1
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Li K, Qi Z, Xie Z, Li W, Yang X, Zhai Y, Zhou X, Xie X, Song W. TDMPP activation of estrogen receptor 2a regulates smc2 and p53 signaling to interfere with liver development in zebrafish (Danio rerio). JOURNAL OF HAZARDOUS MATERIALS 2024; 477:135379. [PMID: 39096633 DOI: 10.1016/j.jhazmat.2024.135379] [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: 05/08/2024] [Revised: 07/27/2024] [Accepted: 07/28/2024] [Indexed: 08/05/2024]
Abstract
Tris (2,6-dimethylphenyl) phosphate (TDMPP), a novel organic phosphorus flame retardant (OPFR), has been found to have estrogenic activity. Estrogens are critical in regulating various biological responses during liver development. However, the effects of TDMPP on zebrafish liver development remain largely unexplored. Here, we utilized a chemical genetic screening approach to assess the estrogenic effects of TDMPP on liver development and to elucidate the underlying molecular mechanism. Our findings revealed that zebrafish larvae exposed to environmentally relevant concentrations of TDMPP (0.05 and 0.5 μM) exhibited concentration-dependent liver impairments, including reduced liver size, histopathological changes, and hepatocyte apoptosis. In addition, E2 caused similar adverse effects to TDMPP, but the pharmacological blockade of estrogen synthesis alleviated the effects on liver development. Chemical inhibitors and morpholino knockdown assays indicated that the reduction of esr2a blocked TDMPP-induced liver impairments, which was further confirmed in the esr2a-/- mutant line. Subsequently, transcriptomic analysis showed that the estrogen receptor activated by TDMPP inhibited the expression of smc2, which was linked to the suppression of liver development through p53 activation. Consistently, overexpression of smc2 and inhibition of p53 evidently rescued hepatic damages induced by TDMPP. Taken together, the above findings identified esr2a, downstream smc2, and p53 as important regulators for the estrogenic effects of TDMPP on liver development. Our work fills crucial gaps in the current knowledge of TDMPP's hepatotoxicity, providing new insights into the adverse effects of TDMPP and the molecular mechanisms of action. These findings underscore the need for further ecological risk assessment and regulatory considerations.
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Affiliation(s)
- Keying Li
- Key Laboratory of Human Genetics and Environmental Medicine, Key Laboratory of Environment and Health, School of Public Health, Xuzhou Medical University, Xuzhou, China
| | - Zhipeng Qi
- Key Laboratory of Human Genetics and Environmental Medicine, Key Laboratory of Environment and Health, School of Public Health, Xuzhou Medical University, Xuzhou, China
| | - Zhuoyi Xie
- Key Laboratory of Human Genetics and Environmental Medicine, Key Laboratory of Environment and Health, School of Public Health, Xuzhou Medical University, Xuzhou, China
| | - Wei Li
- Key Laboratory of Human Genetics and Environmental Medicine, Key Laboratory of Environment and Health, School of Public Health, Xuzhou Medical University, Xuzhou, China
| | - Xinxin Yang
- Key Laboratory of Human Genetics and Environmental Medicine, Key Laboratory of Environment and Health, School of Public Health, Xuzhou Medical University, Xuzhou, China
| | - Yue Zhai
- School of Nursing, Jilin University, Changchun, China
| | - Xiaomai Zhou
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, China
| | - Xunwei Xie
- China Zebrafish Resource Center, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Weiyi Song
- Key Laboratory of Human Genetics and Environmental Medicine, Key Laboratory of Environment and Health, School of Public Health, Xuzhou Medical University, Xuzhou, China.
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2
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Fu K, Zhu B, Sun Y, Zhou Y, Pang H, Ren X, Guo Y, Shi X, Han J, Yang L, Zhou B. Bis(2-ethylhexyl)-tetrabromophthalate Poses a Higher Exposure Risk and Induces Gender-Specific Metabolic Disruptions in Zebrafish Liver. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:4937-4947. [PMID: 38446036 DOI: 10.1021/acs.est.4c00234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Abstract
Bis(2-ethylhexyl)-tetrabromophthalate (TBPH), a typical novel brominated flame retardant, has been ubiquitously identified in various environmental and biotic media. Consequently, there is an urgent need for precise risk assessment based on a comprehensive understanding of internal exposure and the corresponding toxic effects on specific tissues. In this study, we first investigated the toxicokinetic characteristics of TBPH in different tissues using the classical pseudo-first-order toxicokinetic model. We found that TBPH was prone to accumulate in the liver rather than in the gonad, brain, and muscle of both female and male zebrafish, highlighting a higher internal exposure risk for the liver. Furthermore, long-term exposure to TBPH at environmentally relevant concentrations led to increased visceral fat accumulation, signaling potential abnormal liver function. Hepatic transcriptome analysis predominantly implicated glycolipid metabolism pathways. However, alterations in the profile of associated genes and biochemical indicators revealed gender-specific responses following TBPH exposure. Besides, histopathological observations as well as the inflammatory response in the liver confirmed the development of nonalcoholic fatty liver disease, particularly in male zebrafish. Altogether, our findings highlight a higher internal exposure risk for the liver, enhancing our understanding of the gender-specific metabolic-disrupting potential associated with TBPH exposure.
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Affiliation(s)
- Kaiyu Fu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Biran Zhu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- School of Basic Medical Sciences, Hubei University of Chinese Medicine, Wuhan 430065, China
| | - Yumiao Sun
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yuxi Zhou
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hao Pang
- School of Chemistry and Environmental Engineering, Wuhan Institute of Technology, Wuhan 430074, China
| | - Xinxin Ren
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yongyong Guo
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Xiongjie Shi
- College of Life Sciences, the Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Jian Han
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Lihua Yang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Bingsheng Zhou
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
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3
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Chen X, Hu G, He B, Cao Z, He J, Luo H, Li Y, Yu Q. Effect of brominated flame retardants exposure on liver function and the risk of non-alcoholic fatty liver disease in the US population. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 273:116142. [PMID: 38394757 DOI: 10.1016/j.ecoenv.2024.116142] [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: 10/16/2023] [Revised: 02/18/2024] [Accepted: 02/20/2024] [Indexed: 02/25/2024]
Abstract
BACKGROUND The relationship between brominated flame retardants (BFRs) exposure and the human liver was still not well understood. METHODS A total of 3108 participants (age > 12) from the National Health and Nutrition Examination Survey (NHANES) database spanning from 2005 to 2016 were included as the study population, with nine BFRs exhibiting a detection rate of over 70% serving as the exposure factor. The singular effects and combined effects of BFRs exposure on liver injury, non-alcoholic fatty liver disease (NAFLD), and advanced hepatic fibrosis (AHF) were evaluated separately. Finally, COX regression was employed to explore the hazard ratios associated with individual BFRs. RESULTS In our analysis of individual exposures, we found significant positive association of PBB153 with alanine aminotransferase (ALT), PBB153 with aspartate aminotransferase (AST), PBDE47, PBDE85, PBDE99, PBDE100, and PBDE154 with alkaline phosphatase (ALP), PBDE28 and PBB153 with gamma-glutamyl transaminase (GGT), PBB153 with the risk of NAFLD and AHF; and significant negative association of PBB153 with ALP, PBDE28, PBDE47, PBDE99, PBDE100, PBDE85, PBDE209, and PBDE154 with albumin (ALB), PBB153 with AST/ALT. The nonlinear analysis results from Restricted Cubic Spline (RCS) further validated these associations (all P<0.05). In the mixed analysis combining Weighted Quantile Sum (WQS) regression and Quantile G-computation (QGC) analysis, BFRs were positively associated with ALT (β>0, P<0.001), GGT (β>0, P<0.001), and the risk of NAFLD (OR>1, P=0.007). Conversely, BFRs exhibited significant negative correlations with ALP (β<0, P<0.001), ALB (β<0, P<0.001), and AST/ALT (β<0, P<0.001). Furthermore, the COX regression analysis revealed that PBB153 had the highest hazard ratio among the BFRs. CONCLUSIONS BFR exposure may increase the risk of liver injury and NAFLD, with no significant association with AHF risk. The impact of BFR exposure on liver health should not be overlooked, especially in individuals residing in impoverished areas.
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Affiliation(s)
- Xiong Chen
- Department of General Surgery, Affiliated Changsha Hospital of Hunan Normal University, No. 70, Lushan Road, Changsha 410000, PR China
| | - GuoHuang Hu
- Department of General Surgery, Affiliated Changsha Hospital of Hunan Normal University, No. 70, Lushan Road, Changsha 410000, PR China
| | - Bin He
- Department of General Surgery, Affiliated Changsha Hospital of Hunan Normal University, No. 70, Lushan Road, Changsha 410000, PR China
| | - Zhen Cao
- Department of General Surgery, Affiliated Changsha Hospital of Hunan Normal University, No. 70, Lushan Road, Changsha 410000, PR China
| | - JianFeng He
- Department of Vascular Surgery, Affiliated Changsha Hospital of Hunan Normal University, No. 70, Lushan Road, Changsha 410000, PR China
| | - HaiLong Luo
- Department of Endoscopy, Hunan Province Chest Hospital, No. 519, Xianjia Lake Road, Changsha 410000, PR China
| | - YiJin Li
- Department of Colorectal and Anorectal Surgery, Hunan Academy of Traditional Chinese Medicine Affiliated Hospital, No. 58, Lushan Road, Changsha 410000, PR China
| | - QianLe Yu
- Department of General Surgery, Affiliated Changsha Hospital of Hunan Normal University, No. 70, Lushan Road, Changsha 410000, PR China.
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4
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Zhou Y, Li F, Fu K, Zhang Y, Zheng N, Tang H, Xu Z, Luo L, Han J, Yang L, Zhou B. Bis(2-ethylhexyl)-2,3,4,5-tetrabromophthalate Enhances foxo1-Mediated Lipophagy to Remodel Lipid Metabolism in Zebrafish Liver. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:4581-4593. [PMID: 38422554 DOI: 10.1021/acs.est.4c00421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
An emerging environmental contaminant, bis(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (TBPH), can bioaccumulate in the liver and affect hepatic lipid metabolism. However, the in-depth mechanism has yet to be comprehensively explored. In this study, we utilized transgenic zebrafish Tg (Apo14: GFP) to image the interference of TBPH on zebrafish liver development and lipid metabolism at the early development stage. Using integrated lipidomic and transcriptomic analyses to profile the lipid remodeling effect, we uncovered the potential effects of TBPH on lipophagy-related signaling pathways in zebrafish larvae. Decreased lipid contents accompanied by enhanced lipophagy were confirmed by the measurements of Oil Red O staining and transmission electron microscopy in liver tissues. Particularly, the regulatory role of the foxo1 factor was validated via its transcriptional inhibitor. Double immunofluorescence staining integrated with biochemical analysis indicated that the enhanced lipophagy and mitochondrial fatty acid oxidation induced by TBPH were reversed by the foxo1 inhibitor. To summarize, our study reveals, for the first time, the essential role of foxo1-mediated lipophagy in TBPH-induced lipid metabolic disorders and hepatoxicity, providing new insights for metabolic disease studies and ecological health risk assessment of TBPH.
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Affiliation(s)
- Yuxi Zhou
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Fan Li
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kaiyu Fu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yindan Zhang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Na Zheng
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Huijia Tang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, China
| | - Zhixiang Xu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- College of Fisheries and Life Science, Dalian Ocean University, Dalian 116023, China
| | - Lijun Luo
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- College of Fisheries and Life Science, Dalian Ocean University, Dalian 116023, China
| | - Jian Han
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Lihua Yang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Bingsheng Zhou
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
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5
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Fu K, Hua J, Zhang Y, Du M, Han J, Li N, Wang Q, Yang L, Li R, Zhou B. Integrated Studies on Male Reproductive Toxicity of Bis(2-ethylhexyl)-tetrabromophthalate: in Silico, in Vitro, ex Vivo, and in Vivo. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:194-206. [PMID: 38113192 DOI: 10.1021/acs.est.3c07129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
Bis(2-ethylhexyl)tetrabromophthalate (TBPH) has been widely detected in the environment and organisms; thus, its toxic effects on male reproduction were systematically studied. First, we found that TBPH can stably bind to the androgen receptor (AR) based on in silico molecular docking results and observed an antagonistic activity, but not agonistic activity, on the AR signaling pathway using a constructed AR-GRIP1 yeast assay. Subsequently, we validated the adverse effects on male germ cells by observing inhibited androgen production and proliferation in Leydig cells upon in vitro exposure and affected general motility and motive tracks of zebrafish sperm upon ex vivo exposure. Finally, the in vivo reproductive toxicity was demonstrated in male zebrafish by reduced mating behavior in F0 generation when paired with unexposed females and abnormal development of their offspring. In addition, reduced sperm motility and impaired germ cells in male zebrafish were also observed, which may be related to the disturbed homeostasis of sex hormones. Notably, the specifically suppressed AR in the brain provides further evidence for the antagonistic effects as above-mentioned. These results confirmed that TBPH affected male reproduction through a classical nuclear receptor-mediated pathway, which would be helpful for assessing the ecological and health risks of TBPH.
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Affiliation(s)
- Kaiyu Fu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jianghuan Hua
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- School of Basic Medical Sciences, Hubei University of Chinese Medicine, Wuhan 430065, China
| | - Yindan Zhang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mingpu Du
- Ecology and Environment Monitoring and Scientific Research Center, Ecology and Environment Administration of Yangtze River Basin, Ministry of Ecology and Environment, Wuhan 430010, China
| | - Jian Han
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Na Li
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Qiangwei Wang
- Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou 310058, China
| | - Lihua Yang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Ruiwen Li
- Ecology and Environment Monitoring and Scientific Research Center, Ecology and Environment Administration of Yangtze River Basin, Ministry of Ecology and Environment, Wuhan 430010, China
| | - Bingsheng Zhou
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
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6
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Yuan Y, Zhuang Y, Cui Y, Liu Y, Zhang Q, Xiao Q, Meng Q, Jiang J, Hao W, Wei X. IL-10-TG/TPO-T4 axis, the target of bis (2-ethylhexyl) tetrabromophthalate on thyroid function imbalance. Toxicology 2024; 501:153713. [PMID: 38135142 DOI: 10.1016/j.tox.2023.153713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 12/10/2023] [Accepted: 12/17/2023] [Indexed: 12/24/2023]
Abstract
Bis (2-ethylhexyl) tetrabromophthalate (TBPH) is a new type of brominated flame retardant. Some studies suggest that TBPH exposure may be associated with thyroid damage. However, there is a paucity of research on the authentic exposure-related effects and molecular mechanisms in animals or cells. In this study, we used male Sprague-Dawley (SD) rats and the Nthy ori3-1 cell line (the human thyroid follicular epithelial cell) to explore the potential effects of TBPH (5, 50, 500 mg/kg and 1, 10, 100 nM) on the thyroid. The genes and their proteins of cytokines and thyroid-specific proteins, thyroglobulin (TG), thyroid peroxidase (TPO), and sodium iodide cotransporter (NIS) were examined to investigate the possible mechanisms. At the end of the experiment, it was found that 50 and 500 mg/kg TBPH could increase the levels of total thyroxine (TT4) and free thyroxine (FT4) significantly. The messenger RNAs (mRNAs) of Tg, Tpo, Interleukin-6 (Il6), and Interleukin-10 (Il10) in the thyroid tissues from the rats treated with 500 mg/kg were enhanced clearly. Meanwhile, the mRNAs of TG, TPO, IL6, and IL10 were elevated in Nthy ori3-1 cells treated with 100 nM TBPH as well. The mRNAs of TG and TPO were elevated after the knockdown of IL6. To our surprise, after the knockdown of IL10 or the treatment of anti-IL-10-receptor (anti-IL-10-R) antibody, the mRNAs of TG and TPO were significantly reduced, and the effects of TBPH were diminished. In conclusion, our results suggested that the IL-10-IL-10R-TG/TPO-T4 axis is one important target of TBPH in the thyroid.
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Affiliation(s)
- Yuese Yuan
- Department of Toxicology, School of Public Health, Peking University, Beijing 100191, PR China; Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing 100191, PR China
| | - Yimeng Zhuang
- Department of Toxicology, School of Public Health, Peking University, Beijing 100191, PR China; Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing 100191, PR China
| | - Yuan Cui
- Department of Toxicology, School of Public Health, Peking University, Beijing 100191, PR China; Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing 100191, PR China
| | - Yuetong Liu
- Department of Toxicology, School of Public Health, Peking University, Beijing 100191, PR China; Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing 100191, PR China
| | - Qiong Zhang
- Department of Toxicology, School of Public Health, Peking University, Beijing 100191, PR China; Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing 100191, PR China
| | - Qianqian Xiao
- Department of Toxicology, School of Public Health, Peking University, Beijing 100191, PR China; Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing 100191, PR China
| | - Qinghe Meng
- Department of Toxicology, School of Public Health, Peking University, Beijing 100191, PR China; Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing 100191, PR China
| | - Jianjun Jiang
- Department of Toxicology, School of Public Health, Peking University, Beijing 100191, PR China; Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing 100191, PR China
| | - Weidong Hao
- Department of Toxicology, School of Public Health, Peking University, Beijing 100191, PR China; Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing 100191, PR China
| | - Xuetao Wei
- Department of Toxicology, School of Public Health, Peking University, Beijing 100191, PR China; Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing 100191, PR China.
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7
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Marinello WP, Gillera SEA, Han Y, Richardson JR, St Armour G, Horman BM, Patisaul HB. Gestational exposure to FireMaster® 550 (FM 550) disrupts the placenta-brain axis in a socially monogamous rodent species, the prairie vole (Microtus ochrogaster). Mol Cell Endocrinol 2023; 576:112041. [PMID: 37562579 PMCID: PMC10795011 DOI: 10.1016/j.mce.2023.112041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/26/2023] [Accepted: 08/06/2023] [Indexed: 08/12/2023]
Abstract
Gestational flame retardant (FR) exposure has been linked to heightened risk of neurodevelopmental disorders, but the mechanisms remain largely unknown. Historically, toxicologists have relied on traditional, inbred rodent models, yet those do not always best model human vulnerability or biological systems, especially social systems. Here we used prairie voles (Microtus ochrogaster), a monogamous and bi-parental rodent, leveraged for decades to decipher the underpinnings of social behaviors, to examine the impact of fetal FR exposure on gene targets in the mid-gestational placenta and fetal brain. We previously established gestational exposure to the commercial mixture Firemaster 550 (FM 550) impairs sociality, particularly in males. FM 550 exposure disrupted placental monoamine production, particularly serotonin, and genes required for axon guidance and cellular respiration in the fetal brains. Effects were dose and sex specific. These data provide insights on the mechanisms by which FRs impair neurodevelopment and later in life social behaviors.
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Affiliation(s)
- William P Marinello
- Department of Biological Sciences, NC State University, Raleigh, NC, 27695, USA
| | | | - Yoonhee Han
- Department of Environmental Health Sciences, Robert Stempel College of Public Health and Social Work, Florida International University, Miami, FL, 33199, USA
| | - Jason R Richardson
- Department of Environmental Health Sciences, Robert Stempel College of Public Health and Social Work, Florida International University, Miami, FL, 33199, USA
| | - Genevieve St Armour
- Department of Biological Sciences, NC State University, Raleigh, NC, 27695, USA
| | - Brian M Horman
- Department of Biological Sciences, NC State University, Raleigh, NC, 27695, USA
| | - Heather B Patisaul
- Department of Biological Sciences, NC State University, Raleigh, NC, 27695, USA; Center for Human Health and the Environment, NC State University, Raleigh, NC, 27695, USA.
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8
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Li WL, McDaniel TV, de Solla SR, Bradley L, Dove A, McGoldrick D, Helm P, Hung H. Temporal Trends of Legacy and Current-Use Halogenated Flame Retardants in Lake Ontario in Relation to Atmospheric Loadings, Sources, and Environmental Fate. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:14396-14406. [PMID: 37695984 PMCID: PMC10537453 DOI: 10.1021/acs.est.3c04876] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 08/28/2023] [Accepted: 08/29/2023] [Indexed: 09/13/2023]
Abstract
Since the phase-out of polybrominated diphenyl ethers (PBDEs), large amounts of alternative halogenated flame retardants (AHFRs) have been introduced to the market. Due to their persistence and toxicity, halogenated flame retardants (HFRs) have become a concern for the ecosystem and human health. However, there remains limited assessment of the atmospheric loadings, sources, and environmental fate of HFRs in Lake Ontario, which receives urban-related inputs and cumulative chemical inputs from the upstream Great Lakes from Canada and the United States. We combined long-term measurements with a modified multimedia model based on site-specific environmental parameters from Lake Ontario to understand the trends and fate of HFRs. All HFRs were detected in the air, precipitation, lake trout, and herring gull egg samples throughout the sampling periods. General decreasing trends were found for PBDEs, while the temporal trends for AHFRs were not clear. Physical-chemical properties and emissions significantly influence the levels, profiles, and trends. Using the probabilistic modeling, HFR concentrations in lake water and sediment were predicted to be close to the measurement, suggesting a good performance for the modified model. The loadings from tributaries and wastewater effluent were the primary input pathways. Transformations in the water and sedimentation were estimated to be the dominant output pathway for the three HFRs.
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Affiliation(s)
- Wen-Long Li
- Air
Quality Processes Research Section, Environment
and Climate Change Canada, 4905 Dufferin Street, Toronto, Ontario M3H 5T4, Canada
| | - Tana V. McDaniel
- Water
Quality Monitoring and Surveillance Division, Environment and Climate Change Canada, Burlington, Ontario L7S 1A1, Canada
| | - Shane R. de Solla
- Ecotoxicology
and Wildlife Health Division, Environment
and Climate Change Canada, Burlington, Ontario L7S 1A1, Canada
| | - Lisa Bradley
- Water
Quality Monitoring and Surveillance Division, Environment and Climate Change Canada, Burlington, Ontario L7S 1A1, Canada
| | - Alice Dove
- Water
Quality Monitoring and Surveillance Division, Environment and Climate Change Canada, Burlington, Ontario L7S 1A1, Canada
| | - Daryl McGoldrick
- Water
Quality Monitoring and Surveillance Division, Environment and Climate Change Canada, Burlington, Ontario L7S 1A1, Canada
| | - Paul Helm
- Environmental
Monitoring and Reporting Branch, Ontario
Ministry of the Environment, Conservation and Parks, 125 Resources Road, Toronto, Ontario M9P 3V6, Canada
| | - Hayley Hung
- Air
Quality Processes Research Section, Environment
and Climate Change Canada, 4905 Dufferin Street, Toronto, Ontario M3H 5T4, Canada
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9
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Xu M, Wang W, Feng J, Ruan Z, Le Y, Liu Y, Zhang Q, Wang C. The mechanism underlying pentabromoethylbenzene-induced adipogenesis and the obesogenic outcome in both cell and mouse model. ENVIRONMENT INTERNATIONAL 2023; 178:108088. [PMID: 37429055 DOI: 10.1016/j.envint.2023.108088] [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: 05/23/2023] [Revised: 06/30/2023] [Accepted: 07/04/2023] [Indexed: 07/12/2023]
Abstract
Convergent evidence links traditional brominated flame retardants (BFRs) exposure to weight gain, while the obesogenic potency of new BFRs (NBFRs) remain largely unknown. Aiding by luciferase-reporter gene assay, the present study revealed only pentabromoethylbenzene (PBEB), an alternative for penta-BDEs, binds with retinoid X receptor α (RXRα) but not peroxisomeproliferator receptor γ (PPARγ) among the seven testing NBFRs. An apparent induction of adipogenesis in 3T3-L1 cells was observed at nanomolar of PBEB, much lower than penta-BFRs. Mechanistic research uncovered PBEB initiated the adipogenesis by demethylated CpG sites in the PPARγ promoter region. Specifically, activation RXRα by PBEB strengthened the activity of RXRα/PPARγ heterodimer, tightened the interaction between the heterodimer and PPAR response elements, and further enhanced adipogenesis. RNA sequencing combined with k-means clustering analysis exposed adenosine 5'-monophosphate (AMP)-activated protein kinase and phosphoinositide-3-kinase (PI3K)/protein kinase B (AKT) signaling as two predominant pathways that enriched in PBEB-induced lipogenesis. The obesogenic outcome was further corroborated in offspring mice when the maternal mice exposed to environmental relevant doses of PBEB. We found the male offspring exhibited adipocyte hypertrophy and increased weight gain in the epididymal white adipose tissue (eWAT). Consistent with in vitro findings, the reduction in protein phosphorylation of both AMPK and PI3K/AKT were observed within eWAT. Thus, we posited PBEB disrupts the pathways controlling adipogenesis and adipose tissue maintenance, supporting its potential as an environmental obesogen.
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Affiliation(s)
- Mengting Xu
- School of Life Science, Zhejiang Chinese Medical University, Hangzhou 310053, Zhejiang, People's Republic of China
| | - Wanyue Wang
- School of Life Science, Zhejiang Chinese Medical University, Hangzhou 310053, Zhejiang, People's Republic of China
| | - Jiafan Feng
- School of Life Science, Zhejiang Chinese Medical University, Hangzhou 310053, Zhejiang, People's Republic of China
| | - Zheng Ruan
- School of Public Health, Hangzhou Medical College, Hangzhou 310013, Zhejiang, People's Republic of China
| | - Yifei Le
- School of Life Science, Zhejiang Chinese Medical University, Hangzhou 310053, Zhejiang, People's Republic of China
| | - Ying Liu
- School of Life Science, Zhejiang Chinese Medical University, Hangzhou 310053, Zhejiang, People's Republic of China
| | - Quan Zhang
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou 310032, People's Republic of China
| | - Cui Wang
- School of Life Science, Zhejiang Chinese Medical University, Hangzhou 310053, Zhejiang, People's Republic of China.
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10
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Meng W, Sun H, Su G. Plastic packaging-associated chemicals and their hazards - An overview of reviews. CHEMOSPHERE 2023; 331:138795. [PMID: 37116723 DOI: 10.1016/j.chemosphere.2023.138795] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 04/02/2023] [Accepted: 04/25/2023] [Indexed: 05/10/2023]
Abstract
Plastic packaging contains residues from substances used during manufacturing, such as solvents, as well as non-intentionally added substances (NIAS), such as impurities, oligomers, or degradation products. By searching peer-reviewed literature, we found that at least 10,259 chemicals were related to plastic packaging materials, which include chemicals used during manufacturing and/or present in final packaging items. We then summarized and discussed their chemical structures, analytical instruments, migration characteristics, and hazard categories where possible. For plastic packaging chemicals, examination of the literature reveals gas and liquid chromatography hyphenated to a variety of accurate mass analyzers based on the use of high-resolution mass spectrometry is usually used for the identification of unknown migrants coming from plastic packaging. Chemical migration from food packaging is affected by several parameters, including the nature and complexity of the food, contact time, temperature of the system, type of packaging contact layer, and properties of the migrants. A review of the literature reveals that information on adverse effects is only available for approximately 1600 substances. Among them, it appears that additives are more toxic than monomers to wildlife and humans. Neurotoxicity accounted for the highest proportion of toxicity of all types of chemicals, while benzenoids, organic acids, and derivatives were the most toxic types of chemicals. Furthermore, studies have demonstrated that hydrocarbon derivatives, organic nitrogen compounds, and organometallic compounds have the highest proportions of dermatotoxicity, and organohalogen compounds have the highest proportions of hepatotoxicity. The main contributors to skin sensitization are organic salts. This study provides a basis for comprehensively publicizing information on chemicals in plastics, and could be helpful to better understand their potential risks to the environment and humans.
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Affiliation(s)
- Weikun Meng
- Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China
| | - Hao Sun
- Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China
| | - Guanyong Su
- Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China.
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11
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Percy Z, Chen A, Yang W, Braun JM, Lanphear B, Ospina M, Calafat AM, Xie C, Cecil KM, Vuong AM, Xu Y, Yolton K. Childhood urinary organophosphate esters and cognitive abilities in a longitudinal cohort study. ENVIRONMENTAL RESEARCH 2022; 215:114265. [PMID: 36103927 PMCID: PMC9968469 DOI: 10.1016/j.envres.2022.114265] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 08/12/2022] [Accepted: 08/31/2022] [Indexed: 06/13/2023]
Abstract
The use of organophosphate esters (OPEs) as flame retardants, which has increased over the past two decades, raises concerns that OPEs may be harmful to humans, especially children. Animal studies and some human studies have reported that OPEs may adversely impact brain development, but few human studies evaluated OPE exposure during early childhood and neurodevelopmental outcomes. We aimed to fill this knowledge gap with the present study on urinary OPE metabolite concentrations at ages 1-5 years and cognitive abilities at 8 years. We used data of 223 children from the Health Outcomes and Measures of the Environment (HOME) Study, a prospective pregnancy and birth cohort in Cincinnati, Ohio. The point estimates for bis-2-chloroethyl-phosphate (BCEP) and bis(1,3-dichloro-2-propyl)-phosphate (BDCIPP) in association with IQ tended to be small and positive, while the point estimates for diphenyl-phosphate (DPHP) were small and negative, with 95% CIs including the null. However, we did find that socioeconomic status (SES) variables modified associations between OPEs and child IQ, with adverse OPE-IQ associations being stronger in socioeconomically disadvantaged children than in others. We identified an additional 1- to 2-point decrease in Full Scale IQ for every log-unit increase in BDCIPP, BCEP, and DPHP among those with lower maternal education, non-white race, lower income, or living in more deprived neighborhoods. We observed similar results for the Perceptual Reasoning, Verbal Comprehension, and Working Memory Index Scores. We suspect that there is residual confounding related to socioeconomic disadvantage, which was not captured with the available SES variables typically used in epidemiologic studies.
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Affiliation(s)
- Zana Percy
- Department of Environmental and Public Health Sciences, University of Cincinnati, Cincinnati, OH, USA
| | - Aimin Chen
- Department of Biostatistics, Epidemiology and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Weili Yang
- Department of Environmental and Public Health Sciences, University of Cincinnati, Cincinnati, OH, USA
| | - Joseph M Braun
- Department of Epidemiology, Brown University, Providence, RI, USA
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Maria Ospina
- National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Antonia M Calafat
- National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Changchung Xie
- Department of Environmental and Public Health Sciences, University of Cincinnati, Cincinnati, OH, USA
| | - Kim M Cecil
- Department of Radiology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Ann M Vuong
- Department of Epidemiology and Biostatistics, School of Public Health, University of Nevada, Las Vegas, Las Vegas, NV, USA
| | - Yingying Xu
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Kimberly Yolton
- Department of Environmental and Public Health Sciences, University of Cincinnati, Cincinnati, OH, USA; Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
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12
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Wei X, Yang D, Zhang B, Fan X, Du H, Zhu R, Sun X, Zhao M, Gu N. Di-(2-ethylhexyl) phthalate increases plasma glucose and induces lipid metabolic disorders via FoxO1 in adult mice. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 842:156815. [PMID: 35750186 DOI: 10.1016/j.scitotenv.2022.156815] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 06/04/2022] [Accepted: 06/15/2022] [Indexed: 06/15/2023]
Abstract
Di-(2-ethylhexyl) phthalate (DEHP), an endocrine-disrupting chemical (EDC) commonly used as a plasticizer, is responsible for widespread environmental pollution. Epidemiological and experimental data implicate DEHP and its metabolite mono(2-ethylhexyl) phthalate (MEHP) in the occurrence and development of metabolic syndrome. However, the specific effects and potential mechanisms of action of DEHP on glucose and lipid metabolism in adults are currently unclear. In the current study, adult male mice were continuously exposed to DEHP (0, 5, and 25 mg/kg/day) via oral administration and changes in glucose and lipid metabolism explored. Notably, exposure to DEHP led to a significant increase in plasma glucose and hepatic lipid accumulation but had no effect on insulin secretion. Western blot and real-time quantitative PCR showed that DEHP induced insulin resistance and promoted gluconeogenesis and lipid accumulation via overexpression of forkhead box protein O1 (FoxO1), in keeping with hepatic RNA sequencing data. Variations in gut microbiota aggravated these effects while inhibition of FoxO1 reversed the adverse effects of DEHP. Our findings support a key role of FoxO1 in disorders of glucose and lipid metabolism caused by DEHP.
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Affiliation(s)
- Xiangjuan Wei
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Daqian Yang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Boya Zhang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Xingpei Fan
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Haining Du
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Ruijiao Zhu
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Xiaotong Sun
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Meimei Zhao
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Ning Gu
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150006, China.
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13
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Han F, Chen G, Tao G, Xu J, Zhang H, Zhang L, Li H, Zhao Y, Tian D, Kimura SY, Wei X, Ruan Y, Wu C, Xiao S, Zhan M, Zheng W. Thyroid-disrupting effects caused by exposure to alternative flame retardants from groundwater contamination in rural central China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 839:156300. [PMID: 35636535 DOI: 10.1016/j.scitotenv.2022.156300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 05/12/2022] [Accepted: 05/24/2022] [Indexed: 06/15/2023]
Abstract
Accumulating evidence reveals that exposure to alternative flame retardants (AFRs) results in defective thyroid functions. AFRs are detectable in various environmental media in developed cities in China. However, few studies have reported the contamination levels of AFR in groundwater in rural areas, indicating an urgent need to investigate exposure of AFRs and perform health risk assessment for populations that use groundwater as the main source of drinking water. This study investigated the concentrations of AFRs in groundwater in rural areas of central China. Moreover, Nthy-ori-3-1 cells were used to determine the thyroid cytotoxicities and thyroid-interfering effects of a single AFR as well as the mixtures of AFRs based on the AFR contamination levels in real-world. The results revealed that all classes of AFRs were detectable in rural areas in central China. Dechlorane plus, hexabromocyclododecane, bromophenols (BPs), novel brominated flame retardants (NBFRs) and organophosphate flame retardants (OPFRs) exhibited spatial contamination patterns, with an average concentrations (median) of 157.89 ± 88.61 (185.47) pg/L, 0.09 ± 0.29 (not detectable) ng/L, 5.20 ± 5.92 (3.43) ng/L, 3338.11 ± 3758.78 (2836.72) pg/L, and 79.35 ± 97.19 (53.62) ng/L, respectively. The half maximal effective concentrations (EC50) of BPs, OPFRs, and NBFRs ranged 98.4-4012 μM, 42.0-2506 μM, and 10.1-203.7 μM, respectively. Several AFRs exhibited more cytotoxic effects than did traditional brominated flame retardants. It is intriguing that several single AFRs and mixtures at environmentally-relevant exposure levels promoted the viability of Nthy-ori-3-1 cells. Taken together, our study demonstrates that AFRs are present in the groundwater in rural areas in central China and AFRs exhibit thyroid disrupting effects.
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Affiliation(s)
- Fengchan Han
- Key Laboratory of the Public Health Safety, Ministry of Education, Department of Environmental Health, School of Public Health, Fudan University, Shanghai 200032, PR China; Shanghai Municipal Center for Disease Control and Prevention, Shanghai 200336, PR China
| | - Guanghua Chen
- Key Laboratory of the Public Health Safety, Ministry of Education, Department of Environmental Health, School of Public Health, Fudan University, Shanghai 200032, PR China
| | - Gonghua Tao
- Shanghai Municipal Center for Disease Control and Prevention, Shanghai 200336, PR China
| | - Jingshan Xu
- School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, PR China
| | - Huijun Zhang
- Shanghai Municipal Center for Disease Control and Prevention, Shanghai 200336, PR China
| | - Ling Zhang
- Department of Surgery, Huangpu Branch, Shanghai Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, Shanghai 200011, China
| | - Hongliang Li
- Shanghai Pudong New Area Center for Disease Control and Prevention, Fudan University Pudong Institute of Preventive Medicine, Shanghai 200136, PR China
| | - Yijing Zhao
- Shanghai Pudong New Area Center for Disease Control and Prevention, Fudan University Pudong Institute of Preventive Medicine, Shanghai 200136, PR China
| | - Dajun Tian
- Department of Epidemiology and Biostatistics, College for Public Health and Social Justice, 3545 Lafayette Ave., St. Louis, MO 63104, USA
| | - Susana Y Kimura
- Department of Chemistry, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Xiao Wei
- Department of Occupational and Environmental Health, School of Public Health, Guangxi Medical University, Nanning, Guangxi 530021, PR China
| | - Yuanyuan Ruan
- NHC Key Laboratory of Glycoconjugates Research, School of Basic Medical Sciences, Fudan University, Shanghai 200032, PR China; Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, PR China
| | - Chunfeng Wu
- Shanghai Municipal Center for Disease Control and Prevention, Shanghai 200336, PR China
| | - Shuo Xiao
- Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Environmental and Occupational Health Sciences Institute, Rutgers University, Piscataway, NJ 08854, USA.
| | - Ming Zhan
- Shanghai Pudong New Area Center for Disease Control and Prevention, Fudan University Pudong Institute of Preventive Medicine, Shanghai 200136, PR China.
| | - Weiwei Zheng
- Key Laboratory of the Public Health Safety, Ministry of Education, Department of Environmental Health, School of Public Health, Fudan University, Shanghai 200032, PR China; Center for Water and Health, School of Public Health, Fudan University, Shanghai 200032, PR China.
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14
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Witchey SK, Doyle MG, Fredenburg JD, St Armour G, Horman B, Odenkirk MT, Aylor DL, Baker ES, Patisaul HB. Impacts of Gestational FireMaster 550 Exposure on the Neonatal Cortex Are Sex Specific and Largely Attributable to the Organophosphate Esters. Neuroendocrinology 2022; 113:1262-1282. [PMID: 36075192 PMCID: PMC9992460 DOI: 10.1159/000526959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 08/24/2022] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Flame retardants (FRs) are common bodily and environmental pollutants, creating concern about their potential toxicity. We and others have found that the commercial mixture FireMaster® 550 (FM 550) or its individual brominated (BFR) and organophosphate ester (OPFR) components are potential developmental neurotoxicants. Using Wistar rats, we previously reported that developmental exposure to FM 550 or its component classes produced sex- and compound-specific effects on adult socioemotional behaviors. The underlying mechanisms driving the behavioral phenotypes are unknown. METHODS To further mechanistic understanding, here we conducted transcriptomics in parallel with a novel lipidomics approach using cortical tissues from newborn siblings of the rats in the published behavioral study. Inclusion of lipid composition is significant because it is rarely examined in developmental neurotoxicity studies. Pups were gestationally exposed via oral dosing to the dam to FM 550 or the BFR or OPFR components at environmentally relevant doses. RESULTS The neonatal cortex was highly sexually dimorphic in lipid and transcriptome composition, and males were more significantly impacted by FR exposure. Multiple adverse modes of action for the BFRs and OPFRs on neurodevelopment were identified, with the OPFRs being more disruptive than the BFRs via multiple mechanisms including dysregulation of mitochondrial function and disruption of cholinergic and glutamatergic systems. Disrupted mitochondrial function by environmental factors has been linked to a higher risk of autism spectrum disorders and neurodegenerative disorders. Impacted lipid classes included ceramides, sphingomyelins, and triacylglycerides. Robust ceramide upregulation in the OPFR females could suggest a heightened risk of brain metabolic disease. CONCLUSIONS This study reveals multiple mechanisms by which the components of a common FR mixture are developmentally neurotoxic and that the OPFRs may be the compounds of greatest concern.
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Affiliation(s)
- Shannah K Witchey
- Department of Biological Sciences, NC State University, Raleigh, North Carolina, USA
| | - Michael G Doyle
- Department of Chemistry, NC State University, Raleigh, North Carolina, USA
| | - Jacob D Fredenburg
- Department of Biological Sciences, NC State University, Raleigh, North Carolina, USA
| | - Genevieve St Armour
- Department of Biological Sciences, NC State University, Raleigh, North Carolina, USA
| | - Brian Horman
- Department of Biological Sciences, NC State University, Raleigh, North Carolina, USA
| | - Melanie T Odenkirk
- Department of Chemistry, NC State University, Raleigh, North Carolina, USA
| | - David L Aylor
- Department of Biological Sciences, NC State University, Raleigh, North Carolina, USA
- Center for Human Health and the Environment, NC State University, Raleigh, North Carolina, USA
| | - Erin S Baker
- Department of Chemistry, NC State University, Raleigh, North Carolina, USA
| | - Heather B Patisaul
- Center for Human Health and the Environment, NC State University, Raleigh, North Carolina, USA
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15
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Zhou Y, Lei L, Chen P, Guo W, Guo Y, Yang L, Han J, Hu B, Zhou B. Effects of nano-TiO 2 on the bioavailability and toxicity of bis(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (TBPH) in developing zebrafish. CHEMOSPHERE 2022; 295:133862. [PMID: 35124078 DOI: 10.1016/j.chemosphere.2022.133862] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 01/24/2022] [Accepted: 02/01/2022] [Indexed: 06/14/2023]
Abstract
Nanoparticles like nano-TiO2 are suspected to influence the bioavailability and toxicity of co-existing organic or inorganic pollutants differently in aquatic environment. Recently, bis(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (TBPH), a novel brominated flame retardants (NBFRs) with potential lipid-metabolism disruptive effects, has been detected prevalently in multiple environments including where nano-TiO2 was also observed. However, their interaction in aqueous phase and modification of nano-TiO2 on biological processes and toxicity of TBPH at environmental relevant levels remain unknown. Accordingly, we exposed zebrafish embryos to TBPH (1, 10, 100 and 1000 μg/L) alone or with nano-TiO2 (100 μg/L) until 72 h post-fertilization (hpf) with emphasis on their physicochemical interactions in solutions and variations of bioavailability and toxicity regarding lipid metabolism in vivo. Zeta potential, fourier transform infrared (FTIR) spectroscopy and TEM-EDS revealed adsorption and agglomeration between TBPH and nano-TiO2in vitro. Decreased body contents of nano-TiO2 and TBPH implied a reduction of TBPH in bioavailability. The enhanced lipid metabolism and reduced fat storage by TBPH alone were all alleviated by co-exposure to nano-TiO2. The overall results indicate that nano-TiO2 adsorbed TBPH to form size-enlarged agglomerates and led to decreased bioavailability and consequently mitigated lipid metabolism disorders in developing zebrafish embryo/larvae.
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Affiliation(s)
- Yuxi Zhou
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lei Lei
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Pengyu Chen
- Department of Chemistry, Wuhan University, Wuhan, 430072, China
| | - Wei Guo
- School of Life Sciences, Yunnan University, Kunming, 650091, China
| | - Yongyong Guo
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Lihua Yang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Jian Han
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.
| | - Bin Hu
- Department of Chemistry, Wuhan University, Wuhan, 430072, China
| | - Bingsheng Zhou
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
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16
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Zhou Y, Guo W, Lei L, Sun Y, Li R, Guo Y, Yang L, Shi X, Han J, Zhou B. Bis(2-ethylhexyl)-tetrabromophthalate induces zebrafish obesity by altering the brain-gut axis and intestinal microbial composition. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 290:118127. [PMID: 34523534 DOI: 10.1016/j.envpol.2021.118127] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 08/15/2021] [Accepted: 09/05/2021] [Indexed: 06/13/2023]
Abstract
Multiple environmental stressors, including chemicals termed obesogens, contribute to the susceptibility of organisms to obesity. Bis(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (TBPH), a novel brominated flame retardant, is an environmental contaminant that may disrupt lipid metabolism. However, the risk of TBPH leading to obesity remains unknown. Herein, adult female zebrafish fed a normal-fat diet (NFD) or high-fat diet (HFD) were exposed to 0, 0.02 and 2.0 μM TBPH for 6 weeks. The results showed that chronic TBPH exposure lead to significant weight gain, adipocyte hypertrophy, and subcutaneous fat accumulation, which could be enhanced by HFD feeding. HFD individuals also showed significant visceral fat accumulation. Transcription of the main adipokines regulating lipid metabolism associated with the brain-gut axis were significantly affected by TBPH, especially leptin (brain) and adiponectin (intestine). Additionally, peroxisome proliferator-activated nuclear receptor gamma (PPAR-γ) was significantly upregulated in intestine. TBPH increased the abundance of Firmicutes and Bacteroidetes in the gut microbiota in both NFD and HFD groups, resulting in obesity. Interestingly, population diversity analysis indicated that TBPH alone had a comparable impact on gut microbiota composition to that of HDF controls. Thus, TBPH increased the susceptibility of female zebrafish to obesity by disrupting brain-gut axis regulation and gut microbial composition, leading to enhanced fat accumulation under HFD conditions.
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Affiliation(s)
- Yuxi Zhou
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Wei Guo
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lei Lei
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yumiao Sun
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ruiwen Li
- Ecological Environment Monitoring and Scientific Research Center, Changjiang River Basin Ecological Environment Administration, Ministry of Ecology and Environment, Wuhan, 430014, China
| | - Yongyong Guo
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Lihua Yang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Xiongjie Shi
- College of Life Sciences, The Institute for Advanced Studies, Wuhan University, Wuhan, 430072, China
| | - Jian Han
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.
| | - Bingsheng Zhou
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
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17
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Bao Z, Jing Y. Brominated flame retardant TBPH induced oxidative damage and reduced the expression of memory-related proteins in mice, with no discernable impairment of learning and memory. Hum Exp Toxicol 2021; 40:S684-S692. [PMID: 34784780 DOI: 10.1177/09603271211058876] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Bis(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (TBPH) is one of the new brominated flame retardants with adverse neurobehavioral potential. These flame retardants are often added to household furnishings where children would come into contact with them. This study explores whether oral exposure to TBPH for 28 days would impair neurobehavioral function in mice and the role of curcumin (CUR) in this process. CUR is a natural antioxidant and is thought to be of use in the treatment of neurological toxicity due to its neuroprotective effects. Learning and memory of mice exposed to TBPH was investigated using the Morris water maze. Levels of malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH) were determined to assess oxidative damage. Western blot was used to detect the expression of glucose-regulated protein 78-kDa (GRP78), PKR-like ER kinase (PERK), and C/EBP homologous protein (CHOP) in the hippocampus. End-point effects were evaluated through observing post-synaptic density protein-95 (PSD-95), brain-derived neurotrophic factor (BDNF), and phosphorylated cAMP response element binding protein (p-CREB). Although TBPH exposure alone does not impair learning and memory, oxidative stress markers and endoplasmic reticulum stress-associated proteins were adversely affected in exposed mice. TBPH could significantly decrease the levels of BDNF, p-CREB, and PSD-95 in the hippocampus, and these TBPH-induced neurotoxic effects were attenuated by CUR. These findings provide further understanding of the neurotoxic effects of TBPH and the protective effect of CUR on TBPH exposure.
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Affiliation(s)
- Zhang Bao
- Department of Emergency, 117732Affiliated Renhe Hospital of China Three Gorges University, Yichang, China
| | - Yin Jing
- Department of Anesthesiology, 117732Affiliated Renhe Hospital of China Three Gorges University, Yichang, China
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18
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Yin J, Zhang B. Effects of bis(2-ethylhexyl)-2,3,4,5-tetrabromophthalate on liver injury in Balb/c mice. Toxicol Ind Health 2021; 37:547-554. [PMID: 34486454 DOI: 10.1177/07482337211031688] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Bis(2-ethylhexyl) 2,3,4,5-tetrabromophthalate (TBPH) has been used as a replacement in some commercial flame-retardant mixtures. It is widely used in industrial products, so the probability of human exposure to TBPH is high. Yet, little is known about how it is metabolized or its toxicity. To this end, we investigated what effect oral exposure of Balb/c mice to TBPH at concentrations of 200 mg kg-1 had on hepatic damage. Staining results showed liver injury in the mice exposed to TBPH. Oxidative stress markers and endoplasmic reticulum stress associated proteins were altered in the TBPH exposed mice, and these changes could be attenuated by administration of curcumin at 25 mg kg-1. Overall, TBPH induces hepatic damage via increasing oxidative stress, and curcumin plays a protective role in alleviating the TBPH-mediated histopathological alterations in the liver.
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Affiliation(s)
- Jing Yin
- Department of Emergency, Affiliated Renhe Hospital of China Three Gorges University, Yichang, Hubei, China
| | - Bao Zhang
- Department of Emergency, Affiliated Renhe Hospital of China Three Gorges University, Yichang, Hubei, China
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19
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Percy Z, Vuong AM, Xu Y, Xie C, Ospina M, Calafat AM, Hoofnagle A, Lanphear BP, Braun JM, Cecil KM, Dietrich KN, Yolton K, Chen A. Maternal Urinary Organophosphate Esters and Alterations in Maternal and Neonatal Thyroid Hormones. Am J Epidemiol 2021; 190:1793-1802. [PMID: 33778842 DOI: 10.1093/aje/kwab086] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 03/19/2021] [Accepted: 03/23/2021] [Indexed: 12/23/2022] Open
Abstract
Production of organophosphate esters (OPEs), which represent a major flame-retardant class present in consumer goods, has increased over the past 2 decades. Experimental studies suggest that OPEs may be associated with thyroid hormone disruption, but few human studies have examined this association. We quantified OPE metabolites in the urine of 298 pregnant women from Cincinnati, Ohio, in the Health Outcomes and Measures of the Environment Study (enrolled 2003-2006) at 3 time points (16 and 26 weeks' gestation, and at delivery), and thyroid hormones in 16-week maternal and newborn cord sera. Urinary bis(1,3-dichloro-2-propyl)-phosphate concentrations were generally associated with decreased triiodothyronine and thyroxine levels and increased thyroid-stimulating hormone levels in maternal and newborn thyroid hormones in quartile dose-response analyses and multiple informant models. There was weaker evidence for thyroid hormone alterations in association with diphenyl-phosphate and di-n-butyl-phosphate. Bis-2-chloroethyl-phosphate was not associated with alterations in thyroid hormones in any analyses. We did not observe any evidence of effect modification by infant sex. These results suggest that gestational exposure to some OPEs may influence maternal and neonatal thyroid function, although replication in other cohorts is needed.
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20
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Guo W, Lei L, Shi X, Li R, Wang Q, Han J, Yang L, Chen L, Zhou B. Nonalcoholic Fatty Liver Disease Development in Zebrafish upon Exposure to Bis(2-ethylhexyl)-2,3,4,5-tetrabromophthalate, a Novel Brominated Flame Retardant. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:6926-6935. [PMID: 33938212 DOI: 10.1021/acs.est.1c01476] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Bis(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (TBPH), a novel brominated flame retardant, can potentially cause lipid metabolism disorder; however, its biological effects on lipid homeostasis remain unknown. We investigated its ability to cause nonalcoholic fatty liver disease (NAFLD) in zebrafish. Female zebrafish were fed a high-fat diet (HFD, 24% crude fat) or normal diet (ND, 6% crude fat), and exposed to TBPH (0.02, 2.0 μM) for 2 weeks. Consequently, HFD-fed fish showed a higher measured concentration of TBPH than ND-fed fish. Further, TBPH-treated fish in the HFD group showed higher hepatic triglyceride levels and steatosis. In comparison to ND-fed fish, treating HFD-fed fish with TBPH led to an increase in the concentration of several proinflammatory markers (e.g., TNF-α, IL-6); TBPH exposure also caused oxidative stress. In addition, the mRNA levels of genes encoding peroxisome proliferator-activated receptors were increased, and the transcription of genes involved in lipid synthesis, transport, and oxidation was upregulated in both ND- and HFD-fed fish. Both the ND and HFD groups also showed demethylation of the peroxisome proliferator-activated receptor-γ coactivator 1-α gene promoter, accompanied by the upregulation of tet1 and tet2 transcription. To summarize, we found that TBPH amplified the disruption of lipid homeostasis in zebrafish, leading to the enhancement of diet-induced NAFLD progression.
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Affiliation(s)
- Wei Guo
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lei Lei
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiongjie Shi
- College of Life Sciences, the Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Ruiwen Li
- Ecological Environment Monitoring and Scientific Research Center, Changjiang River Basin Ecological Environment Administration, Ministry of Ecology and Environment, Wuhan 430014, China
| | - Qiangwei Wang
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou 310058, China
| | - Jian Han
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Lihua Yang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Lianguo Chen
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Bingsheng Zhou
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
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21
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Zheng Z, Arp HPH, Peters G, Andersson PL. Combining In Silico Tools with Multicriteria Analysis for Alternatives Assessment of Hazardous Chemicals: Accounting for the Transformation Products of decaBDE and Its Alternatives. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:1088-1098. [PMID: 33381962 PMCID: PMC7871322 DOI: 10.1021/acs.est.0c02593] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 12/14/2020] [Accepted: 12/15/2020] [Indexed: 06/12/2023]
Abstract
Transformation products ought to be an important consideration in chemical alternatives assessment. In this study, a recently established hazard ranking tool for alternatives assessment based on in silico data and multicriteria decision analysis (MCDA) methods was further developed to include chemical transformation products. Decabromodiphenyl ether (decaBDE) and five proposed alternatives were selected as case chemicals; biotic and abiotic transformation reactions were considered using five in silico tools. A workflow was developed to select transformation products with the highest occurrence potential. The most probable transformation products of the alternative chemicals were often similarly persistent but more mobile in aquatic environments, which implies an increasing exposure potential. When persistence (P), bioaccumulation (B), mobility in the aquatic environment (M), and toxicity (T) are considered (via PBT, PMT, or PBMT composite scoring), all six flame retardants have at least one transformation product that can be considered more hazardous, across diverse MCDA. Even when considering transformation products, the considered alternatives remain less hazardous than decaBDE, though the range of hazard of the five alternatives was reduced. The least hazardous of the considered alternatives were melamine and bis(2-ethylhexyl)-tetrabromophthalate. This developed tool could be integrated within holistic alternatives assessments considering use and life cycle impacts or additionally prioritizing transformation products within (bio)monitoring screening studies.
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Affiliation(s)
- Ziye Zheng
- Department
of Chemistry, Umeå University, SE-901 87 Umeå, Sweden
| | - Hans Peter H. Arp
- Department
of Environmental Engineering, Norwegian
Geotechnical Institute, Ullevaal
Stadion NO-0806, Oslo, Norway
- Department
of Chemistry, Norwegian University of Science
and Technology (NTNU), NO-7491 Trondheim, Norway
| | - Gregory Peters
- Division
of Environmental Systems Analysis, Chalmers
University of Technology, SE-412 96 Göteborg, Sweden
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22
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Dong L, Wang S, Qu J, You H, Liu D. New understanding of novel brominated flame retardants (NBFRs): Neuro(endocrine) toxicity. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 208:111570. [PMID: 33396099 DOI: 10.1016/j.ecoenv.2020.111570] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 10/22/2020] [Accepted: 10/25/2020] [Indexed: 06/12/2023]
Abstract
Traditional brominated flame retardants (BFRs) negatively affect the environment and human health, especially in the sensitive (developing) nervous system. Considering the physicochemical similarities between novel brominated flame retardants (NBFRs) and BFRs, more and more evidence reveals the neurotoxic effects of NBFRs. We reviewed the neuro(endocrine) toxic effects of NBFRs in vivo and in vitro and discussed their action mechanisms based on the available information. The neurotoxic potential of NBFRs has been demonstrated through direct neurotoxicity and disruption of the neuroendocrine system, with adverse effects on neurobehavioral and reproductive development. Mechanistic studies have shown that the impact of NBFRs is related to the complex interaction of neural and endocrine signals. From disrupting the gender differentiation of the brain, altering serum thyroid/sex hormone levels, gene/protein expression, and so on, to interfere with the feedback effect between different levels of the HPG/HPT axis. In this paper, the mechanism of neurotoxic effects of NBFRs is explored from a new perspective-neuro and endocrine interactions. Gaps in the toxicity data of NBFRs in the neuroendocrine system are supplemented and provide a broader dataset for a complete risk assessment.
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Affiliation(s)
- Liying Dong
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Shutao Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Jinze Qu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Hong You
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai 264209, China.
| | - Dongmei Liu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
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23
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Kassotis CD, Herkert NJ, Hammel SC, Hoffman K, Xia Q, Kullman SW, Sosa JA, Stapleton HM. Thyroid Receptor Antagonism of Chemicals Extracted from Personal Silicone Wristbands within a Papillary Thyroid Cancer Pilot Study. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:15296-15312. [PMID: 33185092 PMCID: PMC7819617 DOI: 10.1021/acs.est.0c05972] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Research suggests that thyroid cancer incidence rates are increasing, and environmental exposures have been postulated to be playing a role. To explore this possibility, we conducted a pilot study to investigate the thyroid disrupting bioactivity of chemical mixtures isolated from personal silicone wristband samplers within a thyroid cancer cohort. Specifically, we evaluated TRβ antagonism of chemical mixtures extracted from wristbands (n = 72) worn by adults in central North Carolina participating in a case-control study on papillary thyroid cancer. Sections of wristbands were solvent-extracted and analyzed via mass spectrometry to quantify a suite of semivolatile chemicals. A second extract from each wristband was used in a bioassay to quantify TRβ antagonism in human embryonic kidney cells (HEK293/17) at concentrations ranging from 0.1 to 10% of the original extract (by volume). Approximately 70% of the sample extracts tested at a 1% extract concentration exhibited significant TRβ antagonism, with a mean of 30% and a range of 0-100%. Inhibited cell viability was noted in >20% of samples that were tested at 5 and 10% concentrations. Antagonism was positively associated with wristband concentrations of several phthalates, organophosphate esters, and brominated flame retardants. These results suggest that personal passive samplers may be useful in evaluating the bioactivities of mixtures that people contact on a daily basis. We also report tentative associations between thyroid receptor antagonism, chemical concentrations, and papillary thyroid cancer case status. Future research utilizing larger sample sizes, prospective data collection, and measurement of serum thyroid hormone levels (which were not possible in this study) should be utilized to more comprehensively evaluate these associations.
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Affiliation(s)
- Christopher D Kassotis
- Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
| | - Nicholas J Herkert
- Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
| | - Stephanie C Hammel
- Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
| | - Kate Hoffman
- Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
| | - Qianyi Xia
- Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
| | - Seth W Kullman
- Toxicology Program, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Julie Ann Sosa
- Department of Surgery, University of California at San Francisco, San Francisco, California 94143, United States
| | - Heather M Stapleton
- Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
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24
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Lu L, Wu H, Cui S, Zhan T, Zhang C, Lu S, Liu W, Zhuang S. Pentabromoethylbenzene Exposure Induces Transcriptome Aberration and Thyroid Dysfunction: In Vitro, in Silico, and in Vivo Investigations. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:12335-12344. [PMID: 32835475 DOI: 10.1021/acs.est.0c03308] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Pentabromoethylbenzene (PBEB), as one of the novel brominated flame retardants (NFBRs), has caused increasing public concern for health risks. Till now, information regarding potential effects of PBEB on thyroid function remains unclear. Herein, we investigated thyroid disruption of PBEB in vitro and in silico and evaluated thyroid dysfunction induced by PBEB using Sprague-Dawley rats. PBEB showed thyroid receptor (TR) β antagonistic activity with IC50 of 9.82 × 10-7 M in the dual-luciferase reporter gene assay and induced relative reorientation of helix 11 (H11) and H12 of the TR ligand binding domain as revealed by molecular dynamics simulations. PBEB (0.2, 2, 20 mg/kg BW/d) markedly altered the transcriptome profile of thyroid with induction of 17, 42, and 119 differentially expressed genes (DEGs) involved in thyroid hormone signaling and synthesis pathway, of which transthyretin and albumin are common DEGs. The 28-d exposure to PBEB significantly decreased the triiodothyronine level (from 7.23 to 5.67 ng/mL) and increased the thyrotropin level (from 7.88 to 12.86 mU/L) for female rats. PBEB consequently reduced thyroid weight and altered its morphology with more depleted follicles. Overall, our study provides the first account of evidence on PBEB exerted thyroid disruption, transcriptome aberration, and morphological alteration, facilitating health risk assessment of PBEB and structurally related NBFRs.
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Affiliation(s)
- Liping Lu
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Hao Wu
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Shixuan Cui
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Tingjie Zhan
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Chunlong Zhang
- Department of Environmental Sciences, University of Houston-Clear Lake, 2700 Bay Area Boulevard, Houston, Texas 77058, United States
| | - Shaoyong Lu
- Department of Pathophysiology, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, China
| | - Weiping Liu
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Shulin Zhuang
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
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25
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Chen Y, Guo M, Liu R, Ma LQ, Cui X. Effects of novel brominated flame retardants and metabolites on cytotoxicity in human umbilical vein endothelial cells. CHEMOSPHERE 2020; 253:126653. [PMID: 32302898 DOI: 10.1016/j.chemosphere.2020.126653] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 03/23/2020] [Accepted: 03/29/2020] [Indexed: 06/11/2023]
Abstract
Novel brominated flame retardants (NBFRs) have been widely used and frequently detected in various environmental matrices. In this study, 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB), bis-(2-ethylhexyl) tetrabromophthalate (TBPH) and their metabolites (namely 2,3,4,5-tetra-bromo benzoic acid (TBBA) and mono(2-ethylhexyl) tetrabromophthalate (TBMEHP)) were exposed to human umbilical vein endothelial cells (HUVECs). Metabolites can induce stronger cytotoxicity than parent compounds with EC50 at 47.3 (TBBA), 8.6 μg/ml (TBMEHP) vs > 200 μg/mL for parent compounds. Gene expression of platelet endothelial cell adhesion molecule-1, the gene associated with blood platelet kinetics, was significantly induced under TBBA and TBMEHP exposure. The in vivo test was consistent with gene expression result that the number of platelets in mouse blood was significantly increased after gavaged with 0.8 μg/mL TBBA and TBMEHP. In addition, TBB or TBPH were exposed to mice via gavage, and higher concentrations of TBBA (4 h, 60.8 ± 12.9 ng/mL, 8 h, 69.4 ± 2.24 ng/mL) in mouse blood were found than those of TBMEHP (4 h, 17.2 ± 4.01 ng/mL, 8 h, 12.8 ± 3.20 ng/mL), indicating that TBB was more readily in vivo metabolized than TBPH. The in vivo metabolism of TBB and TBPH and the stronger toxicity of their metabolites underscore the potential risk through NBFR exposure and the importance of understanding NBFR metabolism process.
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Affiliation(s)
- Yi Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210046, China
| | - Mengfan Guo
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210046, China
| | - Rongyan Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210046, China
| | - Lena Q Ma
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China.
| | - Xinyi Cui
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210046, China.
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26
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Developmental Exposure to the Flame Retardant Mixture Firemaster 550 Compromises Adult Bone Integrity in Male but not Female Rats. Int J Mol Sci 2020; 21:ijms21072553. [PMID: 32272586 PMCID: PMC7178223 DOI: 10.3390/ijms21072553] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 04/01/2020] [Accepted: 04/03/2020] [Indexed: 12/27/2022] Open
Abstract
Flame retardants (FRs) are used in a variety of common items from furniture to carpet to electronics to reduce flammability and combustion, but the potential toxicity of these compounds is raising health concerns globally. Organophosphate FRs (OPFRs) are becoming more prevalent as older, brominated FRs are phased out, but the toxicity of these compounds, and the FR mixtures that contain them, is poorly understood. Work in a variety of in vitro model systems has suggested that FRs may induce metabolic reprogramming such that bone density is compromised at the expense of increasing adiposity. To address this hypothesis, the present studies maternally exposed Wistar rat dams orally across gestation and lactation to 1000 µg daily of the FR mixture Firemaster 550 (FM 550) which contains a mixture of brominated FRs and OPFRs. At six months of age, the offspring of both sexes were examined for evidence of compromised bone composition. Bone density, composition, and marrow were all significantly affected, but only in males. The fact that the phenotype was observed months after exposure suggests that FM 550 altered some fundamental aspect of mesenchymal stem cell reprogramming. The severity of the phenotype and the human-relevance of the dose employed, affirm this is an adverse outcome meriting further exploration.
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27
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Hanas AK, Guigueno MF, Fernie KJ, Letcher RJ, Ste-Marie Chamberland F, Head JA. Assessment of the effects of early life exposure to triphenyl phosphate on fear, boldness, aggression, and activity in Japanese quail (Coturnix japonica) chicks. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 258:113695. [PMID: 31841763 DOI: 10.1016/j.envpol.2019.113695] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 11/13/2019] [Accepted: 11/28/2019] [Indexed: 06/10/2023]
Abstract
Triphenyl phosphate (TPHP) is an organophosphate ester (OPE) used as a flame retardant (FR) and plasticizer. TPHP has previously been shown to disrupt behaviour in fish and mammals, but to our knowledge, this is the first study on the behavioural effects of TPHP in birds. Early life stage Japanese quail (Coturnix japonica) were exposed to nominal doses of 0 ng/g (vehicle-control), 5 ng/g (low dose), 50 ng/g (mid dose), and 100 ng/g (high dose) TPHP, both as embryos (via air cell injection prior to incubation) and as chicks (via daily gavage until 5 days post-hatch). The low dose reflects TPHP levels recorded in wild avian eggs, but actual environmental exposure levels may be higher given that TPHP is known to be rapidly metabolized in birds. We previously reported that the chicks exposed to TPHP in this study experienced reduced growth and resting metabolic rate, and sex-specific changes in thyroid function. The current study focuses on behavioural endpoints. We found that high-TPHP chicks exhibited less neophobia than vehicle-controls, and low-TPHP chicks exhibited more aggression towards conspecifics. No differences were observed in the responses of Japanese quail chicks to activity or tonic immobility (fear response) tests. These data add weight of evidence to previous findings suggesting that TPHP, among other OPEs, can disrupt ecologically-relevant behaviours in exposed vertebrates.
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Affiliation(s)
- Ashley K Hanas
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, Québec, H9X 3V9, Canada
| | - Mélanie F Guigueno
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, Québec, H9X 3V9, Canada; Ecotoxicology and Wildlife Health Division, Environment and Climate Change Canada, Canada Centre for Inland Waters, Burlington, Ontario, L7S 1A1, Canada
| | - Kim J Fernie
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, Québec, H9X 3V9, Canada; Ecotoxicology and Wildlife Health Division, Environment and Climate Change Canada, Canada Centre for Inland Waters, Burlington, Ontario, L7S 1A1, Canada.
| | - Robert J Letcher
- Ecotoxicology and Wildlife Health Division, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, Ontario, K1A 0H3, Canada
| | | | - Jessica A Head
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, Québec, H9X 3V9, Canada
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28
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Guo W, Han J, Wu S, Shi X, Wang Q, Zhou B. Bis(2-ethylhexyl)-2,3,4,5-tetrabromophthalate Affects Lipid Metabolism in Zebrafish Larvae via DNA Methylation Modification. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:355-363. [PMID: 31804803 DOI: 10.1021/acs.est.9b05796] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Bis(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (TBPH) is a ubiquitous environmental contaminant, but its toxicity is not fully understood. Accordingly, we investigated the effects of TBPH and its metabolite, mono-(2-ethyhexyl)tetrabromophthalate (TBMEHP), on lipid metabolism using a zebrafish model. The molecular docking study revealed that TBPH and TBMEHP bind to zebrafish peroxisome proliferator-activated receptor γ (PPARγ), with binding energies similar to rosiglitazone, a PPARγ agonist. Zebrafish embryos 0.75 hpf were exposed to TBPH (0.2-2000 nM) or TBMEHP (0.2-2000 nM) until 72 hpf, and their effects on PPARγ-mediated lipid metabolism were evaluated. Significant regional DNA demethylation of the PPARγ promoter was observed in the larvae at 72 hpf. Demethylation of the PPARγ promoter accompanied by upregulation of tet1 and tet2 transcription caused upregulation of PPARγ transcription and certain downstream genes involved in lipid lipolysis, transport, and metabolism. The triglyceride and total cholesterol concentrations in the larvae were significantly reduced following exposure to TBPH or TBMEHP. Furthermore, significant increases in the whole ATP content and locomotor activity in the 120 hpf larvae were observed. The overall results suggest that both TBPH and TBMEHP affect methylation of the PPARγ promoter, subsequently influencing larvae lipid metabolism via the PPARγ signaling pathway and disrupting energy homeostasis.
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Affiliation(s)
- Wei Guo
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jian Han
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Shengmin Wu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing 210042, China
| | - Xiongjie Shi
- College of Life Sciences, the Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Qiangwei Wang
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou 310058, China
| | - Bingsheng Zhou
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
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29
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Noyes PD, Friedman KP, Browne P, Haselman JT, Gilbert ME, Hornung MW, Barone S, Crofton KM, Laws SC, Stoker TE, Simmons SO, Tietge JE, Degitz SJ. Evaluating Chemicals for Thyroid Disruption: Opportunities and Challenges with in Vitro Testing and Adverse Outcome Pathway Approaches. ENVIRONMENTAL HEALTH PERSPECTIVES 2019; 127:95001. [PMID: 31487205 PMCID: PMC6791490 DOI: 10.1289/ehp5297] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 07/01/2019] [Accepted: 08/13/2019] [Indexed: 05/19/2023]
Abstract
BACKGROUND Extensive clinical and experimental research documents the potential for chemical disruption of thyroid hormone (TH) signaling through multiple molecular targets. Perturbation of TH signaling can lead to abnormal brain development, cognitive impairments, and other adverse outcomes in humans and wildlife. To increase chemical safety screening efficiency and reduce vertebrate animal testing, in vitro assays that identify chemical interactions with molecular targets of the thyroid system have been developed and implemented. OBJECTIVES We present an adverse outcome pathway (AOP) network to link data derived from in vitro assays that measure chemical interactions with thyroid molecular targets to downstream events and adverse outcomes traditionally derived from in vivo testing. We examine the role of new in vitro technologies, in the context of the AOP network, in facilitating consideration of several important regulatory and biological challenges in characterizing chemicals that exert effects through a thyroid mechanism. DISCUSSION There is a substantial body of knowledge describing chemical effects on molecular and physiological regulation of TH signaling and associated adverse outcomes. Until recently, few alternative nonanimal assays were available to interrogate chemical effects on TH signaling. With the development of these new tools, screening large libraries of chemicals for interactions with molecular targets of the thyroid is now possible. Measuring early chemical interactions with targets in the thyroid pathway provides a means of linking adverse outcomes, which may be influenced by many biological processes, to a thyroid mechanism. However, the use of in vitro assays beyond chemical screening is complicated by continuing limits in our knowledge of TH signaling in important life stages and tissues, such as during fetal brain development. Nonetheless, the thyroid AOP network provides an ideal tool for defining causal linkages of a chemical exerting thyroid-dependent effects and identifying research needs to quantify these effects in support of regulatory decision making. https://doi.org/10.1289/EHP5297.
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Affiliation(s)
- Pamela D Noyes
- National Center for Environmental Assessment, Office of Research and Development (ORD), U.S. Environmental Protection Agency (EPA), Washington, DC, USA
| | - Katie Paul Friedman
- National Center for Computational Toxicology, ORD, U.S. EPA, Research Triangle Park, North Carolina, USA
| | - Patience Browne
- Environment Health and Safety Division, Environment Directorate, Organisation for Economic Co-operation and Development (OECD), Paris, France
| | - Jonathan T Haselman
- Mid-Continent Ecology Division, National Health and Environmental Effects Research Laboratory (NHEERL), ORD, U.S. EPA, Duluth, Minnesota, USA
| | - Mary E Gilbert
- Toxicity Assessment Division, NHEERL, ORD, U.S. EPA, Research Triangle Park, North Carolina, USA
| | - Michael W Hornung
- Mid-Continent Ecology Division, National Health and Environmental Effects Research Laboratory (NHEERL), ORD, U.S. EPA, Duluth, Minnesota, USA
| | - Stan Barone
- Office of Pollution Prevention and Toxics, Office of Chemical Safety and Pollution Prevention, U.S. EPA, Washington, DC, USA
| | - Kevin M Crofton
- National Center for Computational Toxicology, ORD, U.S. EPA, Research Triangle Park, North Carolina, USA
| | - Susan C Laws
- Toxicity Assessment Division, NHEERL, ORD, U.S. EPA, Research Triangle Park, North Carolina, USA
| | - Tammy E Stoker
- Toxicity Assessment Division, NHEERL, ORD, U.S. EPA, Research Triangle Park, North Carolina, USA
| | - Steven O Simmons
- National Center for Computational Toxicology, ORD, U.S. EPA, Research Triangle Park, North Carolina, USA
| | - Joseph E Tietge
- Mid-Continent Ecology Division, National Health and Environmental Effects Research Laboratory (NHEERL), ORD, U.S. EPA, Duluth, Minnesota, USA
| | - Sigmund J Degitz
- Mid-Continent Ecology Division, National Health and Environmental Effects Research Laboratory (NHEERL), ORD, U.S. EPA, Duluth, Minnesota, USA
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Zheng Z, Peters GM, Arp HPH, Andersson PL. Combining in Silico Tools with Multicriteria Analysis for Alternatives Assessment of Hazardous Chemicals: A Case Study of Decabromodiphenyl Ether Alternatives. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:6341-6351. [PMID: 31081616 DOI: 10.1021/acs.est.8b07163] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Alternatives assessment is applied for minimizing the risk of unintentionally replacing a hazardous chemical with another hazardous chemical. Central challenges are the diversity of properties to consider and the lack of high-quality experimental data. To address this, a novel alternatives assessment procedure was developed based on in silico data and multicriteria decision analysis (MCDA) methods. As a case study, 16 alternatives to the flame retardant decabromodiphenyl ether were considered. The hazard properties included persistence (P), bioaccumulation potential (B), toxicities (T), and mobility in water (M). Databases were consulted and 2866 experimental data points were collected for the target chemicals; however, these were mostly replicate data points for some hazard criteria for a subset of alternatives. Therefore, in silico data and three MCDA strategies were tested including heat mapping, multiattribute utility theory (MAUT), and Elimination Et Choix Traduisant la REalité (ELECTRE III). The heat map clearly showed that none of the target chemicals are hazard-free, whereas MAUT and ELECTRE III agreed on ranking the "least worst" choices. This study identified several challenges and the complexity in the alternatives assessment processes motivating more case studies combining in silico and MCDA approaches.
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Affiliation(s)
- Ziye Zheng
- Department of Chemistry , Umeå University , SE-901 87 Umeå , Sweden
| | - Gregory M Peters
- Division of Environmental Systems Analysis , Chalmers University of Technology , SE-412 96 Göteborg , Sweden
- School of Civil and Environmental Engineering , University of New South Wales , AU-2052 Sydney , Australia
| | - Hans Peter H Arp
- Department of Environmental Engineering , Norwegian Geotechnical Institute , Ullevaal Stadion , NO-0806 Oslo , Norway
- Department of Chemistry , Norwegian University of Science and Technology (NTNU) , NO-7491 Trondheim , Norway
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Huang W, Bencic DC, Flick RL, Nacci DE, Clark BW, Burkhard L, Lahren T, Biales AD. Characterization of the Fundulus heteroclitus embryo transcriptional response and development of a gene expression-based fingerprint of exposure for the alternative flame retardant, TBPH (bis (2-ethylhexyl)-tetrabromophthalate). ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 247:696-705. [PMID: 30721860 PMCID: PMC7495336 DOI: 10.1016/j.envpol.2019.01.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 12/18/2018] [Accepted: 01/03/2019] [Indexed: 05/07/2023]
Abstract
Although alternative Flame Retardant (FR) chemicals are expected to be safer than the legacy FRs they replace, their risks to human health and the environment are often poorly characterized. This study used a small volume, fish embryo system to reveal potential mechanisms of action and diagnostic exposure patterns for TBPH (bis (2-ethylhexyl)-tetrabromophthalate), a component of several widely-used commercial products. Two different concentration of TBPH were applied to sensitive early life stages of an ecologically important test species, Fundulus heteroclitus (Atlantic killifish), with a well-annotated genome. Exposed fish embryos were sampled for transcriptomics or chemical analysis of parent compound and primary metabolite or observed for development and survival through larval stage. Global transcript profiling using RNA-seq was conducted (n = 16 per treatment) to provide a non-targeted and statistically robust approach to characterize TBPH gene expression patterns. Transcriptomic analysis revealed a dose-response in the expression of genes associated with a surprisingly limited number of biological pathways, but included the aryl hydrocarbon receptor signal transduction pathway, which is known to respond to several toxicologically-important chemical classes. A transcriptional fingerprint using Random Forests was developed that was able to perfectly discriminate exposed vs. non-exposed individuals in test sets. These results suggest that TBPH has a relatively low potential for developmental toxicity (at least in fishes), despite concerns related to its structural similarities to endocrine disrupting chemicals and that the early life stage Fundulus system may provide a convenient test system for exposure characterization. More broadly, this study advances the usefulness of a biological testing and analysis system utilizing non-targeted transcriptomics profiling and early developmental endpoints that complements current screening methods to characterize chemicals of ecological and human health concern.
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Affiliation(s)
- Weichun Huang
- U.S. EPA Office of Research and Development, National Exposure Research Laboratory, 26 W. Martin Luther King Dr., Cincinnati, OH, 45268, USA
| | - David C Bencic
- U.S. EPA Office of Research and Development, National Exposure Research Laboratory, 26 W. Martin Luther King Dr., Cincinnati, OH, 45268, USA
| | - Robert L Flick
- U.S. EPA Office of Research and Development, National Exposure Research Laboratory, 26 W. Martin Luther King Dr., Cincinnati, OH, 45268, USA
| | - Diane E Nacci
- U.S. EPA National Health and Environmental Effects Research Laboratory, 27 Tarzwell Drive Narragansett, RI, 02882, USA
| | - Bryan W Clark
- U.S. EPA National Health and Environmental Effects Research Laboratory, 27 Tarzwell Drive Narragansett, RI, 02882, USA
| | - Lawrence Burkhard
- U.S. EPA National Health and Environmental Effects Research Laboratory, 6201 Congdon Boulevard, Duluth, MN, 55804, USA
| | - Tylor Lahren
- U.S. EPA National Health and Environmental Effects Research Laboratory, 6201 Congdon Boulevard, Duluth, MN, 55804, USA
| | - Adam D Biales
- U.S. EPA Office of Research and Development, National Exposure Research Laboratory, 26 W. Martin Luther King Dr., Cincinnati, OH, 45268, USA.
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Lounis M, Leconte S, Rousselle C, Belzunces LP, Desauziers V, Lopez-Cuesta JM, Julien JM, Guenot D, Bourgeois D. Fireproofing of domestic upholstered furniture: Migration of flame retardants and potential risks. JOURNAL OF HAZARDOUS MATERIALS 2019; 366:556-562. [PMID: 30572295 DOI: 10.1016/j.jhazmat.2018.11.110] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 11/29/2018] [Accepted: 11/30/2018] [Indexed: 06/09/2023]
Abstract
Flame retardants (FRs) are widely incorporated in polyurethane foams to decrease their fire reaction. Currently, the risks associated with the use of FRs in domestic upholstered furniture (UF) are evaluated according to FRs volatility and potency to be emitted into the atmosphere. However, exposure via contact and dermal penetration, mediated by sweat, has not been considered so far. Our study provides an identification of the latest-generation of FRs most commonly used in UF, and an evaluation of their potency to migrate into artificial sweat. First of all, an extensive literature search, along with surveys with professionals, led to the identification of twenty-two FRs and synergists commonly used in France and Europe. Then, migration into artificial sweat of various FRs embedded into synthetic or commercially available polymer matrix was studied and evidenced. These results were analysed in the light of their potential effects on human health and the environment. Based on the migration's data, it is not possible to clearly rule out potential effects of FRs on human and environment health. Therefore, the authors consider that the use of FRs in domestic upholstery does not seem to be justified due to potential risks and a lack of clear benefits.
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Affiliation(s)
- Mohammed Lounis
- French Agency for Food, Environmental and Occupational Health Safety (ANSES), Risk Assessment Department, 14 rue Pierre Marie Curie, F-94701 Maisons-Alfort Cedex, France
| | - Stéphane Leconte
- French Agency for Food, Environmental and Occupational Health Safety (ANSES), Risk Assessment Department, 14 rue Pierre Marie Curie, F-94701 Maisons-Alfort Cedex, France.
| | - Christophe Rousselle
- French Agency for Food, Environmental and Occupational Health Safety (ANSES), Risk Assessment Department, 14 rue Pierre Marie Curie, F-94701 Maisons-Alfort Cedex, France
| | - Luc P Belzunces
- INRA, Laboratoire de Toxicologie Environnementale, UR 406 A&E, CS 40509, 84914 Avignon Cedex 9, France
| | - Valérie Desauziers
- Centre des Matériaux des Mines d'Alès (C2MA), IMT Mines Alès, 6 avenue de Clavières, 30319 Alès cedex, France
| | - José-Marie Lopez-Cuesta
- Centre des Matériaux des Mines d'Alès (C2MA), IMT Mines Alès, 6 avenue de Clavières, 30319 Alès cedex, France
| | - Jean Mario Julien
- Laboratoire national de métrologie et d'essais, Pôle chimie et physico-chimie des matériaux, 29, avenue Roger Hennequin, 78197 Trappes Cedex, France
| | - Dominique Guenot
- Unité de recherche EA 3430 - Progression tumorale et microenvironnement, Approches translationnelles et épidémiologie, Bâtiment Inserm U1113, 3 avenue Molière, 67200 Strasbourg, France
| | - Damien Bourgeois
- Laboratoire des Systèmes Hybrides pour la Séparation (LHYS), Institut de Chimie Séparative de Marcoule (UMR 5257 ICSM), Site de Marcoule, bat. 426, BP 17171, 30207 Bagnols sur Cèze Cedex, France
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Babayemi JO, Osibanjo O, Sindiku O, Weber R. Inventory and substance flow analysis of polybrominated diphenyl ethers in the Nigerian transport sector-end-of-life vehicles policy and management. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:31805-31818. [PMID: 27068907 DOI: 10.1007/s11356-016-6574-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2016] [Accepted: 03/27/2016] [Indexed: 04/16/2023]
Abstract
Recently, certain polybrominated diphenyl ethers (PBDEs) have been listed as persistent organic pollutants (POPs) in the Stockholm Convention. In this study, a preliminary material and substance flow analysis of commercial pentabromodiphenyl ether (c-PentaBDE) was conducted for motor vehicles-a major use sector for POP-PBDE in polyurethane (PUR) foam-for Nigeria. The methodology of the Stockholm Convention PBDE inventory guidance was used for the calculation of c-PentaBDE. Material/substance flow analysis was conducted applying the STAN software. The time frame for this analysis was 1980-2010, considering that this was the period when POP-PBDE-containing vehicles were largely imported into Nigeria.It is estimated that the approximately 19 million passenger cars imported from 1980 to 2010 contained ca. 270 t of POP-PBDEs in ca. 401,000 t of PUR foam. A major share of cars from the USA and only a small share of cars from Europe and Asia were impacted. This simplified material and substance flow of PUR foams and POP-PBDEs in motor vehicles demonstrated the potential for environmental/human contamination and pollution of recycling/reuse for Nigeria and other developing countries.The study developed the first preliminary inventory of end-of-life vehicles for Nigeria, following which the environment ministry has taken up the important issue of end-of-life vehicles management. Considering that a range of other pollutants are contained in vehicles (e.g. heavy metals, flame retardants, PCBs, chlorofluorocarbons, hydrofluorocarbons and waste oil), this initiated activity should finally lead to an integrated management of pollutants and resources from the transport sector.
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Affiliation(s)
- J O Babayemi
- Department of Chemistry, Faculty of Science, University of Ibadan, Ibadan, Nigeria
| | - O Osibanjo
- Department of Chemistry, Faculty of Science, University of Ibadan, Ibadan, Nigeria
- Basel Convention Coordinating Centre for Training and Technology Transfer for the African Region, University of Ibadan, 1 Ijoma Road, Ibadan, Nigeria
| | - O Sindiku
- Department of Chemistry, Faculty of Science, University of Ibadan, Ibadan, Nigeria
| | - R Weber
- POPs Environmental Consulting, Lindenfirststr. 23, 73527, Schwaebisch Gmuend, Germany.
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Nacci D, Clark B, La Guardia MJ, Miller K, Champlin D, Kirby I, Bertrand A, Jayaraman S. Bioaccumulation and effects of dietary exposure to the alternative flame retardant, bis(2-ethylhexyl) tetrabromophthalate (TBPH), in the Atlantic killifish, Fundulus heteroclitus. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2018; 37:2350-2360. [PMID: 29846010 PMCID: PMC6123825 DOI: 10.1002/etc.4180] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 02/05/2018] [Accepted: 05/29/2018] [Indexed: 05/23/2023]
Abstract
Bis(2-ethylhexyl) tetrabromophthalate (TBPH), a high production volume flame retardant chemical used as a replacement for banned flame retardants, has been detected in media and human and wildlife tissues globally. We describe bioaccumulation and biological effects from dietary exposure of TBPH to an estuarine fish, Atlantic killifish, Fundulus heteroclitus. Briefly, adult fish were fed carrier control or chemically amended diets for 28 d, followed by 14 d of control diet feeding. Diets were amended with TBPH (TBPH_LO diet, 139 μg/g dry wt, or TBPH_HI diet, 4360 μg/g dry wt) or a polychlorinated biphenyl congener (PCB153 diet, 13 μg/g dry wt), which was included as a positive control for bioaccumulation. Although bioaccumulation of either chemical correlated with fish size, only a small proportion of the TBPH offered (<0.5% total TBPH) had bioaccumulated into TBPH-treated fish by 28 d. In contrast, 24.5% of the PCB153 offered was accounted for in 28-d PCB-treated fish. Although 28-d bioaccumulated concentrations of TBPH differed by sex and treatment, sexes did not differ in their rates of TBPH bioaccumulation, and the time to achieve 50% of 28 d concentration (T1/2 ) was estimated to be 13 d. Depuration rates of TBPH did not differ by sex or treatment, and the time after exposure to achieve T1/2 was estimated to be 22 d. Independent of treatment, male fish grew faster than female fish, but for both sexes reproductive condition (gonadal somatic index) declined unexpectedly over the experimental period. Across treatments, only the TBPH_LO treatment affected growth, reducing male but increasing female growth rates by small amounts relative to respective controls. In summary, our study used very high concentrations of dietary TBPH to contaminate fish tissues above the highest levels reported to date in wild biota, yet we observed few adverse biological effects. Environ Toxicol Chem 2018;37:2350-2360. © 2018 SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.
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Affiliation(s)
- Diane Nacci
- Atlantic Ecology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Narragansett, Rhode Island, USA
| | - Bryan Clark
- Atlantic Ecology Division, Oak Ridge Institute for Science and Education, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Narragansett, Rhode Island, USA
| | - Mark J La Guardia
- Aquatic Health Sciences, Virginia Institute of Marine Science, College of William & Mary, Gloucester Point, Virginia, USA
| | - Ken Miller
- CSC Government Solutions, A CSRA Company, Alexandria, Virginia, USA
| | - Denise Champlin
- Atlantic Ecology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Narragansett, Rhode Island, USA
| | - Ian Kirby
- Atlantic Ecology Division, Student Services Contractor, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Narragansett, Rhode Island, USA
| | - Ashley Bertrand
- Atlantic Ecology Division, Student Services Contractor, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Narragansett, Rhode Island, USA
| | - Saro Jayaraman
- Atlantic Ecology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Narragansett, Rhode Island, USA
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Validation of an automated counting procedure for phthalate-induced testicular multinucleated germ cells. Toxicol Lett 2018; 290:55-61. [PMID: 29571896 DOI: 10.1016/j.toxlet.2018.03.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 03/06/2018] [Accepted: 03/18/2018] [Indexed: 12/12/2022]
Abstract
In utero exposure to certain phthalate esters results in testicular toxicity, characterized at the tissue level by induction of multinucleated germ cells (MNGs) in rat, mouse, and human fetal testis. Phthalate exposures also result in a decrease in testicular testosterone in rats. The anti-androgenic effects of phthalates have been more thoroughly quantified than testicular pathology due to the significant time requirement associated with manual counting of MNGs on histological sections. An automated counting method was developed in ImageJ to quantify MNGs in digital images of hematoxylin-stained rat fetal testis tissue sections. Timed pregnant Sprague Dawley rats were exposed by daily oral gavage from gestation day 17 to 21 with one of eight phthalate test compounds or corn oil vehicle. Both the manual counting method and the automated image analysis method identified di-n-butyl phthalate, butyl benzyl phthalate, dipentyl phthalate, and di-(2-ethylhexyl) phthalate as positive for induction of MNGs. Dimethyl phthalate, diethyl phthalate, the brominated phthalate di-(2-ethylhexyl) tetrabromophthalate, and dioctyl terephthalate were negative. The correlation between automated and manual scoring metrics was high (r = 0.923). Results of MNG analysis were consistent with these compounds' anti-androgenic activities, which were confirmed in an ex vivo testosterone production assay. In conclusion, we have developed a reliable image analysis method that can be used to facilitate dose-response studies for the reproducible induction of MNGs by in utero phthalate exposure.
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Ma WL, Li WL, Zhang ZF, Liu LY, Song WW, Huo CY, Yuan YX, Li YF. Occurrence and source apportionment of atmospheric halogenated flame retardants in Lhasa City in the Tibetan Plateau, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 607-608:1109-1116. [PMID: 28724249 DOI: 10.1016/j.scitotenv.2017.07.112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Revised: 07/12/2017] [Accepted: 07/12/2017] [Indexed: 06/07/2023]
Abstract
Active air samples were collected in Lhasa, one of the highest cities in the world (3650m above sea level) located in the Tibetan Plateau, and were analyzed for 38 halogenated flame retardants (HFRs), including polybrominated diphenyl ethers (PBDEs), non-PBDE brominated flame retardants (NBFRs) and dechlorane plus (DPs). The median concentrations of PBDEs, NBFRs and DPs were 40, 23 and 0.21pg/m3, respectively. Correlation analysis indicated the common source and/or similar environmental behavior for several HFRs. The Clausius-Clapeyron equation was applied to diagnose the sources of lower molecular weight HFRs (LMW-HFRs), which suggested that the gaseous LMW-HFRs at Lhasa were more controlled by regional or long-range atmospheric transport rather than the temperature-driven evaporation from local contaminated surfaces. Finally, the potential source contribution function model was applied to assess the influences of air parcels on the atmospheric concentrations of HFRs in Lhasa, which suggested that the sources of higher molecular weight HFRs (HMW-HFRs) were mostly originated from local emissions, while the others were originated from long-range atmospheric transport.
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Affiliation(s)
- Wan-Li Ma
- International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Wen-Long Li
- International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Zi-Feng Zhang
- International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Li-Yan Liu
- International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Wei-Wei Song
- International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Chun-Yan Huo
- International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Yi-Xing Yuan
- International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Yi-Fan Li
- International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; IJRC-PTS-NA, Toronto M2N 6X9, Canada.
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Ginsberg GL, Belleggia G. Use of Monte Carlo analysis in a risk-based prioritization of toxic constituents in house dust. ENVIRONMENT INTERNATIONAL 2017; 109:101-113. [PMID: 28890219 DOI: 10.1016/j.envint.2017.06.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 06/07/2017] [Accepted: 06/10/2017] [Indexed: 06/07/2023]
Abstract
Many chemicals have been detected in house dust with exposures to the general public and particularly young children of potential health concern. House dust is also an indicator of chemicals present in consumer products and the built environment that may constitute a health risk. The current analysis compiles a database of recent house dust concentrations from the United States and Canada, focusing upon semi-volatile constituents. Seven constituents from the phthalate and flame retardant categories were selected for risk-based screening and prioritization: diethylhexyl phthalate (DEHP), butyl benzyl phthalate (BBzP), diisononyl phthalate (DINP), a pentabrominated diphenyl ether congener (BDE-99), hexabromocyclododecane (HBCDD), tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) and tris(2-chloroethyl) phosphate (TCEP). Monte Carlo analysis was used to represent the variability in house dust concentration as well as the uncertainty in the toxicology database in the estimation of children's exposure and risk. Constituents were prioritized based upon the percentage of the distribution of risk results for cancer and non-cancer endpoints that exceeded a hazard quotient (HQ) of 1. The greatest percent HQ exceedances were for DEHP (cancer and non-cancer), BDE-99 (non-cancer) and TDCIPP (cancer). Current uses and the potential for reducing levels of these constituents in house dust are discussed. Exposure and risk for other phthalates and flame retardants in house dust may increase if they are used to substitute for these prioritized constituents. Therefore, alternative assessment and green chemistry solutions are important elements in decreasing children's exposure to chemicals of concern in the indoor environment.
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Affiliation(s)
- Gary L Ginsberg
- Department of Community Medicine, MPH Program, University of Connecticut Health Center School of Medicine, Farmington, CT, USA.
| | - Giuliana Belleggia
- Department of Community Medicine, MPH Program, University of Connecticut Health Center School of Medicine, Farmington, CT, USA
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Peng H, Sun J, Saunders DMV, Codling G, Wiseman S, Jones PD, Giesy JP. Hydroxylated 2-Ethylhexyl tetrabromobenzoate isomers in house dust and their agonistic potencies with several nuclear receptors. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 227:578-586. [PMID: 28505588 DOI: 10.1016/j.envpol.2017.04.094] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 04/28/2017] [Accepted: 04/29/2017] [Indexed: 06/07/2023]
Abstract
In the current study, by combining ultra-high resolution (UHR) MS1 spectra, MS2 spectra, and derivatization, three hydroxylated isomers of 2-ethylhexyl tetrabromobenzoate (OH-TBB) were identified in Firemaster® 550 and BZ-54 technical products. Also, a new LC-UHRMS method, using atmospheric pressure chemical ionization (APCI), was developed for simultaneous analysis of OH-TBB, TBB, hydroxylated bis(2-ethylhexyl)-tetrabromophthalate (OH-TBPH) and TBPH in 23 samples of dust collected from houses in Saskatoon, SK, Canada. OH-TBBs were detected in 91% of samples, with a geometric mean concentration of 0.21 ng/g, which was slightly less than those of OH-TBPH (0.35 ng/g). TBB was detected in 100% of samples of dust with a geometric mean concentration of 992 ng/g. Significant (p < 0.001) log-linear relationships between concentrations of OH-TBBs, TBB, or OH-TBPHs and TBPH in dust support the hypothesis of a common source of these compounds. OH-TBBs were found to be strong agonists of peroxisome proliferator-activated receptor gamma (PPARγ) and weaker agonists of the estrogen receptor (ER), but no agonistic potencies was observed with the androgen receptor (AR). Occurrence of OH-TBBs in technical products and house dust, together with their relatively strong PPARγ potencies, indicated their potential risk to health of humans.
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Affiliation(s)
- Hui Peng
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada
| | - Jianxian Sun
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada.
| | - David M V Saunders
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada
| | - Garry Codling
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada
| | - Steve Wiseman
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada
| | - Paul D Jones
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada; School of Environment and Sustainability, 117 Science Place, Saskatoon, SK, S7N 5C8, Canada
| | - John P Giesy
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada; Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, SK, S7N 5B3, Canada; Zoology Department, Center for Integrative Toxicology, Michigan State University, East Lansing, MI, USA; Department of Biology and Chemistry, City University of Hong Kong, Kowloon, People's Republic of China; School of Biological Sciences, University of Hong Kong, People's Republic of China; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, People's Republic of China
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Xiang P, Liu RY, Sun HJ, Yang YW, Cui XY, Ma LQ. Effects of novel brominated flame retardant TBPH and its metabolite TBMEHP on human vascular endothelial cells: Implication for human health risks. ENVIRONMENTAL RESEARCH 2017; 156:834-842. [PMID: 28318508 DOI: 10.1016/j.envres.2017.02.028] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 02/23/2017] [Accepted: 02/24/2017] [Indexed: 06/06/2023]
Abstract
As a replacement for polybrominated diphenyl ethers, bis-(2-ethylhexyl) tetrabromophthalate (TBPH) is widely used as a novel flame retardant and has been detected in many environmental matrix including human blood. TBPH can be metabolized into mono-(2-ethyhexyl) tetrabromophthalate (TBMEHP) by carboxylesterase. However, their adverse effects on human vascular endothelium and their potential impacts on human cardiovascular disease are unknown. In this study, their adverse effects and associated molecular mechanisms on human vascular endothelial cells (HUVECs) were investigated. A concentration-dependent inhibition on HUVECs' viability and growth was observed for TBMEHP but not for TBPH. TBMEHP induced a marked G0/G1 cell cycle arrest and robust cell apoptosis at 1μg/mL by inducing expression of p53, GADD45α and cyclin dependent kinase (CDK) inhibitors (p21and p27) while suppressing the expression of cyclin D1, CDK2, CDK6, and Bcl-2. Unlike TBMEHP, TBPH caused early apoptosis after G2/M phase arrest only at 10μg/mL via up-regulation of p21 and down-regulation of CDK2 and CDK4. TBMEHP decreased mitochondrial membrane potential and increased caspase-3 activity at 1μg/mL, suggesting that activation of p53 and mitochondrial pathway were involved in the cell apoptosis. The data showed that TBPH and TBMEHP induced different cell cycle arrest and apoptosis through different molecular mechanisms with much higher toxicity for TBMEHP. Our study implies that the metabolites of TBPH, possibly other novel brominated flame retardants, may be of potential concern for human cardiovascular disease.
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Affiliation(s)
- Ping Xiang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046, People's Republic of China
| | - Rong-Yan Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046, People's Republic of China
| | - Hong-Jie Sun
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046, People's Republic of China
| | - Yun-Wen Yang
- The State Key Laboratory of Pharmaceutical Biotechnology, College of Life Science, Nanjing University, Nanjing 210046, People's Republic of China
| | - Xin-Yi Cui
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046, People's Republic of China.
| | - Lena Q Ma
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046, People's Republic of China; Soil and Water Science Department, University of Florida, Gainesville, FL 32611, United States.
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Smythe TA, Butt CM, Stapleton HM, Pleskach K, Ratnayake G, Song CY, Riddell N, Konstantinov A, Tomy GT. Impacts of Unregulated Novel Brominated Flame Retardants on Human Liver Thyroid Deiodination and Sulfotransferation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:7245-7253. [PMID: 28541672 DOI: 10.1021/acs.est.7b01143] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The inhibitory effects of five novel brominated flame retardants, 1,2-bis(2,4,5-tribromophenoxy)ethane (BTBPE), decabromodiphenylethane (DBDPE), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB), bis(2-ethylhexyl)tetrabromophthalate (BEH-TEBP), and β-tetrabromoethylcyclohexane (β-TBECH), on thyroid hormone deiodinase (DIO) and sulfotransferase (SULT) activity were investigated using human in vitro liver microsomal and cytosolic bioassays. Enzymatic activity was measured by incubating active human liver subcellular fractions with thyroid hormones (T4 and rT3 separately) and measuring changes in thyroid hormone (T4, T3, rT3, and 3,3'-T2) concentrations. Only DBDPE showed inhibition of both outer and inner ring deiodination (O and IRD) of T3 and 3,3'-T2 formation from T4, respectively, with an estimated IC50 of 160 nM; no statistically significant inhibition of SULT activity was observed. ORD inhibition of 3,3'-T2 formation from rT3 was also observed (IC50 ∼ 100 nM). The kinetics of T4 O and IRD were also investigated, although a definitive mechanism could not be identified as the Michaelis-Menten parameters and maximal rate constants were not significantly different. Concentrations tested were intentionally above expected environmental levels, and this study suggests that these NBFRs are not potent human liver DIO and SULT inhibitors. To our knowledge, DBDPE is the first example of a nonhydroxylated contaminant inhibiting DIO activity, and further study of the mechanism of action is warranted.
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Affiliation(s)
- Tristan A Smythe
- Department of Chemistry, University of Manitoba , Winnipeg, MB R3T 2N2, Canada
| | - Craig M Butt
- Nicholas School of the Environment, Duke University , Durham, North Carolina 27708, United States
| | - Heather M Stapleton
- Nicholas School of the Environment, Duke University , Durham, North Carolina 27708, United States
| | - Kerri Pleskach
- Department of Fisheries and Oceans Canada, Freshwater Institute , Winnipeg, MB R3T 2N6, Canada
| | | | - Chae Yoon Song
- Department of Chemistry, McGill University , Montreal, QC H3A 0G4, Canada
| | - Nicole Riddell
- Wellington Laboratories, Inc. , 345 Southgate Drive, Guelph, ON N1G 3M5, Canada
| | - Alex Konstantinov
- Wellington Laboratories, Inc. , 345 Southgate Drive, Guelph, ON N1G 3M5, Canada
| | - Gregg T Tomy
- Department of Chemistry, University of Manitoba , Winnipeg, MB R3T 2N2, Canada
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Tung EWY, Ahmed S, Peshdary V, Atlas E. Firemaster® 550 and its components isopropylated triphenyl phosphate and triphenyl phosphate enhance adipogenesis and transcriptional activity of peroxisome proliferator activated receptor (Pparγ) on the adipocyte protein 2 (aP2) promoter. PLoS One 2017; 12:e0175855. [PMID: 28437481 PMCID: PMC5402942 DOI: 10.1371/journal.pone.0175855] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 03/31/2017] [Indexed: 01/10/2023] Open
Abstract
Firemaster® 550 (FM550) is a chemical mixture currently used as an additive flame retardant in commercial products, and is comprised of 2-ethylhexyl-2,3,4,5-tertrabromobenzoate (TBB), bis(2-ethylhexyl) tetrabromophthalate (TBPH), triphenyl phosphate (TPP), and isopropylated triphenyl phosphate (IPTP). Animal and in vitro studies suggest that FM550, TPP and IPTP may have adipogenic effects and may exert these effects through PPARγ activation. Using murine 3T3-L1 preadipocytes, we investigated the detailed expression of transcription factors and adipogenic markers in response to FM550 and its components. Further we investigated the mechanism of action of the peroxisome proliferator-activated receptor gamma (PPARγ) on downstream targets of the receptor by focussing on the mature adipocyte marker, adipocyte protein 2 (aP2). In addition, we set to elucidate the components responsible for the adipogenic effects seen in the FM550 mixture. We show that FM550 and its components TPP, IPTP, and TBPH, but not TBB induced lipid accumulation in a dose-dependent manner. Interestingly, despite displaying enhanced lipid accumulation, TBPH did not alter the mRNA or protein expression of terminal differentiation markers. In contrast, FM550, TPP, and IPTP treatment enhanced lipid accumulation, and mRNA and protein expression of terminal differentiation markers. To further delineate the mechanisms of action of FM550 and its components we focussed on aP2 promoter activity. For this purpose we used the enhancer region of the mouse aP2 promoter using a 584-bp reporter construct containing an active PPRE located 5.4 kb away from the transcription start site of aP2. Exposure to FM550, IPTP, and TPP significantly increased PPARγ mediated aP2 enhancer activity. Furthermore, we show that TPP- and IPTP-dependent upregulation of aP2 was significantly inhibited by the selective PPARγ antagonist GW9662. In addition, chromatin immunoprecipitation experiments showed that IPTP and TPP treatment led to the recruitment of PPARγ to the regulatory region of aP2.
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Affiliation(s)
- Emily W. Y. Tung
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
| | - Shaimaa Ahmed
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
| | - Vian Peshdary
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
| | - Ella Atlas
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
- * E-mail:
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Soubry A, Hoyo C, Butt CM, Fieuws S, Price TM, Murphy SK, Stapleton HM. Human exposure to flame-retardants is associated with aberrant DNA methylation at imprinted genes in sperm. ENVIRONMENTAL EPIGENETICS 2017; 3:dvx003. [PMID: 29492305 PMCID: PMC5804543 DOI: 10.1093/eep/dvx003] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 02/15/2017] [Accepted: 02/27/2017] [Indexed: 05/18/2023]
Abstract
Emerging evidence suggests that early exposure to endocrine disrupting chemicals has long-term consequences that can influence disease risk in offspring. During gametogenesis, imprinted genes are reasonable epigenetic targets with the ability to retain and transfer environmental messages. We hypothesized that exposures to organophosphate (OP) flame-retardants can alter DNA methylation in human sperm cells affecting offspring's health. Sperm and urine samples were collected from 67 men in North Carolina, USA. Urinary metabolites of a chlorinated OP, tris(1,3-dichloro-2-propyl) phosphate, and two non-chlorinated OPs, triphenyl phosphate and mono-isopropylphenyl diphenyl phosphate, were measured using liquid-chromatography tandem mass-spectrometry. Sperm DNA methylation at multiple CpG sites of the regulatory differentially methylated regions (DMRs) of imprinted genes GRB10, H19, IGF2, MEG3, NDN, NNAT, PEG1/MEST, PEG3, PLAGL1, SNRPN, and SGCE/PEG10 was quantified using bisulfite pyrosequencing. Regression models were used to determine potential associations between OP concentrations and DNA methylation. We found that men with higher concentrations of urinary OP metabolites, known to originate from flame-retardants, have a slightly higher fraction of sperm cells that are aberrantly methylated. After adjusting for age, obesity-status and multiple testing, exposure to mono-isopropylphenyl diphenyl phosphate was significantly related to hypermethylation at the MEG3, NDN, SNRPN DMRs. Exposure to triphenyl phosphate was associated with hypermethylation at the GRB10 DMR; and tris(1,3-dichloro-2-propyl) phosphate exposure was associated with altered methylation at the MEG3 and H19 DMRs. Although measured methylation differences were small, implications for public health can be substantial. Interestingly, our data indicated that a multiplicity of OPs in the human body is associated with increased DNA methylation aberrancies in sperm, compared to exposure to few OPs. Further research is required in larger study populations to determine if our findings can be generalized.
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Affiliation(s)
- Adelheid Soubry
- Epidemiology Research Unit, Faculty of Medicine, Department of Public Health and Primary Care, KU Leuven, Kapucijnenvoer 35, Blok D, Box 7001, University of Leuven, Leuven, Belgium
| | - Cathrine Hoyo
- Department of Biological Sciences, Center for Human Health and the Environment, North Carolina State University, Campus Box 7633, Raleigh, NC 27633, USA
| | - Craig M. Butt
- Nicholas School of the Environment, Duke University, Box 90328, 450 Research Drive, Durham, NC 27708, USA
| | - Steffen Fieuws
- L-Biostat, Faculty of Medicine, Department of Public Health and Primary Care, KU Leuven - University of Leuven, Kapucijnenvoer 35, Leuven, Belgium
| | - Thomas M. Price
- Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Duke University Medical Center, Box 3143, Durham, NC 27713, USA
| | - Susan K. Murphy
- Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Duke University Medical Center, Box 91012, B223 LSRC, 450 Research Drive, Durham, NC 27708, USA
| | - Heather M. Stapleton
- Nicholas School of the Environment, Duke University, Box 90328, 450 Research Drive, Durham, NC 27708, USA
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Hoffman K, Sosa JA, Stapleton HM. Do flame retardant chemicals increase the risk for thyroid dysregulation and cancer? Curr Opin Oncol 2017; 29:7-13. [PMID: 27755165 PMCID: PMC10037316 DOI: 10.1097/cco.0000000000000335] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE OF REVIEW Flame retardant chemicals are added to consumer products to reduce fire incidence and severity; approximately 1.5 million tons of these chemicals are used annually. However, their widespread use has led to their ubiquitous presence in the environment and chronic accumulation in human tissues. We summarize current trends in human flame retardant chemical exposure, and review recent data highlighting concerns for thyroid dysregulation and cancer risk in human populations. RECENT FINDINGS Polybrominated diphenyl ethers were once commonly used as flame retardant chemicals, but recently were phased out. Exposure is associated with thyroid dysregulation (mainly T4 reductions) in animals, with new work focusing on specific mechanisms of action. Polybrominated diphenyl ethers also impact human thyroid regulation and are related to clinical thyroid disease, but associations appear both dose and life-stage dependent. Emerging data suggest that common alternate flame retardant chemicals may be more potent thyroid disruptors than their predecessors, which is particularly concerning given increasing levels of exposure. SUMMARY Potential health impacts of flame retardant chemicals are only beginning to be understood for 'legacy flame retardant chemicals' (i.e., polybrominated diphenyl ethers), and are largely unevaluated for newer-use chemicals. Cumulatively, current data suggest impact on thyroid regulation is likely, potentially implicating flame retardant chemicals in thyroid disease and cancers for which thyroid dysregulation impacts risk or prognosis.
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Affiliation(s)
- Kate Hoffman
- aNicholas School of the Environment, Duke University bDepartments of Surgery and Medicine cDuke Cancer Institute and Duke Clinical Research Institute, Duke University Medical Center, Durham, North Carolina, USA
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Haggard DE, Das SR, Tanguay RL. Comparative Toxicogenomic Responses to the Flame Retardant mITP in Developing Zebrafish. Chem Res Toxicol 2016; 30:508-515. [PMID: 27957850 DOI: 10.1021/acs.chemrestox.6b00423] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Monosubstituted isopropylated triaryl phosphate (mITP) is a major component of Firemaster 550, an additive flame retardant mixture commonly used in polyurethane foams. Developmental toxicity studies in zebrafish established mITP as the most toxic component of FM 550, which causes pericardial edema and heart looping failure. Mechanistic studies showed that mITP is an aryl hydrocarbon receptor (AhR) ligand; however, the cardiotoxic effects of mITP were independent of the AhR. We performed comparative whole genome transcriptomics in wild-type and ahr2hu3335 zebrafish, which lack functional ahr2, to identify transcriptional signatures causally involved in the mechanism of mITP-induced cardiotoxicity. Regardless of ahr2 status, mITP exposure resulted in decreased expression of transcripts related to the synthesis of all-trans-retinoic acid and a host of Hox genes. Clustered gene ontology enrichment analysis showed unique enrichment in biological processes related to xenobiotic metabolism and response to external stimuli in wild-type samples. Transcript enrichments overlapping both genotypes involved the retinoid metabolic process and sensory/visual perception biological processes. Examination of the gene-gene interaction network of the differentially expressed transcripts in both genetic backgrounds demonstrated a strong AhR interaction network specific to wild-type samples, with overlapping genes regulated by retinoic acid receptors (RARs). A transcriptome analysis of control ahr2-null zebrafish identified potential cross-talk among AhR, Nrf2, and Hif1α. Collectively, we confirmed that mITP is an AhR ligand and present evidence in support of our hypothesis that mITP's developmental cardiotoxic effects are mediated by inhibition at the RAR level.
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Affiliation(s)
- Derik E Haggard
- Department of Environmental and Molecular Toxicology, Oregon State University , Corvallis, Oregon 97333, United States
| | - Siba R Das
- Pacific Northwest Diabetes Research Institute , Seattle, Washington 98122, United States
| | - Robert L Tanguay
- Department of Environmental and Molecular Toxicology, Oregon State University , Corvallis, Oregon 97333, United States
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Peng H, Saunders DMV, Sun J, Jones PD, Wong CKC, Liu H, Giesy JP. Mutagenic Azo Dyes, Rather Than Flame Retardants, Are the Predominant Brominated Compounds in House Dust. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:12669-12677. [PMID: 27934287 DOI: 10.1021/acs.est.6b03954] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Characterization of toxicological profiles by use of traditional targeted strategies might underestimate the risk of environmental mixtures. Unbiased identification of prioritized compounds provides a promising strategy for meeting regulatory needs. In this study, untargeted screening of brominated compounds in house dust was conducted using a data-independent precursor isolation and characteristic fragment (DIPIC-Frag) approach, which used data-independent acquisition (DIA) and a chemometric strategy to detect peaks and align precursor ions. A total of 1008 brominated compound peaks were identified in 23 house dust samples. Precursor ions and formulas were identified for 738 (73%) of the brominated compounds. A correlation matrix was used to cluster brominated compounds; three large groups were found for the 140 high-abundance brominated compounds, and only 24 (17%) of these compounds were previously known flame retardants. The predominant class of unknown brominated compounds was predicted to consist of nitrogen-containing compounds. Following further validation by authentic standards, these compounds (56%) were determined to be novel brominated azo dyes. The mutagenicity of one major component was investigated, and mutagenicity was observed at environmentally relevant concentrations. Results of this study demonstrated the existence of numerous unknown brominated compounds in house dust, with mutagenic azo dyes unexpectedly being identified as the predominant compounds.
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Affiliation(s)
- Hui Peng
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada
| | - David M V Saunders
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada
| | - Jianxian Sun
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada
| | - Paul D Jones
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada
- School of Environment and Sustainability, University of Saskatchewan , 117 Science Place, Saskatoon, SK S7N 5C8, Canada
| | - Chris K C Wong
- Department of Biology, Croucher Institute for Environmental Sciences, Hong Kong Baptist University , Hong Kong, China
| | - Hongling Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Nanjing, People's Republic of China
| | - John P Giesy
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Nanjing, People's Republic of China
- Center for Integrative Toxicology, Zoology Department, Michigan State University , 1129 Farm Lane Road, East Lansing, Michigan 48824, United States
- School of Biological Sciences, University of Hong Kong , Hong Kong Special Administrative Region, People's Republic of China
- Department of Veterinary Biomedical Sciences, University of Saskatchewan , Saskatoon, Saskatchewan, Canada S7N 5B3
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Frederiksen M, Vorkamp K, Jensen NM, Sørensen JA, Knudsen LE, Sørensen LS, Webster TF, Nielsen JB. Dermal uptake and percutaneous penetration of ten flame retardants in a human skin ex vivo model. CHEMOSPHERE 2016; 162:308-314. [PMID: 27513551 DOI: 10.1016/j.chemosphere.2016.07.100] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 07/28/2016] [Accepted: 07/29/2016] [Indexed: 06/06/2023]
Abstract
The dermal uptake and percutaneous penetration of ten organic flame retardants was measured using an ex vivo human skin model. The studied compounds were DBDPE, BTBPE, TBP-DBPE, EH-TBB, BEH-TEBP, α, β and γ-HBCDD as well as syn- and anti-DDC-CO. Little or none of the applied flame retardants was recovered in either type of the receptor fluids used (physiological and worst-case). However, significant fractions were recovered in the skin depot, particularly in the upper skin layers. The primary effect of the worst-case receptor fluid was deeper penetration into the skin. The recovered mass was used to calculate lower- and upper-bound permeability coefficients kp. Despite large structural variation between the studied compounds, a clear, significant decreasing trend of kp was observed with increasing log Kow. The results indicate that the dermis may provide a significant barrier for these highly lipophilic compounds. However, based on our results, dermal uptake should be considered in exposure assessments, though it may proceed in a time-lagged manner compared to less hydrophobic compounds.
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Affiliation(s)
- Marie Frederiksen
- Danish Building Research Institute, Aalborg University, A.C. Meyers Vænge 15, 2450 Copenhagen SV, Denmark.
| | - Katrin Vorkamp
- Department of Environmental Science, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Niels Martin Jensen
- Department of Plastic and Reconstructive Surgery, Odense University Hospital, Sdr. Boulevard 29, 5000 Odense C, Denmark
| | - Jens Ahm Sørensen
- Department of Plastic and Reconstructive Surgery, Odense University Hospital, Sdr. Boulevard 29, 5000 Odense C, Denmark
| | - Lisbeth E Knudsen
- Department of Public Health, University of Copenhagen, Øster Farimagsgade 5A, 2100 Copenhagen Ø, Denmark
| | - Lars S Sørensen
- Danish Building Research Institute, Aalborg University, A.C. Meyers Vænge 15, 2450 Copenhagen SV, Denmark
| | - Thomas F Webster
- Department of Environmental Health, Boston University School of Public Health, 715 Albany St, Boston, MA 02118, USA
| | - Jesper B Nielsen
- Department of Public Health, University of Southern Denmark, J.B. Winsløws Vej 9B, 5000 Odense C, Denmark
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Klopčič I, Skledar DG, Mašič LP, Dolenc MS. Comparison of in vitro hormone activities of novel flame retardants TBB, TBPH and their metabolites TBBA and TBMEPH using reporter gene assays. CHEMOSPHERE 2016; 160:244-51. [PMID: 27380226 DOI: 10.1016/j.chemosphere.2016.06.091] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 06/22/2016] [Accepted: 06/24/2016] [Indexed: 05/02/2023]
Abstract
The anti-androgenic and anti-thyroid hormonal activities of the two novel brominated flame retardants, TBB and TBPH and of their metabolites TBBA and TBMEPH have been compared using the luciferase reporter gene assays. Only the parent compounds TBB and TBPH exhibited anti-glucocorticoid activity with IC50 values of 1.9 μM and 0.3 μM. Furthermore, mode of action for these two compounds is by direct competing to the glucocorticoid receptor (GR) with IC50 values of 0.03 μM and 0.002 μM. All four tested compounds possess anti-androgenic and anti-thyroid hormonal activities, without agonist activities on the respective receptors. Anti-androgenic activities with IC50 values of 43.5 μM, 0.1 μM, 47.5 μM and 1.3 μM were found for TBB, TBPH, TBBA and TBMEPH. The anti-thyroid hormonal IC50 values of 37.5 μM, 0.1 μM, 22.8 μM and 32.3 μM for TBB, TBPH, TBBA and TBMEPH, together with the above quoted results, indicate that metabolism can modify anti-androgenic, anti-glucocorticoid and anti-thyroid hormonal effects of these novel brominated flame retardants. Furthermore, the parent flame retardants are shown to be able to disrupt the function of the GR as antagonists by direct competition to the receptor.
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Affiliation(s)
- Ivana Klopčič
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000 Ljubljana, Slovenia
| | - Darja Gramec Skledar
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000 Ljubljana, Slovenia
| | | | - Marija Sollner Dolenc
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000 Ljubljana, Slovenia.
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Carignan CC, Fang M, Stapleton HM, Heiger-Bernays W, McClean MD, Webster TF. Urinary biomarkers of flame retardant exposure among collegiate U.S. gymnasts. ENVIRONMENT INTERNATIONAL 2016; 94:362-368. [PMID: 27395335 PMCID: PMC4980234 DOI: 10.1016/j.envint.2016.06.030] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 06/01/2016] [Accepted: 06/26/2016] [Indexed: 05/22/2023]
Abstract
Flame retardants are widely used in polyurethane foam materials including gymnastics safety equipment such as pit cubes and landing mats. We previously reported elevated concentrations of flame retardants in the air and dust of a U.S. gymnastics training facility and elevated PentaBDE in the serum of collegiate gymnasts. Our objective in this pilot study was to compare urinary biomarkers of exposure to other flame retardants and additives of polyurethane foam including tris(1,3-dichloro-2-propyl) phosphate (TDCIPP), triphenyl phosphate (TPHP) and 2-ethylhexyl- 2,3,4,5-tetrabromobenzoate (EH-TBB) in samples collected from 11 collegiate gymnasts before and after a gymnastics practice (n=53 urine samples total). We identified a 50% increase in the TPHP biomarker (p=0.03) from before to after practice, a non-significant 22% increase in the TDCIPP biomarker (p=0.14) and no change for the EH-TBB biomarker. These preliminary results indicate that the gymnastics training environment can be a source of recreational exposure to flame retardants. Such exposures are likely widespread, as we identified flame retardants in 89% of foam samples collected from gyms across the U.S.
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Affiliation(s)
- Courtney C Carignan
- Department of Environmental Health, Boston University School of Public Health, Boston, MA, USA; Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA.
| | - Mingliang Fang
- Nicholas School of the Environment, Duke University, Durham, NC, USA; School of Civil and Environmental Engineering, Nanyang Technological University, Singapore.
| | | | - Wendy Heiger-Bernays
- Department of Environmental Health, Boston University School of Public Health, Boston, MA, USA.
| | - Michael D McClean
- Department of Environmental Health, Boston University School of Public Health, Boston, MA, USA.
| | - Thomas F Webster
- Department of Environmental Health, Boston University School of Public Health, Boston, MA, USA.
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Gramec Skledar D, Tomašič T, Carino A, Distrutti E, Fiorucci S, Peterlin Mašič L. New brominated flame retardants and their metabolites as activators of the pregnane X receptor. Toxicol Lett 2016; 259:116-123. [DOI: 10.1016/j.toxlet.2016.08.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 08/01/2016] [Accepted: 08/05/2016] [Indexed: 01/30/2023]
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Watt J, Webster TF, Schlezinger JJ. Generalized Concentration Addition Modeling Predicts Mixture Effects of Environmental PPARγ Agonists. Toxicol Sci 2016; 153:18-27. [PMID: 27255385 DOI: 10.1093/toxsci/kfw100] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The vast array of potential environmental toxicant combinations necessitates the development of efficient strategies for predicting toxic effects of mixtures. Current practices emphasize the use of concentration addition to predict joint effects of endocrine disrupting chemicals in coexposures. Generalized concentration addition (GCA) is one such method for predicting joint effects of coexposures to chemicals and has the advantage of allowing for mixture components to have differences in efficacy (ie, dose-response curve maxima). Peroxisome proliferator-activated receptor gamma (PPARγ) is a nuclear receptor that plays a central role in regulating lipid homeostasis, insulin sensitivity, and bone quality and is the target of an increasing number of environmental toxicants. Here, we tested the applicability of GCA in predicting mixture effects of therapeutic (rosiglitazone and nonthiazolidinedione partial agonist) and environmental PPARγ ligands (phthalate compounds identified using EPA's ToxCast database). Transcriptional activation of human PPARγ1 by individual compounds and mixtures was assessed using a peroxisome proliferator response element-driven luciferase reporter. Using individual dose-response parameters and GCA, we generated predictions of PPARγ activation by the mixtures, and we compared these predictions with the empirical data. At high concentrations, GCA provided a better estimation of the experimental response compared with 3 alternative models: toxic equivalency factor, effect summation and independent action. These alternatives provided reasonable fits to the data at low concentrations in this system. These experiments support the implementation of GCA in mixtures analysis with endocrine disrupting compounds and establish PPARγ as an important target for further studies of chemical mixtures.
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Affiliation(s)
- James Watt
- Boston University School of Public Health, Boston, Massachusetts 02118
| | - Thomas F Webster
- Boston University School of Public Health, Boston, Massachusetts 02118
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