1
|
Wang M, Yang Y, Xu Y. Brain nuclear receptors and cardiovascular function. Cell Biosci 2023; 13:14. [PMID: 36670468 PMCID: PMC9854230 DOI: 10.1186/s13578-023-00962-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 01/12/2023] [Indexed: 01/22/2023] Open
Abstract
Brain-heart interaction has raised up increasing attentions. Nuclear receptors (NRs) are abundantly expressed in the brain, and emerging evidence indicates that a number of these brain NRs regulate multiple aspects of cardiovascular diseases (CVDs), including hypertension, heart failure, atherosclerosis, etc. In this review, we will elaborate recent findings that have established the physiological relevance of brain NRs in the context of cardiovascular function. In addition, we will discuss the currently available evidence regarding the distinct neuronal populations that respond to brain NRs in the cardiovascular control. These findings suggest connections between cardiac control and brain dynamics through NR signaling, which may lead to novel tools for the treatment of pathological changes in the CVDs.
Collapse
Affiliation(s)
- Mengjie Wang
- grid.508989.50000 0004 6410 7501Department of Pediatrics, USDA/ARS Children’s Nutrition Research Center, Baylor College of Medicine, Houston, TX USA
| | - Yongjie Yang
- grid.508989.50000 0004 6410 7501Department of Pediatrics, USDA/ARS Children’s Nutrition Research Center, Baylor College of Medicine, Houston, TX USA
| | - Yong Xu
- grid.508989.50000 0004 6410 7501Department of Pediatrics, USDA/ARS Children’s Nutrition Research Center, Baylor College of Medicine, Houston, TX USA ,grid.39382.330000 0001 2160 926XDepartment of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX USA
| |
Collapse
|
2
|
Russell LE, Zhou Y, Almousa AA, Sodhi JK, Nwabufo CK, Lauschke VM. Pharmacogenomics in the era of next generation sequencing - from byte to bedside. Drug Metab Rev 2021; 53:253-278. [PMID: 33820459 DOI: 10.1080/03602532.2021.1909613] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Pharmacogenetic research has resulted in the identification of a multitude of genetic variants that impact drug response or toxicity. These polymorphisms are mostly common and have been included as actionable information in the labels of numerous drugs. In addition to common variants, recent advances in Next Generation Sequencing (NGS) technologies have resulted in the identification of a plethora of rare and population-specific pharmacogenetic variations with unclear functional consequences that are not accessible by conventional forward genetics strategies. In this review, we discuss how comprehensive sequencing information can be translated into personalized pharmacogenomic advice in the age of NGS. Specifically, we provide an update of the functional impacts of rare pharmacogenetic variability and how this information can be leveraged to improve pharmacogenetic guidance. Furthermore, we critically discuss the current status of implementation of pharmacogenetic testing across drug development and layers of care. We identify major gaps and provide perspectives on how these can be minimized to optimize the utilization of NGS data for personalized clinical decision-support.
Collapse
Affiliation(s)
| | - Yitian Zhou
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Ahmed A Almousa
- Department of Pharmacy, London Health Sciences Center, Victoria Hospital, London, ON, Canada
| | - Jasleen K Sodhi
- Department of Bioengineering and Therapeutic Sciences, Schools of Pharmacy and Medicine, University of California San Francisco, San Francisco, CA, USA.,Department of Drug Metabolism and Pharmacokinetics, Plexxikon, Inc., Berkeley, CA, USA
| | | | - Volker M Lauschke
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| |
Collapse
|
3
|
McDonough CM, Xu HS, Guo TL. Toxicity of bisphenol analogues on the reproductive, nervous, and immune systems, and their relationships to gut microbiome and metabolism: insights from a multi-species comparison. Crit Rev Toxicol 2021; 51:283-300. [PMID: 33949917 DOI: 10.1080/10408444.2021.1908224] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Bisphenols are common chemicals found in plastics and epoxy resins. Over the past decades, many studies have shown that bisphenol A (BPA) is a potential endocrine-disrupting chemical that may cause multisystem toxicity. However, the relative safety of BPA analogues is a controversial subject. Herein, we conducted a review of the reproductive toxicity, neurotoxicity, immunotoxicity, metabolic toxicity and gut microbiome toxicity of the BPA analogues in various species, including Caenorhabditis elegans, zebrafish, turtles, sheep, rodents, and humans. In addition, the mechanisms of action were discussed with focus on bisphenol S and bisphenol F. It was found that these BPA analogues exert their toxic effects on different organs and systems through various mechanisms including epigenetic modifications and effects on cell signaling pathways, microbiome, and metabolome in different species. More research is needed to study the relative toxicity of the lesser-known BPA analogues compared to BPA, both systemically and organ specifically, and to better define the underlying mechanisms of action, in particular, the potentials of disrupting microbiome and metabolism.
Collapse
Affiliation(s)
- Callie M McDonough
- Department of Veterinary Biosciences and Diagnostic Imaging, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Hannah Shibo Xu
- Department of Veterinary Biosciences and Diagnostic Imaging, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Tai L Guo
- Department of Veterinary Biosciences and Diagnostic Imaging, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| |
Collapse
|
4
|
Abstract
The regulation of brain cytochrome P450 enzymes (CYPs) is different compared with respective hepatic enzymes. This may result from anatomical bases and physiological functions of the two organs. The brain is composed of a variety of functional structures built of different interconnected cell types endowed with specific receptors that receive various neuronal signals from other brain regions. Those signals activate transcription factors or alter functioning of enzyme proteins. Moreover, the blood-brain barrier (BBB) does not allow free penetration of all substances from the periphery into the brain. Differences in neurotransmitter signaling, availability to endogenous and exogenous active substances, and levels of transcription factors between neuronal and hepatic cells lead to differentiated expression and susceptibility to the regulation of CYP genes in the brain and liver. Herein, we briefly describe the CYP enzymes of CYP1-3 families, their distribution in the brain, and discuss brain-specific regulation of CYP genes. In parallel, a comparison to liver CYP regulation is presented. CYP enzymes play an essential role in maintaining the levels of bioactive molecules within normal ranges. These enzymes modulate the metabolism of endogenous neurochemicals, such as neurosteroids, dopamine, serotonin, melatonin, anandamide, and exogenous substances, including psychotropics, drugs of abuse, neurotoxins, and carcinogens. The role of these enzymes is not restricted to xenobiotic-induced neurotoxicity, but they are also involved in brain physiology. Therefore, it is crucial to recognize the function and regulation of CYP enzymes in the brain to build a foundation for future medicine and neuroprotection and for personalized treatment of brain diseases.
Collapse
Affiliation(s)
- Wojciech Kuban
- Department of Pharmacokinetics and Drug Metabolism, Maj Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland
| | - Władysława Anna Daniel
- Department of Pharmacokinetics and Drug Metabolism, Maj Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland
| |
Collapse
|
5
|
Oliviero F, Lukowicz C, Boussadia B, Forner-Piquer I, Pascussi JM, Marchi N, Mselli-Lakhal L. Constitutive Androstane Receptor: A Peripheral and a Neurovascular Stress or Environmental Sensor. Cells 2020; 9:E2426. [PMID: 33171992 PMCID: PMC7694609 DOI: 10.3390/cells9112426] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 10/27/2020] [Accepted: 11/02/2020] [Indexed: 12/11/2022] Open
Abstract
Xenobiotic nuclear receptors (NR) are intracellular players involved in an increasing number of physiological processes. Examined and characterized in peripheral organs where they govern metabolic, transport and detoxification mechanisms, accumulating data suggest a functional expression of specific NR at the neurovascular unit (NVU). Here, we focus on the Constitutive Androstane Receptor (CAR), expressed in detoxifying organs such as the liver, intestines and kidneys. By direct and indirect activation, CAR is implicated in hepatic detoxification of xenobiotics, environmental contaminants, and endogenous molecules (bilirubin, bile acids). Importantly, CAR participates in physiological stress adaptation responses, hormonal and energy homeostasis due to glucose and lipid sensing. We next analyze the emerging evidence supporting a role of CAR in NVU cells including the blood-brain barrier (BBB), a key vascular interface regulating communications between the brain and the periphery. We address the emerging concept of how CAR may regulate specific P450 cytochromes at the NVU and the associated relevance to brain diseases. A clear understanding of how CAR engages during pathological conditions could enable new mechanistic, and perhaps pharmacological, entry-points within a peripheral-brain axis.
Collapse
Affiliation(s)
- Fabiana Oliviero
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, 31027 Toulouse, France; (F.O.); (C.L.)
| | - Céline Lukowicz
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, 31027 Toulouse, France; (F.O.); (C.L.)
| | - Badreddine Boussadia
- Cerebrovascular and Glia Research, Institute of Functional Genomics (UMR 5203 CNRS–U 1191 INSERM, University of Montpellier), 34094 Montpellier, France; (B.B.); (I.F.-P.); (J.-M.P.)
| | - Isabel Forner-Piquer
- Cerebrovascular and Glia Research, Institute of Functional Genomics (UMR 5203 CNRS–U 1191 INSERM, University of Montpellier), 34094 Montpellier, France; (B.B.); (I.F.-P.); (J.-M.P.)
| | - Jean-Marc Pascussi
- Cerebrovascular and Glia Research, Institute of Functional Genomics (UMR 5203 CNRS–U 1191 INSERM, University of Montpellier), 34094 Montpellier, France; (B.B.); (I.F.-P.); (J.-M.P.)
| | - Nicola Marchi
- Cerebrovascular and Glia Research, Institute of Functional Genomics (UMR 5203 CNRS–U 1191 INSERM, University of Montpellier), 34094 Montpellier, France; (B.B.); (I.F.-P.); (J.-M.P.)
| | - Laila Mselli-Lakhal
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, 31027 Toulouse, France; (F.O.); (C.L.)
| |
Collapse
|
6
|
Daujat-Chavanieu M, Gerbal-Chaloin S. Regulation of CAR and PXR Expression in Health and Disease. Cells 2020; 9:E2395. [PMID: 33142929 PMCID: PMC7692647 DOI: 10.3390/cells9112395] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 10/22/2020] [Accepted: 10/28/2020] [Indexed: 12/12/2022] Open
Abstract
Pregnane X receptor (PXR, NR1I2) and constitutive androstane receptor (CAR, NR1I3) are members of the nuclear receptor superfamily that mainly act as ligand-activated transcription factors. Their functions have long been associated with the regulation of drug metabolism and disposition, and it is now well established that they are implicated in physiological and pathological conditions. Considerable efforts have been made to understand the regulation of their activity by their cognate ligand; however, additional regulatory mechanisms, among which the regulation of their expression, modulate their pleiotropic effects. This review summarizes the current knowledge on CAR and PXR expression during development and adult life; tissue distribution; spatial, temporal, and metabolic regulations; as well as in pathological situations, including chronic diseases and cancers. The expression of CAR and PXR is modulated by complex regulatory mechanisms that involve the interplay of transcription factors and also post-transcriptional and epigenetic modifications. Moreover, many environmental stimuli affect CAR and PXR expression through mechanisms that have not been elucidated.
Collapse
Affiliation(s)
| | - Sabine Gerbal-Chaloin
- IRMB, University of Montpellier, INSERM, CHU Montpellier, 34295 Montpellier, France;
| |
Collapse
|
7
|
Torres-Vergara P, Ho YS, Espinoza F, Nualart F, Escudero C, Penny J. The constitutive androstane receptor and pregnane X receptor in the brain. Br J Pharmacol 2020; 177:2666-2682. [PMID: 32201941 DOI: 10.1111/bph.15055] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 03/11/2020] [Accepted: 03/12/2020] [Indexed: 12/16/2022] Open
Abstract
Since their discovery, the orphan nuclear receptors constitutive androstane receptor (CAR;NR1I3) and pregnane X receptor (PXR;NR1I2) have been regarded as master regulators of drug disposition and detoxification mechanisms. They regulate the metabolism and transport of endogenous mediators and xenobiotics in organs including the liver, intestine and brain. However, with proposals of new physiological functions for NR1I3 and NR1I2, there is increasing interest in the role of these receptors in influencing brain function. This review will summarise key findings regarding the expression and function of NR1I3 and NR1I2 in the brain, hereby highlighting the need for further research in this field.
Collapse
Affiliation(s)
- Pablo Torres-Vergara
- Departamento de Farmacia, Facultad de Farmacia, Universidad de Concepción, Concepción, Chile.,Centro de Microscopía Avanzada, CMA-BIO BIO, Laboratorio de Neurobiología y Células Madres NeuroCellT, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile.,Group of Research and Innovation in Vascular Health (GRIVAS Health), Universidad del Bío Bío, Chillán, Chile
| | - Yu Siong Ho
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Health and Medicine, The University of Manchester, Manchester, UK
| | - Francisca Espinoza
- Centro de Microscopía Avanzada, CMA-BIO BIO, Laboratorio de Neurobiología y Células Madres NeuroCellT, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Francisco Nualart
- Centro de Microscopía Avanzada, CMA-BIO BIO, Laboratorio de Neurobiología y Células Madres NeuroCellT, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Carlos Escudero
- Laboratorio de FisiologíaVascular, Departamento de Ciencias Básicas, Facultad de Ciencias Básicas, Universidad del Bío-Bío, Chillán, Chile.,Group of Research and Innovation in Vascular Health (GRIVAS Health), Universidad del Bío Bío, Chillán, Chile
| | - Jeffrey Penny
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Health and Medicine, The University of Manchester, Manchester, UK
| |
Collapse
|
8
|
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
| |
Collapse
|
9
|
Duszka K, Wahli W. Enteric Microbiota⁻Gut⁻Brain Axis from the Perspective of Nuclear Receptors. Int J Mol Sci 2018; 19:ijms19082210. [PMID: 30060580 PMCID: PMC6121494 DOI: 10.3390/ijms19082210] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 07/18/2018] [Accepted: 07/23/2018] [Indexed: 12/12/2022] Open
Abstract
Nuclear receptors (NRs) play a key role in regulating virtually all body functions, thus maintaining a healthy operating body with all its complex systems. Recently, gut microbiota emerged as major factor contributing to the health of the whole organism. Enteric bacteria have multiple ways to influence their host and several of them involve communication with the brain. Mounting evidence of cooperation between gut flora and NRs is already available. However, the full potential of the microbiota interconnection with NRs remains to be uncovered. Herewith, we present the current state of knowledge on the multifaceted roles of NRs in the enteric microbiota–gut–brain axis.
Collapse
Affiliation(s)
- Kalina Duszka
- Department of Nutritional Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria.
| | - Walter Wahli
- Lee Kong Chian School of Medicine, Nanyang Technological, 11 Mandalay Road, Singapore 308232, Singapore.
- Center for Integrative Genomics, University of Lausanne, Génopode, CH-1015 Lausanne, Switzerland.
| |
Collapse
|
10
|
McMillan DM, Tyndale RF. CYP-mediated drug metabolism in the brain impacts drug response. Pharmacol Ther 2018; 184:189-200. [DOI: 10.1016/j.pharmthera.2017.10.008] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
11
|
Abstract
The nuclear receptor family of transcription factor proteins mediates endocrine function and plays critical roles in the development, physiology and pharmacology. Malfunctioning nuclear receptors are associated with several disease states. The functional activity of nuclear receptors is regulated by small molecular hormonal and synthetic molecules. Multiple sources of evidence have identified and distinguished between the different allosteric pathways initiated by ligands, DNA and cofactors such as co-activators and co-repressors. Also, these biophysical studies are attempting to determine how these pathways that regulate co-activator and DNA recognition can control gene transcription. Thus, there is a growing interest in determining the genome-scale impact of allostery in nuclear receptors. Today, it is accepted that a detailed understanding of the allosteric regulatory pathways within the nuclear receptor molecular complex will enable the development of efficient drug therapies in the long term.
Collapse
Affiliation(s)
- Elias J Fernandez
- Department of Biochemistry & Cellular and Molecular Biology, The University of Tennessee, USA.
| |
Collapse
|
12
|
Mbatchi LC, Brouillet JP, Evrard A. Genetic variations of the xenoreceptors NR1I2 and NR1I3 and their effect on drug disposition and response variability. Pharmacogenomics 2017; 19:61-77. [PMID: 29199543 DOI: 10.2217/pgs-2017-0121] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
NR1I2 (PXR) and NR1I3 (CAR) are nuclear receptors that are classified as xenoreceptors. Upon activation by various xenobiotics, including marketed drugs, they regulate the transcription level of major drug-metabolizing enzymes and transporters and facilitate the elimination of xenobiotics from the body. The modulation of the activity of these two xenoreceptors by various ligands is a major source of pharmacokinetic variability of environmental origin. NR1I2 and NR1I3 genetic polymorphisms can affect the pharmacokinetics and therapeutic response to many drugs, such as irinotecan, tacrolimus and atazanavir. This review provides an overview of NR1I2 and NR1I3 pharmacogenetic studies in various therapeutic fields (oncology, immunomodulation and infectiology) and discusses the implementation of NR1I2 and NR1I3 genetic polymorphism testing in the clinical routine.
Collapse
Affiliation(s)
- Litaty Céphanoée Mbatchi
- Laboratoire de biochimie, Centre Hospitalier Universitaire (CHU) of Nîmes, Hôpital Carémeau, Nîmes, France.,IRCM, Institut de Recherche en Cancérologie de Montpellier, Montpellier, F-34298, INSERM, U1194 France.,Laboratoire de Pharmacocinétique, Faculté de Pharmacie, Université de Montpellier, Montpellier, France
| | - Jean-Paul Brouillet
- Laboratoire de biochimie, Centre Hospitalier Universitaire (CHU) of Nîmes, Hôpital Carémeau, Nîmes, France.,IRCM, Institut de Recherche en Cancérologie de Montpellier, Montpellier, F-34298, INSERM, U1194 France
| | - Alexandre Evrard
- Laboratoire de biochimie, Centre Hospitalier Universitaire (CHU) of Nîmes, Hôpital Carémeau, Nîmes, France.,IRCM, Institut de Recherche en Cancérologie de Montpellier, Montpellier, F-34298, INSERM, U1194 France.,Laboratoire de Pharmacocinétique, Faculté de Pharmacie, Université de Montpellier, Montpellier, France
| |
Collapse
|
13
|
Hardesty JE, Wahlang B, Falkner KC, Clair HB, Clark BJ, Ceresa BP, Prough RA, Cave MC. Polychlorinated biphenyls disrupt hepatic epidermal growth factor receptor signaling. Xenobiotica 2017; 47:807-820. [PMID: 27458090 DOI: 10.1080/00498254.2016.1217572] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
1. Polychlorinated biphenyls (PCBs) are persistent environmental pollutants that disrupt hepatic xenobiotic and intermediary metabolism, leading to metabolic syndrome and nonalcoholic steatohepatitis (NASH). 2. Since phenobarbital indirectly activates Constitutive Androstane Receptor (CAR) by antagonizing growth factor binding to the epidermal growth factor receptor (EGFR), we hypothesized that PCBs may also diminish EGFR signaling. 3. The effects of the PCB mixture Aroclor 1260 on the protein phosphorylation cascade triggered by EGFR activation were determined in murine (in vitro and in vivo) and human models (in vitro). EGFR tyrosine residue phosphorylation was decreased by PCBs in all models tested. 4. The IC50 values for Aroclor 1260 concentrations that decreased Y1173 phosphorylation of EGFR were similar in murine AML-12 and human HepG2 cells (∼2-4 μg/mL). Both dioxin and non-dioxin-like PCB congeners decreased EGFR phosphorylation in cell culture. 5. PCB treatment reduced phosphorylation of downstream EGFR effectors including Akt and mTOR, as well as other phosphoprotein targets including STAT3 and c-RAF in vivo. 6. PCBs diminish EGFR signaling in human and murine hepatocyte models and may dysregulate critical phosphoprotein regulators of energy metabolism and nutrition, providing a new mechanism of action in environmental diseases.
Collapse
Affiliation(s)
- Josiah E Hardesty
- a Department of Biochemistry and Molecular Genetics , University of Louisville School of Medicine , Louisville , KY , USA
| | - Banrida Wahlang
- b University of Kentucky Superfund Research Center, University of Kentucky , Lexington , KY , USA
| | - K Cameron Falkner
- c Department of Medicine , Division of Gastroenterology, Hepatology and Nutrition , and
| | - Heather B Clair
- a Department of Biochemistry and Molecular Genetics , University of Louisville School of Medicine , Louisville , KY , USA
| | - Barbara J Clark
- a Department of Biochemistry and Molecular Genetics , University of Louisville School of Medicine , Louisville , KY , USA
| | - Brian P Ceresa
- d Department of Pharmacology and Toxicology , University of Louisville School of Medicine , Louisville , KY , USA
| | - Russell A Prough
- a Department of Biochemistry and Molecular Genetics , University of Louisville School of Medicine , Louisville , KY , USA
| | - Matthew C Cave
- a Department of Biochemistry and Molecular Genetics , University of Louisville School of Medicine , Louisville , KY , USA.,c Department of Medicine , Division of Gastroenterology, Hepatology and Nutrition , and.,d Department of Pharmacology and Toxicology , University of Louisville School of Medicine , Louisville , KY , USA.,e The Robley Rex Veterans Affairs Medical Center , Louisville , KY , USA , and.,f The Kentucky One Health Jewish Hospital Liver Transplant Program , Louisville , KY , USA
| |
Collapse
|
14
|
Cheng SL, Bammler TK, Cui JY. RNA Sequencing Reveals Age and Species Differences of Constitutive Androstane Receptor-Targeted Drug-Processing Genes in the Liver. Drug Metab Dispos 2017; 45:867-882. [PMID: 28232382 DOI: 10.1124/dmd.117.075135] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 02/17/2017] [Indexed: 12/26/2022] Open
Abstract
The constitutive androstane receptor (CAR/Nr1i3) is an important xenobiotic-sensing nuclear receptor that is highly expressed in the liver and is well known to have species differences. During development, age-specific activation of CAR may lead to modified pharmacokinetics and toxicokinetics of drugs and environmental chemicals, leading to higher risks for adverse drug reactions in newborns and children. The goal of this study was to systematically investigate the age- and species-specific regulation of various drug-processing genes (DPGs) after neonatal or adult CAR activation in the livers of wild-type, CAR-null, and humanized CAR transgenic mice. At either 5 or 60 days of age, the three genotypes of mice were administered a species-appropriate CAR ligand or vehicle once daily for 4 days (i.p.). The majority of DPGs were differentially regulated by age and/or CAR activation. Thirty-six DPGs were commonly upregulated by CAR activation regardless of age or species of CAR. Although the cumulative mRNAs of uptake transporters were not readily altered by CAR, the cumulative phase I and phase II enzymes as well as efflux transporters were all increased after CAR activation in both species. In general, mouse CAR activation produced comparable or even greater fold increases of many DPGs in newborns than in adults; conversely, humanized CAR activation produced weaker induction in newborns than in adults. Western blotting and enzyme activity assays confirmed the age and species specificities of selected CAR-targeted DPGs. In conclusion, this study systematically compared the effect of age and species of CAR proteins on the regulation of DPGs in the liver and demonstrated that the regulation of xenobiotic biotransformation by CAR is profoundly modified by age and species.
Collapse
Affiliation(s)
- Sunny Lihua Cheng
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington
| | - Theo K Bammler
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington
| | - Julia Yue Cui
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington
| |
Collapse
|
15
|
Pinne M, Ponce E, Raucy JL. Transactivation Assays to Assess Canine and Rodent Pregnane X Receptor (PXR) and Constitutive Androstane Receptor (CAR) Activation. PLoS One 2016; 11:e0164642. [PMID: 27732639 PMCID: PMC5061317 DOI: 10.1371/journal.pone.0164642] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 09/28/2016] [Indexed: 11/21/2022] Open
Abstract
The pregnane X receptor (PXR/SXR, NR1I2) and constitutive androstane receptor (CAR, NR1I3) are nuclear receptors (NRs) involved in the regulation of many genes including cytochrome P450 enzymes (CYPs) and transporters important in metabolism and uptake of both endogenous substrates and xenobiotics. Activation of these receptors can lead to adverse drug effects as well as drug-drug interactions. Depending on which nuclear receptor is activated will determine which adverse effect could occur, making identification important. Screening for NR activation by New Molecular Entities (NMEs) using cell-based transactivation assays is the singular high throughput method currently available for identifying the activation of a particular NR. Moreover, screening for species-specific NR activation can minimize the use of animals in drug development and toxicology studies. With this in mind, we have developed in vitro transactivation assays to identify compounds that activate canine and rat PXR and CAR3. We found differences in specificity for canine and rat PXR, with the best activator for canine PXR being 10 μM SR12813 (60.1 ± 3.1-fold) and for rat PXR, 10 μM dexamethasone (60.9 ± 8.4 fold). Of the 19 test agents examined, 10 and 9 significantly activated rat and canine PXR at varying degrees, respectively. In contrast, 5 compounds exhibited statistically significant activation of rat CAR3 and 4 activated the canine receptor. For canine CAR3, 50 μM artemisinin proved to be the best activator (7.3 ± 1.8 and 10.5 ± 2.2 fold) while clotrimazole (10 μM) was the primary activator of the rat variant (13.7 ± 0.8 and 26.9 ± 1.3 fold). Results from these studies demonstrated that cell-based transactivation assays can detect species-specific activators and revealed that PXR was activated by at least twice as many compounds as was CAR3, suggesting that there are many more agonists for PXR than CAR.
Collapse
Affiliation(s)
- Marija Pinne
- Puracyp, Inc., Carlsbad, California, United States of America
- * E-mail:
| | - Elsa Ponce
- Puracyp, Inc., Carlsbad, California, United States of America
| | - Judy L. Raucy
- Puracyp, Inc., Carlsbad, California, United States of America
| |
Collapse
|
16
|
Park S, Cheng SL, Cui JY. Characterizing drug-metabolizing enzymes and transporters that are bona fide CAR-target genes in mouse intestine. Acta Pharm Sin B 2016; 6:475-491. [PMID: 27709017 PMCID: PMC5045557 DOI: 10.1016/j.apsb.2016.07.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 04/29/2016] [Accepted: 05/20/2016] [Indexed: 12/26/2022] Open
Abstract
Intestine is responsible for the biotransformation of many orally-exposed chemicals. The constitutive androstane receptor (CAR/Nr1i3) is known to up-regulate many genes encoding drug-metabolizing enzymes and transporters (drug-processing genes/DPGs) in liver, but less is known regarding its effect in intestine. Sixty-day-old wild-type and Car−/− mice were administered the CAR-ligand TCPOBOP or vehicle once daily for 4 days. In wild-type mice, Car mRNA was down-regulated by TCPOBOP in liver and duodenum. Car−/− mice had altered basal intestinal expression of many DPGs in a section-specific manner. Consistent with the liver data (Aleksunes and Klaassen, 2012), TCPOBOP up-regulated many DPGs (Cyp2b10, Cyp3a11, Aldh1a1, Aldh1a7, Gsta1, Gsta4, Gstm1-m4, Gstt1, Ugt1a1, Ugt2b34, Ugt2b36, and Mrp2–4) in specific sections of small intestine in a CAR-dependent manner. However, the mRNAs of Nqo1 and Papss2 were previously known to be up-regulated by TCPOBOP in liver but were not altered in intestine. Interestingly, many known CAR-target genes were highest expressed in colon where CAR is minimally expressed, suggesting that additional regulators are involved in regulating their expression. In conclusion, CAR regulates the basal expression of many DPGs in intestine, and although many hepatic CAR-targeted DPGs were bona fide CAR-targets in intestine, pharmacological activation of CAR in liver and intestine are not identical.
Collapse
Key Words
- Aldh, aldehyde dehydrogenase
- Asbt, solute carrier family 10, member 2 (apical sodium/bile acid cotransporter)
- CAR
- CAR, constitutive androstane receptor
- CITCO, 6-(4-chlorophenyl)imidazo [2,1-b](1,3)thiazole-5-carbaldehyde O-(3,4-dichlorobenzyl)oxime
- Cq, quantification cycle
- Cyp, cytochrome P450
- DPGs, drug-processing genes (genes that encodes drug metabolizing enzymes or transporters)
- Drug-metabolizing enzymes
- Drug-processing genes
- Gst, glutathione S-trasnferase
- H3, Histone 3
- HRP, horseradish peroxidase
- Intestine
- Mice
- Mrp, multi-drug resistance-associated protein (ABC transporter family C member)
- Nqo1, NAD(P)H dehydrogenase quinone 1
- Nrf2, nuclear factor erythroid 2-related factor 2
- Oatp, organic anion transporting polypeptide (solute carrier organic anion transporter family member)
- PBS, phosphate-buffered saline
- PBST, phosphate-buffered saline with 0.05% tween 20
- PPARα, peroxisome proliferator activated receptor alpha
- PVDF, polyvinylidene difluoride
- Papss2, 3ʹ-phosphoadenosine 5ʹ-phosphosulfate synthase 2
- ST buffer, sucrose Tris buffer
- Sult, sulfotransferase
- TCPOBOP, 3,3ʹ,5,5ʹ-tetrachloro-1,4-bis(pyridyloxy)benzene
- Transporters
- Ugt, UDP glucuronosyltransferase
- WT, wild-type
- cDNA, complementary DNA
- ddCq, delta delta Cq
- hCAR, human constitutive androstane receptor
- qPCR, quantitative polymerase chain reaction
Collapse
|
17
|
Chai SC, Cherian MT, Wang YM, Chen T. Small-molecule modulators of PXR and CAR. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1859:1141-1154. [PMID: 26921498 PMCID: PMC4975625 DOI: 10.1016/j.bbagrm.2016.02.013] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 02/06/2016] [Accepted: 02/06/2016] [Indexed: 12/27/2022]
Abstract
Two nuclear receptors, the pregnane X receptor (PXR) and the constitutive androstane receptor (CAR), participate in the xenobiotic detoxification system by regulating the expression of drug-metabolizing enzymes and transporters in order to degrade and excrete foreign chemicals or endogenous metabolites. This review aims to expand the perceived relevance of PXR and CAR beyond their established role as master xenosensors to disease-oriented areas, emphasizing their modulation by small molecules. Structural studies of these receptors have provided much-needed insight into the nature of their binding promiscuity and the important elements that lead to ligand binding. Reports of species- and isoform-selective activation highlight the need for further scrutiny when extrapolating from animal data to humans, as animal models are at the forefront of early drug discovery. This article is part of a Special Issue entitled: Xenobiotic nuclear receptors: New Tricks for An Old Dog, edited by Dr. Wen Xie.
Collapse
Affiliation(s)
- Sergio C Chai
- Department of Chemical Biology and Therapeutics, 262 Danny Thomas Place, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Milu T Cherian
- Department of Chemical Biology and Therapeutics, 262 Danny Thomas Place, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Yue-Ming Wang
- Department of Chemical Biology and Therapeutics, 262 Danny Thomas Place, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Taosheng Chen
- Department of Chemical Biology and Therapeutics, 262 Danny Thomas Place, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
| |
Collapse
|
18
|
Amacher DE. The regulation of human hepatic drug transporter expression by activation of xenobiotic-sensing nuclear receptors. Expert Opin Drug Metab Toxicol 2016; 12:1463-1477. [PMID: 27548410 DOI: 10.1080/17425255.2016.1223626] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
INTRODUCTION If a drug is found to be an inducer of hepatic drug metabolizing enzymes via activation of nuclear receptors such as pregnane X receptor (PXR) or constitutive androstane receptor (CAR), it is likely that drug transporters regulated through these same receptors will be induced as well. This review highlights what is currently known about the molecular mechanisms that regulate transporter expression and where the research is directed. Areas covered: This review is focused on publications that describe the role of activated hepatic nuclear receptors in the subsequent regulation of drug uptake and/or efflux transporters following exposure to xenobiotics. Expert opinion: Many of the published studies on the role of nuclear receptors in the regulation of drug transporters involve non-human test animals. But due to species response differences, these associations are not always applicable to humans. For this reason, some relevant human in vitro models have been developed, such as primary or cryopreserved human hepatocytes, human liver slices, or HepG2 or HuH7 cell lines transiently or stably transfected with PXR expression and reporter constructs as well as in vivo models such as PXR-humanized mice. These human-relevant test systems will continue to be developed and applied for the testing of investigational drugs.
Collapse
|
19
|
McMillin M, DeMorrow S. Effects of bile acids on neurological function and disease. FASEB J 2016; 30:3658-3668. [PMID: 27468758 DOI: 10.1096/fj.201600275r] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 07/18/2016] [Indexed: 12/14/2022]
Abstract
Bile acids are synthesized from cholesterol and are known to be involved with the emulsification and digestion of dietary lipids and fat-soluble vitamins. Outside of this role, bile acids can act as cell signaling effectors through binding and activating receptors on both the cell membrane and nucleus. Numerous reports have investigated these signaling pathways in conditions where the liver is damaged. More recently, effort has been made to investigate the role of bile acids in diseases outside of those associated with liver damage. This review summarizes recent findings on the influences that bile acids can exert in normal neurological function and their contribution to diseases of the nervous system, with the intent of highlighting the role of these metabolites as potential players in neurological disorders.-McMillin, M., DeMorrow, S. Effects of bile acids on neurological function and disease.
Collapse
Affiliation(s)
- Matthew McMillin
- Texas A&M University Health Science Center, College of Medicine, Department of Internal Medicine, Temple, Texas, USA; and.,Central Texas Veterans Health Care System, Temple, Texas, USA
| | - Sharon DeMorrow
- Texas A&M University Health Science Center, College of Medicine, Department of Internal Medicine, Temple, Texas, USA; and .,Central Texas Veterans Health Care System, Temple, Texas, USA
| |
Collapse
|
20
|
Pearce RE, Gaedigk R, Twist GP, Dai H, Riffel AK, Leeder JS, Gaedigk A. Developmental Expression of CYP2B6: A Comprehensive Analysis of mRNA Expression, Protein Content and Bupropion Hydroxylase Activity and the Impact of Genetic Variation. Drug Metab Dispos 2016; 44:948-58. [PMID: 26608082 PMCID: PMC4931886 DOI: 10.1124/dmd.115.067546] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 11/19/2015] [Indexed: 01/11/2023] Open
Abstract
Although CYP2B6 catalyzes the biotransformation of many drugs used clinically for children and adults, information regarding the effects of development on CYP2B6 expression and activity are scarce. Utilizing a large panel of human liver samples (201 donors: 24 fetal, 141 pediatric, and 36 adult), we quantified CYP2B6 mRNA and protein expression levels, characterized CYP2B6 (bupropion hydroxylase) activity in human liver microsomes (HLMs), and performed an extensive genotype analysis to differentiate CYP2B6 haplotypes such that the impact of genetic variation on these parameters could be assessed. Fetal livers contained extremely low levels of CYP2B6 mRNA relative to postnatal samples and fetal HLMs did not appear to catalyze bupropion hydroxylation; however, fetal CYP2B6 protein levels were not significantly different from postnatal levels. Considerable interindividual variation in CYP2B6 mRNA expression, protein levels, and activity was observed in postnatal HLMs (mRNA, ∼40,000-fold; protein, ∼300-fold; activity, ∼600-fold). The extremely wide range of interindividual variability in CYP2B6 expression and activity was significantly associated with age (P < 0.01) following log transformation of the data. Our data suggest that CYP2B6 activity appears as early as the first day of life, increases through infancy, and by 1 year of age, CYP2B6 levels and activity may approach those of adults. Surprisingly, CYP2B6 interindividual variability was not significantly associated with genetic variation in CYP2B6, nor was it associated with differences in gender or ethnicity, suggesting that factors other than these are largely responsible for the wide range of variability in CYP2B6 expression and activity observed among a large group of individuals/samples.
Collapse
Affiliation(s)
- Robin E Pearce
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation (R.E.P., R.G., G.P.T., A.K.R., J.S.L., A.G.), and Health Services and Outcomes Research (H.D.), Children's Mercy Kansas City, Kansas City, Missouri; and Department of Pediatrics, School of Medicine, University of Missouri-Kansas City, Kansas City, Missouri (R.E.P., R.G., H.D., J.S.L., A.G.)
| | - Roger Gaedigk
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation (R.E.P., R.G., G.P.T., A.K.R., J.S.L., A.G.), and Health Services and Outcomes Research (H.D.), Children's Mercy Kansas City, Kansas City, Missouri; and Department of Pediatrics, School of Medicine, University of Missouri-Kansas City, Kansas City, Missouri (R.E.P., R.G., H.D., J.S.L., A.G.)
| | - Greyson P Twist
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation (R.E.P., R.G., G.P.T., A.K.R., J.S.L., A.G.), and Health Services and Outcomes Research (H.D.), Children's Mercy Kansas City, Kansas City, Missouri; and Department of Pediatrics, School of Medicine, University of Missouri-Kansas City, Kansas City, Missouri (R.E.P., R.G., H.D., J.S.L., A.G.)
| | - Hongying Dai
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation (R.E.P., R.G., G.P.T., A.K.R., J.S.L., A.G.), and Health Services and Outcomes Research (H.D.), Children's Mercy Kansas City, Kansas City, Missouri; and Department of Pediatrics, School of Medicine, University of Missouri-Kansas City, Kansas City, Missouri (R.E.P., R.G., H.D., J.S.L., A.G.)
| | - Amanda K Riffel
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation (R.E.P., R.G., G.P.T., A.K.R., J.S.L., A.G.), and Health Services and Outcomes Research (H.D.), Children's Mercy Kansas City, Kansas City, Missouri; and Department of Pediatrics, School of Medicine, University of Missouri-Kansas City, Kansas City, Missouri (R.E.P., R.G., H.D., J.S.L., A.G.)
| | - J Steven Leeder
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation (R.E.P., R.G., G.P.T., A.K.R., J.S.L., A.G.), and Health Services and Outcomes Research (H.D.), Children's Mercy Kansas City, Kansas City, Missouri; and Department of Pediatrics, School of Medicine, University of Missouri-Kansas City, Kansas City, Missouri (R.E.P., R.G., H.D., J.S.L., A.G.)
| | - Andrea Gaedigk
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation (R.E.P., R.G., G.P.T., A.K.R., J.S.L., A.G.), and Health Services and Outcomes Research (H.D.), Children's Mercy Kansas City, Kansas City, Missouri; and Department of Pediatrics, School of Medicine, University of Missouri-Kansas City, Kansas City, Missouri (R.E.P., R.G., H.D., J.S.L., A.G.)
| |
Collapse
|
21
|
Ghosh C, Hossain M, Solanki J, Dadas A, Marchi N, Janigro D. Pathophysiological implications of neurovascular P450 in brain disorders. Drug Discov Today 2016; 21:1609-1619. [PMID: 27312874 DOI: 10.1016/j.drudis.2016.06.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 04/14/2016] [Accepted: 06/06/2016] [Indexed: 01/12/2023]
Abstract
Over the past decades, the significance of cytochrome P450 (CYP) enzymes has expanded beyond their role as peripheral drug metabolizers in the liver and gut. CYP enzymes are also functionally active at the neurovascular interface. CYP expression is modulated by disease states, impacting cellular functions, detoxification, and reactivity to toxic stimuli and brain drug biotransformation. Unveiling the physiological and molecular complexity of brain P450 enzymes will improve our understanding of the mechanisms underlying brain drug availability, pharmacological efficacy, and neurotoxic adverse effects from pharmacotherapy targeting brain disorders.
Collapse
Affiliation(s)
- Chaitali Ghosh
- Cerebrovascular Research, Cleveland Clinic Lerner Research Institute, Cleveland, OH, USA; Department of Biomedical Engineering, Cleveland Clinic Lerner Research Institute, Cleveland, OH, USA; Department of Molecular Medicine, Cleveland Clinic Lerner Research Institute, Cleveland, OH, USA.
| | - Mohammed Hossain
- Cerebrovascular Research, Cleveland Clinic Lerner Research Institute, Cleveland, OH, USA; Department of Biomedical Engineering, Cleveland Clinic Lerner Research Institute, Cleveland, OH, USA
| | | | - Aaron Dadas
- The Ohio State University, Columbus, OH, USA
| | - Nicola Marchi
- Cerebrovascular Mechanisms of Brain Disorders, Department of Neuroscience, Institute of Functional Genomics (CNRS/INSERM), Montpellier, France
| | - Damir Janigro
- Flocel Inc. and Case Western Reserve University, Cleveland, OH, USA
| |
Collapse
|
22
|
Mackowiak B, Wang H. Mechanisms of xenobiotic receptor activation: Direct vs. indirect. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2016; 1859:1130-1140. [PMID: 26877237 DOI: 10.1016/j.bbagrm.2016.02.006] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 02/05/2016] [Accepted: 02/06/2016] [Indexed: 12/31/2022]
Abstract
The so-called xenobiotic receptors (XRs) have functionally evolved into cellular sensors for both endogenous and exogenous stimuli by regulating the transcription of genes encoding drug-metabolizing enzymes and transporters, as well as those involving energy homeostasis, cell proliferation, and/or immune responses. Unlike prototypical steroid hormone receptors, XRs are activated through both direct ligand-binding and ligand-independent (indirect) mechanisms by a plethora of structurally unrelated chemicals. This review covers research literature that discusses direct vs. indirect activation of XRs. A particular focus is centered on the signaling control of the constitutive androstane receptor (CAR), the pregnane X receptor (PXR), and the aryl hydrocarbon receptor (AhR). We expect that this review will shed light on both the common and distinct mechanisms associated with activation of these three XRs. This article is part of a Special Issue entitled: Xenobiotic nuclear receptors: New Tricks for An Old Dog, edited by Dr. Wen Xie.
Collapse
Affiliation(s)
- Bryan Mackowiak
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, 20 Penn Street, Baltimore, MD 21201, United States
| | - Hongbing Wang
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, 20 Penn Street, Baltimore, MD 21201, United States.
| |
Collapse
|
23
|
Inouye Y. [Structure and Function of the Nuclear Receptor Constitutive Androstane Receptor]. YAKUGAKU ZASSHI 2016; 136:297-308. [PMID: 26831808 DOI: 10.1248/yakushi.15-00215] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Animal defense mechanisms against both endogenous and exogenous toxic compounds function mainly through receptor-type transcription factors, including the constitutive androstane receptor (CAR). Following xenobiotic stimulation, CAR translocates into the nucleus and transactivates its target genes including oxygenic and conjugative enzymes and transporters in hepatocytes. We identified subcellular localization signals in the rat CAR: two nuclear localization signals (NLS1 and 2); two nuclear export signals (NES1 and 2); and a cytoplasmic retention region. The nuclear import of CAR is regulated by the importin-Ran system and microtubule network. Five splice variants (SV1-5) were identified in rat liver in addition to wild-type CAR. When expressed in immortalized cells, their artificial transcripts were inactive as transcription factors. A CAR mutant with three consecutive alanine residues inserted into the ligand-binding domain of CAR showed ligand-dependent activation of target genes in immortalized cells, which is in marked contrast to the constitutive transactivating nature of wild-type CAR. Using this assay system, androstenol and clotrimazole, both of which are inverse agonists of CAR, were classified as an antagonist and weak agonist, respectively. A member of the DEAD box DNA/RNA helicase family (DP97) and protein arginine methyltransferase 5 (PRMT5) were found to be gene (or promotor)-specific coactivators of CAR. The expression of the CAR gene might be under the control of clock genes mediated by the nuclear receptor Rev-erb-α.
Collapse
|
24
|
Rondini EA, Duniec-Dmuchowski Z, Kocarek TA. Nonsterol Isoprenoids Activate Human Constitutive Androstane Receptor in an Isoform-Selective Manner in Primary Cultured Mouse Hepatocytes. ACTA ACUST UNITED AC 2016; 44:595-604. [PMID: 26798158 DOI: 10.1124/dmd.115.068551] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 01/20/2016] [Indexed: 12/26/2022]
Abstract
Our laboratory previously reported that accumulation of nonsterol isoprenoids following treatment with the squalene synthase inhibitor, squalestatin 1 (SQ1) markedly induced cytochrome P450 (CYP)2B1 mRNA and reporter activity in primary cultured rat hepatocytes, which was dependent on activation of the constitutive androstane receptor (CAR). The objective of the current study was to evaluate whether isoprenoids likewise activate murine CAR (mCAR) or one or more isoforms of human CAR (hCAR) produced by alternative splicing (SPTV, hCAR2; APYLT, hCAR3). We found that SQ1 significantly induced Cyp2b10 mRNA (∼3.5-fold) in primary hepatocytes isolated from both CAR-wild-type and humanized CAR transgenic mice, whereas the 3-hydroxy-3-methylglutaryl-CoA reductase inhibitor pravastatin had no effect. In the absence of CAR, basal Cyp2b10 mRNA levels were reduced by 28-fold and the effect of SQ1 on Cyp2b10 induction was attenuated. Cotransfection with an expression plasmid for hCAR1, but not hCAR2 or hCAR3, mediated SQ1-induced CYP2B1 and CYP2B6 reporter activation in hepatocytes isolated from CAR-knockout mice. This effect was also observed following treatment with the isoprenoid trans,trans-farnesol. The direct agonist CITCO increased interaction of hCAR1, hCAR2, and hCAR3 with steroid receptor coactivator-1. However, no significant effect on coactivator recruitment was observed with SQ1, suggesting an indirect activation mechanism. Further results from an in vitro ligand binding assay demonstrated that neither farnesol nor other isoprenoids are direct ligands for hCAR1. Collectively, our findings demonstrate that SQ1 activates CYP2B transcriptional responses through farnesol metabolism in an hCAR1-dependent manner. Further, this effect probably occurs through an indirect mechanism.
Collapse
Affiliation(s)
- Elizabeth A Rondini
- Institute of Environmental Health Sciences, Wayne State University, Detroit, Michigan
| | | | - Thomas A Kocarek
- Institute of Environmental Health Sciences, Wayne State University, Detroit, Michigan
| |
Collapse
|
25
|
Cherian MT, Chai SC, Chen T. Small-molecule modulators of the constitutive androstane receptor. Expert Opin Drug Metab Toxicol 2015; 11:1099-114. [PMID: 25979168 DOI: 10.1517/17425255.2015.1043887] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
INTRODUCTION The constitutive androstane receptor (CAR) induces drug-metabolizing enzymes for xenobiotic metabolism. AREAS COVERED This review covers recent advances in elucidating the biological functions of CAR and its modulation by a growing number of agonists and inhibitors. EXPERT OPINION Extrapolation of animal CAR function to that of humans should be carefully scrutinized, particularly when rodents are used in evaluating the metabolic profile and carcinogenic properties of clinical drugs and environmental chemicals. Continuous efforts are needed to discover novel CAR inhibitors, with extensive understanding of their inhibitory mechanism, species selectivity, and discriminating power against other xenobiotic sensors.
Collapse
Affiliation(s)
- Milu T Cherian
- Postdoctoral fellow, St. Jude Children's Research Hospital, Department of Chemical Biology and Therapeutics , 262 Danny Thomas Place, Memphis, TN 38105 , USA
| | | | | |
Collapse
|
26
|
Shahabi P, Siest G, Meyer UA, Visvikis-Siest S. Human cytochrome P450 epoxygenases: Variability in expression and role in inflammation-related disorders. Pharmacol Ther 2014; 144:134-61. [DOI: 10.1016/j.pharmthera.2014.05.011] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 05/15/2014] [Indexed: 12/19/2022]
|
27
|
Ibrahim ZS, Ahmed MM, El-Shazly SA, Ishizuka M, Fujita S. Clofibric acid induces hepatic CYP 2B1/2 via constitutive androstane receptor not via peroxisome proliferator activated receptor alpha in rat. Biosci Biotechnol Biochem 2014; 78:1550-9. [PMID: 25052003 DOI: 10.1080/09168451.2014.923302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Peroxisome proliferator activated receptor α (PPARα) ligands, fibrates used to control hyperlipidemia. We demonstrated CYP2B induction by clofibric acid (CFA) however, the mechanism was not clear. In this study, HepG2 cells transfected with expression plasmid of mouse constitutive androstane receptor (CAR) or PPARα were treated with CFA, phenobarbital (PB) or TCPOBOP. Luciferase assays showed that CFA increased CYP2B1 transcription to the same level as PB, or TCPOBOP in HepG2 transfected with mouse CAR But failed to induce it in PPARα transfected cells. CYP2B expressions were increased with PB or CFA in Wistar female rats (having normal levels of CAR) but not in Wistar Kyoto female rats (having low levels of CAR). The induction of CYP2B by PB or CFA was comparable to nuclear CAR levels. CAR nuclear translocation was induced by CFA in both rat strains. This indicates that fibrates can activate CAR and that fibrates-insulin sensitization effect may occur through CAR, while hypolipidemic effect may operate through PPARα.
Collapse
Affiliation(s)
- Zein Shaban Ibrahim
- a Faculty of Veterinary Medicine, Department of Physiology , Kafrelsheikh University , Kafrelsheikh , Egypt
| | | | | | | | | |
Collapse
|
28
|
Pinne M, Raucy JL. Advantages of cell-based high-volume screening assays to assess nuclear receptor activation during drug discovery. Expert Opin Drug Discov 2014; 9:669-86. [DOI: 10.1517/17460441.2014.913019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
|
29
|
Lau AJ, Chang TKH. Fetal bovine serum and human constitutive androstane receptor: evidence for activation of the SV23 splice variant by artemisinin, artemether, and arteether in a serum-free cell culture system. Toxicol Appl Pharmacol 2014; 277:221-30. [PMID: 24721719 DOI: 10.1016/j.taap.2014.03.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 03/08/2014] [Accepted: 03/26/2014] [Indexed: 10/25/2022]
Abstract
The naturally occurring SV23 splice variant of human constitutive androstane receptor (hCAR-SV23) is activated by di-(2-ethylhexyl)phthalate (DEHP), which is detected as a contaminant in fetal bovine serum (FBS). In our initial experiment, we compared the effect of dialyzed FBS, charcoal-stripped, dextran-treated FBS (CS-FBS), and regular FBS on the basal activity and ligand-activation of hCAR-SV23 in a cell-based reporter gene assay. In transfected HepG2 cells cultured in medium supplemented with 10% FBS, basal hCAR-SV23 activity varied with the type of FBS (regular>dialyzed>CS). DEHP increased hCAR-SV23 activity when 10% CS-FBS, but not regular FBS or dialyzed FBS, was used. With increasing concentrations (1-10%) of regular FBS or CS-FBS, hCAR-SV23 basal activity increased, whereas in DEHP-treated cells, hCAR-SV23 activity remained similar (regular FBS) or slightly increased (CS-FBS). Subsequent experiments identified a serum-free culture condition to detect DEHP activation of hCAR-SV23. Under this condition, artemisinin, artemether, and arteether increased hCAR-SV23 activity, whereas they decreased it in cells cultured in medium supplemented with 10% regular FBS. By comparison, FBS increased the basal activity of the wild-type isoform of hCAR (hCAR-WT), whereas it did not affect the basal activity of the SV24 splice variant (hCAR-SV24) or ligand activation of hCAR-SV24 and hCAR-WT by 6-(4-chlorophenyl)imidazo[2,1-b][1,3]thiazole-5-carbaldehyde O-(3,4-dichlorobenzyl)oxime (CITCO). The use of serum-free culture condition was suitable for detecting CITCO activation of hCAR-WT and hCAR-SV24. In conclusion, FBS leads to erroneous classification of pharmacological ligands of hCAR-SV23 in cell-based assays, but investigations on functional ligands of hCAR isoforms can be conducted in serum-free culture condition.
Collapse
Affiliation(s)
- Aik Jiang Lau
- Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Thomas K H Chang
- Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia, Canada.
| |
Collapse
|
30
|
Godoy P, Hewitt NJ, Albrecht U, Andersen ME, Ansari N, Bhattacharya S, Bode JG, Bolleyn J, Borner C, Böttger J, Braeuning A, Budinsky RA, Burkhardt B, Cameron NR, Camussi G, Cho CS, Choi YJ, Craig Rowlands J, Dahmen U, Damm G, Dirsch O, Donato MT, Dong J, Dooley S, Drasdo D, Eakins R, Ferreira KS, Fonsato V, Fraczek J, Gebhardt R, Gibson A, Glanemann M, Goldring CEP, Gómez-Lechón MJ, Groothuis GMM, Gustavsson L, Guyot C, Hallifax D, Hammad S, Hayward A, Häussinger D, Hellerbrand C, Hewitt P, Hoehme S, Holzhütter HG, Houston JB, Hrach J, Ito K, Jaeschke H, Keitel V, Kelm JM, Kevin Park B, Kordes C, Kullak-Ublick GA, LeCluyse EL, Lu P, Luebke-Wheeler J, Lutz A, Maltman DJ, Matz-Soja M, McMullen P, Merfort I, Messner S, Meyer C, Mwinyi J, Naisbitt DJ, Nussler AK, Olinga P, Pampaloni F, Pi J, Pluta L, Przyborski SA, Ramachandran A, Rogiers V, Rowe C, Schelcher C, Schmich K, Schwarz M, Singh B, Stelzer EHK, Stieger B, Stöber R, Sugiyama Y, Tetta C, Thasler WE, Vanhaecke T, Vinken M, Weiss TS, Widera A, Woods CG, Xu JJ, Yarborough KM, Hengstler JG. Recent advances in 2D and 3D in vitro systems using primary hepatocytes, alternative hepatocyte sources and non-parenchymal liver cells and their use in investigating mechanisms of hepatotoxicity, cell signaling and ADME. Arch Toxicol 2013; 87:1315-530. [PMID: 23974980 PMCID: PMC3753504 DOI: 10.1007/s00204-013-1078-5] [Citation(s) in RCA: 1062] [Impact Index Per Article: 96.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 05/06/2013] [Indexed: 12/15/2022]
Abstract
This review encompasses the most important advances in liver functions and hepatotoxicity and analyzes which mechanisms can be studied in vitro. In a complex architecture of nested, zonated lobules, the liver consists of approximately 80 % hepatocytes and 20 % non-parenchymal cells, the latter being involved in a secondary phase that may dramatically aggravate the initial damage. Hepatotoxicity, as well as hepatic metabolism, is controlled by a set of nuclear receptors (including PXR, CAR, HNF-4α, FXR, LXR, SHP, VDR and PPAR) and signaling pathways. When isolating liver cells, some pathways are activated, e.g., the RAS/MEK/ERK pathway, whereas others are silenced (e.g. HNF-4α), resulting in up- and downregulation of hundreds of genes. An understanding of these changes is crucial for a correct interpretation of in vitro data. The possibilities and limitations of the most useful liver in vitro systems are summarized, including three-dimensional culture techniques, co-cultures with non-parenchymal cells, hepatospheres, precision cut liver slices and the isolated perfused liver. Also discussed is how closely hepatoma, stem cell and iPS cell-derived hepatocyte-like-cells resemble real hepatocytes. Finally, a summary is given of the state of the art of liver in vitro and mathematical modeling systems that are currently used in the pharmaceutical industry with an emphasis on drug metabolism, prediction of clearance, drug interaction, transporter studies and hepatotoxicity. One key message is that despite our enthusiasm for in vitro systems, we must never lose sight of the in vivo situation. Although hepatocytes have been isolated for decades, the hunt for relevant alternative systems has only just begun.
Collapse
Affiliation(s)
- Patricio Godoy
- Leibniz Research Centre for Working Environment and Human Factors (IFADO), 44139 Dortmund, Germany
| | | | - Ute Albrecht
- Clinic for Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | - Melvin E. Andersen
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC USA
| | - Nariman Ansari
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University Frankfurt, Max-von-Laue-Str. 15, 60438 Frankfurt am Main, Germany
| | - Sudin Bhattacharya
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC USA
| | - Johannes Georg Bode
- Clinic for Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | - Jennifer Bolleyn
- Department of Toxicology, Centre for Pharmaceutical Research, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, 1090 Brussels, Belgium
| | - Christoph Borner
- Institute of Molecular Medicine and Cell Research, University of Freiburg, Freiburg, Germany
| | - Jan Böttger
- Institute of Biochemistry, Faculty of Medicine, University of Leipzig, 04103 Leipzig, Germany
| | - Albert Braeuning
- Department of Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Wilhelmstr. 56, 72074 Tübingen, Germany
| | - Robert A. Budinsky
- Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI USA
| | - Britta Burkhardt
- BG Trauma Center, Siegfried Weller Institut, Eberhard Karls University Tübingen, 72076 Tübingen, Germany
| | - Neil R. Cameron
- Department of Chemistry, Durham University, Durham, DH1 3LE UK
| | - Giovanni Camussi
- Department of Medical Sciences, University of Torino, 10126 Turin, Italy
| | - Chong-Su Cho
- Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, 151-921 Korea
| | - Yun-Jaie Choi
- Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, 151-921 Korea
| | - J. Craig Rowlands
- Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI USA
| | - Uta Dahmen
- Experimental Transplantation Surgery, Department of General Visceral, and Vascular Surgery, Friedrich-Schiller-University Jena, 07745 Jena, Germany
| | - Georg Damm
- Department of General-, Visceral- and Transplantation Surgery, Charité University Medicine Berlin, 13353 Berlin, Germany
| | - Olaf Dirsch
- Institute of Pathology, Friedrich-Schiller-University Jena, 07745 Jena, Germany
| | - María Teresa Donato
- Unidad de Hepatología Experimental, IIS Hospital La Fe Avda Campanar 21, 46009 Valencia, Spain
- CIBERehd, Fondo de Investigaciones Sanitarias, Barcelona, Spain
- Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad de Valencia, Valencia, Spain
| | - Jian Dong
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC USA
| | - Steven Dooley
- Department of Medicine II, Section Molecular Hepatology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Dirk Drasdo
- Interdisciplinary Center for Bioinformatics (IZBI), University of Leipzig, 04107 Leipzig, Germany
- INRIA (French National Institute for Research in Computer Science and Control), Domaine de Voluceau-Rocquencourt, B.P. 105, 78153 Le Chesnay Cedex, France
- UPMC University of Paris 06, CNRS UMR 7598, Laboratoire Jacques-Louis Lions, 4, pl. Jussieu, 75252 Paris cedex 05, France
| | - Rowena Eakins
- Department of Molecular and Clinical Pharmacology, Centre for Drug Safety Science, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Karine Sá Ferreira
- Institute of Molecular Medicine and Cell Research, University of Freiburg, Freiburg, Germany
- GRK 1104 From Cells to Organs, Molecular Mechanisms of Organogenesis, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Valentina Fonsato
- Department of Medical Sciences, University of Torino, 10126 Turin, Italy
| | - Joanna Fraczek
- Department of Toxicology, Centre for Pharmaceutical Research, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, 1090 Brussels, Belgium
| | - Rolf Gebhardt
- Institute of Biochemistry, Faculty of Medicine, University of Leipzig, 04103 Leipzig, Germany
| | - Andrew Gibson
- Department of Molecular and Clinical Pharmacology, Centre for Drug Safety Science, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Matthias Glanemann
- Department of General-, Visceral- and Transplantation Surgery, Charité University Medicine Berlin, 13353 Berlin, Germany
| | - Chris E. P. Goldring
- Department of Molecular and Clinical Pharmacology, Centre for Drug Safety Science, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - María José Gómez-Lechón
- Unidad de Hepatología Experimental, IIS Hospital La Fe Avda Campanar 21, 46009 Valencia, Spain
- CIBERehd, Fondo de Investigaciones Sanitarias, Barcelona, Spain
| | - Geny M. M. Groothuis
- Department of Pharmacy, Pharmacokinetics Toxicology and Targeting, University of Groningen, A. Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Lena Gustavsson
- Department of Laboratory Medicine (Malmö), Center for Molecular Pathology, Lund University, Jan Waldenströms gata 59, 205 02 Malmö, Sweden
| | - Christelle Guyot
- Department of Clinical Pharmacology and Toxicology, University Hospital, 8091 Zurich, Switzerland
| | - David Hallifax
- Centre for Applied Pharmacokinetic Research (CAPKR), School of Pharmacy and Pharmaceutical Sciences, University of Manchester, Oxford Road, Manchester, M13 9PT UK
| | - Seddik Hammad
- Department of Forensic Medicine and Veterinary Toxicology, Faculty of Veterinary Medicine, South Valley University, Qena, Egypt
| | - Adam Hayward
- Biological and Biomedical Sciences, Durham University, Durham, DH13LE UK
| | - Dieter Häussinger
- Clinic for Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | - Claus Hellerbrand
- Department of Medicine I, University Hospital Regensburg, 93053 Regensburg, Germany
| | | | - Stefan Hoehme
- Interdisciplinary Center for Bioinformatics (IZBI), University of Leipzig, 04107 Leipzig, Germany
| | - Hermann-Georg Holzhütter
- Institut für Biochemie Abteilung Mathematische Systembiochemie, Universitätsmedizin Berlin (Charité), Charitéplatz 1, 10117 Berlin, Germany
| | - J. Brian Houston
- Centre for Applied Pharmacokinetic Research (CAPKR), School of Pharmacy and Pharmaceutical Sciences, University of Manchester, Oxford Road, Manchester, M13 9PT UK
| | | | - Kiyomi Ito
- Research Institute of Pharmaceutical Sciences, Musashino University, 1-1-20 Shinmachi, Nishitokyo-shi, Tokyo, 202-8585 Japan
| | - Hartmut Jaeschke
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 USA
| | - Verena Keitel
- Clinic for Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | | | - B. Kevin Park
- Department of Molecular and Clinical Pharmacology, Centre for Drug Safety Science, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Claus Kordes
- Clinic for Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | - Gerd A. Kullak-Ublick
- Department of Clinical Pharmacology and Toxicology, University Hospital, 8091 Zurich, Switzerland
| | - Edward L. LeCluyse
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC USA
| | - Peng Lu
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC USA
| | | | - Anna Lutz
- Department of Pharmaceutical Biology and Biotechnology, University of Freiburg, Freiburg, Germany
| | - Daniel J. Maltman
- Reinnervate Limited, NETPark Incubator, Thomas Wright Way, Sedgefield, TS21 3FD UK
| | - Madlen Matz-Soja
- Institute of Biochemistry, Faculty of Medicine, University of Leipzig, 04103 Leipzig, Germany
| | - Patrick McMullen
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC USA
| | - Irmgard Merfort
- Department of Pharmaceutical Biology and Biotechnology, University of Freiburg, Freiburg, Germany
| | | | - Christoph Meyer
- Department of Medicine II, Section Molecular Hepatology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Jessica Mwinyi
- Department of Clinical Pharmacology and Toxicology, University Hospital, 8091 Zurich, Switzerland
| | - Dean J. Naisbitt
- Department of Molecular and Clinical Pharmacology, Centre for Drug Safety Science, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Andreas K. Nussler
- BG Trauma Center, Siegfried Weller Institut, Eberhard Karls University Tübingen, 72076 Tübingen, Germany
| | - Peter Olinga
- Division of Pharmaceutical Technology and Biopharmacy, Department of Pharmacy, University of Groningen, 9713 AV Groningen, The Netherlands
| | - Francesco Pampaloni
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University Frankfurt, Max-von-Laue-Str. 15, 60438 Frankfurt am Main, Germany
| | - Jingbo Pi
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC USA
| | - Linda Pluta
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC USA
| | - Stefan A. Przyborski
- Reinnervate Limited, NETPark Incubator, Thomas Wright Way, Sedgefield, TS21 3FD UK
- Biological and Biomedical Sciences, Durham University, Durham, DH13LE UK
| | - Anup Ramachandran
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 USA
| | - Vera Rogiers
- Department of Toxicology, Centre for Pharmaceutical Research, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, 1090 Brussels, Belgium
| | - Cliff Rowe
- Department of Molecular and Clinical Pharmacology, Centre for Drug Safety Science, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Celine Schelcher
- Department of Surgery, Liver Regeneration, Core Facility, Human in Vitro Models of the Liver, Ludwig Maximilians University of Munich, Munich, Germany
| | - Kathrin Schmich
- Department of Pharmaceutical Biology and Biotechnology, University of Freiburg, Freiburg, Germany
| | - Michael Schwarz
- Department of Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Wilhelmstr. 56, 72074 Tübingen, Germany
| | - Bijay Singh
- Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, 151-921 Korea
| | - Ernst H. K. Stelzer
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University Frankfurt, Max-von-Laue-Str. 15, 60438 Frankfurt am Main, Germany
| | - Bruno Stieger
- Department of Clinical Pharmacology and Toxicology, University Hospital, 8091 Zurich, Switzerland
| | - Regina Stöber
- Leibniz Research Centre for Working Environment and Human Factors (IFADO), 44139 Dortmund, Germany
| | - Yuichi Sugiyama
- Sugiyama Laboratory, RIKEN Innovation Center, RIKEN, Yokohama Biopharmaceutical R&D Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045 Japan
| | - Ciro Tetta
- Fresenius Medical Care, Bad Homburg, Germany
| | - Wolfgang E. Thasler
- Department of Surgery, Ludwig-Maximilians-University of Munich Hospital Grosshadern, Munich, Germany
| | - Tamara Vanhaecke
- Department of Toxicology, Centre for Pharmaceutical Research, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, 1090 Brussels, Belgium
| | - Mathieu Vinken
- Department of Toxicology, Centre for Pharmaceutical Research, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, 1090 Brussels, Belgium
| | - Thomas S. Weiss
- Department of Pediatrics and Juvenile Medicine, University of Regensburg Hospital, Regensburg, Germany
| | - Agata Widera
- Leibniz Research Centre for Working Environment and Human Factors (IFADO), 44139 Dortmund, Germany
| | - Courtney G. Woods
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC USA
| | | | | | - Jan G. Hengstler
- Leibniz Research Centre for Working Environment and Human Factors (IFADO), 44139 Dortmund, Germany
| |
Collapse
|
31
|
Role of nuclear receptors in the regulation of drug transporters in the brain. Trends Pharmacol Sci 2013; 34:361-72. [PMID: 23769624 DOI: 10.1016/j.tips.2013.05.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 04/24/2013] [Accepted: 05/08/2013] [Indexed: 02/07/2023]
Abstract
ATP-binding cassette membrane-associated drug efflux transporters and solute carrier influx transporters, expressed at the blood-brain barrier, blood-cerebrospinal fluid barrier, and in brain parenchyma, are important determinants of drug disposition in the central nervous system. Targeting the regulatory pathways that govern the expression of these transporters could provide novel approaches to selectively alter drug permeability into the brain. Nuclear receptors are ligand-activated transcription factors which regulate the gene expression of several metabolic enzymes and drug efflux/influx transporters. Although efforts have primarily been focused on investigating these regulatory pathways in peripheral organs (i.e., liver and intestine), recent findings demonstrate their significance in the brain. This review addresses the role of nuclear receptors in the regulation of drug transporter functional expression in the brain. An in-depth understanding of these pathways could guide the development of novel pharmacotherapy with either enhanced efficacy in the central nervous system or minimal associated neurotoxicity.
Collapse
|
32
|
Molina-Molina JM, Amaya E, Grimaldi M, Sáenz JM, Real M, Fernández MF, Balaguer P, Olea N. In vitro study on the agonistic and antagonistic activities of bisphenol-S and other bisphenol-A congeners and derivatives via nuclear receptors. Toxicol Appl Pharmacol 2013; 272:127-36. [PMID: 23714657 DOI: 10.1016/j.taap.2013.05.015] [Citation(s) in RCA: 265] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Revised: 05/09/2013] [Accepted: 05/14/2013] [Indexed: 01/02/2023]
Abstract
Bisphenols are a group of chemicals structurally similar to bisphenol-A (BPA) in current use as the primary raw material in the production of polycarbonate and epoxy resins. Some bisphenols are intended to replace BPA in several industrial applications. This is the case of bisphenol-S (BPS), which has an excellent stability at high temperature and resistance to sunlight. Studies on the endocrine properties of BPS have focused on its interaction with human estrogen receptor alpha (hERα), but information on its interaction with other nuclear receptors is scarce. The aim of this study was to investigate interactions of BPS, BPF, BPA and its halogenated derivatives, tetrachlorobisphenol A (TCBPA), and tetrabromobisphenol A (TBBPA), with human estrogen receptors (hERα and hERβ), androgen receptor (hAR), and pregnane X receptor (hPXR), using a panel of in vitro bioassays based on competitive binding to nuclear receptors (NRs), reporter gene expression, and cell proliferation assessment. BPS, BPF, and BPA efficiently activated both ERs, while TCBPA behaved as weak hERα agonist. Unlike BPF and BPA, BPS was more active in the hERβ versus hERα assay. BPF and BPA were full hAR antagonists (BPA>BPF), whereas BPA and BPS were weak hAR agonists. Only BPA, TCBPA, and TBBPA, were hPXR agonists (TCBPA>TBBPA>BPA). These findings provide evidence that BPA congeners and derivatives disrupt multiple NRs and may therefore interfere with the endocrine system. Hence, further research is needed to evaluate the potential endocrine-disrupting activity of putative BPA substitutes.
Collapse
Affiliation(s)
- José-Manuel Molina-Molina
- Laboratory of Medical Investigations, San Cecilio University Hospital, University of Granada, Cíber en Epidemiología y Salud Pública (CIBERESP), Granada E-18071, Spain.
| | | | | | | | | | | | | | | |
Collapse
|
33
|
Abstract
Cytochrome P450 enzymes (CYPs) metabolize many drugs that act on the central nervous system (CNS), such as antidepressants and antipsychotics; drugs of abuse; endogenous neurochemicals, such as serotonin and dopamine; neurotoxins; and carcinogens. This takes place primarily in the liver, but metabolism can also occur in extrahepatic organs, including the brain. This is important for CNS-acting drugs, as variation in brain CYP-mediated metabolism may be a contributing factor when plasma levels do not predict drug response. This review summarizes the characterization of CYPs in the brain, using examples from the CYP2 subfamily, and discusses sources of variation in brain CYP levels and metabolism. Some recent experiments are described that demonstrate how changes in brain CYP metabolism can influence drug response, toxicity and drug-induced behaviours. Advancing knowledge of brain CYP-mediated metabolism may help us understand why patients respond differently to drugs used in psychiatry and predict risk for psychiatric disorders, including neurodegenerative diseases and substance abuse.
Collapse
Affiliation(s)
| | - Rachel F. Tyndale
- Correspondence to: R.F. Tyndale, Department of Pharmacology and Toxicology, 1 King’s College Circle, Toronto ON M5S 1A8;
| |
Collapse
|
34
|
Choi EJ, Jang YJ, Cha EY, Shin JG, Lee SS. Identification and characterization of novel alternative splice variants of human constitutive androstane receptor in liver samples of Koreans and Caucasians. Drug Metab Dispos 2013; 41:888-96. [PMID: 23378627 DOI: 10.1124/dmd.112.049791] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Human constitutive androstane receptor (hCAR, NR1I3) is a member of the orphan nuclear receptor family and regulates the transcription of many drug-metabolizing enzymes and drug transporters. Previous studies have shown that the hCAR gene produces a number of different kinds of mRNA splicing variants (SVs) in non-Asian ethnicities. In the present study, we identified 18 hCAR SVs (SV1-SV18), including four novel SVs in Korean human livers. Among the four novel SVs, SV2 showed enhanced transactivation activity when cotransfected with CYP2B6 reporter gene, whereas other SVs were nonfunctional. When profiles of major hCAR SVs were compared among 30 livers from Korean patients and 20 livers from Caucasian patients, the relative composition of each SV showed interethnic variation as well as interindividual variation. The most predominant form of hCAR SV was not wild type, but either SV4 or SV7. The summed relative amounts of SV4 and SV7 ranged from 34.5 to 57.6% in the 30 Korean livers and from 47.2 to 82.6% in the 20 Caucasian livers, suggesting large interindividual variation. The mean relative amount of nonfunctional SV9 was significantly higher in Koreans (29.8%) than in Caucasians (12.8%). The mean relative amount of novel SV2 was 9.7% in Korean livers and 3.5% in Caucasian livers. Expression profiling of hCAR proteins in human livers also supported large interindividual variation in the expressional ratio of wild-type and SVs. Our results describe for the first time the direct comparison of hCAR SV profiles between Koreans and Caucasians. The functional relevance of these interindividual and interethnic variations of hCAR mRNA expression needs to be further characterized.
Collapse
Affiliation(s)
- Eun-Jung Choi
- Department of Pharmacology and PharmacoGenomics Research Center, Inje University College of Medicine, Paik Hospital, Busan, Republic of Korea
| | | | | | | | | |
Collapse
|
35
|
Wallace BD, Redinbo MR. Xenobiotic-sensing nuclear receptors involved in drug metabolism: a structural perspective. Drug Metab Rev 2012; 45:79-100. [PMID: 23210723 DOI: 10.3109/03602532.2012.740049] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Xenobiotic compounds undergo a critical range of biotransformations performed by the phase I, II, and III drug-metabolizing enzymes. The oxidation, conjugation, and transportation of potentially harmful xenobiotic and endobiotic compounds achieved by these catalytic systems are significantly regulated, at the gene expression level, by members of the nuclear receptor (NR) family of ligand-modulated transcription factors. Activation of NRs by a variety of endo- and exogenous chemicals are elemental to induction and repression of drug-metabolism pathways. The master xenobiotic sensing NRs, the promiscuous pregnane X receptor and less-promiscuous constitutive androstane receptor are crucial to initial ligand recognition, jump-starting the metabolic process. Other receptors, including farnesoid X receptor, vitamin D receptor, hepatocyte nuclear factor 4 alpha, peroxisome proliferator activated receptor, glucocorticoid receptor, liver X receptor, and RAR-related orphan receptor, are not directly linked to promiscuous xenobiotic binding, but clearly play important roles in the modulation of metabolic gene expression. Crystallographic studies of the ligand-binding domains of nine NRs involved in drug metabolism provide key insights into ligand-based and constitutive activity, coregulator recruitment, and gene regulation. Structures of other, noncanonical transcription factors also shed light on secondary, but important, pathways of control. Pharmacological targeting of some of these nuclear and atypical receptors has been instituted as a means to treat metabolic and developmental disorders and provides a future avenue to be explored for other members of the xenobiotic-sensing NRs.
Collapse
Affiliation(s)
- Bret D Wallace
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | | |
Collapse
|
36
|
Swart M, Whitehorn H, Ren Y, Smith P, Ramesar RS, Dandara C. PXR and CAR single nucleotide polymorphisms influence plasma efavirenz levels in South African HIV/AIDS patients. BMC MEDICAL GENETICS 2012; 13:112. [PMID: 23173844 PMCID: PMC3523080 DOI: 10.1186/1471-2350-13-112] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Accepted: 11/12/2012] [Indexed: 12/02/2022]
Abstract
Background This study investigated variation in NR1I2 and NR1I3 and its effect on plasma efavirenz levels in HIV/AIDS patients. Variability in plasma drug levels has largely led research on identifying causative variants in drug metabolising enzyme (DME) genes, with little focus on the nuclear receptor genes NR1I2 and NR1I3, coding for PXR and CAR, respectively, that are involved in regulating DMEs. Methods 464 Bantu-speaking South Africans comprising of HIV/AIDS patients on efavirenz-based treatment (n=301) and 163 healthy subjects were genotyped for 6 SNPs in NR1I2 and NR1I3. 32 of the 301 patients had their DNA binding domains (DBDs) in NR1I2 and NR1I3 sequenced. Results Significantly decreased efavirenz plasma concentrations were observed in patients carrying the NR1I3 rs3003596C/C and T/C genotypes (P=0.015 and P=0.010, respectively). Sequencing resulted in the discovery of a further 13 SNPs, 3 of which are novel variants in the DBD of NR1I2. There were significant differences in the distribution of NR1I2 and NR1I3 SNPs between South Africans when compared to Caucasian, Asian and Yoruba population groups. Conclusion For the realisation of personalised medicine, PXR and CAR genetic variation should be taken into consideration because of their involvement in the regulation of DMEs.
Collapse
Affiliation(s)
- Marelize Swart
- Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Observatory, South Africa
| | | | | | | | | | | |
Collapse
|
37
|
Zhang YKJ, Lu H, Klaassen CD. Expression of human CAR splicing variants in BAC-transgenic mice. Toxicol Sci 2012; 132:142-50. [PMID: 23152187 DOI: 10.1093/toxsci/kfs321] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The nuclear receptor constitutive androstane receptor (CAR) is a key regulator for drug metabolism in liver. Human CAR (hCAR) transcripts are subjected to alternative splicing. Some hCAR splicing variants (SVs) have been shown to encode functional proteins by reporter assays. However, in vivo research on the activity of these hCAR SVs has been impeded by the absence of a valid model. This study engineered an hCAR-BAC-transgenic (hCAR-TG) mouse model by integrating the 8.5-kbp hCAR gene as well as 73-kbp upstream and 91-kbp downstream human genomic DNA into the genome of CAR-null mice. A series of experiments demonstrate that (1) the expression of major hCAR mRNA SVs, SV0-4, in livers of hCAR-TG mice is comparable to that in human livers; (2) the hCAR SVs are predominantly expressed in liver, which resembles the tissue distribution of CAR in humans, but diverges from that in mice; and (3) major hCAR mRNA SVs increase markedly in postnatal livers of hCAR-TG mice, which mimics the ontogeny of CAR mRNA in humans. Thus, the transgene likely contains all the functional regulatory elements controlling proper spatial and temporal expression of the hCAR gene. Moreover, hCAR-TG mice respond to the hCAR-specific agonist 6-(4-chlorophenyl)imidazo[2,1-b] [1,3]thiazole-5-carbaldehyde O-(3,4-dichlorobenzyl)oxime instead of the mouse CAR agonist 1,4-bis[2-(3,5-dichloropyridyloxy)]benzene, as well as the common CAR activator, phenobarbital, suggesting that hCAR is fully functional in livers of transgenic mice. In summary, the hCAR-TG mice developed by this study represent a valid model for studying in vivo function and regulation of hCAR and its splicing variants.
Collapse
Affiliation(s)
- Yu-Kun Jennifer Zhang
- Department of Pharmacology, University of Kansas Medical Center, Kansas City, KS, USA
| | | | | |
Collapse
|
38
|
Van der Heyden S, Croubels S, Gadeyne C, Ducatelle R, Daminet S, Murua Escobar H, Sterenczak K, Polis I, Schauvliege S, Hesta M, Chiers K. Influence of P-glycoprotein modulation on plasma concentrations and pharmacokinetics of orally administered prednisolone in dogs. Am J Vet Res 2012; 73:900-7. [PMID: 22620706 DOI: 10.2460/ajvr.73.6.900] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate the impact of modulation of the membrane-bound efflux pump P-glycoprotein (P-gp) on plasma concentrations of orally administered prednisolone in dogs. ANIMALS 7 healthy adult Beagles. PROCEDURES Each dog received 3 treatments (control [no treatment], rifampicin [100 mg/d, PO, for 21 days, as an inducer of P-gp], and ketoconazole [100 mg/d, PO, for 21 days, as an inhibitor of P-gp]). A single dose of prednisolone (1 mg/kg, PO) was administered on day 8 of each treatment period. There was a 7-day washout period between subsequent treatments. Plasma concentrations of prednisolone were determined by use of a validated liquid chromatography-tandem mass spectrometry method. Duodenum and colon biopsy specimens were obtained endoscopically from anesthetized dogs and assessed for P-gp protein labeling via immunohistochemical analysis and mRNA quantification via real-time PCR assay. Total fecal collection was performed for evaluation of effects of P-gp modulation on digestion of nutrients. RESULTS Rifampicin treatment upregulated duodenal P-gp in dogs and significantly reduced the area under the plasma concentration-time curve of prednisolone. Ketoconazole typically downregulated expression of duodenal P-gp, with a subsequent increase in the area under the plasma concentration-time curve of prednisolone. There was a noticeable interindividual difference in response. Digestion of nutrients was not affected. CONCLUSIONS AND CLINICAL RELEVANCE Modulation of P-gp expression influenced plasma concentrations of prednisolone after oral administration in dogs. Thus, treatment response to prednisolone may be influenced by coadministration of P-gp-modulating medications or feed ingredients.
Collapse
Affiliation(s)
- Sara Van der Heyden
- Department of Pathology, Bacteriology and Poultry Diseases, Faculty of Veterinary Medicine, Ghent University, 9820 Merelbeke, Belgium.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Laurenzana EM, Chen T, Kannuswamy M, Sell BE, Strom SC, Li Y, Omiecinski CJ. The orphan nuclear receptor DAX-1 functions as a potent corepressor of the constitutive androstane receptor (NR1I3). Mol Pharmacol 2012; 82:918-28. [PMID: 22896671 DOI: 10.1124/mol.112.080721] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Regulation of gene transcription is controlled in part by nuclear receptors that function coordinately with coregulator proteins. The human constitutive androstane receptor (CAR; NR1I3) is expressed primarily in liver and regulates the expression of genes involved in xenobiotic metabolism as well as hormone, energy, and lipid homeostasis. In this report, DAX-1, a nuclear receptor family member with corepressor properties, was identified as a potent CAR regulator. Results of transaction and mutational studies demonstrated that both DAX-1's downstream LXXLL and its PCFQVLP motifs were critical contributors to DAX-1's corepression activities, although two other LXXM/LL motifs located nearer the N terminus had no impact on the CAR functional interaction. Deletion of DAX-1's C-terminal transcription silencing domain restored CAR1 transactivation activity in reporter assays to approximately 90% of control, demonstrating its critical function in mediating the CAR repression activities. Furthermore, results obtained from mammalian two-hybrid experiments assessing various domain configurations of the respective receptors showed that full-length DAX-1 inhibited the CAR-SRC1 interaction by approximately 50%, whereas the same interaction was restored to 90% of control when the DAX-1 transcription silencing domain was deleted. Direct interaction between CAR and DAX-1 was demonstrated with both alpha-screen and coimmunoprecipitation experiments, and this interaction was enhanced in the presence of the CAR activator 6-(4-chlorophenyl)imidazo[2,1-b]thiazole-5-carbaldehyde O-(3,4-dichlorobenzyl)oxime (CITCO). Results obtained in primary human hepatocytes further demonstrated DAX-1 inhibition of CAR-mediated CITCO induction of the CYP2B6 target gene. The results of this investigation identify DAX-1 as a novel and potent CAR corepressor and suggest that DAX-1 functions as a coordinate hepatic regulator of CAR's biological function.
Collapse
Affiliation(s)
- Elizabeth M Laurenzana
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | | | | | | | | | | | | |
Collapse
|
40
|
Chew SC, Lim JSL, Singh O, Wong M, Lee EJD, Chowbay B. Genetic variations of NR1I3 and NR2B1 in Asian populations. Drug Metab Pharmacokinet 2012; 28:169-76. [PMID: 22850739 DOI: 10.2133/dmpk.dmpk-12-sc-060] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Several nuclear receptors are being increasingly recognized for their role as master xenosensors. Among them, CAR-RXRα heterodimer, as encoded by NR1I3 and NR2B1, responds to the presence of drug compounds and regulates the transcription of a wide array of genes involved in their disposition. To investigate the frequency distribution and linkage disequilibrium patterns of NR1I3 and NR2B1 genetic variations, these genes were screened in 168 healthy local Asian subjects, namely Chinese, Malays, and Indians (n=56 subjects each). A total of 38 and 88 SNPs were identified in NR1I3 and NR2B1, respectively. Among them, there were 13 and 43 novel SNPs present at low allelic frequencies (<10%) in NR1I3 and NR2B1, respectively. Notably, the genetic variations in the NR1I3 and NR2B1 genes were mainly confined to the introns whilst the exons were highly conserved across the ethnic populations. Indians harboured distinct frequency distributions from Chinese and Malays in both genes. Based on the linkage disequilibrium patterns of both genes, a number of tag-SNPs were selected for each population (n=8-13 for NR1I3; n=12-18 for NR2B1). In-silico prediction analyses revealed a number of possible functional SNPs. Our data would be valuable for future pharmacogenetic studies on the drug substrates of CAR-RXRα target genes.
Collapse
Affiliation(s)
- Sin Chi Chew
- Laboratory of Clinical Pharmacology, Division of Medical Sciences, Humphrey Oei Institute of Cancer Research, National Cancer Centre, Singapore, Singapore
| | | | | | | | | | | |
Collapse
|
41
|
Meyer zu Schwabedissen HE, Oswald S, Bresser C, Nassif A, Modess C, Desta Z, Ogburn ET, Marinova M, Lütjohann D, Spielhagen C, Nauck M, Kroemer HK, Siegmund W. Compartment-specific gene regulation of the CAR inducer efavirenz in vivo. Clin Pharmacol Ther 2012; 92:103-11. [PMID: 22588604 DOI: 10.1038/clpt.2012.34] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Nuclear receptors such as the constitutive androstane receptor (CAR) are central factors that link drug exposure to the activities of drug metabolism and elimination. In order to determine the in vivo effects of efavirenz, a CAR activator, the expression of target genes was determined in duodenal biopsies obtained from 12 healthy volunteers before treatment and after 10 days of treatment with efavirenz; concomitant administration of the cholesterol inhibitor ezetimibe produced no significant difference. However, in in vitro studies, efavirenz significantly increased CYP2B6 expression in several cell types, suggesting that the drug transactivates CAR. This hypothesis is supported by our findings that there is significant induction of CAR target genes in in vivo peripheral blood mononuclear cells (PBMCs) isolated from healthy volunteers treated with multiple doses of efavirenz. The impact of efavirenz on hepatic metabolism in vivo was confirmed by significant changes in plasma 4β-hydroxycholesterol and bilirubin levels and the area under the curve (AUC) of efavirenz. Induction of CYP2B6 mRNA expression correlated with the decrease in the AUC of efavirenz (r = 0.61; P = 0.036). Taken together, our results provide evidence that efavirenz exerts compartment-specific inductive capacity in vivo.
Collapse
|
42
|
Monitoring Cyp2b10 mRNA expression at cessation of 2-year carcinogenesis bioassay in mouse liver provides evidence for a carcinogenic mechanism devoid of human relevance: The dalcetrapib experience. Toxicol Appl Pharmacol 2012; 259:355-65. [DOI: 10.1016/j.taap.2012.01.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Revised: 01/16/2012] [Accepted: 01/19/2012] [Indexed: 11/23/2022]
|
43
|
Berthier A, Oger F, Gheeraert C, Boulahtouf A, Le Guével R, Balaguer P, Staels B, Salbert G, Lefebvre P. The novel antibacterial compound walrycin A induces human PXR transcriptional activity. Toxicol Sci 2012; 127:225-35. [PMID: 22314385 DOI: 10.1093/toxsci/kfs073] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The human pregnane X receptor (PXR) is a ligand-regulated transcription factor belonging to the nuclear receptor superfamily. PXR is activated by a large, structurally diverse, set of endogenous and xenobiotic compounds and coordinates the expression of genes central to metabolism and excretion of potentially harmful chemicals and therapeutic drugs in humans. Walrycin A is a novel antibacterial compound targeting the WalK/WalR two-component signal transduction system of Gram (+) bacteria. Here, we report that, in hepatoma cells, walrycin A potently activates a gene set known to be regulated by the xenobiotic sensor PXR. Walrycin A was as efficient as the reference PXR agonist rifampicin to activate PXR in a transactivation assay at noncytotoxic concentrations. Using a limited proteolysis assay, we show that walrycin A induces conformational changes at a concentration which correlates with walrycin A ability to enhance the expression of prototypic target genes, suggesting that walrycin A interacts with PXR. The activation of the canonical human PXR target gene CYP3A4 by walrycin A is dose and PXR dependent. Finally, in silico docking experiments suggest that the walrycin A oxidation product Russig's blue is the actual ligand for PXR. Taken together, these results identify walrycin A as a novel human PXR activator.
Collapse
|
44
|
Lau AJ, Yang G, Chang TKH. Isoform-selective activation of human constitutive androstane receptor by Ginkgo biloba extract: functional analysis of the SV23, SV24, and SV25 splice variants. J Pharmacol Exp Ther 2011; 339:704-15. [PMID: 21862659 DOI: 10.1124/jpet.111.186130] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Naturally occurring splice variants of human constitutive androstane receptor (hCAR) exist, including hCAR-SV23 (insertion of amino acids SPTV), hCAR-SV24 (APYLT), and hCAR-SV25 (SPTV and APYLT). An extract of Ginkgo biloba was reported to activate hCAR-SV24 and the wild type (hCAR-WT). However, it is not known whether it selectively affects hCAR splice variants, how it activates hCAR isoforms, and which chemical is responsible for the effects of the extract. Therefore, we evaluated the impact of G. biloba extract on the functionality of hCAR-SV23, hCAR-SV24, hCAR-SV25, and hCAR-WT and compared it with that of phenobarbital, di-(2-ethylhexyl)phthalate (DEHP), 6-(4-chlorophenyl)imidazo[2,1-b][1,3]thiazole-5-carbaldehyde O-(3,4-dichlorobenzyl)oxime (CITCO), and 1,4-bis-[2-(3,5-dichloropyridyloxy)]benzene (TCPOBOP) in cell-based reporter gene assays. Among the hCAR splice variants investigated, only hCAR-SV23 was activated by G. biloba extract, and this required cotransfection of a retinoid X receptor α (RXRα) expression plasmid. The extract activated hCAR-SV23 to a lesser extent than hCAR-WT, but ginkgolide A, ginkgolide B, ginkgolide C, ginkgolide J, and bilobalide were not responsible for the effects of the extract. CITCO activated hCAR-SV23, hCAR-SV24, and hCAR-WT. By comparison, phenobarbital activated hCAR-WT, whereas DEHP activated hCAR-SV23, hCAR-SV24 (with exogenous RXRα supplementation), and hCAR-WT. TCPOBOP did not affect the activity of any of the isoforms. G. biloba extract and phenobarbital did not bind or recruit coactivators to the ligand-binding domains of hCAR-WT and hCAR-SV23, whereas positive results were obtained with the controls (CITCO for hCAR-WT and DEHP for hCAR-SV23). In conclusion, G. biloba extract activates hCAR in an isoform-selective manner, and hCAR-SV23, hCAR-SV24, and hCAR-WT have overlapping, but distinct, sets of ligands.
Collapse
Affiliation(s)
- Aik Jiang Lau
- Faculty of Pharmaceutical Sciences, The University of British Columbia, 2146 East Mall, Vancouver, British Columbia, V6T 1Z3, Canada
| | | | | |
Collapse
|
45
|
Crist RC, Roth JJ, Waldman SA, Buchberg AM. A conserved tissue-specific homeodomain-less isoform of MEIS1 is downregulated in colorectal cancer. PLoS One 2011; 6:e23665. [PMID: 21858198 PMCID: PMC3157405 DOI: 10.1371/journal.pone.0023665] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Accepted: 07/22/2011] [Indexed: 01/16/2023] Open
Abstract
Colorectal cancer is one of the most common cancers in developed nations and is the result of both environmental and genetic factors. Many of the genetic lesions observed in colorectal cancer alter expression of homeobox genes, which encode homeodomain transcription factors. The MEIS1 homeobox gene is known to be involved in several hematological malignancies and solid tumors and recent evidence suggests that expression of the MEIS1 transcript is altered in colorectal cancer. Despite this potential connection, little is known about the role of the gene in the intestines. We probed murine gastrointestinal tissue samples with an N-terminal Meis1 antibody, revealing expression of two previously described isoforms, as well as two novel Meis1 products. A 32 kD Meis1 product was expressed in the nuclei of non-epithelial cells in the stomach and colon, while a 27 kD product was expressed in the cytoplasm of epithelial cells in the proximal colon. Our data suggest that the 27 kD and 32 kD Meis1 proteins are both forms of the Meis1d protein, a homeodomain-less isoform whose transcript was previously identified in cDNA screens. Both the MEIS1D transcript and protein were expressed in human colon mucosa. Expression of the MEIS1D protein was downregulated in 83% (10/12) of primary colorectal cancer samples compared to matched normal mucosa, indicating that MEIS1D is a biomarker of colorectal tumorigenesis. The decreased expression of MEIS1D in colon tumors also suggests that this conserved homeodomain-less isoform may act as a tumor suppressor in human colorectal cancer.
Collapse
Affiliation(s)
- Richard C. Crist
- Department of Microbiology and Immunology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Jacquelyn J. Roth
- Department of Microbiology and Immunology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Scott A. Waldman
- Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Arthur M. Buchberg
- Department of Microbiology and Immunology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- * E-mail:
| |
Collapse
|
46
|
Chan GNY, Hoque MT, Cummins CL, Bendayan R. Regulation of P-glycoprotein by orphan nuclear receptors in human brain microvessel endothelial cells. J Neurochem 2011; 118:163-75. [DOI: 10.1111/j.1471-4159.2011.07288.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
47
|
Abstract
Interindividual differences in drug transporter expression can result in variability in drug response. This variation in gene expression is determined, in part, by the actions of nuclear hormone receptors that act as xenobiotic- and endobiotic-sensing transcription factors. Among the ligand-activated nuclear receptors, signaling through the pregnane X receptor (PXR), constitutive androstane receptor (CAR), farnesoid X receptor (FXR), and vitamin D receptor (VDR) constitute major pathways regulating drug transporter expression in tissues. Hence, these endobiotic- and xenobiotic-sensing nuclear receptors are intrinsically involved in environmental influences of drug response. Moreover, because nuclear receptor genes are polymorphic, these transcription factors are also thought to contribute to heritability of variable drug action. In this chapter, the molecular aspects of drug transporter gene regulation by ligand-activated nuclear receptors will be reviewed including their clinical relevance.
Collapse
|
48
|
DeKeyser JG, Laurenzana EM, Peterson EC, Chen T, Omiecinski CJ. Selective phthalate activation of naturally occurring human constitutive androstane receptor splice variants and the pregnane X receptor. Toxicol Sci 2011; 120:381-91. [PMID: 21227907 DOI: 10.1093/toxsci/kfq394] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Phthalates and other endocrine-disruptive chemicals are manufactured in large quantities for use as plasticizers and other commercial applications, resulting in ubiquitous human exposure and thus, concern regarding their toxicity. Innate defense against small molecule exposures is controlled in large part by the constitutive androstane receptor (CAR) and the pregnane X receptor (PXR). The human CAR gene undergoes multiple alternative splicing events resulting in the CAR2 and CAR3 variant receptors. Recent studies from our laboratory show that CAR2 is potently and specifically activated by di(2-ethylhexyl) phthalate (DEHP). We hypothesized that alternative splicing is a mechanism for increasing CAR's functional diversity, broadening the human receptors' repertoire of response to environmental xenobiotics. In these studies, we examine the interaction of alternatively spliced CARs and PXR with a range of suspected endocrine disruptors, including phthalates, bisphenol A (BPA), and 4-N-nonylphenol (NP). Transactivation and two-hybrid studies in COS-1 cells revealed differential selectivity of endocrine-disrupting chemicals for the variant CAR and PXR. Ex vivo studies showed DEHP and di-isononyl phthalate potently induced CYP2B6 and CYP3A4 expression in human hepatocytes. Mutation analysis of CAR2, in silico modeling, and ligand docking studies suggested that the SPTV amino acid insertion of CAR2 creates a unique ligand-binding pocket. Alternative gene splicing results in variant CAR receptors that selectively recognize phthalates and BPA. The interaction of phthalates with CAR and PXR suggests a xenobiotic response that is complex and biologically redundant.
Collapse
Affiliation(s)
- Joshua G DeKeyser
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | | | | | | | | |
Collapse
|
49
|
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.
Collapse
Affiliation(s)
- Haishan Li
- University of Maryland School of Pharmacy, Department of Pharmaceutical Sciences, 20 Penn Street, Baltimore, MD 21201, USA
| | | |
Collapse
|
50
|
Wang X, Sykes DB, Miller DS. Constitutive androstane receptor-mediated up-regulation of ATP-driven xenobiotic efflux transporters at the blood-brain barrier. Mol Pharmacol 2010; 78:376-83. [PMID: 20547735 DOI: 10.1124/mol.110.063685] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
ATP-driven efflux transporters at the blood-brain barrier both protect against neurotoxicants and limit drug delivery to the brain. In other barrier and excretory tissues, efflux transporter expression is regulated by certain ligand-activated nuclear receptors. Here we identified constitutive androstane receptor (CAR) as a positive regulator of P-glycoprotein, multidrug resistance-associated protein 2 (Mrp2), and breast cancer resistance protein (BCRP) expression in rat and mouse brain capillaries. Exposing rat brain capillaries to the CAR activator, phenobarbital (PB), increased the transport activity and protein expression (Western blots) of P-glycoprotein, Mrp2, and BCRP. Induction of transport was abolished by the protein phosphatase 2A inhibitor, OA. Similar effects on transporter activity and expression were found when mouse brain capillaries were exposed to the mouse-specific CAR ligand, 1,4-bis-[2-(3,5-dichloropyridyloxy)]benzene (TCPOBOP). In brain capillaries from CAR-null mice, TCPOBOP did not increase transporter activity. Finally, treating mice with 0.33 mg/kg TCPOBOP or rats with 80 mg/kg PB increased P-glycoprotein-, Mrp2-, and BCRP-mediated transport and protein expression in brain capillaries assayed ex vivo. Thus, CAR activation selectively tightens the blood-brain barrier by increasing transport activity and protein expression of three xenobiotic efflux pumps.
Collapse
Affiliation(s)
- Xueqian Wang
- Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | | | | |
Collapse
|