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Anderson MJ, Ibrahim AS, Cooper BR, Woolcock AD, Moore GE, Taylor SD. Effects of administration of ascorbic acid and low-dose hydrocortisone after infusion of sublethal doses of lipopolysaccharide to horses. J Vet Intern Med 2020; 34:2710-2718. [PMID: 33026127 PMCID: PMC7694830 DOI: 10.1111/jvim.15896] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 08/17/2020] [Accepted: 08/19/2020] [Indexed: 01/07/2023] Open
Abstract
Background Sepsis is associated with ascorbic acid (AA) depletion and critical illness‐related corticosteroid insufficiency (CIRCI) in humans. Hypotheses Intravenous infusion of lipopolysaccharide (LPS) would (a) decrease endogneous AA concentrations, (b) induce CIRCI and (c) administration of a combination of AA and hydrocortisone (HC) would have decreased indices of inflammation compared to either drug alone. Animals Thirty‐two healthy horses. Methods Randomized placebo‐controlled experimental trial. Horses were assigned to 1 of 4 groups (saline, AA and HC, AA only, or HC only). Treatments were administered 1 hour after completion of LPS infusion. Clinical signs, clinicopathological variables, pro‐inflammatory cytokine gene expression and production, and plasma AA concentrations were assessed at various time points. Serum cortisol concentrations and ACTH stimulation tests were used to detect CIRCI. Results There was no effect of drug on clinical signs or pro‐inflammatory cytokine gene expression or production compared to controls at any time point. Administration of AA was associated with higher blood neutrophil counts 6 hours after LPS infusion (11.01 ± 1.02 K/μl) compared to other groups (8.99 ± 0.94 K/μL; P < .009). Adminstration of HC was associated with higher blood neutrophil counts 12 hours after LPS infusion (10.40 ± 0.75 K/μl) compared to other groups (6.88 ± 0.68 K/μl; P < .001). Serum cortisol increased from 5.11 ± 1.48 μg/dL before LPS administration to 9.59 ± 1.83 μg/dL 1 h after completion of LPS infusion (T1) without an effect of treatment (P = 0.59). Conclusions and Clinical Importance Ascorbic acid and HC appeared to protect against LPS‐induced neutrophil depletion and could be considered as adjunctive therapy in horses with endotoxemia.
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Affiliation(s)
- Melinda J Anderson
- Department of Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, Indiana, USA
| | - Alina S Ibrahim
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, Indiana, USA
| | - Bruce R Cooper
- Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, USA
| | - Andrew D Woolcock
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, Indiana, USA
| | - George E Moore
- Department of Veterinary Administration, College of Veterinary Medicine, Purdue University, West Lafayette, Indiana, USA
| | - Sandra D Taylor
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, Indiana, USA
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Vandewalle J, Libert C. Glucocorticoids in Sepsis: To Be or Not to Be. Front Immunol 2020; 11:1318. [PMID: 32849493 PMCID: PMC7396579 DOI: 10.3389/fimmu.2020.01318] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 05/26/2020] [Indexed: 12/12/2022] Open
Abstract
Sepsis is a highly lethal syndrome resulting from dysregulated immune and metabolic responses to infection, thereby compromising host homeostasis. Activation of the hypothalamic–pituitary–adrenal (HPA) axis and subsequently adrenocortical glucocorticoid (GC) production during sepsis are important regulatory processes to maintain homeostasis. Multiple preclinical studies have proven the pivotal role of endogenous GCs in tolerance against sepsis by counteracting several of the sepsis characteristics, such as excessive inflammation, vascular defects, and hypoglycemia. Sepsis is however often complicated by dysfunction of the HPA axis, resulting from critical-illness-related corticosteroid insufficiency (CIRCI) and GC resistance. Therefore, GCs have been tested as an adjunctive therapy in sepsis and septic shock in different randomized clinical trials (RCTs). Nonetheless, these studies produced conflicting results. Interestingly, adding vitamin C and thiamin to GC therapy enhances the effects of GCs, probably by reducing GC resistance, and this results in an impressive reduction in sepsis mortality as was shown in two recent preliminary retrospective before–after studies. Multiple RCTs are currently underway to validate this new combination therapy in sepsis.
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Affiliation(s)
- Jolien Vandewalle
- Center for Inflammation Research, VIB, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Claude Libert
- Center for Inflammation Research, VIB, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
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3
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The role of glucocorticoids as adjunctive treatment for sepsis in the modern era. THE LANCET RESPIRATORY MEDICINE 2018; 6:793-800. [PMID: 30006071 DOI: 10.1016/s2213-2600(18)30265-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Revised: 06/06/2018] [Accepted: 06/13/2018] [Indexed: 12/12/2022]
Abstract
Glucocorticoids have been used as adjunctive therapy in patients with sepsis and septic shock for more than four decades. The rationale for the use of glucocorticoids is that this class of drugs downregulates the proinflammatory response and limits the anti-inflammatory response while preserving innate immunity. Between 1976 and 2017, 22 randomised placebo-controlled trials have been published evaluating the benefit of glucocorticoids in patients with community-acquired pneumonia, sepsis, and septic shock. These studies produced conflicting results. In 2018, two large randomised controlled trials (RCTs) were published evaluating the role of hydrocortisone in patients with septic shock. The Activated Protein C and Corticosteroids for Human Septic Shock (APROCCHSS) trial reported a reduction in 90-day mortality whereas the Adjunctive Corticosteroid Treatment in Critically Ill Patients with Septic Shock (ADRENAL) trial reported no mortality benefit. This Viewpoint critically appraises these two RCTs and evaluates the use of glucocorticoids in the treatment of sepsis and septic shock in the modern era.
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Marik PE, Khangoora V, Rivera R, Hooper MH, Catravas J. Hydrocortisone, Vitamin C, and Thiamine for the Treatment of Severe Sepsis and Septic Shock: A Retrospective Before-After Study. Chest 2017; 151:1229-1238. [PMID: 27940189 DOI: 10.1016/j.chest.2016.11.036] [Citation(s) in RCA: 593] [Impact Index Per Article: 84.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 10/31/2016] [Accepted: 11/16/2016] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND The global burden of sepsis is estimated as 15 to 19 million cases annually, with a mortality rate approaching 60% in low-income countries. METHODS In this retrospective before-after clinical study, we compared the outcome and clinical course of consecutive septic patients treated with intravenous vitamin C, hydrocortisone, and thiamine during a 7-month period (treatment group) with a control group treated in our ICU during the preceding 7 months. The primary outcome was hospital survival. A propensity score was generated to adjust the primary outcome. RESULTS There were 47 patients in both treatment and control groups, with no significant differences in baseline characteristics between the two groups. The hospital mortality was 8.5% (4 of 47) in the treatment group compared with 40.4% (19 of 47) in the control group (P < .001). The propensity adjusted odds of mortality in the patients treated with the vitamin C protocol was 0.13 (95% CI, 0.04-0.48; P = .002). The Sepsis-Related Organ Failure Assessment score decreased in all patients in the treatment group, with none developing progressive organ failure. All patients in the treatment group were weaned off vasopressors, a mean of 18.3 ± 9.8 h after starting treatment with the vitamin C protocol. The mean duration of vasopressor use was 54.9 ± 28.4 h in the control group (P < .001). CONCLUSIONS Our results suggest that the early use of intravenous vitamin C, together with corticosteroids and thiamine, are effective in preventing progressive organ dysfunction, including acute kidney injury, and in reducing the mortality of patients with severe sepsis and septic shock. Additional studies are required to confirm these preliminary findings.
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Affiliation(s)
- Paul E Marik
- Division of Pulmonary and Critical Care Medicine, Eastern Virginia Medical School, Norfolk, VA.
| | - Vikramjit Khangoora
- Division of Pulmonary and Critical Care Medicine, Eastern Virginia Medical School, Norfolk, VA
| | - Racquel Rivera
- Department of Pharmacy, Sentara Norfolk General Hospital, Norfolk, VA
| | - Michael H Hooper
- Division of Pulmonary and Critical Care Medicine, Eastern Virginia Medical School, Norfolk, VA
| | - John Catravas
- School of Medical Diagnostic & Translational Sciences, College of Health Sciences, Old Dominion University, Norfolk, VA; Department of Medicine and Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, VA
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5
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Stephenson ST, Brown LAS, Helms MN, Qu H, Brown SD, Brown MR, Fitzpatrick AM. Cysteine oxidation impairs systemic glucocorticoid responsiveness in children with difficult-to-treat asthma. J Allergy Clin Immunol 2015; 136:454-61.e9. [PMID: 25748343 DOI: 10.1016/j.jaci.2015.01.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 01/12/2015] [Accepted: 01/21/2015] [Indexed: 11/17/2022]
Abstract
BACKGROUND The mechanisms underlying glucocorticoid responsiveness are largely unknown. Although redox regulation of the glucocorticoid receptor (GR) has been reported, it has not been studied in asthmatic patients. OBJECTIVE We characterized systemic cysteine oxidation and its association with inflammatory and clinical features in healthy children and children with difficult-to-treat asthma. We hypothesized that cysteine oxidation would be associated with increased markers of oxidative stress and inflammation, increased features of asthma severity, decreased clinically defined glucocorticoid responsiveness, and impaired GR function. METHODS PBMCs were collected from healthy children (n = 16) and children with asthma (n = 118) aged 6 to 17 years. Children with difficult-to-treat asthma underwent glucocorticoid responsiveness testing with intramuscular triamcinolone. Cysteine, cystine, and inflammatory chemokines and reactive oxygen species generation were quantified, and expression and activity of the GR were assessed. RESULTS Cysteine oxidation was present in children with difficult-to-treat asthma and accompanied by increased reactive oxygen species generation and increased CCL3 and CXCL1 mRNA expression. Children with the greatest extent of cysteine oxidation had more features of asthma severity, including poorer symptom control, greater medication use, and less glucocorticoid responsiveness despite inhaled glucocorticoid therapy. Cysteine oxidation also modified the GR protein by decreasing available sulfhydryl groups and decreasing nuclear GR expression and activity. CONCLUSIONS A highly oxidized cysteine redox state promotes a posttranslational modification of the GR that might inhibit its function. Given that cysteine oxidation is prevalent in children with difficult-to-treat asthma, the cysteine redox state might represent a potential therapeutic target for restoration of glucocorticoid responsiveness in this population.
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Affiliation(s)
| | - Lou Ann S Brown
- Emory University Department of Pediatrics, Atlanta, Ga; Children's Healthcare of Atlanta Center for Cystic Fibrosis and Airways Disease Research, Atlanta, Ga
| | - My N Helms
- Emory University Department of Pediatrics, Atlanta, Ga; Children's Healthcare of Atlanta Center for Cystic Fibrosis and Airways Disease Research, Atlanta, Ga
| | - Hongyan Qu
- Emory University Department of Pediatrics, Atlanta, Ga
| | | | - Milton R Brown
- Emory University Department of Pediatrics, Atlanta, Ga; Children's Healthcare of Atlanta Center for Cystic Fibrosis and Airways Disease Research, Atlanta, Ga
| | - Anne M Fitzpatrick
- Emory University Department of Pediatrics, Atlanta, Ga; Children's Healthcare of Atlanta Center for Cystic Fibrosis and Airways Disease Research, Atlanta, Ga.
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6
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Carter EL, Ragsdale SW. Modulation of nuclear receptor function by cellular redox poise. J Inorg Biochem 2014; 133:92-103. [PMID: 24495544 DOI: 10.1016/j.jinorgbio.2014.01.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 12/28/2013] [Accepted: 01/09/2014] [Indexed: 02/09/2023]
Abstract
Nuclear receptors (NRs) are ligand-responsive transcription factors involved in diverse cellular processes ranging from metabolism to circadian rhythms. This review focuses on NRs that contain redox-active thiol groups, a common feature within the superfamily. We will begin by describing NRs, how they regulate various cellular processes and how binding ligands, corepressors and/or coactivators modulate their activity. We will then describe the general area of redox regulation, especially as it pertains to thiol-disulfide interconversion and the cellular systems that respond to and govern this redox equilibrium. Lastly, we will discuss specific examples of NRs whose activities are regulated by redox-active thiols. Glucocorticoid, estrogen, and the heme-responsive receptor, Rev-erb, will be described in the most detail as they exhibit archetypal redox regulatory mechanisms.
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Affiliation(s)
- Eric L Carter
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Stephen W Ragsdale
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.
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7
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Rodiño-Janeiro BK, Paradela-Dobarro B, Castiñeiras-Landeira MI, Raposeiras-Roubín S, González-Juanatey JR, Álvarez E. Current status of NADPH oxidase research in cardiovascular pharmacology. Vasc Health Risk Manag 2013; 9:401-28. [PMID: 23983473 PMCID: PMC3750863 DOI: 10.2147/vhrm.s33053] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The implications of reactive oxygen species in cardiovascular disease have been known for some decades. Rationally, therapeutic antioxidant strategies combating oxidative stress have been developed, but the results of clinical trials have not been as good as expected. Therefore, to move forward in the design of new therapeutic strategies for cardiovascular disease based on prevention of production of reactive oxygen species, steps must be taken on two fronts, ie, comprehension of reduction-oxidation signaling pathways and the pathophysiologic roles of reactive oxygen species, and development of new, less toxic, and more selective nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitors, to clarify both the role of each NADPH oxidase isoform and their utility in clinical practice. In this review, we analyze the value of NADPH oxidase as a therapeutic target for cardiovascular disease and the old and new pharmacologic agents or strategies to prevent NADPH oxidase activity. Some inhibitors and different direct or indirect approaches are available. Regarding direct NADPH oxidase inhibition, the specificity of NADPH oxidase is the focus of current investigations, whereas the chemical structure-activity relationship studies of known inhibitors have provided pharmacophore models with which to search for new molecules. From a general point of view, small-molecule inhibitors are preferred because of their hydrosolubility and oral bioavailability. However, other possibilities are not closed, with peptide inhibitors or monoclonal antibodies against NADPH oxidase isoforms continuing to be under investigation as well as the ongoing search for naturally occurring compounds. Likewise, some different approaches include inhibition of assembly of the NADPH oxidase complex, subcellular translocation, post-transductional modifications, calcium entry/release, electron transfer, and genetic expression. High-throughput screens for any of these activities could provide new inhibitors. All this knowledge and the research presently underway will likely result in development of new drugs for inhibition of NADPH oxidase and application of therapeutic approaches based on their action, for the treatment of cardiovascular disease in the next few years.
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Affiliation(s)
- Bruno K Rodiño-Janeiro
- Health Research Institute of Santiago de Compostela, Santiago de Compostela,
Spain
- European Molecular Biology Laboratory, Grenoble, France
| | | | | | - Sergio Raposeiras-Roubín
- Health Research Institute of Santiago de Compostela, Santiago de Compostela,
Spain
- Cardiology Department, University Clinic Hospital of Santiago de Compostela,
Santiago de Compostela, Spain
| | - José R González-Juanatey
- Health Research Institute of Santiago de Compostela, Santiago de Compostela,
Spain
- Cardiology Department, University Clinic Hospital of Santiago de Compostela,
Santiago de Compostela, Spain
- Medicine Department, University of Santiago de Compostela, Santiago de Compostela,
Spain
| | - Ezequiel Álvarez
- Health Research Institute of Santiago de Compostela, Santiago de Compostela,
Spain
- Medicine Department, University of Santiago de Compostela, Santiago de Compostela,
Spain
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8
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Targeting microglia-mediated neurotoxicity: the potential of NOX2 inhibitors. Cell Mol Life Sci 2012; 69:2409-27. [PMID: 22581365 DOI: 10.1007/s00018-012-1015-4] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Revised: 04/18/2012] [Accepted: 04/20/2012] [Indexed: 12/24/2022]
Abstract
Microglia are key sentinels of central nervous system health, and their dysfunction has been widely implicated in the progressive nature of neurodegenerative diseases. While microglia can produce a host of factors that are toxic to neighboring neurons, NOX2 has been implicated as a common and essential mechanism of microglia-mediated neurotoxicity. Accumulating evidence indicates that activation of the NOX2 enzyme complex in microglia is neurotoxic, both through the production of extracellular reactive oxygen species that damage neighboring neurons as well as the initiation of redox signaling in microglia that amplifies the pro-inflammatory response. More specifically, evidence supports that NOX2 redox signaling enhances microglial sensitivity to pro-inflammatory stimuli, and amplifies the production of neurotoxic cytokines, to promote chronic and neurotoxic microglial activation. Here, we describe the evidence denoting the role of NOX2 in microglia-mediated neurotoxicity with an emphasis on Alzheimer's and Parkinson's disease, describe available inhibitors that have been tested, and detail evidence of the neuroprotective and therapeutic potential of targeting this enzyme complex to regulate microglia.
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9
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Van Bogaert T, De Bosscher K, Libert C. Crosstalk between TNF and glucocorticoid receptor signaling pathways. Cytokine Growth Factor Rev 2010; 21:275-86. [PMID: 20456998 DOI: 10.1016/j.cytogfr.2010.04.003] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
TNF is a Janus-faced protein. It possesses impressive anti-tumor activities, but it is also one of the strongest known pro-inflammatory cytokines, which hampers its use as a systemic anti-cancer agent. TNF has been shown to play a detrimental role in inflammatory diseases such as rheumatoid arthritis and inflammatory bowel disease. Glucocorticoids are strongly anti-inflammatory and exert their therapeutic effects through binding to their receptor, the glucocorticoid receptor. Therefore, glucocorticoids have been used for over half a century for the treatment of inflammatory diseases. However, many patients are or become resistant to the therapeutic effects of glucocorticoids. Inflammatory cytokines have been suggested to play an important role in this steroid insensitivity or glucocorticoid resistance. This review aims to highlight the mechanisms of mutual inhibition between TNF and GR signaling pathways.
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Affiliation(s)
- Tom Van Bogaert
- Department of Biomedical Molecular Biology, Ghent University, Belgium
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10
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Abstract
Reactive oxygen species (ROS) are generated in response to growth factors, cytokines, G protein-coupled receptor agonists, or shear stress, and function as signaling molecules in nonphagocytes. However, it is poorly understood how freely diffusible ROS can activate specific signaling, so-called "redox signaling." NADPH oxidases are a major source of ROS and now recognized to have specific subcellular localizations, and this targeting to specific compartments is required for localized ROS production. One important mechanism may involve the interaction of oxidase subunits with various targeting proteins localized in lamellipodial leading edge and focal adhesions/complexes. ROS are believed to inactivate protein tyrosine phosphatases, thereby establishing a positive-feedback system that promotes activation of specific redox signaling pathways involved in various functions. Additionally, ROS production may be localized through interactions of NADPH oxidase with signaling platforms associated with caveolae/lipid rafts, endosomes, and nucleus. These indicate that the specificity of ROS-mediated signal transduction may be modulated by the localization of Nox isoforms and their regulatory subunits within specific subcellular compartments. This review summarizes the recent progress on compartmentalization of redox signaling via activation of NADPH oxidase, which is implicated in cell biology and pathophysiologies.
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Affiliation(s)
- Masuko Ushio-Fukai
- Department of Pharmacology, Center for Lung and Vascular Biology, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, Illinois 60612, USA.
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11
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Rolland A, Boquet I, Norreel JC, Moret V, Laras Y, Kraus JL. Discovery of new small molecules that influence neuroblast cell migration from the subventricular zone. Bioorg Med Chem Lett 2008; 18:169-74. [PMID: 18024032 DOI: 10.1016/j.bmcl.2007.10.112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2007] [Revised: 10/29/2007] [Accepted: 10/30/2007] [Indexed: 10/22/2022]
Abstract
Using SVZ (subventricular zone) tissue explants from one-day-old mice, we investigated the activity of new amino aromatic disulfide analogues and polyazamacrocycles on the migration of SVZ cells (neuroblasts). We found that among the tested analogues, non-peptidic disulfide derivative 8 significantly decreases the migration of neuroblasts from SVZ cells, and antagonized the stimulating activity of disulfide cyclic peptide 1. Discovery of compounds 1 and 8 constitutes new chemical tools which could be used to understand the mechanism of neuroblast migration during neurogenesis and eventually to identify specific genes involved in the neurogenesis.
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Affiliation(s)
- Amandine Rolland
- Laboratoire de Chimie Biomoléculaire, UMR-CNRS 6216, IBDML, Université de la Méditerranée, Parc Scientifique de Luminy, case 901, 13288 Marseille cedex 9, France
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12
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Hansen JM, Go YM, Jones DP. Nuclear and mitochondrial compartmentation of oxidative stress and redox signaling. Annu Rev Pharmacol Toxicol 2006; 46:215-34. [PMID: 16402904 DOI: 10.1146/annurev.pharmtox.46.120604.141122] [Citation(s) in RCA: 299] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
New methods to measure thiol oxidation show that redox compartmentation functions as a mechanism for specificity in redox signaling and oxidative stress. Redox Western analysis and redox-sensitive green fluorescent proteins provide means to quantify thiol/disulfide redox changes in specific subcellular compartments. Analyses using these techniques show that the relative redox states from most reducing to most oxidizing are mitochondria > nuclei > cytoplasm > endoplasmic reticulum > extracellular space. Mitochondrial thiols are an important target of oxidant-induced apoptosis and necrosis and are especially vulnerable to oxidation because of the relatively alkaline pH. Maintenance of a relatively reduced nuclear redox state is critical for transcription factor binding in transcriptional activation in response to oxidative stress. The new methods are applicable to a broad range of experimental systems and their use will provide improved understanding of the pharmacologic and toxicologic actions of drugs and toxicants.
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Affiliation(s)
- Jason M Hansen
- Department of Medicine and Clinical Biomarkers Laboratory, Division of Pulmonary Medicine, Emory University, Atlanta, GA 30322, USA.
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13
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Tanaka H, Makino Y, Okamoto K. Thioredoxin in the endocrine response to stress. VITAMINS AND HORMONES 1999; 57:153-75. [PMID: 10232049 DOI: 10.1016/s0083-6729(08)60643-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Adaptation to stress evokes a variety of biological responses, including activation of the hypothalamic--pituitary--adrenal (HPA) axis and synthesis of a panel of stress-response proteins at cellular levels: for example, expression of thioredoxin (TRX) is significantly induced under oxidative conditions. Glucocorticoids, as a peripheral effector of the HPA axis, exert their action via interaction with a ligand-inducible transcription factor glucocorticoid receptor (GR). However, how these stress responses coordinately regulate cellular metabolism is still unknown. We demonstrate that either antisense TRX expression or cellular treatment with H2O2 negatively modulates GR function and decreases glucocorticoid-inducible gene expression. Impaired cellular response to glucocorticoids is rescued by overexpression of TRX, most probably through the functional replenishment of the GR. Moreover, not only the ligand binding domain but the DNA binding domain of the GR is also suggested to be a direct target of TRX. Together, we propose that cellular glucocorticoid responsiveness is coordinately modulated by redox state and TRX level, suggesting that cross-talk between neuro-endocrine control of stress responses and cellular antioxidant systems may be essential for mammalian adaptation processes.
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Affiliation(s)
- H Tanaka
- Second Department of Internal Medicine, Asahikawa Medical College, Japan
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14
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Okamoto K, Tanaka H, Ogawa H, Makino Y, Eguchi H, Hayashi S, Yoshikawa N, Poellinger L, Umesono K, Makino I. Redox-dependent regulation of nuclear import of the glucocorticoid receptor. J Biol Chem 1999; 274:10363-71. [PMID: 10187825 DOI: 10.1074/jbc.274.15.10363] [Citation(s) in RCA: 138] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
A number of transcription factors including the glucocorticoid receptor (GR) are regulated in a redox-dependent fashion. We have previously reported that the functional activity of the GR is suppressed under oxidative conditions and restored in the presence of reducing reagents. In the present study, we have used a chimeric human GR fused to the Aequorea green fluorescent protein and demonstrated that both ligand-dependent and -independent nuclear translocation of the GR is impaired under oxidative conditions in living cells. Substitution of Cys-481 for Ser within NL1 of the human GR resulted in reduction of sensitivity to oxidative treatment, strongly indicating that Cys-481 is one of the target amino acids for redox regulation of the receptor. Taken together, we may conclude that redox-dependent regulation of nuclear translocation of the GR constitutes an important mechanism for modulation of glucocorticoid-dependent signal transduction.
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Affiliation(s)
- K Okamoto
- Second Department of Internal Medicine, Asahikawa Medical College, Nishikagura, Asahikawa 078-8510, Japan
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15
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Makino Y, Yoshikawa N, Okamoto K, Hirota K, Yodoi J, Makino I, Tanaka H. Direct association with thioredoxin allows redox regulation of glucocorticoid receptor function. J Biol Chem 1999; 274:3182-8. [PMID: 9915858 DOI: 10.1074/jbc.274.5.3182] [Citation(s) in RCA: 157] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The glucocorticoid receptor (GR) is considered to belong to a class of transcription factors, the functions of which are exposed to redox regulation. We have recently demonstrated that thioredoxin (TRX), a cellular reducing catalyst, plays an important role in restoration of GR function in vivo under oxidative conditions. Although both the ligand binding domain and other domains of the GR have been suggested to be modulated by TRX, the molecular mechanism of the interaction is largely unknown. In the present study, we hypothesized that the DNA binding domain (DBD) of the GR, which is highly conserved among the nuclear receptors, is also responsible for communication with TRX in vivo. Mammalian two-hybrid assay and glutathione S-transferase pull-down assay revealed the direct association between TRX and the GR DBD. Moreover, analysis of subcellular localization of TRX and the chimeric protein harboring herpes simplex viral protein 16 transactivation domain and the GR DBD indicated that the interaction might take place in the nucleus under oxidative conditions. Together these observations indicate that TRX, via a direct association with the conserved DBD motif, may represent a key mediator operating in interplay between cellular redox signaling and nuclear receptor-mediated signal transduction.
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Affiliation(s)
- Y Makino
- Second Department of Internal Medicine, Asahikawa Medical College, 4-5-3 Nishikagura, Asahikawa 078-8510, Japan
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16
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Tanaka H, Makino Y, Okamoto K, Iida T, Yan K, Yoshikawa N. Redox regulation of the glucocorticoid receptor. Antioxid Redox Signal 1999; 1:403-23. [PMID: 11233142 DOI: 10.1089/ars.1999.1.4-403] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Redox regulation is currently considered as a mode of signal transduction for coordinated regulation of a variety of cellular processes. The transcriptional regulation of gene expression is also influenced by cellular redox state, most possibly through the oxido-reductive modification of transcription factors. The glucocorticoid receptor belongs to a nuclear receptor superfamily and acts as a ligand-dependent transcription factor. We demonstrate that the glucocorticoid receptor function is regulated via redox-dependent mechanisms at multiple levels. Moreover, it is suggested that redox regulation of the receptor function is one of dynamic cellular responses to environmental stimuli and plays an important role in orchestrated crosstalk between central and peripheral stress responses.
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Affiliation(s)
- H Tanaka
- Department of Clinical Immunology and AIDS Research Center, Institute of Medical Science, University of Tokyo, Japan.
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Okamoto K, Tanaka H, Makino Y, Makino I. Restoration of the glucocorticoid receptor function by the phosphodiester compound of vitamins C and E, EPC-K1 (L-ascorbic acid 2-[3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-2H-1-benzopyran-6-yl hydrogen phosphate] potassium salt), via a redox-dependent mechanism. Biochem Pharmacol 1998; 56:79-86. [PMID: 9698091 DOI: 10.1016/s0006-2952(98)00121-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We examined the effect of the novel antioxidant EPC-K1 (L-ascorbic acid 2-[3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-2H -1-benzopyran-6-yl hydrogen phosphate] potassium salt) on glucocorticoid receptor function. We used cloned CHOpMTGR cells in which human glucocorticoid receptor cDNA was stably transfected and the glucocorticoid receptor was expressed at high levels. We recently suggested that glucocorticoid-mediated gene expression is modulated via the cellular redox state [Makino et al., J Clin Invest 98: 2469-2477, 1996]. In the present study, this issue was clearly evidenced by the finding that cellular treatment with H2O2 decreased the ligand binding and transcriptional activity of the glucocorticoid receptor, and we showed that these inhibitory effects of H2O2 were effectively titrated by the addition of EPC-K1. Moreover, DNA-binding activity of the bacterially expressed DNA-binding domain of the glucocorticoid receptor was repressed by the thiol-oxidizing reagent diamide; EPC-K1 also counteracted this repressive effect of diamide. Thus, the redox state was indicated to influence glucocorticoid receptor function at various steps, and EPC-K1 may be useful in restoring the cellular glucocorticoid-responsiveness in oxidative conditions.
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Affiliation(s)
- K Okamoto
- Second Department of Internal Medicine, Asahikawa Medical College, Nishikagura, Japan
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18
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Del Monaco M, Covello SP, Kennedy SH, Gilinger G, Litwack G, Uitto J. Identification of novel glucocorticoid-response elements in human elastin promoter and demonstration of nucleotide sequence specificity of the receptor binding. J Invest Dermatol 1997; 108:938-42. [PMID: 9182826 DOI: 10.1111/1523-1747.ep12295241] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Glucocorticoids exert their action on gene expression through activation of cytoplasmic glucocorticoid receptors (GRs) that bind to glucocorticoid response elements (GREs). The consensus GRE consists of two half sites (underlined), AGAACANNNTGTTCT. We have recently cloned the entire human elastin gene. Nucleotide sequencing of the promoter region disclosed the presence of three putative GREs with the downstream half-site sequence TGTTCC that has homology with the consensus GRE, although the upstream half site showed no homology. To examine the functionality of these putative GREs in binding to the GRs, we performed gel mobility shift and supershift assays with synthetic oligomers containing the putative GREs and a recombinant GR protein, expressed in a baculovirus system. All three GREs identified in the elastin promoter bound the receptor. A chimeric oligonucleotide containing the upstream consensus GRE half site and the downstream elastin promoter GRE half site was capable of binding the receptor, and this binding could be competed with the elastin promoter GRE. Nonconservative substitution of single nucleotides (positions 1-6) in the elastin GRE indicated that mutations in the positions 1-3 and 6 had relatively little effect, but substitutions in positions 4 and 5 rendered the oligomer less effective in competing for the binding. These observations suggest that the downstream half site of GREs in the human elastin promoter is sufficient for receptor binding and certain nucleotides are critical for the efficient binding. The results also imply that the three GREs within the human elastin promoter are active and mediate the glucocorticoid-induced up-regulation of human elastin promoter activity.
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Affiliation(s)
- M Del Monaco
- Department of Dermatology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
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19
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Makino Y, Okamoto K, Yoshikawa N, Aoshima M, Hirota K, Yodoi J, Umesono K, Makino I, Tanaka H. Thioredoxin: a redox-regulating cellular cofactor for glucocorticoid hormone action. Cross talk between endocrine control of stress response and cellular antioxidant defense system. J Clin Invest 1996; 98:2469-77. [PMID: 8958209 PMCID: PMC507704 DOI: 10.1172/jci119065] [Citation(s) in RCA: 137] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Adaptation to stress evokes a variety of biological responses, including activation of the hypothalamic-pituitary-adrenal (HPA) axis and synthesis of a panel of stress-response proteins at cellular levels: for example, expression of thioredoxin (TRX) is significantly induced under oxidative conditions. Glucocorticoids, as a peripheral effector of the HPA axis, exert their actions via interaction with a ligand-inducible transcription factor glucocorticoid receptor (GR). However, how these stress responses coordinately regulate cellular metabolism is still unknown. In this study, we demonstrated that either antisense TRX expression or cellular treatment with H2O2 negatively modulates GR function and decreases glucocorticoid-inducible gene expression. Impaired cellular response to glucocorticoids is rescued by overexpression of TRX, most possibly through the functional replenishment of the GR. Moreover, not only the ligand binding domain but the DNA binding domain of the GR is also suggested to be a direct target of TRX. Together, we here present evidence showing that cellular glucocorticoid responsiveness is coordinately modulated by redox state and TRX level and propose that cross talk between neuroendocrine control of stress responses and cellular antioxidant systems may be essential for mammalian adaptation processes.
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Affiliation(s)
- Y Makino
- Second Department of Internal Medicine, Asahikawa Medical College, Japan
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20
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Affiliation(s)
- S S Simons
- Steroid Hormones Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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21
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Absence of intramolecular disulfides in the structure and function of native rat glucocorticoid receptors. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)42378-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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22
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Karle JM, Olmeda R, Park AS. Aminosulfhydryl and aminodisulfide compounds enhance binding of the glucocorticoid receptor complex to deoxyribonucleic acid-coated cellulose and to chromatin. J Steroid Biochem Mol Biol 1993; 46:289-97. [PMID: 9831477 DOI: 10.1016/0960-0760(93)90218-l] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In the presence of amine-containing sulfhydryl compounds, binding of heat-transformed cytosolic rat liver glucocorticoid receptor complex (GRC) to double-stranded calf thymus DNA-coated cellulose and to rat liver chromatin was enhanced up to 10-fold. These observations were made under conditions when a maximum of 8% of the total GRC bound to DNA in the absence of test compound. Compounds which did not contain both a sulfhydryl and amine group were inactive. Phosphorothioate derivatives of the active sulfhydryl compounds were also inactive. However, pretreatment of the phosphorothioate compounds with alkaline phosphatase restored activity. Upon centrifugation at 8800g, amine-containing disulfide compounds at millimolar concentrations caused considerable sedimentation of the GRC in the absence of DNA-coated cellulose or chromatin and no apparent increase in GRC binding to DNA or chromatin. Amine-containing disulfide compounds at micromolar concentrations did not cause heavy sedimentation of the GRC and enhanced binding of the GRC to DNA-coated cellulose up to 9.5-fold. Thus, diaminosulfhydryl compounds and the disulfide 1,18-diamino-6,13-diaza-9,10-dithiaoctadecane (WR 149,024) possess both the ability to restore and preserve the steroid binding capacity of the glucocorticoid receptor and to enhance binding of the GRC to DNA and chromatin.
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Affiliation(s)
- J M Karle
- Department of Pharmacology, Division of Experimental Therapeutics, Walter Reed Army Institute of Research, Washington, DC 20307-5100, USA
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23
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Wynn R, Richards FM. Unnatural amino acid packing mutants of Escherichia coli thioredoxin produced by combined mutagenesis/chemical modification techniques. Protein Sci 1993; 2:395-403. [PMID: 8453377 PMCID: PMC2142390 DOI: 10.1002/pro.5560020311] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
We have produced several mutants of Escherichia coli thioredoxin (Trx) using a combined mutagenesis/chemical modification technique. The protein C32S, C35S, L78C Trx was produced using standard mutagenesis procedures. After unfolding the protein with guanidine hydrochloride (GdmCl), the normally buried cysteine residue was modified with a series of straight chain aliphatic thiosulfonates, which produced cysteine disulfides to methane, ethane, 1-n-propane, 1-n-butane, and 1-n-pentane thiols. These mutants all show native-like CD spectra and the ability to activate T7 gene 5 protein DNA polymerase activity. In addition, all mutants show normal unfolding transitions in GdmCl solutions. However, the midpoint of the transition, [GdmCl]1/2, and the free energy of unfolding at zero denaturant concentration, delta G(H2O), give inverse orders of stability. This effect is due to changes in m, the dependence of delta G0 unfolding on the GdmCl concentration. The method described here may be used to produce unnatural amino acids in the hydrophobic cores of proteins.
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Affiliation(s)
- R Wynn
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511
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24
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D'souza A, Hinduja IN, Puri CP. Antiprogestin ZK-98.299 and progesterone display differential binding characteristics in the human myometrial cytosol. BIOCHIMICA ET BIOPHYSICA ACTA 1992; 1175:73-80. [PMID: 1482698 DOI: 10.1016/0167-4889(92)90011-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
To investigate whether the synthetic progesterone antagonist ZK-98.299 binds to progesterone receptor or also has distinct binding sites, the binding characteristics of ZK-98.299 were compared with those of progesterone in the human myometrial cytosol. [3H]ZK-98.299 and [3H]progesterone showed specific binding in the myometrial cytosol and the binding of each radiolabelled ligand could be displaced with the respective ligand in a dose-response manner. However, while the binding of [3H]progesterone could be completely blocked with progesterone or ZK 98.299, the binding of [3H]ZK-98.299 could not be displaced more than 50%. The non-specific binding of [3H]ZK-98.299 was very high as compared to that of [3H]progesterone. Using [3H]progesterone, the relative binding affinity (RBA) of progesterone was more than that of ZK 98.299, whereas using [3H]ZK-98.299 the RBA of ZK 98.299 exceeded that of progesterone. Treatment of myometrial cytosol with increasing concentrations of -SH-modifying agents (iodoacetamide (IA) 0-10 mM or N-ethylmaleimide (NEM) 0-1000 nM) decreased the binding of progesterone by over 80%, whereas similar treatment did not have appreciable effect on the binding of [3H]ZK-98.299. Although both preformed ligand-receptor complexes were relatively stable in the presence of IA and NEM, the [3H]progesterone-receptor complex was more sensitive as compared to the [3H]ZK-98.299-receptor complex. The addition of 20 mM molybdate in the cytosol had a protective effect against the -SH-modifying agents. [3H]ZK-98.299 and [3H]progesterone-receptor complexes also showed differential stability when incubated at elevated temperatures (25 degrees C and 37 degrees C), [3H]ZK-98.299-binding sites being more thermolabile as compared to [3H]progesterone binding sites. Prior occupation of the receptor by the two ligands gave the complexes the ability to resist an elevated temperature of 25 degrees C. Moreover, molybdate stabilized both the liganded and unoccupied receptors at 25 degrees C. When the ligand-receptor complexes were applied onto a prefocused polyacrylamide gel, the progesterone and ZK-98.299-receptor complexes were resolved and focused at pH 7.2 and 8.4, respectively. The results of this study suggest that although progesterone and ZK-98.299 are mutually competitive for binding to progesterone receptor, ZK-98.299 also has distinct binding sites.
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Affiliation(s)
- A D'souza
- Institute for Research in Reproduction (ICMR), Parel, Bombay, India
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25
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Dunderski J, Stanosević J, Ristić B, Trajković D, Matić G. In vivo effects of cadmium on rat liver glucocorticoid receptor functional properties. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1992; 24:1065-72. [PMID: 1397500 DOI: 10.1016/0020-711x(92)90375-b] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
1. Cadmium (Cd2+) administered in vivo induced a 40% reduction of rat liver glucocorticoid receptor (GR) capacity and inhibition of glucocorticoid-receptor complexes binding to mouse mammary tumor virus (MMTV) DNA fragment containing GR consensus sequence. 2. The effect of Cd2+ on the GR binding activity can be reversed with DTT, suggesting Cd2+ interaction with thiol groups. 3. Cd(2+)-related GR modification seems to be mediated by Cd2+ binding to cytoplasmic components included in the regulation of the receptor function, although the direct binding of the metal to the receptor thiols could not be ruled out.
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Affiliation(s)
- J Dunderski
- Department of Ecology, Sinisa Stanković Institute for Biological Research, Belgrade, Yugoslavia
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26
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Vessières A, Top S, Vaillant C, Osella D, Mornon JP, Jaouen G. Carbonylmetallcluster-modifizierte Östradiole als Suizid-Substrate zur Untersuchung von Rezeptorproteinen: Anwendung beim Östradiol-Rezeptor. Angew Chem Int Ed Engl 1992. [DOI: 10.1002/ange.19921040633] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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27
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Nath R, Bhakta A, Moudgil VK. ZK98299--a new antiprogesterone: biochemical characterization of steroid binding parameters in the calf uterine cytosol. Arch Biochem Biophys 1992; 292:303-10. [PMID: 1727646 DOI: 10.1016/0003-9861(92)90083-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We have examined steroid binding characteristics of a newly synthesized antisteroid, ZK98299 [onapristone, 11 beta-(4-dimethylaminophenyl)-17 alpha-hydroxy-17 beta-(3-hydroxypropyl)- 13 alpha-methyl-4,9-gonadien-3-one], in the calf uterus cytosol and compared the nature of this interaction with the binding of progesterone receptor (PR) agonist R5020 [promegestone, 17,21-dimethylpregna-4,9-diene-3,20-dione]. In the freshly prepared cytosol, [3H]ZK98299 interacted specifically with a macromolecule: the binding was abolished in the presence of excess progestins (R5020 and progesterone) and the antiprogesterone ZK98299. The high affinity (Kd = 2.5 nM) interaction between [3H]ZK98299 and PR was temperature- and time-dependent, reaching an optimum by 2-3 h at 0 degrees C, and was facilitated by 20 mM Na2MoO4. Under nontransforming conditions, [3H]ZK98299-receptor complexes sedimented as 8 S species in 8-30% linear glycerol gradients. Upon salt or thermal transformation, there was a loss of the 8 S form, with only a small fraction of total complexes (5-7%) binding to DNA-cellulose. In contrast, transformed [3H]R5020-receptor complexes exhibited a greater extent of binding (25-55%) to DNA-cellulose. [3H]ZK98299-receptor complexes could be resolved into two ionic species over DEAE-Sephacel following incubation of the complexes at 0 or 23 degrees C. [3H]ZK98299 binding was sensitive to sulfhydryl group modification as beta-mercaptoethanol increased the extent of steroid binding. Although treatment with iodoacetamide (IA) abolished [3H]R5020 binding, there was a significant (nearly twofold) increase in the [3H]ZK98299 binding. The results of this study point to similarities and differences between the steroid binding properties of the uterine PR occupied by R5020 and ZK98299: both steroids appear to bind the same 8 S receptor but exhibit differential DNA binding and sensitivity to IA. The reported antagonist properties of ZK98299 may, therefore, be explained on the basis of a distinct receptor conformation induced by the antisteroid.
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Affiliation(s)
- R Nath
- Department of Biological Sciences, Oakland University, Rochester, Michigan 48309-4401
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28
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Redox manipulation of DNA binding activity and BuGR epitope reactivity of the glucocorticoid receptor. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)99253-7] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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29
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Matthews KS, Chakerian AE, Gardner JA. Protein chemical modification as probe of structure-function relationships. Methods Enzymol 1991; 208:468-96. [PMID: 1779844 DOI: 10.1016/0076-6879(91)08025-d] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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30
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Meshinchi S, Matić G, Hutchison KA, Pratt WB. Selective molybdate-directed covalent modification of sulfhydryl groups in the steroid-binding versus the DNA-binding domain of the glucocorticoid receptor. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)38446-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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31
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Blanchardie P, Denis M, Orsonneau JL, Lustenberger P. Reaction of tyrosyl-modifying reagents with the ligand- and DNA-binding domains of the rabbit liver glucocorticoid receptor. JOURNAL OF STEROID BIOCHEMISTRY 1990; 36:15-23. [PMID: 2362444 DOI: 10.1016/0022-4731(90)90109-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We have studied the effects of p-nitrobenzenesulfonyl fluoride, 4-fluorosulfonyl-1-hydroxy-2-naphtoic acid, 7-chloro-4-nitrobenz-2-oxa-1,3-diazole and tetranitromethane on the glucocorticoid receptor from rabbit liver. Our results show that all tyrosine modifying reagents inhibit the binding of [3H]dexamethasone to the receptor. Equilibrium binding experiments revealed that only 4-fluorosulfonyl-1-hydroxy-2-naphtoic acid is a competitive inhibitor while the other chemical probes decrease the concentration of binding sites. Transformation of glucocorticoid-receptor complexes was markedly reduced when heat treatment was performed in the presence of tyrosyl-directed reagents. Taken together, these results indicate for the first time that critical tyrosyl moieties may be involved in both hormone binding and transformation of the glucocorticoid receptor.
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Affiliation(s)
- P Blanchardie
- Université de Nantes, Faculté de Médecine CHR, Hôtel-Dieu Laboratoire de Biochimie, France
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32
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Simons SS, Chakraborti PK, Cavanaugh AH. Arsenite and cadmium(II) as probes of glucocorticoid receptor structure and function. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)39922-3] [Citation(s) in RCA: 62] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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33
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Cavanaugh AH, Simons SS. Glucocorticoid receptor binding to calf thymus DNA. 1. Identification and characterization of a macromolecular factor involved in receptor-steroid complex binding to DNA. Biochemistry 1990; 29:989-96. [PMID: 1692738 DOI: 10.1021/bi00456a022] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Activation of receptor-steroid complexes to a form with high affinity for DNA is a poorly understood process involving multiple components in addition to the holoreceptor. Employing rat HTC cells as the source of glucocorticoid receptor, we show that maximal receptor binding to calf thymus DNA is mediated by a previously unknown small molecular weight factor. This factor can be removed from cytosolic preparations of receptor by gel filtration chromatography. Salt extraction of crude nuclear pellets afforded much larger amounts of a similar DNA-binding activity factor. The cytoplasmic factor and the more abundant nuclear factor were identical on the basis of their similar physical properties. The factor was precipitable in the crude state with (NH4)2SO4 and stable to heat as well as freezing and thawing. Chromatography on DNA-cellulose revealed that the factor itself did not bind to DNA. The factor could be filtered through a Centricon C-3 microconcentrator (molecular weight cutoff approximately 3000) but was excluded from Sephadex G-10 columns. These parameters enable us to determine an apparent molecular weight of 700-3000 for this factor. The presence of large amounts of this factor in nuclei accounts for the previously unexplained observation that, following size exclusion chromatography, more activated complexes bind to nuclei than to DNA. These data indicate that some, but not all, of the activated complexes require factor to be able to bind to DNA. The predominantly nuclear localization of this factor, coupled with its ability to increase DNA binding, attests to the biological relevance of this factor in the whole cell action of receptor-glucocorticoid complexes.
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Affiliation(s)
- A H Cavanaugh
- Laboratory of Analytical Chemistry, NIDDK, National Institutes of Health, Bethesda, Maryland 20892
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34
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Cavanaugh AH, Simons SS. Glucocorticoid receptor binding to calf thymus DNA. 2. Role of a DNA-binding activity factor in receptor heterogeneity and a multistep mechanism of receptor activation. Biochemistry 1990; 29:996-1002. [PMID: 1692739 DOI: 10.1021/bi00456a023] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In the preceding paper [Cavanaugh, A. H., & Simons, S. S., Jr. (1990) Biochemistry (preceding paper in this issue)], we characterized an apparently identical factor in the cytosol and the nuclear extract of HTC cells that is required for the DNA binding of approximately 43% of the activated receptor-glucocorticoid complexes. In the present study, both those activated complexes that are influenced by this factor and the role of this factor in the process of activation are examined. We find that sodium arsenite inhibits only the DNA binding of those complexes that require factor. Conversely, methyl methane-thiolsulfonate inhibits the DNA binding of only those complexes that are independent of factor. These results provide direct chemical evidence for two populations of activated complexes. Double-reciprocal plots revealed that the increase in DNA binding with endogenous factor occurred by recruiting new complexes for DNA binding as opposed to increasing the binding affinity of existing complexes. These results further suggest that factor associates only with the receptor-steroid complex and does not additionally interact with DNA. A saturable association of factor with complexes was indicated since the amount of available factor in cytosolic solutions decreased after activation of the complexes. Sodium molybdate is known to inhibit the activation of HTC cell receptor-steroid complexes. When factor was added to complexes that had been subjected to activating conditions in the presence of the inhibitor sodium molybdate, no increased DNA binding was observed.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- A H Cavanaugh
- Laboratory of Analytical Chemistry, NIDDK, National Institutes of Health, Bethesda, Maryland 20892
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35
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Direct Evidence for Intra- and Intermolecular Disulfide Bond Formation in the Human Glucocorticoid Receptor. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)83475-5] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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36
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Mammalian Progesterone Receptor Shows Differential Sensitivity to Sulfhydryl Group Modifying Agents When Bound to Agonist and Antagonist Ligands. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)94163-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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37
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Vessières A, Vaillant C, Salmain M, Jaouen G. Organometallic derivatives of estradiol as bioligands: targetted binding of the estradiol receptor. JOURNAL OF STEROID BIOCHEMISTRY 1989; 34:301-5. [PMID: 2626021 DOI: 10.1016/0022-4731(89)90097-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The complexation of estrogens by transitional metal units e.g. (alkyne)Co2(CO)6 and (alkyne)Mo2Cp2(CO)4, at the 17 alpha-position brings about a dramatic change in the chemical behavior of these compounds with respect to that of the free ligands. The 17 beta-OH function becomes particularly labile, even in weakly acidic medium, giving rise to carbenium ion-like species, from which, depending on the metal and the nucleophile, substitution, elimination and rearrangement take place. This situation provides the basis for a new type of active site directed-reagent for estradiol receptor. The hypothesis of vicinal space positioning of an acidic and a nucleophilic group in the estradiol receptor cavity is examined in the light of the amino-acid composition of the steroid binding domain. The requirement of the sulfhydryl group of a cysteine residue is suspected in the first step of the receptor inactivation process.
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Affiliation(s)
- A Vessières
- Ecole Nationale Supérieure de Chimie de Paris, U.R.A. C.N.R.S. 403, France
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38
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Miller NR, Simons SS. Steroid binding to hepatoma tissue culture cell glucocorticoid receptors involves at least two sulfhydryl groups. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)68167-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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39
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Luttge WG, Emadian SM. Further chemical differentiation of type I and type II adrenocorticosteroid receptors in mouse brain cytosol: evidence for a new class of glucocorticoid receptors. Brain Res 1988; 453:41-50. [PMID: 2456836 DOI: 10.1016/0006-8993(88)90141-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
There are at least two classes of intracellular receptors for adrenocorticosteroid hormones in brain. Type I receptors have a high affinity for the naturally occurring gluco- and mineralocorticoids, corticosterone (CORT) and aldosterone (ALDO), respectively, and a very low affinity for synthetic glucocorticoids such as dexamethasone (DEX). type II receptors have a high affinity for the synthetic glucocorticoids, a lower affinity for CORT and a very low affinity for ALDO. In recent studies with mouse brain cytosol we have found a number of other biochemical differences between these two receptor types. In the present study, brain cytosol from adrenalectomized mice was prepared in HEPES buffer and subjected to various potentially inactivating treatments prior to assessment of Type I and Type II receptor specific binding capacity by incubation for 24 h at 0 degrees C with [3H]ALDO +/- [1H]RU 26988 (to prevent or permit the cross-binding of [3H]ALDO to Type II receptors) or [3H]DEX +/- [1H]Prorenone (to prevent or permit the cross-binding of [3H]DEX to Type I receptors), respectively. These studies revealed that 10-20% of the high-affinity (Kd = 3 nM) [3H]DEX specific binding capacity remained even after extensive, high concentration and repeated pretreatments with dextran-coated charcoal (DDC. to remove endogenous sulfhydryl-reducing reagents and other biochemicals). These procedures had little effect on Type I receptors. Further analyses revealed that DCC-resistant [3H]DEX binders were not Type I receptors since they were not saturated by [1H]Prorenone. These binders were also not inactivated by aging steroid-free cytosol at 0 degree C or by treating it with buffers containing 0.3 M KCl. Since these
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Affiliation(s)
- W G Luttge
- Department of Neuroscience, University of Florida College of Medicine, Gainesville 32610
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40
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Henry EC, Kester JE, Gasiewicz TA. Effects of SH-modifying reagents on the rat hepatic Ah receptor: inhibition of ligand binding and transformation, and disruption of the ligand-receptor complex. BIOCHIMICA ET BIOPHYSICA ACTA 1988; 964:361-76. [PMID: 2831991 DOI: 10.1016/0304-4165(88)90037-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The importance of sulfhydryl (SH) groups in maintenance of physicochemical properties of the rat hepatic Ah receptor was demonstrated using a variety of sulfhydryl (SH)-modifying reagents. Inhibition of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) specific binding was approximately equivalent by 5,5'-dithiobis(2-nitrobenzoate), mersalyl, N-ethylmaleimide, and p-chloromercuriphenylsulfonate, whose inhibition curves were steep in the concentration range close to that of nonprotein SH groups in cytosol (ED50 values 50-200 microM or 13-48 nmol/mg cytosolic protein). Inhibition by p-hydroxymercuribenzoate (PHMB), although exhibiting a lower ED50, was more gradual over this range; iodoacetamide was an order of magnitude less potent. The ability of dithiothreitol to reverse binding inhibition induced by 150 microM (approximately 60 nmol/mg protein) mersalyl diminished with time; it decreased more rapidly in the simultaneous presence of TCDD and mersalyl than when mersalyl was present alone, consistent with increased accessibility of key SH group(s) due to conformational changes attending TCDD-receptor complex formation. Brief exposure of unoccupied receptor to mersalyl prior to TCDD binding caused slower sedimentation of the complex in 0-KCl sucrose gradients and alterations in its elution profiles on DEAE- and DNA-Sepharose suggestive of some impairment of the transformation process. When reagents were added to the transformed TCDD-receptor complex, loss of binding was observed only at concentrations which were an order of magnitude higher than those inhibiting TCDD binding. Loss of binding by each reagent was biphasic, and except for that caused by mersalyl, was not complete even after 6-8 h. Dithiothreitol was able to reverse the effects of mersalyl or PHMB only partially and only if added during the early phase (10-30 min) of binding loss. Mersalyl was much more potent in disrupting the untransformed than the transformed TCDD receptor complex. Physical alteration of the mersalyl-treated TCDD-receptor complex was evident from gel filtration, sucrose gradients, and DNA- and DEAE-Sepharose chromatography. Our results are in striking contrast to the effects of these reagents on steroid receptors, whose bound steroid hormone ligand is rapidly and reversibly displaced by lower concentrations of reagent.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- E C Henry
- Department of Biophysics, University of Rochester Medical Center, NY 14642
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41
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Tienrungroj W, Pratt SE, Grippo JF, Holmgren A, Pratt WB. The heat-stable cytosolic factor that promotes glucocorticoid receptor binding to DNA is neither thioredoxin nor ribonuclease. JOURNAL OF STEROID BIOCHEMISTRY 1987; 28:449-57. [PMID: 3682813 DOI: 10.1016/0022-4731(87)90501-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Treatment of rat liver cytosol containing temperature-transformed [3H]dexamethasone-bound receptors at 0 degree C with the sulfhydryl modifying reagent methyl methanethiosulfonate (MMTS) inhibits the DNA-binding activity of the receptor, and DNA-binding activity is restored after addition of dithiothreitol (DTT). However, transformed receptors that are treated with MMTS and then separated from low Mr components of cytosol by passage through a column of Sephadex G-50 have very little DNA-binding activity when DTT is added to regenerate sulfhydryl moities. The receptors will bind to DNA if whole liver cytosol or boiled liver cytosol is added in addition to DTT. The effect of boiled cytosol is mimicked by purified rat thioredoxin or bovine RNase A in a manner that does not reflect the reducing activity of the former or the catalytic activity of the latter. This suggests that the reported ability of each of these heat-stable peptides to stimulate DNA binding by glucocorticoid receptors is not a biologically relevant action. We suggest that stimulation of DNA binding of partially purified receptors by boiled cytosol does not constitute a reconstitution of a complete cytosolic system in which the dissociated receptor must associate with a specific heat-stable accessory protein required for DNA binding, as has been suggested in the "two-step" model of receptor transformation recently proposed by Schmidt et al. (Schmidt T.J., Miller-Diener, A., Webb M.L. and Litwack G. (1985) J. biol. Chem. 260, 16255-16262).
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Affiliation(s)
- W Tienrungroj
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor 48109-0010
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42
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Abstract
This brief review explores some recent observations relating to the structure of untransformed glucocorticoid and progesterone receptors and the mechanism by which the receptors are transformed to the DNA-binding state. In their molybdatestabilized, untransformed state, progesterone and glucocorticoid receptors exist as a heteromeric 8-9S complex containing one unit of steroid binding phosphoprotein and one or two units of the 90 kD heat shock protein hsp90. When the receptors are transformed, the steroid-binding protein dissociates from hsp90. In cytosol preparations, temperature-mediated dissociation proceeds much more rapidly in the presence of hormone. The dissociated receptor binds to DNA with high affinity, regardless of whether it is in the hormone-bound or the hormone-free state. These observations raise the possibility that the primary, and perhaps the only, role for the hormone is to promote dissociation of the receptor-hsp90 complex. Molybdate, vanadate, and tungstate inhibit receptor transformation to the DNA-binding form, an effect that appears to reflect the ability of these transition metal oxyanions to stabilize the complex between the steroid receptor and hsp90. By promoting the formation of disulfide bonds, hydrogen peroxide also stabilizes the glucocorticoid receptor-hsp90 complex and prevents receptor transformation. A small, heat-stable factor present in all cytosol preparations inhibits receptor transformation, and, when the factor is removed, glucocorticoid receptors are rapidly transformed. This ubiquitous factor has the physical properties of a metal anion, and it is proposed that molybdate and vanadate affect steroid receptor complexes by interacting with a metal anion-binding site that is normally occupied by this endogenous receptor-stabilizing factor.
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Affiliation(s)
- W B Pratt
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor 48109
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43
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Simons SS. Selective covalent labeling of cysteines in bovine serum albumin and in hepatoma tissue culture cell glucocorticoid receptors by dexamethasone 21-mesylate. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)47986-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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44
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Reker CE, LaPointe MC, Kovacic-Milivojević B, Chiou WJ, Vedeckis WV. A possible role for dephosphorylation in glucocorticoid receptor transformation. JOURNAL OF STEROID BIOCHEMISTRY 1987; 26:653-65. [PMID: 3112467 DOI: 10.1016/0022-4731(87)91037-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Addition of bovine intestinal alkaline phosphatase to mouse AtT-20 cell cytosol increases the rate of glucocorticoid receptor transformation, as evidenced by a change in sedimentation rate from 9.1S to 5.2S. Acid phosphatases are completely ineffective in this regard. Alkaline phosphatase-promoted receptor transformation is both time- and dose-dependent. A variety of phosphatase inhibitors are effective in inhibiting this process, the most potent being transition metal oxyanions such as molybdate, tungstate, and arsenate. The ability of the various inhibitors to suppress alkaline phosphatase-promoted receptor transformation does not correspond well with their potencies for inhibiting para-nitrophenyl phosphate hydrolysis. However, a better correspondence between the inhibition of endogenous receptor transformation and total cytosolic phosphatase activity is observed, and both sodium fluoride and glucose-1-phosphate inhibit endogenous receptor transformation. The protease inhibitors phenyl-methylsulfonyl fluoride and antipain have no effect on receptor transformation. Surprisingly, leupeptin is effective in inhibiting alkaline phosphatase-promoted receptor transformation. Although this raises the possibility of a contaminating protease activity in the alkaline phosphatase enzyme preparation, treatment of covalently affinity-labeled receptor with the enzyme shows no proteolysis of the receptor or any other non-specifically labeled cytosolic protein. Thus, it is possible that a novel action of leupeptin, unrelated to its protease-inhibitory activity, may be involved in the suppression of receptor transformation. The studies presented here suggest that dephosphorylation of some component in cytosol is involved in the destabilization of receptor subunit interactions, resulting in glucocorticoid receptor transformation.
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45
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Tienrungroj W, Meshinchi S, Sanchez ER, Pratt SE, Grippo JF, Holmgren A, Pratt WB. The role of sulfhydryl groups in permitting transformation and DNA binding of the glucocorticoid receptor. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)48192-6] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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46
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Denison MS, Vella LM, Okey AB. Structure and function of the Ah receptor: sulfhydryl groups required for binding of 2,3,7,8-tetrachlorodibenzo-p-dioxin to cytosolic receptor from rodent livers. Arch Biochem Biophys 1987; 252:388-95. [PMID: 3028264 DOI: 10.1016/0003-9861(87)90045-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Cytosol from rodent liver was exposed to a variety of sulfhydryl-modifying reagents to determine if the cytosolic Ah receptor contained reactive sulfhydryl groups that were essential for preservation of the receptor's ligand binding function. At a 2 mM concentration in rat liver cytosol, all sulfhydryl-modifying reagents tested (except iodoacetamide) both blocked binding of [3H]2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to unoccupied receptor and caused release of [3H]TCDD from receptor sites that had been labeled with [3H]TCDD before exposure to the sulfhydryl-modifying reagent. Exposure of cytosol to iodoacetamide before labeling with [3H]TCDD prevented subsequent specific binding of [3H]TCDD, but iodoacetamide was not effective at displacing previously bound [3H]TCDD from the Ah receptor. The mercurial reagents, mersalyl, mercuric chloride, and p-hydroxymercuribenzoate, were more effective at releasing bound [3H]TCDD from previously labeled sites than were alkylating agents (iodoacetamide, N-ethylmaleimide) or the disulfide compound 5,5'-dithiobis(2-nitrobenzoate). Presence of bound [3H]TCDD substantially protected the Ah receptor against loss of ligand binding function when the cytosol was exposed to sulfhydryl-modifying reagents. This may indicate that the critical sulfhydryl groups lie in or near the ligand binding site on the receptor. Subtle differences exist between the Ah receptor and the receptors for steroid hormones in response to a spectrum of sulfhydryl-modifying reagents, but the Ah receptor clearly contains a sulfhydryl group (or groups) essential for maintaining the receptor in a state in which it can bind ligands specifically and with high affinity.
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Sanchez ER, Tienrungroj W, Dalman FC, Lin AL. Glucocorticoid receptor phosphorylation in mouse L-cells. JOURNAL OF STEROID BIOCHEMISTRY 1987; 27:215-25. [PMID: 3320532 DOI: 10.1016/0022-4731(87)90313-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
This paper summarizes our observations on the phosphorylation state of untransformed and transformed glucocorticoid receptors isolated from 32P-labeled L-cells. The 300-350-kDa 9S untransformed murine glucocorticoid receptor complex is composed of a 100-kDa steroid-binding phosphoprotein and one or possibly two units of the 90-kDa heat shock protein (hsp90), which is also a phosphoprotein. Transformation of this complex to the 4S DNA-binding state is accompanied by dissociation of hsp90. When receptors in cytosol are transformed by heating at 25 degrees C, there is no gross change in the degree of phosphorylation of the steroid-binding protein. Both receptors that are bound to DNA after transformation under cell-free conditions and receptors that are located in the nucleus of cells incubated at 37 degrees C in the presence of glucocorticoid are labeled with 32P. The results of experiments in which the 32P-labeled receptor was submitted to limited proteolysis suggest that the 16-kDa DNA-binding domain is phosphorylated and that the 28-kDa steroid-binding domain is not.
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Affiliation(s)
- E R Sanchez
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor 48109
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48
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Pinsky L, Kaufman M. Genetics of steroid receptors and their disorders. ADVANCES IN HUMAN GENETICS 1987; 16:299-472. [PMID: 3551549 DOI: 10.1007/978-1-4757-0620-8_5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
MESH Headings
- Androgens/metabolism
- Animals
- Cells, Cultured
- Disease Models, Animal
- Endocrine System Diseases/genetics
- Endocrine System Diseases/metabolism
- Female
- Fibroblasts/metabolism
- Glucocorticoids/metabolism
- Humans
- Hypogonadism/genetics
- Hypogonadism/metabolism
- Infertility, Male/genetics
- Infertility, Male/metabolism
- Male
- Neoplasms/genetics
- Neoplasms/metabolism
- Neoplasms, Hormone-Dependent/genetics
- Neoplasms, Hormone-Dependent/metabolism
- Receptors, Androgen/genetics
- Receptors, Androgen/metabolism
- Receptors, Glucocorticoid/genetics
- Receptors, Glucocorticoid/metabolism
- Receptors, Steroid/genetics
- Receptors, Steroid/metabolism
- Skin
- Steroids/metabolism
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49
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Wilson EM, Wright BT, Yarbrough WG. The possible role of disulfide bond reduction in transformation of the 10 S androgen receptor. J Biol Chem 1986. [DOI: 10.1016/s0021-9258(19)84590-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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50
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Sanchez ER, Housley PR, Pratt WB. The molybdate-stabilized glucocorticoid binding complex of L-cells contains a 98-100 kdalton steroid binding phosphoprotein and a 90 kdalton nonsteroid-binding phosphoprotein that is part of the murine heat-shock complex. JOURNAL OF STEROID BIOCHEMISTRY 1986; 24:9-18. [PMID: 3517499 DOI: 10.1016/0022-4731(86)90025-7] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
This paper summarizes our work performed with glucocorticoid-binding complexes in molybdate-stabilized cytosol prepared from 32P-labeled L-cells. In our early work, we showed that cytosol prepared from 32P-labeled L-cells contains two phosphoproteins (a 90 and a 98-100 kdalton protein) that elute from an affinity resin of deoxycorticosterone agarose in a manner consistent with the predicted behavior of the glucocorticoid receptor. Both phosphoproteins are immunoadsorbed onto protein-A-Sepharose from molybdate-stabilized cytosol incubated with a monoclonal antibody against the receptor. The 98-100 kdalton phosphoprotein binds steroid and the 90 kdalton phosphoprotein is a structurally different, nonsteroid-binding protein that is bound to the untransformed, molybdate-stabilized glucocorticoid receptor. The 90 kdalton protein reacts on Western blots with a monoclonal antibody raised against a 90 kdalton protein from the water mold Achlya ambisexualis. This antibody recognizes an epitope that is conserved in 90 kdalton phosphoproteins from rodent and human cells, and it reacts with the 90 kdalton phosphoprotein that copurifies with the molybdate-stabilized, untransformed chick oviduct progesterone receptor. The 90 kdalton nonsteroid-binding phosphoprotein is an abundant cytosolic protein that dissociates from the glucocorticoid receptor when it is transformed, and unlike the steroid-binding protein, it does not bind to DNA. The 90 kdalton phosphoprotein determines the acidic behavior of the untransformed glucocorticoid receptor on DEAE-cellulose. This abundant cytosolic 90 kdalton phosphoprotein reacts with rabbit antiserum raised against the gel purified 89 kdalton chicken heat-shock protein (hsp89). This antiserum recognizes 90 kdalton heat-shock proteins in human, rodent, frog and Drosophila cells. Immunoadsorption of molybdate-stabilized cytosol with antibody directed against the 98-100 kdalton steroid receptor results in the immune-specific adsorption of a 90 kdalton phosphoprotein that reacts with anti-hsp89 antibody on Western blots. These observations suggest that, like the transforming proteins from several avian sarcoma viruses, the untransformed glucocorticoid receptor exists in a complex with the 90 kdalton heat-shock protein.
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