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Zhang W, Xue Z, Cao Q, Zong Y, Li X, Ma Y, Jia C, Liu C, Ding N, Wang R. Characterization of medaka (Oryzias latipes) AHRs and the comparison of two model fishes-Medaka vs. zebrafish: The subform-specific sensitivity to dioxin. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 945:174136. [PMID: 38901578 DOI: 10.1016/j.scitotenv.2024.174136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 06/16/2024] [Accepted: 06/17/2024] [Indexed: 06/22/2024]
Abstract
Dioxins and the emerging dioxin-like compounds (DLCs) have recruited increasing concerns about their environmental contamination, toxicity, health impacts, and mechanisms. Based on the structural similarity of dioxins and many DLCs, their toxicity was predominantly mediated by the dioxin receptor (aryl hydrocarbon receptor, AHR) in animals (including human), which can be different in expression and function among species and then possibly produce the species-specific risk or toxicity. To date, characterizing the AHR of additional species other than human and rodents can increase the accuracy of toxicity/risk evaluation and increase knowledge about AHR biology. As a key model, the medaka AHR has not been clearly characterized. Through genome survey and phylogenetic analysis, we identified four AHRs (olaAHR1a, olaAHR1b, olaAHR2a, and olaAHR2b) and two ARNTs (olaARNT1 and olaARNT2). The medaka AHR pathway was conserved in expression in nine tested tissues, of which olaAHR2a represented the predominant subform with greater abundance. Medaka AHRs and ARNTs were functional and could be efficiently transactivated by the classical dioxin congener 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), although olaAHR1a did not seem to cooperate with olaARNT2. In terms of function/sensitivity, the EC50 values of medaka olaAHR1a (9.01 ± 1.43 nM), olaAHR1b (4.00 ± 1.10 nM), olaAHR2a (8.75 ± 3.34 nM), and olaAHR2b (3.06 ± 0.81 nM) showed slight differences; however, they were all at the nM level. The sensitivity of four medaka AHRs to TCDD was similar to that of zebrafish dreAHR2 (the dominant form, EC50 = 3.14 ± 4.19 nM), but these medaka AHRs were more sensitive than zebrafish dreAHR1b (EC50 = 27.05 ± 18.51 nM). The additional comparison also indicated that the EC50 values in various species were usually within the nM range, but AHRs of certain subforms/species can vary by one or two orders of magnitude. In summary, the present study will enhance the understanding of AHR and help improve research on the ecotoxicity of dioxins/DLCs.
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Affiliation(s)
- Wanglong Zhang
- College of Life Sciences, Qufu Normal University, Qufu, Shandong 273165, China.
| | - Zhenhong Xue
- College of Life Sciences, Qufu Normal University, Qufu, Shandong 273165, China
| | - Qining Cao
- College of Life Sciences, Qufu Normal University, Qufu, Shandong 273165, China
| | - Yanjiao Zong
- College of Life Sciences, Qufu Normal University, Qufu, Shandong 273165, China
| | - Xingyang Li
- College of Life Sciences, Qufu Normal University, Qufu, Shandong 273165, China
| | - Yongchao Ma
- Department of Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Chuanxing Jia
- College of Life Sciences, Qufu Normal University, Qufu, Shandong 273165, China
| | - Chunchen Liu
- College of Life Sciences, Qufu Normal University, Qufu, Shandong 273165, China
| | - Ning Ding
- College of Life Sciences, Qufu Normal University, Qufu, Shandong 273165, China.
| | - Renjun Wang
- College of Life Sciences, Qufu Normal University, Qufu, Shandong 273165, China
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Takeda K, Sarata A, Terasaki M, Kubota A, Shimizu K, Kamata R. Assessment of the Aryl Hydrocarbon Receptor-Mediated Effects of Aromatic Sensitizers in Paper Recycling Effluent Employing Zebrafish Embryos and in Silico Docking. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2024; 43:2176-2188. [PMID: 39092783 DOI: 10.1002/etc.5969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 07/08/2024] [Accepted: 07/09/2024] [Indexed: 08/04/2024]
Abstract
Aromatic sensitizers and related substances (SRCs), which are crucial in the paper industry for facilitating color-forming and color-developing chemical reactions, inadvertently contaminate effluents during paper recycling. Owing to their structural resemblance to endocrine-disrupting aromatic organic compounds, concerns have arisen about potential adverse effects on aquatic organisms. We focused on SRC effects via the aryl hydrocarbon receptor (AHR), employing molecular docking simulations and zebrafish (Danio rerio) embryo exposure assessments. Molecular docking revealed heightened binding affinities between certain SRCs in the paper recycling effluents and zebrafish Ahr2 and human AHR, which are pivotal components in the SRC toxicity mechanism. Fertilized zebrafish eggs were exposed to SRCs for up to 96 h post fertilization; among these substances, benzyl 2-naphthyl ether (BNE) caused morphological abnormalities, such as pericardial edema and shortened body length, at relatively low concentrations (1 μM) during embryogenesis. Gene expression of cytochrome P450 1A (cyp1a) and ahr2 was also significantly increased by BNE. Co-exposure to the AHR antagonist CH-223191 only partially mitigated BNE's phenotypic effects, despite the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin being relatively well restored by CH-223191, indicating BNE's AHR-independent toxic mechanisms. Furthermore, some SRCs, including BNE, exhibited in silico binding affinity to the estrogen receptor and upregulation of cyp19a1b gene expression. Therefore, additional insights into the toxicity of SRCs and their mechanisms are essential. The present results provide important information on SRCs and other papermaking chemicals that could help minimize the environmental impact of the paper industry. Environ Toxicol Chem 2024;43:2176-2188. © 2024 SETAC.
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Affiliation(s)
- Kazuki Takeda
- Laboratory of Toxicology, School of Veterinary Medicine, Kitasato University, Towada-shi, Aomori, Japan
- Department of Computer Science, Tokyo Institute of Technology, Yokohama-shi, Kanagawa, Japan
| | - Aoi Sarata
- Laboratory of Toxicology, School of Veterinary Medicine, Kitasato University, Towada-shi, Aomori, Japan
| | - Masanori Terasaki
- Environmental Chemistry Laboratory, Graduate School of Arts and Sciences, Iwate University, Morioka City, Iwate, Japan
| | - Akira Kubota
- Laboratory of Toxicology, Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| | - Keita Shimizu
- Laboratory of Toxicology, School of Veterinary Medicine, Kitasato University, Towada-shi, Aomori, Japan
| | - Ryo Kamata
- Laboratory of Toxicology, School of Veterinary Medicine, Kitasato University, Towada-shi, Aomori, Japan
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Chen F, Pu S, Tian L, Zhang H, Zhou H, Yan Y, Hu X, Wu Q, Chen X, Cheng SH, Xu S. Radix Rehmanniae Praeparata promoted zebrafish fin regeneration through aryl hydrocarbon receptor-dependent autophagy. JOURNAL OF ETHNOPHARMACOLOGY 2024; 331:118272. [PMID: 38710459 DOI: 10.1016/j.jep.2024.118272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 04/21/2024] [Accepted: 04/28/2024] [Indexed: 05/08/2024]
Abstract
HEADINGS ETHNOPHARMACOLOGICAL RELEVANCE Rehmanniae Radix Praeparata (RRP), a staple in traditional Chinese medicine, is derived from Rehmannia glutinosa Libosch and is renowned for its wound-healing properties. Despite its clinical prevalence, the molecular mechanisms underlying RRP's wound-healing effects have not been fully elucidated. AIM OF THE STUDY This research endeavored to delineate the molecular and cellular mechanisms underlying the beneficial effects of RRP on wound healing, utilizing a zebrafish model. MATERIALS AND METHODS Zebrafish larvae at 3 days post-fertilization were amputated at the fin and subsequently treated with RRP. The pro-wound healing and regenerative effects of RRP were evaluated through morphological analysis, assessment of cell proliferation and apoptosis, Additionally, mechanistic insights were gained through a comprehensive approach encompassing network pharmacology analysis, cell tracing, RNA-sequencing, CRISPR/Cas9 gene editing, and pharmacological inhibition. RESULTS Our findings demonstrate that RRP significantly accelerates caudal fin regeneration in zebrafish following injury by suppressing cell apoptosis, promoting cell proliferation, and upregulating the expression of regenerative-related genes. Furthermore, RRP triggers autophagy signals during the regenerative process, which is attenuated by the autophagy inhibitor chloroquine (CQ). Notably, the administration of RRP enhances the expression of ahr1 and ahr2 in the regenerating fin. Genetic knockout of ahr1a, ahr1b, or ahr2 using CRISPR/Cas9, or pharmacological blockade of AHR signals with the antagonist CH-223191, diminishes the regenerative potential of RRP. Remarkably, zebrafish lacking ahr2 completely lose their fin regeneration ability. Additionally, inhibition of AHR signaling suppresses autophagy signaling during fin regeneration. CONCLUSIONS This study uncovers that RRP stimulates fin regeneration in zebrafish by inducing AHR signals and, at least partially, activating the autophagy process. These findings provide novel insights into the molecular mechanisms underlying the wound-healing effects of RRP and may pave the way for the development of novel therapeutic strategies.
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Affiliation(s)
- Fengyan Chen
- Guangxi Universities Key Laboratory of Stem Cell and Biopharmaceutical Technology, Guangxi Normal University, Guangxi Zhuang Autonomous Region, Guilin, China; Research Center for Biomedical Sciences, Guangxi Normal University, Guangxi Zhuang Autonomous Region, Guilin, China; College of Life Sciences, Guangxi Normal University, Guangxi Zhuang Autonomous Region, Guilin, China
| | - Shiming Pu
- Guangxi Universities Key Laboratory of Stem Cell and Biopharmaceutical Technology, Guangxi Normal University, Guangxi Zhuang Autonomous Region, Guilin, China; Research Center for Biomedical Sciences, Guangxi Normal University, Guangxi Zhuang Autonomous Region, Guilin, China; College of Life Sciences, Guangxi Normal University, Guangxi Zhuang Autonomous Region, Guilin, China
| | - Li Tian
- Department of Biomedical Sciences, College of Veterinary Medicine and Life Science, City University of Hong Kong, Hong Kong SAR, China
| | - Huan Zhang
- Department of Food Science and Nutrition, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Huixian Zhou
- Guangxi Universities Key Laboratory of Stem Cell and Biopharmaceutical Technology, Guangxi Normal University, Guangxi Zhuang Autonomous Region, Guilin, China; Research Center for Biomedical Sciences, Guangxi Normal University, Guangxi Zhuang Autonomous Region, Guilin, China; College of Life Sciences, Guangxi Normal University, Guangxi Zhuang Autonomous Region, Guilin, China
| | - Yijing Yan
- Guangxi Universities Key Laboratory of Stem Cell and Biopharmaceutical Technology, Guangxi Normal University, Guangxi Zhuang Autonomous Region, Guilin, China; Research Center for Biomedical Sciences, Guangxi Normal University, Guangxi Zhuang Autonomous Region, Guilin, China; College of Life Sciences, Guangxi Normal University, Guangxi Zhuang Autonomous Region, Guilin, China
| | - Xiaolin Hu
- School of Economics and Management, Guangxi Normal University, Guangxi Zhuang Autonomous Region, Guilin, China
| | - Qiong Wu
- Guangxi Universities Key Laboratory of Stem Cell and Biopharmaceutical Technology, Guangxi Normal University, Guangxi Zhuang Autonomous Region, Guilin, China; Research Center for Biomedical Sciences, Guangxi Normal University, Guangxi Zhuang Autonomous Region, Guilin, China; College of Life Sciences, Guangxi Normal University, Guangxi Zhuang Autonomous Region, Guilin, China
| | - Xueping Chen
- Vitargent (International) Biotechnology Limited, Unit 516, 5/F. Biotech Centre 2, No. 11 Science Park West Avenue, Hong Kong Science Park, Shatin, Hong Kong SAR, China
| | - Shuk Han Cheng
- Department of Biomedical Sciences, College of Veterinary Medicine and Life Science, City University of Hong Kong, Hong Kong SAR, China
| | - Shisan Xu
- Guangxi Universities Key Laboratory of Stem Cell and Biopharmaceutical Technology, Guangxi Normal University, Guangxi Zhuang Autonomous Region, Guilin, China; Research Center for Biomedical Sciences, Guangxi Normal University, Guangxi Zhuang Autonomous Region, Guilin, China; College of Life Sciences, Guangxi Normal University, Guangxi Zhuang Autonomous Region, Guilin, China.
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Disner GR, Fernandes TADM, Nishiyama-Jr MY, Lima C, Wincent E, Lopes-Ferreira M. TnP and AHR-CYP1A1 Signaling Crosstalk in an Injury-Induced Zebrafish Inflammation Model. Pharmaceuticals (Basel) 2024; 17:1155. [PMID: 39338318 PMCID: PMC11435205 DOI: 10.3390/ph17091155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2024] [Revised: 08/21/2024] [Accepted: 08/29/2024] [Indexed: 09/30/2024] Open
Abstract
Aryl Hydrocarbon Receptor (AHR) signaling is crucial for regulating the biotransformation of xenobiotics and physiological processes like inflammation and immunity. Meanwhile, Thalassophryne nattereri Peptide (TnP), a promising anti-inflammatory candidate from toadfish venom, demonstrates therapeutic effects through immunomodulation. However, its influence on AHR signaling remains unexplored. This study aimed to elucidate TnP's molecular mechanisms on the AHR-cytochrome P450, family 1 (CYP1) pathway upon injury-induced inflammation in wild-type (WT) and Ahr2-knockdown (KD) zebrafish larvae through transcriptomic analysis and Cyp1a reporters. TnP, while unable to directly activate AHR, potentiated AHR activation by the high-affinity ligand 6-Formylindolo [3,2-b]carbazole (FICZ), implying a role as a CYP1A inhibitor, confirmed by in vitro studies. This interplay suggests TnP's ability to modulate the AHR-CYP1 complex, prompting investigations into its influence on biotransformation pathways and injury-induced inflammation. Here, the inflammation model alone resulted in a significant response on the transcriptome, with most differentially expressed genes (DEGs) being upregulated across the groups. Ahr2-KD resulted in an overall greater number of DEGs, as did treatment with the higher dose of TnP in both WT and KD embryos. Genes related to oxidative stress and inflammatory response were the most apparent under inflamed conditions for both WT and KD groups, e.g., Tnfrsf1a, Irf1b, and Mmp9. TnP, specifically, induces the expression of Hspa5, Hsp90aa1.2, Cxcr3.3, and Mpeg1.2. Overall, this study suggests an interplay between TnP and the AHR-CYP1 pathway, stressing the inflammatory modulation through AHR-dependent mechanisms. Altogether, these results may offer new avenues in novel therapeutic strategies, such as based on natural bioactive molecules, harnessing AHR modulation for targeted and sustained drug effects in inflammatory conditions.
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Affiliation(s)
- Geonildo Rodrigo Disner
- Immunoregulation Unit, Laboratory of Applied Toxinology (CeTICS/FAPESP), Butantan Institute, São Paulo 05585-000, Brazil
- Unit of System Toxicology, Institute of Environmental Medicine, Karolinska Institutet, 171 77 Solna, Sweden
| | - Thales Alves de Melo Fernandes
- Nucleus of Bioinformatics and Computational Biology, Laboratory of Applied Toxinology, Butantan Institute, São Paulo 05585-000, Brazil
| | - Milton Yutaka Nishiyama-Jr
- Nucleus of Bioinformatics and Computational Biology, Laboratory of Applied Toxinology, Butantan Institute, São Paulo 05585-000, Brazil
| | - Carla Lima
- Immunoregulation Unit, Laboratory of Applied Toxinology (CeTICS/FAPESP), Butantan Institute, São Paulo 05585-000, Brazil
| | - Emma Wincent
- Unit of System Toxicology, Institute of Environmental Medicine, Karolinska Institutet, 171 77 Solna, Sweden
| | - Monica Lopes-Ferreira
- Immunoregulation Unit, Laboratory of Applied Toxinology (CeTICS/FAPESP), Butantan Institute, São Paulo 05585-000, Brazil
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Miller JT, Clark BW, Reid NM, Karchner SI, Roach JL, Hahn ME, Nacci D, Whitehead A. Independently evolved pollution resistance in four killifish populations is largely explained by few variants of large effect. Evol Appl 2024; 17:e13648. [PMID: 38293268 PMCID: PMC10824703 DOI: 10.1111/eva.13648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 01/02/2024] [Accepted: 01/09/2024] [Indexed: 02/01/2024] Open
Abstract
The genetic architecture of phenotypic traits can affect the mode and tempo of trait evolution. Human-altered environments can impose strong natural selection, where successful evolutionary adaptation requires swift and large phenotypic shifts. In these scenarios, theory predicts that adaptation is due to a few adaptive variants of large effect, but empirical studies that have revealed the genetic architecture of rapidly evolved phenotypes are rare, especially for populations inhabiting polluted environments. Fundulus killifish have repeatedly evolved adaptive resistance to extreme pollution in urban estuaries. Prior studies, including genome scans for signatures of natural selection, have revealed some of the genes and pathways important for evolved pollution resistance, and provide context for the genotype-phenotype association studies reported here. We created multiple quantitative trait locus (QTL) mapping families using progenitors from four different resistant populations, and using RAD-seq genetically mapped variation in sensitivity (developmental perturbations) following embryonic exposure to a model toxicant PCB-126. We found that one to two large-effect QTL loci accounted for resistance to PCB-mediated developmental toxicity. QTLs harbored candidate genes that govern the regulation of aryl hydrocarbon receptor (AHR) signaling. One QTL locus was shared across all populations and another was shared across three populations. One QTL locus showed strong signatures of recent natural selection in the corresponding wild population but another QTL locus did not. Some candidate genes for PCB resistance inferred from genome scans in wild populations were identified as QTL, but some key candidate genes were not. We conclude that rapidly evolved resistance to the developmental defects normally caused by PCB-126 is governed by few genes of large effect. However, other aspects of resistance beyond developmental phenotypes may be governed by additional loci, such that comprehensive resistance to PCB-126, and to the mixtures of chemicals that distinguish urban estuaries more broadly, may be more genetically complex.
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Affiliation(s)
- Jeffrey T. Miller
- Department of Environmental Toxicology, Center for Population Biology, Coastal and Marine Sciences InstituteUniversity of California, DavisDavisCaliforniaUSA
- Present address:
Molecular, Cellular, and Biomedical SciencesUniversity of New HampshireDurhamNew HampshireUSA
| | - Bryan W. Clark
- Office of Research and Development, Center for Environmental Measurement and Modeling, Atlantic Coastal Environmental Sciences DivisionUS Environmental Protection AgencyNarragansettRhode IslandUSA
| | - Noah M. Reid
- Department of Molecular & Cell BiologyUniversity of ConnecticutStorrsConnecticutUSA
| | - Sibel I. Karchner
- Biology DepartmentWoods Hole Oceanographic InstitutionWoods HoleMassachusettsUSA
| | - Jennifer L. Roach
- Department of Environmental Toxicology, Center for Population Biology, Coastal and Marine Sciences InstituteUniversity of California, DavisDavisCaliforniaUSA
| | - Mark E. Hahn
- Biology DepartmentWoods Hole Oceanographic InstitutionWoods HoleMassachusettsUSA
| | - Diane Nacci
- Office of Research and Development, Center for Environmental Measurement and Modeling, Atlantic Coastal Environmental Sciences DivisionUS Environmental Protection AgencyNarragansettRhode IslandUSA
| | - Andrew Whitehead
- Department of Environmental Toxicology, Center for Population Biology, Coastal and Marine Sciences InstituteUniversity of California, DavisDavisCaliforniaUSA
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Cintrón-Rivera LG, Burns N, Patel R, Plavicki JS. Exposure to the aryl hydrocarbon receptor agonist dioxin disrupts formation of the muscle, nerves, and vasculature in the developing jaw. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 337:122499. [PMID: 37660771 DOI: 10.1016/j.envpol.2023.122499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 08/14/2023] [Accepted: 08/31/2023] [Indexed: 09/05/2023]
Abstract
Human exposure to environmental pollutants can disrupt embryonic development and impact juvenile and adult health outcomes by adversely affecting cell and organ function. Notwithstanding, environmental contamination continues to increase due to industrial development, insufficient regulations, and the mobilization of pollutants as a result of extreme weather events. Dioxins are a class of structurally related persistent organic pollutants that are highly toxic, carcinogenic, and teratogenic. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is the most potent dioxin compound and has been shown to induce toxic effects in developing organisms by activating the aryl hydrocarbon receptor (AHR), a ligand activated transcription factor targeted by multiple persistent organic pollutants. Contaminant-induced AHR activation results in malformations of the craniofacial cartilages and neurocranium; however, the mechanisms mediating these phenotypes are not well understood. In this study, we utilized the optically transparent zebrafish model to elucidate novel cellular targets and potential transcriptional targets underlying TCDD-induced craniofacial malformations. To this end, we exposed zebrafish embryos at 4 h post fertilization to TCDD and employed a mixed-methods approach utilizing immunohistochemistry staining, transgenic reporter lines, fixed and in vivo confocal imaging, and timelapse microscopy to determine the targets mediating TCDD-induced craniofacial phenotypes. Our data indicate that embryonic TCDD exposure reduced jaw and pharyngeal arch Sox10+ chondrocytes and Tcf21+ pharyngeal mesoderm progenitors. Exposure to TCDD correspondingly led to a reduction in collagen type II deposition in Sox10+ domains. Embryonic TCDD exposure impaired development of tissues derived from or guided by Tcf21+ progenitors, namely: nerves, muscle, and vasculature. Specifically, TCDD exposure disrupted development of the hyoid and mandibular arch muscles, decreased neural innervation of the jaw, resulted in compression of cranial nerves V and VII, and led to jaw vasculature malformations. Collectively, these findings reveal novel structural targets and potential transcriptional targets of TCDD-induced toxicity, showcasing how contaminant exposures lead to congenital craniofacial malformations.
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Affiliation(s)
- Layra G Cintrón-Rivera
- Department of Pathology and Laboratory Medicine, Brown University, 70 Ship St, Providence, RI, 02903, USA
| | - Nicole Burns
- Department of Pathology and Laboratory Medicine, Brown University, 70 Ship St, Providence, RI, 02903, USA
| | - Ratna Patel
- Department of Pathology and Laboratory Medicine, Brown University, 70 Ship St, Providence, RI, 02903, USA
| | - Jessica S Plavicki
- Department of Pathology and Laboratory Medicine, Brown University, 70 Ship St, Providence, RI, 02903, USA.
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Elizalde MJ, Gorelick DA. Mechanistic toxicology in light of genetic compensation. Toxicol Sci 2023; 197:kfad113. [PMID: 37941503 PMCID: PMC10823772 DOI: 10.1093/toxsci/kfad113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2023] Open
Abstract
Mechanistic toxicology seeks to identify the molecular and cellular mechanisms by which toxicants exert their deleterious effects. One powerful approach is to generate mutations in genes that respond to a particular toxicant, and then test how such mutations change the effects of the toxicant. CRISPR is a rapid and versatile approach to generate mutations in cultured cells and in animal models. Many studies use CRISPR to generate short insertions or deletions in a target gene and then assume that the resulting mutation, such as a premature termination codon, causes a loss of functional protein. However, recent studies demonstrate that this assumption is flawed. Cells can compensate for short insertion and deletion mutations, leading toxicologists to draw erroneous conclusions from mutant studies. In this review, we will discuss mechanisms by which a mutation in one gene may be rescued by compensatory activity. We will discuss how CRISPR insertion and deletion mutations are susceptible to compensation by transcriptional adaptation, alternative splicing, and rescue by maternally derived gene products. We will review evidence that measuring levels of messenger RNA transcribed from a mutated gene is an unreliable indicator of the severity of the mutation. Finally, we provide guidelines for using CRISPR to generate mutations that avoid compensation.
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Affiliation(s)
- Mary Jane Elizalde
- Department of Molecular & Cellular Biology, Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX 77030, United States
| | - Daniel A Gorelick
- Department of Molecular & Cellular Biology, Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX 77030, United States
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8
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Edwards HE, Elizalde MJ, Souder JP, Gorelick DA. Hemato-vascular specification requires arnt1 and arnt2 genes in zebrafish embryos. Development 2023; 150:dev200500. [PMID: 37039097 PMCID: PMC10163348 DOI: 10.1242/dev.200500] [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: 01/04/2022] [Accepted: 03/27/2023] [Indexed: 04/12/2023]
Abstract
During embryonic development, a subset of cells in the mesoderm germ layer are specified as hemato-vascular progenitor cells, which then differentiate into endothelial cells and hematopoietic stem and progenitor cells. In zebrafish, the transcription factor npas4l (cloche) is required for the specification of hemato-vascular progenitor cells. However, it is unclear whether npas4l is the sole factor at the top of the hemato-vascular specification cascade. Here, we show that arnt1 and arnt2 genes are required for hemato-vascular specification. We found that arnt1;arnt2 double mutant zebrafish embryos, but not arnt1 or arnt2 single mutants, lack blood cells and most endothelial cells. arnt1/2 mutants have reduced or absent expression of etsrp and tal1, the earliest known endothelial and hematopoietic transcription factor genes. We found that Npas4l binds both Arnt1 and Arnt2 proteins in vitro, consistent with the idea that PAS domain-containing bHLH transcription factors act in a multimeric complex to regulate gene expression. Our results demonstrate that npas4l, arnt1 and arnt2 act together to regulate endothelial and hematopoietic cell fate, where each gene is necessary, but not sufficient, to drive hemato-vascular specification.
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Affiliation(s)
- Hailey E. Edwards
- Center for Precision Environmental Health, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Mary Jane Elizalde
- Center for Precision Environmental Health, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jaclyn P. Souder
- Center for Precision Environmental Health, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Daniel A. Gorelick
- Center for Precision Environmental Health, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
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Miller JT, Clark BW, Reid NM, Karchner SI, Roach JL, Hahn ME, Nacci D, Whitehead A. Independently evolved pollution resistance in four killifish populations is largely explained by few variants of large effect. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.07.536079. [PMID: 37066319 PMCID: PMC10104127 DOI: 10.1101/2023.04.07.536079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Abstract
The genetic architecture of phenotypic traits can affect the mode and tempo of trait evolution. Human-altered environments can impose strong natural selection, where successful evolutionary adaptation requires swift and large phenotypic shifts. In these scenarios, theory predicts the influence of few adaptive variants of large effect, but empirical studies that have revealed the genetic architecture of rapidly evolved phenotypes are rare, especially for populations inhabiting polluted environments. Fundulus killifish have repeatedly evolved adaptive resistance to extreme pollution in urban estuaries. Prior studies, including genome scans for signatures of natural selection, have revealed some of the genes and pathways important for evolved pollution resistance, and provide context for the genotype-phenotype association studies reported here. We created multiple quantitative trait locus (QTL) mapping families using progenitors from four different resistant populations, and genetically mapped variation in sensitivity (developmental perturbations) following embryonic exposure to a model toxicant PCB-126. We found that a few large-effect QTL loci accounted for resistance to PCB-mediated developmental toxicity. QTLs harbored candidate genes that govern the regulation of aryl hydrocarbon receptor (AHR) signaling, where some (but not all) of these QTL loci were shared across all populations, and some (but not all) of these loci showed signatures of recent natural selection in the corresponding wild population. Some strong candidate genes for PCB resistance inferred from genome scans in wild populations were identified as QTL, but some key candidate genes were not. We conclude that rapidly evolved resistance to the developmental defects normally caused by PCB-126 is governed by few genes of large effect. However, other aspects of resistance beyond developmental phenotypes may be governed by additional loci, such that comprehensive resistance to PCB-126, and to the mixtures of chemicals that distinguish urban estuaries more broadly, may be more genetically complex.
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Affiliation(s)
- Jeffrey T Miller
- Department of Environmental Toxicology, Center for Population Biology, Coastal and Marine Sciences Institute, University of California, Davis, CA
| | - Bryan W Clark
- US Environmental Protection Agency, Office of Research and Development, Center for Environmental Measurement and Modeling, Atlantic Coastal Environmental Sciences Division, Narragansett, RI
| | - Noah M Reid
- Department of Molecular & Cell Biology, University of Connecticut, Storrs, CT
| | - Sibel I Karchner
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA
| | - Jennifer L Roach
- Department of Environmental Toxicology, Center for Population Biology, Coastal and Marine Sciences Institute, University of California, Davis, CA
| | - Mark E Hahn
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA
| | - Diane Nacci
- US Environmental Protection Agency, Office of Research and Development, Center for Environmental Measurement and Modeling, Atlantic Coastal Environmental Sciences Division, Narragansett, RI
| | - Andrew Whitehead
- Department of Environmental Toxicology, Center for Population Biology, Coastal and Marine Sciences Institute, University of California, Davis, CA
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Mi P, Li N, Ai K, Li L, Yuan D. AhR-mediated lipid peroxidation contributes to TCDD-induced cardiac defects in zebrafish. CHEMOSPHERE 2023; 317:137942. [PMID: 36702031 DOI: 10.1016/j.chemosphere.2023.137942] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 01/20/2023] [Accepted: 01/21/2023] [Indexed: 06/18/2023]
Abstract
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), a persistent environmental contaminant that activates the aryl hydrocarbon receptor (AhR) pathway, has been reported to cause cardiac damage. However, the mechanism underlying AhR-induced cardiac defects in response to TCDD exposure remains unclear. In this study, we characterized the impacts of TCDD exposure on heart morphology and cardiac function in zebrafish. TCDD exposure in the early developmental stage of zebrafish embryos led to morphological heart malformation and pericardial edema, concomitant with reduced cardiac function. These cardiac defects were attenuated by inhibiting AhR activity with CH223191. Transcriptome profiling showed that, along with an upregulation of the AhR signaling pathway by TCDD treatment, the expression of pro-ferroptotic genes was upregulated, while that of genes implicated in glutathione metabolism were downregulated. Moreover, lipid peroxidation, as indicated by malonaldehyde (MDA) production, was increased in TCDD-exposed cardiac tissue. Accordingly, inhibiting lipid peroxidation with liproxstatin-1 reversed the adverse cardiac effects induced by TCDD treatment. Taken together, our findings demonstrate that AhR-mediated lipid peroxidation contributes to cardiac defects in the early developmental stage in zebrafish embryos exposed to TCDD.
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Affiliation(s)
- Ping Mi
- Department of Biochemistry & Molecular Biology, School of Basic Medical Sciences, Shandong University, Jinan, Shandong, 250012, China; Key Laboratory of Experimental Teratology, Ministry of Education, Shandong University, Jinan, Shandong, 250012, China
| | - Na Li
- Department of Histology and Embryology, School of Basic Medical Sciences, Shandong University, Jinan, Shandong, 250012, China; Key Laboratory of Experimental Teratology, Ministry of Education, Shandong University, Jinan, Shandong, 250012, China
| | - Kang Ai
- Department of Histology and Embryology, School of Basic Medical Sciences, Shandong University, Jinan, Shandong, 250012, China; Key Laboratory of Experimental Teratology, Ministry of Education, Shandong University, Jinan, Shandong, 250012, China
| | - Lei Li
- Department of Histology and Embryology, School of Basic Medical Sciences, Shandong University, Jinan, Shandong, 250012, China; Key Laboratory of Experimental Teratology, Ministry of Education, Shandong University, Jinan, Shandong, 250012, China.
| | - Detian Yuan
- Department of Biochemistry & Molecular Biology, School of Basic Medical Sciences, Shandong University, Jinan, Shandong, 250012, China.
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11
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Kossack ME, Manz KE, Martin NR, Pennell KD, Plavicki J. Environmentally relevant uptake, elimination, and metabolic changes following early embryonic exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin in zebrafish. CHEMOSPHERE 2023; 310:136723. [PMID: 36241106 PMCID: PMC9835613 DOI: 10.1016/j.chemosphere.2022.136723] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 08/16/2022] [Accepted: 09/30/2022] [Indexed: 06/03/2023]
Abstract
Dioxin and dioxin-like compounds are ubiquitous environmental contaminants that induce toxicity by binding to the aryl hydrocarbon receptor (AHR), a ligand activated transcription factor. The zebrafish model has been used to define the developmental toxicity observed following exposure to exogenous AHR ligands such as the potent agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (dioxin, TCDD). While the model has successfully identified cellular targets of TCDD and molecular mechanisms mediating TCDD-induced phenotypes, fundamental information such as the body burden produced by standard exposure models is still unknown. We performed targeted gas chromatography (GC) high-resolution mass spectrometry (HRMS) in tandem with non-targeted liquid chromatography (LC) HRMS to quantify TCDD uptake, model the elimination dynamics of TCDD, and determine how TCDD exposure affects the zebrafish metabolome. We found that 50 ppt, 10 ppb, and 1 ppb waterborne exposures to TCDD during early embryogenesis produced environmentally relevant body burdens: 38 ± 4.34, 26.6 ± 1.2, and 8.53 ± 0.341 pg/embryo, respectively, at 24 hours post fertilization. TCDD exposure was associated with the dysregulation of metabolic pathways that are associated with the AHR signaling pathway as well as pathways shown to be affected in mammals following TCDD exposure. In addition, we discovered that TCDD exposure affected several metabolic pathways that are critical for brain development and function including glutamate metabolism, chondroitin sulfate biosynthesis, and tyrosine metabolism. Together, these data demonstrate that existing exposure methods produce environmentally relevant body burdens of TCDD in zebrafish and provide insight into the biochemical pathways impacted by toxicant-induced AHR activation.
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Affiliation(s)
- Michelle E Kossack
- Department of Pathology and Laboratory Medicine, Brown University, 70 Ship St, Providence, RI, 02903, USA
| | - Katherine E Manz
- School of Engineering, Brown University, 184 Hope St, Box D, Providence, RI, 02903, USA
| | - Nathan R Martin
- Department of Pathology and Laboratory Medicine, Brown University, 70 Ship St, Providence, RI, 02903, USA
| | - Kurt D Pennell
- School of Engineering, Brown University, 184 Hope St, Box D, Providence, RI, 02903, USA
| | - Jessica Plavicki
- Department of Pathology and Laboratory Medicine, Brown University, 70 Ship St, Providence, RI, 02903, USA.
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12
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Martin NR, Patel R, Kossack ME, Tian L, Camarillo MA, Cintrón-Rivera LG, Gawdzik JC, Yue MS, Nwagugo FO, Elemans LMH, Plavicki JS. Proper modulation of AHR signaling is necessary for establishing neural connectivity and oligodendrocyte precursor cell development in the embryonic zebrafish brain. Front Mol Neurosci 2022; 15:1032302. [PMID: 36523606 PMCID: PMC9745199 DOI: 10.3389/fnmol.2022.1032302] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 10/24/2022] [Indexed: 12/03/2022] Open
Abstract
2,3,7,8-tetrachlorodibenzo-[p]-dioxin (TCDD) is a persistent global pollutant that exhibits a high affinity for the aryl hydrocarbon receptor (AHR), a ligand activated transcription factor. Epidemiological studies have associated AHR agonist exposure with multiple human neuropathologies. Consistent with the human data, research studies using laboratory models have linked pollutant-induced AHR activation to disruptions in learning and memory as well as motor impairments. Our understanding of endogenous AHR functions in brain development is limited and, correspondingly, scientists are still determining which cell types and brain regions are sensitive to AHR modulation. To identify novel phenotypes resulting from pollutant-induced AHR activation and ahr2 loss of function, we utilized the optically transparent zebrafish model. Early embryonic TCDD exposure impaired embryonic brain morphogenesis, resulted in ventriculomegaly, and disrupted neural connectivity in the optic tectum, habenula, cerebellum, and olfactory bulb. Altered neural network formation was accompanied by reduced expression of synaptic vesicle 2. Loss of ahr2 function also impaired nascent network development, but did not affect gross brain or ventricular morphology. To determine whether neural AHR activation was sufficient to disrupt connectivity, we used the Gal4/UAS system to express a constitutively active AHR specifically in differentiated neurons and observed disruptions only in the cerebellum; thus, suggesting that the phenotypes resulting from global AHR activation likely involve multiple cell types. Consistent with this hypothesis, we found that TCDD exposure reduced the number of oligodendrocyte precursor cells and their derivatives. Together, our findings indicate that proper modulation of AHR signaling is necessary for the growth and maturation of the embryonic zebrafish brain.
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Affiliation(s)
- Nathan R. Martin
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, United States
| | - Ratna Patel
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, United States
| | - Michelle E. Kossack
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, United States
| | - Lucy Tian
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, United States
| | - Manuel A. Camarillo
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, United States
| | - Layra G. Cintrón-Rivera
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, United States
| | - Joseph C. Gawdzik
- Molecular and Environmental Toxicology Center, University of Wisconsin at Madison, Madison, WI, United States,Division of Pharmaceutical Sciences, University of Wisconsin at Madison, Madison, WI, United States
| | - Monica S. Yue
- Molecular and Environmental Toxicology Center, University of Wisconsin at Madison, Madison, WI, United States,Division of Pharmaceutical Sciences, University of Wisconsin at Madison, Madison, WI, United States
| | - Favour O. Nwagugo
- Department of Biology, University of Maryland Baltimore County, Baltimore, MD, United States
| | - Loes M. H. Elemans
- Division of Toxicology, Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, Netherlands
| | - Jessica S. Plavicki
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, United States,*Correspondence: Jessica S. Plavicki,
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13
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Karim N, Lin LW, Van Eenennaam JP, Fangue NA, Schreier AD, Phillips MA, Rice RH. Epidermal cell cultures from white and green sturgeon (Acipenser transmontanus and medirostris): Expression of TGM1-like transglutaminases and CYP4501A. PLoS One 2022; 17:e0265218. [PMID: 35294467 PMCID: PMC8926185 DOI: 10.1371/journal.pone.0265218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 02/25/2022] [Indexed: 11/18/2022] Open
Abstract
Using a system optimized for propagating human keratinocytes, culture of skin samples from white and green sturgeons generated epithelial cells capable of making cross-linked protein envelopes. Two distinct forms of TGM1-like mRNA were molecularly cloned from the cells of white sturgeon and detected in green sturgeon cells, accounting for their cellular envelope forming ability. The protein translated from each displayed a cluster of cysteine residues resembling the membrane anchorage region expressed in epidermal cells of teleosts and tetrapods. One of the two mRNA forms (called A) was present at considerably higher levels than the other (called B) in both species. Continuous lines of white sturgeon epidermal cells were established and characterized. Size measurements indicated that a substantial fraction of the cells became enlarged, appearing similar to squames in human epidermal keratinocyte cultures. The cultures also expressed CYP1A, a cytochrome P450 enzyme inducible by activation of aryl hydrocarbon receptor 2 in fish. The cells gradually improved in growth rate over a dozen passages while retaining envelope forming ability, TGM1 expression and CYP1A inducibility. These cell lines are thus potential models for studying evolution of fish epidermis leading to terrestrial adaptation and for testing sturgeon sensitivity to environmental stresses such as pollution.
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Affiliation(s)
- Noreen Karim
- Department of Environmental Toxicology, University of California, Davis, California, United States of America
- * E-mail:
| | - Lo-Wei Lin
- Department of Environmental Toxicology, University of California, Davis, California, United States of America
| | - Joel P. Van Eenennaam
- Department of Animal Science, University of California, Davis, California, United States of America
| | - Nann A. Fangue
- Department of Wildlife, Fish and Conservation Biology, University of California, Davis, California, United States of America
| | - Andrea D. Schreier
- Department of Animal Science, University of California, Davis, California, United States of America
| | - Marjorie A. Phillips
- Department of Environmental Toxicology, University of California, Davis, California, United States of America
| | - Robert H. Rice
- Department of Environmental Toxicology, University of California, Davis, California, United States of America
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14
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Xu X, Zhang X, Yuan Y, Zhao Y, Fares HM, Yang M, Wen Q, Taha R, Sun L. Species-Specific Differences in Aryl Hydrocarbon Receptor Responses: How and Why? Int J Mol Sci 2021; 22:ijms222413293. [PMID: 34948089 PMCID: PMC8708342 DOI: 10.3390/ijms222413293] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 11/19/2021] [Accepted: 12/03/2021] [Indexed: 12/16/2022] Open
Abstract
The aryl hydrocarbon receptor (AhR) is a transcription factor that regulates a wide range of biological and toxicological effects by binding to specific ligands. AhR ligands exist in various internal and external ecological systems, such as in a wide variety of hydrophobic environmental contaminants and naturally occurring chemicals. Most of these ligands have shown differential responses among different species. Understanding the differences and their mechanisms helps in designing better experimental animal models, improves our understanding of the environmental toxicants related to AhR, and helps to screen and develop new drugs. This review systematically discusses the species differences in AhR activation effects and their modes of action. We focus on the species differences following AhR activation from two aspects: (1) the molecular configuration and activation of AhR and (2) the contrast of cis-acting elements corresponding to AhR. The variations in the responses seen in humans and other species following the activation of the AhR signaling pathway can be attributed to both factors.
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Affiliation(s)
- Xiaoting Xu
- Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing 210009, China; (X.X.); (X.Z.); (Y.Y.); (Y.Z.); (H.M.F.); (M.Y.); (Q.W.); (R.T.)
| | - Xi Zhang
- Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing 210009, China; (X.X.); (X.Z.); (Y.Y.); (Y.Z.); (H.M.F.); (M.Y.); (Q.W.); (R.T.)
| | - Yuzhu Yuan
- Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing 210009, China; (X.X.); (X.Z.); (Y.Y.); (Y.Z.); (H.M.F.); (M.Y.); (Q.W.); (R.T.)
| | - Yongrui Zhao
- Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing 210009, China; (X.X.); (X.Z.); (Y.Y.); (Y.Z.); (H.M.F.); (M.Y.); (Q.W.); (R.T.)
| | - Hamza M. Fares
- Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing 210009, China; (X.X.); (X.Z.); (Y.Y.); (Y.Z.); (H.M.F.); (M.Y.); (Q.W.); (R.T.)
| | - Mengjiao Yang
- Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing 210009, China; (X.X.); (X.Z.); (Y.Y.); (Y.Z.); (H.M.F.); (M.Y.); (Q.W.); (R.T.)
| | - Qing Wen
- Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing 210009, China; (X.X.); (X.Z.); (Y.Y.); (Y.Z.); (H.M.F.); (M.Y.); (Q.W.); (R.T.)
| | - Reham Taha
- Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing 210009, China; (X.X.); (X.Z.); (Y.Y.); (Y.Z.); (H.M.F.); (M.Y.); (Q.W.); (R.T.)
| | - Lixin Sun
- Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing 210009, China; (X.X.); (X.Z.); (Y.Y.); (Y.Z.); (H.M.F.); (M.Y.); (Q.W.); (R.T.)
- Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, Ministry of Education, Nanjing 210009, China
- Correspondence: ; Tel.: +86-151-9599-9925
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15
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Navarrete J, Wilson P, Allsing N, Gordon C, Margolis R, Schwartz AV, Cho C, Rogowski B, Topps J, George UZ, Sant KE. The ecotoxicological contaminant tris(4-chlorophenyl)methanol (TCPMOH) impacts embryonic development in zebrafish (Danio rerio). AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2021; 235:105815. [PMID: 33838494 PMCID: PMC8113121 DOI: 10.1016/j.aquatox.2021.105815] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 03/15/2021] [Accepted: 03/19/2021] [Indexed: 06/12/2023]
Abstract
Tris(4-chlorophenyl)methanol (TCPMOH) is a water contaminant with unknown etiology, but is believed to be a byproduct of DDT manufacturing. It is highly persistent in the environment, and bioaccumulates in marine species. TCPMOH has also been measured in human breast milk, which poses a risk for developing infants. However, almost no toxicity data is currently available. In this study, we investigate the hazard posed by developmental TCPMOH exposures using the zebrafish model (Danio rerio). Zebrafish (Danio rerio) embryos were exposed to 0, 0.1, 0.5, 1, or 5 µM TCPMOH beginning at 24 h post fertilization (hpf). Embryonic mortality and incidence of morphological deformities increased in a concentration-dependent manner with TCPMOH exposure. RNA sequencing assessed changes in gene expression associated with acute (4 hour) exposures to 50 nM TCPMOH. Developmental exposure to TCPMOH decreased expression of ahr2, as well as metabolic enzymes cyp1a1, cyp1b1, cyp1c1, cyp1c2, and cyp2y3 (p<0.05). These findings were concordant with decreased Cyp1a1 induction measured by the ethoxyresorufin-O-deethylase (EROD) assay (p<0.05). Pathways associated with xenobiotic metabolism, lipid metabolism, and transcriptional and translational regulation were decreased. Pathways involved in DNA replication and repair, carbohydrate metabolism, and endocrine function were upregulated. Overall, this study demonstrates that TCPMOH is acutely toxic to zebrafish embryos at elevated concentrations.
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Affiliation(s)
- Julian Navarrete
- San Diego State University School of Public Health, 5500 Campanile Dr., Hardy Tower 119, San Diego, CA, 92182, USA
| | - Peyton Wilson
- San Diego State University School of Public Health, 5500 Campanile Dr., Hardy Tower 119, San Diego, CA, 92182, USA
| | - Nicholas Allsing
- San Diego State University Biology Department, San Diego, CA, 92182, USA
| | - Chandi Gordon
- San Diego State University School of Public Health, 5500 Campanile Dr., Hardy Tower 119, San Diego, CA, 92182, USA
| | - Rachel Margolis
- San Diego State University School of Public Health, 5500 Campanile Dr., Hardy Tower 119, San Diego, CA, 92182, USA
| | - Ashley V Schwartz
- San Diego State University Department of Mathematics, San Diego, CA, 92182, USA
| | - Christine Cho
- San Diego State University School of Public Health, 5500 Campanile Dr., Hardy Tower 119, San Diego, CA, 92182, USA
| | - Brynn Rogowski
- San Diego State University School of Public Health, 5500 Campanile Dr., Hardy Tower 119, San Diego, CA, 92182, USA
| | - Jennifer Topps
- San Diego State University School of Public Health, 5500 Campanile Dr., Hardy Tower 119, San Diego, CA, 92182, USA
| | - Uduak Z George
- San Diego State University Department of Mathematics, San Diego, CA, 92182, USA
| | - Karilyn E Sant
- San Diego State University School of Public Health, 5500 Campanile Dr., Hardy Tower 119, San Diego, CA, 92182, USA.
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16
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Singleman C, Holtzman NG. PCB and TCDD derived embryonic cardiac defects result from a novel AhR pathway. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2021; 233:105794. [PMID: 33662880 DOI: 10.1016/j.aquatox.2021.105794] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Revised: 01/30/2021] [Accepted: 02/20/2021] [Indexed: 06/12/2023]
Abstract
Polychlorinated biphenyls (PCBs) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) are environmental contaminants known to impact cardiac development, a key step in the embryonic development of most animals. To date, little is understood of the molecular mechanism driving the observed cardiac defects in exposed fishes. The literature shows PCB & TCDD derived cardiac defects are concurrent with, but not caused by, expression of cyp1A, due to activation of the aryl hydrocarbon receptor (AhR) gene activation pathway. However, in this study, detailed visualization of fish hearts exposed to PCBs and TCDD show that, in addition to a failure of cardiac looping in early heart development, the inner endocardial lining of the heart fails to maintain proper cell adhesion and tissue integrity. The resulting gap between the endocardium and myocardium in both zebrafish and Atlantic sturgeon suggested functional faults in endothelial adherens junction formation. Thus, we explored the molecular mechanism triggering cardiac defects using immunohistochemistry to identify the location and phosphorylation state of key regulatory and adhesion molecules. We hypothesized that PCB and TCDD activates AhR, phosphorylating Src, which then phosphorylates the endothelial adherens junction protein, VEcadherin. When phosphorylated, VEcadherin dimers, found in the endocardium and vasculature, separate, reducing tissue integrity. In zebrafish, treatment with PCB and TCDD contaminants leads to higher phosphorylation of VEcadherin in cardiac tissue suggesting that these cells have reduced connectivity. Small molecule inhibition of Src phosphorylation prevents contaminant stimulated phosphorylation of VEcadherin and rescues both cardiac function and gross morphology. Atlantic sturgeon hearts show parallels to contaminant exposed zebrafish cardiac phenotype at the tissue level. These data suggest that the mechanism for PCB and TCDD action in the heart is, in part, distinct from the canonical mechanism described in the literature and that cardiac defects are impacted by this nongenomic mechanism.
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Affiliation(s)
- Corinna Singleman
- Department of Biology, Queens College, City University of New York, 65-30 Kissena Blvd, Queens NY 11367-1597, USA; The Graduate Center, City University of New York, 365 Fifth Avenue, New York, NY 10016, USA
| | - Nathalia G Holtzman
- Department of Biology, Queens College, City University of New York, 65-30 Kissena Blvd, Queens NY 11367-1597, USA; The Graduate Center, City University of New York, 365 Fifth Avenue, New York, NY 10016, USA.
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17
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Shankar P, Dasgupta S, Hahn ME, Tanguay RL. A Review of the Functional Roles of the Zebrafish Aryl Hydrocarbon Receptors. Toxicol Sci 2020; 178:215-238. [PMID: 32976604 PMCID: PMC7706399 DOI: 10.1093/toxsci/kfaa143] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Over the last 2 decades, the zebrafish (Danio rerio) has emerged as a stellar model for unraveling molecular signaling events mediated by the aryl hydrocarbon receptor (AHR), an important ligand-activated receptor found in all eumetazoan animals. Zebrafish have 3 AHRs-AHR1a, AHR1b, and AHR2, and studies have demonstrated the diversity of both the endogenous and toxicological functions of the zebrafish AHRs. In this contemporary review, we first highlight the evolution of the zebrafish ahr genes, and the characteristics of the receptors including developmental and adult expression, their endogenous and inducible roles, and the predicted ligands from homology modeling studies. We then review the toxicity of a broad spectrum of AHR ligands across multiple life stages (early stage, and adult), discuss their transcriptomic and epigenetic mechanisms of action, and report on any known interactions between the AHRs and other signaling pathways. Through this article, we summarize the promising research that furthers our understanding of the complex AHR pathway through the extensive use of zebrafish as a model, coupled with a large array of molecular techniques. As much of the research has focused on the functions of AHR2 during development and the mechanism of TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin) toxicity, we illustrate the need to address the considerable knowledge gap in our understanding of both the mechanistic roles of AHR1a and AHR1b, and the diverse modes of toxicity of the various AHR ligands.
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Affiliation(s)
- Prarthana Shankar
- Department of Environmental and Molecular Toxicology, The Sinnhuber Aquatic Research Laboratory, Oregon State University, Corvallis, Oregon 97331
| | - Subham Dasgupta
- Department of Environmental and Molecular Toxicology, The Sinnhuber Aquatic Research Laboratory, Oregon State University, Corvallis, Oregon 97331
| | - Mark E Hahn
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543
| | - Robyn L Tanguay
- Department of Environmental and Molecular Toxicology, The Sinnhuber Aquatic Research Laboratory, Oregon State University, Corvallis, Oregon 97331
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18
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Aranguren-Abadía L, Donald CE, Eilertsen M, Gharbi N, Tronci V, Sørhus E, Mayer P, Nilsen TO, Meier S, Goksøyr A, Karlsen OA. Expression and localization of the aryl hydrocarbon receptors and cytochrome P450 1A during early development of Atlantic cod (Gadus morhua). AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2020; 226:105558. [PMID: 32673888 DOI: 10.1016/j.aquatox.2020.105558] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 06/25/2020] [Accepted: 07/01/2020] [Indexed: 06/11/2023]
Abstract
The aryl hydrocarbon receptor (Ahr) is a ligand-activated transcription factor that mediates the toxicity of dioxins and dioxin-like compounds (DLCs) in vertebrates. Two clades of the Ahr family exist in teleosts (Ahr1 and Ahr2), and it has been demonstrated that Ahr2 is the main protein involved in mediating the toxicity of dioxins and DLCs in most teleost species. Recently, we characterized the Atlantic cod (Gadus morhua) Ahr1a and Ahr2a receptors. To further explore a possible subfunction partitioning of Ahr1a and Ahr2a in Atlantic cod we have mapped the expression and localization of ahr1a and ahr2a in early developmental stages. Atlantic cod embryos were continuously exposed in a passive-dosing exposure system to the Ahr agonist, benzo[a]pyrene (B[a]P), from five days post fertilization (dpf) until three days post hatching (dph). Expression of ahr1a, ahr2a, and the Ahr-target genes, cyp1a and ahrrb, was assessed in embryos (8 dpf and 10 dpf) and larvae (3 dph) with quantitative real-time PCR analyses (qPCR), while in situ hybridization was used to assess the localization of expression of ahr1a, ahr2a and cyp1a. Quantitative measurements showed an increased cyp1a expression in B[a]P-exposed samples at all sampling points, and for ahr2a at 10 dpf, confirming the activation of the Ahr-signalling pathway. Furthermore, B[a]P strongly induced ahr2a and cyp1a expression in the cardiovascular system and skin, respectively, of embryos and larvae. Induced expression of both ahr2a and cyp1a was also revealed in the liver of B[a]P-exposed larvae. Our results suggest that Ahr2a is the major subtype involved in mediating responses to B[a]P in early developmental stages of Atlantic cod, which involves transcriptional regulation of biotransformation genes, such as cyp1a. The focused expression of ahr1a in the eye of embryos and larvae, and the presence of ahr2a transcripts in the jaws and fin nodes, further indicate evolved specialized roles of the two Ahrs in ontogenesis.
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Affiliation(s)
| | | | - Mariann Eilertsen
- Department of Biological Sciences, University of Bergen, Bergen, Norway
| | - Naouel Gharbi
- NORCE Norwegian Research Centre AS, Uni Research Environment, Bergen, Norway
| | - Valentina Tronci
- NORCE Norwegian Research Centre AS, Uni Research Environment, Bergen, Norway
| | - Elin Sørhus
- Institute of Marine Research, Bergen, Norway
| | - Philipp Mayer
- Department of Environmental Engineering, Technical University of Denmark, Lyngby, Denmark
| | - Tom Ole Nilsen
- Department of Biological Sciences, University of Bergen, Bergen, Norway
| | | | - Anders Goksøyr
- Department of Biological Sciences, University of Bergen, Bergen, Norway; Institute of Marine Research, Bergen, Norway
| | - Odd André Karlsen
- Department of Biological Sciences, University of Bergen, Bergen, Norway.
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19
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Heusinkveld HJ, Schoonen WG, Hodemaekers HM, Nugraha A, Sirks JJ, Veenma V, Sujan C, Pennings JL, Wackers PF, Palazzolo L, Eberini I, Rorije E, van der Ven LT. Distinguishing mode of action of compounds inducing craniofacial malformations in zebrafish embryos to support dose-response modeling in combined exposures. Reprod Toxicol 2020; 96:114-127. [DOI: 10.1016/j.reprotox.2020.06.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 05/26/2020] [Accepted: 06/01/2020] [Indexed: 02/06/2023]
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Song JY, Casanova-Nakayama A, Möller AM, Kitamura SI, Nakayama K, Segner H. Aryl Hydrocarbon Receptor Signaling Is Functional in Immune Cells of Rainbow Trout ( Oncorhynchus mykiss). Int J Mol Sci 2020; 21:E6323. [PMID: 32878328 PMCID: PMC7503690 DOI: 10.3390/ijms21176323] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 08/25/2020] [Accepted: 08/28/2020] [Indexed: 12/25/2022] Open
Abstract
The arylhydrocarbon receptor (AhR) is an important signaling pathway in the immune system of mammals. In addition to its physiological functions, the receptor mediates the immunotoxic actions of a diverse range of environmental contaminants that bind to and activate the AhR, including planar halogenated aromatic hydrocarbons (PHAHs or dioxin-like compounds) and polynuclear aromatic hydrocarbons (PAHs). AhR-binding xenobiotics are immunotoxic not only to mammals but to teleost fish as well. To date, however, it is unknown if the AhR pathway is active in the immune system of fish and thus may act as molecular initiating event in the immunotoxicity of AhR-binding xenobiotics to fish. The present study aims to examine the presence of functional AhR signaling in immune cells of rainbow trout (Oncorhynchus mykiss). Focus is given to the toxicologically relevant AhR2 clade. By means of RT-qPCR and in situ hybdridization, we show that immune cells of rainbow trout express ahr 2α and ahr 2β mRNA; this applies for immune cells isolated from the head kidney and from the peripheral blood. Furthermore, we show that in vivo as well as in vitro exposure to the AhR ligand, benzo(a)pyrene (BaP), causes upregulation of the AhR-regulated gene, cytochrome p4501a, in rainbow trout immune cells, and that this induction is inhibited by co-treatment with an AhR antagonist. Taken together, these findings provide evidence that functional AhR signaling exists in the immune cells of the teleost species, rainbow trout.
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Affiliation(s)
- Jun-Young Song
- Centre for Fish and Wildlife Health, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland; (J.-Y.S.); (A.C.-N.); (A.-M.M.)
- Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, Ehime 790-8577, Japan; (S.-I.K.); (K.N.)
| | - Ayako Casanova-Nakayama
- Centre for Fish and Wildlife Health, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland; (J.-Y.S.); (A.C.-N.); (A.-M.M.)
| | - Anja-Maria Möller
- Centre for Fish and Wildlife Health, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland; (J.-Y.S.); (A.C.-N.); (A.-M.M.)
| | - Shin-Ichi Kitamura
- Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, Ehime 790-8577, Japan; (S.-I.K.); (K.N.)
| | - Kei Nakayama
- Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, Ehime 790-8577, Japan; (S.-I.K.); (K.N.)
| | - Helmut Segner
- Centre for Fish and Wildlife Health, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland; (J.-Y.S.); (A.C.-N.); (A.-M.M.)
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21
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Shrestha R, Lieberth J, Tillman S, Natalizio J, Bloomekatz J. Using Zebrafish to Analyze the Genetic and Environmental Etiologies of Congenital Heart Defects. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1236:189-223. [PMID: 32304074 DOI: 10.1007/978-981-15-2389-2_8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Congenital heart defects (CHDs) are among the most common human birth defects. However, the etiology of a large proportion of CHDs remains undefined. Studies identifying the molecular and cellular mechanisms that underlie cardiac development have been critical to elucidating the origin of CHDs. Building upon this knowledge to understand the pathogenesis of CHDs requires examining how genetic or environmental stress changes normal cardiac development. Due to strong molecular conservation to humans and unique technical advantages, studies using zebrafish have elucidated both fundamental principles of cardiac development and have been used to create cardiac disease models. In this chapter we examine the unique toolset available to zebrafish researchers and how those tools are used to interrogate the genetic and environmental contributions to CHDs.
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Affiliation(s)
- Rabina Shrestha
- Department of Biology, University of Mississippi, Oxford, MS, USA
| | - Jaret Lieberth
- Department of Biology, University of Mississippi, Oxford, MS, USA
| | - Savanna Tillman
- Department of Biology, University of Mississippi, Oxford, MS, USA
| | - Joseph Natalizio
- Department of Biology, University of Mississippi, Oxford, MS, USA
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22
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Aranguren-Abadía L, Lille-Langøy R, Madsen AK, Karchner SI, Franks DG, Yadetie F, Hahn ME, Goksøyr A, Karlsen OA. Molecular and Functional Properties of the Atlantic Cod ( Gadus morhua) Aryl Hydrocarbon Receptors Ahr1a and Ahr2a. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:1033-1044. [PMID: 31852180 PMCID: PMC7003535 DOI: 10.1021/acs.est.9b05312] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The aryl hydrocarbon receptor (Ahr) is a ligand-activated transcription factor that mediates the toxicity of halogenated and polycyclic aromatic hydrocarbons in vertebrates. Atlantic cod (Gadus morhua) has recently emerged as a model organism in environmental toxicology studies, and increased knowledge of Ahr-mediated responses to xenobiotics is imperative. Genome mining and phylogenetic analyses revealed two Ahr-encoding genes in the Atlantic cod genome, gmahr1a and gmahr2a. In vitro binding assays showed that both gmAhr proteins bind to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), but stronger binding to gmAhr1a was observed. Transactivation studies with a reporter gene assay revealed that gmAhr1a is one order of magnitude more sensitive to TCDD than gmAhr2a, but the maximal responses of the receptors were similar. Other well-known Ahr agonists, such as β-naphthoflavone (BNF), 3,3',4,4',5-pentachlorobiphenyl (PCB126), and 6-formylindolo[3,2-b]carbazole (FICZ), also activated the gmAhr proteins, but gmAhr1a was, in general, the more sensitive receptor and produced the highest efficacies. The induction of cyp1a in exposed precision-cut cod liver slices confirmed the activation of the Ahr signaling pathway ex vivo. In conclusion, the differences in transcriptional activation by gmAhr's with various agonists, the distinct binding properties with TCDD and BNF, and the distinct tissue-specific expression profiles indicate different functional specializations of the Atlantic cod Ahr's.
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Affiliation(s)
| | | | | | - Sibel I. Karchner
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Diana G. Franks
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Fekadu Yadetie
- Department of Biological Sciences, University of Bergen, Bergen, Norway
| | - Mark E. Hahn
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Anders Goksøyr
- Department of Biological Sciences, University of Bergen, Bergen, Norway
| | - Odd André Karlsen
- Department of Biological Sciences, University of Bergen, Bergen, Norway
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23
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Crawford KA, Clark BW, Heiger-Bernays WJ, Karchner SI, Hahn ME, Nacci DE, Schlezinger JJ. Tributyltin disrupts fin development in Fundulus heteroclitus from both PCB-sensitive and resistant populations: Investigations of potential interactions between AHR and PPARγ. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2020; 218:105334. [PMID: 31743820 PMCID: PMC6935467 DOI: 10.1016/j.aquatox.2019.105334] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 10/07/2019] [Accepted: 10/12/2019] [Indexed: 05/09/2023]
Abstract
Tributyltin (TBT) and dioxin-like polychlorinated biphenyls (PCBs) are environmental contaminants that are highly toxic to fish and co-occur in New Bedford Harbor (NBH), an estuarine Superfund site located in Massachusetts, USA. Atlantic killifish (Fundulus heteroclitus) that reside in NBH (and other highly contaminated sites along the east coast of the United States) have developed resistance to activation of the aryl hydrocarbon receptor (AHR) pathway and the toxicity of dioxin-like chemicals, such as 3,3',4,4',5-pentachlorobiphenyl, PCB126. In many biological systems, TBT disregulates adipose and bone development via the PPARγ-RXR pathway; AHR activation also disrupts adipose and bone homeostasis, potentially through molecular crosstalk between AHR and PPARγ. However, little is known about how co-exposure and the interaction of these pathways modulate the toxicological effects of these contaminants. Here, we tested the hypotheses that TBT would induce teratogenesis in killifish via activation of PPARγ and that PCB126 co-exposure would suppress PPARγ pathway activation in PCB-sensitive killifish from a reference site (Scorton Creek, SC, PCB-sensitive) but not in PCB-tolerant NBH killifish. Killifish embryos from both populations exposed to TBT (50 and 100 nM) displayed caudal fin deformities. TBT did not change the expression of pparg or its target genes related to adipogenesis (fabp11a and fabp1b) in either population. However, expression of osx/sp7, an osteoblast marker gene, and col2a1b, a chondroblast marker gene, was significantly suppressed by TBT only in SC killifish. An RXR-specific agonist, but not a PPARγ-specific agonist, induced caudal fin deformities like those observed in TBT-treated embryos. PCB126 did not induce caudal fin deformities and did not exacerbate TBT-induced fin deformities. Further, PCB126 increased expression of pparg in SC embryos and not NBH embryos, but did not change the expression of fabp1b. Taken together, these results suggest that in killifish embryos the PPARγ pathway is regulated in part by AHR, but is minimally active at least in this early life stage. In killifish, RXR activation, rather than PPARγ activation, appears to be the mechanism by which TBT induces caudal fin teratogenicity, which is not modulated by AHR responsiveness.
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Affiliation(s)
- K A Crawford
- Department of Environmental Health, Boston University School of Public Health, Boston, MA, USA; Boston University Superfund Research Program, Boston, MA, USA; Oak Ridge Institute for Science and Education at Atlantic Ecology Division, Office of Research and Development, US Environmental Protection Agency, Narragansett, RI, USA
| | - B W Clark
- Boston University Superfund Research Program, Boston, MA, USA; Oak Ridge Institute for Science and Education at Atlantic Ecology Division, Office of Research and Development, US Environmental Protection Agency, Narragansett, RI, USA
| | - W J Heiger-Bernays
- Department of Environmental Health, Boston University School of Public Health, Boston, MA, USA; Boston University Superfund Research Program, Boston, MA, USA; Oak Ridge Institute for Science and Education at Atlantic Ecology Division, Office of Research and Development, US Environmental Protection Agency, Narragansett, RI, USA
| | - S I Karchner
- Boston University Superfund Research Program, Boston, MA, USA; Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA; Oak Ridge Institute for Science and Education at Atlantic Ecology Division, Office of Research and Development, US Environmental Protection Agency, Narragansett, RI, USA
| | - M E Hahn
- Boston University Superfund Research Program, Boston, MA, USA; Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA; Oak Ridge Institute for Science and Education at Atlantic Ecology Division, Office of Research and Development, US Environmental Protection Agency, Narragansett, RI, USA
| | - D E Nacci
- Atlantic Ecology Division, Office of Research and Development, US Environmental Protection Agency, Narragansett, RI, USA; Oak Ridge Institute for Science and Education at Atlantic Ecology Division, Office of Research and Development, US Environmental Protection Agency, Narragansett, RI, USA
| | - J J Schlezinger
- Department of Environmental Health, Boston University School of Public Health, Boston, MA, USA; Boston University Superfund Research Program, Boston, MA, USA; Oak Ridge Institute for Science and Education at Atlantic Ecology Division, Office of Research and Development, US Environmental Protection Agency, Narragansett, RI, USA.
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24
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Abstract
A major goal of translational toxicology is to identify adverse chemical effects and determine whether they are conserved or divergent across experimental systems. Translational toxicology encompasses assessment of chemical toxicity across multiple life stages, determination of toxic mode-of-action, computational prediction modeling, and identification of interventions that protect or restore health following toxic chemical exposures. The zebrafish is increasingly used in translational toxicology because it combines the genetic and physiological advantages of mammalian models with the higher-throughput capabilities and genetic manipulability of invertebrate models. Here, we review recent literature demonstrating the power of the zebrafish as a model for addressing all four activities of translational toxicology. Important data gaps and challenges associated with using zebrafish for translational toxicology are also discussed.
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Affiliation(s)
- Tamara Tal
- Department of Bioanalytical Ecotoxicology, Helmholtz Centre for Environmental Research – UFZ, Permoserstraβe 15 04318 Leipzig, Germany
- Corresponding authors: Pamela Lein, Department of Molecular Sciences, School of Veterinary Medicine, University of California, Davis, CA 95616 USA, +1-530-752-1970, ; Tamara Tal, Department of Bioanalytical Ecotoxicology, Helmholtz Centre for Environmental Research – UFZ, Leipzig, Germany, +49-341-236-1524,
| | - Bianca Yaghoobi
- Department of Molecular Sciences, University of California, Davis School of Veterinary Medicine, 1089 Veterinary Medicine Drive, Davis, CA 95616 USA
| | - Pamela J. Lein
- Department of Molecular Sciences, University of California, Davis School of Veterinary Medicine, 1089 Veterinary Medicine Drive, Davis, CA 95616 USA
- Corresponding authors: Pamela Lein, Department of Molecular Sciences, School of Veterinary Medicine, University of California, Davis, CA 95616 USA, +1-530-752-1970, ; Tamara Tal, Department of Bioanalytical Ecotoxicology, Helmholtz Centre for Environmental Research – UFZ, Leipzig, Germany, +49-341-236-1524,
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