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Wang T, Taub ME, Chan TS. A novel system to determine activity of individual uridine 5'-diphospho-glucuronosyltransferase (UGT) isoforms: Recombinant UGT-beads. J Biol Chem 2024; 300:107278. [PMID: 38599380 PMCID: PMC11098952 DOI: 10.1016/j.jbc.2024.107278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Revised: 03/28/2024] [Accepted: 04/03/2024] [Indexed: 04/12/2024] Open
Abstract
Previous work demonstrated that human liver microsomes (HLMs) can spontaneously bind to silica-coated magnetizable beads (HLM-beads) and that these HLM-beads retain uridine 5'-diphospho-glucuronosyltransferase (UGT) activity. However, the contributions of individual UGT isoforms are not directly assessable in this system except through use of model inhibitors. Thus, a preparation wherein recombinant UGT (rUGT) microsomes bound to these same beads to form rUGT-beads of individual UGT isoforms would provide a novel system for measuring the contribution of individual UGT isoforms in a direct manner. To this end, the enzyme activities and kinetic parameter estimates of various rUGT isoforms in rUGT-beads were investigated, as well as the impact of fatty acids (FAs) on enzyme activity. The catalytic efficiencies (Vmax/Km) of the tested rUGTs were twofold to sevenfold higher in rUGT-beads compared with rUGT microsomes, except for rUGT1A6, where Vmax is the maximum product formation rate normalized to milligram of microsomal protein (pmol/min/mg protein). Interestingly, in contrast to traditional rUGT preparations, the sequestration of UGT-inhibitory FA using bovine serum albumin did not alter the catalytic efficiency (Vmax/Km) of the rUGTs in rUGT-beads. Moreover, the increase in catalytic efficiency of rUGT-beads over rUGT microsomes was similar to increases in catalytic efficiency noted with rUGT microsomes (not bound to beads) incubated with bovine serum albumin, suggesting the beads in some way altered the potential for FAs to inhibit activity. The rUGT-bead system may serve as a useful albumin-free tool to determine kinetic constants for UGT substrates, particularly those that exhibit high binding to albumin.
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Affiliation(s)
- Ting Wang
- Department of Drug Metabolism and Pharmacokinetics, Boehringer Ingelheim Pharmaceuticals, Inc, Ridgefield, Connecticut, USA.
| | - Mitchell E Taub
- Department of Drug Metabolism and Pharmacokinetics, Boehringer Ingelheim Pharmaceuticals, Inc, Ridgefield, Connecticut, USA
| | - Tom S Chan
- Department of Drug Metabolism and Pharmacokinetics, Boehringer Ingelheim Pharmaceuticals, Inc, Ridgefield, Connecticut, USA
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A Novel Method for Predicting the Human Inherent Clearance and Its Application in the Study of the Pharmacokinetics and Drug-Drug Interaction between Azidothymidine and Fluconazole Mediated by UGT Enzyme. Pharmaceutics 2021; 13:pharmaceutics13101734. [PMID: 34684027 PMCID: PMC8538957 DOI: 10.3390/pharmaceutics13101734] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 10/13/2021] [Accepted: 10/15/2021] [Indexed: 11/23/2022] Open
Abstract
In order to improve the benefit–risk ratio of pharmacokinetic (PK) research in the early development of new drugs, in silico and in vitro methods were constructed and improved. Models of intrinsic clearance rate (CLint) were constructed based on the quantitative structure–activity relationship (QSAR) of 7882 collected compounds. Moreover, a novel in vitro metabolic method, the Bio-PK dynamic metabolic system, was constructed and combined with a physiology-based pharmacokinetic model (PBPK) model to predict the metabolism and the drug–drug interaction (DDI) of azidothymidine (AZT) and fluconazole (FCZ) mediated by the phase II metabolic enzyme UDP-glycosyltransferase (UGT) in humans. Compared with the QSAR models reported previously, the goodness of fit of our CLint model was slightly improved (determination coefficient (R2) = 0.58 vs. 0.25–0.45). Meanwhile, compared with the predicted clearance of 61.96 L/h (fold error: 2.95–3.13) using CLint (8 µL/min/mg) from traditional microsomal experiment, the predicted clearance using CLint (25 μL/min/mg) from Bio-PK system was increased to 143.26 L/h (fold error: 1.27–1.36). The predicted Cmax and AUC (the area under the concentration–time curve) ratio were 1.32 and 1.84 (fold error: 1.36 and 1.05) in a DDI study with an inhibition coefficient (Ki) of 13.97 μM from the Bio-PK system. The results indicate that the Bio-PK system more truly reflects the dynamic metabolism and DDI of AZT and FCZ in the body. In summary, the novel in silico and in vitro method may provide new ideas for the optimization of drug metabolism and DDI research methods in early drug development.
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Kiiski I, Ollikainen E, Artes S, Järvinen P, Jokinen V, Sikanen T. Drug glucuronidation assays on human liver microsomes immobilized on microfluidic flow-through reactors. Eur J Pharm Sci 2021; 158:105677. [DOI: 10.1016/j.ejps.2020.105677] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 11/06/2020] [Accepted: 12/07/2020] [Indexed: 11/26/2022]
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Zhou J, Argikar UA, Miners JO. Enzyme Kinetics of Uridine Diphosphate Glucuronosyltransferases (UGTs). Methods Mol Biol 2021; 2342:301-338. [PMID: 34272700 DOI: 10.1007/978-1-0716-1554-6_12] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Glucuronidation, catalyzed by uridine diphosphate glucuronosyltransferases (UGTs), is an important process for the metabolism and clearance of many lipophilic chemicals, including drugs, environmental chemicals, and endogenous compounds. Glucuronidation is a bisubstrate reaction that requires the aglycone and the cofactor, UDP-GlcUA. Accumulating evidence suggests that the bisubstrate reaction follows a compulsory-order ternary mechanism. To simplify the kinetic modeling of glucuronidation reactions in vitro, UDP-GlcUA is usually added to incubations in large excess. Many factors have been shown to influence UGT activity and kinetics in vitro, and these must be accounted for during experimental design and data interpretation. While the assessment of drug-drug interactions resulting from UGT inhibition has been challenging in the past, the increasing availability of UGT enzyme-selective substrate and inhibitor "probes" provides the prospect for more reliable reaction phenotyping and assessment of drug-drug interaction potential. Although extrapolation of the in vitro intrinsic clearance of a glucuronidated drug often underpredicts in vivo clearance, careful selection of in vitro experimental conditions and inclusion of extrahepatic glucuronidation may improve the predictivity of in vitro-in vivo extrapolation. Physiologically based pharmacokinetic (PBPK) modeling has also shown to be of value for predicting PK of drugs eliminated by glucuronidation.
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Affiliation(s)
- Jin Zhou
- Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, CT, USA.
| | - Upendra A Argikar
- Translational Medicine, Novartis Institutes for BioMedical Research, Inc., Cambridge, MA, USA
| | - John O Miners
- Department of Clinical Pharmacology, College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
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5
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Miners JO, Rowland A, Novak JJ, Lapham K, Goosen TC. Evidence-based strategies for the characterisation of human drug and chemical glucuronidation in vitro and UDP-glucuronosyltransferase reaction phenotyping. Pharmacol Ther 2020; 218:107689. [PMID: 32980440 DOI: 10.1016/j.pharmthera.2020.107689] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 09/17/2020] [Accepted: 09/18/2020] [Indexed: 12/26/2022]
Abstract
Enzymes of the UDP-glucuronosyltransferase (UGT) superfamily contribute to the elimination of drugs from almost all therapeutic classes. Awareness of the importance of glucuronidation as a drug clearance mechanism along with increased knowledge of the enzymology of drug and chemical metabolism has stimulated interest in the development and application of approaches for the characterisation of human drug glucuronidation in vitro, in particular reaction phenotyping (the fractional contribution of the individual UGT enzymes responsible for the glucuronidation of a given drug), assessment of metabolic stability, and UGT enzyme inhibition by drugs and other xenobiotics. In turn, this has permitted the implementation of in vitro - in vivo extrapolation approaches for the prediction of drug metabolic clearance, intestinal availability, and drug-drug interaction liability, all of which are of considerable importance in pre-clinical drug development. Indeed, regulatory agencies (FDA and EMA) require UGT reaction phenotyping for new chemical entities if glucuronidation accounts for ≥25% of total metabolism. In vitro studies are most commonly performed with recombinant UGT enzymes and human liver microsomes (HLM) as the enzyme sources. Despite the widespread use of in vitro approaches for the characterisation of drug and chemical glucuronidation by HLM and recombinant enzymes, evidence-based guidelines relating to experimental approaches are lacking. Here we present evidence-based strategies for the characterisation of drug and chemical glucuronidation in vitro, and for UGT reaction phenotyping. We anticipate that the strategies will inform practice, encourage development of standardised experimental procedures where feasible, and guide ongoing research in the field.
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Affiliation(s)
- John O Miners
- Department of Clinical Pharmacology and Flinders Centre for Innovation in Cancer, College of Medicine and Public Health, Flinders University, Adelaide, Australia.
| | - Andrew Rowland
- Department of Clinical Pharmacology and Flinders Centre for Innovation in Cancer, College of Medicine and Public Health, Flinders University, Adelaide, Australia
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6
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Badée J, Qiu N, Collier AC, Takahashi RH, Forrest WF, Parrott N, Schmidt S, Fowler S. Characterization of the Ontogeny of Hepatic UDP-Glucuronosyltransferase Enzymes Based on Glucuronidation Activity Measured in Human Liver Microsomes. J Clin Pharmacol 2020; 59 Suppl 1:S42-S55. [PMID: 31502688 DOI: 10.1002/jcph.1493] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 06/26/2019] [Indexed: 02/06/2023]
Abstract
An understanding of the postnatal development of hepatic UDP-glucuronosyltransferase (UGT) enzymes is required for accurate prediction of the age-dependent changes in pharmacokinetics of many drugs used in children. However, the maturation rate of hepatic UGT isoforms remains a major knowledge gap. This study aimed to establish the age-associated changes in glucuronidation activity of 10 major hepatic UGT isoforms in humans, namely, UGT1A1, UGT1A3, UGT1A4, UGT1A6, UGT1A9, UGT2B4, UGT2B7, UGT2B10, UGT2B15, and UGT2B17. Human liver microsomes from pediatric and adult donors were incubated under optimized incubation conditions to assess the activity rates of hepatic UGT isoforms using a panel of 19 in vitro UGT probe substrates and clinically used drugs. Statistically strong correlations of glucuronidation activities allowed the ontogeny of UGT1A1, UGT1A4, UGT2B7, UGT2B10, and UGT2B15 to be established using multiple selective UGT substrates and matched human liver microsome samples. The postnatal development of hepatic UGTs is isoform-dependent using either individual or cross-correlated selective isoform substrates. Maximal adult activity was reached at different times ranging from within a month (UGT1A1, UGT2B4, UGT2B7, UGT2B10, and UGT2B15), during infancy (UGT1A3, UGT1A4, and UGT1A9), to adolescence (UGT1A6 and UGT2B17). This study provides an extensive characterization of the postnatal ontogeny profiles of hepatic UGT enzymes that are instrumental for predicting drug disposition via in vitro-in vivo extrapolation algorithms and verifying pharmacokinetic predictions against in vivo observations via pediatric physiologically based pharmacokinetic modeling in pediatric patients.
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Affiliation(s)
- Justine Badée
- Department of Pharmaceutics, Center for Pharmacometrics and Systems Pharmacology, University of Florida at Lake Nona, Orlando, Florida, USA
| | - Nahong Qiu
- Pharmaceutical Sciences, Roche Pharma Research and Early Development, Roche Innovation Centre Basel, Basel, Switzerland
| | - Abby C Collier
- Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Ryan H Takahashi
- Department of Drug Metabolism and Pharmacokinetics, Genentech, Inc., South San Francisco, California, USA
| | - William F Forrest
- Department of Bioinformatics and Computational Biology, Genentech, Inc., South San Francisco, California, USA
| | - Neil Parrott
- Pharmaceutical Sciences, Roche Pharma Research and Early Development, Roche Innovation Centre Basel, Basel, Switzerland
| | - Stephan Schmidt
- Department of Pharmaceutics, Center for Pharmacometrics and Systems Pharmacology, University of Florida at Lake Nona, Orlando, Florida, USA
| | - Stephen Fowler
- Pharmaceutical Sciences, Roche Pharma Research and Early Development, Roche Innovation Centre Basel, Basel, Switzerland
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Hallifax D, Houston J. Use of Segregated Hepatocyte Scaling Factors and Cross-Species Relationships to Resolve Clearance Dependence in the Prediction of Human Hepatic Clearance. Drug Metab Dispos 2019; 47:320-327. [DOI: 10.1124/dmd.118.085191] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 12/20/2018] [Indexed: 11/22/2022] Open
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8
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Lv X, Zhang JB, Hou J, Dou TY, Ge GB, Hu WZ, Yang L. Chemical Probes for Human UDP-Glucuronosyltransferases: A Comprehensive Review. Biotechnol J 2018; 14:e1800002. [PMID: 30192065 DOI: 10.1002/biot.201800002] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 08/19/2018] [Indexed: 01/11/2023]
Abstract
UGTs play crucial roles in the metabolism and detoxification of both endogenous and xenobiotic compounds. The key roles of UGTs in human health have garnered great interest in the design and development of specific probes for human UGTs. However, in contrast to other human enzymes, the probe substrates for human UGTs are rarely reported, owing to the highly overlapping substrate specificities of UGTs and the lack of the integrated crystal structures of UGTs. Over the past decades, many efforts are made to develop specific probe substrates for UGTs and use them in both basic research and drug discovery. This review focuses on recent progress in the development of probe substrates for UGTs and their biomedical applications. A long list of chemical probes for UGTs, including non-fluorescent and fluorescent probes along with their structural information and kinetic parameters, are prepared and analyzed. Additionally, challenges and future directions in this field are highlighted in the final section. All information and knowledge presented in this review provide practical tools/methods for measuring UGT activities in complex biological samples, which will be very helpful for rapid screening and characterization of UGT modulators, and for exploring the relevance of UGT enzymes to human diseases.
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Affiliation(s)
- Xia Lv
- Key Laboratory of Biotechnology and Bioresources Utilization, Ministry of Education, College of Life Science, Dalian Minzu University, Dalian, 116600, China.,Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | | | - Jie Hou
- Dalian Medical University, Dalian, 116044, China
| | - Tong-Yi Dou
- School of Life Science and Medicine, Dalian University of Technology, Panjin, 124221, China
| | - Guang-Bo Ge
- Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | - Wen-Zhong Hu
- Key Laboratory of Biotechnology and Bioresources Utilization, Ministry of Education, College of Life Science, Dalian Minzu University, Dalian, 116600, China
| | - Ling Yang
- Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
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Lapham K, Lin J, Novak J, Orozco C, Niosi M, Di L, Goosen TC, Ryu S, Riccardi K, Eng H, Cameron KO, Kalgutkar AS. 6-Chloro-5-[4-(1-Hydroxycyclobutyl)Phenyl]-1H-Indole-3-Carboxylic Acid is a Highly Selective Substrate for Glucuronidation by UGT1A1, Relative toβ-Estradiol. Drug Metab Dispos 2018; 46:1836-1846. [DOI: 10.1124/dmd.118.083709] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 09/05/2018] [Indexed: 12/14/2022] Open
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10
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Xu C, Gao J, Zhang HF, Gao N, Guo YY, Fang Y, Wen Q, Qiao HL. Content and Activities of UGT2B7 in Human Liver In Vitro and Predicted In Vivo: A Bottom-Up Approach. Drug Metab Dispos 2018; 46:1351-1359. [PMID: 29929994 DOI: 10.1124/dmd.118.082024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 06/18/2018] [Indexed: 01/11/2023] Open
Abstract
UDP-glucuronosyltransferase 2B7 (UGT2B7) is one of the most significant isoforms of UGTs in human liver. This research measured UGT2B7 protein content and activities, including maximum velocity (Vmax) and intrinsic clearance (CLint), in human liver at isoform, microsomal, liver tissue, and liver levels and identified the factors that influence expression. We determined absolute protein content by liquid chromatography-tandem mass spectroscopy and activities using the probe drug zidovudine in 82 normal human liver microsomes. Using a bottom-up method for derivation, we showed UGT2B7 content at the microsomal, liver tissue, and liver levels, as well as activities at the isoform, microsomal, liver tissue, and liver levels in vitro, and predicted hepatic clearance in vivo, with median, range, variation, and 95% and 50% prediction intervals. With regard to the intrinsic activities, the maximum velocity (Vmax) had a median (range) of 7.5 (2-24) pmol/min per picomole of 2B7, and the CLint was 0.08 (0.02-0.31) μl/min per picomole of 2B7. Determinations at liver level showed larger variations than at microsomal level, so it was more suitable for evaluating individual differences. By analyzing factors that affect UGT2B7, we found that: 1) The content at the liver tissue and liver levels correlated positively with activities; 2) the mutant heterozygotes of -327G>A, -900A>G, -161C>T may lead to decreased protein content and increased intrinsic CLint; and 3) the transcription factor pregnane X receptor mRNA expression level was positively associated with the measured protein content. In all, we showed that protein content and activities at different levels and the factors that influence content provide valuable information for UGT2B7 research and clinically individualized medication.
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Affiliation(s)
- Chen Xu
- Institute of Clinical Pharmacology, Zhengzhou University, Zhengzhou, People's Republic of China
| | - Jie Gao
- Institute of Clinical Pharmacology, Zhengzhou University, Zhengzhou, People's Republic of China
| | - Hai-Feng Zhang
- Institute of Clinical Pharmacology, Zhengzhou University, Zhengzhou, People's Republic of China
| | - Na Gao
- Institute of Clinical Pharmacology, Zhengzhou University, Zhengzhou, People's Republic of China
| | - Yuan-Yuan Guo
- Institute of Clinical Pharmacology, Zhengzhou University, Zhengzhou, People's Republic of China
| | - Yan Fang
- Institute of Clinical Pharmacology, Zhengzhou University, Zhengzhou, People's Republic of China
| | - Qiang Wen
- Institute of Clinical Pharmacology, Zhengzhou University, Zhengzhou, People's Republic of China
| | - Hai-Ling Qiao
- Institute of Clinical Pharmacology, Zhengzhou University, Zhengzhou, People's Republic of China
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Huguet J, Gaudette F, Michaud V, Turgeon J. Development and validation of probe drug cocktails for the characterization of CYP450-mediated metabolism by human heart microsomes. Xenobiotica 2018; 49:187-199. [PMID: 29448869 DOI: 10.1080/00498254.2018.1438684] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
1. The objective of our study was to develop and validate a cocktail approach to allow the simultaneous characterization of various CYP450-mediated oxidations by human heart microsomes for nine probe drug substrates, namely, 7-ethoxyresorufin, bupropion, repaglinide, tolbutamide, bufuralol, chlorzoxazone, ebastine, midazolam and dodecanoic acid. 2. The first validation step was conducted using recombinant human CYP450 isoenzymes by comparing activity measured for each probe drug as a function of (1) buffer used, (2) selectivity towards specific isoenzymes and (3) drug interactions between probes. Activity was all measured by validated LC-MSMS methods. 3. Two cocktails were then constituted with seven of the nine drugs and subjected to kinetic validation. Finally, all probe drugs were incubated with human heart microsomes prepared from ventricular tissues obtained from 12 patients undergoing cardiac transplantation. 4. Validated cocktail #1 including bupropion, chlorzoxazone, ebastine and midazolam was used to characterize CYP2B6-, 2E1-, 2J2- and 3A5-mediated metabolism in human hearts. 5. Cocktail #2 which includes bufuralol, 7-ethoxyresorufin and repaglinide failed the validation step. Substrates in cocktail #2 as well as tolbutamide and dodecanoic acid had to be incubated separately because of their physico-chemical characteristics (solubility and ionization) or drug interactions. 6. Activity in HHM was the highest towards ebastine, chlorzoxazone and tolbutamide.
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Affiliation(s)
- Jade Huguet
- a CRCHUM, University of Montreal , Montreal , Canada.,b Faculty of Pharmacy , University of Montreal , Montreal , Canada
| | | | - Veronique Michaud
- a CRCHUM, University of Montreal , Montreal , Canada.,b Faculty of Pharmacy , University of Montreal , Montreal , Canada.,c College of Pharmacy , University of Florida, Lake Nona Campus , Orlando , FL , USA
| | - Jacques Turgeon
- c College of Pharmacy , University of Florida, Lake Nona Campus , Orlando , FL , USA
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den Braver-Sewradj SP, den Braver MW, Baze A, Decorde J, Fonsi M, Bachellier P, Vermeulen NPE, Commandeur JNM, Richert L, Vos JC. Direct comparison of UDP-glucuronosyltransferase and cytochrome P450 activities in human liver microsomes, plated and suspended primary human hepatocytes from five liver donors. Eur J Pharm Sci 2017; 109:96-110. [PMID: 28778465 DOI: 10.1016/j.ejps.2017.07.032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 07/27/2017] [Accepted: 07/28/2017] [Indexed: 11/26/2022]
Abstract
UDP-glucuronosyltransferases (UGTs) and cytochrome P450s (CYPs) are the major enzymes involved in hepatic metabolism of drugs. Hepatic drug metabolism is commonly investigated using human liver microsomes (HLM) or primary human hepatocytes (PHH). We describe the development of a sensitive assay to phenotype activities of six major hepatic UGT isoforms (UGT1A1, UGT1A3, UGT1A4, UGT1A6, UGT1A9 and UGT2B7) in intact PHH by analysis of glucuronidation of selective probe substrates. The non-selective, general substrate 7-hydroxycoumarin was included for comparison. For each liver donor preparation (five donors) UGT activities in cryopreserved suspended and plated PHH were compared to HLM prepared from the same donors. Standard CYP reaction phenotyping of seven major isoforms was performed in parallel. For all donors, CYP- and UGT-isoforms activity profiles were comparable in PHH and HLM, indicating that reaction phenotyping with selective probe substrates in intact cells primarily reflects respective CYP or UGT activity. System-dependent effects on UGT and CYP isoform activity were still found. While UGT activity of UGT1A1 was equivalent in plated and suspended PHH, UGT1A3, UGT1A6 and UGT2B7 activity was higher in suspended PHH and UGT1A9 and UGT1A4 activity was higher in plated PHH. The well-known decrease in activity of most CYP isoforms in plated compared to suspended PHH was confirmed. Importantly, we found a significant loss in CYP2C19 and CYP2B6 in HLM, activity being lower than in intact cells. Taken together, these findings implicate that, dependent on the UGT or CYP isoforms involved in the metabolism of a given compound, the outcome of metabolic assays is strongly dependent on the choice of the in vitro system. The currently described UGT- and CYP- activity profiling method can be used as a standard assay in intact cells and can especially aid in reaction phenotyping of in vitro systems for which a limited number of cells are available.
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Affiliation(s)
- Shalenie P den Braver-Sewradj
- AIMMS-Division of Molecular Toxicology, Department of Chemistry & Pharmaceutical Sciences, Vrije Universiteit Amsterdam, O
- 2 building, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands
| | - Michiel W den Braver
- AIMMS-Division of Molecular Toxicology, Department of Chemistry & Pharmaceutical Sciences, Vrije Universiteit Amsterdam, O
- 2 building, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands
| | - Audrey Baze
- Kaly-Cell, 20A Rue du Général Leclerc, Plobsheim, France; UNISTRA, 4 Rue Blaise Pascal, Strasbourg, France
| | | | | | - Philippe Bachellier
- UNISTRA, 4 Rue Blaise Pascal, Strasbourg, France; Centre de Chirurgie Viscérale et de Transplantation, Hôpital de Hautepierre, 67098 Strasbourg, France
| | - Nico P E Vermeulen
- AIMMS-Division of Molecular Toxicology, Department of Chemistry & Pharmaceutical Sciences, Vrije Universiteit Amsterdam, O
- 2 building, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands
| | - Jan N M Commandeur
- AIMMS-Division of Molecular Toxicology, Department of Chemistry & Pharmaceutical Sciences, Vrije Universiteit Amsterdam, O
- 2 building, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands
| | - Lysiane Richert
- Kaly-Cell, 20A Rue du Général Leclerc, Plobsheim, France; PEPITE EA4267, Univ. Bourgogne Franche-Comté, F-25000 Besançon, France.
| | - J Chris Vos
- AIMMS-Division of Molecular Toxicology, Department of Chemistry & Pharmaceutical Sciences, Vrije Universiteit Amsterdam, O
- 2 building, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands.
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Wood FL, Houston JB, Hallifax D. Clearance Prediction Methodology Needs Fundamental Improvement: Trends Common to Rat and Human Hepatocytes/Microsomes and Implications for Experimental Methodology. Drug Metab Dispos 2017; 45:1178-1188. [DOI: 10.1124/dmd.117.077040] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 09/06/2017] [Indexed: 01/07/2023] Open
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14
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Argikar UA, Potter PM, Hutzler JM, Marathe PH. Challenges and Opportunities with Non-CYP Enzymes Aldehyde Oxidase, Carboxylesterase, and UDP-Glucuronosyltransferase: Focus on Reaction Phenotyping and Prediction of Human Clearance. AAPS JOURNAL 2016; 18:1391-1405. [PMID: 27495117 DOI: 10.1208/s12248-016-9962-6] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 07/13/2016] [Indexed: 01/28/2023]
Abstract
Over the years, significant progress has been made in reducing metabolic instability due to cytochrome P450-mediated oxidation. High-throughput metabolic stability screening has enabled the advancement of compounds with little to no oxidative metabolism. Furthermore, high lipophilicity and low aqueous solubility of presently pursued chemotypes reduces the probability of renal excretion. As such, these low microsomal turnover compounds are often substrates for non-CYP-mediated metabolism. UGTs, esterases, and aldehyde oxidase are major enzymes involved in catalyzing such metabolism. Hepatocytes provide an excellent tool to identify such pathways including elucidation of major metabolites. To predict human PK parameters for P450-mediated metabolism, in vitro-in vivo extrapolation using hepatic microsomes, hepatocytes, and intestinal microsomes has been actively investigated. However, such methods have not been sufficiently evaluated for non-P450 enzymes. In addition to the involvement of the liver, extrahepatic enzymes (intestine, kidney, lung) are also likely to contribute to these pathways. While there has been considerable progress in predicting metabolic pathways and clearance primarily mediated by the liver, progress in characterizing extrahepatic metabolism and prediction of clearance has been slow. Well-characterized in vitro systems or in vivo animal models to assess drug-drug interaction potential and intersubject variability due to polymorphism are not available. Here we focus on the utility of appropriate in vitro studies to characterize non-CYP-mediated metabolism and to understand the enzymes involved followed by pharmacokinetic studies in the appropriately characterized surrogate species. The review will highlight progress made in establishing in vitro-in vivo correlation, predicting human clearance and avoiding costly clinical failures when non-CYP-mediated metabolic pathways are predominant.
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Affiliation(s)
- Upendra A Argikar
- Analytical Sciences and Imaging, Novartis Institutes for Biomedical Research, Inc., Cambridge, Massachusetts, USA
| | - Philip M Potter
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - J Matthew Hutzler
- Q2 Solutions, Bioanalytical and ADME Labs, Indianapolis, Indiana, USA
| | - Punit H Marathe
- Department of Metabolism and Pharmacokinetics, Bristol-Myers Squibb, Princeton, New Jersey, USA.
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15
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Prediction of the metabolic clearance of benzophenone-2, and its interaction with isoeugenol and coumarin using cryopreserved human hepatocytes in primary culture. Food Chem Toxicol 2016; 90:55-63. [DOI: 10.1016/j.fct.2016.01.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 12/27/2015] [Accepted: 01/13/2016] [Indexed: 01/30/2023]
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16
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Yuan L, Qian S, Xiao Y, Sun H, Zeng S. Homo- and hetero-dimerization of human UDP-glucuronosyltransferase 2B7 (UGT2B7) wild type and its allelic variants affect zidovudine glucuronidation activity. Biochem Pharmacol 2015; 95:58-70. [DOI: 10.1016/j.bcp.2015.03.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 03/03/2015] [Indexed: 10/23/2022]
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17
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Prediction of hepatic and intestinal glucuronidation using in vitro–in vivo extrapolation. Drug Metab Pharmacokinet 2015; 30:21-9. [DOI: 10.1016/j.dmpk.2014.10.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 10/01/2014] [Accepted: 10/02/2014] [Indexed: 12/11/2022]
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18
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Tian XG, Wang C, Ge GB, Ning J, Ai CZ, Hong JY, Cai YX, Huo XK, Hou J, Liu KX, Sun HZ, Ma XC. A highly selective probe for UDP-glucuronosyltransferase 2B7 (UGT2B7) in human microsomes: isoform specificity, kinetic characterization, and applications. RSC Adv 2015. [DOI: 10.1039/c4ra09819f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
3-Epideacetycinobufagin (EDCB) was found to be a highly isoform-specific probe for 3-glucuronidation mediated by UDP-glucuronosyltransferase 2B7 (UGT2B7). The reaction was well-characterized, suggesting that EDCB can be used to measure the catalytic activity of UGT2B7.
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19
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Zientek MA, Youdim K. Reaction phenotyping: advances in the experimental strategies used to characterize the contribution of drug-metabolizing enzymes. Drug Metab Dispos 2014; 43:163-81. [PMID: 25297949 DOI: 10.1124/dmd.114.058750] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
During the process of drug discovery, the pharmaceutical industry is faced with numerous challenges. One challenge is the successful prediction of the major routes of human clearance of new medications. For compounds cleared by metabolism, accurate predictions help provide an early risk assessment of their potential to exhibit significant interpatient differences in pharmacokinetics via routes of metabolism catalyzed by functionally polymorphic enzymes and/or clinically significant metabolic drug-drug interactions. This review details the most recent and emerging in vitro strategies used by drug metabolism and pharmacokinetic scientists to better determine rates and routes of metabolic clearance and how to translate these parameters to estimate the amount these routes contribute to overall clearance, commonly referred to as fraction metabolized. The enzymes covered in this review include cytochrome P450s together with other enzymatic pathways whose involvement in metabolic clearance has become increasingly important as efforts to mitigate cytochrome P450 clearance are successful. Advances in the prediction of the fraction metabolized include newly developed methods to differentiate CYP3A4 from the polymorphic enzyme CYP3A5, scaling tools for UDP-glucuronosyltranferase, and estimation of fraction metabolized for substrates of aldehyde oxidase.
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Affiliation(s)
- Michael A Zientek
- Worldwide Research and Development, Pharmacokinetics, Pharmacodynamics, and Metabolism, Pfizer Inc., San Diego, California (M.A.Z.); and Roche Pharmaceutical Research and Early Development, Pharmaceutical Sciences, F. Hoffmann-La Roche Ltd, Roche Innovation Center Basel, Basel, Switzerland (K.Y.)
| | - Kuresh Youdim
- Worldwide Research and Development, Pharmacokinetics, Pharmacodynamics, and Metabolism, Pfizer Inc., San Diego, California (M.A.Z.); and Roche Pharmaceutical Research and Early Development, Pharmaceutical Sciences, F. Hoffmann-La Roche Ltd, Roche Innovation Center Basel, Basel, Switzerland (K.Y.)
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20
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Galetin A. Rationalizing underprediction of drug clearance from enzyme and transporter kinetic data: from in vitro tools to mechanistic modeling. Methods Mol Biol 2014; 1113:255-88. [PMID: 24523117 DOI: 10.1007/978-1-62703-758-7_13] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Over the years, there has been an increase in the number and quality of available in vitro tools for the assessment of clearance. Complexity of data analysis and modelling of corresponding in vitro data has increased in an analogous manner, in particular for the simultaneous characterization of transporter and metabolism kinetics, together with intracellular binding and passive diffusion. In the current chapter, the impact of different factors on the in vitro-in vivo extrapolation of clearance will be addressed in a stepwise manner, from the selection of the most adequate in vitro system and experimental design/condition to the corresponding modelling of data generated. The application of static or physiologically based pharmacokinetic models in the prediction of clearance will be discussed, highlighting limitations and current challenges of some of the approaches. Particular focus will be on the ability of in vitro and in silico predictive tools to overcome the trend of clearance underprediction. Improvements made as a result of inclusion of extrahepatic metabolism and consideration of transporter-metabolism interplay across different organs will be discussed.
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Affiliation(s)
- Aleksandra Galetin
- Manchester Pharmacy School, The University of Manchester, Stopford Building, Oxford Road, Manchester, UK
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21
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Abstract
Glucuronidation, catalyzed by uridine diphosphate glucuronosyltransferases (UGTs), is an important process for the metabolism and clearance of many lipophilic chemicals, including drugs, environmental chemicals, and endogenous compounds. Glucuronidation is a bi-substrate reaction that requires the aglycone and a cofactor, UDPGA. Accumulating evidence suggests that the bi-substrate reaction follows a compulsory-order ternary mechanism. To simplify the kinetic modelling of glucuronidation reactions in vitro, UDPGA is usually added to incubations in large excess. Many factors have been shown to influence UGT activity and kinetics in vitro, and these must be accounted for in experimental design and data interpretation. Assessing drug-drug interactions (DDIs) involving UGT inhibition remains challenging. However, the increasing availability of UGT enzyme-specific substrate and inhibitor "probes" provides the prospect for more reliable reaction phenotyping and assessment of DDI potential. Although extrapolation of the in vitro intrinsic clearance of a glucuronidated drug often under-predicts in vivo clearance, careful selection of in vitro experimental conditions and inclusion of extrahepatic glucuronidation may improve the predictivity of in vitro-in vivo extrapolation (IVIVE).
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22
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Tian X, Liang S, Wang C, Wu B, Ge G, Deng S, Liu K, Yang L, Ma X. Regioselective glucuronidation of andrographolide and its major derivatives: metabolite identification, isozyme contribution, and species differences. AAPS JOURNAL 2014; 17:156-66. [PMID: 25204783 DOI: 10.1208/s12248-014-9658-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 08/21/2014] [Indexed: 01/16/2023]
Abstract
Andrographolide (AND) and two of its derivatives, deoxyandrographolide (DEO) and dehydroandrographolide (DEH), are widely used in clinical practice as anti-inflammatory agents. However, UDP-glucuronosyltransferase (UGT)-mediated phase II metabolism of these compounds is not fully understood. In this study, glucuronidation of AND, DEO, and DEH was characterized using liver microsomes and recombinant UGT enzymes. We isolated six glucuronides and identified them using 1D and 2D nuclear magnetic resonance (NMR) spectroscopy. We also systematically analyzed various kinetic parameters (K m, V max, and CLint) for glucuronidation of AND, DEO, and DEH. Among 12 commercially available UGT enzymes, UGT1A3, 1A4, 2B4, and 2B7 exhibited metabolic activities toward AND, DEO, and DEH. Further, UGT2B7 made the greatest contribution to glucuronidation of all three anti-inflammatory agents. Regioselective glucuronidation showed considerable species differences. 19-O-Glucuronides were present in liver microsomes from all species except rats. 3-O-Glucuronides were produced by pig and cynomolgus monkey liver microsomes for all compounds, and 3-O-glucuronide of DEH was detected in mouse and rat liver microsomes (RLM). Variations in K m values were 48.6-fold (1.93-93.6 μM) and 49.5-fold (2.01-99.1 μM) for 19-O-glucuronide and 3-O-glucuronide formation, respectively. Total intrinsic clearances (CLint) for 3-O- and 19-O-glucuronidation varied 4.8-fold (22.7-110 μL min(-1) mg(-1)), 10.6-fold (94.2-991 μL min(-1) mg(-1)), and 8.3-fold (122-1,010 μL min(-1) mg(-1)), for AND, DEH, and DEO, respectively. Our results indicate that UGT2B7 is the major UGT enzyme involved in the metabolism of AND, DEO, and DEH. Metabolic pathways in the glucuronidation of AND, DEO, and DEH showed considerable species differences.
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Affiliation(s)
- Xiangge Tian
- College of Pharmacy, Academy of Integrative Medicine, Dalian Medical University, Dalian, 116044, China
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23
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The sonic hedgehog factor GLI1 imparts drug resistance through inducible glucuronidation. Nature 2014; 511:90-3. [PMID: 24870236 PMCID: PMC4138053 DOI: 10.1038/nature13283] [Citation(s) in RCA: 145] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Accepted: 03/26/2014] [Indexed: 12/18/2022]
Abstract
Drug resistance is a major hurdle in oncology. Responses of acute myeloid leukaemia (AML) patients to cytarabine (Ara-C)-based therapies are often short lived with a median overall survival of months. Therapies are under development to improve outcomes and include targeting the eukaryotic translation initiation factor (eIF4E) with its inhibitor ribavirin. In a Phase II clinical trial in poor prognosis AML, ribavirin monotherapy yielded promising responses including remissions; however, all patients relapsed. Here we identify a novel form of drug resistance to ribavirin and Ara-C. We observe that the sonic hedgehog transcription factor glioma-associated protein 1 (GLI1) and the UDP glucuronosyltransferase (UGT1A) family of enzymes are elevated in resistant cells. UGT1As add glucuronic acid to many drugs, modifying their activity in diverse tissues. GLI1 alone is sufficient to drive UGT1A-dependent glucuronidation of ribavirin and Ara-C, and thus drug resistance. Resistance is overcome by genetic or pharmacological inhibition of GLI1, revealing a potential strategy to overcome drug resistance in some patients.
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24
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Ramsden D, Tweedie DJ, St. George R, Chen LZ, Li Y. Generating an In Vitro–In Vivo Correlation for Metabolism and Liver Enrichment of a Hepatitis C Virus Drug, Faldaprevir, Using a Rat Hepatocyte Model (HepatoPac). Drug Metab Dispos 2013; 42:407-14. [DOI: 10.1124/dmd.113.055947] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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25
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Du J, You T, Chen X, Zhong D. Stereoselective Glucuronidation of Ornidazole in Humans: Predominant Contribution of UDP-Glucuronosyltransferases 1A9 and 2B7. Drug Metab Dispos 2013; 41:1306-18. [DOI: 10.1124/dmd.113.051235] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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26
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Konopnicki CM, Dickmann LJ, Tracy JM, Tukey RH, Wienkers LC, Foti RS. Evaluation of UGT protein interactions in human hepatocytes: effect of siRNA down regulation of UGT1A9 and UGT2B7 on propofol glucuronidation in human hepatocytes. Arch Biochem Biophys 2013; 535:143-9. [PMID: 23562620 DOI: 10.1016/j.abb.2013.03.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 03/21/2013] [Accepted: 03/22/2013] [Indexed: 12/11/2022]
Abstract
Previous experiments performed in recombinant systems have suggested that protein-protein interactions occur between the UGTs and may play a significant role in modulating enzyme activity. However, evidence of UGT protein-protein interactions either in vivo or in more physiologically relevant in vitro systems has yet to be demonstrated. In this study, we examined oligomerization and its ability to affect glucuronidation in plated human hepatocytes. siRNA down regulation experiments and activity studies were used to examine changes in metabolite formation of one UGT isoform due to down regulation of a second UGT isoform. Selective siRNA directed towards UGT1A9 or UGT2B7 resulted in significant and selective decreases in their respective mRNA levels. As expected, the metabolism of the UGT1A9 substrate propofol decreased with UGT1A9 down regulation. Interestingly, UGT1A9 activity, but not UGT1A9 mRNA expression, was also diminished when UGT2B7 expression was selectively inhibited, implying potential interactions between the two isoforms. Minor changes to UGT1A4, UGT2B4 and UGT2B7 activity were also observed when UGT1A9 expression was selectively down regulated. To our knowledge, this represents the first piece of evidence that UGT protein-protein interactions occur in human hepatocytes and suggests that expression levels of UGT2B7 may directly impact the glucuronidation activity of selective UGT1A9 substrates.
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Affiliation(s)
- Camille M Konopnicki
- Department of Chemistry and Biochemistry, University of California, 9500 Gilman Drive La Jolla, San Diego, CA 92093, USA
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27
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Krekels EHJ, Johnson TN, den Hoedt SM, Rostami-Hodjegan A, Danhof M, Tibboel D, Knibbe CAJ. From Pediatric Covariate Model to Semiphysiological Function for Maturation: Part II-Sensitivity to Physiological and Physicochemical Properties. CPT Pharmacometrics Syst Pharmacol 2012; 1:e10. [PMID: 23887362 PMCID: PMC3603432 DOI: 10.1038/psp.2012.12] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Accepted: 08/23/2012] [Indexed: 01/15/2023] Open
Abstract
To develop a maturation function for drug glucuronidation in children, that can be used in population and physiologically based modeling approaches, the physiological and physicochemical basis of a semiphysiological glucuronidation function for children was untangled using Simcyp. The results show that using the currently available in vitro data, in vivo morphine and zidovudine clearances were under predicted by the physiologically based model in Simcyp. The maturation profile was similar to the clinically observed profile except for the first 2 weeks of life, and liver size and UGT2B7 ontogeny are the physiological drivers of the maturation of glucuronidation. Physicochemical drug parameters did not affect this maturation profile, although log P and pKa influenced the absolute value of clearance. The results suggest that the semiphysiological glucuronidation function for young children can be used to predict the developmental clearance profile of other UGT2B7 substrates, though scenarios with nonlinear kinetics and high-extraction ratios require further investigation.CPT: Pharmacometrics & Systems Pharmacology (2012) 1, e10; doi:10.1038/psp.2012.12; advance online publication 10 October 2012.
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Affiliation(s)
- E H J Krekels
- Division of Pharmacology, Leiden/Amsterdam Center for Drug Research, Leiden, The Netherlands
- Department of Pediatric Intensive Care and Pediatric Surgery, Erasmus MC-Sophia Children's Hospital, Rotterdam, The Netherlands
| | - T N Johnson
- Simcyp Limited, Blades Enterprize Centre, Sheffield, UK
| | - S M den Hoedt
- Division of Pharmacology, Leiden/Amsterdam Center for Drug Research, Leiden, The Netherlands
| | - A Rostami-Hodjegan
- Simcyp Limited, Blades Enterprize Centre, Sheffield, UK
- School of Pharmacy and Pharmaceutical Sciences, University of Manchester, Manchester, UK
| | - M Danhof
- Division of Pharmacology, Leiden/Amsterdam Center for Drug Research, Leiden, The Netherlands
| | - D Tibboel
- Department of Pediatric Intensive Care and Pediatric Surgery, Erasmus MC-Sophia Children's Hospital, Rotterdam, The Netherlands
| | - C A J Knibbe
- Division of Pharmacology, Leiden/Amsterdam Center for Drug Research, Leiden, The Netherlands
- Department of Pediatric Intensive Care and Pediatric Surgery, Erasmus MC-Sophia Children's Hospital, Rotterdam, The Netherlands
- Department of Clinical Pharmacy, St. Antonius Hospital, Nieuwegein, The Netherlands
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28
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Walsky RL, Bauman JN, Bourcier K, Giddens G, Lapham K, Negahban A, Ryder TF, Obach RS, Hyland R, Goosen TC. Optimized assays for human UDP-glucuronosyltransferase (UGT) activities: altered alamethicin concentration and utility to screen for UGT inhibitors. Drug Metab Dispos 2012; 40:1051-65. [PMID: 22357286 DOI: 10.1124/dmd.111.043117] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The measurement of the effect of new chemical entities on human UDP-glucuronosyltransferase (UGT) marker activities using in vitro experimentation represents an important experimental approach in drug development to guide clinical drug-interaction study designs or support claims that no in vivo interaction will occur. Selective high-performance liquid chromatography-tandem mass spectrometry functional assays of authentic glucuronides for five major hepatic UGT probe substrates were developed: β-estradiol-3-glucuronide (UGT1A1), trifluoperazine-N-glucuronide (UGT1A4), 5-hydroxytryptophol-O-glucuronide (UGT1A6), propofol-O-glucuronide (UGT1A9), and zidovudine-5'-glucuronide (UGT2B7). High analytical sensitivity permitted characterization of enzyme kinetic parameters at low human liver microsomal and recombinant UGT protein concentration (0.025 mg/ml), which led to a new recommended optimal universal alamethicin activation concentration of 10 μg/ml for microsomes. Alamethicin was not required for recombinant UGT incubations. Apparent enzyme kinetic parameters, particularly for UGT1A1 and UGT1A4, were affected by nonspecific binding. Unbound intrinsic clearance for UGT1A9 and UGT2B7 increased significantly after addition of 2% bovine serum albumin, with minimal changes for UGT1A1, UGT1A4, and UGT1A6. Eleven potential UGT and cytochrome P450 inhibitors were evaluated as UGT inhibitors, resulting in observation of nonselective UGT inhibition by chrysin, mefenamic acid, silibinin, tangeretin, ketoconazole, itraconazole, ritonavir, and verapamil. The pan-cytochrome P450 inhibitor, 1-aminobenzotriazole, minimally inhibited UGT activities and may be useful in reaction phenotyping of mixed UGT and cytochrome P450 substrates. These methods should prove useful in the routine assessments of the potential for new drug candidates to elicit pharmacokinetic drug interactions via inhibition of human UGT activities and the identification of UGT enzyme-selective chemical inhibitors.
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Affiliation(s)
- Robert L Walsky
- Department of Pharmacokinetics, Dynamics, and Metabolism, Pfizer Inc., Groton, Connecticut 06340, USA
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29
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Manevski N, Moreolo PS, Yli-Kauhaluoma J, Finel M. Bovine serum albumin decreases Km values of human UDP-glucuronosyltransferases 1A9 and 2B7 and increases Vmax values of UGT1A9. Drug Metab Dispos 2011; 39:2117-29. [PMID: 21856742 DOI: 10.1124/dmd.111.041418] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The human UDP-glucuronosyltransferase (UGT) enzymes UGT1A9 and UGT2B7 play important roles in the hepatic glucuronidation of many drugs. The presence of bovine serum albumin (BSA) during in vitro assays was recently reported to lower the K(m) values of both these UGTs for their aglycone substrates without affecting the corresponding V(max) values. Nonetheless, using the specific substrates entacapone and zidovudine (AZT) for UGT1A9 and UGT2B7, respectively, and using an improved ultrafiltration method for measuring drug binding to BSA and to biological membranes, we found that the presence of BSA during the glucuronidation reaction leads to a large increase in the V(max) value of UGT1A9, in addition to lowering its K(m) value. On the other hand, in the case of UGT2B7, our results agree with the previously described effect of BSA, namely lowering the K(m) value without a large effect on the enzyme's V(max) value. The unexpected BSA effect on UGT1A9 was independent of the expression system because it was found in a recombinant enzyme that was expressed in baculovirus-infected insect cells as well as in the native enzyme in human liver microsomes. Moreover, the effect of BSA on the kinetics of 4-methylumbelliferone glucuronidation by recombinant UGT1A9 was similar to its effect on entacapone glucuronidation. Contrary to the aglycone substrates, the effect of BSA on the apparent K(m) of UGT1A9 for the cosubstrate UDP-α-D-glucuronic acid was nonsignificant. Our findings call for further investigations of the BSA effects on different UGTs and the inhibitors that it may remove.
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Affiliation(s)
- Nenad Manevski
- Division of Pharmaceutical Chemistry, and Centre for Drug Research, Faculty of Pharmacy, P.O. Box 56 (Viikinkaari 5), FI-00014 University of Helsinki, Finland
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30
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Automation and Miniaturization of the Bioluminescent UGT-Glo Assay for Screening of UDP-Glucuronosyltransferase Inhibition by Various Compounds. ACTA ACUST UNITED AC 2011; 16:38-46. [DOI: 10.1016/j.jala.2010.05.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2010] [Indexed: 11/19/2022]
Abstract
The uridine 5'-diphospho-glucuronosyltransferase (UGT) family of enzymes is involved in the metabolism of various compounds. These enzymes transfer a hydrophilic glucuronic acid moiety to their substrates, rendering them more water soluble and amenable to excretion. The UGTs act on various endogenous substrates, such as bilirubin, 17β-estradiol, and testosterone, and drugs and other xenobiotics. The function of these enzymes is essential for the clearance of drugs and toxicants, and alteration of UGT activity is a potential cause of adverse drug—drug interactions in vivo. This has stimulated an increased interest in the study of UGT function and inhibition, and the desire to profile new drug entities against UGT enzymes, similar to CYP450 profiling. However, certain factors have hindered the development of a robust method for UGT profiling. Current methods for assessing UGT enzyme activity are laborious and involve protein precipitation and/or chromatographic separation steps, which are not amenable to rapid screening applications for UGT inhibitors or substrates. The approach presented here is a bioluminescent assay for measuring UGT enzyme activity and inhibition in vitro. Using flexible, robust instrumentation in a 384-well microplate format, this study highlights the quick and easy assay implementation for estimation of inhibition kinetics with a variety of known and suspected UGT substrates and inhibitors.
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31
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Nakamori F, Naritomi Y, Furutani M, Takamura F, Miura H, Murai H, Terashita S, Teramura T. Correlation of Intrinsic in vitro and in vivo Clearance for Drugs Metabolized by Hepatic UDP-glucuronosyltransferases in Rats. Drug Metab Pharmacokinet 2011; 26:465-73. [DOI: 10.2133/dmpk.dmpk-11-rg-018] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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32
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Dostalek M, Court MH, Hazarika S, Akhlaghi F. Diabetes mellitus reduces activity of human UDP-glucuronosyltransferase 2B7 in liver and kidney leading to decreased formation of mycophenolic acid acyl-glucuronide metabolite. Drug Metab Dispos 2010; 39:448-55. [PMID: 21123165 DOI: 10.1124/dmd.110.036608] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Mycophenolic acid (MPA) is an immunosuppressive agent commonly used after organ transplantation. Altered concentrations of MPA metabolites have been reported in diabetic kidney transplant recipients, although the reason for this difference is unknown. We aimed to compare MPA biotransformation and UDP-glucuronosyltransferase (UGT) expression and activity between liver (n = 16) and kidney (n = 8) from diabetic and nondiabetic donors. Glucuronidation of MPA, as well as the expression and probe substrate activity of UGTs primarily responsible for MPA phenol glucuronide (MPAG) formation (UGT1A1 and UGT1A9), and MPA acyl glucuronide (AcMPAG) formation (UGT2B7), was characterized. We have found that both diabetic and nondiabetic human liver microsomes and kidney microsomes formed MPAG with similar efficiency; however, AcMPAG formation was significantly lower in diabetic samples. This finding is supported by markedly lower glucuronidation of the UGT2B7 probe zidovudine, UGT2B7 protein, and UGT2B7 mRNA in diabetic tissues. UGT genetic polymorphism did not explain this difference because UGT2B7*2 or *1c genotype were not associated with altered microsomal UGT2B7 protein levels or AcMPAG formation. Furthermore, mRNA expression and probe activities for UGT1A1 or UGT1A9, both forming MPAG but not AcMPAG, were comparable between diabetic and nondiabetic tissues, suggesting the effect may be specific to UGT2B7-mediated AcMPAG formation. These findings suggest that diabetes mellitus is associated with significantly reduced UGT2B7 mRNA expression, protein level, and enzymatic activity of human liver and kidney, explaining in part the relatively low circulating concentrations of AcMPAG in diabetic patients.
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Affiliation(s)
- Miroslav Dostalek
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, Rhode Island 02881, USA
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33
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Miners JO, Mackenzie PI, Knights KM. The prediction of drug-glucuronidation parameters in humans: UDP-glucuronosyltransferase enzyme-selective substrate and inhibitor probes for reaction phenotyping and in vitro-in vivo extrapolation of drug clearance and drug-drug interaction potential. Drug Metab Rev 2010; 42:196-208. [PMID: 19795925 DOI: 10.3109/03602530903210716] [Citation(s) in RCA: 188] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Major advances in the characterization of uridine diphosphate (UDP)-glucuronosyltransferase (UGT) enzyme substrate and inhibitor selectivities and the development of experimental paradigms to investigate xenobiotic glucuronidation in vitro now permit the prediction of a range of drug-glucuronidation parameters in humans. In particular, the availability of substrate and inhibitor "probes" for the major hepatic drug metabolizing UGTs together with batteries of recombinant enzymes allow the reaction phenotyping of drug glucuronidation reactions. Additionally, in vitro experimental approaches and scaling strategies have been successfully applied to the quantitative prediction of in vivo clearance via glucuronidation and drug-drug interaction potential.
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Affiliation(s)
- John O Miners
- Department of Clinical Pharmacology, Flinders University School of Medicine, Adelaide, Australia.
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34
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Nakagawa N, Katoh M, Yoshioka Y, Nakajima M, Yokoi T. Inhibitory effects of Kampo medicine on human UGT2B7 activity. Drug Metab Pharmacokinet 2010; 24:490-9. [PMID: 20045984 DOI: 10.2133/dmpk.24.490] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Kampo medicine is traditional Japanese medicine modified from the Chinese original. Kampo medicine is a mixture of several medicinal herbs and includes many ingredients such as glycosides. Glycosides are hydrolyzed to aglycons by intestinal bacterial flora and absorbed into the body. Aglycons such as baicalein and glycyrrhetinic acid can be conjugated by UDP-glucuronosyltransferase (UGT) in human liver or small intestine. UGT2B7 is one of the major isoforms responsible for drug conjugation including morphine 3- and 3'- azido-3'-deoxythymidine (AZT) glucuronidation. The present study investigates the effects of 51 Kampo medicines, 14 medicinal herbs and 11 ingredients on UGT2B7 activity in human liver microsomes. Morphine 3-glucuronidation was inhibited by more than 50% by 9 of 51 Kampo medicines such as Ryo-kei-jutsu-kan-to. AZT glucuronidation was inhibited by more than 50% by 24 of 51 Kampo medicines such as Jumi-haidoku-to. Medicinal herbs such as Daio (Rhei Rhizoma), Kanzo (Glycyrrhizae Radix) and Keihi (Cinnamomi Cortex) exhibited more than 80% inhibition on both glucuronidations. The major ingredients of these medicinal herbs inhibited UGT2B7 activity with low K(i). Kampo medicines were found to inhibit the UGT2B7 activity and may cause drug interactions via the inhibition of UGT.
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Affiliation(s)
- Nao Nakagawa
- Drug Metabolism and Toxicology, Division of Pharmaceutical Sciences, Graduate School of Medical Science, Kanazawa University, Kanazawa 920-1192, Japan
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Sweeny DJ, Li W, Clough J, Bhamidipati S, Singh R, Park G, Baluom M, Grossbard E, Lau DTW. Metabolism of Fostamatinib, the Oral Methylene Phosphate Prodrug of the Spleen Tyrosine Kinase Inhibitor R406 in Humans: Contribution of Hepatic and Gut Bacterial Processes to the Overall Biotransformation. Drug Metab Dispos 2010; 38:1166-76. [DOI: 10.1124/dmd.110.032151] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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36
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Chang JH, Yoo P, Lee T, Klopf W, Takao D. The role of pH in the glucuronidation of raloxifene, mycophenolic acid and ezetimibe. Mol Pharm 2009; 6:1216-27. [PMID: 19449843 DOI: 10.1021/mp900065b] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The UDP-glucuronosyltransferase (UGT) active site faces the lumen of the endoplasmic reticulum and is enclosed behind a lipid bilayer. Consequently, observed UGT activity is latent in microsomal preparations, and thus, mechanical and/or chemical disruptions of the vesicle membrane are commonly employed to better expose the active site. The aim of the present investigation was to explore the impact of incubation pH on the glucuronidation of raloxifene, mycophenolic acid (MPA) and ezetimibe, which are basic, acidic and neutral compounds, respectively. Their glucuronidation was examined in human liver microsomal incubations by monitoring for the production of the glucuronide metabolites at pHs ranging between 5.4 and 9.4. Compared to physiological pH, unbound intrinsic clearance (CL(int,u)) was 11- and 12-fold higher at pH 9.4 for raloxifene 4'-glucuronide (R4G) and raloxifene 6-glucuronide (R6G), respectively; whereas a 10-fold increase was observed at pH 5.4 for MPA glucuronide (MPAG). In contrast, ezetimibe glucuronidation did not vary as the pH deviated from 7.4. Kinetic analysis revealed that increases in CL(int,u) were accompanied by less than a 2-fold change in V(max). Instead, K(m,u) decreased 8-, 13- and 5-fold for R4G, R6G and MPAG, respectively. Similar pH dependency on glucuronidation was observed in experiments utilizing recombinant UGT enzymes (recUGT). Particularly, recUGT1A9 was one of the major isoforms involved in the glucuronidation of raloxifene and MPA. While the highest rate of glucuronidation was found at pH 9.4 for raloxifene, the pH for optimal glucuronidation of MPA was between 5.4 and 7.4. In summary, these results suggest that microsomal glucuronidation may be enhanced for acidic and basic compounds by altering the incubation pH, perhaps by improving substrate membrane permeability.
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Affiliation(s)
- Jae H Chang
- Non-Clinical Safety, Department of Drug Metabolism and Pharmacokinetics, Roche Palo Alto, Palo Alto, California 94304, USA.
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Soars MG, Webborn PJH, Riley RJ. Impact of Hepatic Uptake Transporters on Pharmacokinetics and Drug−Drug Interactions: Use of Assays and Models for Decision Making in the Pharmaceutical Industry. Mol Pharm 2009; 6:1662-77. [DOI: 10.1021/mp800246x] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Mathew G. Soars
- Department of Discovery DMPK, AstraZeneca R&D Charnwood, Bakewell Road, Loughborough, Leicestershire LE11 5RH, U.K
| | - Peter J. H. Webborn
- Department of Discovery DMPK, AstraZeneca R&D Charnwood, Bakewell Road, Loughborough, Leicestershire LE11 5RH, U.K
| | - Robert J. Riley
- Department of Discovery DMPK, AstraZeneca R&D Charnwood, Bakewell Road, Loughborough, Leicestershire LE11 5RH, U.K
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Bock KW, Köhle C. Topological aspects of oligomeric UDP-glucuronosyltransferases in endoplasmic reticulum membranes: Advances and open questions. Biochem Pharmacol 2009; 77:1458-65. [DOI: 10.1016/j.bcp.2008.12.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2008] [Revised: 12/04/2008] [Accepted: 12/09/2008] [Indexed: 11/24/2022]
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Rowland A, Knights KM, Mackenzie PI, Miners JO. Characterization of the Binding of Drugs to Human Intestinal Fatty Acid Binding Protein (IFABP): Potential Role of IFABP as an Alternative to Albumin for in Vitro-in Vivo Extrapolation of Drug Kinetic Parameters. Drug Metab Dispos 2009; 37:1395-403. [DOI: 10.1124/dmd.109.027656] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
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Cubitt HE, Houston JB, Galetin A. Relative Importance of Intestinal and Hepatic Glucuronidation—Impact on the Prediction of Drug Clearance. Pharm Res 2009; 26:1073-83. [DOI: 10.1007/s11095-008-9823-9] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2008] [Accepted: 12/29/2008] [Indexed: 11/30/2022]
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41
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Kilford PJ, Stringer R, Sohal B, Houston JB, Galetin A. Prediction of Drug Clearance by Glucuronidation from in Vitro Data: Use of Combined Cytochrome P450 and UDP-Glucuronosyltransferase Cofactors in Alamethicin-Activated Human Liver Microsomes. Drug Metab Dispos 2008; 37:82-9. [DOI: 10.1124/dmd.108.023853] [Citation(s) in RCA: 150] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Zhao P. The use of hepatocytes in evaluating time-dependent inactivation of P450 in vivo. Expert Opin Drug Metab Toxicol 2008; 4:151-64. [PMID: 18330044 DOI: 10.1517/17425255.4.2.151] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND Time-dependent inactivation (TDI) of P450 is an important mechanism of drug interactions. The quantitative in vitro - in vivo correlation of TDI using systems such as human liver microsomes requires a comprehensive understanding of in vitro kinetics, pharmacokinetics, inhibition mechanisms, and homeostasis of the enzyme being inactivated. OBJECTIVE To evaluate the use of hepatocytes in predicting TDI. METHODS The theoretical basis of in vitro - in vivo correlation of TDI and the progress in using microsomes and hepatocytes to predict TDI in vivo are reviewed. RESULTS/CONCLUSION Factors that may impact prediction accuracy, such as nonspecific binding, metabolism of inactivator, active transport, and sequential inhibitory metabolites, can be assessed by performing 'in vitro-in vitro' correlation between microsomes and hepatocytes. Together with microsomal data and the aid of computer modeling and simulation, hepatocytes provide a powerful tool to optimize the integrated approaches aimed at quantitatively predicting TDI in vivo.
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Affiliation(s)
- Ping Zhao
- Sonus Pharmaceuticals, Bothell, WA 98021, USA.
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Rowland A, Knights KM, Mackenzie PI, Miners JO. The “Albumin Effect” and Drug Glucuronidation: Bovine Serum Albumin and Fatty Acid-Free Human Serum Albumin Enhance the Glucuronidation of UDP-Glucuronosyltransferase (UGT) 1A9 Substrates but Not UGT1A1 and UGT1A6 Activities. Drug Metab Dispos 2008; 36:1056-62. [DOI: 10.1124/dmd.108.021105] [Citation(s) in RCA: 134] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Brown HS, Chadwick A, Houston JB. Use of Isolated Hepatocyte Preparations for Cytochrome P450 Inhibition Studies: Comparison with Microsomes forKiDetermination. Drug Metab Dispos 2007; 35:2119-26. [PMID: 17724064 DOI: 10.1124/dmd.107.017095] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Predicting drug-drug interactions requires an assessment of the drug concentration available to the enzyme active site, both in vivo, and within an in vitro incubation. These predictions are confounded when the inhibitor accumulates within the liver, either as a result of active transport processes or intracellular binding (including lysosomal trapping). In theory, hepatocytes should provide a more accurate estimation of inhibitory potency compared with microsomes for those compounds that undergo hepatic accumulation. However, they are not routinely used for Ki determination and there is limited comparative information available. Therefore, the aims of this study were to compare Ki values determined in rat microsomes and freshly isolated hepatocytes using six cytochrome P450 inhibitors (miconazole, fluconazole, ketoconazole, quinine, fluoxetine, and fluvoxamine) with a range of uptake properties (cell-to-medium concentration ratios 4.2-6000). Inhibition studies were performed using four probe substrates for CYP2C, CYP2D, and CYP3A enzymes (tolbutamide and phenytoin, dextromethorphan and midazolam, respectively). Comparison of unbound Ki values (range 0.05-30 microM) showed good agreement between microsomes and hepatocytes for inhibition of 18 pathways of metabolism. In addition to this, there was no relationship between the cell-to-medium concentration ratios (covering over 3 orders of magnitude) and the microsomal to hepatocyte Ki ratio of these inhibitors. These data suggest that the hepatic accumulation of these inhibitors results from intracellular binding rather than the involvement of uptake transporters and indicate that microsomes and hepatocytes appear to be equivalent for determining the inhibitory potency of the six inhibitors investigated in the present study.
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Affiliation(s)
- Hayley S Brown
- Centre for Applied Pharmacokinetic Research, School of Pharmacy and Pharmaceutical Sciences, University of Manchester, Manchester, United Kingdom
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Hewitt NJ, Lechón MJG, Houston JB, Hallifax D, Brown HS, Maurel P, Kenna JG, Gustavsson L, Lohmann C, Skonberg C, Guillouzo A, Tuschl G, Li AP, LeCluyse E, Groothuis GMM, Hengstler JG. Primary hepatocytes: current understanding of the regulation of metabolic enzymes and transporter proteins, and pharmaceutical practice for the use of hepatocytes in metabolism, enzyme induction, transporter, clearance, and hepatotoxicity studies. Drug Metab Rev 2007; 39:159-234. [PMID: 17364884 DOI: 10.1080/03602530601093489] [Citation(s) in RCA: 523] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This review brings you up-to-date with the hepatocyte research on: 1) in vitro-in vivo correlations of metabolism and clearance; 2) CYP enzyme induction, regulation, and cross-talk using human hepatocytes and hepatocyte-like cell lines; 3) the function and regulation of hepatic transporters and models used to elucidate their role in drug clearance; 4) mechanisms and examples of idiosyncratic and intrinsic hepatotoxicity; and 5) alternative cell systems to primary human hepatocytes. We also report pharmaceutical perspectives of these topics and compare methods and interpretations for the drug development process.
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Affiliation(s)
- Nicola J Hewitt
- Scientific Writing Services, Wingertstrasse, Erzhausen, Germany.
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Ritter JK. Intestinal UGTs as potential modifiers of pharmacokinetics and biological responses to drugs and xenobiotics. Expert Opin Drug Metab Toxicol 2007; 3:93-107. [PMID: 17269897 DOI: 10.1517/17425255.3.1.93] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Uridine 5'-diphosphate-glucuronosyltransferases (UGTs) are the biological catalysts of glucuronidation, a major pathway of conjugative metabolism of drugs and xenobiotics. In addition to the liver and kidney, UGTs are highly expressed in the gastrointestinal tract, where they have the potential to influence the pharmacokinetics and biological effects of ingested drugs and xenobiotics. This paper reviews the current evidence for the contributions of intestinal UGTs to presystemic 'first-pass' metabolism and drug bioavailability, the extent of enterohepatic cycling and the clearance of drugs from plasma, as well as their influence on biological responses to drugs, including drug toxicity. The prediction of the effects of intestinal glucuronidation on these processes depends on knowledge of the types and amounts of UGTs expressed in the small intestine and their specific glucuronidating activities. Whereas the types of UGTs expressed in human gastrointestinal tract are well characterized, further research is needed to understand the absolute amounts of UGTs in the small intestine and the causes of observed high-interindividual variability in the intestinal expression of UGTs.
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Affiliation(s)
- Joseph K Ritter
- Virginia Commonwealth University, Department of Pharmacology and Toxicology, School of Medicine, Box 980613, Richmond, Virginia 23298-0613, USA.
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Mano Y, Usui T, Kamimura H. Comparison of inhibition potentials of drugs against zidovudine glucuronidation in rat hepatocytes and liver microsomes. Drug Metab Dispos 2007; 35:602-6. [PMID: 17267620 DOI: 10.1124/dmd.106.014225] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hepatocytes and liver microsomes are considered to be useful for investigating drug metabolism catalyzed mainly via glucuronidation. However, there have been few reports comparing the glucuronidation inhibition potentials of drug in hepatocytes to those in liver microsomes. 3'-Azido-3'-deoxythymidine (AZT, zidovudine) glucuronidation (AZTG) is the major metabolic pathway for AZT. In this study, the inhibition potentials of drugs against UDP-glucuronosyltransferase (UGT)-catalyzed AZTG in the hepatocytes and liver microsomes of rats are compared. The AZTG inhibition potentials of diclofenac, diflunisal, fluconazole, indomethacin, ketoprofen, mefenamic acid, naproxen, niflumic acid, and valproic acid in liver microsomes and hepatocytes were investigated using liquid chromatography with tandem mass spectrometry. Diflunisal (inhibition type: noncompetitive) inhibited AZTG most potently in rat liver microsomes (RLMs) with an IC(50) value of 34 microM. The IC(50) values of diclofenac, fluconazole, indomethacin, ketoprofen, mefenamic acid, naproxen, niflumic acid, and valproic acid against AZTG in RLMs ranged from 34 to 1791 microM. Diclofenac, diflunisal, indomethacin, ketoprofen, naproxen, and valproic acid inhibited AZTG in hepatocytes with IC(50) values of 58, 37, 88, 361, 486, and 281 microM, respectively. These values were similar to those obtained in RLMs. In conclusion, the AZT glucuronidation inhibition potentials of drugs in the hepatocytes and liver microsomes of rats were found to be similar, and liver microsomes can be useful for evaluating UGT isozyme inhibition potentials.
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Affiliation(s)
- Yuji Mano
- Drug Metabolism Research Laboratories, Astellas Pharma Inc., 1-8, Azusawa 1-Chome, Itabashi-ku, Tokyo, 174-8511, Japan.
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Rowland A, Gaganis P, Elliot DJ, Mackenzie PI, Knights KM, Miners JO. Binding of Inhibitory Fatty Acids Is Responsible for the Enhancement of UDP-Glucuronosyltransferase 2B7 Activity by Albumin: Implications for in Vitro-in Vivo Extrapolation. J Pharmacol Exp Ther 2007; 321:137-47. [PMID: 17237258 DOI: 10.1124/jpet.106.118216] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Studies were performed to elucidate the mechanism responsible for the reduction in Km values of UDP-glucuronosyltransferase 2B7 (UGT2B7) substrates observed for incubations conducted in the presence of albumin. Addition of bovine serum albumin (BSA) and fatty acid-free human serum albumin (HSA-FAF), but not "crude" HSA, resulted in an approximate 90% reduction in the Km values for the glucuronidation of zidovudine (AZT) by human liver microsomes (HLM) and UGT2B7 and a 50 to 75% reduction in the S50 for 4-methylumbelliferone (4MU) glucuronidation by UGT2B7, without affecting Vmax. Oleic, linoleic, and arachidonic acids were shown to be the most abundant unsaturated long-chain fatty acids present in crude HSA and in the membranes of HLM and human embryonic kidney (HEK)293 cells, and it was demonstrated that these and other unsaturated long-chain fatty acids were UGT2B7 substrates. Glucuronides with Rf (retention factor) values corresponding to the glucuronides of linoleic and arachidonic acid were detected when HLM and HEK293 cell lysates were incubated with radiolabeled cofactor, and the intensity of the bands was modulated by the presence of crude HSA (increased) and BSA or HSA-FAF (decreased). Oleic, linoleic, and arachidonic acid inhibited AZT and 4MU glucuronidation by HLM and/or UGT2B7, due to an increase in Km/S50 without a change in Vmax. Addition of BSA and HSA-FAF reversed the inhibition. Likewise, coexpression of UGT2B7 and HSA in HEK293 cells reduced the Km/S50 values of these substrates. It is postulated that BSA and HSA-FAF sequester inhibitory fatty acids released during incubations, and the apparent high Km values observed for UGT2B7 substrates arise from the presence of these endogenous inhibitors.
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Affiliation(s)
- Andrew Rowland
- Department of Clinical Pharmacology, Flinders Medical Centre, Bedford Park, SA 5042, Australia
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Mano Y, Usui T, Kamimura H. Inhibitory potential of nonsteroidal anti-inflammatory drugs on UDP-glucuronosyltransferase 2B7 in human liver microsomes. Eur J Clin Pharmacol 2007; 63:211-6. [PMID: 17200831 DOI: 10.1007/s00228-006-0241-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2006] [Accepted: 11/20/2006] [Indexed: 10/23/2022]
Abstract
OBJECTIVE A number of nonsteroidal anti-inflammatory drugs (NSAIDs) are subject to glucuronidation in humans, and UDP-glucuronosyltransferase (UGT) 2B7 is involved in the glucuronidation of many NSAIDs. The objective of this study was to identify a NSAID with potent inhibitory potential against UGT2B7 using liquid chromatography with tandem mass spectrometry (LC-MS/MS). METHODS A rapid screening method for detecting the inhibitory potential of various drugs against UGT2B7 was established using a LC-MS/MS system. The effects of nine NSAIDs (acetaminophen, diclofenac, diflunisal, indomethacin, ketoprofen, mefenamic acid, naproxen, niflumic acid, and salicylic acid) against UGT2B7-catalyzed 3'-azido-3'-deoxythymidine glucuronidation (AZTG) were investigated in human liver microsomes (HLM) and recombinant human UGT2B7. RESULTS Mefenamic acid inhibited AZTG most potently, with an IC(50) value of 0.3 microM, and its inhibition type was not competitive. The IC(50) values for diclofenac, diflunisal, indomethacin, ketoprofen, naproxen, and niflumic acid against AZTG were 6.8, 178, 51, 40, 23, and 83 microM, respectively, while those for acetaminophen and salicylic acid were >100 microM. The IC(50) values for NSAIDs against AZTG in recombinant human UGT2B7 were similar to those obtained in HLM. CONCLUSION The method established in this study is useful for identifying drugs with inhibitory potential against human UGT2B7. Among the nine NSAIDs investigated, mefenamic acid had the strongest inhibitory effect on UGT2B7-catalyzed AZTG in HLM. Thus, caution might be exercised when mefenamic acid is coadministered with drugs possessing UGT2B7 as a main elimination pathway.
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Affiliation(s)
- Yuji Mano
- Drug Metabolism Research Laboratories, Astellas Pharma Inc., 1-8, Azusawa 1-Chome, Itabashi-ku, Tokyo 174-8511, Japan.
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Ishida K, Honda M, Shimizu T, Taguchi M, Hashimoto Y. Stereoselective Metabolism of Carvedilol by the .BETA.-Naphthoflavone-Inducible Enzyme in Human Intestinal Epithelial Caco-2 Cells. Biol Pharm Bull 2007; 30:1930-3. [DOI: 10.1248/bpb.30.1930] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Kazuya Ishida
- Graduate School of Pharmaceutical Sciences, University of Toyama
| | - Mutsuko Honda
- Graduate School of Pharmaceutical Sciences, University of Toyama
| | - Takako Shimizu
- Graduate School of Pharmaceutical Sciences, University of Toyama
| | - Masato Taguchi
- Graduate School of Pharmaceutical Sciences, University of Toyama
| | - Yukiya Hashimoto
- Graduate School of Pharmaceutical Sciences, University of Toyama
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