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Lungu-Mitea S, Han Y, Lundqvist J. Development, scrutiny, and modulation of transient reporter gene assays of the xenobiotic metabolism pathway in zebrafish hepatocytes. Cell Biol Toxicol 2023; 39:991-1013. [PMID: 34654992 PMCID: PMC10406726 DOI: 10.1007/s10565-021-09659-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Accepted: 09/25/2021] [Indexed: 10/20/2022]
Abstract
The "toxicology in the twenty-first century" paradigm shift demands the development of alternative in vitro test systems. Especially in the field of ecotoxicology, coverage of aquatic species-specific assays is relatively scarce. Transient reporter gene assays could be a quick, economical, and reliable bridging technology. However, the user should be aware of potential pitfalls that are influenced by reporter vector geometry. Here, we report the development of an AhR-responsive transient reporter-gene assay in the permanent zebrafish hepatocytes cell line (ZFL). Additionally, we disclose how viral, constitutive promoters within reporter-gene assay cassettes induce squelching of the primary signal. To counter this, we designed a novel normalization vector, bearing an endogenous zebrafish-derived genomic promoter (zfEF1aPro), which rescues the squelching-delimited system, thus, giving new insights into the modulation of transient reporter systems under xenobiotic stress. Finally, we uncovered how the ubiquitously used ligand BNF promiscuously activates multiple toxicity pathways of the xenobiotic metabolism and cellular stress response in an orchestral manner, presumably leading to a concentration-related inhibition of the AhR/ARNT/XRE-toxicity pathway and non-monotonous concentration-response curves. We named such a multi-level inhibitory mechanism that might mask effects as "maisonette squelching." A transient reporter gene assay in zebrafish cell lines utilizing endogenous regulatory gene elements shows increased in vitro toxicity testing performance. Synthetic and constitutive promotors interfere with signal transduction ("squelching") and might increase cellular stress (cytotoxicity). The squelching phenomenon might occur on multiple levels (toxicity pathway crosstalk and normalization vector), leading to a complete silencing of the reporter signal.
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Affiliation(s)
- Sebastian Lungu-Mitea
- Department of Biomedicine and Veterinary Public Health, Swedish University of Agricultural Sciences, Box 7028, 750 07, Uppsala, Sweden.
| | - Yuxin Han
- Department of Biomedicine and Veterinary Public Health, Swedish University of Agricultural Sciences, Box 7028, 750 07, Uppsala, Sweden
| | - Johan Lundqvist
- Department of Biomedicine and Veterinary Public Health, Swedish University of Agricultural Sciences, Box 7028, 750 07, Uppsala, Sweden
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2
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Hammond CL, Roztocil E, Gupta V, Feldon SE, Woeller CF. More than Meets the Eye: The Aryl Hydrocarbon Receptor is an Environmental Sensor, Physiological Regulator and a Therapeutic Target in Ocular Disease. FRONTIERS IN TOXICOLOGY 2022; 4:791082. [PMID: 35295218 PMCID: PMC8915869 DOI: 10.3389/ftox.2022.791082] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 02/08/2022] [Indexed: 12/22/2022] Open
Abstract
The aryl hydrocarbon receptor (AHR) is a ligand activated transcription factor originally identified as an environmental sensor of xenobiotic chemicals. However, studies have revealed that the AHR regulates crucial aspects of cell growth and metabolism, development and the immune system. The importance of the AHR and AHR signaling in eye development, toxicology and disease is now being uncovered. The AHR is expressed in many ocular tissues including the retina, choroid, cornea and the orbit. A significant role for the AHR in age-related macular degeneration (AMD), autoimmune uveitis, and other ocular diseases has been identified. Ligands for the AHR are structurally diverse organic molecules from exogenous and endogenous sources. Natural AHR ligands include metabolites of tryptophan and byproducts of the microbiome. Xenobiotic AHR ligands include persistent environmental pollutants such as dioxins, benzo (a) pyrene [B (a) P] and polychlorinated biphenyls (PCBs). Pharmaceutical agents including the proton pump inhibitors, esomeprazole and lansoprazole, and the immunosuppressive drug, leflunomide, activate the AHR. In this review, we highlight the role of the AHR in the eye and discuss how AHR signaling is involved in responding to endogenous and environmental stimuli. We also present the emerging concept that the AHR is a promising therapeutic target for eye disease.
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Affiliation(s)
| | | | | | | | - Collynn F. Woeller
- Flaum Eye Institute, Rochester, NY, United States
- Department of Environmental Medicine, School of Medicine and Dentistry, University of Rochester, Rochester, NY, United States
- *Correspondence: Collynn F. Woeller,
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3
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Abstract
As manufacturing processes and development of new synthetic compounds increase to keep pace with the expanding global demand, environmental health, and the effects of toxicant exposure are emerging as critical public health concerns. Additionally, chemicals that naturally occur in the environment, such as metals, have profound effects on human and animal health. Many of these compounds are in the news: lead, arsenic, and endocrine disruptors such as bisphenol A have all been widely publicized as causing disease or damage to humans and wildlife in recent years. Despite the widespread appreciation that environmental toxins can be harmful, there is limited understanding of how many toxins cause disease. Zebrafish are at the forefront of toxicology research; this system has been widely used as a tool to detect toxins in water samples and to investigate the mechanisms of action of environmental toxins and their related diseases. The benefits of zebrafish for studying vertebrate development are equally useful for studying teratogens. Here, we review how zebrafish are being used both to detect the presence of some toxins as well as to identify how environmental exposures affect human health and disease. We focus on areas where zebrafish have been most effectively used in ecotoxicology and in environmental health, including investigation of exposures to endocrine disruptors, industrial waste byproducts, and arsenic.
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Affiliation(s)
- Kathryn Bambino
- Icahn School of Medicine at Mount Sinai, New York, United States
| | - Jaime Chu
- Icahn School of Medicine at Mount Sinai, New York, United States.
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4
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Pawar N, Gireesh-Babu P, Sabnis S, Rasal K, Murthy R, Zaidi SGS, Sivasubbu S, Chaudhari A. Development of a fluorescent transgenic zebrafish biosensor for sensing aquatic heavy metal pollution. Transgenic Res 2016; 25:617-27. [DOI: 10.1007/s11248-016-9959-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 04/18/2016] [Indexed: 11/29/2022]
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5
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Wang WD, Chen GT, Hsu HJ, Wu CY. Aryl hydrocarbon receptor 2 mediates the toxicity of Paclobutrazol on the digestive system of zebrafish embryos. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2015; 159:13-22. [PMID: 25500619 DOI: 10.1016/j.aquatox.2014.11.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Revised: 11/18/2014] [Accepted: 11/20/2014] [Indexed: 06/04/2023]
Abstract
Paclobutrazol (PBZ), a trazole-containing fungicide and plant growth retardant, has been widely used for over 30 years to regulate plant growth and promote early fruit setting. Long-term usage of PBZ in agriculture and natural environments has resulted in residual PBZ in the soil and water. Chronic exposure to waterborne PBZ can cause various physiological effects in fish, including hepatic steatosis, antioxidant activity, and disruption of spermatogenesis. We have previously shown that PBZ also affects the rates of zebrafish embryonic survival and hatching, and causes developmental failure of the head skeleton and eyes; here, we further show that PBZ has embryonic toxic effects on digestive organs of zebrafish, and describe the underlying mechanisms. PBZ treatment of embryos resulted in dose-dependent morphological and functional abnormalities of the digestive organs. Real-time RT-PCR and in situ hybridization were used to show that PBZ strongly induces cyp1a1 expression in the digestive system, and slightly induces ahr2 expression in zebrafish embryos. Knockdown of ahr2 with morpholino oligonucleotides prevents PBZ toxicity. Thus, the toxic effect of PBZ on digestive organs is mediated by AhR2, as was previously reported for retene and TCDD. These findings have implications for understanding the potential toxicity of PBZ during embryogenesis, and thus the potential impact of fungicides on public health and the environment.
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Affiliation(s)
- Wen-Der Wang
- Department of Bio-Agricultural Sciences, National Chiayi University, Chiayi City, Taiwan.
| | - Guan-Ting Chen
- Department of Bio-Agricultural Sciences, National Chiayi University, Chiayi City, Taiwan
| | - Hwei-Jan Hsu
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei City, Taiwan
| | - Chang-Yi Wu
- Department of Biological Sciences, National Sun Yat-Sen University, Kaohsiung City, Taiwan
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6
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Abstract
The use of transgenics in fish is a relatively recent development for advancing understanding of genetic mechanisms and developmental processes, improving aquaculture, and for pharmaceutical discovery. Transgenic fish have also been applied in ecotoxicology where they have the potential to provide more advanced and integrated systems for assessing health impacts of chemicals. The zebrafish (Daniorerio) is the most popular fish for transgenic models, for reasons including their high fecundity, transparency of their embryos, rapid organogenesis and availability of extensive genetic resources. The most commonly used technique for producing transgenic zebrafish is via microinjection of transgenes into fertilized eggs. Transposon and meganuclease have become the most reliable methods for insertion of the genetic construct in the production of stable transgenic fish lines. The GAL4-UAS system, where GAL4 is placed under the control of a desired promoter and UAS is fused with a fluorescent marker, has greatly enhanced model development for studies in ecotoxicology. Transgenic fish have been developed to study for the effects of heavy metal toxicity (via heat-shock protein genes), oxidative stress (via an electrophile-responsive element), for various organic chemicals acting through the aryl hydrocarbon receptor, thyroid and glucocorticoid response pathways, and estrogenicity. These models vary in their sensitivity with only very few able to detect responses for environmentally relevant exposures. Nevertheless, the potential of these systems for analyses of chemical effects in real time and across multiple targets in intact organisms is considerable. Here we illustrate the techniques used for generating transgenic zebrafish and assess progress in the development and application of transgenic fish (principally zebrafish) for studies in environmental toxicology. We further provide a viewpoint on future development opportunities.
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Affiliation(s)
- Okhyun Lee
- Biosciences, College of Life & Environmental Sciences, University of Exeter , Exeter, Devon , UK
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7
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Bugel SM, Tanguay RL, Planchart A. Zebrafish: A marvel of high-throughput biology for 21 st century toxicology. Curr Environ Health Rep 2014; 1:341-352. [PMID: 25678986 DOI: 10.1007/s40572-014-0029-5] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The evolutionary conservation of genomic, biochemical and developmental features between zebrafish and humans is gradually coming into focus with the end result that the zebrafish embryo model has emerged as a powerful tool for uncovering the effects of environmental exposures on a multitude of biological processes with direct relevance to human health. In this review, we highlight advances in automation, high-throughput (HT) screening, and analysis that leverage the power of the zebrafish embryo model for unparalleled advances in our understanding of how chemicals in our environment affect our health and wellbeing.
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Affiliation(s)
- Sean M Bugel
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97333
| | - Robert L Tanguay
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97333
| | - Antonio Planchart
- Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695
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8
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Delov V, Muth-Köhne E, Schäfers C, Fenske M. Transgenic fluorescent zebrafish Tg(fli1:EGFP)y¹ for the identification of vasotoxicity within the zFET. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2014; 150:189-200. [PMID: 24685623 DOI: 10.1016/j.aquatox.2014.03.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Revised: 02/12/2014] [Accepted: 03/09/2014] [Indexed: 06/03/2023]
Abstract
The fish embryo toxicity test (FET) is currently one of the most advocated animal alternative tests in ecotoxicology. To date, the application of the FET with zebrafish (zFET) has focused on acute toxicity assessment, where only lethal morphological effects are accounted for. An application of the zFET beyond acute toxicity, however, necessitates the establishment of more refined and quantifiable toxicological endpoints. A valuable tool in this context is the use of gene expression-dependent fluorescent markers that can even be measured in vivo. We investigated the application of embryos of Tg(fli1:EGFP)(y1) for the identification of vasotoxic substances within the zFET. Tg(fli1:EGFP)(y1) fish express enhanced GFP in the entire vasculature under the control of the fli1 promoter, and thus enable the visualization of vascular defects in live zebrafish embryos. We assessed the fli1 driven EGFP-expression in the intersegmental blood vessels (ISVs) qualitatively and quantitatively, and found an exposure concentration related increase in vascular damage for chemicals like triclosan, cartap and genistein. The fluorescence endpoint ISV-length allowed an earlier and more sensitive detection of vasotoxins than the bright field assessment method. In combination with the standard bright field morphological effect assessment, an increase in significance and value of the zFET for a mechanism-specific toxicity evaluation was achieved. This study highlights the benefits of using transgenic zebrafish as convenient tools for identifying toxicity in vivo and to increase sensitivity and specificity of the zFET.
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Affiliation(s)
- Vera Delov
- Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Forckenbeckstr. 6, 52074 Aachen, Germany; Institute for Molecular Biotechnology (Biology VII), RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany.
| | - Elke Muth-Köhne
- Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Auf dem Aberg 1, 57392 Schmallenberg, Germany
| | - Christoph Schäfers
- Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Auf dem Aberg 1, 57392 Schmallenberg, Germany
| | - Martina Fenske
- Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Forckenbeckstr. 6, 52074 Aachen, Germany; Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Auf dem Aberg 1, 57392 Schmallenberg, Germany.
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9
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Dai YJ, Jia YF, Chen N, Bian WP, Li QK, Ma YB, Chen YL, Pei DS. Zebrafish as a model system to study toxicology. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2014; 33:11-7. [PMID: 24307630 DOI: 10.1002/etc.2406] [Citation(s) in RCA: 352] [Impact Index Per Article: 35.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 07/08/2013] [Accepted: 09/03/2013] [Indexed: 05/22/2023]
Abstract
Monitoring and assessing the effects of contaminants in the aquatic eco-environment is critical in protecting human health and the environment. The zebrafish has been widely used as a prominent model organism in different fields because of its small size, low cost, diverse adaptability, short breeding cycle, high fecundity, and transparent embryos. Recent studies have demonstrated that zebrafish sensitivity can aid in monitoring environmental contaminants, especially with the application of transgenic technology in this area. The present review provides a brief overview of recent studies on wild-type and transgenic zebrafish as a model system to monitor toxic heavy metals, endocrine disruptors, and organic pollutants for toxicology. The authors address the new direction of developing high-throughput detection of genetically modified transparent zebrafish to open a new window for monitoring environmental pollutants.
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Affiliation(s)
- Yu-Jie Dai
- Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, China
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10
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Basu S, Sachidanandan C. Zebrafish: a multifaceted tool for chemical biologists. Chem Rev 2013; 113:7952-80. [PMID: 23819893 DOI: 10.1021/cr4000013] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Sandeep Basu
- Council of Scientific and Industrial Research-Institute of Genomics & Integrative Biology (CSIR-IGIB) , South Campus, New Delhi 110025, India
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11
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Kim KH, Park HJ, Kim JH, Kim S, Williams DR, Kim MK, Jung YD, Teraoka H, Park HC, Choy HE, Shin BA, Choi SY. Cyp1a reporter zebrafish reveals target tissues for dioxin. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2013; 134-135:57-65. [PMID: 23587668 DOI: 10.1016/j.aquatox.2013.03.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Revised: 02/25/2013] [Accepted: 03/04/2013] [Indexed: 06/02/2023]
Abstract
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is the unintentional byproduct of various industrial processes, is classified as human carcinogen and could disrupt reproductive, developmental and endocrine systems. Induction of cyp1a1 is used as an indicator of TCDD exposure. We sought to determine tissues that are vulnerable to TCDD toxicity using a transgenic zebrafish (Danio rerio) model. We inserted a nuclear enhanced green fluorescent protein gene (EGFP) into the start codon of a zebrafish cyp1a gene in a fosmid clone using DNA recombineering. The resulting recombineered fosmid was then used to generate cyp1a reporter zebrafish, embryos of which were exposed to TCDD. Expression pattern of EGFP in the reporter zebrafish mirrored that of endogenous cyp1a mRNA. In addition, exposure of the embryos to TCDD at as low as 10 pM for 72 h, which does not elicit morphological abnormalities of embryos, markedly increased GFP expression. Furthermore, the reporter embryos responded to other AhR ligands as well. Exposure of the embryos to TCDD revealed previously reported (the cardiovascular system, liver, pancreas, kidney, swim bladder and skin) and unreported target tissues (retinal bipolar cells, otic vesicle, lateral line, cloaca and pectoral fin bud) for TCDD. Transgenic cyp1a reporter zebrafish we have developed can further understanding of ecotoxicological relevance and human health risks by TCDD. In addition, they could be used to identify agonists of AhR and antidotes to TCDD toxicity.
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Affiliation(s)
- Kun-Hee Kim
- Department of Biomedical Sciences, Chonnam National University Medical School, Gwangju, Republic of Korea
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12
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Schock EN, Ford WC, Midgley KJ, Fader JG, Giavasis MN, McWhorter ML. The effects of carbaryl on the development of zebrafish (Danio rerio) embryos. Zebrafish 2012; 9:169-78. [PMID: 23094693 DOI: 10.1089/zeb.2012.0747] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
In the United States, Sevin(™) brand insecticide is one of the most commonly used insecticides. The active ingredient in Sevin(™), carbaryl (1-napthyl-N-methylcarbamate), is a known acetylcholinesterase (AChE) inhibitor that prevents the breakdown of acetylcholine to acetate and choline at the synapse. While carbaryl successfully causes the death of insects by paralysis, it has also been shown to have negative effects on the development of several nontarget species. To study the effects of carbaryl on nontarget species, zebrafish (Danio rerio) were used, as they are a good model for both toxicology and development studies. Our study suggests that carbaryl induces changes in morphology, specifically in embryo size and shape. Additionally, carbaryl causes defects in heart formation that is characterized by a decrease in heart rate and a developmental delay/defect in cardiac looping. A significant decrease in the number of spinal cord neurons present was also observed. Further investigation showed that there was an increase in cell death in carbaryl-treated embryos. The results indicate that carbaryl may have a greater environmental impact than initially intended. Our study, which was conducted solely by undergraduates at a liberal arts college, indicates that carbaryl may be detrimental to the development of nontarget species.
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Affiliation(s)
- Elizabeth N Schock
- Biochemistry and Molecular Biology Program, Wittenberg University , Springfield, Ohio 45501, USA
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13
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Lee O, Tyler CR, Kudoh T. Development of a transient expression assay for detecting environmental oestrogens in zebrafish and medaka embryos. BMC Biotechnol 2012; 12:32. [PMID: 22726887 PMCID: PMC3410757 DOI: 10.1186/1472-6750-12-32] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Accepted: 06/24/2012] [Indexed: 12/02/2022] Open
Abstract
Background Oestrogenic contaminants are widespread in the aquatic environment and have been shown to induce adverse effects in both wildlife (most notably in fish) and humans, raising international concern. Available detecting and testing systems are limited in their capacity to elucidate oestrogen signalling pathways and physiological impacts. Here we developed a transient expression assay to investigate the effects of oestrogenic chemicals in fish early life stages and to identify target organs for oestrogenic effects. To enhance the response sensitivity to oestrogen, we adopted the use of multiple tandem oestrogen responsive elements (EREc38) in a Tol2 transposon mediated Gal4ff-UAS system. The plasmid constructed (pTol2_ERE-TATA-Gal4ff), contains three copies of oestrogen response elements (3ERE) that on exposure to oestrogen induces expression of Gal4ff which this in turn binds Gal4-responsive Upstream Activated Sequence (UAS) elements, driving the expression of a second reporter gene, EGFP (Enhanced Green Fluorescent Protein). Results The response of our construct to oestrogen exposure in zebrafish embryos was examined using a transient expression assay. The two plasmids were injected into 1–2 cell staged zebrafish embryos, and the embryos were exposed to various oestrogens including the natural steroid oestrogen 17ß-oestradiol (E2), the synthetic oestrogen 17α- ethinyloestradiol (EE2), and the relatively weak environmental oestrogen nonylphenol (NP), and GFP expression was examined in the subsequent embryos using fluorescent microscopy. There was no GFP expression detected in unexposed embryos, but specific and mosaic expression of GFP was detected in the liver, heart, somite muscle and some other tissue cells for exposures to steroid oestrogen treatments (EE2; 10 ng/L, E2; 100 ng/L, after 72 h exposures). For the NP exposures, GFP expression was observed at 10 μg NP/L after 72 h (100 μg NP/L was toxic to the fish). We also demonstrate that our construct works in medaka, another model fish test species, suggesting the transient assay is applicable for testing oestrogenic chemicals in fish generally. Conclusion Our results indicate that the transient expression assay system can be used as a rapid integrated testing system for environmental oestrogens and to detect the oestrogenic target sites in developing fish embryos.
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Affiliation(s)
- Okhyun Lee
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, Devon, EX4 4PS, UK
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14
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Detection of water toxicity using cytochrome P450 transgenic zebrafish as live biosensor: For polychlorinated biphenyls toxicity. Biosens Bioelectron 2012; 31:548-53. [DOI: 10.1016/j.bios.2011.10.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Revised: 10/03/2011] [Accepted: 10/06/2011] [Indexed: 11/20/2022]
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15
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Tsujita T, Li L, Nakajima H, Iwamoto N, Nakajima-Takagi Y, Ohashi K, Kawakami K, Kumagai Y, Freeman BA, Yamamoto M, Kobayashi M. Nitro-fatty acids and cyclopentenone prostaglandins share strategies to activate the Keap1-Nrf2 system: a study using green fluorescent protein transgenic zebrafish. Genes Cells 2011; 16:46-57. [PMID: 21143560 PMCID: PMC4124525 DOI: 10.1111/j.1365-2443.2010.01466.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Nitro-fatty acids are electrophilic fatty acids produced in vivo from nitrogen peroxide that have many physiological activities. We recently demonstrated that nitro-fatty acids activate the Keap1-Nrf2 system, which protects cells from damage owing to electrophilic or oxidative stresses via transactivating an array of cytoprotective genes, although the molecular mechanism how they activate Nrf2 is unclear. A number of chemical compounds with different structures have been reported to activate the Keap1-Nrf2 system, which can be categorized into at least six classes based on their sensing pathways. In this study, we showed that nitro-oleic acid (OA-NO₂), one of major nitro-fatty acids, activates Nrf2 in the same manner that of a cyclopentenone prostaglandin 15-deoxy-Δ(12,14) -prostaglandin J₂ (15d-PGJ₂) using transgenic zebrafish that expresses green fluorescent protein (GFP) in response to Nrf2 activators. In transgenic embryos, GFP was induced in the whole body by treatment with OA-NO₂, 15d-PGJ₂ or diethylmaleate (DEM), but not with hydrogen peroxide (H₂O₂), when exogenous Nrf2 and Keap1 were co-overexpressed. Induction by OA-NO₂ or 15d-PGJ₂ but not DEM was observed, even when a C151S mutation was introduced in Keap1. Our results support the contention that OA-NO₂ and 15d-PGJ₂ share an analogous cysteine code as electrophiles and also have similar anti-inflammatory roles.
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Affiliation(s)
- Tadayuki Tsujita
- Institute of Basic Medical Sciences, Graduate School of Comprehensive Human Sciences, Center for TARA, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8577, Japan
- ERATO Environmental Response Project, Japan Science and Technology Agency, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8577, Japan
| | - Li Li
- Institute of Basic Medical Sciences, Graduate School of Comprehensive Human Sciences, Center for TARA, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8577, Japan
| | - Hitomi Nakajima
- Institute of Basic Medical Sciences, Graduate School of Comprehensive Human Sciences, Center for TARA, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8577, Japan
| | - Noriko Iwamoto
- Institute of Community Medicine, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8575, Japan
| | - Yaeko Nakajima-Takagi
- Institute of Basic Medical Sciences, Graduate School of Comprehensive Human Sciences, Center for TARA, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8577, Japan
| | - Ken Ohashi
- Institute of Basic Medical Sciences, Graduate School of Comprehensive Human Sciences, Center for TARA, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8577, Japan
| | - Koichi Kawakami
- Division of Molecular and Developmental Biology, National Institute of Genetics, and Department of Genetics, Graduate University for Advanced Studies (SOKENDAI), 1111 Yata, Mishima 411-8570, Japan
| | - Yoshito Kumagai
- Institute of Community Medicine, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8575, Japan
| | - Bruce A. Freeman
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Masayuki Yamamoto
- ERATO Environmental Response Project, Japan Science and Technology Agency, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8577, Japan
- Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, 2-1 Seiryo-cho, Aoba-ku, Sendai 980-8575, Japan
| | - Makoto Kobayashi
- Institute of Basic Medical Sciences, Graduate School of Comprehensive Human Sciences, Center for TARA, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8577, Japan
- ERATO Environmental Response Project, Japan Science and Technology Agency, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8577, Japan
- Correspondence:
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16
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Kato Y, Kobayashi K, Watanabe H, Iguchi T. Introduction of foreign DNA into the water flea, Daphnia magna, by electroporation. ECOTOXICOLOGY (LONDON, ENGLAND) 2010; 19:589-92. [PMID: 20099028 DOI: 10.1007/s10646-010-0460-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/11/2010] [Indexed: 05/11/2023]
Abstract
Daphnids inhabit a diverse array of aquatic environments and they are a good model for understanding response and adaptation to environmental changes and they have been used one of standard organisms in ecotoxicology. Recent progress of genomics changed the tools for analyzing responses of daphnids, because gene expression changes can be observed before the emergence of prominent adverse effect such as immobility of the organism. Thus understanding of biological changes from gene expression level can be one of the sensitive tools for the evaluation of environmental response of organisms. However, there was no technique for genetic manipulation in daphnids. Hence, we have developed a gene introduction technique based on electroporation. There are two critical points for the successful introduction of foreign DNA into D. magna. (1) Injection of DNA into blood stream. (2) Usage of very low voltage for the electroporation. The injected DNA containing green fluorescent protein (GFP) could be introduced daphnids and the expression of GFP could be detected in living daphnids. This is the first report of gene introduction to daphnids and, together with the emerging genome sequences, will be useful for the expanding our use of daphnid in ecotoxicology.
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Stegeman JJ, Goldstone JV, Hahn ME. Perspectives on zebrafish as a model in environmental toxicology. FISH PHYSIOLOGY 2010. [DOI: 10.1016/s1546-5098(10)02910-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Ohte N, Miyoshi I, Sane DC, Little WC. Zebrafish with antisense-knockdown of cardiac troponin C as a model of hereditary dilated cardiomyopathy. Circ J 2009; 73:1595-6. [PMID: 19706986 DOI: 10.1253/circj.cj-09-0523] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Kim DJ, Seok SH, Baek MW, Lee HY, Na YR, Park SH, Lee HK, Dutta NK, Kawakami K, Park JH. Estrogen-responsive transient expression assay using a brain aromatase-based reporter gene in zebrafish (Danio rerio). Comp Med 2009; 59:416-423. [PMID: 19887024 PMCID: PMC2771600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2008] [Revised: 10/17/2008] [Accepted: 01/20/2009] [Indexed: 05/28/2023]
Abstract
Whereas endogenous estrogens play an important role in the development, maintenance, and function of female and male reproductive organs, xenoestrogens present in the environment disrupt normal endocrine function in humans and wildlife. Various in vivo and in vitro assays have been developed to screen these xenoestrogens. However, traditional in vivo assays are laborious and unsuitable for large-scale screening, and in vitro assays do not necessarily replicate in vivo functioning. To overcome these limitations, we developed a transient expression assay in zebrafish, into which a brain aromatase (cyp19a1b)-based estrogen-responsive reporter gene was introduced. In response to 17beta-estradiol (10(-6) M) and heptachlor (10(-6) M), zebrafish embryos carrying the reporter construct expressed enhanced green fluorescent protein in the olfactory bulb, telencephalon, preoptic area, and mediobasal hypothalamus. This system will serve to model the in vivo conversion and breakdown of estrogenic compounds and thus provide a rapid preliminary screening method to estimate their estrogenicity.
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Affiliation(s)
- Dong-Jae Kim
- Department of Laboratory Animal Medicine, College of Veterinary Medicine, and BK2 Program for Veterinary Science, Seoul National University, Seoul, South Korea
| | - Seung-Hyeok Seok
- Department of Laboratory Animal Medicine, College of Veterinary Medicine, and BK2 Program for Veterinary Science, Seoul National University, Seoul, South Korea
| | - Min-Won Baek
- Department of Laboratory Animal Medicine, College of Veterinary Medicine, and BK2 Program for Veterinary Science, Seoul National University, Seoul, South Korea
| | - Hui-Young Lee
- Department of Laboratory Animal Medicine, College of Veterinary Medicine, and BK2 Program for Veterinary Science, Seoul National University, Seoul, South Korea
| | - Yi-Rang Na
- Department of Laboratory Animal Medicine, College of Veterinary Medicine, and BK2 Program for Veterinary Science, Seoul National University, Seoul, South Korea
| | - Sung-Hoon Park
- Department of Laboratory Animal Medicine, College of Veterinary Medicine, and BK2 Program for Veterinary Science, Seoul National University, Seoul, South Korea
| | - Hyun-Kyoung Lee
- Department of Laboratory Animal Medicine, College of Veterinary Medicine, and BK2 Program for Veterinary Science, Seoul National University, Seoul, South Korea
| | - Noton Kumar Dutta
- Department of Laboratory Animal Medicine, College of Veterinary Medicine, and BK2 Program for Veterinary Science, Seoul National University, Seoul, South Korea
| | - Koichi Kawakami
- Division of Molecular and Developmental Biology, National Institute of Genetics and Department of Genetics, The Graduate University of Advanced Studies, Mishima, Japan
| | - Jae-Hak Park
- Department of Laboratory Animal Medicine, College of Veterinary Medicine, and BK2 Program for Veterinary Science, Seoul National University, Seoul, South Korea
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Mattingly CJ, Hampton TH, Brothers KM, Griffin NE, Planchart A. Perturbation of defense pathways by low-dose arsenic exposure in zebrafish embryos. ENVIRONMENTAL HEALTH PERSPECTIVES 2009; 117:981-7. [PMID: 19590694 PMCID: PMC2702417 DOI: 10.1289/ehp.0900555] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2009] [Accepted: 02/22/2009] [Indexed: 04/14/2023]
Abstract
BACKGROUND Exposure to arsenic is a critical risk factor in the complex interplay among genetics, the environment, and human disease. Despite the potential for in utero exposure, the mechanism of arsenic action on vertebrate development and disease is unknown. OBJECTIVES The objective of this study was to identify genes and gene networks perturbed by arsenic during development in order to enhance understanding of the molecular mechanisms of arsenic action. METHODS We exposed zebrafish embryos at 0.25-1.25 hr postfertilization to 10 or 100 ppb arsenic for 24 or 48 hr. We then used total RNA to interrogate genome microarrays and to test levels of gene expression changes by quantitative real-time polymerase chain reaction (QPCR). Computational analysis was used to identify gene expression networks perturbed by arsenic during vertebrate development. RESULTS We identified a set of 99 genes that responded to low levels of arsenic. Nineteen of these genes were predicted to function in a common regulatory network that was significantly associated with immune response and cancer (p < 10(-41)). Arsenic-mediated expression changes were validated by QPCR. CONCLUSIONS In this study we demonstrated that arsenic significantly down-regulates expression levels of multiple genes potentially critical for regulating the establishment of an immune response. The data also provide molecular evidence consistent with phenotypic observations reported in other model systems. Additional mechanistic studies will help explain molecular events regulating early stages of the immune system and long-term consequences of arsenic-mediated perturbation of this system during development.
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Affiliation(s)
| | - Thomas H. Hampton
- Center for Environmental Health Sciences, Dartmouth Medical School, Hanover, New Hampshire, USA
| | | | - Nina E. Griffin
- Mount Desert Island Biological Laboratory, Salisbury Cove, Maine, USA
| | - Antonio Planchart
- Mount Desert Island Biological Laboratory, Salisbury Cove, Maine, USA
- Address correspondence to A. Planchart, Mount Desert Island Biological Laboratory, P.O. Box 35, Old Bar Harbor Rd., Salisbury Cove, ME 04679 USA. Telephone: (207) 288-9880 ext. 443. Fax: (207) 288-2130. E-mail:
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Yang L, Ho NY, Alshut R, Legradi J, Weiss C, Reischl M, Mikut R, Liebel U, Müller F, Strähle U. Zebrafish embryos as models for embryotoxic and teratological effects of chemicals. Reprod Toxicol 2009; 28:245-53. [PMID: 19406227 DOI: 10.1016/j.reprotox.2009.04.013] [Citation(s) in RCA: 204] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2009] [Revised: 04/07/2009] [Accepted: 04/20/2009] [Indexed: 01/04/2023]
Abstract
The experimental virtues of the zebrafish embryo such as small size, development outside of the mother, cheap maintenance of the adult made the zebrafish an excellent model for phenotypic genetic and more recently also chemical screens. The availability of a genome sequence and several thousand mutants and transgenic lines together with gene arrays and a broad spectrum of techniques to manipulate gene functions add further to the experimental strength of this model. Pioneering studies suggest that chemicals can have in many cases very similar toxicological and teratological effects in zebrafish embryos and humans. In certain areas such as cardiotoxicity, the zebrafish appears to outplay the traditional rodent models of toxicity testing. Several pilot projects used zebrafish embryos to identify new chemical entities with specific biological functions. In combination with the establishment of transgenic sensor lines and the further development of existing and new automated imaging systems, the zebrafish embryos could therefore be used as cost-effective and ethically acceptable animal models for drug screening as well as toxicity testing.
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Affiliation(s)
- Lixin Yang
- Institute of Toxicology and Genetics, Forschungszentrum Karlsruhe in the Helmholtz Association, Karlsruhe Institute of Technology, PO Box 3640, Karlsruhe 76021, Germany
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Scholz S, Fischer S, Gündel U, Küster E, Luckenbach T, Voelker D. The zebrafish embryo model in environmental risk assessment--applications beyond acute toxicity testing. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2008; 15:394-404. [PMID: 18575912 DOI: 10.1007/s11356-008-0018-z] [Citation(s) in RCA: 395] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2007] [Accepted: 05/27/2008] [Indexed: 05/20/2023]
Abstract
BACKGROUND, AIM, AND SCOPE The use of fish embryos is not regulated by current legislations on animal welfare and is therefore considered as a refinement, if not replacement of animal experiments. Fish embryos represent an attractive model for environmental risk assessment of chemicals since they offer the possibility to perform small-scale, high-throughput analyses. MAIN FEATURES Beyond their application for determining the acute toxicity, fish embryos are also excellent models for studies aimed at the understanding of toxic mechanisms and the indication of possible adverse and long-term effects. Therefore, we have reviewed the scientific literature in order to indicate alternative applications of the fish embryo model with focus on embryos of the zebrafish. RESULTS AND DISCUSSIONS The analysis of the mode of action is important for the risk assessment of environmental chemicals and can assist in indicating adverse and long-term effects. Toxicogenomics present a promising approach to unravel the potential mechanisms. Therefore, we present examples of the use of zebrafish embryos to study the effect of chemicals on gene and protein patterns, and the potential implications of differential expression for toxicity. The possible application of other methods, such as kinase arrays or metabolomic profiling, is also highlighted. Furthermore, we show examples of toxicokinetic studies (bioconcentration, ABC transporters) and discuss limitations that might be caused by the potential barrier function of the chorion. Finally, we demonstrate that biomarkers of endocrine disruption, immune modulation, genotoxicity or chronic toxicity could be used as indicators or predictors of sub-acute and long-term effects. CONCLUSIONS The zebrafish embryo represents a model with an impressive range of possible applications in environmental sciences. Particularly, the adaptation of molecular, system-wide approaches from biomedical research is likely to extend its use in ecotoxicology. RECOMMENDATIONS AND PERSPECTIVES Challenges for future research are (1) the identification of further suitable molecular markers as indicators of the mode of action, (2) the establishment of strong links between (molecular) effects in short-term assays in embryos and long-term (toxic) effects on individuals, (3) the definition of limitations of the model and (4) the development of tests that can be used for regulatory purposes.
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Affiliation(s)
- Stefan Scholz
- Department of Cell Toxicology, UFZ-Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig, Germany.
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Kasai A, Hiramatsu N, Hayakawa K, Yao J, Kitamura M. Direct, continuous monitoring of air pollution by transgenic sensor mice responsive to halogenated and polycyclic aromatic hydrocarbons. ENVIRONMENTAL HEALTH PERSPECTIVES 2008; 116:349-354. [PMID: 18335102 PMCID: PMC2265056 DOI: 10.1289/ehp.10722] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2007] [Accepted: 12/19/2007] [Indexed: 05/26/2023]
Abstract
BACKGROUND The aryl hydrocarbon receptor (AhR, also called the dioxin receptor) plays crucial roles in toxicologic responses of animals to environmental pollutants, especially to halogenated and polycyclic aromatic hydrocarbons. To achieve direct, continuous risk assessment of air pollution using biological systems, we generated transgenic sensor mice that produce secreted alkaline phosphatase (SEAP) under the control of AhR. METHODS To characterize responses of the mice to AhR agonists, sensor mice were orally administered 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 3-methylcholanthrene (3MC), benzo[a]pyrene (B[a]P), or beta-naphthoflavone (BNF), and serum levels of SEAP were evaluated. To monitor air pollution caused by cigarette smoke, we placed the mice each day in an experimental smoking room, and evaluated activity of serum SEAP for up to 4 days. Activation of AhR in individual organs was also examined by reverse transcription-polymerase chain reaction (RT-PCR) analysis of SEAP. RESULTS In response to oral exposure to TCDD, sensor mice exhibited dramatic and sustained activation of AhR. The mice also responded sensitively to 3MC, B[a]P, and BNF. Activation of AhR was dose dependent, and the liver was identified as the main responding organ. After exposure to the smoking environment, sensor mice consistently exhibited transient, reversible activation of AhR. RT-PCR analysis of SEAP revealed that activation of AhR occurred predominantly in the lung. CONCLUSION We are the first laboratory to demonstrate successfully direct, comprehensive monitoring of air pollution using genetically engineered mammals. The established system would be useful for real risk assessment of halogenated and polycyclic aromatic hydrocarbons in the air, especially in smoking environments.
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Affiliation(s)
| | | | | | | | - Masanori Kitamura
- Address correspondence to M. Kitamura, Department of Molecular Signaling, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Shimokato 1110, Chuo, Yamanashi 409-3898, Japan. Telephone: 81-55-273-8054. Fax: 81-55-273-8054. E-mail:
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24
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Matz CJ, Treble RG, Krone PH. Accumulation and elimination of cadmium in larval stage zebrafish following acute exposure. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2007; 66:44-8. [PMID: 16376426 DOI: 10.1016/j.ecoenv.2005.11.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2005] [Revised: 10/28/2005] [Accepted: 11/05/2005] [Indexed: 05/05/2023]
Abstract
A number of recent studies have examined the impact of acute cadmium exposure on early zebrafish development at the morphological, cellular, and molecular levels. However, no information on the accumulation and elimination of cadmium during early life stages of zebrafish development has been available. Here we have quantified cadmium accumulation in larval zebrafish (Danio rerio) by graphite furnace atomic absorption spectroscopy following short-term acute exposure and recovery periods. Zebrafish (80 h postfertilization) were exposed to various concentrations of cadmium (0.2, 1.0, 5.0, 25, 125 microM) for 3 h. Cadmium accumulation in larvae increased with exposure concentration. After exposure at 5.0, 25, and 125 microM cadmium, the fish were allowed to recover in freshwater for 0, 12, or 24 h. Cadmium content did not show a statistically significant decrease over the recovery period when exposed to 5.0 or 25 microM cadmium, whereas significant losses over the recovery period were observed following 125 microM exposure. These results suggest that the larval zebrafish decrease total cadmium body burden only following relatively high short-term acutely toxic exposures.
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Affiliation(s)
- Carlyn J Matz
- Department of Anatomy and Cell Biology, University of Saskatchewan, 107 Wiggins Road, Saskatoon, Saskatchewan, Canada S7N 5E5
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Zeng Z, Shan T, Tong Y, Lam SH, Gong Z. Development of estrogen-responsive transgenic medaka for environmental monitoring of endocrine disrupters. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2005; 39:9001-8. [PMID: 16323805 DOI: 10.1021/es050728l] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
To develop a transgenic fish system to monitor environmental pollution, we generated a mvtg1:gfp transgenic medaka line, in which the gfp reporter gene was under the control of medaka vitellogenin1 (mvtg1) gene promoter. In this transgenic line, GFP was exclusively expressed in the liver of the mature adult female. Male and juvenile transgenic fish did not express GFP but could be induced to express GFP in the liver after exposure to 17-beta-estradiol (E2). Concurrent accumulation of mvtg1 and gfp mRNAs was observed during both development and estrogen treatment, indicating that the gfp transgene was faithfully expressed under the mvtg1 promoter. Dose- and time-dependent induction of GFP expression by E2 was investigated in male transgenic fish. The lowest-observed-effect concentration (LOEC) of E2 to induce GFP expression was 0.5 microg/L by observation of live fish and 0.05-0.1 microg/L by observation of dissection-exposed liver in a 30 day exposure experiment. GFP expression was observed within 36 h after treatment in high concentrations of E2 (5 microg/L), and it took longer to detect GFP expression under lower concentrations of E2. By removal and readdition of E2, we demonstrated that GFP expression was repeatedly induced. Finally, we also demonstrated that GFP expression could be induced by other estrogenic compounds, including 17-alpha-ethynylestradiol (EE2, 0.05 microg/L), diethylstibestrol (DES, 5 microg/L), estriol (10 microg/ L), and bisphenol A (BPA, 1 mg/L), but not by weak estrogenic chemicals such as nonylphenol (NP, up to 1 mg/ L) and methoxychlor (MXC, up to 20 microg/L). Our experiments indicated the broad application of the transgenic line to monitor a wide range of estrogenic chemicals.
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Affiliation(s)
- Zhiqiang Zeng
- Department of Biological Sciences, National University of Singapore, Singapore
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26
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Kang MJ, Lee DY, Joo WA, Kim CW. Plasma Protein Level Changes in Waste Incineration Workers Exposed to 2,3,7,8-Tetrachlorodibenzo-p-dioxin. J Proteome Res 2005; 4:1248-55. [PMID: 16083274 DOI: 10.1021/pr049756d] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin) is a chemical compound which is known to induce severe reproductive and developmental problems, immune system damage, and interference with regulatory hormones. To characterize changes in the expression of plasma proteins caused by exposure to TCDD, we analyzed plasma samples from workers at municipal incinerators using two-dimensional gel electrophoresis (2-DE). Proteins exhibiting differences in expression were identified by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) and electrospray ionization quadrupole (ESI-Q) TOF mass spectrometry. One newly expressed protein was identified as the adrenomedulin binding protein (AMBP). Seven overexpressed proteins were identified in this study, and the most overexpressed protein was identified as alpha-fetoprotein (AFP). In addition, we cultured HepG2 cells in the presence of TCDD, to determine the effects of TCDD on the AFP and albumin expression in mRNA and protein levels, via RT-PCR and Western blotting, respectively. TCDD treatment resulted in an increase in the mRNA and protein expression levels of AFP, but reduced albumin expression. According to our results, exposure to TCDD may induce liver disease or cancer, and the proteins identified in this study could help reveal the mechanisms underlying TCDD toxicity.
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Affiliation(s)
- Mee Jeong Kang
- School of Life Sciences and Biotechnology, Korea University, 1-5 Anam-dong, Sungbuk-gu, Seoul 136-701 Seoul, Korea
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Lein P, Silbergeld E, Locke P, Goldberg AM. In vitro and other alternative approaches to developmental neurotoxicity testing (DNT). ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2005; 19:735-744. [PMID: 21783550 DOI: 10.1016/j.etap.2004.12.035] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
To address the growing need for scientifically valid and humane alternatives to developmental neurotoxicity testing (DNT), we propose that basic research scientists in developmental neurobiology be brought together with mechanistic toxicologists and policy analysts to develop the science and policy for DNT alternatives that are based on evolutionarily conserved mechanisms of neurodevelopment. In this article we briefly review in vitro and other alternative models and present our rationale for proposing that resources be focused on adapting alternative simple organism systems for DNT. We recognize that alternatives to DNT will not completely replace a DNT paradigm that involves in vivo testing in mammals. However, we believe that alternatives will be of great value in prioritizing chemicals and in identifying mechanisms of developmental neurotoxicity, which in turn will be useful in refining and reducing in vivo mammalian tests for exposures most likely to be hazardous to the developing human nervous system.
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Affiliation(s)
- Pamela Lein
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, USA; Center for Research on Occupational and Environmental Toxicology, Oregon Health and Science University, CROET/L606, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
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Hill AJ, Teraoka H, Heideman W, Peterson RE. Zebrafish as a Model Vertebrate for Investigating Chemical Toxicity. Toxicol Sci 2005; 86:6-19. [PMID: 15703261 DOI: 10.1093/toxsci/kfi110] [Citation(s) in RCA: 862] [Impact Index Per Article: 45.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Zebrafish (Danio rerio) has been a prominent model vertebrate in a variety of biological disciplines. Substantial information gathered from developmental and genetic research, together with near-completion of the zebrafish genome project, has placed zebrafish in an attractive position for use as a toxicological model. Although still in its infancy, there is a clear potential for zebrafish to provide valuable new insights into chemical toxicity, drug discovery, and human disease using recent advances in forward and reverse genetic techniques coupled with large-scale, high-throughput screening. Here we present an overview of the rapidly increasing use of zebrafish in toxicology. Advantages of the zebrafish both in identifying endpoints of toxicity and in elucidating mechanisms of toxicity are highlighted.
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Affiliation(s)
- Adrian J Hill
- School of Pharmacy, University of Wisconsin, Madison, Wisconsin 53705, USA
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Arun KHS, Kaul CL, Ramarao P. Green fluorescent proteins in receptor research: An emerging tool for drug discovery. J Pharmacol Toxicol Methods 2005; 51:1-23. [PMID: 15596111 DOI: 10.1016/j.vascn.2004.07.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2003] [Accepted: 07/27/2004] [Indexed: 01/20/2023]
Abstract
In the last five years, green fluorescent protein (GFP) has emerged from being a mere curiosity to become a reliable tool for molecular pharmacological research. GFP produces an intense and stable green fluorescence noncatalytically by absorbing blue light maximally at 395 nm and emitting green light with a peak at 509 nm. It consists of 238 amino acids and its molecular mass is 27-30 kDa. GFP fluorescence occurs without cofactors and this property allows GFP fluorescence to be utilised in nonnative organisms, wherein it can be used as a reporter. This use of GFP permits real-time analysis of receptor dynamics. The emitted fluorescence can be used as a nontoxic marker and detected using fluorescence-activated cell sorting (FACS), thus avoiding any staining procedure, expensive mRNA analysis or hazardous radiolabeled binding assays. The potential value of GFP has also been recognized in orphan receptor research, where various GFP-tagged therapeutic proteins have been constructed in an attempt to identify the endogenous ligand(s). These chimeric proteins have been used to determine the site and time course of receptor expression and to relate receptor dynamics with therapeutic outcome. The preparation of new GFP constructs for identifying germ layer cells (endodermal, ectodermal, and mesodermal), as well as neuronal, haematopoietic, endothelial, and cartilage cells, has provided a useful battery of tissue/receptor-specific screening assays for new chemical entities. Genetically engineered cells with GFP expression have provided a valuable tool for automated analysis, and can be adapted for high-throughput systems. GFP is being increasingly utilised for the study of receptor dynamics, where, having already proved beneficial, it will likely continue to contribute towards the search for new classes of drugs, as well as to "de-orphaning" orphan receptors.
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Affiliation(s)
- K H S Arun
- Cardiovascular and Receptorology Laboratory, Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research, Phase-X, Sector 67, S.A.S. Nagar (Mohali)-160 062, Punjab, India
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Hinton DE, Kullman SW, Hardman RC, Volz DC, Chen PJ, Carney M, Bencic DC. Resolving mechanisms of toxicity while pursuing ecotoxicological relevance? MARINE POLLUTION BULLETIN 2005; 51:635-48. [PMID: 16154600 DOI: 10.1016/j.marpolbul.2005.07.020] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
In this age of modern biology, aquatic toxicological research has pursued mechanisms of action of toxicants. This has provided potential tools for ecotoxicologic investigations. However, problems of biocomplexity and issues at higher levels of biological organization remain a challenge. In the 1980s and 1990s and continuing to a lesser extent today, organisms residing in highly contaminated field sites or exposed in the laboratory to calibrated concentrations of individual compounds were carefully analyzed for their responses to priority pollutants. Correlation of biochemical and structural analyses in cultured cells and tissues, as well as the in vivo exposures led to the production and application of biomarkers of exposure and effect and to our awareness of genotoxicity and its chronic manifestations, such as neoplasms, in wild fishes. To gain acceptance of these findings in the greater environmental toxicology community, "validation of the model" versus other, better-established often rodent models, was necessary and became a major focus. Resultant biomarkers were applied to heavily contaminated and reference field sites as part of effects assessment and with investigations following large-scale disasters such as oil spills or industrial accidents. Over the past 15 years, in the laboratory, small aquarium fish models such as medaka (Oryzias latipes), zebrafish (Danio rerio), platyfish (Xiphophorus species), fathead minnow (Pimephales promelas), and sheepshead minnow (Cyprinodon variegatus) were increasingly used establishing mechanisms of toxicants. Today, the same organisms provide reliable information at higher levels of biological organization relevant to ecotoxicology. We review studies resolving mechanisms of toxicity and discuss ways to address biocomplexity, mixtures of contaminants, and the need to relate individual level responses to populations and communities.
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Affiliation(s)
- David E Hinton
- Laboratory of Molecular Aquatic Toxicology, Division of Environmental Sciences and Policy, Nicholas School of the Environment and Earth Sciences, Duke University Durham, NC 277-8-0328, USA.
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Blanco GA, Cooper EL. Immune systems, geographic information systems (GIS), environment and health impacts. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2004; 7:465-480. [PMID: 15586880 DOI: 10.1080/10937400490512375] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Exposure to dioxins, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) has been related to alterations in cellular and humoral immune responses in both adaptive and innate immune systems of most animal species. These compounds share a common signaling mechanism to exert their effects on cells of the immune system, which includes the aryl-hydrocarbon receptor (AhR) and the AhR nuclear translocator (ARN). Recently, the interference of AhR-ARNT with the nuclear factor (NF)-kappaB signaling pathway has been proposed as a critical event in the adverse effects on the immune system. Studies on the effects of these AhR-ARNT-related toxicants on the immune system of higher and lower phylum animals and knowledge of intracellular mechanisms of toxicity may contribute to development of biomarkers of ecotoxicant exposure and effects. Biomarkers of this kind allow sampling over extended geographic areas, in several sentinel species, including wildlife animals, and facilitate the building of risk models and risk maps of environmentally induced diseases. On the basis of location, biomarker sampled data obtained through evaluation of ecotoxicant exposure and effects on the immune system in sentinel species can be further integrated and analyzed together with other sources of environmental geographic information, or human population health data, by means of geographic information systems (GIS). The spatial analysis capability of GIS can help to evaluate the complex relationships of overlaid information and to identify areas with high risk indices or "hot spots." This integrative approach can be useful in studies contributing to support environmental and health-related policies and regulations.
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Affiliation(s)
- Guillermo A Blanco
- Department of Immunology, IDEHU-National Research Council (CONICET), School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina.
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SEOK SH, PARK D, PARK JH, CHO SA, BAEK MW, LEE HY, KIM DJ, JIN B, RYU DY, PARK JH. .BETA.-Naphthoflavone Caused Up-Regulation of AhR Regulated GFP in Transgenic Zebrafish. Exp Anim 2004. [DOI: 10.1538/expanim.53.479] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Affiliation(s)
- Seung-Hyeok SEOK
- Department of Laboratory Animal Medicine, College of Veterinary Medicine and School of Agricultural Biotechnology, Seoul National University
| | - DukWoong PARK
- Environmental Health, College of Veterinary Medicine and School of Agricultural Biotechnology, Seoul National University
| | - Jong-Hwan PARK
- Department of Laboratory Animal Medicine, College of Veterinary Medicine and School of Agricultural Biotechnology, Seoul National University
| | - Sun-A CHO
- Department of Laboratory Animal Medicine, College of Veterinary Medicine and School of Agricultural Biotechnology, Seoul National University
| | - Min-Won BAEK
- Department of Laboratory Animal Medicine, College of Veterinary Medicine and School of Agricultural Biotechnology, Seoul National University
| | - Hui-Young LEE
- Department of Laboratory Animal Medicine, College of Veterinary Medicine and School of Agricultural Biotechnology, Seoul National University
| | - Dong-Jae KIM
- Department of Laboratory Animal Medicine, College of Veterinary Medicine and School of Agricultural Biotechnology, Seoul National University
| | - BoHwan JIN
- Environmental Health, College of Veterinary Medicine and School of Agricultural Biotechnology, Seoul National University
| | - Doug-Young RYU
- Environmental Health, College of Veterinary Medicine and School of Agricultural Biotechnology, Seoul National University
| | - Jae-Hak PARK
- Department of Laboratory Animal Medicine, College of Veterinary Medicine and School of Agricultural Biotechnology, Seoul National University
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Affiliation(s)
- Calum A MacRae
- Developmental Biology Laboratory and Cardiovascular Research Center, Massachusetts General Hospital, Charlestown, MA 02129, USA
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Abstract
It is widely believed that embryos and infants during development are highly sensitive to chemicals that cause serious damage to growth. However, knowledge on the mechanisms of developmental toxicity is scarce. One reason for this is limited convenient model system other than organ cultures using rodents to study the various aspects of developmental toxicology. Cultured cells are not always adequate for this purpose, since events in morphogenesis are processed through interactions with other tissues. We focused on zebrafish embryo (Danio rerio), one of the most important organisms in developmental biology. Saturation mutagenesis, applied to drosophila and nematode to define the functions of genes, has been carried out in zebrafish but almost no other vertebrate, and several thousand lines are available due to the rapid growth and transparent body of this embryo. Enhanced databases for the genome and ESTs are available at websites with abundant genetic and biological background. By targeted gene knock-down with morpholino-modified antisense oligonucleotieds (morpholinos), the translation of a specific protein can be transiently blocked for several days. Many reporter systems in vivo have been established mainly as GFP-transgenic fish for environmental chemicals. Although several excellent studies have been performed with zebrafish embryos on the effects of chemicals, the developmental toxicology of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has been most extensively studied to date. We have found that TCDD induces apoptosis in dorsal midbrain with a concomitant decrease in local blood flow, using developing zebrafish. TCDD seems to produce oxidative stress through CYP1A induction in vascular endothelium, resulting in local circulation failure and apoptosis in the dorsal midbrain. In addition to applications in toxicology, an experimental system with zebrafish embryos could help to clarify the mechanism of congenital anomaly, which arises from genetic mutation.
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Affiliation(s)
- Hiroki Teraoka
- Department of Toxicology, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu 069-8501, Japan.
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Kuramoto N, Baba K, Gion K, Sugiyama C, Taniura H, Yoneda Y. Xenobiotic response element binding enriched in both nuclear and microsomal fractions of rat cerebellum. J Neurochem 2003; 85:264-73. [PMID: 12641748 DOI: 10.1046/j.1471-4159.2003.01679.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Xenobiotic response element (XRE) is a core nucleotide sequence at the upstream of inducible target genes for the transcription factor aryl hydrocarbon receptor (AhR) that is responsible for signal transduction of exogenous environmental pollutants in eukaryotic cells. Immunoblotting analysis revealed the constitutive expression of AhR-related proteins in rat liver and brain, while specific binding of a radiolabelled probe containing XRE was detected in nuclear preparations of both liver and brain on gel retardation electrophoresis. Among discrete rat brain structures examined, cerebellum exhibited the highest XRE binding with less potent binding in hypothalamus, midbrain, medulla-oblongata, hippocampus, cerebral cortex and striatum. In contrast to liver and hippocampus, cerebellum also contained unusually higher XRE binding in microsomal fractions than that in either nuclear or mitochondrial fractions. Limited proteolysis by V8 protease did not markedly affect XRE binding in cerebellar nuclear extracts, with concomitant diminution of that in hepatic and hippocampal nuclear extracts. In primary cultured cerebellar neurons, indigo was effective in significantly increasing XRE binding only when determined immediately after sustained exposure for 120 min in the presence of high potassium chloride. These results suggest the abundance of as-yet unidentified proteins with high affinity for XRE and responsiveness to indigo in both nuclear and microsomal fractions of rat cerebellum.
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Affiliation(s)
- Nobuyuki Kuramoto
- Laboratory of Molecular Pharmacology, Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa, Ishikawa, Japan
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Spitsbergen JM, Kent ML. The state of the art of the zebrafish model for toxicology and toxicologic pathology research--advantages and current limitations. Toxicol Pathol 2003; 31 Suppl:62-87. [PMID: 12597434 PMCID: PMC1909756 DOI: 10.1080/01926230390174959] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The zebrafish (Danio rerio) is now the pre-eminent vertebrate model system for clarification of the roles of specific genes and signaling pathways in development. The zebrafish genome will be completely sequenced within the next 1-2 years. Together with the substantial historical database regarding basic developmental biology, toxicology, and gene transfer, the rich foundation of molecular genetic and genomic data makes zebrafish a powerful model system for clarifying mechanisms in toxicity. In contrast to the highly advanced knowledge base on molecular developmental genetics in zebrafish, our database regarding infectious and noninfectious diseases and pathologic lesions in zebrafish lags far behind the information available on most other domestic mammalian and avian species, particularly rodents. Currently, minimal data are available regarding spontaneous neoplasm rates or spontaneous aging lesions in any of the commonly used wild-type or mutant lines of zebrafish. Therefore, to fully utilize the potential of zebrafish as an animal model for understanding human development, disease, and toxicology we must greatly advance our knowledge on zebrafish diseases and pathology.
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Affiliation(s)
- Jan M Spitsbergen
- Department of Environmental and Molecular Toxicology and Marine/Freshwater Biomedical Sciences Center, Oregon State University, Corvallis, Oregon 97333, USA.
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Yu YA, Szalay AA, Wang G, Oberg K. Visualization of molecular and cellular events with green fluorescent proteins in developing embryos: a review. LUMINESCENCE 2003; 18:1-18. [PMID: 12536374 DOI: 10.1002/bio.701] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
During the past 5 years, green fluorescent protein (GFP) has become one of the most widely used in vivo protein markers for studying a number of different molecular processes during development, such as promoter activation, gene expression, protein trafficking and cell lineage determination. GFP fluorescence allows observation of dynamic developmental processes in real time, in both transiently and stably transformed cells, as well as in live embryos. In this review, we include the most up-to-date use of GFP during embryonic development and point out the unique contribution of GFP visualization, which resulted in novel discoveries.
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Affiliation(s)
- Yong A Yu
- Division of Biochemistry, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA
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Kuramoto N, Goto E, Masamune Y, Gion K, Yoneda Y. Existence of xenobiotic response element binding in Dictyostelium. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1578:1-11. [PMID: 12393182 DOI: 10.1016/s0167-4781(02)00449-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Xenobiotic response element (XRE) is a core nucleotide sequence at the upstream of inducible target genes for the transcription factor aryl hydrocarbon receptor (AhR) that is responsible for recognition of exogenous environmental pollutants in eukaryotic cells. Gel retardation electrophoresis revealed the presence of binding of a radiolabeled probe containing XRE in both cytosolic and nuclear preparations of the slime mold Dictyostelium. Unlabeled XRE probe was more potent in competing for XRE binding in both fractions than unlabeled XRE probe with a point mutation at the core element. Limited proteolysis by V8 protease did not markedly affect XRE binding in both fractions, while XRE binding decreased during in vitro incubation at 30 degrees C for up to 24 h at decline rates proportional to increasing pHs at a range of 6.5-8.5 in cytosolic fractions in a manner different from those in nuclear fractions. Deprivation of nutrients induced aggregation of cells within 4-8 h later, followed by formation of first finger tips around 12 h later and subsequent development to mobile slugs within 16 h and then to fruit bodies between 20 and 24 h later. The starvation led to a marked decrement of XRE binding in cytosolic fractions 4-36 h later, followed by a robust but transient increment of that in nuclear extracts 12-20 h afterward. However, XRE binding was not affected by antibodies against AhR-related proteins known to date in both fractions irrespective of nutritional conditions. These results suggest the abundance of as-yet unidentified proteins with high affinity for XRE in the slime mold Dictyostelium. The possibility that those proteins may be translocated from the cytoplasm to the nucleus in response to cellular development during starvation is feasible.
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Affiliation(s)
- Nobuyuki Kuramoto
- Department of Molecular Pharmacology, Kanazawa University Faculty of Pharmaceutical Sciences, 13-1 Takara-machi, Ishikawa 920-0934, Kanazawa, Japan.
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Blechinger SR, Warren JT, Kuwada JY, Krone PH. Developmental toxicology of cadmium in living embryos of a stable transgenic zebrafish line. ENVIRONMENTAL HEALTH PERSPECTIVES 2002; 110:1041-6. [PMID: 12361930 PMCID: PMC1241031 DOI: 10.1289/ehp.021101041] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The toxic effects of cadmium and other heavy metals have been well established, and many of these and other environmental pollutants are known to be embryotoxic or teratogenic. However, it has proven difficult to identify individual cells that respond to toxicants among the wide range of cell populations in an intact animal, particularly during early development when cells are continually changing their molecular and physiologic characteristics as they differentiate. Here we report the establishment of an in vivo system that uses hsp70 gene activation as a measure of cadmium toxicity in living early larvae of transgenic zebrafish carrying a stably integrated hsp70-enhanced green fluorescent protein (eGFP) reporter gene. We demonstrate that eGFP expression in this strain of fish acts as an accurate and reproducible indicator of cell-specific induction of hsp70 gene expression. Furthermore, the transgene responds in a dose-dependent manner at concentrations similar to those observed for morphologic indicators of early-life-stage toxicity and is sensitive enough to detect cadmium at doses below the median combined adverse effect concentration and the median lethal concentration. The stable nature of this transgenic line should allow for extremely rapid and reproducible toxicologic profiling of embryos and larvae throughout development.
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Affiliation(s)
- Scott R Blechinger
- Department of Anatomy and Cell Biology, and Toxicology Group, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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Mattingly CJ, Toscano WA. Posttranscriptional silencing of cytochrome P4501A1 (CYP1A1) during zebrafish (Danio rerio) development. Dev Dyn 2001; 222:645-54. [PMID: 11748833 DOI: 10.1002/dvdy.1215] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Induction patterns of cytochrome P4501A1 (CYP1A1), an early biochemical marker of exposure to the environmental toxicant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, or dioxin) were investigated during zebrafish (Danio rerio) development. A zebrafish CYP1A1 cDNA fragment was cloned and used to detect CYP1A1 mRNA in embryos exposed to TCDD (1 or 10 nM). Induction of CYP1A1 activity was dependent on age and state of hatch. CYP1A1 mRNA was observed by 15 hr postfertilization. CYP1A1 protein and monooxygenase activity were not detected until 3 days postfertilization and after hatch, as determined by Western immunoblot analysis and ethoxyresorufin O-deethylase (EROD) activity, respectively. In contrast to embryos, concomitant induction of mRNA and activity was detected in juvenile zebrafish (3 days posthatch) after 6 hr of TCDD exposure. Asynchronous induction of CYP1A1 mRNA and activity during development may be a general regulatory mechanism, as similar ontogenetic expression of this gene was demonstrated in mouse embryos. To our knowledge, this is the first report of CYP1A1 posttranscriptional silencing during embryogenesis. Our data suggest that TCDD-mediated induction of CYP1A1 activity is regulated differentially in developing and mature systems.
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Affiliation(s)
- C J Mattingly
- Interdisciplinary Program in Molecular Cellular Toxicology, Tulane University, The Tulane/Xavier Center for Bioenvironmental Research, New Orleans, Louisiana, USA
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