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Hu K, Tu H, Xie J, Yang Z, Li Z, Chen Y, Liu Y. Phenylalanine Residues in the Active Site of CYP2E1 Participate in Determining the Binding Orientation and Metabolism-Dependent Genotoxicity of Aromatic Compounds. TOXICS 2023; 11:495. [PMID: 37368596 DOI: 10.3390/toxics11060495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/25/2023] [Accepted: 05/29/2023] [Indexed: 06/29/2023]
Abstract
The composition of amino acids forming the active site of a CYP enzyme is impactful in its substrate selectivity. For CYP2E1, the role of PHE residues in the formation of effective binding orientations for its aromatic substrates remains unclear. In this study, molecular docking and molecular dynamics analysis were performed to reflect the interactions between PHEs in the active site of human CYP2E1 and various aromatic compounds known as its substrates. The results indicated that the orientation of 1-methylpyrene (1-MP) in the active site was highly determined by the presence of PHEs, PHE478 contributing to the binding free energy most significantly. Moreover, by building a random forest model the relationship between each of 19 molecular descriptors of polychlorinated biphenyl (PCB) compounds (from molecular docking, quantum mechanics, and physicochemical properties) and their human CYP2E1-dependent mutagenicityas established mostly in our lab, was investigated. The presence of PHEs did not appear to significantly modify the electronic or structural feature of each bound ligand (PCB), instead, the flexibility of the conformation of PHEs contributed substantially to the effective binding energy and orientation. It is supposed that PHE residues adjust their own conformation to permit a suitablly shaped cavity for holding the ligand and forming its orientation as favorable for a biochemical reaction. This study has provided some insights into the role of PHEs in guiding the interactive adaptation of the active site of human CYP2E1 for the binding and metabolism of aromatic substrates.
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Affiliation(s)
- Keqi Hu
- Department of Science and Education, Guangdong Second Provincial General Hospital, 466 Xingang Middle Road, Guangzhou 510317, China
- Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Hongwei Tu
- Guangdong Provincial Center for Disease Control and Prevention, Qunxian Road, Panyu District, Guangzhou 511430, China
| | - Jiayi Xie
- Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Zongying Yang
- Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Zihuan Li
- Department of Science and Education, Guangdong Second Provincial General Hospital, 466 Xingang Middle Road, Guangzhou 510317, China
- Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Yijing Chen
- Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Yungang Liu
- Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou 510515, China
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Hu K, Cai L, Li Z, Glatt H, Shi M, Liu Y. Human CYP2E1-dependent mutagenicity of benzene and its hydroxylated metabolites in V79-derived cells: Suppression and enhancement by ethanol pretreatment. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:622-634. [PMID: 32285472 DOI: 10.1002/em.22375] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 03/25/2020] [Accepted: 04/03/2020] [Indexed: 06/11/2023]
Abstract
Benzene is a human carcinogen that requires metabolic activation. We previously observed that benzene and its hydroxylated metabolites induce micronuclei in mammalian cells expressing human CYP2E1. This study was initially aimed to study another endpoint, the induction of gene mutations by those compounds in the same cell models. A V79-derived cell line expressing human CYP2E1 and sulfotransferase (SULT) 1A1 (V79-hCYP2E1-hSULT1A1) pretreated with ethanol (a CYP2E1 stabilizer) was used in the hprt gene mutagenicity assay. Phenol, hydroquinone, catechol, and 1,2,4-trihydroxybenzene all induced gene mutations, while they were inactive, or only weakly positive (hydroquinone), in parental V79-Mz cells. Unexpectedly, benzene was non-mutagenic in both cell lines, but it became positive in V79-hCYP2E1-hSULT1A1 cells using regimes of short exposure/long recovery without ethanol pretreatment, for both gene mutations and micronuclei formation. In silico molecular simulation showed binding energies and positions favorable for each compound to be oxidized by human CYP2E1, benzene demonstrating the highest affinity. By tunnel analysis, ethanol binding did not limit benzene to pass tunnel S, which was specifically active for benzene. However, its end product, acetic acid, decreased the occurrence of tunnel S from 5.4 to 2.2% and extended the length of its bottleneck from 5.5 to 9.0 Å. With residual ethanol molecules still being present in CYP2E1 for a period of time after benzene exposure, the acetic acid formed could limit the entrance of benzene, thus inhibit its metabolic activation. In summary, ethanol may interfere with the activation of benzene to mutagenic metabolites, at least in cultured cells.
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Affiliation(s)
- Keqi Hu
- Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou, China
| | - Lu Cai
- Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou, China
| | - Zihuan Li
- Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou, China
| | - Hansruedi Glatt
- Department of Nutritional Toxicology, German Institute of Human Nutrition (DIfE), Nuthetal, Germany
- Department of Food Safety, Federal Institute for Risk Assessment (BfR), Berlin, Germany
| | - Ming Shi
- Department of Environmental and Occupational Health, School of Public Health, Guangdong Medical University, Dongguan, China
| | - Yungang Liu
- Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou, China
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PTP4A3, A Novel Target Gene of HIF-1alpha, Participates in Benzene-Induced Cell Proliferation Inhibition and Apoptosis through PI3K/AKT Pathway. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17030910. [PMID: 32024182 PMCID: PMC7037067 DOI: 10.3390/ijerph17030910] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 01/23/2020] [Accepted: 01/30/2020] [Indexed: 02/07/2023]
Abstract
Benzene, a commonly used chemical, has been confirmed to specifically affect the hematopoietic system as well as overall human health. PTP4A3 is overexpressed in leukemia cells and is related to cell proliferation. We previously found that HIF-1alpha was involved in benzene toxicity and PTP4A3 may be the target gene of HIF-1alpha via ChIP-seq. The aim of this study is to confirm the relationship between HIF-1alpha and PTP4A3 in benzene toxicity, as well as the function of PTP4A3 on cell toxicity induced by 1,4-benzoquinone (1,4-BQ). Our results indicate that HIF-1alpha could regulate PTP4A3 with in vivo and in vitro experiments. A cell line with suppressed PTP4A3 was established to investigate the function of PTP4A3 in 1,4-BQ toxicity in vitro. The results revealed that cell proliferation inhibition was more aggravated in PTP4A3 low-expression cells than in the control cells after 1,4-BQ treatment. The relative oxygen species (ROS) significantly increased in cells with inhibited PTP4A3, while the rise was inferior to the control cells at the 20 μM 1,4-BQ group. An increase in DNA damage was seen in PTP4A3 down-regulated cells at the 10 μM 1,4-BQ group, whereas the results reversed at the concentration of 20 μM. Moreover, the apoptosis rate increased higher in down-regulated PTP4A3 cells after 1,4-BQ exposure. In addition, PI3K/AKT pathway was significantly restrained in cells with inhibited PTP4A3 after 1,4-BQ treatment. Our results indicate that HIF-1alpha may regulate PTP4A3 to be involved in benzene toxicity. Inhibition of PTP4A3 could aggravate cell proliferation suppression and apoptosis by regulating PI3K/AKT pathway after 1,4-BQ treatment.
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Luijten M, Ball NS, Dearfield KL, Gollapudi BB, Johnson GE, Madia F, Peel L, Pfuhler S, Settivari RS, ter Burg W, White PA, van Benthem J. Utility of a next generation framework for assessment of genomic damage: A case study using the industrial chemical benzene. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:94-113. [PMID: 31709603 PMCID: PMC6972600 DOI: 10.1002/em.22346] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 10/31/2019] [Accepted: 11/06/2019] [Indexed: 05/22/2023]
Abstract
We recently published a next generation framework for assessing the risk of genomic damage via exposure to chemical substances. The framework entails a systematic approach with the aim to quantify risk levels for substances that induce genomic damage contributing to human adverse health outcomes. Here, we evaluated the utility of the framework for assessing the risk for industrial chemicals, using the case of benzene. Benzene is a well-studied substance that is generally considered a genotoxic carcinogen and is known to cause leukemia. The case study limits its focus on occupational and general population health as it relates to benzene exposure. Using the framework as guidance, available data on benzene considered relevant for assessment of genetic damage were collected. Based on these data, we were able to conduct quantitative analyses for relevant data sets to estimate acceptable exposure levels and to characterize the risk of genetic damage. Key observations include the need for robust exposure assessments, the importance of information on toxicokinetic properties, and the benefits of cheminformatics. The framework points to the need for further improvement on understanding of the mechanism(s) of action involved, which would also provide support for the use of targeted tests rather than a prescribed set of assays. Overall, this case study demonstrates the utility of the next generation framework to quantitatively model human risk on the basis of genetic damage, thereby enabling a new, innovative risk assessment concept. Environ. Mol. Mutagen. 61:94-113, 2020. © 2019 The Authors. Environmental and Molecular Mutagenesis published by Wiley Periodicals, Inc. on behalf of Environmental Mutagen Society.
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Affiliation(s)
- Mirjam Luijten
- Centre for Health ProtectionNational Institute for Public Health and the Environment (RIVM)BilthovenThe Netherlands
| | | | | | | | - George E. Johnson
- Swansea University Medical School, Swansea UniversitySwanseaUnited Kingdom
| | - Federica Madia
- European Commission, Joint Research Centre (JRC)IspraItaly
| | - Lauren Peel
- Health and Environmental Sciences InstituteWashingtonDistrict of Columbia
| | | | | | - Wouter ter Burg
- Centre for Safety of Substances and ProductsNational Institute for Public Health and the Environment (RIVM)BilthovenThe Netherlands
| | - Paul A. White
- Department of BiologyUniversity of OttawaOttawaOntarioCanada
| | - Jan van Benthem
- Centre for Health ProtectionNational Institute for Public Health and the Environment (RIVM)BilthovenThe Netherlands
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Jin G, Cai L, Hu K, Luo Y, Chen Y, Glatt H, Liu Y. Mutagenic Activity of N-Nitrosodiethylamine in Cell Lines Expressing Human CYP2E1-Adequacy of Dimethylsulfoxide as Solvent. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2019; 60:214-226. [PMID: 30387191 DOI: 10.1002/em.22264] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 10/14/2018] [Accepted: 10/26/2018] [Indexed: 06/08/2023]
Abstract
Human CYP2E1 metabolizes many xenobiotics of low-molecular weight, thereby activating various promutagens/procarcinogens. In toxicological studies in vitro, dimethylsulfoxide (DMSO) is a common vehicle for organic compounds. However, it was observed to potently inhibit CYP2E1 activity. We were interested in whether it affects CYP2E1-dependent mutagenic responses. In this study, N-nitrosodiethylamine (NDEA), which is soluble in both water and DMSO, was used as a model promutagen. It induced Hprt gene mutations and micronuclei in a Chinese hamster V79-derived cell line expressing both human CYP2E1 and sulfotransferase (SULT) 1A1 (V79-hCYP2E1-hSULT1A1) even at low-micromolar concentrations, but was inactive in parental V79 cells. Mutagenicity of NDEA was also observed in a recombinant V79-hCYP2E1 cell line that expresses human CYP2E1 at a lower level. NDEA induced micronuclei in human L-02 hepatocytes which expressed CYP2E1 even more weakly. DMSO did not modify NDEA-induced gene mutations or micronuclei, up to 0.2% (v:v, the highest noncytotoxic concentration) in V79-hCYP2E1-hSULT1A1 cells. In parental V79-Mz cells, NDEA induced micronuclei with Aroclor 1254-induced rat liver S9 mix, and this effect was unaffected by DMSO up to 0.2%. However, it inhibited the effect of NDEA in L-02 (by 44%) and V79-hCYP2E1 cells (by 70%) at 0.2%, with the effects of NDEA remaining statistically significant. No effect of DMSO was observed on CYP2E1 protein expression in V79-hCYP2E1-hSULT1A1 or its mRNA transcripts in each cell line. We conclude that DMSO may not significantly affect CYP2E1-dependent mutagenic effects, at concentrations up to 0.2% in cells with relatively high CYP2E1 expression. Environ. Mol. Mutagen. 60:214-226, 2019. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Guifang Jin
- Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou, People's Republic of China
| | - Lu Cai
- Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou, People's Republic of China
| | - Keqi Hu
- Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou, People's Republic of China
| | - Yuyi Luo
- Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou, People's Republic of China
| | - Yuting Chen
- Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou, People's Republic of China
| | - Hansruedi Glatt
- Department of Nutritional Toxicology, German Institute of Human Nutrition (DIfE), Nuthetal, Germany
- Department of Food Safety, Federal Institute for Risk Assessment (BfR), Berlin, Germany
| | - Yungang Liu
- Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou, People's Republic of China
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Man Z, Meng X, Sun F, Pu Y, Xu K, Sun R, Zhang J, Yin L, Pu Y. Global Identification of HIF-1α Target Genes in Benzene Poisoning Mouse Bone Marrow Cells. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2018; 15:ijerph15112531. [PMID: 30424520 PMCID: PMC6266356 DOI: 10.3390/ijerph15112531] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 11/02/2018] [Accepted: 11/09/2018] [Indexed: 11/16/2022]
Abstract
Benzene is a hematopoietic toxicant, and hematopoietic cells in bone marrow (BM) are one of the main targets for its action, especially hematopoietic stem cells (HSCs). Hypoxia-inducible factor-1α (HIF-1α) is associated with the metabolism and physiological functions of HSCs. We previously found that the mechanism of regulation of HIF-1α is involved in benzene-induced hematopoietic toxicity. In this study, chromatin immunoprecipitation sequencing (ChIP-Seq) technologies were used to analyze the genome-wide binding spectrum of HIF-1α in mouse BM cells, and specific HIF-1α target genes and pathways associated with benzene toxicity were screened and validated. By application of the ChIP-Seq technique, we identified target genes HIF-1α directly binds to and regulates. Forty-two differentially down-regulated genes containing the HIF-1α specific binding site hypoxia response element (HRE) were found, of which 25 genes were with biological function. Moreover, the enrichment analysis of signal pathways indicated that these genes were significantly enriched in the Jak-STAT signaling pathway, Natural killer cell mediated cytotoxicity, the Fc epsilon RI signaling pathway, Pyrimidine metabolism, the T cell receptor signaling pathway, and Transcriptional misregulation in cancer. After verification, 11 genes involved in HSC self-renewal, cell cycle, differentiation, and apoptosis pathways were found to be significantly reduced, and may participate in benzene-induced hematotoxicity. Our study provides a new academic clue for the mechanism of benzene hematotoxicity.
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Affiliation(s)
- Zhaodi Man
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education of China, School of Public Health, Southeast University, Nanjing 210009, China.
| | - Xing Meng
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education of China, School of Public Health, Southeast University, Nanjing 210009, China.
| | - Fengxia Sun
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education of China, School of Public Health, Southeast University, Nanjing 210009, China.
| | - Yunqiu Pu
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education of China, School of Public Health, Southeast University, Nanjing 210009, China.
| | - Kai Xu
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education of China, School of Public Health, Southeast University, Nanjing 210009, China.
| | - Rongli Sun
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education of China, School of Public Health, Southeast University, Nanjing 210009, China.
| | - Juan Zhang
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education of China, School of Public Health, Southeast University, Nanjing 210009, China.
| | - Lihong Yin
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education of China, School of Public Health, Southeast University, Nanjing 210009, China.
| | - Yuepu Pu
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education of China, School of Public Health, Southeast University, Nanjing 210009, China.
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de Montellano PRO. 1-Aminobenzotriazole: A Mechanism-Based Cytochrome P450 Inhibitor and Probe of Cytochrome P450 Biology. Med Chem 2018; 8:038. [PMID: 30221034 PMCID: PMC6137267 DOI: 10.4172/2161-0444.1000495] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
1-Aminobenzotriazole (1-ABT) is a pan-specific, mechanism-based inactivator of the xenobiotic metabolizing forms of cytochrome P450 in animals, plants, insects, and microorganisms. It has been widely used to investigate the biological roles of cytochrome P450 enzymes, their participation in the metabolism of both endobiotics and xenobiotics, and their contributions to the metabolism-dependent toxicity of drugs and chemicals. This review is a comprehensive evaluation of the chemistry, discovery, and use of 1-aminobenzotriazole in these contexts from its introduction in 1981 to the present.
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Jiménez-Garza O, Guo L, Byun HM, Carrieri M, Bartolucci GB, Zhong J, Baccarelli AA. Promoter methylation status in genes related with inflammation, nitrosative stress and xenobiotic metabolism in low-level benzene exposure: Searching for biomarkers of oncogenesis. Food Chem Toxicol 2017; 109:669-676. [DOI: 10.1016/j.fct.2017.08.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 08/15/2017] [Indexed: 12/13/2022]
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Wang H, Wei L, Wu Y, Jia H, Jiang H, Liu Y. Induction of micronuclei and cell cycle arrest by some tri- and tetrachlorobiphenyls in mammalian cells deficient in xenobiotic-metabolizing enzymes. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2017; 58:199-208. [PMID: 28444994 DOI: 10.1002/em.22090] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Accepted: 03/31/2017] [Indexed: 06/07/2023]
Abstract
Polychlorinated biphenyls (PCBs) are persistent organic pollutants with continued public health concerns. The lower chlorinated biphenyls are supposed to be mutagenic following metabolic activation. However, in a preliminary study, we recently observed induction of micronuclei by several PCBs in a subclone of Chinese hamster V79 cell line, V79-Mz, which is deficient in xenobiotic-metabolizing enzyme activities. In this study, metabolism-free genotoxicity of PCBs was investigated, using 10 tri- and tetrachlorobiphenyls, in V79, V79-Mz, and human hepatoma (HepG2) cell lines. Among the four tetrachlorobiphenyls, 2,4,4',5- and 2,3'4,4'-tetrachlorobiphenyl-both having a noncoplanar configuration-induced micronuclei in V79-Mz cells, while their coplanar analogs 3,4,4',5- and 3,3',4,4'-tetrachlorobiphenyl were inactive. Furthermore, 2,3,3'- (PCB 20) and 2,3,4'-trichlorobiphenyl (PCB 22) started to induce micronuclei in V79-Mz cells at 10 μM and higher concentrations, demonstrating more potent effects than observed with 2,2',3-, 2,2',4-, 2,2',5, and 2,4,4'-trichlorobiphenyl. As representative compounds, PCB 20 and 22 induced micronuclei in relatively high concentrations in HepG2 cells (p53-proficient), though they did not induce Hprt gene mutations in V79-Mz cells. PCB 20 and 22 increased mitotic index and induced cell cycle arrest at the G2/M phase, with effects more potent in V79-Mz than in V79 cells. This study suggests that 2,3,4'- and 2,3,3'-substituted PCBs are micronuclei inducers and G2/M arresters among a number of trichlorobiphenyls in mammalian cell lines, though with potency lower than that observed recently in V79-derived cells expressing human CYP2E1. Similarly, some noncoplanar tetrachlorobiphenyls possess metabolism-independent chromosome-damaging potentials. Environ. Mol. Mutagen. 58:199-208, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Haiyan Wang
- Department of Toxicology, School of Public Health, Southern Medical University, Guangdong Provincial Key Laboratory of Tropical Disease Research, Guangzhou, 510515, China
| | - Liwen Wei
- Department of Toxicology, School of Public Health, Southern Medical University, Guangdong Provincial Key Laboratory of Tropical Disease Research, Guangzhou, 510515, China
| | - Yifan Wu
- Department of Toxicology, School of Public Health, Southern Medical University, Guangdong Provincial Key Laboratory of Tropical Disease Research, Guangzhou, 510515, China
| | - Hansi Jia
- Department of Toxicology, School of Public Health, Southern Medical University, Guangdong Provincial Key Laboratory of Tropical Disease Research, Guangzhou, 510515, China
| | - Hao Jiang
- Department of Toxicology, School of Public Health, Southern Medical University, Guangdong Provincial Key Laboratory of Tropical Disease Research, Guangzhou, 510515, China
| | - Yungang Liu
- Department of Toxicology, School of Public Health, Southern Medical University, Guangdong Provincial Key Laboratory of Tropical Disease Research, Guangzhou, 510515, China
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Hartman JH, Miller GP, Meyer JN. Toxicological Implications of Mitochondrial Localization of CYP2E1. Toxicol Res (Camb) 2017; 6:273-289. [PMID: 28989700 DOI: 10.1039/c7tx00020k] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Cytochrome P450 2E1 (CYP2E1) metabolizes an extensive array of pollutants, drugs, and other small molecules, often resulting in bioactivation to reactive metabolites. Therefore, it is unsurprising that it has been the subject of decades of research publications and reviews. However, while CYP2E1 has historically been studied in the endoplasmic reticulum (erCYP2E1), active CYP2E1 is also present in mitochondria (mtCYP2E1). Relatively few studies have specifically focused on mtCYP2E1, but there is growing interest in this form of the enzyme as a driver in toxicological mechanisms given its activity and location. Many previous studies have linked total CYP2E1 to conditions that involve mitochondrial dysfunction (fasting, diabetes, non-alcoholic steatohepatitis, and obesity). Furthermore, a large number of reactive metabolites that are formed by CYP2E1 through metabolism of drugs and pollutants have been demonstrated to cause mitochondrial dysfunction. Finally, there appears to be significant inter-individual variability in targeting to the mitochondria, which could constitute a source of variability in individual response to exposures. This review discusses those outcomes, the biochemical properties and toxicological consequences of mtCYP2E1, and highlights important knowledge gaps and future directions. Overall, we feel that this exciting area of research is rich with new and important questions about the relationship between mtCYP2E1, mitochondrial dysfunction, and pathology.
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Affiliation(s)
| | - Grover P Miller
- Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR
| | - Joel N Meyer
- Nicholas School of the Environment, Duke University, Durham, NC
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Jia H, Zhang C, Glatt H, Liu Y. Role of exposure/recovery schedule in micronuclei induction by several promutagens in V79-derived cells expressing human CYP2E1 and SULT1A1. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2016; 808:27-37. [DOI: 10.1016/j.mrgentox.2016.08.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Revised: 08/17/2016] [Accepted: 08/18/2016] [Indexed: 01/14/2023]
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12
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Zhang C, Lai Y, Jin G, Glatt H, Wei Q, Liu Y. Human CYP2E1-dependent mutagenicity of mono- and dichlorobiphenyls in Chinese hamster (V79)-derived cells. CHEMOSPHERE 2016; 144:1908-1915. [PMID: 26547025 DOI: 10.1016/j.chemosphere.2015.10.083] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2015] [Revised: 10/19/2015] [Accepted: 10/20/2015] [Indexed: 06/05/2023]
Abstract
Polychlorinated biphenyls (PCBs) are a group of persistent organic pollutants with confirmed carcinogenicity to humans. Metabolic activation of lower chlorinated PCBs to genotoxic metabolites may involve hydroxylation and further oxidation, and some hydroxylated metabolites may be sulfo-conjugated. However, the genotoxicity of individual PCB compounds is largely unknown. In this study, 15 mono- and dichlorobiphenyls were investigated for genotoxicity using the micronucleus and Hprt mutagenicity assays in a Chinese hamster V79-derived cell line expressing both human cytochrome P450 (CYP) 2E1 and human sulfotransferase (SULT) 1A1 (V79-hCYP2E1-hSULT1A1). All tested compounds were inactive in both assays in V79 control cells. However, eight dichlorobiphenyls strongly induced micronuclei and other congeners were weakly positive for this endpoint in V79-hCYP2E1-hSULT1A1 cells. The effects of each PCB in V79-hCYP2E1-hSULT1A1 cells were abolished or reduced in the presence of a CYP2E1 inhibitor (1-aminobenzotriazole), or enhanced by pretreatment of the cells with (CYP2E1-inducing) ethanol, while the genotoxicity was not significantly affected by a SULT1 inhibitor (pentachlorophenol). As representative dichlorobiphenyls, PCB 5, 10, 8 and 11 (2,3-, 2,5-, 2,4'- and 3,3'-dichlorobiphenyl, respectively) strongly induced Hprt gene mutations in V79-hCYP2E1-hSULT1A1 cells in a concentration-dependent manner. This is the first indication that human CYP2E1 is capable of converting a series of dichlorobiphenyls to strong mutagens.
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Affiliation(s)
- Chiteng Zhang
- Department of Toxicology, School of Public Health and Tropical Medicine, Southern Medical University, 1023 S. Shatai Road, Guangzhou 510515, China
| | - Yanmei Lai
- Department of Toxicology, School of Public Health and Tropical Medicine, Southern Medical University, 1023 S. Shatai Road, Guangzhou 510515, China
| | - Guifang Jin
- Department of Toxicology, School of Public Health and Tropical Medicine, Southern Medical University, 1023 S. Shatai Road, Guangzhou 510515, China
| | - Hansruedi Glatt
- Department of Nutritional Toxicology, German Institute of Human Nutrition (DIfE), Arthur-Scheunert- Allee 114-116, D-14558 Nuthetal, Germany; Department of Food Safety, Federal Institute for Risk Assessment (BfR), Max-Hohrn-Straße 8-10, D-10589 Berlin, Germany
| | - Qinzhi Wei
- Department of Toxicology, School of Public Health and Tropical Medicine, Southern Medical University, 1023 S. Shatai Road, Guangzhou 510515, China
| | - Yungang Liu
- Department of Toxicology, School of Public Health and Tropical Medicine, Southern Medical University, 1023 S. Shatai Road, Guangzhou 510515, China.
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Benzene-Induced Aberrant miRNA Expression Profile in Hematopoietic Progenitor Cells in C57BL/6 Mice. Int J Mol Sci 2015; 16:27058-71. [PMID: 26569237 PMCID: PMC4661859 DOI: 10.3390/ijms161126001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 10/29/2015] [Accepted: 11/02/2015] [Indexed: 12/24/2022] Open
Abstract
Benzene is a common environmental pollutant that causes hematological alterations. MicroRNAs (miRNAs) may play a role in benzene-induced hematotoxicity. In this study, C57BL/6 mice showed significant hematotoxicity after exposure to 150 mg/kg benzene for 4 weeks. Benzene exposure decreased not only the number of cells in peripheral blood but also hematopoietic progenitor cells in the bone marrow. Meanwhile, RNA from Lin− cells sorted from the bone marrow was applied to aberrant miRNA expression profile using Illumina sequencing. We found that 5 miRNAs were overexpressed and 45 miRNAs were downregulated in the benzene exposure group. Sequencing results were confirmed through qRT-PCR. Furthermore, we also identified five miRNAs which significantly altered in Lin−c-Kit+ cells obtained from benzene-exposed mice, including mmu-miR-34a-5p; mmu-miR-342-3p; mmu-miR-100-5p; mmu-miR-181a-5p; and mmu-miR-196b-5p. In summary, we successfully established a classical animal model to induce significant hematotoxicity by benzene injection. Benzene exposure may cause severe hematotoxicity not only to blood cells in peripheral circulation but also to hematopoietic cells in bone marrow. Benzene exposure also alters miRNA expression in hematopoietic progenitor cells. This study suggests that benzene induces alteration in hematopoiesis and hematopoiesis-associated miRNAs.
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