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Giratallah H, Chenoweth MJ, Pouget JG, El-Boraie A, Alsaafin A, Lerman C, Knight J, Tyndale RF. CYP2A6 associates with respiratory disease risk and younger age of diagnosis: a phenome-wide association Mendelian Randomization study. Hum Mol Genet 2024; 33:198-210. [PMID: 37802914 PMCID: PMC10772040 DOI: 10.1093/hmg/ddad172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 09/21/2023] [Accepted: 10/02/2023] [Indexed: 10/08/2023] Open
Abstract
CYP2A6, a genetically variable enzyme, inactivates nicotine, activates carcinogens, and metabolizes many pharmaceuticals. Variation in CYP2A6 influences smoking behaviors and tobacco-related disease risk. This phenome-wide association study examined associations between a reconstructed version of our weighted genetic risk score (wGRS) for CYP2A6 activity with diseases in the UK Biobank (N = 395 887). Causal effects of phenotypic CYP2A6 activity (measured as the nicotine metabolite ratio: 3'-hydroxycotinine/cotinine) on the phenome-wide significant (PWS) signals were then estimated in two-sample Mendelian Randomization using the wGRS as the instrument. Time-to-diagnosis age was compared between faster versus slower CYP2A6 metabolizers for the PWS signals in survival analyses. In the total sample, six PWS signals were identified: two lung cancers and four obstructive respiratory diseases PheCodes, where faster CYP2A6 activity was associated with greater disease risk (Ps < 1 × 10-6). A significant CYP2A6-by-smoking status interaction was found (Psinteraction < 0.05); in current smokers, the same six PWS signals were found as identified in the total group, whereas no PWS signals were found in former or never smokers. In the total sample and current smokers, CYP2A6 activity causal estimates on the six PWS signals were significant in Mendelian Randomization (Ps < 5 × 10-5). Additionally, faster CYP2A6 metabolizer status was associated with younger age of disease diagnosis for the six PWS signals (Ps < 5 × 10-4, in current smokers). These findings support a role for faster CYP2A6 activity as a causal risk factor for lung cancers and obstructive respiratory diseases among current smokers, and a younger onset of these diseases. This research utilized the UK Biobank Resource.
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Affiliation(s)
- Haidy Giratallah
- Department of Pharmacology and Toxicology, University of Toronto, 1 King’s College Circle, Toronto, ON M5S 1A8, Canada
- Campbell Family Mental Health Research Institute, CAMH, 250 College St, Toronto, ON M5T 1R8, Canada
| | - Meghan J Chenoweth
- Department of Pharmacology and Toxicology, University of Toronto, 1 King’s College Circle, Toronto, ON M5S 1A8, Canada
- Campbell Family Mental Health Research Institute, CAMH, 250 College St, Toronto, ON M5T 1R8, Canada
- Department of Psychiatry, University of Toronto, 1 King’s College Circle, Toronto, ON M5S 1A8, Canada
| | - Jennie G Pouget
- Campbell Family Mental Health Research Institute, CAMH, 250 College St, Toronto, ON M5T 1R8, Canada
- Department of Psychiatry, University of Toronto, 1 King’s College Circle, Toronto, ON M5S 1A8, Canada
| | - Ahmed El-Boraie
- Department of Pharmacology and Toxicology, University of Toronto, 1 King’s College Circle, Toronto, ON M5S 1A8, Canada
- Campbell Family Mental Health Research Institute, CAMH, 250 College St, Toronto, ON M5T 1R8, Canada
| | - Alaa Alsaafin
- Department of Pharmacology and Toxicology, University of Toronto, 1 King’s College Circle, Toronto, ON M5S 1A8, Canada
- Campbell Family Mental Health Research Institute, CAMH, 250 College St, Toronto, ON M5T 1R8, Canada
| | - Caryn Lerman
- Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Ave, Los Angeles, CA 90033, United States
| | - Jo Knight
- Department of Psychiatry, University of Toronto, 1 King’s College Circle, Toronto, ON M5S 1A8, Canada
- Data Science Institute, Lancaster University Medical School, Lancaster LA1 4YE, United Kingdom
| | - Rachel F Tyndale
- Department of Pharmacology and Toxicology, University of Toronto, 1 King’s College Circle, Toronto, ON M5S 1A8, Canada
- Campbell Family Mental Health Research Institute, CAMH, 250 College St, Toronto, ON M5T 1R8, Canada
- Department of Psychiatry, University of Toronto, 1 King’s College Circle, Toronto, ON M5S 1A8, Canada
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Popescu RG, Bulgaru C, Untea A, Vlassa M, Filip M, Hermenean A, Marin D, Țăranu I, Georgescu SE, Dinischiotu A. The Effectiveness of Dietary Byproduct Antioxidants on Induced CYP Genes Expression and Histological Alteration in Piglets Liver and Kidney Fed with Aflatoxin B1 and Ochratoxin A. Toxins (Basel) 2021; 13:148. [PMID: 33671978 PMCID: PMC7919288 DOI: 10.3390/toxins13020148] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 02/12/2021] [Accepted: 02/13/2021] [Indexed: 02/07/2023] Open
Abstract
The purpose of this study was to investigate the potential of a byproduct mixture derived from grapeseed and sea buckthorn oil industry to mitigate the harmful damage produced by ochratoxin A and aflatoxin B1 at hepatic and renal level in piglets after weaning. Forty cross-bred TOPIGS-40 hybrid piglets after weaning were assigned to three experimental groups (E1, E2, E3) and one control group (C), and fed with experimental diets for 30 days. The basal diet was served as a control and contained normal compound feed for starter piglets without mycotoxins. The experimental groups were fed as follows: E1-basal diet plus a mixture (1:1) of two byproducts (grapeseed and sea buckthorn meal); E2-the basal diet experimentally contaminated with mycotoxins (479 ppb OTA and 62ppb AFB1); and E3-basal diet containing 5% of the mixture (1:1) of grapeseed and sea buckthorn meal and contaminated with the mix of OTA and AFB1. After 4 weeks, the animals were slaughtered, and tissue samples were taken from liver and kidney in order to perform gene expression and histological analysis. The gene expression analysis showed that when weaned piglets were fed with contaminated diet, the expression of most analyzed genes was downregulated. Among the CYP450 family, CYP1A2 was the gene with the highest downregulation. According to these results, in liver, we found that mycotoxins induced histomorphological alterations in liver and kidney and had an effect on the expression level of CYP1A2, CYP2A19, CYP2E1, and CYP3A29, but we did not detect important changes in the expression level of CY4A24, MRP2 and GSTA1 genes.
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Affiliation(s)
- Roua Gabriela Popescu
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Bucharest, Splaiul Independentei No. 91–95, 050095 Bucharest, Romania; (R.G.P.); (A.D.)
| | - Cristina Bulgaru
- Laboratory of Animal Biology, National Institute for Research and Development for Biology and Animal Nutrition, Calea Bucuresti No. 1, Balotesti, 077015 Ilfov, Romania; (C.B.); (A.U.); (D.M.)
| | - Arabela Untea
- Laboratory of Animal Biology, National Institute for Research and Development for Biology and Animal Nutrition, Calea Bucuresti No. 1, Balotesti, 077015 Ilfov, Romania; (C.B.); (A.U.); (D.M.)
| | - Mihaela Vlassa
- Raluca Ripan Institute for Research in Chemistry, Babeş Bolyai University, 30 Fântânele Street, 400294 Cluj-Napoca, Romania; (M.V.); (M.F.)
| | - Miuta Filip
- Raluca Ripan Institute for Research in Chemistry, Babeş Bolyai University, 30 Fântânele Street, 400294 Cluj-Napoca, Romania; (M.V.); (M.F.)
| | - Anca Hermenean
- “Aurel Ardelean” Institute of Life Sciences, Vasile Godis Western University of Arad, Rebreanu 86, 310414 Arad, Romania;
| | - Daniela Marin
- Laboratory of Animal Biology, National Institute for Research and Development for Biology and Animal Nutrition, Calea Bucuresti No. 1, Balotesti, 077015 Ilfov, Romania; (C.B.); (A.U.); (D.M.)
| | - Ionelia Țăranu
- Laboratory of Animal Biology, National Institute for Research and Development for Biology and Animal Nutrition, Calea Bucuresti No. 1, Balotesti, 077015 Ilfov, Romania; (C.B.); (A.U.); (D.M.)
| | - Sergiu Emil Georgescu
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Bucharest, Splaiul Independentei No. 91–95, 050095 Bucharest, Romania; (R.G.P.); (A.D.)
| | - Anca Dinischiotu
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Bucharest, Splaiul Independentei No. 91–95, 050095 Bucharest, Romania; (R.G.P.); (A.D.)
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Hakkola J, Hukkanen J, Turpeinen M, Pelkonen O. Inhibition and induction of CYP enzymes in humans: an update. Arch Toxicol 2020; 94:3671-3722. [PMID: 33111191 PMCID: PMC7603454 DOI: 10.1007/s00204-020-02936-7] [Citation(s) in RCA: 148] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 10/12/2020] [Indexed: 12/17/2022]
Abstract
The cytochrome P450 (CYP) enzyme family is the most important enzyme system catalyzing the phase 1 metabolism of pharmaceuticals and other xenobiotics such as herbal remedies and toxic compounds in the environment. The inhibition and induction of CYPs are major mechanisms causing pharmacokinetic drug–drug interactions. This review presents a comprehensive update on the inhibitors and inducers of the specific CYP enzymes in humans. The focus is on the more recent human in vitro and in vivo findings since the publication of our previous review on this topic in 2008. In addition to the general presentation of inhibitory drugs and inducers of human CYP enzymes by drugs, herbal remedies, and toxic compounds, an in-depth view on tyrosine-kinase inhibitors and antiretroviral HIV medications as victims and perpetrators of drug–drug interactions is provided as examples of the current trends in the field. Also, a concise overview of the mechanisms of CYP induction is presented to aid the understanding of the induction phenomena.
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Affiliation(s)
- Jukka Hakkola
- Research Unit of Biomedicine, Pharmacology and Toxicology, University of Oulu, POB 5000, 90014, Oulu, Finland.,Biocenter Oulu, University of Oulu, Oulu, Finland.,Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland
| | - Janne Hukkanen
- Biocenter Oulu, University of Oulu, Oulu, Finland.,Research Unit of Internal Medicine, Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland
| | - Miia Turpeinen
- Research Unit of Biomedicine, Pharmacology and Toxicology, University of Oulu, POB 5000, 90014, Oulu, Finland.,Administration Center, Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland
| | - Olavi Pelkonen
- Research Unit of Biomedicine, Pharmacology and Toxicology, University of Oulu, POB 5000, 90014, Oulu, Finland.
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Consumption of baby kale increased cytochrome P450 1A2 (CYP1A2) activity and influenced bilirubin metabolism in a randomized clinical trial. J Funct Foods 2020. [DOI: 10.1016/j.jff.2019.103624] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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Jabbarzadeh Kaboli P, Afzalipour Khoshkbejari M, Mohammadi M, Abiri A, Mokhtarian R, Vazifemand R, Amanollahi S, Yazdi Sani S, Li M, Zhao Y, Wu X, Shen J, Cho CH, Xiao Z. Targets and mechanisms of sulforaphane derivatives obtained from cruciferous plants with special focus on breast cancer - contradictory effects and future perspectives. Biomed Pharmacother 2019; 121:109635. [PMID: 31739165 DOI: 10.1016/j.biopha.2019.109635] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 10/29/2019] [Accepted: 10/31/2019] [Indexed: 12/15/2022] Open
Abstract
Breast cancer is the most common type of cancer among women. Therefore, discovery of new and effective drugs with fewer side effects is necessary to treat it. Sulforaphane (SFN) is an organosulfur compound obtained from cruciferous plants, such as broccoli and mustard, and it has the potential to treat breast cancer. Hence, it is vital to find out how SFN targets certain genes and cellular pathways in treating breast cancer. In this review, molecular targets and cellular pathways of SFN are described. Studies have shown SFN inhibits cell proliferation, causes apoptosis, stops cell cycle and has anti-oxidant activities. Increasing reactive oxygen species (ROS) produces oxidative stress, activates inflammatory transcription factors, and these result in inflammation leading to cancer. Increasing anti-oxidant potential of cells and discovering new targets to reduce ROS creation reduces oxidative stress and it eventually reduces cancer risks. In short, SFN effectively affects histone deacetylases involved in chromatin remodeling, gene expression, and Nrf2 anti-oxidant signaling. This review points to the potential of SFN to treat breast cancer as well as the importance of other new cruciferous compounds, derived from and isolated from mustard, to target Keap1 and Akt, two key regulators of cellular homeostasis.
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Affiliation(s)
- Parham Jabbarzadeh Kaboli
- Laboratory of Molecular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, 646000, Sichuan, PR China; South Sichuan Institution for Translational Medicine, Luzhou, 646000, Sichuan, PR China; Drug Discovery Research Group, Parham Academy of Biomedical Sciences, The Heritage B-16-10, Selangor, 43300, Malaysia.
| | | | - Mahsa Mohammadi
- Department of Chemistry, Central Tehran Branch, Islamic Azad University, Tehran, Iran
| | - Ardavan Abiri
- Department of Medicinal Chemistry, Faculty of Pharmacy, Kerman University of Medical Sciences, Kerman, Iran
| | - Roya Mokhtarian
- Drug Discovery Research Group, Parham Academy of Biomedical Sciences, The Heritage B-16-10, Selangor, 43300, Malaysia
| | - Reza Vazifemand
- Laboratory of Virology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, UPM Serdang, Selangor, 43400, Malaysia
| | - Shima Amanollahi
- Drug Discovery Research Group, Parham Academy of Biomedical Sciences, The Heritage B-16-10, Selangor, 43300, Malaysia; School of Mathematical, Physical, and Natural Sciences, University of Florence, Firenze, 50134, Italy
| | - Shaghayegh Yazdi Sani
- Drug Discovery Research Group, Parham Academy of Biomedical Sciences, The Heritage B-16-10, Selangor, 43300, Malaysia
| | - Mingxing Li
- Laboratory of Molecular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, 646000, Sichuan, PR China; South Sichuan Institution for Translational Medicine, Luzhou, 646000, Sichuan, PR China
| | - Yueshui Zhao
- Laboratory of Molecular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, 646000, Sichuan, PR China; South Sichuan Institution for Translational Medicine, Luzhou, 646000, Sichuan, PR China
| | - Xu Wu
- Laboratory of Molecular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, 646000, Sichuan, PR China; South Sichuan Institution for Translational Medicine, Luzhou, 646000, Sichuan, PR China
| | - Jing Shen
- Laboratory of Molecular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, 646000, Sichuan, PR China; South Sichuan Institution for Translational Medicine, Luzhou, 646000, Sichuan, PR China
| | - Chi Hin Cho
- Laboratory of Molecular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, 646000, Sichuan, PR China; South Sichuan Institution for Translational Medicine, Luzhou, 646000, Sichuan, PR China
| | - Zhangang Xiao
- Laboratory of Molecular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, 646000, Sichuan, PR China; South Sichuan Institution for Translational Medicine, Luzhou, 646000, Sichuan, PR China.
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6
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Lu Y, Cederbaum AI. Cytochrome P450s and Alcoholic Liver Disease. Curr Pharm Des 2018; 24:1502-1517. [PMID: 29637855 PMCID: PMC6053342 DOI: 10.2174/1381612824666180410091511] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 03/30/2018] [Accepted: 04/06/2018] [Indexed: 12/19/2022]
Abstract
Alcohol consumption causes liver diseases, designated as Alcoholic Liver Disease (ALD). Because alcohol is detoxified by alcohol dehydrogenase (ADH), a major ethanol metabolism system, the development of ALD was initially believed to be due to malnutrition caused by alcohol metabolism in liver. The discovery of the microsomal ethanol oxidizing system (MEOS) changed this dogma. Cytochrome P450 enzymes (CYP) constitute the major components of MEOS. Cytochrome P450 2E1 (CYP2E1) in MEOS is one of the major ROS generators in liver and is considered to be contributive to ALD. Our labs have been studying the relationship between CYP2E1 and ALD for many years. Recently, we found that human CYP2A6 and its mouse analog CYP2A5 are also induced by alcohol. In mice, the alcohol induction of CYP2A5 is CYP2E1-dependent. Unlike CYP2E1, CYP2A5 protects against the development of ALD. The relationship of CYP2E1, CYP2A5, and ALD is a major focus of this review.
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Affiliation(s)
- Yongke Lu
- Department of Health Sciences, College of Public Health, East Tennessee State University
- Center of Excellence for Inflammation, Infectious Disease and Immunity, East Tennessee State University
| | - Arthur I. Cederbaum
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai
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Chen X, Ward SC, Cederbaum AI, Xiong H, Lu Y. Alcoholic fatty liver is enhanced in CYP2A5 knockout mice: The role of the PPARα-FGF21 axis. Toxicology 2017; 379:12-21. [PMID: 28131861 DOI: 10.1016/j.tox.2017.01.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 01/16/2017] [Accepted: 01/23/2017] [Indexed: 01/05/2023]
Abstract
BACKGROUND & AIMS Cytochrome P450 2A5 (CYP2A5) is induced by ethanol, and the ethanol induction of CYP2A5 is regulated by nuclear factor-erythroid 2-related factor 2 (NRF2). Cyp2a5 knockout (Cyp2a5-/-) mice develop more severe alcoholic fatty liver than Cyp2a5+/+ mice. Fibroblast growth factor 21 (FGF21), a PPARα-regulated liver hormone, is involved in hepatic lipid metabolism. Alcoholic and non-alcoholic fatty liver are enhanced in Pparα knockout (Pparα-/-) mice. This study investigates the relationship between the PPARα-FGF21 axis and the enhanced alcoholic fatty liver in Cyp2a5-/- mice. METHODS Mice were fed the Lieber-Decarli ethanol diet to induce alcoholic fatty liver. RESULTS More severe alcoholic fatty liver disease was developed in Cyp2a5-/- mice than in Cyp2a5+/+ mice. Basal FGF21 levels were higher in Cyp2a5-/- mice than in Cyp2a5+/+ mice, but ethanol did not further increase the elevated FGF21 levels in Cyp2a5-/- mice while FGF21 was induced by ethanol in Cyp2a5+/+ mice. Basal levels of serum FGF21 were lower in Pparα-/- mice than in Pparα+/+ mice; ethanol induced FGF21 in Pparα+/+ mice but not in Pparα-/- mice, whereas ethanol induced hypertriglyceridemia in Pparα-/- mice but not in Pparα+/+ mice. Administration of recombinant FGF21 normalized serum FGF21 and triglyceride in Pparα-/- mice. Alcoholic fatty liver was enhanced in liver-specific Fgf21 knockout mice. Pparα and Cyp2a5 double knockout (Pparα-/-/Cyp2a5-/-) mice developed more severe alcoholic fatty liver than Pparα+/+/Cyp2a5-/- mice. CONCLUSIONS These results suggest that CYP2A5 protects against the development of alcoholic fatty liver disease, and the PPARα-FGF21 axis contributes to the protective effects of CYP2A5 on alcoholic fatty liver disease.
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Affiliation(s)
- Xue Chen
- Department of Health Sciences, College of Public Health, East Tennessee State University, Johnson City, TN, United States
| | - Stephen C Ward
- Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, New York, United States
| | - Arthur I Cederbaum
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, United States
| | - Huabao Xiong
- Division of Immunology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States
| | - Yongke Lu
- Department of Health Sciences, College of Public Health, East Tennessee State University, Johnson City, TN, United States; Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, United States.
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Leung TM, Lu Y. Alcoholic Liver Disease: from CYP2E1 to CYP2A5. Curr Mol Pharmacol 2017; 10:172-178. [PMID: 26278389 PMCID: PMC5856453 DOI: 10.2174/1874467208666150817111846] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 08/07/2015] [Accepted: 08/07/2015] [Indexed: 02/08/2023]
Abstract
This article reviews recent studies on CYP2E1-mediated alcoholic liver injury, the induction of CYP2A5 by alcohol and the mechanism for this upregulation, especially the permissive role of CYP2E1 in the induction of CYP2A5 by alcohol and the CYP2E1-ROS-Nrf2 pathway, and protective effects of CYP2A5 against ethanol-induced oxidative liver injury. Ethanol can induce CYP2E1, an active generator of reactive oxygen species (ROS), and CYP2E1 is a contributing factor for alcoholinduced oxidative liver injury. CYP2A5, another isoform of cytochrome P450, can also be induced by ethanol. Chronic feeding of ethanol to wild type mice increased CYP2A5 catalytic activity, protein and mRNA levels as compared to pair-fed controls. This induction was blunted in CYP2E1 knockout (cyp2e1-/-) mice but was restored when human CYP2E1 was reintroduced and expressed in cyp2e1-/- mice. Ethanol-induced CYP2E1 co-localized with CYP2A5 and preceded the elevation of CYP2A5. The antioxidants N-acetyl cysteine and vitamin C lowered the alcohol elevation of ROS and blunted the alcohol induction of CYP2A5, but not CYP2E1, suggesting ROS play a novel role in the crosstalk between CYP2E1 and CYP2A5. The antioxidants blocked the activation of Nrf2, a transcription factor known to upregulate expression of CYP2A5. When alcohol-induced liver injury was enhanced in Nrf2 knockout (Nrf2-/-) mice, alcohol elevation of CYP2A5 but not CYP2E1 was also lower in Nrf2-/- mice. CYP2A5 knockout (cyp2a5-/-) mice exhibited an enhanced alcoholic liver injury compared with WT mice as indicated by serum ALT, steatosis and necroinflammation. Alcohol-induced hyperglycemia were observed in cyp2a5-/- mice but not in WT mice.
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Affiliation(s)
- Tung Ming Leung
- Graduate Program in Public Health, Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount. United States
| | - Yongke Lu
- Department of Structural and Chemical Biology, Box 1677, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY, 10029. United States
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Esteras N, Dinkova-Kostova AT, Abramov AY. Nrf2 activation in the treatment of neurodegenerative diseases: a focus on its role in mitochondrial bioenergetics and function. Biol Chem 2016; 397:383-400. [PMID: 26812787 DOI: 10.1515/hsz-2015-0295] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 01/07/2016] [Indexed: 12/16/2022]
Abstract
The nuclear factor erythroid-derived 2 (NF-E2)-related factor 2 (Nrf2) is a transcription factor well-known for its function in controlling the basal and inducible expression of a variety of antioxidant and detoxifying enzymes. As part of its cytoprotective activity, increasing evidence supports its role in metabolism and mitochondrial bioenergetics and function. Neurodegenerative diseases are excellent candidates for Nrf2-targeted treatments. Most neurodegenerative conditions such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, frontotemporal dementia and Friedreich's ataxia are characterized by oxidative stress, misfolded protein aggregates, and chronic inflammation, the common targets of Nrf2 therapeutic strategies. Together with them, mitochondrial dysfunction is implicated in the pathogenesis of most neurodegenerative disorders. The recently recognized ability of Nrf2 to regulate intermediary metabolism and mitochondrial function makes Nrf2 activation an attractive and comprehensive strategy for the treatment of neurodegenerative disorders. This review aims to focus on the potential therapeutic role of Nrf2 activation in neurodegeneration, with special emphasis on mitochondrial bioenergetics and function, metabolism and the role of transporters, all of which collectively contribute to the cytoprotective activity of this transcription factor.
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Lu Y, Cederbaum AI. Alcohol Upregulation of CYP2A5: Role of Reactive Oxygen Species. REACTIVE OXYGEN SPECIES (APEX, N.C.) 2016; 1:117-130. [PMID: 29756048 PMCID: PMC5944604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Hepatic cytochrome P450 (CYP) 2E1 and CYP2A5 activate many important drugs and hepatotoxins. CYP2E1 is induced by alcohol, but whether CYP2A5 is upregulated by alcohol is not known. This article reviews recent studies on the induction of CYP2A5 by alcohol and the mechanism and role of reactive oxygen species (ROS) in this upregulation. Chronic feeding of ethanol to wild type mice increased CYP2A5 catalytic activity and protein and mRNA levels. This induction was blunted in CYP2E1 knockout mice and by a CYP2E1 inhibitor, but was restored in CYP2E1 knockin mice, suggesting a role for CYP2E1 in the induction of CYP2A5 by alcohol. Since CYP2E1 actively generates ROS, the possible role of ROS in the induction of CYP2A5 by alcohol was determined. ROS production was elevated by ethanol treatment. The antioxidants N-acetyl cysteine and vitamin C lowered the alcohol-induced elevation of ROS and blunted the alcohol-mediated induction of CYP2A5. These results suggest that ROS play a novel role in the crosstalk between CYP2E1 and CYP2A5. Alcohol treatment activated nuclear factor erythroid 2 (NFE2)-related factor 2 (Nrf2), a transcription factor which up-regulates expression of CYP2A5. The antioxidants blocked the activation of Nrf2. The alcohol-induced elevation of CYP2A5, but not CYP2E1, was lower in Nrf2 knockout mice. We propose that increased generation of ROS from the alcohol-induced CYP2E1 activates Nrf2, which subsequently up-regulates the expression of CYP2A5. Thus, a novel consequence of the alcohol-mediated induction of CYP2E1 and increase in ROS is the activation of redox-sensitive transcription factors, such as Nrf2, and expression of CYP2A5. Further perspectives on this alcohol-CYP2E1-ROS-Nrf2-CYP2A5 pathway are presented.
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Affiliation(s)
- Yongke Lu
- Department of Structural and Chemical Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Arthur I Cederbaum
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
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The role of CYP2A5 in liver injury and fibrosis: chemical-specific difference. Naunyn Schmiedebergs Arch Pharmacol 2015; 389:33-43. [PMID: 26363552 DOI: 10.1007/s00210-015-1172-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 08/30/2015] [Indexed: 12/20/2022]
Abstract
Liver injuries induced by carbon tetrachloride (CCL4) or thioacetamide (TAA) are dependent on cytochrome P450 2E1 (CYP2E1). CYP2A5 can be induced by TAA but not by CCL4. In this study, liver injury including fibrosis induced by CCL4 or TAA were investigated in wild-type (WT) mice and CYP2A5 knockout (cyp2a5 (-/-) ) mice as well as in CYP2E1 knockout (cyp2e1 (-/-) ) mice as a comparison. Acute and subchronic liver injuries including fibrosis were induced by CCL4 and TAA in WT mice but not in cyp2e1 (-/-) mice, confirming the indispensable role of CYP2E1 in CCL4 and TAA hepatotoxicity. WT mice and cyp2a5 (-/-) mice developed comparable acute liver injury induced by a single injection of CCL4 as well as subchronic liver injury including fibrosis induced by 1 month of repeated administration of CCL4, suggesting that CYP2A5 does not affect CCL4-induced liver injury and fibrosis. However, while 200 mg/kg TAA-induced acute liver injury was comparable in WT mice and cyp2a5 (-/-) mice, 75 and 100 mg/kg TAA-induced liver injury were more severe in cyp2a5 (-/-) mice than those found in WT mice. After multiple injections with 200 mg/kg TAA for 1 month, while subchronic liver injury as indicated by serum aminotransferases was comparable in WT mice and cyp2a5 (-/-) mice, liver fibrosis was more severe in cyp2a5 (-/-) mice than that found in WT mice. These results suggest that while both CCL4- and TAA-induced liver injuries and fibrosis are CYP2E1 dependent, under some conditions, CYP2A5 may protect against TAA-induced liver injury and fibrosis, but it does not affect CCL4 hepatotoxicity.
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Hu H, Yu T, Arpiainen S, Lang MA, Hakkola J, Abu-Bakar A. Tumour suppressor protein p53 regulates the stress activated bilirubin oxidase cytochrome P450 2A6. Toxicol Appl Pharmacol 2015; 289:30-9. [PMID: 26343999 DOI: 10.1016/j.taap.2015.08.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 08/31/2015] [Accepted: 08/31/2015] [Indexed: 12/20/2022]
Abstract
Human cytochrome P450 (CYP) 2A6 enzyme has been proposed to play a role in cellular defence against chemical-induced oxidative stress. The encoding gene is regulated by various stress activated transcription factors. This paper demonstrates that p53 is a novel transcriptional regulator of the gene. Sequence analysis of the CYP2A6 promoter revealed six putative p53 binding sites in a 3kb proximate promoter region. The site closest to transcription start site (TSS) is highly homologous with the p53 consensus sequence. Transfection with various stepwise deletions of CYP2A6-5'-Luc constructs--down to -160bp from the TSS--showed p53 responsiveness in p53 overexpressed C3A cells. However, a further deletion from -160 to -74bp, including the putative p53 binding site, totally abolished the p53 responsiveness. Electrophoretic mobility shift assay with a probe containing the putative binding site showed specific binding of p53. A point mutation at the binding site abolished both the binding and responsiveness of the recombinant gene to p53. Up-regulation of the endogenous p53 with benzo[α]pyrene--a well-known p53 activator--increased the expression of the p53 responsive positive control and the CYP2A6-5'-Luc construct containing the intact p53 binding site but not the mutated CYP2A6-5'-Luc construct. Finally, inducibility of the native CYP2A6 gene by benzo[α]pyrene was demonstrated by dose-dependent increases in CYP2A6 mRNA and protein levels along with increased p53 levels in the nucleus. Collectively, the results indicate that p53 protein is a regulator of the CYP2A6 gene in C3A cells and further support the putative cytoprotective role of CYP2A6.
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Affiliation(s)
- Hao Hu
- The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland, Australia.
| | - Ting Yu
- The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland, Australia.
| | - Satu Arpiainen
- Institute of Biomedicine, Department of Pharmacology and Toxicology and Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland.
| | - Matti A Lang
- The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland, Australia.
| | - Jukka Hakkola
- Institute of Biomedicine, Department of Pharmacology and Toxicology and Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland.
| | - A'edah Abu-Bakar
- The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland, Australia.
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Hong F, Liu X, Ward S, Xiong H, Cederbaum AI, Lu Y. Absence of cytochrome P450 2A5 enhances alcohol-induced liver injury in mice. Dig Liver Dis 2015; 47:470-7. [PMID: 25804444 PMCID: PMC4442740 DOI: 10.1016/j.dld.2015.02.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 02/05/2015] [Accepted: 02/26/2015] [Indexed: 12/11/2022]
Abstract
BACKGROUND Ethanol can induce cytochrome P450 2E1, an active generator of reactive oxygen species, and this cytochrome is considered a risk factor for oxidative liver injury. Recently, we found that in addition to P450 2E1 also cytochrome P450 2A5, another isoform of cytochrome P450, can be induced by ethanol, and that ethanol induction of cytochrome P450 2A5 is P450 2E1-dependent. AIMS To investigate the role of cytochrome P450 2A5 in alcohol-induced liver injury. METHODS Cytochrome P450 2A5-knockout mice and wild type mice were fed the Lieber-Decarli ethanol liquid diet to induce liver injury. Controls were fed the Lieber-Decarli control diet. RESULTS After 4 weeks of feeding with Lieber-Decarli diet, ethanol-induced liver injury was enhanced in the knockout mice compared with wild type mice, as indicated by serum transaminases, hepatic fat accumulation (steatosis), and necroinflammation observed in liver sections with Haematoxylin & Eosin staining. Ethanol-induced oxidative stress was also higher in the knockout mice than the wild types. Ethanol feeding induced cytochrome P450 2A5 in wild type mice but not in the knockout mice, while induction of cytochrome P450 2E1 was comparable in the knockout and wild type mice. CONCLUSION These results suggest that cytochrome P450 2A5 protects against ethanol-induced oxidative liver injury.
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Affiliation(s)
- Feng Hong
- Institute of liver diseases, Affiliated Hospital of Jining Medical University, Jining, China
| | - Xiyu Liu
- Department of Hepatobiliary and Pancreatic Surgery, the First Bethune Hospital, Jilin University, Jilin 130021, China
| | - Stephen Ward
- Department of Pathology, Icahn School of Medicine at Mount Sinai, One Gustave L Levy Place, New York, NY 10029
| | - Huabao Xiong
- Division of Immunology, Department of medicine, Icahn School of Medicine at Mount Sinai, One Gustave L Levy Place, New York, NY 10029
| | - Arthur I. Cederbaum
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, One Gustave L Levy Place, New York, NY 10029
| | - Yongke Lu
- Department of Structural and Chemical Biology, Icahn School of Medicine at Mount Sinai, One Gustave L Levy Place, New York, NY 10029
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Nakano M, Fukushima Y, Yokota SI, Fukami T, Takamiya M, Aoki Y, Yokoi T, Nakajima M. CYP2A7 Pseudogene Transcript Affects CYP2A6 Expression in Human Liver by Acting as a Decoy for miR-126*. Drug Metab Dispos 2015; 43:703-12. [DOI: 10.1124/dmd.115.063255] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
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Identification and quantification of the basal and inducible Nrf2-dependent proteomes in mouse liver: biochemical, pharmacological and toxicological implications. J Proteomics 2014; 108:171-87. [PMID: 24859727 PMCID: PMC4115266 DOI: 10.1016/j.jprot.2014.05.007] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 04/30/2014] [Accepted: 05/13/2014] [Indexed: 01/06/2023]
Abstract
The transcription factor Nrf2 is a master regulator of cellular defence: Nrf2 null mice (Nrf2(−/−)) are highly susceptible to chemically induced toxicities. We report a comparative iTRAQ-based study in Nrf2(−/−) mice treated with a potent inducer, methyl-2-cyano-3,12-dioxooleana-1,9(11)dien-28-oate (CDDO-me; bardoxolone -methyl), to define both the Nrf2-dependent basal and inducible hepatoproteomes. One thousand five hundred twenty-one proteins were fully quantified (FDR < 1%). One hundred sixty-one were significantly different (P < 0.05) between WT and Nrf2(−/−) mice, confirming extensive constitutive regulation by Nrf2. Treatment with CDDO-me (3 mg/kg; i.p.) resulted in significantly altered expression of 43 proteins at 24 h in WT animals. Six proteins were regulated at both basal and inducible levels exhibiting the largest dynamic range of Nrf2 regulation: cytochrome P4502A5 (CYP2A5; 17.2-fold), glutathione-S-transferase-Mu 3 (GSTM3; 6.4-fold), glutathione-S-transferase Mu 1 (GSTM1; 5.9-fold), ectonucleoside-triphosphate diphosphohydrolase (ENTPD5; 4.6-fold), UDP-glucose-6-dehydrogenase (UDPGDH; 4.1-fold) and epoxide hydrolase (EPHX1; 3.0-fold). These proteins, or their products, thus provide a potential source of biomarkers for Nrf2 activity. ENTPD5 is of interest due to its emerging role in AKT signalling and, to our knowledge, this protein has not been previously shown to be Nrf2-dependent. Only two proteins altered by CDDO-me in WT animals were similarly affected in Nrf2(−/−) mice, demonstrating the high degree of selectivity of CDDO-me for the Nrf2:Keap1 signalling pathway. Biological significance The Nrf2:Keap1 signalling pathway is attracting considerable interest as a therapeutic target for different disease conditions. For example, CDDO-me (bardoxolone methyl) was investigated in clinical trials for the treatment of acute kidney disease, and dimethyl fumarate, recently approved for reducing relapse rate in multiple sclerosis, is a potent Nrf2 inducer. Such compounds have been suggested to act through multiple mechanisms; therefore, it is important to define the selectivity of Nrf2 inducers to assess the potential for off-target effects that may lead to adverse drug reactions, and to provide biomarkers with which to assess therapeutic efficacy. Whilst there is considerable information on the global action of such inducers at the mRNA level, this is the first study to catalogue the hepatic protein expression profile following acute exposure to CDDO-me in mice. At a dose shown to evoke maximal Nrf2 induction in the liver, CDDO-me appeared highly selective for known Nrf2-regulated proteins. Using the transgenic Nrf2(−/−) mouse model, it could be shown that 97% of proteins induced in wild type mice were associated with a functioning Nrf2 signalling pathway. This analysis allowed us to identify a panel of proteins that were regulated both basally and following Nrf2 induction. Identification of these proteins, which display a large magnitude of variation in their expression, provides a rich source of potential biomarkers for Nrf2 activity for use in experimental animals, and which may be translatable to man to define individual susceptibility to chemical stress, including that associated with drugs, and also to monitor the pharmacological response to Nrf2 inducers. Liver proteomes from WT, Nrf2-null and Nrf2-induced mice were compared by iTRAQ Of 1521 proteins quantified, 161 were regulated basally and 43 following induction Six proteins were both basally and inducibly regulated, with high dynamic ranges In order of fold change, these proteins were CYP2A5, GSTM3, GSTM1, ENTPD5, G6PD, EPHX1 These proteins may yield translatable biomarkers for clinical development
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Gao B, Doan A, Hybertson BM. The clinical potential of influencing Nrf2 signaling in degenerative and immunological disorders. Clin Pharmacol 2014; 6:19-34. [PMID: 24520207 PMCID: PMC3917919 DOI: 10.2147/cpaa.s35078] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Nuclear factor (erythroid-derived 2)-like 2 (Nrf2; encoded in humans by the NFE2L2 gene) is a transcription factor that regulates the gene expression of a wide variety of cytoprotective phase II detoxification and antioxidant enzymes through a promoter sequence known as the antioxidant-responsive element (ARE). The ARE is a promoter element found in many cytoprotective genes; therefore, Nrf2 plays a pivotal role in the ARE-driven cellular defense system against environmental stresses. Agents that target the ARE/Nrf2 pathway have been tested in a wide variety of disorders, with at least one new Nrf2-activating drug now approved by the US Food and Drug Administration. Examination of in vitro and in vivo experimental results, and taking into account recent human clinical trial results, has led to an opinion that Nrf2-activating strategies – which can include drugs, foods, dietary supplements, and exercise – are likely best targeted at disease prevention, disease recurrence prevention, or slowing of disease progression in early stage illnesses; they may also be useful as an interventional strategy. However, this rubric may be viewed even more conservatively in the pathophysiology of cancer. The activation of the Nrf2 pathway has been widely accepted as offering chemoprevention benefit, but it may be unhelpful or even harmful in the setting of established cancers. For example, Nrf2 activation might interfere with chemotherapies or radiotherapies or otherwise give tumor cells additional growth and survival advantages, unless they already possess mutations that fully activate their Nrf2 pathway constitutively. With all this in mind, the ARE/Nrf2 pathway remains of great interest as a possible target for the pharmacological control of degenerative and immunological diseases, both by activation and by inhibition, and its regulation remains a promising biological target for the development of new therapies.
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Affiliation(s)
- Bifeng Gao
- Department of Medicine, Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - An Doan
- Department of Medicine, Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Brooks M Hybertson
- Department of Medicine, Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
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Siddiqui MA, Ahmad J, Farshori NN, Saquib Q, Jahan S, Kashyap MP, Ahamed M, Musarrat J, Al-Khedhairy AA. Rotenone-induced oxidative stress and apoptosis in human liver HepG2 cells. Mol Cell Biochem 2013; 384:59-69. [PMID: 23963993 DOI: 10.1007/s11010-013-1781-9] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2013] [Accepted: 08/09/2013] [Indexed: 02/06/2023]
Abstract
Rotenone, a commonly used pesticide, is well documented to induce selective degeneration in dopaminergic neurons and motor dysfunction. Such rotenone-induced neurodegenration has been primarily suggested through mitochondria-mediated apoptosis and reactive oxygen species (ROS) generation. But the status of rotenone induced changes in liver, the major metabolic site is poorly investigated. Thus, the present investigation was aimed to study the oxidative stress-induced cytotoxicity and apoptotic cell death in human liver cells-HepG2 receiving experimental exposure of rotenone (12.5-250 μM) for 24 h. Rotenone depicted a dose-dependent cytotoxic response in HepG2 cells. These cytotoxic responses were in concurrence with the markers associated with oxidative stress such as an increase in ROS generation and lipid peroxidation as well as a decrease in the glutathione, catalase, and superoxide dismutase levels. The decrease in mitochondrial membrane potential also confirms the impaired mitochondrial activity. The events of cytotoxicity and oxidative stress were found to be associated with up-regulation in the expressions (mRNA and protein) of pro-apoptotic markers viz., p53, Bax, and caspase-3, and down-regulation of anti-apoptotic marker Bcl-2. The data obtain in this study indicate that rotenone-induced cytotoxicity in HepG2 cells via ROS-induced oxidative stress and mitochondria-mediated apoptosis involving p53, Bax/Bcl-2, and caspase-3.
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Affiliation(s)
- M A Siddiqui
- Department of Zoology, College of Science, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia,
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Kojima M, Degawa M. Serum androgen level is determined by autosomal dominant inheritance and regulates sex-related CYP genes in pigs. Biochem Biophys Res Commun 2013. [DOI: 10.1016/j.bbrc.2012.11.060] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Ande A, Earla R, Jin M, Silverstein PS, Mitra AK, Kumar A, Kumar S. An LC-MS/MS method for concurrent determination of nicotine metabolites and the role of CYP2A6 in nicotine metabolite-mediated oxidative stress in SVGA astrocytes. Drug Alcohol Depend 2012; 125:49-59. [PMID: 22498344 PMCID: PMC3413753 DOI: 10.1016/j.drugalcdep.2012.03.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Revised: 03/15/2012] [Accepted: 03/16/2012] [Indexed: 11/28/2022]
Abstract
BACKGROUND Nicotine is known to generate oxidative stress through cytochrome P450 2A6 (CYP2A6)-mediated metabolism in the liver and other organs, including macrophages. This study has been designed to examine the role of CYP2A6 in nicotine metabolism and oxidative stress in SVGA cells, an immortalized human astrocyte cell line. METHODS SVGA astrocytes were treated with 1 μM nicotine, followed by determination of mRNA and protein levels of several CYPs using quantitative RT-PCR and western blot analyses, respectively. Quantitation of nicotine and the nicotine metabolites, cotinine and nicotine-derived nitrosamine ketones (NNK), was performed using an LC-MS/MS method. The generation of reactive oxygen species (ROS) was measured using flow cytometry. RESULTS Nicotine significantly upregulated mRNA and protein expression of the most abundantly expressed CYPs in SVGA astrocytes, CYP2A6 and CYP1A1. To characterize the metabolism of nicotine in astrocytes, a highly sensitive LC-MS/MS method was developed which is capable of quantifying very low concentrations of nicotine (0.3 ng/mL), cotinine and NNK (0.11 ng/mL). The LC-MS/MS results showed that nicotine is steadily metabolized to cotinine and NNK from 0.5 to 4h. Finally, we showed that nicotine initially causes an increase in ROS formation which is then gradually decreased, perhaps due to the increase in superoxide dismutase level. Nicotine metabolism and ROS formation by CYP2A6 were further confirmed by using tryptamine, a selective inhibitor of CYP2A6, which significantly lowered the levels of cotinine and NNK and inhibited ROS formation. CONCLUSIONS CYP2A6 plays a key role in nicotine metabolism and oxidative stress in astrocytes, and this has implications in nicotine-associated brain toxicity.
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Affiliation(s)
- Anusha Ande
- Pharmacology and Toxicology, School of Pharmacy, 3253 Health Sciences Building, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO 64108, USA
| | - Ravinder Earla
- Pharmaceutical Sciences, School of Pharmacy, 5258 Health Sciences Building, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO 64108, USA
| | - Mengyao Jin
- Pharmacology and Toxicology, School of Pharmacy, 3253 Health Sciences Building, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO 64108, USA
| | - Peter S Silverstein
- Pharmacology and Toxicology, School of Pharmacy, 3253 Health Sciences Building, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO 64108, USA
| | - Ashim K Mitra
- Pharmaceutical Sciences, School of Pharmacy, 5258 Health Sciences Building, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO 64108, USA
| | - Anil Kumar
- Pharmacology and Toxicology, School of Pharmacy, 3253 Health Sciences Building, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO 64108, USA
| | - Santosh Kumar
- Pharmacology and Toxicology, School of Pharmacy, 3253 Health Sciences Building, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO 64108, USA,Corresponding author: Division of Pharmacology and Toxicology, School of Pharmacy, University of Missouri-Kansas City, 2464 Charlotte St. Kansas City, MO 64108, USA Phone: 816-235-5494, Fax: 816-235-1776,
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Wu KC, Cui JY, Klaassen CD. Effect of graded Nrf2 activation on phase-I and -II drug metabolizing enzymes and transporters in mouse liver. PLoS One 2012; 7:e39006. [PMID: 22808024 PMCID: PMC3395627 DOI: 10.1371/journal.pone.0039006] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Accepted: 05/16/2012] [Indexed: 02/07/2023] Open
Abstract
Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that induces a battery of cytoprotective genes in response to oxidative/electrophilic stress. Kelch-like ECH associating protein 1 (Keap1) sequesters Nrf2 in the cytosol. The purpose of this study was to investigate the role of Nrf2 in regulating the mRNA of genes encoding drug metabolizing enzymes and xenobiotic transporters. Microarray analysis was performed in livers of Nrf2-null, wild-type, Keap1-knockdown mice with increased Nrf2 activation, and Keap1-hepatocyte knockout mice with maximum Nrf2 activation. In general, Nrf2 did not have a marked effect on uptake transporters, but the mRNAs of organic anion transporting polypeptide 1a1, sodium taurocholate cotransporting polypeptide, and organic anion transporter 2 were decreased with Nrf2 activation. The effect of Nrf2 on cytochrome P450 (Cyp) genes was minimal, with only Cyp2a5, Cyp2c50, Cyp2c54, and Cyp2g1 increased, and Cyp2u1 decreased with enhanced Nrf2 activation. However, Nrf2 increased mRNA of many other phase-I enzymes, such as aldo-keto reductases, carbonyl reductases, and aldehyde dehydrogenase 1. Many genes involved in phase-II drug metabolism were induced by Nrf2, including glutathione S-transferases, UDP- glucuronosyltransferases, and UDP-glucuronic acid synthesis enzymes. Efflux transporters, such as multidrug resistance-associated proteins, breast cancer resistant protein, as well as ATP-binding cassette g5 and g8 were induced by Nrf2. In conclusion, Nrf2 markedly alters hepatic mRNA of a large number of drug metabolizing enzymes and xenobiotic transporters, and thus Nrf2 plays a central role in xenobiotic metabolism and detoxification.
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Affiliation(s)
- Kai Connie Wu
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas, United States of America
| | - Julia Yue Cui
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas, United States of America
| | - Curtis D. Klaassen
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas, United States of America
- * E-mail:
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Lu Y, Zhang XH, Cederbaum AI. Ethanol induction of CYP2A5: role of CYP2E1-ROS-Nrf2 pathway. Toxicol Sci 2012; 128:427-38. [PMID: 22552773 DOI: 10.1093/toxsci/kfs164] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Chronic ethanol consumption was previously shown to induce CYP2A5 in mice, and this induction of CYP2A5 by ethanol was CYP2E1 dependent. In this study, the mechanisms of CYP2E1-dependent ethanol induction of CYP2A5 were investigated. CYP2E1 was induced by chronic ethanol consumption to the same degree in wild-type (WT) mice and CYP2A5 knockout (Cyp2a5 (-/-)) mice, suggesting that unlike the CYP2E1-dependent ethanol induction of CYP2A5, ethanol induction of CYP2E1 is not CYP2A5 dependent. Microsomal ethanol oxidation was about 25% lower in Cyp2a5 (-/-) mice compared with that in WT mice, suggesting that CYP2A5 can oxidize ethanol although to a lesser extent than CYP2E1 does. CYP2A5 was induced by short-term ethanol consumption in human CYP2E1 transgenic knockin (Cyp2e1 (-/-) KI) mice but not in CYP2E1 knockout (Cyp2e1 (-/-)) mice. The redox-sensitive transcription factor nuclear factor-erythroid 2-related factor 2 (Nrf2) was also induced by acute ethanol in Cyp2e1 (-/-) KI mice but not in Cyp2e1 (-/-) mice. Ethanol induction of CYP2A5 in Nrf2 knockout (Nrf2 (-/-)) mice was lower compared with that in WT mice, whereas CYP2E1 induction by ethanol was comparable in WT and Nrf2 (-/-) mice. Antioxidants (N-acetyl-cysteine and vitamin C), which blocked oxidative stress induced by chronic ethanol in WT mice and acute ethanol in Cyp2e1 (-/-) KI mice, also blunted the induction of CYP2A5 and Nrf2 by ethanol but not the induction of CYP2E1 by ethanol. These results suggest that oxidative stress induced by ethanol via induction of CYP2E1 upregulates Nrf2 activity, which in turn regulates ethanol induction of CYP2A5. Results obtained from primary hepatocytes, mice gavaged with binge ethanol or fed chronic ethanol, show that Nrf2-regulated ethanol induction of CYP2A5 protects against ethanol-induced steatosis.
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Affiliation(s)
- Yongke Lu
- Department of Medicine, Division of Liver Diseases, Mount Sinai School of Medicine New York, New York 10029, USA.
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Abu-Bakar A, Arthur DM, Wikman AS, Rahnasto M, Juvonen RO, Vepsäläinen J, Raunio H, Ng JC, Lang MA. Metabolism of bilirubin by human cytochrome P450 2A6. Toxicol Appl Pharmacol 2012; 261:50-8. [DOI: 10.1016/j.taap.2012.03.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 03/13/2012] [Accepted: 03/16/2012] [Indexed: 10/28/2022]
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Jin M, Kumar A, Kumar S. Ethanol-mediated regulation of cytochrome P450 2A6 expression in monocytes: role of oxidative stress-mediated PKC/MEK/Nrf2 pathway. PLoS One 2012; 7:e35505. [PMID: 22530035 PMCID: PMC3329463 DOI: 10.1371/journal.pone.0035505] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Accepted: 03/16/2012] [Indexed: 11/19/2022] Open
Abstract
Cytochrome P450 2A6 (CYP2A6) is known to metabolize nicotine, the major constituent of tobacco, leading to the production of toxic metabolites and induction of oxidative stress that result in liver damage and lung cancer. Recently, we have shown that CYP2A6 is induced by ethanol and metabolizes nicotine into cotinine and other metabolites leading to generation of reactive oxygen species (ROS) in U937 monocytes. However, the mechanism by which CYP2A6 is induced by ethanol is unknown. In this study, we have examined the role of the PKC/Nrf2 pathway (protein kinase C-mediated phosphorylation and translocation of nuclear erythroid 2-related factor 2 to the nucleus) in ethanol-mediated CYP2A6 induction. Our results showed that 100 mM ethanol significantly induced CYP2A6 mRNA and protein (~150%) and increased ROS formation, and induction of gene expression and ROS were both completely blocked by treatment with either a CYP2E1 inhibitor (diallyl sulfide) or an antioxidant (vitamin C). The results suggest the role of oxidative stress in the regulation of CYP2A6 expression. Subsequently, we investigated the role of Nrf2 pathway in oxidative stress-mediated regulation of CYP2A6 expression in U937 monocytes. Our results showed that butylated hydroxyanisole, a stabilizer of nuclear Nrf2, increased CYP2A6 levels >200%. Staurosporine, an inhibitor of PKC, completely abolished ethanol-induced CYP2A6 expression. Furthermore, our results showed that a specific inhibitor of mitogen-activated protein kinase kinase (MEK) (U0126) completely abolished ethanol-mediated CYP2A6 induction and Nrf2 translocation. Overall, these results suggest that CYP2E1-mediated oxidative stress produced as a result of ethanol metabolism translocates Nrf2 into the nucleus through PKC/MEK pathway, resulting in the induction of CYP2A6 in monocytes. An increased level of CYP2A6 in monocytes is expected to further increase oxidative stress in smokers through CYP2A6-mediated nicotine metabolism. Thus, this study has clinical relevance because of the high incidence of alcohol use among smokers, especially in HIV-infected individuals.
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Affiliation(s)
- Mengyao Jin
- Division of Pharmacology and Toxicology, School of Pharmacy, University of Missouri-Kansas City, Kansas City, Missouri, United States of America.
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The contribution of common CYP2A6 alleles to variation in nicotine metabolism among European-Americans. Pharmacogenet Genomics 2011; 21:403-16. [PMID: 21597399 DOI: 10.1097/fpc.0b013e328346e8c0] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To study the association between cytochrome P450 2A6 (CYP2A6) genotype and metabolism of nicotine to cotinine, identify functional polymorphisms, and develop a predictive genetic model of nicotine metabolism. METHODS The conversion of deuterated (D2)-nicotine to D2-cotinine was quantified in 189 European-Americans and the contribution of CYP2A6 genotype to variability in first-pass nicotine metabolism was assessed. Specifically, (i) single time point measures of D2-cotinine/(D2-cotinine+D2-nicotine) after oral administration were used as a metric of CYP2A6 activity; (ii) the impact of CYP2A6 haplotype was treated as acting multiplicatively; (iii) parameter estimates were calculated for all haplotypes in the subject pool, defined by a set of polymorphisms previously reported to affect function, including gene copy number; and (iv) a minimum number of predictive polymorphisms were justified to be included in the model based on statistical evidence of differences between haplotypes. RESULTS The final model includes seven polymorphisms and fits the phenotype, 30-min after D2-nicotine oral administration, with R=0.719. The predictive power of the model is robust: parameter estimates calculated in men (n=89) predict the phenotype in women (n=100) with R=0.758 and vice versa with R=0.617; estimates calculated in current smokers (n=102) predict the phenotype in former-smokers (n=86) with R=0.690 and vice versa with R=0.703. Comparisons of haplotypes also demonstrate that CYP2A6*12 is a loss-of-function allele indistinguishable from CYP2A6*4 and CYP2A6*2 and that the CYP2A6*1B 5'-untranslated region conversion has negligible impact on metabolism. After controlling for CYP2A6 genotype, modest associations were found between increased metabolism and both female sex (P=4.8×10) and current smoking (P=0.02). CONCLUSION Among European-Americans, seven polymorphisms in the CYP2A6 gene explain the majority of variability in the metabolism of nicotine to cotinine after oral administration. Parameters determined from this in-vivo experiment can be used to predict nicotine metabolism based on CYP2A6 genotype.
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A conserved antioxidant response element (ARE) in the promoter of human carbonyl reductase 3 (CBR3) mediates induction by the master redox switch Nrf2. Biochem Pharmacol 2011; 83:139-48. [PMID: 22001310 DOI: 10.1016/j.bcp.2011.09.027] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Revised: 09/28/2011] [Accepted: 09/28/2011] [Indexed: 01/22/2023]
Abstract
Carbonyl reductase activity catalyzes the two electron reduction of several endogenous and exogenous carbonyl substrates. Recent data indicate that the expression of human carbonyl reductase 3 (CBR3) is regulated by the master redox switch Nrf2. Nrf2 binds to conserved antioxidant response elements (AREs) in the promoters of target genes. The presence of functional AREs in the CBR3 promoter has not yet been reported. In this study, experiments with reporter constructs showed that the prototypical Nrf2 activator tert-butyl hydroquinone (t-BHQ) induces CBR3 promoter activity in cultures of HepG2 (2.7-fold; p<0.05) and MCF-7 cells (22-fold; p<0.01). Computational searches identified a conserved ARE in the distal CBR3 promoter region ((-2698)ARE). Deletion of this ARE from a 4212-bp CBR3 promoter construct impacted basal promoter activity and induction of promoter activity in response to treatment with t-BHQ. Deletion of (-2698)ARE also impacted the induction of CBR3 promoter activity in cells overexpressing Nrf2. Electrophoretic mobility shift assays (EMSA) demonstrated increased binding of specific protein complexes to (-2698)ARE in nuclear extracts from t-BHQ treated cells. The presence of Nrf2 in the specific nuclear protein-(-2698)ARE complexes was evidenced in EMSA experiments with anti-Nrf2 antibodies. These data suggest that the distal (-2698)ARE mediates the induction of human CBR3 in response to prototypical activators of Nrf2.
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Jin M, Earla R, Shah A, Earla RL, Gupte R, Mitra AK, Kumar A, Kumar S. A LC-MS/MS method for concurrent determination of nicotine metabolites and role of CYP2A6 in nicotine metabolism in U937 macrophages: implications in oxidative stress in HIV + smokers. J Neuroimmune Pharmacol 2011; 7:289-99. [PMID: 21655912 DOI: 10.1007/s11481-011-9283-6] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Accepted: 05/24/2011] [Indexed: 11/25/2022]
Abstract
Nicotine, the major constituent of tobacco, is predominantly metabolized by liver CYP2A6 into cotinine and many other compounds, including nicotine-derived nitrosamine ketone (NNK), which is known to cause oxidative stress. We have recently shown that CYP2A6 is highly expressed in U937 monocyte-derived macrophages. In this study we investigated the role of CYP2A6 in nicotine metabolism and oxidative stress in U937 macrophages. To study nicotine metabolism, we developed a highly sensitive LC-MS/MS method for simultaneous quantitative determination of nicotine, cotinine, and NNK. The LC-MS/MS analysis was carried out by multiple reaction monitoring mass transitions with m/z of 163.2/130.1, 177.4/98.3, and 208.4/122.1 for nicotine, cotinine, and NNK, respectively. The calibration curves were linear within 3.3-1028.1 ng/ml for nicotine and 0.3-652.6 ng/ml for cotinine and NNK. This novel method was then applied to quantify nicotine metabolites, cotinine and NNK, in nicotine-treated U937 macrophages. Cotinine and NNK initially formed at 30 min, followed by a peak at 2-3 h. The role of CYP2A6 in nicotine metabolism in U937 macrophages was further confirmed by using CYP2A6-selective inhibitor, tryptamine, which significantly decreased cotinine (70%) and completely inhibited NNK formations. Finally, we showed that nicotine-treated macrophages increase the formation of oxidant at 30-60 min, which is consistent with the initial formation of cotinine and NNK. In conclusion, we have developed a new LCMS/MS method for concurrent determination of nicotine metabolites and analyzed the role of CYP2A6 in nicotine metabolism and oxidative stress in U937 macrophages, which may have implications in viral replication among HIV + smokers.
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Affiliation(s)
- Mengyao Jin
- Division of Pharmacology and Toxicology, School of Pharmacy, University of Missouri-Kansas City, Kansas, MO 64108, USA
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