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Kou Z, Tran F, Dai W. Heavy metals, oxidative stress, and the role of AhR signaling. Toxicol Appl Pharmacol 2024; 482:116769. [PMID: 38007072 PMCID: PMC10988536 DOI: 10.1016/j.taap.2023.116769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 11/12/2023] [Accepted: 11/18/2023] [Indexed: 11/27/2023]
Abstract
The Aryl Hydrocarbon Receptor (AhR) is a ligand-activated transcriptional factor pivotal in responding to environmental stress and maintaining cellular homeostasis. Exposure to specific xenobiotics or industrial compounds in the environment activates AhR and its subsequent signaling, inducing oxidative stress and related toxicity. Past research has also identified and characterized several classes of endogenous ligands, particularly some tryptophan (Trp) metabolic/catabolic products, that act as AhR agonists, influencing a variety of physiological and pathological states, including the modulation of immune responses and cell death. Heavy metals, being non-essential elements in the human body, are generally perceived as toxic and hazardous, originating either naturally or from industrial activities. Emerging evidence indicates that heavy metals significantly influence AhR activation and its downstream signaling. This review consolidates current knowledge on the modulation of the AhR signaling pathway by heavy metals, explores the consequences of co-exposure to AhR ligands and heavy metals, and investigates the interplay between oxidative stress and AhR activation, focusing on the regulation of immune responses and ferroptosis.
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Affiliation(s)
- Ziyue Kou
- Division of Environmental Medicine, Department of Medicine, Grossman School of Medicine, New York University, 341 East 25(th) Street, New York, NY 10010, United States of America
| | - Franklin Tran
- Division of Environmental Medicine, Department of Medicine, Grossman School of Medicine, New York University, 341 East 25(th) Street, New York, NY 10010, United States of America
| | - Wei Dai
- Division of Environmental Medicine, Department of Medicine, Grossman School of Medicine, New York University, 341 East 25(th) Street, New York, NY 10010, United States of America.
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2
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Wiggins BG, Wang YF, Burke A, Grunberg N, Vlachaki Walker JM, Dore M, Chahrour C, Pennycook BR, Sanchez-Garrido J, Vernia S, Barr AR, Frankel G, Birdsey GM, Randi AM, Schiering C. Endothelial sensing of AHR ligands regulates intestinal homeostasis. Nature 2023; 621:821-829. [PMID: 37586410 PMCID: PMC10533400 DOI: 10.1038/s41586-023-06508-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 08/02/2023] [Indexed: 08/18/2023]
Abstract
Endothelial cells line the blood and lymphatic vasculature, and act as an essential physical barrier, control nutrient transport, facilitate tissue immunosurveillance and coordinate angiogenesis and lymphangiogenesis1,2. In the intestine, dietary and microbial cues are particularly important in the regulation of organ homeostasis. However, whether enteric endothelial cells actively sense and integrate such signals is currently unknown. Here we show that the aryl hydrocarbon receptor (AHR) acts as a critical node for endothelial cell sensing of dietary metabolites in adult mice and human primary endothelial cells. We first established a comprehensive single-cell endothelial atlas of the mouse small intestine, uncovering the cellular complexity and functional heterogeneity of blood and lymphatic endothelial cells. Analyses of AHR-mediated responses at single-cell resolution identified tissue-protective transcriptional signatures and regulatory networks promoting cellular quiescence and vascular normalcy at steady state. Endothelial AHR deficiency in adult mice resulted in dysregulated inflammatory responses and the initiation of proliferative pathways. Furthermore, endothelial sensing of dietary AHR ligands was required for optimal protection against enteric infection. In human endothelial cells, AHR signalling promoted quiescence and restrained activation by inflammatory mediators. Together, our data provide a comprehensive dissection of the effect of environmental sensing across the spectrum of enteric endothelia, demonstrating that endothelial AHR signalling integrates dietary cues to maintain tissue homeostasis by promoting endothelial cell quiescence and vascular normalcy.
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Affiliation(s)
- Benjamin G Wiggins
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, UK.
- MRC London Institute of Medical Sciences, London, UK.
| | - Yi-Fang Wang
- MRC London Institute of Medical Sciences, London, UK
| | - Alice Burke
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, UK
- MRC London Institute of Medical Sciences, London, UK
| | - Nil Grunberg
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, UK
- MRC London Institute of Medical Sciences, London, UK
| | - Julia M Vlachaki Walker
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, UK
- MRC London Institute of Medical Sciences, London, UK
| | - Marian Dore
- MRC London Institute of Medical Sciences, London, UK
| | | | - Betheney R Pennycook
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, UK
- MRC London Institute of Medical Sciences, London, UK
| | | | - Santiago Vernia
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, UK
- MRC London Institute of Medical Sciences, London, UK
| | - Alexis R Barr
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, UK
- MRC London Institute of Medical Sciences, London, UK
| | - Gad Frankel
- Department of Life Sciences, Imperial College London, London, UK
| | - Graeme M Birdsey
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Anna M Randi
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Chris Schiering
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, UK.
- MRC London Institute of Medical Sciences, London, UK.
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3
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Guerra-Ojeda S, Suarez A, Valls A, Verdú D, Pereda J, Ortiz-Zapater E, Carretero J, Mauricio MD, Serna E. The Role of Aryl Hydrocarbon Receptor in the Endothelium: A Systematic Review. Int J Mol Sci 2023; 24:13537. [PMID: 37686342 PMCID: PMC10488274 DOI: 10.3390/ijms241713537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 08/12/2023] [Accepted: 08/29/2023] [Indexed: 09/10/2023] Open
Abstract
Activation of the aryl hydrocarbon receptor (AhR) has been shown to be important in physiological processes other than detoxification, including vascular homeostasis. Although AhR is highly expressed in the endothelium, its function has been poorly studied. This systematic review aims to summarise current knowledge on the AhR role in the endothelium and its cardiovascular implications. We focus on endogenous AhR agonists, such as some uremic toxins and other agonists unrelated to environmental pollutants, as well as studies using AhR knockout models. We conclude that AhR activation leads to vascular oxidative stress and endothelial dysfunction and that blocking AhR signalling could provide a new target for the treatment of vascular disorders such as cardiovascular complications in patients with chronic kidney disease or pulmonary arterial hypertension.
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Affiliation(s)
- Sol Guerra-Ojeda
- Department of Physiology, University of Valencia, 46010 Valencia, Spain; (S.G.-O.); (A.S.); (A.V.); (D.V.); (J.P.); (J.C.); (E.S.)
- Biomedical Research Institute INCLIVA, University of Valencia, 46010 Valencia, Spain;
| | - Andrea Suarez
- Department of Physiology, University of Valencia, 46010 Valencia, Spain; (S.G.-O.); (A.S.); (A.V.); (D.V.); (J.P.); (J.C.); (E.S.)
- Biomedical Research Institute INCLIVA, University of Valencia, 46010 Valencia, Spain;
| | - Alicia Valls
- Department of Physiology, University of Valencia, 46010 Valencia, Spain; (S.G.-O.); (A.S.); (A.V.); (D.V.); (J.P.); (J.C.); (E.S.)
| | - David Verdú
- Department of Physiology, University of Valencia, 46010 Valencia, Spain; (S.G.-O.); (A.S.); (A.V.); (D.V.); (J.P.); (J.C.); (E.S.)
| | - Javier Pereda
- Department of Physiology, University of Valencia, 46010 Valencia, Spain; (S.G.-O.); (A.S.); (A.V.); (D.V.); (J.P.); (J.C.); (E.S.)
| | - Elena Ortiz-Zapater
- Biomedical Research Institute INCLIVA, University of Valencia, 46010 Valencia, Spain;
- Department of Biochemistry and Molecular Biology, University of Valencia, 46010 Valencia, Spain
| | - Julián Carretero
- Department of Physiology, University of Valencia, 46010 Valencia, Spain; (S.G.-O.); (A.S.); (A.V.); (D.V.); (J.P.); (J.C.); (E.S.)
| | - Maria D. Mauricio
- Department of Physiology, University of Valencia, 46010 Valencia, Spain; (S.G.-O.); (A.S.); (A.V.); (D.V.); (J.P.); (J.C.); (E.S.)
- Biomedical Research Institute INCLIVA, University of Valencia, 46010 Valencia, Spain;
| | - Eva Serna
- Department of Physiology, University of Valencia, 46010 Valencia, Spain; (S.G.-O.); (A.S.); (A.V.); (D.V.); (J.P.); (J.C.); (E.S.)
- Biomedical Research Institute INCLIVA, University of Valencia, 46010 Valencia, Spain;
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4
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Yeoh BS, Golonka RM, Saha P, Kandalgaonkar MR, Tian Y, Osman I, Patterson AD, Gewirtz AT, Joe B, Vijay-Kumar M. Urine-based Detection of Congenital Portosystemic Shunt in C57BL/6 Mice. FUNCTION 2023; 4:zqad040. [PMID: 37575479 PMCID: PMC10413929 DOI: 10.1093/function/zqad040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 07/22/2023] [Accepted: 07/25/2023] [Indexed: 08/15/2023] Open
Abstract
Sporadic occurrence of congenital portosystemic shunt (PSS) at a rate of ∼1 out of 10 among C57BL/6 J mice, which are widely used in biomedical research, results in aberrancies in serologic, metabolic, and physiologic parameters. Therefore, mice with PSS should be identified as outliers in research. Accordingly, we sought methods to, reliably and efficiently, identify PSS mice. Serum total bile acids ≥ 40 µm is a bona fide biomarker of PSS in mice but utility of this biomarker is limited by its cost and invasiveness, particularly if large numbers of mice are to be screened. This led us to investigate if assay of urine might serve as a simple, inexpensive, noninvasive means of PSS diagnosis. Metabolome profiling uncovered that Krebs cycle intermediates, that is, citrate, α-ketoglutarate, and fumarate, were strikingly and distinctly elevated in the urine of PSS mice. We leveraged the iron-chelating and pH-lowering properties of such metabolites as the basis for 3 urine-based PSS screening tests: urinary iron-chelation assay, pH strip test, and phenol red assay. Our findings demonstrate the feasibility of using these colorimetric assays, whereby their readout can be assessed by direct observation, to diagnose PSS in an inexpensive, rapid, and noninvasive manner. Application of our urinary PSS screening protocols can aid biomedical research by enabling stratification of PSS mice, which, at present, likely confound numerous ongoing studies.
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Affiliation(s)
- Beng San Yeoh
- Department of Physiology and Pharmacology, The University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA
| | - Rachel M Golonka
- Department of Physiology and Pharmacology, The University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA
| | - Piu Saha
- Department of Physiology and Pharmacology, The University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA
| | - Mrunmayee R Kandalgaonkar
- Department of Physiology and Pharmacology, The University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA
| | - Yuan Tian
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Islam Osman
- Department of Physiology and Pharmacology, The University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA
| | - Andrew D Patterson
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Andrew T Gewirtz
- Center for Inflammation, Immunity & Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA
| | - Bina Joe
- Department of Physiology and Pharmacology, The University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA
| | - Matam Vijay-Kumar
- Department of Physiology and Pharmacology, The University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA
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5
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Panda SK, Peng V, Sudan R, Ulezko Antonova A, Di Luccia B, Ohara TE, Fachi JL, Grajales-Reyes GE, Jaeger N, Trsan T, Gilfillan S, Cella M, Colonna M. Repression of the aryl-hydrocarbon receptor prevents oxidative stress and ferroptosis of intestinal intraepithelial lymphocytes. Immunity 2023; 56:797-812.e4. [PMID: 36801011 PMCID: PMC10101911 DOI: 10.1016/j.immuni.2023.01.023] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 12/05/2022] [Accepted: 01/18/2023] [Indexed: 02/18/2023]
Abstract
The aryl-hydrocarbon receptor (AHR) is a ligand-activated transcription factor that buoys intestinal immune responses. AHR induces its own negative regulator, the AHR repressor (AHRR). Here, we show that AHRR is vital to sustaining intestinal intraepithelial lymphocytes (IELs). AHRR deficiency reduced IEL representation in a cell-intrinsic fashion. Single-cell RNA sequencing revealed an oxidative stress profile in Ahrr-/- IELs. AHRR deficiency unleashed AHR-induced expression of CYP1A1, a monooxygenase that generates reactive oxygen species, increasing redox imbalance, lipid peroxidation, and ferroptosis in Ahrr-/- IELs. Dietary supplementation with selenium or vitamin E to restore redox homeostasis rescued Ahrr-/- IELs. Loss of IELs in Ahrr-/- mice caused susceptibility to Clostridium difficile infection and dextran sodium-sulfate-induced colitis. Inflamed tissue of inflammatory bowel disease patients showed reduced Ahrr expression that may contribute to disease. We conclude that AHR signaling must be tightly regulated to prevent oxidative stress and ferroptosis of IELs and to preserve intestinal immune responses.
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Affiliation(s)
- Santosh K Panda
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Vincent Peng
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Raki Sudan
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Alina Ulezko Antonova
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Blanda Di Luccia
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Takahiro E Ohara
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Jose Luis Fachi
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Gary E Grajales-Reyes
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Natalia Jaeger
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Tihana Trsan
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Susan Gilfillan
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Marina Cella
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Marco Colonna
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA.
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6
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Patil NY, Friedman JE, Joshi AD. Role of Hepatic Aryl Hydrocarbon Receptor in Non-Alcoholic Fatty Liver Disease. RECEPTORS (BASEL, SWITZERLAND) 2023; 2:1-15. [PMID: 37284280 PMCID: PMC10240927 DOI: 10.3390/receptors2010001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Numerous nuclear receptors including farnesoid X receptor, liver X receptor, peroxisome proliferator-activated receptors, pregnane X receptor, hepatic nuclear factors have been extensively studied within the context of non-alcoholic fatty liver disease (NAFLD). Following the first description of the Aryl hydrocarbon Receptor (AhR) in the 1970s and decades of research which unveiled its role in toxicity and pathophysiological processes, the functional significance of AhR in NAFLD has not been completely decoded. Recently, multiple research groups have utilized a plethora of in vitro and in vivo models that mimic NAFLD pathology to investigate the functional significance of AhR in fatty liver disease. This review provides a comprehensive account of studies describing both the beneficial and possible detrimental role of AhR in NAFLD. A plausible reconciliation for the paradox indicating AhR as a 'double-edged sword' in NAFLD is discussed. Finally, understanding AhR ligands and their signaling in NAFLD will facilitate us to probe AhR as a potential drug target to design innovative therapeutics against NAFLD in the near future.
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Affiliation(s)
- Nikhil Y. Patil
- Department of Pharmaceutical Sciences, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
| | - Jacob E. Friedman
- Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
| | - Aditya D. Joshi
- Department of Pharmaceutical Sciences, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
- Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73117, USA
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7
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Ortiz NR, Guy N, Garcia YA, Sivils JC, Galigniana MD, Cox MB. Functions of the Hsp90-Binding FKBP Immunophilins. Subcell Biochem 2023; 101:41-80. [PMID: 36520303 DOI: 10.1007/978-3-031-14740-1_2] [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: 12/23/2022]
Abstract
The Hsp90 chaperone is known to interact with a diverse array of client proteins. However, in every case examined, Hsp90 is also accompanied by a single or several co-chaperone proteins. One class of co-chaperone contains a tetratricopeptide repeat (TPR) domain that targets the co-chaperone to the C-terminal region of Hsp90. Within this class are Hsp90-binding peptidylprolyl isomerases, most of which belong to the FK506-binding protein (FKBP) family. Despite the common association of FKBP co-chaperones with Hsp90, it is abundantly clear that the client protein influences, and is often influenced by, the particular FKBP bound to Hsp90. Examples include Xap2 in aryl hydrocarbon receptor complexes and FKBP52 in steroid receptor complexes. In this chapter, we discuss the known functional roles played by FKBP co-chaperones and, where possible, relate distinctive functions to structural differences between FKBP members.
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Affiliation(s)
- Nina R Ortiz
- Border Biomedical Research Center and Department of Biological Sciences, University of Texas at El Paso, El Paso, TX, USA
| | - Naihsuan Guy
- Border Biomedical Research Center and Department of Biological Sciences, University of Texas at El Paso, El Paso, TX, USA
| | - Yenni A Garcia
- Border Biomedical Research Center and Department of Biological Sciences, University of Texas at El Paso, El Paso, TX, USA
| | - Jeffrey C Sivils
- Border Biomedical Research Center and Department of Biological Sciences, University of Texas at El Paso, El Paso, TX, USA
| | - Mario D Galigniana
- Departamento de Química Biológica/IQUIBICEN, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Biología y Medicina Experimental/CONICET, Buenos Aires, Argentina
| | - Marc B Cox
- Border Biomedical Research Center and Department of Biological Sciences, University of Texas at El Paso, El Paso, TX, USA.
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Texas at El Paso, El Paso, TX, USA.
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8
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Kossack ME, Manz KE, Martin NR, Pennell KD, Plavicki J. Environmentally relevant uptake, elimination, and metabolic changes following early embryonic exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin in zebrafish. CHEMOSPHERE 2023; 310:136723. [PMID: 36241106 PMCID: PMC9835613 DOI: 10.1016/j.chemosphere.2022.136723] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 08/16/2022] [Accepted: 09/30/2022] [Indexed: 06/03/2023]
Abstract
Dioxin and dioxin-like compounds are ubiquitous environmental contaminants that induce toxicity by binding to the aryl hydrocarbon receptor (AHR), a ligand activated transcription factor. The zebrafish model has been used to define the developmental toxicity observed following exposure to exogenous AHR ligands such as the potent agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (dioxin, TCDD). While the model has successfully identified cellular targets of TCDD and molecular mechanisms mediating TCDD-induced phenotypes, fundamental information such as the body burden produced by standard exposure models is still unknown. We performed targeted gas chromatography (GC) high-resolution mass spectrometry (HRMS) in tandem with non-targeted liquid chromatography (LC) HRMS to quantify TCDD uptake, model the elimination dynamics of TCDD, and determine how TCDD exposure affects the zebrafish metabolome. We found that 50 ppt, 10 ppb, and 1 ppb waterborne exposures to TCDD during early embryogenesis produced environmentally relevant body burdens: 38 ± 4.34, 26.6 ± 1.2, and 8.53 ± 0.341 pg/embryo, respectively, at 24 hours post fertilization. TCDD exposure was associated with the dysregulation of metabolic pathways that are associated with the AHR signaling pathway as well as pathways shown to be affected in mammals following TCDD exposure. In addition, we discovered that TCDD exposure affected several metabolic pathways that are critical for brain development and function including glutamate metabolism, chondroitin sulfate biosynthesis, and tyrosine metabolism. Together, these data demonstrate that existing exposure methods produce environmentally relevant body burdens of TCDD in zebrafish and provide insight into the biochemical pathways impacted by toxicant-induced AHR activation.
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Affiliation(s)
- Michelle E Kossack
- Department of Pathology and Laboratory Medicine, Brown University, 70 Ship St, Providence, RI, 02903, USA
| | - Katherine E Manz
- School of Engineering, Brown University, 184 Hope St, Box D, Providence, RI, 02903, USA
| | - Nathan R Martin
- Department of Pathology and Laboratory Medicine, Brown University, 70 Ship St, Providence, RI, 02903, USA
| | - Kurt D Pennell
- School of Engineering, Brown University, 184 Hope St, Box D, Providence, RI, 02903, USA
| | - Jessica Plavicki
- Department of Pathology and Laboratory Medicine, Brown University, 70 Ship St, Providence, RI, 02903, USA.
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Tryptophan Metabolites Regulate Neuropentraxin 1 Expression in Endothelial Cells. Int J Mol Sci 2022; 23:ijms23042369. [PMID: 35216489 PMCID: PMC8874566 DOI: 10.3390/ijms23042369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 02/11/2022] [Accepted: 02/16/2022] [Indexed: 11/18/2022] Open
Abstract
In patients with chronic kidney disease (CKD) and in animal models of CKD, the transcription factor Aryl Hydrocabon Receptor (AhR) is overactivated. In addition to the canonical AhR targets constituting the AhR signature, numerous other genes are regulated by this factor. We identified neuronal pentraxin 1 (NPTX1) as a new AhR target. Belonging to the inflammatory protein family, NPTX1 seems of prime interest regarding the inflammatory state observed in CKD. Endothelial cells were exposed to tryptophan-derived toxins, indoxyl sulfate (IS) and indole-3-acetic acid (IAA). The adenine mouse model of CKD was used to analyze NPTX1 expression in the burden of uremia. NPTX1 expression was quantified by RT-PCR and western blot. AhR involvement was analyzed using silencing RNA. We found that IS and IAA upregulated NPTX1 expression in an AhR-dependent way. Furthermore, this effect was not restricted to uremic indolic toxins since the dioxin 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and the tryptophan photoproduct 6-formylindolo[3,2-b]carbazole (FICZ) do the same. In CKD mice, NPTX1 expression was increased in the aorta. Therefore, NPTX1 is a new target of AhR and further work is necessary to elucidate its exact role during CKD.
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Nuclear Receptors in Myocardial and Cerebral Ischemia-Mechanisms of Action and Therapeutic Strategies. Int J Mol Sci 2021; 22:ijms222212326. [PMID: 34830207 PMCID: PMC8617737 DOI: 10.3390/ijms222212326] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 11/08/2021] [Accepted: 11/10/2021] [Indexed: 12/12/2022] Open
Abstract
Nearly 18 million people died from cardiovascular diseases in 2019, of these 85% were due to heart attack and stroke. The available therapies although efficacious, have narrow therapeutic window and long list of contraindications. Therefore, there is still an urgent need to find novel molecular targets that could protect the brain and heart against ischemia without evoking major side effects. Nuclear receptors are one of the promising targets for anti-ischemic drugs. Modulation of estrogen receptors (ERs) and peroxisome proliferator-activated receptors (PPARs) by their ligands is known to exert neuro-, and cardioprotective effects through anti-apoptotic, anti-inflammatory or anti-oxidant action. Recently, it has been shown that the expression of aryl hydrocarbon receptor (AhR) is strongly increased after brain or heart ischemia and evokes an activation of apoptosis or inflammation in injury site. We hypothesize that activation of ERs and PPARs and inhibition of AhR signaling pathways could be a promising strategy to protect the heart and the brain against ischemia. In this Review, we will discuss currently available knowledge on the mechanisms of action of ERs, PPARs and AhR in experimental models of stroke and myocardial infarction and future perspectives to use them as novel targets in cardiovascular diseases.
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Larigot L, Benoit L, Koual M, Tomkiewicz C, Barouki R, Coumoul X. Aryl Hydrocarbon Receptor and Its Diverse Ligands and Functions: An Exposome Receptor. Annu Rev Pharmacol Toxicol 2021; 62:383-404. [PMID: 34499523 DOI: 10.1146/annurev-pharmtox-052220-115707] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The aryl hydrocarbon receptor (AhR) is a transcriptional factor that regulates multiple functions following its activation by a variety of ligands, including xenobiotics, natural products, microbiome metabolites, and endogenous molecules. Because of this diversity, the AhR constitutes an exposome receptor. One of its main functions is to regulate several lines of defense against chemical insults and bacterial infections. Indeed, in addition to its well-established detoxication function, it has several functions at physiological barriers, and it plays a critical role in immunomodulation. The AhR is also involved in the development of several organs and their homeostatic maintenance. Its activity depends on the type of ligand and on the time frame of the receptor activation, which can be either sustained or transient, leading in some cases to opposite modes of regulations as illustrated in the regulation of different cancer pathways. The development of selective modulators and their pharmacological characterization are important areas of research. Expected final online publication date for the Annual Review of Pharmacology and Toxicology, Volume 62 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Lucie Larigot
- INSERM UMR-S1124, T3S, Toxicologie Environnementale, Cibles thérapeutiques, Signalisation cellulaire et Biomarqueurs, and Université de Paris, 75006 Paris, France;
| | - Louise Benoit
- INSERM UMR-S1124, T3S, Toxicologie Environnementale, Cibles thérapeutiques, Signalisation cellulaire et Biomarqueurs, and Université de Paris, 75006 Paris, France; .,Service de Chirurgie Cancérologique Gynécologique et du Sein, Assistance Publique-Hôpitaux de Paris, Hôpital Européen Georges-Pompidou, 75015 Paris, France
| | - Meriem Koual
- INSERM UMR-S1124, T3S, Toxicologie Environnementale, Cibles thérapeutiques, Signalisation cellulaire et Biomarqueurs, and Université de Paris, 75006 Paris, France; .,Service de Chirurgie Cancérologique Gynécologique et du Sein, Assistance Publique-Hôpitaux de Paris, Hôpital Européen Georges-Pompidou, 75015 Paris, France
| | - Céline Tomkiewicz
- INSERM UMR-S1124, T3S, Toxicologie Environnementale, Cibles thérapeutiques, Signalisation cellulaire et Biomarqueurs, and Université de Paris, 75006 Paris, France;
| | - Robert Barouki
- INSERM UMR-S1124, T3S, Toxicologie Environnementale, Cibles thérapeutiques, Signalisation cellulaire et Biomarqueurs, and Université de Paris, 75006 Paris, France; .,Service de Chirurgie Cancérologique Gynécologique et du Sein, Assistance Publique-Hôpitaux de Paris, Hôpital Européen Georges-Pompidou, 75015 Paris, France
| | - Xavier Coumoul
- INSERM UMR-S1124, T3S, Toxicologie Environnementale, Cibles thérapeutiques, Signalisation cellulaire et Biomarqueurs, and Université de Paris, 75006 Paris, France;
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12
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Abstract
The aryl hydrocarbon receptor (AHR) is a ligand activated transcription factor that is a member of the PER-ARNT-SIM superfamily of environmental sensors. This receptor has been a molecule of interest for many years in the field of toxicology, as it was originally discovered to mediate the toxic effects of certain environmental pollutants like benzo(a)pyrene and 2,3,7,8-tetrachlorodibenzo-p-dioxin. While all animals express this protein, there is naturally occurring variability in receptor size and responsiveness to ligand. This naturally occurring variation, particularly in mice, has been an essential tool in the discovery and early characterization of the AHR. Genetic models including congenic mice and induced mutations at the Ahr locus have proven invaluable in further understanding the role of the AHR in adaptive metabolism and TCDD-induced toxicity. The creation and examination of Ahr null mice revealed an important physiological role for the AHR in vascular and hepatic development and mediation of the immune system. In this review, we attempt to provide an overview to many of the AHR models that have aided in the understanding of AHR biology thus far. We describe the naturally occurring polymorphisms, congenic models, induced mutations at the Ahr locus and at the binding partner Ah Receptor Nuclear Translocator and chaperone, Ah receptor associated 9 loci in mice, with a brief description of naturally occurring and induced mutations in rats.
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Affiliation(s)
- Rachel H Wilson
- Molecular and Environmental Toxicology Center, University of Wisconsin, Madison, WI, USA.,Department of Oncology, School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
| | - Christopher A Bradfield
- Molecular and Environmental Toxicology Center, University of Wisconsin, Madison, WI, USA.,Department of Oncology, School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA.,Biotechnology Center, University of Wisconsin, Madison, WI, USA
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13
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Wilson RH, Carney PR, Glover E, Parrott JC, Rojas BL, Moran SM, Yee JS, Nukaya M, Goetz NA, Rubinstein CD, Krentz KJ, Xing Y, Bradfield CA. Generation of an Allelic Series at the Ahr Locus Using an Edited Recombinant Approach. Toxicol Sci 2021; 180:239-251. [PMID: 33480436 DOI: 10.1093/toxsci/kfab005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor and a member of the PER-ARNT-SIM (PAS) superfamily of environmental sensors. The AHR is involved in a series of biological processes including adaptive metabolism of xenobiotics, toxicity of certain environmental pollutants, vascular development, fertility, and immune function. Mouse models, including the Ahr null and Ahr conditional null (Ahrfx) mice, are widely used for the study of AHR-mediated biology and toxicity. The Ahr conditional null mouse harbors the low-affinity Ahrd allele that exhibits approximately a 10-fold lower binding affinity for certain xenobiotic AHR ligands than the widely used C57BL/6 mouse that harbors the higher affinity Ahrb1 allele. Here, we report a novel mouse model that introduces a V375A polymorphism that converts the low-affinity allele into a high-affinity allele, offering a more sensitive conditional model. In the generation of this novel conditional allele, two additional mutants arose, including a 3-bp deletion in the PAS-B domain (AhrNG367R) and an early termination codon in the PAS-B domain (AhrTer383). The AhrNG367R allele presents as a phenocopy of the null and the AhrTer383 allele presents as an antimorph when assessing for the ductus venosus and liver lobe weight endpoints. These new models represent a series of tools that will be useful in further characterizing AHR biology.
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Affiliation(s)
- Rachel H Wilson
- Molecular and Environmental Toxicology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.,Department of Oncology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Patrick R Carney
- Molecular and Environmental Toxicology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.,Department of Oncology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Edward Glover
- Department of Oncology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Jessica C Parrott
- Molecular and Environmental Toxicology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.,Department of Oncology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Brenda L Rojas
- Molecular and Environmental Toxicology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.,Department of Oncology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.,Biotechnology Center, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Susan M Moran
- Department of Oncology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Jeremiah S Yee
- Molecular and Environmental Toxicology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.,Department of Oncology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Manabu Nukaya
- Molecular and Environmental Toxicology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Nicholas A Goetz
- Department of Oncology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Clifford D Rubinstein
- Biotechnology Center, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Kathy J Krentz
- Biotechnology Center, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Yongna Xing
- Molecular and Environmental Toxicology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.,Department of Oncology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Christopher A Bradfield
- Molecular and Environmental Toxicology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.,Department of Oncology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.,Biotechnology Center, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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14
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Jurgelewicz A, Dornbos P, Warren M, Nault R, Arkatkar A, Lin H, Threadgill DW, Zacharewski T, LaPres JJ. Genetics-Based Approach to Identify Novel Genes Regulated by the Aryl Hydrocarbon Receptor in Mouse Liver. Toxicol Sci 2021; 181:285-294. [PMID: 33720361 PMCID: PMC8599770 DOI: 10.1093/toxsci/kfab032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor in the Per-Arnt-Sim superfamily of environmental sensors that is linked to several metabolic diseases, including nonalcoholic fatty liver disease. Much remains unknown regarding the impact of genetic variation in AHR-driven disease, as past studies have focused on a small number of inbred strains. Recently, the presence of a wide range of interindividual variability amongst humans was reported in response to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), the prototypical ligand of the AHR. In this study, a panel of 14 diverse mouse strains was exposed to TCDD for 10 days to characterize the AHR-mediated response across genetic backgrounds. Responses to TCDD are heavily dependent on genetic background. Although mice carry 1 of 4 Ahr alleles known to impact the affinity to AHR-ligands, we observed significant intra-allelic variability suggesting the presence of novel genetic modifiers of AHR signaling. A regression-based approach was used to scan for genes regulated by the AHR and/or associated with TCDD-induced phenotypes. The approach identified 7 genes, 2 of which are novel, that are likely regulated by the AHR based on association with hepatic TCDD burden (p ≤ .05). Finally, we identified 1 gene, Dio1, which was associated with change in percent body fat across the diverse set of strains (p ≤ .05). Overall, the results in this study exemplify the power of genetics-based approaches in identifying novel genes that are putatively regulated by the AHR.
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Affiliation(s)
- Amanda Jurgelewicz
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan 48824, USA,Institute for Integrative Toxicology, Michigan State University, East Lansing, Michigan 48824, USA
| | - Peter Dornbos
- Institute for Integrative Toxicology, Michigan State University, East Lansing, Michigan 48824, USA,Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA
| | - Melanie Warren
- Interdisciplinary Program in Toxicology, Texas A&M University, College Station, Texas 77843, USA
| | - Rance Nault
- Institute for Integrative Toxicology, Michigan State University, East Lansing, Michigan 48824, USA,Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA
| | - Anooj Arkatkar
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA
| | - Hui Lin
- The Dow Chemical Company, Environmental Technology Center, Midland, Michigan 48674, USA
| | - David W Threadgill
- Interdisciplinary Program in Toxicology, Texas A&M University, College Station, Texas 77843, USA
| | - Tim Zacharewski
- Institute for Integrative Toxicology, Michigan State University, East Lansing, Michigan 48824, USA,Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA
| | - John J LaPres
- Institute for Integrative Toxicology, Michigan State University, East Lansing, Michigan 48824, USA,Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA,To whom correspondence should be addressed at Department of Biochemistry and Molecular Biology, Michigan State University, 603 Wilson Road, Room 224, East Lansing, MI 48824-1319. E-mail:
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15
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Noble AJ, Pearson JF, Boden JM, Horwood LJ, Gemmell NJ, Kennedy MA, Osborne AJ. A validation of Illumina EPIC array system with bisulfite-based amplicon sequencing. PeerJ 2021; 9:e10762. [PMID: 33614276 PMCID: PMC7881719 DOI: 10.7717/peerj.10762] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 12/22/2020] [Indexed: 12/16/2022] Open
Abstract
The Illumina Infinium® MethylationEPIC BeadChip system (hereafter EPIC array) is considered to be the current gold standard detection method for assessing DNA methylation at the genome-wide level. EPIC arrays are often used for hypothesis generation or pilot studies, the natural conclusion to which is to validate methylation candidates and expand these in a larger cohort, in a targeted manner. As such, an accurate smaller-scale, targeted technique, that generates data at the individual CpG level that is equivalent to the EPIC array, is needed. Here, we tested an alternative DNA methylation detection technique, known as bisulfite-based amplicon sequencing (BSAS), to determine its ability to validate CpG sites detected in EPIC array studies. BSAS was able to detect differential DNA methylation at CpG sites to a degree which correlates highly with the EPIC array system at some loci. However, BSAS correlated less well with EPIC array data in some instances, and most notably, when the magnitude of change via EPIC array was greater than 5%. Therefore, our data suggests that BSAS can be used to validate EPIC array data, but each locus must be compared on an individual basis, before being taken forward into large scale screening. Further, BSAS does offer advantages compared to the probe-based EPIC array; BSAS amplifies a region of the genome (∼500 bp) around a CpG of interest, allowing analyses of other CpGs in the region that may not be present on the EPIC array, aiding discovery of novel CpG sites and differentially methylated regions of interest. We conclude that BSAS offers a valid investigative tool for specific regions of the genome that are currently not contained on the array system.
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Affiliation(s)
- Alexandra J Noble
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - John F Pearson
- Department of Pathology and Biomedical Sciences, University of Otago, Christchurch, New Zealand
| | - Joseph M Boden
- Department of Psychological Medicine, University of Otago, Christchurch, New Zealand
| | - L John Horwood
- Department of Psychological Medicine, University of Otago, Christchurch, New Zealand
| | - Neil J Gemmell
- Department of Anatomy, Univeristy of Otago, Dunedin, New Zealand
| | - Martin A Kennedy
- Department of Pathology and Biomedical Sciences, University of Otago, Christchurch, New Zealand
| | - Amy J Osborne
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
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16
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Wang Z, Snyder M, Kenison JE, Yang K, Lara B, Lydell E, Bennani K, Novikov O, Federico A, Monti S, Sherr DH. How the AHR Became Important in Cancer: The Role of Chronically Active AHR in Cancer Aggression. Int J Mol Sci 2020; 22:ijms22010387. [PMID: 33396563 PMCID: PMC7795223 DOI: 10.3390/ijms22010387] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 12/25/2020] [Accepted: 12/28/2020] [Indexed: 12/13/2022] Open
Abstract
For decades, the aryl hydrocarbon receptor (AHR) was studied for its role in environmental chemical toxicity i.e., as a quirk of nature and a mediator of unintended consequences of human pollution. During that period, it was not certain that the AHR had a “normal” physiological function. However, the ongoing accumulation of data from an ever-expanding variety of studies on cancer, cancer immunity, autoimmunity, organ development, and other areas bears witness to a staggering array of AHR-controlled normal and pathological activities. The objective of this review is to discuss how the AHR has gone from a likely contributor to genotoxic environmental carcinogen-induced cancer to a master regulator of malignant cell progression and cancer aggression. Particular focus is placed on the association between AHR activity and poor cancer outcomes, feedback loops that control chronic AHR activity in cancer, and the role of chronically active AHR in driving cancer cell invasion, migration, cancer stem cell characteristics, and survival.
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Affiliation(s)
- Zhongyan Wang
- Department of Environmental Health, Boston University School of Public Health, Boston, MA 02118, USA; (Z.W.); (K.Y.); (E.L.)
| | - Megan Snyder
- Graduate Program in Genetics and Genomics, Division of Graduate Medical Sciences, Boston University School of Medicine, Boston, MA 02118, USA;
| | - Jessica E. Kenison
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA 02118, USA;
| | - Kangkang Yang
- Department of Environmental Health, Boston University School of Public Health, Boston, MA 02118, USA; (Z.W.); (K.Y.); (E.L.)
| | - Brian Lara
- Department of Environmental Health, Boston University, Boston, MA 02118, USA; (B.L.); (K.B.)
| | - Emily Lydell
- Department of Environmental Health, Boston University School of Public Health, Boston, MA 02118, USA; (Z.W.); (K.Y.); (E.L.)
| | - Kawtar Bennani
- Department of Environmental Health, Boston University, Boston, MA 02118, USA; (B.L.); (K.B.)
| | | | - Anthony Federico
- Division of Computational Biomedicine, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA; (A.F.); (S.M.)
| | - Stefano Monti
- Division of Computational Biomedicine, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA; (A.F.); (S.M.)
| | - David H. Sherr
- Department of Environmental Health, Boston University School of Public Health, Boston, MA 02118, USA; (Z.W.); (K.Y.); (E.L.)
- Correspondence: ; Tel.: +1-617-358-1707
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17
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Serna E, Cespedes C, Vina J. Anti-Aging Physiological Roles of Aryl Hydrocarbon Receptor and Its Dietary Regulators. Int J Mol Sci 2020; 22:ijms22010374. [PMID: 33396477 PMCID: PMC7795126 DOI: 10.3390/ijms22010374] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 12/18/2020] [Accepted: 12/26/2020] [Indexed: 01/13/2023] Open
Abstract
The vast majority of the literature on the aryl hydrocarbon receptor is concerned with its functions in xenobiotic detoxification. However, in the course of evolution, this receptor had to have physiological (rather than toxicological) functions. Our aim was to review the aryl hydrocarbon receptor’s role in the physiological functions involved in aging. This study was performed by searching the MEDLINE and Google Academic databases. A total of 34 articles were selected that focused specifically on the aryl hydrocarbon receptor and aging, the aryl hydrocarbon receptor and physiological functions, and the combination of both. This receptor’s main physiological functions (mediated by the modulation of gene expression) were cell regeneration, the immune reaction, intestinal homeostasis, and cell proliferation. Furthermore, it was shown that the loss of this receptor led to premature aging. This process may be caused by the dysregulation of hematopoietic stem cells, loss of glucose and lipid homeostasis, increase in inflammation, and deterioration of the brain. We conclude that the aryl hydrocarbon receptor, apart from its well-established role in xenobiotic detoxication, plays an important role in physiological functions and in the aging process. Modulation of the signaling pathway of this receptor could be a therapeutic target of interest in aging.
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Affiliation(s)
- Eva Serna
- Correspondence: ; Tel.: +34-96-386-41-00 (ext. 83171)
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18
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Li Y, Zhou C, Lei W, Wang K, Zheng J. Roles of aryl hydrocarbon receptor in endothelial angiogenic responses†. Biol Reprod 2020; 103:927-937. [PMID: 32716482 PMCID: PMC7731988 DOI: 10.1093/biolre/ioaa128] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/14/2020] [Accepted: 07/20/2020] [Indexed: 12/23/2022] Open
Abstract
Aryl hydrocarbon receptor (AhR) is a transcription factor, which can be activated by a plethora of structure-diverse ligands. Historically, AhR is known for its involvements in regulation of metabolism of xenobiotics. However, normal physiological roles of AhR have been defined in other essential biological processes, including vascular growth and function, reproduction, and immunoresponses. In contrast, aberrant expression and activation of the AhR signaling pathway occur in a variety of human diseases, many of which (e.g., preeclampsia, atherosclerosis, and hypertension) could be associated with endothelial dysfunction. Indeed, emerging evidence has shown that either exogenous or endogenous AhR ligands can induce endothelial dysfunction in either an AhR-dependent or AhR-independent manner, possibly reliant on the blood vessel origin (artery and vein) of endothelial cells. Given that the AhR signaling pathway has broad impacts on endothelial and cardiovascular function, AhR ligands, AhR, and their downstream genes could be considered novel therapeutic targets for those endothelial-related diseases. This review will discuss the current knowledge of AhR's mediation on endothelial function and potential mechanisms underlying these actions with a focus on placental endothelial cells.
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Affiliation(s)
- Yan Li
- Department of Obstetrics and Gynecology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Chi Zhou
- Department of Obstetrics and Gynecology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Wei Lei
- Department of Cardiovascular Medicine, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China
| | - Kai Wang
- Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, China
| | - Jing Zheng
- Department of Obstetrics and Gynecology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Cardiovascular Medicine, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China
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19
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Csanaky IL, Lickteig AJ, Zhang Y, Klaassen CD. Effects of patent ductus venosus on bile acid homeostasis in aryl hydrocarbon receptor (AhR)-null mice. Toxicol Appl Pharmacol 2020; 403:115136. [PMID: 32679164 DOI: 10.1016/j.taap.2020.115136] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 07/06/2020] [Accepted: 07/10/2020] [Indexed: 12/20/2022]
Abstract
The Aryl hydrocarbon receptor (AhR) is primarily known as one of the xenosensors and regulators of drug-metabolizing genes. Bile acids (BAs) are synthesized in the liver, and undergo several enterohepatic recirculations in which the liver removes BAs from the portal blood, minimizing the BAs that spill over into the systemic circulation. Previous studies revealed a lifelong patent ductus venosus (PDV) in AhR-null mice. Increased concentration of total BAs (Σ-BAs) in AhR-null mice is known; however, the impact of PDV on BA homeostasis in liver and bile remains unclear. This work investigated the consequences of PDV on BA homeostasis by comparing AhR-null and wild-type (WT) mice of both genders. In serum, Σ-BAs were markedly higher (64-85-fold) in AhR-null mice than in WT mice, especially due to the increase of tri-OH primary BAs (86-142-fold). Despite the extremely high concentration of serum BAs, the concentration of BAs in livers of AhR-null mice remained similar to WT mice. AhR-null livers were protected against increased BA influx by downregulation of uptake transporters and BA synthetic enzymes in the alternative pathway. Although livers of AhR-null mice are 20-25% smaller than WT mice, biliary excretion of BAs was maintained in the AhR-null mice, and even tended to increase. Surprisingly, intestinal Fgf15 expression was not increased, even though there was a marked increase in serum BA concentrations. Although PDV resulted in extremely high BA concentrations in serum of AhR-null mice, they maintained a concentration of BAs in liver and biliary excretion of BAs similar to control mice.
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Affiliation(s)
- Iván L Csanaky
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Division of Gastroenterology, Children's Mercy Hospital, Kansas City, Missouri 64108, USA; Department of Pediatrics, University of Kansas Medical Center, Kansas City, Kansas 66160, USA.
| | - Andrew J Lickteig
- Department of Internal Medicine, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
| | - Youcai Zhang
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China
| | - Curtis D Klaassen
- Department of Internal Medicine, University of Kansas Medical Center, Kansas City, Kansas 66160, USA.
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20
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Aryl Hydrocarbon Receptor (AHR) Ligands as Selective AHR Modulators (SAhRMs). Int J Mol Sci 2020; 21:ijms21186654. [PMID: 32932962 PMCID: PMC7555580 DOI: 10.3390/ijms21186654] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 09/01/2020] [Accepted: 09/09/2020] [Indexed: 02/06/2023] Open
Abstract
The aryl hydrocarbon receptor (AhR) was first identified as the intracellular protein that bound and mediated the toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, dioxin) and dioxin-like compounds (DLCs). Subsequent studies show that the AhR plays an important role in maintaining cellular homeostasis and in pathophysiology, and there is increasing evidence that the AhR is an important drug target. The AhR binds structurally diverse compounds, including pharmaceuticals, phytochemicals and endogenous biochemicals, some of which may serve as endogenous ligands. Classification of DLCs and non-DLCs based on their persistence (metabolism), toxicities, binding to wild-type/mutant AhR and structural similarities have been reported. This review provides data suggesting that ligands for the AhR are selective AhR modulators (SAhRMs) that exhibit tissue/cell-specific AhR agonist and antagonist activities, and that their functional diversity is similar to selective receptor modulators that target steroid hormone and other nuclear receptors.
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21
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Che X, Dai W. Aryl Hydrocarbon Receptor: Its Regulation and Roles in Transformation and Tumorigenesis. Curr Drug Targets 2020; 20:625-634. [PMID: 30411679 DOI: 10.2174/1389450120666181109092225] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Revised: 11/07/2018] [Accepted: 11/07/2018] [Indexed: 01/07/2023]
Abstract
AhR is an environmental response gene that mediates cellular responses to a variety of xenobiotic compounds that frequently function as AhR ligands. Many AhR ligands are classified as carcinogens or pro-carcinogens. Thus, AhR itself acts as a major mediator of the carcinogenic effect of many xenobiotics in vivo. In this concise review, mechanisms by which AhR trans-activates downstream target gene expression, modulates immune responses, and mediates malignant transformation and tumor development are discussed. Moreover, activation of AhR by post-translational modifications and crosstalk with other transcription factors or signaling pathways are also summarized.
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Affiliation(s)
- Xun Che
- Department of Environmental Medicine, New York University Langone Health, New York, NY 10010, United States
| | - Wei Dai
- Department of Environmental Medicine, New York University Langone Health, New York, NY 10010, United States
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22
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Safe S, Jayaraman A, Chapkin RS. Ah receptor ligands and their impacts on gut resilience: structure-activity effects. Crit Rev Toxicol 2020; 50:463-473. [PMID: 32597352 DOI: 10.1080/10408444.2020.1773759] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD, dioxin) and structurally related halogenated aromatics modulate gene expression and induce biochemical and toxic responses that are mediated by initial binding to the aryl hydrocarbon receptor (AhR). The AhR also binds structurally diverse compound including pharmaceuticals, endogenous biochemicals, health-promoting phytochemicals, and microbial metabolites. Many of these AhR ligands do not induce TCDD-like toxic responses and some AhR ligands such as microbial metabolites of tryptophan play a role in maintaining gut health and protecting against intestinal inflammation and cancer. Many AhR ligands exhibit tissue- and response-specific AhR agonist or antagonist activities, and act as selective AhR modulators (SAhRMs) and this SAhRM-like activity has also been observed in AhR-ligand-mediated effects in the intestine. This review summarizes studies showing that several AhR ligands including phytochemicals and TCDD protect against dextran sodium sulfate-induced intestinal inflammation. In contrast, AhR ligands such as oxazole compounds enhance intestinal inflammation suggesting that AhR-mediated gut health can be enhanced or decreased by selective AhR modulators and this needs to be considered in development of AhR ligands for therapeutic applications in treating intestinal inflammation.
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Affiliation(s)
- Stephen Safe
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX, USA
| | - Arul Jayaraman
- Department of Chemical Engineering, Texas A&M University, College Station, TX, USA
| | - Robert S Chapkin
- Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, TX, USA
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23
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Avilla MN, Malecki KMC, Hahn ME, Wilson RH, Bradfield CA. The Ah Receptor: Adaptive Metabolism, Ligand Diversity, and the Xenokine Model. Chem Res Toxicol 2020; 33:860-879. [PMID: 32259433 PMCID: PMC7175458 DOI: 10.1021/acs.chemrestox.9b00476] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Indexed: 12/12/2022]
Abstract
The Ah receptor (AHR) has been studied for almost five decades. Yet, we still have many important questions about its role in normal physiology and development. Moreover, we still do not fully understand how this protein mediates the adverse effects of a variety of environmental pollutants, such as the polycyclic aromatic hydrocarbons (PAHs), the chlorinated dibenzo-p-dioxins ("dioxins"), and many polyhalogenated biphenyls. To provide a platform for future research, we provide the historical underpinnings of our current state of knowledge about AHR signal transduction, identify a few areas of needed research, and then develop concepts such as adaptive metabolism, ligand structural diversity, and the importance of proligands in receptor activation. We finish with a discussion of the cognate physiological role of the AHR, our perspective on why this receptor is so highly conserved, and how we might think about its cognate ligands in the future.
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Affiliation(s)
- Mele N. Avilla
- Molecular and Environmental Toxicology
Center, Department of Population Health
Sciences, University of Wisconsin School
of Medicine and Public Health, Madison, Wisconsin 53726-2379, United States
| | - Kristen M. C. Malecki
- Molecular and Environmental Toxicology
Center, Department of Population Health
Sciences, University of Wisconsin School
of Medicine and Public Health, Madison, Wisconsin 53726-2379, United States
| | - Mark E. Hahn
- Biology
Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543-1050, United States
| | - Rachel H. Wilson
- Molecular and Environmental Toxicology
Center, Department of Population Health
Sciences, University of Wisconsin School
of Medicine and Public Health, Madison, Wisconsin 53726-2379, United States
| | - Christopher A. Bradfield
- Molecular and Environmental Toxicology
Center, Department of Population Health
Sciences, University of Wisconsin School
of Medicine and Public Health, Madison, Wisconsin 53726-2379, United States
- McArdle
Laboratory for Cancer Research, University of Wisconsin School of Medicine
and Public Health, Madison, Wisconsin 53705-227, United States
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24
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Brinkmann V, Ale-Agha N, Haendeler J, Ventura N. The Aryl Hydrocarbon Receptor (AhR) in the Aging Process: Another Puzzling Role for This Highly Conserved Transcription Factor. Front Physiol 2020; 10:1561. [PMID: 32009975 PMCID: PMC6971224 DOI: 10.3389/fphys.2019.01561] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 12/11/2019] [Indexed: 12/26/2022] Open
Abstract
Aging is the most important risk factor for the development of major life-threatening diseases such as cardiovascular disorders, cancer, and neurodegenerative disorders. The aging process is characterized by the accumulation of damage to intracellular macromolecules and it is concurrently shaped by genetic, environmental and nutritional factors. These factors influence the functionality of mitochondria, which play a central role in the aging process. Mitochondrial dysfunction is one of the hallmarks of aging and is associated with increased fluxes of ROS leading to damage of mitochondrial components, impaired metabolism of fatty acids, dysregulated glucose metabolism, and damage of adjacent organelles. Interestingly, many of the environmental (e.g., pollutants and other toxicants) and nutritional (e.g., flavonoids, carotenoids) factors influencing aging and mitochondrial function also directly or indirectly affect the activity of a highly conserved transcription factor, the Aryl hydrocarbon Receptor (AhR). Therefore, it is not surprising that many studies have already indicated a role of this versatile transcription factor in the aging process. We also recently found that the AhR promotes aging phenotypes across species. In this manuscript, we systematically review the existing literature on the contradictory studies indicating either pro- or anti-aging effects of the AhR and try to reconcile the seemingly conflicting data considering a possible dependency on the animal model, tissue, as well as level of AhR expression and activation. Moreover, given the crucial role of mitochondria in the aging process, we summarize the growing body of evidence pointing toward the influence of AhR on mitochondria, which can be of potential relevance for aging.
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Affiliation(s)
- Vanessa Brinkmann
- IUF - Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany
| | - Niloofar Ale-Agha
- IUF - Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany
| | - Judith Haendeler
- IUF - Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany.,Institute of Clinical Chemistry and Laboratory Diagnostic, Medical Faculty, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany
| | - Natascia Ventura
- IUF - Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany.,Institute of Clinical Chemistry and Laboratory Diagnostic, Medical Faculty, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany
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25
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Taguchi K, Kensler TW. Nrf2 in liver toxicology. Arch Pharm Res 2019; 43:337-349. [PMID: 31782059 DOI: 10.1007/s12272-019-01192-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 11/19/2019] [Indexed: 12/14/2022]
Abstract
Liver plays essential roles in the metabolism of many endogenous chemicals and exogenous toxicants. Mechanistic studies in liver have been at the forefront of efforts to probe the roles of bioactivation and detoxication of environmental toxins and toxicants in hepatotoxicity. Moreover, idiosyncratic hepatoxicity remains a key barrier in the clinical development of drugs. The now vast Nrf2 field emerged in part from biochemical and molecular studies on chemical inducers of hepatic detoxication enzymes and subsequent characterization of the modulation of drug/toxicant induced hepatotoxicities in mice through disruption of either Nrf2 or Keap1 genes. In general, loss of Nrf2 increases the sensitivity to such toxic chemicals, highlighting a central role of this transcription factor and its downstream target genes as a modifier to chemical stress. In this review, we summarize the impact of Nrf2 on the toxicology of multiple hepatotoxicants, and discuss efforts to utilize the Nrf2 response in predictive toxicology.
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Affiliation(s)
- Keiko Taguchi
- Department of Medical Biochemistry, Graduate School of Medicine, Tohoku University, 2-1 Seiryo-machi, Aoba, Sendai, 980-8575, Japan.
| | - Thomas W Kensler
- Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N, Seattle, WA, 98109, USA
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26
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Chen WC, Chang LH, Huang SS, Huang YJ, Chih CL, Kuo HC, Lee YH, Lee IH. Aryl hydrocarbon receptor modulates stroke-induced astrogliosis and neurogenesis in the adult mouse brain. J Neuroinflammation 2019; 16:187. [PMID: 31606043 PMCID: PMC6790016 DOI: 10.1186/s12974-019-1572-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 08/29/2019] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND The aryl hydrocarbon receptor (AHR) is a ligand-dependent transcription factor activated by environmental agonists and dietary tryptophan metabolites for the immune response and cell cycle regulation. Emerging evidence suggests that AHR activation after acute stroke may play a role in brain ischemic injury. However, whether AHR activation alters poststroke astrogliosis and neurogenesis remains unknown. METHODS We adopted conditional knockout of AHR from nestin-expressing neural stem/progenitor cells (AHRcKO) and wild-type (WT) mice in the permanent middle cerebral artery occlusion (MCAO) model. WT mice were treated with either vehicle or the AHR antagonist 6,2',4'-trimethoxyflavone (TMF, 5 mg/kg/day) intraperitoneally. The animals were examined at 2 and 7 days after MCAO. RESULTS The AHR signaling pathway was significantly upregulated after stroke. Both TMF-treated WT and AHRcKO mice showed significantly decreased infarct volume, improved sensorimotor, and nonspatial working memory functions compared with their respective controls. AHR immunoreactivities were increased predominantly in activated microglia and astrocytes after MCAO compared with the normal WT controls. The TMF-treated WT and AHRcKO mice demonstrated significant amelioration of astrogliosis and microgliosis. Interestingly, these mice also showed augmentation of neural progenitor cell proliferation at the ipsilesional neurogenic subventricular zone (SVZ) and the hippocampal subgranular zone. At the peri-infarct cortex, the ipsilesional SVZ/striatum, and the hippocampus, both the TMF-treated and AHRcKO mice demonstrated downregulated IL-1β, IL-6, IFN-γ, CXCL1, and S100β, and concomitantly upregulated Neurogenin 2 and Neurogenin 1. CONCLUSION Neural cell-specific AHR activation following acute ischemic stroke increased astrogliosis and suppressed neurogenesis in adult mice. AHR inhibition in acute stroke may potentially benefit functional outcomes likely through reducing proinflammatory gliosis and preserving neurogenesis.
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Affiliation(s)
- Wan-Ci Chen
- Department and Institute of Physiology, National Yang-Ming University, No.155, Sec. 2, Linong Street, Beitou District, Taipei, 11217, Taiwan
| | - Li-Hsin Chang
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan
| | - Shiang-Suo Huang
- Department of Pharmacology, Institute of Medicine, Chung-Shan Medical University, Taichung, Taiwan
| | - Yu-Jie Huang
- Department and Institute of Physiology, National Yang-Ming University, No.155, Sec. 2, Linong Street, Beitou District, Taipei, 11217, Taiwan
| | | | - Hung-Chih Kuo
- Stem Cell Program, Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Yi-Hsuan Lee
- Department and Institute of Physiology, National Yang-Ming University, No.155, Sec. 2, Linong Street, Beitou District, Taipei, 11217, Taiwan. .,Brain Research Center, National Yang-Ming University, Taipei, Taiwan.
| | - I-Hui Lee
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan. .,Brain Research Center, National Yang-Ming University, Taipei, Taiwan. .,Division of Cerebrovascular Diseases, Neurological Institute, Taipei Veterans General Hospital, No.201, Sec. 2, Shipai Rd., Beitou District, Taipei, 11217, Taiwan.
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Urolithin A Is a Dietary Microbiota-Derived Human Aryl Hydrocarbon Receptor Antagonist. Metabolites 2018; 8:metabo8040086. [PMID: 30501068 PMCID: PMC6315438 DOI: 10.3390/metabo8040086] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 11/19/2018] [Accepted: 11/27/2018] [Indexed: 12/16/2022] Open
Abstract
Urolithins (e.g., UroA and B) are gut microbiota-derived metabolites of the natural polyphenol ellagic acid. Urolithins are associated with various health benefits, including attenuation of inflammatory signaling, anti-cancer effects and repression of lipid accumulation. The molecular mechanisms underlying the beneficial effects of urolithins remain unclear. We hypothesize that some of the human health benefits of urolithins are mediated through the aryl hydrocarbon receptor (AHR). Utilizing a cell-based reporter system, we tested urolithins for the capacity to modulate AHR activity. Cytochrome P450 1A1 (CYP1A1) mRNA levels were assessed by real-time quantitative polymerase chain reaction. Competitive ligand binding assays were performed to determine whether UroA is a direct ligand for the AHR. Subcellular AHR protein levels were examined utilizing immunoblotting analysis. AHR expression was repressed in Caco-2 cells by siRNA transfection to investigate AHR-dependency. UroA and B were able to antagonize 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced AHR-mediated transcriptional activity. Furthermore, UroA and B attenuated TCDD-mediated stimulation of CYP1A1 mRNA levels. In addition, competitive ligand binding assays characterized UroA as a direct AHR ligand. Consistent with other AHR antagonists, UroA failed to induce AHR retention in the nucleus. AHR is necessary for UroA-mediated attenuation of cytokine-induced interleukin 6 (IL6) and prostaglandin-endoperoxide synthase 2 (PTGS2) expression in Caco-2 cells. Here we identified UroA as the first dietary-derived human selective AHR antagonist produced by the gut microbiota through multi-step metabolism. Furthermore, previously reported anti-inflammatory activity of UroA may at least in part be mediated through AHR.
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28
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Safe S, Han H, Goldsby J, Mohankumar K, Chapkin RS. Aryl Hydrocarbon Receptor (AhR) Ligands as Selective AhR Modulators: Genomic Studies. CURRENT OPINION IN TOXICOLOGY 2018; 11-12:10-20. [PMID: 31453421 DOI: 10.1016/j.cotox.2018.11.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The aryl hydrocarbon receptor (AhR) binds structurally diverse ligands that vary from the environmental toxicant 2,3,7,8-tetrachlorodibenzo-B-dioxin (TCDD) to AhR- active pharmaceuticals and health-promoting phytochemicals. There are remarkable differences in the toxicity of TCDD and related halogenated aromatics (HAs) vs. health promoting AhR ligands, and genomic analysis shows that even among the toxic HAs, there are differences in their regulation of genes and pathways. Thus, like ligands for other receptors, AhR ligands are selective AhR modulators (SAhRMs) which exhibit variable tissue-, organ- and species-specific genomic and functional activities.
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Affiliation(s)
- Stephen Safe
- Department of Veterinary Physiology and Pharmacology
| | - Huajun Han
- Department of Biochemistry & Biophysics
- Department of Nutrition & Food Science
- Program in Integrative Nutrition & Complex Diseases, Texas A&M University, College Station, TX, USA
| | - Jennifer Goldsby
- Department of Nutrition & Food Science
- Program in Integrative Nutrition & Complex Diseases, Texas A&M University, College Station, TX, USA
| | | | - Robert S Chapkin
- Department of Biochemistry & Biophysics
- Department of Nutrition & Food Science
- Program in Integrative Nutrition & Complex Diseases, Texas A&M University, College Station, TX, USA
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29
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Ghotbaddini M, Moultrie V, Powell JB. Constitutive Aryl Hydrocarbon Receptor Signaling in Prostate Cancer Progression. ACTA ACUST UNITED AC 2018; 2:11-16. [PMID: 31328183 PMCID: PMC6641558 DOI: 10.29245/2578-2967/2018/5.1136] [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] [Indexed: 11/12/2022]
Abstract
Research on the aryl hydrocarbon receptor (AhR) has largely focused on its activation by various environmental toxins. Consequently, only limited inferences have been made regarding its constitutive activity in the absence of an exogenous ligands. Evidence has shown that AhR is constitutively active in advanced prostate cancer cell lines which model castration resistant prostate cancer (CRPC). CRPC cells can thrive in an androgen depleted environment. However, AR signaling still plays a major role. Although several mechanisms have been suggested for the sustained AR signaling, much is still unknown. Recent studies suggest that crosstalk between constitutive AhR and Src kinase may sustained AR signaling in CRPC. AhR forms a protein complex with Src and plays a role in regulating Src activity. Several groups have reported that tyrosine phosphorylation of AR protein by Src leads to AR activation, thereby promoting the development of CRPC. This review evaluates reports that implicate constitutive AhR as a key regulator of AR signaling in CRPC by utilizing Src as a signaling intermediate.
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Affiliation(s)
- Maryam Ghotbaddini
- Clark Atlanta University- Center for Cancer Research and Therapeutic Development 223 James P Brawley Drive Atlanta, Georgia, USA
| | - Vivian Moultrie
- Clark Atlanta University- Center for Cancer Research and Therapeutic Development 223 James P Brawley Drive Atlanta, Georgia, USA
| | - Joann B Powell
- Clark Atlanta University- Center for Cancer Research and Therapeutic Development 223 James P Brawley Drive Atlanta, Georgia, USA
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30
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Gutiérrez-Vázquez C, Quintana FJ. Regulation of the Immune Response by the Aryl Hydrocarbon Receptor. Immunity 2018; 48:19-33. [PMID: 29343438 DOI: 10.1016/j.immuni.2017.12.012] [Citation(s) in RCA: 556] [Impact Index Per Article: 92.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 10/04/2017] [Accepted: 12/21/2017] [Indexed: 12/14/2022]
Abstract
The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that is activated by small molecules provided by the diet, microorganisms, metabolism, and pollutants. AhR is expressed by a number of immune cells, and thus AhR signaling provides a molecular pathway that integrates the effects of the environment and metabolism on the immune response. Studies have shown that AhR signaling plays important roles in the immune system in health and disease. As its activity is regulated by small molecules, AhR also constitutes a potential target for therapeutic immunomodulation. In this review we discuss the role of AhR in the regulation of the immune response in the context of autoimmunity, infection, and cancer, as well as the potential opportunities and challenges of developing AhR-targeted therapeutics.
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Affiliation(s)
- Cristina Gutiérrez-Vázquez
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Francisco J Quintana
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA; The Broad Institute of MIT and Harvard, Cambridge, MA, USA.
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31
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Larigot L, Juricek L, Dairou J, Coumoul X. AhR signaling pathways and regulatory functions. BIOCHIMIE OPEN 2018; 7:1-9. [PMID: 30003042 PMCID: PMC6039966 DOI: 10.1016/j.biopen.2018.05.001] [Citation(s) in RCA: 340] [Impact Index Per Article: 56.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Accepted: 05/28/2018] [Indexed: 12/12/2022]
Abstract
Animals and humans are exposed each day to a multitude of chemicals in the air, water and food. They have developed a battery of enzymes and transporters that facilitate the biotransformation and elimination of these compounds. Moreover, a majority of these enzymes and transporters are inducible due to the activation of xenobiotic receptors which act as transcription factors for the regulation of their target genes (such as xenobiotic metabolizing enzymes, see below §4 for the AhR). These receptors include several members of the nuclear/steroid receptor family (CAR for Constitutive Androstane Receptor, PXR for Pregnane X Receptor) but also the Aryl hydrocarbon Receptor or AhR, a member of the bHLH-PAS family (basic Helix-Loop-Helix - Period/ARNT/Single minded). In addition to the regulation of xenobiotic metabolism, numerous alternative functions have been characterized for the AhR since its discovery. These alternative functions will be described in this review along with its endogenous functions as revealed by experiments performed on knock-out animals.
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Affiliation(s)
- Lucie Larigot
- INSERM UMR-S 1124, Toxicologie Pharmacologie et Signalisation Cellulaire, 45 rue des Saints-Pères, 75006 Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, 45 rue des Saints-Pères, 75006 Paris, France
| | - Ludmila Juricek
- INSERM UMR-S 1124, Toxicologie Pharmacologie et Signalisation Cellulaire, 45 rue des Saints-Pères, 75006 Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, 45 rue des Saints-Pères, 75006 Paris, France
| | - Julien Dairou
- CNRS 8601, 45 rue des Saints-Pères, 75006 Paris, France
| | - Xavier Coumoul
- INSERM UMR-S 1124, Toxicologie Pharmacologie et Signalisation Cellulaire, 45 rue des Saints-Pères, 75006 Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, 45 rue des Saints-Pères, 75006 Paris, France
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32
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Morales-Hernández A, Nacarino-Palma A, Moreno-Marín N, Barrasa E, Paniagua-Quiñones B, Catalina-Fernández I, Alvarez-Barrientos A, Bustelo XR, Merino JM, Fernández-Salguero PM. Lung regeneration after toxic injury is improved in absence of dioxin receptor. Stem Cell Res 2017; 25:61-71. [PMID: 29107893 DOI: 10.1016/j.scr.2017.10.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 08/07/2017] [Accepted: 10/09/2017] [Indexed: 12/26/2022] Open
Abstract
Recent experimental evidences from cellular systems and from mammalian and non-mammalian animal models highlight novel functions for the aryl hydrocarbon/dioxin receptor (AhR) in maintaining cell differentiation and tissue homeostasis. Notably, AhR depletion stimulates an undifferentiated and pluripotent phenotype likely associated to a mesenchymal transition in epithelial cells and to increased primary tumorigenesis and metastasis in melanoma. In this work, we have used a lung model of epithelial regeneration to investigate whether AhR regulates proper tissue repair by adjusting the expansion of undifferentiated stem-like cells. AhR-null mice developed a faster and more efficient repair of the lung bronchiolar epithelium upon naphthalene injury that required increased cell proliferation and the earlier activation of stem-like Clara, Basal and neuroepithelial cells precursors. Increased basal content in multipotent Sca1+/CD31-/CD4- cells and in cells expressing pluripotency factors NANOG and OCT4 could also improve re-epithelialization in AhR-null lungs. The reduced response of AhR-deficient lungs to Sonic Hedgehog (Shh) repression shortly after injury may also help their improved bronchiolar epithelium repair. These results support a role for AhR in the regenerative response against toxins, and open the possibility of modulating its activation level to favor recovery from lesions caused by environmental contaminants.
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Affiliation(s)
| | - Ana Nacarino-Palma
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Extremadura, 06071 Badajoz, Spain
| | - Nuria Moreno-Marín
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Extremadura, 06071 Badajoz, Spain
| | - Eva Barrasa
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Extremadura, 06071 Badajoz, Spain
| | - Beroé Paniagua-Quiñones
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Extremadura, 06071 Badajoz, Spain
| | | | | | - Xosé R Bustelo
- Centro de Investigación del Cáncer and CIBERONC, CSIC-Universidad de Salamanca, 37007 Salamanca, Spain
| | - Jaime M Merino
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Extremadura, 06071 Badajoz, Spain.
| | - Pedro M Fernández-Salguero
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Extremadura, 06071 Badajoz, Spain.
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Gao WQ, Ma J, Sun LL, Li Q, Zhu RY, Jin J. Paclitaxel-mediated human aryl hydrocarbon receptor mRNA translation by an internal ribosomal entry site-dependent mechanism. Oncol Rep 2017; 38:3211-3219. [PMID: 29048649 DOI: 10.3892/or.2017.5958] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 05/02/2017] [Indexed: 11/06/2022] Open
Abstract
The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that is best known in mediating the toxicities of dioxins and dioxin-like compounds. AHR is activated by a variety of endogenous ligands and participating in tumor development. Thus, it will provide a new approach for cancer prevention and treatment to study the translation mechanism of AHR in tumor cells. In this study, we show that the 5'-untranslated region (UTR) of AHR mRNA contains an internal ribosome entry site (IRES). After mapping the entire AHR 5'-UTR, we determined that the full-length 5'-UTR is indispensable for the highest IRES activity. Interestingly, we found that AHR expression is induced in ovarian (A2780), breast (MDA-MB231), hepatic (Bel7402) and colorectal cancer cells (SW620) by chemotherapeutic drug paclitaxel (PTX) through IRES-dependent translation mechanism. Moreover, IRES activity is increased in the PTX-resistant ovarian cancer cells in which AHR protein expression was also enhanced. These results strongly suggest an important role for AHR IRES-dependent translation mechanism in cancer cell response to paclitaxel treatment.
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Affiliation(s)
- Wen-Qing Gao
- Laboratory of Molecular Pharmacology, School of Pharmaceutical Sciences, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| | - Jing Ma
- Laboratory of Molecular Pharmacology, School of Pharmaceutical Sciences, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| | - Liu-Liu Sun
- Laboratory of Molecular Pharmacology, School of Pharmaceutical Sciences, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| | - Qi Li
- Laboratory of Molecular Pharmacology, School of Pharmaceutical Sciences, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| | - Rui-Yu Zhu
- Laboratory of Molecular Pharmacology, School of Pharmaceutical Sciences, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| | - Jian Jin
- Laboratory of Molecular Pharmacology, School of Pharmaceutical Sciences, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
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Dioxin Receptor Adjusts Liver Regeneration After Acute Toxic Injury and Protects Against Liver Carcinogenesis. Sci Rep 2017; 7:10420. [PMID: 28874739 PMCID: PMC5585208 DOI: 10.1038/s41598-017-10984-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 08/17/2017] [Indexed: 12/15/2022] Open
Abstract
The aryl hydrocarbon receptor (AhR) has roles in cell proliferation, differentiation and organ homeostasis, including the liver. AhR depletion induces undifferentiation and pluripotency in normal and transformed cells. Here, AhR-null mice (AhR-/-) were used to explore whether AhR controls liver regeneration and carcinogenesis by restricting the expansion of stem-like cells and the expression of pluripotency genes. Short-term CCl4 liver damage was earlier and more efficiently repaired in AhR-/- than in AhR+/+ mice. Stem-like CK14 + and TBX3 + and pluripotency-expressing OCT4 + and NANOG + cells expanded sooner in AhR-/- than in AhR+/+ regenerating livers. Stem-like side population cells (SP) isolated from AhR-/- livers had increased β-catenin (β-Cat) signaling with overexpression of Axin2, Dkk1 and Cyclin D1. Interestingly, β-Cat, Axin2 and Dkk1 also increased during regeneration but more notably in AhR-null livers. Liver carcinogenesis induced by diethylnitrosamine (DEN) produced large carcinomas in all AhR-/- mice but mostly premalignant adenomas in less than half of AhR+/+ mice. AhR-null tumoral tissue, but not their surrounding non-tumoral parenchyma, had nuclear β-Cat and Axin2 overexpression. OCT4 and NANOG were nevertheless similarly expressed in AhR+/+ and AhR-/- lesions. We suggest that AhR may serve to adjust liver repair and to block tumorigenesis by modulating stem-like cells and β-Cat signaling.
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35
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Short Chain Fatty Acids Enhance Aryl Hydrocarbon (Ah) Responsiveness in Mouse Colonocytes and Caco-2 Human Colon Cancer Cells. Sci Rep 2017; 7:10163. [PMID: 28860561 PMCID: PMC5579248 DOI: 10.1038/s41598-017-10824-x] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 08/15/2017] [Indexed: 02/07/2023] Open
Abstract
Aryl hydrocarbon receptor (AhR) ligands are important for gastrointestinal health and play a role in gut inflammation and the induction of T regulatory cells, and the short chain fatty acids (SCFAs) butyrate, propionate and acetate also induce similar protective responses. Initial studies with butyrate demonstrated that this compound significantly increased expression of Ah-responsive genes such as Cyp1a1/CYP1A1 in YAMC mouse colonocytes and Caco-2 human colon cancer cell lines. Butyrate synergistically enhanced AhR ligand-induced Cyp1a1/CYP1A1 in these cells with comparable enhancement being observed for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and also microbiota-derived AhR ligands tryptamine, indole and 1,4-dihydroxy-2-naphthoic acid (DHNA). The effects of butyrate on enhancing induction of Cyp1b1/CYP1B1, AhR repressor (Ahrr/AhRR) and TCDD-inducible poly(ADP-ribose)polymerase (Tiparp/TiPARP) by AhR ligands were gene- and cell context-dependent with the Caco-2 cells being the most responsive cell line. Like butyrate and propionate, the prototypical hydroxyamic acid-derived histone deacetylase (HDAC) inhibitors Panobinostat and Vorinostat also enhanced AhR ligand-mediated induction and this was accompanied by enhanced histone acetylation. Acetate also enhanced basal and ligand-inducible Ah responsiveness and histone acetylation, demonstrating that acetate was an HDAC inhibitor. These results demonstrate SCFA-AhR ligand interactions in YAMC and Caco-2 cells where SCFAs synergistically enhance basal and ligand-induced expression of AhR-responsive genes.
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Aryl hydrocarbon receptor (AHR): "pioneer member" of the basic-helix/loop/helix per-Arnt-sim (bHLH/PAS) family of "sensors" of foreign and endogenous signals. Prog Lipid Res 2017; 67:38-57. [PMID: 28606467 DOI: 10.1016/j.plipres.2017.06.001] [Citation(s) in RCA: 159] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 05/05/2017] [Accepted: 06/05/2017] [Indexed: 12/21/2022]
Abstract
The basic-helix/loop/helix per-Arnt-sim (bHLH/PAS) family comprises many transcription factors, found throughout all three kingdoms of life; bHLH/PAS members "sense" innumerable intracellular and extracellular "signals" - including endogenous compounds, foreign chemicals, gas molecules, redox potential, photons (light), gravity, heat, and osmotic pressure. These signals then initiate downstream signaling pathways involved in responding to that signal. The term "PAS", abbreviation for "per-Arnt-sim" was first coined in 1991. Although the mouse Arnt gene was not identified until 1991, evidence of its co-transcriptional binding partner, aryl hydrocarbon receptor (AHR), was first reported in 1974 as a "sensor" of foreign chemicals, up-regulating cytochrome P450 family 1 (CYP1) and other enzyme activities that usually metabolize the signaling chemical. Within a few years, AHR was proposed also to participate in inflammation. The mouse [Ah] locus was shown (1973-1989) to be relevant to chemical carcinogenesis, mutagenesis, toxicity and teratogenesis, the mouse Ahr gene was cloned in 1992, and the first Ahr(-/-) knockout mouse line was reported in 1995. After thousands of studies from the early 1970s to present day, we now realize that AHR participates in dozens of signaling pathways involved in critical-life processes, affecting virtually every organ and cell-type in the animal, including many invertebrates.
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Abstract
Although most of pituitary adenomas are benign, they may cause significant burden to patients. Sporadic adenomas represent the vast majority of the cases, where recognized somatic mutations (eg, GNAS or USP8), as well as altered gene-expression profile often affecting cell cycle proteins have been identified. More rarely, germline mutations predisposing to pituitary adenomas -as part of a syndrome (eg, MEN1 or Carney complex), or isolated to the pituitary (AIP or GPR101) can be identified. These alterations influence the biological behavior, clinical presentations and therapeutic responses, and their full understanding helps to provide appropriate care for these patients.
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Affiliation(s)
- Pedro Marques
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Márta Korbonits
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK.
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Whitehead A, Clark BW, Reid NM, Hahn ME, Nacci D. When evolution is the solution to pollution: Key principles, and lessons from rapid repeated adaptation of killifish ( Fundulus heteroclitus) populations. Evol Appl 2017; 10:762-783. [PMID: 29151869 PMCID: PMC5680427 DOI: 10.1111/eva.12470] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 02/10/2017] [Indexed: 12/18/2022] Open
Abstract
For most species, evolutionary adaptation is not expected to be sufficiently rapid to buffer the effects of human‐mediated environmental changes, including environmental pollution. Here we review how key features of populations, the characteristics of environmental pollution, and the genetic architecture underlying adaptive traits, may interact to shape the likelihood of evolutionary rescue from pollution. Large populations of Atlantic killifish (Fundulus heteroclitus) persist in some of the most contaminated estuaries of the United States, and killifish studies have provided some of the first insights into the types of genomic changes that enable rapid evolutionary rescue from complexly degraded environments. We describe how selection by industrial pollutants and other stressors has acted on multiple populations of killifish and posit that extreme nucleotide diversity uniquely positions this species for successful evolutionary adaptation. Mechanistic studies have identified some of the genetic underpinnings of adaptation to a well‐studied class of toxic pollutants; however, multiple genetic regions under selection in wild populations seem to reflect more complex responses to diverse native stressors and/or compensatory responses to primary adaptation. The discovery of these pollution‐adapted killifish populations suggests that the evolutionary influence of anthropogenic stressors as selective agents occurs widely. Yet adaptation to chemical pollution in terrestrial and aquatic vertebrate wildlife may rarely be a successful “solution to pollution” because potentially adaptive phenotypes may be complex and incur fitness costs, and therefore be unlikely to evolve quickly enough, especially in species with small population sizes.
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Affiliation(s)
- Andrew Whitehead
- Department of Environmental Toxicology University of California Davis Davis CA USA
| | - Bryan W Clark
- Atlantic Ecology Division National Health and Environmental Effects Research Laboratory Office of Research and Development Oak Ridge Institute for Science and Education US Environmental Protection Agency Narragansett RI USA
| | - Noah M Reid
- Department of Molecular and Cell Biology University of Connecticut Storrs CT USA
| | - Mark E Hahn
- Department of Biology Woods Hole Oceanographic Institution Woods Hole MA USA.,Superfund Research Program Boston University Boston MA USA
| | - Diane Nacci
- Atlantic Ecology Division National Health and Environmental Effects Research Laboratory Office of Research and Development US Environmental Protection Agency Narragansett RI USA
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Schiering C, Wincent E, Metidji A, Iseppon A, Li Y, Potocnik AJ, Omenetti S, Henderson CJ, Wolf CR, Nebert DW, Stockinger B. Feedback control of AHR signalling regulates intestinal immunity. Nature 2017; 542:242-245. [PMID: 28146477 PMCID: PMC5302159 DOI: 10.1038/nature21080] [Citation(s) in RCA: 343] [Impact Index Per Article: 49.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 12/22/2016] [Indexed: 01/17/2023]
Abstract
The aryl hydrocarbon receptor (AHR) recognizes xenobiotics as well as natural compounds such as tryptophan metabolites, dietary components and microbiota-derived factors, and it is important for maintenance of homeostasis at mucosal surfaces. AHR activation induces cytochrome P4501 (CYP1) enzymes, which oxygenate AHR ligands, leading to their metabolic clearance and detoxification. Thus, CYP1 enzymes have an important feedback role that curtails the duration of AHR signalling, but it remains unclear whether they also regulate AHR ligand availability in vivo. Here we show that dysregulated expression of Cyp1a1 in mice depletes the reservoir of natural AHR ligands, generating a quasi AHR-deficient state. Constitutive expression of Cyp1a1 throughout the body or restricted specifically to intestinal epithelial cells resulted in loss of AHR-dependent type 3 innate lymphoid cells and T helper 17 cells and increased susceptibility to enteric infection. The deleterious effects of excessive AHR ligand degradation on intestinal immune functions could be counter-balanced by increasing the intake of AHR ligands in the diet. Thus, our data indicate that intestinal epithelial cells serve as gatekeepers for the supply of AHR ligands to the host and emphasize the importance of feedback control in modulating AHR pathway activation.
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Affiliation(s)
| | - Emma Wincent
- Swedish Toxicology Sciences Research Center, Södertälje, Sweden
| | | | | | - Ying Li
- The Francis Crick Institute, London, UK
| | - Alexandre J Potocnik
- Institute of Immunology and Infection Research, The University of Edinburgh, Edinburgh, UK
| | | | - Colin J Henderson
- Dundee University School of Medicine, Division of Cancer Research, Dundee, UK
| | - C Roland Wolf
- Dundee University School of Medicine, Division of Cancer Research, Dundee, UK
| | - Daniel W Nebert
- University of Cincinnati, Department of Environmental Health, Cincinnati, Ohio, USA
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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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Novikov O, Wang Z, Stanford EA, Parks AJ, Ramirez-Cardenas A, Landesman E, Laklouk I, Sarita-Reyes C, Gusenleitner D, Li A, Monti S, Manteiga S, Lee K, Sherr DH. An Aryl Hydrocarbon Receptor-Mediated Amplification Loop That Enforces Cell Migration in ER-/PR-/Her2- Human Breast Cancer Cells. Mol Pharmacol 2016; 90:674-688. [PMID: 27573671 PMCID: PMC5074452 DOI: 10.1124/mol.116.105361] [Citation(s) in RCA: 110] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 08/24/2016] [Indexed: 12/18/2022] Open
Abstract
The endogenous ligand-activated aryl hydrocarbon receptor (AHR) plays an important role in numerous biologic processes. As the known number of AHR-mediated processes grows, so too does the importance of determining what endogenous AHR ligands are produced, how their production is regulated, and what biologic consequences ensue. Consequently, our studies were designed primarily to determine whether ER−/PR−/Her2− breast cancer cells have the potential to produce endogenous AHR ligands and, if so, how production of these ligands is controlled. We postulated that: 1) malignant cells produce tryptophan-derived AHR ligand(s) through the kynurenine pathway; 2) these metabolites have the potential to drive AHR-dependent breast cancer migration; 3) the AHR controls expression of a rate-limiting kynurenine pathway enzyme(s) in a closed amplification loop; and 4) environmental AHR ligands mimic the effects of endogenous ligands. Data presented in this work indicate that primary human breast cancers, and their metastases, express high levels of AHR and tryptophan-2,3-dioxygenase (TDO); representative ER−/PR−/Her2− cell lines express TDO and produce sufficient intracellular kynurenine and xanthurenic acid concentrations to chronically activate the AHR. TDO overexpression, or excess kynurenine or xanthurenic acid, accelerates migration in an AHR-dependent fashion. Environmental AHR ligands 2,3,7,8-tetrachlorodibenzo[p]dioxin and benzo[a]pyrene mimic this effect. AHR knockdown or inhibition significantly reduces TDO2 expression. These studies identify, for the first time, a positive amplification loop in which AHR-dependent TDO2 expression contributes to endogenous AHR ligand production. The net biologic effect of AHR activation by endogenous ligands, which can be mimicked by environmental ligands, is an increase in tumor cell migration, a measure of tumor aggressiveness.
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Affiliation(s)
- Olga Novikov
- Department of Environmental Health, Boston University School of Public Health, Boston, Massachusetts (O.N., Z.W., E.A.S., A.J.P., A.R.-C., D.H.S.); Boston University Molecular and Translational Medicine Program, Boston, Massachusetts (O.N., E.A.S.); Department of Medicine, Division of Computational Biomedicine, Boston University School of Medicine, Boston, Massachusetts (D.G., A.L., S.Mo.); Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, Massachusetts (E.L., I.L., C.S.-R.); and Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts (S.Ma., K.L.)
| | - Zhongyan Wang
- Department of Environmental Health, Boston University School of Public Health, Boston, Massachusetts (O.N., Z.W., E.A.S., A.J.P., A.R.-C., D.H.S.); Boston University Molecular and Translational Medicine Program, Boston, Massachusetts (O.N., E.A.S.); Department of Medicine, Division of Computational Biomedicine, Boston University School of Medicine, Boston, Massachusetts (D.G., A.L., S.Mo.); Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, Massachusetts (E.L., I.L., C.S.-R.); and Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts (S.Ma., K.L.)
| | - Elizabeth A Stanford
- Department of Environmental Health, Boston University School of Public Health, Boston, Massachusetts (O.N., Z.W., E.A.S., A.J.P., A.R.-C., D.H.S.); Boston University Molecular and Translational Medicine Program, Boston, Massachusetts (O.N., E.A.S.); Department of Medicine, Division of Computational Biomedicine, Boston University School of Medicine, Boston, Massachusetts (D.G., A.L., S.Mo.); Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, Massachusetts (E.L., I.L., C.S.-R.); and Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts (S.Ma., K.L.)
| | - Ashley J Parks
- Department of Environmental Health, Boston University School of Public Health, Boston, Massachusetts (O.N., Z.W., E.A.S., A.J.P., A.R.-C., D.H.S.); Boston University Molecular and Translational Medicine Program, Boston, Massachusetts (O.N., E.A.S.); Department of Medicine, Division of Computational Biomedicine, Boston University School of Medicine, Boston, Massachusetts (D.G., A.L., S.Mo.); Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, Massachusetts (E.L., I.L., C.S.-R.); and Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts (S.Ma., K.L.)
| | - Alejandra Ramirez-Cardenas
- Department of Environmental Health, Boston University School of Public Health, Boston, Massachusetts (O.N., Z.W., E.A.S., A.J.P., A.R.-C., D.H.S.); Boston University Molecular and Translational Medicine Program, Boston, Massachusetts (O.N., E.A.S.); Department of Medicine, Division of Computational Biomedicine, Boston University School of Medicine, Boston, Massachusetts (D.G., A.L., S.Mo.); Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, Massachusetts (E.L., I.L., C.S.-R.); and Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts (S.Ma., K.L.)
| | - Esther Landesman
- Department of Environmental Health, Boston University School of Public Health, Boston, Massachusetts (O.N., Z.W., E.A.S., A.J.P., A.R.-C., D.H.S.); Boston University Molecular and Translational Medicine Program, Boston, Massachusetts (O.N., E.A.S.); Department of Medicine, Division of Computational Biomedicine, Boston University School of Medicine, Boston, Massachusetts (D.G., A.L., S.Mo.); Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, Massachusetts (E.L., I.L., C.S.-R.); and Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts (S.Ma., K.L.)
| | - Israa Laklouk
- Department of Environmental Health, Boston University School of Public Health, Boston, Massachusetts (O.N., Z.W., E.A.S., A.J.P., A.R.-C., D.H.S.); Boston University Molecular and Translational Medicine Program, Boston, Massachusetts (O.N., E.A.S.); Department of Medicine, Division of Computational Biomedicine, Boston University School of Medicine, Boston, Massachusetts (D.G., A.L., S.Mo.); Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, Massachusetts (E.L., I.L., C.S.-R.); and Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts (S.Ma., K.L.)
| | - Carmen Sarita-Reyes
- Department of Environmental Health, Boston University School of Public Health, Boston, Massachusetts (O.N., Z.W., E.A.S., A.J.P., A.R.-C., D.H.S.); Boston University Molecular and Translational Medicine Program, Boston, Massachusetts (O.N., E.A.S.); Department of Medicine, Division of Computational Biomedicine, Boston University School of Medicine, Boston, Massachusetts (D.G., A.L., S.Mo.); Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, Massachusetts (E.L., I.L., C.S.-R.); and Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts (S.Ma., K.L.)
| | - Daniel Gusenleitner
- Department of Environmental Health, Boston University School of Public Health, Boston, Massachusetts (O.N., Z.W., E.A.S., A.J.P., A.R.-C., D.H.S.); Boston University Molecular and Translational Medicine Program, Boston, Massachusetts (O.N., E.A.S.); Department of Medicine, Division of Computational Biomedicine, Boston University School of Medicine, Boston, Massachusetts (D.G., A.L., S.Mo.); Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, Massachusetts (E.L., I.L., C.S.-R.); and Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts (S.Ma., K.L.)
| | - Amy Li
- Department of Environmental Health, Boston University School of Public Health, Boston, Massachusetts (O.N., Z.W., E.A.S., A.J.P., A.R.-C., D.H.S.); Boston University Molecular and Translational Medicine Program, Boston, Massachusetts (O.N., E.A.S.); Department of Medicine, Division of Computational Biomedicine, Boston University School of Medicine, Boston, Massachusetts (D.G., A.L., S.Mo.); Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, Massachusetts (E.L., I.L., C.S.-R.); and Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts (S.Ma., K.L.)
| | - Stefano Monti
- Department of Environmental Health, Boston University School of Public Health, Boston, Massachusetts (O.N., Z.W., E.A.S., A.J.P., A.R.-C., D.H.S.); Boston University Molecular and Translational Medicine Program, Boston, Massachusetts (O.N., E.A.S.); Department of Medicine, Division of Computational Biomedicine, Boston University School of Medicine, Boston, Massachusetts (D.G., A.L., S.Mo.); Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, Massachusetts (E.L., I.L., C.S.-R.); and Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts (S.Ma., K.L.)
| | - Sara Manteiga
- Department of Environmental Health, Boston University School of Public Health, Boston, Massachusetts (O.N., Z.W., E.A.S., A.J.P., A.R.-C., D.H.S.); Boston University Molecular and Translational Medicine Program, Boston, Massachusetts (O.N., E.A.S.); Department of Medicine, Division of Computational Biomedicine, Boston University School of Medicine, Boston, Massachusetts (D.G., A.L., S.Mo.); Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, Massachusetts (E.L., I.L., C.S.-R.); and Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts (S.Ma., K.L.)
| | - Kyongbum Lee
- Department of Environmental Health, Boston University School of Public Health, Boston, Massachusetts (O.N., Z.W., E.A.S., A.J.P., A.R.-C., D.H.S.); Boston University Molecular and Translational Medicine Program, Boston, Massachusetts (O.N., E.A.S.); Department of Medicine, Division of Computational Biomedicine, Boston University School of Medicine, Boston, Massachusetts (D.G., A.L., S.Mo.); Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, Massachusetts (E.L., I.L., C.S.-R.); and Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts (S.Ma., K.L.)
| | - David H Sherr
- Department of Environmental Health, Boston University School of Public Health, Boston, Massachusetts (O.N., Z.W., E.A.S., A.J.P., A.R.-C., D.H.S.); Boston University Molecular and Translational Medicine Program, Boston, Massachusetts (O.N., E.A.S.); Department of Medicine, Division of Computational Biomedicine, Boston University School of Medicine, Boston, Massachusetts (D.G., A.L., S.Mo.); Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, Massachusetts (E.L., I.L., C.S.-R.); and Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts (S.Ma., K.L.)
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Palatnik A, Xin H, Su EJ. Dichotomous effects of aryl hydrocarbon receptor (AHR) activation on human fetoplacental endothelial cell function. Placenta 2016; 44:61-8. [PMID: 27452439 DOI: 10.1016/j.placenta.2016.06.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 04/26/2016] [Accepted: 06/10/2016] [Indexed: 12/29/2022]
Abstract
INTRODUCTION Maternal cigarette smoking is associated with elevated fetoplacental vascular resistance and fetal growth restriction (FGR). While studies have demonstrated varying effects of nicotine on blood flow, the role of polycyclic aromatic hydrocarbons (PAHs), abundant toxins in cigarette smoke that cross the placenta, has not been elucidated. We hypothesized that exposure of human fetoplacental endothelial cells (ECs) to the PAH benzo[a]yrene (BaP) would result in up-regulation of cyclooxygenase-2 (PTGS2) and preferential production of vasoconstrictive prostanoids via activation of the aryl hydrocarbon receptor (AHR) pathway. METHODS ECs were isolated, cultured, and treated with vehicle or BaP. ECs were subjected to real-time PCR, western blotting, enzyme immunoassays, wound scratch assays, tube formation assays, and RNA interference against AHR. Statistical analyses were performed with Student's t-test, one-way ANOVA followed by multiple comparisons testing when appropriate, or the Kruskal-Wallis H test. RESULTS BaP induced PTGS2 expression (p < 0.05) and production of the stable metabolite of prostacyclin (p = 0.001) in fetoplacental ECs without affecting thromboxane. These effects were ablated by PTGS2 inhibition (p < 0.01) and RNA interference of AHR (p < 0.001). Surprisingly, despite the induction of prostacyclin, EC migration (p = 0.007) and tube formation (p = 0.003) were inhibited by BaP. AHR inhibition, however, rescued tube formation (p = 0.008). DISCUSSION BaP-mediated AHR activation results in induction of PTGS2 expression and enhanced production of prostacyclin metabolite. Despite an increase in this vasodilatory and pro-angiogenic prostanoid, BaP exposure also impairs EC migration and angiogenesis through AHR. This suggests that PAH may adversely affect the fetoplacental vasculature through its regulation of angiogenesis.
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Affiliation(s)
- Anna Palatnik
- Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
| | - Hong Xin
- Department of Obstetrics and Gynecology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Emily J Su
- Department of Obstetrics and Gynecology, University of Colorado School of Medicine, Aurora, CO, USA
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Mulero-Navarro S, Fernandez-Salguero PM. New Trends in Aryl Hydrocarbon Receptor Biology. Front Cell Dev Biol 2016; 4:45. [PMID: 27243009 PMCID: PMC4863130 DOI: 10.3389/fcell.2016.00045] [Citation(s) in RCA: 161] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 04/28/2016] [Indexed: 12/28/2022] Open
Abstract
Traditionally considered as a critical intermediate in the toxic and carcinogenic response to dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin, TCDD), the Aryl hydrocarbon/Dioxin receptor (AhR) has proven to be also an important regulator of cell physiology and organ homeostasis. AhR has become an interesting and actual area of research mainly boosted by a significant number of recent studies analyzing its contribution to the proper functioning of the immune, hepatic, cardiovascular, vascular and reproductive systems. At the cellular level, AhR establishes functional interactions with signaling pathways governing cell proliferation and cell cycle, cell morphology, cell adhesion and cell migration. Two exciting new aspects in AhR biology deal with its implication in the control of cell differentiation and its more than likely involvement in cell pluripotency and stemness. In fact, it is possible that AhR could help modulate the balance between differentiation and pluripotency in normal and transformed tumor cells. At the molecular level, AhR regulates an increasingly large array of physiologically relevant genes either by traditional transcription-dependent mechanisms or by unforeseen processes involving genomic insulators, chromatin dynamics and the transcription of mobile genetic elements. AhR is also closely related to epigenetics, not only from the point of view of target gene expression but also with respect to its own regulation by promoter methylation. It is reasonable to consider that deregulation of these many functions could have a causative role, or at least contribute to, human disease. Consequently, several laboratories have proposed that AhR could be a valuable tool as diagnostic marker and/or therapeutic target in human pathologies. An additional point of interest is the possibility of regulating AhR activity by endogenous non-toxic low weight molecules agonist or antagonist molecules that could be present or included in the diet. In this review, we will address these molecular and functional features of AhR biology within physiological and pathological contexts.
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Affiliation(s)
- Sonia Mulero-Navarro
- Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Ciencias, Universidad de Extremadura Badajoz, Spain
| | - Pedro M Fernandez-Salguero
- Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Ciencias, Universidad de Extremadura Badajoz, Spain
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Van den Bossche L, van Steenbeek F. Canine congenital portosystemic shunts: Disconnections dissected. Vet J 2016; 211:14-20. [DOI: 10.1016/j.tvjl.2015.09.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 09/28/2015] [Accepted: 09/29/2015] [Indexed: 10/22/2022]
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The aryl hydrocarbon receptor promotes aging phenotypes across species. Sci Rep 2016; 6:19618. [PMID: 26790370 PMCID: PMC4726214 DOI: 10.1038/srep19618] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 12/16/2015] [Indexed: 02/06/2023] Open
Abstract
The ubiquitously expressed aryl hydrocarbon receptor (AhR) induces drug metabolizing enzymes as well as regulators of cell growth, differentiation and apoptosis. Certain AhR ligands promote atherosclerosis, an age-associated vascular disease. Therefore, we investigated the role of AhR in vascular functionality and aging. We report a lower pulse wave velocity in young and old AhR-deficient mice, indicative of enhanced vessel elasticity. Moreover, endothelial nitric oxide synthase (eNOS) showed increased activity in the aortas of these animals, which was reflected in increased NO production. Ex vivo, AhR activation reduced the migratory capacity of primary human endothelial cells. AhR overexpression as well as treatment with a receptor ligand, impaired eNOS activation and reduced S-NO content. All three are signs of endothelial dysfunction. Furthermore, AhR expression in blood cells of healthy human volunteers positively correlated with vessel stiffness. In the aging model Caenorhabditis elegans, AhR-deficiency resulted in increased mean life span, motility, pharynx pumping and heat shock resistance, suggesting healthier aging. Thus, AhR seems to have a negative impact on vascular and organismal aging. Finally, our data from human subjects suggest that AhR expression levels could serve as an additional, new predictor of vessel aging.
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Hubbard TD, Murray IA, Perdew GH. Indole and Tryptophan Metabolism: Endogenous and Dietary Routes to Ah Receptor Activation. Drug Metab Dispos 2015; 43:1522-35. [PMID: 26041783 PMCID: PMC4576673 DOI: 10.1124/dmd.115.064246] [Citation(s) in RCA: 406] [Impact Index Per Article: 45.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 06/02/2015] [Indexed: 12/31/2022] Open
Abstract
The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor recognized for its role in xenobiotic metabolism. The physiologic function of AHR has expanded to include roles in immune regulation, organogenesis, mucosal barrier function, and the cell cycle. These functions are likely dependent upon ligand-mediated activation of the receptor. High-affinity ligands of AHR have been classically defined as xenobiotics, such as polychlorinated biphenyls and dioxins. Identification of endogenous AHR ligands is key to understanding the physiologic functions of this enigmatic receptor. Metabolic pathways targeting the amino acid tryptophan and indole can lead to a myriad of metabolites, some of which are AHR ligands. Many of these ligands exhibit species selective preferential binding to AHR. The discovery of specific tryptophan metabolites as AHR ligands may provide insight concerning where AHR is activated in an organism, such as at the site of inflammation and within the intestinal tract.
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Affiliation(s)
- Troy D Hubbard
- Graduate Program in Biochemistry, Microbiology, and Molecular Biology (T.D.H.), and Center for Molecular Toxicology and Carcinogenesis and the Department of Veterinary and Biomedical Sciences (T.D.H., I.A.M., G.H.P)., Pennsylvania State University, University Park, Pennsylvania
| | - Iain A Murray
- Graduate Program in Biochemistry, Microbiology, and Molecular Biology (T.D.H.), and Center for Molecular Toxicology and Carcinogenesis and the Department of Veterinary and Biomedical Sciences (T.D.H., I.A.M., G.H.P)., Pennsylvania State University, University Park, Pennsylvania
| | - Gary H Perdew
- Graduate Program in Biochemistry, Microbiology, and Molecular Biology (T.D.H.), and Center for Molecular Toxicology and Carcinogenesis and the Department of Veterinary and Biomedical Sciences (T.D.H., I.A.M., G.H.P)., Pennsylvania State University, University Park, Pennsylvania
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Baker NA, Shoemaker R, English V, Larian N, Sunkara M, Morris AJ, Walker M, Yiannikouris F, Cassis LA. Effects of Adipocyte Aryl Hydrocarbon Receptor Deficiency on PCB-Induced Disruption of Glucose Homeostasis in Lean and Obese Mice. ENVIRONMENTAL HEALTH PERSPECTIVES 2015; 123:944-50. [PMID: 25734695 PMCID: PMC4590748 DOI: 10.1289/ehp.1408594] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 03/02/2015] [Indexed: 05/08/2023]
Abstract
BACKGROUND Coplanar polychlorinated biphenyls (PCBs) promote adipocyte inflammation and impair glucose homeostasis in lean mice. The diabetes-promoting effects of lipophilic PCBs have been observed only during weight loss in obese mice. The molecular mechanisms linking PCB exposures to impaired glucose metabolism are unclear. OBJECTIVES In this study we tested the hypothesis that coplanar PCBs act at adipocyte aryl hydrocarbon receptors (AhRs) to promote adipose inflammation and impair glucose homeostasis in lean mice and in obese mice during weight loss. METHODS AND RESULTS PCB-77 administration impaired glucose and insulin tolerance in LF (low fat diet)-fed control (AhR(fl/fl)) mice but not in adipocyte AhR-deficient mice (AhR(AdQ)). Unexpectedly, AhR(AdQ) mice exhibited increased fat mass when fed a standard LF or high fat (HF) diet. In mice fed a HF diet, both genotypes became obese, but AhR(AdQ) mice administered vehicle (VEH) exhibited increased body weight, adipose mass, adipose inflammation, and impaired glucose tolerance compared with AhR(fl/fl) controls. Impairment of glucose homeostasis in response to PCB-77 was not observed in obese mice of either genotype. However, upon weight loss, AhR(fl/fl) mice administered PCB-77 exhibited increased abundance of adipose tumor necrosis factor-α (TNF-α) mRNA and impaired glucose homeostasis compared with those administered VEH. In contrast, PCB-77 had no effect on TNF-α or glucose homeostasis in AhR(AdQ) mice exhibiting weight loss. CONCLUSIONS Our results demonstrate that adipocyte AhR mediates PCB-induced adipose inflammation and impairment of glucose homeostasis in mice. Moreover, deficiency of AhR in adipocytes augmented the development of obesity, indicating that endogenous ligand(s) for AhR regulate adipose homeostasis.
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Affiliation(s)
- Nicki A Baker
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, Kentucky, USA
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Dever DP, Adham ZO, Thompson B, Genestine M, Cherry J, Olschowka JA, DiCicco-Bloom E, Opanashuk LA. Aryl hydrocarbon receptor deletion in cerebellar granule neuron precursors impairs neurogenesis. Dev Neurobiol 2015; 76:533-50. [PMID: 26243376 DOI: 10.1002/dneu.22330] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 07/28/2015] [Indexed: 11/12/2022]
Abstract
The aryl hydrocarbon receptor (AhR) is a ligand-activated member of the basic-helix-loop-helix/PER-ARNT-SIM(PAS) transcription factor superfamily that also mediates the toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Increasing evidence suggests that AhR influences the development of many tissues, including the central nervous system. Our previous studies suggest that sustained AhR activation by TCDD and/or AhR deletion disrupts cerebellar granule neuron precursor (GNP) development. In the current study, to determine whether endogenous AhR controls GNP development in a cell-autonomous manner, we created a GNP-specific AhR deletion mouse, AhR(fx/fx) /Math1(CRE/+) (AhR CKO). Selective AhR deletion in GNPs produced abnormalities in proliferation and differentiation. Specifically, fewer GNPs were engaged in S-phase, as demonstrated by ∼25% reductions in thymidine (in vitro) and Bromodeoxyuridine (in vivo) incorporation. Furthermore, total granule neuron numbers in the internal granule layer at PND21 and PND60 were diminished in AhR conditional knockout (CKO) mice compared with controls. Conversely, differentiation was enhanced, including ∼40% increase in neurite outgrowth and 50% increase in GABARα6 receptor expression in deletion mutants. Our results suggest that AhR activity plays a role in regulating granule neuron number and differentiation, possibly by coordinating this GNP developmental transition. These studies provide novel insights for understanding the normal roles of AhR signaling during cerebellar granule cell neurogenesis and may have important implications for the effects of environmental factors in cerebellar dysgenesis.
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Affiliation(s)
- Daniel P Dever
- Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, Rochester, New York, 14642
| | - Zachariah O Adham
- Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, Rochester, New York, 14642
| | - Bryan Thompson
- Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, Rochester, New York, 14642
| | - Matthieu Genestine
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers, the State University of New Jersey, Piscataway, New Jersey, 08854
| | - Jonathan Cherry
- Department of Pathology and Laboratory Medicine, University of Rochester School of Medicine and Dentistry, Rochester, New York, 14642
| | - John A Olschowka
- Department of Neurobiology and Anatomy, University of Rochester School of Medicine and Dentistry, Rochester, New York, 14642
| | - Emanuel DiCicco-Bloom
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers, the State University of New Jersey, Piscataway, New Jersey, 08854
| | - Lisa A Opanashuk
- Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, Rochester, New York, 14642
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Guy NC, Garcia YA, Sivils JC, Galigniana MD, Cox MB. Functions of the Hsp90-binding FKBP immunophilins. Subcell Biochem 2015; 78:35-68. [PMID: 25487015 DOI: 10.1007/978-3-319-11731-7_2] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Hsp90 functionally interacts with a broad array of client proteins, but in every case examined Hsp90 is accompanied by one or more co-chaperones. One class of co-chaperone contains a tetratricopeptide repeat domain that targets the co-chaperone to the C-terminal region of Hsp90. Within this class are Hsp90-binding peptidylprolyl isomerases, most of which belong to the FK506-binding protein (FKBP) family. Despite the common association of FKBP co-chaperones with Hsp90, it is now clear that the client protein influences, and is influenced by, the particular FKBP bound to Hsp90. Examples include Xap2 in aryl hydrocarbon receptor complexes and FKBP52 in steroid receptor complexes. In this chapter, we discuss the known functional roles played by FKBP co-chaperones and, where possible, relate distinctive functions to structural differences between FKBP members.
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Affiliation(s)
- Naihsuan C Guy
- Department of Biological Sciences, Border Biomedical Research Center, University of Texas at El Paso, 79968, El Paso, TX, USA,
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Brokken LJS, Giwercman YL. Gene-environment interactions in male reproductive health: special reference to the aryl hydrocarbon receptor signaling pathway. Asian J Androl 2014; 16:89-96. [PMID: 24369137 PMCID: PMC3901886 DOI: 10.4103/1008-682x.122193] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Over the last few decades, there have been numerous reports of adverse effects on the reproductive health of wildlife and laboratory animals caused by exposure to endocrine disrupting chemicals (EDCs). The increasing trends in human male reproductive disorders and the mounting evidence for causative environmental factors have therefore sparked growing interest in the health threat posed to humans by EDCs, which are substances in our food, environment and consumer items that interfere with hormone action, biosynthesis or metabolism, resulting in disrupted tissue homeostasis or reproductive function. The mechanisms of EDCs involve a wide array of actions and pathways. Examples include the estrogenic, androgenic, thyroid and retinoid pathways, in which the EDCs may act directly as agonists or antagonists, or indirectly via other nuclear receptors. Dioxins and dioxin-like EDCs exert their biological and toxicological actions through activation of the aryl hydrocarbon-receptor, which besides inducing transcription of detoxifying enzymes also regulates transcriptional activity of other nuclear receptors. There is increasing evidence that genetic predispositions may modify the susceptibility to adverse effects of toxic chemicals. In this review, potential consequences of hereditary predisposition and EDCs are discussed, with a special focus on the currently available publications on interactions between dioxin and androgen signaling.
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Affiliation(s)
- Leon J S Brokken
- Department of Clinical Sciences, Molecular Genetic Reproductive Medicine, Lund University, Malmö, Sweden
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