1
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Carceller-Zazo E, Sevilla LM, Pons-Alonso O, Chiner-Oms Á, Amazit L, An Vu T, Vitellius G, Viengchareun S, Comas I, Jaszczyszyn Y, Abella M, Alegre-Martí A, Estébanez-Perpiñá E, Lombès M, Pérez P. The mineralocorticoid receptor modulates timing and location of genomic binding by glucocorticoid receptor in response to synthetic glucocorticoids in keratinocytes. FASEB J 2023; 37:e22709. [PMID: 36527388 DOI: 10.1096/fj.202201199rr] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 11/29/2022] [Accepted: 12/02/2022] [Indexed: 12/23/2022]
Abstract
Glucocorticoids (GCs) exert potent antiproliferative and anti-inflammatory properties, explaining their therapeutic efficacy for skin diseases. GCs act by binding to the GC receptor (GR) and the mineralocorticoid receptor (MR), co-expressed in classical and non-classical targets including keratinocytes. Using knockout mice, we previously demonstrated that GR and MR exert essential nonoverlapping functions in skin homeostasis. These closely related receptors may homo- or heterodimerize to regulate transcription, and theoretically bind identical GC-response elements (GRE). We assessed the contribution of MR to GR genomic binding and the transcriptional response to the synthetic GC dexamethasone (Dex) using control (CO) and MR knockout (MREKO ) keratinocytes. GR chromatin immunoprecipitation (ChIP)-seq identified peaks common and unique to both genotypes upon Dex treatment (1 h). GREs, AP-1, TEAD, and p53 motifs were enriched in CO and MREKO peaks. However, GR genomic binding was 35% reduced in MREKO , with significantly decreased GRE enrichment, and reduced nuclear GR. Surface plasmon resonance determined steady state affinity constants, suggesting preferred dimer formation as MR-MR > GR-MR ~ GR-GR; however, kinetic studies demonstrated that GR-containing dimers had the longest lifetimes. Despite GR-binding differences, RNA-seq identified largely similar subsets of differentially expressed genes in both genotypes upon Dex treatment (3 h). However, time-course experiments showed gene-dependent differences in the magnitude of expression, which correlated with earlier and more pronounced GR binding to GRE sites unique to CO including near Nr3c1. Our data show that endogenous MR has an impact on the kinetics and differential genomic binding of GR, affecting the time-course, specificity, and magnitude of GC transcriptional responses in keratinocytes.
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Affiliation(s)
- Elena Carceller-Zazo
- Inserm, Physiologie et Physiopathologie Endocriniennes, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Lisa M Sevilla
- Department of Pathology and Molecular and Cell Therapy, Instituto de Biomedicina de Valencia (IBV-CSIC), Valencia, Spain
| | - Omar Pons-Alonso
- Department of Pathology and Molecular and Cell Therapy, Instituto de Biomedicina de Valencia (IBV-CSIC), Valencia, Spain
| | - Álvaro Chiner-Oms
- Department of Genomics and Proteomics, Instituto de Biomedicina de Valencia (IBV-CSIC), Valencia, Spain
| | - Larbi Amazit
- Inserm, Physiologie et Physiopathologie Endocriniennes, Université Paris-Saclay, Le Kremlin-Bicêtre, France.,Unité Mixte de Service UMS-44, Le Kremlin Bicêtre, France
| | - Thi An Vu
- Inserm, Physiologie et Physiopathologie Endocriniennes, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Géraldine Vitellius
- Inserm, Physiologie et Physiopathologie Endocriniennes, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Say Viengchareun
- Inserm, Physiologie et Physiopathologie Endocriniennes, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Iñaki Comas
- Department of Genomics and Proteomics, Instituto de Biomedicina de Valencia (IBV-CSIC), Valencia, Spain
| | - Yan Jaszczyszyn
- CEA, CNRS, Institute for Integrative Biology of the Cell, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Montserrat Abella
- Structural Biology of Nuclear Receptors, Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, University of Barcelona, Barcelona, Spain.,Institute of Biomedicine of the University of Barcelona (IBUB), University of Barcelona, Barcelona, Spain
| | - Andrea Alegre-Martí
- Structural Biology of Nuclear Receptors, Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, University of Barcelona, Barcelona, Spain.,Institute of Biomedicine of the University of Barcelona (IBUB), University of Barcelona, Barcelona, Spain
| | - Eva Estébanez-Perpiñá
- Structural Biology of Nuclear Receptors, Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, University of Barcelona, Barcelona, Spain.,Institute of Biomedicine of the University of Barcelona (IBUB), University of Barcelona, Barcelona, Spain
| | - Marc Lombès
- Inserm, Physiologie et Physiopathologie Endocriniennes, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Paloma Pérez
- Department of Pathology and Molecular and Cell Therapy, Instituto de Biomedicina de Valencia (IBV-CSIC), Valencia, Spain
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2
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Nishi M, Kawata M. Brain Corticosteroid Receptor Dynamics and Trafficking: Implications from Live Cell Imaging. Neuroscientist 2016; 12:119-33. [PMID: 16514009 DOI: 10.1177/1073858405279691] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Adrenal corticosteroids (cortisol in humans or corticosterone in rodents) exert numerous effects in the central nervous system that regulate the stress response, mood, learning and memory, and various neuroendocrine functions. Corticosterone actions in the brain are mediated by two corticosteroid receptors, glucocorticoid receptor (GR) and mineralocorticoid receptor (MR), and they show a high degree of colocalization in the hippocampal region. These receptors predominantly reside in the cytoplasm without ligand and are translocated into the nucleus upon ligand binding to act as transcriptional factors. Thus, their subcellualr localizations are an important component of their biological activity. Given the differential action of MR and GR in the central nervous system, it is important to elucidate how the trafficking of these receptors between the cytoplasm and the nucleus and their interactions are regulated by ligand or other molecules to exert transcriptional activity. In this review, the authors focus on the nucleocytoplasmic and subnuclear trafficking of GR and MR in neural cells and nonneural cells and discuss various factors affecting the dynamics of these receptors.
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Affiliation(s)
- Mayumi Nishi
- Department of Anatomy and Neurobiology, Kyoto Prefectural University of Medicine, Kyoto, Japan.
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3
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Oka K, Kohno S, Urushitani H, Guillette LJ, Ohta Y, Iguchi T, Katsu Y. Molecular cloning and characterization of the corticoid receptors from the American alligator. Mol Cell Endocrinol 2013; 365:153-61. [PMID: 23127802 DOI: 10.1016/j.mce.2012.10.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Revised: 10/11/2012] [Accepted: 10/12/2012] [Indexed: 01/04/2023]
Abstract
Steroid hormones are essential for health in vertebrates. Corticosteroids, for example, have a regulatory role in many physiological functions, such as osmoregulation, respiration, immune responses, stress responses, reproduction, growth, and metabolism. Although extensively studied in mammals and some non-mammalian species, the molecular mechanisms of corticosteroid hormone (glucocorticoids and mineralocorticoids) action are poorly understood in reptiles. Here, we have evaluated hormone receptor-ligand interactions in the American alligator (Alligator mississippiensis), following the isolation of cDNAs encoding a glucocorticoid receptor (GR) and a mineralocorticoid receptor (MR). The full-length alligator GR (aGR) and aMR cDNAs were obtained using 5' and 3' rapid amplification cDNA ends (RACE). The deduced amino acid sequences exhibited high identity to the chicken orthologs (aGR: 83%; aMR: 90%). Using transient transfection assays of mammalian cells, both aGR and aMR proteins displayed corticosteroid-dependent activation of transcription from keto-steroid hormone responsive, murine mammary tumor virus promoters. We further compared the ligand-specifity of human, chicken, Xenopus, and zebrafish GR and MR. We found that the alligator and chicken GR/MR have very similar amino acid sequences, and this translates to very similar ligand specificity. This is the first report of the full-coding regions of a reptilian GR and MR, and the examination of their transactivation by steroid hormones.
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Affiliation(s)
- Kaori Oka
- Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
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4
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Nishi M, Tanaka M, Matsuda KI, Sunaguchi M, Kawata M. Visualization of glucocorticoid receptor and mineralocorticoid receptor interactions in living cells with GFP-based fluorescence resonance energy transfer. J Neurosci 2004; 24:4918-27. [PMID: 15163683 PMCID: PMC6729363 DOI: 10.1523/jneurosci.5495-03.2004] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2003] [Revised: 04/05/2004] [Accepted: 04/09/2004] [Indexed: 11/21/2022] Open
Abstract
Adrenal corticosteroids readily enter the brain and exert markedly diverse effects, including stress responses in the target neural cells via two receptor systems, the mineralocorticoid receptor (MR) and the glucocorticoid receptor (GR). It has been shown that the GR and MR are highly colocalized in the hippocampus. Given the differential action of the MR and GR in the hippocampal region, it is important to elucidate how these receptors interact with each other in response to corticosteroids. We investigated the heterodimerization of the MR and GR with green fluorescent protein-based fluorescence resonance energy transfer (FRET) microscopy in living cells with spatiotemporal manner. FRET was evaluated in three ways: (1) ratio imaging; (2) emission spectra; and (3) acceptor photobleaching. FRET analysis demonstrated that cyan fluorescent protein-GR and yellow fluorescent protein-MR form heterodimers after corticosterone (CORT) treatment both in the nucleus of cultured hippocampal neurons and COS-1 cells, whereas they do not form heterodimers in the cytoplasm. The content of the GR-MR heterodimer was higher at 10(-6) m CORT than at 10(-9) m CORT and reached a maximum level after 60 min of CORT treatment in both cultured hippocampal neurons and COS-1 cells. The distribution pattern of heterodimers in the nucleus of cultured hippocampal neurons was more restricted than that in COS-1 cells. The present study using mutant fusion proteins in nuclear localization signal showed that these corticosteroid receptors are not translocated into the nucleus in the form of heterodimers even after treatment with ligand and thus allow no heterodimerization to take place in the cytoplasm. These results obtained with FRET analyses give new insights into the sites, time course, and effects of ligand concentration on heterodimersization of the GR and MR.
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Affiliation(s)
- Mayumi Nishi
- Department of Anatomy and Neurobiology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan.
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5
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Yoshikawa N, Makino Y, Okamoto K, Morimoto C, Makino I, Tanaka H. Distinct interaction of cortivazol with the ligand binding domain confers glucocorticoid receptor specificity: cortivazol is a specific ligand for the glucocorticoid receptor. J Biol Chem 2002; 277:5529-40. [PMID: 11741935 DOI: 10.1074/jbc.m107946200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Ligand-receptor coupling is one of the important constituents of signal transduction and is essential for physiological transmission of actions of endogenous substances including steroid hormones. However, molecular mechanisms of the redundancy between glucocorticoid and mineralocorticoid actions remain unknown because of complicated cross-talk among, for example, these adrenal steroids, their cognate receptors, and target genes. Receptor-specific ligand that can distinctly modulate target gene expression should be developed to overcome this issue. In this report, we showed that a pyrazolosteroid cortivazol (CVZ) does not induce either nuclear translocation or transactivation function of the mineralocorticoid receptor (MR) but does both for the glucocorticoid receptor (GR). Moreover, deletion analysis of the C-terminal end of the GR has revealed that CVZ interacts with the distinct portion of the ligand binding domain (LBD) and differentially modulates the ligand-dependent interaction between transcription intermediary factor 2 and the LBD when compared with cortisol, dexamethasone, and aldosterone. Thus, it is indicated that CVZ may not be only a molecular probe for the analysis of the redundancy between the GR and MR in vivo but also a useful reagent to clarify structure-function relationship of the GR LBD.
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MESH Headings
- Active Transport, Cell Nucleus
- Amino Acid Sequence
- Animals
- Blotting, Western
- CHO Cells
- COS Cells
- Cell Line
- Cricetinae
- DNA, Complementary/metabolism
- Dose-Response Relationship, Drug
- Gene Deletion
- Genes, Reporter
- Glucocorticoids/chemistry
- Glucocorticoids/metabolism
- Green Fluorescent Proteins
- HSP90 Heat-Shock Proteins/metabolism
- HeLa Cells
- Humans
- Kinetics
- Ligands
- Luminescent Proteins/metabolism
- Microscopy, Fluorescence
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Mutation
- Plasmids/metabolism
- Precipitin Tests
- Pregnatrienes/chemistry
- Pregnatrienes/metabolism
- Protein Binding
- Protein Structure, Tertiary
- Protein Transport
- Receptors, Glucocorticoid/chemistry
- Receptors, Glucocorticoid/metabolism
- Recombinant Fusion Proteins/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Sequence Homology, Amino Acid
- Structure-Activity Relationship
- Time Factors
- Transcriptional Activation
- Transfection
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Affiliation(s)
- Noritada Yoshikawa
- Division of Clinical Immunology, Advanced Clinical Research Center, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo, Japan
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6
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Beavan S, Horner A, Bord S, Ireland D, Compston J. Colocalization of glucocorticoid and mineralocorticoid receptors in human bone. J Bone Miner Res 2001; 16:1496-504. [PMID: 11499872 DOI: 10.1359/jbmr.2001.16.8.1496] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Osteoporosis is a poorly understood but common complication of glucocorticoid therapy. The actions of glucocorticoids are mediated via glucocorticoid receptors (GRs), but in vitro, glucocorticoids also can bind to mineralocorticoid receptors (MRs). It is not known if MR protein is present in human bone and little is known of GR isoform expression (GRalpha and GRbeta). GR and MR protein expression and possible sites of action were investigated in neonatal rib and adult iliac crest biopsy specimens using antibodies specific for MR, GRalpha, and GRalphabeta. Colocalization [MR GRalpha] [MR GRalphabeta] was performed using fluorescent-conjugated secondary antibodies. GRalpha, GRbeta, and MR show distinct but overlapping patterns of expression, suggesting important functions for each receptor type. Osteoclasts showed no staining for GRalpha but strong staining for GRalphabeta, indicating expression of GRbeta and a specific role in addition to antagonizing the transcriptional activity of GRalpha. MR also was observed in osteoclasts and colocalized with GRalphabeta. Coexpression of MR, GRalpha, and GRalphabeta was seen in osteoblasts. Reverse-transcription-polymerase chain reaction (RT-PCR) of cultured osteoblast RNA confirmed expression of both GRalpha and GRbeta. Osteocytes stained with MR, GRalpha, and GRalphabeta antibodies but to a lesser degree than osteoblasts. In the neonatal rib cartilage, staining for GRalpha, GRalphabeta, and MR was present in approximately one-half of the resting and hypertrophic chondrocytes and in most of proliferating chondrocytes and chondrocytes within the mineralizing matrix. Identification of MR raises the possibility that the physiological and pharmacologic effects of glucocorticoids on bone may be mediated via MR as well as GR and that GRalpha, GRbeta, and MR synergize to influence corticosteroid metabolism in human bone.
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Affiliation(s)
- S Beavan
- Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, United Kingdom
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7
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Govindan MV, Warriar N. Reconstitution of the N-terminal transcription activation function of human mineralocorticoid receptor in a defective human glucocorticoid receptor. J Biol Chem 1998; 273:24439-47. [PMID: 9733735 DOI: 10.1074/jbc.273.38.24439] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
N-terminal sequences involved in transcription activation by the human mineralocorticoid receptor (hMR) have yet to be defined. We have addressed this issue and generated overlapping internal deletion mutants hMRDelta59-162, hMRDelta59-247, hMRDelta59-328, hMRDelta162-247, hMRDelta247-328, hMRDelta247-382, and hMRDelta328-382 with intact DNA-binding and hormone-binding domains. A second set of mutant receptors with unique BglII sites was generated to facilitate the isolations of fragments. Immunodetection with anti-hMR peptide antibodies and hormone-binding assays showed that the mutations did not affect the expression of the receptors or ability to bind aldosterone. Distribution of aldosterone binding activity of wild type and deletion mutants expressed in HeLa cells was predominantly nuclear. Furthermore, deletion of sequences between 59 and 390 did not affect DNA binding activity. Transfection studies with HeLa cells revealed a region around residue 247 that was crucial for normal receptor function. Deletion of amino acids 59-162 did not affect the transcriptional activity of the hMR. However, deletion of sequences 247-382 and 328-382 markedly decreased the transcription activation function. The induction of the reporter gene by the chimera hGRDelta71-262/hMR328-382 was 2-fold higher than with the wild type hGR, but 200-fold when compared with hGRDelta71-262, indicating that the AF-1 domain is located between positions 328 and 382 in the hMR.
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Affiliation(s)
- M V Govindan
- Centre Recherche Hôtel-Dieu Québec and Laval University, Côte du Palais, Québec G1R 2J6, Canada.
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8
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Bamberger CM, Bamberger AM, Wald M, Chrousos GP, Schulte HM. Inhibition of mineralocorticoid activity by the beta-isoform of the human glucocorticoid receptor. J Steroid Biochem Mol Biol 1997; 60:43-50. [PMID: 9182857 DOI: 10.1016/s0960-0760(96)00167-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Mineralocorticoids and glucocorticoids are important regulators of electrolyte homeostasis and arterial blood pressure. Their effects are mediated by the mineralocorticoid (MR) and the glucocorticoid receptor (GR), respectively. The present study was designed to determine how the two isoforms of the human GR, the "classic" GR alpha and the non-hormone-binding GR beta, interfere with the transcriptional effects of the hormone-activated human MR. COS-7 monkey kidney cells were transfected with different mineralocorticoid-responsive reporter plasmids and a vector expressing the human MR protein. Different amounts of either control, GR alpha, or GR beta plasmid were co-transfected, and luciferase activity was measured after stimulation with aldosterone and/or dexamethasone. MR-mediated stimulation of transcription was enhanced by co-transfection of the GR alpha expression vector. In contrast, MR-mediated stimulation of transcription was strongly inhibited by co-transfection of equal amounts of the GR beta expression vector. Reverse transcription-polymerase chain reaction (RT-PCR) showed expression of both GR isoforms as well as of MR in the human kidney. These data indicate that the two isoforms of the human GR exert opposite effects on mineralocorticoid activity. We conclude that the ratio between GR alpha and GR beta can define the sensitivity of mineralocorticoid target tissues to aldosterone. Imbalances of this ratio may participate in clinical syndromes of impaired or augmented mineralocorticoid sensitivity, such as certain cases of pseudohypoaldosteronism or, possibly, primary arterial hypertension.
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Affiliation(s)
- C M Bamberger
- IHF Institute for Hormone and Fertility Research, University of Hamburg, Germany
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9
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Liu W, Wang J, Sauter NK, Pearce D. Steroid receptor heterodimerization demonstrated in vitro and in vivo. Proc Natl Acad Sci U S A 1995; 92:12480-4. [PMID: 8618925 PMCID: PMC40381 DOI: 10.1073/pnas.92.26.12480] [Citation(s) in RCA: 163] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The mineralocorticoid and glucocorticoid receptors (MR and GR, respectively) are members of the intracellular receptor superfamily that bind as homodimers to the same hormone response elements (HREs). Physiological evidence suggests that MR and GR interact with each other in cells that express both receptors, implying that they might directly interact in the regulation of transcription initiation. Indeed, we have found that coexpressed MR and GR interact functionally at the transcriptional level and furthermore that they interact physically through heterodimer formation at a shared HRE in vitro and in vivo. We suggest from these findings that heterodimerization may play an important role in steroid receptor transcriptional regulation.
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Affiliation(s)
- W Liu
- Department of Medicine, San Francisco General Hospital, CA, USA
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10
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Boulanger J, Reyes-Moreno C, Koutsilieris M. Mediation of glucocorticoid receptor function by the activation of latent transforming growth factor beta 1 in MG-63 human osteosarcoma cells. Int J Cancer 1995; 61:692-7. [PMID: 7768643 DOI: 10.1002/ijc.2910610517] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We analyzed glucocorticoid receptor function using ligand binding assays, DNA band-shift analysis and trans-activation of the murine mammary tumor virus-thymidine kinase-chloramphenicol acetyltransferase reporter gene in transiently transfected MG-63 human osteosarcoma cells. Dexamethasone increased the distribution of MG-63 cells in the G1/G0 phase of the cell cycle, thus decreasing the rate of DNA synthesis and cell growth. Its effect on MG-63 cell growth was neutralized by RU486 and anti-transforming growth factor beta 1 (TGF beta 1) antibody. In addition, (i) dexamethasone increased the levels of active TGF beta 1 in MG-63-conditioned media without significantly altering the expression of TGF beta 1 mRNA in MG-63 cells and (ii) TGF beta 1 inhibited proliferation of MG-63 cells. Therefore, we conclude that glucocorticoid receptor function is mediated by the activation of latent-TGF beta 1 in MG-63 osteosarcoma cells.
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Affiliation(s)
- J Boulanger
- Molecular Endocrinology, Research Center, Centre Hospitalier de l'Université Laval, St. Foy, Québec, Canada
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11
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Reyes-Moreno C, Frenette G, Boulanger J, Lavergne E, Govindan MV, Koutsilieris M. Mediation of glucocorticoid receptor function by transforming growth factor beta I expression in human PC-3 prostate cancer cells. Prostate 1995; 26:260-9. [PMID: 7753711 DOI: 10.1002/pros.2990260506] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We investigated the role of glucocorticoids in controlling the proliferation of androgen-independent PC-3 human prostate cancer cells via the action of transforming growth factor beta 1 (TGF beta 1). The presence of glucocorticoid receptor (GR) in PC-3 cells was detected by immunoblotting analysis using a rabbit anti-GR polyclonal antibody against the synthetic human GR peptide (hGR383-393). In PC-3 cells, GR bound radiolabeled dexamethasone with an affinity similar to wild-type GR. In addition, GR-ligand complex bound radiolabeled DNA as detected by DNA band-shift analysis on gel electrophoresis and trans-activated the mouse mammary tumor virus-thymidine kinase-chloramphenicol acetyltransferase chimeric gene in transiently transfected PC-3 cells. Dexamethasone (0.1 up to 100 nM) and TGF beta 1 (0.5 up to 50 ng/ml) inhibited PC-3 cell proliferation. TGF beta 1 and dexamethasone both increased the distribution of PC-3 cells into the G1/G0 phase of the cell cycle. Platelet-derived growth factor (PDGF) stimulated the proliferation of PC-3 cells and overcame dexamethasone's inhibition of PC-3 cell growth. Dexamethasone's inhibition (10(-7) M) of PC-3 cell growth was completely neutralized by RU 486 (10(-6)M) and partly neutralized by anti-TGF beta 1 polyclonal antibody. Furthermore, dexamethasone up modulated the expression of TGF beta 1 mRNA in PC-3 cells. Because dexamethasone's inhibition was neutralized at least in part by an anti-TGF beta 1 polyclonal antibody and dexamethasone up modulated the expression of TGF beta 1 mRNA in PC-3 cells, we conclude that GR function in human PC-3 prostate cancer cells is mediated at least in part by TGF beta 1 expression.
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Affiliation(s)
- C Reyes-Moreno
- Department of Molecular Endocrinology, C.H.U.L, Laval University, St Foy, Quebec, Canada
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12
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Couette B, Le Ricousse S, Fortin D, Rafestin-Oblin ME, Richard-Foy H. The establishment of the long terminal repeat of the mouse mammary tumor virus into CV-1 cells allows a functional analysis of steroid receptors. BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1219:607-12. [PMID: 7948018 DOI: 10.1016/0167-4781(94)90219-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
To analyze in situ the effects of mineralocorticoid receptor (MR) on the nucleo-protein organization of the target MMTV promoter, we have established a new cell line by integrating in CV-1 cells a construct containing the long terminal repeat of the mouse mammary tumor virus (MMTV-LTR). The MMTV-LTR contains glucocorticoid response elements (GREs), known to interact with MR. CV-1 cells were selected because they lack glucocorticoid receptor (GR). The absence of GR in the host cell line allows the selective analysis of transcription activation by aldosterone in cells expressing MR transiently. The CV-1 cells were transfected with the construct pMAMneoCAT, a plasmid containing the MMTV promoter driving the chloramphenicol acetyl transferase (CAT) gene and a gene for neomycin selection. A neomycin-resistant clone (M8), which contains two copies of the unrearranged construct was characterized. The integrated MMTV promoter is functional, as demonstrated by the induction of the CAT activity upon addition of aldosterone, dexamethasone, and R5020 to M8 cells transiently transfected with MR, GR, and progesterone receptor (PR) expression vectors, respectively. Induction of the CAT activity by dexamethasone or progesterone was 2 to 3-fold higher than by aldosterone. These differences in CAT activities were not related to differences in the levels of receptor expression. In the transiently transfected M8 cells, MR and PR contents were similar (50-70 fmol/mg protein) while GR content was higher (250 fmol/mg protein). Thus, this new cell line M8, provides a useful tool for selectively studying the effect of MR on a target promoter organized into chromatin.
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MESH Headings
- Aldosterone/pharmacology
- Animals
- Cells, Cultured
- Chlorocebus aethiops
- Dexamethasone/pharmacology
- Dose-Response Relationship, Drug
- Gene Expression Regulation/drug effects
- Mammary Tumor Virus, Mouse/genetics
- Promegestone/pharmacology
- Receptors, Glucocorticoid/genetics
- Receptors, Glucocorticoid/metabolism
- Receptors, Mineralocorticoid/genetics
- Receptors, Mineralocorticoid/metabolism
- Receptors, Progesterone/genetics
- Receptors, Progesterone/metabolism
- Receptors, Steroid/genetics
- Receptors, Steroid/metabolism
- Recombinant Fusion Proteins/biosynthesis
- Repetitive Sequences, Nucleic Acid/genetics
- Signal Transduction
- Steroids/pharmacology
- Transcription, Genetic
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Affiliation(s)
- B Couette
- INSERM U246, Faculté de Médecine Xavier Bichat, Paris, France
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13
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Warriar N, Pagé N, Govindan MV. Transcription activation of mouse mammary tumor virus-chloramphenicol acetyltransferase: a model to study the metabolism of cortisol. Biochemistry 1994; 33:12837-43. [PMID: 7947689 DOI: 10.1021/bi00209a015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The human 11 beta-hydroxysteroid dehydrogenase (h11 beta-HSD) inactivates the active corticosteroid cortisol to its inactive metabolite cortisone. We have developed transactivation analyses of the reporter chimeric gene mouse mammary tumor virus-chloramphenicol acetyltransferase (MMTV-CAT) to study the catalytic activity of h11 beta-HSD introduced by cotransfection into receptor and 11 beta-HSD deficient CV-1 cells. Assay of 11 beta-HSD expressed in CV-1 cells by cotransfection showed that the catalyzed dehydrogenation of cortisol to cortisone was 2-fold higher in the presence of NADP. The reductase activity was dependent on the coenzyme NADPH. The addition of increasing concentrations of the inhibitor carbenoxolone (CBX) in the incubates blocked the enzyme activity in a dose dependent fashion. In CV-1 cells cotransfected with expression vectors of either human glucocorticoid (hGR1-777) or mineralocorticoid (hMR1-984) and the reporter plasmid MMTV-CAT, dexamethasone (DEX), aldosterone (ALDO), cortisol, and corticosterone induction of CAT activity was dose dependent. Cotransfection of CV-1 cells transfected with 10 micrograms of 11 beta-HSD expression vector reduced the transactivation of MMTV-CAT by hGR or hMR in the presence of either cortisol or corticosterone to basal values. The concomitant addition of 100 nM cortisone and 1 microM NADPH to these transfectants elevated CAT activity. These data show that transactivation analyses can be used to study the 11 beta-HSD-catalyzed regulation of corticosteroid levels, which triggers physiological processes and in certain cases provides an alternative to animal experimentation.
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Affiliation(s)
- N Warriar
- Medical Research Council Group in Molecular Endocrinology, CHUL Research Center, Québec, Canada
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14
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Warriar N, Yu C, Pagé N, Govindan MV. Substitution of Cys-560 by Phe, Trp, Tyr, and Ser in the first zinc finger of human androgen receptor affects hormonal sensitivity and transcriptional activation. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(19)62007-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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15
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Warriar N, Yu C, Govindan MV. Hormone binding domain of human glucocorticoid receptor. Enhancement of transactivation function by substitution mutants M565R and A573Q. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(19)62006-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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16
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Jausons-Loffreda N, Balaguer P, Auzou G, Pons M. Development of specific bioluminescent in vitro assays for selecting potential antimineralocorticoids. J Steroid Biochem Mol Biol 1994; 49:31-8. [PMID: 8003437 DOI: 10.1016/0960-0760(94)90297-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Efficient antimineralocorticoid selection requires a reliable, discriminating and easy assay for monitoring biological activity of not only the specific receptor, but also closely related receptors such as glucocorticoid and progestin. These related activities should be as low as possible to obtain specific antimineralocorticoid compounds. In this paper, we describe two cellular models used for easy and specific measurement of mineralocorticoid and progestin activities. These models involve the induction of firefly luciferase under hormonal control mediated by a chimeric receptor. The first model comprises transiently transfected MCF-7 cells, whereas the second uses stably transfected HeLa cells. Glucocorticoid activity was assayed with the classic tyrosine-aminotransferase induction method in HTC cells. Six compounds of a new family of 11 beta-substituted-17-spirolactone steroids were thus studied and compared to control compounds. Five of them showed antimineralocorticoid activity and one was active at a concentration lower than that of mespirenone.
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17
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Abstract
The mineralocorticoid and glucocorticoid receptors (MR and GR, respectively) are closely related members of the nuclear receptor superfamily. Despite marked functional similarities and a high degree of sequence conservation between MR and GR, the mineralocorticoid and glucocorticoid hormones elicit markedly different physiological effects, even in cells expressing both receptors. Hormone specificity is, in part, determined by the actions of 11 beta-hydroxysteroid dehydrogenase. However, other mechanisms must obtain in cells that express both receptors and respond differentially to the two classes of hormone. Indeed, MR and GR, while functionally redundant in some contexts, in others display distinct transcriptional specificities. In particular, in the presence of members of the AP1 family of regulatory factors, cJun and cFos, a composite response element, plfG, is GR-specific. Transcription from a plfG-linked gene is stimulated by GR in the presence of cJun and repressed by GR in the presence of cJun and cFos. MR neither stimulates nor represses transcription in the same contexts, thus indicating that receptor transcriptional specificities can be distinguished by differential interactions with nonreceptor factors at a composite response element. The implications of these findings for mineralocorticoid and glucocorticoid hormone specificity in various tissues are discussed.
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Affiliation(s)
- D Pearce
- Department of Medicine, San Francisco General Hospital, CA 94110
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18
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Horisberger JD, Rossier BC. Aldosterone regulation of gene transcription leading to control of ion transport. Hypertension 1992; 19:221-7. [PMID: 1372288 DOI: 10.1161/01.hyp.19.3.221] [Citation(s) in RCA: 101] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Aldosterone, like other steroid hormones, initiates its effects by binding to intracellular receptors; these receptors are then able to control the transcription of several genes. The products of these genes eventually modulate the activity of ionic transport systems located in the apical and the basolateral membrane of specialized epithelial cells, thereby modulating the excretion of Na+ and K+ ions. Considerable progress has been made recently in understanding these mechanisms and the structure of the proteins involved in these processes. A novel principle has been discovered to explain the selective effect of aldosterone on its target epithelia. These tissues exclude competing glucocorticoid hormones by the activity of the 11 beta-hydroxysteroid dehydrogenase to allow aldosterone, an enzyme-resistant steroid, to bind to its receptors. Aldosterone induces numerous changes in the activity of membrane ion transport systems and enzymes and cell morphology. Although the enhancement of Na,K-ATPase synthesis and the increase of the number of active Na+ channels in the apical membrane appear as both direct and primary effects, the mechanisms of the other effects remain to be determined. The knowledge of the primary structure of several elements of the aldosterone response system (e.g., mineralocorticoid receptor and Na,K-ATPase) allows us to understand abnormal regulation of Na+ balance at the molecular level and, potentially, to identify genetic alterations responsible for these defects.
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Affiliation(s)
- J D Horisberger
- Institut de Pharmacologie, Université de Lausanne, Switzerland
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