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Chandran S, Cairns MT, O'Brien M, O'Connell E, Mashayekhi K, Smith TJ. Effects of combined progesterone and 17β-estradiol treatment on the transcriptome of cultured human myometrial smooth muscle cells. Physiol Genomics 2015; 48:50-61. [PMID: 26534934 DOI: 10.1152/physiolgenomics.00021.2015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 10/23/2015] [Indexed: 11/22/2022] Open
Abstract
A transcriptomic analysis of cultured human uterine smooth muscle cells (hUtSMCs) was performed to examine gene expression profiles in smooth muscle in an environment containing the two major steroid hormones that regulate the human myometrium in physiological states associated with estrous, pregnancy, labor, and pathophysiological states such as leiomyoma and endometrial cancer. hUtSMCs were treated with progesterone (P4) and 17β-estradiol (E2) individually and in combination, in the presence and absence of RU486 (mifepristone). Transcription of many genes was modulated in the presence of P4 or E2 alone, but almost six times more genes were transcriptionally modulated in the presence of the P4/E2 hormone combination. In total 796 annotated genes were significantly differentially expressed in the presence of both P4 and E2 relative to their expression in untreated cells. Functional withdrawal of P4 by addition of RU486 effectively reversed almost all transcriptional changes caused by P4/E2 treatment. Gene ontology analysis of differentially expressed genes revealed a strong association between P4/E2 treatment and downregulated expression of genes involved in cell communication, signal transduction, channel activity, inflammatory response, and differentiation. Upregulated processes included cell survival, gene transcription, steroid hormone biosynthesis, muscle development, insulin receptor signaling, and cell growth.
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Affiliation(s)
- Sreenath Chandran
- National Centre for Biomedical Engineering Science, National University of Ireland Galway, Galway, Ireland
| | - Michael T Cairns
- National Centre for Biomedical Engineering Science, National University of Ireland Galway, Galway, Ireland
| | - Margaret O'Brien
- National Centre for Biomedical Engineering Science, National University of Ireland Galway, Galway, Ireland
| | - Enda O'Connell
- National Centre for Biomedical Engineering Science, National University of Ireland Galway, Galway, Ireland
| | - Kaveh Mashayekhi
- National Centre for Biomedical Engineering Science, National University of Ireland Galway, Galway, Ireland
| | - Terry J Smith
- National Centre for Biomedical Engineering Science, National University of Ireland Galway, Galway, Ireland
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52
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Mellor CL, Steinmetz FP, Cronin MTD. The identification of nuclear receptors associated with hepatic steatosis to develop and extend adverse outcome pathways. Crit Rev Toxicol 2015; 46:138-52. [PMID: 26451809 DOI: 10.3109/10408444.2015.1089471] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The development of adverse outcome pathways (AOPs) is becoming a key component of twenty-first century toxicology. AOPs provide a conceptual framework that links the molecular initiating event to an adverse outcome through organized toxicological knowledge, bridging the gap from chemistry to toxicological effect. As nuclear receptors (NRs) play essential roles for many physiological processes within the body, they are used regularly as drug targets for therapies to treat many diseases including diabetes, cancer and neurodegenerative diseases. Due to the heightened development of NR ligands, there is increased need for the identification of related AOPs to facilitate their risk assessment. Many NR ligands have been linked specifically to steatosis. This article reviews and summarizes the role of NR and their importance with links between NR examined to identify plausible putative AOPs. The following NRs are shown to induce hepatic steatosis upon ligand binding: aryl hydrocarbon receptor, constitutive androstane receptor, oestrogen receptor, glucocorticoid receptor, farnesoid X receptor, liver X receptor, peroxisome proliferator-activated receptor, pregnane X receptor and the retinoic acid receptor. A preliminary, putative AOP was formed for NR binding linked to hepatic steatosis as the adverse outcome.
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Affiliation(s)
- Claire L Mellor
- a School of Pharmacy and Biomolecular Sciences , Liverpool John Moores University , Liverpool , England
| | - Fabian P Steinmetz
- a School of Pharmacy and Biomolecular Sciences , Liverpool John Moores University , Liverpool , England
| | - Mark T D Cronin
- a School of Pharmacy and Biomolecular Sciences , Liverpool John Moores University , Liverpool , England
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Liu YL, Jang S, Wang SM, Chen CH, Li FY. Investigation on critical structural motifs of ligands for triggering glucocorticoid receptor nuclear migration through molecular docking simulations. J Biomol Struct Dyn 2015. [DOI: 10.1080/07391102.2015.1074113] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Abstract
Endogenous glucocorticoids regulate a variety of physiologic processes and are crucial to the systemic stress response. Glucocorticoid receptors are expressed throughout the body, but there is considerable heterogeneity in glucocorticoid sensitivity and induced biological responses across tissues. The immunoregulatory properties of glucocorticoids are exploited in the clinic for the treatment of inflammatory and autoimmune disorders as well as certain hematological malignancies, but adverse side effects hamper prolonged use. Fully understanding the molecular events that shape the physiologic effects of glucocorticoid treatment will provide insight into optimal glucocorticoid therapies, reliable assessment of glucocorticoid sensitivity in patients, and may advance the development of novel GR agonists that exert immunosuppressive effects while avoiding harmful side effects. In this review, we provide an overview of mechanisms that affect glucocorticoid specificity and sensitivity in health and disease, focusing on the distinct isoforms of the glucocorticoid receptor and their unique regulatory and functional properties.
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Affiliation(s)
- Derek W Cain
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC, USA
| | - John A Cidlowski
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC, USA.
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Duma D, Cidlowski JA. Generating diversity in glucocorticoid receptor signaling: mechanisms, receptor isoforms, and post-translational modifications. Horm Mol Biol Clin Investig 2015; 3:319-28. [PMID: 25961204 DOI: 10.1515/hmbci.2010.039] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2010] [Accepted: 07/30/2010] [Indexed: 11/15/2022]
Abstract
Glucocorticoids are necessary for life after birth and regulate numerous homeostatic functions in man, including glucose homeostasis, protein catabolism, skeletal growth, respiratory function, inflammation, development, behavior, and apoptosis. In a clinical setting, they are widely used as anti-inflammatory agents to control both acute and chronic inflammation. Unfortunately, owing to their broad range of physiological actions, patients treated with glucocorticoids for long periods of time experience a variety of serious side effects, including metabolic syndrome, bone loss, and psychiatric disorders including depression, mania, and psychosis. Our understanding of how one hormone or drug regulates all of these diverse processes is limited. Recent studies have shown that multiple glucocorticoid receptor isoforms are produced from one gene via combinations of alternative mRNA splicing and alternative translation initiation. These isoforms possess unique tissue distribution patterns and transcriptional regulatory profiles. Owing to variation in the N-terminal and C-terminal length of glucocorticoid receptor isoforms, different post-translational modifications including ubiquitination, phosphorylation, and sumoylation are predicted, contributing to the complexity of glucocorticoid signaling. Furthermore, increasing evidence suggests that unique glucocorticoid receptor isoform compositions within cells could determine the cell-specific response to glucocorticoids. In this review, we will outline the recent advances made in the characterization of the transcriptional activity and the selective regulation of apoptosis by the various glucocorticoid receptor isoforms.
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Chatzopoulou A, Roy U, Meijer AH, Alia A, Spaink HP, Schaaf MJM. Transcriptional and metabolic effects of glucocorticoid receptor α and β signaling in zebrafish. Endocrinology 2015; 156:1757-69. [PMID: 25756310 DOI: 10.1210/en.2014-1941] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
In humans and zebrafish, 2 glucocorticoid (GC) receptor (GR) splice variants exist: the canonical GR α-isoform (GRα), and the GRβ. In the present study, we have used the zebrafish model system in order to reveal genes affected by each of these 2 receptor isoforms. By injecting zebrafish embryos with different splice-blocking morpholinos, we could knock down both GR isoforms or could target the alternative splicing of the GR pre-mRNA in favor of the GRβ. In addition, specific GRβ overexpression was achieved by injecting mRNA. Embryos were treated with the synthetic GC dexamethasone, and transcriptome analysis was performed. Two distinct gene clusters were found that were regulated by GRα: one that was regulated by GRα under basal conditions (presence of endogenous cortisol only), and one that was regulated upon increased activation of GRα (using a pharmacological dose of dexamathasone). GRβ may act as a dominant-negative inhibitor of GRα when GRβ is overexpressed and the GRα expression level is knocked down simultaneously. However, without GRα knockdown, no evidence for this activity was found. In addition, the data indicate regulation of gene transcription through other mechanisms of action by GRβ. We also investigated the concentrations of several metabolites using nuclear magnetic resonance spectroscopy. We found that dexamethasone treatment and knockdown of GRα together with overexpression of GRβ had opposite effects on glucose, amino acid, and fatty acid levels. Thus, we have shed new light on the molecular mechanisms of GC-induced effects on metabolism, which are known to increase the risk of obesity, hyperglycemia, and diabetes.
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Affiliation(s)
- Antonia Chatzopoulou
- Department of Animal Sciences and Health (A.C., A.H.M., H.P.S., M.J.M.S.), Institute of Biology, Leiden University, 2333CC Leiden, The Netherlands; Department of Biophysical Organic Chemistry/Solid State NMR (U.R., A.A.), Leiden Institute of Chemistry, Leiden University, 2333CC Leiden, The Netherlands; and Institute of Medical Physics and Biophysics (A.A.), University of Leipzig, D-04107 Leipzig, Germany
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57
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Jeong S, Patel N, Edlund CK, Hartiala J, Hazelett DJ, Itakura T, Wu PC, Avery RL, Davis JL, Flynn HW, Lalwani G, Puliafito CA, Wafapoor H, Hijikata M, Keicho N, Gao X, Argüeso P, Allayee H, Coetzee GA, Pletcher MT, Conti DV, Schwartz SG, Eaton AM, Fini ME. Identification of a Novel Mucin Gene HCG22 Associated With Steroid-Induced Ocular Hypertension. Invest Ophthalmol Vis Sci 2015; 56:2737-48. [PMID: 25813999 PMCID: PMC4416661 DOI: 10.1167/iovs.14-14803] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 12/04/2014] [Indexed: 12/24/2022] Open
Abstract
PURPOSE The pathophysiology of ocular hypertension (OH) leading to primary open-angle glaucoma shares many features with a secondary form of OH caused by treatment with glucocorticoids, but also exhibits distinct differences. In this study, a pharmacogenomics approach was taken to discover candidate genes for this disorder. METHODS A genome-wide association study was performed, followed by an independent candidate gene study, using a cohort enrolled from patients treated with off-label intravitreal triamcinolone, and handling change in IOP as a quantitative trait. RESULTS An intergenic quantitative trait locus (QTL) was identified at chromosome 6p21.33 near the 5' end of HCG22 that attained the accepted statistical threshold for genome-level significance. The HCG22 transcript, encoding a novel mucin protein, was expressed in trabecular meshwork cells, and expression was stimulated by IL-1, and inhibited by triamcinolone acetate and TGF-β. Bioinformatic analysis defined the QTL as an approximately 4 kilobase (kb) linkage disequilibrium block containing 10 common single nucleotide polymorphisms (SNPs). Four of these SNPs were identified in the National Center for Biotechnology Information (NCBI) GTEx eQTL browser as modifiers of HCG22 expression. Most are predicted to disrupt or improve motifs for transcription factor binding, the most relevant being disruption of the glucocorticoid receptor binding motif. A second QTL was identified within the predicted signal peptide of the HCG22 encoded protein that could affect its secretion. Translation, O-glycosylation, and secretion of the predicted HCG22 protein was verified in cultured trabecular meshwork cells. CONCLUSIONS Identification of two independent QTLs that could affect expression of the HCG22 mucin gene product via two different mechanisms (transcription or secretion) is highly suggestive of a role in steroid-induced OH.
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Affiliation(s)
- Shinwu Jeong
- USC Institute for Genetic Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States 2USC Eye Institute/Department of Ophthalmology, Keck School of Medicine of USC, University of Southern California
| | - Nitin Patel
- USC Institute for Genetic Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States
| | - Christopher K Edlund
- Department of Preventive Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States
| | - Jaana Hartiala
- USC Institute for Genetic Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States
| | - Dennis J Hazelett
- USC/Norris Comprehensive Cancer Center, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States
| | - Tatsuo Itakura
- USC Institute for Genetic Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States
| | - Pei-Chang Wu
- USC Institute for Genetic Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States 5Department of Ophthalmology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan
| | - Robert L Avery
- California Retina Consultants, Santa Barbara, California, United States
| | - Janet L Davis
- Bascom Palmer Eye Institute and Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Harry W Flynn
- Bascom Palmer Eye Institute and Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Geeta Lalwani
- Bascom Palmer Eye Institute and Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Carmen A Puliafito
- USC Eye Institute/Department of Ophthalmology, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States 7Bascom Palmer Eye Institute and Department of Ophthalmology, University of Miami Miller School of Med
| | | | - Minako Hijikata
- Department of Pathophysiology and Host Defense, The Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association, Tokyo, Japan
| | - Naoto Keicho
- Department of Pathophysiology and Host Defense, The Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association, Tokyo, Japan
| | - Xiaoyi Gao
- Department of Ophthalmology and Visual Sciences, University of Illinois, Chicago, Illinois, United States
| | - Pablo Argüeso
- The Schepens Eye Research Institute, Massachusetts Eye & Ear Infirmary and Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States
| | - Hooman Allayee
- USC Institute for Genetic Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States 3Department of Preventive Medicine, Keck School of Medicine of USC, University of Southern California, Los Angele
| | - Gerhard A Coetzee
- Department of Preventive Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States 4USC/Norris Comprehensive Cancer Center, Keck School of Medicine of USC, University of Southern California, Los An
| | - Mathew T Pletcher
- Department of Molecular Therapeutics, The Scripps Research Institute-Scripps Florida, Jupiter, Florida, United States
| | - David V Conti
- Department of Preventive Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States
| | - Stephen G Schwartz
- Bascom Palmer Eye Institute and Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida, United States
| | | | - M Elizabeth Fini
- USC Institute for Genetic Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States 2USC Eye Institute/Department of Ophthalmology, Keck School of Medicine of USC, University of Southern California
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58
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Ferris J, Li M, Leatherland JF, King WA. Estrogen and glucocorticoid receptor agonists and antagonists in oocytes modulate the pattern of expression of genes that encode nuclear receptor proteins in very early stage rainbow trout (Oncorhynchus mykiss) embryos. FISH PHYSIOLOGY AND BIOCHEMISTRY 2015; 41:255-265. [PMID: 25523437 DOI: 10.1007/s10695-014-0021-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 12/09/2014] [Indexed: 06/04/2023]
Abstract
Previous studies show that changes in estrogen (ER) and glucocorticoid receptor (GR) function in rainbow trout (Oncorhynchus mykiss) oocytes modulate the growth performance phenotype of embryo and juvenile progeny; the present study was undertaken to determine whether this altered growth performance is associated with changes in the expression of several growth-related genes in early-stage embryos. Unfertilized oocytes were incubated in the presence of various combinations of GR and ER agonists and antagonists; the oocytes were then fertilized and the expression of genes that encode for six nuclear receptor superfamily (NRS) proteins (GR1, GR2, ERα, ERβ, TRα, and TRβ) and the two IGF peptides (IGF1 and IGF2) were measured in the 7-, 13-, and 26-dpf embryos. By day 26 of embryogenesis, the expression of the six NRS-related genes of interest and that of igf2 were significantly enhanced in embryos reared from ER agonist- or ER antagonist-treated oocytes, regardless of whether the GR agonist, cortisol, was also included in the initial oocyte incubation medium. Conversely, the igf1 expression pattern among treatment groups was significantly enhanced in the cortisol-only treatment group and in the ER antagonist and GR antagonist groups that were co-incubated with cortisol. Additionally, in the ER agonist treatment groups igf1 expression was significantly inhibited when cortisol was included in the oocyte incubation medium. The findings show that a single in ovo exposure to the receptor agonists/antagonists markedly changed the programming of the expression of NRS-related and IGF-related genes of the early-stage trout embryos.
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Affiliation(s)
- Jacqueline Ferris
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada
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Contador D, Ezquer F, Espinosa M, Arango-Rodriguez M, Puebla C, Sobrevia L, Conget P. Dexamethasone and rosiglitazone are sufficient and necessary for producing functional adipocytes from mesenchymal stem cells. Exp Biol Med (Maywood) 2015; 240:1235-46. [PMID: 25595190 DOI: 10.1177/1535370214566565] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Accepted: 11/17/2014] [Indexed: 12/13/2022] Open
Abstract
The final product of adipogenesis is a functional adipocyte. This mature cell acquires the necessary machinery for lipid metabolism, loses its proliferation potential, increases its insulin sensitivity, and secretes adipokines. Multipotent mesechymal stromal cells have been recognized as a source of adipocytes both in vivo and in vitro. The in vitro adipogenic differentiation of human MSC (hMSC) has been induced up to now by using a complex stimulus which includes dexamethasone, 3-isobutyl-1-methylxanthine, indomethacin, and insulin (a classical cocktail) and evaluated according to morphological changes. The present work was aimed at demonstrating that the simultaneous activation of dexamethasone's canonical signaling pathways, through the glucocorticoid receptor and CCAAT-enhancer-binding proteins (C/EBPs) and rosiglitazone through peroxisome proliferator-activated receptor gamma (PPAR-gamma) is sufficient yet necessary for inducing hMSC adipogenic differentiation. It was also ascertained that hMSC exposed just to dexamethasone and rosiglitazone (D&R) differentiated into cells which accumulated neutral lipid droplets, expressed C/EBP-alpha, PPAR-gamma, aP2, lipoprotein lipase, acyl-CoA synthetase, phosphoenolpyruvate carboxykinase, adiponectin, and leptin genes but did not proliferate. Glucose uptake was dose dependent on insulin stimulus and high levels of adipokines were secreted (i.e. displaying not only the morphology but also expressing mature adipocytes' specific genes and functional characteristics). This work has demonstrated that (i) the activating C/EBPs and PPAR-gamma signaling pathways were sufficient to induce adipogenic differentiation from hMSC, (ii) D&R producing functional adipocytes from hMSC, (iii) D&R induce adipogenic differentiation from mammalian MSC (including those which are refractory to classical adipogenic differentiation stimuli). D&R would thus seem to be a useful tool for MSC characterization, studying adipogenesis pathways and producing functional adipocytes.
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Affiliation(s)
- David Contador
- Center for Regenerative Medicine, School of Medicine, Clínica Alemana Universidad del Desarrollo, Santiago 7710162, Chile
| | - Fernando Ezquer
- Center for Regenerative Medicine, School of Medicine, Clínica Alemana Universidad del Desarrollo, Santiago 7710162, Chile
| | - Maximiliano Espinosa
- Center for Regenerative Medicine, School of Medicine, Clínica Alemana Universidad del Desarrollo, Santiago 7710162, Chile
| | - Martha Arango-Rodriguez
- Center for Regenerative Medicine, School of Medicine, Clínica Alemana Universidad del Desarrollo, Santiago 7710162, Chile
| | - Carlos Puebla
- Cellular and Molecular Physiology Laboratory, Obstetrics and Gynecology Division, Faculty of Medicine, P. Universidad Católica de Chile, Santiago 8330024, Chile
| | - Luis Sobrevia
- Cellular and Molecular Physiology Laboratory, Obstetrics and Gynecology Division, Faculty of Medicine, P. Universidad Católica de Chile, Santiago 8330024, Chile
| | - Paulette Conget
- Center for Regenerative Medicine, School of Medicine, Clínica Alemana Universidad del Desarrollo, Santiago 7710162, Chile
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Keenan CR, Radojicic D, Li M, Radwan A, Stewart AG. Heterogeneity in mechanisms influencing glucocorticoid sensitivity: the need for a systems biology approach to treatment of glucocorticoid-resistant inflammation. Pharmacol Ther 2015; 150:81-93. [PMID: 25596317 DOI: 10.1016/j.pharmthera.2015.01.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 01/05/2015] [Indexed: 12/14/2022]
Abstract
Glucocorticoids (GCs) have impressive anti-inflammatory and immunosuppressive effects and show a diversity of actions across a variety of cell phenotypes. Implicit in efforts to optimize GCs as anti-inflammatory agents for any or all indications is the notion that the relevant mechanism(s) of action of GCs are fully elucidated. However, recent advances in understanding GC signalling mechanisms have revealed remarkable complexity and contextual dependence, calling into question whether the mechanisms of action are sufficiently well-described to embark on optimization. In the current review, we address evidence for differences in the mechanism of action in different cell types and contexts, and discuss contrasts in mechanisms of glucocorticoid insensitivity, with a focus on asthma and Chronic Obstructive Pulmonary Disease (COPD). Given this complexity, we consider the potential breadth of impact and selectivity of strategies directed to reversing the glucocorticoid insensitivity.
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Affiliation(s)
- Christine R Keenan
- Lung Health Research Centre, Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Danica Radojicic
- Lung Health Research Centre, Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Meina Li
- Lung Health Research Centre, Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Asmaa Radwan
- Lung Health Research Centre, Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Alastair G Stewart
- Lung Health Research Centre, Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, Victoria 3010, Australia.
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Falchi M, Varricchio L, Martelli F, Masiello F, Federici G, Zingariello M, Girelli G, Whitsett C, Petricoin EF, Moestrup SK, Zeuner A, Migliaccio AR. Dexamethasone targeted directly to macrophages induces macrophage niches that promote erythroid expansion. Haematologica 2014; 100:178-87. [PMID: 25533803 DOI: 10.3324/haematol.2014.114405] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Cultures of human CD34(pos) cells stimulated with erythroid growth factors plus dexamethasone, a model for stress erythropoiesis, generate numerous erythroid cells plus a few macrophages (approx. 3%; 3:1 positive and negative for CD169). Interactions occurring between erythroblasts and macrophages in these cultures and the biological effects associated with these interactions were documented by live phase-contrast videomicroscopy. Macrophages expressed high motility interacting with hundreds/thousands of erythroblasts per hour. CD169(pos) macrophages established multiple rapid 'loose' interactions with proerythroblasts leading to formation of transient erythroblastic island-like structures. By contrast, CD169(neg) macrophages established 'tight' interactions with mature erythroblasts and phagocytosed these cells. 'Loose' interactions of CD169(pos) macrophages were associated with proerythroblast cytokinesis (the M phase of the cell cycle) suggesting that these interactions may promote proerythroblast duplication. This hypothesis was tested by experiments that showed that as few as 103 macrophages significantly increased levels of 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide incorporation frequency in S/G2/M and cytokinesis expressed by proerythroblasts over 24 h of culture. These effects were observed also when macrophages were co-cultured with dexamethasone directly conjugated to a macrophage-specific CD163 antibody. In conclusion, in addition to promoting proerythroblast proliferation directly, dexamethasone stimulates expansion of these cells indirectly by stimulating maturation and cytokinesis supporting activity of macrophages.
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Affiliation(s)
- Mario Falchi
- National AIDS Center, New York, NY, USA Tisch Cancer Institute, Mount Sinai School of Medicine, New York, NY, USA
| | - Lilian Varricchio
- Tisch Cancer Institute, Mount Sinai School of Medicine, New York, NY, USA
| | - Fabrizio Martelli
- Tisch Cancer Institute, Mount Sinai School of Medicine, New York, NY, USA Hematology/Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Francesca Masiello
- Hematology/Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Giulia Federici
- Regina Elena National Cancer Institute, Rome, Italy Hematology/Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | | | | | - Carolyn Whitsett
- Kings County Hospital and Downstate Medical Center, Brooklyn, NY, USA
| | - Emanuel F Petricoin
- Center for Applied Proteomics and Molecular Medicine, George Mason University, Manassas, VA, USA
| | - Søren Kragh Moestrup
- Department of Biomedicine, University of Aarhus, Aarhus C, Denmark Institute of Molecular Medicine, University of Souther Denmark, Denmark
| | - Ann Zeuner
- Hematology/Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Anna Rita Migliaccio
- Tisch Cancer Institute, Mount Sinai School of Medicine, New York, NY, USA Hematology/Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
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62
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Varricchio L, Migliaccio AR. The role of glucocorticoid receptor (GR) polymorphisms in human erythropoiesis. AMERICAN JOURNAL OF BLOOD RESEARCH 2014; 4:53-72. [PMID: 25755906 PMCID: PMC4348794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 11/21/2014] [Indexed: 06/04/2023]
Abstract
Glucocorticoids are endogenous steroid hormones that regulate several biological functions including proliferation, differentiation and apoptosis in numerous cell types in response to stress. Synthetic glucocorticoids, such as dexamethasone (Dex) are used to treat a variety of diseases ranging from allergy to depression. Glucocorticoids exert their effects by passively entering into cells and binding to a specific Glucocorticoid Receptor (GR) present in the cytoplasm. Once activated by its ligand, GR may elicit cytoplasmic (mainly suppression of p53), and nuclear (regulation of transcription of GR responsive genes), responses. Human GR is highly polymorphic and may encode > 260 different isoforms. This polymorphism is emerging as the leading cause for the variability of phenotype and response to glucocorticoid therapy observed in human populations. Studies in mice and clinical observations indicate that GR controls also the response to erythroid stress. This knowledge has been exploited in-vivo by using synthetic GR agonists for treatment of the erythropoietin-refractory congenic Diamond Blackfan Anemia and in-vitro to develop culture conditions that may theoretically generate red cells in numbers sufficient for transfusion. However, the effect exerted by GR polymorphism on the variability of the phenotype of genetic and acquired erythroid disorders observed in the human population is still poorly appreciated. This review will summarize current knowledge on the biological activity of GR and of its polymorphism in non-hematopoietic diseases and discuss the implications of these observations for erythropoiesis.
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Affiliation(s)
- Lilian Varricchio
- Tisch Cancer Institute, Mount Sinai School of MedicineNew York, NY 10029, USA
| | - Anna Rita Migliaccio
- Tisch Cancer Institute, Mount Sinai School of MedicineNew York, NY 10029, USA
- Istituto Superiore di Sanita’ Viale Regina Elena 299Italy
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63
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Glucocorticoid Receptor β Acts as a Co-activator of T-Cell Factor 4 and Enhances Glioma Cell Proliferation. Mol Neurobiol 2014; 52:1106-1118. [PMID: 25301232 DOI: 10.1007/s12035-014-8900-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Accepted: 09/16/2014] [Indexed: 12/13/2022]
Abstract
We previously reported that glucocorticoid receptor β (GRβ) regulates injury-mediated astrocyte activation and contributes to glioma pathogenesis via modulation of β-catenin/T-cell factor/lymphoid enhancer factor (TCF/LEF) transcriptional activity. The aim of this study was to characterize the mechanism behind cross-talk between GRβ and β-catenin/TCF in the progression of glioma. Here, we reported that GRβ knockdown reduced U118 and Shg44 glioma cell proliferation in vitro and in vivo. Mechanistically, we found that GRβ knockdown decreased TCF/LEF transcriptional activity without affecting β-catenin/TCF complex. Both GRα and GRβ directly interact with TCF-4, while only GRβ is required for sustaining TCF/LEF activity under hormone-free condition. GRβ bound to the N-terminus domain of TCF-4 its influence on Wnt signaling required both ligand- and DNA-binding domains (LBD and DBD, respectively). GRβ and TCF-4 interaction is enough to maintain the TCF/LEF activity at a high level in the absence of β-catenin stabilization. Taken together, these results suggest a novel cross-talk between GRβ and TCF-4 which regulates Wnt signaling and the proliferation in gliomas.
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Fleseriu M, Findling JW, Koch CA, Schlaffer SM, Buchfelder M, Gross C. Changes in plasma ACTH levels and corticotroph tumor size in patients with Cushing's disease during long-term treatment with the glucocorticoid receptor antagonist mifepristone. J Clin Endocrinol Metab 2014; 99:3718-27. [PMID: 25013998 PMCID: PMC4399272 DOI: 10.1210/jc.2014-1843] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
CONTEXT Pituitary effects of long-term therapy with mifepristone, a glucocorticoid receptor antagonist, in Cushing's disease (CD) patients are not well understood. OBJECTIVE Our objective was to report changes in ACTH and pituitary magnetic resonance imaging (MRI) findings during long-term use of mifepristone in CD patients. DESIGN AND SETTING The Study of the Efficacy and Safety of Mifepristone in the Treatment of Endogenous Cushing's Syndrome (SEISMIC) was a 24-week, open-label study of mifepristone, and its long-term extension (LTE) is a multicenter U.S. study. PATIENTS Forty-three CD patients (mean age 45.3 years) were enrolled in SEISMIC with 27 continuing into the LTE study. INTERVENTIONS Mifepristone (300-1200 mg) was administered once daily. MAIN OUTCOME MEASURES ACTH and pituitary MRI were assessed at baseline and at regular intervals during treatment. RESULTS A ≥2-fold increase in ACTH was observed in 72% of patients treated for a median duration of 11.3 months. The mean peak increase in ACTH was 2.76 ± 1.65-fold during SEISMIC, and mean ACTH concentrations remained stable during the LTE. ACTH was directly correlated with mifepristone dose and declined to near baseline levels after mifepristone discontinuation. Tumor regressed in 2 patients and progressed in 3 patients with macroadenomas. An additional microadenoma was identified after 25 months of treatment after a baseline tumor-negative MRI. CONCLUSIONS In the largest prospective study to date, long-term mifepristone treatment increased ACTH in approximately two-thirds of patients with CD. ACTH elevations were observed within the first few weeks of treatment, were dose-dependent, and generally remained stable over time. Corticotroph tumor progression and regression may occur over time, but patients may have significant increases in ACTH levels without evidence of tumor growth.
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Affiliation(s)
- Maria Fleseriu
- Oregon Health & Science University (M.F.), Portland, Oregon 97239; Medical College of Wisconsin (J.W.F.), Milwaukee, Wisconsin 53051; University of Mississippi Medical Center (C.A.K.), Jackson, Mississippi 39216; University of Erlangen-Nürnberg (S.-M.S., M.B.), 91054 Erlangen, Germany; and Corcept Therapeutics (C.G.), Menlo Park, California 94025
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Abstract
Antiprogestins constitute a group of compounds, developed since the early 1980s, that bind progesterone receptors with different affinities. The first clinical uses for antiprogestins were in reproductive medicine, e.g., menstrual regulation, emergency contraception, and termination of early pregnancies. These initial applications, however, belied the capacity for these compounds to interfere with cell growth. Within the context of gynecological diseases, antiprogestins can block the growth of and kill gynecological-related cancer cells, such as those originating in the breast, ovary, endometrium, and cervix. They can also interrupt the excessive growth of cells giving rise to benign gynecological diseases such as endometriosis and leiomyomata (uterine fibroids). In this article, we present a review of the literature providing support for the antigrowth activity that antiprogestins impose on cells in various gynecological diseases. We also provide a summary of the cellular and molecular mechanisms reported for these compounds that lead to cell growth inhibition and death. The preclinical knowledge gained during the past few years provides robust evidence to encourage the use of antiprogestins in order to alleviate the burden of gynecological diseases, either as monotherapies or as adjuvants of other therapies with the perspective of allowing for long-term treatments with tolerable side effects. The key to the clinical success of antiprogestins in this field probably lies in selecting those patients who will benefit from this therapy. This can be achieved by defining the genetic makeup required - within each particular gynecological disease - for attaining an objective response to antiprogestin-driven growth inhibition therapy.Free Spanish abstractA Spanish translation of this abstract is freely available at http://www.reproduction-online.org/content/149/1/15/suppl/DC1.
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Affiliation(s)
- Alicia A Goyeneche
- Division of Basic Biomedical SciencesSanford School of Medicine, The University of South Dakota, Vermillion, South Dakota 57069, USA
| | - Carlos M Telleria
- Division of Basic Biomedical SciencesSanford School of Medicine, The University of South Dakota, Vermillion, South Dakota 57069, USA
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Vandevyver S, Dejager L, Libert C. Comprehensive overview of the structure and regulation of the glucocorticoid receptor. Endocr Rev 2014; 35:671-93. [PMID: 24937701 DOI: 10.1210/er.2014-1010] [Citation(s) in RCA: 163] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Glucocorticoids are among the most prescribed drugs worldwide for the treatment of numerous immune and inflammatory disorders. They exert their actions by binding to the glucocorticoid receptor (GR), a member of the nuclear receptor superfamily. There are several GR isoforms resulting from alternative RNA splicing and translation initiation of the GR transcript. Additionally, these isoforms are all subject to several transcriptional, post-transcriptional, and post-translational modifications, all of which affect the protein's stability and/or function. In this review, we summarize recent knowledge on the distinct GR isoforms and the processes that generate them. We also review the importance of all known transcriptional, post-transcriptional, and post-translational modifications, including the regulation of GR by microRNAs. Moreover, we discuss the crucial role of the putative GR-bound DNA sequence as an allosteric ligand influencing GR structure and activity. Finally, we describe how the differential composition and distinct regulation at multiple levels of different GR species could account for the wide and diverse effects of glucocorticoids.
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Affiliation(s)
- Sofie Vandevyver
- Inflammation Research Center (S.V., L.D., C.L.), Flanders Institute for Biotechnology, B9052 Ghent, Belgium; and Department of Biomedical Molecular Biology (S.V., L.D., C.L.), Ghent University, B9052 Ghent, Belgium
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Tian R, Hou G, Li D, Yuan TF. A possible change process of inflammatory cytokines in the prolonged chronic stress and its ultimate implications for health. ScientificWorldJournal 2014; 2014:780616. [PMID: 24995360 PMCID: PMC4065693 DOI: 10.1155/2014/780616] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 04/19/2014] [Accepted: 04/22/2014] [Indexed: 01/02/2023] Open
Abstract
Sustained stress triggers series of changes in the brain and the body. At the early stage of stress, the activated hypothalamus-pituitary-adrenal (HPA) axis and sympathetic nervous system (SNS) axis can upregulate the levels of glucocorticoid (GCs) and catecholamines (CAs), respectively, and then they in turn inhibit the secretion of proinflammatory cytokines directly or indirectly while promoting the secretion of anti-inflammatory cytokines. At the prolonged stage, the sustained activated HPA demonstrates cortisol-resistance. At the same time, the inflammation related transcription pathway, such as nuclear-factor kappa-B (NF-κB) signaling, may be inhibited. Additionally, the inflammatory cytokines mediate a negative feedback regulation on themselves. Collectively, these regulations may increase the proinflammatory cytokines while decreasing the anti-inflammatory cytokines. This may further activate NF-κB and increase the proinflammation cytokines, which in turn reduce the inflammatory responses, contributing to various diseases.
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Affiliation(s)
- Rui Tian
- Department of Psychology, Zhejiang Sci-Tech University, 579 Mailbox, Hangzhou 310018, China
| | - Gonglin Hou
- Department of Psychology, Zhejiang Sci-Tech University, 579 Mailbox, Hangzhou 310018, China
| | - Dan Li
- Department of Psychology, Zhejiang Sci-Tech University, 579 Mailbox, Hangzhou 310018, China
| | - Ti-Fei Yuan
- Department of Psychology, Nanjing Normal University, Nanjing 210097, China
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Gamarra-Luques CD, Hapon MB, Goyeneche AA, Telleria CM. Resistance to cisplatin and paclitaxel does not affect the sensitivity of human ovarian cancer cells to antiprogestin-induced cytotoxicity. J Ovarian Res 2014; 7:45. [PMID: 24795781 PMCID: PMC4007005 DOI: 10.1186/1757-2215-7-45] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 04/21/2014] [Indexed: 12/22/2022] Open
Abstract
Background Antiprogestin compounds have been shown to be effective in blocking the growth of ovarian cancer cells of different genetic backgrounds. Herein we studied the anti-ovarian cancer effect of a series of antiprogestins sharing the chemical backbone of the most characterized antiprogestin, mifepristone, but with unique modifications in position C-17 of the steroid ring. We assessed the effect of mifepristone-like antiprogestins on the growth of ovarian cancer cells sensitive to the standard combination therapy cisplatin-paclitaxel or made double-resistant upon six cycles of pulse-selection with the drugs used at clinically relevant concentrations and exposure times. Methods IGROV-1 and SKOV-3 cells were pulsed with 20 μM cisplatin for 1 h followed by 100 nM paclitaxel for 3 h once a week for six weeks. The cells that did not die and repopulate the culture after the chemotherapies were termed Platinum-Taxane-EScape cells (PTES). Parental cells were compared against their PTES derivatives in their responses to further platinum-taxane treatments. Moreover, both ovarian cancer cells and their PTES siblings were exposed to escalating doses of the various antiprogestin derivatives. We assessed cell growth, viability and sub-G1 DNA content using microcapillary cytometry. Cyclin-dependent kinase inhibitors p21cip1 and p27kip1 and cleavage of downstream caspase-3 substrate PARP were used to assess whether cell fate, as a consequence of treatment, was limited to cytostasis or progressed to lethality. Results Cells subjected to six pulse-selection cycles of cisplatin-paclitaxel gave rise to sibling derivatives that displayed ~2-7 fold reduction in their sensitivities to further chemotherapy. However, regardless of the sensitivity the cells developed to the combination cisplatin-paclitaxel, they displayed similar sensitivity to the antiprogestins, which blocked their growth in a dose-related manner, with lower concentrations causing cytostasis, and higher concentrations causing lethality. Conclusions Antiprogestins carrying a backbone similar to mifepristone are cytotoxic to ovarian cancer cells in a manner that does not depend on the sensitivity the cells have to the standard ovarian cancer chemotherapeutics, cisplatin and paclitaxel. Thus, antiprogestin therapy could be used to treat ovarian cancer cells showing resistance to both platinum and taxanes.
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Affiliation(s)
- Carlos D Gamarra-Luques
- Division of Basic Biomedical Sciences, Sanford School of Medicine, The University of South, Dakota, 414 East Clark Street, Vermillion, SD 57069, USA ; Present Address: Institute of Medicine and Experimental Biology of Cuyo, National Council for Scientific and Technical Research (CONICET), Mendoza, Argentina
| | - Maria B Hapon
- Division of Basic Biomedical Sciences, Sanford School of Medicine, The University of South, Dakota, 414 East Clark Street, Vermillion, SD 57069, USA ; Present Address: Institute of Medicine and Experimental Biology of Cuyo, National Council for Scientific and Technical Research (CONICET), Mendoza, Argentina
| | - Alicia A Goyeneche
- Division of Basic Biomedical Sciences, Sanford School of Medicine, The University of South, Dakota, 414 East Clark Street, Vermillion, SD 57069, USA
| | - Carlos M Telleria
- Division of Basic Biomedical Sciences, Sanford School of Medicine, The University of South, Dakota, 414 East Clark Street, Vermillion, SD 57069, USA
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Bellavance MA, Rivest S. The HPA - Immune Axis and the Immunomodulatory Actions of Glucocorticoids in the Brain. Front Immunol 2014; 5:136. [PMID: 24744759 PMCID: PMC3978367 DOI: 10.3389/fimmu.2014.00136] [Citation(s) in RCA: 272] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 03/18/2014] [Indexed: 12/20/2022] Open
Abstract
In response to physiological and psychogenic stressors, the hypothalamic–pituitary–adrenal (HPA) axis orchestrates the systemic release of glucocorticoids (GCs). By virtue of nearly ubiquitous expression of the GC receptor and the multifaceted metabolic, cardiovascular, cognitive, and immunologic functions of GCs, this system plays an essential role in the response to stress and restoration of an homeostatic state. GCs act on almost all types of immune cells and were long recognized to perform salient immunosuppressive and anti-inflammatory functions through various genomic and non-genomic mechanisms. These renowned effects of the steroid hormone have been exploited in the clinic for the past 70 years and synthetic GC derivatives are commonly used for the therapy of various allergic, autoimmune, inflammatory, and hematological disorders. The role of the HPA axis and GCs in restraining immune responses across the organism is however still debated in light of accumulating evidence suggesting that GCs can also have both permissive and stimulatory effects on the immune system under specific conditions. Such paradoxical actions of GCs are particularly evident in the brain, where substantial data support either a beneficial or detrimental role of the steroid hormone. In this review, we examine the roles of GCs on the innate immune system with a particular focus on the CNS compartment. We also dissect the numerous molecular mechanisms through which GCs exert their effects and discuss the various parameters influencing the paradoxical immunomodulatory functions of GCs in the brain.
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Affiliation(s)
- Marc-André Bellavance
- Faculty of medicine, Department of Molecular Medicine, Neuroscience Laboratory, CHU de Québec Research Center, Laval University , Québec, QC , Canada
| | - Serge Rivest
- Faculty of medicine, Department of Molecular Medicine, Neuroscience Laboratory, CHU de Québec Research Center, Laval University , Québec, QC , Canada
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Dominance of the strongest: inflammatory cytokines versus glucocorticoids. Cytokine Growth Factor Rev 2013; 25:21-33. [PMID: 24412262 DOI: 10.1016/j.cytogfr.2013.12.006] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Accepted: 12/15/2013] [Indexed: 02/08/2023]
Abstract
Pro-inflammatory cytokines are involved in the pathogenesis of many inflammatory diseases, and the excessive expression of many of them is normally counteracted by glucocorticoids (GCs), which are steroids that bind to the glucocorticoid receptor (GR). Hence, GCs are potent inhibitors of inflammation, and they are widely used to treat inflammatory diseases, such as asthma, rheumatoid arthritis and inflammatory bowel disease. However, despite the success of GC therapy, many patients show some degree of GC unresponsiveness, called GC resistance (GCR). This is a serious problem because it limits the full therapeutic exploitation of the anti-inflammatory power of GCs. Patients with reduced GC responses often have higher cytokine levels, and there is a complex interplay between GCs and cytokines: GCs downregulate pro-inflammatory cytokines while cytokines limit GC action. Treatment of inflammatory diseases with GCs is successful when GCs dominate. But when cytokines overrule the anti-inflammatory actions of GCs, patients become GC insensitive. New insights into the molecular mechanisms of GR-mediated actions and GCR are needed for the design of more effective GC-based therapies.
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Whirledge S, Cidlowski JA. A role for glucocorticoids in stress-impaired reproduction: beyond the hypothalamus and pituitary. Endocrinology 2013; 154:4450-68. [PMID: 24064362 PMCID: PMC3836069 DOI: 10.1210/en.2013-1652] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
In addition to the well-characterized role of the sex steroid receptors in regulating fertility and reproduction, reproductive events are also mediated by the hypothalamic-pituitary-adrenal axis in response to an individual's environment. Glucocorticoid secretion in response to stress contributes to the well-characterized suppression of the hypothalamic-pituitary-gonadal axis through central actions in the hypothalamus and pituitary. However, both animal and in vitro studies indicate that other components of the reproductive system are also regulated by glucocorticoids. Furthermore, in the absence of stress, it appears that homeostatic glucocorticoid signaling plays a significant role in reproduction and fertility in all tissues comprising the hypothalamic-pituitary-gonadal axis. Indeed, as central regulators of the immune response, glucocorticoids are uniquely poised to integrate an individual's infectious, inflammatory, stress, nutritional, and metabolic status through glucocorticoid receptor signaling in target tissues. Endocrine signaling between tissues regulating the immune and stress response and those determining reproductive status provides an evolutionary advantage, facilitating the trade-off between reproductive investment and offspring fitness. This review focuses on the actions of glucocorticoids in tissues important for fertility and reproduction, highlighting recent studies that show glucocorticoid signaling plays a significant role throughout the hypothalamic-pituitary-gonadal axis and characterizing these effects as permissive or inhibitory in terms of facilitating reproductive success.
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Affiliation(s)
- Shannon Whirledge
- NIEHS/NIH, MD F3-07, P.O. Box 12233, Research Triangle Park, North Carolina 27709.
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Quax RA, Manenschijn L, Koper JW, Hazes JM, Lamberts SWJ, van Rossum EFC, Feelders RA. Glucocorticoid sensitivity in health and disease. Nat Rev Endocrinol 2013; 9:670-86. [PMID: 24080732 DOI: 10.1038/nrendo.2013.183] [Citation(s) in RCA: 206] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Glucocorticoids regulate many physiological processes and have an essential role in the systemic response to stress. For example, gene transcription is modulated by the glucocorticoid-glucocorticoid receptor complex via several mechanisms. The ultimate biologic responses to glucocorticoids are determined by not only the concentration of glucocorticoids but also the differences between individuals in glucocorticoid sensitivity, which is influenced by multiple factors. Differences in sensitivity to glucocorticoids in healthy individuals are partly genetically determined by functional polymorphisms of the gene that encodes the glucocorticoid receptor. Hereditary syndromes have also been identified that are associated with increased and decreased sensitivity to glucocorticoids. As a result of their anti-inflammatory properties, glucocorticoids are widely used in the treatment of allergic, inflammatory and haematological disorders. The variety in clinical responses to treatment with glucocorticoids reflects the considerable variation in glucocorticoid sensitivity between individuals. In immune-mediated disorders, proinflammatory cytokines can induce localized resistance to glucocorticoids via several mechanisms. Individual differences in how tissues respond to glucocorticoids might also be involved in the predisposition for and pathogenesis of the metabolic syndrome and mood disorders. In this Review, we summarize the mechanisms that influence glucocorticoid sensitivity in health and disease and discuss possible strategies to modulate glucocorticoid responsiveness.
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Affiliation(s)
- Rogier A Quax
- Department of Internal Medicine, Division of Endocrinology, Erasmus Medical Center, 's-Gravendijkwal 230, 3015 CE Rotterdam, Netherlands
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The biology of the glucocorticoid receptor: new signaling mechanisms in health and disease. J Allergy Clin Immunol 2013; 132:1033-44. [PMID: 24084075 DOI: 10.1016/j.jaci.2013.09.007] [Citation(s) in RCA: 663] [Impact Index Per Article: 60.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 09/05/2013] [Accepted: 09/06/2013] [Indexed: 12/20/2022]
Abstract
Glucocorticoids are primary stress hormones necessary for life that regulate numerous physiologic processes in an effort to maintain homeostasis. Synthetic derivatives of these hormones have been mainstays in the clinic for treating inflammatory diseases, autoimmune disorders, and hematologic cancers. The physiologic and pharmacologic actions of glucocorticoids are mediated by the glucocorticoid receptor (GR), a member of the nuclear receptor superfamily of ligand-dependent transcription factors. Ligand-occupied GR induces or represses the transcription of thousands of genes through direct binding to DNA response elements, physically associating with other transcription factors, or both. The traditional view that glucocorticoids act through a single GR protein has changed dramatically with the discovery of a large cohort of receptor isoforms with unique expression, gene-regulatory, and functional profiles. These GR subtypes are derived from a single gene by means of alternative splicing and alternative translation initiation mechanisms. Posttranslational modification of these GR isoforms further expands the diversity of glucocorticoid responses. Here we discuss the origin and molecular properties of the GR isoforms and their contribution to the specificity and sensitivity of glucocorticoid signaling in healthy and diseased tissues.
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Kadmiel M, Cidlowski JA. Glucocorticoid receptor signaling in health and disease. Trends Pharmacol Sci 2013; 34:518-30. [PMID: 23953592 PMCID: PMC3951203 DOI: 10.1016/j.tips.2013.07.003] [Citation(s) in RCA: 547] [Impact Index Per Article: 49.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 06/30/2013] [Accepted: 07/08/2013] [Indexed: 12/20/2022]
Abstract
Glucocorticoids are steroid hormones regulated in a circadian and stress-associated manner to maintain various metabolic and homeostatic functions that are necessary for life. Synthetic glucocorticoids are widely prescribed drugs for many conditions including asthma, chronic obstructive pulmonary disease (COPD), and inflammatory disorders of the eye. Research in the past few years has begun to unravel the profound complexity of glucocorticoid signaling and has contributed remarkably to improved therapeutic strategies. Glucocorticoids signal through the glucocorticoid receptor (GR), a member of the superfamily of nuclear receptors, in both genomic and non-genomic ways in almost every tissue in the human body. In this review, we provide an update on glucocorticoid receptor signaling and highlight the role of GR signaling in physiological and pathophysiological conditions in the major organ systems in the human body.
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Affiliation(s)
- Mahita Kadmiel
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, 111 T.W. Alexander Dr., MD F3-07, Research Triangle Park, NC 27709
| | - John A. Cidlowski
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, 111 T.W. Alexander Dr., MD F3-07, Research Triangle Park, NC 27709
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DuBois DC, Sukumaran S, Jusko WJ, Almon RR. Evidence for a glucocorticoid receptor beta splice variant in the rat and its physiological regulation in liver. Steroids 2013; 78:312-20. [PMID: 23257260 PMCID: PMC3552070 DOI: 10.1016/j.steroids.2012.11.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 10/22/2012] [Accepted: 11/22/2012] [Indexed: 12/23/2022]
Abstract
Glucocorticoids are important regulators of metabolism and immune function. Synthetic glucocorticoids are extensively used for immunosuppression/anti-inflammatory therapy. Since the glucocorticoid receptor (GR) is central to most hormone effects; its in vivo regulation will influence hormone/drug action. An alternative splice variant, GRβ, is present in humans and may function as a dominant negative regulator of GR transcriptional activity. Recently, a similar splice variant was reported in mouse, although the mechanism of alternative splicing differs from that in humans. We present evidence that a splice variant of GR with an alternative C-terminus also occurs in the rat by a mechanism of intron inclusion. A highly quantitative qRT-PCR assay for the simultaneous measurement of both splice variants in a single sample was developed in order to accurately measure their regulation. We used this assay to assess the tissue specific expression of both mRNAs, and demonstrate that GRα is predominant in all tissues. In addition, the regulation of both GRα and GRβ mRNA by various physiological factors in rat liver was assessed. GRα showed a robust circadian rhythm, which was entrained with the circadian oscillation of the endogenous hormone. Time series experiments showed that both corticosteroids and LPS but not insulin dosing resulted in the transient down-regulation of GRα mRNA. LPS treatment also resulted in down-regulation of GRβ expression. A modest up-regulation in GRβ expression was observed only in animals having chronically elevated plasma insulin concentrations. However the expression of GRβ was significantly lower than that of GRα in all cases.
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Affiliation(s)
- Debra C DuBois
- Department of Biological Sciences, State University of New York at Buffalo, Buffalo, NY 14260, USA.
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Brandhagen BN, Tieszen CR, Ulmer TM, Tracy MS, Goyeneche AA, Telleria CM. Cytostasis and morphological changes induced by mifepristone in human metastatic cancer cells involve cytoskeletal filamentous actin reorganization and impairment of cell adhesion dynamics. BMC Cancer 2013; 13:35. [PMID: 23351358 PMCID: PMC3562154 DOI: 10.1186/1471-2407-13-35] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Accepted: 01/24/2013] [Indexed: 01/07/2023] Open
Abstract
Background Changes in cell shape and plasticity in cytoskeletal dynamics are critically involved in cell adhesion, migration, invasion and the overall process of metastasis. Previous work in our laboratory demonstrated that the synthetic steroid mifepristone inhibited the growth of highly metastatic cancer cells, while simultaneously causing striking changes in cellular morphology. Here we assessed whether such morphological alterations developed in response to cytostatic concentrations of mifepristone are reversible or permanent, involve rearrangement of cytoskeletal proteins, and/or affect the adhesive capacity of the cells. Methods Cancer cell lines of the ovary (SKOV-3), breast (MDA-MB-231), prostate (LNCaP), and nervous system (U87MG) were exposed to cytostatic concentrations of mifepristone and studied by phase-contrast microscopy. The transient or permanent nature of the cytostasis and morphological changes caused by mifepristone was assessed, as well as the rearrangement of cytoskeletal proteins. De-adhesion and adhesion assays were utilized to determine if mifepristone-arrested and morphologically dysregulated cells had abnormal de-adhesion/adhesion dynamics when compared to vehicle-treated controls. Results Mifepristone-treated cells displayed a long, thin, spindle-like shape with boundaries resembling those of loosely adhered cells. Growth arrest and morphology changes caused by mifepristone were reversible in SKOV-3, MDA-MB-231 and U87MG, but not in LNCaP cells that instead became senescent. All cancer cell types exposed to mifepristone displayed greatly increased actin ruffling in association with accelerated de-adhesion from the culture plate, and delayed adhesion capacity to various extracellular matrix components. Conclusions Cytostatic concentrations of mifepristone induced alterations in the cellular structure of a panel of aggressive, highly metastatic cancer cells of different tissues of origin. Such changes were associated with re-distribution of actin fibers that mainly form non-adhesive membrane ruffles, leading to dysregulated cellular adhesion capacity.
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Affiliation(s)
- BreeAnn N Brandhagen
- Division of Basic Biomedical Science, Sanford School of Medicine of The University of South Dakota, 414 East Clark Street, Vermillion, SD 57069, USA
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Barnes PJ. Corticosteroid resistance in patients with asthma and chronic obstructive pulmonary disease. J Allergy Clin Immunol 2013; 131:636-45. [PMID: 23360759 DOI: 10.1016/j.jaci.2012.12.1564] [Citation(s) in RCA: 491] [Impact Index Per Article: 44.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 12/05/2012] [Accepted: 12/10/2012] [Indexed: 12/21/2022]
Abstract
Reduced responsiveness to the anti-inflammatory effects of corticosteroids is a major barrier to effective management of asthma in smokers and patients with severe asthma and in the majority of patients with chronic obstructive pulmonary disease (COPD). The molecular mechanisms leading to steroid resistance are now better understood, and this has identified new targets for therapy. In patients with severe asthma, several molecular mechanisms have been identified that might account for reduced steroid responsiveness, including reduced nuclear translocation of glucocorticoid receptor (GR) α after binding corticosteroids. This might be due to modification of the GR by means of phosphorylation as a result of activation of several kinases (p38 mitogen-activated protein kinase α, p38 mitogen-activated protein kinase γ, and c-Jun N-terminal kinase 1), which in turn might be due to reduced activity and expression of phosphatases, such as mitogen-activated protein kinase phosphatase 1 and protein phosphatase A2. Other mechanisms proposed include increased expression of GRβ, which competes with and thus inhibits activated GRα; increased secretion of macrophage migration inhibitory factor; competition with the transcription factor activator protein 1; and reduced expression of histone deacetylase (HDAC) 2. HDAC2 appears to mediate the action of steroids to switch off activated inflammatory genes, but in patients with COPD, patients with severe asthma, and smokers with asthma, HDAC2 activity and expression are reduced by oxidative stress through activation of phosphoinositide 3-kinase δ. Strategies for managing steroid resistance include alternative anti-inflammatory drugs, but a novel approach is to reverse steroid resistance by increasing HDAC2 expression, which can be achieved with theophylline and phosphoinositide 3-kinase δ inhibitors. Long-acting β2-agonists can also increase steroid responsiveness by reversing GRα phosphorylation. Identifying the molecular mechanisms of steroid resistance in asthmatic patients and patients with COPD can thus lead to more effective anti-inflammatory treatments.
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Affiliation(s)
- Peter J Barnes
- National Heart and Lung Institute, Imperial College, London, United Kingdom.
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78
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Bellavance MA, Rivest S. The neuroendocrine control of the innate immune system in health and brain diseases. Immunol Rev 2012; 248:36-55. [PMID: 22725953 DOI: 10.1111/j.1600-065x.2012.01129.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The innate immune reaction takes place in the brain during immunogenic challenges, injury, and disease. Such a response is highly regulated by numerous anti-inflammatory mechanisms that may directly affect the ultimate consequences of such a reaction within the cerebral environment. The neuroendocrine control of this innate immune system by glucocorticoids is critical for the delicate balance between cell survival and damage in the presence of inflammatory mediators. Glucocorticoids play key roles in regulating the expression of inflammatory genes, and they also have the ability to modulate numerous functions that may ultimately lead to brain damage or repair after injury. Here we review these mechanisms and discuss data supporting both neuroprotective and detrimental roles of the neuroendocrine control of innate immunity.
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Affiliation(s)
- Marc-André Bellavance
- Laboratory of Endocrinology and Genomics, CHUQ Research Center and Department of Molecular Medicine, Faculty of Medicine, Laval University, Québec, Canada
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79
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Li M, Leatherland JF, Vijayan MM, King WA, Madan P. Glucocorticoid receptor activation following elevated oocyte cortisol content is associated with zygote activation, early embryo cell division, and IGF system gene responses in rainbow trout. J Endocrinol 2012; 215:137-49. [PMID: 22782383 DOI: 10.1530/joe-12-0030] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Increased in ovo cortisol content of rainbow trout oocytes from ~3·5 to ~5·0 ng.oocyte(-1) before fertilization enhances the growth of embryos and juveniles and changes the long-term expression pattern of IGF-related genes. This study used embryos reared from oocytes enriched with cortisol and the glucocorticoid receptor (GR) antagonist, RU486, to determine whether the growth-promoting actions of cortisol involve GR protein activation and modulation of gr expression. Whole-mount in situ immunohistofluorescence studies of zygotes showed that enhanced oocyte cortisol increased the immunofluorescent GR signal and activated the relocation of GR from a general distribution throughout the cytoplasm to an accumulation in the peri-nuclear cytoplasm. In ovo cortisol treatment increased the number of embryonic cells within 48-h post-fertilization, and RU486 partially suppressed this cortisol stimulation of cell duplication. In addition, there was complex interplay between the expression of gr and igf system-related genes spatiotemporally in the different treatment groups, suggesting a role for GR in the regulation of the expression of development. Taken together, these findings indicate an essential role for GR in the regulation of epigenomic events in very early embryos that promoted the long-term growth effects of the embryos and juvenile fish. Moreover, the pretreatment of the oocyte with RU486 had a significant suppressive effect on the maternal mRNA transcript number of gr and igf system-related genes in oocytes and very early stage embryos, suggesting an action of antagonist on the stability of the maternal transcriptome.
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MESH Headings
- Animals
- Cell Division/genetics
- Cell Division/physiology
- Cleavage Stage, Ovum/cytology
- Cleavage Stage, Ovum/metabolism
- Cleavage Stage, Ovum/physiology
- Embryo, Nonmammalian/cytology
- Embryo, Nonmammalian/metabolism
- Embryo, Nonmammalian/physiology
- Female
- Gene Expression Regulation, Developmental
- Hydrocortisone/analysis
- Hydrocortisone/metabolism
- Oncorhynchus mykiss/embryology
- Oncorhynchus mykiss/genetics
- Oncorhynchus mykiss/metabolism
- Oncorhynchus mykiss/physiology
- Oocytes/chemistry
- Oocytes/metabolism
- Receptors, Glucocorticoid/agonists
- Receptors, Glucocorticoid/metabolism
- Receptors, Glucocorticoid/physiology
- Receptors, Somatomedin/genetics
- Receptors, Somatomedin/metabolism
- Signal Transduction/genetics
- Somatomedins/genetics
- Somatomedins/metabolism
- Time Factors
- Up-Regulation/physiology
- Zygote/metabolism
- Zygote/physiology
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Affiliation(s)
- Mao Li
- Department of Biomedical Sciences, University of Guelph, Guelph, Ontario, Canada N1G 2W1
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80
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Yang N, Ray DW, Matthews LC. Current concepts in glucocorticoid resistance. Steroids 2012; 77:1041-9. [PMID: 22728894 DOI: 10.1016/j.steroids.2012.05.007] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Revised: 05/24/2012] [Accepted: 05/29/2012] [Indexed: 01/04/2023]
Abstract
Glucocorticoids (GCs) are the most potent anti-inflammatory agents known. A major factor limiting their clinical use is the wide variation in responsiveness to therapy. The high doses of GC required for less responsive patients means a high risk of developing very serious side effects. Variation in sensitivity between individuals can be due to a number of factors. Congenital, generalized GC resistance is very rare, and is due to mutations in the glucocorticoid receptor (GR) gene, the receptor that mediates the cellular effects of GC. A more common problem is acquired GC resistance. This localized, disease-associated GC resistance is a serious therapeutic concern and limits therapeutic response in patients with chronic inflammatory disease. It is now believed that localized resistance can be attributed to changes in the cellular microenvironment, as a consequence of chronic inflammation. Multiple factors have been identified, including alterations in both GR-dependent and -independent signaling downstream of cytokine action, oxidative stress, hypoxia and serum derived factors. The underlying mechanisms are now being elucidated, and are discussed here. Attempts to augment tissue GC sensitivity are predicted to permit safe and effective use of low-dose GC therapy in inflammatory disease.
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Affiliation(s)
- Nan Yang
- Endocrine Sciences Research Group, Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK
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81
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Ligr M, Li Y, Logan SK, Taneja S, Melamed J, Lepor H, Garabedian MJ, Lee P. Mifepristone inhibits GRβ coupled prostate cancer cell proliferation. J Urol 2012; 188:981-8. [PMID: 22819113 DOI: 10.1016/j.juro.2012.04.102] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Indexed: 10/28/2022]
Abstract
PURPOSE The GR gene produces GRα and GRβ isoforms by alternative splicing of a C-terminal exon. GRα binds glucocorticoids, modulates transcription in a glucocorticoid dependent manner and has a growth inhibitory role in prostate cells. Due to this role glucocorticoids are often used to treat androgen independent prostate cancer. In contrast, GRβ has intrinsic transcriptional activity and binds mifepristone (RU486) but not glucocorticoids to control gene expression. To our knowledge the role of GRβ in prostate cell proliferation is unknown. MATERIALS AND METHODS We determined GRβ levels in various prostate cancer cell lines by reverse transcriptase-polymerase chain reaction and Western blot. The effect of GRβ on the kinetics of prostate cancer cell growth was determined by cell counting and flow cytometry upon mifepristone and dexamethasone treatment. Cell proliferation was also examined after siRNA mediated knockdown and over expression of GRβ. RESULTS GRβ mRNA and protein were up-regulated in LNCaP cells that over expressed the androgen receptor co-factor ARA70β. Treatment of LNCaP-ARA70β with mifepristone or siRNA targeting GRβ inhibited proliferation compared to that of parental LNCaP cells. The immortal but nontumorigenic RC165 prostate cell line and the tumorigenic DU145 prostate cell line with endogenous GRβ also showed partial growth reduction upon GRβ depletion but to a lesser extent than LNCaP-ARA70β cells. The growth stimulatory effect of ARA70β on LNCaP cells was partly GRβ dependent, as was the proliferation of RC165 cells and to a lesser extent of DU145 cells. CONCLUSIONS Results suggest that patients with a primary tumor that expresses GRβ and ARA70β may benefit from mifepristone.
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Affiliation(s)
- Martin Ligr
- Department of Pathology, New York University School of Medicine, New York, New York 10010, USA
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82
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Boscaro M, Giacchetti G, Ronconi V. Visceral adipose tissue: emerging role of gluco- and mineralocorticoid hormones in the setting of cardiometabolic alterations. Ann N Y Acad Sci 2012; 1264:87-102. [PMID: 22804097 PMCID: PMC3464353 DOI: 10.1111/j.1749-6632.2012.06597.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Several clinical and experimental lines of evidence have highlighted the detrimental effects of visceral adipose tissue excess on cardiometabolic parameters. Besides, recent findings have shown the effects of gluco-and mineralocorticoid hormones on adipose tissue and have also underscored the interplay existing between such adrenal steroids and their respective receptors in the modulation of adipose tissue biology. While the fundamental role played by glucocorticoids on adipocyte differentiation and storage was already well known, the relevance of the mineralocorticoids in the physiology of the adipose organ is of recent acquisition. The local and systemic renin–angiotensin–aldosterone system (RAAS) acting on adipose tissue seems to contribute to the development of the cardiometabolic phenotype so that its modulation can have deep impact on human health. A better understanding of the pathophysiology of the adipose organ is of crucial importance in order to identify possible therapeutic approaches that can avoid the development of such cardiovascular and metabolic sequelae.
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Affiliation(s)
- Marco Boscaro
- Division of Endocrinology, Ospedali Riuniti "Umberto I-G.M. Lancisi-G. Salesi," Università Politecnica delle Marche, Ancona, Italy
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83
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Merkulov VM, Merkulova TI. Glucocorticoid receptor isoforms generated by alternative splicing and alternative translation initiation. ACTA ACUST UNITED AC 2012. [DOI: 10.1134/s2079059712030070] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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84
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Goleva E, Jackson LP, Gleason M, Leung DYM. Usefulness of PBMCs to predict clinical response to corticosteroids in asthmatic patients. J Allergy Clin Immunol 2012; 129:687-693.e1. [PMID: 22236730 DOI: 10.1016/j.jaci.2011.12.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Revised: 11/23/2011] [Accepted: 12/01/2011] [Indexed: 11/17/2022]
Abstract
BACKGROUND Blood tests are needed to identify steroid-resistant (SR) asthmatic patients early so that they can be managed with alternative anti-inflammatory therapy. OBJECTIVE We sought to assess the usefulness of peripheral blood to predict steroid response in asthmatic patients. METHODS Nineteen asthmatic patients with FEV(1) of less than 80% of predicted value were classified as SR or steroid sensitive (SS) based on change in lung FEV(1) percentage after 7 days of oral prednisone. Blood was collected at baseline (visit 1) and 30 days after prednisone administration (visit 3). PBMCs were cultured for 4 hours with or without 10(-7) mol/L dexamethasone, and cellular response to dexamethasone was determined by using real-time PCR based on expression analysis of steroid-regulated genes. Suppression of PHA-induced T-cell proliferation by dexamethasone was assessed. RESULTS Prednisone significantly improved FEV(1) percentages in SS asthmatic patients (mean ± SE: 17.5% ± 2.4%) but not SR asthmatic patients (0.8% ± 2.0%, P < .001). Before prednisone treatment, mitogen-induced kinase phosphatase 1 (P = .01) and IL-8 mRNA (P < .05) levels were significantly higher in PBMCs from SR asthmatic patients. TNF-α (P < .05) and IL-8 fold suppression by dexamethasone (P < .05) were significantly reduced in PBMCs from SR asthmatic patients. The expression of glucocorticoid receptor (GCR) β, but not GCR-α, was significantly increased in PBMCs of SR asthmatic patients (P = .01). The dexamethasone inhibitory concentration of 50% for PBMC proliferation was significantly higher for SR asthmatic patients (P < .05). These markers no longer differed between groups in PBMCs 30 days after prednisone administration. The composite score of assays at baseline before prednisone was significantly different between SR and SS asthmatic patients (P < .001). CONCLUSIONS PBMCs from SR asthmatic patients have higher baseline mitogen-induced kinase phosphatase 1, IL-8, and GCR-β mRNA levels; have a lower GCR-α/GCR-β mRNA ratio; are less responsive to suppression of TNF-α and IL-8 by dexamethasone; and require more dexamethasone to suppress T-cell proliferation compared with SS asthmatic patients.
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Affiliation(s)
- Elena Goleva
- Division of Pediatric Allergy and Immunology, National Jewish Health, Denver, CO 80206, USA
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85
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Parathyroid hormone-related protein and glucocorticoid receptor beta are regulated by cortisol in the kidney of male mice. Life Sci 2011; 89:615-20. [DOI: 10.1016/j.lfs.2011.08.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Revised: 07/20/2011] [Accepted: 07/27/2011] [Indexed: 11/22/2022]
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86
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Kino T, Charmandari E, Chrousos GP. Glucocorticoid receptor: implications for rheumatic diseases. Clin Exp Rheumatol 2011; 29:S32-S41. [PMID: 22018181 PMCID: PMC3630375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Accepted: 09/14/2011] [Indexed: 05/31/2023]
Abstract
The glucocorticoid receptor (GR), a member of the nuclear receptor superfamily, mediates most of the known biologic effects of glucocorticoids. The human GR gene consists of 9 exons and expresses 2 alternative splicing isoforms, the GRα and GRβ. GRα is the classic receptor that binds to glucocorticoids and mediates most of the known actions of glucocorticoids, while GRβ does not bind to these hormones and exerts a dominant negative effect upon the GRα-induced transcriptional activity. Each of the two GR splice isoforms has 8 translational variants with specific transcriptional activity and tissue distribution. GRα consists of three subdomains, translocates from the cytoplasm into the nucleus upon binding to glucocorticoids, and regulates the transcriptional activity of numerous glucocorticoid-responsive genes either by binding to its cognate DNA sequences or by interacting with other transcription factors. In addition to these genomic actions, the GR also exerts rapid, non-genomic effects, which are possibly mediated by membrane-localised receptors or by translocation into the mitochondria. All these actions of the GR appear to play an important role in the regulation of the immune system. Specifically, the splicing variant GRβ may be involved in the pathogenesis of rheumatic diseases, while the circadian regulation of the GR activity via acetylation by the Clock transcription factor may have therapeutic implications for the preferential timing of glucocorticoid administration in autoimmune inflammatory disorders.
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Affiliation(s)
- T Kino
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
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87
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Abstract
Current therapy for asthma is highly effective. β(2)-Adrenergic receptor (β(2)AR) agonists are the most effective bronchodilators and relax airway smooth muscle cells through increased cAMP concentrations and directly opening large conductance Ca(2+) channels. β(2)AR may also activate alternative signaling pathways that may have detrimental effects in asthma. Glucocorticoids are the most effective anti-inflammatory treatments and switch off multiple activated inflammatory genes through recruitment of histone deacetylase-2, activating anti-inflammatory genes, and through increasing mRNA stability of inflammatory genes. There are beneficial molecular interactions between β(2)AR and glucocorticoid-activated pathways. Understanding these signaling pathways may lead to even more effective therapies in the future.
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Affiliation(s)
- Peter J Barnes
- National Heart and Lung Institute, Imperial College, London SW3 6LY, United Kingdom.
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88
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Abstract
Glucocorticoids are the most effective anti-inflammatory therapy for asthma yet are relatively ineffective in chronic obstructive pulmonary disease. Glucocorticoids suppress inflammation via several molecular mechanisms. Glucocorticoids suppress the multiple inflammatory genes that are activated in chronic inflammatory diseases, such as asthma, by reversing histone acetylation of activated inflammatory genes through binding of ligand-bound glucocorticoid receptors (GR) to co-activator molecules and recruitment of histone deacetylase-2 to the activated inflammatory gene transcription complex (trans-repression). At higher concentrations of glucocorticoids GR homodimers interact with DNA recognition sites to activate transcription through increased histone acetylation of anti-inflammatory genes and transcription of several genes linked to glucocorticoid side effects (trans-activation). Glucocorticoids also have post-transcriptional effects and decrease stability of some pro-inflammatory mRNA species. Decreased glucocorticoid responsiveness is found in patients with severe asthma and asthmatics who smoke, as well as in all patients with chronic obstructive pulmonary disease. Several molecular mechanisms of glucocorticoid resistance have now been identified which involve post-translational modifications of GR. Histone deacetylase-2 is markedly reduced in activity and expression as a result of oxidative/nitrative stress so that inflammation becomes resistant to the anti-inflammatory actions of glucocorticoids. Dissociated glucocorticoids and selective GR modulators which show improved trans-repression over trans-activation effects have been developed to reduce side effects, but so far it has been difficult to dissociate anti-inflammatory effects from adverse effects. In patients with glucocorticoid resistance alternative anti-inflammatory treatments are being investigated as well as drugs that may reverse the molecular mechanisms of glucocorticoid resistance.
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Affiliation(s)
- Peter J Barnes
- National Heart & Lung Institute, Imperial College, London, UK.
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89
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Tieszen CR, Goyeneche AA, Brandhagen BN, Ortbahn CT, Telleria CM. Antiprogestin mifepristone inhibits the growth of cancer cells of reproductive and non-reproductive origin regardless of progesterone receptor expression. BMC Cancer 2011; 11:207. [PMID: 21619605 PMCID: PMC3125282 DOI: 10.1186/1471-2407-11-207] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2011] [Accepted: 05/27/2011] [Indexed: 01/20/2023] Open
Abstract
Background Mifepristone (MF) has been largely used in reproductive medicine due to its capacity to modulate the progesterone receptor (PR). The study of MF has been expanded to the field of oncology; yet it remains unclear whether the expression of PR is required for MF to act as an anti-cancer agent. Our laboratory has shown that MF is a potent inhibitor of ovarian cancer cell growth. In this study we questioned whether the growth inhibitory properties of MF observed in ovarian cancer cells would translate to other cancers of reproductive and non-reproductive origin and, importantly, whether its efficacy is related to the expression of cognate PR. Methods Dose-response experiments were conducted with cancer cell lines of the nervous system, breast, prostate, ovary, and bone. Cultures were exposed to vehicle or increasing concentrations of MF for 72 h and analysed for cell number and cell cycle traverse, and hypodiploid DNA content characteristic of apoptotic cell death. For all cell lines, expression of steroid hormone receptors upon treatment with vehicle or cytostatic doses of MF for 24 h was studied by Western blot, whereas the activity of the G1/S regulatory protein Cdk2 in both treatment groups was monitored in vitro by the capacity of Cdk2 to phosphorylate histone H1. Results MF growth inhibited all cancer cell lines regardless of tissue of origin and hormone responsiveness, and reduced the activity of Cdk2. Cancer cells in which MF induced G1 growth arrest were less susceptible to lethality in the presence of high concentrations of MF, when compared to cancer cells that did not accumulate in G1. While all cancer cell lines were growth inhibited by MF, only the breast cancer MCF-7 cells expressed cognate PR. Conclusions Antiprogestin MF inhibits the growth of different cancer cell lines with a cytostatic effect at lower concentrations in association with a decline in the activity of the cell cycle regulatory protein Cdk2, and apoptotic lethality at higher doses in association with increased hypodiploid DNA content. Contrary to common opinion, growth inhibition of cancer cells by antiprogestin MF is not dependent upon expression of classical, nuclear PR.
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Affiliation(s)
- Chelsea R Tieszen
- Division of Basic Biomedical Sciences, Sanford School of Medicine of The University of South Dakota, Vermillion, SD, USA
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90
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91
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Yang S, Thiel KW, Leslie KK. Progesterone: the ultimate endometrial tumor suppressor. Trends Endocrinol Metab 2011; 22:145-52. [PMID: 21353793 PMCID: PMC4062362 DOI: 10.1016/j.tem.2011.01.005] [Citation(s) in RCA: 136] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2010] [Revised: 01/11/2011] [Accepted: 01/20/2011] [Indexed: 01/05/2023]
Abstract
The uterine endometrium is exquisitely sensitive to steroid hormones that act through well-described nuclear receptors. Estrogen drives epithelial proliferation, and progesterone inhibits growth and causes cell differentiation. The importance of progesterone as a key inhibitor of carcinogenesis is reflected by the observation that women who ovulate and produce progesterone almost never get endometrial cancer. In this review we describe seminal research findings that define progesterone as the major endometrial tumor suppressor. We discuss the genes and diverse signaling pathways that are controlled by progesterone through progesterone receptors (PRs) and also the multiple factors that regulate progesterone/PR activity. By defining these progesterone-regulated factors and pathways we identify the principal therapeutic opportunities to control the growth of endometrial cancer.
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Affiliation(s)
- Shujie Yang
- Department of Obstetrics & Gynecology and Holden Comprehensive Cancer Center,The University of Iowa, Iowa City, Iowa 52242, USA
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92
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Oakley RH, Cidlowski JA. Cellular processing of the glucocorticoid receptor gene and protein: new mechanisms for generating tissue-specific actions of glucocorticoids. J Biol Chem 2011; 286:3177-84. [PMID: 21149445 PMCID: PMC3030321 DOI: 10.1074/jbc.r110.179325] [Citation(s) in RCA: 255] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Glucocorticoids regulate numerous physiological processes and are mainstays in the treatment of inflammation, autoimmune disease, and cancer. The traditional view that glucocorticoids act through a single glucocorticoid receptor (GR) protein has changed in recent years with the discovery of a large cohort of receptor subtypes arising from alternative processing of the GR gene. These isoforms differ in their expression, gene regulatory, and functional profiles. Post-translational modification of these proteins further expands GR diversity. Here, we discuss the origin and molecular properties of the GR isoforms and their contribution to the sensitivity and specificity of the glucocorticoid response.
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Affiliation(s)
- Robert H. Oakley
- From the Laboratory of Signal Transduction, NIEHS, National Institutes of Heath, Department of Health and Human Services, Research Triangle Park, North Carolina 27709
| | - John A. Cidlowski
- From the Laboratory of Signal Transduction, NIEHS, National Institutes of Heath, Department of Health and Human Services, Research Triangle Park, North Carolina 27709
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93
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Cervellati F, Pavan B, Lunghi L, Manni E, Fabbri E, Mascoli C, Biondi C, Patella A, Vesce F. Betamethasone, progesterone and RU-486 (mifepristone) exert similar effects on connexin expression in trophoblast-derived HTR-8/SVneo cells. Reprod Fertil Dev 2011; 23:319-28. [PMID: 21211465 DOI: 10.1071/rd10077] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Accepted: 07/13/2010] [Indexed: 12/16/2023] Open
Abstract
Connexins (Cx) are membrane proteins able to influence cell trophoblast responses, such as proliferation, differentiation, migration and invasiveness. Likewise, glucocorticoids are also known to modulate many factors involved in implantation, including trophoblast gap-junction intercellular communication, although their influence on pregnancy is controversial. In order to investigate the effects of betamethasone, a synthetic glucocorticoid, on Cx and glucocorticoid receptor (GR) expression and localisation, as well as on cell proliferation, the extravillous trophoblast-derived HTR-8/SVneo cell line was used as a model. The results, confirmed by means of immunofluorescence, demonstrate that betamethasone selectively modifies GR and Cx expression, enhancing the GRα isoform without affecting GRβ, and inhibiting Cx40 expression whilst increasing that of Cx43 and Cx45. Furthermore, betamethasone was shown to exert an inhibitory action on cell proliferation. In this model the abortion drug RU-486 (mifepristone), reported to be a GR antagonist, did not counteract this effect of betamethasone. On the contrary, it induced responses similar to those of the hormone. Knowing that RU-486 is also a potent progesterone-receptor antagonist, the effect of progesterone alone and in combination with the drug on Cx expression and cell proliferation was then tested. Progesterone showed the same effect as betamethasone on Cx expression, but it did not affect proliferation. Based on these results, neither the abortion effects of RU-486 nor the protective action of betamethasone and progesterone are exerted by modulation of Cx. RU-486 did not antagonise the progesterone effect, suggesting that its abortive action does not involve alteration of trophoblast Cx expression.
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Affiliation(s)
- F Cervellati
- Department of Biology and Evolution, Section of General Physiology, University of Ferrara, Ferrara, Italy
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94
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Trebble P, Matthews L, Blaikley J, Wayte AWO, Black GCM, Wilton A, Ray DW. Familial glucocorticoid resistance caused by a novel frameshift glucocorticoid receptor mutation. J Clin Endocrinol Metab 2010; 95:E490-9. [PMID: 20861124 PMCID: PMC4110505 DOI: 10.1210/jc.2010-0705] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Familial glucocorticoid resistance is a rare condition with a typical presentation of women with hirsutism and hypertension, with or without hypokalemia. OBJECTIVE The aim was to determine the cause of apparent glucocorticoid resistance in a young woman. PATIENTS AND METHODS We studied a family with a novel glucocorticoid receptor (GR) mutation and a surprisingly mild phenotype. Their discovery resulted from serendipitous measurement of serum cortisol with little biochemical or clinical evidence for either hyperandrogenism or mineralocorticoid excess. RESULTS The causative mutation was identified as a frameshift mutation in exon 6. Transformed peripheral blood lymphocytes were generated to analyze GR expression in vitro. Carriers of the mutation had less full-length GR, but the predicted mutant GR protein was not detected. However, this does not exclude expression in vivo, and so the mutant GR (Δ612GR) was expressed in vitro. Simple reporter gene assays suggested that Δ612GR has dominant negative activity. Δ612GR was not subject to ligand-dependent Ser211 phosphorylation or to ligand-dependent degradation. A fluorophore-tagged construct showed that Δ612GR did not translocate to the nucleus in response to ligand and retarded translocation of the wild-type GR. These data suggest that Δ612GR is not capable of binding ligand and exerts dominant negative activity through heterodimerization with wild-type GR. CONCLUSION Therefore, we describe a novel, naturally occurring GR mutation that results in familial glucocorticoid resistance. The mutant GR protein, if expressed in vivo, is predicted to exert dominant negative activity by impairing wild-type GR nuclear translocation.
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Affiliation(s)
- P Trebble
- School of Medicine, University of Manchester, Manchester Academic Health Sciences Centre, Oxford Road, Manchester M13 9PT, United Kingdom
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95
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Pietras T, Panek M, Tworek D, Oszajca K, Wujcik R, Górski P, Kuna P, Szemraj J. The Bcl I single nucleotide polymorphism of the human glucocorticoid receptor gene h-GR/NR3C1 promoter in patients with bronchial asthma: pilot study. Mol Biol Rep 2010; 38:3953-8. [PMID: 21113676 PMCID: PMC3115143 DOI: 10.1007/s11033-010-0512-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Accepted: 11/13/2010] [Indexed: 12/24/2022]
Abstract
Bcl I in the promoter polymorphism observed within h-GR/NR3C1 gene may play an important role in the development of bronchial asthma and resistance to GCs in the severe bronchial asthma. The aim of the investigation was to study the correlation between this h-GR/NR3C1 gene polymorphism and occurrence of asthma in the population of Polish asthmatics. Peripheral blood was obtained from 70 healthy volunteers and 59 asthma patients. Structuralized anamnesis, spirometry and allergy skin prick tests were performed in all participants. Genotyping was carried out with PCR–RFLP method. In healthy, non-atopic population variants of Bcl I: GG, GC, CC were found with frequency 0.129/0.471/0.400, respectively. In asthma patients Bcl I: GG, GC, CC occurred with respective frequencies of 0.410/0.462/0.128. Chi-square analysis revealed a significantly different (P < 0.05) distribution between cases and controls for the Bcl I polymorphism. The Bcl I polymorphism of h-GR/NR3C1 gene is significantly associated with bronchial asthma, susceptibility to the development of severe form and resistance to GCs in Polish population.
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Affiliation(s)
- Tadeusz Pietras
- Department of Pneumology and Allergology, Medical University of Lodz, Kopcińskiego 22, 90-153, Lodz, Poland.
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96
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Li LB, Leung DYM, Martin RJ, Goleva E. Inhibition of histone deacetylase 2 expression by elevated glucocorticoid receptor beta in steroid-resistant asthma. Am J Respir Crit Care Med 2010; 182:877-83. [PMID: 20538962 PMCID: PMC2970859 DOI: 10.1164/rccm.201001-0015oc] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Accepted: 06/10/2010] [Indexed: 01/08/2023] Open
Abstract
RATIONALE Cross-talk between glucocorticoid receptors and histone deacetylases (HDACs) under steroid-insensitive conditions has not been explored. OBJECTIVES To evaluate expression and interaction of HDACs with glucocorticoid receptor isoforms in bronchoalveolar lavage and peripheral blood mononuclear cells from steroid-resistant versus steroid-sensitive patients with asthma. METHODS Expression of HDACs 1 through 11 was measured by real-time polymerase chain reaction in primary cells and in the DO11.10 cell line, designed to overexpress glucocorticoid receptor β. Glucocorticoid receptor β expression was inhibited in bronchoalveolar lavage cells by small interfering RNA. Human HDAC2 promoter fragments were cloned into a luciferase reporter vector, and transiently transfected with glucocorticoid receptor α- and β-encoding plasmids into the cells. Luciferase activity was then assayed in response to glucocorticoids. MEASUREMENTS AND MAIN RESULTS Levels of HDAC2 mRNA, but not other histone deacetylases, were significantly decreased in bronchoalveolar lavage cells but not in peripheral blood mononuclear cells from steroid-resistant patients with asthma. Overexpression of glucocorticoid receptor β in DO11.10 cells selectively reduced HDAC2 mRNA and protein levels. Silencing of glucocorticoid receptor β in bronchoalveolar lavage cells from patients with asthma significantly increased HDAC2 mRNA. Luciferase activity assays with HDAC2 promoter reporter constructs identified two glucocorticoid-inducible regions in the HDAC2 promoter. Promoter activity was increased more than fourfold in dexamethasone-treated cells cotransfected with glucocorticoid receptor α. Cotransfection of glucocorticoid receptor β abolished this effect in a dose-dependent manner. CONCLUSIONS Glucocorticoid receptor β controls expression of histone deacetylase 2 by inhibiting glucocorticoid response elements in its promoter. This highlights a novel mechanism by which glucocorticoid receptor β promotes steroid insensitivity (Li et al.: J Allergy Clin Immunol 2009;123:S146; and Li et al.: J Allergy Clin Immunol 2010;125:AB104).
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Affiliation(s)
- Ling-bo Li
- Department of Pediatrics, National Jewish Health, Denver; Department of Pediatrics, University of Colorado Denver, Aurora; and Department of Medicine, National Jewish Health, Denver, Colorado
| | - Donald Y. M. Leung
- Department of Pediatrics, National Jewish Health, Denver; Department of Pediatrics, University of Colorado Denver, Aurora; and Department of Medicine, National Jewish Health, Denver, Colorado
| | - Richard J. Martin
- Department of Pediatrics, National Jewish Health, Denver; Department of Pediatrics, University of Colorado Denver, Aurora; and Department of Medicine, National Jewish Health, Denver, Colorado
| | - Elena Goleva
- Department of Pediatrics, National Jewish Health, Denver; Department of Pediatrics, University of Colorado Denver, Aurora; and Department of Medicine, National Jewish Health, Denver, Colorado
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97
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De Bosscher K, Beck IM, Haegeman G. Classic glucocorticoids versus non-steroidal glucocorticoid receptor modulators: survival of the fittest regulator of the immune system? Brain Behav Immun 2010; 24:1035-42. [PMID: 20600811 DOI: 10.1016/j.bbi.2010.06.010] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2010] [Revised: 06/07/2010] [Accepted: 06/17/2010] [Indexed: 12/31/2022] Open
Abstract
The search for novel glucocorticoid receptor (GR) modulators with similar anti-inflammatory properties as conventional steroids, but with a reduction in the number or severity of the side effects has been a long-standing goal, and still remains a challenge today. The quest for these so-called 'dissociated GR ligands' is mainly based on the hypothesis that the occurrence of undesirable side effects is mostly associated with GR-mediated transactivation, whereas transrepression of many pro-inflammatory genes (e.g. cytokines and enzymes involved in inflammatory processes) is more involved in GR-mediated anti-inflammatory effects. As glucocorticoids (GCs) can also enhance the transcription of anti-inflammatory genes, the GR-mediated activation-repression dissociation hypothesis has to be nuanced. However, an enhanced selectivity of GR-affected genes, while upholding the desired anti-inflammatory potential, is still believed to contribute to a more beneficial therapeutic profile with fewer side effects. The initial pharmacological focus on steroidal scaffolds as a basis to dissociate the functionalities of GR has, due to a lack of success, recently been shifted to a focus on non-steroidal ligands. The current work reviews recent advances on the characterization of a generation of novel non-steroidal GR ligands.
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Affiliation(s)
- Karolien De Bosscher
- Laboratory of Eukaryotic Gene Expression & Signal Transduction, Department of Physiology, Ghent University, K.L. Ledeganckstraat 35, Gent, Belgium.
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98
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Marwick JA, Adcock IM, Chung KF. Overcoming reduced glucocorticoid sensitivity in airway disease: molecular mechanisms and therapeutic approaches. Drugs 2010; 70:929-48. [PMID: 20481652 DOI: 10.2165/10898520-000000000-00000] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
There is a considerable and growing unmet medical need in respiratory disease concerning effective anti-inflammatory therapies for conditions such as severe asthma, chronic obstructive pulmonary disease and cystic fibrosis. These diseases share a predominant characteristic of an enhanced and uncontrolled inflammatory response in the lungs, which contributes to disease progression, hospitalization and mortality. These diseases are poorly controlled by current anti-inflammatory therapies including glucocorticoids, which are otherwise effective in many other inflammatory conditions or in milder disease such as asthma. The exact cause of this apparent impairment of glucocorticoid function remains largely unclear; however, recent studies have now implicated a number of possible mechanisms. Central among these is an elevation of the oxidant burden in the lungs and the resulting reduction in the activity of histone deacetylase (HDAC)-2. This contributes to both the enhancement of proinflammatory mediator expression and the impaired ability of the glucocorticoid receptor (GR)-alpha to repress proinflammatory gene expression. The oxidant-mediated reduction in HDAC-2 activity is, in part, a result of an elevation in the phosphoinositol 3-kinase (PI3K) delta/Akt signalling pathway. Blockade of the PI3Kdelta pathway restores glucocortiocoid function in both in vitro and in vivo models, and in primary cells from disease. In addition, inhibition of the PI3Kdelta and PI3Kgamma isoforms is anti-inflammatory in both innate and adaptive immune responses. Consequently, selective inhibition of this pathway may provide a therapeutic strategy both as a novel anti-inflammatory and in combination therapy with glucocorticoids to restore their function. However, a number of other oxidant-related and -unrelated mechanisms, including altered kinase signalling and expression of the dominant negative GRbeta, may also play a role in the development of glucocorticoid insensitivity. Further elucidation of these mechanisms and pathways will enable novel therapeutic targeting for alternative anti-inflammatory drugs or combination therapies providing restoration for the anti-inflammatory action of glucocorticoids.
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Affiliation(s)
- John A Marwick
- MRC Centre for Inflammation Research, Queens Medical Research Institute, University of Edinburgh Medical School, Edinburgh, UK.
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99
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Hinds TD, Ramakrishnan S, Cash HA, Stechschulte LA, Heinrich G, Najjar SM, Sanchez ER. Discovery of glucocorticoid receptor-beta in mice with a role in metabolism. Mol Endocrinol 2010; 24:1715-27. [PMID: 20660300 DOI: 10.1210/me.2009-0411] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Glucocorticoid hormones control diverse physiological processes, including metabolism and immunity, by activating the major glucocorticoid receptor (GR) isoform, GRalpha. However, humans express an alternative isoform, human (h)GRbeta, that acts as an inhibitor of hGRalpha to produce a state of glucocorticoid resistance. Indeed, evidence exists that hGRbeta contributes to many diseases and resistance to glucocorticoid hormone therapy. However, rigorous testing of the GRbeta contribution has not been possible, because rodents, especially mice, are not thought to express the beta-isoform. Here, we report expression of GRbeta mRNA and protein in the mouse. The mGRbeta isoform arises from a distinct alternative splicing mechanism utilizing intron 8, rather than exon 9 as in humans. The splicing event produces a form of beta that is similar in structure and functionality to hGRbeta. Mouse (m)GRbeta has a degenerate C-terminal region that is the same size as hGRbeta. Using a variety of newly developed tools, such as a mGRbeta-specific antibody and constructs for overexpression and short hairpin RNA knockdown, we demonstrate that mGRbeta cannot bind dexamethasone agonist, is inhibitory of mGRalpha, and is up-regulated by inflammatory signals. These properties are the same as reported for hGRbeta. Additionally, novel data is presented that mGRbeta is involved in metabolism. When murine tissue culture cells are treated with insulin, no effect on mGRalpha expression was observed, but GRbeta was elevated. In mice subjected to fasting-refeeding, a large increase of GRbeta was seen in the liver, whereas mGRalpha was unchanged. This work uncovers the much-needed rodent model of GRbeta for investigations of physiology and disease.
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Affiliation(s)
- Terry D Hinds
- Department of Physiology and Pharmacology, University of Toledo College of Medicine, 3035 Arlington Avenue, Toledo, OH 43614-5804, USA
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100
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Mechanisms and resistance in glucocorticoid control of inflammation. J Steroid Biochem Mol Biol 2010; 120:76-85. [PMID: 20188830 DOI: 10.1016/j.jsbmb.2010.02.018] [Citation(s) in RCA: 207] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Revised: 02/15/2010] [Accepted: 02/16/2010] [Indexed: 12/13/2022]
Abstract
Glucocorticoids are the most effective anti-inflammatory therapy for many chronic inflammatory and immune diseases, such as asthma, but are relatively ineffective in other diseases such as chronic obstructive pulmonary disease (COPD). Glucocorticoids suppress inflammation by several mechanisms. Glucocorticoids suppress the multiple inflammatory genes that are activated in chronic inflammatory diseases, such as asthma, by reversing histone acetylation of activated inflammatory genes through binding of liganded glucocorticoid receptors (GR) to coactivator molecules and recruitment of histone deacetylase-2 (HDAC2) to the activated transcription complex. At higher concentrations of glucocorticoids GR homodimers interact with DNA recognition sites to activate transcription through increased histone acetylation of anti-inflammatory genes and transcription of several genes linked to glucocorticoid side effects. Decreased glucocorticoid responsiveness is found in patients with severe asthma and asthmatics who smoke, as well as in all patients with COPD and cystic fibrosis. Several molecular mechanisms of glucocorticoid resistance have now been identified. HDAC2 is markedly reduced in activity and expression as a result of oxidative/nitrative stress so that inflammation becomes resistant to the anti-inflammatory actions of glucocorticoids. Dissociated glucocorticoids have been developed to reduce side effects but so far it has been difficult to dissociate anti-inflammatory effects from adverse effects. In patients with glucocorticoid resistance alternative anti-inflammatory treatments are being investigated as well as drugs that may reverse the molecular mechanism of glucocorticoid resistance.
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