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Houser CL, Fenner KN, Lawrence BP. Timing influences the impact of aryl hydrocarbon receptor activation on the humoral immune response to respiratory viral infection. Toxicol Appl Pharmacol 2024; 489:117010. [PMID: 38901696 PMCID: PMC11240840 DOI: 10.1016/j.taap.2024.117010] [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: 04/04/2024] [Revised: 06/05/2024] [Accepted: 06/15/2024] [Indexed: 06/22/2024]
Abstract
Humoral responses to respiratory viruses, such as influenza viruses, develop over time and are central to protection from repeated infection with the same or similar viruses. Epidemiological and experimental studies have linked exposures to environmental contaminants that bind the aryl hydrocarbon receptor (AHR) with modulated antibody responses to pathogenic microorganisms and common vaccinations. Other studies have prompted investigation into the potential therapeutic applications of compounds that activate AHR. Herein, using two different AHR ligands [2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and 2-(1H-Indol-3-ylcarbonyl)-4-thiazolecarboxylic acid methyl ester (ITE), to modulate the duration of AHR activity, we show that the humoral response to viral infection is dependent upon the duration and timing of AHR signaling, and that different cellular elements of the response have different sensitivities. When AHR activation was initiated prior to infection with influenza A virus, there was suppression of all measured elements of the humoral response (i.e., the frequency of T follicular helper cells, germinal center B cells, plasma cells, and circulating virus-specific antibody). However, when the timing of AHR activation was adjusted to either early (days -1 to +5 relative to infection) or later (days +5 onwards), then AHR activation affected different aspects of the overall humoral response. These findings highlight the importance of considering the timing of AHR activation in relation to triggering an immune response, particularly when targeting the AHR to manipulate disease processes.
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Affiliation(s)
- Cassandra L Houser
- Department of Microbiology & Immunology, University of Rochester, Rochester NY14642, USA
| | - Kristina N Fenner
- Department of Environmental Medicine, University of Rochester, Rochester NY14642, USA
| | - B Paige Lawrence
- Department of Microbiology & Immunology, University of Rochester, Rochester NY14642, USA; Department of Environmental Medicine, University of Rochester, Rochester NY14642, USA.
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2
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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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3
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Eaton DL, Simon TW, Kaminski NE, Perdew GH, Nebert DW. The 2022 revised WHO TEFs for dioxins and dioxin-like chemicals: The importance of considering the use of species-specific information to determine relative effective potency for human-based risk assessment. Regul Toxicol Pharmacol 2024; 149:105599. [PMID: 38490576 DOI: 10.1016/j.yrtph.2024.105599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 02/25/2024] [Accepted: 03/05/2024] [Indexed: 03/17/2024]
Affiliation(s)
- David L Eaton
- Dept. Environmental Occupational Health Sciences, School of Public Health, University of Washington, Seattle, WA, USA.
| | | | - Norbert E Kaminski
- Food and Consumer Product Ingredient Safety Endowed Chair, Department of Pharmacology and Toxicology, Institute for Integrative Toxicology, Director, Center for Reseaerch on Ingredient Safety, Michigan State University, East Lansing, MI, USA
| | - Gary H Perdew
- H. Thomas and Dorothy Willits Hallowell Chair in Agricultural Sciences, 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, Department of Pediatrics & Molecular Developmental Biology, Division of Human Genetics, Cincinnati Children's Research Foundation, Cincinnati, OH, USA
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4
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Fitch S, Blanchette A, Haws LC, Franke K, Ring C, DeVito M, Wheeler M, Walker N, Birnbaum L, Van Ede KI, Antunes Fernandes EC, Wikoff DS. Systematic update to the mammalian relative potency estimate database and development of best estimate toxic equivalency factors for dioxin-like compounds. Regul Toxicol Pharmacol 2024; 147:105571. [PMID: 38244664 PMCID: PMC11059105 DOI: 10.1016/j.yrtph.2024.105571] [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: 05/02/2023] [Revised: 11/22/2023] [Accepted: 01/17/2024] [Indexed: 01/22/2024]
Abstract
The World Health Organization (WHO) assesses potential health risks of dioxin-like compounds using Toxic Equivalency Factors (TEFs). This study systematically updated the relative potency (REP) database underlying the 2005 WHO TEFs and applied advanced methods for quantitative integration of study quality and dose-response. Data obtained from fifty-one publications more than doubled the size of the previous REP database (∼1300 datasets). REP quality and relevance for these data was assessed via application of a consensus-based weighting framework. Using Bayesian dose-response modeling, available data were modeled to produce standardized dose/concentration-response Hill curves. Study quality and REP data were synthesized via Bayesian meta-analysis to integrate dose/concentration-response data, author-calculated REPs and benchmark ratios. The output is a prediction of the most likely relationship between each congener and its reference as model-predicted TEF uncertainty distributions, or the 'best estimate TEF' (BE-TEF). The resulting weighted BE-TEFs were similar to the 2005 TEFs, though provide more information to inform selection of TEF values as well as to provide risk assessors and managers with information needed to quantitatively characterize uncertainty around TEF values. Collectively, these efforts produce an updated REP database and an objective, reproducible approach to support development of TEF values based on all available data.
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Affiliation(s)
- S Fitch
- ToxStrategies, Katy, TX, USA.
| | | | | | - K Franke
- ToxStrategies, Asheville, NC, USA
| | - C Ring
- ToxStrategies, Austin, TX, USA
| | - M DeVito
- Environmental Protection Agency, Center for Computational Toxicology and Exposure, Research Triangle Park, NC, USA
| | - M Wheeler
- National Institute of Environmental Health Sciences/National Institutes of Health, Research Triangle Park, NC, USA
| | - N Walker
- National Institute of Environmental Health Sciences/National Institutes of Health, Research Triangle Park, NC, USA
| | - L Birnbaum
- National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA; Nicholas School of the Environment, Duke University, Durham, NC, USA
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5
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Nebert DW. Gene-Environment Interactions: My Unique Journey. Annu Rev Pharmacol Toxicol 2024; 64:1-26. [PMID: 37788491 DOI: 10.1146/annurev-pharmtox-022323-082311] [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: 10/05/2023]
Abstract
I am deeply honored to be invited to write this scientific autobiography. As a physician-scientist, pediatrician, molecular biologist, and geneticist, I have authored/coauthored more than 600 publications in the fields of clinical medicine, biochemistry, biophysics, pharmacology, drug metabolism, toxicology, molecular biology, cancer, standardized gene nomenclature, developmental toxicology and teratogenesis, mouse genetics, human genetics, and evolutionary genomics. Looking back, I think my career can be divided into four distinct research areas, which I summarize mostly chronologically in this article: (a) discovery and characterization of the AHR/CYP1 axis, (b) pharmacogenomics and genetic prediction of response to drugs and other environmental toxicants, (c) standardized drug-metabolizing gene nomenclature based on evolutionary divergence, and (d) discovery and characterization of the SLC39A8 gene encoding the ZIP8 metal cation influx transporter. Collectively, all four topics embrace gene-environment interactions, hence the title of my autobiography.
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Affiliation(s)
- Daniel W Nebert
- Department of Environmental and Public Health Sciences and Center for Environmental Genetics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
- Department of Pediatrics and Molecular Developmental Biology, Division of Human Genetics, Cincinnati Children's Hospital, Cincinnati, Ohio, USA;
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6
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DeVito M, Bokkers B, van Duursen MBM, van Ede K, Feeley M, Antunes Fernandes Gáspár E, Haws L, Kennedy S, Peterson RE, Hoogenboom R, Nohara K, Petersen K, Rider C, Rose M, Safe S, Schrenk D, Wheeler MW, Wikoff DS, Zhao B, van den Berg M. The 2022 world health organization reevaluation of human and mammalian toxic equivalency factors for polychlorinated dioxins, dibenzofurans and biphenyls. Regul Toxicol Pharmacol 2024; 146:105525. [PMID: 37972849 PMCID: PMC10870838 DOI: 10.1016/j.yrtph.2023.105525] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 10/21/2023] [Accepted: 11/01/2023] [Indexed: 11/19/2023]
Abstract
In October 2022, the World Health Organization (WHO) convened an expert panel in Lisbon, Portugal in which the 2005 WHO TEFs for chlorinated dioxin-like compounds were reevaluated. In contrast to earlier panels that employed expert judgement and consensus-based assignment of TEF values, the present effort employed an update to the 2006 REP database, a consensus-based weighting scheme, a Bayesian dose response modeling and meta-analysis to derive "Best-Estimate" TEFs. The updated database contains almost double the number of datasets from the earlier version and includes metadata that informs the weighting scheme. The Bayesian analysis of this dataset results in an unbiased quantitative assessment of the congener-specific potencies with uncertainty estimates. The "Best-Estimate" TEF derived from the model was used to assign 2022 WHO-TEFs for almost all congeners and these values were not rounded to half-logs as was done previously. The exception was for the mono-ortho PCBs, for which the panel agreed to retain their 2005 WHO-TEFs due to limited and heterogenous data available for these compounds. Applying these new TEFs to a limited set of dioxin-like chemical concentrations measured in human milk and seafood indicates that the total toxic equivalents will tend to be lower than when using the 2005 TEFs.
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Affiliation(s)
- Michael DeVito
- Center for Computational Toxicology and Exposure, United States Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Bas Bokkers
- Centre for Safety of Substances and Products, National Institute for Public Health, And the Environment (RIVM), Bilthoven, the Netherlands
| | - Majorie B M van Duursen
- Amsterdam Institute for Life and Environment, Environmental Health & Toxicology, Vrije Universiteit, Amsterdam, the Netherlands
| | | | | | | | | | - Sean Kennedy
- Department of Biology, University of Ottawa, Canada
| | | | - Ron Hoogenboom
- Wageningen Food Safety Research (WFSR), Wageningen, the Netherlands
| | - Keiko Nohara
- Health and Environmental Risk Division, National Institute for Environmental Studies, Tsukuba, 305-8506, Japan
| | - Kim Petersen
- Department of Nutrition and Food Safety, Standards and Scientific Advice on Food and Nutrition, World Health Organization, Geneva Switzerland.
| | - Cynthia Rider
- National Institute of Environmental Health Science, Division of the Translational Toxicology, Durham, USA
| | - Martin Rose
- FERA Science Ltd, Sand Hutton, York, YO41 1LZ, UK; Manchester Institute of Biotechnology, University of Manchester, Manchester, UK
| | - Stephen Safe
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX, 77843, USA
| | - Dieter Schrenk
- Food Chemistry and Toxicology Department, University of Kaiserslautern, D-67663, Kaiserslautern, Germany
| | - Matthew W Wheeler
- Biostatistics and Computational Biology Branch, National Institute of Environmental Health Sciences, RTP, NC, USA
| | | | - Bin Zhao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Martin van den Berg
- Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 104, 3584 CM, Utrecht, the Netherlands
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Head KZ, Bolatimi OE, Gripshover TC, Tan M, Li Y, Audam TN, Jones SP, Klinge CM, Cave MC, Wahlang B. Investigating the effects of long-term Aroclor 1260 exposure on fatty liver disease in a diet-induced obesity mouse model. FRONTIERS IN GASTROENTEROLOGY (LAUSANNE, SWITZERLAND) 2023; 2:1180712. [PMID: 37426695 PMCID: PMC10327714 DOI: 10.3389/fgstr.2023.1180712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Introduction Polychlorinated biphenyls (PCBs) are persistent environmental toxicants that have been implicated in numerous health disorders including liver diseases such as non-alcoholic fatty liver disease (NAFLD). Toxicant-associated NAFLD, also known as toxicant-associated fatty liver disease (TAFLD), consists of a spectrum of disorders ranging from steatosis and steatohepatitis to fibrosis and hepatocellular carcinoma. Previously, our group demonstrated that 12-week exposure to the PCB mixture, Aroclor 1260, exacerbated steatohepatitis in high-fat diet (HFD)-fed mice; however, the longer-term effects of PCBs on TAFLD remain to be elucidated. This study aims to examine the longer-term effects of Aroclor 1260 (>30 weeks) in a diet-induced obesity model to better understand how duration of exposure can impact TAFLD. Methods Male C57BL/6 mice were exposed to Aroclor 1260 (20 mg/kg) or vehicle control by oral gavage at the beginning of the study period and fed either a low-fat diet (LFD) or HFD throughout the study period. Results Aroclor 1260 exposure (>30 weeks) led to steatohepatitis only in LFD-fed mice. Several Aroclor 1260 exposed LFD-fed mice also developed hepatocellular carcinoma (25%), which was absent in HFD-fed mice. The LFD+Aroclor1260 group also exhibited decreased hepatic Cyp7a1 expression and increased pro-fibrotic Acta2 expression. In contrast, longer term Aroclor 1260 exposure in conjunction with HFD did not exacerbate steatosis or inflammatory responses beyond those observed with HFD alone. Further, hepatic xenobiotic receptor activation by Aroclor 1260 was absent at 31 weeks post exposure, suggesting PCB redistribution to the adipose and other extra-hepatic tissues with time. Discussion Overall, the results demonstrated that longer-term PCB exposure worsened TAFLD outcomes independent of HFD feeding and suggests altered energy metabolism as a potential mechanism fueling PCB mediated toxicity without dietary insult. Additional research exploring mechanisms for these longer-term PCB mediated toxicity in TAFLD is warranted.
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Affiliation(s)
- Kimberly Z. Head
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, School of Medicine, University of Louisville, Louisville, KY, United States
- The Hepatobiology and Toxicology Center, University of Louisville, Louisville, KY, United States
| | - Oluwanifemi E. Bolatimi
- Department of Pharmacology and Toxicology, School of Medicine, University of Louisville, Louisville, KY, United States
| | - Tyler C. Gripshover
- Department of Pharmacology and Toxicology, School of Medicine, University of Louisville, Louisville, KY, United States
| | - Min Tan
- Department of Surgery, School of Medicine, University of Louisville, Louisville, KY, United States
| | - Yan Li
- Department of Surgery, School of Medicine, University of Louisville, Louisville, KY, United States
| | - Timothy N. Audam
- Center for Cardiometabolic Science, Department of Medicine, Division of Environmental Medicine, Christina Lee Brown Envirome Institute, University of Louisville, Louisville, KY, United States
| | - Steven P. Jones
- Center for Cardiometabolic Science, Department of Medicine, Division of Environmental Medicine, Christina Lee Brown Envirome Institute, University of Louisville, Louisville, KY, United States
| | - Carolyn M. Klinge
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Louisville, Louisville, KY, United States
- The Center for Integrative Environmental Health Sciences, University of Louisville, Louisville, KY, United States
| | - Matthew C. Cave
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, School of Medicine, University of Louisville, Louisville, KY, United States
- The Hepatobiology and Toxicology Center, University of Louisville, Louisville, KY, United States
- Department of Pharmacology and Toxicology, School of Medicine, University of Louisville, Louisville, KY, United States
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Louisville, Louisville, KY, United States
- The Center for Integrative Environmental Health Sciences, University of Louisville, Louisville, KY, United States
- University of Louisville (UofL) Superfund Research Center, University of Louisville, Louisville, KY, United States
- Robley Rex Department of Veterans Affairs Medical Center, Louisville, KY, United States
| | - Banrida Wahlang
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, School of Medicine, University of Louisville, Louisville, KY, United States
- The Hepatobiology and Toxicology Center, University of Louisville, Louisville, KY, United States
- The Center for Integrative Environmental Health Sciences, University of Louisville, Louisville, KY, United States
- University of Louisville (UofL) Superfund Research Center, University of Louisville, Louisville, KY, United States
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8
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Gripshover TC, Wahlang B, Head KZ, Young JL, Luo J, Mustafa MT, Kirpich IA, Cave MC. The environmental pollutant, polychlorinated biphenyl 126, alters liver function in a rodent model of alcohol-associated liver disease. ALCOHOL, CLINICAL & EXPERIMENTAL RESEARCH 2023; 47:60-75. [PMID: 36377258 PMCID: PMC9974797 DOI: 10.1111/acer.14976] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 11/08/2022] [Accepted: 11/10/2022] [Indexed: 11/16/2022]
Abstract
BACKGROUND The prevalence of alcohol-associated liver disease (ALD), a subtype of fatty liver disease (FLD), continues to rise. ALD is a major cause of preventable death. Polychlorinated biphenyl (PCB) 126 is an environmentally relevant, dioxin-like pollutant whose negative metabolic effects have been well documented. In human and animal studies, PCB has been associated with the severity of nonalcoholic fatty liver disease (NAFLD). However, few studies have investigated whether exposures to environmental toxicants can worsen ALD. Thus, the objective of the current study was to develop an alcohol-plus-toxicant model to study how an environmental pollutant, PCB 126, impacts rodent ALD pathology. METHODS Briefly, male C57BL/6J mice were exposed to 0.2 mg/kg PCB 126 or corn oil vehicle four days prior to ethanol feeding using the chronic-binge (10-plus-one) model. RESULTS Concentrations of macromolecules, including hepatic lipids, carbohydrates, and protein (albumin) were impacted. Exposure to PCB 126 exacerbated hepatic steatosis and hepatomegaly in mice exposed to the chemical and fed an ethanol diet. Gene expression and the analysis of blood chemistry showed a potential net increase and retention of hepatic lipids and reductions in lipid oxidation and clearance capabilities. Depletion of glycogen and glucose was evident, which contributes to disease progression by generating systemic malnutrition. Granulocytic immune infiltrates were present but driven solely by ethanol feeding. Hepatic albumin gene expression and plasma levels were decreased by ~50% indicating a potential compromise of liver function. Finally, gene expression analyses indicated that the aryl hydrocarbon receptor and constitutive androstane receptor were activated by PCB 126 and ethanol, respectively. CONCLUSIONS Various environmental toxicants are known to modify or enhance FLD in high-fat diet models. Findings from the present study suggest that they interact with other lifestyle factors such as alcohol consumption to reprogram intermediary metabolism resulting in exacerbated ethanol-associated systemic malnutrition in ALD.
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Affiliation(s)
- Tyler C. Gripshover
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY 40202, USA
- Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, School of Medicine, University of Louisville, Louisville, KY 40202, USA
- University of Louisville Superfund Research Program, University of Louisville, Louisville, KY 40202, USA
| | - Banrida Wahlang
- Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, School of Medicine, University of Louisville, Louisville, KY 40202, USA
- Hepatobiology & Toxicology COBRE, University of Louisville School of Medicine, Louisville, KY 40202, USA
- University of Louisville Alcohol Research Center, University of Louisville, Louisville, KY 40202, USA
- University of Louisville Superfund Research Program, University of Louisville, Louisville, KY 40202, USA
| | - Kimberly Z. Head
- Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, School of Medicine, University of Louisville, Louisville, KY 40202, USA
- Hepatobiology & Toxicology COBRE, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Jamie L. Young
- Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, School of Medicine, University of Louisville, Louisville, KY 40202, USA
| | - Jianzhu Luo
- Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, School of Medicine, University of Louisville, Louisville, KY 40202, USA
| | - Muhammad T. Mustafa
- The Center for Integrative Environmental Health Sciences, University of Louisville, Louisville, KY, 40202, USA
| | - Irina A. Kirpich
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY 40202, USA
- Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, School of Medicine, University of Louisville, Louisville, KY 40202, USA
- Hepatobiology & Toxicology COBRE, University of Louisville School of Medicine, Louisville, KY 40202, USA
- University of Louisville Alcohol Research Center, University of Louisville, Louisville, KY 40202, USA
| | - Matthew C. Cave
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY 40202, USA
- Department of Biochemistry and Molecular Genetics, University of Louisville School of Medicine, Louisville, KY 40202, USA
- Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, School of Medicine, University of Louisville, Louisville, KY 40202, USA
- The Robley Rex Veterans Affairs Medical Center, Louisville, KY 40206, USA
- The Liver Transplant Program at UofL Health - Jewish Hospital Trager Transplant Center, Louisville, KY 40202 USA
- Hepatobiology & Toxicology COBRE, University of Louisville School of Medicine, Louisville, KY 40202, USA
- University of Louisville Alcohol Research Center, University of Louisville, Louisville, KY 40202, USA
- University of Louisville Superfund Research Program, University of Louisville, Louisville, KY 40202, USA
- The Center for Integrative Environmental Health Sciences, University of Louisville, Louisville, KY, 40202, USA
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9
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Chen Y, Cai Y, Chen C, Li M, Lu L, Yu Z, Wang S, Fang L, Xu S. Aroclor 1254 induced inhibitory effects on osteoblast differentiation in murine MC3T3-E1 cells through oxidative stress. Front Endocrinol (Lausanne) 2022; 13:940624. [PMID: 36353240 PMCID: PMC9637744 DOI: 10.3389/fendo.2022.940624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Accepted: 10/04/2022] [Indexed: 11/21/2022] Open
Abstract
This study aimed to evaluate the osteotoxicity of polychlorinated biphenyls in murine osteoblastic MC3T3-E1 cells, and to explore the underlying mechanism focused on oxidative stress. The cells were exposed to Aroclor 1254 at concentrations of 2.5-20 µmol/L, and then cell viability, oxidative stress, intracellular calcium concentration, osteocalcin content, and calcium nodules formation were measured. Aroclor 1254 reduced cell viability and induced overproduction of intracellular reactive oxygen species in a dose-dependent manner. Activity of superoxide dismutase was decreased, and malondialdehyde content was promoted after exposure. Moreover, inhibitory effects of Aroclor 1254 on calcium metabolism and mineralization of osteoblasts were observed, as indicated by reduction of the intracellular calcium concentration, osteocalcin content, and modules formation rate. The decreased expression of osteocalcin, alkaline phosphatase, bone sialoprotein, and transient receptor potential vanilloid 6 further confirmed the impairment of Aroclor 1254 on calcium homeostasis and osteoblast differentiation. Addition of the antioxidant N-acetyl-L-cysteine partially restored the inhibitory effects on calcium metabolism and mineralization. In general, Aroclor 1254 exposure reduces calcium homeostasis, osteoblast differentiation and bone formation, and oxidative stress plays a vital role in the underlying molecular mechanism of osteotoxicity.
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Affiliation(s)
- Yu Chen
- Department of Orthopaedic Surgery (I), Shuguang Hospital, Shanghai University of Chinese Traditional Medicine, Shanghai, China
| | - Yuwei Cai
- Department of Orthopaedic Surgery (I), Shuguang Hospital, Shanghai University of Chinese Traditional Medicine, Shanghai, China
| | - Chunxiang Chen
- Department of Neurology, Yueyang Hospital of Integrated Chinese and Western Medicine Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Mengting Li
- Department of Neurology, Yueyang Hospital of Integrated Chinese and Western Medicine Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Lingdan Lu
- Department of Neurology, Yueyang Hospital of Integrated Chinese and Western Medicine Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Zhongxiang Yu
- Department of Orthopaedic Surgery (I), Shuguang Hospital, Shanghai University of Chinese Traditional Medicine, Shanghai, China
| | - Shuqiang Wang
- Department of Orthopaedic Surgery, Yueyang Hospital of Integrated Chinese and Western Medicine Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Lei Fang
- Department of Orthopaedic Surgery (I), Shuguang Hospital, Shanghai University of Chinese Traditional Medicine, Shanghai, China
- *Correspondence: Lei Fang, ; Shengming Xu,
| | - Shengming Xu
- Department of Orthopaedic Surgery (I), Shuguang Hospital, Shanghai University of Chinese Traditional Medicine, Shanghai, China
- *Correspondence: Lei Fang, ; Shengming Xu,
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10
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Kubota A, Terasaki M, Takai R, Kobayashi M, Muromoto R, Kojima H. 5-Aminosalicylic Acid, A Weak Agonist for Aryl Hydrocarbon Receptor That Induces Splenic Regulatory T Cells. Pharmacology 2021; 107:28-34. [PMID: 34915497 DOI: 10.1159/000520404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 10/21/2021] [Indexed: 11/19/2022]
Abstract
INTRODUCTION 5-Aminosalicylic acid (5-ASA) is widely used as a key drug in inflammatory bowel disease. It has been recently reported that 5-ASA induces CD4 + Foxp3 + regulatory T cells (Tregs) in the colon via the aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor that regulates inflammation. However, the role of 5-ASA as an AhR agonist that induces Tregs in the spleen remains unknown. METHODS In the present study, we investigated these themes using an AhR-mediated transactivation assay and flow cytometry analysis. The experiments were conducted by using DR-EcoScreen cells and C57BL/6 mice. RESULTS The DR-EcoScreen cell-based transactivation assay revealed that 5-ASA acted as a weak AhR agonist at concentrations of ≥300 μM (1.31-1.45-fold), and that a typical AhR agonist, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), activated AhR at a concentration of 0.1 nM (22.8-fold). In addition, the treatment of mouse splenic cells with 300 μM 5-ASA in a primary culture assay significantly induced CD4+CD25 + Foxp3 + Tregs (control vs. 5-ASA: 9.0% vs. 12.65%, p < 0.05), while 0.1 nM TCDD also showed significant induction of Tregs (control vs. TCDD: 9.0% vs. 14.1%, p < 0.05). Interestingly, this induction was eliminated by co-treatment with an AhR antagonist, CH-223191. DISCUSSION These results suggest that 5-ASA is a weak agonist of AhR and thereby induces Tregs in spleen cells. Our findings may provide useful insights into the mechanism by which 5-ASA regulates inflammation.
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Affiliation(s)
- Atsuhito Kubota
- School of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, Japan,
| | - Masaru Terasaki
- School of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, Japan
- Advanced Research Promotion Center, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, Japan
| | - Rie Takai
- Advanced Research Promotion Center, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, Japan
| | - Masaki Kobayashi
- Laboratory of Clinical Pharmaceutics & Therapeutics, Division of Pharma Sciences, Faculty of Pharmaceutical Sciences "Sapporo,", Hokkaido, Japan
| | - Ryuta Muromoto
- Department of Immunology, Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Hiroyuki Kojima
- School of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, Japan
- Advanced Research Promotion Center, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, Japan
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Applicability of Scrape Loading-Dye Transfer Assay for Non-Genotoxic Carcinogen Testing. Int J Mol Sci 2021; 22:ijms22168977. [PMID: 34445682 PMCID: PMC8396440 DOI: 10.3390/ijms22168977] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 07/30/2021] [Accepted: 07/31/2021] [Indexed: 12/27/2022] Open
Abstract
Dysregulation of gap junction intercellular communication (GJIC) is recognized as one of the key hallmarks for identifying non-genotoxic carcinogens (NGTxC). Currently, there is a demand for in vitro assays addressing the gap junction hallmark, which would have the potential to eventually become an integral part of an integrated approach to the testing and assessment (IATA) of NGTxC. The scrape loading-dye transfer (SL-DT) technique is a simple assay for the functional evaluation of GJIC in various in vitro cultured mammalian cells and represents an interesting candidate assay. Out of the various techniques for evaluating GJIC, the SL-DT assay has been used frequently to assess the effects of various chemicals on GJIC in toxicological and tumor promotion research. In this review, we systematically searched the existing literature to gather papers assessing GJIC using the SL-DT assay in a rat liver epithelial cell line, WB-F344, after treating with chemicals, especially environmental and food toxicants, drugs, reproductive-, cardio- and neuro-toxicants and chemical tumor promoters. We discuss findings derived from the SL-DT assay with the known knowledge about the tumor-promoting activity and carcinogenicity of the assessed chemicals to evaluate the predictive capacity of the SL-DT assay in terms of its sensitivity, specificity and accuracy for identifying carcinogens. These data represent important information with respect to the applicability of the SL-DT assay for the testing of NGTxC within the IATA framework.
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Wang Y, Hu C, Fang T, Jin Y, Wu R. Perspective on prenatal polychlorinated biphenyl exposure and the development of the progeny nervous system (Review). Int J Mol Med 2021; 48:150. [PMID: 34132363 PMCID: PMC8219518 DOI: 10.3892/ijmm.2021.4983] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Accepted: 05/26/2021] [Indexed: 02/05/2023] Open
Abstract
The developmental origins of health and disease concept illustrates that exposure in early life to various factors may affect the offspring's long-term susceptibility to disease. During development, the nervous system is sensitive and vulnerable to the environmental insults. Polychlorinated biphenyls (PCBs), which are divided into dioxin-like (DL-PCBs) and non-dioxin-like PCBs (NDL-PCBs), are synthetic persistent environmental endocrine-disrupting chemicals. The toxicological mechanisms of DL-PCBs have been associated with the activation of the aryl hydrocarbon receptor and NDL-PCBs have been associated with ryanodine receptor-mediated calcium ion channels, which affect neuronal migration, promote dendritic growth and alter neuronal connectivity. In addition, PCB accumulation in the placenta destroys the fetal placental unit and affects endocrine function, particularly thyroid hormones and the dopaminergic system, leading to neuroendocrine disorders. However, epidemiological investigations have not achieved a consistent result in different study cohorts. The present review summarizes the epidemiological differences and possible mechanisms of the effects of intrauterine PCB exposure on neurological development.
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Affiliation(s)
- Yinfeng Wang
- Department of Gynecology and Obstetrics, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310006, P.R. China
| | - Changchang Hu
- Department of Gynecology and Obstetrics, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310006, P.R. China
| | - Tao Fang
- Department of Gynecology and Obstetrics, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310006, P.R. China
| | - Yang Jin
- Department of Gynecology and Obstetrics, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310006, P.R. China
| | - Ruijin Wu
- Department of Gynecology and Obstetrics, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310006, P.R. China
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Abstract
Polychlorinated biphenyls (PCBs) have been associated with abnormal liver enzymes and suspected nonalcoholic fatty liver disease (NAFLD) in cohort studies. NAFLD affects greater than 25% of the global population and may result in liver-related mortality. Both dioxin-like and non-dioxin-like PCBs have been associated with NAFLD, but their effects and mechanisms differ. Dioxin-like PCBs altered the gut:liver axis and microbiome and caused hepatic steatosis by disrupting hepatic lipid metabolism. In contrast, NDL PCBs reduced the liver's protective responses to promote diet-induced NAFLD. Mechanisms included the disruption of phosphoprotein signaling resulting in altered nuclear receptor function.
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