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Franco ME, Schönenberger R, Hollender J, Schirmer K. Organ-specific biotransformation in salmonids: Insight into intrinsic enzyme activity and biotransformation of three micropollutants. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 925:171769. [PMID: 38499104 DOI: 10.1016/j.scitotenv.2024.171769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 02/25/2024] [Accepted: 03/15/2024] [Indexed: 03/20/2024]
Abstract
Aquatic ecosystems continue to be threatened by chemical pollution. To what extent organisms are able to cope with chemical exposure depends on their ability to display mechanisms of defense across different organs. Among these mechanisms, biotransformation processes represent key physiological responses that facilitate detoxification and reduce the bioaccumulation potential of chemicals. Biotransformation does not only depend on the ability of different organs to display biotransformation enzymes but also on the affinity of chemicals towards these enzymes. In the present study, we explored the ability of different organs and of two freshwater fish to support biotransformation processes through the determination of in vitro phase I and II biotransformation enzyme activity, and their role in supporting intrinsic clearance and the formation of biotransformation products. Three environmentally relevant pollutants were evaluated: the polycyclic aromatic hydrocarbon (PAH) pyrene (as recommended by the OECD 319b test guideline), the fungicide azoxystrobin, and the pharmaceutical propranolol. Comparative studies using S9 sub-cellular fractions derived from the liver, intestine, gills, and brain of brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss) revealed significant phase I and II enzyme activity in all organs. However, organ- and species-specific differences were found. In brown trout, significant extrahepatic biotransformation was observed for pyrene but not for azoxystrobin and propranolol. In rainbow trout, the brain appeared to biotransform azoxystrobin. In this same species, propranolol appeared to be biotransformed by the intestine and gills. Biotransformation products could be detected only from hepatic biotransformation, and their profiles and formation rates displayed species-specific patterns and occurred at different magnitudes. Altogether, our findings further contribute to the current understanding of organ-specific biotransformation capacity, beyond the expression and activity of enzymes, and its dependence on specific enzyme-chemical interactions to support mechanisms of defense against exposure.
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Affiliation(s)
- Marco E Franco
- Department of Environmental Toxicology, Swiss Federal Institute of Aquatic Science and Technology, Eawag, 8600 Dübendorf, Switzerland
| | - René Schönenberger
- Department of Environmental Toxicology, Swiss Federal Institute of Aquatic Science and Technology, Eawag, 8600 Dübendorf, Switzerland
| | - Juliane Hollender
- Department of Environmental Chemistry, Swiss Federal Institute of Aquatic Science and Technology, Eawag, 8600 Dübendorf, Switzerland; Department of Environmental Systems Science, ETH Zürich, 8092 Zürich, Switzerland
| | - Kristin Schirmer
- Department of Environmental Toxicology, Swiss Federal Institute of Aquatic Science and Technology, Eawag, 8600 Dübendorf, Switzerland; Department of Environmental Systems Science, ETH Zürich, 8092 Zürich, Switzerland; School of Architecture, Civil and Environmental Engineering, EPF Lausanne, 1015 Lausanne, Switzerland.
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2
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Kong Y, Fu W, Wang L, Li F, Li W, Yue X. Molecular characterization of SPATA6 and association of its SNPs with testicular size in sheep. Theriogenology 2024; 215:205-213. [PMID: 38096624 DOI: 10.1016/j.theriogenology.2023.12.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 12/05/2023] [Accepted: 12/05/2023] [Indexed: 01/06/2024]
Abstract
The testis is an important organ for maintaining fertility in males, and testis size is positively correlated with ejaculate volume, sperm motility, thus fertility. Spermatogenesis-associated 6 (SPATA6) is an evolutionarily conserved testis-specific gene reported in many species. However, the effect of SPATA6 expression levels on testicular development and the effect of single nucleotide polymorphisms (SNPs) on testis and epididymis phenotype in sheep have not been studied. The purpose of the research was to investigate the expression profile of SPATA6 and its effect on testicular development and to confirm the effect of SNPs on the testis and epididymis phenotype. In this study, we detected a 1245bp coding sequence (CDS) of SPATA6 and encoded 414 amino acids. The expression levels of SPATA6 were significantly higher in the testis than in other tissues and gradually increased with testis development. Moreover, the expression level in the large testis was significantly higher than that in the small testis at six months. A total of 11 SNPs were detected in the coding region of SPATA6 by cDNA-pooling sequencing and improved multiplex ligation detection reaction (iMLDR) methods. Correlation analysis showed that SNP2 (c. 3631C > G) significantly affected left epididymis weight (LEW) and right epididymis weight (REW), and SNP10 (c. 937 A > G) significantly affected REW. And the combined genotype of SNP1 (c. 4245 G > A) and SNP2 significantly affected REW. The current study concluded that SPATA6 plays an important role in testicular development and the SNPs significantly associated with the epididymis phenotype can provide molecular markers for the early selection of high-fertility Hu sheep.
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Affiliation(s)
- Yuanyuan Kong
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, China; Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, China; Engineering Research Center of Grassland Industry, Ministry of Education, China; College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China
| | - Weiwei Fu
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, China; Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, China; Engineering Research Center of Grassland Industry, Ministry of Education, China; College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China
| | - Li Wang
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, China; Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, China; Engineering Research Center of Grassland Industry, Ministry of Education, China; College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China
| | - Fadi Li
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, China; Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, China; Engineering Research Center of Grassland Industry, Ministry of Education, China; College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China
| | - Wanhong Li
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, China; Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, China; Engineering Research Center of Grassland Industry, Ministry of Education, China; College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China
| | - Xiangpeng Yue
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, China; Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, China; Engineering Research Center of Grassland Industry, Ministry of Education, China; College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China.
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Induction by Phenobarbital of Phase I and II Xenobiotic-Metabolizing Enzymes in Bovine Liver: An Overall Catalytic and Immunochemical Characterization. Int J Mol Sci 2022; 23:ijms23073564. [PMID: 35408925 PMCID: PMC8998613 DOI: 10.3390/ijms23073564] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 03/14/2022] [Accepted: 03/21/2022] [Indexed: 12/15/2022] Open
Abstract
In cattle, phenobarbital (PB) upregulates target drug-metabolizing enzyme (DME) mRNA levels. However, few data about PB's post-transcriptional effects are actually available. This work provides the first, and an almost complete, characterization of PB-dependent changes in DME catalytic activities in bovine liver using common probe substrates and confirmatory immunoblotting investigations. As expected, PB increased the total cytochrome P450 (CYP) content and the extent of metyrapone binding; moreover, an augmentation of protein amounts and related enzyme activities was observed for known PB targets such as CYP2B, 2C, and 3A, but also CYP2E1. However, contradictory results were obtained for CYP1A, while a decreased catalytic activity was observed for flavin-containing monooxygenases 1 and 3. The barbiturate had no effect on the chosen hydrolytic and conjugative DMEs. For the first time, we also measured the 26S proteasome activity, and the increase observed in PB-treated cattle would suggest this post-translational event might contribute to cattle DME regulation. Overall, this study increased the knowledge of cattle hepatic drug metabolism, and further confirmed the presence of species differences in DME expression and activity between cattle, humans, and rodents. This reinforced the need for an extensive characterization and understanding of comparative molecular mechanisms involved in expression, regulation, and function of DMEs.
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Comparison of antagonistic effects of nanoparticle-selenium, selenium-enriched yeast and sodium selenite against cadmium-induced cardiotoxicity via AHR/CAR/PXR/Nrf2 pathways activation. J Nutr Biochem 2022; 105:108992. [DOI: 10.1016/j.jnutbio.2022.108992] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 11/19/2021] [Accepted: 02/22/2022] [Indexed: 02/08/2023]
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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.
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Affiliation(s)
| | - Sabine Gerbal-Chaloin
- IRMB, University of Montpellier, INSERM, CHU Montpellier, 34295 Montpellier, France;
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Indra R, Pompach P, Vavrová K, Jáklová K, Heger Z, Adam V, Eckschlager T, Kopečková K, Arlt VM, Stiborová M. Cytochrome P450 and flavin-containing monooxygenase enzymes are responsible for differential oxidation of the anti-thyroid-cancer drug vandetanib by human and rat hepatic microsomal systems. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2020; 74:103310. [PMID: 31837525 DOI: 10.1016/j.etap.2019.103310] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 11/24/2019] [Accepted: 12/02/2019] [Indexed: 06/10/2023]
Abstract
We studied the in vitro metabolism of the anti-thyroid-cancer drug vandetanib in a rat animal model and demonstrated that N-desmethylvandetanib and vandetanib N-oxide are formed by NADPH- or NADH-mediated reactions catalyzed by rat hepatic microsomes and pure biotransformation enzymes. In addition to the structural characterization of vandetanib metabolites, individual rat enzymes [cytochrome P450 (CYP) and flavin-containing monooxygenase (FMO)] capable of oxidizing vandetanib were identified. Generation of N-desmethylvandetanib, but not that of vandetanib N-oxide, was attenuated by CYP3A and 2C inhibitors while inhibition of FMO decreased formation of vandetanib N-oxide. These results indicate that liver microsomal CYP2C/3A and FMO1 are major enzymes participating in the formation of N-desmethylvandetanib and vandetanib N-oxide, respectively. Rat recombinant CYP2C11 > >3A1 > 3A2 > 1A1 > 1A2 > 2D1 > 2D2 were effective in catalyzing the formation of N-desmethylvandetanib. Results of the present study explain differences between the CYP- and FMO-catalyzed vandetanib oxidation in rat and human liver reported previously and the enzymatic mechanisms underlying this phenomenon.
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Affiliation(s)
- Radek Indra
- Department of Biochemistry, Faculty of Science, Charles University, Albertov, 2030, 128 40 Prague 2, Czech Republic
| | - Petr Pompach
- Department of Biochemistry, Faculty of Science, Charles University, Albertov, 2030, 128 40 Prague 2, Czech Republic
| | - Katarína Vavrová
- Department of Biochemistry, Faculty of Science, Charles University, Albertov, 2030, 128 40 Prague 2, Czech Republic
| | - Kateřina Jáklová
- Department of Biochemistry, Faculty of Science, Charles University, Albertov, 2030, 128 40 Prague 2, Czech Republic
| | - Zbyněk Heger
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, 61300 Brno, Czech Republic
| | - Vojtěch Adam
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, 61300 Brno, Czech Republic
| | - Tomáš Eckschlager
- Department of Pediatric Hematology and Oncology, 2nd Medical Faculty, Charles University and University Hospital Motol, 150 06 Prague, Czech Republic
| | - Kateřina Kopečková
- Department of Oncology, 2nd Faculty of Medicine, Charles University and University Hospital Motol, 150 06 Prague 5, Czech Republic
| | - Volker Manfred Arlt
- Department of Analytical, Environmental and Forensic Sciences, MRC-PHE Centre for Environment and Health, King's College London, 150 Stamford Street, London SE1 9NH, United Kingdom
| | - Marie Stiborová
- Department of Biochemistry, Faculty of Science, Charles University, Albertov, 2030, 128 40 Prague 2, Czech Republic.
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Ren T, Yang M, Xiao M, Zhu J, Xie W, Zuo Z. Time-dependent inhibition of carbamazepine metabolism by piperine in anti-epileptic treatment. Life Sci 2019; 218:314-323. [DOI: 10.1016/j.lfs.2018.12.060] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 12/31/2018] [Accepted: 12/31/2018] [Indexed: 11/25/2022]
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8
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Gabbia D, Pozzo L, Zigiotto G, Roverso M, Sacchi D, Dalla Pozza A, Carrara M, Bogialli S, Floreani A, Guido M, De Martin S. Dexamethasone counteracts hepatic inflammation and oxidative stress in cholestatic rats via CAR activation. PLoS One 2018; 13:e0204336. [PMID: 30252871 PMCID: PMC6155538 DOI: 10.1371/journal.pone.0204336] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 09/06/2018] [Indexed: 12/19/2022] Open
Abstract
Glucocorticoids (GCs) are currently used for the therapeutic management of cholestatic diseases, but their use and molecular mechanism remain controversial. The aims of this study were 1) to assess the therapeutic effect of a 2-week treatment with the GC dexamethasone on hepatic damage in bile duct-ligated rats; 2) to investigate its effect on the activation of the nuclear receptors (NRs) pregnane X receptor (PXR), constitutive androstane receptor (CAR) and GC receptor (GR), and NF-kB, as well as on oxidative stress and bile acid (BA) hepatic composition. Cholestasis was induced by ligation of bile duct (BDL animals) in 16 male Wistar-Kyoto rats, and eight of them were daily treated by oral gavage with 0.125 mg/ml/kg DEX for 14 days. Eight Sham-operated rats were used as controls. Severity of cholestasis was assessed histologically and on plasma biochemical parameters. The nuclear expression of NF-kB (p65), GR, PXR and CAR was measured in hepatic tissue by Western Blot. Oxidative stress was evaluated by measuring malondialdehyde, carbonylated proteins, GHS and ROS content in rat livers. LC-MS was used to measure the plasma and liver concentration of 7 BAs. Histological findings and a significant drop in several markers of inflammation (p65 nuclear translocation, mRNA expressions of TNF-α, IL-1β, IL-6) showed that DEX treatment reversed cholestasis-induced inflammation, and similar results have been obtained with oxidative stress markers. The nuclear expression of p65 and CAR were inversely correlated, with the latter increasing significantly after DEX treatment (p<0.01 vs vehicle). Hepatic BA levels tended to drop in the untreated cholestatic rats, whereas they were similar to those of healthy rats in DEX-treated animals. Plasma BAs decreased significantly in DEX-treated animals with respect to untreated cholestatic rats. In conclusion, DEX reduces inflammation and oxidative stress in BDL rats, and probably CAR is responsible for this effect. Therefore, this NR represents a promising pharmacological target for managing cholestatic and inflammatory liver diseases.
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Affiliation(s)
- Daniela Gabbia
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
| | - Luisa Pozzo
- Institute of Agricultural Biology and Biotechnology, CNR, Pisa, Italy
| | - Giorgia Zigiotto
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
| | - Marco Roverso
- Department of Chemical Sciences, University of Padova, Padova, Italy
| | - Diana Sacchi
- Department of Medicine, General Pathology and Cytopathology Unit, University of Padova, Padova, Italy
| | - Arianna Dalla Pozza
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
| | - Maria Carrara
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
| | - Sara Bogialli
- Department of Chemical Sciences, University of Padova, Padova, Italy
| | - Annarosa Floreani
- Department of Surgery, Oncology and Gastroenterology, University of Padova, Padova, Italy
| | - Maria Guido
- Department of Medicine, General Pathology and Cytopathology Unit, University of Padova, Padova, Italy
| | - Sara De Martin
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
- * E-mail:
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Guo J, Li W, Wu Y, Jing X, Huang J, Zhang J, Xiang W, Ren R, Lv Z, Xiao J, Guo F. Meclizine Prevents Ovariectomy-Induced Bone Loss and Inhibits Osteoclastogenesis Partially by Upregulating PXR. Front Pharmacol 2017; 8:693. [PMID: 29046637 PMCID: PMC5632684 DOI: 10.3389/fphar.2017.00693] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 09/19/2017] [Indexed: 12/13/2022] Open
Abstract
Pregnane X receptor (PXR) which belongs to the nuclear hormone receptor superfamily plays vital roles in several biological functions, especially in the inflammatory procedure. Besides that, PXR is revealed by recent studies to have essential effects on bone tissue. As an agonist of PXR, meclizine is a piperazine-derived histamine H1 antagonist, and has been frequently used for prevention and treatment of vomiting and nausea. Because osteoclastogenesis is characterized by the activation of inflammation-related signaling pathways, we speculated that meclizine may affect formation and function of osteoclast. In the present study, we explored the effect of meclizine on RANKL-induced osteoclastogenesis both in vivo and in vitro. In primary bone marrow-derived macrophages (BMMs), meclizine reduced osteoclast formation and bone resorption in a dose-dependent manner, while knockdown of PXR with siRNA partially abrogated the osteoclastogenesis inhibition of meclizine. On the one hand, at the molecular level, meclizine attenuated RANKL-induced activation of c-Fos, NFATc1, nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPKs), including ERK and p38, but not JNK. Meanwhile, meclizine reduced the expression of osteoclast-specific genes, including TRAP, MMP9, Cathepsin K and NFATc1. On the other hand, meclizine decreased OVX-induced bone loss by repressing osteoclast activity. In conclusion, our results indicated that meclizine inhibits osteoclastogenesis via regulation of several RANKL signaling pathways and PXR was involved in the processes. Therefore, meclizine may be considered as a novel therapeutic candidate for osteoclast-related diseases.
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Affiliation(s)
- Jiachao Guo
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Weijin Li
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yingxing Wu
- Department of Otolaryngology-Head and Neck Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xingzhi Jing
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Junming Huang
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jiaming Zhang
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Wei Xiang
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ranyue Ren
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhengtao Lv
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jun Xiao
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Fengjing Guo
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Comparison of the oxidation of carcinogenic aristolochic acid I and II by microsomal cytochromes P450 in vitro: experimental and theoretical approaches. MONATSHEFTE FUR CHEMIE 2017; 148:1971-1981. [PMID: 29104318 PMCID: PMC5653735 DOI: 10.1007/s00706-017-2014-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 05/29/2017] [Indexed: 12/03/2022]
Abstract
Abstract The herbal drug aristolochic acid, a natural mixture of 8-methoxy-6-nitrophenanthro[3,4-d]-1,3-dioxole-5-carboxylic acid (AAI) and 6-nitrophenanthro[3,4-d]-1,3-dioxole-5-carboxylic acid (AAII), is derived from Aristolochia species and is the cause of two nephropathies. Ingestion of aristolochic acid is associated with the development of urothelial tumors linked with aristolochic acid nephropathy and is implicated in the development of Balkan endemic nephropathy-associated urothelial tumors. The O-demethylated metabolite of AAI, 8-hydroxyaristolochic acid (AAIa), is the detoxification product of AAI generated by its oxidative metabolism. Whereas the formation of AAIa from AAI by cytochrome P450 (CYP) enzymes has been found in vitro and in vivo, this metabolite has not been found from AAII as yet. Therefore, the present study has been designed to compare the amenability of AAI and AAII to oxidation; experimental and theoretical approaches were used for such a study. In the case of experimental approaches, the enzyme (CYP)-mediated formation of AAIa from both carcinogens was investigated using CYP enzymes present in subcellular microsomal fractions and recombinant CYP enzymes. We found that in contrast to AAI, AAII is oxidized only by several CYP enzymatic systems and their efficiency is much lower for oxidation of AAII than AAI. Using the theoretical approaches, such as flexible in silico docking methods and ab initio calculations, contribution to explanation of these differences was established. Indeed, the results found by both used approaches determined the reasons why AAI is better oxidized than AAII; the key factor causing the differences in AAI and AAII oxidation is their different amenability to chemical oxidation. Graphical abstract ![]()
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11
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Stiborová M, Indra R, Moserová M, Šulc M, Hodek P, Frei E, Schmeiser HH, Arlt VM. NADPH- and NADH-dependent metabolism of and DNA adduct formation by benzo[ a]pyrene catalyzed with rat hepatic microsomes and cytochrome P450 1A1. MONATSHEFTE FUR CHEMIE 2016; 147:847-855. [PMID: 27110038 PMCID: PMC4828493 DOI: 10.1007/s00706-016-1713-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 02/11/2016] [Indexed: 11/11/2022]
Abstract
ABSTRACT Benzo[a]pyrene (BaP) is a human carcinogen that covalently binds to DNA after metabolic activation by cytochrome P450 (CYP) enzymes. Here we investigated the efficiencies of rat hepatic microsomes and rat recombinant CYP1A1 expressed with its reductase, NADPH:CYP oxidoreductase (POR), NADH:cytochrome b5 reductase, epoxide hydrolase and/or cytochrome b5 in Supersomes™ to metabolize this carcinogen. We also studied the effectiveness of coenzymes of two of the microsomal reductases, NADPH as a coenzyme of POR, and NADH as a coenzyme of NADH:cytochrome b5 reductase, to mediate BaP metabolism in these systems. Up to eight BaP metabolites and two DNA adducts were generated by the systems, both in the presence of NADPH and NADH. Among BaP metabolites, BaP-9,10-dihydrodiol, BaP-4,5-dihydrodiol, BaP-7,8-dihydrodiol, BaP-1,6-dione, BaP-3,6-dione, BaP-9-ol, BaP-3-ol, and a metabolite of unknown structure were formed by hepatic microsomes and rat CYP1A1. One of two DNA adducts formed by examined enzymatic systems (rat hepatic microsomes and rat CYP1A1) was characterized to be 10-(deoxyguanosin-N2-yl)-7,8,9-trihydroxy-7,8,9,10-tetrahydrobenzo[a]pyrene (dG-N2-BPDE), while another adduct has similar chromatographic properties on polyethylaneimine-cellulose thin layer chromatography to a guanine adduct derived from reaction with 9-hydroxy-BaP-4,5-oxide. In the presence of either of the reductase cofactors tested, NADPH or NADH, cytochrome b5 stimulated CYP1A1-mediated formation of both BaP-DNA adducts. The results demonstrate that NADH can act as a sole electron donor for both the first and the second reduction of CYP1A1 during its reaction cycle catalyzing oxidation of BaP, and suggest that the NADH:cytochrome b5 reductase as the NADH-dependent reductase might substitute POR in this enzymatic system. GRAPHICAL ABSTRACT
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Affiliation(s)
- Marie Stiborová
- />Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Radek Indra
- />Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Michaela Moserová
- />Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Miroslav Šulc
- />Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Petr Hodek
- />Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Eva Frei
- />Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Heinz H. Schmeiser
- />Division of Radiopharmaceutical Chemistry, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Volker M. Arlt
- />Analytical and Environmental Sciences Division, MRC-PHE Centre for Environment and Health, King’s College London, London, SE1 9NH UK
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Okamatsu G, Komatsu T, Ono Y, Inoue H, Uchide T, Onaga T, Endoh D, Kitazawa T, Hiraga T, Uno Y, Teraoka H. Characterization of feline cytochrome P450 2B6. Xenobiotica 2016; 47:93-102. [DOI: 10.3109/00498254.2016.1145754] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Gaku Okamatsu
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido, Japan and
| | - Tetsuya Komatsu
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido, Japan and
| | - Yuka Ono
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido, Japan and
| | - Hiroki Inoue
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido, Japan and
| | - Tsuyoshi Uchide
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido, Japan and
| | - Takenori Onaga
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido, Japan and
| | - Daiji Endoh
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido, Japan and
| | - Takio Kitazawa
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido, Japan and
| | - Takeo Hiraga
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido, Japan and
| | - Yasuhiro Uno
- Pharmacokinetics and Bioanalysis Center, Shin Nippon Biomedical Laboratories, Ltd., Kainan, Wakayama, Japan
| | - Hiroki Teraoka
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido, Japan and
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13
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A functional polymorphism in the 3'-UTR of PXR interacts with smoking to increase lung cancer risk in southern and eastern Chinese smoker. Int J Mol Sci 2014; 15:17457-68. [PMID: 25268617 PMCID: PMC4227172 DOI: 10.3390/ijms151017457] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 06/17/2014] [Accepted: 08/06/2014] [Indexed: 12/13/2022] Open
Abstract
Pregnane X receptor (PXR) is an important member of the nuclear receptor superfamily that copes with various endobiotic and xenobiotic stimuli, such as carcinogens by regulating an array of environmental response genes. Low PXR expression has been shown to promote tumor initiation and metastasis. The aim of the current study was to investigate whether the single nucleotide polymorphisms (SNPs) of PXR could alter lung cancer susceptibility in Chinese by affecting the function or expression of PXR. We genotyped three putatively functional SNPs of PXR (i.e., rs3814055C>T, rs3732360C>T, and rs3814058C>T) and analyzed their associations with lung cancer risk in a two-stage case-control study with a total of 1559 lung cancer cases and 1679 controls in the southern and eastern Chinese population. We found that in comparison to the rs3814058CC common genotype, the rs3814058T variants (TC/TT) which is located in the 3'-untranslated region (3'-UTR) of PXR conferred a consistently increased risk of lung cancer in both the southern Chinese (odd ratios (OR) = 1.24, 95% confidence interval (CI) = 1.03−1.49) and the eastern Chinese (OR = 1.33, 95% CI = 1.02−1.75). The variants also significantly interacted with smoking on increasing cancer risk (p = 0.023). Moreover, lung cancer tissues with the rs3814058T variants showed significantly lower PXR expression than those with rs3814058CC genotype in the smokers (p = 0.041). These results suggested that the rs3814058C>T polymorphism of PXR interacts with smoking on increasing lung cancer risk in Chinese smokers, which might be a functional genetic biomarker for lung cancer.
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14
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Qiao E, Ji M, Wu J, Ma R, Zhang X, He Y, Zha Q, Song X, Zhu LW, Tang J. Expression of the PXR gene in various types of cancer and drug resistance. Oncol Lett 2013; 5:1093-1100. [PMID: 23599746 PMCID: PMC3628904 DOI: 10.3892/ol.2013.1149] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 01/02/2013] [Indexed: 01/13/2023] Open
Abstract
Pregnane X receptor (PXR) is a member of the nuclear receptor superfamily of ligand-regulated transcription factors. PXR is a key xenobiotic receptor that regulates the expression of genes implicated in drug metabolism, detoxification and clearance, including drug metabolizing enzymes and transporters, suggesting that it is significant in the drug resistance of cancer cells. PXR is expressed in a wide range of tissues in the human body. Studies have demonstrated that PXR is expressed in a variety of tumor types, correlating not only with drug resistance but also with the cell proliferation, apoptosis and prognosis of cancer. The purpose of the present review is to provide a comprehensive review of PXR and its potential roles in multidrug resistance and the biological characteristics of PXR-positive tumors.
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Affiliation(s)
- Enqi Qiao
- Department of General Surgery, Jiangsu Cancer Hospital, Affiliated to Nanjing Medical University, Nanjing 210009
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15
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Zancanella V, Giantin M, Lopparelli RM, Nebbia C, Dacasto M. Tissue distribution and phenobarbital induction of target SLC- and ABC- transporters in cattle. J Vet Pharmacol Ther 2012; 36:358-69. [PMID: 22897113 DOI: 10.1111/j.1365-2885.2012.01427.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Accepted: 07/07/2012] [Indexed: 01/16/2023]
Abstract
In veterinary pharmaco-toxicological sciences, few data about uptake and efflux drug transporters (DTs) expression and regulation phenomena have been published. In this study, the tissue distribution and transcriptional modulation of solute carrier (SLC) and ATP-binding cassette (ABC) DTs were investigated in cattle orally administered with phenobarbital (PB) by using a quantitative real-time RT-PCR approach. The criterion for target gene selection was the PB-responsiveness in human and rodent model species. All target DTs were expressed in the liver. Only two of the seven PB-responsive target DTs (SLCO1B3 and SLC10A1) were not constitutively expressed in cattle extra-hepatic tissues. The greatest number of DTs (SLCO2B1, ABCB1, ABCC2, ABCG2) were expressed in intestine and testis, followed by, adrenal gland (SLCO2B1, ABCB1, ABCG2), lung (ABCB1, ABCG2), kidney, and skeletal muscle (ABCG2). PB administration never altered DTs mRNA levels, except for an increase in hepatic ABCC2 mRNA and a down-regulation of renal ABCG2. Altogether, these results confirm only to some extent data obtained in humans and laboratory species; clearly, they should be considered a preliminary step for further molecular investigations about species-differences in DT gene expression and regulation as well as in DT expression and function.
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Affiliation(s)
- V Zancanella
- Dipartimento di Biomedicina Comparata e Alimentazione, viale dell'Università 16, Padova, Italy
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16
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Zancanella V, Giantin M, Lopparelli RM, Nebbia C, Dacasto M. Constitutive expression and phenobarbital modulation of drug metabolizing enzymes and related nuclear receptors in cattle liver and extra-hepatic tissues. Xenobiotica 2012; 42:1096-109. [PMID: 22694178 DOI: 10.3109/00498254.2012.694493] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In humans and rodents, phenobarbital (PB) induces hepatic and extra-hepatic drug metabolizing enzymes (DMEs) through the activation of specific nuclear receptors (NRs). In contrast, few data about PB transcriptional effects in veterinary species are available. The constitutive expression and modulation of PB-responsive NR and DME genes, following an oral PB challenge, were investigated in cattle liver and extra-hepatic tissues (duodenum, kidney, lung, testis, adrenal and muscle). Likewise to humans and rodents, target genes were expressed to a lower extent compared to the liver with few exceptions. Phenobarbital significantly affected hepatic CYP2B22, 2C31, 2C87, 3A and UDP-glucuronosyltransferase 1A1-like, glutathione S-transferase A1-like and sulfotransferase 1A1-like (SULT1A1-like) mRNAs and apoprotein amounts; in extra-hepatic tissues, only duodenum showed a significant down-regulation of SULT1A1-like gene and apoprotein. Nuclear receptor mRNAs were never affected by PB. Presented data are the first evidence about the constitutive expression of foremost DME and NR genes in cattle extra-hepatic tissues, and the data obtained following a PB challenge are suggestive of species-differences in drug metabolism; altogether, these information are of value for the extrapolation of pharmacotoxicological data among species, the characterization of drug-drug interactions as well as the animal and consumer's risk caused by harmful residues formation.
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Affiliation(s)
- Vanessa Zancanella
- Dipartimento di Biomedicina Comparata e Alimentazione, Agripolis Legnaro, Padova, Italy
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17
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Comparison of three fluorescent CYP3A substrates in two vertebrate models: pig and Atlantic salmon. Animal 2012; 6:633-40. [DOI: 10.1017/s1751731111002096] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
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18
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Traber MG, Labut EM, Leonard SW, Lebold KM. α-Tocopherol injections in rats up-regulate hepatic ABC transporters, but not cytochrome P450 enzymes. Free Radic Biol Med 2011; 51:2031-40. [PMID: 21945367 PMCID: PMC3208783 DOI: 10.1016/j.freeradbiomed.2011.08.033] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Revised: 08/25/2011] [Accepted: 08/26/2011] [Indexed: 12/11/2022]
Abstract
The role of hepatic xenobiotic regulatory mechanisms in modulating hepatic α-tocopherol concentrations during excess vitamin E administration remains unclear. We hypothesized that increased hepatic α-tocopherol would cause a marked xenobiotic response. Thus, we assessed cytochrome P450 oxidation systems (phase I), conjugation systems (phase II), and transporters (phase III) after daily α-tocopherol injections (100mg/kg body wt) for up to 9days in rats. α-Tocopherol injections increased hepatic α-tocopherol concentrations nearly 20-fold, along with a 10-fold increase in the hepatic α-tocopherol metabolites α-CEHC and α-CMBHC. Expression of phase I (CYP3A2, CYP3A1, CYP2B2) and phase II (SULT2A1) proteins and/or mRNAs was variably affected by α-tocopherol injections; however, expression of phase III transporter genes was consistently changed by α-tocopherol. Two liver efflux transporter genes, ABCB1b and ABCG2, were up-regulated after α-tocopherol injections, whereas OATP, a liver influx transporter, was down-regulated. Thus, an overload of hepatic α-tocopherol increases its own metabolism and increases expression of genes of transporters that are postulated to lead to increased excretion of both vitamin E and its metabolites.
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Affiliation(s)
- Maret G Traber
- Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA.
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19
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Wang B, Robertson LW, Wang K, Ludewig G. Species difference in the regulation of cytochrome P450 2S1: lack of induction in rats by the aryl hydrocarbon receptor agonist PCB126. Xenobiotica 2011; 41:1031-43. [PMID: 21970748 DOI: 10.3109/00498254.2011.603763] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
CYP2S1 is an evolutionarily conserved, mainly extra-hepatic member of the CYP2 family and proposed to be regulated by the aryl hydrocarbon receptor (AhR). The present study explores AhR's regulation of CYP2S1 in male Sprague Dawley rats using PCB126 (3,3',4,4',5-pentachlorobiphenyl), the most potent AhR agonist among the PCBs. Additionally, CYP2S1 expression was examined after treatments with the classic CYP-inducers β-naphthoflavone (β-NF, AhR activator), phenobarbital (PB, CAR activator) and dexamethasone (Dex, PXR activator). CYP2S1 and CYP1A1/2, CYP1B1, CYP2B and CYP3A mRNAs were measured in liver, lung, spleen, stomach, kidney, and thymus at different time points. Constitutive CYP2S1 was expressed at comparable levels to other CYPs with the highest expression levels in stomach, kidney and lung. CYP2S1 mRNA was only non-significantly elevated by β-NF in liver tissues. PCB126 did not increase CYP2S1 mRNA in any organ and at any time point examined despite a significant induction of CYP1 genes. PCB126 reduced CYP2S1 mRNA by 40% (not significant) from the 7th post-exposure day in thymus. PB and Dex had no effect on CYP2S1 mRNA levels. These observations show that in this model CYP2S1 is not, or only weakly, regulated by AhR and not induced by CAR or PXR activators.
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Affiliation(s)
- Bingxuan Wang
- Human Toxicology, University of Iowa, Iowa City, USA
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20
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Nuclear receptor PXR, transcriptional circuits and metabolic relevance. Biochim Biophys Acta Mol Basis Dis 2011; 1812:956-63. [PMID: 21295138 DOI: 10.1016/j.bbadis.2011.01.014] [Citation(s) in RCA: 167] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Revised: 01/25/2011] [Accepted: 01/26/2011] [Indexed: 12/14/2022]
Abstract
The pregnane X receptor (PXR, NR1I2) is a ligand activated transcription factor that belongs to the nuclear hormone receptor (NR) superfamily. PXR is highly expressed in the liver and intestine, but low levels of expression have also been found in many other tissues. PXR plays an integral role in xenobiotic and endobiotic metabolism by regulating the expression of drug-metabolizing enzymes and transporters, as well as genes implicated in the metabolism of endobiotics. PXR exerts its transcriptional regulation by binding to its DNA response elements as a heterodimer with the retinoid X receptor (RXR) and recruitment of a host of coactivators. The biological and physiological implications of PXR activation are broad, ranging from drug metabolism and drug-drug interactions to the homeostasis of numerous endobiotics, such as glucose, lipids, steroids, bile acids, bilirubin, retinoic acid, and bone minerals. The purpose of this article is to provide an overview on the transcriptional circuits and metabolic relevance controlled by PXR. This article is part of a Special Issue entitled: Translating Nuclear Receptors from Health to Disease.
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21
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Huang L, Bi HC, Liu YH, Wang YT, Xue XP, Huang M. CAR-mediated Up-regulation of CYP3A4 Expression in LS174T Cells by Chinese Herbal Compounds. Drug Metab Pharmacokinet 2011; 26:331-40. [DOI: 10.2133/dmpk.dmpk-10-rg-115] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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22
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Fery Y, Mueller SO, Schrenk D. Development of stably transfected human and rat hepatoma cell lines for the species-specific assessment of xenobiotic response enhancer module (XREM)-dependent induction of drug metabolism. Toxicology 2010; 277:11-9. [PMID: 20832446 DOI: 10.1016/j.tox.2010.08.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Revised: 08/11/2010] [Accepted: 08/13/2010] [Indexed: 11/15/2022]
Abstract
Based on our current knowledge, PXR holds a key position in the induction of a selective battery of enzymes and transporters of drug metabolism. In order to prevent serious adverse drug effects or unpredicted drug-drug interactions (DDI), it is compulsory to investigate the possible inducing potency of drugs under development. Furthermore, analysis of the inducing potency of environmental pollutants and new or manufactured chemicals is part of toxicological risk assessment. In non-transfected human HepG2 and rat H4IIE hepatoma cells, we examined the characteristics of expression of 45 genes involved in drug metabolism. A few gene products such as CYP2B6 or CYP3A4 mRNA were prominent in HepG2 cells while their major rat counterparts were, e.g., CYP2B3 or CYP3A1/3A3. Furthermore, a number of xenobiotic receptors including PXR were expressed in both cell lines. A number of genes were regulated in a cell type and species-specific manner after incubation with the prototypical PXR agonists rifampicin or dexamethasone, respectively. Then, we established cell-based reporter gene assays for screening for PXR-dependent induction of drug metabolism. HepG2 and H4IIE cells were stably transfected with a reporter gene containing PXR responsive elements (XREMs) which mediate the induction of PXR target genes such as CYP3A enzymes. With both stable cell lines the CYP inducers clotrimazole, dexamethasone, omeprazole, phenobarbital, rifampicin, as well as the drug candidate EMD 392949 and the brominated flame retardants hexabromocylododecane (HBCD) and a pentabromodiphenyl ether (pentaBDE) mixture were screened. In the human HepG2-XREM3 and rat H4IIE-XREM3 cells, clotrimazole and HBCD were found as common activators of the human and rat PXR whereas pentaBDE was more effective with the human cell system. Omeprazole and phenobarbital did not induce the rat PXR-dependent reporter gene expression in H4IIE-XREM3 cells, while a moderate increase was found in HepG2-XREM3 cells. EMD 392949 also acted as inducer in human but not in rat cells confirming in vivo observations. In summary, the established PXR-dependent in vitro system allows the simultaneous, fast, and species-specific screening of chemicals, environmental contaminants, food ingredients and drugs for CYP3A induction in cells of human and rat origin.
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Affiliation(s)
- Yvonne Fery
- Food Chemistry and Toxicology, University of Kaiserslautern, Erwin-Schroedinger-Strasse 52, D-67663 Kaiserslautern, Germany
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23
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Species-specific induction of CYP2B by 2,4,6-tryphenyldioxane-1,3 (TPD). Life Sci 2009; 85:815-21. [DOI: 10.1016/j.lfs.2009.10.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2009] [Revised: 09/14/2009] [Accepted: 10/26/2009] [Indexed: 11/15/2022]
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24
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Mustacich DJ, Gohil K, Bruno RS, Yan M, Leonard SW, Ho E, Cross CE, Traber MG. Alpha-tocopherol modulates genes involved in hepatic xenobiotic pathways in mice. J Nutr Biochem 2008; 20:469-76. [PMID: 18789671 DOI: 10.1016/j.jnutbio.2008.05.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2008] [Revised: 05/02/2008] [Accepted: 05/08/2008] [Indexed: 12/11/2022]
Abstract
Hepatic proteins involved in xenobiotic pathways (Phases I, II and III) are responsible for the metabolism and disposition of endogenous and exogenous compounds including dietary phytochemicals. To test the hypothesis that elevated alpha-tocopherol intakes alter gene expression of hepatic xenobiotic pathways, mice were fed diets supplemented with either 1000 IU (+E) or 35 IU (E) all-rac-alpha-tocopheryl acetate for 4 months; liver RNA was isolated, and gene expression was determined using both whole genome microarray and real-time quantitative polymerase chain reaction analyses. Hepatic alpha-tocopherol (173+/-18 vs. 21+/-1 nmol/g, mean+/-S.E.) and its metabolite (2,5,7,8-tetramethyl-2-(2'-carboxyethyl)-6-hydroxychroman, 0.232+/-0.046 vs. 0.031+/-0.019 nmol/g) concentrations were approximately eightfold higher following the +E dietary treatment. In +E relative to E mice, gene expression of Phase I enzymes, P450 oxidoreductase and cytochrome P450 3a11 increased 1.6- and 4.0-fold, respectively; two Phase II genes, sulfotransferase 2a and glutathione S-transferase mu 3, increased 10.8- and 1.9-fold respectively, and a Phase III biliary transporter, Abcb1a, doubled. Thus, consumption of high-level dietary alpha-tocopherol simultaneously coordinated Phase I, II and III gene expression. These data demonstrate that increased hepatic alpha-tocopherol modulates its own concentrations through increasing xenobiotic metabolism, a process that may alter metabolism of other foreign compounds, such as therapeutic drugs and phytochemicals, in humans.
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Affiliation(s)
- Debbie J Mustacich
- Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA
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25
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Nannelli A, Chirulli V, Longo V, Gervasi PG. Expression and induction by rifampicin of CAR- and PXR-regulated CYP2B and CYP3A in liver, kidney and airways of pig. Toxicology 2008; 252:105-12. [PMID: 18786598 DOI: 10.1016/j.tox.2008.08.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2008] [Revised: 07/23/2008] [Accepted: 08/13/2008] [Indexed: 10/21/2022]
Abstract
The transcript levels of CYP2B22, 3A22, 3A29, 3A46, CAR, PXR and HNF4alpha were investigated in liver, kidney and airways from control and rifampicin-treated male pigs. The presence and induction of CYP genes transcription were studied by RT-PCR, real-time PCR, Western blotting and enzymatic activity whereas the expression of receptors was studied by RT-PCR or real-time PCR. Pretreatment with rifampicin resulted in a transcriptional activation, although to different extents, of all the CYP3A genes in liver but not in kidney, lung, bronchi or trachea. In the hepatic microsomes, the induction of CYP3A genes was accompanied by an increase of CYP3As marker activities and of two protein bands immunoreactive with anti-human CYP3A4. The CYP2B22 transcript was found to be markedly induced only in liver and kidney. In parallel, a protein band immunoreactive with anti-rat CYP2B1 was elevated while enhanced CYP2B marker activities were observed in hepatic and renal microsomes. As expected, based on human data, the basal expression of CAR, PXR and HNF4alpha was found to be high in liver and low in airways and not susceptible to induction by rifampicin. A significant expression of these transcriptional factors was also demonstrated in kidney. Thus, it is likely that rifampicin induced CYP2B22 both in liver and kidney of pig, not via activation of CAR, but via PXR, through a cross-talk mechanism, as previously observed in human liver. Taken together, our results demonstrated a differential expression and regulation of three individual CYP3As, CYP2B22, CAR, PXR and HNF4alpha genes in liver, kidney and airways of pig.
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Affiliation(s)
- Annalisa Nannelli
- Istituto di Fisiologia Clinica, CNR, Area della Ricerca CNR, via Moruzzi, 1, 56100 Pisa, Italy
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26
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Chirulli V, Marvasi L, Zaghini A, Fiorio R, Longo V, Gervasi PG. Inducibility of AhR-regulated CYP genes by β-naphthoflavone in the liver, lung, kidney and heart of the pig. Toxicology 2007; 240:25-37. [PMID: 17804143 DOI: 10.1016/j.tox.2007.07.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2007] [Revised: 07/04/2007] [Accepted: 07/07/2007] [Indexed: 11/30/2022]
Abstract
The presence and inducibility of CYP enzymes belonging to the family 1 (CYP 1A1, 1A2 and 1B1) and AhR have been studied in liver, lung, kidney and heart of control and beta-naphthoflavone (beta NF)-treated pigs. Segments of so far undescribed genes for porcine CYP 1A2, 1B1 and AhR were identified by RT-PCR and their sequences found to be highly homologous to those of the corresponding human genes. The mRNA level of CYP 1A1 was induced by beta NF, although to a different extent, in liver, lung, kidney and heart. This transcriptional activation of CYP 1A1 was accompanied in microsomes of all these organs by an induction of 7-ethoxyresorufin deethylase activity (a marker of this isoform) and an increase in a protein band immunoreactive with anti-rat CYP 1A1. An increase in CYP 1A2 transcription and in activity of microsomal 7-methoxyresorufin demethylase and acetanilide 4-hydroxylase (both markers of 1A2) was observed in the liver and, to a very small extent, in the lung but not in kidney and heart. As to CYP 1B1, its transcription was detected in liver, lung and heart only following the beta NF treatment; however this mRNA expression did result in any detectable microsomal 17beta-estradiol 4-hydroxylase activity (a marker of this isoform). The CYPs induced by beta NF were further investigated by using some other marker activities. It was found that porcine CYP 1A1 and 1A2, unlike the human counterparts, could only deethylate 7-ethoxycomarin to a very small extent, if at all, whereas 7-ethoxy 4-trifluoromethylcoumarin was a good substrate for pig CYP 1A1. Overall, our results demonstrated a differential expression and regulation of the AhR-mediated CYP genes in liver, lung, kidney and heart of the pig.naphthoflavone.
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Affiliation(s)
- Vera Chirulli
- Istituto di Fisiologia Clinica, CNR, via Moruzzi 1, 56100 Pisa, Italy
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27
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Mustacich DJ, Vo AT, Elias VD, Payne K, Sullivan L, Leonard SW, Traber MG. Regulatory mechanisms to control tissue alpha-tocopherol. Free Radic Biol Med 2007; 43:610-8. [PMID: 17640571 PMCID: PMC2693716 DOI: 10.1016/j.freeradbiomed.2007.05.027] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2007] [Revised: 04/25/2007] [Accepted: 05/23/2007] [Indexed: 10/23/2022]
Abstract
To test the hypothesis that hepatic regulation of alpha-tocopherol metabolism would be sufficient to prevent overaccumulation of alpha-tocopherol in extrahepatic tissues and that administration of high doses of alpha-tocopherol would up-regulate extrahepatic xenobiotic pathways, rats received daily subcutaneous injections of either vehicle or 0.5, 1, 2, or 10 mg alpha-tocopherol/100 g body wt for 9 days. Liver alpha-tocopherol increased 15-fold in rats given 10 mg alpha-tocopherol/100 g body wt (mg/100 g) compared with controls. Hepatic alpha-tocopherol metabolites increased with increasing alpha-tocopherol doses, reaching 40-fold in rats given the highest dose. In rats injected with 10 mg/100 g, lung and duodenum alpha-tocopherol concentrations increased 3-fold, whereas alpha-tocopherol concentrations of other extrahepatic tissues increased 2-fold or less. With the exception of muscle, daily administration of less than 2 mg/100 g failed to increase alpha-tocopherol concentrations in extrahepatic tissues. Lung cytochrome P450 3A and 1A levels were unchanged by administration of alpha-tocopherol at any dose. In contrast, lung P-glycoprotein (MDR1) levels increased dose dependently and expression of this xenobiotic transport protein was correlated with lung alpha-tocopherol concentrations (R(2)=0.88, p<0.05). Increased lung MDR1 may provide protection from exposure to environmental toxins by increasing alveolar space alpha-tocopherol.
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Affiliation(s)
- Debbie J Mustacich
- Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA
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28
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Shibayama Y, Ushinohama K, Ikeda R, Yoshikawa Y, Motoya T, Takeda Y, Yamada K. Effect of methotrexate treatment on expression levels of multidrug resistance protein 2, breast cancer resistance protein and organic anion transporters Oat1, Oat2 and Oat3 in rats. Cancer Sci 2006; 97:1260-6. [PMID: 16925582 PMCID: PMC11159268 DOI: 10.1111/j.1349-7006.2006.00304.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The ATP binding cassette (ABC) transporters, multidrug resistance protein 2 (Mrp2; Abcc2) and breast cancer resistance protein (Bcrp; Abcg2), and organic anion transporters (Oats) mediate excretion of methotrexate (MTX) and many other drugs. However, it is not known whether MTX treatment leads to any changes in the expression of these transporters. We examined the effect of MTX treatment on expression of Mrp2, Bcrp and Oats in rats. MTX was single injected intraperitoneally at doses of 10, 50 and 150 mg/kg, and then Western blot analysis was performed. The levels of Mrp2, Oat1 and Oat2 on day 1 after the treatment showed no significant change. Four days after injection of 150 mg/kg MTX, the Mrp2 levels in the liver and ileum, but not in the kidney, were markedly down-regulated to 20 +/- 3.6% and 8.9 +/- 3.8% (mean +/- SEM) of controls, respectively. Renal Oat1 and Oat3 were also down-regulated to 56.4 +/- 4.3% (Oat1) and 54.3 +/- 5.5% (Oat3) of controls. These effects of MTX were almost recovered by leucovorin which rescues normal cells from MTX toxicity. MTX treatment also decreased mRNA levels of constitutive androstane receptor (CAR) and pregnane X receptor (PXR) to 65.5 +/- 17.9% and 59.6 +/- 14.5% of controls in the liver, respectively. MTX treatment has no apparent effect on expression levels of Bcrp, cytochrome P450 2B6 and 3A1. In conclusion, these data indicate that MTX treatment down-regulates expression levels of Mrp2, Oat1 and Oat3, and its effects are recovered by leucovorin.
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Affiliation(s)
- Yoshihiko Shibayama
- Department of Clinical Pharmacy and Pharmacology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8520, Japan
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Pustylnyak VO, Gulyaeva LF, Lyakhovich VV. CAR expression and inducibility of CYP2B genes in liver of rats treated with PB-like inducers. Toxicology 2005; 216:147-53. [PMID: 16153763 DOI: 10.1016/j.tox.2005.08.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2005] [Revised: 08/02/2005] [Accepted: 08/02/2005] [Indexed: 11/20/2022]
Abstract
The expression of the CAR gene and inducibility of CYP2B protein in the liver of male Wistar rats treated with phenobarbital (PB) and triphenyldioxane (TPD) were investigated. To clarify the role of phosphorylation/dephosphorylation in these processes, rats were treated with inhibitors of Ca(2+)/calmodulin-dependent kinase II (W7) or protein phosphatases PP1 and PP2A (OA) before induction. Constitutive expression of the CAR gene in livers of untreated rats was detected by multiplex RT-PCR. Treatment with W7 resulted in a 2.8-fold induction of CAR gene expression, whereas OA led to a 2.4-fold decrease of the mRNA level. The same results were obtained for CYP2B genes expression, which were increased by W7 treatment (two-fold) and decreased by OA (2.3-fold). PB-induction did not lead to significant alteration in the level of CAR gene expression, although CYP2B genes expression was enhanced two-fold over control values. TPD caused a two-fold increase of both CAR and CYP2B mRNA levels. Both inducers reduced the effects of inhibitors on CAR gene expression. Results of EMSA showed that PB, TPD or W7 alone induced formation of complexes of NR1 with nuclear proteins. Appearance of the complexes correlated with an increase in CYP2B expression, and their intensities were modulated by the protein kinase inhibitors. Thus, our results demonstrate that constitutive expressions of CAR as well as CYP2B during induction are regulated by phosphorylation/dephosphorylation processes.
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Affiliation(s)
- Vladimir O Pustylnyak
- Institute of Molecular Biology and Biophysics, Timakova str. 2, Novosibirsk 630117, Russia.
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