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Johnson H, Dubiel J, Collins CH, Eriksson ANM, Lu Z, Doering JA, Wiseman S. Assessing the Toxicity of Benzotriazole Ultraviolet Stabilizers to Fishes: Insights into Aryl Hydrocarbon Receptor-Mediated Effects. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:110-120. [PMID: 38112502 PMCID: PMC10785820 DOI: 10.1021/acs.est.3c06117] [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: 07/30/2023] [Revised: 11/30/2023] [Accepted: 12/01/2023] [Indexed: 12/21/2023]
Abstract
Benzotriazole ultraviolet stabilizers (BUVSs) are chemicals used to mitigate UV-induced damage to manufactured goods. Their presence in aquatic environments and biota raises concerns, as certain BUVSs activate the aryl hydrocarbon receptor (AhR), which is linked to adverse effects in fish. However, potencies of BUVSs as AhR agonists and species sensitivities to AhR activation are poorly understood. This study evaluated the toxicity of three BUVSs using embryotoxicity assays. Zebrafish (Danio rerio) embryos exposed to BUVSs by microinjection suffered dose-dependent increases in mortality, with LD50 values of 4772, 11 608, and 56 292 ng/g-egg for UV-P, UV-9, and UV-090, respectively. The potencies and species sensitivities to AhR2 activation by BUVSs were assessed using a luciferase reporter gene assay with COS-7 cells transfected with the AhR2 of zebrafish and eight other fishes. The rank order of potency for activation of the AhR2 from all nine species was UV-P > UV-9 > UV-090. However, AhR2s among species differed in sensitivities to activation by up to 100-fold. An approximate reversed rank order of species sensitivity was observed compared to the rank order of sensitivity to 2,3,7,8-tetrachlorodibenzo[p]dioxin, the prototypical AhR agonist. Despite this, a pre-existing quantitative adverse outcome pathway linking AhR activation to embryo lethality could predict embryotoxicities of BUVSs in zebrafish.
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Affiliation(s)
- Hunter
M. Johnson
- Department
of Biological Science, University of Lethbridge, Lethbridge, Alberta T1K 3M4, Canada
| | - Justin Dubiel
- Department
of Biological Science, University of Lethbridge, Lethbridge, Alberta T1K 3M4, Canada
| | - Cameron H. Collins
- Department
of Environmental Sciences, College of the Coast and Environmental, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Andreas N. M. Eriksson
- Department
of Biological Science, University of Lethbridge, Lethbridge, Alberta T1K 3M4, Canada
| | - Zhe Lu
- Institut
des Sciences de la Mer de Rimouski, Université du Québec
à Rimouski, Rimouski, Québec G5L 3A1, Canada
| | - Jon A. Doering
- Department
of Biological Science, University of Lethbridge, Lethbridge, Alberta T1K 3M4, Canada
- Department
of Environmental Sciences, College of the Coast and Environmental, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Steve Wiseman
- Department
of Biological Science, University of Lethbridge, Lethbridge, Alberta T1K 3M4, Canada
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Dubiel J, Green D, Raza Y, Johnson HM, Xia Z, Tomy GT, Hontela A, Doering JA, Wiseman S. Alkylation of Benz[a]anthracene Affects Toxicity to Early-Life Stage Zebrafish and In Vitro Aryl Hydrocarbon Receptor 2 Transactivation in a Position-Dependent Manner. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2022; 41:1993-2002. [PMID: 35694968 DOI: 10.1002/etc.5396] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 05/09/2022] [Accepted: 05/26/2022] [Indexed: 06/15/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are structurally diverse organic chemicals that can have adverse effects on the health of fishes through activation of aryl hydrocarbon receptor 2 (AhR2). They are ubiquitous in the environment, but alkyl PAHs are more abundant in some environmental matrices. However, relatively little is known regarding the effects of alkylation on the toxicity of PAHs to fishes in vivo and how this relates to potency for activation of AhR2 in vitro. Therefore, the objectives of the present study were to determine the toxicity of benz[a]anthracene and three alkylated homologs representing various alkylation positions to early life stages of zebrafish (Danio rerio) and to assess the potency of each for activation of the zebrafish AhR2 in a standardized in vitro AhR transactivation assay. Exposure of embryos to each of the PAHs caused a dose-dependent increase in mortality and malformations characteristic of AhR2 activation. Each alkyl homolog had in vivo toxicities and in vitro AhR2 activation potencies different from those of the parent PAH in a position-dependent manner. However, there was no statistically significant linear relationship between responses measured in these assays. The results suggest a need for further investigation into the effect of alkylation on the toxicity of PAHs to fishes and greater consideration of the contribution of alkylated homologs in ecological risk assessments. Environ Toxicol Chem 2022;41:1993-2002. © 2022 SETAC.
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Affiliation(s)
- Justin Dubiel
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada
| | - Derek Green
- Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Yamin Raza
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada
| | - Hunter M Johnson
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada
| | - Zhe Xia
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Gregg T Tomy
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Alice Hontela
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada
| | - Jon A Doering
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada
- Department of Environmental Sciences, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Steve Wiseman
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada
- Water Institute for Sustainable Environments, Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada
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Jamshed L, Debnath A, Jamshed S, Wish JV, Raine JC, Tomy GT, Thomas PJ, Holloway AC. An Emerging Cross-Species Marker for Organismal Health: Tryptophan-Kynurenine Pathway. Int J Mol Sci 2022; 23:6300. [PMID: 35682980 PMCID: PMC9181223 DOI: 10.3390/ijms23116300] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 05/26/2022] [Accepted: 05/30/2022] [Indexed: 02/01/2023] Open
Abstract
Tryptophan (TRP) is an essential dietary amino acid that, unless otherwise committed to protein synthesis, undergoes metabolism via the Tryptophan-Kynurenine (TRP-KYN) pathway in vertebrate organisms. TRP and its metabolites have key roles in diverse physiological processes including cell growth and maintenance, immunity, disease states and the coordination of adaptive responses to environmental and dietary cues. Changes in TRP metabolism can alter the availability of TRP for protein and serotonin biosynthesis as well as alter levels of the immune-active KYN pathway metabolites. There is now considerable evidence which has shown that the TRP-KYN pathway can be influenced by various stressors including glucocorticoids (marker of chronic stress), infection, inflammation and oxidative stress, and environmental toxicants. While there is little known regarding the role of TRP metabolism following exposure to environmental contaminants, there is evidence of linkages between chemically induced metabolic perturbations and altered TRP enzymes and KYN metabolites. Moreover, the TRP-KYN pathway is conserved across vertebrate species and can be influenced by exposure to xenobiotics, therefore, understanding how this pathway is regulated may have broader implications for environmental and wildlife toxicology. The goal of this narrative review is to (1) identify key pathways affecting Trp-Kyn metabolism in vertebrates and (2) highlight consequences of altered tryptophan metabolism in mammals, birds, amphibians, and fish. We discuss current literature available across species, highlight gaps in the current state of knowledge, and further postulate that the kynurenine to tryptophan ratio can be used as a novel biomarker for assessing organismal and, more broadly, ecosystem health.
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Affiliation(s)
- Laiba Jamshed
- Department of Obstetrics and Gynecology, McMaster University, Hamilton, ON L8S 4K1, Canada; (L.J.); (A.D.); (S.J.)
| | - Amrita Debnath
- Department of Obstetrics and Gynecology, McMaster University, Hamilton, ON L8S 4K1, Canada; (L.J.); (A.D.); (S.J.)
| | - Shanza Jamshed
- Department of Obstetrics and Gynecology, McMaster University, Hamilton, ON L8S 4K1, Canada; (L.J.); (A.D.); (S.J.)
| | - Jade V. Wish
- Department of Chemistry, Centre for Oil and Gas Research and Development (COGRAD), University of Manitoba, 586 Parker Building, 144 Dysart Rd., Winnipeg, MB R3T 2N2, Canada; (J.V.W.); (G.T.T.)
| | - Jason C. Raine
- Quesnel River Research Centre, University of Northern British Columbia, Prince George, BC V2N 4Z9, Canada;
| | - Gregg T. Tomy
- Department of Chemistry, Centre for Oil and Gas Research and Development (COGRAD), University of Manitoba, 586 Parker Building, 144 Dysart Rd., Winnipeg, MB R3T 2N2, Canada; (J.V.W.); (G.T.T.)
| | - Philippe J. Thomas
- Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, ON K1A 0H3, Canada;
| | - Alison C. Holloway
- Department of Obstetrics and Gynecology, McMaster University, Hamilton, ON L8S 4K1, Canada; (L.J.); (A.D.); (S.J.)
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4
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Larigot L, Bui LC, de Bouvier M, Pierre O, Pinon G, Fiocca J, Ozeir M, Tourette C, Ottolenghi C, Imbeaud S, Pontoizeau C, Blaise BJ, Chevallier A, Tomkiewicz C, Legrand B, Elena-Herrmann B, Néri C, Brinkmann V, Nioche P, Barouki R, Ventura N, Dairou J, Coumoul X. Identification of Modulators of the C. elegans Aryl Hydrocarbon Receptor and Characterization of Transcriptomic and Metabolic AhR-1 Profiles. Antioxidants (Basel) 2022; 11:antiox11051030. [PMID: 35624894 PMCID: PMC9137885 DOI: 10.3390/antiox11051030] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 05/06/2022] [Accepted: 05/18/2022] [Indexed: 02/02/2023] Open
Abstract
The Aryl hydrocarbon Receptor (AhR) is a xenobiotic sensor in vertebrates, regulating the metabolism of its own ligands. However, no ligand has been identified to date for any AhR in invertebrates. In C. elegans, the AhR ortholog, AHR-1, displays physiological functions. Therefore, we compared the transcriptomic and metabolic profiles of worms expressing AHR-1 or not and investigated the putative panel of chemical AHR-1 modulators. The metabolomic profiling indicated a role for AHR-1 in amino acids, carbohydrates, and fatty acids metabolism. The transcriptional profiling in neurons expressing AHR-1, identified 95 down-regulated genes and 76 up-regulated genes associated with neuronal and metabolic functions in the nervous system. A gene reporter system allowed us to identify several AHR-1 modulators including bacterial, dietary, or environmental compounds. These results shed new light on the biological functions of AHR-1 in C. elegans and perspectives on the evolution of the AhR functions across species.
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Affiliation(s)
- Lucie Larigot
- INSERM UMR-S1124, T3S, Toxicologie Environnementale, Cibles Thérapeutiques, Signalisation Cellulaire et Biomarqueurs, Université Paris Cité, 75006 Paris, France; (L.L.); (L.-C.B.); (M.d.B.); (O.P.); (G.P.); (J.F.); (M.O.); (C.O.); (A.C.); (C.T.); (B.L.); (P.N.); (R.B.)
- CNRS UMR 8601, Metabolism, Pharmacochemistry and Neurochemistry, Université Paris Cité, 75006 Paris, France
| | - Linh-Chi Bui
- INSERM UMR-S1124, T3S, Toxicologie Environnementale, Cibles Thérapeutiques, Signalisation Cellulaire et Biomarqueurs, Université Paris Cité, 75006 Paris, France; (L.L.); (L.-C.B.); (M.d.B.); (O.P.); (G.P.); (J.F.); (M.O.); (C.O.); (A.C.); (C.T.); (B.L.); (P.N.); (R.B.)
- Unité de biologie fonctionnelle et adaptative, UMR 8251, CNRS, Université Paris Cité, 75013 Paris, France
| | - Marine de Bouvier
- INSERM UMR-S1124, T3S, Toxicologie Environnementale, Cibles Thérapeutiques, Signalisation Cellulaire et Biomarqueurs, Université Paris Cité, 75006 Paris, France; (L.L.); (L.-C.B.); (M.d.B.); (O.P.); (G.P.); (J.F.); (M.O.); (C.O.); (A.C.); (C.T.); (B.L.); (P.N.); (R.B.)
| | - Ophélie Pierre
- INSERM UMR-S1124, T3S, Toxicologie Environnementale, Cibles Thérapeutiques, Signalisation Cellulaire et Biomarqueurs, Université Paris Cité, 75006 Paris, France; (L.L.); (L.-C.B.); (M.d.B.); (O.P.); (G.P.); (J.F.); (M.O.); (C.O.); (A.C.); (C.T.); (B.L.); (P.N.); (R.B.)
- Laboratoire Interactions Epithéliums-Neurones (LIEN), Université de Brest, EA4685, 29200 Brest, France
| | - Grégory Pinon
- INSERM UMR-S1124, T3S, Toxicologie Environnementale, Cibles Thérapeutiques, Signalisation Cellulaire et Biomarqueurs, Université Paris Cité, 75006 Paris, France; (L.L.); (L.-C.B.); (M.d.B.); (O.P.); (G.P.); (J.F.); (M.O.); (C.O.); (A.C.); (C.T.); (B.L.); (P.N.); (R.B.)
- Structural and Molecular Analysis Platform, Biomedtech Facilities, Université Paris Cité, 75006 Paris, France
| | - Justine Fiocca
- INSERM UMR-S1124, T3S, Toxicologie Environnementale, Cibles Thérapeutiques, Signalisation Cellulaire et Biomarqueurs, Université Paris Cité, 75006 Paris, France; (L.L.); (L.-C.B.); (M.d.B.); (O.P.); (G.P.); (J.F.); (M.O.); (C.O.); (A.C.); (C.T.); (B.L.); (P.N.); (R.B.)
- Structural and Molecular Analysis Platform, Biomedtech Facilities, Université Paris Cité, 75006 Paris, France
| | - Mohammad Ozeir
- INSERM UMR-S1124, T3S, Toxicologie Environnementale, Cibles Thérapeutiques, Signalisation Cellulaire et Biomarqueurs, Université Paris Cité, 75006 Paris, France; (L.L.); (L.-C.B.); (M.d.B.); (O.P.); (G.P.); (J.F.); (M.O.); (C.O.); (A.C.); (C.T.); (B.L.); (P.N.); (R.B.)
- Structural and Molecular Analysis Platform, Biomedtech Facilities, Université Paris Cité, 75006 Paris, France
| | - Cendrine Tourette
- Centre Paul Broca, INSERM U894 Neuronal Cell Biology & Pathology & EA Université Paris Cité, 75014 Paris, France;
| | - Chris Ottolenghi
- INSERM UMR-S1124, T3S, Toxicologie Environnementale, Cibles Thérapeutiques, Signalisation Cellulaire et Biomarqueurs, Université Paris Cité, 75006 Paris, France; (L.L.); (L.-C.B.); (M.d.B.); (O.P.); (G.P.); (J.F.); (M.O.); (C.O.); (A.C.); (C.T.); (B.L.); (P.N.); (R.B.)
- AP-HP, Hôpital Necker-Enfants Malades, Service de Biochimie Métabolique, 75015 Paris, France;
| | - Sandrine Imbeaud
- Gif/Orsay DNA MicroArray Platform, 91190 Gif sur Yvette, France;
| | - Clément Pontoizeau
- AP-HP, Hôpital Necker-Enfants Malades, Service de Biochimie Métabolique, 75015 Paris, France;
- Centre de Résonance Magnétique Nucléaire à Très Hauts Champs, Univ. Lyon, CNRS, UCBL, ENS Lyon, 69100 Villeurbanne, France; (B.J.B.); (B.E.-H.)
| | - Benjamin J. Blaise
- Centre de Résonance Magnétique Nucléaire à Très Hauts Champs, Univ. Lyon, CNRS, UCBL, ENS Lyon, 69100 Villeurbanne, France; (B.J.B.); (B.E.-H.)
| | - Aline Chevallier
- INSERM UMR-S1124, T3S, Toxicologie Environnementale, Cibles Thérapeutiques, Signalisation Cellulaire et Biomarqueurs, Université Paris Cité, 75006 Paris, France; (L.L.); (L.-C.B.); (M.d.B.); (O.P.); (G.P.); (J.F.); (M.O.); (C.O.); (A.C.); (C.T.); (B.L.); (P.N.); (R.B.)
| | - Céline Tomkiewicz
- INSERM UMR-S1124, T3S, Toxicologie Environnementale, Cibles Thérapeutiques, Signalisation Cellulaire et Biomarqueurs, Université Paris Cité, 75006 Paris, France; (L.L.); (L.-C.B.); (M.d.B.); (O.P.); (G.P.); (J.F.); (M.O.); (C.O.); (A.C.); (C.T.); (B.L.); (P.N.); (R.B.)
| | - Béatrice Legrand
- INSERM UMR-S1124, T3S, Toxicologie Environnementale, Cibles Thérapeutiques, Signalisation Cellulaire et Biomarqueurs, Université Paris Cité, 75006 Paris, France; (L.L.); (L.-C.B.); (M.d.B.); (O.P.); (G.P.); (J.F.); (M.O.); (C.O.); (A.C.); (C.T.); (B.L.); (P.N.); (R.B.)
| | - Bénédicte Elena-Herrmann
- Centre de Résonance Magnétique Nucléaire à Très Hauts Champs, Univ. Lyon, CNRS, UCBL, ENS Lyon, 69100 Villeurbanne, France; (B.J.B.); (B.E.-H.)
- Institute for Advanced Biosciences, Univ. Grenoble Alpes, CNRS, INSERM, 38000 Grenoble, France
| | - Christian Néri
- CNRS UMR 8256, Inserm ERL U1164, Sorbonne Université, 75005 Paris, France;
| | - Vanessa Brinkmann
- Institute of Clinical Chemistry and Laboratory Diagnostic, Medical Faculty, Heinrich Heine University, Düsseldorf, Moorenstr 5, 40225 Düsseldorf, Germany; (V.B.); (N.V.)
- Leibniz Institute for Environmental Medicine (IUF), Auf’m Hennekamp 50, 40225 Düsseldorf, Germany
| | - Pierre Nioche
- INSERM UMR-S1124, T3S, Toxicologie Environnementale, Cibles Thérapeutiques, Signalisation Cellulaire et Biomarqueurs, Université Paris Cité, 75006 Paris, France; (L.L.); (L.-C.B.); (M.d.B.); (O.P.); (G.P.); (J.F.); (M.O.); (C.O.); (A.C.); (C.T.); (B.L.); (P.N.); (R.B.)
- Structural and Molecular Analysis Platform, Biomedtech Facilities, Université Paris Cité, 75006 Paris, France
| | - Robert Barouki
- INSERM UMR-S1124, T3S, Toxicologie Environnementale, Cibles Thérapeutiques, Signalisation Cellulaire et Biomarqueurs, Université Paris Cité, 75006 Paris, France; (L.L.); (L.-C.B.); (M.d.B.); (O.P.); (G.P.); (J.F.); (M.O.); (C.O.); (A.C.); (C.T.); (B.L.); (P.N.); (R.B.)
- Assistance Publique-Hôpitaux de Paris, Hôpital Necker, 75015 Paris, France
| | - Natascia Ventura
- Institute of Clinical Chemistry and Laboratory Diagnostic, Medical Faculty, Heinrich Heine University, Düsseldorf, Moorenstr 5, 40225 Düsseldorf, Germany; (V.B.); (N.V.)
- Leibniz Institute for Environmental Medicine (IUF), Auf’m Hennekamp 50, 40225 Düsseldorf, Germany
| | - Julien Dairou
- CNRS UMR 8601, Metabolism, Pharmacochemistry and Neurochemistry, Université Paris Cité, 75006 Paris, France
- Correspondence: (J.D.); (X.C.); Tel.: +33-1-42-86-91-21 (J.D.); +33-1-42-86-33-59 (X.C.)
| | - Xavier Coumoul
- INSERM UMR-S1124, T3S, Toxicologie Environnementale, Cibles Thérapeutiques, Signalisation Cellulaire et Biomarqueurs, Université Paris Cité, 75006 Paris, France; (L.L.); (L.-C.B.); (M.d.B.); (O.P.); (G.P.); (J.F.); (M.O.); (C.O.); (A.C.); (C.T.); (B.L.); (P.N.); (R.B.)
- Correspondence: (J.D.); (X.C.); Tel.: +33-1-42-86-91-21 (J.D.); +33-1-42-86-33-59 (X.C.)
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Rannug A. 6-Formylindolo[3,2-b]carbazole, a Potent Ligand for the Aryl Hydrocarbon Receptor Produced Both Endogenously and by Microorganisms, can Either Promote or Restrain Inflammatory Responses. FRONTIERS IN TOXICOLOGY 2022; 4:775010. [PMID: 35295226 PMCID: PMC8915874 DOI: 10.3389/ftox.2022.775010] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 01/11/2022] [Indexed: 12/13/2022] Open
Abstract
The aryl hydrocarbon receptor (AHR) binds major physiological modifiers of the immune system. The endogenous 6-formylindolo[3,2-b]carbazole (FICZ), which binds with higher affinity than any other compound yet tested, including TCDD, plays a well-documented role in maintaining the homeostasis of the intestines and skin. The effects of transient activation of AHR by FICZ differ from those associated with continuous stimulation and, depending on the dose, include either differentiation into T helper 17 cells that express proinflammatory cytokines or into regulatory T cells or macrophages with anti-inflammatory properties. Moreover, in experimental models of human diseases high doses stimulate the production of immunosuppressive cytokines and suppress pathogenic autoimmunity. In our earlier studies we characterized the formation of FICZ from tryptophan via the precursor molecules indole-3-pyruvate and indole-3-acetaldehyde. In the gut formation of these precursor molecules is catalyzed by microbial aromatic-amino-acid transaminase ArAT. Interestingly, tryptophan can also be converted into indole-3-pyruvate by the amino-acid catabolizing enzyme interleukin-4 induced gene 1 (IL4I1), which is secreted by host immune cells. By thus generating derivatives of tryptophan that activate AHR, IL4I1 may have a role to play in anti-inflammatory responses, as well as in a tumor escape mechanism that reduces survival in cancer patients. The realization that FICZ can be produced from tryptophan by sunlight, by enzymes expressed in our cells (IL4I1), and by microorganisms as well makes it highly likely that this compound is ubiquitous in humans. A diurnal oscillation in the level of FICZ that depends on the production by the fluctuating number of microbes might influence not only intestinal and dermal immunity locally, but also systemic immunity.
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Sharin T, Williams KL, Chiu S, Crump D, O'Brien JM. Toxicity Screening of Bisphenol A Replacement Compounds: Cytotoxicity and mRNA Expression in Primary Hepatocytes of Chicken and Double-Crested Cormorant. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2021; 40:1368-1378. [PMID: 33465250 DOI: 10.1002/etc.4985] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 12/17/2020] [Accepted: 01/13/2021] [Indexed: 06/12/2023]
Abstract
A market for bisphenol A (BPA) replacement compounds has emerged as a result of restrictions on the use of BPA. Some of these compounds have been detected in the environment; however, little is known about their toxicological properties. In the present study, an avian in vitro toxicogenomic approach was used to compare the effects of 5 BPA alternatives. Cell viability and mRNA expression were compared in primary embryonic hepatocytes of chicken (CEH) and double-crested cormorant (DCEH) exposed to 4,4'-(propane-2,2-diyl) diphenol (BPA), bis (4-hydroxyphenyl) methane (BPF), bis (3-allyl-4-hydroxyphenyl) sulfone (TGSH), 7-bis (4-hydroxyphenylthio)-3,5-dioxaheptane (DD-70), 2,2-bis (4-hydroxyphenyl) hexafluoropropane (BPAF), and 4-hydroxyphenyl 4-isoprooxyphenylsulfone (BPSIP). Changes in gene expression were determined using 2 polymerase chain reaction (PCR) arrays: 1) species-specific ToxChips that contain genes representing toxicologically relevant pathways, and 2) chicken-specific AestroChip that measures estrogen responsive genes. In CEH and DCEH, BPA alternatives TGSH, DD-70, and BPAF were most cytotoxic. Some of the replacement compounds changed the expression of genes related to xenobiotic metabolism, bile acid, and cholesterol regulation. The rank order based on the number of genes altered on the chicken ToxChip array was TGSH > DD-70 > BPAF = BPF > 17β estradiol (E2) > BPSIP > BPA. On the cormorant ToxChip array, BPSIP altered the greatest number of genes. Based on the chicken AestroChip data, BPSIP and BPF were slightly estrogenic. These results suggest that the replacement compounds have comparable or even greater toxicity than BPA and act via different mechanisms. Environ Toxicol Chem 2021;40:1368-1378. © 2021 Her Majesty the Queen in Right of Canada. Reproduced with the permission of the Minister of Environment and Climate Change Canada.
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Affiliation(s)
- Tasnia Sharin
- Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, Ontario, Canada
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Kim L Williams
- Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, Ontario, Canada
| | - Suzanne Chiu
- Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, Ontario, Canada
| | - Doug Crump
- Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, Ontario, Canada
| | - Jason M O'Brien
- Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, Ontario, Canada
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7
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Doan TQ, Connolly L, Igout A, Muller M, Scippo ML. In vitro differential responses of rat and human aryl hydrocarbon receptor to two distinct ligands and to different polyphenols. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 265:114966. [PMID: 32563119 DOI: 10.1016/j.envpol.2020.114966] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 05/27/2020] [Accepted: 06/03/2020] [Indexed: 06/11/2023]
Abstract
TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin) and several other environment/food-borne toxic compounds induce their toxicity via the aryl hydrocarbon receptor (AhR). AhR is also modulated by various endogenous ligands e.g. highly potent tryptophan (Trp)-derivative FICZ (6-formylindolo[3,2-b]carbazole) and natural ligands abundant in the human diet e.g. polyphenols. Therefore, evaluating AhR species-specific responses is crucial for understanding AhR physiological functions, establishing risk assessments, and exploring the applicability of AhR mediators in drug and food industry towards human-based usages. We studied AhR transactivation of FICZ/TCDD in vitro in a time-dependent and species-specific manner using dioxin responsive luciferase reporter gene assays derived from rat (DR-H4IIE) and human (DR-HepG2) hepatoma cells. We observed for the first time that FICZ potency was similar in both cell lines and was 40 times higher than TCDD in DR-HepG2 cells. Depleting Trp-derivative endogenously produced ligands by using culture medium without Trp, resulted in 3-fold higher AhR activation upon adding FICZ in DR-H4IIE cells, in contrast to DR-HepG2 cells which revealed a fast degradation of FICZ induction from 10 h post-exposure to complete disappearance after 24 h. Seven polyphenols and a mixture thereof, chosen based on commercially recommended doses and adjusted to human realistic exposure, caused rat and human species-specific AhR responses. Two isoflavones (daidzein and genistein) induced rat AhR synergistic effects with FICZ and/or TCDD, while quercetin, chrysin, curcumin, resveratrol, and the mixture exerted a strong inhibitory effect on the human AhR. Strikingly, resveratrol and quercetin at their realistic nanomolar concentrations acted additively in the mixture to abolish human AhR activation induced by various TCDD concentrations. Taken together, these results illustrate the species-specific complexity of AhR transcriptional activities modulated by various ligands and highlight the need for studies of human-based approaches.
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Affiliation(s)
- T Q Doan
- Laboratory of Food Analysis, FARAH-Veterinary Public Health, University of Liège, Liège, 4000, Belgium
| | - L Connolly
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Northern Ireland, BT9 5DL, UK
| | - A Igout
- Department of Biomedical and Preclinical Sciences, University of Liège, Liège, 4000, Belgium
| | - M Muller
- GIGA-R, Laboratory for Organogenesis and Regeneration, University of Liège, Liège, 4000, Belgium
| | - M L Scippo
- Laboratory of Food Analysis, FARAH-Veterinary Public Health, University of Liège, Liège, 4000, Belgium.
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8
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Koh DH, Hwang JH, Park JG, Song WS, Iwata H, Kim EY. The AHR1-ARNT1 dimerization pair is a major regulator of the response to natural ligands, but not to TCDD, in the chicken. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 201:110835. [PMID: 32563159 DOI: 10.1016/j.ecoenv.2020.110835] [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: 02/17/2020] [Revised: 05/28/2020] [Accepted: 05/30/2020] [Indexed: 06/11/2023]
Abstract
The activation of the aryl hydrocarbon receptor (AHR) occurs through the binding of dioxin-like compounds (DLCs) or natural ligands. In this pathway, the AHR-ARNT (AHR nuclear translocator) heterodimer serves to regulate critical physiological functions, such as immune responses and the metabolism of xenobiotics. Birds have three AHR isoforms (AHR1, AHR1β, and AHR2) and two ARNT isoforms (ARNT1 and ARNT2). However, how AHR and ARNT dimerization pair in birds regulates the AHR signaling pathway in an isoform-specific manner remains unknown. In this study, we initially sought to clarify the major chicken AHR-ARNT (ckAHR-ckARNT) pairs by estimating the mRNA tissue distributions of various ckAHR and ckARNT isoforms. Our results indicated that the ckAHR1-ckARNT1 represented the major dimerization pair in most tissues except the brain. We then measured the transactivation potencies of various ckAHR-ckARNT pairs by natural ligands and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), in in vitro reporter gene assays using COS-7 and LMH cell lines. Our results from the in vitro assays demonstrated that the ckAHR1-ckARNT1 pair was strongly activated by the five natural ligands, namely, 6-formylindolo [3,2-b]carbazole, L-kynurenin, kynurenic acid, indoxyl-3-sulfate, and 1,3,7-tribromodibenzo-p-dioxin, but not by TCDD. In in silico ligand docking simulations with ckAHR1 homology models, all the natural ligands showed a interaction pattern that was distinct from that observed with anthropogenic DLCs, including TCDD. In conclusion, our findings indicate that the ckAHR1-ckARNT1 may be the most important dimerization pair in most tissues for regulating the physiological functions driven by natural ligands, although it was less reactive to TCDD.
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Affiliation(s)
- Dong-Hee Koh
- Department of Life and Nanopharmaceutical Science, Kyung Hee University, Hoegi-Dong, Dongdaemun-Gu, Seoul, 130-701, South Korea
| | - Ji-Hee Hwang
- Department of Life and Nanopharmaceutical Science, Kyung Hee University, Hoegi-Dong, Dongdaemun-Gu, Seoul, 130-701, South Korea
| | - Jae-Gon Park
- Department of Life and Nanopharmaceutical Science, Kyung Hee University, Hoegi-Dong, Dongdaemun-Gu, Seoul, 130-701, South Korea
| | - Woo-Seon Song
- Department of Life and Nanopharmaceutical Science, Kyung Hee University, Hoegi-Dong, Dongdaemun-Gu, Seoul, 130-701, South Korea
| | - Hisato Iwata
- Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, 790-8577, Japan.
| | - Eun-Young Kim
- Department of Life and Nanopharmaceutical Science, Kyung Hee University, Hoegi-Dong, Dongdaemun-Gu, Seoul, 130-701, South Korea; Department of Biology, Kyung Hee University, Hoegi-Dong, Dongdaemun-Gu, Seoul, 130-701, South Korea.
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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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10
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Rannug A, Rannug U. The tryptophan derivative 6-formylindolo[3,2-b]carbazole, FICZ, a dynamic mediator of endogenous aryl hydrocarbon receptor signaling, balances cell growth and differentiation. Crit Rev Toxicol 2018; 48:555-574. [PMID: 30226107 DOI: 10.1080/10408444.2018.1493086] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The aryl hydrocarbon receptor (AHR) is not essential to survival, but does act as a key regulator of many normal physiological events. The role of this receptor in toxicological processes has been studied extensively, primarily employing the high-affinity ligand 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). However, regulation of physiological responses by endogenous AHR ligands remains to be elucidated. Here, we review developments in this field, with a focus on 6-formylindolo[3,2-b]carbazole (FICZ), the endogenous ligand with the highest affinity to the receptor reported to date. The binding of FICZ to different isoforms of the AHR seems to be evolutionarily well conserved and there is a feedback loop that controls AHR activity through metabolic degradation of FICZ via the highly inducible cytochrome P450 1A1. Several investigations provide strong evidence that FICZ plays a critical role in normal physiological processes and can ameliorate immune diseases with remarkable efficiency. Low levels of FICZ are pro-inflammatory, providing resistance to pathogenic bacteria, stimulating the anti-tumor functions, and promoting the differentiation of cancer cells by repressing genes in cancer stem cells. In contrast, at high concentrations FICZ behaves in a manner similar to TCDD, exhibiting toxicity toward fish and bird embryos, immune suppression, and activation of cancer progression. The findings are indicative of a dual role for endogenously activated AHR in barrier tissues, aiding clearance of infections and suppressing immunity to terminate a vicious cycle that might otherwise lead to disease. There is not much support for the AHR ligand-specific immune responses proposed, the differences between FICZ and TCDD in this context appear to be explained by the rapid metabolism of FICZ.
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Affiliation(s)
- Agneta Rannug
- a Karolinska Institutet, Institute of Environmental Medicine , Stockholm , Sweden
| | - Ulf Rannug
- b Department of Molecular Biosciences , The Wenner-Gren Institute, Stockholm University , Stockholm , Sweden
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11
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Janosik T, Rannug A, Rannug U, Wahlström N, Slätt J, Bergman J. Chemistry and Properties of Indolocarbazoles. Chem Rev 2018; 118:9058-9128. [PMID: 30191712 DOI: 10.1021/acs.chemrev.8b00186] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The indolocarbazoles are an important class of nitrogen heterocycles which has evolved significantly in recent years, with numerous studies focusing on their diverse biological effects, or targeting new materials with potential applications in organic electronics. This review aims at providing a broad survey of the chemistry and properties of indolocarbazoles from an interdisciplinary point of view, with particular emphasis on practical synthetic aspects, as well as certain topics which have not been previously accounted for in detail, such as the occurrence, formation, biological activities, and metabolism of indolo[3,2- b]carbazoles. The literature of the past decade forms the basis of the text, which is further supplemented with older key references.
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Affiliation(s)
- Tomasz Janosik
- Research Institutes of Sweden , Bioscience and Materials, RISE Surface, Process and Formulation , SE-151 36 Södertälje , Sweden
| | - Agneta Rannug
- Institute of Environmental Medicine , Karolinska Institutet , SE-171 77 Stockholm , Sweden
| | - Ulf Rannug
- Department of Molecular Biosciences, The Wenner-Gren Institute , Stockholm University , SE-106 91 Stockholm , Sweden
| | | | - Johnny Slätt
- Department of Chemistry, Applied Physical Chemistry , KTH Royal Institute of Technology , SE-100 44 Stockholm , Sweden
| | - Jan Bergman
- Karolinska Institutet , Department of Biosciences and Nutrition , SE-141 83 Huddinge , Sweden
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12
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Yu M, Wang Q, Ma Y, Li L, Yu K, Zhang Z, Chen G, Li X, Xiao W, Xu P, Yang H. Aryl Hydrocarbon Receptor Activation Modulates Intestinal Epithelial Barrier Function by Maintaining Tight Junction Integrity. Int J Biol Sci 2018; 14:69-77. [PMID: 29483826 PMCID: PMC5821050 DOI: 10.7150/ijbs.22259] [Citation(s) in RCA: 136] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 12/14/2017] [Indexed: 12/19/2022] Open
Abstract
Activation of Aryl hydrocarbon receptor (AhR) is involved in the control of intestinal mucosal homeostasis. Intestinal barrier dysfunction contributes to the development of many intestinal diseases, such as inflammatory bowel disease (IBD). In this study, we investigated the mechanisms of AhR activation in the maintenance of intestinal barrier function. Adult C57BL/6 mice were treated with dextran sulphate sodium (DSS) for 7 days, with or without 6-Formylindolo(3,2-b)carbazole (FICZ), a ligand of AhR. We found that AhR activation by FICZ attenuated the decreased TJ protein expression in the colonic mucosa of the DSS-induced mice. Further, the increase of both MLC phosphorylation and MLCK expression in the mice with DSS-induced colitis was also significantly inhibited by FICZ induced AhR activation. For in vitro experiments, Caco-2 cells were treated with tumour necrosis factor alpha (TNF-α)/interferon gamma (IFN-γ) for 48 h, with or without FICZ. AhR activation prevented TNF-α/IFN-γ-induced decrease in TER and morphological disruption of the TJs in Caco-2 monolayers. It also inhibited TNF-α/IFN-γ-induced increase in MLCK expression and MLC phosphorylation by suppression of NF-κB p65 signaling pathway. Thus, AhR-activating factors might have potential as therapeutic agents for the treatment of patients with IBD.
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Affiliation(s)
- Min Yu
- Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Qimeng Wang
- Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Yuanhang Ma
- Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Liangzi Li
- Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Kun Yu
- Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Zhicao Zhang
- Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Guoqing Chen
- Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Xiangsheng Li
- Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Weidong Xiao
- Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Pengyuan Xu
- Department of Gastrointestinal Surgery, the Second Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Hua Yang
- Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
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13
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Kim IS, Hwang JH, Hirano M, Iwata H, Kim EY. In vitro and in silico evaluation of transactivation potencies of avian AHR1 and AHR2 by endogenous ligands: Implications for the physiological role of avian AHR2. Comp Biochem Physiol C Toxicol Pharmacol 2016; 187:1-9. [PMID: 27060260 DOI: 10.1016/j.cbpc.2016.03.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 02/05/2016] [Accepted: 03/29/2016] [Indexed: 02/09/2023]
Abstract
Aryl hydrocarbon receptor (AHR) is well conserved from invertebrates to vertebrates, and it mediates the toxic effects of exogenous ligands, including dioxins. Recent studies reported that AHRs activated by endogenous ligands play critical roles in mammalian physiological homeostasis. Avian species possess at least two AHR isoforms (AHR1 and AHR2), which exhibit species- and isoform-specific transactivation potencies to exogenous ligands, whereas mammals possess a single AHR. To delineate the profiles and roles of endogenous ligands for avian AHR isoforms, we investigated in vitro transactivation potencies of avian AHRs (AHR1 and AHR2 from the jungle crow, Corvus macrorhynchos; common cormorant, Phalacrocorax carbo; and black-footed albatross, Phoebastria nigripes) treated with the endogenous tryptophan metabolites 6-formylindolo [3,2-b] carbazole (FICZ), l-kynurenine (l-Kyn), kynurenic acid (KYNA), and indoxyl sulfate (IS). Furthermore, we analyzed the binding mode of these ligands to each avian AHR isoform by in silico docking simulations. The EC50 of FICZ (0.009-0.032nM) was similar regardless of the species or isoform of AHR. The estimated in silico binding mode of FICZ to AHRs was well conserved in both isoforms. The transactivation potencies of avian AHRs to other tryptophan metabolites were 10(5)-10(7) fold lower than those for FICZ, and EC50 values varied in a species- and isoform-specific manner. This was consistent with poor conservation of the binding mode of l-Kyn, KYNA, and IS predicted in in silico docking simulations. Our results suggest that in avian species, FICZ is the most potent endogenous AHR ligand, and that AHR1 and AHR2 are physiologically functional.
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Affiliation(s)
- In-Sung Kim
- Department of Biology, Kyung Hee University, Hoegi Dong, Dongdaemun-Gu, Seoul 130-701, Republic of Korea
| | - Ji-Hee Hwang
- Department of Biology, Kyung Hee University, Hoegi Dong, Dongdaemun-Gu, Seoul 130-701, Republic of Korea; Department of Life and Nanopharmaceutical Science, Kyung Hee University, Hoegi Dong, Dongdaemun-Gu, Seoul 130-701, Republic of Korea
| | - Masashi Hirano
- Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama 790-8577, Japan
| | - Hisato Iwata
- Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama 790-8577, Japan
| | - Eun-Young Kim
- Department of Biology, Kyung Hee University, Hoegi Dong, Dongdaemun-Gu, Seoul 130-701, Republic of Korea; Department of Life and Nanopharmaceutical Science, Kyung Hee University, Hoegi Dong, Dongdaemun-Gu, Seoul 130-701, Republic of Korea.
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14
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Time-dependent transcriptomic and biochemical responses of 6-formylindolo[3,2-b]carbazole (FICZ) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) are explained by AHR activation time. Biochem Pharmacol 2016; 115:134-43. [PMID: 27301797 DOI: 10.1016/j.bcp.2016.06.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 06/08/2016] [Indexed: 12/31/2022]
Abstract
6-Formylindolo[3,2-b]carbazole (FICZ) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) are ligands of the aryl hydrocarbon receptor (AHR) and bind to the AHR with high affinity. Until recently, TCDD was considered to be the most potent AHR agonist, but several recent studies indicate that FICZ binds with greater affinity to the AHR than TCDD. To advance our understanding of the similarities and differences of the effects of FICZ and TCDD exposure in chicken embryo hepatocyte (CEH) cultures, we compared relative expression changes of 27 dioxin-responsive genes by the use of a chicken PCR array, porphyrin accumulation and ethoxyresorufin-O-deethylase (EROD) activity at different time points. In addition, an egg injection study was performed to assess the effects of FICZ on the developing chicken embryo. The results of the current study showed: (1) mean EROD-derived relative potency values for FICZ compared to TCDD changed as a function of time (i.e. 9, 0.004, 0.0008 and 0.00008 at 3, 8, 24, and 48h, respectively) in CEH cultures; (2) FICZ exposure did not result in porphyrin accumulation in CEH cultures; (3) concordance between gene expression profiles for FICZ and TCDD was time- and concentration-dependent, and (4) no mortality or morphological abnormalities were observed in chicken embryos injected with 0.87ng FICZ/g egg into the air cell. The results presented herein suggest that while FICZ and TCDD share similar molecular targets, transient versus sustained AHR activation by FICZ and TCDD result in differential transcriptomic responses. Moreover, rapid metabolism of FICZ in hepatocytes resulted in a significant decrease in the induction of EROD activity.
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15
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Hwang JH, Park JY, Park HJ, Bak SM, Hirano M, Iwata H, Park YS, Kim EY. Ecological factors drive natural selection pressure of avian aryl hydrocarbon receptor 1 genotypes. Sci Rep 2016; 6:27526. [PMID: 27283192 PMCID: PMC4901312 DOI: 10.1038/srep27526] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 05/20/2016] [Indexed: 01/26/2023] Open
Abstract
The aryl hydrocarbon receptor (AHR) mediates dioxin toxicities. Several studies have suggested that two amino acid residues corresponding to the 324th and 380th positions in the ligand binding domain (LBD) of the chicken AHR1 (Ile_Ser as high sensitivity, Ile_Ala as moderate sensitivity, and Val_Ala as low sensitivity), could be an important factor determining dioxin sensitivity in avian species. Here, we analyzed the association between ecological factors and AHR1 LBD genotypes of 113 avian species. Cluster analyses showed that 2 major clusters and sub-clusters of the cluster 3 were associated with specific AHR1 genotypes depending on the food, habitat, and migration of the animal. The majority of the species with Ile_Ala type were the Passeriformes, which are omnivorous or herbivorous feeders in the terrestrial environment. The species with Val_Ala type was primarily composed of raptors and waterbirds, which have been exposed to naturally occurring dioxins. An in vitro reporter gene assay revealed that the sensitivity to a natural dioxin, 1,3,7-tribromodibenzo-p-dioxin was in the order of Ile_Ser > Ile_Ala > Val_Ala. These results suggest that ecological factors related to the exposure of natural dioxins contribute to natural selection of the avian AHR1 genotype, which consequently leads to different sensitivity to man-made dioxins.
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Affiliation(s)
- Ji-Hee Hwang
- Department of Life and Nanopharmaceutical Science and Department of Biology, Kyung Hee University, Hoegi-Dong, Dongdaemun-Gu, Seoul 130-701, Korea
| | - Jin-Young Park
- Nature Conservation Research Division, National Institute of Environmental Research, Hwangyoungro 42, Seo-Gu, Incheon 404-708, Korea
| | - Hae-Jeong Park
- Department of Life and Nanopharmaceutical Science and Department of Biology, Kyung Hee University, Hoegi-Dong, Dongdaemun-Gu, Seoul 130-701, Korea
| | - Su-Min Bak
- Department of Life and Nanopharmaceutical Science and Department of Biology, Kyung Hee University, Hoegi-Dong, Dongdaemun-Gu, Seoul 130-701, Korea
| | - Masashi Hirano
- Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama, 790-8577, Japan
| | - Hisato Iwata
- Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama, 790-8577, Japan
| | - Young-Suk Park
- Department of Life and Nanopharmaceutical Science and Department of Biology, Kyung Hee University, Hoegi-Dong, Dongdaemun-Gu, Seoul 130-701, Korea
| | - Eun-Young Kim
- Department of Life and Nanopharmaceutical Science and Department of Biology, Kyung Hee University, Hoegi-Dong, Dongdaemun-Gu, Seoul 130-701, Korea
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16
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Wincent E, Kubota A, Timme-Laragy A, Jönsson ME, Hahn ME, Stegeman JJ. Biological effects of 6-formylindolo[3,2-b]carbazole (FICZ) in vivo are enhanced by loss of CYP1A function in an Ahr2-dependent manner. Biochem Pharmacol 2016; 110-111:117-29. [PMID: 27112072 DOI: 10.1016/j.bcp.2016.04.012] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 04/21/2016] [Indexed: 12/12/2022]
Abstract
6-Formylindolo[3,2-b]carbazole (FICZ) is a potent aryl hydrocarbon receptor (AHR) agonist that is efficiently metabolized by AHR-regulated cytochrome P4501 enzymes. FICZ is a proposed physiological AHR ligand that induces its own degradation as part of a regulatory negative feedback loop. In vitro studies in cells show that CYP1 inhibition in the presence of FICZ results in enhanced AHR activation, suggesting that FICZ accumulates in the cell when its metabolism is blocked. We used zebrafish (Danio rerio) embryos to investigate the in vivo effects of FICZ when CYP1A is knocked down or inhibited. Embryos were injected with morpholino antisense oligonucleotides targeting CYP1A (CYP1A-MO), Ahr2, or a combination of both. FICZ exposure of non-injected embryos or embryos injected with control morpholino had little effect. In CYP1A-MO-injected embryos, however, FICZ dramatically increased mortality, incidence and severity of pericardial edema and circulation failure, reduced hatching frequency, blocked swim bladder inflation, and strongly potentiated expression of Ahr2-regulated genes. These effects were substantially reduced in embryos with a combined knockdown of Ahr2 and CYP1A, indicating that the toxicity was mediated at least partly by Ahr2. Co-exposure to the CYP1 inhibitor alpha-naphthoflavone (αNF) and FICZ had similar effects as the combination of CYP1A-MO and FICZ. HPLC analysis of FICZ-exposed embryos showed increased levels of FICZ after concomitant CYP1A-MO injection or αNF co-exposure. Together, these results show that a functioning CYP1/AHR feedback loop is crucial for regulation of AHR signaling by a potential physiological ligand in vivo and further highlights the role of CYP1 enzymes in regulating biological effects of FICZ.
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Affiliation(s)
- Emma Wincent
- Institute of Environmental Medicine, Karolinska Institutet, 17177 Stockholm, Sweden; Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543-1050, USA.
| | - Akira Kubota
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543-1050, USA.
| | - Alicia Timme-Laragy
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543-1050, USA.
| | - Maria E Jönsson
- Department of Environmental Toxicology, Uppsala University, 75236 Uppsala, Sweden.
| | - Mark E Hahn
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543-1050, USA.
| | - John J Stegeman
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543-1050, USA.
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Jönsson ME, Mattsson A, Shaik S, Brunström B. Toxicity and cytochrome P450 1A mRNA induction by 6-formylindolo[3,2-b]carbazole (FICZ) in chicken and Japanese quail embryos. Comp Biochem Physiol C Toxicol Pharmacol 2016; 179:125-36. [PMID: 26456929 DOI: 10.1016/j.cbpc.2015.09.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2015] [Revised: 09/24/2015] [Accepted: 09/25/2015] [Indexed: 12/22/2022]
Abstract
The tryptophan derivative formylindolo[3,2-b]carbazole (FICZ) binds with high ligand affinity to the aryl hydrocarbon receptor (AHR) and is readily degraded by AHR-regulated cytochrome P450 family 1 (CYP1) enzymes. Whether in vivo exposure to FICZ can result in toxic effects has not been examined and the main objective of this study was to determine if FICZ is embryotoxic in birds. We examined toxicity and CYP1 mRNA induction of FICZ in embryos from chicken (Gallus domesticus) and Japanese quail (Coturnix japonica) exposed to FICZ (2-200μgkg(-1)) by yolk and air sac injections. FICZ caused liver toxicity, embryo mortality, and CYP1A4 and CYP1A5 induction in both species with similar potency. This is in stark contrast to the very large difference in sensitivity of these species to halogenated AHR agonists. We also exposed chicken embryos to a low dose of FICZ (4μgkg(-1)) in combination with a CYP inhibitor, ketoconazole (KCZ). The mixture of FICZ and KCZ was lethal while FICZ alone had no effect at 4μgkg(-1). Furthermore, mixed exposure to FICZ and KCZ caused stronger and more long-lasting hepatic CYP1A4 induction than exposure to each compound alone. These findings indicate reduced biotransformation of FICZ by co-treatment with KCZ as a cause for the enhanced effects although additive AHR activation is also possible. To conclude, FICZ is toxic to bird embryos and it seems reasonable that the toxicity by FICZ involves AHR activation. However, the molecular targets and biological events leading to hepatic damage and mortality are unknown.
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Affiliation(s)
- Maria E Jönsson
- Department of Environmental Toxicology, Uppsala University, Uppsala, Sweden.
| | - Anna Mattsson
- Department of Environmental Toxicology, Uppsala University, Uppsala, Sweden
| | - Siraz Shaik
- Department of Environmental Toxicology, Uppsala University, Uppsala, Sweden
| | - Björn Brunström
- Department of Environmental Toxicology, Uppsala University, Uppsala, Sweden
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Shoots J, Fraccalvieri D, Franks DG, Denison MS, Hahn ME, Bonati L, Powell WH. An Aryl Hydrocarbon Receptor from the Salamander Ambystoma mexicanum Exhibits Low Sensitivity to 2,3,7,8-Tetrachlorodibenzo-p-dioxin. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:6993-7001. [PMID: 25941739 PMCID: PMC4454367 DOI: 10.1021/acs.est.5b01299] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Structural features of the aryl hydrocarbon receptor (AHR) can underlie species- and population-specific differences in its affinity for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). These differences often explain variations in TCDD toxicity. Frogs are relatively insensitive to dioxin, and Xenopus AHRs bind TCDD with low affinity. Weak TCDD binding results from the combination of three residues in the ligand-binding domain: A354 and A370, and N325. Here we sought to determine whether this mechanism of weak TCDD binding is shared by other amphibian AHRs. We isolated an AHR cDNA from the Mexican axolotl (Ambystoma mexicanum). The encoded polypeptide contains identical residues at positions that confer low TCDD affinity to X. laevis AHRs (A364, A380, and N335), and homology modeling predicts they protrude into the binding cavity. Axolotl AHR bound one-tenth the TCDD of mouse AHR in velocity sedimentation analysis, and in transactivation assays, the EC50 for TCDD was 23 nM, similar to X. laevis AHR1β (27 nM) and greater than AHR containing the mouse ligand-binding domain (0.08 nM). Sequence, modeled structure, and function indicate that axolotl AHR binds TCDD weakly, predicting that A. mexicanum lacks sensitivity toTCDD toxicity. We hypothesize that this characteristic of axolotl and Xenopus AHRs arose in a common ancestor of the Caudata and Anura.
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Affiliation(s)
- Jenny Shoots
- Biology Department, Kenyon College, Gambier, OH 43022 USA
| | - Domenico Fraccalvieri
- Department of Earth and Environmental Sciences, University of Milano-Bicocca, 20126 Milan, Italy
| | - Diana G. Franks
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543 USA
| | - Michael S. Denison
- Department of Environmental Toxicology, University of California, Davis, CA 95616 USA
| | - Mark E. Hahn
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543 USA
| | - Laura Bonati
- Department of Earth and Environmental Sciences, University of Milano-Bicocca, 20126 Milan, Italy
| | - Wade H. Powell
- Biology Department, Kenyon College, Gambier, OH 43022 USA
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Hirano M, Hwang JH, Park HJ, Bak SM, Iwata H, Kim EY. In silico analysis of the interaction of avian aryl hydrocarbon receptors and dioxins to decipher isoform-, ligand-, and species-specific activations. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:3795-804. [PMID: 25692546 DOI: 10.1021/es505733f] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The aryl hydrocarbon receptor (AHR) mediates toxic responses to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and other dioxin-like compounds (DLCs). Avian species possess multiple AHR isoforms (AHR1, AHR1β, and AHR2) that exhibit species- and isoform-specific responses to ligands. To account for the ligand preference in terms of the structural features of avian AHRs, we generated in silico homology models of the ligand-binding domain of avian AHRs based on holo human HIF-2α (PDB entry 3H7W ). Molecular docking simulations of TCDD and other DLCs with avian AHR1s and AHR2s using ASEDock indicated that the interaction energy increased with the number of substituted chlorine atoms in congeners, supporting AHR transactivation potencies and World Health Organization TCDD toxic equivalency factors of congeners. The potential interaction energies of an endogenous AHR ligand, 6-formylindolo [3,2-b] carbazole (FICZ) to avian AHRs were lower than those of TCDD, which was supported by a greater potency of FICZ for in vitro AHR-mediated transactivation than TCDD. The molecular dynamics simulation revealed that mean square displacements in Ile324 and Ser380 of TCDD-bound AHR1 of the chicken, the most sensitive species to TCDD, were smaller than those in other avian AHR1s, suggesting that the dynamic stability of these amino acid residues contribute to TCDD preference. For avian AHR2, the corresponding residues (Val/Ser or Val/Ala type) were not responsible for differential TCDD sensitivity. Application of the three-dimensional reference interaction site model showed that the stabilization of TCDD binding to avian AHRs may be due to the solvation effect depending on the characteristics of two amino acids corresponding to Ile324 and Ser380 in chicken AHR1. This study demonstrates that in silico simulations of AHRs and ligands could be used to predict isoform-, ligand-, and species-specific interactions.
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Affiliation(s)
- Masashi Hirano
- †Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama 790-8577, Japan
| | - Ji-Hee Hwang
- ‡Department of Life and Nanopharmaceutical Science and Department of Biology, Kyung Hee University, Hoegi-Dong, Dongdaemun-Gu, Seoul 130-701, Korea
| | - Hae-Jeong Park
- ‡Department of Life and Nanopharmaceutical Science and Department of Biology, Kyung Hee University, Hoegi-Dong, Dongdaemun-Gu, Seoul 130-701, Korea
| | - Su-Min Bak
- ‡Department of Life and Nanopharmaceutical Science and Department of Biology, Kyung Hee University, Hoegi-Dong, Dongdaemun-Gu, Seoul 130-701, Korea
| | - Hisato Iwata
- †Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama 790-8577, Japan
| | - Eun-Young Kim
- ‡Department of Life and Nanopharmaceutical Science and Department of Biology, Kyung Hee University, Hoegi-Dong, Dongdaemun-Gu, Seoul 130-701, Korea
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