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Tomkiewicz C, Coumoul X, Nioche P, Barouki R, Blanc EB. Costs of molecular adaptation to the chemical exposome: a focus on xenobiotic metabolism pathways. Philos Trans R Soc Lond B Biol Sci 2024; 379:20220510. [PMID: 38310928 PMCID: PMC10838638 DOI: 10.1098/rstb.2022.0510] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Accepted: 12/04/2023] [Indexed: 02/06/2024] Open
Abstract
Organisms adapt to their environment through different pathways. In vertebrates, xenobiotics are detected, metabolized and eliminated through the inducible xenobiotic-metabolizing pathways (XMP) which can also generate reactive toxic intermediates. In this review, we will discuss the impacts of the chemical exposome complexity on the balance between detoxication and side effects. There is a large discrepancy between the limited number of proteins involved in these pathways (few dozens) and the diversity and complexity of the chemical exposome (tens of thousands of chemicals). Several XMP proteins have a low specificity which allows them to bind and/or metabolize a large number of chemicals. This leads to undesired consequences, such as cross-inhibition, inefficient metabolism, release of toxic intermediates, etc. Furthermore, several XMP proteins have endogenous functions that may be disrupted upon exposure to exogenous chemicals. The gut microbiome produces a very large number of metabolites that enter the body and are part of the chemical exposome. It can metabolize xenobiotics and either eliminate them or lead to toxic derivatives. The complex interactions between chemicals of different origins will be illustrated by the diverse roles of the aryl hydrocarbon receptor which binds and transduces the signals of a large number of xenobiotics, microbiome metabolites, dietary chemicals and endogenous compounds. This article is part of the theme issue 'Endocrine responses to environmental variation: conceptual approaches and recent developments'.
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Affiliation(s)
| | - Xavier Coumoul
- Université Paris Cité, Inserm unit UMRS 1124, 75006 Paris, France
| | - Pierre Nioche
- Université Paris Cité, Inserm unit UMRS 1124, 75006 Paris, France
| | - Robert Barouki
- Université Paris Cité, Inserm unit UMRS 1124, 75006 Paris, France
- Hôpital Necker Enfants malades, AP-HP, 75006 Paris, France
| | - Etienne B. Blanc
- Université Paris Cité, Inserm unit UMRS 1124, 75006 Paris, France
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2
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Opitz CA, Holfelder P, Prentzell MT, Trump S. The complex biology of aryl hydrocarbon receptor activation in cancer and beyond. Biochem Pharmacol 2023; 216:115798. [PMID: 37696456 PMCID: PMC10570930 DOI: 10.1016/j.bcp.2023.115798] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 09/08/2023] [Accepted: 09/08/2023] [Indexed: 09/13/2023]
Abstract
The aryl hydrocarbon receptor (AHR) signaling pathway is a complex regulatory network that plays a critical role in various biological processes, including cellular metabolism, development, and immune responses. The complexity of AHR signaling arises from multiple factors, including the diverse ligands that activate the receptor, the expression level of AHR itself, and its interaction with the AHR nuclear translocator (ARNT). Additionally, the AHR crosstalks with the AHR repressor (AHRR) or other transcription factors and signaling pathways and it can also mediate non-genomic effects. Finally, posttranslational modifications of the AHR and its interaction partners, epigenetic regulation of AHR and its target genes, as well as AHR-mediated induction of enzymes that degrade AHR-activating ligands may contribute to the context-specificity of AHR activation. Understanding the complexity of AHR signaling is crucial for deciphering its physiological and pathological roles and developing therapeutic strategies targeting this pathway. Ongoing research continues to unravel the intricacies of AHR signaling, shedding light on the regulatory mechanisms controlling its diverse functions.
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Affiliation(s)
- Christiane A Opitz
- German Cancer Research Center (DKFZ), Heidelberg, Division of Metabolic Crosstalk in Cancer and the German Cancer Consortium (DKTK), DKFZ Core Center Heidelberg, 69120 Heidelberg, Germany; Neurology Clinic and National Center for Tumor Diseases, 69120 Heidelberg, Germany.
| | - Pauline Holfelder
- German Cancer Research Center (DKFZ), Heidelberg, Division of Metabolic Crosstalk in Cancer and the German Cancer Consortium (DKTK), DKFZ Core Center Heidelberg, 69120 Heidelberg, Germany; Faculty of Bioscience, Heidelberg University, 69120 Heidelberg, Germany
| | - Mirja Tamara Prentzell
- German Cancer Research Center (DKFZ), Heidelberg, Division of Metabolic Crosstalk in Cancer and the German Cancer Consortium (DKTK), DKFZ Core Center Heidelberg, 69120 Heidelberg, Germany; Faculty of Bioscience, Heidelberg University, 69120 Heidelberg, Germany
| | - Saskia Trump
- Molecular Epidemiology Unit, Berlin Institute of Health at Charité and the German Cancer Consortium (DKTK), Partner Site Berlin, a partnership between DKFZ and Charité -Universitätsmedizin Berlin, 10117 Berlin, Germany
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3
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Bian J, Zhao J, Zhao Y, Hao X, He S, Li Y, Huang L. Impact of individual factors on DNA methylation of drug metabolism genes: A systematic review. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2023; 64:401-415. [PMID: 37522536 DOI: 10.1002/em.22567] [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: 05/04/2023] [Revised: 07/12/2023] [Accepted: 07/26/2023] [Indexed: 08/01/2023]
Abstract
Individual differences in drug response have always existed in clinical treatment. Many non-genetic factors show non-negligible impacts on personalized medicine. Emerging studies have demonstrated epigenetic could connect non-genetic factors and individual treatment differences. We used systematic retrieval methods and reviewed studies that showed individual factors' impact on DNA methylation of drug metabolism genes. In total, 68 studies were included, and half (n = 36) were cohort studies. Six aspects of individual factors were summarized from the perspective of personalized medicine: parental exposure, environmental pollutants exposure, obesity and diet, drugs, gender and others. The most research (n = 11) focused on ABCG1 methylation. The majority of studies showed non-genetic factors could result in a significant DNA methylation alteration in drug metabolism genes, which subsequently affects the pharmacokinetic processes. However, the underlying mechanism remained unknown. Finally, some viewpoints were presented for future research.
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Affiliation(s)
- Jialu Bian
- Department of Pharmacy, People's Hospital of Peking University, Beijing, China
- Department of Pharmacy Administration and Clinical Pharmacy, School of Pharmaceutical Science, Peking University, Beijing, China
| | - Jinxia Zhao
- Department of Pharmacy, People's Hospital of Peking University, Beijing, China
- Department of Pharmacy Administration and Clinical Pharmacy, School of Pharmaceutical Science, Peking University, Beijing, China
| | - Yinyu Zhao
- Department of Pharmacy, People's Hospital of Peking University, Beijing, China
- Department of Pharmacy Administration and Clinical Pharmacy, School of Pharmaceutical Science, Peking University, Beijing, China
| | - Xu Hao
- Department of Pharmacy, People's Hospital of Peking University, Beijing, China
| | - Shiyu He
- Department of Pharmacy, People's Hospital of Peking University, Beijing, China
- Department of Pharmacy Administration and Clinical Pharmacy, School of Pharmaceutical Science, Peking University, Beijing, China
| | - Yuanyuan Li
- Department of Pharmacy, People's Hospital of Peking University, Beijing, China
| | - Lin Huang
- Department of Pharmacy, People's Hospital of Peking University, Beijing, China
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4
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Salminen A. Aryl hydrocarbon receptor (AhR) impairs circadian regulation: impact on the aging process. Ageing Res Rev 2023; 87:101928. [PMID: 37031728 DOI: 10.1016/j.arr.2023.101928] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 03/23/2023] [Accepted: 04/06/2023] [Indexed: 04/11/2023]
Abstract
Circadian clocks control the internal sleep-wake rhythmicity of 24hours which is synchronized by the solar cycle. Circadian regulation of metabolism evolved about 2.5 billion years ago, i.e., the rhythmicity has been conserved from cyanobacteria and Archaea through to mammals although the mechanisms utilized have developed with evolution. While the aryl hydrocarbon receptor (AhR) is an evolutionarily conserved defence mechanism against environmental threats, it has gained many novel functions during evolution, such as the regulation of cell cycle, proteostasis, and many immune functions. There is robust evidence that AhR signaling impairs circadian rhythmicity, e.g., by interacting with the core BMAL1/CLOCK complex and disturbing the epigenetic regulation of clock genes. The maintenance of circadian rhythms is impaired with aging, disturbing metabolism and many important functions in aged organisms. Interestingly, it is known that AhR signaling promotes an age-related tissue degeneration, e.g., it is able to inhibit autophagy, enhance cellular senescence, and disrupt extracellular matrix. These alterations are rather similar to those induced by a long-term impairment of circadian rhythms. However, it is not known whether AhR signaling enhances the aging process by impairing circadian homeostasis. I will examine the experimental evidence indicating that AhR signaling is able to promote the age-related degeneration via a disruption of circadian rhythmicity.
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Affiliation(s)
- Antero Salminen
- Department of Neurology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland.
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5
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Zhu J, Li G, Huang Q, Wen J, Deng Y, Jiang J. TET3-mediated DNA demethylation and chromatin remodeling regulate T-2 toxin-induced human CYP1A1 expression and cytotoxicity in HepG2 cells. Biochem Pharmacol 2023; 211:115506. [PMID: 36948362 DOI: 10.1016/j.bcp.2023.115506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 03/13/2023] [Accepted: 03/14/2023] [Indexed: 03/24/2023]
Abstract
T-2 toxin is a hazardous environmental pollutant that poses a risk to both farm animals and humans. Our previous research has reported that T-2 toxin highly induced the expression of human cytochrome P450 1A1 (CYP1A1), which may be a representative inducible marker of T-2 toxin and mediate the toxicity of T-2 toxin. In this study, we found that T-2 toxin decreased the DNA methylation levels of the CpG islands on the CYP1A1 promoter by inducing the expression of eleven translocation family protein 3 (TET3) and facilitating its binding to the promoter. These DNA methylation changes then generated an activated chromatin structure on the CYP1A1 promoter by releasing the repressor complex methyl-binding protein 2 (MeCP2) and histone deacetylase 2 (HDAC2), increasing the active histone modification markers, including H3K4ac, H3K9ac and H3K14ac, and facilitating RNA pol II and NRF1/Sp1 recruitment, which ultimately led to the transcriptional activation of CYP1A1. Interestingly, TET3-mediated CYP1A1 induction enhanced the cytotoxicity of T-2 toxin through inhibiting cell proliferation. Our results demonstrate that T-2 toxin-induced CYP1A1 expression is detrimental to cells and clearly show how T-2 toxin inhibits cell proliferation through regulating CYP1A1 expression from an epigenetic perspective. The findings broaden our current knowledge of the epigenetic mechanisms regulating environmental factors-induced CYP1A1 expression and cytotoxicity. TET3 may serve as a potential new target for toxicogenic detoxification.
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Affiliation(s)
- Jiahui Zhu
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou 510642, Guangdong, P. R. China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, Guangdong, P. R. China; Key Laboratory of Zoonosis of the Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou 510642, Guangdong, P. R. China
| | - Guihong Li
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou 510642, Guangdong, P. R. China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, Guangdong, P. R. China; Key Laboratory of Zoonosis of the Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou 510642, Guangdong, P. R. China
| | - Qiang Huang
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou 510642, Guangdong, P. R. China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, Guangdong, P. R. China; Key Laboratory of Zoonosis of the Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou 510642, Guangdong, P. R. China
| | - Jikai Wen
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou 510642, Guangdong, P. R. China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, Guangdong, P. R. China; Key Laboratory of Zoonosis of the Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou 510642, Guangdong, P. R. China
| | - Yiqun Deng
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou 510642, Guangdong, P. R. China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, Guangdong, P. R. China; Key Laboratory of Zoonosis of the Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou 510642, Guangdong, P. R. China.
| | - Jun Jiang
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou 510642, Guangdong, P. R. China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, Guangdong, P. R. China; Key Laboratory of Zoonosis of the Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou 510642, Guangdong, P. R. China.
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6
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Abudahab S, Price ET, Dozmorov MG, Deshpande LS, McClay JL. The Aryl Hydrocarbon Receptor, Epigenetics and the Aging Process. J Nutr Health Aging 2023; 27:291-300. [PMID: 37170437 PMCID: PMC10947811 DOI: 10.1007/s12603-023-1908-1] [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] [Indexed: 05/13/2023]
Abstract
The aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor, classically associated with the regulation of xenobiotic metabolism in response to environmental toxins. In recent years, transgenic rodent models have implicated AhR in aging and longevity. Moreover, several AhR ligands, such as resveratrol and quercetin, are compounds proven to extend the lifespan of model organisms. In this paper, we first review AhR biology with a focus on aging and highlight several AhR ligands with potential anti-aging properties. We outline how AhR-driven expression of xenobiotic metabolism genes into old age may be a key mechanism through which moderate induction of AhR elicits positive benefits on longevity and healthspan. Furthermore, via integration of publicly available datasets, we show that liver-specific AhR target genes are enriched among genes subject to epigenetic aging. Changes to epigenetic states can profoundly affect transcription factor binding and are a hallmark of the aging process. We suggest that the interplay between AhR and epigenetic aging should be the subject of future research and outline several key gaps in the current literature. Finally, we recommend that a broad range of non-toxic AhR ligands should be investigated for their potential to promote healthspan and longevity.
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Affiliation(s)
- S Abudahab
- Sara Abudahab, Smith Building, 410 North 12th Street, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA 23298-0533, USA.
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7
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Iizuka T, Yin P, Zuberi A, Kujawa S, Coon JS, Björvang RD, Damdimopoulou P, Pacyga DC, Strakovsky RS, Flaws JA, Bulun SE. Mono-(2-ethyl-5-hydroxyhexyl) phthalate promotes uterine leiomyoma cell survival through tryptophan-kynurenine-AHR pathway activation. Proc Natl Acad Sci U S A 2022; 119:e2208886119. [PMID: 36375056 PMCID: PMC9704719 DOI: 10.1073/pnas.2208886119] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 10/03/2022] [Indexed: 11/15/2022] Open
Abstract
Uterine leiomyoma is the most common tumor in women and causes severe morbidity in 15 to 30% of reproductive-age women. Epidemiological studies consistently indicate a correlation between leiomyoma development and exposure to endocrine-disrupting chemical phthalates, especially di-(2-ethylhexyl) phthalate (DEHP); however, the underlying mechanisms are unknown. Here, among the most commonly encountered phthalate metabolites, we found the strongest association between the urine levels of mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), the principal DEHP metabolite, and the risk of uterine leiomyoma diagnosis (n = 712 patients). The treatment of primary leiomyoma and smooth muscle cells (n = 29) with various mixtures of phthalate metabolites, at concentrations equivalent to those detected in urine samples, significantly increased cell viability and decreased apoptosis. MEHHP had the strongest effects on both cell viability and apoptosis. MEHHP increased cellular tryptophan and kynurenine levels strikingly and induced the expression of the tryptophan transporters SLC7A5 and SLC7A8, as well as, tryptophan 2,3-dioxygenase (TDO2), the key enzyme catalyzing the conversion of tryptophan to kynurenine that is the endogenous ligand of aryl hydrocarbon receptor (AHR). MEHHP stimulated nuclear localization of AHR and up-regulated the expression of CYP1A1 and CYP1B1, two prototype targets of AHR. siRNA knockdown or pharmacological inhibition of SLC7A5/SLC7A8, TDO2, or AHR abolished MEHHP-mediated effects on leiomyoma cell survival. These findings indicate that MEHHP promotes leiomyoma cell survival by activating the tryptophan-kynurenine-AHR pathway. This study pinpoints MEHHP exposure as a high-risk factor for leiomyoma growth, uncovers a mechanism by which exposure to environmental phthalate impacts leiomyoma pathogenesis, and may lead to the development of novel druggable targets.
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Affiliation(s)
- Takashi Iizuka
- Division of Reproductive Science in Medicine, Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60610
| | - Ping Yin
- Division of Reproductive Science in Medicine, Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60610
| | - Azna Zuberi
- Division of Reproductive Science in Medicine, Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60610
| | - Stacy Kujawa
- Division of Reproductive Science in Medicine, Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60610
| | - John S. Coon
- Division of Reproductive Science in Medicine, Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60610
| | - Richelle D. Björvang
- Division of Obstetrics and Gynecology, Department of Clinical Science, Intervention and Technology, Karolinska Institute and Karolinska University Hospital, 171 64 Stockholm, Sweden
| | - Pauliina Damdimopoulou
- Division of Obstetrics and Gynecology, Department of Clinical Science, Intervention and Technology, Karolinska Institute and Karolinska University Hospital, 171 64 Stockholm, Sweden
| | - Diana C. Pacyga
- Department of Food Science and Human Nutrition, Institute for Integrative Toxicology, Michigan State University, East Lansing, MI 48824
| | - Rita S. Strakovsky
- Department of Food Science and Human Nutrition, Institute for Integrative Toxicology, Michigan State University, East Lansing, MI 48824
| | - Jodi A. Flaws
- Department of Comparative Bioscience, University of Illinois at Urbana–Champagne, Urbana, IL 61802
| | - Serdar E. Bulun
- Division of Reproductive Science in Medicine, Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60610
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8
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Re DB, Yan B, Calderón-Garcidueñas L, Andrew AS, Tischbein M, Stommel EW. A perspective on persistent toxicants in veterans and amyotrophic lateral sclerosis: identifying exposures determining higher ALS risk. J Neurol 2022; 269:2359-2377. [PMID: 34973105 PMCID: PMC9021134 DOI: 10.1007/s00415-021-10928-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 11/30/2021] [Accepted: 12/01/2021] [Indexed: 02/07/2023]
Abstract
Multiple studies indicate that United States veterans have an increased risk of developing amyotrophic lateral sclerosis (ALS) compared to civilians. However, the responsible etiological factors are unknown. In the general population, specific occupational (e.g. truck drivers, airline pilots) and environmental exposures (e.g. metals, pesticides) are associated with an increased ALS risk. As such, the increased prevalence of ALS in veterans strongly suggests that there are exposures experienced by military personnel that are disproportionate to civilians. During service, veterans may encounter numerous neurotoxic exposures (e.g. burn pits, engine exhaust, firing ranges). So far, however, there is a paucity of studies investigating environmental factors contributing to ALS in veterans and even fewer assessing their exposure using biomarkers. Herein, we discuss ALS pathogenesis in relation to a series of persistent neurotoxicants (often emitted as mixtures) including: chemical elements, nanoparticles and lipophilic toxicants such as dioxins, polycyclic aromatic hydrocarbons and polychlorinated biphenyls. We propose these toxicants should be directly measured in veteran central nervous system tissue, where they may have accumulated for decades. Specific toxicants (or mixtures thereof) may accelerate ALS development following a multistep hypothesis or act synergistically with other service-linked exposures (e.g. head trauma/concussions). Such possibilities could explain the lower age of onset observed in veterans compared to civilians. Identifying high-risk exposures within vulnerable populations is key to understanding ALS etiopathogenesis and is urgently needed to act upon modifiable risk factors for military personnel who deserve enhanced protection during their years of service, not only for their short-term, but also long-term health.
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Affiliation(s)
- Diane B Re
- Department of Environmental Health Science, Center for Motor Neuron Biology and Disease, Columbia University, New York, NY, USA
| | - Beizhan Yan
- Department of Geochemistry, Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, USA
| | - Lilian Calderón-Garcidueñas
- Department Biomedical Sciences, College of Health, University of Montana, Missoula, MT, USA
- Universidad del Valle de México, Mexico City, Mexico
| | - Angeline S Andrew
- Department of Neurology, Geisel School of Medicine at Dartmouth, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA
| | - Maeve Tischbein
- Department of Neurology, Geisel School of Medicine at Dartmouth, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA
| | - Elijah W Stommel
- Department of Neurology, Geisel School of Medicine at Dartmouth, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA.
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9
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Habano W, Miura T, Terashima J, Ozawa S. Aryl hydrocarbon receptor as a DNA methylation reader in the stress response pathway. Toxicology 2022; 470:153154. [PMID: 35301058 DOI: 10.1016/j.tox.2022.153154] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 01/31/2022] [Accepted: 03/10/2022] [Indexed: 10/18/2022]
Abstract
The aryl hydrocarbon receptor (AhR) mediates various cellular responses upon exposure to exogenous and endogenous stress factors. In these responses, AhR plays a dual role as a stress sensor for detecting various AhR ligands and as a transcription factor that upregulates the expression of downstream effector genes, such as those encoding drug-metabolizing enzymes. As a transcription factor, it selectively binds to the unmethylated form of a specific sequence called the xenobiotic responsive element (XRE). We suggest that AhR is a novel DNA methylation reader, unlike classical methylation readers, such as methyl-CpG-binding protein 2, which binds to methylated sequences. Under physiological conditions of continuous exposure to endogenous AhR ligands, such as kynurenine, methylation states of the individual target XREs must be strictly regulated to select and coordinate the expression of downstream genes responsible for maintaining homeostasis in the body. In contrast, long-term exposure to AhR ligands frequently leads to changes in the methylation patterns around the XRE sequence. These data indicate that AhR may contribute to the adaptive cellular response to various stresses by modulating DNA methylation. Thus, the DNA methylation profile of AhR target genes should be dynamically controlled through a balance between robustness and flexibility under both physiological and stress conditions. AhR is a pivotal player in the regulation of stress response as it shows versatility by functioning as a stress sensor, methylation reader, and putative methylation modulator.
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Affiliation(s)
- Wataru Habano
- Division of Pharmacodynamics and Molecular Genetics, Department of Clinical Pharmaceutical Sciences, School of Pharmacy, Iwate Medical University, Shiwa 028-3694, Iwate, Japan.
| | - Toshitaka Miura
- Division of Pharmacodynamics and Molecular Genetics, Department of Clinical Pharmaceutical Sciences, School of Pharmacy, Iwate Medical University, Shiwa 028-3694, Iwate, Japan
| | - Jun Terashima
- Division of Pharmacodynamics and Molecular Genetics, Department of Clinical Pharmaceutical Sciences, School of Pharmacy, Iwate Medical University, Shiwa 028-3694, Iwate, Japan
| | - Shogo Ozawa
- Division of Pharmacodynamics and Molecular Genetics, Department of Clinical Pharmaceutical Sciences, School of Pharmacy, Iwate Medical University, Shiwa 028-3694, Iwate, Japan
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10
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Aluru N, Engelhardt J. OUP accepted manuscript. Toxicol Sci 2022; 188:75-87. [PMID: 35477799 PMCID: PMC9237993 DOI: 10.1093/toxsci/kfac044] [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] [Indexed: 11/13/2022] Open
Abstract
Exposure to environmental toxicants during preconception has been shown to affect offspring health and epigenetic mechanisms such as DNA methylation are hypothesized to be involved in adverse outcomes. However, studies addressing the effects of exposure to environmental toxicants during preconception on epigenetic changes in gametes are limited. The objective of this study is to determine the effect of preconceptional exposure to a dioxin-like polychlorinated biphenyl (3,3',4,4',5-pentachlorobiphenyl [PCB126]) on DNA methylation and gene expression in testis. Adult zebrafish were exposed to 3 and 10 nM PCB126 for 24 h and testis tissue was sampled at 7 days postexposure for histology, DNA methylation, and gene expression profiling. Reduced representation bisulfite sequencing revealed 37 and 92 differentially methylated regions (DMRs) in response to 3 and 10 nM PCB126 exposures, respectively. Among them, 19 DMRs were found to be common between both PCB126 treatment groups. Gene ontology (GO) analysis of DMRs revealed that enrichment of terms such as RNA processing, iron-sulfur cluster assembly, and gluconeogenesis. Gene expression profiling showed differential expression of 40 and 1621 genes in response to 3 and 10 nM PCB126 exposures, respectively. GO analysis of differentially expressed genes revealed enrichment of terms related to xenobiotic metabolism, oxidative stress, and immune function. There is no overlap in the GO terms or individual genes between DNA methylation and RNA sequencing results, but functionally many of the altered pathways have been shown to cause spermatogenic defects.
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Affiliation(s)
| | - Jan Engelhardt
- Bioinformatics Group, Department of Computer Science and Interdisciplinary Center for Bioinformatics, University of Leipzig, Leipzig D-04107, Germany
- Department of Evolutionary Biology, University of Vienna, Vienna A-1030, Austria
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11
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Jiang J, Zhu J, Liu Q, Zhang T, Wen J, Xia J, Deng Y. Role of DNA methylation-related chromatin remodeling in aryl hydrocarbon receptor-dependent regulation of T-2 toxin highly inducible Cytochrome P450 1A4 gene. FASEB J 2021; 35:e21469. [PMID: 33788981 DOI: 10.1096/fj.202002570rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 02/05/2021] [Accepted: 02/08/2021] [Indexed: 11/11/2022]
Abstract
Mycotoxins are toxic secondary metabolites produced by food-contaminating fungi, which lead to global epigenetic changes and cause toxicity to both farm animals and humans. However, whether mycotoxins induce gene-specific epigenetic alterations associated with inducible downstream gene expression is unclear as are the underlying regulatory mechanisms. Here, we found that T-2 toxin and its deacetylated metabolites but not deoxynivalenol (DON) or other representative mycotoxins highly induced the expression of cytochrome P450 1A4 (CYP1A4) in both Leghorn male hepatoma (LMH) cells and chicken primary hepatocytes, and this effect was related to the regulation of both aryl hydrocarbon receptor (AhR) and DNA methylation. We used methylation-sensitive restriction enzyme digestion-qPCR (MSRE-qPCR) and chromatin immunoprecipitation (ChIP) assays and found that the binding of DNA methyltransferase 1 (DNMT1) and histone deacetylase 2 (HDAC2) to highly methylated CpG island 3-2 at the enhancer of CYP1A4 was accompanied by the recruitment of the repressive histone modification marker H3K27me3, inducing a silent state. In turn, T-2 toxin stimulation enriched the binding of AhR to demethylated CpG island 3-2, which facilitated p300 and H3K9ac recruitment and ultimately generated an activated chromatin structure at the enhancer by increasing the active histone modification markers, including H3K4me3, H3K27ac, and H3K14ac. Interestingly, T-2 toxin-induced AhR activation also facilitated RNA polymerase II binding to CpG island 2, which may form a transcriptionally active chromatin structure at the promoter and ultimately transactivate CYP1A4. Our findings provide novel insights into the epigenetic regulation of T-2 toxin-induced gene expression.
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Affiliation(s)
- Jun Jiang
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, P.R. China.,Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, P.R. China.,Key Laboratory of Zoonosis of the Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, P.R. China
| | - Jiahui Zhu
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, P.R. China.,Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, P.R. China.,Key Laboratory of Zoonosis of the Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, P.R. China
| | - Qian Liu
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, P.R. China.,Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, P.R. China.,Key Laboratory of Zoonosis of the Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, P.R. China
| | - Tingting Zhang
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, P.R. China.,Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, P.R. China.,Key Laboratory of Zoonosis of the Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, P.R. China
| | - Jikai Wen
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, P.R. China.,Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, P.R. China.,Key Laboratory of Zoonosis of the Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, P.R. China
| | - Jianhong Xia
- Key Laboratory of Regenerative Biology of Chinese Academy of Sciences, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, P.R. China
| | - Yiqun Deng
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, P.R. China.,Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, P.R. China.,Key Laboratory of Zoonosis of the Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, P.R. China
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12
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Weinhouse C. The roles of inducible chromatin and transcriptional memory in cellular defense system responses to redox-active pollutants. Free Radic Biol Med 2021; 170:85-108. [PMID: 33789123 PMCID: PMC8382302 DOI: 10.1016/j.freeradbiomed.2021.03.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 03/12/2021] [Accepted: 03/15/2021] [Indexed: 12/17/2022]
Abstract
People are exposed to wide range of redox-active environmental pollutants. Air pollution, heavy metals, pesticides, and endocrine disrupting chemicals can disrupt cellular redox status. Redox-active pollutants in our environment all trigger their own sets of specific cellular responses, but they also activate a common set of general stress responses that buffer the cell against homeostatic insults. These cellular defense system (CDS) pathways include the heat shock response, the oxidative stress response, the hypoxia response, the unfolded protein response, the DNA damage response, and the general stress response mediated by the stress-activated p38 mitogen-activated protein kinase. Over the past two decades, the field of environmental epigenetics has investigated epigenetic responses to environmental pollutants, including redox-active pollutants. Studies of these responses highlight the role of chromatin modifications in controlling the transcriptional response to pollutants and the role of transcriptional memory, often referred to as "epigenetic reprogramming", in predisposing previously exposed individuals to more potent transcriptional responses on secondary challenge. My central thesis in this review is that high dose or chronic exposure to redox-active pollutants leads to transcriptional memories at CDS target genes that influence the cell's ability to mount protective responses. To support this thesis, I will: (1) summarize the known chromatin features required for inducible gene activation; (2) review the known forms of transcriptional memory; (3) discuss the roles of inducible chromatin and transcriptional memory in CDS responses that are activated by redox-active environmental pollutants; and (4) propose a conceptual framework for CDS pathway responsiveness as a readout of total cellular exposure to redox-active pollutants.
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Affiliation(s)
- Caren Weinhouse
- Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR, 97214, USA.
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13
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Anderson G. Tumour Microenvironment: Roles of the Aryl Hydrocarbon Receptor, O-GlcNAcylation, Acetyl-CoA and Melatonergic Pathway in Regulating Dynamic Metabolic Interactions across Cell Types-Tumour Microenvironment and Metabolism. Int J Mol Sci 2020; 22:E141. [PMID: 33375613 PMCID: PMC7795031 DOI: 10.3390/ijms22010141] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 12/21/2020] [Accepted: 12/22/2020] [Indexed: 02/07/2023] Open
Abstract
This article reviews the dynamic interactions of the tumour microenvironment, highlighting the roles of acetyl-CoA and melatonergic pathway regulation in determining the interactions between oxidative phosphorylation (OXPHOS) and glycolysis across the array of cells forming the tumour microenvironment. Many of the factors associated with tumour progression and immune resistance, such as yin yang (YY)1 and glycogen synthase kinase (GSK)3β, regulate acetyl-CoA and the melatonergic pathway, thereby having significant impacts on the dynamic interactions of the different types of cells present in the tumour microenvironment. The association of the aryl hydrocarbon receptor (AhR) with immune suppression in the tumour microenvironment may be mediated by the AhR-induced cytochrome P450 (CYP)1b1-driven 'backward' conversion of melatonin to its immediate precursor N-acetylserotonin (NAS). NAS within tumours and released from tumour microenvironment cells activates the brain-derived neurotrophic factor (BDNF) receptor, TrkB, thereby increasing the survival and proliferation of cancer stem-like cells. Acetyl-CoA is a crucial co-substrate for initiation of the melatonergic pathway, as well as co-ordinating the interactions of OXPHOS and glycolysis in all cells of the tumour microenvironment. This provides a model of the tumour microenvironment that emphasises the roles of acetyl-CoA and the melatonergic pathway in shaping the dynamic intercellular metabolic interactions of the various cells within the tumour microenvironment. The potentiation of YY1 and GSK3β by O-GlcNAcylation will drive changes in metabolism in tumours and tumour microenvironment cells in association with their regulation of the melatonergic pathway. The emphasis on metabolic interactions across cell types in the tumour microenvironment provides novel future research and treatment directions.
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Affiliation(s)
- George Anderson
- Clinical Research Communications (CRC) Scotland & London, Eccleston Square, London SW1V 6UT, UK
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14
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Ascorbic acid during the suckling period is required for proper DNA demethylation in the liver. Sci Rep 2020; 10:21228. [PMID: 33277554 PMCID: PMC7718234 DOI: 10.1038/s41598-020-77962-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 11/19/2020] [Indexed: 12/12/2022] Open
Abstract
Ascorbic acid (AA, vitamin C) serves as a cofactor for ten-eleven translocation (TET) enzymes and induces DNA demethylation in vitro. However, its role in DNA demethylation in vivo remains unclear. We previously reported that DNA demethylation in the mouse liver was enhanced during the suckling period. Therefore, we hypothesized that DNA demethylation is enhanced in an AA-dependent manner during the suckling period. To examine our hypothesis, we employed wild-type (WT) mice, which synthesize AA, and senescence marker protein-30/gluconolactonase (SMP30/GNL) knockout (KO) mice, which cannot synthesize AA, and analyzed the DNA methylation status in the livers of offspring in both the suckling period and adulthood. SMP30/GNL KO offspring showed DNA hypermethylation in the liver possibly due to low plasma and hepatic AA levels during the suckling period despite the administration of rescue-dose AA to dams. Furthermore, DNA hypermethylation of the fibroblast growth factor 21 gene (Fgf21), a PPARα target gene, persisted into adulthood. In contrast, a high-dose AA administration to SMP30/GNL KO dams during the lactation period restored DNA demethylation in the livers of offspring. Even though a slight increase was observed in plasma AA levels with the administration of rescue-dose AA to WT dams during the gestation and lactation periods, DNA demethylation in the livers of offspring was minimally enhanced. The present results demonstrate that AA intake during the suckling period is required for proper DNA demethylation in the liver.
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15
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de Gannes M, Ko CI, Zhang X, Biesiada J, Niu L, Koch SE, Medvedovic M, Rubinstein J, Puga A. Dioxin Disrupts Dynamic DNA Methylation Patterns in Genes That Govern Cardiomyocyte Maturation. Toxicol Sci 2020; 178:325-337. [PMID: 33017471 DOI: 10.1093/toxsci/kfaa153] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Congenital heart disease (CHD), the leading birth defect worldwide, has a largely unknown etiology, likely to result from complex interactions between genetic and environmental factors during heart development, at a time when the heart adapts to diverse physiological and pathophysiological conditions. Crucial among these is the regulation of cardiomyocyte development and postnatal maturation, governed by dynamic changes in DNA methylation. Previous work from our laboratory has shown that exposure to the environmental toxicant tetrachlorodibenzo-p-dioxin (TCDD) disrupts several molecular networks responsible for heart development and function. To test the hypothesis that the disruption caused by TCDD in the heart results from changes in DNA methylation and gene expression patterns of cardiomyocytes, we established a stable mouse embryonic stem cell line expressing a puromycin resistance selectable marker under control of the cardiomyocyte-specific Nkx2-5 promoter. Differentiation of these cells in the presence of puromycin induces the expression of a large suite of cardiomyocyte-specific markers. To assess the consequences of TCDD treatment on gene expression and DNA methylation in these cardiomyocytes, we subjected them to transcriptome and methylome analyses in the presence of TCDD. Unlike control cardiomyocytes maintained in vehicle, the TCDD-treated cardiomyocytes showed extensive gene expression changes, with a significant correlation between differential RNA expression and DNA methylation in 111 genes, many of which are key elements of pathways that regulate cardiovascular development and function. Our findings provide an important clue toward the elucidation of the complex interactions between genetic and epigenetic mechanisms after developmental TCDD exposure that may contribute to CHD.
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Affiliation(s)
- Matthew de Gannes
- Department of Environmental Health and Center for Environmental Genetics
| | - Chia-I Ko
- Department of Environmental Health and Center for Environmental Genetics
| | - Xiang Zhang
- Department of Environmental Health and Center for Environmental Genetics
| | - Jacek Biesiada
- Department of Environmental Health and Center for Environmental Genetics
| | - Liang Niu
- Department of Environmental Health and Center for Environmental Genetics
| | - Sheryl E Koch
- Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267
| | - Mario Medvedovic
- Department of Environmental Health and Center for Environmental Genetics
| | - Jack Rubinstein
- Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267
| | - Alvaro Puga
- Department of Environmental Health and Center for Environmental Genetics
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16
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Hitzman RT, Dunlap TL, Howell CE, Chen SN, Vollmer G, Pauli GF, Bolton JL, Dietz BM. 6-Prenylnaringenin from Hops Disrupts ERα-Mediated Downregulation of CYP1A1 to Facilitate Estrogen Detoxification. Chem Res Toxicol 2020; 33:2793-2803. [PMID: 32986415 DOI: 10.1021/acs.chemrestox.0c00194] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Botanical dietary supplements (BDS) containing hops are sold as women's health supplements due to the potent hop phytoestrogen, 8-prenylnaringenin (8-PN), and the cytoprotective chalcone, xanthohumol. Previous studies have shown a standardized hop extract to beneficially influence chemical estrogen carcinogenesis in vitro by fostering detoxified 2-hydroxylation over genotoxic 4-hydroxylation estrogen metabolism. In this study, hop extract and its bioactive compounds were investigated for its mechanism of action within the chemical estrogen carcinogenesis pathway, which is mainly mediated through the 4-hydroxylation pathway catalyzed by CYP1B1 that can form gentoxic quinones. Aryl hydrocarbon receptor (AhR) agonists induce CYP1A1 and CYP1B1, while estrogen receptor alpha (ERα) inhibits transcription of CYP1A1, the enzyme responsible for 2-hydroxylated estrogens and the estrogen detoxification pathway. An In-Cell Western MCF-7 cell assay revealed hop extract and 6-prenylnaringenin (6-PN) degraded ERα via an AhR-dependent mechanism. Reverse transcription PCR and xenobiotic response element luciferase assays showed hop extract and 6-PN-mediated activation of AhR and induction of CYP1A1. A reduction in estrogen-mediated DNA (cytosine-5)-methyltransferase 1 (DNMT1) downregulation of CYP1A1 accompanied this activity in a chromatin immunoprecipitation assay. Ultimately, hop extract and 6-PN induced preferential metabolism of estrogens to their detoxified form in vitro. These results suggest that the standardized hop extract and 6-PN activate AhR to attenuate epigenetic inhibition of CYP1A1 through degradation of ERα, ultimately increasing 2-hydroxylated estrogens. A new mechanism of action rationalizes the positive influence of hop BDS and 6-PN on oxidative estrogen metabolism in vitro and, thus, potentially on chemical estrogen carcinogenesis. The findings underscore the importance of elucidating various biological mechanisms of action and standardizing BDS to multiple phytoconstituents for optimal resilience promoting properties.
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Affiliation(s)
- Ryan T Hitzman
- UIC/NIH Center for Botanical Dietary Supplements Research, Program for Collaborative Research in the Pharmaceutical Sciences (PCRPS), and Department of Pharmaceutical Sciences (M/C 781), College of Pharmacy, University of Illinois at Chicago, 833 S. Wood Street, Chicago, Illinois 60612-7231, United States
| | - Tareisha L Dunlap
- UIC/NIH Center for Botanical Dietary Supplements Research, Program for Collaborative Research in the Pharmaceutical Sciences (PCRPS), and Department of Pharmaceutical Sciences (M/C 781), College of Pharmacy, University of Illinois at Chicago, 833 S. Wood Street, Chicago, Illinois 60612-7231, United States
| | - Caitlin E Howell
- UIC/NIH Center for Botanical Dietary Supplements Research, Program for Collaborative Research in the Pharmaceutical Sciences (PCRPS), and Department of Pharmaceutical Sciences (M/C 781), College of Pharmacy, University of Illinois at Chicago, 833 S. Wood Street, Chicago, Illinois 60612-7231, United States
| | - Shao-Nong Chen
- UIC/NIH Center for Botanical Dietary Supplements Research, Program for Collaborative Research in the Pharmaceutical Sciences (PCRPS), and Department of Pharmaceutical Sciences (M/C 781), College of Pharmacy, University of Illinois at Chicago, 833 S. Wood Street, Chicago, Illinois 60612-7231, United States
| | - Günter Vollmer
- UIC/NIH Center for Botanical Dietary Supplements Research, Program for Collaborative Research in the Pharmaceutical Sciences (PCRPS), and Department of Pharmaceutical Sciences (M/C 781), College of Pharmacy, University of Illinois at Chicago, 833 S. Wood Street, Chicago, Illinois 60612-7231, United States.,Department of Biology, Technische Universität Dresden, Dresden, Germany
| | - Guido F Pauli
- UIC/NIH Center for Botanical Dietary Supplements Research, Program for Collaborative Research in the Pharmaceutical Sciences (PCRPS), and Department of Pharmaceutical Sciences (M/C 781), College of Pharmacy, University of Illinois at Chicago, 833 S. Wood Street, Chicago, Illinois 60612-7231, United States
| | - Judy L Bolton
- UIC/NIH Center for Botanical Dietary Supplements Research, Program for Collaborative Research in the Pharmaceutical Sciences (PCRPS), and Department of Pharmaceutical Sciences (M/C 781), College of Pharmacy, University of Illinois at Chicago, 833 S. Wood Street, Chicago, Illinois 60612-7231, United States
| | - Birgit M Dietz
- UIC/NIH Center for Botanical Dietary Supplements Research, Program for Collaborative Research in the Pharmaceutical Sciences (PCRPS), and Department of Pharmaceutical Sciences (M/C 781), College of Pharmacy, University of Illinois at Chicago, 833 S. Wood Street, Chicago, Illinois 60612-7231, United States
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17
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Wajda A, Łapczuk-Romańska J, Paradowska-Gorycka A. Epigenetic Regulations of AhR in the Aspect of Immunomodulation. Int J Mol Sci 2020; 21:E6404. [PMID: 32899152 PMCID: PMC7504141 DOI: 10.3390/ijms21176404] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/27/2020] [Accepted: 08/28/2020] [Indexed: 02/07/2023] Open
Abstract
Environmental factors contribute to autoimmune disease manifestation, and as regarded today, AhR has become an important factor in studies of immunomodulation. Besides immunological aspects, AhR also plays a role in pharmacological, toxicological and many other physiological processes such as adaptive metabolism. In recent years, epigenetic mechanisms have provided new insight into gene regulation and reveal a new contribution to autoimmune disease pathogenesis. DNA methylation, histone modifications, chromatin alterations, microRNA and consequently non-genetic changes in phenotypes connect with environmental factors. Increasing data reveals AhR cross-roads with the most significant in immunology pathways. Although study on epigenetic modulations in autoimmune diseases is still not well understood, therefore future research will help us understand their pathophysiology and help to find new therapeutic strategies. Present literature review sheds the light on the common ground between remodeling chromatin compounds and autoimmune antibodies used in diagnostics. In the proposed review we summarize recent findings that describe epigenetic factors which regulate AhR activity and impact diverse immunological responses and pathological changes.
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Affiliation(s)
- Anna Wajda
- Department of Molecular Biology, National Institute of Geriatrics, Rheumatology and Rehabilitation, 02-637 Warsaw, Poland;
| | - Joanna Łapczuk-Romańska
- Department of Experimental and Clinical Pharmacology, Pomeranian Medical University, 70-111 Szczecin, Poland;
| | - Agnieszka Paradowska-Gorycka
- Department of Molecular Biology, National Institute of Geriatrics, Rheumatology and Rehabilitation, 02-637 Warsaw, Poland;
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18
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Akhtar S, Hourani S, Therachiyil L, Al-Dhfyan A, Agouni A, Zeidan A, Uddin S, Korashy HM. Epigenetic Regulation of Cancer Stem Cells by the Aryl Hydrocarbon Receptor Pathway. Semin Cancer Biol 2020; 83:177-196. [PMID: 32877761 DOI: 10.1016/j.semcancer.2020.08.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/20/2020] [Accepted: 08/23/2020] [Indexed: 12/14/2022]
Abstract
Compelling evidence has demonstrated that tumor bulk comprises distinctive subset of cells generally referred as cancer stem cells (CSCs) that have been proposed as a strong sustainer and promoter of tumorigenesis and therapeutic resistance. These distinguished properties of CSCs have raised interest in understanding the molecular mechanisms that govern the maintenance of these cells. Numerous experimental and epidemiological studies have demonstrated that exposure to environmental toxins such as the polycyclic aromatic hydrocarbons (PAHs) is strongly involved in cancer initiation and progression. The PAH-induced carcinogenesis is shown to be mediated through the activation of a cytosolic receptor, aryl hydrocarbon receptor (AhR)/Cytochrome P4501A pathway, suggesting a possible direct link between AhR and CSCs. Several recent studies have investigated the role of AhR in CSCs self-renewal and maintenance, however the molecular mechanisms and particularly the epigenetic regulations of CSCs by the AhR/CYP1A pathway have not been reviewed before. In this review, we first summarize the crosstalk between AhR and cancer genetics, with a particular emphasis on the mechanisms relevant to CSCs such as Wnt/β-catenin, Notch, NF-κB, and PTEN-PI3K/Akt signaling pathways. The second part of this review discusses the recent advances and studies highlighting the epigenetic mechanisms mediated by the AhR/CYP1A pathway that control CSC gene expression, self-renewal, and chemoresistance in various human cancers. Furthermore, the review also sheds light on the importance of targeting the epigenetic pathways as a novel therapeutic approach against CSCs.
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Affiliation(s)
- Sabah Akhtar
- Department of Pharmaceutical Sciences, College of Pharmacy, QU Health, Qatar University, Doha, Qatar
| | - Shireen Hourani
- Department of Pharmaceutical Sciences, College of Pharmacy, QU Health, Qatar University, Doha, Qatar
| | - Lubna Therachiyil
- Department of Pharmaceutical Sciences, College of Pharmacy, QU Health, Qatar University, Doha, Qatar; Translational Research Institute, Academic Health System, Hamad Medical Corporation, Doha, Qatar
| | - Abdullah Al-Dhfyan
- Stem Cell & Tissue Re-Engineering, King Faisal Specialist Hospital and Research Centre, Riyadh, 11211, Saudi Arabia
| | - Abdelali Agouni
- Department of Pharmaceutical Sciences, College of Pharmacy, QU Health, Qatar University, Doha, Qatar
| | - Asad Zeidan
- Department of Biomedical Sciences, College of Medicine, QU Health, Qatar University, Doha, Qatar
| | - Shahab Uddin
- Translational Research Institute, Academic Health System, Hamad Medical Corporation, Doha, Qatar
| | - Hesham M Korashy
- Department of Pharmaceutical Sciences, College of Pharmacy, QU Health, Qatar University, Doha, Qatar.
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19
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Giampaolino P, Della Corte L, Foreste V, Barra F, Ferrero S, Bifulco G. Dioxin and endometriosis: a new possible relation based on epigenetic theory. Gynecol Endocrinol 2020; 36:279-284. [PMID: 31805795 DOI: 10.1080/09513590.2019.1698024] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Endometriosis is a chronic disease characterized by the growth of endometrial-like glands and stroma outside the uterine cavity. Nowadays, the exact etiology of endometriosis is unclear and the interaction between a variety of environmental physical and chemical compounds may potentially promote the disease in women with an individual susceptibility. The first demonstration of a relation between an environmental factor and endometriosis was obtained with the chronic dietary exposure of a primate colony to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Besides the well-known dioxin's pathway of action, several papers are focusing on the role of epigenetic mechanisms, a way through which the genome responds to the environment and can lead to permanent changes in gene expression until affecting the phenotypes or cause disease. In this review, we focus on the possible role of dioxin epigenetics modification in endometriosis.
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Affiliation(s)
| | - Luigi Della Corte
- Department of Neuroscience, Reproductive Sciences and Dentistry, School of Medicine, University of Naples Federico II, Naples, Italy
| | - Virginia Foreste
- Department of Neuroscience, Reproductive Sciences and Dentistry, School of Medicine, University of Naples Federico II, Naples, Italy
| | - Fabio Barra
- Academic Unit of Obstetrics and Gynecology, Ospedale Policlinico San Martino, Genoa, Italy
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DiNOGMI), University of Genoa, Genoa, Italy
| | - Simone Ferrero
- Academic Unit of Obstetrics and Gynecology, Ospedale Policlinico San Martino, Genoa, Italy
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DiNOGMI), University of Genoa, Genoa, Italy
| | - Giuseppe Bifulco
- Department of Neuroscience, Reproductive Sciences and Dentistry, School of Medicine, University of Naples Federico II, Naples, Italy
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20
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Ectopic Methylation of a Single Persistently Unmethylated CpG in the Promoter of the Vitellogenin Gene Abolishes Its Inducibility by Estrogen through Attenuation of Upstream Stimulating Factor Binding. Mol Cell Biol 2019; 39:MCB.00436-19. [PMID: 31548262 DOI: 10.1128/mcb.00436-19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 09/15/2019] [Indexed: 01/02/2023] Open
Abstract
The enhancer/promoter of the vitellogenin II gene (VTG) has been extensively studied as a model system of vertebrate transcriptional control. While deletion mutagenesis and in vivo footprinting identified the transcription factor (TF) binding sites governing its tissue specificity, DNase hypersensitivity and DNA methylation studies revealed the epigenetic changes accompanying its hormone-dependent activation. Moreover, upon induction with estrogen (E2), the region flanking the estrogen-responsive element (ERE) was reported to undergo active DNA demethylation. We now show that although the VTG ERE is methylated in embryonic chicken liver and in LMH/2A hepatocytes, its induction by E2 was not accompanied by extensive demethylation. In contrast, E2 failed to activate a VTG enhancer/promoter-controlled luciferase reporter gene methylated by SssI. Surprisingly, this inducibility difference could be traced not to the ERE but rather to a single CpG in an E-box (CACGTG) sequence upstream of the VTG TATA box, which is unmethylated in vivo but methylated by SssI. We demonstrate that this E-box binds the upstream stimulating factor USF1/2. Selective methylation of the CpG within this binding site with an E-box-specific DNA methyltransferase, Eco72IM, was sufficient to attenuate USF1/2 binding in vitro and abolish the hormone-induced transcription of the VTG gene in the reporter system.
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21
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Ye W, Chen R, Chen X, Huang B, Lin R, Xie X, Chen J, Jiang J, Deng Y, Wen J. AhR regulates the expression of human cytochrome P450 1A1 (CYP1A1) by recruiting Sp1. FEBS J 2019; 286:4215-4231. [PMID: 31199573 DOI: 10.1111/febs.14956] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 04/09/2019] [Accepted: 06/11/2019] [Indexed: 12/28/2022]
Abstract
Cytochrome P450 1A1 (CYP1A1) is abundant in the kidney, liver, and intestine and is involved in the phase I metabolism of numerous endogenous and exogenous compounds. Therefore, exploring the regulatory mechanism of its basal expression in humans is particularly important to understand the bioactivation of several procarcinogens to their carcinogenic derivatives. Site-specific mutagenesis and deletion of the transcription factor binding site determined the core cis-acting elements in the human CYP1A1 proximal and distal promoter regions. The proximal promoter region [overlapping xenobiotic-responsive element (XRE) and GC box sequences] determined the basal expression of CYP1A1. In human hepatocellular carcinoma cells (HepG2) with aryl hydrocarbon receptor (AhR) or specificity protein 1 (Sp1) knockdown, we confirmed that AhR and Sp1 are involved in basal CYP1A1 expression. In HepG2 cells overexpressing either AhR or Sp1, AhR determined the proximal transactivation of basal CYP1A1 expression. Via DNA affinity precipitation assays and ChIP, we found that AhR bound to the promoter and recruited Sp1 to transactivate CYP1A1 expression. The coordinated interaction between Sp1 and AhR was identified to be DNA mediated. Our work revealed a basal regulatory mechanism of an interesting human gene by which AhR interacts with Sp1 through DNA and recruits Sp1 to regulate basal CYP1A1 expression.
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Affiliation(s)
- Wenchu Ye
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University Guangzhou, Guangzhou, Guangdong, 510642, China
- Key Laboratory of Zoonosis of Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, Guangdong, 510642, China
| | - Ruohong Chen
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University Guangzhou, Guangzhou, Guangdong, 510642, China
- Key Laboratory of Zoonosis of Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, Guangdong, 510642, China
| | - Xiaoxuan Chen
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University Guangzhou, Guangzhou, Guangdong, 510642, China
- Key Laboratory of Zoonosis of Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, Guangdong, 510642, China
| | - Boyan Huang
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University Guangzhou, Guangzhou, Guangdong, 510642, China
- Key Laboratory of Zoonosis of Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, Guangdong, 510642, China
| | - Ruqin Lin
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University Guangzhou, Guangzhou, Guangdong, 510642, China
- Key Laboratory of Zoonosis of Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, Guangdong, 510642, China
| | - Xuan Xie
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University Guangzhou, Guangzhou, Guangdong, 510642, China
- Key Laboratory of Zoonosis of Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, Guangdong, 510642, China
| | - Jiongjie Chen
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University Guangzhou, Guangzhou, Guangdong, 510642, China
- Key Laboratory of Zoonosis of Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, Guangdong, 510642, China
| | - Jun Jiang
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University Guangzhou, Guangzhou, Guangdong, 510642, China
- Key Laboratory of Zoonosis of Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, Guangdong, 510642, China
| | - Yiqun Deng
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University Guangzhou, Guangzhou, Guangdong, 510642, China
- Key Laboratory of Zoonosis of Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, Guangdong, 510642, China
| | - Jikai Wen
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University Guangzhou, Guangzhou, Guangdong, 510642, China
- Key Laboratory of Zoonosis of Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, Guangdong, 510642, China
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22
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Differential methylation pattern of xenobiotic metabolizing genes and susceptibility to Balkan endemic nephropathy, in a cohort of Romanian patients. J Nephrol 2019; 33:91-100. [DOI: 10.1007/s40620-019-00621-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 06/13/2019] [Indexed: 01/20/2023]
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23
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Akemann C, Meyer DN, Gurdziel K, Baker TR. Developmental Dioxin Exposure Alters the Methylome of Adult Male Zebrafish Gonads. Front Genet 2019; 9:719. [PMID: 30687390 PMCID: PMC6336703 DOI: 10.3389/fgene.2018.00719] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Accepted: 12/21/2018] [Indexed: 01/20/2023] Open
Abstract
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a persistent environmental toxicant and endocrine disrupting compound with reproductive and developmental effects in humans and model organisms, including zebrafish. Our previous microarray and histological studies found defects in spermatogenesis and fertility of zebrafish in response to acute developmental TCDD exposure. These effects are apparent following exposure during reproductive development, modeling fetal basis of adult-onset disease. Some outcomes of these previous studies (reduced fertility, changes in sex ratio, transcriptomic alterations) are also transgenerational – persisting to unexposed generations – through the male germline. We hypothesized that DNA methylation could be a possible mechanism for these reproductive effects and performed whole genome bisulfite sequencing (WGBS), which identifies whole genome DNA methylation status at the base pair level, on testes of adult zebrafish exposed to TCDD (two separate hour-long exposures to 50 pg/mL TCDD at 3 and 7 weeks post fertilization). In response to TCDD exposure, multiple genes were differentially methylated; many of which are involved in reproductive processes or epigenetic modifications, suggesting a role of DNA methylation in later-life health outcomes. Additionally, several differentially methylated genes corresponded with gene expression changes identified in TCDD-exposed zebrafish testes, indicating a potential link between DNA methylation and gene expression. Ingenuity pathway analysis of WGBS and microarray data revealed genes involved in reproductive processes and development, RNA regulation, the cell cycle, and cellular morphology and development. We conclude that site-specific changes in DNA methylation of adult zebrafish testes occur in response to acute developmental TCDD exposure.
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Affiliation(s)
- Camille Akemann
- Department of Pharmacology, Wayne State University, Detroit, MI, United States
| | - Danielle N Meyer
- Department of Pharmacology, Wayne State University, Detroit, MI, United States.,Institute of Environmental Health Sciences, Wayne State University, Detroit, MI, United States
| | - Katherine Gurdziel
- Applied Genome Technology Center, School of Medicine, Wayne State University, Detroit, MI, United States
| | - Tracie R Baker
- Department of Pharmacology, Wayne State University, Detroit, MI, United States.,Institute of Environmental Health Sciences, Wayne State University, Detroit, MI, United States
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24
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Patrizi B, Siciliani de Cumis M. TCDD Toxicity Mediated by Epigenetic Mechanisms. Int J Mol Sci 2018; 19:ijms19124101. [PMID: 30567322 PMCID: PMC6320947 DOI: 10.3390/ijms19124101] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 12/11/2018] [Accepted: 12/14/2018] [Indexed: 12/27/2022] Open
Abstract
Dioxins are highly toxic and persistent halogenated organic pollutants belonging to two families i.e., Polychlorinated Dibenzo-p-Dioxins (PCDDs) and Polychlorinated Dibenzo Furans (PCDFs). They can cause cancer, reproductive and developmental issues, damage to the immune system, and can deeply interfere with the endocrine system. Dioxins toxicity is mediated by the Aryl-hydrocarbon Receptor (AhR) which mediates the cellular metabolic adaptation to these planar aromatic xenobiotics through the classical transcriptional regulation pathway, including AhR binding of ligand in the cytosol, translocation of the receptor to the nucleus, dimerization with the AhR nuclear translocator, and the binding of this heterodimeric transcription factor to dioxin-responsive elements which regulate the expression of genes involved in xenobiotic metabolism. 2,3,7,8-TCDD is the most toxic among dioxins showing the highest affinity toward the AhR receptor. Beside this classical and well-studied pathway, a number of papers are dealing with the role of epigenetic mechanisms in the response to environmental xenobiotics. In this review, we report on the potential role of epigenetic mechanisms in dioxins-induced cellular response by inspecting recent literature and focusing our attention on epigenetic mechanisms induced by the most toxic 2,3,7,8-TCDD.
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Affiliation(s)
- Barbara Patrizi
- National Institute of Optics-National Research Council (INO-CNR), Via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy.
- European Laboratory for Non-Linear Spectroscopy (LENS), Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy.
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25
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Xie X, Jiang J, Ye W, Chen R, Deng Y, Wen J. Sp1, Instead of AhR, Regulates the Basal Transcription of Porcine CYP1A1 at the Proximal Promoter. Front Pharmacol 2018; 9:927. [PMID: 30174605 PMCID: PMC6107784 DOI: 10.3389/fphar.2018.00927] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2018] [Accepted: 07/30/2018] [Indexed: 12/31/2022] Open
Abstract
Pigs are commonly used as an animal model to evaluate the toxic effects of exogenous compounds. Cytochrome P450 1A1 (CYP1A1) metabolizes numerous exogenous compounds and is abundantly expressed in the liver, kidneys, and intestines. The high amino acid similarity between human and porcine CYP1A1 indicates that they probably have the same metabolic characteristics. Therefore, understanding the regulatory mechanism of CYP1A1 expression in pigs is particularly important for predicting the toxicology and metabolic kinetics of exogenous chemicals. Currently, the transcriptional regulation of porcine CYP1A1 has rarely been studied, especially regarding basal transcription. In this study, we first confirmed that the key regulatory elements of porcine CYP1A1 basal transactivation are in the proximal promoter region using promoter truncation analysis via a dual luciferase assay in a porcine kidney cell line LLC-PK1. Two overlapping cis-elements, the xenobiotic response element (XRE) and GC box, in this proximal region potentially play key roles in the basal transactivation of porcine CYP1A1. Furthermore, using electrophoretic mobility shift assay and chromatin immunoprecipitation, the GC box binding protein Sp1 was confirmed to bind to the proximal promoter of porcine CYP1A1, instead of AhR, the XRE binding protein. In LLC-PK1 cells, by knocking down either Sp1 or AhR, the expression of porcine CYP1A1 at the mRNA level and protein level was significantly downregulated, suggesting both proteins are important for porcine CYP1A1 expression. However, promoter activity analysis in LLC-PK1 cells treated with an AhR agonist and antagonist confirmed that AhR does not participate in the basal regulation of porcine CYP1A1 at the proximal promoter. In conclusion, our study revealed that the proximal promoter is the key regulatory region for porcine CYP1A1 basal expression. Although AhR plays an important role in the transactivation of porcine CYP1A1 expression, the key determinant transcription factor for its basal transactivation is Sp1 at the proximal promoter of porcine CYP1A1.
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Affiliation(s)
- Xuan Xie
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, China.,Key Laboratory of Zoonosis of Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, China
| | - Jun Jiang
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, China.,Key Laboratory of Zoonosis of Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, China
| | - Wenchu Ye
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, China.,Key Laboratory of Zoonosis of Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, China
| | - Ruohong Chen
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, China.,Key Laboratory of Zoonosis of Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, China
| | - Yiqun Deng
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, China.,Key Laboratory of Zoonosis of Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, China
| | - Jikai Wen
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, China.,Key Laboratory of Zoonosis of Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, China
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Aiba T, Saito T, Hayashi A, Sato S, Yunokawa H, Maruyama T, Fujibuchi W, Ohsako S. Does the prenatal bisphenol A exposure alter DNA methylation levels in the mouse hippocampus?: An analysis using a high-sensitivity methylome technique. Genes Environ 2018; 40:12. [PMID: 29881475 PMCID: PMC5985587 DOI: 10.1186/s41021-018-0099-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 04/11/2018] [Indexed: 12/31/2022] Open
Abstract
Background There is still considerable debate about the effects of exposure to bisphenol A (BPA) an endocrine disrupter at low doses. Recently, many studies using animal models have shown that prenatal BPA exposure induces behavioral and neuronal disorders due to epigenetic changes in the brain. However, striking evidence of epigenomic changes has to be shown. Methods To investigate whether low-dose BPA exposure in the fetal stage can alter CpG methylation levels in the central nervous system, the hippocampus of the inbred C57BL/6 J mouse as the target tissue was collected to detect alterations in CpG methylation levels using a highly sensitive method of genome-wide DNA methylation analysis, methylated site display-amplified fragment length polymorphism (MSD-AFLP). Results BPA showed the sex-hormone like effects on male reproductive organs. Although we examined the methylation levels of 43,840 CpG sites in the control and BPA (200 μg/kg/day)-treated group (6 mice per group), we found no statistically significant changes in methylation levels in any CpG sites. Conclusions At least under the experimental condition in this study, it is considered that the effect of low-dose BPA exposure during the fetal stage on hippocampal DNA methylation levels is extremely small.
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Affiliation(s)
- Toshiki Aiba
- 1Laboratory of Environmental Health Science, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8654 Japan.,2Department of Radiation Effects Research, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555 Japan
| | - Toshiyuki Saito
- 2Department of Radiation Effects Research, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555 Japan
| | - Akiko Hayashi
- 2Department of Radiation Effects Research, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555 Japan
| | - Shinji Sato
- Maze, Inc, 1-2-17 Sennincho, Hachioji-shi, Tokyo, 193-0835 Japan
| | | | - Toru Maruyama
- 4Center for iPS Cell Research and Application, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto, 606-8507 Japan
| | - Wataru Fujibuchi
- 4Center for iPS Cell Research and Application, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto, 606-8507 Japan
| | - Seiichiroh Ohsako
- 1Laboratory of Environmental Health Science, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8654 Japan
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27
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Kawahori K, Hashimoto K, Yuan X, Tsujimoto K, Hanzawa N, Hamaguchi M, Kase S, Fujita K, Tagawa K, Okazawa H, Nakajima Y, Shibusawa N, Yamada M, Ogawa Y. Mild Maternal Hypothyroxinemia During Pregnancy Induces Persistent DNA Hypermethylation in the Hippocampal Brain-Derived Neurotrophic Factor Gene in Mouse Offspring. Thyroid 2018; 28:395-406. [PMID: 29415629 DOI: 10.1089/thy.2017.0331] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND Thyroid hormones are essential for normal development of the central nervous system (CNS). Experimental rodents have shown that even a subtle thyroid hormone insufficiency in circulating maternal thyroid hormones during pregnancy may adversely affect neurodevelopment in offspring, resulting in irreversible cognitive deficits. This may be due to the persistent reduced expression of the hippocampal brain-derived neurotrophic factor gene Bdnf, which plays a crucial role in CNS development. However, the underlying molecular mechanisms remain unclear. METHODS Thiamazole (MMI; 0.025% [w/v]) was administered to dams from two weeks prior to conception until delivery, which succeeded in inducing mild maternal hypothyroxinemia during pregnancy. Serum thyroid hormone and thyrotropin levels of the offspring derived from dams with mild maternal hypothyroxinemia (M offspring) and the control offspring (C offspring) were measured. At 70 days after birth, several behavior tests were performed on the offspring. Gene expression and DNA methylation status were also evaluated in the promoter region of Bdnf exon IV, which is largely responsible for neural activity-dependent Bdnf gene expression, in the hippocampus of the offspring at day 28 and day 70. RESULTS No significant differences in serum thyroid hormone or thyrotropin levels were found between M and C offspring at day 28 and day 70. M offspring showed an impaired learning capacity in the behavior tests. Hippocampal steady-state Bdnf exon IV expression was significantly weaker in M offspring than it was in C offspring at day 28. At day 70, hippocampal Bdnf exon IV expression at the basal level was comparable between M and C offspring. However, it was significantly weaker in M offspring than in C offspring after the behavior tests. Persistent DNA hypermethylation was also found in the promoter region of Bdnf exon IV in the hippocampus of M offspring compared to that of C offspring, which may cause the attenuation of Bdnf exon IV expression in M offspring. CONCLUSIONS Mild maternal hypothyroxinemia induces persistent DNA hypermethylation in Bdnf exon IV in offspring as epigenetic memory, which may result in long-term cognitive disorders.
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Affiliation(s)
- Kenichi Kawahori
- 1 Department of Molecular Endocrinology and Metabolism, Tokyo Medical and Dental University , Tokyo, Japan
| | - Koshi Hashimoto
- 2 Department of Preemptive Medicine and Metabolism, Tokyo Medical and Dental University , Tokyo, Japan
| | - Xunmei Yuan
- 3 Department of Molecular and Cellular Metabolism, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University , Tokyo, Japan
| | - Kazutaka Tsujimoto
- 1 Department of Molecular Endocrinology and Metabolism, Tokyo Medical and Dental University , Tokyo, Japan
| | - Nozomi Hanzawa
- 1 Department of Molecular Endocrinology and Metabolism, Tokyo Medical and Dental University , Tokyo, Japan
| | - Miho Hamaguchi
- 3 Department of Molecular and Cellular Metabolism, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University , Tokyo, Japan
| | - Saori Kase
- 1 Department of Molecular Endocrinology and Metabolism, Tokyo Medical and Dental University , Tokyo, Japan
| | - Kyota Fujita
- 4 Department of Neuropathology, Medical Research Institute and Center for Brain Integration Research, Tokyo Medical and Dental University , Tokyo, Japan
| | - Kazuhiko Tagawa
- 4 Department of Neuropathology, Medical Research Institute and Center for Brain Integration Research, Tokyo Medical and Dental University , Tokyo, Japan
| | - Hitoshi Okazawa
- 4 Department of Neuropathology, Medical Research Institute and Center for Brain Integration Research, Tokyo Medical and Dental University , Tokyo, Japan
| | - Yasuyo Nakajima
- 5 Department of Medicine and Molecular Science, Gunma University Graduate School of Medicine , Gunma, Japan
| | - Nobuyuki Shibusawa
- 5 Department of Medicine and Molecular Science, Gunma University Graduate School of Medicine , Gunma, Japan
| | - Masanobu Yamada
- 5 Department of Medicine and Molecular Science, Gunma University Graduate School of Medicine , Gunma, Japan
| | - Yoshihiro Ogawa
- 3 Department of Molecular and Cellular Metabolism, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University , Tokyo, Japan
- 6 Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University , Fukuoka, Japan
- 7 Japan Agency for Medical Research and Development , CREST, Tokyo, Japan
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28
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Epigenetic modulation of Fgf21 in the perinatal mouse liver ameliorates diet-induced obesity in adulthood. Nat Commun 2018; 9:636. [PMID: 29434210 PMCID: PMC5809372 DOI: 10.1038/s41467-018-03038-w] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Accepted: 01/15/2018] [Indexed: 01/03/2023] Open
Abstract
The nutritional environment to which animals are exposed in early life can lead to epigenetic changes in the genome that influence the risk of obesity in later life. Here, we demonstrate that the fibroblast growth factor-21 gene (Fgf21) is subject to peroxisome proliferator-activated receptor (PPAR) α-dependent DNA demethylation in the liver during the postnatal period. Reductions in Fgf21 methylation can be enhanced via pharmacologic activation of PPARα during the suckling period. We also reveal that the DNA methylation status of Fgf21, once established in early life, is relatively stable and persists into adulthood. Reduced DNA methylation is associated with enhanced induction of hepatic FGF21 expression after PPARα activation, which may partly explain the attenuation of diet-induced obesity in adulthood. We propose that Fgf21 methylation represents a form of epigenetic memory that persists into adulthood, and it may have a role in the developmental programming of obesity.
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29
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Kurita H, Aiba T, Saito T, Ohsako S. Detection of dioxin-induced demethylation of mouse Cyp1a1 gene promoter by a new labeling method for short DNA fragments possessing 5'-methylcytosine at the end. Genes Environ 2018; 40:1. [PMID: 29339976 PMCID: PMC5761092 DOI: 10.1186/s41021-017-0089-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 11/09/2017] [Indexed: 11/10/2022] Open
Abstract
Environmental factors stimulate alteration of DNA methylation level. Investigation of the genome-wide DNA methylation status is important for environmental health studies. We here designed a genomic DNA amplification and labeling protocol using a methylation-sensitive restriction enzyme HinP1 I. This method can specifically amplify genomic DNA fragments possessing methyl-CpG at the end. The fragments are a relatively short size and dominantly located on CpG-islands. By using the samples prepared by this method, a dioxin-induced change in the methylation level of the mouse Cyp1a1 promoter was successfully evaluated using oligonucleotide probes covalently bound onto a glass plate. The method developed in this paper would be useful for other genome-wide analysis platforms for the large scale epigenome-wide association studies (EWAS) including human epidemiological samples.
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Affiliation(s)
- Hisaka Kurita
- Laboratory of Environmental Health Science, Center for Disease Biology and Integrative Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655 Japan.,Laboratory of Medical Therapeutics and Molecular Therapeutics, Gifu Pharmaceutical University, Daigaku-Nishi, Gifu, 501-1196 Japan
| | - Toshiki Aiba
- Laboratory of Environmental Health Science, Center for Disease Biology and Integrative Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655 Japan.,Department of Radiation Effects Research, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555 Japan
| | - Toshiyuki Saito
- Department of Radiation Effects Research, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555 Japan
| | - Seiichiroh Ohsako
- Laboratory of Environmental Health Science, Center for Disease Biology and Integrative Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655 Japan.,Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 Japan
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30
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Brandenburg J, Head JA. Effects of in ovo exposure to benzo[k]fluoranthene (BkF) on CYP1A expression and promoter methylation in developing chicken embryos. Comp Biochem Physiol C Toxicol Pharmacol 2018; 204:88-96. [PMID: 29203322 DOI: 10.1016/j.cbpc.2017.11.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 11/27/2017] [Accepted: 11/28/2017] [Indexed: 12/28/2022]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are toxic environmental pollutants that are potent teratogens. Recent research suggests that early life exposure to PAHs can affect health outcomes later in life. Some of these latent responses may be mediated by epigenetic mechanisms such as DNA methylation. The role of DNA methylation in regulating responses to PAHs in birds is currently unknown. Here, we assess the effect of in ovo exposure to the model PAH, benzo[k]fluoranthene (BkF), on aryl hydrocarbon receptor (AHR) mediated cytochrome P4501A (CYP1A) gene expression and promoter methylation in chicken embryos. Fertilized chicken eggs were injected with BkF (0-100μg/kg) prior to incubation. BkF exposure was associated with an increase in CYP1A4 and CYP1A5 mRNA levels at mid-incubation (embryonic day 10), which dropped to baseline levels towards the end of the incubation period (embryonic day 19). The transient induction in CYP1A expression was accompanied by small but significant increases in CYP1A promoter methylation, which persisted until after shortly after hatching. Methylation within the CYP1A promoter was correlated with levels of CYP1A5, but not CYP1A4 mRNA. Characterization of the role of DNA methylation in the AHR response pathway may increase our understanding of the effects of early life exposure to PAHs in birds.
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Affiliation(s)
- Jonas Brandenburg
- Department of Natural Resource Sciences, McGill University, Montreal, QC, Canada
| | - Jessica A Head
- Department of Natural Resource Sciences, McGill University, Montreal, QC, Canada.
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31
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Hale MD, Galligan TM, Rainwater TR, Moore BC, Wilkinson PM, Guillette LJ, Parrott BB. AHR and CYP1A expression link historical contamination events to modern day developmental effects in the American alligator. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 230:1050-1061. [PMID: 28764121 DOI: 10.1016/j.envpol.2017.07.065] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 07/16/2017] [Accepted: 07/19/2017] [Indexed: 05/16/2023]
Abstract
The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that initiates a transcriptional pathway responsible for the expression of CYP1A subfamily members, key to the metabolism of xenobiotic compounds. Toxic planar halogenated aromatic hydrocarbons, including dioxin and PCBs, are capable of activating the AHR, and while dioxin and PCB inputs into the environment have been dramatically curbed following strict regulatory efforts in the United States, they persist in the environment and exposures remain relevant today. Little is known regarding the effects that long-term chronic exposures to dioxin or dioxin-like compounds might have on the development and subsequent health of offspring from exposed individuals, nor is much known regarding AHR expression in reptilians. Here, we characterize AHR and CYP1A gene expression in embryonic and juvenile specimen of a long-lived, apex predator, the American alligator (Alligator mississippiensis), and investigate variation in gene expression profiles in offspring collected from sites conveying differential exposures to environmental contaminants. Both age- and tissue-dependent patterning of AHR isoform expression are detected. We characterize two downstream transcriptional targets of the AHR, CYP1A1 and CYP1A2, and describe conserved elements of their genomic architecture. When comparisons across different sites are made, hepatic expression of CYP1A2, a direct target of the AHR, appears elevated in embryos from a site associated with a dioxin point source and previously characterized PCB contamination. Elevated CYP1A2 expression is not persistent, as site-specific variation was absent in juveniles originating from field-collected eggs but reared under lab conditions. Our results illustrate the patterning of AHR gene expression in a long-lived environmental model species, and indicate a potential contemporary influence of historical contamination. This research presents a novel opportunity to link contamination events to critical genetic pathways during embryonic development, and carries significant potential to inform our understanding of potential health effects in wildlife and humans.
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Affiliation(s)
- Matthew D Hale
- Savannah River Ecology Laboratory, P.O. Drawer E, Aiken, SC 29802, United States; Odum School of Ecology, University of Georgia, Athens, GA 30602, United States
| | - Thomas M Galligan
- Marine Biomedicine and Environmental Sciences Program, Hollings Marine Laboratory and the Medical University of South Carolina, Charleston, SC 29412, United States
| | - Thomas R Rainwater
- Tom Yawkey Wildlife Center & Belle W. Baruch Institute of Coastal Ecology and Forest Science, Clemson University, Georgetown, SC 29442, United States
| | - Brandon C Moore
- Department of Biology, Sewanee: the University of the South, Sewanee, TN 37383, United States
| | - Philip M Wilkinson
- Tom Yawkey Wildlife Center Heritage Preserve, South Carolina Department of Natural Resources, Georgetown, SC 29440, United States
| | - Louis J Guillette
- Marine Biomedicine and Environmental Sciences Program, Hollings Marine Laboratory and the Medical University of South Carolina, Charleston, SC 29412, United States
| | - Benjamin B Parrott
- Savannah River Ecology Laboratory, P.O. Drawer E, Aiken, SC 29802, United States; Odum School of Ecology, University of Georgia, Athens, GA 30602, United States.
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32
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Merches K, Haarmann-Stemmann T, Weighardt H, Krutmann J, Esser C. AHR in the skin: From the mediator of chloracne to a therapeutic panacea? CURRENT OPINION IN TOXICOLOGY 2017. [DOI: 10.1016/j.cotox.2017.02.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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33
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Fiorito F, Santamaria R, Irace C, De Martino L, Iovane G. 2,3,7,8-tetrachlorodibenzo-p-dioxin and the viral infection. ENVIRONMENTAL RESEARCH 2017; 153:27-34. [PMID: 27883971 DOI: 10.1016/j.envres.2016.11.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Revised: 10/13/2016] [Accepted: 11/09/2016] [Indexed: 06/06/2023]
Abstract
Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a widespread highly toxic environmental contaminant, suppresses immune response and leads to an increased susceptibility to infectious agents. In particular, several studies have provided evidence that TCDD decreases resistance to numerous viruses. Indeed, in vivo and in vitro investigations showed that the presence of TCDD is able to interfere with the replication of both human and animal viruses, such as influenza A viruses, coxsackie virus B3, immunodeficiency virus type-1 (HIV-1), cytomegalovirus (CMV), herpes simplex II, and bovine herpesvirus 1. Moreover, TCDD could induce an exacerbation of latent infection produced by HIV-1, CMV or Epstein-Barr virus. In this review, we first describe the general effects of TCDD exposure on mammalian cells, then we focus on its influence on the viral infections. Overall, the available data support the concept that TCDD exposure may act as an additional risk factor in promoting of viral diseases.
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Affiliation(s)
- Filomena Fiorito
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, 80137 Naples, Italy; Istituto Zooprofilattico Sperimentale del Mezzogiorno, Via Salute 2, Portici, 80055 Naples, Italy.
| | - Rita Santamaria
- Department of Pharmacy, University of Naples "Federico II", Via D. Montesano 49, 80131 Naples, Italy
| | - Carlo Irace
- Department of Pharmacy, University of Naples "Federico II", Via D. Montesano 49, 80131 Naples, Italy
| | - Luisa De Martino
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, 80137 Naples, Italy.
| | - Giuseppe Iovane
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, 80137 Naples, Italy
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34
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Abstract
Recent evidence from embryonic stem cells suggests that the aryl hydrocarbon receptor (AHR) plays a central role in the regulation of pluripotency, a short-lived property of cells in the early blastula inner cell mass (ICM). Four key observations support this conclusion. The first is the temporal association between upregulation of AHR expression and the onset of cell differentiation, which argues for the AHR as a determinant of cell fate decisions. The second is the repression of the pluripotency factors OCT4 and NANOG by the AHR, which depresses their function and contributes to the cell's exit from pluripotency. The third is the temporal association between changes in global DNA methylation and stage-dependent AHR expression, which parallel each other during embryonic development, suggesting that AHR helps configure a repressive chromatin structure that controls differentiation. The fourth is the incidence of early developmental aberrations that take place in Ahr-null mice and cause the disruption of their embryonic program, which is likely to be a consequence of the loss of pluripotency of the Ahr-/- ICM cells. In this short review, we will focus on the modulation of pluripotency as a novel function of the AHR, and on the potentially detrimental developmental outcomes that may result from exposure to environmental toxicants. This line of enquiry brings us to the tantalizing conclusion that by activating mechanisms that modulate pluripotency, AHR regulates embryonic development. The likelihood that exposure to environmental AHR ligands might disrupt developmental processes is a reasonable corollary to this conclusion.
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Affiliation(s)
- Chia-I Ko
- Department of Environmental Health and Center for Environmental Genetics University of Cincinnati College of Medicine 160 Panzeca Way, Cincinnati, Ohio, 45267, USA
| | - Alvaro Puga
- Department of Environmental Health and Center for Environmental Genetics University of Cincinnati College of Medicine 160 Panzeca Way, Cincinnati, Ohio, 45267, USA
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