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Kakutani H, Yuzuriha T, Nakao T, Ohta S. Long-term orally exposure of dioxins affects antigen-specific antibody production in mice. Toxicol Rep 2022; 9:53-57. [PMID: 35004181 PMCID: PMC8717457 DOI: 10.1016/j.toxrep.2021.12.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 12/15/2021] [Accepted: 12/18/2021] [Indexed: 11/24/2022] Open
Abstract
Antigen-specific (OVA) antibody production in the serum increased dose-dependently by TCDD concentrations below 500 ng/kg after long-term (10 weeks) exposure. Similar increases were seen in fecal and vaginal samples but were not significant. Th1 and Th2 lymphocyte responses, as determined by antibody and cytokine production, also significantly increased dose-dependently up to 500 ng/kg TCDD, and the Th1/Th2 balance was shifted toward Th1.
Dioxins are persistent environmental toxins that are still present in the food supply despite strong efforts to minimize exposure. Dioxins ingested by humans accumulate in fat and are excreted very slowly, so their long-term effects at low concentrations are a matter of concern. It is necessary to consider long-term, low-dose continuous administration under conditions that are as close as possible to a person's diet. In this study, we orally administered 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), the most common dioxin, at low doses in mice and observed the immunological effects. We found that antigen-specific (OVA) antibody production in the serum increased dose-dependently by TCDD concentrations below 500 ng/kg after long-term (10 weeks) exposure. Similar increases were seen in fecal and vaginal samples but were not significant. Th1 and Th2 lymphocyte responses, as determined by antibody and cytokine production, also significantly increased dose-dependently up to 500 ng/kg TCDD, and the Th1/Th2 balance was shifted toward Th1. These results indicate that low-dose, long-term TCDD exposure results in immunological abnormalities, perhaps by increasing antigen permeability. Different doses of dioxins may have opposing effects, being immunostimulatory at low doses (100 ng/kg/day) and immunosuppressive at high doses (500 ng/kg/day).
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Key Words
- 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD)
- AhR, aryl hydrocarbon receptor
- EROD, ethoxyresorufin O-deethylase
- IFN-γ, interferon-gamma
- IL-10, interleukin-10
- IL-13, interleukin-13
- IL-17, interleukin-17
- IL-2, interleukin-2
- IL-4, interleukin-4
- Ig, immunoglobulin
- OVA, ovalbumin
- OVA-specific antibody titer
- Subclinical oral exposure of TCDD
- TCDD, 2,3,7,8-tetrachlorobibenzo-p-dioxin
- TDI, tolerable daily intake
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Affiliation(s)
- Hideki Kakutani
- Laboratory of Disease Prevention, Faculty of Pharmaceutical Sciences, Setsunan University, 45-1 Nagaotoge-cho, Hirakata, Osaka 573-0101, Japan
| | - Tomohiro Yuzuriha
- Laboratory of Disease Prevention, Faculty of Pharmaceutical Sciences, Setsunan University, 45-1 Nagaotoge-cho, Hirakata, Osaka 573-0101, Japan
| | - Teruyuki Nakao
- Laboratory of Disease Prevention, Faculty of Pharmaceutical Sciences, Setsunan University, 45-1 Nagaotoge-cho, Hirakata, Osaka 573-0101, Japan
| | - Souichi Ohta
- Laboratory of Disease Prevention, Faculty of Pharmaceutical Sciences, Setsunan University, 45-1 Nagaotoge-cho, Hirakata, Osaka 573-0101, Japan
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Zhang R, Wu Q, Qi X, Wang X, Zhang X, Song C, Peng Y, Crump D, Zhang X. Using In Vitro and Machine Learning Approaches to Determine Species-Specific Dioxin-like Potency and Congener-Specific Relative Sensitivity among Birds for Brominated Dioxin Analogues. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:16056-16066. [PMID: 34761675 DOI: 10.1021/acs.est.1c05951] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
There is a paucity of experimental data regarding dioxin-like toxicity of polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs) and non-ortho polybrominated biphenyls (PBBs). In this study, avian aryl hydrocarbon receptor 1 (AHR1)-luciferase reporter gene assays were used to determine their species-specific dioxin-like potencies (DLPs) and congener-specific interspecies relative sensitivities in birds. The results suggested that DLPs of the brominated congeners for chicken-like (Ile324_Ser380) species did not always follow World Health Organization toxicity equivalency factors of their chlorinated analogues. For ring-necked pheasant-like (Ile324_Ala380) and Japanese quail-like (Val324_Ala380) species, the difference in DLP for several congeners was 1 or even 2 orders of magnitude. Moreover, molecular docking and molecular dynamics simulation were performed to explore the interactions between the brominated congeners and AHR1-ligand-binding domain (LBD). The molecular mechanics energy (EMM) between each congener and each individual amino acid (AA) residue in AHR1-LBD was calculated. These EMM values could finely characterize the final conformation of species-specific AHR1-LBD for each brominated congener. Based on this, mechanism-driven generalized linear models were successfully built using machine learning algorithms and the spline approximation method, and these models could qualitatively predict the complex relationships between AHR1 conformations and DLPs or avian interspecies relative sensitivity to brominated dioxin-like compounds (DLCs). In addition, several AAs conserved among birds were found to potentially interact with species-specific AAs, thereby inducing species-specific interactions between AHR1 and brominated DLCs. The present study provides a novel strategy to facilitate the development of mechanism-driven computational prediction models for supporting safety assessment of DLCs, as well as a basis for the ecotoxicological risk assessment of brominated congeners in birds.
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Affiliation(s)
- Rui Zhang
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, China
| | - Qiuxuan Wu
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, China
| | - Xiaoyi Qi
- Department of Gynecology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250021, China
- Department of Gynecology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan 250021, China
| | - Xiaoxiang Wang
- State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- Yuanshang Technology Co., Ltd., Shenzhen 518126, China
| | - Xuesheng Zhang
- School of Resources and Environmental Engineering, Anhui University, Hefei 230601, China
| | - Chao Song
- Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China
- Laboratory of Quality & Safety Risk Assessment for Aquatic Products on Environmental Factors (Wuxi), Ministry of Agriculture, Wuxi 214081, China
| | - Ying Peng
- Research and Development Center for Watershed Environmental Eco-Engineering, Beijing Normal University, Zhuhai 519087, China
| | - Doug Crump
- Ecotoxicology and Wildlife Health Division, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa K1A 0H3, Canada
| | - Xiaowei Zhang
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
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Yang Y, Zheng M, Yang L, Jin R, Li C, Liu X, Liu G. Profiles, spatial distributions and inventory of brominated dioxin and furan emissions from secondary nonferrous smelting industries in China. JOURNAL OF HAZARDOUS MATERIALS 2021; 419:126415. [PMID: 34166953 DOI: 10.1016/j.jhazmat.2021.126415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 06/08/2021] [Accepted: 06/14/2021] [Indexed: 06/13/2023]
Abstract
Nonferrous metallurgical processes are important sources of carcinogenic polybrominated dibenzo-p-dioxin and dibenzofuran (PBDD/Fs) that transport globally. Studies on the profiles, spatial distributions and inventory of PBDD/F emissions into the atmosphere from nonferrous metallurgical plants are needed for better source control. In this study, field investigations on PBDD/F emissions from typical nonferrous metallurgical plants were conducted to characterize the PBDD/F profiles and derive their emission factors. Based on the PBDD/F profiles, diagnostic ratios of PBDD/Fs for secondary copper, zinc and lead smelting were proposed for identifying the potential sources of PBDD/Fs in environment. The PBDD/F emission factors for the secondary copper, lead, and zinc smelting plants were 0.71, 1.65, and 1.54 μg toxic equivalents/t, respectively. The estimated annual input of PBDD/Fs into atmosphere by secondary nonferrous metallurgical plants in China was 212.4 g by mass and 3511.3 mg by toxic equivalents, which is of significance for further evolving a global inventory. The spatial distribution of PBDD/F emissions from nonferrous metallurgical plants in China was mapped. Larger amounts of PBDD/Fs were emitted in the southeastern coastal region and northern China than elsewhere in China.
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Affiliation(s)
- Yuanping Yang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Minghui Zheng
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China; School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310000, China
| | - Lili Yang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Rong Jin
- School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310000, China
| | - Cui Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoyun Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guorui Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China; School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310000, China.
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Fernandes AR, Falandysz J. Polybrominated dibenzo-p-dioxins and furans (PBDD/Fs): Contamination in food, humans and dietary exposure. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 761:143191. [PMID: 33160676 DOI: 10.1016/j.scitotenv.2020.143191] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 10/15/2020] [Accepted: 10/16/2020] [Indexed: 05/11/2023]
Abstract
Polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) have been recognised as environmental pollutants for decades but their occurrence in food has only recently been reported. They elicit the same type of toxic response as analogous polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) with similar potencies and effects, and share similar origins - inadvertent production during combustion and occurrence as by-products in industrial chemicals. Surprisingly, PBDD/Fs have received considerably less attention than PCDD/Fs, perhaps because determination requires a higher degree of analytical competence, a result of the higher adsorptivity and lability associated with carbon-bromine bonding. For most populations, the principal exposure pathway is dietary intake. The PBDD/F toxicity arising from occurrence in foods has often been expressed as toxic equivalents (TEQs) using the same scheme developed for PCDD/Fs. This approach is convenient, but resulting TEQ estimates are more uncertain, given the known differences in response for some analogous congeners and also the different patterns of PBDD/F occurrence confirmed by the newer data. Further studies to consolidate potency factors would help to refine TEQ estimates. Characteristically, most foods and human tissues show more frequent and higher PBDF concentrations relative to PBDDs, reflecting major source patterns. Occurrence in food ranges from <0.01 to several thousand pg/g (or up to 0.3 pg TEQ/g whole weight) which is comparable to PCDD/F occurrence (ΣPBDD/F TEQs are underestimated as not all relevant congeners are included). Plant based foods show higher PBDD/F: PCDD/F TEQ ratios. Reported PBDD/F dietary intakes suggest that some population groups, particularly young children, may exceed the revised tolerable weekly intake for dioxin-like contaminants (2 pg TEQ/kg bw/week), even for mean consumption estimated with lower bound data. It is evident that the omission of PBDD/Fs from the TEQ scheme results in a significant underestimation of the cumulative toxicity and associated risk arising from this mode of action.
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Affiliation(s)
- Alwyn R Fernandes
- School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
| | - Jerzy Falandysz
- University of Gdańsk, Environmental Chemistry and Ecotoxicology, 80-308 Gdańsk, Poland
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Diletti G, Ceci R, De Benedictis A, Leva M, Migliorati G, Pirito L, Vairano I, Fernandes AR. Polybrominated dibenzo-p-dioxins and furans (PBDD/Fs) in Italian food: Occurrence and dietary exposure. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 741:139916. [PMID: 32585481 DOI: 10.1016/j.scitotenv.2020.139916] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 03/09/2020] [Accepted: 06/01/2020] [Indexed: 06/11/2023]
Abstract
Human exposure to polychlorinated dioxins and furans (PCDD/Fs) through the dietary pathway is widely recognised and regulations in some regions of the world help to limit food contamination. Similar information on the analogous polybrominated dioxins and furans (PBDD/Fs) is scarce, partly due to the higher threshold to analytical access and unavailability of some standard materials. The analytical methodology developed here determined twelve planar PBDD/F congeners using 13Carbon labelled PBDD/F surrogates and high resolution mass spectrometric detection, and was extensively validated prior to the analysis of a range of commonly consumed Italian foods. The methodology also allowed simultaneous determination of PCDD/Fs and polychlorinated biphenyls (PCBs). The results show that PBDD/Fs occurred in different foods over a range of concentrations from <0.001 pg/g to 4.58 pg/g in fish. The dietary exposure (upper bound) of different Italian population groups, resulting from these occurrence levels was estimated using the toxic equivalency (TEQ) approach that is commonly used for dioxin-like contaminants and ranged from 0.17 to 0.42 pg TEQ/kg bodyweight/day (lower bound - 0.01 pg TEQ/kg bodyweight/day) depending on the population subgroup. Although precautionary, upper bound values may provide a more realistic estimate of toxicity as not all congeners and foods were measured. As expected, children were more highly exposed than adults due to lower body weight. These exposure levels were between a quarter and a third of that arising from the sum of PCDD/Fs and PCBs (0.61 to 1.38 pg WHO-TEQ/kg bodyweight/day), but they contribute to dioxin-like toxicity. If this data is considered in view of the revised tolerable dioxin-like dietary intake published by EFSA in 2018, it is evident that the tolerable weekly intake of 2 pg/kg bodyweight/week would be exceeded by some of the assessed population sub-groups, or all sub-groups if the cumulative intake is considered.
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Affiliation(s)
- Gianfranco Diletti
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise G. Caporale, via Campo Boario, 64100 Teramo, TE, Italy
| | - Roberta Ceci
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise G. Caporale, via Campo Boario, 64100 Teramo, TE, Italy
| | - Alfonso De Benedictis
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise G. Caporale, via Campo Boario, 64100 Teramo, TE, Italy
| | - Manuela Leva
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise G. Caporale, via Campo Boario, 64100 Teramo, TE, Italy
| | - Giacomo Migliorati
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise G. Caporale, via Campo Boario, 64100 Teramo, TE, Italy
| | - Luigi Pirito
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise G. Caporale, via Campo Boario, 64100 Teramo, TE, Italy
| | - Ilaria Vairano
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise G. Caporale, via Campo Boario, 64100 Teramo, TE, Italy
| | - Alwyn R Fernandes
- School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
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Singh A, Hakk H, Lupton S. Facile synthesis of bromo- and mixed bromo/chloro dibenzo-p-dioxins and [ 14C]-labeled 1,3,7,8-tetrabromodibenzo-p-dioxin. CHEMOSPHERE 2020; 239:124626. [PMID: 31518918 DOI: 10.1016/j.chemosphere.2019.124626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 08/16/2019] [Accepted: 08/19/2019] [Indexed: 06/10/2023]
Abstract
Polybrominated dibenzo-p-dioxins (PBDDs) and mixed bromo/chloro dibenzo-p-dioxins (PXDDs) are persistent organic pollutants that can possess the same toxicity as their fully chlorinated analogs (PCDDs) and have been identified in the same matrices. Herein a general synthetic methodology is described to produce multiple congeners of PBDDs and PXDDs with varying degrees of halogenation and substitution patterns for use as analytical and/or internal standards, and for absorption, disposition, metabolism, and excretion (ADME) studies. The syntheses of PBDDs and PXDDs were accomplished by condensing a common precursor, 4,5-dibromo catechol, with variable precursors, i.e., polychlorinated 1-chloro-2-nitrobenzenes or polybrominated 1-fluoro-2-nitrobenzenes, to introduce a desired number of halogens and specific substitution patterns. Initial attempts to synthesize PBDDs and PXDDs were performed in potassium carbonate with DMSO at 145-150 °C. PXDDs syntheses resulted in formation of the desired products at >90% purity but attempts at higher brominated PBDDs syntheses resulted in dehalogenated by-products. To preclude by-product formation, additional syntheses for some PBDDs were conducted by refluxing the precursors in acetonitrile, which resulted in pure products at higher yield. Six PXDDs ranging from four to six halogens were synthesized (20-84% yield), of which three contained the halogen substitution pattern of 2,3,7,8. Five PBDDs ranging from four to six bromines were produced in 23-83% yield, three of which were toxic. Using the initial DMSO method, [14C]-1,3,7,8-tetrabromodibenzo-p-dioxin (0.26 μCi/μmol; 11% overall yield) was synthesized from commercially available [14C]-phenol to allow an ADME study to be conducted.
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Affiliation(s)
- Anuradha Singh
- United States Department of Agriculture, Agricultural Research Service, Edward T. Schafer Agricultural Research Center, Fargo, ND, 58102, USA
| | - Heldur Hakk
- United States Department of Agriculture, Agricultural Research Service, Edward T. Schafer Agricultural Research Center, Fargo, ND, 58102, USA.
| | - Sara Lupton
- United States Department of Agriculture, Agricultural Research Service, Edward T. Schafer Agricultural Research Center, Fargo, ND, 58102, USA
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Nguyen HT, Tsuchiya MCL, Yoo J, Iida M, Agusa T, Hirano M, Kim EY, Miyazaki T, Nose M, Iwata H. Strain differences in the proteome of dioxin-sensitive and dioxin-resistant mice treated with 2,3,7,8-tetrabromodibenzo-p-dioxin. Arch Toxicol 2016; 91:1763-1782. [PMID: 27604104 DOI: 10.1007/s00204-016-1834-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 08/24/2016] [Indexed: 11/28/2022]
Abstract
Dioxins cause various toxic effects through the aryl hydrocarbon receptor (AHR) in vertebrates, with dramatic species and strain differences in susceptibility. Although inbred mouse strains C3H/HeJ-lpr/lpr (C3H/lpr) and MRL/MpJ-lpr/lpr (MRL/lpr) are known as dioxin-sensitive and dioxin-resistant mice, respectively, the molecular mechanism underlying this difference remains unclear. The difference in the hepatic proteome of the two mouse strains treated with vehicle or 2,3,7,8-tetrabromodibenzo-p-dioxin (TBDD) was investigated by a proteomic approach of two-dimensional electrophoresis (2-DE) coupled with matrix-assisted laser desorption/ionization time-of-flight/time-of-flight tandem mass spectrometry (MALDI-TOF/TOF). To confirm the strain-difference in response to TBDD treatment, cytochrome P450 (CYP) 1A1 and 1A2 protein levels were measured in both strains. A dose of 10 µg/kg body weight of TBDD induced hepatic CYP1A1 and CYP1A2 expression in both strains, but the expression levels of both CYP1A proteins were higher in C3H/lpr mice than in MRL/lpr mice, supporting that C3H/lpr mice are more sensitive to dioxins than MRL/lpr mice. Proteins that were more induced or suppressed by TBDD treatment in C3H/lpr mice were successfully identified by 2-DE and MALDI-TOF/TOF, including proteins responsible for AHR activation through production of endogenous ligands such as aspartate aminotransferase, indolethylamine N-methyltransferase, and aldehyde dehydrogenases, as well as proteins reducing oxidative stress, such as superoxide dismutase and peroxiredoxins. Taken together, our results provide insights into the molecular mechanism underlying the high dioxin susceptibility of the C3H/lpr strain, in which AHR activation by TBDD is more prompted by the production of endogenous ligands, but the adaptation to oxidative stress is also acquired.
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Affiliation(s)
- Hoa Thanh Nguyen
- Laboratory of Environmental Toxicology, Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, 790-8577, Japan
| | - Maria Claret Lauan Tsuchiya
- Laboratory of Environmental Toxicology, Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, 790-8577, Japan.,Institute of Biological Sciences, University of the Philippines Los Baños, Laguna, Philippines
| | - Jean Yoo
- Laboratory of Environmental Toxicology, Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, 790-8577, Japan
| | - Midori Iida
- Graduate School of Computer Science and System Engineering, Kyushu Institute of Technology, Iizuka, 820-0067, Japan
| | - Tetsuro Agusa
- Laboratory of Environmental Toxicology, Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, 790-8577, Japan.,Graduate School of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto, Kumamoto, 862-8502, Japan
| | - Masashi Hirano
- Laboratory of Environmental Toxicology, Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, 790-8577, Japan
| | - Eun-Young Kim
- Department of Life and Nanopharmaceutical Science and Department of Biology, Kyung Hee University, Seoul, 130-701, Korea
| | | | - Masato Nose
- Institute for Promotion of Advanced Science and Technology, Ehime University, Matsuyama, 790-8577, Japan
| | - Hisato Iwata
- Laboratory of Environmental Toxicology, Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, 790-8577, Japan.
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van den Berg M, Denison MS, Birnbaum LS, Devito MJ, Fiedler H, Falandysz J, Rose M, Schrenk D, Safe S, Tohyama C, Tritscher A, Tysklind M, Peterson RE. Polybrominated dibenzo-p-dioxins, dibenzofurans, and biphenyls: inclusion in the toxicity equivalency factor concept for dioxin-like compounds. Toxicol Sci 2013; 133:197-208. [PMID: 23492812 DOI: 10.1093/toxsci/kft070] [Citation(s) in RCA: 154] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
In 2011, a joint World Health Organization (WHO) and United Nations Environment Programme (UNEP) expert consultation took place, during which the possible inclusion of brominated analogues of the dioxin-like compounds in the WHO Toxicity Equivalency Factor (TEF) scheme was evaluated. The expert panel concluded that polybrominated dibenzo-p-dioxins (PBDDs), dibenzofurans (PBDFs), and some dioxin-like biphenyls (dl-PBBs) may contribute significantly in daily human background exposure to the total dioxin toxic equivalencies (TEQs). These compounds are also commonly found in the aquatic environment. Available data for fish toxicity were evaluated for possible inclusion in the WHO-UNEP TEF scheme (van den Berg et al., 1998). Because of the limited database, it was decided not to derive specific WHO-UNEP TEFs for fish, but for ecotoxicological risk assessment, the use of specific relative effect potencies (REPs) from fish embryo assays is recommended. Based on the limited mammalian REP database for these brominated compounds, it was concluded that sufficient differentiation from the present TEF values of the chlorinated analogues (van den Berg et al., 2006) was not possible. However, the REPs for PBDDs, PBDFs, and non-ortho dl-PBBs in mammals closely follow those of the chlorinated analogues, at least within one order of magnitude. Therefore, the use of similar interim TEF values for brominated and chlorinated congeners for human risk assessment is recommended, pending more detailed information in the future.
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Affiliation(s)
- Martin van den Berg
- Institute for Risk Assessment Sciences-IRAS and WHO Collaborating Centre for Environmental Health Risk Assessment, Utrecht University, Utrecht, The Netherlands.
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Erickson PR, Grandbois M, Arnold WA, McNeill K. Photochemical formation of brominated dioxins and other products of concern from hydroxylated polybrominated diphenyl ethers (OH-PBDEs). ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:8174-8180. [PMID: 22765251 DOI: 10.1021/es3016183] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The photochemical conversion of selected hydroxylated polybrominated diphenyl ethers (OH-PBDEs) to dioxins and other products was investigated. OH-PBDEs, which are both transformation products of polybrominated diphenyl ethers and naturally occurring compounds, undergo direct photolysis to yield a number of products that may have a higher toxicity than their parent. The compounds investigated were 6-OH-PBDE 99, 6'-OH-PBDE 100, and 6'-OH-PBDE 118. Of special interest was 6'-OH-PBDE 118, a potential transformation product of PBDE 153 that is capable of photochemically generating 2,3,7,8-tetrabromodibenzo-p-dioxin, the most toxic brominated dioxin congener. Photolysis experiments were conducted at two different pH values to assess the photochemical behavior of both the phenol and phenolate form of the compounds. The percent conversion to dioxin and other photoproducts was determined and the natural product, 6-OH-PBDE 99, was found to have the highest conversion to dioxin (7%). The reaction quantum yields ranged from 0.027 to 0.16 across all photolysis conditions. In addition, it is shown that all three compounds are capable of photochemically generating other compounds of concern, including brominated phenols and a dibenzofuran.
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Affiliation(s)
- Paul R Erickson
- Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, 8092 Zurich, Switzerland
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Haijima A, Endo T, Zhang Y, Miyazaki W, Kakeyama M, Tohyama C. In utero and lactational exposure to low doses of chlorinated and brominated dioxins induces deficits in the fear memory of male mice. Neurotoxicology 2010; 31:385-90. [PMID: 20398696 DOI: 10.1016/j.neuro.2010.04.004] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Revised: 03/20/2010] [Accepted: 04/06/2010] [Indexed: 01/10/2023]
Abstract
Environmental-level in utero and lactational exposures to dioxins have been considered to affect brain functions of offspring. Here, we determined whether in utero and lactational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and 2,3,7,8-tetrabromodibenzo-p-dioxin (TBDD), at the dose that does not harm the dams, affects the acquisition and retention of fear memory in mouse offspring. Pregnant C57BL/6J mice were administered by gavages TCDD or TBDD at a dose of 0 or 3.0 microg/kg body weight on gestation day 12.5, and their male offspring were examined for their behavior in adulthood. In the fear conditioning, a paired presentation of tone and foot shock was repeated three times, and retention tests for contextual and auditory fear memory were carried out 1 and 24h after the fear conditioning. Groups of mice that were exposed to TCDD and TBDD in utero and via lactation showed deficits in the contextual and auditory retention tests at 1 and 24h retention intervals. The present results suggest that maternal exposure to a low dose of TCDD or TBDD disrupts the functions of memory and emotion in male mouse offspring, and that the developmental toxicities of these chemicals are similar to each other.
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Affiliation(s)
- Asahi Haijima
- Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo 113-0033, Japan
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