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From Nucleus to Organs: Insights of Aryl Hydrocarbon Receptor Molecular Mechanisms. Int J Mol Sci 2022; 23:ijms232314919. [PMID: 36499247 PMCID: PMC9738205 DOI: 10.3390/ijms232314919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 11/23/2022] [Accepted: 11/24/2022] [Indexed: 11/30/2022] Open
Abstract
The aryl hydrocarbon receptor (AHR) is a markedly established regulator of a plethora of cellular and molecular processes. Its initial role in the detoxification of xenobiotic compounds has been partially overshadowed by its involvement in homeostatic and organ physiology processes. In fact, the discovery of its ability to bind specific target regulatory sequences has allowed for the understanding of how AHR modulates such processes. Thereby, AHR presents functions in transcriptional regulation, chromatin architecture modifications and participation in different key signaling pathways. Interestingly, such fields of influence end up affecting organ and tissue homeostasis, including regenerative response both to endogenous and exogenous stimuli. Therefore, from classical spheres such as canonical transcriptional regulation in embryonic development, cell migration, differentiation or tumor progression to modern approaches in epigenetics, senescence, immune system or microbiome, this review covers all aspects derived from the balance between regulation/deregulation of AHR and its physio-pathological consequences.
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Patil NY, Rus I, Downing E, Mandala A, Friedman JE, Joshi AD. Cinnabarinic Acid Provides Hepatoprotection Against Nonalcoholic Fatty Liver Disease. J Pharmacol Exp Ther 2022; 383:32-43. [PMID: 35933113 PMCID: PMC9513857 DOI: 10.1124/jpet.122.001301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 07/12/2022] [Indexed: 11/22/2022] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a chronic condition in which excess lipids accumulate in the liver and can lead to a range of progressive liver disorders including non-alcoholic steatohepatitis, liver cirrhosis, and hepatocellular carcinoma. While lifestyle and diet modifications have proven to be effective as NAFLD treatments, they are not sustainable in the long-term, and currently no pharmacological therapies are approved to treat NAFLD. Our previous studies demonstrated that cinnabarinic acid (CA), a novel endogenous Aryl hydrocarbon Receptor (AhR) agonist, activates the AhR target gene, Stanniocalcin 2, and confers cytoprotection against a plethora of ER/oxidative stressors. In this study, the hepatoprotective and anti-steatotic properties of CA were examined against free fatty-acid-induced in vitro and high-fat-diet fed in vivo NAFLD models. The results demonstrated that CA treatment significantly lowered weight gain and attenuated hepatic lipotoxicity both before and after the established fatty liver, thereby protecting against steatosis, inflammation, and liver injury. CA mitigated intracellular free fatty acid uptake concomitant with the downregulation of CD36/fatty acid translocase. Genes involved in fatty acid and triglyceride synthesis were also downregulated in response to CA treatment. Additionally, suppressing AhR and Stc2 expression using RNA interference in vitro verified that the hepatoprotective effects of CA were absolutely dependent on both AhR and its target, Stc2. Collectively, our results demonstrate that the endogenous AhR agonist, CA, confers hepatoprotection against NAFLD by regulating hepatic fatty acid uptake and lipogenesis. SIGNIFICANCE STATEMENT: In this study using in vitro and in vivo models, we demonstrate that cinnabarinic acid (CA), an endogenous AhR agonist, provides protection against non-alcoholic fatty liver disease. CA bestows cytoprotection against steatosis and liver injury by controlling expression of several key genes associated with lipid metabolism pathways, limiting the hepatic lipid uptake, and controlling liver inflammation. Moreover, CA-induced hepatoprotection is absolutely dependent on AhR and Stc2 expression.
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Affiliation(s)
- Nikhil Y Patil
- Department of Pharmaceutical Sciences (N.Y.P., I.R., E.D., A.D.J.) and Harold Hamm Diabetes Center (A.M., J.E.F., A.D.J.), University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Iulia Rus
- Department of Pharmaceutical Sciences (N.Y.P., I.R., E.D., A.D.J.) and Harold Hamm Diabetes Center (A.M., J.E.F., A.D.J.), University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Emma Downing
- Department of Pharmaceutical Sciences (N.Y.P., I.R., E.D., A.D.J.) and Harold Hamm Diabetes Center (A.M., J.E.F., A.D.J.), University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Ashok Mandala
- Department of Pharmaceutical Sciences (N.Y.P., I.R., E.D., A.D.J.) and Harold Hamm Diabetes Center (A.M., J.E.F., A.D.J.), University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Jacob E Friedman
- Department of Pharmaceutical Sciences (N.Y.P., I.R., E.D., A.D.J.) and Harold Hamm Diabetes Center (A.M., J.E.F., A.D.J.), University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Aditya D Joshi
- Department of Pharmaceutical Sciences (N.Y.P., I.R., E.D., A.D.J.) and Harold Hamm Diabetes Center (A.M., J.E.F., A.D.J.), University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
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Nacarino-Palma A, Rico-Leo EM, Campisi J, Ramanathan A, González-Rico FJ, Rejano-Gordillo CM, Ordiales-Talavero A, Merino JM, Fernández-Salguero PM. Aryl hydrocarbon receptor blocks aging-induced senescence in the liver and fibroblast cells. Aging (Albany NY) 2022; 14:4281-4304. [PMID: 35619220 PMCID: PMC9186759 DOI: 10.18632/aging.204103] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 03/06/2022] [Indexed: 01/10/2023]
Abstract
Aging impairs organismal homeostasis leading to multiple pathologies. Yet, the mechanisms and molecular intermediates involved are largely unknown. Here, we report that aged aryl hydrocarbon receptor-null mice (AhR-/-) had exacerbated cellular senescence and more liver progenitor cells. Senescence-associated markers β-galactosidase (SA-β-Gal), p16Ink4a and p21Cip1 and genes encoding senescence-associated secretory phenotype (SASP) factors TNF and IL1 were overexpressed in aged AhR-/- livers. Chromatin immunoprecipitation showed that AhR binding to those gene promoters repressed their expression, thus adjusting physiological levels in AhR+/+ livers. MCP-2, MMP12 and FGF secreted by senescent cells were overproduced in aged AhR-null livers. Supporting the relationship between senescence and stemness, liver progenitor cells were overrepresented in AhR-/- mice, probably contributing to increased hepatocarcinoma burden. These AhR roles are not liver-specific since adult and embryonic AhR-null fibroblasts underwent senescence in culture, overexpressing SA-β-Gal, p16Ink4a and p21Cip1. Notably, depletion of senescent cells with the senolytic agent navitoclax restored expression of senescent markers in AhR-/- fibroblasts, whereas senescence induction by palbociclib induced an AhR-null-like phenotype in AhR+/+ fibroblasts. AhR levels were downregulated by senescence in mouse lungs but restored upon depletion of p16Ink4a-expressing senescent cells. Thus, AhR restricts age-induced senescence associated to a differentiated phenotype eventually inducing resistance to liver tumorigenesis.
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Affiliation(s)
- Ana Nacarino-Palma
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Extremadura, Badajoz 06071, Spain.,Instituto Universitario de Investigación Biosanitaria de Extremadura (INUBE), Badajoz 06071, Spain
| | - Eva M Rico-Leo
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Extremadura, Badajoz 06071, Spain.,Instituto Universitario de Investigación Biosanitaria de Extremadura (INUBE), Badajoz 06071, Spain
| | - Judith Campisi
- Buck Institute for Research on Aging, Novato, CA 94945, USA.,Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | | | - Francisco J González-Rico
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Extremadura, Badajoz 06071, Spain.,Instituto Universitario de Investigación Biosanitaria de Extremadura (INUBE), Badajoz 06071, Spain
| | - Claudia M Rejano-Gordillo
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Extremadura, Badajoz 06071, Spain.,Instituto Universitario de Investigación Biosanitaria de Extremadura (INUBE), Badajoz 06071, Spain
| | - Ana Ordiales-Talavero
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Extremadura, Badajoz 06071, Spain.,Instituto Universitario de Investigación Biosanitaria de Extremadura (INUBE), Badajoz 06071, Spain
| | - Jaime M Merino
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Extremadura, Badajoz 06071, Spain.,Instituto Universitario de Investigación Biosanitaria de Extremadura (INUBE), Badajoz 06071, Spain
| | - Pedro M Fernández-Salguero
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Extremadura, Badajoz 06071, Spain.,Instituto Universitario de Investigación Biosanitaria de Extremadura (INUBE), Badajoz 06071, Spain
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Vazquez JH, Kennon-McGill S, Byrum SD, Mackintosh SG, Jaeschke H, Williams DK, Lee WM, Dranoff JA, McGill MR. Proteomics Indicates Lactate Dehydrogenase Is Prognostic in Acetaminophen-Induced Acute Liver Failure Patients and Reveals Altered Signaling Pathways. Toxicol Sci 2022; 187:25-34. [PMID: 35172013 PMCID: PMC9216044 DOI: 10.1093/toxsci/kfac015] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/29/2023] Open
Abstract
Better biomarkers to predict death early in acute liver failure (ALF) are needed. To that end, we obtained early (study day 1) and later (day 3) serum samples from transplant-free survivors (n = 28) and nonsurvivors (n = 30) of acetaminophen-induced ALF from the NIH-sponsored Acute Liver Failure Study Group and from control volunteers (n = 10). To identify proteins that increase early in serum during ALF, we selected individuals from this cohort for whom alanine aminotransferase was lower on day 1 than day 3, indicating a time point before peak injury (n = 10/group). We then performed untargeted proteomics on their day 1 samples. Out of 1682 quantifiable proteins, 361 were ≥ 4-fold elevated or decreased in ALF patients versus controls and 16 of those were further elevated or decreased ≥ 4-fold in nonsurvivors versus survivors, indicating potential to predict death. Interestingly, 1 of the biomarkers was lactate dehydrogenase (LDH), which is already measured in most clinical laboratories. To validate our proteomics results and to confirm the prognostic potential of LDH, we measured LDH activity in all day 1 and 3 samples from all 58 ALF patients. LDH was elevated in the nonsurvivors versus survivors on both days. In addition, it had prognostic value similar to the model for end-stage liver disease and outperformed the King's College Criteria, while a combination of model for end-stage liver disease and LDH together outperformed either alone. Finally, bioinformatics analysis of our proteomics data revealed alteration of numerous signaling pathways that may be important in liver regeneration. Overall, we conclude LDH can predict death in APAP-induced ALF.
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Affiliation(s)
- Joel H Vazquez
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA
| | - Stefanie Kennon-McGill
- Department of Environmental and Occupational Health, Fay W. Boozman College of Public Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA
| | - Stephanie D Byrum
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA
| | - Samuel G Mackintosh
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA
| | - Hartmut Jaeschke
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
| | - D Keith Williams
- Department of Biostatistics, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA
| | - William M Lee
- Division of Digestive and Liver Diseases, Department of Internal Medicine, University of Texas Southwestern Med School, Dallas, Texas 75390, USA
| | - Jonathan A Dranoff
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA
| | - Mitchell R McGill
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA
- Department of Environmental and Occupational Health, Fay W. Boozman College of Public Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA
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Rejano-Gordillo C, Ordiales-Talavero A, Nacarino-Palma A, Merino JM, González-Rico FJ, Fernández-Salguero PM. Aryl Hydrocarbon Receptor: From Homeostasis to Tumor Progression. Front Cell Dev Biol 2022; 10:884004. [PMID: 35465323 PMCID: PMC9022225 DOI: 10.3389/fcell.2022.884004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 03/15/2022] [Indexed: 12/19/2022] Open
Abstract
Transcription factor aryl hydrocarbon receptor (AHR) has emerged as one of the main regulators involved both in different homeostatic cell functions and tumor progression. Being a member of the family of basic-helix-loop-helix (bHLH) transcriptional regulators, this intracellular receptor has become a key member in differentiation, pluripotency, chromatin dynamics and cell reprogramming processes, with plenty of new targets identified in the last decade. Besides this role in tissue homeostasis, one enthralling feature of AHR is its capacity of acting as an oncogene or tumor suppressor depending on the specific organ, tissue and cell type. Together with its well-known modulation of cell adhesion and migration in a cell-type specific manner in epithelial-mesenchymal transition (EMT), this duality has also contributed to the arise of its clinical interest, highlighting a new potential as therapeutic tool, diagnosis and prognosis marker. Therefore, a deregulation of AHR-controlled pathways may have a causal role in contributing to physiological and homeostatic failures, tumor progression and dissemination. With that firmly in mind, this review will address the remarkable capability of AHR to exert a different function influenced by the phenotype of the target cell and its potential consequences.
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Affiliation(s)
- Claudia Rejano-Gordillo
- Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain
| | - Ana Ordiales-Talavero
- Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain
| | - Ana Nacarino-Palma
- Chronic Diseases Research Centre (CEDOC), Rua Do Instituto Bacteriológico, Lisboa, Portugal
| | - Jaime M. Merino
- Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain
| | - Francisco J. González-Rico
- Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain
- *Correspondence: Francisco J. González-Rico, ; Pedro M. Fernández-Salguero,
| | - Pedro M. Fernández-Salguero
- Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain
- *Correspondence: Francisco J. González-Rico, ; Pedro M. Fernández-Salguero,
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Rico-Leo EM, Lorenzo-Martín LF, Román ÁC, Bustelo XR, Merino JM, Fernández-Salguero PM. Aryl hydrocarbon receptor controls skin homeostasis, regeneration, and hair follicle cycling by adjusting epidermal stem cell function. Stem Cells 2021; 39:1733-1750. [PMID: 34423894 DOI: 10.1002/stem.3443] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 07/28/2021] [Indexed: 12/20/2022]
Abstract
Skin integrity requires constant maintenance of a quiescent, yet responsive, population of stem cells. While interfollicular epidermal progenitors control normal homeostasis, hair follicle stem cells residing within the bulge provide regenerative potential during hair cycle and in response to wounding. The aryl hydrocarbon receptor (AhR) modulates cell plasticity and differentiation and its overactivation results in severe skin lesions in humans. However, its physiological role in skin homeostasis and hair growth is unknown. Reconstitution assays grafting primary keratinocytes and dermal fibroblasts into nude mice and 3-D epidermal equivalents revealed a positive role for AhR in skin regeneration, epidermal differentiation, and stem cell maintenance. Furthermore, lack of receptor expression in AhR-/- mice delayed morphogenesis and impaired hair regrowth with a phenotype closely correlating with a reduction in suprabasal bulge stem cells (α6low CD34+ ). Moreover, RNA-microarray and RT-qPCR analyses of fluorescence-activated cell sorting (FACS)-isolated bulge stem cells revealed that AhR depletion impaired transcriptional signatures typical of both epidermal progenitors and bulge stem cells but upregulated differentiation markers likely compromising their undifferentiated phenotype. Altogether, our findings support that AhR controls skin regeneration and homeostasis by ensuring epidermal stem cell identity and highlights this receptor as potential target for the treatment of cutaneous pathologies.
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Affiliation(s)
- Eva María Rico-Leo
- Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain.,Instituto Universitario de Investigación Biosanitaria de Extremadura (INUBE), Badajoz, Spain
| | | | - Ángel Carlos Román
- Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain
| | - Xosé Ramón Bustelo
- Centro de Investigación del Cáncer and CIBERONC, CSIC-Universidad de Salamanca, Salamanca, Spain
| | - Jaime María Merino
- Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain.,Instituto Universitario de Investigación Biosanitaria de Extremadura (INUBE), Badajoz, Spain
| | - Pedro María Fernández-Salguero
- Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain.,Instituto Universitario de Investigación Biosanitaria de Extremadura (INUBE), Badajoz, Spain
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Zablon HA, Ko CI, Puga A. Converging Roles of the Aryl Hydrocarbon Receptor in Early Embryonic Development, Maintenance of Stemness, and Tissue Repair. Toxicol Sci 2021; 182:1-9. [PMID: 34009372 PMCID: PMC8285021 DOI: 10.1093/toxsci/kfab050] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor well-known for its adaptive role as a sensor of environmental toxicants and mediator of the metabolic detoxification of xenobiotic ligands. In addition, a growing body of experimental data has provided indisputable evidence that the AHR regulates critical functions of cell physiology and embryonic development. Recent studies have shown that the naïve AHR-that is, unliganded to xenobiotics but activated endogenously-has a crucial role in maintenance of embryonic stem cell pluripotency, tissue repair, and regulation of cancer stem cell stemness. Depending on the cellular context, AHR silences the expression of pluripotency genes Oct4 and Nanog and potentiates differentiation, whereas curtailing cellular plasticity and stemness. In these processes, AHR-mediated contextual responses and outcomes are dictated by changes of interacting partners in signaling pathways, gene networks, and cell-type-specific genomic structures. In this review, we focus on AHR-mediated changes of genomic architecture as an emerging mechanism for the AHR to regulate gene expression at the transcriptional level. Collective evidence places this receptor as a physiological hub connecting multiple biological processes whose disruption impacts on embryonic development, tissue repair, and maintenance or loss of stemness.
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Affiliation(s)
| | | | - Alvaro Puga
- Department of Environmental and Public Health Sciences, Center for Environmental Genetics, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, USA
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Kamelia L, Rietjens IMCM, Boogaard PJ. Developmental toxicity testing of the fume condensate extracts of bitumen and oxidized asphalt in a series of in vitro alternative assays. Toxicol In Vitro 2021; 75:105195. [PMID: 34022403 DOI: 10.1016/j.tiv.2021.105195] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 05/03/2021] [Accepted: 05/15/2021] [Indexed: 12/26/2022]
Abstract
The potential developmental toxicity and mode-of-action of fume condensate extracts of bitumen and oxidized asphalt were evaluated in the aryl hydrocarbon receptor (AhR) CALUX assay, the zebrafish embryotoxicity test (ZET), and the mouse embryonic stem cell test (mEST). In the AhR CALUX assay, both fume condensate extracts showed a concentration-dependent AhR induction following 6-h of exposure, but this activity was substantially reduced after 24-h, indicating a transient AhR activation. The main effect observed in the ZET was early embryonic lethality that occurred mostly in the 24 h-post-fertilization (hpf). This typically reflects non-specific toxicity rather than in vitro developmental toxicity of the fume condensate extracts tested since this effect was not seen as a result of the whole cumulative exposure period in the ZET (up to 96 hpf). No malformations were seen in any zebrafish embryo exposed to these fume condensate extracts, although some developed pericardial and/or yolk-sac edemas. Furthermore, both fume condensate extracts tested negative in the mEST. In conclusion, the results show that fume condensate extracts of bitumen and oxidized asphalt do not induce any in vitro developmental toxicity, which is in line with the results observed in the in vivo prenatal developmental toxicity studies performed with the same materials.
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Affiliation(s)
- Lenny Kamelia
- Division of Toxicology, Wageningen University and Research, 6708 WE, Wageningen, The Netherlands.
| | - Ivonne M C M Rietjens
- Division of Toxicology, Wageningen University and Research, 6708 WE, Wageningen, The Netherlands
| | - Peter J Boogaard
- Division of Toxicology, Wageningen University and Research, 6708 WE, Wageningen, The Netherlands; Shell Health, Shell International Bv, PO Box 162, 2501 AN, The Hague, The Netherlands
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Zaragoza-Ojeda M, Apatiga-Vega E, Arenas-Huertero F. Role of aryl hydrocarbon receptor in central nervous system tumors: Biological and therapeutic implications. Oncol Lett 2021; 21:460. [PMID: 33907570 PMCID: PMC8063300 DOI: 10.3892/ol.2021.12721] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 01/25/2021] [Indexed: 12/12/2022] Open
Abstract
Aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor, whose canonical pathway mainly regulates the genes involved in xenobiotic metabolism. However, it can also regulate several responses in a non-canonical manner, such as proliferation, differentiation, cell death and cell adhesion. AhR plays an important role in central nervous system tumors, as it can regulate several cellular responses via different pathways. The polymorphisms of the AHR gene have been associated with the development of gliomas. In addition, the metabolism of tumor cells promotes tumor growth, particularly in tryptophan synthesis, where some metabolites, such as kynurenine, can activate the AhR pathway, triggering cell proliferation in astrocytomas, medulloblastomas and glioblastomas. Furthermore, as part of the changes in neuroblastomas, AHR is able to downregulate the expression of proto-oncogene c-Myc, induce differentiation in tumor cells, and cause cell cycle arrest and apoptosis. Collectively, these data suggested that the modulation of the AhR pathway may downregulate tumor growth, providing a novel strategy for applications for the treatment of certain tumors through the control of the AhR pathway.
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Affiliation(s)
- Montserrat Zaragoza-Ojeda
- Laboratorio de Investigación en Patología Experimental, Hospital Infantil de México Federico Gómez, Mexico City 06720, México.,Posgrado en Ciencias Biológicas, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Mexico City 04510, México
| | - Elisa Apatiga-Vega
- Laboratorio de Investigación en Patología Experimental, Hospital Infantil de México Federico Gómez, Mexico City 06720, México
| | - Francisco Arenas-Huertero
- Laboratorio de Investigación en Patología Experimental, Hospital Infantil de México Federico Gómez, Mexico City 06720, México
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10
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Chen Q, Ding X, Lei J, Qiu L. Comparison of the biological behaviors of palatal mesenchymal and epithelial cells induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin in vitro. Toxicol Lett 2020; 333:90-96. [PMID: 32768652 DOI: 10.1016/j.toxlet.2020.08.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 07/24/2020] [Accepted: 08/02/2020] [Indexed: 12/11/2022]
Abstract
2,3,7,8-Tetrachlorodibenzo- p-dioxin (TCDD) effectively induces cleft palate at increased doses, but its mechanism of involvement is unclear, and arguments have examined palatal shelf contact and/or fusion failure. The role of different types of cells constituting palatal skulls remains elusive regarding TCDD dosage. No reports have simultaneously compared the biological behaviors of TCDD- induced mesenchymal and epithelial cells in vitro. This study employed primary epithelial and mesenchymal cells as models in vitro to explore proliferation, migration, apoptosis and epithelial-to-mesenchymal transition with two different doses of TCDD (10 nmol/L, 100 nmol/L), contrasted with a control group without TCDD. Interestingly, we found the EMT process of primary palatal epithelial cells occurred automatically in vitro without helping bilateral palatal contact. The results showed that, with the low dose of TCDD, transformation of epithelial cells to mesenchymal cells was inhibited, and mesenchymal cell proliferation and migration were promoted. At high doses, mesenchymal cells decreased, preventing palate development, uprising and contact, while the EMT of epithelial cells decreased. Regardless of dose of TCDD, no impact on migration and apoptosis of epithelial cells was noted, but there was increased apoptosis of mesenchymal cell in a dose-dependent manner.
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Affiliation(s)
- Qiang Chen
- Department of Burn and Plastic Surgery Children's hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders; Chongqing Key Laboratory of Pediatrics.
| | - Xionghui Ding
- Department of Burn and Plastic Surgery Children's hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders; Chongqing Key Laboratory of Pediatrics.
| | - Junqiu Lei
- Department of Burn and Plastic Surgery Children's hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders; Chongqing Key Laboratory of Pediatrics.
| | - Lin Qiu
- Department of Burn and Plastic Surgery Children's hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders; Chongqing Key Laboratory of Pediatrics.
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11
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Arenas-Huertero F, Zaragoza-Ojeda M, Sánchez-Alarcón J, Milić M, Šegvić Klarić M, Montiel-González JM, Valencia-Quintana R. Involvement of Ahr Pathway in Toxicity of Aflatoxins and Other Mycotoxins. Front Microbiol 2019; 10:2347. [PMID: 31681212 PMCID: PMC6798329 DOI: 10.3389/fmicb.2019.02347] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 09/26/2019] [Indexed: 12/18/2022] Open
Abstract
The purpose of this review is to present information about the role of activation of aflatoxins and other mycotoxins, of the aryl hydrocarbon receptor (AhR) pathway. Aflatoxins and other mycotoxins are a diverse group of secondary metabolites that can be contaminants in a broad range of agricultural products and feeds. Some species of Aspergillus, Alternaria, Penicilium, and Fusarium are major producers of mycotoxins, some of which are toxic and carcinogenic. Several aflatoxins are planar molecules that can activate the AhR. AhR participates in the detoxification of several xenobiotic substances and activates phase I and phase II detoxification pathways. But it is important to recognize that AhR activation also affects differentiation, cell adhesion, proliferation, and immune response among others. Any examination of the effects of aflatoxins and other toxins that act as activators to AhR must consider the potential of the disruption of several cellular functions in order to extend the perception thus far about the toxic and carcinogenic effects of these toxins. There have been no Reviews of existing data between the relation of AhR and aflatoxins and this one attempts to give information precisely about this dichotomy.
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Affiliation(s)
- Francisco Arenas-Huertero
- Experimental Pathology Research Laboratory, Children’s Hospital of Mexico Federico Gómez, Mexico, Mexico
| | - Montserrat Zaragoza-Ojeda
- Experimental Pathology Research Laboratory, Children’s Hospital of Mexico Federico Gómez, Mexico, Mexico
| | - Juana Sánchez-Alarcón
- Rafael Villalobos-Pietrini Laboratory of Genomic Toxicology and Environmental Chemistry, Faculty of Agrobiology, Autonomous University of Tlaxcala, Tlaxcala, Mexico
| | - Mirta Milić
- Mutagenesis Unit, Institute for Medical Research and Occupational Health, Zagreb, Croatia
| | - Maja Šegvić Klarić
- Department of Microbiology, Faculty of Pharmacy and Biochemistry, University of Zagreb, Zagreb, Croatia
| | - José M. Montiel-González
- Rafael Villalobos-Pietrini Laboratory of Genomic Toxicology and Environmental Chemistry, Faculty of Agrobiology, Autonomous University of Tlaxcala, Tlaxcala, Mexico
| | - Rafael Valencia-Quintana
- Rafael Villalobos-Pietrini Laboratory of Genomic Toxicology and Environmental Chemistry, Faculty of Agrobiology, Autonomous University of Tlaxcala, Tlaxcala, Mexico
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12
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Steenbergen R, Oti M, Ter Horst R, Tat W, Neufeldt C, Belovodskiy A, Chua TT, Cho WJ, Joyce M, Dutilh BE, Tyrrell DL. Establishing normal metabolism and differentiation in hepatocellular carcinoma cells by culturing in adult human serum. Sci Rep 2018; 8:11685. [PMID: 30076349 PMCID: PMC6076254 DOI: 10.1038/s41598-018-29763-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 07/05/2018] [Indexed: 12/31/2022] Open
Abstract
Tissue culture medium routinely contains fetal bovine serum (FBS). Here we show that culturing human hepatoma cells in their native, adult serum (human serum, HS) results in the restoration of key morphological and metabolic features of normal liver cells. When moved to HS, these cells show differential transcription of 22–32% of the genes, stop proliferating, and assume a hepatocyte-like morphology. Metabolic analysis shows that the Warburg-like metabolic profile, typical for FBS-cultured cells, is replaced by a diverse metabolic profile consistent with in vivo hepatocytes, including the formation of large lipid and glycogen stores, increased glycogenesis, increased beta-oxidation and ketogenesis, and decreased glycolysis. Finally, organ-specific functions are restored, including xenobiotics degradation and secretion of bile, VLDL and albumin. Thus, organ-specific functions are not necessarily lost in cell cultures, but might be merely suppressed in FBS. The effect of serum is often overseen in cell culture and we provide a detailed study in the changes that occur and provide insight in some of the serum components that may play a role in the establishment of the differentiated phenotype.
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Affiliation(s)
- Rineke Steenbergen
- Li Ka Shing Institute of Virology, Dept. of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada.
| | - Martin Oti
- Carlos Chagas Filho Biophysics Institute (IBCCF), Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Rob Ter Horst
- Centre for Molecular and Biomolecular Informatics, Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Wilson Tat
- Li Ka Shing Institute of Virology, Dept. of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada
| | - Chris Neufeldt
- Li Ka Shing Institute of Virology, Dept. of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada
| | - Alexandr Belovodskiy
- Li Ka Shing Institute of Virology, Dept. of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada
| | - Tiing Tiing Chua
- Li Ka Shing Institute of Virology, Dept. of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada
| | - Woo Jung Cho
- Li Ka Shing Institute of Virology, Dept. of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada
| | - Michael Joyce
- Li Ka Shing Institute of Virology, Dept. of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada
| | - Bas E Dutilh
- Centre for Molecular and Biomolecular Informatics, Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.,Theoretical Biology and Bioinformatics, Utrecht University, Utrecht, The Netherlands
| | - D Lorne Tyrrell
- Li Ka Shing Institute of Virology, Dept. of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada
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13
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Brown MR, Garside H, Thompson E, Atwal S, Bean C, Goodall T, Sullivan M, Graham MJ. From the Cover: Development and Application of a Dual Rat and Human AHR Activation Assay. Toxicol Sci 2018; 160:408-419. [PMID: 29029351 DOI: 10.1093/toxsci/kfx188] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Significant prolonged aryl hydrocarbon receptor (AHR) activation, classically exhibited following exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin, can cause a variety of undesirable toxicological effects. Novel pharmaceutical chemistries also have the potential to cause activation of AHR and consequent toxicities in pre-clinical species and man. Previous methods either employed relatively expensive and low-throughput primary hepatocyte dosing with PCR endpoint, or low resolution overexpressing reporter gene assays. We have developed, validated and applied an in vitro microtitre plate imaging-based medium throughput screening assay for the assessment of endogenous species-specific AHR activation potential via detection of induction of the surrogate transcriptional target Cytochrome P450 CYP1A1. Routine testing of pharmaceutical drug development candidate chemistries using this assay can influence the chemical design process and highlight AHR liabilities. This assay should be introduced such that human AHR activation liability is flagged early for confirmatory testing.
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Affiliation(s)
- Martin R Brown
- Discovery Sciences, AstraZeneca R&D Darwin, Cambridge CB4 0WG, UK
| | - Helen Garside
- Discovery Safety & Metabolism, AstraZeneca R&D, Macclesfield, Cheshire SK10 4TG, UK
| | - Emma Thompson
- Discovery Safety & Metabolism, AstraZeneca R&D, Macclesfield, Cheshire SK10 4TG, UK
| | - Saseela Atwal
- Discovery Safety & Metabolism, AstraZeneca R&D, Macclesfield, Cheshire SK10 4TG, UK
| | - Chloe Bean
- AstraZeneca R&D Charnwood, Loughborough, Leics LE11 5RH, UK
| | - Tony Goodall
- AstraZeneca R&D Charnwood, Loughborough, Leics LE11 5RH, UK
| | | | - Mark J Graham
- AstraZeneca R&D Charnwood, Loughborough, Leics LE11 5RH, UK
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14
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Moreno-Marín N, Merino JM, Alvarez-Barrientos A, Patel DP, Takahashi S, González-Sancho JM, Gandolfo P, Rios RM, Muñoz A, Gonzalez FJ, Fernández-Salguero PM. Aryl Hydrocarbon Receptor Promotes Liver Polyploidization and Inhibits PI3K, ERK, and Wnt/β-Catenin Signaling. iScience 2018; 4:44-63. [PMID: 30240752 PMCID: PMC6147018 DOI: 10.1016/j.isci.2018.05.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Revised: 04/25/2018] [Accepted: 05/09/2018] [Indexed: 01/02/2023] Open
Abstract
Aryl hydrocarbon receptor (AhR) deficiency alters tissue homeostasis. However, how AhR regulates organ maturation and differentiation remains mostly unknown. Liver differentiation entails a polyploidization process fundamental for cell growth, metabolism, and stress responses. Here, we report that AhR regulates polyploidization during the preweaning-to-adult mouse liver maturation. Preweaning AhR-null (AhR−/−) livers had smaller hepatocytes, hypercellularity, altered cell cycle regulation, and enhanced proliferation. Those phenotypes persisted in adult AhR−/− mice and correlated with compromised polyploidy, predominance of diploid hepatocytes, and enlarged centrosomes. Phosphatidylinositol-3-phosphate kinase (PI3K), extracellular signal-regulated kinase (ERK), and Wnt/β-catenin signaling remained upregulated from preweaning to adult AhR-null liver, likely increasing mammalian target of rapamycin (mTOR) activation. Metabolomics revealed the deregulation of mitochondrial oxidative phosphorylation intermediates succinate and fumarate in AhR−/− liver. Consistently, PI3K, ERK, and Wnt/β-catenin inhibition partially rescued polyploidy in AhR−/− mice. Thus, AhR may integrate survival, proliferation, and metabolism for liver polyploidization. Since tumor cells tend to be polyploid, AhR modulation could have therapeutic value in the liver. AhR is required for liver polyploidization during preweaning-to-adult transition INS-R/PI3K/AKT, ERK, Wnt/β-Cat and mTOR are downregulated during liver polyploidization Reduced polyploidy relates with enhanced mitochondrial metabolism in AhR-null liver Understanding how AhR modulates polyploidy may provide strategies against cancer
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Affiliation(s)
- Nuria Moreno-Marín
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Badajoz 06071, Spain
| | - Jaime M Merino
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Badajoz 06071, Spain
| | - Alberto Alvarez-Barrientos
- Servicio de Técnicas Aplicadas a las Biociencias (STAB), Universidad de Extremadura, Badajoz, Badajoz 06071, Spain
| | - Daxeshkumar P Patel
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Shogo Takahashi
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - José M González-Sancho
- Instituto de Investigaciones Biomédicas "Alberto Sols", Consejo Superior de Investigaciones Científicas - Universidad Autónoma de Madrid, and CIBER de Cáncer (CIBERONC), Instituto de Salud Carlos III, Madrid 28029, Spain
| | - Pablo Gandolfo
- Cell Signaling Department, CABIMER-CSIC, Sevilla 41092, Spain
| | - Rosa M Rios
- Cell Signaling Department, CABIMER-CSIC, Sevilla 41092, Spain
| | - Alberto Muñoz
- Instituto de Investigaciones Biomédicas "Alberto Sols", Consejo Superior de Investigaciones Científicas - Universidad Autónoma de Madrid, and CIBER de Cáncer (CIBERONC), Instituto de Salud Carlos III, Madrid 28029, Spain
| | - Frank J Gonzalez
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Pedro M Fernández-Salguero
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Badajoz 06071, Spain.
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15
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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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16
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Go RE, Hwang KA, Kim CW, Byun YS, Nam KH, Choi KC. Effect of dioxin and 17β-estradiol on the expression of cytochrome P450 1A1 gene via an estrogen receptor dependent pathway in cellular and xenografted models. ENVIRONMENTAL TOXICOLOGY 2017; 32:2225-2233. [PMID: 28618207 DOI: 10.1002/tox.22438] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 05/14/2017] [Accepted: 05/28/2017] [Indexed: 06/07/2023]
Abstract
Cytochrome P450 (CYP) 1A1 plays a major role in the metabolic activation of procarcinogens to carcinogens via aryl hydrocarbon receptor (AhR) pathway. Especially, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is known as an agonist of AhR. In estrogen responsive cancers, 17β-estradiol (E2) may influence on AhR dependent expression of CYP1 family via the interaction between estrogen receptor (ER) and AhR. In the present study, the effect of E2/ER on the expression of AhR and CYP1A1 genes was investigated for MCF-7 clonal variant (MCF-7 CV) breast cancer cells expressing ER. In reverse transcription-PCR and Western blot analysis, mRNA expression level of AhR was not altered, but its protein expression level was increased by TCDD or E2. The transcriptional and translational levels of CYP1A1 appeared to be increased by TCDD or E2. The increased expression of AhR and CYP1A1 induced by E2 was restored to the control level by the co-treatment of ICI 182,780, indicating that E2 induced the protein expression levels of AhR and CYP1A1 like TCDD via an ER dependent pathway. In an in vivo xenograft mouse model transplanted with MCF-7 CV cells, the protein expression levels of AhR and CYP1A1 of tumor masses were also increased by E2 or TCDD. Taken together, these results indicate that E2 may promote AhR dependent expression of CYP1A1 via ER dependent pathway in MCF-7 CV cells expressing ER in the absence of TCDD, an agonist of AhR. The relevance of E2 and ER in CYP1A1 activation of estrogen responsive cancers may be targeted for developing more effective cancer treatments.
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Affiliation(s)
- Ryeo-Eun Go
- Laboratory of Biochemistry and Immunology, Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea
| | - Kyung-A Hwang
- Laboratory of Biochemistry and Immunology, Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea
| | - Cho-Won Kim
- Laboratory of Biochemistry and Immunology, Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea
| | - Yong-Sub Byun
- Laboratory of Biochemistry and Immunology, Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea
- Laboratory Animal Resource Center, Korea Research Institute of Bioscience and Biotechnology, Ochang-eup, Cheongwon-gun, Chungbuk, Republic of Korea
| | - Ki-Hoan Nam
- Laboratory Animal Resource Center, Korea Research Institute of Bioscience and Biotechnology, Ochang-eup, Cheongwon-gun, Chungbuk, Republic of Korea
| | - Kyung-Chul Choi
- Laboratory of Biochemistry and Immunology, Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea
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17
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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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18
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Wright EJ, De Castro KP, Joshi AD, Elferink CJ. Canonical and non-canonical aryl hydrocarbon receptor signaling pathways. CURRENT OPINION IN TOXICOLOGY 2017; 2:87-92. [PMID: 32296737 DOI: 10.1016/j.cotox.2017.01.001] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Decades of research on the Aryl hydrocarbon Receptor (AhR) has unveiled its involvement in the toxicity of halogenated and polycyclic aromatic hydrocarbons, and a myriad of normal physiological processes. The molecular dissection of AhR biology has centered on a canonical signaling pathway in an effort to mechanistically reconcile the diverse pathophysiological effects of exposure to environmental pollutants. As a consequence, we now know that canonical signaling can explain many but not all of the AhR-mediated effects. Here we describe recent findings that point to non-canonical signaling pathways, and focus on a novel AhR interaction with the Krüppel-like Factor 6 protein responsible for previously un-recognized epigenetic changes in the chromatin affecting gene expression.
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Affiliation(s)
- Eric J Wright
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555-0654, USA
| | - Karen Pereira De Castro
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555-0654, USA
| | - Aditya D Joshi
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555-0654, USA
| | - Cornelis J Elferink
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555-0654, USA
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19
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Gao L, Wang Y, Yao Y, Zhang G, Han G, Wu W. 2,3,7,8-Tetrachlorodibenzo- p -dioxin Mediated Cleft palate by Mouse Embryonic Palate Mesenchymal Cells. Arch Oral Biol 2016; 71:150-154. [DOI: 10.1016/j.archoralbio.2016.08.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 07/19/2016] [Accepted: 08/02/2016] [Indexed: 01/15/2023]
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20
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Lu X, Ji C, Tong W, Lian X, Wu Y, Fan X, Gao Y. Integrated analysis of microRNA and mRNA expression profiles highlights the complex and dynamic behavior of toosendanin-induced liver injury in mice. Sci Rep 2016; 6:34225. [PMID: 27703232 PMCID: PMC5050432 DOI: 10.1038/srep34225] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 09/01/2016] [Indexed: 01/04/2023] Open
Abstract
Triterpenoid Toosendanin (TSN) exhibits a plenty of pharmacological effects in human and great values in agriculture. However, the hepatotoxicity caused by TSN or Melia-family plants containing TSN used in traditional Chinese medicine has been reported, and the mechanisms of TSN-induced liver injury (TILI) still remain largely unknown. In this study, the dose- and time-dependent effects of TSN on mice liver were investigated by an integrated microRNA-mRNA approach as well as the general toxicological assessments. As the results, the dose- and time-dependent liver injury and alterations in global microRNA and mRNA expressions were detected. Particularly, 9-days 80 mg/kg TSN exposure caused most serious liver injury in mice, and the hepatic adaptation to TILI was unexpectedly observed after 21-days 80 mg/kg TSN administration. Based on the pathway analysis of the intersections between predicted targets of differentially expressed microRNAs and differentially expressed mRNAs at three time points, it revealed that TILI may be caused by glutathione depletion, mitochondrial dysfunction and lipid dysmetabolism, ultimately leading to hepatocytes necrosis in liver, while liver regeneration may play an important role in the hepatic adaptation to TILI. Our results demonstrated that the integrated microRNA-mRNA approach could provide new insight into the complex and dynamic behavior of TILI.
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Affiliation(s)
- Xiaoyan Lu
- Pharmaceutical Informatics Institute, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Cai Ji
- Pharmaceutical Informatics Institute, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Wei Tong
- Pharmaceutical Informatics Institute, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Xueping Lian
- Pharmaceutical Informatics Institute, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Ying Wu
- Pharmaceutical Informatics Institute, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Xiaohui Fan
- Pharmaceutical Informatics Institute, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yue Gao
- Department of Pharmacology and Toxicology, Beijing Institute of Radiation Medicine, Beijing 100850, China
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2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) increases necroinflammation and hepatic stellate cell activation but does not exacerbate experimental liver fibrosis in mice. Toxicol Appl Pharmacol 2016; 311:42-51. [PMID: 27693115 DOI: 10.1016/j.taap.2016.09.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 09/21/2016] [Accepted: 09/26/2016] [Indexed: 12/12/2022]
Abstract
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a persistent environmental contaminant and high-affinity ligand for the aryl hydrocarbon receptor (AhR). Increasing evidence indicates that AhR signaling contributes to wound healing, which involves the coordinated deposition and remodeling of the extracellular matrix. In the liver, wound healing is attributed to the activation of hepatic stellate cells (HSCs), which mediate fibrogenesis through the production of soluble mediators and collagen type I. We recently reported that TCDD treatment increases the activation of human HSCs in vitro. The goal of this study was to determine how TCDD impacts HSC activation in vivo using a mouse model of experimental liver fibrosis. To elicit fibrosis, C57BL6/male mice were treated twice weekly for 8weeks with 0.5ml/kg carbon tetrachloride (CCl4). TCDD (20μg/kg) or peanut oil (vehicle) was administered once a week during the last 2weeks. Results indicate that TCDD increased liver-body-weight ratios, serum alanine aminotransferase activity, and hepatic necroinflammation in CCl4-treated mice. Likewise, TCDD treatment increased mRNA expression of HSC activation and fibrogenesis genes, namely α-smooth muscle actin, desmin, delta-like homolog-1, TGF-β1, and collagen type I. However, TCDD treatment did not exacerbate fibrosis, nor did it increase the collagen content of the liver. Instead, TCDD increased hepatic collagenase activity and increased expression of matrix metalloproteinase (MMP)-13 and the matrix regulatory proteins, TIMP-1 and PAI-1. These results support the conclusion that TCDD increases CCl4-induced liver damage and exacerbates HSC activation, yet collagen deposition and the development of fibrosis may be limited by TCDD-mediated changes in extracellular matrix remodeling.
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Wyler SL, D'Ingillo SL, Lamb CL, Mitchell KA. Monocyte chemoattractant protein-1 is not required for liver regeneration after partial hepatectomy. JOURNAL OF INFLAMMATION-LONDON 2016; 13:28. [PMID: 27555804 PMCID: PMC4994209 DOI: 10.1186/s12950-016-0136-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 08/16/2016] [Indexed: 01/12/2023]
Abstract
Background Liver regeneration following 70 % partial hepatectomy (PH) requires the coordinated expression of soluble mediators produced by macrophages. Monocyte chemoattractant protein-1 (MCP-1) is a potent stimulus of monocyte recruitment and macrophage activation. The goal of this study was to determine how MCP-1 contributes to liver regeneration. Methods PH was performed on anesthetized C57Bl/6 (wild type) and MCP-1 knockout mice, and macrophage-produced cytokines and hepatocyte proliferation were measured. Results In wild type mice, hepatic MCP-1 protein levels increased 4–6 h after PH, and elevated plasma MCP-1 levels were detected 12 h after PH. Hepatocyte proliferation was comparable in MCP-1 knockout and wild type mice, as was the expression of macrophage-derived cytokines, TNFα and IL-6, and levels of phosphorylated STAT3. The number of CCR2+ cells in the liver was similar in MCP-1 knockout and wild type mice, which suggests that other chemokines may recruit CCR2+ cells in the absence of MCP-1. Studies with CCR2 knockout mice revealed that hepatocyte proliferation was suppressed ~40 % compared to wild type mice 36 h after PH, but proliferation and liver-body-weight ratios were similar at 48 h. Conclusion These findings suggest that MCP-1 is not required for PH-induced liver regeneration, yet the role of CCR2 warrants further study.
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Affiliation(s)
- Stephanie L Wyler
- Department of Biological Sciences, Boise State University, 1910 University Drive, Boise, ID 83725-1515 USA
| | - Shawna L D'Ingillo
- Department of Biological Sciences, Boise State University, 1910 University Drive, Boise, ID 83725-1515 USA
| | - Cheri L Lamb
- Biomolecular Sciences Ph.D. Program, Boise State University, Boise, ID 83725 USA
| | - Kristen A Mitchell
- Department of Biological Sciences, Boise State University, 1910 University Drive, Boise, ID 83725-1515 USA ; Biomolecular Sciences Ph.D. Program, Boise State University, Boise, ID 83725 USA
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Baginskaya NV, Kashina EV, Shamanina MY, Ilnitskaya SI, Kaledin VI, Mordvinov VA. Correlation of susceptibility to ortho-aminoazotoluene-induced hepatocarcinogenesis with Car and Ahr signaling pathway activation in mice. ACTA ACUST UNITED AC 2016. [DOI: 10.1134/s2079059716040043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Environmental Ligands of the Aryl Hydrocarbon Receptor and Their Effects in Models of Adult Liver Progenitor Cells. Stem Cells Int 2016; 2016:4326194. [PMID: 27274734 PMCID: PMC4870370 DOI: 10.1155/2016/4326194] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 04/07/2016] [Indexed: 12/20/2022] Open
Abstract
The toxicity of environmental and dietary ligands of the aryl hydrocarbon receptor (AhR) in mature liver parenchymal cells is well appreciated, while considerably less attention has been paid to their impact on cell populations exhibiting phenotypic features of liver progenitor cells. Here, we discuss the results suggesting that the consequences of the AhR activation in the cellular models derived from bipotent liver progenitors could markedly differ from those in hepatocytes. In contact-inhibited liver progenitor cells, the AhR agonists induce a range of effects potentially linked with tumor promotion. They can stimulate cell cycle progression/proliferation and deregulate cell-to-cell communication, which is associated with downregulation of proteins forming gap junctions, adherens junctions, and desmosomes (such as connexin 43, E-cadherin, β-catenin, and plakoglobin), as well as with reduced cell adhesion and inhibition of intercellular communication. At the same time, toxic AhR ligands may affect the activity of the signaling pathways contributing to regulation of liver progenitor cell activation and/or differentiation, such as downregulation of Wnt/β-catenin and TGF-β signaling, or upregulation of transcriptional targets of YAP/TAZ, the effectors of Hippo signaling pathway. These data illustrate the need to better understand the potential role of liver progenitors in the AhR-mediated liver carcinogenesis and tumor promotion.
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Esser C, Rannug A. The aryl hydrocarbon receptor in barrier organ physiology, immunology, and toxicology. Pharmacol Rev 2015; 67:259-79. [PMID: 25657351 DOI: 10.1124/pr.114.009001] [Citation(s) in RCA: 337] [Impact Index Per Article: 37.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The aryl hydrocarbon receptor (AhR) is an evolutionarily old transcription factor belonging to the Per-ARNT-Sim-basic helix-loop-helix protein family. AhR translocates into the nucleus upon binding of various small molecules into the pocket of its single-ligand binding domain. AhR binding to both xenobiotic and endogenous ligands results in highly cell-specific transcriptome changes and in changes in cellular functions. We discuss here the role of AhR for immune cells of the barrier organs: skin, gut, and lung. Both adaptive and innate immune cells require AhR signaling at critical checkpoints. We also discuss the current two prevailing views-namely, 1) AhR as a promiscuous sensor for small chemicals and 2) a role for AhR as a balancing factor for cell differentiation and function, which is controlled by levels of endogenous high-affinity ligands. AhR signaling is considered a promising drug and preventive target, particularly for cancer, inflammatory, and autoimmune diseases. Therefore, understanding its biology is of great importance.
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Affiliation(s)
- Charlotte Esser
- Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany (C.E.); and Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden (A.R.)
| | - Agneta Rannug
- Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany (C.E.); and Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden (A.R.)
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26
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Jackson DP, Joshi AD, Elferink CJ. Ah Receptor Pathway Intricacies; Signaling Through Diverse Protein Partners and DNA-Motifs. Toxicol Res (Camb) 2015; 4:1143-1158. [PMID: 26783425 PMCID: PMC4714567 DOI: 10.1039/c4tx00236a] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The Ah receptor is a transcription factor that modulates gene expression via interactions with multiple protein partners; these are reviewed, including the novel NC-XRE pathway involving KLF6.
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27
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Kim S, Han L, Yu B, Hähnke VD, Bolton EE, Bryant SH. PubChem structure-activity relationship (SAR) clusters. J Cheminform 2015; 7:33. [PMID: 26150895 PMCID: PMC4492103 DOI: 10.1186/s13321-015-0070-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 04/21/2015] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Developing structure-activity relationships (SARs) of molecules is an important approach in facilitating hit exploration in the early stage of drug discovery. Although information on millions of compounds and their bioactivities is freely available to the public, it is very challenging to infer a meaningful and novel SAR from that information. RESULTS Research discussed in the present paper employed a bioactivity-centered clustering approach to group 843,845 non-inactive compounds stored in PubChem according to both structural similarity and bioactivity similarity, with the aim of mining bioactivity data in PubChem for useful SAR information. The compounds were clustered in three bioactivity similarity contexts: (1) non-inactive in a given bioassay, (2) non-inactive against a given protein, and (3) non-inactive against proteins involved in a given pathway. In each context, these small molecules were clustered according to their two-dimensional (2-D) and three-dimensional (3-D) structural similarities. The resulting 18 million clusters, named "PubChem SAR clusters", were delivered in such a way that each cluster contains a group of small molecules similar to each other in both structure and bioactivity. CONCLUSIONS The PubChem SAR clusters, pre-computed using publicly available bioactivity information, make it possible to quickly navigate and narrow down the compounds of interest. Each SAR cluster can be a useful resource in developing a meaningful SAR or enable one to design or expand compound libraries from the cluster. It can also help to predict the potential therapeutic effects and pharmacological actions of less-known compounds from those of well-known compounds (i.e., drugs) in the same cluster.
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Affiliation(s)
- Sunghwan Kim
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Department of Health and Human Services, 8600 Rockville Pike, Bethesda, MD 20894 USA
| | - Lianyi Han
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Department of Health and Human Services, 8600 Rockville Pike, Bethesda, MD 20894 USA
| | - Bo Yu
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Department of Health and Human Services, 8600 Rockville Pike, Bethesda, MD 20894 USA
| | - Volker D Hähnke
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Department of Health and Human Services, 8600 Rockville Pike, Bethesda, MD 20894 USA
| | - Evan E Bolton
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Department of Health and Human Services, 8600 Rockville Pike, Bethesda, MD 20894 USA
| | - Stephen H Bryant
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Department of Health and Human Services, 8600 Rockville Pike, Bethesda, MD 20894 USA
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The aryl hydrocarbon receptor-dependent disruption of contact inhibition in rat liver WB-F344 epithelial cells is linked with induction of survivin, but not with inhibition of apoptosis. Toxicology 2015; 333:37-44. [DOI: 10.1016/j.tox.2015.04.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 03/31/2015] [Accepted: 04/01/2015] [Indexed: 11/23/2022]
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Joshi AD, Carter DE, Harper TA, Elferink CJ. Aryl hydrocarbon receptor-dependent stanniocalcin 2 induction by cinnabarinic acid provides cytoprotection against endoplasmic reticulum and oxidative stress. J Pharmacol Exp Ther 2015; 353:201-12. [PMID: 25672339 PMCID: PMC11047083 DOI: 10.1124/jpet.114.222265] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 02/10/2015] [Indexed: 12/13/2022] Open
Abstract
The aryl hydrocarbon receptor (AhR) is a cytosolic ligand-activated transcription factor historically known for its role in xenobiotic metabolism. Although AhR activity has previously been shown to play a cytoprotective role against intrinsic apoptotic stimuli, the underlying mechanism by which AhR confers cytoprotection against apoptosis is largely unknown. Here, we demonstrate that activation of AhR by the tryptophan catabolite cinnabarinic acid (CA) directly upregulates expression of stanniocalcin 2 (Stc2) to elicit cytoprotection against apoptosis induced by endoplasmic reticulum stress and oxidative stress. Chromatin immunoprecipitation studies demonstrated that CA treatment induces direct AhR binding to a region of the Stc2 promoter containing multiple xenobiotic response elements. Using isolated primary hepatocytes from AhR wild-type (AhR floxed) and liver-specific AhR conditional knockout mice, we showed that pretreatment with CA conferred cytoprotection against hydrogen peroxide (H(2)O(2))-, thapsigargin-, and ethanol-induced apoptosis in an AhR-dependent manner. Furthermore, suppressing Stc2 expression using RNA interference confirmed that the cytoprotective properties of CA against H(2)O(2), thapsigargin, and ethanol injury were absolutely dependent on Stc2. Immunochemistry revealed the presence of Stc2 in the endoplasmic reticulum and on the cell surface, consistent with Stc2 secretion and autocrine and/or paracrine signaling. Finally, in vivo data using a mouse model of acute alcohol hepatotoxicity demonstrated that CA provided cytoprotection against ethanol-induced apoptosis, hepatic microvesicular steatosis, and liver injury. Collectively, our data uncovered a novel mechanism for AhR-mediated cytoprotection in the liver that is dependent on CA-induced Stc2 activity.
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Affiliation(s)
- Aditya D Joshi
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas (A.D.J., D.E.C., C.J.E.); and Linus Pauling Institute, Oregon State University, Corvallis, Oregon (T.A.H.)
| | - Dwayne E Carter
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas (A.D.J., D.E.C., C.J.E.); and Linus Pauling Institute, Oregon State University, Corvallis, Oregon (T.A.H.)
| | - Tod A Harper
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas (A.D.J., D.E.C., C.J.E.); and Linus Pauling Institute, Oregon State University, Corvallis, Oregon (T.A.H.)
| | - Cornelis J Elferink
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas (A.D.J., D.E.C., C.J.E.); and Linus Pauling Institute, Oregon State University, Corvallis, Oregon (T.A.H.)
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Lindén J, Lensu S, Pohjanvirta R. Effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on hormones of energy balance in a TCDD-sensitive and a TCDD-resistant rat strain. Int J Mol Sci 2014; 15:13938-66. [PMID: 25119860 PMCID: PMC4159833 DOI: 10.3390/ijms150813938] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 07/24/2014] [Accepted: 07/29/2014] [Indexed: 01/16/2023] Open
Abstract
One of the hallmarks of the acute toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a drastically reduced feed intake by an unknown mechanism. To further elucidate this wasting syndrome, we followed the effects of a single large dose (100 μg/kg) of TCDD on the serum levels of several energy balance-influencing hormones, clinical chemistry variables, and hepatic aryl hydrocarbon receptor (AHR) expression in two rat strains that differ widely in their TCDD sensitivities, for up to 10 days. TCDD affected most of the analytes in sensitive Long-Evans rats, while there were few alterations in the resistant Han/Wistar strain. However, analyses of feed-restricted unexposed Long-Evans rats indicated several of the perturbations to be secondary to energy deficiency. Notable increases in ghrelin and glucagon occurred in TCDD-treated Long-Evans rats alone, which links these hormones to the wasting syndrome. The newly found energy balance regulators, insulin-like growth factor 1 and fibroblast growth factor 21 (FGF-21), appeared to function in concert in body weight loss-induced metabolic state, and FGF-21 was putatively linked to increased lipolysis induced by TCDD. Finally, we demonstrate a reverse set of changes in the AHR protein and mRNA response to TCDD and feed restriction, suggesting that AHR might function also as a physiological regulator, possibly involved in the maintenance of energy balance.
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Affiliation(s)
- Jere Lindén
- Department of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, P.O. Box 66, FI-00014 Helsinki, Finland.
| | - Sanna Lensu
- Department of Biology of Physical Activity, Faculty of Sport and Health Sciences, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland.
| | - Raimo Pohjanvirta
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, P.O. Box 66, FI-00014 Helsinki, Finland.
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Kazantseva YA, Yarushkin AA, Pustylnyak VO. CAR-mediated repression of Foxo1 transcriptional activity regulates the cell cycle inhibitor p21 in mouse livers. Toxicology 2014; 321:73-9. [PMID: 24769335 DOI: 10.1016/j.tox.2014.04.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 04/14/2014] [Accepted: 04/15/2014] [Indexed: 01/29/2023]
Abstract
1,4-Bis[2-(3,5-dichloropyridyloxy)]benzene (TCPOBOP), an agonist of constitutive androstane receptor (CAR), is a well-known strong primary chemical mitogen for the mouse liver. Despite extensive investigation of the role of CAR in the regulation of cell proliferation, our knowledge of the intricate mediating mechanism is incomplete. In this study, we demonstrated that long-term CAR activation by TCPOBOP increased liver-to-body weight ratio and decreased tumour suppressor Foxo1 expression and transcriptional activity, which were correlated with reduced expression of genes regulated by Foxo1, including the cell-cycle inhibitor Cdkn1a(p21), and upregulation of the cell-cycle regulator Cyclin D1. Moreover, we demonstrated the negative regulatory effect of TCPOBOP-activated CAR on the association of Foxo1 with the target Foxo1 itself and Cdkn1a(p21) promoters. Thus, we identified CAR-mediated repression of cell cycle inhibitor p21, as mediated by repression of FOXO1 expression and transcriptional activity. CAR-FOXO1 cross-talk may provide new opportunities for understanding liver diseases and developing more effective therapeutic approaches to better drug treatments.
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Affiliation(s)
- Yuliya A Kazantseva
- Institute of Molecular Biology and Biophysics SB RAMS, Timakova str. 2, Novosibirsk 630117, Russia
| | - Andrei A Yarushkin
- Institute of Molecular Biology and Biophysics SB RAMS, Timakova str. 2, Novosibirsk 630117, Russia
| | - Vladimir O Pustylnyak
- Institute of Molecular Biology and Biophysics SB RAMS, Timakova str. 2, Novosibirsk 630117, Russia; Novosibirsk State University, Pirogova str. 2, Novosibirsk 630090, Russia.
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32
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Jackson DP, Li H, Mitchell KA, Joshi AD, Elferink CJ. Ah receptor-mediated suppression of liver regeneration through NC-XRE-driven p21Cip1 expression. Mol Pharmacol 2014; 85:533-41. [PMID: 24431146 DOI: 10.1124/mol.113.089730] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Previous studies in hepatocyte-derived cell lines and the whole liver established that the aryl hydrocarbon receptor (AhR) can disrupt G1-phase cell cycle progression following exposure to persistent AhR agonists, such as TCDD (dioxin, 2,3,7,8-tetrachlorodibenzo-p-dioxin). Growth arrest was attributed to inhibition of G1-phase cyclin-dependent kinase 2 (CDK2) activity. The present study examined the effect of TCDD exposure on liver regeneration following 70% partial hepatectomy in mice lacking the Cip/Kip inhibitors p21(Cip1) or p27(Kip1) responsible for regulating CDK2 activity. Assessment of the regenerative process in wild-type, p21(Cip1) knockout, and p27(Kip1) knockout mice confirmed that TCDD-induced inhibition of liver regeneration is entirely dependent on p21(Cip1) expression. Compared with wild-type mice, the absence of p21(Cip1) expression completely abrogated the TCDD inhibition, and accelerated hepatocyte progression through G1 phase during the regenerative process. Analysis of the transcriptional response determined that increased p21(Cip1) expression during liver regeneration involved an AhR-dependent mechanism. Chromatin immunoprecipitation studies revealed that p21(Cip1) induction required AhR binding to the newly characterized nonconsensus xenobiotic response element, in conjunction with the tumor suppressor protein Kruppel-like factor 6 functioning as an AhR binding partner. The evidence also suggests that AhR functionality following partial hepatectomy is dependent on a p21(Cip1)-regulated signaling process, intimately linking AhR biology to the G1-phase cell cycle program.
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Affiliation(s)
- Daniel P Jackson
- Department of Pharmacology and Toxicology (D.P.J., A.D.J., C.J.E.) and Department of Pediatrics (H.L.), University of Texas Medical Branch, Galveston, Texas; and Department of Biological Sciences, Boise State University, Boise, Idaho (K.A.M.)
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Budinsky RA, Schrenk D, Simon T, Van den Berg M, Reichard JF, Silkworth JB, Aylward LL, Brix A, Gasiewicz T, Kaminski N, Perdew G, Starr TB, Walker NJ, Rowlands JC. Mode of action and dose–response framework analysis for receptor-mediated toxicity: The aryl hydrocarbon receptor as a case study. Crit Rev Toxicol 2013; 44:83-119. [DOI: 10.3109/10408444.2013.835787] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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34
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Faust D, Kletting S, Ueberham E, Dietrich C. Aryl hydrocarbon receptor-dependent cell cycle arrest in isolated mouse oval cells. Toxicol Lett 2013; 223:73-80. [DOI: 10.1016/j.toxlet.2013.08.022] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 08/26/2013] [Accepted: 08/28/2013] [Indexed: 12/16/2022]
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Godoy P, Hewitt NJ, Albrecht U, Andersen ME, Ansari N, Bhattacharya S, Bode JG, Bolleyn J, Borner C, Böttger J, Braeuning A, Budinsky RA, Burkhardt B, Cameron NR, Camussi G, Cho CS, Choi YJ, Craig Rowlands J, Dahmen U, Damm G, Dirsch O, Donato MT, Dong J, Dooley S, Drasdo D, Eakins R, Ferreira KS, Fonsato V, Fraczek J, Gebhardt R, Gibson A, Glanemann M, Goldring CEP, Gómez-Lechón MJ, Groothuis GMM, Gustavsson L, Guyot C, Hallifax D, Hammad S, Hayward A, Häussinger D, Hellerbrand C, Hewitt P, Hoehme S, Holzhütter HG, Houston JB, Hrach J, Ito K, Jaeschke H, Keitel V, Kelm JM, Kevin Park B, Kordes C, Kullak-Ublick GA, LeCluyse EL, Lu P, Luebke-Wheeler J, Lutz A, Maltman DJ, Matz-Soja M, McMullen P, Merfort I, Messner S, Meyer C, Mwinyi J, Naisbitt DJ, Nussler AK, Olinga P, Pampaloni F, Pi J, Pluta L, Przyborski SA, Ramachandran A, Rogiers V, Rowe C, Schelcher C, Schmich K, Schwarz M, Singh B, Stelzer EHK, Stieger B, Stöber R, Sugiyama Y, Tetta C, Thasler WE, Vanhaecke T, Vinken M, Weiss TS, Widera A, Woods CG, Xu JJ, Yarborough KM, Hengstler JG. Recent advances in 2D and 3D in vitro systems using primary hepatocytes, alternative hepatocyte sources and non-parenchymal liver cells and their use in investigating mechanisms of hepatotoxicity, cell signaling and ADME. Arch Toxicol 2013; 87:1315-530. [PMID: 23974980 PMCID: PMC3753504 DOI: 10.1007/s00204-013-1078-5] [Citation(s) in RCA: 1051] [Impact Index Per Article: 95.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 05/06/2013] [Indexed: 12/15/2022]
Abstract
This review encompasses the most important advances in liver functions and hepatotoxicity and analyzes which mechanisms can be studied in vitro. In a complex architecture of nested, zonated lobules, the liver consists of approximately 80 % hepatocytes and 20 % non-parenchymal cells, the latter being involved in a secondary phase that may dramatically aggravate the initial damage. Hepatotoxicity, as well as hepatic metabolism, is controlled by a set of nuclear receptors (including PXR, CAR, HNF-4α, FXR, LXR, SHP, VDR and PPAR) and signaling pathways. When isolating liver cells, some pathways are activated, e.g., the RAS/MEK/ERK pathway, whereas others are silenced (e.g. HNF-4α), resulting in up- and downregulation of hundreds of genes. An understanding of these changes is crucial for a correct interpretation of in vitro data. The possibilities and limitations of the most useful liver in vitro systems are summarized, including three-dimensional culture techniques, co-cultures with non-parenchymal cells, hepatospheres, precision cut liver slices and the isolated perfused liver. Also discussed is how closely hepatoma, stem cell and iPS cell-derived hepatocyte-like-cells resemble real hepatocytes. Finally, a summary is given of the state of the art of liver in vitro and mathematical modeling systems that are currently used in the pharmaceutical industry with an emphasis on drug metabolism, prediction of clearance, drug interaction, transporter studies and hepatotoxicity. One key message is that despite our enthusiasm for in vitro systems, we must never lose sight of the in vivo situation. Although hepatocytes have been isolated for decades, the hunt for relevant alternative systems has only just begun.
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Affiliation(s)
- Patricio Godoy
- Leibniz Research Centre for Working Environment and Human Factors (IFADO), 44139 Dortmund, Germany
| | | | - Ute Albrecht
- Clinic for Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | - Melvin E. Andersen
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC USA
| | - Nariman Ansari
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University Frankfurt, Max-von-Laue-Str. 15, 60438 Frankfurt am Main, Germany
| | - Sudin Bhattacharya
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC USA
| | - Johannes Georg Bode
- Clinic for Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | - Jennifer Bolleyn
- Department of Toxicology, Centre for Pharmaceutical Research, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, 1090 Brussels, Belgium
| | - Christoph Borner
- Institute of Molecular Medicine and Cell Research, University of Freiburg, Freiburg, Germany
| | - Jan Böttger
- Institute of Biochemistry, Faculty of Medicine, University of Leipzig, 04103 Leipzig, Germany
| | - Albert Braeuning
- Department of Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Wilhelmstr. 56, 72074 Tübingen, Germany
| | - Robert A. Budinsky
- Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI USA
| | - Britta Burkhardt
- BG Trauma Center, Siegfried Weller Institut, Eberhard Karls University Tübingen, 72076 Tübingen, Germany
| | - Neil R. Cameron
- Department of Chemistry, Durham University, Durham, DH1 3LE UK
| | - Giovanni Camussi
- Department of Medical Sciences, University of Torino, 10126 Turin, Italy
| | - Chong-Su Cho
- Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, 151-921 Korea
| | - Yun-Jaie Choi
- Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, 151-921 Korea
| | - J. Craig Rowlands
- Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI USA
| | - Uta Dahmen
- Experimental Transplantation Surgery, Department of General Visceral, and Vascular Surgery, Friedrich-Schiller-University Jena, 07745 Jena, Germany
| | - Georg Damm
- Department of General-, Visceral- and Transplantation Surgery, Charité University Medicine Berlin, 13353 Berlin, Germany
| | - Olaf Dirsch
- Institute of Pathology, Friedrich-Schiller-University Jena, 07745 Jena, Germany
| | - María Teresa Donato
- Unidad de Hepatología Experimental, IIS Hospital La Fe Avda Campanar 21, 46009 Valencia, Spain
- CIBERehd, Fondo de Investigaciones Sanitarias, Barcelona, Spain
- Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad de Valencia, Valencia, Spain
| | - Jian Dong
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC USA
| | - Steven Dooley
- Department of Medicine II, Section Molecular Hepatology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Dirk Drasdo
- Interdisciplinary Center for Bioinformatics (IZBI), University of Leipzig, 04107 Leipzig, Germany
- INRIA (French National Institute for Research in Computer Science and Control), Domaine de Voluceau-Rocquencourt, B.P. 105, 78153 Le Chesnay Cedex, France
- UPMC University of Paris 06, CNRS UMR 7598, Laboratoire Jacques-Louis Lions, 4, pl. Jussieu, 75252 Paris cedex 05, France
| | - Rowena Eakins
- Department of Molecular and Clinical Pharmacology, Centre for Drug Safety Science, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Karine Sá Ferreira
- Institute of Molecular Medicine and Cell Research, University of Freiburg, Freiburg, Germany
- GRK 1104 From Cells to Organs, Molecular Mechanisms of Organogenesis, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Valentina Fonsato
- Department of Medical Sciences, University of Torino, 10126 Turin, Italy
| | - Joanna Fraczek
- Department of Toxicology, Centre for Pharmaceutical Research, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, 1090 Brussels, Belgium
| | - Rolf Gebhardt
- Institute of Biochemistry, Faculty of Medicine, University of Leipzig, 04103 Leipzig, Germany
| | - Andrew Gibson
- Department of Molecular and Clinical Pharmacology, Centre for Drug Safety Science, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Matthias Glanemann
- Department of General-, Visceral- and Transplantation Surgery, Charité University Medicine Berlin, 13353 Berlin, Germany
| | - Chris E. P. Goldring
- Department of Molecular and Clinical Pharmacology, Centre for Drug Safety Science, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - María José Gómez-Lechón
- Unidad de Hepatología Experimental, IIS Hospital La Fe Avda Campanar 21, 46009 Valencia, Spain
- CIBERehd, Fondo de Investigaciones Sanitarias, Barcelona, Spain
| | - Geny M. M. Groothuis
- Department of Pharmacy, Pharmacokinetics Toxicology and Targeting, University of Groningen, A. Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Lena Gustavsson
- Department of Laboratory Medicine (Malmö), Center for Molecular Pathology, Lund University, Jan Waldenströms gata 59, 205 02 Malmö, Sweden
| | - Christelle Guyot
- Department of Clinical Pharmacology and Toxicology, University Hospital, 8091 Zurich, Switzerland
| | - David Hallifax
- Centre for Applied Pharmacokinetic Research (CAPKR), School of Pharmacy and Pharmaceutical Sciences, University of Manchester, Oxford Road, Manchester, M13 9PT UK
| | - Seddik Hammad
- Department of Forensic Medicine and Veterinary Toxicology, Faculty of Veterinary Medicine, South Valley University, Qena, Egypt
| | - Adam Hayward
- Biological and Biomedical Sciences, Durham University, Durham, DH13LE UK
| | - Dieter Häussinger
- Clinic for Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | - Claus Hellerbrand
- Department of Medicine I, University Hospital Regensburg, 93053 Regensburg, Germany
| | | | - Stefan Hoehme
- Interdisciplinary Center for Bioinformatics (IZBI), University of Leipzig, 04107 Leipzig, Germany
| | - Hermann-Georg Holzhütter
- Institut für Biochemie Abteilung Mathematische Systembiochemie, Universitätsmedizin Berlin (Charité), Charitéplatz 1, 10117 Berlin, Germany
| | - J. Brian Houston
- Centre for Applied Pharmacokinetic Research (CAPKR), School of Pharmacy and Pharmaceutical Sciences, University of Manchester, Oxford Road, Manchester, M13 9PT UK
| | | | - Kiyomi Ito
- Research Institute of Pharmaceutical Sciences, Musashino University, 1-1-20 Shinmachi, Nishitokyo-shi, Tokyo, 202-8585 Japan
| | - Hartmut Jaeschke
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 USA
| | - Verena Keitel
- Clinic for Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | | | - B. Kevin Park
- Department of Molecular and Clinical Pharmacology, Centre for Drug Safety Science, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Claus Kordes
- Clinic for Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | - Gerd A. Kullak-Ublick
- Department of Clinical Pharmacology and Toxicology, University Hospital, 8091 Zurich, Switzerland
| | - Edward L. LeCluyse
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC USA
| | - Peng Lu
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC USA
| | | | - Anna Lutz
- Department of Pharmaceutical Biology and Biotechnology, University of Freiburg, Freiburg, Germany
| | - Daniel J. Maltman
- Reinnervate Limited, NETPark Incubator, Thomas Wright Way, Sedgefield, TS21 3FD UK
| | - Madlen Matz-Soja
- Institute of Biochemistry, Faculty of Medicine, University of Leipzig, 04103 Leipzig, Germany
| | - Patrick McMullen
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC USA
| | - Irmgard Merfort
- Department of Pharmaceutical Biology and Biotechnology, University of Freiburg, Freiburg, Germany
| | | | - Christoph Meyer
- Department of Medicine II, Section Molecular Hepatology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Jessica Mwinyi
- Department of Clinical Pharmacology and Toxicology, University Hospital, 8091 Zurich, Switzerland
| | - Dean J. Naisbitt
- Department of Molecular and Clinical Pharmacology, Centre for Drug Safety Science, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Andreas K. Nussler
- BG Trauma Center, Siegfried Weller Institut, Eberhard Karls University Tübingen, 72076 Tübingen, Germany
| | - Peter Olinga
- Division of Pharmaceutical Technology and Biopharmacy, Department of Pharmacy, University of Groningen, 9713 AV Groningen, The Netherlands
| | - Francesco Pampaloni
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University Frankfurt, Max-von-Laue-Str. 15, 60438 Frankfurt am Main, Germany
| | - Jingbo Pi
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC USA
| | - Linda Pluta
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC USA
| | - Stefan A. Przyborski
- Reinnervate Limited, NETPark Incubator, Thomas Wright Way, Sedgefield, TS21 3FD UK
- Biological and Biomedical Sciences, Durham University, Durham, DH13LE UK
| | - Anup Ramachandran
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 USA
| | - Vera Rogiers
- Department of Toxicology, Centre for Pharmaceutical Research, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, 1090 Brussels, Belgium
| | - Cliff Rowe
- Department of Molecular and Clinical Pharmacology, Centre for Drug Safety Science, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Celine Schelcher
- Department of Surgery, Liver Regeneration, Core Facility, Human in Vitro Models of the Liver, Ludwig Maximilians University of Munich, Munich, Germany
| | - Kathrin Schmich
- Department of Pharmaceutical Biology and Biotechnology, University of Freiburg, Freiburg, Germany
| | - Michael Schwarz
- Department of Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Wilhelmstr. 56, 72074 Tübingen, Germany
| | - Bijay Singh
- Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, 151-921 Korea
| | - Ernst H. K. Stelzer
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University Frankfurt, Max-von-Laue-Str. 15, 60438 Frankfurt am Main, Germany
| | - Bruno Stieger
- Department of Clinical Pharmacology and Toxicology, University Hospital, 8091 Zurich, Switzerland
| | - Regina Stöber
- Leibniz Research Centre for Working Environment and Human Factors (IFADO), 44139 Dortmund, Germany
| | - Yuichi Sugiyama
- Sugiyama Laboratory, RIKEN Innovation Center, RIKEN, Yokohama Biopharmaceutical R&D Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045 Japan
| | - Ciro Tetta
- Fresenius Medical Care, Bad Homburg, Germany
| | - Wolfgang E. Thasler
- Department of Surgery, Ludwig-Maximilians-University of Munich Hospital Grosshadern, Munich, Germany
| | - Tamara Vanhaecke
- Department of Toxicology, Centre for Pharmaceutical Research, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, 1090 Brussels, Belgium
| | - Mathieu Vinken
- Department of Toxicology, Centre for Pharmaceutical Research, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, 1090 Brussels, Belgium
| | - Thomas S. Weiss
- Department of Pediatrics and Juvenile Medicine, University of Regensburg Hospital, Regensburg, Germany
| | - Agata Widera
- Leibniz Research Centre for Working Environment and Human Factors (IFADO), 44139 Dortmund, Germany
| | - Courtney G. Woods
- The Hamner Institutes for Health Sciences, Research Triangle Park, NC USA
| | | | | | - Jan G. Hengstler
- Leibniz Research Centre for Working Environment and Human Factors (IFADO), 44139 Dortmund, Germany
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Wilson SR, Joshi AD, Elferink CJ. The tumor suppressor Kruppel-like factor 6 is a novel aryl hydrocarbon receptor DNA binding partner. J Pharmacol Exp Ther 2013; 345:419-29. [PMID: 23512538 DOI: 10.1124/jpet.113.203786] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The aryl hydrocarbon receptor (AhR) is a ligand-mediated basic helix-loop-helix transcription factor of the Per/Arnt/Sim family that regulates adaptive and toxic responses to a variety of chemical pollutants, including polycyclic aromatic hydrocarbons and halogenated aromatic hydrocarbons, most notably 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Ligand activation leads to AhR nuclear translocation and binding to a xenobiotic response element (XRE) in association with the Arnt to regulate gene expression. Several recent genome-wide transcriptional studies identified numerous AhR target genes that lack the canonical XRE recognition site in the promoter regions. Characterization of one such target gene, the plasminogen activator inhibitor 1, identified a novel nonconsensus XRE (NC-XRE) that confers TCDD responsiveness independently of the Arnt protein. Studies reported here show that the NC-XRE is a recognition site for the AhR and a new binding partner, the Kruppel-like factor (KLF) family member KLF6. In vivo chromatin immunoprecipitations and in vitro DNA binding studies demonstrate that the AhR and KLF6 proteins form an obligatory heterodimer necessary for NC-XRE binding. Mutational analyses show that the protein-protein interactions involve the AhR C terminus and KLF6 N terminus, respectively. Moreover, NC-XRE binding depends on the 5' basic region in KLF6 rather than the previously characterized zinc finger DNA binding domain. Collectively, the results unmask a novel AhR signaling mechanism distinct from the canonical XRE-driven process that will enrich our future understanding of AhR biology.
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Affiliation(s)
- Shelly R Wilson
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA
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Yuan Q, Loya K, Rani B, Möbus S, Balakrishnan A, Lamle J, Cathomen T, Vogel A, Manns MP, Ott M, Cantz T, Sharma AD. MicroRNA-221 overexpression accelerates hepatocyte proliferation during liver regeneration. Hepatology 2013; 57:299-310. [PMID: 22821679 DOI: 10.1002/hep.25984] [Citation(s) in RCA: 115] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Accepted: 07/06/2012] [Indexed: 02/06/2023]
Abstract
UNLABELLED The tightly controlled replication of hepatocytes in liver regeneration and uncontrolled proliferation of tumor cells in hepatocellular carcinoma (HCC) are often modulated by common regulatory pathways. Several microRNAs (miRNAs) are involved in HCC progression by modulating posttranscriptional expression of multiple target genes. miR-221, which is frequently up-regulated in HCCs, delays fulminant liver failure in mice by inhibiting apoptosis, indicating a pleiotropic role of miR-221 in hepatocytes. Here, we hypothesize that modulation of miR-221 targets in primary hepatocytes enhances proliferation, providing novel clues for enhanced liver regeneration. We demonstrate that miR-221 enhances proliferation of in vitro cultivated primary hepatocytes. Furthermore, applying two-thirds partial hepatectomy as a surgically induced liver regeneration model we show that adeno-associated virus-mediated overexpression of miR-221 in the mouse liver also accelerates hepatocyte proliferation in vivo. miR-221 overexpression leads to rapid S-phase entry of hepatocytes during liver regeneration. In addition to the known targets p27 and p57, we identify Aryl hydrocarbon nuclear translocator (Arnt) messenger RNA (mRNA) as a novel target of miR-221, which contributes to the pro-proliferative activity of miR-221. CONCLUSION miR-221 overexpression accelerates hepatocyte proliferation. Pharmacological intervention targeting miR-221 may thus be therapeutically beneficial in liver failure by preventing apoptosis and by inducing liver regeneration.
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Affiliation(s)
- Qinggong Yuan
- Cluster of Excellence REBIRTH, Hannover Medical School, Hannover, Germany
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Harper TA, Joshi AD, Elferink CJ. Identification of stanniocalcin 2 as a novel aryl hydrocarbon receptor target gene. J Pharmacol Exp Ther 2012; 344:579-88. [PMID: 23269473 DOI: 10.1124/jpet.112.201111] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Proper hepatocyte function is vital for survival; thus, unrepaired destruction of the parenchymal tissue leading to liver decompensation is devastating. Therefore, understanding the homeostatic process regulating liver regeneration is clinically important, and evidence that the aryl hydrocarbon receptor (AhR) can promote cell survival after intrinsic apoptotic stimuli is integral to the regenerative process. The current study uses primary hepatocytes to identify survival mechanisms consistent with normal AhR biology. Taking advantage of the Cre-lox system to manipulate AhR status, we designed a comprehensive microarray analysis to identify immediate and direct changes in the transcriptome concomitant with the loss of the AhR. As a result, we identified a unique data set with minimal overlap, compared with previous array studies, culminating in the identification of Stanniocalcin 2 (Stc2) as a novel receptor target gene previously reported to have a cytoprotective role in endoplasmic reticulum stress. The Stc2 promoter contains multiple putative xenobiotic response elements clustered in a 250-bp region that was shown to recruit the AhR by chromatin immunoprecipitation. Of interest, Stc2 gene expression is refractory to classic exogenous AhR agonists, but responds to cellular stress in an AhR-dependent mechanism consistent with a process promoting cell survival.
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Affiliation(s)
- Tod A Harper
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555-0654, USA
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Hofsteen P, Mehta V, Kim MS, Peterson RE, Heideman W. TCDD inhibits heart regeneration in adult zebrafish. Toxicol Sci 2012. [PMID: 23204111 DOI: 10.1093/toxsci/kfs329] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Normal adult zebrafish can completely regenerate lost myocardium following partial amputation of the ventricle apex. We report that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) significantly impairs this regeneration. Adult male zebrafish were injected with vehicle (control) or TCDD (70ng/g, ip) 1 day prior to partial amputation of the ventricle apex. Gross observation and histological analysis of the amputated heart at 21 days postamputation revealed that TCDD-exposed fish had not progressed beyond the initial clot formation stage, whereas the vehicle control fish showed substantial recovery and almost complete resolution of the formed clot. In contrast, hearts that were not surgically wounded showed no signs of TCDD toxicity. Striking features in the TCDD-exposed hearts were the absence of the normal sheath of new tissue enveloping the wound and the absence of intense cell proliferation at the site of the wound. In addition, the patterns of collagen deposition at the wound site were different between the TCDD and vehicle groups. Because the receptor for TCDD is the aryl hydrocarbon receptor ligand-activated transcriptional regulator, we examined the effects of TCDD exposure on gene expression in the ventricle using DNA microarrays. Samples were collected just prior to amputation and at 6h and 7 days postamputation. TCDD-pretreated hearts had dysregulated expression of genes involved in heart function, tissue regeneration, cell growth, and extracellular matrix. Because embryonic, but not adult, hearts are major targets for TCDD-induced cardiotoxicity, we speculate that the need for embryonic-like cells in regeneration is connected with the effects of TCDD in inhibiting the response to wounding.
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Horras CJ, Lamb CL, King AL, Hanley JR, Mitchell KA. Consequences of TCDD treatment on intra-hepatic lymphocytes during liver regeneration. J Immunotoxicol 2012; 9:359-67. [PMID: 22530936 DOI: 10.3109/1547691x.2012.664577] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Increasing evidence demonstrates a physiological role for the aryl hydrocarbon receptor (AhR) in regulating hepatocyte cell cycle progression. Previous studies have used a murine model of liver regeneration to show that exposure to the potent exogenous AhR ligand, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), suppresses hepatocyte proliferation in vivo. Based on recent reports that natural killer (NK) cells negatively regulate liver regeneration, coupled with the well-established immunomodulatory effects of TCDD, it was hypothesized that alterations in lymphocyte activation contribute to the suppression of liver regeneration in TCDD-treated mice. To test this, mice were treated with TCDD (20 μg/kg) 1 day prior to 70% partial hepatectomy (PH), in which two-thirds of the liver was surgically resected. Lymphocytes were collected from the remnant liver and analyzed by flow cytometry. Whereas exposure to TCDD did not alter the number of NK cells or CD3(+) T-cells recovered from the regenerating liver, it reduced the percentage and number of intra-hepatic NKT cells 42 h after PH. With regard to lymphocyte activation, TCDD treatment transiently increased CD69 expression on NK and NKT cells 12 h after PH, but had no effect on intracellular levels of IFNγ in NK, NKT, or CD3(+) T-cells. To determine the relevance of NK cells to the suppression of liver regeneration by TCDD, mice were treated with anti-Asialo GM-1 (ASGM-1) antibody to deplete NK cells prior to TCDD treatment and PH, and hepatocyte proliferation was measured using bromodeoxyuridine incorporation. Exposure to TCDD was found to inhibit hepatocyte proliferation in the regenerating liver of NK cell-depleted mice and control mice to the same extent. Hence, it is unlikely that enhanced numbers or increased activation of NK cells contribute to the suppression of liver regeneration in TCDD-treated mice.
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Affiliation(s)
- Christopher J Horras
- Department of Biological Sciences, Boise State University, Boise, ID 83725-1515, USA
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41
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Black MB, Budinsky RA, Dombkowski A, Cukovic D, LeCluyse EL, Ferguson SS, Thomas RS, Rowlands JC. Cross-species comparisons of transcriptomic alterations in human and rat primary hepatocytes exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin. Toxicol Sci 2012; 127:199-215. [PMID: 22298810 DOI: 10.1093/toxsci/kfs069] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A toxicogenomics approach was used to qualitatively and quantitatively compare the gene expression changes in human and rat primary hepatocytes exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Hepatocytes from five individual rats and five individual humans were exposed for 24 h to 11 concentrations of TCDD ranging from 0.00001 to 100nM and a vehicle control. Gene expression changes were analyzed using whole-genome microarrays containing 13,002 orthologs. Significant changes in expression of individual orthologs at any concentration (fold change [FC] ± 1.5 and false discovery rate < 0.05) were higher in the rat (1547) compared with human hepatocytes (475). Only 158 differentially expressed orthologs were common between rats and humans. Enrichment analysis was performed on the differentially expressed orthologs in each species with 49 and 34 enriched human and rat pathways, respectively. Only 12 enriched pathways were shared between the two species. The results demonstrate significant cross-species differences in expression at both the gene and pathway level. Benchmark dose analysis of gene expression changes showed an average 18-fold cross-species difference in potency among differentially expressed orthologs with the rat more sensitive than the human. Similar cross-species differences in potency were observed for signaling pathways. Using the maximum FC in gene expression as a measure of efficacy, the human hepatocytes showed on average a 20% lower efficacy among the individual orthologs showing differential expression. The results provide evidence for divergent cross-species gene expression changes in response to TCDD and are consistent with epidemiological and clinical evidence showing humans to be less sensitive to TCDD-induced hepatotoxicity.
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Affiliation(s)
- Michael B Black
- The Hamner Institutes for Health Sciences, Research Triangle Park, North Carolina 27709, USA
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Mehta V, Vezina CM. Potential protective mechanisms of aryl hydrocarbon receptor (AHR) signaling in benign prostatic hyperplasia. Differentiation 2012; 82:211-9. [PMID: 21684673 DOI: 10.1016/j.diff.2011.05.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2011] [Revised: 05/20/2011] [Accepted: 05/27/2011] [Indexed: 11/17/2022]
Abstract
The aryl hydrocarbon receptor (AHR) is an evolutionarily conserved ligand activated transcription factor best known for its role in mediating toxic responses to dioxin-like environmental contaminants. However, AHR signaling has also emerged as an active participant in processes of normal development and disease progression. Here, we review the role of AHR signaling in prostate development and disease processes, with a particular emphasis on benign prostatic hyperplasia (BPH). Inappropriate AHR activation has recently been associated with a decreased risk of symptomatic BPH in humans and has been shown to impair prostate development and disrupt endocrine signaling in rodents. We highlight known physiological responses to AHR activation in prostate and other tissues and discuss potential mechanisms by which it may act in adult human prostate to protect against symptomatic BPH.
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Affiliation(s)
- Vatsal Mehta
- Department of Comparative Biosciences, University of Wisconsin, 1656 Linden Drive, Madison, WI 53706, USA
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43
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Huang G, Elferink CJ. A novel nonconsensus xenobiotic response element capable of mediating aryl hydrocarbon receptor-dependent gene expression. Mol Pharmacol 2011; 81:338-47. [PMID: 22113079 DOI: 10.1124/mol.111.075952] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The aryl hydrocarbon receptor (AhR) is a mediator of xenobiotic toxicity, best recognized for conveying the deleterious effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure. The AhR functions as a ligand-activated transcription factor that binds to a canonical xenobiotic response element (XRE) in association with the heterodimerization partner, the AhR nuclear translocator (Arnt) protein. However, within the repertoire of AhR target genes identified in recent years, many lack a clearly defined XRE highlighting the growing realization that AhR-mediated gene expression seems to involve additional mechanisms distinct from the well characterized process involving the XRE. The present study characterized a novel nonconsensus XRE (NC-XRE) in the promoter of the plasminogen activator inhibitor-1 (PAI-1) gene that recruits a novel protein-DNA complex responsible for TCDD-inducible expression. DNA binding studies and reporter assays identified key residues in the NC-XRE necessary for protein-DNA binding and function, respectively. Functional studies with AhR expression constructs confirm that TCDD-inducibility is AhR-dependent and requires direct AhR-DNA binding to the NC-XRE. Chromatin immunoprecipitation and RNA interference studies reveal that the Arnt protein is not a component of the NC-XRE-bound AhR complex, suggesting that in contrast to the XRE, AhR-dependent gene expression mediated through the NC-XRE may involve a new DNA binding partner.
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Affiliation(s)
- Gengming Huang
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555-0654, USA
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44
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Lew BJ, Manickam R, Lawrence BP. Activation of the aryl hydrocarbon receptor during pregnancy in the mouse alters mammary development through direct effects on stromal and epithelial tissues. Biol Reprod 2011; 84:1094-102. [PMID: 21270426 DOI: 10.1095/biolreprod.110.087544] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Activation of the aryl hydrocarbon receptor (AHR), an environment-sensing transcription factor, causes profound impairment of mammary gland differentiation during pregnancy. Defects include decreased ductal branching, poorly formed alveolar structures, suppressed expression of milk proteins, and failure to nutritionally support offspring. AHR is activated by numerous environmental toxins, such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and plays an as yet poorly understood role in development and reproduction. To better understand how AHR activation affects pregnancy-associated mammary gland differentiation, we used a combination of ex vivo differentiation, mammary epithelial transplantation, and AHR-deficient mice to determine whether AHR modulates mammary development through a direct effect on mammary epithelial cells (MECs) or by altering paracrine or systemic factors that drive pregnancy-associated differentiation. Studies using mutant mice that express an AHR protein lacking the DNA-binding domain show that defects in pregnancy-associated differentiation require AHR:DNA interactions. We then used fluorescence-based cell sorting to compare changes in gene expression in MECs and whole mammary tissue to gain insight into affected signaling pathways. Our data indicate that activation of the AHR during pregnancy directly affects mammary tissue development via both a direct effect on MECs and through changes in cells of the fat pad, and point to gene targets in MECs and stromal tissues as putative AHR targets.
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Affiliation(s)
- Betina J Lew
- Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, New York, USA
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45
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Mitchell KA, Wilson SR, Elferink CJ. The activated aryl hydrocarbon receptor synergizes mitogen-induced murine liver hyperplasia. Toxicology 2010; 276:103-9. [PMID: 20637255 DOI: 10.1016/j.tox.2010.07.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Revised: 07/01/2010] [Accepted: 07/06/2010] [Indexed: 11/18/2022]
Abstract
Mechanisms of hepatocyte proliferation triggered by tissue loss are distinguishable from those that promote proliferation in the intact liver in response to mitogens. Previous studies demonstrate that exogenous activation of the aryl hydrocarbon receptor (AhR), a soluble ligand-activated transcription factor in the basic helix-loop-helix family of proteins, suppresses compensatory liver regeneration elicited by surgical partial hepatectomy. The goal of the present study was to determine how AhR activation modulates hepatocyte cell cycle progression in the intact liver following treatment with the hepatomitogen, 1,4-bis[2-(3,5-dichloropyridyloxy)] benzene (TCPOBOP). Mice were pretreated with the exogenous AhR agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) 24h prior to treatment with TCPOBOP (3 mg/kg).). In contrast to the suppressive effects of AhR activation observed during compensatory regeneration, TCDD pretreatment resulted in a 30-50% increase in hepatocyte proliferation in the intact liver of TCPOBOP-treated mice. Although pretreatment with TCDD suppressed CDK2 kinase activity and increased the association of CDK2 with negative regulatory proteins p21Cip1 and p27Kip1, a corresponding increase in CDK4/cyclin D1 association and CDK4 activity which culminated in enhanced phosphorylation of retinoblastoma protein, consistent with the increased proliferative response. These findings are in stark contrast to previous observations that the activated AhR can suppress hepatocyte proliferation in vivo and reveal a new complexity to AhR-mediated cell cycle control.
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Affiliation(s)
- Kristen A Mitchell
- Department of Pharmacology and Toxicology, School of Medicine, University of Texas Medical Branch, Galveston, TX 77555-1031, USA
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46
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Wang T, Gavin HM, Arlt VM, Lawrence BP, Fenton SE, Medina D, Vorderstrasse BA. Aryl hydrocarbon receptor activation during pregnancy, and in adult nulliparous mice, delays the subsequent development of DMBA-induced mammary tumors. Int J Cancer 2010; 128:1509-23. [PMID: 20521247 DOI: 10.1002/ijc.25493] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2009] [Accepted: 05/18/2010] [Indexed: 12/13/2022]
Abstract
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), the prototypic ligand for the aryl hydrocarbon receptor (AhR), promotes tumor formation in some model systems. However, with regard to breast cancer, epidemiological and animal studies are inconclusive as to whether exposure increases tumor incidence or may instead be protective. We have previously reported that mice exposed to TCDD during pregnancy have impaired differentiation of mammary tissue, including decreased branching and poor development of lobuloalveolar structures. Because normal pregnancy-induced mammary differentiation may protect against subsequent neoplastic transformation, we hypothesized that TCDD-treated mice would be more susceptible to chemical carcinogenesis after parturition. To test this, mice were treated with TCDD or vehicle during pregnancy. Four weeks later, 7,12-dimethylbenz[a]anthracene (DMBA) was administered to induce mammary tumor formation. Contrary to our hypothesis, TCDD-exposed parous mice showed a 4-week delay in tumor formation relative to controls, and they had a lower tumor incidence throughout the 27-week time course. The same results were obtained in nulliparous mice given TCDD and DMBA on the same schedule. We next addressed whether the delayed tumor incidence was a reflection of decreased tumor initiation, by testing the formation of DMBA-DNA adducts and preneoplastic lesions, induction of cytochrome P450s, and cell proliferation. None of these markers of tumor initiation differed between vehicle- and TCDD-treated animals. The expression of CXCL12 and CXCR4 was also measured to address their possible role in tumorigenesis. Taken together, our results suggest that AhR activation by TCDD slows the promotion of preneoplastic lesions to overt mammary tumors.
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Affiliation(s)
- Tao Wang
- Department of Pharmaceutical Sciences, Washington State University, Pullman, WA, USA
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47
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Potential health-modulating effects of isoflavones and metabolites via activation of PPAR and AhR. Nutrients 2010; 2:241-79. [PMID: 22254019 PMCID: PMC3257647 DOI: 10.3390/nu2030241] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Accepted: 02/23/2010] [Indexed: 12/24/2022] Open
Abstract
Isoflavones have multiple actions on cell functions. The most prominent one is the activation of estrogen receptors. Other functions are often overlooked, but are equally important and explain the beneficial health effects of isoflavones. Isoflavones are potent dual PPARα/γ agonists and exert anti-inflammatory activity, which may contribute to the prevention of metabolic syndrome, atherosclerosis and various other inflammatory diseases. Some isoflavones are potent aryl hydrocarbon receptor (AhR) agonists and induce cell cycle arrest, chemoprevention and modulate xenobiotic metabolism. This review discusses effects mediated by the activation of AhR and PPARs and casts a light on the concerted action of isoflavones.
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48
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Mccurley AT, Callard GV. Time course Analysis of Gene expression patterns in ZebrafIsh Eye during Optic Nerve Regeneration. J Exp Neurosci 2010. [DOI: 10.4137/jen.s5006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
It is well-established that neurons in the adult mammalian central nervous system (CNS) are terminally differentiated and, if injured, will be unable to regenerate their connections. In contrast to mammals, zebrafish and other teleosts display a robust neuroregenerative response. Following optic nerve crush (ONX), retinal ganglion cells (RGC) regrow their axons to synapse with topographically correct targets in the optic tectum, such that vision is restored in ~21 days. What accounts for these differences between teleostean and mammalian responses to neural injury is not fully understood. A time course analysis of global gene expression patterns in the zebrafish eye after ONX can help to elucidate cellular and molecular mechanisms that contribute to a successful neuroregeneration. To define different phases of regeneration after ONX, alpha tubulin 1 ( tuba1) and growth-associated protein 43 ( gap43), markers previously shown to correspond to morphophological events, were measured by real time quantitative PCR (qPCR). Microarray analysis was then performed at defined intervals (6 hours, 1, 4, 12, and 21 days) post-ONX and compared to SHAM. Results show that optic nerve damage induces multiple, phase-related transcriptional programs, with the maximum number of genes changed and highest fold-change occurring at 4 days. Several functional groups affected by optic nerve regeneration, including cell adhesion, apoptosis, cell cycle, energy metabolism, ion channel activity, and calcium signaling, were identified. Utilizing the whole eye allowed us to identify signaling contributions from the vitreous, immune and glial cells as well as the neural cells of the retina. Comparisons between our dataset and transcriptional profiles from other models of regeneration in zebrafish retina, heart and fin revealed a subset of commonly regulated transcripts, indicating shared mechanisms in different regenerating tissues. Knowledge of gene expression patterns in all components of the eye in a model of successful regeneration provides an entry point for functional analyses, and will help in devising hypotheses for testing normal and toxic regulatory factors.
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Affiliation(s)
- Amy T. Mccurley
- Department of Biology, Boston University, 5 cummington street, Boston, MA 02215 USA
| | - Gloria V. Callard
- Department of Biology, Boston University, 5 cummington street, Boston, MA 02215 USA
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Bisson WH, Koch DC, O'Donnell EF, Khalil SM, Kerkvliet NI, Tanguay RL, Abagyan R, Kolluri SK. Modeling of the aryl hydrocarbon receptor (AhR) ligand binding domain and its utility in virtual ligand screening to predict new AhR ligands. J Med Chem 2009; 52:5635-41. [PMID: 19719119 DOI: 10.1021/jm900199u] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor; the AhR Per-AhR/Arnt-Sim (PAS) domain binds ligands. We developed homology models of the AhR PAS domain to characterize previously observed intra- and interspecies differences in ligand binding using molecular docking. In silico structure-based virtual ligand screening using our model resulted in the identification of pinocembrin and 5-hydroxy-7-methoxyflavone, which promoted nuclear translocation and transcriptional activation of AhR and AhR-dependent induction of endogenous target genes.
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Affiliation(s)
- William H Bisson
- Cancer Biology Laboratory, Environmental Health Sciences Center, Oregon State University, Corvallis, Oregon 97331, USA
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50
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Simon T, Aylward LL, Kirman CR, Rowlands JC, Budinsky RA. Estimates of Cancer Potency of 2,3,7,8-Tetrachlorodibenzo(p)dioxin Using Linear and Nonlinear Dose-Response Modeling and Toxicokinetics. Toxicol Sci 2009; 112:490-506. [DOI: 10.1093/toxsci/kfp232] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
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