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Hong X, Yuan L, Zhao X, Shan Y, Qin T, Li J, Zha J. Embryonic Exposure to Organophosphate Flame Retardants (OPFRs) Differentially Induces Cardiotoxicity in Rare Minnow ( Gobiocypris rarus). ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024. [PMID: 39069658 DOI: 10.1021/acs.est.4c01927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
Organophosphorus flame retardants (OPFRs) such as triphenyl phosphate (TPHP) and tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) were reported to impair cardiac function in fish. However, limited information is available regarding their cardiotoxic mechanisms. Using rare minnow (Gobiocypris rarus) as a model, we found that both TPHP and TDCIPP exposures decreased heart rate at 96 h postfertilization (hpf) in embryos. Atropine (an mAChR antagonist) can significantly attenuate the bradycardia caused by TPHP, but only marginally attenuated in TDCIPP treatment, suggesting that TDCIPP-induced bradycardia is independent of mAChR. Unlike TDCIPP, although TPHP-induced bradycardia could be reversed by transferring larvae to a clean medium, the inhibitory effect of AChE activity persisted compared to 96 hpf, indicating the existence of other bradycardia regulatory mechanisms. Transcriptome profiling revealed cardiotoxicity-related pathways in treatments at 24 and 72 hpf in embryos/larvae. Similar transcriptional alterations were also confirmed in the hearts of adult fish. Further studies verified that TPHP and TDCIPP can interfere with Na+/Ca2+ transport and lead to disorders of cardiac excitation-contraction coupling in larvae. Our findings provide useful clues for unveiling the differential cardiotoxic mechanisms of OPFRs and identifying abnormal Na+/Ca2+ transport as one of a select few known factors sufficient to impair fish cardiac function.
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Affiliation(s)
- Xiangsheng Hong
- National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Lilai Yuan
- Fishery Resource and Environment Research Center, Chinese Academy of Fishery Sciences, Beijing 100141, China
| | - Xu Zhao
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Environmental Protection of the People's Republic of China, Guangzhou 510655, China
| | - Yuan Shan
- National Fisheries Technology Extension Center and China Society of Fisheries, Beijing 100125, China
| | - Tianlong Qin
- Aquatic Technology Promotion Guidance Center for Wuhan, 821 Development Avenue, Jiangan District, Wuhan 430014, China
| | - Jiasu Li
- National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Jinmiao Zha
- National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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2
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Yu Z, Zhang Y, Kong R, Xiao Y, Li B, Liu C, Yu L. Tris(1,3-dichloro-2-propyl) Phosphate Inhibits Early Embryonic Development by Binding to Gsk-3β Protein in Zebrafish. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2023; 260:106588. [PMID: 37267805 DOI: 10.1016/j.aquatox.2023.106588] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/21/2023] [Accepted: 05/23/2023] [Indexed: 06/04/2023]
Abstract
Recently, several studies have reported that exposure to tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) results in abnormal development of zebrafish embryos in blastocyst and gastrula stages, but molecular mechanisms are still not clear. This lacking strongly affects the interspecific extrapolation of embryonic toxicity induced by TDCIPP and hazard evaluation. In this study, zebrafish embryos were exposed to 100, 500 or 1000 μg/L TDCIPP, and 6-bromoindirubin-3'-oxime (BIO, 35.62 μg/L) was used as a positive control. Results demonstrated that treatment with TDCIPP or BIO caused an abnormal stacking of blastomere cells in mid blastula transition (MBT) stage, and subsequently resulted in epiboly delay of zebrafish embryos. TDCIPP and BIO up-regulated the expression of β-catenin protein and increased its accumulation in nuclei of embryonic cells. This accumulation was considered as a driver for early embryonic developmental toxicity of TDCIPP. Furthermore, TDCIPP and BIO partly shared the same modes of action, and both of them could bind to Gsk-3β protein, and then decreased the phosphorylation level of Gsk-3β in TYR·216 site and lastly inhibited the activity of Gsk-3β kinase, which was responsible for the increased concentrations of β-catenin protein in embryonic cells and accumulation in nuclei. Our findings provide new mechanisms for clarifying the early embryonic developmental toxicity of TDCIPP in zebrafish.
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Affiliation(s)
- Zichen Yu
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Yongkang Zhang
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Ren Kong
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, China
| | - Yongjie Xiao
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Boqun Li
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Chunsheng Liu
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, China.
| | - Liqin Yu
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China.
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Chen Y, Wang J, Yu Z, Xiao L, Xu J, Zhao K, Zhang H, Shang X, Liu C. Transcriptomic and metabolomic analyses revealed epiboly delayed mechanisms of 2,5-dichloro-1, 4-benuinone on zebrafish embryos. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023:10.1007/s11356-023-27145-4. [PMID: 37165267 DOI: 10.1007/s11356-023-27145-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 04/17/2023] [Indexed: 05/12/2023]
Abstract
2,5-Dichloro-1,4-benzenediol (2,5-DCBQ) is a putative disinfection by-product that belongs to the halogenated benzoquinone class. However, its developmental toxicity and related mechanism remained unclarified. In our study, we used zebrafish embryos as the model and exposed them to graded concentrations of 2,5-DCBQ (100, 200, 300, 400 μg/L). We found that the rate of epiboly abnormalities increased significantly in a concentration-dependent manner. The results of whole-mount in situ hybridization (WISH) indicated that the expression patterns and levels of chordin (dorsoventral marker), foxa2 (endodermal marker), eve1 (ventral mesodermal marker), and foxb1a (ectodermal marker) were altered, suggesting that 2,5-DCBQ might affect the germ layer development of zebrafish embryos. Integrated transcriptomic and metabolomic analyses were adopted to explore the molecular mechanisms of embryonic developmental delays. The results showed that 2,5-DCBQ exposure induced 1163 differentially expressed genes (DEGs) and 37 differential metabolites (DEMs). Bioinformatic analysis enriched the most affected molecular pathways (Wnt signaling pathway, cell adhesion molecules, actin cytoskeleton regulation) and metabolic pathways (purine metabolism, aminoacyl-tRNA biosynthesis, arginine and proline metabolism) in zebrafish embryos. To summarize, our findings broadened the molecular mechanisms of 2,5-DCBQ embryotoxicity through multi-omics and bioinformatic analyses.
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Affiliation(s)
- Yuanyao Chen
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Qiaokou District, Wuhan, 430030, People's Republic of China
| | - Jingming Wang
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Qiaokou District, Wuhan, 430030, People's Republic of China
| | - Zhiquan Yu
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Qiaokou District, Wuhan, 430030, People's Republic of China
| | - Lin Xiao
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Qiaokou District, Wuhan, 430030, People's Republic of China
| | - Jia Xu
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Qiaokou District, Wuhan, 430030, People's Republic of China
| | - Kai Zhao
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Qiaokou District, Wuhan, 430030, People's Republic of China
| | - Huiping Zhang
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Qiaokou District, Wuhan, 430030, People's Republic of China
| | - Xuejun Shang
- Department of Andrology, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, 210002, People's Republic of China
| | - Chunyan Liu
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Qiaokou District, Wuhan, 430030, People's Republic of China.
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Dou M, Wang L. A review on organophosphate esters: Physiochemical properties, applications, and toxicities as well as occurrence and human exposure in dust environment. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 325:116601. [PMID: 36326529 DOI: 10.1016/j.jenvman.2022.116601] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 10/14/2022] [Accepted: 10/20/2022] [Indexed: 06/16/2023]
Abstract
Organophosphate esters (OPEs) are widely used as flame retardants and plasticizers in the world. The use of OPEs has increased rapidly due to the prohibition of polybrominated diphenyl ethers. However, OPEs are mainly added to various materials by physical mixing, they are therefore easy to be released into the environment through volatilization, leaching, and abrasion during their production, use, transportation, and after disposal. Dust, as an important medium for human exposure to OPEs, has attracted extensive attention. Here, this article reviewed the current knowledge on the physiochemical properties, consumptions and applications, and ecotoxicities of OPEs, also synthesized the available data on the occurrence of 13 OPEs in outdoor and indoor dust environments around the world over the past decade. The results showed that the sum of OPEs (ΣOPEs) was the highest in outdoor dust from an e-waste disposal area in Tianjin of China (range: 1390-42700 ng/g dw; mean: 11500 ng/g dw). The highest ΣOPEs was found in Japan for home dust (range: 9300-11000000 ng/g dw; mean: 266543 ng/g dw), Sweden for office dust (range: 14000-1600000 ng/g dw; mean: 360100 ng/g dw) and daycare center dust (range: 40000-4600000 ng/g dw; mean: 1990800 ng/g dw), and Brazil for car dust (range: 108000-2050000 ng/g dw; mean: 541000 ng/g dw). The use pattern of OPEs differed in different regions and countries. The exposure and risk assessment based on the data of OPEs in home dust indicated that the average daily intakes of OPEs via dust ingestion for children and adults were lower than the corresponding reference doses; and that the current human exposure to OPEs through indoor dust ingestion were not likely to pose risks to human health. Finally, the review pointed out the gaps of current research and provided the directions for further study on OPEs in dust environment.
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Affiliation(s)
- Mingshan Dou
- Department of Environmental Science and Engineering, School of Geography and Tourism, Shaanxi Normal University, Xi'an, 710119, China
| | - Lijun Wang
- Department of Environmental Science and Engineering, School of Geography and Tourism, Shaanxi Normal University, Xi'an, 710119, China.
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Avila-Barnard S, Dasgupta S, Cheng V, Reddam A, Wiegand JL, Volz DC. Tris(1,3-dichloro-2-propyl) phosphate disrupts the trajectory of cytosine methylation within developing zebrafish embryos. ENVIRONMENTAL RESEARCH 2022; 211:113078. [PMID: 35248566 PMCID: PMC9177764 DOI: 10.1016/j.envres.2022.113078] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 03/01/2022] [Accepted: 03/02/2022] [Indexed: 05/04/2023]
Abstract
Tris (1,3-dichloro-2-propyl) phosphate (TDCIPP) is an organophosphate ester-based flame retardant widely used within the United States. Within zebrafish, initiation of TDCIPP exposure at 0.75 h post-fertilization (hpf) reliably disrupts cytosine methylation from cleavage (2 hpf) through early-gastrulation (6 hpf). Therefore, the objective of this study was to determine whether TDCIPP-induced effects on cytosine methylation persist beyond 6 hpf. First, we exposed embryos to vehicle or TDCIPP from 0.75 hpf to 6, 24, or 48 hpf, and then conducted bisulfite amplicon sequencing of a target locus (lmo7b) using genomic DNA derived from whole embryos. Within both vehicle- and TDCIPP-treated embryos, CpG methylation was similar at 6 hpf and CHG/CHH methylation were similar at 24 and 48 hpf (relative to 6 hpf). However, relative to 6 hpf within the same treatment, CpG methylation was lower within vehicle-treated embryos at 48 hpf and TDCIPP-treated embryos at 24 and 48 hpf - an effect that was driven by acceleration of CpG hypomethylation. Similar to our previous findings with DNA methyltransferase, we found that, even at high μM concentrations, TDCIPP had no effect on zebrafish and human thymine DNA glycosylase activity (a key enzyme that decreases CpG methylation), suggesting that TDCIPP-induced effects on CpG methylation are not driven by direct interaction with thymine DNA glycosylase. Finally, using 5-methylcytosine (5-mC)-specific whole-mount immunochemistry and automated imaging, we found that exposure to TDCIPP increased 5-mC abundance within the yolk of blastula-stage embryos, suggesting that TDCIPP may impact cytosine methylation of maternally loaded mRNAs during the maternal-to-zygotic transition. Overall, our findings suggest that TDCIPP disrupts the trajectory of cytosine methylation during zebrafish embryogenesis, effects which do not appear to be driven by direct interaction of TDCIPP with key enzymes that regulate cytosine methylation.
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Affiliation(s)
- Sarah Avila-Barnard
- Department of Environmental Sciences, University of California, Riverside, CA, USA
| | - Subham Dasgupta
- Department of Environmental Sciences, University of California, Riverside, CA, USA
| | - Vanessa Cheng
- Department of Environmental Sciences, University of California, Riverside, CA, USA
| | - Aalekhya Reddam
- Department of Environmental Sciences, University of California, Riverside, CA, USA
| | - Jenna L Wiegand
- Department of Environmental Sciences, University of California, Riverside, CA, USA
| | - David C Volz
- Department of Environmental Sciences, University of California, Riverside, CA, USA.
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Occurrence, Distribution, and Risk of Organophosphate Flame Retardants in Sediments from Jiulong River Estuary and Adjacent Western Taiwan Strait, China. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19042449. [PMID: 35206636 PMCID: PMC8872513 DOI: 10.3390/ijerph19042449] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 02/12/2022] [Accepted: 02/18/2022] [Indexed: 02/04/2023]
Abstract
Organophosphate ester flame retardants (OPFRs) are widely prevalent in the environment and are of significant concern because of their potential toxicity to human health and wildlife. In this study, the concentration, frequency, spatial distribution, potential sources, and ecological risks of OPFRs in sediments from the Jiulong River estuary and the adjacent western Taiwan Strait were investigated. Concentrations of four of the five studied OPFRs were between <LOD and 36.6 ng/g. The distribution of all OPFRs, except 2-Ethylhexyl diphenyl phosphate (EHDPP), remained highly consistent with hydrological (salinity) trends. Furthermore, a significantly positive correlation between EHDPP and total concentrations suggested that it may be the dominant contaminant at both sites. Principal element analysis indicated multiple sources of OPFRs, which were categorized as emissions from road runoff and surface traffic, effects of atmospheric deposition and hydrologic conditions, and a combination of industrial and population effects. Ecological risk indicates that tris (chloroethyl) phosphate (TCEP) and triphosphate ester (2,3-dibromopropyl) (TDBPP) have almost no risk, tris (clorisopropyl) phosphate (TCPP) generally has low risk, while EHDPP has moderate risk with the highest value of 0.487 in the sediments from both sites. Meanwhile, TCPP and TCEP exhibit lower theoretical health risks but are still not negligible. Overall, this work provides data to support global pollutant studies and facilitate the implementation of pollutant control strategies.
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Shankar P, McClure RS, Waters KM, Tanguay RL. Gene co-expression network analysis in zebrafish reveals chemical class specific modules. BMC Genomics 2021; 22:658. [PMID: 34517816 PMCID: PMC8438978 DOI: 10.1186/s12864-021-07940-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 08/15/2021] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Zebrafish is a popular animal model used for high-throughput screening of chemical hazards, however, investigations of transcriptomic mechanisms of toxicity are still needed. Here, our goal was to identify genes and biological pathways that Aryl Hydrocarbon Receptor 2 (AHR2) Activators and flame retardant chemicals (FRCs) alter in developing zebrafish. Taking advantage of a compendium of phenotypically-anchored RNA sequencing data collected from 48-h post fertilization (hpf) zebrafish, we inferred a co-expression network that grouped genes based on their transcriptional response. RESULTS Genes responding to the FRCs and AHR2 Activators localized to distinct regions of the network, with FRCs inducing a broader response related to neurobehavior. AHR2 Activators centered in one region related to chemical stress responses. We also discovered several highly co-expressed genes in this module, including cyp1a, and we subsequently show that these genes are definitively within the AHR2 signaling pathway. Systematic removal of the two chemical types from the data, and analysis of network changes identified neurogenesis associated with FRCs, and regulation of vascular development associated with both chemical classes. We also identified highly connected genes responding specifically to each class that are potential biomarkers of exposure. CONCLUSIONS Overall, we created the first zebrafish chemical-specific gene co-expression network illuminating how chemicals alter the transcriptome relative to each other. In addition to our conclusions regarding FRCs and AHR2 Activators, our network can be leveraged by other studies investigating chemical mechanisms of toxicity.
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Affiliation(s)
- Prarthana Shankar
- Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory, 28645 East Highway 34, Oregon State University, Corvallis, OR, 97331, USA
| | - Ryan S McClure
- Biological Sciences Division, Pacific National Northwest Laboratory, 902 Battelle Boulevard, P.O. Box 999, Richland, WA, 99352, USA
| | - Katrina M Waters
- Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory, 28645 East Highway 34, Oregon State University, Corvallis, OR, 97331, USA.,Biological Sciences Division, Pacific National Northwest Laboratory, 902 Battelle Boulevard, P.O. Box 999, Richland, WA, 99352, USA
| | - Robyn L Tanguay
- Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory, 28645 East Highway 34, Oregon State University, Corvallis, OR, 97331, USA.
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Chen MH, Ma WL. A review on the occurrence of organophosphate flame retardants in the aquatic environment in China and implications for risk assessment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 783:147064. [PMID: 34088162 DOI: 10.1016/j.scitotenv.2021.147064] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 04/01/2021] [Accepted: 04/02/2021] [Indexed: 05/28/2023]
Abstract
Organophosphate flame retardants (OPFRs), used extensively as substitutes for polybrominated diphenyl ethers, are ubiquitous environmental contaminants. OPFR pollution in aquatic environments, the main sink of pollutants, has been studied extensively over the past decade. Here, we review the current knowledge on the consumption and applications of OPFRs, and on their ecotoxicity in aquatic environments worldwide. We also synthesize the available evidence on the occurrence of OPFRs in aquatic environments in China (wastewater treatment plant influent and effluent, surface water, sediment, aquatic biota, and drinking water). Across China, the measured concentrations of OPFRs differ by more than three orders of magnitude. Risk assessments based on these measurements indicate a low level of ecological risk from OPFRs in most aquatic environments in China, and a low risk to human health from drinking water and aquatic products. Finally, we identify gaps in the current knowledge and directions for further research on OPFRs in aquatic environments.
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Affiliation(s)
- Mei-Hong Chen
- 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; Heilongjiang Provincial Key Laboratory of Polar Environment and Ecosystem (HPKL-PEE), Harbin 150090, China
| | - 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; Heilongjiang Provincial Key Laboratory of Polar Environment and Ecosystem (HPKL-PEE), Harbin 150090, China.
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9
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Lee JS, Morita Y, Kawai YK, Covaci A, Kubota A. Developmental circulatory failure caused by metabolites of organophosphorus flame retardants in zebrafish, Danio rerio. CHEMOSPHERE 2020; 246:125738. [PMID: 31918085 DOI: 10.1016/j.chemosphere.2019.125738] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 12/20/2019] [Accepted: 12/23/2019] [Indexed: 06/10/2023]
Abstract
Organophosphate triesters are used worldwide as additives in flame retardants and plasticizer as a replacement of polybrominated diphenyl ethers. Increasing evidence on human exposure to and environmental contamination with organophosphorus flame retardants (OPFRs) requires an adequate toxicity assessment for this class of chemicals. While developmental toxicity of several OPFRs has been reported, developmental effects of OPFR metabolites have still to be understood. The present study aimed at characterizing developmental effects of OPFR metabolites using zebrafish embryos (Danio rerio). Triphenyl phosphate (TPHP) and two of its metabolites, 3-hydroxylphenyl diphenyl phosphate and 4-hydroxylphenyl diphenyl phosphate, were most potent for inducing pericardial edema and reduction in blood flow in trunk vessels. Other TPHP metabolites, such as diphenyl phosphate and 4-hydroxylphenyl phenyl phosphate, showed no substantial increase in circulatory failure at concentrations up to 30 μM. Tris (1,3-dichloro-2-propyl) phosphate showed circulatory failure at 30 μM, but its metabolite bis(1,3-dichloro-2-propyl) phosphate did not. Neither tris(2-chloroethyl) phosphate nor its metabolite bis(2-chloroethyl) phosphate, induced circulatory failure. The circulatory failure appeared to be enhanced with the increase in the octanol-water partition coefficients of OPFRs and their metabolites, suggesting that developmental circulatory failure posed by these chemicals could be estimated by their bioaccumulative potential. The present study demonstrated developmental circulatory failure of hydroxylated TPHP metabolites, which was almost equipotent to TPHP. Diester OPFR metabolites showed no major developmental toxicity at the concentrations used in this study. The current results establish the foundation for further understanding the similarities and differences in the toxic mechanisms between OPFRs and their metabolites.
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Affiliation(s)
- Jae Seung Lee
- Laboratory of Toxicology, Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada-cho Nishi, Obihiro, 080-8555, Hokkaido, Japan
| | - Yuri Morita
- Laboratory of Toxicology, Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada-cho Nishi, Obihiro, 080-8555, Hokkaido, Japan
| | - Yusuke K Kawai
- Laboratory of Toxicology, Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada-cho Nishi, Obihiro, 080-8555, Hokkaido, Japan
| | - Adrian Covaci
- Toxicological Centre, Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - Akira Kubota
- Laboratory of Toxicology, Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada-cho Nishi, Obihiro, 080-8555, Hokkaido, Japan.
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10
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Reddam A, Tait G, Herkert N, Hammel SC, Stapleton HM, Volz DC. Longer commutes are associated with increased human exposure to tris(1,3-dichloro-2-propyl) phosphate. ENVIRONMENT INTERNATIONAL 2020; 136:105499. [PMID: 31999975 PMCID: PMC7061053 DOI: 10.1016/j.envint.2020.105499] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 01/15/2020] [Accepted: 01/15/2020] [Indexed: 05/21/2023]
Abstract
Organophosphate esters (OPEs) are a class of semi-volatile organic compounds (SVOCs) used as flame retardants, plasticizers, and anti-foaming agents. Due to stringent flammability standards in vehicles and the ability of OPEs to migrate out of end-use products, elevated concentrations of OPEs have been found in car dust samples around the world. As many residents of Southern California spend a significant amount of time in their vehicles, there is potential for increased exposure to OPEs associated with longer commute times. As approximately 70% of the University of California, Riverside's undergraduate population commutes, the objective of this study was to use silicone wristbands to monitor personal exposure to OPEs and determine if exposure was associated with commute time in a subset of these students. Participants were asked to wear wristbands for five continuous days and complete daily surveys about the amount of time spent commuting. Data were then used to calculate a participant-specific total commute score. Components of Firemaster 550 (triphenyl phosphate, or TPHP, and isopropylated triaryl phosphate isomers) and Firemaster 600 (TPHP and tert-butylated triaryl phosphate isomers) - both widely used commercial flame retardant formulations - were strongly correlated with other OPEs detected within participant wristbands. Moreover, the concentration of tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) was significantly correlated with the concentration of several Firemaster 500 components and tris(2-chloroisopropyl) phosphate (TCIPP). Finally, out of all OPEs measured, TDCIPP was significantly and positively correlated with total commute score, indicating that longer commutes are associated with increased human exposure to TDCIPP. Overall, our findings raise concerns about the potential for chronic TDCIPP exposure within vehicles and other forms of transportation, particularly within densely populated and traffic-congested areas such as Southern California.
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Affiliation(s)
- Aalekhya Reddam
- Environmental Toxicology Graduate Program, University of California, Riverside, CA, USA; Department of Environmental Sciences, University of California, Riverside, CA, USA
| | - George Tait
- Nicholas School of the Environment, Duke University, Durham, NC, USA
| | - Nicholas Herkert
- Nicholas School of the Environment, Duke University, Durham, NC, USA
| | | | | | - David C Volz
- Department of Environmental Sciences, University of California, Riverside, CA, USA.
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Dasgupta S, Reddam A, Liu Z, Liu J, Volz DC. High-content screening in zebrafish identifies perfluorooctanesulfonamide as a potent developmental toxicant. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 256:113550. [PMID: 31706782 PMCID: PMC6920544 DOI: 10.1016/j.envpol.2019.113550] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Revised: 10/27/2019] [Accepted: 10/30/2019] [Indexed: 05/20/2023]
Abstract
Per- and polyfluoroalkyl substances (PFASs) have been used for decades within industrial processes and consumer products, resulting in frequent detection within the environment. Using zebrafish embryos, we screened 38 PFASs for developmental toxicity and revealed that perfluorooctanesulfonamide (PFOSA) was the most potent developmental toxicant, resulting in elevated mortality and developmental abnormalities following exposure from 6 to 24 h post fertilization (hpf) and 6 to 72 hpf. PFOSA resulted in a concentration-dependent increase in mortality and abnormalities, with surviving embryos exhibiting a >12-h delay in development at 24 hpf. Exposures initiated at 0.75 hpf also resulted in a concentration-dependent delay in epiboly, although these effects were not driven by a specific sensitive window of development. We relied on mRNA-sequencing to identify the potential association of PFOSA-induced developmental delays with impacts on the embryonic transcriptome. Relative to stage-matched vehicle controls, these data revealed that pathways related to hepatotoxicity and lipid transport were disrupted in embryos exposed to PFOSA from 0.75 to 14 hpf and 0.75 to 24 hpf. Therefore, we measured liver area as well as neutral lipids in 128-hpf embryos exposed to vehicle (0.1% DMSO) or PFOSA from 0.75 to 24 hpf and clean water from 24 to 128 hpf, and showed that PFOSA exposure from 0.75 to 24 hpf resulted in a decrease in liver area and increase in yolk sac neutral lipids at 128 hpf. Overall, our findings show that early exposure to PFOSA adversely impacts embryogenesis, an effect that may lead to altered lipid transport and liver development.
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Affiliation(s)
- Subham Dasgupta
- Department of Environmental Sciences, University of California, Riverside, CA, USA
| | - Aalekhya Reddam
- Department of Environmental Sciences, University of California, Riverside, CA, USA; Environmental Toxicology Graduate Program, University of California, Riverside, CA, USA
| | - Zekun Liu
- Department of Chemical and Environmental Engineering, University of California, Riverside, CA, USA
| | - Jinyong Liu
- Department of Chemical and Environmental Engineering, University of California, Riverside, CA, USA
| | - David C Volz
- Department of Environmental Sciences, University of California, Riverside, CA, USA.
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