Identification of Human UDP-Glucuronosyltransferases Involved in <i>N</i>-Carbamoyl Glucuronidation of Lorcaserin

Sadeque, Abu; Usmani, Khawja A.; Palamar, Safet; Cerny, Matthew A.; Chen, Weichao G.

doi:10.1124/dmd.111.043448

Cited by 23 publications

(15 citation statements)

References 32 publications

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“…In the current studies, this appears to be the quantitatively predominant metabolite of (+)-PQ in the human hepatocytes, and we have also observed it in plasma and urine of human subjects receiving primaquine (manuscript in preparation). Such N -carbamoyl glucuronides are unusual, but have been reported as minor products for other drugs containing primary and secondary amines [ 27 , 28 ]. Incubation of these drugs in a high CO 2 environment with UDP-glucuronyltransferases can readily yield the carbamoyl glucuronides.…”

Section: Discussionmentioning

confidence: 99%

Differential kinetic profiles and metabolism of primaquine enantiomers by human hepatocytes

Fasinu

Avula

Tekwani

et al. 2016

Malar J

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BackgroundThe clinical utility of primaquine (PQ), used as a racemic mixture of two enantiomers, is limited due to metabolism-linked hemolytic toxicity in individuals with genetic deficiency in glucose-6-phosphate dehydrogenase. The current study investigated differential metabolism of PQ enantiomers in light of the suggestions that toxicity and efficacy might be largely enantioselective.MethodsStable isotope 13C-labelled primaquine and its two enantiomers (+)-PQ, (−)-PQ were separately incubated with cryopreserved human hepatocytes. Time-tracked substrate depletion and metabolite production were monitored via UHPLC–MS/MS.ResultsThe initial half-life of 217 and 65 min; elimination rate constants (λ) of 0.19 and 0.64 h−1; intrinsic clearance (Clint) of 2.55 and 8.49 (µL/min)/million cells, which when up-scaled yielded Clint of 6.49 and 21.6 (mL/min)/kg body mass was obtained respectively for (+)- and (−)-PQ. The extrapolation of in vitro intrinsic clearance to in vivo human hepatic blood clearance, performed using the well-stirred liver model, showed that the rate of hepatic clearance of (+)-PQ was only 45 % that of (−)-PQ. Two major primary routes of metabolism were observed—oxidative deamination of the terminal amine and hydroxylations on the quinoline moiety of PQ. The major deaminated metabolite, carboxyprimaquine (CPQ) was preferentially generated from the (−)-PQ. Other deaminated metabolites including PQ terminal alcohol (m/z 261), a cyclized side chain derivative from the aldehyde (m/z 241), cyclized carboxylic acid derivative (m/z 257), a quinone-imine product of hydroxylated CPQ (m/z 289), CPQ glucuronide (m/z 451) and the glucuronide of PQ alcohol (m/z 437) were all preferentially generated from the (−)-PQ. The major quinoline oxidation product (m/z 274) was preferentially generated from (+)-PQ. In addition to the products of the two metabolic pathways, two other major metabolites were observed: a prominent glycosylated conjugate of PQ on the terminal amine (m/z 422), peaking by 30 min and preferentially generated by (+)-PQ; and the carbamoyl glucuronide of PQ (m/z 480) exclusively generated from (+)-PQ.ConclusionMetabolism of PQ showed enantioselectivity. These findings may provide important information in establishing clinical differences in PQ enantiomers.

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Section: Discussionmentioning

confidence: 99%

Differential kinetic profiles and metabolism of primaquine enantiomers by human hepatocytes

Fasinu

Avula

Tekwani

et al. 2016

Malar J

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“…Although all hepatic UGT isoforms are generally variable, UGT2B17 shows extensively greater interindividual variability in its protein abundance and activity (Fallon et al, 2013;Neumann et al, 2016), and it is expressed in a variety of tissues, such as liver, intestine, kidney, testis, uterus, placenta, mammary gland, adrenal gland, skin, and prostate (Beaulieu et al, 1996;Ekstrom et al, 2013). Numerous endogenous steroids, including testosterone (T), dihydrotestosterone (DHT), androstane-3-a, 17-b-diol (3-a-diol), androsterone and estradiol, and xenobiotics (e.g., 17-dihydroexemestane, vorinostat, lorcaserin) have been identified as substrates of UGT2B17 (Beaulieu et al, 1996;Wong et al, 2011;Sadeque et al, 2012;Chen et al, 2016b;Neumann et al, 2016). The expression of UGT2B17 in sex hormone-sensitive organs also indicates its role in sex hormone homeostasis.…”

Section: Introductionmentioning

confidence: 99%

Hepatic Abundance and Activity of Androgen- and Drug-Metabolizing Enzyme UGT2B17 Are Associated with Genotype, Age, and Sex

et al. 2018

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The major objective of this study was to investigate the association of genetic and nongenetic factors with variability in protein abundance and in vitro activity of the androgen-metabolizing enzyme UGT2B17 in human liver microsomes ( = 455). UGT2B17 abundance was quantified by liquid chromatography-tandem mass spectrometry proteomics, and enzyme activity was determined by using testosterone and dihydrotestosterone as in vitro probe substrates. Genotyping or gene resequencing and mRNA expression were also evaluated. Multivariate analysis was used to test the association of UGT2B17 copy number variation, single nucleotide polymorphisms (SNPs), age, and sex with its mRNA expression, abundance, and activity. UGT2B17 gene copy number and SNPs (rs7436962, rs9996186, rs28374627, and rs4860305) were associated with gene expression, protein levels, and androgen glucuronidation rates in a gene dose-dependent manner. UGT2B17 protein (mean ± S.D. picomoles per milligram of microsomal protein) is sparsely expressed in children younger than 9 years (0.12 ± 0.24 years) but profoundly increases from age 9 years to adults (∼10-fold) with ∼2.6-fold greater abundance in males than in females (1.2 vs. 0.47). Association of androgen glucuronidation with UGT2B15 abundance was observed only in the low UGT2B17 expressers. These data can be used to predict variability in the metabolism of UGT2B17 substrates. Drug companies should include UGT2B17 in early phenotyping assays during drug discovery to avoid late clinical failures.

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“…As a member of the uridine diphosphate-glucuronosyltransferse (UGT) family, UGT2B7 is expressed mostly in the human liver, lung and kidney and can transfer endogenic glucuronide group into its substrate [1,2] . This glucuronidation can impact the pharmacological effects of several drugs in vivo such as estriol [3] , 3'-azido-deoxythymidine (AZT) and morphine [4] .…”

Section: Introductionmentioning

confidence: 99%

The regioselective glucuronidation of morphine by dimerized human UGT2B7, 1A1, 1A9 and their allelic variants

Yang

Wang

et al. 2017

Acta Pharmacol Sin

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Uridine diphosphate-glucuronosyltransferase (UGT) 2B7 is expressed mostly in the human liver, lung and kidney and can transfer endogenous glucuronide group into its substrate and impact the pharmacological effects of several drugs such as estriol, AZT and morphine. UGT2B7 and its allelic variants can dimerize with the homologous enzymes UGT1A1 and UGT1A9, as well as their allelic variants, and then change their enzymatic activities in the process of substrate catalysis. The current study was designed to identify this mechanism using morphine as the substrate of UGT2B7. Single-recombinant allozymes, including UGT2B71 (wild type), UGT2B771S (A71S, 211G>T), UGT2B72 (H268Y, 802C>T), UGT2B75 (D398N, 1192G>A), and double-recombinant allozymes formed by the dimerization of UGT1A91 (wild type), UGT1A92 (C3Y, 8G>A), UGT1A93 (M33T, 98T>C), UGT1A95 (D256N, 766G>A), UGT1A1 (wild type) with its splice variant UGT1A1b were established and incubated with morphine in vitro. Each sample was analyzed with HPLC-MS/MS. All enzyme kinetic parameters were then measured and analyzed. From the results, the production ratio of its aberrant metabolism and subsequent metabolites, morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G), changes regioselectively. Double-recombinant allozymes exhibit stronger enzymatic activity catalyzing morphine than the single-recombinant alloyzymes. Compared to UGT2B71, UGT2B72 singles or doubles have lower K values for M3G and M6G, whereas UGT2B75 allozymes perform opposite effects. The double allozymes of UGT1A92 or UGT1A95 with UGT2B7 tend to produce M6G. Interestingly, the majority of single or double allozymes significantly reduce the ratio of M3G to M6G. The UGT1A92-UGT2B71 double enzyme has the lowest M3G:M6G ratio, reflecting that more M6G would form in morphine glucuronide metabolism. This study demonstrates that UGT2B7 common SNPs and their dimers with UGT1A1 and UGT1A9 and their allelic variants can regioselectively affect the generation of two metabolites of morphine via altering the CL ratios of M3G to M6G. These results may predict the effectiveness of morphine antinociception in individualized opioid treatment.

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Identification of Human UDP-Glucuronosyltransferases Involved in N-Carbamoyl Glucuronidation of Lorcaserin

Cited by 23 publications

References 32 publications

Differential kinetic profiles and metabolism of primaquine enantiomers by human hepatocytes

Differential kinetic profiles and metabolism of primaquine enantiomers by human hepatocytes

Hepatic Abundance and Activity of Androgen- and Drug-Metabolizing Enzyme UGT2B17 Are Associated with Genotype, Age, and Sex

The regioselective glucuronidation of morphine by dimerized human UGT2B7, 1A1, 1A9 and their allelic variants

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