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Eaton DL, Simon TW, Kaminski NE, Perdew GH, Nebert DW. Species differences in specific ligand-binding affinity and activation of AHR: The biological basis for calculation of relative effective potencies and toxic equivalence factors. Regul Toxicol Pharmacol 2024; 149:105598. [PMID: 38548044 DOI: 10.1016/j.yrtph.2024.105598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 02/25/2024] [Accepted: 03/05/2024] [Indexed: 05/01/2024]
Abstract
In 2022 the World Health Organization (WHO) published updated 'Toxic Equivalence Factors' (TEFs) for a wide variety of chlorinated dioxins, dibenzofurans and PCBs [collectively referred to as 'dioxin-like chemicals'; DLCs) that interact with the aryl hydrocarbon receptor (AHR)]. Their update used sophisticated statistical analysis of hundreds of published studies that reported estimation of 'Relative Effective Potency' (REP) values for individual DLC congeners. The weighting scheme used in their assessment of each study favored in vivo over in vitro studies and was based largely on rodent studies. In this Commentary, we highlight the large body of published studies that demonstrate large species differences in AHR-ligand activation and provide supporting evidence for our position that the WHO 2022 TEF values intended for use in human risk assessment of DLC mixtures will provide highly misleading overestimates of 'Toxic Equivalent Quotients' (TEQs), because of well-recognized striking differences in AHR ligand affinities between rodent (rat, mouse) and human. The data reviewed in our Commentary support the position that human tissue-derived estimates of REP/TEF values for individual DLC congeners, although uncertain, will provide much better, more realistic estimates of potential activation of the human AHR, when exposure to complex DLC mixtures occurs.
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Affiliation(s)
- David L Eaton
- Department of Environmental Occupational Health Sciences, School of Public Health, University of Washington, Seattle, WA, USA.
| | | | - Norbert E Kaminski
- Department of Pharmacology and Toxicology, Institute for Integrative Toxicology, Michigan State University, East Lansing, MI, USA
| | - Gary H Perdew
- The Pennsylvania State University, State College, PA, USA
| | - Daniel W Nebert
- Department of Environmental and Public Health Sciences, Center for Environmental Genetics, University of Cincinnati College of Medicine, USA; Department of Pediatrics & Molecular Developmental Biology, Division of Human Genetics, Cincinnati Children's Research Foundation, Cincinnati, OH, USA
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2
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Zhao B, Deng J, Ma M, Li N, Zhou J, Li X, Luan T. Environmentally relevant concentrations of 2,3,7,8-TCDD induced inhibition of multicellular alternative splicing and transcriptional dysregulation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 919:170892. [PMID: 38346650 DOI: 10.1016/j.scitotenv.2024.170892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 02/07/2024] [Accepted: 02/09/2024] [Indexed: 02/17/2024]
Abstract
Alternative splicing (AS), found in approximately 95 % of human genes, significantly amplifies protein diversity and is implicated in disease pathogenesis when dysregulated. However, the precise involvement of AS in the toxic mechanisms induced by TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin) remains incompletely elucidated. This study conducted a thorough global AS analysis in six human cell lines following TCDD exposure. Our findings revealed that environmentally relevant concentration (0.1 nM) of TCDD significantly suppressed AS events in all cell types, notably inhibiting diverse splicing events and reducing transcript diversity, potentially attributed to modifications in the splicing patterns of the inhibitory factor family, particularly hnRNP. And we identified 151 genes with substantial AS alterations shared among these cell types, particularly enriched in immune and metabolic pathways. Moreover, TCDD induced cell-specific changes in splicing patterns and transcript levels, with increased sensitivity notably in THP-1 monocyte, potentially linked to aberrant expression of pivotal genes within the spliceosome pathway (DDX5, EFTUD2, PUF60, RBM25, SRSF1, and CRNKL1). This study extends our understanding of disrupted alternative splicing and its relation to the multisystem toxicity of TCDD. It sheds light on how environmental toxins affect post-transcriptional regulatory processes, offering a fresh perspective for toxicology and disease etiology investigations.
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Affiliation(s)
- Bilin Zhao
- Guangdong Provincial Laboratory of Chemistry and Fine Chemical Engineering Jieyang Center, Jieyang 515200, China; Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China
| | - Jiewei Deng
- Guangdong Provincial Laboratory of Chemistry and Fine Chemical Engineering Jieyang Center, Jieyang 515200, China; School of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Guangzhou 510006, China; Smart Medical Innovation Technology Center, Guangdong University of Technology, Guangzhou 510006, China
| | - Mei Ma
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Na Li
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Junlin Zhou
- Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China
| | - Xinyan Li
- Guangdong Provincial Laboratory of Chemistry and Fine Chemical Engineering Jieyang Center, Jieyang 515200, China; School of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Guangzhou 510006, China; Smart Medical Innovation Technology Center, Guangdong University of Technology, Guangzhou 510006, China.
| | - Tiangang Luan
- Guangdong Provincial Laboratory of Chemistry and Fine Chemical Engineering Jieyang Center, Jieyang 515200, China; Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China; Smart Medical Innovation Technology Center, Guangdong University of Technology, Guangzhou 510006, China
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3
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Khan DMIO, Karmaus PWF, Bach A, Crawford RB, Kaminski NE. An in vitro model of human hematopoiesis identifies a regulatory role for the aryl hydrocarbon receptor. Blood Adv 2023; 7:6253-6265. [PMID: 37477592 PMCID: PMC10589788 DOI: 10.1182/bloodadvances.2023010169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 06/22/2023] [Accepted: 07/12/2023] [Indexed: 07/22/2023] Open
Abstract
In vitro models to study simultaneous development of different human immune cells and hematopoietic lineages are lacking. We identified and characterized, using single-cell methods, an in vitro stromal cell-free culture system of human hematopoietic stem and progenitor cell (HSPC) differentiation that allows concurrent development of multiple immune cell lineages. The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor influencing many biological processes in diverse cell types. Using this in vitro model, we found that AHR activation by the highly specific AHR ligand, 2,3,7,8-tetrachlorodibenzo-p-dioxin, drives differentiation of human umbilical cord blood-derived CD34+ HSPCs toward monocytes and granulocytes with a significant decrease in lymphoid and megakaryocyte lineage specification that may lead to reduced immune competence. To our knowledge, we also discovered for the first time, using single-cell modalities, that AHR activation decreased the expression of BCL11A and IRF8 in progenitor cells, which are critical genes involved in hematopoietic lineage specification processes at both transcriptomic and protein levels. Our in vitro model of hematopoiesis, coupled with single-cell tools, therefore allows for a better understanding of the role played by AHR in modulating hematopoietic differentiation.
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Affiliation(s)
- D M Isha Olive Khan
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI
- Institute for Integrative Toxicology, Michigan State University, East Lansing, MI
| | - Peer W. F. Karmaus
- Institute for Integrative Toxicology, Michigan State University, East Lansing, MI
- National Institute of Environmental Health Sciences, Durham, NC
| | - Anthony Bach
- Institute for Integrative Toxicology, Michigan State University, East Lansing, MI
| | - Robert B. Crawford
- Institute for Integrative Toxicology, Michigan State University, East Lansing, MI
| | - Norbert E. Kaminski
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI
- Institute for Integrative Toxicology, Michigan State University, East Lansing, MI
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4
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Stukas D, Jasukaitiene A, Bartkeviciene A, Matthews J, Maimets T, Teino I, Jaudzems K, Gulbinas A, Dambrauskas Z. Targeting AHR Increases Pancreatic Cancer Cell Sensitivity to Gemcitabine through the ELAVL1-DCK Pathway. Int J Mol Sci 2023; 24:13155. [PMID: 37685961 PMCID: PMC10487468 DOI: 10.3390/ijms241713155] [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: 07/18/2023] [Revised: 08/21/2023] [Accepted: 08/22/2023] [Indexed: 09/10/2023] Open
Abstract
The aryl hydrocarbon receptor (AHR) is a transcription factor that is commonly upregulated in pancreatic ductal adenocarcinoma (PDAC). AHR hinders the shuttling of human antigen R (ELAVL1) from the nucleus to the cytoplasm, where it stabilises its target messenger RNAs (mRNAs) and enhances protein expression. Among these target mRNAs are those induced by gemcitabine. Increased AHR expression leads to the sequestration of ELAVL1 in the nucleus, resulting in chemoresistance. This study aimed to investigate the interaction between AHR and ELAVL1 in the pathogenesis of PDAC in vitro. AHR and ELAVL1 genes were silenced by siRNA transfection. The RNA and protein were extracted for quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot (WB) analysis. Direct binding between the ELAVL1 protein and AHR mRNA was examined through immunoprecipitation (IP) assay. Cell viability, clonogenicity, and migration assays were performed. Our study revealed that both AHR and ELAVL1 inter-regulate each other, while also having a role in cell proliferation, migration, and chemoresistance in PDAC cell lines. Notably, both proteins function through distinct mechanisms. The silencing of ELAVL1 disrupts the stability of its target mRNAs, resulting in the decreased expression of numerous cytoprotective proteins. In contrast, the silencing of AHR diminishes cell migration and proliferation and enhances cell sensitivity to gemcitabine through the AHR-ELAVL1-deoxycytidine kinase (DCK) molecular pathway. In conclusion, AHR and ELAVL1 interaction can form a negative feedback loop. By inhibiting AHR expression, PDAC cells become more susceptible to gemcitabine through the ELAVL1-DCK pathway.
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Affiliation(s)
- Darius Stukas
- Surgical Gastroenterology Laboratory, Institute for Digestive Research, Lithuanian University of Health Sciences, Eiveniu 4, 50103 Kaunas, Lithuania; (A.J.); (A.B.); (A.G.); (Z.D.)
| | - Aldona Jasukaitiene
- Surgical Gastroenterology Laboratory, Institute for Digestive Research, Lithuanian University of Health Sciences, Eiveniu 4, 50103 Kaunas, Lithuania; (A.J.); (A.B.); (A.G.); (Z.D.)
| | - Arenida Bartkeviciene
- Surgical Gastroenterology Laboratory, Institute for Digestive Research, Lithuanian University of Health Sciences, Eiveniu 4, 50103 Kaunas, Lithuania; (A.J.); (A.B.); (A.G.); (Z.D.)
| | - Jason Matthews
- Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, 1046 Blindern, 0317 Oslo, Norway;
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Toivo Maimets
- Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia; (T.M.); (I.T.)
| | - Indrek Teino
- Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia; (T.M.); (I.T.)
| | - Kristaps Jaudzems
- Latvian Institute of Organic Synthesis, Aizkraukles 21, LV-1006 Riga, Latvia;
| | - Antanas Gulbinas
- Surgical Gastroenterology Laboratory, Institute for Digestive Research, Lithuanian University of Health Sciences, Eiveniu 4, 50103 Kaunas, Lithuania; (A.J.); (A.B.); (A.G.); (Z.D.)
| | - Zilvinas Dambrauskas
- Surgical Gastroenterology Laboratory, Institute for Digestive Research, Lithuanian University of Health Sciences, Eiveniu 4, 50103 Kaunas, Lithuania; (A.J.); (A.B.); (A.G.); (Z.D.)
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5
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Liu R, Zacharewski TR, Conolly RB, Zhang Q. A Physiologically Based Pharmacokinetic (PBPK) Modeling Framework for Mixtures of Dioxin-like Compounds. TOXICS 2022; 10:toxics10110700. [PMID: 36422908 PMCID: PMC9698634 DOI: 10.3390/toxics10110700] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/03/2022] [Accepted: 11/15/2022] [Indexed: 06/08/2023]
Abstract
Humans are exposed to persistent organic pollutants, such as dioxin-like compounds (DLCs), as mixtures. Understanding and predicting the toxicokinetics and thus internal burden of major constituents of a DLC mixture is important for assessing their contributions to health risks. PBPK models, including dioxin models, traditionally focus on one or a small number of compounds; developing new or extending existing models for mixtures often requires tedious, error-prone coding work. This lack of efficiency to scale up for multi-compound exposures is a major technical barrier toward large-scale mixture PBPK simulations. Congeners in the DLC family, including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), share similar albeit quantitatively different toxicokinetic and toxicodynamic properties. Taking advantage of these similarities, here we reported the development of a human PBPK modeling framework for DLC mixtures that can flexibly accommodate an arbitrary number of congeners. Adapted from existing TCDD models, our mixture model contains the blood and three diffusion-limited compartments-liver, fat, and rest of the body. Depending on the number of congeners in a mixture, varying-length vectors of ordinary differential equations (ODEs) are automatically generated to track the tissue concentrations of the congeners. Shared ODEs are used to account for common variables, including the aryl hydrocarbon receptor (AHR) and CYP1A2, to which the congeners compete for binding. Binary and multi-congener mixture simulations showed that the AHR-mediated cross-induction of CYP1A2 accelerates the sequestration and metabolism of DLC congeners, resulting in consistently lower tissue burdens than in single exposure, except for the liver. Using dietary intake data to simulate lifetime exposures to DLC mixtures, the model demonstrated that the relative contributions of individual congeners to blood or tissue toxic equivalency (TEQ) values are markedly different than those to intake TEQ. In summary, we developed a mixture PBPK modeling framework for DLCs that may be utilized upon further improvement as a quantitative tool to estimate tissue dosimetry and health risks of DLC mixtures.
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Affiliation(s)
- Rongrui Liu
- Lower Merion High School, Ardmore, PA 19003, USA
| | - Tim R. Zacharewski
- Department of Biochemistry and Molecular Biology, Institute for Integrative Toxicology, Michigan State University, East Lansing, MI 48824, USA
| | | | - Qiang Zhang
- Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
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6
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Wu J, Pang T, Lin Z, Zhao M, Jin H. The key player in the pathogenesis of environmental influence of systemic lupus erythematosus: Aryl hydrocarbon receptor. Front Immunol 2022; 13:965941. [PMID: 36110860 PMCID: PMC9468923 DOI: 10.3389/fimmu.2022.965941] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 08/01/2022] [Indexed: 11/28/2022] Open
Abstract
The aryl hydrocarbon receptor was previously known as an environmental receptor that modulates the cellular response to external environmental changes. In essence, the aryl hydrocarbon receptor is a cytoplasmic receptor and transcription factor that is activated by binding to the corresponding ligands, and they transmit relevant information by binding to DNA, thereby activating the transcription of various genes. Therefore, we can understand the development of certain diseases and discover new therapeutic targets by studying the regulation and function of AhR. Several autoimmune diseases, including systemic lupus erythematosus (SLE), have been connected to AhR in previous studies. SLE is a classic autoimmune disease characterized by multi-organ damage and disruption of immune tolerance. We discuss here the homeostatic regulation of AhR and its ligands among various types of immune cells, pathophysiological roles, in addition to the roles of various related cytokines and signaling pathways in the occurrence and development of SLE.
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Abstract
ComptoxAI is a new data infrastructure for computational and artificial intelligence research in predictive toxicology. Here, we describe and showcase ComptoxAI's graph-structured knowledge base in the context of three real-world use-cases, demonstrating that it can rapidly answer complex questions about toxicology that are infeasible using previous technologies and data resources. These use-cases each demonstrate a tool for information retrieval from the knowledge base being used to solve a specific task: The "shortest path" module is used to identify mechanistic links between perfluorooctanoic acid (PFOA) exposure and nonalcoholic fatty liver disease; the "expand network" module identifies communities that are linked to dioxin toxicity; and the quantitative structure-activity relationship (QSAR) dataset generator predicts pregnane X receptor agonism in a set of 4,021 pesticide ingredients. The contents of ComptoxAI's source data are rigorously aggregated from a diverse array of public third-party databases, and ComptoxAI is designed as a free, public, and open-source toolkit to enable diverse classes of users including biomedical researchers, public health and regulatory officials, and the general public to predict toxicology of unknowns and modes of action.
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Affiliation(s)
- Joseph D Romano
- Institute for Biomedical Informatics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Center of Excellence in Environmental Toxicology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Yun Hao
- Institute for Biomedical Informatics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Jason H Moore
- Department of Computational Biomedicine, Cedars-Sinai Medical Center, Los Angeles, California 90069, United States
| | - Trevor M Penning
- Center of Excellence in Environmental Toxicology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Systems Pharmacology & Translational Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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8
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Yang S, Park SH, Oh SW, Kwon K, Yu E, Lee CW, Son YK, Kim C, Lee BH, Cho JY, Kim YJ, Lee J. Antioxidant Activities and Mechanisms of Tomentosin in Human Keratinocytes. Antioxidants (Basel) 2022; 11:antiox11050990. [PMID: 35624854 PMCID: PMC9137523 DOI: 10.3390/antiox11050990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 05/13/2022] [Accepted: 05/14/2022] [Indexed: 11/23/2022] Open
Abstract
Tomentosin, one of natural sesquiterpene lactones sourced from Inula viscosa L., exerts therapeutic effects in various cell types. Here, we investigated the antioxidant activities and the underlying action mechanisms of tomentosin in HaCaT cells (a human keratinocyte cell line). Specifically, we examined the involvement of tomentosin in aryl hydrocarbon receptor (AhR) and nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathways. Treatment with tomentosin for up to 60 min triggered the production of reactive oxygen species (ROS), whereas treatment for 4 h or longer decreased ROS production. Tomentosin treatment also induced the nuclear translocation of Nrf2 and upregulated the expression of Nrf2 and its target genes. These data indicate that tomentosin induces ROS production at an early stage which activates the Nrf2 pathway by disrupting the Nrf2–Keap1 complex. However, at a later stage, ROS levels were reduced by tomentosin-induced upregulation of antioxidant genes. In addition, tomentosin induced the phosphorylation of mitogen-activated protein kinases (MAPKs) including p38 MAPK and c-Jun N-terminal kinase (JNK). SB203580 (a p38 MAPK inhibitor) and SP600125 (a JNK inhibitor) attenuated the tomentosin-induced phosphorylation of Nrf2, suggesting that JNK and p38 MAPK signaling pathways can contribute to the tomentosin-induced Nrf2 activation through phosphorylation of Nrf2. Furthermore, N-acetyl-L-cysteine (NAC) treatment blocked both tomentosin-induced production of ROS and the nuclear translocation of Nrf2. These data suggest that tomentosin-induced Nrf2 signaling is mediated both by tomentosin-induced ROS production and the activation of p38 MAPK and JNK. Moreover, tomentosin inhibited the AhR signaling pathway, as evidenced by the suppression of xenobiotic-response element (XRE) reporter activity and the translocation of AhR into nucleus induced by urban pollutants, especially benzo[a]pyrene. These findings suggest that tomentosin can ameliorate skin damage induced by environmental pollutants.
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Affiliation(s)
- Seyoung Yang
- Molecular Dermatology Laboratory, Department of Integrative Biotechnology, College of Biotechnology and Bioengineering, Sungkyunkwan University, Suwon City 16419, Gyunggi Do, Korea; (S.Y.); (S.W.O.); (K.K.); (E.Y.)
| | - See-Hyoung Park
- Department of Bio and Chemical Engineering, Hongik University, Sejong City 30016, Korea;
| | - Sae Woong Oh
- Molecular Dermatology Laboratory, Department of Integrative Biotechnology, College of Biotechnology and Bioengineering, Sungkyunkwan University, Suwon City 16419, Gyunggi Do, Korea; (S.Y.); (S.W.O.); (K.K.); (E.Y.)
| | - Kitae Kwon
- Molecular Dermatology Laboratory, Department of Integrative Biotechnology, College of Biotechnology and Bioengineering, Sungkyunkwan University, Suwon City 16419, Gyunggi Do, Korea; (S.Y.); (S.W.O.); (K.K.); (E.Y.)
| | - Eunbi Yu
- Molecular Dermatology Laboratory, Department of Integrative Biotechnology, College of Biotechnology and Bioengineering, Sungkyunkwan University, Suwon City 16419, Gyunggi Do, Korea; (S.Y.); (S.W.O.); (K.K.); (E.Y.)
| | - Chae Won Lee
- National Institute of Biological Resources, Environmental Research Complex, Incheon 22689, Korea; (C.W.L.); (Y.K.S.); (C.K.); (B.-H.L.)
| | - Youn Kyoung Son
- National Institute of Biological Resources, Environmental Research Complex, Incheon 22689, Korea; (C.W.L.); (Y.K.S.); (C.K.); (B.-H.L.)
| | - Changmu Kim
- National Institute of Biological Resources, Environmental Research Complex, Incheon 22689, Korea; (C.W.L.); (Y.K.S.); (C.K.); (B.-H.L.)
| | - Byoung-Hee Lee
- National Institute of Biological Resources, Environmental Research Complex, Incheon 22689, Korea; (C.W.L.); (Y.K.S.); (C.K.); (B.-H.L.)
| | - Jae Youl Cho
- Molecular Immunology Laboratory, Department of Integrative Biotechnology, College of Biotechnology and Bioengineering, Sungkyunkwan University, Suwon City 16419, Gyunggi Do, Korea
- Correspondence: (J.Y.C.); (Y.-J.K.); (J.L.); Tel.: +82-31-290-7861 (J.L.)
| | - Youn-Jung Kim
- Department of Marine Sciences, Incheon National University, Incheon 22012, Korea
- Correspondence: (J.Y.C.); (Y.-J.K.); (J.L.); Tel.: +82-31-290-7861 (J.L.)
| | - Jongsung Lee
- Molecular Dermatology Laboratory, Department of Integrative Biotechnology, College of Biotechnology and Bioengineering, Sungkyunkwan University, Suwon City 16419, Gyunggi Do, Korea; (S.Y.); (S.W.O.); (K.K.); (E.Y.)
- Correspondence: (J.Y.C.); (Y.-J.K.); (J.L.); Tel.: +82-31-290-7861 (J.L.)
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Sabuz Vidal O, Deepika D, Schuhmacher M, Kumar V. EDC-induced mechanisms of immunotoxicity: a systematic review. Crit Rev Toxicol 2022; 51:634-652. [PMID: 35015608 DOI: 10.1080/10408444.2021.2009438] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Endocrine-disrupting chemicals (EDCs) refer to a group of chemicals that cause adverse effects in human health, impairing hormone production and regulation, resulting in alteration of homeostasis, reproductive, and developmental, and immune system impairments. The immunotoxicity of EDCs involves many mechanisms altering gene expression that depend on the activation of nuclear receptors such as the aryl hydrocarbon receptor (AHR), the estrogen receptor (ER), and the peroxisome proliferator-activated receptor (PPAR), which also results in skin and intestinal disorders, microbiota alterations and inflammatory diseases. This systematic review aims to review different mechanisms of immunotoxicity and immunomodulation of T cells, focusing on T regulatory (Treg) and Th17 subsets, B cells, and dendritic cells (DCs) caused by specific EDCs such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), bisphenols (BPs) and polyfluoroalkyl substances (PFASs). To achieve this objective, a systematic study was conducted searching various databases including PubMed and Scopus to find in-vitro, in-vivo, and biomonitoring studies that examine EDC-dependent mechanisms of immunotoxicity. While doing the systematic review, we found species- and cell-specific outcomes and a translational gap between in-vitro and in-vivo experiments. Finally, an adverse outcome pathway (AOP) framework is proposed, which explains mechanistically toxicity endpoints emerging from different EDCs having similar key events and can help to improve our understanding of EDCs mechanisms of immunotoxicity. In conclusion, this review provides insights into the mechanisms of immunotoxicity mediated by EDCs and will help to improve human health risk assessment.
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Affiliation(s)
- Oscar Sabuz Vidal
- Environmental Engineering Laboratory, Departament d'Enginyeria Quimica, Universitat Rovira i Virgili, Tarragona, Spain
| | - Deepika Deepika
- Environmental Engineering Laboratory, Departament d'Enginyeria Quimica, Universitat Rovira i Virgili, Tarragona, Spain
| | - Marta Schuhmacher
- Environmental Engineering Laboratory, Departament d'Enginyeria Quimica, Universitat Rovira i Virgili, Tarragona, Spain
| | - Vikas Kumar
- Environmental Engineering Laboratory, Departament d'Enginyeria Quimica, Universitat Rovira i Virgili, Tarragona, Spain.,IISPV, Hospital Universitari Sant Joan de Reus, Universitat Rovira I Virgili, Reus, Spain
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10
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TCDD-induced IL-24 secretion in human chorionic stromal cells inhibits placental trophoblast cell migration and invasion. Reprod Toxicol 2022; 108:10-17. [PMID: 34995713 DOI: 10.1016/j.reprotox.2022.01.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 12/27/2021] [Accepted: 01/02/2022] [Indexed: 12/30/2022]
Abstract
Environmental pollutant dioxins are potentially harmful to pregnant women and can lead to severe adverse outcomes in pregnancy, such as spontaneous abortion and stillbirth. However, little is currently known about the underlying toxicological mechanism. Our previous study reported that the IL-24 gene is a dioxin response gene during 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) treatment. Here, we further tested the effect of TCDD on IL-24 expression in human chorionic stromal cells. We also investigated the effect of IL-24 on the behaviors of human placental trophoblast cells and predicted the potential mechanism underlying these behaviors using functional network analysis. We found that TCDD stimulates IL-24 expression in human chorionic stromal cells in an AhR (aromatic hydrocarbon receptor)-related manner. We also found that IL-24 inhibits the migration and invasion of human placental trophoblast cells, the possible mechanism of which involves thirteen key proteins and mitochondrial function. Our findings suggest that IL-24 is a potential factor induced by TCDD to regulate trophoblast cell invasion, which potentially involves in TCDD-induced abortion.
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11
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Aarts JMMJG, Alink GM, Franssen HJ, Roebroeks W. Evolution of Hominin Detoxification: Neanderthal and Modern Human Ah Receptor Respond Similarly to TCDD. Mol Biol Evol 2021; 38:1292-1305. [PMID: 33230523 PMCID: PMC8042735 DOI: 10.1093/molbev/msaa287] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
In studies of hominin adaptations to fire use, the role of the aryl hydrocarbon receptor (AHR) in the evolution of detoxification has been highlighted, including statements that the modern human AHR confers a significantly better capacity to deal with toxic smoke components than the Neanderthal AHR. To evaluate this, we compared the AHR-controlled induction of cytochrome P4501A1 (CYP1A1) mRNA in HeLa human cervix epithelial adenocarcinoma cells transfected with an Altai-Neanderthal or a modern human reference AHR expression construct, and exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). We compared the complete AHR mRNA sequences including the untranslated regions (UTRs), maintaining the original codon usage. We observe no significant difference in CYP1A1 induction by TCDD between Neanderthal and modern human AHR, whereas a 150–1,000 times difference was previously reported in a study of the AHR coding region optimized for mammalian codon usage and expressed in rat cells. Our study exemplifies that expression in a homologous cellular background is of major importance to determine (ancient) protein activity. The Neanderthal and modern human dose–response curves almost coincide, except for a slightly higher extrapolated maximum for the Neanderthal AHR, possibly caused by a 5′-UTR G-variant known from modern humans (rs7796976). Our results are strongly at odds with a major role of the modern human AHR in the evolution of hominin detoxification of smoke components and consistent with our previous study based on 18 relevant genes in addition to AHR, which concluded that efficient detoxification alleles are more dominant in ancient hominins, chimpanzees, and gorillas than in modern humans.
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Affiliation(s)
- Jac M M J G Aarts
- Human Origins Group, Faculty of Archaeology, Leiden University, Leiden, The Netherlands.,Laboratory of Molecular Biology, Department of Plant Sciences, Wageningen University, Wageningen, The Netherlands
| | - Gerrit M Alink
- Human Origins Group, Faculty of Archaeology, Leiden University, Leiden, The Netherlands
| | - Henk J Franssen
- Laboratory of Molecular Biology, Department of Plant Sciences, Wageningen University, Wageningen, The Netherlands
| | - Wil Roebroeks
- Human Origins Group, Faculty of Archaeology, Leiden University, Leiden, The Netherlands
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12
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Ibrahim R, Brix A, Malarkey DE, Nyska A, Asif M, Ramot Y. Chemical-Induced Oral Squamous Cell Neoplasms in Rodents: An Overview of NTP 2-Year Cancer Studies. Toxicol Pathol 2021; 49:1062-1076. [PMID: 33576321 DOI: 10.1177/0192623321989956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Oral cancer is the seventh most common malignancy worldwide, and lifestyle factors participate in its development. Rodent studies can help identify substances that contribute to its development and provide information on the early stages of carcinogenicity. The National Toxicology Program (NTP) has conducted more than 500 short-term and 2-year toxicology and carcinogenicity studies in rodents, and some of the tested compounds resulted in oral cancer. Our goal was to review the NTP carcinogenic studies to describe those chemicals that have oral carcinogenic outcome in rodents. For this project, we reviewed the results from all NTP carcinogenicity studies and a board-certified veterinary pathologist reviewed the slides from all neoplasms in the oral cavity that were considered treatment related. We have identified 26 chemicals with an adverse effect in the oral cavity. Fourteen chemicals demonstrated clear evidence of carcinogenicity in the oral cavity. We provide information on the carcinogenic findings in rodents together with a detailed description of the morphologic aspects of the oral cancers and speculate that the carcinogenic effects can be induced by different pathological modes of action. The findings reviewed here provide indicators for potential oral carcinogenesis processes in rodent models, which can be further investigated in future mechanistic studies.
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Affiliation(s)
- Ruba Ibrahim
- Faculty of Medicine, 58884Hadassah Medical Center, Jerusalem, Israel.,Department of Dermatology, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Amy Brix
- Experimental Pathology Laboratories, Inc., Research Triangle Park, NC, USA
| | - David E Malarkey
- Division of the National Toxicology Program, 6857National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - Abraham Nyska
- Toxicologic Pathology, Tel Aviv and 26745Tel Aviv University, Israel
| | - Michal Asif
- Faculty of Medicine, 58884Hadassah Medical Center, Jerusalem, Israel.,Department of Dermatology, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Yuval Ramot
- Faculty of Medicine, 58884Hadassah Medical Center, Jerusalem, Israel.,Department of Dermatology, Hebrew University of Jerusalem, Jerusalem, Israel
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13
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Wikoff DS, Urban JD, Ring C, Britt J, Fitch S, Budinsky R, Haws LC. Development of a Range of Plausible Noncancer Toxicity Values for 2,3,7,8-Tetrachlorodibenzo-p-Dioxin Based on Effects on Sperm Count: Application of Systematic Review Methods and Quantitative Integration of Dose Response Using Meta-Regression. Toxicol Sci 2021; 179:162-182. [PMID: 33306106 DOI: 10.1093/toxsci/kfaa171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Regulatory agencies have derived noncancer toxicity values for 2,3,7,8-tetrachlorodibenzo-p-dioxin based on reduced sperm counts relying on single studies from a large body of evidence. Techniques such as meta-regression allow for greater use of the available data while simultaneously providing important information regarding the uncertainty associated with the underlying evidence base when conducting risk assessments. The objective herein was to apply systematic review methods and meta-regression to characterize the dose-response relationship of gestational exposure and epididymal sperm count. Twenty-three publications (20 animal studies consisting of 29 separate rat experimental data sets, and 3 epidemiology studies) met inclusion criteria. Risk of bias evaluation was performed to critically appraise study validity. Low to very low confidence precluded use of available epidemiological data as candidate studies for dose-response due to inconsistencies across the evidence base, high risk of bias, and general lack of biological coherence, including lack of clinical relevance and dose-response concordance. Experimental animal studies, which were found to have higher confidence following the structured assessment of confidence (eg, controlled exposure, biological consistency), were used as the basis of a meta-regression. Multiple models were fit; points of departure were identified and converted to human equivalent doses. The resulting reference dose estimates ranged from approximately 4 to 70 pg/kg/day, depending on model, benchmark response level, and study validity integration approach. This range of reference doses can be used either qualitatively or quantitatively to enhance understanding of human health risk estimates for dioxin-like compounds.
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14
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Nakano N, Sakata N, Katsu Y, Nochise D, Sato E, Takahashi Y, Yamaguchi S, Haga Y, Ikeno S, Motizuki M, Sano K, Yamasaki K, Miyazawa K, Itoh S. Dissociation of the AhR/ARNT complex by TGF-β/Smad signaling represses CYP1A1 gene expression and inhibits benze[a]pyrene-mediated cytotoxicity. J Biol Chem 2020; 295:9033-9051. [PMID: 32409577 PMCID: PMC7335805 DOI: 10.1074/jbc.ra120.013596] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/11/2020] [Indexed: 12/22/2022] Open
Abstract
Cytochrome P450 1A1 (CYP1A1) catalyzes the metabolic activation of polycyclic aromatic hydrocarbons (PAHs) such as benzo[a]pyrene (B[a]P) and is transcriptionally regulated by the aryl hydrocarbon receptor (AhR)/AhR nuclear translocator (ARNT) complex upon exposure to PAHs. Accordingly, inhibition of CYP1A1 expression reduces production of carcinogens from PAHs. Although transcription of the CYP1A1 gene is known to be repressed by transforming growth factor-β (TGF-β), how TGF-β signaling is involved in the suppression of CYP1A1 gene expression has yet to be clarified. In this study, using mammalian cell lines, along with shRNA-mediated gene silencing, CRISPR/Cas9-based genome editing, and reporter gene and quantitative RT-PCR assays, we found that TGF-β signaling dissociates the B[a]P-mediated AhR/ARNT heteromeric complex. Among the examined Smads, Smad family member 3 (Smad3) strongly interacted with both AhR and ARNT via its MH2 domain. Moreover, hypoxia-inducible factor 1α (HIF-1α), which is stabilized upon TGF-β stimulation, also inhibited AhR/ARNT complex formation in the presence of B[a]P. Thus, TGF-β signaling negatively regulated the transcription of the CYP1A1 gene in at least two different ways. Of note, TGF-β abrogated DNA damage in B[a]P-exposed cells. We therefore conclude that TGF-β may protect cells against carcinogenesis because it inhibits CYP1A1-mediated metabolic activation of PAHs as part of its anti-tumorigenic activities.
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Affiliation(s)
- Naoko Nakano
- Laboratory of Biochemistry, Showa Pharmaceutical University, Tokyo, Japan
| | - Nobuo Sakata
- Laboratory of Biochemistry, Showa Pharmaceutical University, Tokyo, Japan
| | - Yuki Katsu
- Laboratory of Biochemistry, Showa Pharmaceutical University, Tokyo, Japan
| | - Daiki Nochise
- Laboratory of Biochemistry, Showa Pharmaceutical University, Tokyo, Japan
| | - Erika Sato
- Laboratory of Biochemistry, Showa Pharmaceutical University, Tokyo, Japan
| | - Yuta Takahashi
- Laboratory of Biochemistry, Showa Pharmaceutical University, Tokyo, Japan
| | - Saori Yamaguchi
- Laboratory of Biochemistry, Showa Pharmaceutical University, Tokyo, Japan
| | - Yoko Haga
- Laboratory of Biochemistry, Showa Pharmaceutical University, Tokyo, Japan
| | - Souichi Ikeno
- Laboratory of Biochemistry, Showa Pharmaceutical University, Tokyo, Japan
| | - Mitsuyoshi Motizuki
- Department of Biochemistry, Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Keigo Sano
- Laboratory of Biochemistry, Showa Pharmaceutical University, Tokyo, Japan
| | - Kohei Yamasaki
- Laboratory of Biochemistry, Showa Pharmaceutical University, Tokyo, Japan
| | - Keiji Miyazawa
- Department of Biochemistry, Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Susumu Itoh
- Laboratory of Biochemistry, Showa Pharmaceutical University, Tokyo, Japan.
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15
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Mahringer A, Bernd A, Miller DS, Fricker G. Aryl hydrocarbon receptor ligands increase ABC transporter activity and protein expression in killifish (Fundulus heteroclitus) renal proximal tubules. Biol Chem 2020; 400:1335-1345. [PMID: 30913027 DOI: 10.1515/hsz-2018-0425] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 03/21/2019] [Indexed: 12/15/2022]
Abstract
Many widespread and persistent organic pollutants, for example, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and some polychlorinated biphenyls, activate the aryl hydrocarbon receptor (AhR) causing it to translocate to the cell nucleus where it transactivates target genes, increasing expression of a number of xenobiotic metabolizing enzymes as well as some transporters. AhR's ability to target transporters within the kidney is essentially unexplored. We show here that exposing isolated killifish (Fundulus heteroclitus) renal proximal tubules to micromolar β-naphthoflavone (BNF) or nanomolar TCDD roughly doubled the transport activity of Multidrug resistance-associated proteins Mrp2 and Mrp4, P-glycoprotein (P-gp) and Breast cancer resistance protein (Bcrp), all ATP-driven xenobiotic efflux pumps and critical determinants of renal xenobiotic excretion. These effects were abolished by actinomycin D and cycloheximide and by the AhR antagonist, α-naphthoflavone, indicating that increased transport activity was dependent on transcription and translation as well as ligand binding to AhR. Quantitative immunostaining of renal tubules exposed to BNF and TCDD showed increased luminal membrane expression of Mrp2, Mrp4, P-gp and Bcrp. Thus, in these renal tubules, the four ABC transporters are targets of AhR action.
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Affiliation(s)
- Anne Mahringer
- Institute of Pharmacy and Molecular Biotechnology, Ruprecht-Karls-University, D-69120 Heidelberg, Germany.,Mount Desert Island Biological Laboratory (MDIBL), Salisbury Cove, ME 04672, USA
| | - Alexandra Bernd
- Institute of Pharmacy and Molecular Biotechnology, Ruprecht-Karls-University, D-69120 Heidelberg, Germany.,Mount Desert Island Biological Laboratory (MDIBL), Salisbury Cove, ME 04672, USA
| | - David S Miller
- Mount Desert Island Biological Laboratory (MDIBL), Salisbury Cove, ME 04672, USA.,Laboratory of Toxicology and Pharmacology and Chemistry, National Institutes of Health/National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Gert Fricker
- Institute of Pharmacy and Molecular Biotechnology, Ruprecht-Karls-University, D-69120 Heidelberg, Germany.,Mount Desert Island Biological Laboratory, Salisbury Cove, ME 04672, USA
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16
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Wikoff D, Haws L, Ring C, Budinsky R. Application of qualitative and quantitative uncertainty assessment tools in developing ranges of plausible toxicity values for 2,3,7,8-tetrachlorodibenzo-p-dioxin. J Appl Toxicol 2019; 39:1293-1310. [PMID: 31257608 PMCID: PMC6771962 DOI: 10.1002/jat.3814] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Revised: 03/22/2019] [Accepted: 04/01/2019] [Indexed: 12/31/2022]
Abstract
Increasing interest in characterizing risk assessment uncertainty is highlighted by recent recommendations from the National Academy of Sciences. In this paper we demonstrate the utility of applying qualitative and quantitative methods for assessing uncertainty to enhance risk-based decision-making for 2,3,7,8-tetrachlorodibenzo-p-dioxin. The approach involved deconstructing the reference dose (RfD) via evaluation of the different assumptions, options, models and methods associated with derivation of the value, culminating in the development of a plausible range of potential values based on such areas of uncertainty. The results demonstrate that overall RfD uncertainty was high based on limitations in the process for selection (e.g., compliance with inclusion criteria related to internal validity of the co-critical studies, consistency with other studies), external validity (e.g., generalizing findings of acute, high-dose exposure scenarios to the general population), and selection and classification of the point of departure using data from the individual studies (e.g., lack of statistical and clinical significance). Building on sensitivity analyses conducted by the US Environmental Protection Agency in 2012, the resulting estimates of RfD values that account for the uncertainties ranged from ~1.5 to 179 pg/kg/day. It is anticipated that the range of RfDs presented herein, along with the characterization of uncertainties, will improve risk assessments of dioxins and provide important information to risk managers, because reliance on a single toxicity value limits the information needed for making decisions and gives a false sense of precision and accuracy.
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17
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Potential Beneficial Effects of Wine Flavonoids on Allergic Diseases. Diseases 2019; 7:diseases7010008. [PMID: 30650667 PMCID: PMC6473930 DOI: 10.3390/diseases7010008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 01/07/2019] [Accepted: 01/09/2019] [Indexed: 12/20/2022] Open
Abstract
Wine, a widely consumed beverage, comprises several biophenols that promote health. Flavonoids, majorly present in red wine, have been shown to have antioxidant, anti-inflammatory, anticancer, and immunomodulatory activities. Regular consumption of red wine (100 mL/day) is estimated to provide an average of 88 mg of flavonoids, whereas recent epidemiological studies indicate that wine is one of the major sources of flavonoid intake amongst wine lovers in European countries (providing an average intake of 291⁻374 mg/day of flavonoids). In addition to being antioxidants, in vitro studies suggest that flavonoids also have anti-allergic activities that inhibit IgE synthesis, activation of mast cells and basophils or other inflammatory cells, and production of inflammatory mediators, including cytokines. Furthermore, they affect the differentiation of naïve CD4+ T cells into effector T cell subsets. Moreover, several studies have reported the benefits of flavonoids in allergic models such as atopic dermatitis, asthma, anaphylaxis, and food allergy; however, evidence in humans is limited to allergic rhinitis and respiratory allergy. Although further evaluation is required, it is expected that an appropriate intake of flavonoids may be beneficial in preventing, and eventually managing, allergic diseases.
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18
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Knutsen HK, Alexander J, Barregård L, Bignami M, Brüschweiler B, Ceccatelli S, Cottrill B, Dinovi M, Edler L, Grasl-Kraupp B, Hogstrand C, Nebbia CS, Oswald IP, Petersen A, Rose M, Roudot AC, Schwerdtle T, Vleminckx C, Vollmer G, Wallace H, Fürst P, Håkansson H, Halldorsson T, Lundebye AK, Pohjanvirta R, Rylander L, Smith A, van Loveren H, Waalkens-Berendsen I, Zeilmaker M, Binaglia M, Gómez Ruiz JÁ, Horváth Z, Christoph E, Ciccolallo L, Ramos Bordajandi L, Steinkellner H, Hoogenboom LR. Risk for animal and human health related to the presence of dioxins and dioxin-like PCBs in feed and food. EFSA J 2018; 16:e05333. [PMID: 32625737 PMCID: PMC7009407 DOI: 10.2903/j.efsa.2018.5333] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The European Commission asked EFSA for a scientific opinion on the risks for animal and human health related to the presence of dioxins (PCDD/Fs) and DL-PCBs in feed and food. The data from experimental animal and epidemiological studies were reviewed and it was decided to base the human risk assessment on effects observed in humans and to use animal data as supportive evidence. The critical effect was on semen quality, following pre- and postnatal exposure. The critical study showed a NOAEL of 7.0 pg WHO2005-TEQ/g fat in blood sampled at age 9 years based on PCDD/F-TEQs. No association was observed when including DL-PCB-TEQs. Using toxicokinetic modelling and taking into account the exposure from breastfeeding and a twofold higher intake during childhood, it was estimated that daily exposure in adolescents and adults should be below 0.25 pg TEQ/kg bw/day. The CONTAM Panel established a TWI of 2 pg TEQ/kg bw/week. With occurrence and consumption data from European countries, the mean and P95 intake of total TEQ by Adolescents, Adults, Elderly and Very Elderly varied between, respectively, 2.1 to 10.5, and 5.3 to 30.4 pg TEQ/kg bw/week, implying a considerable exceedance of the TWI. Toddlers and Other Children showed a higher exposure than older age groups, but this was accounted for when deriving the TWI. Exposure to PCDD/F-TEQ only was on average 2.4- and 2.7-fold lower for mean and P95 exposure than for total TEQ. PCDD/Fs and DL-PCBs are transferred to milk and eggs, and accumulate in fatty tissues and liver. Transfer rates and bioconcentration factors were identified for various species. The CONTAM Panel was not able to identify reference values in most farm and companion animals with the exception of NOAELs for mink, chicken and some fish species. The estimated exposure from feed for these species does not imply a risk.
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19
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Role of mixtures of organic pollutants in the development of metabolic disorders via the activation of xenosensors. CURRENT OPINION IN TOXICOLOGY 2018. [DOI: 10.1016/j.cotox.2018.01.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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20
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Yun C, Katchko KM, Schallmo MS, Jeong S, Yun J, Chen CH, Weiner JA, Park C, George A, Stupp SI, Hsu WK, Hsu EL. Aryl Hydrocarbon Receptor Antagonists Mitigate the Effects of Dioxin on Critical Cellular Functions in Differentiating Human Osteoblast-Like Cells. Int J Mol Sci 2018; 19:ijms19010225. [PMID: 29324662 PMCID: PMC5796174 DOI: 10.3390/ijms19010225] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 12/20/2017] [Accepted: 01/10/2018] [Indexed: 01/31/2023] Open
Abstract
The inhibition of bone healing in humans is a well-established effect associated with cigarette smoking, but the underlying mechanisms are still unclear. Recent work using animal cell lines have implicated the aryl hydrocarbon receptor (AhR) as a mediator of the anti-osteogenic effects of cigarette smoke, but the complexity of cigarette smoke mixtures makes understanding the mechanisms of action a major challenge. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD, dioxin) is a high-affinity AhR ligand that is frequently used to investigate biological processes impacted by AhR activation. Since there are dozens of AhR ligands present in cigarette smoke, we utilized dioxin as a prototype ligand to activate the receptor and explore its effects on pro-osteogenic biomarkers and other factors critical to osteogenesis using a human osteoblast-like cell line. We also explored the capacity for AhR antagonists to protect against dioxin action in this context. We found dioxin to inhibit osteogenic differentiation, whereas co-treatment with various AhR antagonists protected against dioxin action. Dioxin also negatively impacted cell adhesion with a corresponding reduction in the expression of integrin and cadherin proteins, which are known to be involved in this process. Similarly, the dioxin-mediated inhibition of cell migration correlated with reduced expression of the chemokine receptor CXCR4 and its ligand, CXCL12, and co-treatment with antagonists restored migratory capacity. Our results suggest that AhR activation may play a role in the bone regenerative response in humans exposed to AhR activators, such as those present in cigarette smoke. Given the similarity of our results using a human cell line to previous work done in murine cells, animal models may yield data relevant to the human setting. In addition, the AhR may represent a potential therapeutic target for orthopedic patients who smoke cigarettes, or those who are exposed to secondhand smoke or other environmental sources of aryl hydrocarbons.
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Affiliation(s)
- Chawon Yun
- Department of Orthopaedic Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL 60611, USA.
| | - Karina M Katchko
- Department of Orthopaedic Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL 60611, USA.
| | - Michael S Schallmo
- Department of Orthopaedic Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL 60611, USA.
| | - Soyeon Jeong
- Department of Orthopaedic Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL 60611, USA.
| | - Jonghwa Yun
- Department of Orthopaedic Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL 60611, USA.
| | - Charlotte H Chen
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL 60611, USA.
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, USA.
| | - Joseph A Weiner
- Department of Orthopaedic Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL 60611, USA.
| | - Christian Park
- Department of Orthopaedic Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL 60611, USA.
| | - Andrew George
- Department of Orthopaedic Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL 60611, USA.
| | - Samuel I Stupp
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL 60611, USA.
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, USA.
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA.
- Department of Chemistry, Northwestern University, Evanston, IL 60208, USA.
- Department of Medicine, Northwestern University, Chicago, IL 60611, USA.
| | - Wellington K Hsu
- Department of Orthopaedic Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL 60611, USA.
| | - Erin L Hsu
- Department of Orthopaedic Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL 60611, USA.
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21
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Tkachenko A, Bermudez M, Irmer-Stooff S, Genkinger D, Henkler-Stephani F, Wolber G, Luch A. Nuclear transport of the human aryl hydrocarbon receptor and subsequent gene induction relies on its residue histidine 291. Arch Toxicol 2017; 92:1151-1160. [PMID: 29164305 DOI: 10.1007/s00204-017-2129-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 11/15/2017] [Indexed: 12/11/2022]
Abstract
The aryl hydrocarbon receptor (AHR) is a ligand-dependent transcription factor involved in the metabolism of physiological substances and xenobiotics, representing an interesting target in both toxicology and pharmacology. In this study, we investigated the ligand-dependent conjunction of nuclear import of the human AHR in living cells and target gene induction. Our findings strengthen the theory that the AHR triggers a precisely defined and rapid reaction upon binding to endogenous ligands, while the xenobiotic β-naphthoflavone only induces rather unspecific and slow effects. To better illuminate the ligand-mediated responses of the human AHR, we applied site-directed mutagenesis and identified histidine 291 as key residue for AHR functionality, essential for both nuclear import and target gene induction. Contrary, replacing histidine at position 291 by alanine did not affect nucleo-cytoplasmic shuttling, showing that permanent endogenous import and ligand-induced import of the AHR into the nucleus are two independent and differently regulated processes. Combining these observations with our structural investigations using a homology model of the AHR-PAS B domain, we suggest a dual role of histidine 291: (1) a major role for shaping the ligand binding site including direct interactions with ligands and, (2) an essential role for the conformational dynamics of a PAS B loop, which most likely influences the association of the AHR with the AHR nuclear translocator through interference with their protein-protein interface.
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Affiliation(s)
- A Tkachenko
- Department of Chemical and Product Safety, German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Strasse 8-10, 10589, Berlin, Germany.
| | - M Bermudez
- Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Straße 2 + 4, 14195, Berlin, Germany
| | - S Irmer-Stooff
- Department of Chemical and Product Safety, German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Strasse 8-10, 10589, Berlin, Germany
| | - D Genkinger
- Department of Chemical and Product Safety, German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Strasse 8-10, 10589, Berlin, Germany
| | - F Henkler-Stephani
- Department of Chemical and Product Safety, German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Strasse 8-10, 10589, Berlin, Germany
| | - G Wolber
- Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Straße 2 + 4, 14195, Berlin, Germany
| | - A Luch
- Department of Chemical and Product Safety, German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Strasse 8-10, 10589, Berlin, Germany
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22
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Asadzadeh Z, Mohammadi H, Safarzadeh E, Hemmatzadeh M, Mahdian-Shakib A, Jadidi-Niaragh F, Azizi G, Baradaran B. The paradox of Th17 cell functions in tumor immunity. Cell Immunol 2017; 322:15-25. [PMID: 29103586 DOI: 10.1016/j.cellimm.2017.10.015] [Citation(s) in RCA: 142] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Accepted: 10/29/2017] [Indexed: 02/08/2023]
Abstract
Immune system acts as a host defensive mechanism protecting against attacking pathogens and transformed cells, including cancer cells. Th17 cells are a specific subset of T helper lymphocytes determined by high secretion of IL-17 and other inflammatory cytokines. Th17 cells increase tumor progression by activating angiogenesis and immunosuppressive activities. They can also mediate antitumor immune responses through recruiting immune cells into tumors, stimulating effector CD8+ T cells, or surprisingly by altering toward Th1 phenotype and producing IFN-γ, so Th17 cells are supposed as a double-edged sword in cancer. A comprehensive approach to indicating the activity of Th17 cells in tumor progression could help in the planning of new therapeutic approaches specially targeting Th17 cells in cancer.
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Affiliation(s)
- Zahra Asadzadeh
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Immunology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Hamed Mohammadi
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Immunology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Elham Safarzadeh
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Immunology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Maryam Hemmatzadeh
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Immunology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Ahmad Mahdian-Shakib
- Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Farhad Jadidi-Niaragh
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Immunology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Gholamreza Azizi
- Non-Communicable Diseases Research Center, Alborz University of Medical Sciences, Karaj, Iran; Department of Laboratory Medicine, Imam Hassan Mojtaba Hospital, Alborz University of Medical Sciences, Karaj, Iran
| | - Behzad Baradaran
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Immunology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
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One TEF concept does not fit all: The case for human risk assessment of polychlorinated biphenyls. CURRENT OPINION IN TOXICOLOGY 2017. [DOI: 10.1016/j.cotox.2017.01.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Girolami F, Spalenza V, Benedetto A, Manzini L, Badino P, Abete MC, Nebbia C. Comparative liver accumulation of dioxin-like compounds in sheep and cattle: Possible role of AhR-mediated xenobiotic metabolizing enzymes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 571:1222-1229. [PMID: 27476725 DOI: 10.1016/j.scitotenv.2016.07.150] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 07/21/2016] [Accepted: 07/21/2016] [Indexed: 06/06/2023]
Abstract
PCDDs, PCDFs, and PCBs are persistent organic pollutants (POPs) that accumulate in animal products and may pose serious health problems. Those able to bind the aryl hydrocarbon receptor (AhR), eliciting a plethora of toxic responses, are defined dioxin-like (DL) compounds, while the remainders are called non-DL (NDL). An EFSA opinion has highlighted the tendency of ovine liver to specifically accumulate DL-compounds to a greater extent than any other farmed ruminant species. To examine the possible role in such an accumulation of xenobiotic metabolizing enzymes (XME) involved in DL-compound biotransformation, liver samples were collected from ewes and cows reared in an area known for low dioxin contamination. A related paper reported that sheep livers had about 5-fold higher DL-compound concentrations than cattle livers, while the content of the six marker NDL-PCBs did not differ between species. Specimens from the same animals were subjected to gene expression analysis for AhR, AhR nuclear translocator (ARNT) and AhR-dependent oxidative and conjugative pathways; XME protein expression and activities were also investigated. Both AhR and ARNT mRNA levels were about 2-fold lower in ovine samples and the same occurred for CYP1A1 and CYP1A2, being approximately 3- and 9-fold less expressed in sheep compared to cattle, while CYP1B1 could be detectable in cattle only. The results of the immunoblotting and catalytic activity (most notably EROD) measurements of the CYP1A family enzymes were in line with the gene expression data. By contrast, phase II enzyme expression and activities in sheep were higher (UGT1A) or similar (GSTA1, NQO1) to those recorded in cattle. The overall low expression of CYP1 family enzymes in the sheep is in line with the observed liver accumulation of DL-compounds and is expected to affect the kinetics and the dynamics of other POPs such as many polycyclic aromatic hydrocarbons, as well as of toxins (e.g. aflatoxins) or drugs (e.g. benzimidazole anthelmintics) known to be metabolized by those enzymes.
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Affiliation(s)
- F Girolami
- Department of Veterinary Sciences, University of Torino, Largo Braccini 2, Grugliasco, Italy.
| | - V Spalenza
- Department of Veterinary Sciences, University of Torino, Largo Braccini 2, Grugliasco, Italy.
| | - A Benedetto
- Istituto Zooprofilattico di Piemonte, Liguria e Valle d'Aosta, Via Bologna 148, Torino, Italy.
| | - L Manzini
- Department of Veterinary Sciences, University of Torino, Largo Braccini 2, Grugliasco, Italy.
| | - P Badino
- Department of Veterinary Sciences, University of Torino, Largo Braccini 2, Grugliasco, Italy.
| | - M C Abete
- Istituto Zooprofilattico di Piemonte, Liguria e Valle d'Aosta, Via Bologna 148, Torino, Italy.
| | - C Nebbia
- Department of Veterinary Sciences, University of Torino, Largo Braccini 2, Grugliasco, Italy.
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Foster WG, Evans JA, Little J, Arbour L, Moore A, Sauve R, Andrés León J, Luo W. Human exposure to environmental contaminants and congenital anomalies: a critical review. Crit Rev Toxicol 2016; 47:59-84. [PMID: 27685638 DOI: 10.1080/10408444.2016.1211090] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Congenital anomalies are an important cause of infant mortality and disability. Developmental exposure to environmental contaminants is thought to increase the risk for congenital anomalies. Herein, we describe a critical review of the literature conducted between February and March 2014 yielding 3057 references from which 97 unique relevant articles published from 2003 through 2014 were evaluated. Common congenital anomalies including hypospadias, cryptorchidism, anogenital distance (AGD), congenital heart defects and oral clefts were well represented in the literature whereas other outcomes such as neural tube defects, limb deficiency defects and gastroschisis were rarely described. While definitions used for congenital anomalies and methods of ascertainment were usually consistent across studies, inconsistencies were frequently found in grouping of different congenital heart defects. Despite strong links between some congenital anomalies and parental occupation, these studies are unable to provide clear insight into the specific chemicals responsible owing to lack of direct measures of exposure. In comparison, data are mixed for contaminant exposures at concentrations representative of results from contemporary biomonitoring studies. Of the environmental contaminants studied, the association between phthalate exposures and developmental abnormalities of the male reproductive tract received the greatest attention. Important limitations of the literature studied relate to adequacy of sample size, absence of or weaknesses in exposure assessment methodologies, failure to account for biological plausibility and grouping of congenital anomalies with divergent mechanisms. We conclude that the literature is inadequate at this time to support a conclusion that exposure to environmental contaminants are or are not associated with increased risks for congenital anomalies in the general population.
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Affiliation(s)
- Warren G Foster
- a Department of Obstetrics & Gynecology , McMaster University , Hamilton , Ontario , Canada
| | - Jane A Evans
- b Department of Biochemistry and Medical Genetics , University of Manitoba , Winnipeg , Manitoba , Canada
| | - Julian Little
- c School of Epidemiology, Public Health and Preventive Medicine, Faculty of Medicine , University of Ottawa , Ottawa , Ontario , Canada
| | - Laura Arbour
- d Department of Medical Genetics , University of British Columbia , Vancouver , British Columbia , Canada
| | - Aideen Moore
- e Department of Paediatrics , University of Toronto and the Hospital for Sick Children , Toronto , Ontario , Canada
| | - Reg Sauve
- f Department of Community Health Sciences , University of Calgary , Calgary , Alberta , Canada
| | - Juan Andrés León
- g Maternal, Child and Youth Health Surveillance and Epidemiology Division , Centre for Chronic Disease Prevention, Public Health Agency of Canada , Ottawa , Ontario , Canada
| | - Wei Luo
- g Maternal, Child and Youth Health Surveillance and Epidemiology Division , Centre for Chronic Disease Prevention, Public Health Agency of Canada , Ottawa , Ontario , Canada
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van Ede KI, van Duursen MBM, van den Berg M. Evaluation of relative effect potencies (REPs) for dioxin-like compounds to derive systemic or human-specific TEFs to improve human risk assessment. Arch Toxicol 2016; 90:1293-305. [PMID: 27161441 PMCID: PMC4873528 DOI: 10.1007/s00204-016-1724-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 04/21/2016] [Indexed: 01/20/2023]
Abstract
Toxic equivalency factors (TEFs) are generally applied for estimating human risk of dioxins and dioxin-like compounds using systemic (e.g., blood) levels, even though these TEFs are established based on intake doses in rodent studies. This review shows that systemic relative effect potencies (REPs) can deviate substantially from intake REPs, but are similar to in vitro-derived REPs. Interestingly, the in vitro REPs for 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin (HpCDD) and 2,3,4,7,8-pentachlorodibenzofuran (4-PeCDF) are up to one order of magnitude higher than their in vivo REPs and WHO-TEFs, based on oral intake. In addition, clear species-differences in in vitro REPs were apparent for some congeners. Especially the human-derived REP for polychlorinated biphenyl 126 is one to two orders of magnitude lower than rodent REPs and its current WHO-TEF. Next, suggested adapted systemic or human-specific TEFs for these congeners were applied to calculate changes in systemic TEQ concentrations in studies from the USA, Germany and Japan and compared with either the JECFA TDI or USEPA RfD of TCDD. Overall, the effect of such TEF changes for these three congeners on total TEQ roughly balances each other out in the general population. However, results may be different for situations in which a specific group of congeners dominates. For those congeners that show a distinct deviation between either intake and systemic REPs or between rodent- and human-based in vitro REPs, we propose that especially REPs derived from human-based in vitro models are weighted more heavily in establishing systemic or human-specific TEF values to improve human health risk assessment.
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Affiliation(s)
- Karin I van Ede
- Division of Toxicology and Veterinary Pharmacology, Institute for Risk Assessment Sciences (IRAS), Utrecht University, P.O. Box 80.177, NL-3508 TD, Utrecht, The Netherlands.
| | - Majorie B M van Duursen
- Division of Toxicology and Veterinary Pharmacology, Institute for Risk Assessment Sciences (IRAS), Utrecht University, P.O. Box 80.177, NL-3508 TD, Utrecht, The Netherlands
| | - Martin van den Berg
- Division of Toxicology and Veterinary Pharmacology, Institute for Risk Assessment Sciences (IRAS), Utrecht University, P.O. Box 80.177, NL-3508 TD, Utrecht, The Netherlands
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27
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Xeno-sensing activity of the aryl hydrocarbon receptor in human pluripotent stem cell-derived hepatocyte-like cells. Sci Rep 2016; 6:21684. [PMID: 26899675 PMCID: PMC4761945 DOI: 10.1038/srep21684] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 01/27/2016] [Indexed: 12/13/2022] Open
Abstract
Although hepatocyte-like cells derived from human pluripotent stem cells (hPSC-HLCs) are considered a promising model for predicting hepatotoxicity, their application has been restricted because of the low activity of drug metabolizing enzymes (DMEs). Here we found that the low expression of xenobiotic receptors (constitutive androstane receptor, CAR; and pregnane X receptor, PXR) contributes to the low activity of DMEs in hPSC-HLCs. Most CAR- and PXR-regulated DMEs and transporters were transcriptionally down-regulated in hPSC-HLC. Transcriptional expression of CAR and PXR was highly repressed in hPSC-HLCs, whereas mRNA levels of aryl hydrocarbon receptor (AHR) were comparable to those of adult liver. Furthermore, ligand-induced transcriptional activation was observed only at AHR in hPSC-HLCs. Bisulfite sequencing analysis demonstrated that promoter hypermethylation of CAR and PXR was associated with diminished transcriptional activity in hPSC-HLCs. Treatment with AHR-selective ligands increased the transcription of AHR-dependent target genes by direct AHR-DNA binding at the xenobiotic response element. In addition, an antagonist of AHR significantly inhibited AHR-dependent target gene expression. Thus, AHR may function intrinsically as a xenosensor as well as a ligand-dependent transcription factor in hPSC-HLCs. Our results indicate that hPSC-HLCs can be used to screen toxic substances related to AHR signaling and to identify potential AHR-targeted therapeutics.
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Aftabi Y, Colagar AH, Mehrnejad F. An in silico approach to investigate the source of the controversial interpretations about the phenotypic results of the human AhR-gene G1661A polymorphism. J Theor Biol 2016; 393:1-15. [PMID: 26776670 DOI: 10.1016/j.jtbi.2016.01.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2015] [Revised: 12/11/2015] [Accepted: 01/01/2016] [Indexed: 12/21/2022]
Abstract
Aryl hydrocarbon receptor (AhR) acts as an enhancer binding ligand-activated intracellular receptor. Chromatin remodeling components and general transcription factors such as TATA-binding protein (TBP) are evoked on AhR-target genes by interaction with its flexible transactivation domain (TAD). AhR-G1661A single nucleotide polymorphism (SNP: rs2066853) causes an arginine to lysine substitution in the acidic sub-domain of TAD at position 554 (R554K). Although, numerous studies associate the SNP with some abnormalities such as cancer, other reliable investigations refuse the associations. Consequently, the interpretation of the phenotypic results of G1661A-transition has been controversial. In this study, an in silico analysis were performed to investigate the possible effects of the transition on AhR-mRNA, protein structure, interaction properties and modifications. The analysis revealed that the R554K substitution affects secondary structure and solvent accessibility of adjacent residues. Also, it causes to decreasing of the AhR stability; altering the hydropathy features of the local sequence and changing the pattern of the residues at the binding site of the TAD-acidic sub-domain. Generating of new sites for ubiquitination and acetylation for AhR-K554 variant respectively at positions 544 and 560 was predicted. Our findings intensify the idea that the AhR-G1661A transition may affects AhR-TAD interactions, especially with the TBP, which influence AhR-target genes expression. However, the previously reported flexibility of the modular TAD could act as an intervening factor, moderate the SNP effects and causes distinct outcomes in different individuals and tissues.
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Affiliation(s)
- Younes Aftabi
- Department of Molecular and Cell Biology, Faculty of Basic Sciences, University of Mazandaran, Babolsar, Post Code: 47416-95447, Mazandaran, Iran
| | - Abasalt Hosseinzadeh Colagar
- Department of Molecular and Cell Biology, Faculty of Basic Sciences, University of Mazandaran, Babolsar, Post Code: 47416-95447, Mazandaran, Iran.
| | - Faramarz Mehrnejad
- Department of Life Science Engineering, Faculty of New Sciences & Technologies, University of Tehran, P.O. Box: 14395-1561, Tehran, Iran
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29
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Tian J, Feng Y, Fu H, Xie HQ, Jiang JX, Zhao B. The Aryl Hydrocarbon Receptor: A Key Bridging Molecule of External and Internal Chemical Signals. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:9518-31. [PMID: 26079192 PMCID: PMC4696777 DOI: 10.1021/acs.est.5b00385] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The aryl hydrocarbon receptor (AhR) is a highly evolutionary conserved, ligand-activated transcription factor that is best known to mediate the toxicities of dioxins and dioxin-like compounds. Phenotype of AhR-null mice, together with the recent discovery of a variety of endogenous and plant-derived ligands, point to the integral roles of AhR in normal cell physiology, in addition to its roles in sensing the environmental chemicals. Here, we summarize the current knowledge about AhR signaling pathways, its ligands and AhR-mediated effects on cell specialization, host defense and detoxification. AhR-mediated health effects particularly in liver, immune, and nervous systems, as well as in tumorgenesis are discussed. Dioxin-initiated embryotoxicity and immunosuppressive effects in fish and birds are reviewed. Recent data demonstrate that AhR is a convergence point of multiple signaling pathways that inform the cell of its external and internal environments. As such, AhR pathway is a promising potential target for therapeutics targeting nervous, liver, and autoimmune diseases through AhR ligand-mediated interventions and other perturbations of AhR signaling. Additionally, using available laboratory data obtained on animal models, AhR-centered adverse outcome pathway analysis is useful in reexamining known and potential adverse outcomes of specific or mixed compounds on wildlife.
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Affiliation(s)
- Jijing Tian
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- Department of Internal Medicine, Gastroenterology and Hepatology, University of California, Davis, Sacramento, California 95817, United States
| | - Yu Feng
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Hualing Fu
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Heidi Qunhui Xie
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Joy Xiaosong Jiang
- Department of Internal Medicine, Gastroenterology and Hepatology, University of California, Davis, Sacramento, California 95817, United States
- Corresponding Authors: (J.X.J) Phone: 1-916-7340329; fax: 1-916-7347908; . (B.Z.) Phone: 86-010-62842867; fax: 86-010-62842867;
| | - Bin Zhao
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- Corresponding Authors: (J.X.J) Phone: 1-916-7340329; fax: 1-916-7347908; . (B.Z.) Phone: 86-010-62842867; fax: 86-010-62842867;
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30
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Becker RA, Patlewicz G, Simon TW, Rowlands JC, Budinsky RA. The adverse outcome pathway for rodent liver tumor promotion by sustained activation of the aryl hydrocarbon receptor. Regul Toxicol Pharmacol 2015; 73:172-90. [PMID: 26145830 DOI: 10.1016/j.yrtph.2015.06.015] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 06/19/2015] [Accepted: 06/22/2015] [Indexed: 12/29/2022]
Abstract
An Adverse Outcome Pathway (AOP) represents the existing knowledge of a biological pathway leading from initial molecular interactions of a toxicant and progressing through a series of key events (KEs), culminating with an apical adverse outcome (AO) that has to be of regulatory relevance. An AOP based on the mode of action (MOA) of rodent liver tumor promotion by dioxin-like compounds (DLCs) has been developed and the weight of evidence (WoE) of key event relationships (KERs) evaluated using evolved Bradford Hill considerations. Dioxins and DLCs are potent aryl hydrocarbon receptor (AHR) ligands that cause a range of species-specific adverse outcomes. The occurrence of KEs is necessary for inducing downstream biological responses and KEs may occur at the molecular, cellular, tissue and organ levels. The common convention is that an AOP begins with the toxicant interaction with a biological response element; for this AOP, this initial event is binding of a DLC ligand to the AHR. Data from mechanistic studies, lifetime bioassays and approximately thirty initiation-promotion studies have established dioxin and DLCs as rat liver tumor promoters. Such studies clearly show that sustained AHR activation, weeks or months in duration, is necessary to induce rodent liver tumor promotion--hence, sustained AHR activation is deemed the molecular initiating event (MIE). After this MIE, subsequent KEs are 1) changes in cellular growth homeostasis likely associated with expression changes in a number of genes and observed as development of hepatic foci and decreases in apoptosis within foci; 2) extensive liver toxicity observed as the constellation of effects called toxic hepatopathy; 3) cellular proliferation and hyperplasia in several hepatic cell types. This progression of KEs culminates in the AO, the development of hepatocellular adenomas and carcinomas and cholangiolar carcinomas. A rich data set provides both qualitative and quantitative knowledge of the progression of this AOP through KEs and the KERs. Thus, the WoE for this AOP is judged to be strong. Species-specific effects of dioxins and DLCs are well known--humans are less responsive than rodents and rodent species differ in sensitivity between strains. Consequently, application of this AOP to evaluate potential human health risks must take these differences into account.
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Affiliation(s)
- Richard A Becker
- Regulatory and Technical Affairs Department, American Chemistry Council (ACC), Washington, DC 20002, USA.
| | - Grace Patlewicz
- DuPont Haskell Global Centers for Health and Environmental Sciences, Newark, DE 19711, USA
| | - Ted W Simon
- Ted Simon LLC, 4184 Johnston Road, Winston, GA 30187, USA
| | - J Craig Rowlands
- The Dow Chemical Company, Toxicology & Environmental Research & Consulting, 1803 Building Washington Street, Midland, MI 48674, USA
| | - Robert A Budinsky
- The Dow Chemical Company, Toxicology & Environmental Research & Consulting, 1803 Building Washington Street, Midland, MI 48674, USA
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31
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Wourms MJ, Sulentic CEW. The aryl hydrocarbon receptor regulates an essential transcriptional element in the immunoglobulin heavy chain gene. Cell Immunol 2015; 295:60-6. [PMID: 25749007 DOI: 10.1016/j.cellimm.2015.02.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 02/18/2015] [Accepted: 02/19/2015] [Indexed: 01/26/2023]
Abstract
Ig heavy chain (Igh) transcription involves several regulatory elements including the 3'Igh regulatory region (3'IghRR). 3'IghRR activity is modulated by several transcription factors, including NF-κB and AP-1 and potentially the aryl hydrocarbon receptor (AhR). The prototypical AhR ligand 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) inhibits antibody secretion and 3'IghRR activity. However, the exact mechanism is unknown and TCDD can modulate NF-κB and AP-1 in an AhR-independent manner. To determine if the AhR is a significant regulator of the 3'IghRR, we utilized a mouse B-cell line that stably expresses a 3'IghRR-regulated transgene and either an AhR antagonist or shRNA targeting the AhR. Disruption of the AhR pathway reversed TCDD-induced suppression of the 3'IghRR-regulated transgene and of endogenous Ig demonstrating a biologically significant effect of the AhR on 3'IghRR activation. Altered human 3'IGHRR activity by AhR ligands, which include dietary, environmental, and pharmaceutical chemicals, may have significant implications to human diseases previously associated with the 3'IGHRR.
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Affiliation(s)
- Michael J Wourms
- Department of Pharmacology and Toxicology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA
| | - Courtney E W Sulentic
- Department of Pharmacology and Toxicology, Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA.
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Oshchepkov DY, Kashina EV, Antontseva EV, Oshchepkova EA, Mordvinov VA, Furman DP. Dynamics of IL-12 cytokine expression in human macrophages after dioxin exposure. ACTA ACUST UNITED AC 2014. [DOI: 10.1134/s2079059714060161] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Williams EG, Mouchiroud L, Frochaux M, Pandey A, Andreux PA, Deplancke B, Auwerx J. An evolutionarily conserved role for the aryl hydrocarbon receptor in the regulation of movement. PLoS Genet 2014; 10:e1004673. [PMID: 25255223 PMCID: PMC4177751 DOI: 10.1371/journal.pgen.1004673] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 08/14/2014] [Indexed: 02/04/2023] Open
Abstract
The BXD genetic reference population is a recombinant inbred panel descended from crosses between the C57BL/6 (B6) and DBA/2 (D2) strains of mice, which segregate for about 5 million sequence variants. Recently, some of these variants have been established with effects on general metabolic phenotypes such as glucose response and bone strength. Here we phenotype 43 BXD strains and observe they have large variation (-5-fold) in their spontaneous activity during waking hours. QTL analyses indicate that -40% of this variance is attributable to a narrow locus containing the aryl hydrocarbon receptor (Ahr), a basic helix-loop-helix transcription factor with well-established roles in development and xenobiotic metabolism. Strains with the D2 allele of Ahr have reduced gene expression compared to those with the B6 allele, and have significantly higher spontaneous activity. This effect was also observed in B6 mice with a congenic D2 Ahr interval, and in B6 mice with a humanized AHR allele which, like the D2 allele, is expressed much less and has less enzymatic activity than the B6 allele. Ahr is highly conserved in invertebrates, and strikingly inhibition of its orthologs in D. melanogaster and C. elegans (spineless and ahr-1) leads to marked increases in basal activity. In mammals, Ahr has numerous ligands, but most are either non-selective (e.g. resveratrol) or highly toxic (e.g., 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)). Thus, we chose to examine a major environmental influence--long term feeding with high fat diet (HFD)--to see if the effects of Ahr are dependent on major metabolic differences. Interestingly, while HFD robustly halved movement across all strains, the QTL position and effects of Ahr remained unchanged, indicating that the effects are independent. The highly consistent effects of Ahr on movement indicate that changes in its constitutive activity have a role on spontaneous movement and may influence human behavior.
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Affiliation(s)
- Evan G. Williams
- Laboratory of Integrative and Systems Physiology, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Laurent Mouchiroud
- Laboratory of Integrative and Systems Physiology, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Michael Frochaux
- Laboratory of Systems Biology and Genetics, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Ashutosh Pandey
- Center for Integrative and Translational Genomics, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America
| | - Pénélope A. Andreux
- Laboratory of Integrative and Systems Physiology, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Bart Deplancke
- Laboratory of Systems Biology and Genetics, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Johan Auwerx
- Laboratory of Integrative and Systems Physiology, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- * E-mail:
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Brokken LJS, Giwercman YL. Gene-environment interactions in male reproductive health: special reference to the aryl hydrocarbon receptor signaling pathway. Asian J Androl 2014; 16:89-96. [PMID: 24369137 PMCID: PMC3901886 DOI: 10.4103/1008-682x.122193] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Over the last few decades, there have been numerous reports of adverse effects on the reproductive health of wildlife and laboratory animals caused by exposure to endocrine disrupting chemicals (EDCs). The increasing trends in human male reproductive disorders and the mounting evidence for causative environmental factors have therefore sparked growing interest in the health threat posed to humans by EDCs, which are substances in our food, environment and consumer items that interfere with hormone action, biosynthesis or metabolism, resulting in disrupted tissue homeostasis or reproductive function. The mechanisms of EDCs involve a wide array of actions and pathways. Examples include the estrogenic, androgenic, thyroid and retinoid pathways, in which the EDCs may act directly as agonists or antagonists, or indirectly via other nuclear receptors. Dioxins and dioxin-like EDCs exert their biological and toxicological actions through activation of the aryl hydrocarbon-receptor, which besides inducing transcription of detoxifying enzymes also regulates transcriptional activity of other nuclear receptors. There is increasing evidence that genetic predispositions may modify the susceptibility to adverse effects of toxic chemicals. In this review, potential consequences of hereditary predisposition and EDCs are discussed, with a special focus on the currently available publications on interactions between dioxin and androgen signaling.
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Affiliation(s)
- Leon J S Brokken
- Department of Clinical Sciences, Molecular Genetic Reproductive Medicine, Lund University, Malmö, Sweden
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35
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Ghorbanzadeh M, van Ede KI, Larsson M, van Duursen MBM, Poellinger L, Lücke-Johansson S, Machala M, Pěnčíková K, Vondráček J, van den Berg M, Denison MS, Ringsted T, Andersson PL. In Vitro and in Silico Derived Relative Effect Potencies of Ah-Receptor-Mediated Effects by PCDD/Fs and PCBs in Rat, Mouse, and Guinea Pig CALUX Cell Lines. Chem Res Toxicol 2014; 27:1120-32. [DOI: 10.1021/tx5001255] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Karin I. van Ede
- Endocrine Toxicology Group, Institute for Risk Assessment
Sciences, Utrecht University, P.O. Box 80177, NL-3508 TD Utrecht, The Netherlands
| | - Malin Larsson
- Department of Chemistry, Umeå University, SE-901 87 Umeå, Sweden
| | - Majorie B. M. van Duursen
- Endocrine Toxicology Group, Institute for Risk Assessment
Sciences, Utrecht University, P.O. Box 80177, NL-3508 TD Utrecht, The Netherlands
| | - Lorenz Poellinger
- Department
of Cell and Molecular Biology, Karolinska Institute, SE-171 77 Stockholm, Sweden
| | - Sandra Lücke-Johansson
- Department
of Cell and Molecular Biology, Karolinska Institute, SE-171 77 Stockholm, Sweden
| | - Miroslav Machala
- Department of Chemistry
and Toxicology, Veterinary Research Institute, 621 32 Brno, Czech Republic
| | - Kateřina Pěnčíková
- Department of Chemistry
and Toxicology, Veterinary Research Institute, 621 32 Brno, Czech Republic
| | - Jan Vondráček
- Department of Chemistry
and Toxicology, Veterinary Research Institute, 621 32 Brno, Czech Republic
| | - Martin van den Berg
- Endocrine Toxicology Group, Institute for Risk Assessment
Sciences, Utrecht University, P.O. Box 80177, NL-3508 TD Utrecht, The Netherlands
| | - Michael S. Denison
- Department of Environmental Toxicology, University of California, Davis, California 95616, United States
| | - Tine Ringsted
- Department of Chemistry, Umeå University, SE-901 87 Umeå, Sweden
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36
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Bailey SR, Nelson MH, Himes RA, Li Z, Mehrotra S, Paulos CM. Th17 cells in cancer: the ultimate identity crisis. Front Immunol 2014; 5:276. [PMID: 24987392 PMCID: PMC4060300 DOI: 10.3389/fimmu.2014.00276] [Citation(s) in RCA: 225] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 05/27/2014] [Indexed: 12/12/2022] Open
Abstract
T helper 17 (Th17) cells play a complex and controversial role in tumor immunity and have been found to exhibit a fluctuating identity within the context of cancer. The recent, expanding literature on these cells attests to their puzzling nature, either promoting or suppressing tumor growth depending on the malignancy and course of therapeutic intervention investigated. This review addresses several newly appreciated factors that may help delineate Th17 cells' immunological properties in the context of cancer. Several reports suggest that inflammatory signals induced in the tumor milieu regulate the functional fate and antitumor activity of Th17 cells. Recent findings also point to significant alterations in Th17 cells due to their interplay with regulatory T lymphocytes and cytotoxic CD8(+) T cells within the tumor microenvironment. Finally, an appreciation for the stem cell-like properties of Th17 cells that augment their persistence and activity emerges from recent reports. The impact of these factors on Th17 cells' antitumor efficacy and how these factors may be exploited to improve cancer therapies will be discussed.
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Affiliation(s)
- Stefanie R Bailey
- Department of Microbiology and Immunology, Medical University of South Carolina , Charleston, SC , USA ; Department of Surgery, Medical University of South Carolina , Charleston, SC , USA
| | - Michelle H Nelson
- Department of Microbiology and Immunology, Medical University of South Carolina , Charleston, SC , USA ; Department of Surgery, Medical University of South Carolina , Charleston, SC , USA
| | - Richard A Himes
- Department of Chemistry, College of Charleston , Charleston, SC , USA
| | - Zihai Li
- Department of Microbiology and Immunology, Medical University of South Carolina , Charleston, SC , USA
| | - Shikhar Mehrotra
- Department of Surgery, Medical University of South Carolina , Charleston, SC , USA
| | - Chrystal M Paulos
- Department of Microbiology and Immunology, Medical University of South Carolina , Charleston, SC , USA ; Department of Surgery, Medical University of South Carolina , Charleston, SC , USA
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37
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van Ede KI, Gaisch KPJ, van den Berg M, van Duursen MBM. Differential relative effect potencies of some dioxin-like compounds in human peripheral blood lymphocytes and murine splenic cells. Toxicol Lett 2014; 226:43-52. [PMID: 24472611 DOI: 10.1016/j.toxlet.2014.01.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 01/16/2014] [Accepted: 01/17/2014] [Indexed: 11/29/2022]
Abstract
Human risk assessment for dioxin-like compounds is typically based on the concentration measured in blood serum multiplied by their assigned toxic equivalency factor (TEF). Consequently, the actual value of the TEF is very important for accurate human risk assessment. In this study we investigated the effect potencies of three polychlorinated dibenzo-p-dioxins (PCDDs), six polychlorinated dibenzofurans (PCDFs) and 10 polychlorinated biphenyls (PCBs) relative to the reference congener 2,3,7,8-tetrachloro-dibenzo-p-dioxin (TCDD) in in vitro exposed primary human peripheral blood lymphocytes (PBLs) and mouse splenic cells. REPs were determined based on cytochrome P450 (CYP) 1A1, 1B1 and aryl hydrocarbon receptor repressor (AhRR) gene expression as well as CYP1A1 activity in human PBLs and Cyp1a1 gene expression in murine splenic cells. Estimated median human REPs for 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin (1234678-HpCDD), 2,3,4,7,8,-pentachlorodibenzofuran (23478-PeCDF), 1,2,3,4,7,8-hexachlorodibenzofuran (123478-HxCDF) and 1,2,3,4,7,8,9-heptachlorodibenzofuran (1234789-HpCDF) were with 0.1, 1.1, 1 and 0.09, respectively, significantly higher compared to those estimated for mouse with REPs of 0.05, 0.45, 0.09 and 0.04, respectively. Opposite to these results, the estimated median human REP of 3,3',4,4',5-pentachlorobiphenyl (PCB 126), was with 0.001 30-fold lower compared to the mouse REP of 0.03. Furthermore, human REPs for 1234678-HpCDD, 23478-PeCDF, 123478-HxCDF, 1234789-HpCDF and PCB 126 were all outside the ± half log uncertainty range that is taken into account in the WHO-assigned TEFs. Together, these data show congener- and species-specific differences in REPs for some, but not all dioxin-like congeners tested. This suggests that, more emphasis should be placed on human-tissue derived REPs in the establishment of a TEF for human risk assessment.
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Affiliation(s)
- Karin I van Ede
- Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 104, 3584 CM Utrecht, The Netherlands.
| | - Konrad P J Gaisch
- Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 104, 3584 CM Utrecht, The Netherlands.
| | - Martin van den Berg
- Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 104, 3584 CM Utrecht, The Netherlands.
| | - Majorie B M van Duursen
- Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 104, 3584 CM Utrecht, The Netherlands.
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38
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Endocrine effects of chemicals: Aspects of hazard identification and human health risk assessment. Toxicol Lett 2013; 223:280-6. [DOI: 10.1016/j.toxlet.2013.03.022] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 02/27/2013] [Accepted: 03/08/2013] [Indexed: 01/26/2023]
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39
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Budinsky RA, Schrenk D, Simon T, Van den Berg M, Reichard JF, Silkworth JB, Aylward LL, Brix A, Gasiewicz T, Kaminski N, Perdew G, Starr TB, Walker NJ, Rowlands JC. Mode of action and dose–response framework analysis for receptor-mediated toxicity: The aryl hydrocarbon receptor as a case study. Crit Rev Toxicol 2013; 44:83-119. [DOI: 10.3109/10408444.2013.835787] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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40
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Duarte JH, Di Meglio P, Hirota K, Ahlfors H, Stockinger B. Differential influences of the aryl hydrocarbon receptor on Th17 mediated responses in vitro and in vivo. PLoS One 2013; 8:e79819. [PMID: 24244565 PMCID: PMC3828240 DOI: 10.1371/journal.pone.0079819] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 10/04/2013] [Indexed: 11/19/2022] Open
Abstract
The aryl hydrocarbon receptor (AhR) has been attributed with anti-inflammatory effects in the development of pathological immune responses leading to experimental autoimmune encephalomyelitis (EAE) via the induction of regulatory T cells. In agreement with previously published findings, we find that TCDD administration confers protection from EAE, however, this immuno-modulatory effect was not the consequence of de novo Treg generation, but the inhibition of Th17 cell differentiation. Systemic application of FICZ at the time of immunization also reduced EAE pathology albeit to a lesser degree than TCDD. In vitro Th17 differentiation in the presence of AhR agonists, including TCDD, promoted IL-17 and IL-22 expression, but did not induce Treg differentiation. AhR affinity influenced the amounts of IL-17 and IL-22 protein that was secreted by Th17 cells, but did not seem to affect susceptibility to EAE in vivo. Making use of conditional AhR-deficient mice, we show that the anti-inflammatory effect of TCDD depends on AhR activation in both T cells and dendritic cells, further emphasising the ability of TCDD to interfere with T effector cell differentiation in vivo. The dichotomy between the in vivo and in vitro effects of AhR reveals the complexity of the AhR pathway, which has the capacity of affecting different AhR-expressing cell types involved in mounting immune responses, thus participating in defining their outcome.
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MESH Headings
- Animals
- Basic Helix-Loop-Helix Transcription Factors/deficiency
- Basic Helix-Loop-Helix Transcription Factors/genetics
- Basic Helix-Loop-Helix Transcription Factors/immunology
- Carbazoles/pharmacology
- Cell Differentiation/drug effects
- Cells, Cultured
- Dendritic Cells/drug effects
- Dendritic Cells/immunology
- Dendritic Cells/pathology
- Encephalomyelitis, Autoimmune, Experimental/chemically induced
- Encephalomyelitis, Autoimmune, Experimental/genetics
- Encephalomyelitis, Autoimmune, Experimental/immunology
- Encephalomyelitis, Autoimmune, Experimental/pathology
- Environmental Pollutants/pharmacology
- Gene Expression Regulation
- Immunity, Cellular/drug effects
- Immunologic Factors/pharmacology
- Interleukin-17/genetics
- Interleukin-17/immunology
- Interleukins/genetics
- Interleukins/immunology
- Lymphocyte Activation/drug effects
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Myelin-Oligodendrocyte Glycoprotein
- Peptide Fragments
- Polychlorinated Dibenzodioxins/analogs & derivatives
- Polychlorinated Dibenzodioxins/pharmacology
- Receptors, Aryl Hydrocarbon/deficiency
- Receptors, Aryl Hydrocarbon/genetics
- Receptors, Aryl Hydrocarbon/immunology
- Signal Transduction
- T-Lymphocytes, Regulatory/drug effects
- T-Lymphocytes, Regulatory/immunology
- T-Lymphocytes, Regulatory/pathology
- Th17 Cells/drug effects
- Th17 Cells/immunology
- Th17 Cells/pathology
- Interleukin-22
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Affiliation(s)
- João H. Duarte
- Division of Molecular Immunology, MRC National Institute for Medical Research, London, United Kingdom
| | - Paola Di Meglio
- Division of Molecular Immunology, MRC National Institute for Medical Research, London, United Kingdom
| | - Keiji Hirota
- Division of Molecular Immunology, MRC National Institute for Medical Research, London, United Kingdom
| | - Helena Ahlfors
- Division of Molecular Immunology, MRC National Institute for Medical Research, London, United Kingdom
| | - Brigitta Stockinger
- Division of Molecular Immunology, MRC National Institute for Medical Research, London, United Kingdom
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41
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Pierre S, Chevallier A, Teixeira-Clerc F, Ambolet-Camoit A, Bui LC, Bats AS, Fournet JC, Fernandez-Salguero P, Aggerbeck M, Lotersztajn S, Barouki R, Coumoul X. Aryl hydrocarbon receptor-dependent induction of liver fibrosis by dioxin. Toxicol Sci 2013; 137:114-24. [PMID: 24154488 DOI: 10.1093/toxsci/kft236] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The contribution of environmental pollutants to liver fibrosis is an important and poorly explored issue. In vitro studies suggest that the environmental pollutant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and other aryl hydrocarbon receptor (AhR) ligands induce several genes that are known to be upregulated during liver fibrosis. Our aim was to determine whether exposure to such pollutants can lead to liver fibrosis and to characterize the mechanisms of action. Mice were treated for 2, 14, or 42 days, once a week with 25 µg/kg of TCDD. Gene and protein expression, in vitro and in vivo, as well as liver histology were investigated for each treatment. Treatment of mice with TCDD for 2 weeks modified the hepatic expression of markers of fibrosis such as collagen 1A1 and α-smooth muscle actin. This is not observed in AhR knockout mice. Following 6 weeks of treatment, histological features of murine hepatic fibrosis became apparent. In parallel, the levels of inflammatory cytokines (interleukin-1 beta, tumor necrosis factor α) and of markers of activated fibroblasts(fibroblast-specific protein 1) were found to be upregulated. Interestingly, we also found increased expression of genes of the TGF-β pathway and a concomitant decrease of miR-200a levels. Because the transcription factors of the Snail family were shown to be involved in liver fibrosis, we studied their regulation by TCDD. Two members of the Snail family were increased, whereas their negative targets, the epithelial marker E-cadherin and Claudin 1, were decreased. Further, the expression of mesenchymal markers was increased. Finally, we confirmed that Snai2 is a direct transcriptional target of TCDD in the human hepatocarcinoma cell line, HepG2. The AhR ligand, TCDD, induces hepatic fibrosis by directly regulating profibrotic pathways.
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Affiliation(s)
- Stéphane Pierre
- * INSERM UMR-S 747, Toxicologie Pharmacologie et Signalisation Cellulaire, Paris, France
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42
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Godoy P, Hewitt NJ, Albrecht U, Andersen ME, Ansari N, Bhattacharya S, Bode JG, Bolleyn J, Borner C, Böttger J, Braeuning A, Budinsky RA, Burkhardt B, Cameron NR, Camussi G, Cho CS, Choi YJ, Craig Rowlands J, Dahmen U, Damm G, Dirsch O, Donato MT, Dong J, Dooley S, Drasdo D, Eakins R, Ferreira KS, Fonsato V, Fraczek J, Gebhardt R, Gibson A, Glanemann M, Goldring CEP, Gómez-Lechón MJ, Groothuis GMM, Gustavsson L, Guyot C, Hallifax D, Hammad S, Hayward A, Häussinger D, Hellerbrand C, Hewitt P, Hoehme S, Holzhütter HG, Houston JB, Hrach J, Ito K, Jaeschke H, Keitel V, Kelm JM, Kevin Park B, Kordes C, Kullak-Ublick GA, LeCluyse EL, Lu P, Luebke-Wheeler J, Lutz A, Maltman DJ, Matz-Soja M, McMullen P, Merfort I, Messner S, Meyer C, Mwinyi J, Naisbitt DJ, Nussler AK, Olinga P, Pampaloni F, Pi J, Pluta L, Przyborski SA, Ramachandran A, Rogiers V, Rowe C, Schelcher C, Schmich K, Schwarz M, Singh B, Stelzer EHK, Stieger B, Stöber R, Sugiyama Y, Tetta C, Thasler WE, Vanhaecke T, Vinken M, Weiss TS, Widera A, Woods CG, Xu JJ, Yarborough KM, Hengstler JG. Recent advances in 2D and 3D in vitro systems using primary hepatocytes, alternative hepatocyte sources and non-parenchymal liver cells and their use in investigating mechanisms of hepatotoxicity, cell signaling and ADME. Arch Toxicol 2013; 87:1315-530. [PMID: 23974980 PMCID: PMC3753504 DOI: 10.1007/s00204-013-1078-5] [Citation(s) in RCA: 1051] [Impact Index Per Article: 95.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 05/06/2013] [Indexed: 12/15/2022]
Abstract
This review encompasses the most important advances in liver functions and hepatotoxicity and analyzes which mechanisms can be studied in vitro. In a complex architecture of nested, zonated lobules, the liver consists of approximately 80 % hepatocytes and 20 % non-parenchymal cells, the latter being involved in a secondary phase that may dramatically aggravate the initial damage. Hepatotoxicity, as well as hepatic metabolism, is controlled by a set of nuclear receptors (including PXR, CAR, HNF-4α, FXR, LXR, SHP, VDR and PPAR) and signaling pathways. When isolating liver cells, some pathways are activated, e.g., the RAS/MEK/ERK pathway, whereas others are silenced (e.g. HNF-4α), resulting in up- and downregulation of hundreds of genes. An understanding of these changes is crucial for a correct interpretation of in vitro data. The possibilities and limitations of the most useful liver in vitro systems are summarized, including three-dimensional culture techniques, co-cultures with non-parenchymal cells, hepatospheres, precision cut liver slices and the isolated perfused liver. Also discussed is how closely hepatoma, stem cell and iPS cell-derived hepatocyte-like-cells resemble real hepatocytes. Finally, a summary is given of the state of the art of liver in vitro and mathematical modeling systems that are currently used in the pharmaceutical industry with an emphasis on drug metabolism, prediction of clearance, drug interaction, transporter studies and hepatotoxicity. One key message is that despite our enthusiasm for in vitro systems, we must never lose sight of the in vivo situation. Although hepatocytes have been isolated for decades, the hunt for relevant alternative systems has only just begun.
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Affiliation(s)
- Patricio Godoy
- Leibniz Research Centre for Working Environment and Human Factors (IFADO), 44139 Dortmund, Germany
| | | | - Ute Albrecht
- Clinic for Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | - Melvin E. Andersen
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC USA
| | - Nariman Ansari
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University Frankfurt, Max-von-Laue-Str. 15, 60438 Frankfurt am Main, Germany
| | - Sudin Bhattacharya
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC USA
| | - Johannes Georg Bode
- Clinic for Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | - Jennifer Bolleyn
- Department of Toxicology, Centre for Pharmaceutical Research, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, 1090 Brussels, Belgium
| | - Christoph Borner
- Institute of Molecular Medicine and Cell Research, University of Freiburg, Freiburg, Germany
| | - Jan Böttger
- Institute of Biochemistry, Faculty of Medicine, University of Leipzig, 04103 Leipzig, Germany
| | - Albert Braeuning
- Department of Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Wilhelmstr. 56, 72074 Tübingen, Germany
| | - Robert A. Budinsky
- Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI USA
| | - Britta Burkhardt
- BG Trauma Center, Siegfried Weller Institut, Eberhard Karls University Tübingen, 72076 Tübingen, Germany
| | - Neil R. Cameron
- Department of Chemistry, Durham University, Durham, DH1 3LE UK
| | - Giovanni Camussi
- Department of Medical Sciences, University of Torino, 10126 Turin, Italy
| | - Chong-Su Cho
- Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, 151-921 Korea
| | - Yun-Jaie Choi
- Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, 151-921 Korea
| | - J. Craig Rowlands
- Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI USA
| | - Uta Dahmen
- Experimental Transplantation Surgery, Department of General Visceral, and Vascular Surgery, Friedrich-Schiller-University Jena, 07745 Jena, Germany
| | - Georg Damm
- Department of General-, Visceral- and Transplantation Surgery, Charité University Medicine Berlin, 13353 Berlin, Germany
| | - Olaf Dirsch
- Institute of Pathology, Friedrich-Schiller-University Jena, 07745 Jena, Germany
| | - María Teresa Donato
- Unidad de Hepatología Experimental, IIS Hospital La Fe Avda Campanar 21, 46009 Valencia, Spain
- CIBERehd, Fondo de Investigaciones Sanitarias, Barcelona, Spain
- Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad de Valencia, Valencia, Spain
| | - Jian Dong
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC USA
| | - Steven Dooley
- Department of Medicine II, Section Molecular Hepatology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Dirk Drasdo
- Interdisciplinary Center for Bioinformatics (IZBI), University of Leipzig, 04107 Leipzig, Germany
- INRIA (French National Institute for Research in Computer Science and Control), Domaine de Voluceau-Rocquencourt, B.P. 105, 78153 Le Chesnay Cedex, France
- UPMC University of Paris 06, CNRS UMR 7598, Laboratoire Jacques-Louis Lions, 4, pl. Jussieu, 75252 Paris cedex 05, France
| | - Rowena Eakins
- Department of Molecular and Clinical Pharmacology, Centre for Drug Safety Science, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Karine Sá Ferreira
- Institute of Molecular Medicine and Cell Research, University of Freiburg, Freiburg, Germany
- GRK 1104 From Cells to Organs, Molecular Mechanisms of Organogenesis, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Valentina Fonsato
- Department of Medical Sciences, University of Torino, 10126 Turin, Italy
| | - Joanna Fraczek
- Department of Toxicology, Centre for Pharmaceutical Research, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, 1090 Brussels, Belgium
| | - Rolf Gebhardt
- Institute of Biochemistry, Faculty of Medicine, University of Leipzig, 04103 Leipzig, Germany
| | - Andrew Gibson
- Department of Molecular and Clinical Pharmacology, Centre for Drug Safety Science, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Matthias Glanemann
- Department of General-, Visceral- and Transplantation Surgery, Charité University Medicine Berlin, 13353 Berlin, Germany
| | - Chris E. P. Goldring
- Department of Molecular and Clinical Pharmacology, Centre for Drug Safety Science, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - María José Gómez-Lechón
- Unidad de Hepatología Experimental, IIS Hospital La Fe Avda Campanar 21, 46009 Valencia, Spain
- CIBERehd, Fondo de Investigaciones Sanitarias, Barcelona, Spain
| | - Geny M. M. Groothuis
- Department of Pharmacy, Pharmacokinetics Toxicology and Targeting, University of Groningen, A. Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Lena Gustavsson
- Department of Laboratory Medicine (Malmö), Center for Molecular Pathology, Lund University, Jan Waldenströms gata 59, 205 02 Malmö, Sweden
| | - Christelle Guyot
- Department of Clinical Pharmacology and Toxicology, University Hospital, 8091 Zurich, Switzerland
| | - David Hallifax
- Centre for Applied Pharmacokinetic Research (CAPKR), School of Pharmacy and Pharmaceutical Sciences, University of Manchester, Oxford Road, Manchester, M13 9PT UK
| | - Seddik Hammad
- Department of Forensic Medicine and Veterinary Toxicology, Faculty of Veterinary Medicine, South Valley University, Qena, Egypt
| | - Adam Hayward
- Biological and Biomedical Sciences, Durham University, Durham, DH13LE UK
| | - Dieter Häussinger
- Clinic for Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | - Claus Hellerbrand
- Department of Medicine I, University Hospital Regensburg, 93053 Regensburg, Germany
| | | | - Stefan Hoehme
- Interdisciplinary Center for Bioinformatics (IZBI), University of Leipzig, 04107 Leipzig, Germany
| | - Hermann-Georg Holzhütter
- Institut für Biochemie Abteilung Mathematische Systembiochemie, Universitätsmedizin Berlin (Charité), Charitéplatz 1, 10117 Berlin, Germany
| | - J. Brian Houston
- Centre for Applied Pharmacokinetic Research (CAPKR), School of Pharmacy and Pharmaceutical Sciences, University of Manchester, Oxford Road, Manchester, M13 9PT UK
| | | | - Kiyomi Ito
- Research Institute of Pharmaceutical Sciences, Musashino University, 1-1-20 Shinmachi, Nishitokyo-shi, Tokyo, 202-8585 Japan
| | - Hartmut Jaeschke
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 USA
| | - Verena Keitel
- Clinic for Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | | | - B. Kevin Park
- Department of Molecular and Clinical Pharmacology, Centre for Drug Safety Science, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Claus Kordes
- Clinic for Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | - Gerd A. Kullak-Ublick
- Department of Clinical Pharmacology and Toxicology, University Hospital, 8091 Zurich, Switzerland
| | - Edward L. LeCluyse
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC USA
| | - Peng Lu
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC USA
| | | | - Anna Lutz
- Department of Pharmaceutical Biology and Biotechnology, University of Freiburg, Freiburg, Germany
| | - Daniel J. Maltman
- Reinnervate Limited, NETPark Incubator, Thomas Wright Way, Sedgefield, TS21 3FD UK
| | - Madlen Matz-Soja
- Institute of Biochemistry, Faculty of Medicine, University of Leipzig, 04103 Leipzig, Germany
| | - Patrick McMullen
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC USA
| | - Irmgard Merfort
- Department of Pharmaceutical Biology and Biotechnology, University of Freiburg, Freiburg, Germany
| | | | - Christoph Meyer
- Department of Medicine II, Section Molecular Hepatology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Jessica Mwinyi
- Department of Clinical Pharmacology and Toxicology, University Hospital, 8091 Zurich, Switzerland
| | - Dean J. Naisbitt
- Department of Molecular and Clinical Pharmacology, Centre for Drug Safety Science, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Andreas K. Nussler
- BG Trauma Center, Siegfried Weller Institut, Eberhard Karls University Tübingen, 72076 Tübingen, Germany
| | - Peter Olinga
- Division of Pharmaceutical Technology and Biopharmacy, Department of Pharmacy, University of Groningen, 9713 AV Groningen, The Netherlands
| | - Francesco Pampaloni
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University Frankfurt, Max-von-Laue-Str. 15, 60438 Frankfurt am Main, Germany
| | - Jingbo Pi
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC USA
| | - Linda Pluta
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC USA
| | - Stefan A. Przyborski
- Reinnervate Limited, NETPark Incubator, Thomas Wright Way, Sedgefield, TS21 3FD UK
- Biological and Biomedical Sciences, Durham University, Durham, DH13LE UK
| | - Anup Ramachandran
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 USA
| | - Vera Rogiers
- Department of Toxicology, Centre for Pharmaceutical Research, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, 1090 Brussels, Belgium
| | - Cliff Rowe
- Department of Molecular and Clinical Pharmacology, Centre for Drug Safety Science, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Celine Schelcher
- Department of Surgery, Liver Regeneration, Core Facility, Human in Vitro Models of the Liver, Ludwig Maximilians University of Munich, Munich, Germany
| | - Kathrin Schmich
- Department of Pharmaceutical Biology and Biotechnology, University of Freiburg, Freiburg, Germany
| | - Michael Schwarz
- Department of Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Wilhelmstr. 56, 72074 Tübingen, Germany
| | - Bijay Singh
- Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, 151-921 Korea
| | - Ernst H. K. Stelzer
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University Frankfurt, Max-von-Laue-Str. 15, 60438 Frankfurt am Main, Germany
| | - Bruno Stieger
- Department of Clinical Pharmacology and Toxicology, University Hospital, 8091 Zurich, Switzerland
| | - Regina Stöber
- Leibniz Research Centre for Working Environment and Human Factors (IFADO), 44139 Dortmund, Germany
| | - Yuichi Sugiyama
- Sugiyama Laboratory, RIKEN Innovation Center, RIKEN, Yokohama Biopharmaceutical R&D Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045 Japan
| | - Ciro Tetta
- Fresenius Medical Care, Bad Homburg, Germany
| | - Wolfgang E. Thasler
- Department of Surgery, Ludwig-Maximilians-University of Munich Hospital Grosshadern, Munich, Germany
| | - Tamara Vanhaecke
- Department of Toxicology, Centre for Pharmaceutical Research, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, 1090 Brussels, Belgium
| | - Mathieu Vinken
- Department of Toxicology, Centre for Pharmaceutical Research, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, 1090 Brussels, Belgium
| | - Thomas S. Weiss
- Department of Pediatrics and Juvenile Medicine, University of Regensburg Hospital, Regensburg, Germany
| | - Agata Widera
- Leibniz Research Centre for Working Environment and Human Factors (IFADO), 44139 Dortmund, Germany
| | - Courtney G. Woods
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC USA
| | | | | | - Jan G. Hengstler
- Leibniz Research Centre for Working Environment and Human Factors (IFADO), 44139 Dortmund, Germany
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Flavonoids and asthma. Nutrients 2013; 5:2128-43. [PMID: 23752494 PMCID: PMC3725497 DOI: 10.3390/nu5062128] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Revised: 05/03/2013] [Accepted: 05/15/2013] [Indexed: 12/21/2022] Open
Abstract
Asthma is a chronic disease, characterized by airway inflammation, airflow limitation, hyper-reactivity and airway remodeling. It is believed that asthma is caused by the interaction between genetic and environmental factors. The prevalence of allergic diseases, including asthma, has increased worldwide during the past two decades. Although the precise reasons that have caused this increase remain unknown, dietary change is thought to be one of the environmental factors. Flavonoids, which are polyphenolic plant secondary metabolites ubiquitously present in vegetables, fruits and beverages, possess antioxidant and anti-allergic traits, as well as immune-modulating activities. Flavonoids are powerful antioxidants and anti-allergic nutrients that inhibit the release of chemical mediators, synthesis of Th2 type cytokines, such as interleukin (IL)-4 and IL-13, and CD40 ligand expression by high-affinity immunoglobulin E (IgE) receptor-expressing cells, such as mast cells and basophils. They also inhibit IL-4-induced signal transduction and affect the differentiation of naïve CD4+ T cells into effector T-cells through their inhibitory effect on the activation of the aryl hydrocarbon receptor. Various studies of flavonoids in asthmatic animal models have demonstrated their beneficial effects. The results of several epidemiological studies suggest that an increase in flavonoid intake is beneficial for asthma. Moreover, clinical trials of flavonoids have shown their ameliorative effects on symptoms related to asthma. However, these human studies are currently limited; further validation is required to clarify whether an appropriate intake of flavonoids may constitute dietary treatment and for part of a preventive strategy for asthma.
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Hall AP, Elcombe CR, Foster JR, Harada T, Kaufmann W, Knippel A, Küttler K, Malarkey DE, Maronpot RR, Nishikawa A, Nolte T, Schulte A, Strauss V, York MJ. Liver hypertrophy: a review of adaptive (adverse and non-adverse) changes--conclusions from the 3rd International ESTP Expert Workshop. Toxicol Pathol 2012; 40:971-94. [PMID: 22723046 DOI: 10.1177/0192623312448935] [Citation(s) in RCA: 286] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Preclinical toxicity studies have demonstrated that exposure of laboratory animals to liver enzyme inducers during preclinical safety assessment results in a signature of toxicological changes characterized by an increase in liver weight, hepatocellular hypertrophy, cell proliferation, and, frequently in long-term (life-time) studies, hepatocarcinogenesis. Recent advances over the last decade have revealed that for many xenobiotics, these changes may be induced through a common mechanism of action involving activation of the nuclear hormone receptors CAR, PXR, or PPARα. The generation of genetically engineered mice that express altered versions of these nuclear hormone receptors, together with other avenues of investigation, have now demonstrated that sensitivity to many of these effects is rodent-specific. These data are consistent with the available epidemiological and empirical human evidence and lend support to the scientific opinion that these changes have little relevance to man. The ESTP therefore convened an international panel of experts to debate the evidence in order to more clearly define for toxicologic pathologists what is considered adverse in the context of hepatocellular hypertrophy. The results of this workshop concluded that hepatomegaly as a consequence of hepatocellular hypertrophy without histologic or clinical pathology alterations indicative of liver toxicity was considered an adaptive and a non-adverse reaction. This conclusion should normally be reached by an integrative weight of evidence approach.
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Affiliation(s)
- A P Hall
- AstraZeneca Pharmaceuticals, Alderley Park, Macclesfield, Cheshire, UK.
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Black MB, Budinsky RA, Dombkowski A, Cukovic D, LeCluyse EL, Ferguson SS, Thomas RS, Rowlands JC. Cross-species comparisons of transcriptomic alterations in human and rat primary hepatocytes exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin. Toxicol Sci 2012; 127:199-215. [PMID: 22298810 DOI: 10.1093/toxsci/kfs069] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A toxicogenomics approach was used to qualitatively and quantitatively compare the gene expression changes in human and rat primary hepatocytes exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Hepatocytes from five individual rats and five individual humans were exposed for 24 h to 11 concentrations of TCDD ranging from 0.00001 to 100nM and a vehicle control. Gene expression changes were analyzed using whole-genome microarrays containing 13,002 orthologs. Significant changes in expression of individual orthologs at any concentration (fold change [FC] ± 1.5 and false discovery rate < 0.05) were higher in the rat (1547) compared with human hepatocytes (475). Only 158 differentially expressed orthologs were common between rats and humans. Enrichment analysis was performed on the differentially expressed orthologs in each species with 49 and 34 enriched human and rat pathways, respectively. Only 12 enriched pathways were shared between the two species. The results demonstrate significant cross-species differences in expression at both the gene and pathway level. Benchmark dose analysis of gene expression changes showed an average 18-fold cross-species difference in potency among differentially expressed orthologs with the rat more sensitive than the human. Similar cross-species differences in potency were observed for signaling pathways. Using the maximum FC in gene expression as a measure of efficacy, the human hepatocytes showed on average a 20% lower efficacy among the individual orthologs showing differential expression. The results provide evidence for divergent cross-species gene expression changes in response to TCDD and are consistent with epidemiological and clinical evidence showing humans to be less sensitive to TCDD-induced hepatotoxicity.
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Affiliation(s)
- Michael B Black
- The Hamner Institutes for Health Sciences, Research Triangle Park, North Carolina 27709, USA
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Huang MC, Chen FY, Chou MT, Su JGJ. Fluoranthene enhances p53 expression and decreases mutagenesis induced by benzo[a]pyrene. Toxicol Lett 2012; 208:214-24. [DOI: 10.1016/j.toxlet.2011.11.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Revised: 10/23/2011] [Accepted: 11/09/2011] [Indexed: 12/15/2022]
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Su JGJ, Huang MC, Chen FY. 2,3,7,8-Tetrachlorodibenzo-p-dioxin’s Suppression of 1-Nitropyrene-Induced p53 Expression Is Mediated by Cytochrome P450 1A1. Chem Res Toxicol 2011; 24:2167-75. [DOI: 10.1021/tx200309p] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jyan-Gwo Joseph Su
- Department of Biochemical Science and Technology, National Chiayi University, Chiayi 600, Taiwan, ROC
| | - Min-Cong Huang
- Department of Biochemical Science and Technology, National Chiayi University, Chiayi 600, Taiwan, ROC
| | - Fei-Yun Chen
- Department of Biochemical Science and Technology, National Chiayi University, Chiayi 600, Taiwan, ROC
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Denison MS, Soshilov AA, He G, DeGroot DE, Zhao B. Exactly the same but different: promiscuity and diversity in the molecular mechanisms of action of the aryl hydrocarbon (dioxin) receptor. Toxicol Sci 2011; 124:1-22. [PMID: 21908767 DOI: 10.1093/toxsci/kfr218] [Citation(s) in RCA: 561] [Impact Index Per Article: 43.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The Ah receptor (AhR) is a ligand-dependent transcription factor that mediates a wide range of biological and toxicological effects that result from exposure to a structurally diverse variety of synthetic and naturally occurring chemicals. Although the overall mechanism of action of the AhR has been extensively studied and involves a classical nuclear receptor mechanism of action (i.e., ligand-dependent nuclear localization, protein heterodimerization, binding of liganded receptor as a protein complex to its specific DNA recognition sequence and activation of gene expression), details of the exact molecular events that result in most AhR-dependent biochemical, physiological, and toxicological effects are generally lacking. Ongoing research efforts continue to describe an ever-expanding list of ligand-, species-, and tissue-specific spectrum of AhR-dependent biological and toxicological effects that seemingly add even more complexity to the mechanism. However, at the same time, these studies are also identifying and characterizing new pathways and molecular mechanisms by which the AhR exerts its actions and plays key modulatory roles in both endogenous developmental and physiological pathways and response to exogenous chemicals. Here we provide an overview of the classical and nonclassical mechanisms that can contribute to the differential sensitivity and diversity in responses observed in humans and other species following ligand-dependent activation of the AhR signal transduction pathway.
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Affiliation(s)
- Michael S Denison
- Department of Environmental Toxicology, University of California, Davis, California 95616, USA.
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Helmig S, Seelinger JU, Döhrel J, Schneider J. RNA expressions of AHR, ARNT and CYP1B1 are influenced by AHR Arg554Lys polymorphism. Mol Genet Metab 2011; 104:180-4. [PMID: 21742528 DOI: 10.1016/j.ymgme.2011.06.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 06/15/2011] [Accepted: 06/15/2011] [Indexed: 11/26/2022]
Abstract
AIM The aryl hydrocarbon receptor (AHR) is a ligand activated transcription factor that together with Aryl Hydrocarbon Receptor Nuclear Translocator (ARNT) controls the expression of Xenobiotic metabolising enzymes (XME) such as CYP1B1. In the absence of exogenous ligands, AHR is supposed to be involved in promotion of cell cycle progression. Polymorphisms of the AHR gene are suggested to be associated with susceptibility to cancer. Because of its critical role in xenobiotic induced toxicity and carcinogenesis as well as its ligand independent relevance we investigated the effects of AHR Arg554Lys Polymorphism on gene expression level of the AHR, ARNT and CYP1B1. METHODS Detection of the AHR Arg554Lys polymorphism of the AHR gene was performed by rapid capillary PCR with melting curve analysis. The quantitative Real-Time PCR (qRT-PCR) of AHR, ARNT and CYP1B1 mRNAs was carried out in white blood cells from 287 Caucasians. Calculations of expression were made with the 2(-ΔΔCT) method. RESULTS The relative AHR mRNA expression revealed significant differences between the two homozygote AHR genotypes Arg554Arg (11.0±1.0; n=228) and Lys554Lys (0.6±0.4; n=3; p<0.001). Also significant differences were seen between the heterozygote genotype Arg554Lys (13.0±3.0; n=40) and the homozygote Lys554Lys genotype (0.6±0.4; n=3; p<0.001). These differences above were replicated significantly in the relative mRNA expression of ARNT and CYP1B1. Comparing the determined CT-values, a correlation coefficient of R=0.748 for AHR and ARNT, R=0.626 for ARNT and CYP1B1 as well as R=0.533 for AHR and CYP1B1 was calculated. CONCLUSION Our findings suggest that the homozygote variant genotype of AHR Lys554Lys is associated with a significantly lower AHR, ARNT and CYP1B1 mRNA expression.
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Affiliation(s)
- Simone Helmig
- Institut und Poliklinik für Arbeits- und Sozialmedizin, Justus-Liebig-Universität, Aulweg 129, D-35392 Giessen, Germany.
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Gibbons DL, Spencer J. Mouse and human intestinal immunity: same ballpark, different players; different rules, same score. Mucosal Immunol 2011; 4:148-57. [PMID: 21228770 DOI: 10.1038/mi.2010.85] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The study of animal immune physiology and animal models of human disease have accelerated many aspects of translational research by allowing direct, definitive investigations. In particular, the use of mice has allowed genetic manipulation, adoptive transfer, immunization, and focused cell and tissue sampling, which would obviously be unthinkable for studies in humans. However, the disease relevance of some animal models may be uncertain and difficulties in interpretation may occur as a consequence of immunological differences between the two species. In this review, we will consider general differences in the structure and development of human and mouse mucosal lymphoid microenvironments and then discuss species differences in mucosal B- and T-cell biology that relate to the current concepts of intestinal immune function.
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Affiliation(s)
- D L Gibbons
- Peter Gorer Department of Immunobiology, Kings College London, London, UK.
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