: Metabolic mapping of A3 adenosine receptor agonist MRS5980.
abstract: (1S,2R,3S,4R,5S)-4-(2-((5-Chlorothiophen-2-yl)ethynyl)-6-(methylamino)-9H-purin-9-yl)-2,3-dihydroxy-N-methylbicyclo[3.1.0]hexane-1-carboxamide (MRS5980) is an A3AR selective agonist containing multiple receptor affinity- and selectivity-enhancing modifications and a therapeutic candidate drug for many inflammatory diseases. Metabolism-related poor pharmacokinetic behavior and toxicities are a major reason for drug R&D failure. Metabolomics with UPLC-MS was employed to profile the metabolism of MRS5980 and MRS5980-induced disruption of endogenous compounds. Recombinant drug-metabolizing enzymes screening experiment were used to determine the enzymes involved in MRS5980 metabolism. Analysis of lipid metabolism-related genes was performed to investigate the reason for MRS5980-induced lipid metabolic disorders. Unsupervised principal components analysis separated the control and MRS5980 treatment groups in feces, urine, and liver samples, but not in bile and serum. The major ions mainly contributing to the separation of feces and urine were oxidized MRS5980, glutathione (GSH) conjugates and cysteine conjugate (degradation product of the GSH conjugates) of MRS5980. The major ions contributing to the group separation of liver samples were phosphatidylcholines. In vitro incubation experiments showed the involvement of CYP3A enzymes in the oxidative metabolism of MRS5980 and direct GSH reactivity of MRS5980. The electrophilic attack by MRS5980 is a minor pathway and did not alter GSH levels in liver or liver histology, and thus may be of minor clinical consequence. Gene expression analysis further showed decreased expression of PC biosynthetic genes choline kinase a and b, which further accelerated conversion of lysophosphatidylcholine to phosphatidylcholines through increasing the expression of lysophosphatidylcholine acyltransferase 3. These data will be useful to guide rational design of drugs targeting A3AR, considering efficacy, metabolic elimination, and electrophilic reactivity.
authors.affiliation: Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; Department of Toxicology, School of Public Health, Tianjin Medical University, Tianjin 300070, China.
authors.forename: Zhong-Ze
authors.initials: ZZ
authors.lastname: Fang
authors.affiliation: Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0810, USA.
authors.forename: Dilip K
authors.initials: DK
authors.lastname: Tosh
authors.affiliation: Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Naoki
authors.initials: N
authors.lastname: Tanaka
authors.affiliation: Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Haina
authors.initials: H
authors.lastname: Wang
authors.affiliation: Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Kristopher W
authors.initials: KW
authors.lastname: Krausz
authors.affiliation: Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0810, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: O'Connor
authors.affiliation: Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0810, USA. Electronic address: kajacobs@helix.nih.gov.
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Jacobson
authors.affiliation: Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA. Electronic address: gonzalef@mail.nih.gov.
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Gonzalez
mesh_terms: D058909:Adenosine A3 Receptor Agonists / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D006801:Humans; D008297:Male; D055432:Metabolomics / Q000379:methods*; D051379:Mice; D008810:Mice, Inbred C57BL; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism; D043684:Receptor, Adenosine A3 / Q000378:metabolism*
chemical_list: D058909:Adenosine A3 Receptor Agonists; D043684:Receptor, Adenosine A3
keywords: A(3) adenosine receptor (AR); Electrophilies; MRS5980; Metabolomics