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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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Ablating the aryl hydrocarbon receptor (AhR) in CD11c+ cells perturbs intestinal epithelium development and intestinal immunity. Sci Rep 2016; 6:23820. [PMID: 27068235 PMCID: PMC4828637 DOI: 10.1038/srep23820] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 03/09/2016] [Indexed: 12/22/2022] Open
Abstract
Diet and microbiome derived indole derivatives are known to activate the ligand induced transcription factor, the Aryl hydrocarbon Receptor (AhR). While the current understanding of AhR biology has confirmed its role in mucosal lymphocytes, its function in intestinal antigen presenting cells (APCs) is poorly understood. Here, we report that Cre-mediated deletion of AhR in CD11c-expressing cells in C57/BL6 mice is associated with altered intestinal epithelial morphogenesis in vivo. Moreover, when co-cultured with AhR-deficient DCs ex vivo, intestinal organoids showed reduced SRY (sex determining region Y)-box 9 and increased Mucin 2 expression, which correlates with reduced Paneth cells and increased goblet cell differentiation, similar to the data obtained in vivo. Further, characterization of intestinal APC subsets, devoid of AhR, revealed an expression pattern associated with aberrant intrinsic Wnt pathway regulation. At a functional level, the loss of AhR in APCs resulted in a dysfunctional epithelial barrier, associated with a more aggressive chemically induced colitis compared to wild type animals. Our results are consistent with a model whereby the AhR signalling pathway may participate in the regulation of innate immunity through intestinal epithelium development and mucosal immunity.
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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: 351] [Impact Index Per Article: 39.0] [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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Briolotti P, Chaloin L, Balaguer P, Da Silva F, Tománková V, Pascussi JM, Duret C, Fabre JM, Ramos J, Klieber S, Maurel P, Daujat-Chavanieu M, Gerbal-Chaloin S. Analysis of Glycogen Synthase Kinase Inhibitors That Regulate Cytochrome P450 Expression in Primary Human Hepatocytes by Activation of β-Catenin, Aryl Hydrocarbon Receptor and Pregnane X Receptor Signaling. Toxicol Sci 2015; 148:261-75. [DOI: 10.1093/toxsci/kfv177] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Becker RA, Patlewicz G, Simon TW, Rowlands JC, Budinsky RA. The adverse outcome pathway for rodent liver tumor promotion by sustained activation of the aryl hydrocarbon receptor. Regul Toxicol Pharmacol 2015; 73:172-90. [PMID: 26145830 DOI: 10.1016/j.yrtph.2015.06.015] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 06/19/2015] [Accepted: 06/22/2015] [Indexed: 12/29/2022]
Abstract
An Adverse Outcome Pathway (AOP) represents the existing knowledge of a biological pathway leading from initial molecular interactions of a toxicant and progressing through a series of key events (KEs), culminating with an apical adverse outcome (AO) that has to be of regulatory relevance. An AOP based on the mode of action (MOA) of rodent liver tumor promotion by dioxin-like compounds (DLCs) has been developed and the weight of evidence (WoE) of key event relationships (KERs) evaluated using evolved Bradford Hill considerations. Dioxins and DLCs are potent aryl hydrocarbon receptor (AHR) ligands that cause a range of species-specific adverse outcomes. The occurrence of KEs is necessary for inducing downstream biological responses and KEs may occur at the molecular, cellular, tissue and organ levels. The common convention is that an AOP begins with the toxicant interaction with a biological response element; for this AOP, this initial event is binding of a DLC ligand to the AHR. Data from mechanistic studies, lifetime bioassays and approximately thirty initiation-promotion studies have established dioxin and DLCs as rat liver tumor promoters. Such studies clearly show that sustained AHR activation, weeks or months in duration, is necessary to induce rodent liver tumor promotion--hence, sustained AHR activation is deemed the molecular initiating event (MIE). After this MIE, subsequent KEs are 1) changes in cellular growth homeostasis likely associated with expression changes in a number of genes and observed as development of hepatic foci and decreases in apoptosis within foci; 2) extensive liver toxicity observed as the constellation of effects called toxic hepatopathy; 3) cellular proliferation and hyperplasia in several hepatic cell types. This progression of KEs culminates in the AO, the development of hepatocellular adenomas and carcinomas and cholangiolar carcinomas. A rich data set provides both qualitative and quantitative knowledge of the progression of this AOP through KEs and the KERs. Thus, the WoE for this AOP is judged to be strong. Species-specific effects of dioxins and DLCs are well known--humans are less responsive than rodents and rodent species differ in sensitivity between strains. Consequently, application of this AOP to evaluate potential human health risks must take these differences into account.
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Affiliation(s)
- Richard A Becker
- Regulatory and Technical Affairs Department, American Chemistry Council (ACC), Washington, DC 20002, USA.
| | - Grace Patlewicz
- DuPont Haskell Global Centers for Health and Environmental Sciences, Newark, DE 19711, USA
| | - Ted W Simon
- Ted Simon LLC, 4184 Johnston Road, Winston, GA 30187, USA
| | - J Craig Rowlands
- The Dow Chemical Company, Toxicology & Environmental Research & Consulting, 1803 Building Washington Street, Midland, MI 48674, USA
| | - Robert A Budinsky
- The Dow Chemical Company, Toxicology & Environmental Research & Consulting, 1803 Building Washington Street, Midland, MI 48674, USA
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Kabátková M, Zapletal O, Tylichová Z, Neča J, Machala M, Milcová A, Topinka J, Kozubík A, Vondráček J. Inhibition of β-catenin signalling promotes DNA damage elicited by benzo[a]pyrene in a model of human colon cancer cells via CYP1 deregulation. Mutagenesis 2015; 30:565-76. [PMID: 25805023 DOI: 10.1093/mutage/gev019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Deregulation of Wnt/β-catenin signalling plays an important role in the pathogenesis of colorectal cancer. Interestingly, this pathway has been recently implicated in transcriptional control of cytochrome P450 (CYP) family 1 enzymes, which are responsible for bioactivation of a number of dietary carcinogens. In the present study, we investigated the impact of inhibition of Wnt/β-catenin pathway on metabolism and genotoxicity of benzo[a]pyrene (BaP), a highly mutagenic polycyclic aromatic hydrocarbon and an efficient ligand of the aryl hydrocarbon receptor, which is known as a primary regulator of CYP1 expression, in cellular models derived from colorectal tumours. We observed that a synthetic inhibitor of β-catenin, JW74, significantly increased formation of BaP-induced DNA adducts in both colorectal adenoma and carcinoma-derived cell lines. Using the short interfering RNA (siRNA) targeting β-catenin, we then found that β-catenin knockdown in HCT116 colon carcinoma cells significantly enhanced formation of covalent DNA adducts by BaP and histone H2AX phosphorylation, as detected by (32)P-postlabelling technique and immunocytochemistry, respectively, and it also induced expression of DNA damage response genes, such as CDKN1A or DDB2. The increased formation of DNA adducts formed by BaP upon β-catenin knockdown corresponded with enhanced production of major BaP metabolites, as well as with an increased expression/activity of CYP1 enzymes. Finally, using siRNA-mediated knockdown of CYP1A1, we confirmed that this enzyme plays a major role in formation of BaP-induced DNA adducts in HCT116 cells. Taken together, the present results indicated that the siRNA-mediated inhibition of β-catenin signalling, which is aberrantly activated in a majority of colorectal cancers, modulated genotoxicity of dietary carcinogen BaP in colon cell model in vitro, via a mechanism involving up-regulation of CYP1 expression and activity.
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Affiliation(s)
- Markéta Kabátková
- Department of Cytokinetics, Institute of Biophysics, Czech Academy of Sciences, Kralovopolska 135, Brno 61265, Czech Republic, Institute of Experimental Biology, Faculty of Science, Kotlarska 2, Brno 61137, Czech Republicx
| | - Ondřej Zapletal
- Department of Cytokinetics, Institute of Biophysics, Czech Academy of Sciences, Kralovopolska 135, Brno 61265, Czech Republic, Institute of Experimental Biology, Faculty of Science, Kotlarska 2, Brno 61137, Czech Republicx
| | - Zuzana Tylichová
- Department of Cytokinetics, Institute of Biophysics, Czech Academy of Sciences, Kralovopolska 135, Brno 61265, Czech Republic, Institute of Experimental Biology, Faculty of Science, Kotlarska 2, Brno 61137, Czech Republicx
| | - Jiří Neča
- Department of Chemistry and Toxicology, Veterinary Research Institute, Hudcova 70, Brno 62100, Czech Republic and
| | - Miroslav Machala
- Department of Chemistry and Toxicology, Veterinary Research Institute, Hudcova 70, Brno 62100, Czech Republic and
| | - Alena Milcová
- Department of Genetic Ecotoxicology, Institute of Experimental Medicine, Czech Academy of Sciences, Videnska 1083, Prague 14220, Czech Republic
| | - Jan Topinka
- Department of Genetic Ecotoxicology, Institute of Experimental Medicine, Czech Academy of Sciences, Videnska 1083, Prague 14220, Czech Republic
| | - Alois Kozubík
- Department of Cytokinetics, Institute of Biophysics, Czech Academy of Sciences, Kralovopolska 135, Brno 61265, Czech Republic
| | - Jan Vondráček
- Department of Cytokinetics, Institute of Biophysics, Czech Academy of Sciences, Kralovopolska 135, Brno 61265, Czech Republic,
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Combination effects of AHR agonists and Wnt/β-catenin modulators in zebrafish embryos: Implications for physiological and toxicological AHR functions. Toxicol Appl Pharmacol 2015; 284:163-79. [PMID: 25711857 DOI: 10.1016/j.taap.2015.02.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2014] [Accepted: 02/13/2015] [Indexed: 12/30/2022]
Abstract
Wnt/β-catenin signaling regulates essential biological functions and acts in developmental toxicity of some chemicals. The aryl hydrocarbon receptor (AHR) is well-known to mediate developmental toxicity of persistent dioxin-like compounds (DLCs). Recent studies indicate a crosstalk between β-catenin and the AHR in some tissues. However the nature of this crosstalk in embryos is poorly known. We observed that zebrafish embryos exposed to the β-catenin inhibitor XAV939 display effects phenocopying those of the dioxin-like 3,3',4,4',5-pentachlorobiphenyl (PCB126). This led us to investigate the AHR interaction with β-catenin during development and ask whether developmental toxicity of DLCs involves antagonism of β-catenin signaling. We examined phenotypes and transcriptional responses in zebrafish embryos exposed to XAV939 or to a β-catenin activator, 1-azakenpaullone, alone or with AHR agonists, either PCB126 or 6-formylindolo[3,2-b]carbazole (FICZ). Alone 1-azakenpaullone and XAV939 both were embryo-toxic, and we found that in the presence of FICZ, the toxicity of 1-azakenpaullone decreased while the toxicity of XAV939 increased. This rescue of 1-azakenpaullone effects occurred in the time window of Ahr2-mediated toxicity and was reversed by morpholino-oligonucleotide knockdown of Ahr2. Regarding PCB126, addition of either 1-azakenpaullone or XAV939 led to lower mortality than with PCB126 alone but surviving embryos showed severe edemas. 1-Azakenpaullone induced transcription of β-catenin-associated genes, while PCB126 and FICZ blocked this induction. The data indicate a stage-dependent antagonism of β-catenin by Ahr2 in zebrafish embryos. We propose that the AHR has a physiological role in regulating β-catenin during development, and that this is one point of intersection linking toxicological and physiological AHR-governed processes.
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Harrill JA, Parks BB, Wauthier E, Rowlands JC, Reid LM, Thomas RS. Lineage-dependent effects of aryl hydrocarbon receptor agonists contribute to liver tumorigenesis. Hepatology 2015; 61:548-60. [PMID: 25284723 PMCID: PMC4303521 DOI: 10.1002/hep.27547] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 09/18/2014] [Indexed: 12/11/2022]
Abstract
UNLABELLED Rodent cancer bioassays indicate that the aryl hydrocarbon receptor (AHR) agonist, 2,3,7,8-tetracholorodibenzo-p-dioxin (TCDD), causes increases in both hepatocytic and cholangiocytic tumors. Effects of AHR activation have been evaluated on rodent hepatic stem cells (rHpSCs) versus their descendants, hepatoblasts (rHBs), two lineage stages of multipotent, hepatic precursors with overlapping but also distinct phenotypic traits. This was made possible by defining the first successful culture conditions for ex vivo maintenance of rHpScs consisting of a substratum of hyaluronans and Kubota's medium (KM), a serum-free medium designed for endodermal stem/progenitor cells. Supplementation of KM with leukemia inhibitory factor elicited lineage restriction to rHBs. Cultures were treated with various AHR agonists including TCDD, 6-formylindolo-[3,2-b]carbazole (FICZ), and 3-3'-diindolylmethane (DIM) and then analyzed with a combination of immunocytochemistry, gene expression, and high-content image analysis. The AHR agonists increased proliferation of rHpSCs at concentrations producing a persistent AHR activation as indicated by induction of Cyp1a1. By contrast, treatment with TCDD resulted in a rapid loss of viability of rHBs, even though the culture conditions, in the absence of the agonists, were permissive for survival and expansion of rHBs. The effects were not observed with FICZ and at lower concentrations of DIM. CONCLUSION Our findings are consistent with a lineage-dependent mode of action for AHR agonists in rodent liver tumorigenesis through selective expansion of rHpSCs in combination with a toxicity-induced loss of viability of rHBs. These lineage-dependent effects correlate with increased frequency of liver tumors.
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Affiliation(s)
- Joshua A Harrill
- Institute for Chemical Safety Sciences, Hamner Institutes for Health Sciences, Research Triangle ParkNC,Address reprint requests to: Joshua A. Harrill, Ph.D., Center for Toxicology and Environmental Health, 5120 North Shore Dr., North Little Rock, AR 72118. E-mail: or Lola M. Reid, Ph.D., Glaxo Building, Rm. 34; 101 Mason Farm Rd., UNC School of Medicine, Chapel Hill, NC 27599. E-mail:
| | - Bethany B Parks
- Institute for Chemical Safety Sciences, Hamner Institutes for Health Sciences, Research Triangle ParkNC
| | - Eliane Wauthier
- Program in Molecular Biology and Biotechnology, Department of Cell Biology and Physiology, UNC School of MedicineChapel Hill, NC
| | | | - Lola M Reid
- Program in Molecular Biology and Biotechnology, Department of Cell Biology and Physiology, UNC School of MedicineChapel Hill, NC,Address reprint requests to: Joshua A. Harrill, Ph.D., Center for Toxicology and Environmental Health, 5120 North Shore Dr., North Little Rock, AR 72118. E-mail: or Lola M. Reid, Ph.D., Glaxo Building, Rm. 34; 101 Mason Farm Rd., UNC School of Medicine, Chapel Hill, NC 27599. E-mail:
| | - Russell S Thomas
- Institute for Chemical Safety Sciences, Hamner Institutes for Health Sciences, Research Triangle ParkNC
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Schneider AJ, Branam AM, Peterson RE. Intersection of AHR and Wnt signaling in development, health, and disease. Int J Mol Sci 2014; 15:17852-85. [PMID: 25286307 PMCID: PMC4227194 DOI: 10.3390/ijms151017852] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 09/04/2014] [Accepted: 09/18/2014] [Indexed: 12/16/2022] Open
Abstract
The AHR (aryl hydrocarbon receptor) and Wnt (wingless-related MMTV integration site) signaling pathways have been conserved throughout evolution. Appropriately regulated signaling through each pathway is necessary for normal development and health, while dysregulation can lead to developmental defects and disease. Though both pathways have been vigorously studied, there is relatively little research exploring the possibility of crosstalk between these pathways. In this review, we provide a brief background on (1) the roles of both AHR and Wnt signaling in development and disease, and (2) the molecular mechanisms that characterize activation of each pathway. We also discuss the need for careful and complete experimental evaluation of each pathway and describe existing research that explores the intersection of AHR and Wnt signaling. Lastly, to illustrate in detail the intersection of AHR and Wnt signaling, we summarize our recent findings which show that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced disruption of Wnt signaling impairs fetal prostate development.
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Affiliation(s)
- Andrew J Schneider
- School of Pharmacy and Molecular and Environmental Toxicology Center University of Wisconsin, Madison, WI 53705, USA.
| | - Amanda M Branam
- School of Pharmacy and Molecular and Environmental Toxicology Center University of Wisconsin, Madison, WI 53705, USA.
| | - Richard E Peterson
- School of Pharmacy and Molecular and Environmental Toxicology Center University of Wisconsin, Madison, WI 53705, USA.
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Gerbal-Chaloin S, Dumé AS, Briolotti P, Klieber S, Raulet E, Duret C, Fabre JM, Ramos J, Maurel P, Daujat-Chavanieu M. The WNT/β-catenin pathway is a transcriptional regulator of CYP2E1, CYP1A2, and aryl hydrocarbon receptor gene expression in primary human hepatocytes. Mol Pharmacol 2014; 86:624-34. [PMID: 25228302 DOI: 10.1124/mol.114.094797] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The wingless-type MMTV integration site family (WNT)/β-catenin/adenomatous polyposis coli (CTNNB1/APC) pathway has been identified as a regulator of drug-metabolizing enzymes in the rodent liver. Conversely, little is known about the role of this pathway in drug metabolism regulation in human liver. Primary human hepatocytes (PHHs), which are the most physiologically relevant culture system to study drug metabolism in vitro, were used to investigate this issue. This study assessed the link between cytochrome P450 expression and WNT/β-catenin pathway activity in PHHs by modulating its activity with recombinant mouse Wnt3a (the canonical activator), inhibitors of glycogen synthase kinase 3β, and small-interfering RNA to invalidate CTNNB1 or its repressor APC, used separately or in combination. We found that the WNT/β-catenin pathway can be activated in PHHs, as assessed by universal β-catenin target gene expression, leucine-rich repeat containing G protein-coupled receptor 5. Moreover, WNT/β-catenin pathway activation induces the expression of CYP2E1, CYP1A2, and aryl hydrocarbon receptor, but not of CYP3A4, hepatocyte nuclear factor-4α, or pregnane X receptor (PXR) in PHHs. Specifically, we show for the first time that CYP2E1 is transcriptionally regulated by the WNT/β-catenin pathway. Moreover, CYP2E1 induction was accompanied by an increase in its metabolic activity, as indicated by the increased production of 6-OH-chlorzoxazone and by glutathione depletion after incubation with high doses of acetaminophen. In conclusion, the WNT/β-catenin pathway is functional in PHHs, and its induction in PHHs represents a powerful tool to evaluate the hepatotoxicity of drugs that are metabolized by CYP2E1.
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Affiliation(s)
- Sabine Gerbal-Chaloin
- Institut de Recherche en Biothérapie, INSERM, U1040 (S.G.C., A.S.D., P.B., E.R., C.D., P.M., M.D.C.); UMR 1040, Université Montpellier 1 (S.G.C., A.S.D., P.B., E.R., C.D., P.M., M.D.C.); Drug Disposition Domain, Sanofi Aventis (S.K.); Department of Digestive Surgery, CHU Saint Eloi (J.M.F.); Pathological Anatomy Department, CHU Gui de Chauliac (J.R.); and Institut de Recherche en Biothérapie, CHU Montpellier, (M.D.C.), Montpellier, France
| | - Anne-Sophie Dumé
- Institut de Recherche en Biothérapie, INSERM, U1040 (S.G.C., A.S.D., P.B., E.R., C.D., P.M., M.D.C.); UMR 1040, Université Montpellier 1 (S.G.C., A.S.D., P.B., E.R., C.D., P.M., M.D.C.); Drug Disposition Domain, Sanofi Aventis (S.K.); Department of Digestive Surgery, CHU Saint Eloi (J.M.F.); Pathological Anatomy Department, CHU Gui de Chauliac (J.R.); and Institut de Recherche en Biothérapie, CHU Montpellier, (M.D.C.), Montpellier, France
| | - Philippe Briolotti
- Institut de Recherche en Biothérapie, INSERM, U1040 (S.G.C., A.S.D., P.B., E.R., C.D., P.M., M.D.C.); UMR 1040, Université Montpellier 1 (S.G.C., A.S.D., P.B., E.R., C.D., P.M., M.D.C.); Drug Disposition Domain, Sanofi Aventis (S.K.); Department of Digestive Surgery, CHU Saint Eloi (J.M.F.); Pathological Anatomy Department, CHU Gui de Chauliac (J.R.); and Institut de Recherche en Biothérapie, CHU Montpellier, (M.D.C.), Montpellier, France
| | - Sylvie Klieber
- Institut de Recherche en Biothérapie, INSERM, U1040 (S.G.C., A.S.D., P.B., E.R., C.D., P.M., M.D.C.); UMR 1040, Université Montpellier 1 (S.G.C., A.S.D., P.B., E.R., C.D., P.M., M.D.C.); Drug Disposition Domain, Sanofi Aventis (S.K.); Department of Digestive Surgery, CHU Saint Eloi (J.M.F.); Pathological Anatomy Department, CHU Gui de Chauliac (J.R.); and Institut de Recherche en Biothérapie, CHU Montpellier, (M.D.C.), Montpellier, France
| | - Edith Raulet
- Institut de Recherche en Biothérapie, INSERM, U1040 (S.G.C., A.S.D., P.B., E.R., C.D., P.M., M.D.C.); UMR 1040, Université Montpellier 1 (S.G.C., A.S.D., P.B., E.R., C.D., P.M., M.D.C.); Drug Disposition Domain, Sanofi Aventis (S.K.); Department of Digestive Surgery, CHU Saint Eloi (J.M.F.); Pathological Anatomy Department, CHU Gui de Chauliac (J.R.); and Institut de Recherche en Biothérapie, CHU Montpellier, (M.D.C.), Montpellier, France
| | - Cédric Duret
- Institut de Recherche en Biothérapie, INSERM, U1040 (S.G.C., A.S.D., P.B., E.R., C.D., P.M., M.D.C.); UMR 1040, Université Montpellier 1 (S.G.C., A.S.D., P.B., E.R., C.D., P.M., M.D.C.); Drug Disposition Domain, Sanofi Aventis (S.K.); Department of Digestive Surgery, CHU Saint Eloi (J.M.F.); Pathological Anatomy Department, CHU Gui de Chauliac (J.R.); and Institut de Recherche en Biothérapie, CHU Montpellier, (M.D.C.), Montpellier, France
| | - Jean-Michel Fabre
- Institut de Recherche en Biothérapie, INSERM, U1040 (S.G.C., A.S.D., P.B., E.R., C.D., P.M., M.D.C.); UMR 1040, Université Montpellier 1 (S.G.C., A.S.D., P.B., E.R., C.D., P.M., M.D.C.); Drug Disposition Domain, Sanofi Aventis (S.K.); Department of Digestive Surgery, CHU Saint Eloi (J.M.F.); Pathological Anatomy Department, CHU Gui de Chauliac (J.R.); and Institut de Recherche en Biothérapie, CHU Montpellier, (M.D.C.), Montpellier, France
| | - Jeanne Ramos
- Institut de Recherche en Biothérapie, INSERM, U1040 (S.G.C., A.S.D., P.B., E.R., C.D., P.M., M.D.C.); UMR 1040, Université Montpellier 1 (S.G.C., A.S.D., P.B., E.R., C.D., P.M., M.D.C.); Drug Disposition Domain, Sanofi Aventis (S.K.); Department of Digestive Surgery, CHU Saint Eloi (J.M.F.); Pathological Anatomy Department, CHU Gui de Chauliac (J.R.); and Institut de Recherche en Biothérapie, CHU Montpellier, (M.D.C.), Montpellier, France
| | - Patrick Maurel
- Institut de Recherche en Biothérapie, INSERM, U1040 (S.G.C., A.S.D., P.B., E.R., C.D., P.M., M.D.C.); UMR 1040, Université Montpellier 1 (S.G.C., A.S.D., P.B., E.R., C.D., P.M., M.D.C.); Drug Disposition Domain, Sanofi Aventis (S.K.); Department of Digestive Surgery, CHU Saint Eloi (J.M.F.); Pathological Anatomy Department, CHU Gui de Chauliac (J.R.); and Institut de Recherche en Biothérapie, CHU Montpellier, (M.D.C.), Montpellier, France
| | - Martine Daujat-Chavanieu
- Institut de Recherche en Biothérapie, INSERM, U1040 (S.G.C., A.S.D., P.B., E.R., C.D., P.M., M.D.C.); UMR 1040, Université Montpellier 1 (S.G.C., A.S.D., P.B., E.R., C.D., P.M., M.D.C.); Drug Disposition Domain, Sanofi Aventis (S.K.); Department of Digestive Surgery, CHU Saint Eloi (J.M.F.); Pathological Anatomy Department, CHU Gui de Chauliac (J.R.); and Institut de Recherche en Biothérapie, CHU Montpellier, (M.D.C.), Montpellier, France
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Vaas S, Kreft L, Schwarz M, Braeuning A. Cooperation of structurally different aryl hydrocarbon receptor agonists and β-catenin in the regulation of CYP1A expression. Toxicology 2014; 325:31-41. [PMID: 25174530 DOI: 10.1016/j.tox.2014.08.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 08/25/2014] [Accepted: 08/27/2014] [Indexed: 01/22/2023]
Abstract
The ligand-activated nuclear receptor AhR (aryl hydrocarbon receptor) mediates the response of hepatocytes to various exogenous compounds. AhR is classically activated by planar, aromatic hydrocarbons, but also by other, structurally rather unrelated compounds. Recent data show that the canonical Wnt/β-catenin signaling pathway is also involved in the regulation of hepatic zonal gene expression and drug metabolism in mammalian liver. Previous studies indicate that the loss of β-catenin in hepatocytes diminishes the response to the AhR agonists 3-methylcholanthrene (3MC) in vivo and to 2,3,7,8-tetrachlorodibenzo-[p]-dioxin in vitro. The knockout of β-catenin also impairs the zonal pattern of AhR target gene induction by 3MC. However, it is presently unknown whether the chemical nature of the AhR agonist influences the AhR/β-catenin interaction. Moreover, no information is available about the dose-response curves of AhR activation in the absence or presence of Wnt/β-catenin signaling. In the present study, we have analyzed AhR-dependent responses to different concentrations of structurally unrelated AhR agonists in vivo and in vitro. The results demonstrate that β-catenin is essential to obtain the maximum AhR response. Moreover, using transgenic mouse models which allow for the ablation of β-catenin at different age of mice, we demonstrate that the presence of β-catenin, not postnatal developmental effects in β-catenin-deficient livers, is responsible for the observed interplay of β-catenin and the AhR.
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Affiliation(s)
- Sebastian Vaas
- Institute of Experimental and Clinical Pharmacology and Toxicology, Dept. of Toxicology, University of Tübingen, Wilhelmstr. 56, 72074 Tübingen, Germany
| | - Luisa Kreft
- Institute of Experimental and Clinical Pharmacology and Toxicology, Dept. of Toxicology, University of Tübingen, Wilhelmstr. 56, 72074 Tübingen, Germany
| | - Michael Schwarz
- Institute of Experimental and Clinical Pharmacology and Toxicology, Dept. of Toxicology, University of Tübingen, Wilhelmstr. 56, 72074 Tübingen, Germany
| | - Albert Braeuning
- Institute of Experimental and Clinical Pharmacology and Toxicology, Dept. of Toxicology, University of Tübingen, Wilhelmstr. 56, 72074 Tübingen, Germany.
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62
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Formosa R, Vassallo J. cAMP signalling in the normal and tumorigenic pituitary gland. Mol Cell Endocrinol 2014; 392:37-50. [PMID: 24845420 DOI: 10.1016/j.mce.2014.05.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 05/04/2014] [Accepted: 05/05/2014] [Indexed: 01/06/2023]
Abstract
cAMP signalling plays a key role in the normal physiology of the pituitary gland, regulating cellular growth and proliferation, hormone production and release. Deregulation of the cAMP signalling pathway has been reported to be a common occurrence in pituitary tumorigenesis. Several mechanisms have been implicated including somatic mutations, gene-gene interactions and gene-environmental interactions. Somatic mutations in G-proteins and protein kinases directly alter cAMP signalling, while malfunctioning of other signalling pathways such as the Raf/MAPK/ERK, PI3K/Akt/mTOR and Wnt pathways which normally interact with the cAMP pathway may mediate indirect effects on cAMP and varying downstream effectors. The aryl hydrocarbon receptor signalling pathway has been implicated in pituitary tumorigenesis and we review its role in general and specifically in relation to cAMP de-regulation.
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Affiliation(s)
- R Formosa
- Department of Medicine, Faculty of Medicine and Surgery, University of Malta, Level 0, Block A, Mater Dei Hospital, Msida MSD2080, Malta.
| | - J Vassallo
- Department of Medicine, Faculty of Medicine and Surgery, University of Malta, Level 0, Block A, Mater Dei Hospital, Msida MSD2080, Malta.
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Schneider AJ, Moore RW, Branam AM, Abler LL, Keil KP, Mehta V, Vezina CM, Peterson RE. In utero exposure to TCDD alters Wnt signaling during mouse prostate development: linking ventral prostate agenesis to downregulated β-catenin signaling. Toxicol Sci 2014; 141:176-87. [PMID: 24928892 DOI: 10.1093/toxsci/kfu116] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
In utero exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) causes ventral prostate agenesis in C57BL/6J mice by preventing ventral prostatic budding in the embryonic urogenital sinus (UGS). TCDD (5 μg/kg, po) administered to pregnant dams on embryonic day 15.5 (E15.5) activates the aryl hydrocarbon receptor in the UGS mesenchyme, disrupting the mesenchymally derived paracrine signaling that instructs epithelial prostatic budding. How TCDD alters the mesenchymal milieu is not well understood. We previously showed that TCDD disrupts some aspects of Wnt signaling in UGSs grown in vitro. Here we provide the first comprehensive, in vivo characterization of Wnt signaling in male E16.5 UGSs during normal development, and after in utero TCDD exposure. Vehicle- and TCDD-exposed UGSs were probed by in situ hybridization to assess relative abundance and localization of RNA from 46 genes that regulate Wnt signaling. TCDD altered the staining pattern of five genes, increasing staining for Wnt10a and Wnt16 and decreasing staining for Ror2, Rspo2, and Wif1. We also used immunohistochemistry to show, for the first time, activation of β-catenin (CTNNB1) signaling in ventral basal epithelium of control UGSs at E16.5. This onset of CTNNB1 signaling occurred immediately prior to the initiation of ventral prostatic budding and is characterized by a pronounced increase in CTNNB1 nuclear localization and subsequent expression of the CTNNB1 signaling target gene, Lef1. In utero TCDD exposure prevented the onset of CTNNB1 signaling and LEF1 expression in the ventral basal epithelium, thereby elucidating a likely mechanism by which TCDD contributes to failed prostatic budding in the ventral UGS.
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Affiliation(s)
| | - Robert W Moore
- School of Pharmacy, University of Wisconsin, Madison, Wisconsin 53705
| | - Amanda M Branam
- School of Pharmacy, University of Wisconsin, Madison, Wisconsin 53705
| | - Lisa L Abler
- School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin 53706
| | - Kimberly P Keil
- School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin 53706
| | - Vatsal Mehta
- School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin 53706
| | - Chad M Vezina
- School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin 53706
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Pieterse B, Felzel E, Winter R, van der Burg B, Brouwer A. PAH-CALUX, an optimized bioassay for AhR-mediated hazard identification of polycyclic aromatic hydrocarbons (PAHs) as individual compounds and in complex mixtures. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:11651-11659. [PMID: 23987121 DOI: 10.1021/es403810w] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) represent a class of ubiquitously occurring environmental compounds that are implicated in a wide range of toxicological effects. Routine measurement of PAH contamination generally involves chemical analytical analysis of a selected group of representatives, for example, EPA-16, which may result in underestimation of the PAH-related toxicity of a sample. Many high molecular weight PAHs are known ligands of the aryl hydrocarbon receptor (AhR), a nuclear receptor that mediates toxic effects related to these compounds. Making use of this property we developed a PAH CALUX assay, a mammalian, H4IIe- cell-based reporter assay for the hazard identification of total PAH mixtures. The PAH CALUX reporter cell line allows for specific, rapid (4 h exposure time) and reliable quantification of AhR-induced luciferase induction relative to benzo[a]pyrene (BaP), which is used as a positive reference PAH congener. Full dose response relationships with inductions over 100-fold were reached within only 2 h of exposure to BaP. The PAH CALUX is highly sensitive, that is, using a 4 h exposure time, a limit of detection (LOD) of 5.2 × 10(-11) M BaP was achieved, and highly accurate, that is, a repeatability of 5.9% and a reproducibility of 6.6% were established. Screening of a selection of PAHs that were prioritized by the European Union and/or the U.S. Environmental Protection Agency showed that the PAH CALUX bioassay has a high predictability, particularly for carcinogenic PAHs. Experiments with synthetic mixtures and reference materials containing complex PAH mixtures show the suitability of the assay for these types of applications. Moreover, the presented results suggest that application of the PAH CALUX will result in a lower risk of underestimation of the toxicity of a sample than chemical analytical approaches that focus on a limited set of prioritized compounds.
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Affiliation(s)
- B Pieterse
- BioDetection Systems BV. , Science Park 406. Amsterdam, The Netherlands
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65
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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: 1061] [Impact Index Per Article: 96.5] [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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Nakamura M, Ueda Y, Hayashi M, Kato H, Furuhashi T, Morita A. Tobacco smoke-induced skin pigmentation is mediated by the aryl hydrocarbon receptor. Exp Dermatol 2013; 22:556-8. [PMID: 23802610 DOI: 10.1111/exd.12170] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/06/2013] [Indexed: 01/24/2023]
Abstract
It is widely recognized that tobacco smoke causes skin pigmentation. No studies, however, have directly evaluated the mechanisms of the changes in smoker's skin pigmentation. In this study, when cultured with water-soluble tobacco smoke extract, the human epidermal melanocytes grew to a large size and produced more melanins. We evaluated melanocyte activation by quantifying microphthalmia-associated transcription factor (MITF) expression by real-time polymerase chain reaction. MITF expression was significantly and dose-dependently increased by exposure to tobacco smoke extract. The Wnt/β-catenin signalling pathway seemed to mediate the tobacco smoke extract-induced melanocyte activation. Immunocytochemical studies revealed that the activated melanocytes actively expressed aryl hydrocarbon receptors (AhR) around the nuclear membrane. The tobacco smoke extract-induced MITF activation was inhibited by RNA silencing of the AhR. This study provides the evidence that tobacco smoke enhances pigmentation in vitro and that the increase in pigmentation may involve β-catenin- and AhR-mediated mechanisms inside human melanocytes.
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67
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Zhang J, Li X, Jevince AR, Guan L, Wang J, Hall DH, Huang X, Ding M. Neuronal target identification requires AHA-1-mediated fine-tuning of Wnt signaling in C. elegans. PLoS Genet 2013; 9:e1003618. [PMID: 23825972 PMCID: PMC3694823 DOI: 10.1371/journal.pgen.1003618] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Accepted: 05/23/2013] [Indexed: 11/29/2022] Open
Abstract
Electrical synaptic transmission through gap junctions is a vital mode of intercellular communication in the nervous system. The mechanism by which reciprocal target cells find each other during the formation of gap junctions, however, is poorly understood. Here we show that gap junctions are formed between BDU interneurons and PLM mechanoreceptors in C. elegans and the connectivity of BDU with PLM is influenced by Wnt signaling. We further identified two PAS-bHLH family transcription factors, AHA-1 and AHR-1, which function cell-autonomously within BDU and PLM to facilitate the target identification process. aha-1 and ahr-1 act genetically upstream of cam-1. CAM-1, a membrane-bound receptor tyrosine kinase, is present on both BDU and PLM cells and likely serves as a Wnt antagonist. By binding to a cis-regulatory element in the cam-1 promoter, AHA-1 enhances cam-1 transcription. Our study reveals a Wnt-dependent fine-tuning mechanism that is crucial for mutual target cell identification during the formation of gap junction connections. The establishment of functional neuronal circuits requires that different neurons respond selectively to guidance molecules at particular times and in specific locations. In the target region, where cells connect, the same guidance molecules steer the growth of neurites from both the neuron and its target cell. The spatial, temporal, and cell-type-specific regulation of neuronal connection needs to be tightly regulated and precisely coordinated within the neuron and its target cell to achieve effective connection. In this study, we found that the precise connectivity of the BDU interneuron and the PLM mechanoreceptor in the nematode worm Caenorhabditis elegans is influenced by Wnt signaling. BDU-PLM contact also depends on the transcription factor AHA-1, which functions within both BDU and PLM cells to enhance transcription of the gene encoding the trans-membrane receptor CAM-1. CAM-1 is present on BDU and PLM and likely serves as a Wnt antagonist, thus linking transcriptional regulation by AHA-1 to modulation of Wnt signaling. Therefore, our study reveals a locally confined, cell type-specific and cell-autonomous mechanism that mediates mutual target identification.
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Affiliation(s)
- Jingyan Zhang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xia Li
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Angela R. Jevince
- Department of Neuroscience, Albert Einstein College of Medicine, New York, New York, United States of America
| | - Liying Guan
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Jiaming Wang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - David H. Hall
- Department of Neuroscience, Albert Einstein College of Medicine, New York, New York, United States of America
| | - Xun Huang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- * E-mail: (XH); (MD)
| | - Mei Ding
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- * E-mail: (XH); (MD)
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68
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Kasai S, Ishigaki T, Takumi R, Kamimura T, Kikuchi H. Beta-catenin signaling induces CYP1A1 expression by disrupting adherens junctions in Caco-2 human colon carcinoma cells. Biochim Biophys Acta Gen Subj 2013; 1830:2509-16. [PMID: 23174221 DOI: 10.1016/j.bbagen.2012.11.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Revised: 10/15/2012] [Accepted: 11/12/2012] [Indexed: 11/19/2022]
Abstract
BACKGROUND The aryl hydrocarbon (Ah) receptor is one of the best known ligand-activated transcription factors. The present study has focused on the wound-healing process on Ah receptor function. METHODS Depletion of calcium from culture medium of Caco-2 human colon carcinoma cells by transfer to Minimal Essential Medium (Spinner Modification; S-MEM) destroyed adherens junctions and the cells were used as the model of wound-healing process. RESULTS Calcium depletion induced both nuclear translocation of the Ah receptor, and increased expression of CYP1A1 and Slug mRNAs in Caco-2 cells. However, expression of Slug mRNA was not significantly induced by treatment with 2,3,7,8-tetrachlorodibenzo-p-dioxin. Knockdown of the Ah receptor and treatment with Ah receptor antagonists decreased level of CYP1A1 mRNA. The fragment of E-cadherin released by gamma-secretase was not involved in induction of CYP1A1 mRNA following S-MEM treatment. Knockdown of beta-catenin increased levels of Ah receptor mRNA, which may be attributable to direct or indirect involvement of beta-catenin in suppression of the Ah receptor gene. CONCLUSIONS Our results suggest that mRNA induction of some genes by destruction of adherens junctions depends on the Ah receptor. beta-Catenin, one of the components of the adherens junction, was released from the E-cadherin complex, which resulted in its increased interaction with the Ah receptor, and was translocated into the nucleus, and consequently the target genes would be transcribed. GENERAL SIGNIFICANCE Our observations suggest that some aspects of the molecular mechanism of wound healing involve the Ah receptor.
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Affiliation(s)
- Shuya Kasai
- Science of Biosources, United Graduate School of Agricultural Science, Iwate University, Morioka 020-8551, Japan
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69
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Procházková J, Kabátková M, Šmerdová L, Pacherník J, Sykorová D, Kohoutek J, Šimečková P, Hrubá E, Kozubík A, Machala M, Vondráček J. Aryl hydrocarbon receptor negatively regulates expression of the plakoglobin gene (jup). Toxicol Sci 2013; 134:258-70. [PMID: 23690540 DOI: 10.1093/toxsci/kft110] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Plakoglobin is an important component of intercellular junctions, including both desmosomes and adherens junctions, which is known as a tumor suppressor. Although mutations in the plakoglobin gene (Jup) and/or changes in its protein levels have been observed in various disease states, including cancer progression or cardiovascular defects, the information about endogenous or exogenous stimuli orchestrating Jup expression is limited. Here we show that the aryl hydrocarbon receptor (AhR) may regulate Jup expression in a cell-specific manner. We observed a significant suppressive effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a model toxic exogenous activator of the AhR signaling, on Jup expression in a variety of experimental models derived from rodent tissues, including contact-inhibited rat liver progenitor cells (where TCDD induces cell proliferation), rat and mouse hepatoma cell models (where TCDD inhibits cell cycle progression), cardiac cells derived from the mouse embryonic stem cells, or cardiomyocytes isolated from neonatal rat hearts. The small interfering RNA (siRNA)-mediated knockdown of AhR confirmed its role in both basal and TCDD-deregulated Jup expression. The analysis of genomic DNA located ~2.5kb upstream of rat Jup gene revealed a presence of evolutionarily conserved AhR binding motifs, which were confirmed upon their cloning into luciferase reporter construct. The siRNA-mediated knockdown of Jup expression affected both proliferation and attachment of liver progenitor cells. The present data indicate that the AhR may contribute to negative regulation of Jup gene expression in rodent cellular models, which may affect cell adherence and proliferation.
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Affiliation(s)
- Jiřina Procházková
- Department of Cytokinetics, Institute of Biophysics, Academy of Sciences of the Czech Republic, 61265 Brno, Czech Republic
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70
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Branam AM, Davis NM, Moore RW, Schneider AJ, Vezina CM, Peterson RE. TCDD inhibition of canonical Wnt signaling disrupts prostatic bud formation in mouse urogenital sinus. Toxicol Sci 2013; 133:42-53. [PMID: 23429912 DOI: 10.1093/toxsci/kft027] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
In mice, in utero exposure to 2,3,7,8-tetrachlorodibenzo-p- dioxin (TCDD) reduces the number of dorsolateral prostatic buds resulting in a smaller dorsolateral prostate and prevents formation of ventral buds culminating in ventral prostate agenesis. The genes and signaling pathways affected by TCDD that are responsible for disrupting prostate development are largely unknown. Here we show that treatment of urogenital sinus (UGS) organ cultures with known inhibitors of canonical Wnt signaling also inhibits prostatic bud formation. In support of the hypothesis that TCDD decreases canonical Wnt signaling, we identify inhibitory effects of TCDD on multiple components of the canonical Wnt signaling pathway in the UGS that temporally coincide with the inhibitory effect of TCDD on prostatic bud formation: (1) expression of R-spondins (Rspo2 and Rspo3) that promote canonical Wnt signaling is reduced; (2) expression of Lef1, Tcf1, and Wif1, established canonical Wnt target genes, is decreased; (3) expression of Lgr5, a RSPO receptor that activates canonical Wnt signaling, is reduced; and (4) expression of Dickkopfs (Dkks), inhibitors of canonical Wnt signaling, is not increased by TCDD. Thus, the TCDD-induced reduction in canonical Wnt signaling is associated with a decrease in activators (Rspo2 and Rspo3) rather than an increase in inhibitors (Dkk1 and Dkk2) of the pathway. This study focuses on determining whether treatment of TCDD-exposed UGS organ cultures with RSPO2 and/or RSPO3 is capable of rescuing the inhibitory effects of TCDD on canonical Wnt signaling and prostatic bud formation. We discovered that each RSPO alone or in combination partially rescues TCDD inhibition of both canonical Wnt signaling and prostatic bud formation.
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Affiliation(s)
- Amanda M Branam
- School of Pharmacy, University of Wisconsin, Madison, Wisconsin 53705, USA
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71
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Faust D, Vondráček J, Krčmář P, Šmerdová L, Procházková J, Hrubá E, Hulinková P, Kaina B, Dietrich C, Machala M. AhR-mediated changes in global gene expression in rat liver progenitor cells. Arch Toxicol 2012. [DOI: 10.1007/s00204-012-0979-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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72
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Andrysík Z, Procházková J, Kabátková M, Umannová L, Šimečková P, Kohoutek J, Kozubík A, Machala M, Vondráček J. Aryl hydrocarbon receptor-mediated disruption of contact inhibition is associated with connexin43 downregulation and inhibition of gap junctional intercellular communication. Arch Toxicol 2012; 87:491-503. [DOI: 10.1007/s00204-012-0963-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Accepted: 10/11/2012] [Indexed: 11/29/2022]
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73
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Jönsson ME, Kubota A, Timme-Laragy AR, Woodin B, Stegeman JJ. Ahr2-dependence of PCB126 effects on the swim bladder in relation to expression of CYP1 and cox-2 genes in developing zebrafish. Toxicol Appl Pharmacol 2012; 265:166-74. [PMID: 23036320 DOI: 10.1016/j.taap.2012.09.023] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2012] [Revised: 09/18/2012] [Accepted: 09/26/2012] [Indexed: 01/01/2023]
Abstract
The teleost swim bladder is assumed a homolog of the tetrapod lung. Both swim bladder and lung are developmental targets of persistent aryl hydrocarbon receptor (AHR(2)) agonists; in zebrafish (Danio rerio) the swim bladder fails to inflate with exposure to 3,3',4,4',5-pentachlorobiphenyl (PCB126). The mechanism for this effect is unknown, but studies have suggested roles of cytochrome P450 1 (CYP1) and cyclooxygenase 2 (Cox-2) in some Ahr-mediated developmental effects in zebrafish. We determined relationships between swim bladder inflation and CYP1 and Cox-2 mRNA expression in PCB126-exposed zebrafish embryos. We also examined effects on β-catenin dependent transcription, histological effects, and Ahr2 dependence of the effect of PCB126 on swim bladder using morpholinos targeting ahr2. One-day-old embryos were exposed to waterborne PCB126 or carrier (DMSO) for 24h and then held in clean water until day 4, a normal time for swim bladder inflation. The effects of PCB126 were concentration-dependent with EC(50) values of 1.4 to 2.0 nM for induction of the CYP1s, 3.7 and 5.1 nM (or higher) for cox-2a and cox-2b induction, and 2.5 nM for inhibition of swim bladder inflation. Histological defects included a compaction of the developing bladder. Ahr2-morpholino treatment rescued the effect of PCB126 (5 nM) on swim bladder inflation and blocked induction of CYP1A, cox-2a, and cox-2b. With 2nM PCB126 approximately 30% of eleutheroembryos(3) failed to inflate the swim bladder, but there was no difference in CYP1 or cox-2 mRNA expression between those embryos and embryos showing inflated swim bladder. Our results indicate that PCB126 blocks swim bladder inflation via an Ahr2-mediated mechanism. This mechanism seems independent of CYP1 or cox-2 mRNA induction but may involve abnormal development of swim bladder cells.
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Affiliation(s)
- Maria E Jönsson
- Dept. of Environmental Toxicology, Evolutionary Biology, Centre, Uppsala University, Norbyvägen 18A, 752 36 Uppsala, Sweden.
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Mejia-Garcia A, Sanchez-Ocampo EM, Galindo-Gomez S, Shibayama M, Reyes-Hernandez O, Guzman-Leon S, Gonzalez FJ, Elizondo G. 2,3,7,8-Tetrachlorodibenzo-p-dioxin enhances CCl4-induced hepatotoxicity in an aryl hydrocarbon receptor-dependent manner. Xenobiotica 2012; 43:161-8. [PMID: 22834477 DOI: 10.3109/00498254.2012.707790] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Cytochrome P4502E1 (CYP2E1) is involved in the biotransformation of several low molecular weight chemicals and plays an important role in the metabolic activation of carcinogens and hepatotoxins such as CCl(4). Induction of CYP2E1 is exerted mainly at posttranscriptional levels through mRNA and protein stabilization, and there is little evidence of xenobiotic induction at the transcriptional level. Previously, we reported microarray analysis data suggesting a decrease in Cyp2e1 gene expression on Ahr-null livers when compared to wild-type mouse livers. The goal of the present study was to determine whether 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) increased mouse CYP2E1 levels in an AhR-dependent manner and the impact on CCl(4)-induced hepatotoxicity. TCDD treatment induced CYP2E1 mRNA and protein levels in mouse liver, and this effect was aryl hydrocarbon receptor (AhR)-dependent. Moreover, TCDD pre-treatment increased the CCl(4)-induced alanine aminotransferase (ALT) activity, the extent of CCl(4)-induced necrosis, and the number of sinusoidal cells in wild-type animals, while this potentiating effect was not observed in Ahr-null mice. In conclusion, this study revealed that TCDD, probably in an AhR-dependent manner, exacerbated CCl(4)-induced hepatotoxicity through induction of CYP2E1.
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75
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Esser C. Biology and function of the aryl hydrocarbon receptor: report of an international and interdisciplinary conference. Arch Toxicol 2012; 86:1323-9. [DOI: 10.1007/s00204-012-0818-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Accepted: 02/07/2012] [Indexed: 12/31/2022]
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Global gene expression changes in human embryonic lung fibroblasts induced by organic extracts from respirable air particles. Part Fibre Toxicol 2012; 9:1. [PMID: 22239852 PMCID: PMC3275518 DOI: 10.1186/1743-8977-9-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Accepted: 01/12/2012] [Indexed: 12/19/2022] Open
Abstract
Background Recently, we used cell-free assays to demonstrate the toxic effects of complex mixtures of organic extracts from urban air particles (PM2.5) collected in four localities of the Czech Republic (Ostrava-Bartovice, Ostrava-Poruba, Karvina and Trebon) which differed in the extent and sources of air pollution. To obtain further insight into the biological mechanisms of action of the extractable organic matter (EOM) from ambient air particles, human embryonic lung fibroblasts (HEL12469) were treated with the same four EOMs to assess changes in the genome-wide expression profiles compared to DMSO treated controls. Method For this purpose, HEL cells were incubated with subtoxic EOM concentrations of 10, 30, and 60 μg EOM/ml for 24 hours and global gene expression changes were analyzed using human whole genome microarrays (Illumina). The expression of selected genes was verified by quantitative real-time PCR. Results Dose-dependent increases in the number of significantly deregulated transcripts as well as dose-response relationships in the levels of individual transcripts were observed. The transcriptomic data did not differ substantially between the localities, suggesting that the air pollution originating mainly from various sources may have similar biological effects. This was further confirmed by the analysis of deregulated pathways and by identification of the most contributing gene modulations. The number of significantly deregulated KEGG pathways, as identified by Goeman's global test, varied, depending on the locality, between 12 to 29. The Metabolism of xenobiotics by cytochrome P450 exhibited the strongest upregulation in all 4 localities and CYP1B1 had a major contribution to the upregulation of this pathway. Other important deregulated pathways in all 4 localities were ABC transporters (involved in the translocation of exogenous and endogenous metabolites across membranes and DNA repair), the Wnt and TGF-β signaling pathways (associated particularly with tumor promotion and progression), Steroid hormone biosynthesis (involved in the endocrine-disrupting activity of chemicals), and Glycerolipid metabolism (pathways involving the lipids with a glycerol backbone including lipid signaling molecules). Conclusion The microarray data suggested a prominent role of activation of aryl hydrocarbon receptor-dependent gene expression.
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Baljinnyam B, Klauzinska M, Saffo S, Callahan R, Rubin JS. Recombinant R-spondin2 and Wnt3a up- and down-regulate novel target genes in C57MG mouse mammary epithelial cells. PLoS One 2012; 7:e29455. [PMID: 22238613 PMCID: PMC3251591 DOI: 10.1371/journal.pone.0029455] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Accepted: 11/29/2011] [Indexed: 01/05/2023] Open
Abstract
R-spondins (Rspos) comprise a family of four secreted proteins that have important roles in cell proliferation, cell fate determination and organogenesis. Rspos typically exert their effects by potentiating the Wnt/β-catenin signaling pathway. To systematically investigate the impact of Rspo/Wnt on gene expression, we performed a microarray analysis using C57MG mouse mammary epithelial cells treated with recombinant Rspo2 and/or Wnt3a. We observed the up- and down-regulation of several previously unidentified target genes, including ones that encode proteins involved in immune responses, effectors of other growth factor signaling pathways and transcription factors. Dozens of these changes were validated by quantitative real time RT-PCR. Time course experiments showed that Rspo2 typically had little or no effect on Wnt-dependent gene expression at 3 or 6 h, but enhanced expression at 24 h, consistent with biochemical data indicating that Rspo2 acts primarily to sustain rather than acutely increase Wnt pathway activation. Up-regulation of gene expression was inhibited by pre-treatment with Dickkopf1, a Wnt/β-catenin pathway antagonist, and by siRNA knockdown of β-catenin expression. While Dickkopf1 blocked Rspo2/Wnt3a-dependent down-regulation, a number of down-regulated genes were not affected by β-catenin knockdown, suggesting that in these instances down-regulation was mediated by a β-catenin-independent mechanism.
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Affiliation(s)
- Bolormaa Baljinnyam
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Malgorzata Klauzinska
- Oncogenetics Section, Mammary Biology and Tumorigenesis Laboratory, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Saad Saffo
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Robert Callahan
- Oncogenetics Section, Mammary Biology and Tumorigenesis Laboratory, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Jeffrey S. Rubin
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, Bethesda, Maryland, United States of America
- * E-mail:
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