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Rashidian A, Dušek J, Drastik M, Smutná L, Fritsche K, Braeuning A, Pijnenburg D, van Beuningen R, Honkakoski P, Poso A, Kronenberger T, Pavek P. Filling the Blank Space: Branched 4-Nonylphenol Isomers Are Responsible for Robust Constitutive Androstane Receptor (CAR) Activation by Nonylphenol. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:6913-6923. [PMID: 38593436 DOI: 10.1021/acs.est.3c10096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
4-Nonylphenol (4-NP), a para-substituted phenolic compound with a straight or branched carbon chain, is a ubiquitous environmental pollutant and food contaminant. 4-NP, particularly the branched form, has been identified as an endocrine disruptor (ED) with potent activities on estrogen receptors. Constitutive Androstane Receptor (CAR) is another crucial nuclear receptor that regulates hepatic lipid, glucose, and steroid metabolism and is involved in the ED mechanism of action. An NP mixture has been described as an extremely potent activator of both human and rodent CAR. However, detailed mechanistic aspects of CAR activation by 4-NP are enigmatic, and it is not known if 4-NP can directly interact with the CAR ligand binding domain (LBD). Here, we examined interactions of individual branched (22NP, 33NP, and 353NP) and linear 4-NPs with CAR variants using molecular dynamics (MD) simulations, cellular experiments with various CAR expression constructs, recombinant CAR LBD in a TR-FRET assay, or a differentiated HepaRG hepatocyte cellular model. Our results demonstrate that branched 4-NPs display more stable poses to activate both wild-type CAR1 and CAR3 variant LBDs in MD simulations. Consistently, branched 4-NPs activated CAR3 and CAR1 LBD more efficiently than linear 4-NP. Furthermore, in HepaRG cells, we observed that all 4-NPs upregulated CYP2B6 mRNA, a relevant hallmark for CAR activation. This is the first study to provide detailed insights into the direct interaction between individual 4-NPs and human CAR-LBD, as well as its dominant variant CAR3. The work could contribute to the safer use of individual 4-NPs in many areas of industry.
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Affiliation(s)
- Azam Rashidian
- Department of Internal Medicine VIII, University Hospital of Tübingen, Tübingen, Baden-Württemberg 72076, Germany
| | - Jan Dušek
- Department of Pharmacology and Toxicology, Faculty of Pharmacy in Hradec Kralove, Charles University, Akademika Heyrovskeho 1203, Hradec Kralove 500 05, Czech Republic
- Department of Physiology, Faculty of Medicine in Hradec Kralove, Charles University, Šimkova 870, Hradec Králové 500 03, Czech Republic
| | - Martin Drastik
- Department of Biophysics and Physical Chemistry, Faculty of Pharmacy in Hradec Kralove, Charles University, Akademika Heyrovskeho 1203, Hradec Kralove 500 05, Czech Republic
| | - Lucie Smutná
- Department of Pharmacology and Toxicology, Faculty of Pharmacy in Hradec Kralove, Charles University, Akademika Heyrovskeho 1203, Hradec Kralove 500 05, Czech Republic
| | - Kristin Fritsche
- Department Food Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, Berlin 10589, Germany
| | - Albert Braeuning
- Department Food Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, Berlin 10589, Germany
| | - Dirk Pijnenburg
- PamGene International B.V., Wolvenhoek 10, 's-Hertogenbosch 5211HH, Netherlands
| | - Rinie van Beuningen
- PamGene International B.V., Wolvenhoek 10, 's-Hertogenbosch 5211HH, Netherlands
| | - Paavo Honkakoski
- School of Pharmacy, University of Eastern Finland, Yliopistonranta 1 C, Kuopio 72011, Finland
| | - Antti Poso
- Department of Internal Medicine VIII, University Hospital of Tübingen, Tübingen, Baden-Württemberg 72076, Germany
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Kuopio 70211, Finland
- Department of Pharmaceutical and Medicinal Chemistry, Institute of Pharmaceutical Sciences, Eberhard-Karls-Universität, Tübingen, Auf der Morgenstelle 8, Tübingen 72076, Germany
- Tübingen Center for Academic Drug Discovery & Development (TüCAD2), Tübingen 72076, Germany
- Excellence Cluster "Controlling Microbes to Fight Infections" (CMFI), Tübingen 72076, Germany
| | - Thales Kronenberger
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Kuopio 70211, Finland
- Department of Pharmaceutical and Medicinal Chemistry, Institute of Pharmaceutical Sciences, Eberhard-Karls-Universität, Tübingen, Auf der Morgenstelle 8, Tübingen 72076, Germany
- Tübingen Center for Academic Drug Discovery & Development (TüCAD2), Tübingen 72076, Germany
- Excellence Cluster "Controlling Microbes to Fight Infections" (CMFI), Tübingen 72076, Germany
| | - Petr Pavek
- Department of Pharmacology and Toxicology, Faculty of Pharmacy in Hradec Kralove, Charles University, Akademika Heyrovskeho 1203, Hradec Kralove 500 05, Czech Republic
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Honkakoski P. Searching for CAR modulators. Drug Metab Dispos 2022; 50:1002-1009. [DOI: 10.1124/dmd.121.000482] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 02/01/2022] [Indexed: 11/22/2022] Open
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Dau PT, Ishibashi H, Tuyen LH, Sakai H, Hirano M, Kim EY, Iwata H. Assessment of binding potencies of polychlorinated biphenyls and polybrominated diphenyl ethers with Baikal seal and mouse constitutive androstane receptors: Comparisons across species and congeners. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 806:150631. [PMID: 34592282 DOI: 10.1016/j.scitotenv.2021.150631] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 09/23/2021] [Accepted: 09/23/2021] [Indexed: 06/13/2023]
Abstract
The present study evaluated the binding potencies (equilibrium dissociation constant: KD) of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) with the constitutive androstane receptor (CAR)_ligand binding domain (LBD) of the Baikal seal (bsCAR_LBD) and mouse (mCAR_LBD) using a surface plasmon resonance (SPR) biosensor. The binding affinities of individual congeners with mCAR_LBD tended to be higher than those with bsCAR_LBD but the differences were within the same order of magnitude. Notably, PBDE congeners showed higher binding affinities for both CAR_LBDs than PCB congeners. In silico docking simulations demonstrated that PBDEs had more non-covalent interactions with specific amino acid residues in both CAR_LBDs than PCBs, supporting the results of their binding affinities. Binding affinity comparisons among congeners revealed the structural requirements for higher binding; mono or di ortho-, tri meta-, and di para‑chlorine substitutions for PCBs, and di or tri ortho-, mono meta-, and di para‑bromine substitutions for PBDEs. The binding potencies of these congeners unlikely accounted for their previously reported CAR-mediated transactivation potencies, implying that their transactivation is regulated in a ligand-dependent, but a distinct manner from ligand binding. Risk assessment analysis showed that the KD values of individual PCB and PBDE congeners were 1-4 orders of magnitude higher than their respective hepatic concentrations in wild Baikal seal population.
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Affiliation(s)
- Pham Thi Dau
- Centre for Life Science Research, Faculty of Biology, VNU University of Science, 334 Nguyen Trai, Hanoi, Viet Nam.
| | - Hiroshi Ishibashi
- Graduate School of Agriculture, Ehime University, Matsuyama 790-8566, Japan
| | - Le Huu Tuyen
- Research Centre for Environmental Technology and Sustainable Development, VNU University of Science, 334 Nguyen Trai, Hanoi, Viet Nam
| | - Hiroki Sakai
- Division of Pharmacology, Yamaguchi University Graduate School of Medicine, Yamaguchi 755-8505, Japan
| | - Masashi Hirano
- Department of Bioscience, School of Agriculture, Tokai University, 9-1-1 Toroku, Higashi-ku, Kumamoto-shi, Kumamoto 862-8652, Japan
| | - Eun-Young Kim
- Department of Life and Nanopharmaceutical Science and Department of Biology, Kyung Hee University, Hoegi-Dong, Dongdaemun-Gu, Seoul 130-701, Republic of Korea
| | - Hisato Iwata
- Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama 790-8577, Japan.
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Küblbeck J, Niskanen J, Honkakoski P. Metabolism-Disrupting Chemicals and the Constitutive Androstane Receptor CAR. Cells 2020; 9:E2306. [PMID: 33076503 PMCID: PMC7602645 DOI: 10.3390/cells9102306] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 10/13/2020] [Accepted: 10/13/2020] [Indexed: 02/07/2023] Open
Abstract
During the last two decades, the constitutive androstane receptor (CAR; NR1I3) has emerged as a master activator of drug- and xenobiotic-metabolizing enzymes and transporters that govern the clearance of both exogenous and endogenous small molecules. Recent studies indicate that CAR participates, together with other nuclear receptors (NRs) and transcription factors, in regulation of hepatic glucose and lipid metabolism, hepatocyte communication, proliferation and toxicity, and liver tumor development in rodents. Endocrine-disrupting chemicals (EDCs) constitute a wide range of persistent organic compounds that have been associated with aberrations of hormone-dependent physiological processes. Their adverse health effects include metabolic alterations such as diabetes, obesity, and fatty liver disease in animal models and humans exposed to EDCs. As numerous xenobiotics can activate CAR, its role in EDC-elicited adverse metabolic effects has gained much interest. Here, we review the key features and mechanisms of CAR as a xenobiotic-sensing receptor, species differences and selectivity of CAR ligands, contribution of CAR to regulation hepatic metabolism, and evidence for CAR-dependent EDC action therein.
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Affiliation(s)
- Jenni Küblbeck
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, P.O. Box 1627, FI-70210 Kuopio, Finland;
- School of Pharmacy, University of Eastern Finland, P.O. Box 1627, FI-70210 Kuopio, Finland;
| | - Jonna Niskanen
- School of Pharmacy, University of Eastern Finland, P.O. Box 1627, FI-70210 Kuopio, Finland;
| | - Paavo Honkakoski
- School of Pharmacy, University of Eastern Finland, P.O. Box 1627, FI-70210 Kuopio, Finland;
- Division of Pharmacotherapy and Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Campus Box 7569, Chapel Hill, NC 27599-7569, USA
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Excoffon KJDA. The coxsackievirus and adenovirus receptor: virological and biological beauty. FEBS Lett 2020; 594:1828-1837. [PMID: 32298477 DOI: 10.1002/1873-3468.13794] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Revised: 03/31/2020] [Accepted: 04/04/2020] [Indexed: 12/17/2022]
Abstract
The coxsackievirus and adenovirus receptor (CAR) is an essential multifunctional cellular protein that is only beginning to be understood. CAR serves as a receptor for many adenoviruses, human group B coxsackieviruses, swine vesicular disease virus, and possibly other viruses. While named for its function as a viral receptor, CAR is also involved in cell adhesion, immune cell activation, synaptic transmission, and signaling. Knockout mouse models were first to identify some of these biological functions; however, tissue-specific model systems have shed light on the complexity of different CAR isoforms and their specific activities. Many of these functions are mediated by the large number of interacting proteins described so far, and several new putative interactions have recently been discovered. As antiviral and gene therapy strategies that target CAR continue to emerge, future work poised to understand the biological implications of manipulating CAR in vivo is critical.
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Affiliation(s)
- Katherine J D A Excoffon
- Biological Sciences, Wright State University, Dayton, OH, USA.,Spirovant Sciences, Inc, Philadelphia, PA, USA
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Chai SC, Lin W, Li Y, Chen T. Drug discovery technologies to identify and characterize modulators of the pregnane X receptor and the constitutive androstane receptor. Drug Discov Today 2019; 24:906-915. [PMID: 30731240 PMCID: PMC6421094 DOI: 10.1016/j.drudis.2019.01.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 12/27/2018] [Accepted: 01/30/2019] [Indexed: 11/24/2022]
Abstract
The pregnane X receptor (PXR) and the constitutive androstane receptor (CAR) are ligand-activated nuclear receptors (NRs) that are notorious for their role in drug metabolism, causing unintended drug-drug interactions and decreasing drug efficacy. They control the xenobiotic detoxification system by regulating the expression of an array of drug-metabolizing enzymes and transporters that excrete exogenous chemicals and maintain homeostasis of endogenous metabolites. Much effort has been invested in recognizing potential drugs for clinical use that can activate PXR and CAR to enhance the expression of their target genes, and in identifying PXR and CAR inhibitors that can be used as co-therapeutics to prevent adverse effects. Here, we present current technologies and assays used in the quest to characterize PXR and CAR modulators, which range from biochemical to cell-based and animal models.
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Affiliation(s)
- Sergio C Chai
- Department of Chemical Biology & Therapeutics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Wenwei Lin
- Department of Chemical Biology & Therapeutics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Yongtao Li
- Department of Chemical Biology & Therapeutics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Taosheng Chen
- Department of Chemical Biology & Therapeutics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA.
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7
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Prantner V, Cinnamon Y, Küblbeck J, Molnár F, Honkakoski P. Functional Characterization of a Novel Variant of the Constitutive Androstane Receptor (CAR, NR1I3). NUCLEAR RECEPTOR RESEARCH 2018. [DOI: 10.32527/2018/101386] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Viktoria Prantner
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, P.O.Box 1627, FI-70211 Kuopio, Finland. Present address: Neosmart Health Ltd., Aleksanterinkatu 13, FI-00100 Helsinki,
Finland
| | - Yuval Cinnamon
- The Monique and Jacques Roboh Department of Genetic Research, Hadassah - Hebrew University Medical Center, Jerusalem 91120, Israel. Present address: Department of Poultry and Aquaculture Sciences, Institute of Animal Science, Agricultural Research Organization, The Volcani Center, P.O.Box 6, Bet Dagan 50250, Israel
| | - Jenni Küblbeck
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, P.O.Box 1627, FI-70211 Kuopio, Finland
| | - Ferdinand Molnár
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, P.O.Box 1627, FI-70211 Kuopio, Finland. Present address: Department of Biology, School of Sciences and Technology, Nazarbayev University, Astana 010000, Kazakhstan
| | - Paavo Honkakoski
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, P.O.Box 1627, FI-70211 Kuopio, Finland
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Cherian MT, Chai SC, Wright WC, Singh A, Alexandra Casal M, Zheng J, Wu J, Lee RE, Griffin PR, Chen T. CINPA1 binds directly to constitutive androstane receptor and inhibits its activity. Biochem Pharmacol 2018; 152:211-223. [PMID: 29608908 DOI: 10.1016/j.bcp.2018.03.029] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 03/28/2018] [Indexed: 01/28/2023]
Abstract
The constitutive androstane receptor (CAR) and pregnane X receptor (PXR) are xenobiotic sensors that regulate the expression of drug-metabolizing enzymes and efflux transporters. CAR activation promotes drug elimination, thereby reducing therapeutic effectiveness, or causes adverse drug effects via toxic metabolites. CAR inhibitors could be used to attenuate these adverse drug effects. CAR and PXR share ligands and target genes, confounding the understanding of the regulation of receptor-specific activity. We previously identified a small-molecule inhibitor, CINPA1, that inhibits CAR (without activating PXR at lower concentrations) by altering CAR-coregulator interactions and reducing CAR recruitment to DNA response elements of regulated genes. However, solid evidence was not presented for the direct binding of CINPA1 to CAR. In this study, we demonstrate direct interaction of CINPA1 with the CAR ligand-binding domain (CAR-LBD) and identify key residues involved in such interactions through a combination of biophysical and computational methods. We found that CINPA1 resides in the ligand-binding pocket to stabilize the CAR-LBD in a more rigid, less fluid state. Molecular dynamics simulations, together with our previously reported docking model, enabled us to predict which CAR residues were critical for interactions with CINPA1. The importance of these residues for CINPA1 binding were then validated by directed mutations and testing the mutant CAR proteins in transcription reporter and coregulatory interaction assays. We demonstrated strong hydrogen bonding of CINPA1 with N165 and H203 and identified other residues involved in hydrophobic contacts with CINPA1. Overall, our data confirm that CINPA1 directly binds to CAR.
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Affiliation(s)
- Milu T Cherian
- Department of Chemical Biology & Therapeutics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Sergio C Chai
- Department of Chemical Biology & Therapeutics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - William C Wright
- Department of Chemical Biology & Therapeutics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA; Integrated Biomedical Sciences Program, University of Tennessee Health Science Center, 920 Madison Avenue, Memphis, TN 38163, USA
| | - Aman Singh
- Department of Chemical Biology & Therapeutics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA; Integrated Biomedical Sciences Program, University of Tennessee Health Science Center, 920 Madison Avenue, Memphis, TN 38163, USA
| | - Morgan Alexandra Casal
- Department of Chemical Biology & Therapeutics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA; School of Pharmacy, University of Pittsburgh, 3501 Terrace Street, Pittsburgh, PA 15213, USA
| | - Jie Zheng
- Department of Molecular Medicine, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Jing Wu
- Department of Chemical Biology & Therapeutics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Richard E Lee
- Department of Chemical Biology & Therapeutics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Patrick R Griffin
- Department of Molecular Medicine, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Taosheng Chen
- Department of Chemical Biology & Therapeutics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA; Integrated Biomedical Sciences Program, University of Tennessee Health Science Center, 920 Madison Avenue, Memphis, TN 38163, USA.
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Mackowiak B, Li L, Welch MA, Li D, Jones JW, Heyward S, Kane MA, Swaan PW, Wang H. Molecular Basis of Metabolism-Mediated Conversion of PK11195 from an Antagonist to an Agonist of the Constitutive Androstane Receptor. Mol Pharmacol 2017; 92:75-87. [PMID: 28442602 DOI: 10.1124/mol.117.108621] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 04/20/2017] [Indexed: 12/19/2022] Open
Abstract
The constitutive androstane receptor (CAR) plays an important role in xenobiotic metabolism, energy homeostasis, and cell proliferation. Antagonism of the CAR represents a key strategy for studying its function and may have potential clinical applications. However, specific human CAR (hCAR) antagonists are limited and conflicting data on the activity of these compounds have been reported. 1-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinolinecarboxamide (PK11195), a typical peripheral benzodiazepine receptor ligand, has been established as a potent hCAR deactivator in immortalized cells; whether it inhibits hCAR activity under physiologically relevant conditions remains unclear. Here, we investigated the effects of PK11195 on hCAR in metabolically competent human primary hepatocytes (HPH) and HepaRG cells. We show that although PK11195 antagonizes hCAR in HepG2 cells, it induces the expression of CYP2B6 and CYP3A4, targets of hCAR and the pregnane X receptor (PXR), in HPH, HepaRG, and PXR-knockout HepaRG cells. Utilizing a HPH-HepG2 coculture model, we demonstrate that inclusion of HPH converts PK11195 from an antagonist to an agonist of hCAR, and such conversion was attenuated by potent CYP3A4 inhibitor ketoconazole. Metabolically, we show that the N-desmethyl metabolite is responsible for PK11195-mediated hCAR activation by facilitating hCAR interaction with coactivators and enhancing hCAR nuclear translocation in HPHs. Structure-activity analysis revealed that N-demethylation alters the interaction of PK11195 with the binding pocket of hCAR to favor activation. Together, these results indicate that removal of a methyl group switches PK11195 from a potent antagonist of hCAR to an agonist in HPH and highlights the importance of physiologically relevant metabolism when attempting to define the biologic action of small molecules.
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Affiliation(s)
- Bryan Mackowiak
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland (B.M., L.L., M.A.W., D.L., J.W.J., M.A.K., P.W.S., H.W.); and Bioreclamation In Vitro Technologies, Halethorpe, Maryland (S.H.)
| | - Linhao Li
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland (B.M., L.L., M.A.W., D.L., J.W.J., M.A.K., P.W.S., H.W.); and Bioreclamation In Vitro Technologies, Halethorpe, Maryland (S.H.)
| | - Matthew A Welch
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland (B.M., L.L., M.A.W., D.L., J.W.J., M.A.K., P.W.S., H.W.); and Bioreclamation In Vitro Technologies, Halethorpe, Maryland (S.H.)
| | - Daochuan Li
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland (B.M., L.L., M.A.W., D.L., J.W.J., M.A.K., P.W.S., H.W.); and Bioreclamation In Vitro Technologies, Halethorpe, Maryland (S.H.)
| | - Jace W Jones
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland (B.M., L.L., M.A.W., D.L., J.W.J., M.A.K., P.W.S., H.W.); and Bioreclamation In Vitro Technologies, Halethorpe, Maryland (S.H.)
| | - Scott Heyward
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland (B.M., L.L., M.A.W., D.L., J.W.J., M.A.K., P.W.S., H.W.); and Bioreclamation In Vitro Technologies, Halethorpe, Maryland (S.H.)
| | - Maureen A Kane
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland (B.M., L.L., M.A.W., D.L., J.W.J., M.A.K., P.W.S., H.W.); and Bioreclamation In Vitro Technologies, Halethorpe, Maryland (S.H.)
| | - Peter W Swaan
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland (B.M., L.L., M.A.W., D.L., J.W.J., M.A.K., P.W.S., H.W.); and Bioreclamation In Vitro Technologies, Halethorpe, Maryland (S.H.)
| | - Hongbing Wang
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland (B.M., L.L., M.A.W., D.L., J.W.J., M.A.K., P.W.S., H.W.); and Bioreclamation In Vitro Technologies, Halethorpe, Maryland (S.H.)
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10
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Hudson GM, Flannigan KL, Erickson SL, Vicentini FA, Zamponi A, Hirota CL, Alston L, Altier C, Ghosh S, Rioux KP, Mani S, Chang TK, Hirota SA. Constitutive androstane receptor regulates the intestinal mucosal response to injury. Br J Pharmacol 2017; 174:1857-1871. [PMID: 28320072 DOI: 10.1111/bph.13787] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 02/21/2017] [Accepted: 03/14/2017] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND AND PURPOSE The pathogenesis of the inflammatory bowel diseases (IBD), comprising Crohn's disease (CD) and ulcerative colitis (UC), involves aberrant interactions between a genetically susceptible individual, their microbiota and environmental factors. Alterations in xenobiotic receptor expression and function are associated with increased risk for IBD. Here, we have assessed the role of the constitutive androstane receptor (CAR), a xenobiotic receptor closely related to the pregnane X receptor, in the regulation of intestinal mucosal homeostasis. EXPERIMENTAL APPROACH CAR expression was assessed in intestinal mucosal biopsies obtained from CD and UC patients, and in C57/Bl6 mice exposed to dextran sulphate sodium (DSS; 3.5% w/v in drinking water) to evoke intestinal inflammation and tissue damage. CAR-deficient mice were exposed to DSS and mucosal healing assessed. Modulation of wound healing by CAR was assessed in vitro. The therapeutic potential of CAR activation was evaluated, using 3,3',5,5'-tetrachloro-1,4-bis(pyridyloxy)benzene (TCPOBOP), a selective rodent CAR agonist. KEY RESULTS CAR expression was reduced in CD and UC samples, compared with expression in healthy controls. This was reproduced in our DSS studies, where CAR expression was reduced in colitic mice. CAR-deficient mice exhibited reduced healing following DSS exposure. In vitro, CAR activation accelerated intestinal epithelial wound healing by enhancing cell migration. Lastly, treating mice with TCPOBOP, following induction of colitis, enhanced mucosal healing. CONCLUSION AND IMPLICATIONS Our results support the notion that xenobiotic sensing is altered during intestinal inflammation, and suggest that CAR activation may prove effective in enhancing mucosal healing in patients with IBD.
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Affiliation(s)
- Grace M Hudson
- Department of Physiology & Pharmacology, University of Calgary, Calgary, Canada.,Department of Microbiology, Immunology & Infectious Diseases, University of Calgary, Calgary, Canada
| | - Kyle L Flannigan
- Department of Physiology & Pharmacology, University of Calgary, Calgary, Canada.,Department of Microbiology, Immunology & Infectious Diseases, University of Calgary, Calgary, Canada
| | - Sarah L Erickson
- Department of Physiology & Pharmacology, University of Calgary, Calgary, Canada.,Department of Microbiology, Immunology & Infectious Diseases, University of Calgary, Calgary, Canada
| | - Fernando A Vicentini
- Department of Physiology & Pharmacology, University of Calgary, Calgary, Canada.,Department of Microbiology, Immunology & Infectious Diseases, University of Calgary, Calgary, Canada
| | - Alexandra Zamponi
- Department of Physiology & Pharmacology, University of Calgary, Calgary, Canada.,Department of Microbiology, Immunology & Infectious Diseases, University of Calgary, Calgary, Canada
| | | | - Laurie Alston
- Department of Physiology & Pharmacology, University of Calgary, Calgary, Canada.,Department of Microbiology, Immunology & Infectious Diseases, University of Calgary, Calgary, Canada
| | - Christophe Altier
- Department of Physiology & Pharmacology, University of Calgary, Calgary, Canada
| | - Subrata Ghosh
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
| | - Kevin P Rioux
- Department of Medicine, University of Calgary, Calgary, Canada
| | - Sridhar Mani
- Department of Medicine & Genetics, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Thomas K Chang
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada
| | - Simon A Hirota
- Department of Physiology & Pharmacology, University of Calgary, Calgary, Canada.,Department of Microbiology, Immunology & Infectious Diseases, University of Calgary, Calgary, Canada
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Kazantseva YA, Pustylnyak YA, Pustylnyak VO. Role of Nuclear Constitutive Androstane Receptor in Regulation of Hepatocyte Proliferation and Hepatocarcinogenesis. BIOCHEMISTRY (MOSCOW) 2017; 81:338-47. [PMID: 27293091 DOI: 10.1134/s0006297916040040] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Activation of the constitutive androstane receptor (CAR) in hepatocytes occurs as a body adaptation in response to a number of external influences, and its functional activity is primarily related to induction of enzymes detoxifying xenobiotics. However, special attention was recently given to CAR due to the fact that its key role becomes unveiled in various physiological and pathophysiological processes occurring in the liver: gluconeogenesis, metabolism of fatty acids and bilirubin, hormonal regulation, proliferation of hepatocytes, and hepatocarcinogenesis. Here we review the main pathways and mechanisms that elevate hepatocyte proliferative activity related to CAR and whose disturbance may be a pivotal factor in hepatocarcinogenesis.
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Affiliation(s)
- Y A Kazantseva
- Institute of Molecular Biology and Biophysics, Novosibirsk, 630117, Russia
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12
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Lee K, You H, Choi J, No KT. Development of pharmacophore-based classification model for activators of constitutive androstane receptor. Drug Metab Pharmacokinet 2016; 32:172-178. [PMID: 28366619 DOI: 10.1016/j.dmpk.2016.11.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 09/21/2016] [Accepted: 11/10/2016] [Indexed: 10/20/2022]
Abstract
Constitutive androstane receptor (CAR) is predominantly expressed in the liver and is important for regulating drug metabolism and transport. Despite its biological importance, there have been few attempts to develop in silico models to predict the activity of CAR modulated by chemical compounds. The number of in silico studies of CAR may be limited because of CAR's constitutive activity under normal conditions, which makes it difficult to elucidate the key structural features of the interaction between CAR and its ligands. In this study, to address these limitations, we introduced 3D pharmacophore-based descriptors with an integrated ligand and structure-based pharmacophore features, which represent the receptor-ligand interaction. Machine learning methods (support vector machine and artificial neural network) were applied to develop an in silico model with the descriptors containing significant information regarding the ligand binding positions. The best classification model built with a solvent accessibility volume-based filter and the support vector machine showed good predictabilities of 87%, and 85.4% for the training set and validation set, respectively. This demonstrates that our model can be used to accurately predict CAR activators and offers structural information regarding ligand/protein interactions.
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Affiliation(s)
- Kyungro Lee
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, South Korea
| | - Hwan You
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, South Korea
| | - Jiwon Choi
- Bioinformatics & Molecular Design Research Center, Yonsei University, Seoul 03722, South Korea
| | - Kyoung Tai No
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, South Korea; Bioinformatics & Molecular Design Research Center, Yonsei University, Seoul 03722, South Korea.
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13
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Kanno Y, Tanuma N, Yazawa S, Zhao S, Inaba M, Nakamura S, Nemoto K, Inouye Y. Differences in Gene Regulation by Dual Ligands of Nuclear Receptors Constitutive Androstane Receptor (CAR) and Pregnane X Receptor (PXR) in HepG2 Cells Stably Expressing CAR/PXR. Drug Metab Dispos 2016; 44:1158-63. [DOI: 10.1124/dmd.116.070888] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 05/17/2016] [Indexed: 11/22/2022] Open
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14
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Bioinformatic analysis of microRNA networks following the activation of the constitutive androstane receptor (CAR) in mouse liver. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2016; 1859:1228-1237. [PMID: 27080131 DOI: 10.1016/j.bbagrm.2016.04.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 04/01/2016] [Accepted: 04/03/2016] [Indexed: 12/18/2022]
Abstract
The constitutive androstane receptor (CAR; NR1I3) is a member of the nuclear receptor superfamily that functions as a xenosensor, serving to regulate xenobiotic detoxification, lipid homeostasis and energy metabolism. CAR activation is also a key contributor to the development of chemical hepatocarcinogenesis in mice. The underlying pathways affected by CAR in these processes are complex and not fully elucidated. MicroRNAs (miRNAs) have emerged as critical modulators of gene expression and appear to impact many cellular pathways, including those involved in chemical detoxification and liver tumor development. In this study, we used deep sequencing approaches with an Illumina HiSeq platform to differentially profile microRNA expression patterns in livers from wild type C57BL/6J mice following CAR activation with the mouse CAR-specific ligand activator, 1,4-bis-[2-(3,5,-dichloropyridyloxy)] benzene (TCPOBOP). Bioinformatic analyses and pathway evaluations were performed leading to the identification of 51 miRNAs whose expression levels were significantly altered by TCPOBOP treatment, including mmu-miR-802-5p and miR-485-3p. Ingenuity Pathway Analysis of the differentially expressed microRNAs revealed altered effector pathways, including those involved in liver cell growth and proliferation. A functional network among CAR targeted genes and the affected microRNAs was constructed to illustrate how CAR modulation of microRNA expression may potentially mediate its biological role in mouse hepatocyte proliferation. This article is part of a Special Issue entitled: Xenobiotic nuclear receptors: New Tricks for An Old Dog, edited by Dr. Wen Xie.
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15
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Lin W, Yang L, Chai SC, Lu Y, Chen T. Development of CINPA1 analogs as novel and potent inverse agonists of constitutive androstane receptor. Eur J Med Chem 2015; 108:505-528. [PMID: 26717202 DOI: 10.1016/j.ejmech.2015.12.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2015] [Revised: 12/01/2015] [Accepted: 12/10/2015] [Indexed: 11/30/2022]
Abstract
Constitutive androstane receptor (CAR, NR1I3) and pregnane X receptor (PXR, NR1I2) are master regulators of endobiotic and xenobiotic metabolism and disposition. Because CAR is constitutively active in certain cellular contexts, inhibiting CAR might reduce drug-induced hepatotoxicity and resensitize drug-resistant cancer cells to chemotherapeutic drugs. We recently reported a novel CAR inhibitor/inverse agonist CINPA1 (11). Here, we have obtained or designed 54 analogs of CINPA1 and used a time-resolved fluorescence resonance energy transfer (TR-FRET) assay to evaluate their CAR inhibition potency. Many of the 54 analogs showed CAR inverse agonistic activities higher than those of CINPA1, which has an IC50 value of 687 nM. Among them, 72 has an IC50 value of 11.7 nM, which is about 59-fold more potent than CINPA1 and over 10-fold more potent than clotrimazole (an IC50 value of 126.9 nM), the most potent CAR inverse agonist in a biochemical assay previously reported by others. Docking studies provide a molecular explanation of the structure-activity relationship (SAR) observed experimentally. To our knowledge, this effort is the first chemistry endeavor in designing and identifying potent CAR inverse agonists based on a novel chemical scaffold, leading to 72 as the most potent CAR inverse agonist so far. The 54 chemicals presented are novel and unique tools for characterizing CAR's function, and the SAR information gained from these 54 analogs could guide future efforts to develop improved CAR inverse agonists.
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Affiliation(s)
- Wenwei Lin
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Mail Stop 1000, Memphis, TN 38105, United States
| | - Lei Yang
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Mail Stop 1000, Memphis, TN 38105, United States
| | - Sergio C Chai
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Mail Stop 1000, Memphis, TN 38105, United States
| | - Yan Lu
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Mail Stop 1000, Memphis, TN 38105, United States
| | - Taosheng Chen
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Mail Stop 1000, Memphis, TN 38105, United States.
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16
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Küblbeck J, Zancanella V, Prantner V, Molnár F, Squires EJ, Dacasto M, Honkakoski P, Giantin M. Characterization of ligand-dependent activation of bovine and pig constitutive androstane (CAR) and pregnane X receptors (PXR) with interspecies comparisons. Xenobiotica 2015; 46:200-10. [DOI: 10.3109/00498254.2015.1060374] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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17
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Deciphering the roles of the constitutive androstane receptor in energy metabolism. Acta Pharmacol Sin 2015; 36:62-70. [PMID: 25500869 DOI: 10.1038/aps.2014.102] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Accepted: 08/20/2014] [Indexed: 12/21/2022] Open
Abstract
The constitutive androstane receptor (CAR) is initially defined as a xenobiotic nuclear receptor that protects the liver from injury. Detoxification of damaging chemicals is achieved by CAR-mediated induction of drug-metabolizing enzymes and transporters. More recent research has implicated CAR in energy metabolism, suggesting a therapeutic potential for CAR in metabolic diseases, such as type 2 diabetes and obesity. A better understanding of the mechanisms by which CAR regulates energy metabolism will allow us to take advantage of its effectiveness while avoiding its side effects. This review summarizes the current progress on the regulation of CAR nuclear translocation, upstream modulators of CAR activity, and the crosstalk between CAR and other transcriptional factors, with the aim of elucidating how CAR regulates glucose and lipid metabolism.
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18
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Mathäs M, Burk O, Gödtel-Armbrust U, Herlyn H, Wojnowski L, Windshügel B. Structural and functional similarity of amphibian constitutive androstane receptor with mammalian pregnane X receptor. PLoS One 2014; 9:e96263. [PMID: 24797902 PMCID: PMC4010427 DOI: 10.1371/journal.pone.0096263] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 04/04/2014] [Indexed: 11/19/2022] Open
Abstract
The nuclear receptors and xenosensors constitutive androstane receptor (CAR, NR1I3) and pregnane X receptor (PXR, NR1I2) induce the expression of xenobiotic metabolizing enzymes and transporters, which also affects various endobiotics. While human and mouse CAR feature a high basal activity and low induction upon ligand exposure, we recently identified two constitutive androstane receptors in Xenopus laevis (xlCARα and β) that possess PXR-like characteristics such as low basal activity and activation in response to structurally diverse compounds. Using a set of complementary computational and biochemical approaches we provide evidence for xlCARα being the structural and functional counterpart of mammalian PXR. A three-dimensional model of the xlCARα ligand-binding domain (LBD) reveals a human PXR-like L-shaped ligand binding pocket with a larger volume than the binding pockets in human and murine CAR. The shape and amino acid composition of the ligand-binding pocket of xlCAR suggests PXR-like binding of chemically diverse ligands which was confirmed by biochemical methods. Similarly to PXR, xlCARα possesses a flexible helix 11’. Modest increase in the recruitment of coactivator PGC-1α may contribute to the enhanced basal activity of three gain-of-function xlCARα mutants humanizing key LBD amino acid residues. xlCARα and PXR appear to constitute an example of convergent evolution.
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Affiliation(s)
- Marianne Mathäs
- Department of Pharmacology, University Medical Center, Mainz, Germany
| | - Christian Nußhag
- Department of Pharmacology, University Medical Center, Mainz, Germany
| | - Oliver Burk
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany
| | | | - Holger Herlyn
- Institute of Anthropology, Johannes Gutenberg-University, Mainz, Germany
| | - Leszek Wojnowski
- Department of Pharmacology, University Medical Center, Mainz, Germany
| | - Björn Windshügel
- Centre for Bioinformatics, University of Hamburg, Hamburg, Germany
- European ScreeningPort GmbH, Hamburg, Germany
- * E-mail:
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19
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Kanno Y, Tanuma N, Yatsu T, Li W, Koike K, Inouye Y. Nigramide J is a novel potent inverse agonist of the human constitutive androstane receptor. Pharmacol Res Perspect 2014; 2:2. [PMID: 25505573 PMCID: PMC4186399 DOI: 10.1002/prp2.18] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 11/18/2013] [Accepted: 11/19/2013] [Indexed: 11/10/2022] Open
Abstract
The constitutive androstane receptor (CAR, NR1I3) is very important for drug development and for understanding pharmacokinetic drug-drug interactions. We screened by mammalian one hybrid assay among natural compounds to discover novel ligands of human constitutive androstane receptor (hCAR). hCAR transcriptional activity was measured by luciferase assay and mRNA levels of CYP2B6 and CYP3A4 in HepTR-hCAR cells and human primary hepatocytes were measured by real-time RT-PCR. Nigramide J (NJ) whose efficacy is comparable to those of hitherto known inverse agonists such as clotrimazole, PK11195, and ethinylestradiol. NJ is a naturally occurring cyclohexane-type amide alkaloid that was isolated from the roots of Piper nigrum. The suppressive effect of NJ on the CAR-dependent transcriptional activity was found to be species specific, in the descending order of hCAR, rat CAR, and mouse CAR. The unliganded hCAR-dependent transactivation of reporter and endogenous genes was suppressed by NJ at concentrations higher than 5 μmol/L. The ligand-binding cavity of hCAR was shared by NJ and CITCO, because they were competitive in the binding to hCAR. NJ interfered with the interaction of hCAR with coactivator SRC-1, but not with its interaction with the corepressor NCoR1. Furthermore, NJ is agonist of human pregnane X receptor (hPXR). NJ is a dual ligand of hCAR and hPXR, being an agonist of hPXR and an inverse agonist of hCAR.
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Affiliation(s)
- Yuichiro Kanno
- Faculty of Pharmaceutical Sciences, Toho University Miyama 2-2-1, Funabashi, Chiba, 274-8510, Japan
| | - Nobuaki Tanuma
- Faculty of Pharmaceutical Sciences, Toho University Miyama 2-2-1, Funabashi, Chiba, 274-8510, Japan
| | - Tomofumi Yatsu
- Faculty of Pharmaceutical Sciences, Toho University Miyama 2-2-1, Funabashi, Chiba, 274-8510, Japan
| | - Wei Li
- Faculty of Pharmaceutical Sciences, Toho University Miyama 2-2-1, Funabashi, Chiba, 274-8510, Japan
| | - Kazuo Koike
- Faculty of Pharmaceutical Sciences, Toho University Miyama 2-2-1, Funabashi, Chiba, 274-8510, Japan
| | - Yoshio Inouye
- Faculty of Pharmaceutical Sciences, Toho University Miyama 2-2-1, Funabashi, Chiba, 274-8510, Japan
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20
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Modulation of xenobiotic receptors by steroids. Molecules 2013; 18:7389-406. [PMID: 23884115 PMCID: PMC3777271 DOI: 10.3390/molecules18077389] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 06/13/2013] [Accepted: 06/19/2013] [Indexed: 12/13/2022] Open
Abstract
Nuclear receptors (NRs) are ligand-activated transcription factors that regulate the expression of their target genes. NRs play important roles in many human diseases, including metabolic diseases and cancer, and are therefore a key class of therapeutic targets. Steroids play important roles in regulating nuclear receptors; in addition to being ligands of steroid receptors, steroids (and their metabolites) also regulate other NRs, such as the pregnane X receptor and constitutive androstane receptor (termed xenobiotic receptors), which participate in steroid metabolism. Xenobiotic receptors have promiscuous ligand-binding properties, and their structurally diverse ligands include steroids and their metabolites. Therefore, steroids, their metabolism and metabolites, xenobiotic receptors, steroid receptors, and the respective signaling pathways they regulate have functional interactions. This review discusses these functional interactions and their implications for activities mediated by steroid receptors and xenobiotic receptors, focusing on steroids that modulate pathways involving the pregnane X receptor and constitutive androstane receptor. The emphasis of the review is on structure-function studies of xenobiotic receptors bound to steroid ligands.
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21
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Dau PT, Sakai H, Hirano M, Ishibashi H, Tanaka Y, Kameda K, Fujino T, Kim EY, Iwata H. Quantitative Analysis of the Interaction of Constitutive Androstane Receptor with Chemicals and Steroid Receptor Coactivator 1 Using Surface Plasmon Resonance Biosensor Systems: A Case Study of the Baikal Seal (Pusa sibirica) and the Mouse. Toxicol Sci 2012; 131:116-27. [DOI: 10.1093/toxsci/kfs288] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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22
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Abass K, Lämsä V, Reponen P, Küblbeck J, Honkakoski P, Mattila S, Pelkonen O, Hakkola J. Characterization of human cytochrome P450 induction by pesticides. Toxicology 2012; 294:17-26. [DOI: 10.1016/j.tox.2012.01.010] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Revised: 01/17/2012] [Accepted: 01/19/2012] [Indexed: 01/25/2023]
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Yang D, Yang J, Shi D, Deng R, Yan B. Scoparone potentiates transactivation of the bile salt export pump gene and this effect is enhanced by cytochrome P450 metabolism but abolished by a PKC inhibitor. Br J Pharmacol 2012; 164:1547-57. [PMID: 21649640 DOI: 10.1111/j.1476-5381.2011.01522.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Hyperbilirubinaemia and cholestasis are two major forms of liver abnormality. The Chinese herb Yin Chin has been used for thousands of years to treat liver dysfunctions. In mice, this herb and its principal ingredient scoparone were found to accelerate the clearance of bilirubin accompanied by the induction of uridine diphosphate-5'-glucuronosyltransferase-1A1 (UGT1A1), a bilirubin processing enzyme. The aim of this study was to determine whether scoparone induces the expression of human UGT1A1. In addition, the expression of the bile salt export pump (BSEP), a transporter of bile acids, was determined. EXPERIMENTAL APPROACH Primary human hepatocytes and hepatoma line Huh7 were treated with scoparone, chenodeoxycholic acid (CDCA) or both. The expression of UGT1A1 and BSEP mRNA was determined. The activation of the human BSEP promoter reporter by scoparone was determined in Huh7 cells by transient transfection and in mice by bioluminescent imaging. The metabolism of scoparone was investigated by recombinant CYP enzymes and pooled human liver microsomes. KEY RESULTS Scoparone did not enhance the expression of either human BSEP or, surprisingly, UGT1A1. However, scoparone significantly potentiated the expression of BSEP induced by CDCA. Consistent with this, scoparone potentiated the stimulant effect of CDCA on the human BSEP promoter. This potentiation was enhanced by co-transfection of cytochrome P4501A2 but abolished by the PKC inhibitor GF109203X. CONCLUSIONS AND IMPLICATIONS Scoparone and Yin Chin normalize liver function primarily by enhancing the secretion of bile acids, and this effect probably varies depending on the metabolic rate of scoparone.
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Affiliation(s)
- Dongfang Yang
- Department of Biomedical Sciences, Center for Pharmacogenomics and Molecular Therapy, University of Rhode Island, Kingston, RI 02881, USA
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24
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Windshügel B, Poso A. Constitutive activity and ligand-dependent activation of the nuclear receptor CAR-insights from molecular dynamics simulations. J Mol Recognit 2012; 24:875-82. [PMID: 21812062 DOI: 10.1002/jmr.1132] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The constitutive androstane receptor (CAR) possesses, unlike most other nuclear receptors, a pronounced basal activity in vitro whose structural basis is still not fully understood. Using comparative molecular dynamics simulations of CAR X-ray crystal structures, we evaluated the molecular basis for constitutive activity and ligand-dependent receptor activation. Our results suggest that a combination of van der Waals interactions and hydrogen bonds is required to maintain the activation helix in the active conformation also in absence of a ligand. Furthermore, we identified conformational rearrangements within the ligand-binding pocket upon agonist binding and an influence of CAR inducers pregnanedione and CITCO on the helical conformation of the activation helix. Based on the results a model for ligand-dependent CAR activation is suggested.
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Affiliation(s)
- Björn Windshügel
- Faculty of Health Sciences/School of Pharmacy, University of Eastern Finland, P.O. Box 1627, Kuopio 70211, Finland.
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25
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Jyrkkärinne J, Küblbeck J, Pulkkinen J, Honkakoski P, Laatikainen R, Poso A, Laitinen T. Molecular Dynamics Simulations for Human CAR Inverse Agonists. J Chem Inf Model 2012; 52:457-64. [DOI: 10.1021/ci200432k] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Johanna Jyrkkärinne
- University of Eastern Finland, Faculty of Health Sciences,
School of Pharmacy, P.O. Box 1627, FI-70211 Kuopio, Finland
| | - Jenni Küblbeck
- University of Eastern Finland, Faculty of Health Sciences,
School of Pharmacy, P.O. Box 1627, FI-70211 Kuopio, Finland
| | - Juha Pulkkinen
- University of Eastern Finland, Faculty of Health Sciences,
School of Pharmacy, P.O. Box 1627, FI-70211 Kuopio, Finland
| | - Paavo Honkakoski
- University of Eastern Finland, Faculty of Health Sciences,
School of Pharmacy, P.O. Box 1627, FI-70211 Kuopio, Finland
| | - Reino Laatikainen
- University of Eastern Finland, Faculty of Health Sciences,
School of Pharmacy, P.O. Box 1627, FI-70211 Kuopio, Finland
| | - Antti Poso
- University of Eastern Finland, Faculty of Health Sciences,
School of Pharmacy, P.O. Box 1627, FI-70211 Kuopio, Finland
| | - Tuomo Laitinen
- University of Eastern Finland, Faculty of Health Sciences,
School of Pharmacy, P.O. Box 1627, FI-70211 Kuopio, Finland
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26
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Küblbeck J, Laitinen T, Jyrkkärinne J, Rousu T, Tolonen A, Abel T, Kortelainen T, Uusitalo J, Korjamo T, Honkakoski P, Molnár F. Use of comprehensive screening methods to detect selective human CAR activators. Biochem Pharmacol 2011; 82:1994-2007. [DOI: 10.1016/j.bcp.2011.08.027] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Revised: 08/30/2011] [Accepted: 08/31/2011] [Indexed: 01/20/2023]
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27
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Küblbeck J, Jyrkkärinne J, Molnár F, Kuningas T, Patel J, Windshügel B, Nevalainen T, Laitinen T, Sippl W, Poso A, Honkakoski P. New in vitro tools to study human constitutive androstane receptor (CAR) biology: discovery and comparison of human CAR inverse agonists. Mol Pharm 2011; 8:2424-33. [PMID: 22044162 DOI: 10.1021/mp2003658] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The human constitutive androstane receptor (CAR, NR1I3) is one of the key regulators of xenobiotic and endobiotic metabolism. The unique properties of human CAR, such as the high constitutive activity and the complexity of signaling, as well as the lack of functional and predictive cell-based assays to study the properties of the receptor, have hindered the discovery of selective human CAR ligands. Here we report a novel human CAR inverse agonist, 1-[(2-methylbenzofuran-3-yl)methyl]-3-(thiophen-2-ylmethyl) urea (S07662), which suppresses human CAR activity, recruits the corepressor NCoR in cell-based assays, and attenuates the phenytoin- and 6-(4-chlorophenyl)imidazo[2,1-b][1,3]thiazole-5-carbaldehyde O-(3,4-dichlorobenzyl)oxime (CITCO)-induced expression of CYP2B6 mRNA in human primary hepatocytes. The properties of S07662 are also compared with those of known human CAR inverse agonists by using an array of different in vitro and in silico assays. The identified compound S07662 can be used as a chemical tool to study the biological functions of human CAR and also as a starting point for the development of new drugs for various conditions involving the receptor.
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Affiliation(s)
- Jenni Küblbeck
- Faculty of Health Sciences, School of Pharmacy, University of Eastern Finland & Biocenter Kuopio, P.O. Box 1627, FI-70211 Kuopio, Finland.
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Lau AJ, Yang G, Rajaraman G, Baucom CC, Chang TKH. Species-dependent and receptor-selective action of bilobalide on the function of constitutive androstane receptor and pregnane X receptor. Drug Metab Dispos 2011; 40:178-86. [PMID: 22019630 DOI: 10.1124/dmd.111.042879] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Bilobalide is a naturally occurring sesquiterpene trilactone with therapeutic potential in the management of ischemia and neurodegenerative diseases such as Alzheimer's disease. In the present study, we investigated the effect of bilobalide on the activity of rat constitutive androstane receptor (rCAR) and rat pregnane X receptor (rPXR) and compared that with human CAR (hCAR) and human PXR (hPXR). Bilobalide activated rCAR in a luciferase reporter gene assay and increased rCAR target gene expression in cultured rat hepatocytes, as determined by the CYP2B1 mRNA and CYP2B enzyme activity (benzyloxyresorufin O-dealkylation) assays. This increase in hepatocyte CYP2B1 expression by bilobalide was not accompanied by a corresponding increase in rCAR mRNA level. In contrast to the activation of rCAR, the activity of rPXR, hCAR, and hPXR was not influenced by this chemical in cell-based reporter gene assays. Consistent with these results, bilobalide did not alter rPXR, hCAR, or hPXR target gene expression in rat or human hepatocytes, as evaluated by the CYP3A23, CYP2B6, CYP3A4 mRNA assays and the CYP3A (testosterone 6β-hydroxylation) and CYP2B6 (bupropion hydroxylation) enzyme activity assays. Bilobalide was not an antagonist of rPXR, hCAR, or hPXR, as suggested by the finding that it did not attenuate rPXR activation by pregnenolone 16α-carbonitrile, hCAR activation by 6-(4-chlorophenyl)imidazo[2,1-b][1,3]thiazole-5-carbaldehyde O-(3,4-dichlorobenzyl)oxime, or hPXR activation by rifampicin in reporter gene assays. In conclusion, bilobalide is an activator of rCAR, whereas it is not a ligand of rPXR, hCAR, or hPXR. Likewise, it is an inducer of rat CYP2B1, but not of rat CYP3A23, human CYP2B6, or human CYP3A4.
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Affiliation(s)
- Aik Jiang Lau
- Faculty of Pharmaceutical Sciences, The University of British Columbia, 2146 East Mall, Vancouver, British Columbia, V6T 1Z3, Canada
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Kachaylo EM, Pustylnyak VO, Lyakhovich VV, Gulyaeva LF. Constitutive androstane receptor (CAR) is a xenosensor and target for therapy. BIOCHEMISTRY (MOSCOW) 2011; 76:1087-97. [DOI: 10.1134/s0006297911100026] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Pustylnyak V, Kazakova Y, Yarushkin A, Slynko N, Gulyaeva L. Effect of several analogs of 2,4,6-triphenyldioxane-1,3 on CYP2B induction in mouse liver. Chem Biol Interact 2011; 194:134-8. [PMID: 21982821 DOI: 10.1016/j.cbi.2011.09.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Revised: 09/05/2011] [Accepted: 09/22/2011] [Indexed: 11/26/2022]
Abstract
2,4,6-Triphenyldioxane-1,3 (TPD) is a highly effective inducer of CYP2В in rats, but not in mice. Several analogs of TPD were synthesized. All substituents were entered into the same position of TPD (R=H, cisTPD and transTPD; R=N(CH(3))(2), transpDMA; R=NO(2), transpNO(2); R=F, transpF; R=OCH(3), transpMeO). The purpose of the present study was to investigate the effect of TPD analogs on CYP2B induction in mouse livers. Among the six test compounds, four (R=-N(CH(3))(2), -NO(2), -F, -OCH(3)) demonstrated a dose-dependent induction of mouse CYP2B. To further characterize the compounds, we determined ED50s using sigmoidal dose-response curves. The dose-response study has shown that all active compounds have similar potencies to induce CYP2B in mouse livers. Western-blot analysis and multiplex RT-PCR have shown that the increase of CYP2B activity in mouse liver is related to the high content of CYP2B proteins and paralleled the increase of cyp2b10 mRNA level. ChIP results have demonstrated that the transcriptional enhancement of cyp2b10 gene in response to compounds is accompanied by the increased recruitment of the constitutive androstane receptor (CAR) to its specific binding site (PBREM) on the target gene. Thus, minor structural changes in TPD cause dramatic changes in its ability to induce mouse CYP2B, and it is likely several TPD analogs act by activation of mouse CAR.
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Affiliation(s)
- Vladimir Pustylnyak
- Institute of Molecular Biology and Biophysics, SB RAMS, Novosibirsk, Russia.
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Boverhof DR, Chamberlain MP, Elcombe CR, Gonzalez FJ, Heflich RH, Hernández LG, Jacobs AC, Jacobson-Kram D, Luijten M, Maggi A, Manjanatha MG, Benthem JV, Gollapudi BB. Transgenic animal models in toxicology: historical perspectives and future outlook. Toxicol Sci 2011; 121:207-33. [PMID: 21447610 DOI: 10.1093/toxsci/kfr075] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Transgenic animal models are powerful tools for developing a more detailed understanding on the roles of specific genes in biological pathways and systems. Applications of these models have been made within the field of toxicology, most notably for the screening of mutagenic and carcinogenic potential and for the characterization of toxic mechanisms of action. It has long been a goal of research toxicologists to use the data from these models to refine hazard identification and characterization to better inform human health risk assessments. This review provides an overview on the applications of transgenic animal models in the assessment of mutagenicity and carcinogenicity, their use as reporter systems, and as tools for understanding the roles of xenobiotic-metabolizing enzymes and biological receptors in the etiology of chemical toxicity. Perspectives are also shared on the future outlook for these models in toxicology and risk assessment and how transgenic technologies are likely to be an integral tool for toxicity testing in the 21st century.
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Affiliation(s)
- Darrell R Boverhof
- Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, Michigan 48674, USA.
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Li H, Wang H. Activation of xenobiotic receptors: driving into the nucleus. Expert Opin Drug Metab Toxicol 2010; 6:409-26. [PMID: 20113149 DOI: 10.1517/17425251003598886] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
IMPORTANCE OF THE FIELD Xenobiotic receptors (XRs) play pivotal roles in regulating the expression of genes that determine the clearance and detoxification of xenobiotics, such as drugs and environmental chemicals. Recently, it has become increasingly evident that most XRs shuttle between the cytoplasm and nucleus, and activation of such receptors is directly associated with xenobiotic-induced nuclear import. AREAS COVERED IN THIS REVIEW The scope of this review covers research literature that discusses nuclear translocation and activation of XRs, as well as unpublished data generated from this laboratory. Specific emphasis is given to the constitutive androstane receptor (CAR), the pregnane X receptor and the aryl hydrocarbon receptor. WHAT THE READERS WILL GAIN A number of molecular chaperons presumably associated with cellular localization of XRs have been identified. Primary hepatocyte cultures have been established as a unique model retaining inactive CAR in the cytoplasm. Moreover, several splicing variants of human CAR exhibit altered cellular localization and chemical activation. TAKE HOME MESSAGE Nuclear accumulation is an essential step in the activation of XRs. Although great strides have been made, much remains to be understood concerning the mechanisms underlying intracellular localization and trafficking of XRs, which involve both direct ligand-binding and indirect pathways.
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Affiliation(s)
- Haishan Li
- University of Maryland School of Pharmacy, Department of Pharmaceutical Sciences, 20 Penn Street, Baltimore, MD 21201, USA
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Mohutsky MA, Romeike A, Meador V, Lee WM, Fowler J, Francke-Carroll S. Hepatic Drug-Metabolizing Enzyme Induction and Implications for Preclinical and Clinical Risk Assessment. Toxicol Pathol 2010; 38:799-809. [DOI: 10.1177/0192623310375099] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Hepatic drug metabolizing enzyme (DME) induction complicates the development of new drugs owing to altered efficacy of concomitant treatments, reduction in exposure resulting from autoinduction, and potential generation of toxic metabolites. Risk assessment of DME induction during clinical evaluation is confounded by several uncertainties pertaining to hazard identification and dose response analysis. Hepatic DME induction rarely leads to clinical evidence of altered metabolism and toxicity in the patient, which typically occur only if the DME induction is relatively severe. High drug doses are associated with a greater likelihood of hepatic DME induction and downstream effects; therefore, drugs of low potency requiring higher dosing tend to lead to a greater risk of drug–drug interactions. Vigilance in clinical trials for increased or diminished drug effect and, specifically, pharmacokinetic studies in the presence of other drugs and concomitant diseases are necessary for a drug risk assessment profile. Efforts to remove hepatic DME-inducing drugs from development can be facilitated with current in vitro and in vivo assessments and will improve with the development of newer technologies. A carefully tailored case-by-case approach will lead to the development of efficacious drugs with an acceptable risk/benefit profile available to patients.
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Affiliation(s)
| | | | | | - William M. Lee
- Department of Internal Medicine, UT Southwestern Medical Center at Dallas, Dallas, TX, USA
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di Masi A, De Marinis E, Ascenzi P, Marino M. Nuclear receptors CAR and PXR: Molecular, functional, and biomedical aspects. Mol Aspects Med 2009; 30:297-343. [PMID: 19427329 DOI: 10.1016/j.mam.2009.04.002] [Citation(s) in RCA: 213] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2009] [Accepted: 04/28/2009] [Indexed: 12/31/2022]
Abstract
Nuclear receptors (NRs) are ligand-activated transcription factors sharing a common evolutionary history and having similar sequence features at the protein level. Selective ligand(s) for some NRs is not known, therefore these NRs have been named "orphan receptors". Whenever ligands have been recognized for any of the orphan receptor, it has been categorized and grouped as "adopted" orphan receptor. This group includes the constitutive androstane receptor (CAR) and the pregnane X receptor (PXR). They function as sensors of toxic byproducts derived from endogenous metabolites and of exogenous chemicals, in order to enhance their elimination. This unique function of CAR and PXR sets them apart from the steroid hormone receptors. The broad response profile has established that CAR and PXR are xenobiotic sensors that coordinately regulate xenobiotic clearance in the liver and intestine via induction of genes involved in drug and xenobiotic metabolism. In the past few years, research has revealed new and mostly unsuspected roles for CAR and PXR in modulating hormone, lipid, and energy homeostasis as well as cancer and liver steatosis. The purpose of this review is to highlight the structural and molecular bases of CAR and PXR impact on human health, providing information on mechanisms through which diet, chemical exposure, and environment ultimately impact health and disease.
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Affiliation(s)
- Alessandra di Masi
- Department of Biology, University Roma Tre, Viale Guglielmo Marconi 446, I-00146 Roma, Italy
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35
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Jyrkkärinne J, Windshügel B, Rönkkö T, Tervo AJ, Küblbeck J, Lahtela-Kakkonen M, Sippl W, Poso A, Honkakoski P. Insights into ligand-elicited activation of human constitutive androstane receptor based on novel agonists and three-dimensional quantitative structure-activity relationship. J Med Chem 2009; 51:7181-92. [PMID: 18983136 DOI: 10.1021/jm800731b] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The human constitutive androstane receptor (CAR, NR1I3) is an important regulator of xenobiotic metabolism and other physiological processes. So far, only few CAR agonists are known and no explicit mechanism has been proposed for their action. Thus, we aimed to generate a 3D QSAR model that could explain the molecular determinants of CAR agonist action. To obtain a sufficient number of agonists that cover a wide range of activity, we applied a virtual screening approach using both structure- and ligand-based methods. We identified 27 novel human CAR agonists on which a 3D QSAR model was generated. The model, complemented by coregulator recruitment and mutagenesis results, suggests a potential activation mechanism for human CAR and may serve to predict potential activation of CAR for compounds emerging from drug development projects or for chemicals undergoing toxicological risk assessment.
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Affiliation(s)
- Johanna Jyrkkärinne
- Departments of Pharmaceutics and Pharmaceutical Chemistry, University of Kuopio, P.O. Box 1627, 70211 Kuopio, Finland
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Repo S, Jyrkkärinne J, Pulkkinen JT, Laatikainen R, Honkakoski P, Johnson MS. Ligand specificity of constitutive androstane receptor as probed by induced-fit docking and mutagenesis. J Med Chem 2009; 51:7119-31. [PMID: 18973326 DOI: 10.1021/jm800337r] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Constitutive androstane receptor (CAR, NR1I3) belongs to the nuclear receptor family of transcription factors and acts as a chemical sensor of drugs and endogenous compounds. The ligand-binding preferences of CAR are diverse, and more importantly, there are significant species differences in ligand specificity. Here, we show that while certain residues are critical for the basal activity of mouse CAR (mCAR) and/or affect the binding of all tested ligands, mutation of some ligand-binding pocket (LBP) residues (e.g., F171 and Y336) paradoxically decreased the activity of a specific ligand while increasing that of others. Comparisons to previously reported human CAR (hCAR) residues indicated that the function of key CAR residues (e.g., N175, L253) is dramatically different between species. The docking results provide some mechanistic rationale for the ability of 17alpha-ethinyl-3,17beta-estradiol (EE2) to both activate mCAR and repress hCAR.
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Affiliation(s)
- Susanna Repo
- Structural Bioinformatics Laboratory, Department of Biochemistry and Pharmacy, Abo Akademi University, Tykistökatu 6, FI-20520 Turku, Finland
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Fox JE, Burow ME, McLachlan JA, Miller CA. Detecting ligands and dissecting nuclear receptor-signaling pathways using recombinant strains of the yeast Saccharomyces cerevisiae. Nat Protoc 2008; 3:637-45. [PMID: 18388946 DOI: 10.1038/nprot.2008.33] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This is a general protocol for the identification of natural and xenobiotic ligands of metazoan nuclear receptors (NRs) expressed in yeast. Yeast engineered to express an NR and a response element-driven reporter gene provide a system to detect and quantify ligand-dependent transcriptional activity. Such assays allow researchers to measure different types of ligands and determine dose-dependent activation of NRs. This methodology can also be used to examine the components of signal transduction pathways when conducted with mutant or engineered yeast strains expressing additional proteins or having alternate DNA response elements. This assay typically takes 2-3 d to complete, but most of this time entails cell growth rather than 'hands on' time.
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Affiliation(s)
- Jennifer E Fox
- Center for Ecology and Evolutionary Biology, University of Oregon, Eugene, Oregon 97403, USA
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38
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Küblbeck J, Jyrkkärinne J, Poso A, Turpeinen M, Sippl W, Honkakoski P, Windshügel B. Discovery of substituted sulfonamides and thiazolidin-4-one derivatives as agonists of human constitutive androstane receptor. Biochem Pharmacol 2008; 76:1288-97. [PMID: 18786510 DOI: 10.1016/j.bcp.2008.08.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2008] [Revised: 08/11/2008] [Accepted: 08/13/2008] [Indexed: 02/04/2023]
Abstract
The constitutive androstane receptor (CAR; NR1I3) is a nuclear receptor responsible for the recognition of potentially toxic endo- and exogenous compounds whose elimination from the body is accelerated by the CAR-mediated inducible expression of metabolizing enzymes and transporters. Despite the importance of CAR, few human agonists are known so far. Following a sequential virtual screening procedure using a 3D pharmacophore and molecular docking approach, we identified 17 novel agonists that could activate human CAR in vitro and enhance its association with the nuclear receptor co-activator SRC1. Selected agonists also increased the expression of the human CAR target CYP2B6 mRNA in primary hepatocytes. Composed of substituted sulfonamides and thiazolidin-4-one derivatives, these agonists represent two novel chemotypes capable of human CAR activation, thus broadening the agonist spectrum of CAR.
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Affiliation(s)
- Jenni Küblbeck
- Department of Pharmaceutics, University of Kuopio, Yliopistonranta 1C, FI-70210 Kuopio, Finland
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Pelkonen O, Turpeinen M, Hakkola J, Honkakoski P, Hukkanen J, Raunio H. Inhibition and induction of human cytochrome P450 enzymes: current status. Arch Toxicol 2008; 82:667-715. [PMID: 18618097 DOI: 10.1007/s00204-008-0332-8] [Citation(s) in RCA: 374] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2008] [Accepted: 06/16/2008] [Indexed: 02/07/2023]
Abstract
Variability of drug metabolism, especially that of the most important phase I enzymes or cytochrome P450 (CYP) enzymes, is an important complicating factor in many areas of pharmacology and toxicology, in drug development, preclinical toxicity studies, clinical trials, drug therapy, environmental exposures and risk assessment. These frequently enormous consequences in mind, predictive and pre-emptying measures have been a top priority in both pharmacology and toxicology. This means the development of predictive in vitro approaches. The sound prediction is always based on the firm background of basic research on the phenomena of inhibition and induction and their underlying mechanisms; consequently the description of these aspects is the purpose of this review. We cover both inhibition and induction of CYP enzymes, always keeping in mind the basic mechanisms on which to build predictive and preventive in vitro approaches. Just because validation is an essential part of any in vitro-in vivo extrapolation scenario, we cover also necessary in vivo research and findings in order to provide a proper view to justify in vitro approaches and observations.
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Affiliation(s)
- Olavi Pelkonen
- Department of Pharmacology and Toxicology, Institute of Biomedicine, University of Oulu, PO Box 5000 (Aapistie 5 B), 90014 Oulu, Finland.
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40
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Li L, Chen T, Stanton JD, Sueyoshi T, Negishi M, Wang H. The peripheral benzodiazepine receptor ligand 1-(2-chlorophenyl-methylpropyl)-3-isoquinoline-carboxamide is a novel antagonist of human constitutive androstane receptor. Mol Pharmacol 2008; 74:443-53. [PMID: 18492798 DOI: 10.1124/mol.108.046656] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
As a promiscuous xenobiotic sensor, the constitutive androstane receptor (CAR; NR1I3) regulates the expression of multiple drug-metabolizing enzymes and transporters in liver. The constitutively activated nature of CAR in the cell-based transfection assays has hindered its use as a predictor of metabolism-based drug-drug interactions. Here, we have identified 1-(2-chlorophenylmethylpropyl)-3-isoquinoline-carboxamide (PK11195), a typical peripheral benzodiazepine receptor (PBR) ligand, as a selective and potent inhibitor of human (h) CAR. In cell-based transfection assays, PK11195 inhibited the constitutive activity of hCAR more than 80% at the concentration of 10 microM, and the PK11195-inhibited activity was efficiently reactivated by the direct CAR activator, 6-(4-chlorophenyl)imidazo[2,1-b][1,3]thiazole-5-carbaldehyde-O-(3,4-dichlorobenzyl) oxime, but not by the indirect hCAR activator, phenobarbital. Mammalian two-hybrid and GST pull-down assays showed that PK11195 repressed the interactions of hCAR with the coactivators steroid receptor coactivator-1 and glucocorticoid receptor-interacting protein 1 to inhibit hCAR activity. The inhibition by PK11195 specifically occurred to the hCAR: PK1195 strongly activated human pregnane X receptor (PXR), whereas it did not alter the activity of the mouse CAR and mouse PXR. In addition, PBR played no role in the PK11195 inhibition of hCAR because the inhibition fully occurred in the HeLa cells in which the PBR was knocked down by small interfering RNA. In the Car(-/-) mouse liver, PK11195 translocated enhanced yellow fluorescent protein-hCAR into the nucleus. These results are consistent with the conclusion that PK11195 is a novel hCAR-specific antagonist that represses the CAR-coactivator interactions to inhibit the receptor activity inside the nucleus. Thus, PK11195 can be used as a chemical tool for studying the molecular basis of CAR function.
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Affiliation(s)
- Linhao Li
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland at Baltimore, 20 Penn Street, Baltimore, MD 21201, USA
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Abstract
The constitutive androstane receptor (CAR), a member of the NR1I group of nuclear hormone receptors, has been implicated in regulating the expression of genes that are critical in xenobiotic and endobiotic metabolism, uptake and elimination as well as genes involved in various other physiological processes. Hence, functional variation in CAR associated with its expression and/or activity can influence the transcriptional activation of its target genes and could contribute to the observed variation in drug response and toxicity. Moreover, coadministration of agents that are also CAR activators contributes to clinically relevant drug-drug interactions in patients receiving certain combination therapies. This review will discuss the functional significance of known genetic variants in CAR and the most common alternatively spliced isoforms of CAR. We will also discuss the influence of gender and ethnicity on CAR and its target genes. Although genetic polymorphisms in CAR may have an indirect effect on drug disposition, understanding the association of genetic polymorphisms in CAR with the expression of its target genes might help us to better understand the molecular mechanisms underlying the interindividual variation in drug disposition in addition to drug-drug interactions.
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Affiliation(s)
- Jatinder K Lamba
- St Jude Children's Research Hospital, Department of Pharmaceutical Sciences, 332 North Lauderdale Street, Memphis, TN 38105, USA.
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Pustylnyak VO, Gulyaeva LF, Lyakhovich VV. Induction of cytochrome P4502B: Role of regulatory elements and nuclear receptors. BIOCHEMISTRY (MOSCOW) 2007; 72:608-17. [PMID: 17630905 DOI: 10.1134/s000629790706003x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Cytochrome P450 of the 2B subfamily is easily induced by many xenobiotics. In spite of intensive investigations, the molecular mechanisms of regulation of the CYP2B genes are not clear. The nuclear receptor CAR is shown to play a crucial role in the activation of CYP2B genes by xenobiotics, but many problems of CAR activation in different animal species and humans remain unsolved. This review focuses on signaling pathways involved in the control of CYP2B gene expression in mammals.
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Affiliation(s)
- V O Pustylnyak
- Institute of Molecular Biology and Biophysics, Siberian Division of the Russian Academy of Medical Sciences, Novosibirsk 630117, Russia.
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Timsit YE, Negishi M. CAR and PXR: the xenobiotic-sensing receptors. Steroids 2007; 72:231-46. [PMID: 17284330 PMCID: PMC1950246 DOI: 10.1016/j.steroids.2006.12.006] [Citation(s) in RCA: 311] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2006] [Revised: 12/07/2006] [Accepted: 12/11/2006] [Indexed: 01/13/2023]
Abstract
The xenobiotic receptors CAR and PXR constitute two important members of the NR1I nuclear receptor family. They function as sensors of toxic byproducts derived from endogenous metabolism and of exogenous chemicals, in order to enhance their elimination. This unique function of CAR and PXR sets them apart from the steroid hormone receptors. In contrast, the steroid receptors, exemplified by the estrogen receptor (ER) and glucocorticoid receptor (GR), are the sensors that tightly monitor and respond to changes in circulating steroid hormone levels to maintain body homeostasis. This divergence of the chemical- and steroid-sensing functions has evolved to ensure the fidelity of the steroid hormone endocrine regulation while allowing development of metabolic elimination pathways for xenobiotics. The development of the xenobiotic receptors CAR and PXR also reflect the increasing complexity of metabolism in higher organisms, which necessitate novel mechanisms for handling and eliminating metabolic by-products and foreign compounds from the body. The purpose of this review is to discuss similarities and differences between the xenobiotic receptors CAR and PXR with the prototypical steroid hormone receptors ER and GR. Interesting differences in structure explain in part the divergence in function and activation mechanisms of CAR/PXR from ER/GR. In addition, the physiological roles of CAR and PXR will be reviewed, with discussion of interactions of CAR and PXR with endocrine signaling pathways.
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Affiliation(s)
| | - Masahiko Negishi
- *CORRESPONDING AUTHOR ADDRESS: Dr, Masahiko Negishi, Ph.D., Head, Pharmacogenetics Section, Laboratory of Reproductive and Developmental Toxicology, National Institute of Environmental Health Sciences, 111 T.W. Alexander Drive, Research Triangle Park, NC, 27709, Tel: (919) 541-2942, Fax (919) 541-0696,
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Stanley LA, Horsburgh BC, Ross J, Scheer N, Wolf CR. PXR and CAR: nuclear receptors which play a pivotal role in drug disposition and chemical toxicity. Drug Metab Rev 2006; 38:515-97. [PMID: 16877263 DOI: 10.1080/03602530600786232] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Xenobiotic metabolism and detoxification is regulated by receptors (e.g., PXR, CAR) whose characterization has contributed significantly to our understanding of drug responses in humans. Technologies facilitating the screening of compounds for receptor interactions provide valuable tools applicable in drug development. Most use in vitro systems or mice humanized for receptors in vivo. In vitro assays are limited by the reporter systems and cell lines chosen and are uninformative about effects in vivo. Humanized mouse models provide novel, exciting ways of understanding the functions of these genes. This article evaluates these technologies and current knowledge on PXR/CAR-mediated regulation of gene expression.
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Affiliation(s)
- Lesley A Stanley
- Consultant in Investigative Toxicology, St. Andrews, Fife, United Kingdom
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45
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Windshügel B, Jyrkkärinne J, Vanamo J, Poso A, Honkakoski P, Sippl W. Comparison of homology models and X-ray structures of the nuclear receptor CAR: assessing the structural basis of constitutive activity. J Mol Graph Model 2006; 25:644-57. [PMID: 16831563 DOI: 10.1016/j.jmgm.2006.05.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2005] [Revised: 04/28/2006] [Accepted: 05/02/2006] [Indexed: 12/31/2022]
Abstract
The constitutive androstane receptor (CAR) possesses an intrinsic basal activity whose structural basis has been analysed during the last decade. Recently, we published a homology model of the CAR ligand binding domain (LBD) based on the X-ray structures of the closely related pregnane X (PXR) and vitamin D (VDR) receptor. A detailed analysis of the homology model and molecular dynamics (MD) simulations afforded us to propose a potential mechanism underlying the constitutive activity of CAR. Almost simultaneously, X-ray structures of human and mouse CAR LBD were released. In the present study, a detailed analysis and comparison of homology model and X-ray structures is carried out in order to evaluate the quality and reliability of our homology modelling procedure. The hypothesis of the constitutive activity which we proposed on the basis of our modelling results was tested for consistency with the crystal structures. In addition, the features stated to be essential for the basal activity based on the X-ray data were investigated by means of molecular dynamics simulations. Our results show that the homology modelling procedure was able to predict the CAR LBD structure with high accuracy. Structural features that have been revealed as critical for constitutive activity in the model are also observed in the X-ray structures. Furthermore, the MD simulations of the CAR X-ray structures and a detailed analysis of other NRs clarify the role of distinct structural features that have been assigned an important role for the constitutive activity.
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Affiliation(s)
- Björn Windshügel
- Institute of Pharmaceutical Chemistry, Martin-Luther-University Halle-Wittenberg, Wolfgang-Langenbeck-Str. 4, 06120 Halle (Saale), Germany.
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Lempiäinen H, Molnár F, Macias Gonzalez M, Peräkylä M, Carlberg C. Antagonist- and inverse agonist-driven interactions of the vitamin D receptor and the constitutive androstane receptor with corepressor protein. Mol Endocrinol 2005; 19:2258-72. [PMID: 15905360 DOI: 10.1210/me.2004-0534] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Ligand-dependent signal transduction by nuclear receptors (NRs) includes dynamic exchanges of coactivator (CoA) and corepressor (CoR) proteins. Here we focused on the structural determinants of the antagonist- and inverse agonist-enhanced interaction of the endocrine NR vitamin D receptor (VDR) and the adopted orphan NR constitutive androstane receptor (CAR) from two species with the CoR NR corepressor. We found that the pure VDR antagonist ZK168281 and the human CAR inverse agonist clotrimazole are both effective inhibitors of the CoA interaction of their respective receptors, whereas ZK168281 resembled more the mouse CAR inverse agonist androstanol in its ability to recruit CoR proteins. Molecular dynamics simulations resulted in comparable models for the CoR receptor interaction domain peptide bound to VDR/antagonist or CAR/inverse agonist complexes. A salt bridge between the CoR and a conserved lysine in helix 4 of the NR is central to this interaction, but also helix 12 was stabilized by direct contacts with residues of the CoR. Fixation of helix 12 in the antagonistic/inverse agonistic conformation prevents an energetically unfavorable free floatation of the C terminus. The comparable molecular mechanisms that explain the similar functional profile of antagonist and inverse agonists are likely to be extended from VDR and CAR to other members of the NR superfamily and may lead to the design of even more effective ligands.
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Affiliation(s)
- Harri Lempiäinen
- Department of Biochemistry, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland
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