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Lu Y, Ling C, Shoti J, Yang H, Nath A, Keeler GD, Qing K, Srivastava A. Enhanced transgene expression from single-stranded AAV vectors in human cells in vitro and in murine hepatocytes in vivo. MOLECULAR THERAPY. NUCLEIC ACIDS 2024; 35:102196. [PMID: 38766527 PMCID: PMC11101737 DOI: 10.1016/j.omtn.2024.102196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 04/18/2024] [Indexed: 05/22/2024]
Abstract
We identified that distal 10 nucleotides in the D-sequence in AAV2 inverted terminal repeat (ITR) share partial sequence homology to 1/2 binding site of glucocorticoid receptor-binding element (GRE). Here, we describe that (1) purified GR binds to AAV2 D-sequence, and the D-sequence competes with GR binding to its cognate binding site; (2) dexamethasone-mediated activation of GR pathway significantly increases the transduction efficiency of AAV2 vectors in human cells; (3) human osteosarcoma cells, U2OS, which lack expression of GR, are poorly transduced by AAV2 vectors, but stable transfection with a GR expression plasmid restores vector-mediated transgene expression; (4) replacement of the distal 10 nucleotides in the D-sequence of the AAV2 ITR with a full-length GRE consensus sequence significantly enhances transgene expression in human cells in vitro and in murine hepatocytes in vivo; and (5) none of the ITRs in AAV1, AAV3, AAV4, AAV5, and AAV6 genomes contains the GRE 1/2 binding site, and insertion of a full-length GRE consensus sequence in the AAV6-ITR also significantly enhances transgene expression from AAV6 vectors, both in vitro and in vivo. These novel vectors, termed generation Y AAV vectors, which are serotype, transgene, or promoter agnostic, should be useful in human gene therapy.
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Affiliation(s)
- Yuan Lu
- Full Circle Therapeutics, Shanghai, China
| | - Chen Ling
- Department of Genetics, School of Life Sciences, Fudan University, Shanghai, China
| | - Jakob Shoti
- Division of Cellular and Molecular Therapy, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL, USA
| | - Hua Yang
- Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Aneesha Nath
- Department of Pharmacotherapy & Translational Research, University of Florida College of Pharmacy, Gainesville, FL, USA
| | - Geoffrey D. Keeler
- Division of Cellular and Molecular Therapy, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA
| | - Keyun Qing
- Division of Cellular and Molecular Therapy, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA
| | - Arun Srivastava
- Division of Cellular and Molecular Therapy, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL, USA
- Powell Gene Therapy Center, University of Florida College of Medicine, Gainesville, FL, USA
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2
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Lammer NC, Ashraf HM, Ugay DA, Spencer SL, Allen MA, Batey RT, Wuttke DS. RNA binding by the glucocorticoid receptor attenuates dexamethasone-induced gene activation. Sci Rep 2023; 13:9385. [PMID: 37296231 PMCID: PMC10251336 DOI: 10.1038/s41598-023-35549-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 05/19/2023] [Indexed: 06/12/2023] Open
Abstract
The glucocorticoid receptor (GR) is a ligand-activated transcription factor that regulates a suite of genes through direct binding of GR to specific DNA promoter elements. GR also interacts with RNA, but the function of this RNA-binding activity remains elusive. Current models speculate that RNA could repress the transcriptional activity of GR. To investigate the function of the GR-RNA interaction on GR's transcriptional activity, we generated cells that stably express a mutant of GR with reduced RNA binding affinity and treated the cells with the GR agonist dexamethasone. Changes in the dexamethasone-driven transcriptome were quantified using 4-thiouridine labeling of RNAs followed by high-throughput sequencing. We find that while many genes are unaffected, GR-RNA binding is repressive for specific subsets of genes in both dexamethasone-dependent and independent contexts. Genes that are dexamethasone-dependent are activated directly by chromatin-bound GR, suggesting a competition-based repression mechanism in which increasing local concentrations of RNA may compete with DNA for binding to GR at sites of transcription. Unexpectedly, genes that are dexamethasone-independent instead display a localization to specific chromosomal regions, which points to changes in chromatin accessibility or architecture. These results show that RNA binding plays a fundamental role in regulating GR function and highlights potential functions for transcription factor-RNA interactions.
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Affiliation(s)
- Nickolaus C Lammer
- Department of Biochemistry, University of Colorado, Boulder, CO, 80309, USA
| | - Humza M Ashraf
- Department of Biochemistry, University of Colorado, Boulder, CO, 80309, USA
| | - Daniella A Ugay
- Department of Biochemistry, University of Colorado, Boulder, CO, 80309, USA
| | - Sabrina L Spencer
- Department of Biochemistry, University of Colorado, Boulder, CO, 80309, USA
- BioFrontiers Institute, University of Colorado, Boulder, CO, 80309, USA
| | - Mary A Allen
- BioFrontiers Institute, University of Colorado, Boulder, CO, 80309, USA
| | - Robert T Batey
- Department of Biochemistry, University of Colorado, Boulder, CO, 80309, USA.
| | - Deborah S Wuttke
- Department of Biochemistry, University of Colorado, Boulder, CO, 80309, USA.
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3
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Varricchio L, Geer EB, Martelli F, Mazzarini M, Funnell A, Bieker JJ, Papayannopoulou T, Migliaccio AR. Patients with hypercortisolemic Cushing disease possess a distinct class of hematopoietic progenitor cells leading to erythrocytosis. Haematologica 2023; 108:1053-1067. [PMID: 35861015 PMCID: PMC10071118 DOI: 10.3324/haematol.2021.280542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 05/11/2022] [Indexed: 11/09/2022] Open
Abstract
Although human cell cultures stimulated with dexamethasone suggest that the glucocorticoid receptor (GR) activates stress erythropoiesis, the effects of GR activation on erythropoiesis in vivo remain poorly understood. We characterized the phenotype of a large cohort of patients with Cushing disease, a rare condition associated with elevated cortisol levels. Results from hypercortisolemic patients with active Cushing disease were compared with those obtained from eucortisolemic patients after remission and from volunteers without the disease. Patients with active Cushing disease exhibited erythrocytosis associated with normal hemoglobin F levels. In addition, their blood contained elevated numbers of GR-induced CD163+ monocytes and a unique class of CD34+ cells expressing CD110, CD36, CD133 and the GR-target gene CXCR4. When cultured, these CD34+ cells generated similarly large numbers of immature erythroid cells in the presence and absence of dexamethasone, with raised expression of the GR-target gene GILZ. Of interest, blood from patients with Cushing disease in remission maintained high numbers of CD163+ monocytes and, although their CD34+ cells had a normal phenotype, these cells were unresponsive to added dexamethasone. Collectively, these results indicate that chronic exposure to excess glucocorticoids in vivo leads to erythrocytosis by generating erythroid progenitor cells with a constitutively active GR. Although remission rescues the erythrocytosis and the phenotype of the circulating CD34+ cells, a memory of other prior changes is maintained in remission.
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Affiliation(s)
- Lilian Varricchio
- Division of Hematology and Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Eliza B Geer
- Multidisciplinary Pituitary and Skull Base Tumor Center, Departments of Medicine and Neurosurgery, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Fabrizio Martelli
- National Center for Drug Research and Evaluation, Istituto Superiore di Sanità, Rome
| | - Maria Mazzarini
- Department of Biomedical and Neuromotorial Sciences, Alma Mater Studiorum University, Bologna, Italy; Altius Institute for Biomedical Sciences, Seattle, WA
| | | | - James J Bieker
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY
| | | | - Anna Rita Migliaccio
- Altius Institute for Biomedical Sciences, Seattle, WA, USA; Center for Integrated Biomedical Research, Campus Bio-medico, Rome.
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4
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Butz H, Saskői É, Krokker L, Vereczki V, Alpár A, Likó I, Tóth E, Szőcs E, Cserepes M, Nagy K, Kacskovics I, Patócs A. Context-Dependent Role of Glucocorticoid Receptor Alpha and Beta in Breast Cancer Cell Behaviour. Cells 2023; 12:cells12050784. [PMID: 36899920 PMCID: PMC10000936 DOI: 10.3390/cells12050784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 02/22/2023] [Accepted: 02/24/2023] [Indexed: 03/06/2023] Open
Abstract
Background. The dual role of GCs has been observed in breast cancer; however, due to many concomitant factors, GR action in cancer biology is still ambiguous. In this study, we aimed to unravel the context-dependent action of GR in breast cancer. Methods. GR expression was characterized in multiple cohorts: (1) 24,256 breast cancer specimens on the RNA level, 220 samples on the protein level and correlated with clinicopathological data; (2) oestrogen receptor (ER)-positive and -negative cell lines were used to test for the presence of ER and ligand, and the effect of the GRβ isoform following GRα and GRβ overexpression on GR action, by in vitro functional assays. Results. We found that GR expression was higher in ER- breast cancer cells compared to ER+ ones, and GR-transactivated genes were implicated mainly in cell migration. Immunohistochemistry showed mostly cytoplasmic but heterogenous staining irrespective of ER status. GRα increased cell proliferation, viability, and the migration of ER- cells. GRβ had a similar effect on breast cancer cell viability, proliferation, and migration. However, the GRβ isoform had the opposite effect depending on the presence of ER: an increased dead cell ratio was found in ER+ breast cancer cells compared to ER- ones. Interestingly, GRα and GRβ action did not depend on the presence of the ligand, suggesting the role of the "intrinsic", ligand-independent action of GR in breast cancer. Conclusions. Staining differences using different GR antibodies may be the reason behind controversial findings in the literature regarding the expression of GR protein and clinicopathological data. Therefore, caution in the interpretation of immunohistochemistry should be applied. By dissecting the effects of GRα and GRβ, we found that the presence of the GR in the context of ER had a different effect on cancer cell behaviour, but independently of ligand availability. Additionally, GR-transactivated genes are mostly involved in cell migration, which raises GR's importance in disease progression.
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Affiliation(s)
- Henriett Butz
- Department of Molecular Genetics and the National Tumour Biology Laboratory, National Institute of Oncology, H-1122 Budapest, Hungary
- Department of Oncology Biobank, National Institute of Oncology, H-1122 Budapest, Hungary
- Hereditary Tumours Research Group, Hungarian Academy of Sciences, Semmelweis University, H-1089 Budapest, Hungary
- Department of Laboratory Medicine, Semmelweis University, H-1089 Budapest, Hungary
- Correspondence:
| | - Éva Saskői
- Department of Oncology Biobank, National Institute of Oncology, H-1122 Budapest, Hungary
| | - Lilla Krokker
- Hereditary Tumours Research Group, Hungarian Academy of Sciences, Semmelweis University, H-1089 Budapest, Hungary
- Department of Laboratory Medicine, Semmelweis University, H-1089 Budapest, Hungary
| | - Viktória Vereczki
- Department of Molecular Genetics and the National Tumour Biology Laboratory, National Institute of Oncology, H-1122 Budapest, Hungary
| | - Alán Alpár
- Department of Anatomy, Semmelweis University, H-1094 Budapest, Hungary
| | - István Likó
- Hereditary Tumours Research Group, Hungarian Academy of Sciences, Semmelweis University, H-1089 Budapest, Hungary
| | - Erika Tóth
- Department of Pathology, National Institute of Oncology, H-1122 Budapest, Hungary
| | - Erika Szőcs
- Department of Oncology Biobank, National Institute of Oncology, H-1122 Budapest, Hungary
| | - Mihály Cserepes
- Department of Experimental Pharmacology, National Institute of Oncology, H-1122 Budapest, Hungary
| | | | | | - Attila Patócs
- Department of Molecular Genetics and the National Tumour Biology Laboratory, National Institute of Oncology, H-1122 Budapest, Hungary
- Department of Oncology Biobank, National Institute of Oncology, H-1122 Budapest, Hungary
- Hereditary Tumours Research Group, Hungarian Academy of Sciences, Semmelweis University, H-1089 Budapest, Hungary
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5
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Progesterone Sporadically Induces Reactivation from Latency in Female Calves but Proficiently Stimulates Bovine Herpesvirus 1 Productive Infection. J Virol 2022; 96:e0213021. [PMID: 35019726 DOI: 10.1128/jvi.02130-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Acute infection of the ocular, oral, or nasal cavity by bovine herpesvirus 1 (BoHV-1) culminates in lifelong latency in sensory neurons within trigeminal ganglia. The BoHV-1 latency reactivation cycle, including calves latently infected with commercially available modified live vaccines, can lead to reproductive complications, including abortions. Recent studies demonstrated progesterone stimulated BoHV-1 productive infection and sporadically induced reactivation from latency in male rabbits. The progesterone receptor (PR) and progesterone transactivate the immediate early transcription unit 1 (IEtu1) promoter and the infected cell protein 0 (bICP0) early promoter. These viral promoters drive expression of two viral transcriptional regulatory proteins (bICP0 and bICP4) that are crucial for productive infection. Based on these observations, we hypothesize that progesterone induces reactivation in a subset of calves latently infected with BoHV-1. These studies demonstrated progesterone was less efficient than dexamethasone at initiating reactivation from latency in female calves. Notably, heat stress correlated with enhancing the ability of progesterone to induce reactivation from latency. Previous studies demonstrated that heat stress activates the glucocorticoid receptor (GR), which suggested GR activation augments progesterone-mediated reactivation from latency. Additional studies revealed GR and PR cooperatively stimulated productive infection and synergistically transactivated the IEtu1 promoter when cultures were treated with dexamethasone. Mutating one or both GR binding sites in the IEtu1 promoter blocked transactivation. Collectively, these studies indicated that progesterone intermittently triggered reactivation from latency, and heat stress augmented reactivation from reactivation. Finally, these studies suggest progesterone enhances virus spread in tissues and cells where PR is abundantly expressed. IMPORTANCE Steroid hormone fluctuations are predicted to enhance or initiate bovine herpesvirus 1 (BoHV-1) replication and virus spread in cattle. For example, stress increases the incidence of BoHV-1 reactivation from latency in cattle, and the synthetic corticosteroid dexamethasone consistently induces reactivation from latency. The glucocorticoid receptor (GR) and dexamethasone stimulate key viral regulatory promoters and productive infection, in part because the viral genome contains numerous consensus GR-responsive elements (GREs). The progesterone receptor (PR) and GR belong to the type I nuclear hormone receptor family. PR and progesterone specifically bind to and transactivate viral promoters that contain GREs and stimulate BoHV-1 productive infection. Although progesterone did not induce reactivation from latency in female calves as efficiently as dexamethasone, heat stress enhanced progesterone-mediated reactivation from latency. Consequently, we predict that low levels of stressful stimuli can cooperate with progesterone to induce reactivation from latency or promote virus spread.
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6
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Butz H, Patócs A. Mechanisms behind context-dependent role of glucocorticoids in breast cancer progression. Cancer Metastasis Rev 2022; 41:803-832. [PMID: 35761157 PMCID: PMC9758252 DOI: 10.1007/s10555-022-10047-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 06/09/2022] [Indexed: 02/08/2023]
Abstract
Glucocorticoids (GCs), mostly dexamethasone (dex), are routinely administered as adjuvant therapy to manage side effects in breast cancer. However, recently, it has been revealed that dex triggers different effects and correlates with opposite outcomes depending on the breast cancer molecular subtype. This has raised new concerns regarding the generalized use of GC and suggested that the context-dependent effects of GCs can be taken into potential consideration during treatment design. Based on this, attention has recently been drawn to the role of the glucocorticoid receptor (GR) in development and progression of breast cancer. Therefore, in this comprehensive review, we aimed to summarize the different mechanisms behind different context-dependent GC actions in breast cancer by applying a multilevel examination, starting from the association of variants of the GR-encoding gene to expression at the mRNA and protein level of the receptor, and its interactions with other factors influencing GC action in breast cancer. The role of GCs in chemosensitivity and chemoresistance observed during breast cancer therapy is discussed. In addition, experiences using GC targeting therapeutic options (already used and investigated in preclinical and clinical trials), such as classic GC dexamethasone, selective glucocorticoid receptor agonists and modulators, the GC antagonist mifepristone, and GR coregulators, are also summarized. Evidence presented can aid a better understanding of the biology of context-dependent GC action that can lead to further advances in the personalized therapy of breast cancer by the evaluation of GR along with the conventional estrogen receptor (ER) and progesterone receptor (PR) in the routine diagnostic procedure.
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Affiliation(s)
- Henriett Butz
- Department of Molecular Genetics and the National Tumor Biology Laboratory, National Institute of Oncology, Budapest, Hungary.
- Hereditary Tumours Research Group, Hungarian Academy of Sciences-Semmelweis University, Budapest, Hungary.
- Department of Laboratory Medicine, Semmelweis University, Budapest, Hungary.
| | - Attila Patócs
- Department of Molecular Genetics and the National Tumor Biology Laboratory, National Institute of Oncology, Budapest, Hungary
- Hereditary Tumours Research Group, Hungarian Academy of Sciences-Semmelweis University, Budapest, Hungary
- Department of Laboratory Medicine, Semmelweis University, Budapest, Hungary
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7
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Han YM, Kim MS, Jo J, Shin D, Kwon SH, SEO JB, Kang D, Lee BD, Ryu H, Hwang EM, Kim JM, Patel PD, Lyons DM, Schatzberg AF, Her S. Decoding the temporal nature of brain GR activity in the NFκB signal transition leading to depressive-like behavior. Mol Psychiatry 2021; 26:5087-5096. [PMID: 33483691 PMCID: PMC7821461 DOI: 10.1038/s41380-021-01016-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 11/17/2020] [Accepted: 01/05/2021] [Indexed: 01/30/2023]
Abstract
The fine-tuning of neuroinflammation is crucial for brain homeostasis as well as its immune response. The transcription factor, nuclear factor-κ-B (NFκB) is a key inflammatory player that is antagonized via anti-inflammatory actions exerted by the glucocorticoid receptor (GR). However, technical limitations have restricted our understanding of how GR is involved in the dynamics of NFκB in vivo. In this study, we used an improved lentiviral-based reporter to elucidate the time course of NFκB and GR activities during behavioral changes from sickness to depression induced by a systemic lipopolysaccharide challenge. The trajectory of NFκB activity established a behavioral basis for the NFκB signal transition involved in three phases, sickness-early-phase, normal-middle-phase, and depressive-like-late-phase. The temporal shift in brain GR activity was differentially involved in the transition of NFκB signals during the normal and depressive-like phases. The middle-phase GR effectively inhibited NFκB in a glucocorticoid-dependent manner, but the late-phase GR had no inhibitory action. Furthermore, we revealed the cryptic role of basal GR activity in the early NFκB signal transition, as evidenced by the fact that blocking GR activity with RU486 led to early depressive-like episodes through the emergence of the brain NFκB activity. These results highlight the inhibitory action of GR on NFκB by the basal and activated hypothalamic-pituitary-adrenal (HPA)-axis during body-to-brain inflammatory spread, providing clues about molecular mechanisms underlying systemic inflammation caused by such as COVID-19 infection, leading to depression.
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Affiliation(s)
- Young-Min Han
- grid.410885.00000 0000 9149 5707Seoul Centre, Korea Basic Science Institute, Seoul, South Korea
| | - Min Sun Kim
- grid.410885.00000 0000 9149 5707Seoul Centre, Korea Basic Science Institute, Seoul, South Korea
| | - Juyeong Jo
- grid.410885.00000 0000 9149 5707Seoul Centre, Korea Basic Science Institute, Seoul, South Korea
| | - Daiha Shin
- grid.410885.00000 0000 9149 5707Seoul Centre, Korea Basic Science Institute, Seoul, South Korea
| | - Seung-Hae Kwon
- grid.410885.00000 0000 9149 5707Seoul Centre, Korea Basic Science Institute, Seoul, South Korea
| | - Jong Bok SEO
- grid.410885.00000 0000 9149 5707Seoul Centre, Korea Basic Science Institute, Seoul, South Korea
| | - Dongmin Kang
- grid.255649.90000 0001 2171 7754Department of Life Science, Ewha Womans University, Seoul, South Korea
| | - Byoung Dae Lee
- grid.289247.20000 0001 2171 7818Department of Physiology, School of Medicine, Kyung Hee University, Seoul, South Korea
| | - Hoon Ryu
- grid.35541.360000000121053345Neuroscience Centre, Korea Institute of Science and Technology, Seoul, South Korea
| | - Eun Mi Hwang
- grid.35541.360000000121053345Center for Functional Connectomics, Korea Institute of Science and Technology, Seoul, South Korea
| | - Jae-Min Kim
- grid.14005.300000 0001 0356 9399Department of Psychiatry, Chonnam National University Medical School, Seoul, South Korea
| | - Paresh D. Patel
- grid.412590.b0000 0000 9081 2336Department of Psychiatry, Molecular and Behavioral Neuroscience Institute, University of Michigan Medical Centre, Ann Arbor, MI USA
| | - David M. Lyons
- grid.168010.e0000000419368956Departments of Psychiatry, Stanford University Medical Centre, Stanford, CA USA
| | - Alan F. Schatzberg
- grid.168010.e0000000419368956Departments of Psychiatry, Stanford University Medical Centre, Stanford, CA USA
| | - Song Her
- Seoul Centre, Korea Basic Science Institute, Seoul, South Korea.
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8
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Sarkar P, Rao BD, Chattopadhyay A. Cell Cycle Dependent Modulation of Membrane Dipole Potential and Neurotransmitter Receptor Activity: Role of Membrane Cholesterol. ACS Chem Neurosci 2020; 11:2890-2899. [PMID: 32786305 DOI: 10.1021/acschemneuro.0c00499] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The cell cycle is a sequential multistep process essential for growth and proliferation of cells that make up multicellular organisms. A number of nuclear and cytoplasmic proteins are known to modulate the cell cycle. Yet, the role of lipids, membrane organization, and physical properties in cell cycle progression remains largely elusive. Membrane dipole potential is an important physicochemical property and originates due to the electrostatic potential difference within the membrane because of nonrandom arrangement of amphiphile dipoles and water molecules at the membrane interface. In this work, we explored the modulation of membrane dipole potential in various stages of the cell cycle in CHO-K1 cells. Our results show that membrane dipole potential is highest in the G1 phase relative to S and G2/M phases. This was accompanied by regulation of membrane cholesterol content in the cell cycle. The highest cholesterol content was found in the G1 phase with a considerable reduction in cholesterol in S and G2/M phases. Interestingly, we noted a similarity in the dependence of membrane dipole potential and cholesterol with progress of the cell cycle. In addition, we observed an increase in neutral lipid (which contains esterified cholesterol) content as cells progressed from the G1 to G2/M phase via the S phase of the cell cycle. Importantly, we further observed a cell cycle dependent reduction in ligand binding activity of serotonin1A receptors expressed in CHO-K1 cells. To the best of our knowledge, these results constitute the first report of cell cycle dependent modulation of membrane dipole potential and activity of a neurotransmitter receptor belonging to the G protein-coupled receptor family. We envision that understanding the basis of cell cycle events from a biophysical perspective would result in a deeper appreciation of the cell cycle and its regulation in relation to cellular function.
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Affiliation(s)
- Parijat Sarkar
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
| | - Bhagyashree D. Rao
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
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9
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Marinello W, Feng L, Allen TK. Progestins Inhibit Interleukin-1β-Induced Matrix Metalloproteinase 1 and Interleukin 8 Expression via the Glucocorticoid Receptor in Primary Human Amnion Mesenchymal Cells. Front Physiol 2020; 11:900. [PMID: 32792990 PMCID: PMC7394241 DOI: 10.3389/fphys.2020.00900] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 07/06/2020] [Indexed: 12/18/2022] Open
Abstract
Preterm premature rupture of membranes is a leading cause of preterm births. Cytokine induced matrix metalloproteinase1 and interleukin 8 production from amnion mesenchymal cells may contribute to fetal membrane weakening and rupture. Progestins inhibit inflammation induced fetal membrane weakening but their effect on the inflammatory response of amnion mesenchymal cells is unknown. This study was designed to determine the role of progesterone receptor membrane component 1 and the glucocorticoid receptor in mediating the effects of progestins on interleukin-1β induced matrix metalloproteinase 1 and interleukin-8 expression in human amnion mesenchymal cells. Primary amnion mesenchymal cells harvested from human fetal membranes were passaged once and treated with vehicle, progesterone or medroxyprogesterone acetate at 10-6 M for 1 h followed by stimulation with interleukin-1β at 1 ng/ml for 24 h. Medroxyprogesterone acetate but not progesterone inhibited interleukin-1β-induced interlukin-8 and matrix metalloproteinase 1 mRNA expression. In subsequent dose response studies, medroxyprogesterone acetate, but not progesterone, at doses of 10-6-10-8 M inhibited interleukin-1β induced interleukin-8 and matrix metalloproteinase 1 mRNA expression. We further demonstrated that inhibition of glucocorticoid receptor expression, but not progesterone receptor membrane component 1 knockdown with small interfering RNA transfection, resulted in a reversal in medroxyprogesterone acetate's (10-7 M) inhibition of interleukin-1β- induced matrix metalloproteinase 1 mRNA expression and interleukin-8 mRNA expression and protein expression. Our findings demonstrate that medroxyprogesterone acetate exerts its anti-inflammatory effect primarily through the glucocorticoid receptor in human amnion mesenchymal cells. Modulation of glucocorticoid receptor signaling pathways maybe a useful therapeutic strategy for preventing inflammation induced fetal membrane weakening leading to preterm premature rupture of membranes.
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Affiliation(s)
- William Marinello
- Department of Anesthesiology, Duke University Hospital, Durham, NC, United States
| | - Liping Feng
- Department of Obstetrics and Gynecology, Duke University Hospital, Durham, NC, United States
| | - Terrence K. Allen
- Department of Anesthesiology, Duke University Hospital, Durham, NC, United States
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10
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Mazaira GI, Echeverria PC, Galigniana MD. Nucleocytoplasmic shuttling of the glucocorticoid receptor is influenced by tetratricopeptide repeat-containing proteins. J Cell Sci 2020; 133:jcs238873. [PMID: 32467326 DOI: 10.1242/jcs.238873] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 04/07/2020] [Indexed: 08/31/2023] Open
Abstract
It has been demonstrated that tetratricopeptide-repeat (TPR) domain proteins regulate the subcellular localization of glucocorticoid receptor (GR). This study analyses the influence of the TPR domain of high molecular weight immunophilins in the retrograde transport and nuclear retention of GR. Overexpression of the TPR peptide prevented efficient nuclear accumulation of the GR by disrupting the formation of complexes with the dynein-associated immunophilin FKBP52 (also known as FKBP4), the adaptor transporter importin-β1 (KPNB1), the nuclear pore-associated glycoprotein Nup62 and nuclear matrix-associated structures. We also show that nuclear import of GR was impaired, whereas GR nuclear export was enhanced. Interestingly, the CRM1 (exportin-1) inhibitor leptomycin-B abolished the effects of TPR peptide overexpression, although the drug did not inhibit GR nuclear export itself. This indicates the existence of a TPR-domain-dependent mechanism for the export of nuclear proteins. The expression balance of those TPR domain proteins bound to the GR-Hsp90 complex may determine the subcellular localization and nucleocytoplasmic properties of the receptor, and thereby its pleiotropic biological properties in different tissues and cell types.
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Affiliation(s)
- Gisela I Mazaira
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires 1428, Argentina
| | - Pablo C Echeverria
- Département de Biologie Cellulaire, Université de Genève, Sciences III, Genève 1211, Switzerland
| | - Mario D Galigniana
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires 1428, Argentina
- Instituto de Biología y Medicina Experimental (IBYME)-CONICET, Buenos Aires 1428, Argentina
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11
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Kershaw S, Morgan DJ, Boyd J, Spiller DG, Kitchen G, Zindy E, Iqbal M, Rattray M, Sanderson CM, Brass A, Jorgensen C, Hussell T, Matthews LC, Ray DW. Glucocorticoids rapidly inhibit cell migration through a novel, non-transcriptional HDAC6 pathway. J Cell Sci 2020; 133:jcs242842. [PMID: 32381682 PMCID: PMC7295589 DOI: 10.1242/jcs.242842] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 04/21/2020] [Indexed: 12/12/2022] Open
Abstract
Glucocorticoids (GCs) act through the glucocorticoid receptor (GR, also known as NR3C1) to regulate immunity, energy metabolism and tissue repair. Upon ligand binding, activated GR mediates cellular effects by regulating gene expression, but some GR effects can occur rapidly without new transcription. Here, we show that GCs rapidly inhibit cell migration, in response to both GR agonist and antagonist ligand binding. The inhibitory effect on migration is prevented by GR knockdown with siRNA, confirming GR specificity, but not by actinomycin D treatment, suggesting a non-transcriptional mechanism. We identified a rapid onset increase in microtubule polymerisation following GC treatment, identifying cytoskeletal stabilisation as the likely mechanism of action. HDAC6 overexpression, but not knockdown of αTAT1, rescued the GC effect, implicating HDAC6 as the GR effector. Consistent with this hypothesis, ligand-dependent cytoplasmic interaction between GR and HDAC6 was demonstrated by quantitative imaging. Taken together, we propose that activated GR inhibits HDAC6 function, and thereby increases the stability of the microtubule network to reduce cell motility. We therefore report a novel, non-transcriptional mechanism whereby GCs impair cell motility through inhibition of HDAC6 and rapid reorganization of the cell architecture.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Stephen Kershaw
- Systems Oncology, Cancer Research UK Manchester Institute, Manchester, SK10 4TG, UK
| | - David J Morgan
- Manchester Collaborative Centre for Inflammation Research, University of Manchester, Manchester, M13 9PT, UK
- Lydia Becker Institute of Immunology and Inflammation University of Manchester, Manchester, M13 9PT, UK
| | - James Boyd
- Division of Cellular and Molecular Physiology, University of Liverpool, Liverpool, L69 3BX, UK
| | - David G Spiller
- Platform Sciences, Enabling Technologies, and Infrastructure, University of Manchester, Manchester, M13 9PT, UK
| | - Gareth Kitchen
- Division of Diabetes, Endocrinology, and Gastroenterology, University of Manchester, Manchester, M13 9PT, UK
| | - Egor Zindy
- Division of Informatics, Imaging, and Data Sciences, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, M13 9PT, UK
| | - Mudassar Iqbal
- Division of Informatics, Imaging, and Data Sciences, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, M13 9PT, UK
| | - Magnus Rattray
- Division of Informatics, Imaging, and Data Sciences, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, M13 9PT, UK
| | - Christopher M Sanderson
- Division of Cellular and Molecular Physiology, University of Liverpool, Liverpool, L69 3BX, UK
| | - Andrew Brass
- Division of Informatics, Imaging, and Data Sciences, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, M13 9PT, UK
| | - Claus Jorgensen
- Systems Oncology, Cancer Research UK Manchester Institute, Manchester, SK10 4TG, UK
| | - Tracy Hussell
- Manchester Collaborative Centre for Inflammation Research, University of Manchester, Manchester, M13 9PT, UK
- Lydia Becker Institute of Immunology and Inflammation University of Manchester, Manchester, M13 9PT, UK
| | - Laura C Matthews
- Leeds Institute of Cancer and Pathology, Faculty of Medicine and Health, University of Leeds, Leeds, LS2 9JT, UK
| | - David W Ray
- Division of Diabetes, Endocrinology, and Gastroenterology, University of Manchester, Manchester, M13 9PT, UK
- Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford, OX3 7LE, and NIHR Oxford Biomedical Research Centre, John Radcliffe Hospital, Oxford, OX3 9DU, UK
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12
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Manjari P, Hyder I, Dang AK. Implantation associated divergence in neutrophil glucocorticoid and cysteine-X-cysteine receptor genes in cattle. Mol Biol Rep 2019; 46:5493-5499. [PMID: 31165367 DOI: 10.1007/s11033-019-04865-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 05/09/2019] [Indexed: 10/26/2022]
Abstract
The differential roles of Interferon-tau (IFNT) and Progesterone (P4) in triggering pro- and anti-inflammatory responses during peri-implantation period were assessed in cows. An ex vivo study was done by isolating neutrophils from the animals post artificial insemination (AI) at defined intervals and analyzing the expression changes of Glucocorticoid receptor-α (GRα) and Interleukin-8 receptor (CXCR1) genes. An in vitro study was also done isolating neutrophils from prepubertal heifers subjecting them to IFNT and Progesterone P4 supplementation separately. We observed that from day 14 post Artificial Insemination, there is a significant up-regulation of neutrophil GRα and CXCR1 in pregnant and non-pregnant cows respectively. The in vitro study showed that IFNT significantly up-regulates GRα whereas P4 significantly up-regulates CXCR1. The total leukocyte count and neutrophil count were also significantly higher in non-pregnant cows. We conclude that IFNT efficiently mediates neutrophil immunosuppression during peri-implantation period in cows by interacting with Interleukin 8 receptor and can also exert ligand independent actions on GRα.
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Affiliation(s)
- P Manjari
- Krishi Vigyan Kendra, KVK Venkatagiri (YSR Horticulture University), Nellore, Andhra Pradesh, 524132, India.
| | - Iqbal Hyder
- Department of Veterinary Physiology, NTR CVSc, Gannavaram, 521102, India.,Institute of Farm Animal Genetics (FLI), Mariensee, 31535, Neustadt, Germany
| | - A K Dang
- Division of Dairy Cattle Physiology, ICAR-NDRI, Karnal, Haryana, 132001, India
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Rigalli JP, Tocchetti GN, Weiss J. Modulation of ABC Transporters by Nuclear Receptors: Physiological, Pathological and Pharmacological Aspects. Curr Med Chem 2019; 26:1079-1112. [DOI: 10.2174/0929867324666170920141707] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 07/24/2017] [Accepted: 08/08/2017] [Indexed: 12/11/2022]
Abstract
ABC transporters are membrane proteins mediating the efflux of endo- and xenobiotics. Transporter expression is not static but instead is subject to a dynamic modulation aiming at responding to changes in the internal environment and thus at maintaining homeostatic conditions. Nuclear receptors are ligand modulated transcription factors that get activated upon changes in the intracellular concentrations of the respective agonists and bind to response elements within the promoter of ABC transporters, thus modulating their expression and, consequently, their activity. This review compiles information about transporter regulation by nuclear receptors classified according to the perpetrator compounds and the biological effects resulting from the regulation. Modulation by hormone receptors is involved in maintaining endocrine homeostasis and may also lead to an altered efflux of other substrates in cases of altered hormonal levels. Xenobiotic receptors play a key role in limiting the accumulation of potentially harmful compounds. In addition, their frequent activation by therapeutic agents makes them common molecular elements mediating drug-drug interactions and cancer multidrug resistance. Finally, lipid and retinoid receptors are usually activated by endogenous molecules, thus sensing metabolic changes and inducing ABC transporters to counteract potential alterations. Furthermore, the axis nuclear receptor-ABC transporter constitutes a promising therapeutic target for the treatment of several disease states like cancer, atherosclerosis and dyslipidemia. In the current work, we summarize the information available on the pharmacological potential of nuclear receptor modulators and discuss their applicability in the clinical practice.
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Affiliation(s)
- Juan Pablo Rigalli
- Department of Clinical Pharmacology and Pharmacoepidemiology. University of Heidelberg. Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Guillermo Nicolás Tocchetti
- Department of Clinical Pharmacology and Pharmacoepidemiology. University of Heidelberg. Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Johanna Weiss
- Department of Clinical Pharmacology and Pharmacoepidemiology. University of Heidelberg. Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
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Cui X, Pertile R, Eyles DW. The vitamin D receptor (VDR) binds to the nuclear matrix via its hinge domain: A potential mechanism for the reduction in VDR mediated transcription in mitotic cells. Mol Cell Endocrinol 2018; 472:18-25. [PMID: 29183808 DOI: 10.1016/j.mce.2017.11.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 11/15/2017] [Accepted: 11/16/2017] [Indexed: 12/17/2022]
Abstract
Vitamin D is best known for its regulation of calcium homeostasis. Vitamin D exerts its genomic actions via the vitamin D receptor (VDR). As a member of the superfamily of nuclear receptors (NR), the VDR is primarily located within the nucleus of non-dividing cells. We show here that the VDR relocates from the nucleus into the cytoplasm across all stages of cell division in CHO cells. Furthermore, we show that the VDR is transcriptionally inert during cell division. In addition, 1α, 25 dihydroxyvitamin D (1,25(OH)2D3) promotes VDR binding to the nuclear matrix. Finally, we assessed the structural nature of VDR binding to the nuclear matrix. Mutation of the hinge domain reduced VDR's ability to bind to the nuclear matrix and to initiate transcription in response to 1,25(OH)2D3. Taken together, our data suggest that the association between the VDR and the nuclear matrix accounts for the apparent cytosolic distribution as the matrix disperses within the cytoplasm when cells divide. This may also explain the dramatic reduction in VDR mediated transcription during cell division. Our data also confirm that similar to other NRs, the hinge domain of the VDR is responsible for this association.
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Affiliation(s)
- Xiaoying Cui
- Queensland Brain Institute, University of Queensland, Qld 4072, Australia
| | - Renata Pertile
- Queensland Brain Institute, University of Queensland, Qld 4072, Australia
| | - Darryl W Eyles
- Queensland Brain Institute, University of Queensland, Qld 4072, Australia; Queensland Centre for Mental Health Research, Wacol, Qld 4076, Australia.
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15
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Ribociclib, a Cdk4/Cdk6 kinase inhibitor, enhances glucocorticoid sensitivity in B-acute lymphoblastic leukemia (B-All). Biochem Pharmacol 2018; 153:230-241. [PMID: 29408328 DOI: 10.1016/j.bcp.2018.01.050] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 01/31/2018] [Indexed: 12/15/2022]
Abstract
Dysregulation of the cyclin D1-CDK4/CDK6 complex is frequently observed in almost all human cancer and contributes to aberrant cell proliferation and consequent tumorigenesis. Although many reports described the importance of CDK4/CDK6 in different set of human tumors, only few studies have been performed on leukemia. By gene expression analysis performed in a cohort of childhood patients affected by B-acute lymphoblastic leukemia (B-ALL) we found that both CDK4 and CDK6 are highly expressed. Moreover, reverse phase protein array (RPPA) analysis showed that cyclin D1 levels are higher in patients undergoing relapse. Starting from these considerations, we evaluated the effect of dual inhibition of CDK4/CDK6 in B-ALL and if this inhibition could enhance cytotoxic killing of leukemia cells after combination treatment with dexamethasone. We treated B-ALL cell lines with ribociclib, a highly specific CDK4/6 inhibitor. As expected, treatment with ribociclib induced growth inhibition of B-ALL cell lines, accompanied by strong cell cycle arrest in G1 phase, along with a dose-dependent decrease in phosphorylated retinoblastoma protein. Ribociclib exposure strongly synergizes with dexamethasone in SEM and RCH-ACV, two dexamethasone-resistant cell lines, along with a strong decrease in proliferation and a significant increase in apoptotic cell death. These results were also confirmed on primary cultures derived from bone marrow of pediatric patients affected by B-ALL. Immunoblot analysis showed a significant increase in glucocorticoid receptor (GR) along with some of its target genes, after combined treatment with ribociclib and dexamethasone. Altogether our findings support the concept that pharmacologic inhibition of CDK4/CDK6 may represent a useful therapeutic strategy to control cell proliferation in B-ALL and provide new insight in understanding potential mechanism of glucocorticoid resistance.
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Ptushkina M, Poolman T, Iqbal M, Ashe M, Petersen J, Woodburn J, Rattray M, Whetton A, Ray D. A non-transcriptional role for the glucocorticoid receptor in mediating the cell stress response. Sci Rep 2017; 7:12101. [PMID: 28935859 PMCID: PMC5608759 DOI: 10.1038/s41598-017-09722-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 07/17/2017] [Indexed: 11/25/2022] Open
Abstract
The glucocorticoid receptor (GR) is essential for the stress response in mammals. We investigated potential non-transcriptional roles of GR in cellular stress response using fission yeast as a model.We surprisingly discovered marked heat stress resistance in yeast ectopically expressing human GR, which required expression of both the N-terminal transactivation domain, and the C-terminal ligand binding domain, but not the DNA-binding domain of the GR. This effect was not affected by GR ligand exposure, and occurred without significant GR nuclear accumulation. Mechanistically, the GR survival effect required Hsp104, and, indeed, GR expression increased Hsp104 expression. Proteomic analysis revealed GR binding to translasome components, including eIF3, a known partner for Sty1, a pattern of protein interaction which we confirmed using yeast two-hybrid studies.Taken together, we find evidence for a novel pathway conferring stress resistance in yeast that can be activated by the human GR, acting by protein-protein mechanisms in the cytoplasm. This suggests that in organisms where GR is natively expressed, GR likely contributes to stress responses through non-transcriptional mechanisms in addition to its well-established transcriptional responses.
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Affiliation(s)
- Marina Ptushkina
- School of Medical Sciences, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, M13 9PT, UK.
- Manchester Academic Health Sciences Centre, Manchester, M13 9PT, UK.
| | - Toryn Poolman
- School of Medical Sciences, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, M13 9PT, UK
- Manchester Academic Health Sciences Centre, Manchester, M13 9PT, UK
| | - Mudassar Iqbal
- School of Medical Sciences, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, M13 9PT, UK
- Manchester Academic Health Sciences Centre, Manchester, M13 9PT, UK
| | - Mark Ashe
- School of Medical Sciences, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, M13 9PT, UK
- Manchester Academic Health Sciences Centre, Manchester, M13 9PT, UK
| | - Janni Petersen
- School of Health Science, Flinders University, South Australia Sturt Road 5042, GPO Box 2100, Adelaide, Australia
| | - Joanna Woodburn
- School of Medical Sciences, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, M13 9PT, UK
- Manchester Academic Health Sciences Centre, Manchester, M13 9PT, UK
| | - Magnus Rattray
- School of Medical Sciences, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, M13 9PT, UK
- Manchester Academic Health Sciences Centre, Manchester, M13 9PT, UK
| | - Anthony Whetton
- Division of Cancer, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PT, UK
- Manchester Academic Health Sciences Centre, Manchester, M13 9PT, UK
| | - David Ray
- School of Medical Sciences, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, M13 9PT, UK.
- Manchester Academic Health Sciences Centre, Manchester, M13 9PT, UK.
- Department of Endocrinology, Manchester Royal Infirmary, Manchester, M13 9WL, UK.
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17
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Scheschowitsch K, Leite JA, Assreuy J. New Insights in Glucocorticoid Receptor Signaling-More Than Just a Ligand-Binding Receptor. Front Endocrinol (Lausanne) 2017; 8:16. [PMID: 28220107 PMCID: PMC5292432 DOI: 10.3389/fendo.2017.00016] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 01/18/2017] [Indexed: 12/20/2022] Open
Abstract
The clinical use of classical glucocorticoids (GC) is narrowed by the many side effects it causes and the resistance to GC observed in some diseases. Since the great majority of GC effects depend on the activation of a glucocorticoid receptor (GR), many research groups had focused to better understand the signaling pathways involving those receptors. Transgenic animal models and genetic modifications of the receptor brought a huge insight into GR mechanisms of action. This in turn opened a new window for the search of selective GR modulators that ideally may have agonistic and antagonistic combined effects and activate one specific signaling pathway, inducing mostly transrepression or transactivation mechanisms. Another important research field concerns to posttranslational modifications that affect the GR and consequently also affect its signaling and function. In this mini review, we discuss many of those aspects of GR signaling, as well as findings like the ligand-independent activation of GR, which add another layer of complexity in GR signaling pathways. Although several recent data have been added to the GR field, much work has yet to be done, especially to find out the biological relevance of those alternative GR signaling pathways. Improving the knowledge about alternative GR signaling pathways and understanding how these pathways intercommunicate and in which situations they are relevant might help to develop new strategies to take benefit of it and to improve GC or other compounds efficacy causing minimal side effects.
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Affiliation(s)
- Karin Scheschowitsch
- Department of Pharmacology, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Jacqueline Alves Leite
- Department of Pharmacology, Institute of Biomedical Sciences, Universidade de São Paulo, São Paulo, Brazil
| | - Jamil Assreuy
- Department of Pharmacology, Universidade Federal de Santa Catarina, Florianópolis, Brazil
- *Correspondence: Jamil Assreuy,
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18
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Hapgood JP, Avenant C, Moliki JM. Glucocorticoid-independent modulation of GR activity: Implications for immunotherapy. Pharmacol Ther 2016; 165:93-113. [PMID: 27288728 DOI: 10.1016/j.pharmthera.2016.06.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 05/16/2016] [Indexed: 12/19/2022]
Abstract
Pharmacological doses of glucocorticoids (GCs), acting via the glucocorticoid receptor (GR) to repress inflammation and immune function, remain the most effective therapy in the treatment of inflammatory and immune diseases. Since many patients on GC therapy exhibit GC resistance and severe side-effects, much research is focused on developing more selective GCs and combination therapies, with greater anti-inflammatory potency. GCs mediate their classical genomic transcriptional effects by binding to the cytoplasmic GR, followed by nuclear translocation and modulation of transcription of target genes by direct DNA binding of the GR or its tethering to other transcription factors. Recent evidence suggests, however, that the responses mediated by the GR are much more complex and involve multiple parallel mechanisms integrating simultaneous signals from other receptors, both in the absence and presence of GCs, to shift the sensitivity of a target cell to GCs. The level of cellular stress, immune activation status, or the cell cycle phase may be crucial for determining GC sensitivity and GC responsiveness as well as subcellular localization of the GR and GR levels. Central to the development of new drugs that target GR signaling alone or as add-on therapies, is an in-depth understanding of the molecular mechanisms of GC-independent GR desensitization, priming and activation of the unliganded GR, as well as synergy and cross-talk with other signaling pathways. This review will discuss the information currently available on these topics and their relevance to immunotherapy, as well as identify unanswered questions and future areas of research.
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Affiliation(s)
- Janet P Hapgood
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag X3, Rondebosch, 7700, South Africa.
| | - Chanel Avenant
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag X3, Rondebosch, 7700, South Africa
| | - Johnson M Moliki
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag X3, Rondebosch, 7700, South Africa
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19
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Zheng Y, Murphy LC. Regulation of steroid hormone receptors and coregulators during the cell cycle highlights potential novel function in addition to roles as transcription factors. NUCLEAR RECEPTOR SIGNALING 2016; 14:e001. [PMID: 26778927 PMCID: PMC4714463 DOI: 10.1621/nrs.14001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 10/01/2015] [Indexed: 01/15/2023]
Abstract
Cell cycle progression is tightly controlled by several kinase families including Cyclin-Dependent Kinases, Polo-Like Kinases, and Aurora Kinases. A large amount of data show that steroid hormone receptors and various components of the cell cycle, including cell cycle regulated kinases, interact, and this often results in altered transcriptional activity of the receptor. Furthermore, steroid hormones, through their receptors, can also regulate the transcriptional expression of genes that are required for cell cycle regulation. However, emerging data suggest that steroid hormone receptors may have roles in cell cycle progression independent of their transcriptional activity. The following is a review of how steroid receptors and their coregulators can regulate or be regulated by the cell cycle machinery, with a particular focus on roles independent of transcription in G2/M.
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Affiliation(s)
- Yingfeng Zheng
- Department of Biochemistry and Medical Genetics (YZ, LCM), University of Manitoba; Manitoba Institute of Cell Biology (YZ, LCM), CancerCare Manitoba, Winnipeg, Manitoba, Canada
| | - Leigh C Murphy
- Department of Biochemistry and Medical Genetics (YZ, LCM), University of Manitoba; Manitoba Institute of Cell Biology (YZ, LCM), CancerCare Manitoba, Winnipeg, Manitoba, Canada
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20
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Nicolaides NC, Charmandari E. Chrousos syndrome: from molecular pathogenesis to therapeutic management. Eur J Clin Invest 2015; 45:504-14. [PMID: 25715669 DOI: 10.1111/eci.12426] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Accepted: 02/23/2015] [Indexed: 12/14/2022]
Abstract
BACKGROUND Primary Generalized Glucocorticoid Resistance or Chrousos syndrome is a rare genetic condition characterized by end-organ insensitivity to glucocorticoids owing to inactivating mutations of the NR3C1 gene. MATERIALS AND METHODS We conducted a systematic review of the published, peer-reviewed medical literature using MEDLINE (1975 through November 2014) to identify original articles and reviews on this topic. The search terms included 'primary generalized glucocorticoid resistance', 'Chrousos syndrome', 'glucocorticoid receptor gene' and 'glucocorticoid receptor mutations'. RESULTS Only a few cases of Chrousos syndrome have been described to date, ranging from asymptomatic to severe forms of mineralocorticoid and/or androgen excess. All reported cases have been associated with point mutations or deletions in the NR3C1 gene. The tremendous progress of molecular biology has enabled us to apply standard methods to investigate the molecular mechanisms of action of the mutant glucocorticoid receptors (GRs). We and others have identified and functionally characterized novel mutations causing Chrousos syndrome, while structural biology has enabled us to have a better understanding of how conformational changes of the receptor cause glucocorticoid resistance. In this review, we also present our results of the functional characterization of two recently described mutations, and we discuss the diagnostic approaches and therapeutic management of patients with Chrousos syndrome. CONCLUSIONS Although Chrousos syndrome is a rare condition, many clinical cases remain unrecognized for a long time. We recommend determination of the 24-h urinary free cortisol excretion and sequencing of the NR3C1 gene in patients with hyperandrogenism and/or hypertension of unknown origin.
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Affiliation(s)
- Nicolas C Nicolaides
- Division of Endocrinology, Metabolism and Diabetes, First Department of Pediatrics, University of Athens Medical School, 'Aghia Sophia' Children's Hospital, Athens, Greece; Division of Endocrinology and Metabolism, Clinical Research Center, Biomedical Research Foundation of the Academy of Athens, Athens, Greece
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21
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Glucocorticoid receptor regulates accurate chromosome segregation and is associated with malignancy. Proc Natl Acad Sci U S A 2015; 112:5479-84. [PMID: 25847991 DOI: 10.1073/pnas.1411356112] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The glucocorticoid receptor (GR) is a member of the nuclear receptor superfamily, which controls programs regulating cell proliferation, differentiation, and apoptosis. We have identified an unexpected role for GR in mitosis. We discovered that specifically modified GR species accumulate at the mitotic spindle during mitosis in a distribution that overlaps with Aurora kinases. We found that Aurora A was required to mediate mitosis-driven GR phosphorylation, but not recruitment of GR to the spindle. GR was necessary for mitotic progression, with increased time to complete mitosis, frequency of mitotic aberrations, and death in mitosis observed following GR knockdown. Complementation studies revealed an essential role for the GR ligand-binding domain, but no clear requirement for ligand binding in regulating chromosome segregation. The GR N-terminal domain, and specifically phosphosites S203 and S211, were not required. Reduced GR expression results in a cell cycle phenotype, with isolated cells from mouse and human subjects showing changes in chromosome content over prolonged passage. Furthermore, GR haploinsufficient mice have an increased incidence of tumor formation, and, strikingly, these tumors are further depleted for GR, implying additional GR loss as a consequence of cell transformation. We identified reduced GR expression in a panel of human liver, lung, prostate, colon, and breast cancers. We therefore reveal an unexpected role for the GR in promoting accurate chromosome segregation during mitosis, which is causally linked to tumorigenesis, making GR an authentic tumor suppressor gene.
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22
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Abstract
The androgen receptor (AR) is a critical oncogene in prostate cancer (PCa) development and progression. In this study, we demonstrate cell-cycle-dependent regulation of AR activity, localization, and phosphorylation. We show that for three AR-target genes, androgen-stimulated AR transactivation is highest during the G1 phase, decreased during S-phase, and abrogated during G2/M. This change in AR transactivation parallels changes in AR localization and phosphorylation. A combination of imaging techniques and quantitative analysis reveals nuclear AR localization during interphase and the exclusion of the majority, but not all, AR from chromatin during mitosis. Flow cytometry analyses using a phospho-S308 AR-specific antibody in asynchronous and chemically enriched G2/M PCa cells revealed ligand-independent induction of S308 phosphorylation in mitosis when CDK1 is activated. Consistent with our flow cytometry data, IP-western blotting revealed an increase in S308 phosphorylation in G2/M, and the results of an in vitro kinase assay indicated that CDK1 was able to phosphorylate the AR on S308. Pharmacological inhibition of CDK1 activity resulted in decreased S308 phosphorylation in PCa cells. Importantly, using a combination of anti-total AR and phospho-S308-specific antibodies in immunofluorescence experiments, we showed that the AR is excluded from condensed chromatin in mitotic cells when it was phosphorylated on S308. In summary, we show that the phosphorylation of the AR on S308 by CDK1 during mitosis regulates AR localization and correlates with changes in AR transcriptional activity. These findings have important implications for understanding the function of AR as an oncogene.
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Affiliation(s)
- Yulia Koryakina
- Department of MicrobiologyImmunology, and Cancer Biology, University of Virginia, Jordan Hall Room 2-16, 1300 Jefferson Park Avenue, PO Box 800734, Charlottesville, Virginia 22908, USASidney Kimmel Cancer CenterThomas Jefferson University, Philadelphia, Pennsylvania, USACancer Center MemberUniversity of Virginia, Charlottesville, Virginia, USA
| | - Karen E Knudsen
- Department of MicrobiologyImmunology, and Cancer Biology, University of Virginia, Jordan Hall Room 2-16, 1300 Jefferson Park Avenue, PO Box 800734, Charlottesville, Virginia 22908, USASidney Kimmel Cancer CenterThomas Jefferson University, Philadelphia, Pennsylvania, USACancer Center MemberUniversity of Virginia, Charlottesville, Virginia, USA
| | - Daniel Gioeli
- Department of MicrobiologyImmunology, and Cancer Biology, University of Virginia, Jordan Hall Room 2-16, 1300 Jefferson Park Avenue, PO Box 800734, Charlottesville, Virginia 22908, USASidney Kimmel Cancer CenterThomas Jefferson University, Philadelphia, Pennsylvania, USACancer Center MemberUniversity of Virginia, Charlottesville, Virginia, USA Department of MicrobiologyImmunology, and Cancer Biology, University of Virginia, Jordan Hall Room 2-16, 1300 Jefferson Park Avenue, PO Box 800734, Charlottesville, Virginia 22908, USASidney Kimmel Cancer CenterThomas Jefferson University, Philadelphia, Pennsylvania, USACancer Center MemberUniversity of Virginia, Charlottesville, Virginia, USA
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23
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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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Russell GM, Lightman SL. Can side effects of steroid treatments be minimized by the temporal aspects of delivery method? Expert Opin Drug Saf 2014; 13:1501-13. [DOI: 10.1517/14740338.2014.965141] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Wehmeyer L, Du Toit A, Lang DM, Hapgood JP. Lipid raft- and protein kinase C-mediated synergism between glucocorticoid- and gonadotropin-releasing hormone signaling results in decreased cell proliferation. J Biol Chem 2014; 289:10235-51. [PMID: 24558046 DOI: 10.1074/jbc.m113.544742] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cross-talk between the glucocorticoid receptor (GR) and other receptors is emerging as a mechanism for fine-tuning cellular responses. We have previously shown that gonadotropin-releasing hormone (GnRH) ligand-independently activates the GR and synergistically modulates glucocorticoid-induced transcription of an endogenous gene in LβT2 pituitary gonadotrope precursor cells. Here, we investigated GR and GnRH receptor (GnRHR) cross-talk that involves co-localization with lipid rafts in LβT2 cells. We report that the GnRHR and a small population of the GR co-localize with the lipid raft protein flotillin-1 (Flot-1) at the plasma membrane and that the GR is present in a complex with Flot-1, independent of the presence of ligands. We found that the SGK-1 gene is up-regulated by Dex and GnRH alone, whereas a combination of both ligands resulted in a synergistic increase in SGK-1 mRNA levels. Using siRNA-mediated knockdown and antagonist strategies, we show that the gene-specific synergistic transcriptional response requires the GR, GnRHR, and Flot-1 as well as the protein kinase C pathway. Interestingly, although several GR cofactors are differentially recruited to the SGK-1 promoter in the presence of Dex and GnRH, GR levels remain unchanged compared with Dex treatment alone, suggesting that lipid raft association of the GR has a role in enhancing its transcriptional output in the nucleus. Finally, we show that Dex plus GnRH synergistically inhibit cell proliferation in a manner dependent on SGK-1 and Flot-1. Collectively the results support a mechanism whereby GR and GnRHR cross-talk within Flot-1-containing lipid rafts modulates cell proliferation via PKC activation and SGK-1 up-regulation.
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Affiliation(s)
- Lancelot Wehmeyer
- From the Department of Molecular and Cell Biology, Faculty of Science and
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Pattern of heat shock factor and heat shock protein expression in lymphocytes of bipolar patients: increased HSP70-glucocorticoid receptor heterocomplex. J Psychiatr Res 2013; 47:1725-36. [PMID: 23938235 DOI: 10.1016/j.jpsychires.2013.07.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Revised: 05/22/2013] [Accepted: 07/17/2013] [Indexed: 12/21/2022]
Abstract
Bipolar disorder (BD), a stress-related disease, is characterized by altered glucocorticoid receptor (GR) signalling. Stress response includes activation of heat shock factor (HSF) and subsequent heat shock protein (HSP) synthesis which regulate GR folding and function. The objective of this study was to investigate the possible role of HSFs, HSPs and their interaction with GR in BD. We applied immunoprecipitation, SDS-PAGE/Western blot analysis and electrophoretic mobility shift assay (EMSA) in lymphocytes (whole cell or nuclear extracts) from BD patients and healthy subjects and determined the HSPs (HSP90 and HSP70), the heterocomplexes HSP90-GR and HSP70-GR, the HSFs (HSF1 and HSF4) as well as the HSF-DNA binding. The HSP70-GR heterocomplex was elevated (p < 0.05) in BD patients vs healthy subjects, and nuclear HSP70 was reduced (p ≤ 0.01) in bipolar manic patients. Protein levels of HSF1, HSF4, HSP90, HSP90-GR heterocomplex, and HSF-DNA binding remained unaltered in BD patients vs healthy subjects. The corresponding effect sizes (ES) indicated a large ES for HSP70-GR, HSP70, HSF-DNA binding and HSF4, and a medium ES for HSP90, HSF1 and HSP90-GR between healthy subjects and bipolar patients. Significant correlations among HSFs, HSPs, GR and HSP70-GR heterocomplex were observed in healthy subjects, which were abrogated in bipolar patients. The higher interaction between GR and HSP70 and the disturbances in the relations among heat shock response parameters and GR as observed in our BD patients may provide novel insights into the contribution of these factors in BD aetiopathogenesis.
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Nayebosadri A, Ji JY. Endothelial nuclear lamina is not required for glucocorticoid receptor nuclear import but does affect receptor-mediated transcription activation. Am J Physiol Cell Physiol 2013; 305:C309-22. [PMID: 23703529 DOI: 10.1152/ajpcell.00293.2012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The lamina serves to maintain the nuclear structure and stiffness while acting as a scaffold for heterochromatin and many transcriptional proteins. Its role in endothelial mechanotransduction, specifically how nuclear mechanics impact gene regulation under shear stress, is not fully understood. In this study, we successfully silenced lamin A/C in bovine aortic endothelial cells to determine its role in both glucocorticoid receptor (GR) nuclear translocation and glucocorticoid response element (GRE) transcriptional activation in response to dexamethasone and shear stress. Nuclear translocation of GR, an anti-inflammatory nuclear receptor, in response to dexamethasone or shear stress (5, 10, and 25 dyn/cm(2)) was observed via time-lapse cell imaging and quantified using a Bayesian image analysis algorithm. Transcriptional activity of the GRE promoter was assessed using a dual-luciferase reporter plasmid. We found no dependence on nuclear lamina for GR translocation from the cytoplasm into the nucleus. However, the absence of lamin A/C led to significantly increased expression of luciferase under dexamethasone and shear stress induction as well as changes in histone protein function. PCR results for NF-κB inhibitor alpha (NF-κBIA) and dual specificity phosphatase 1 (DUSP1) genes further supported our luciferase data with increased expression in the absence of lamin. Our results suggest that absence of lamin A/C does not hinder passage of GR into the nucleus, but nuclear lamina is important to properly regulate GRE transcription. Nuclear lamina, rather than histone deacetylase (HDAC), is a more significant mediator of shear stress-induced transcriptional activity, while dexamethasone-initiated transcription is more HDAC dependent. Our findings provide more insights into the molecular pathways involved in nuclear mechanotransduction.
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Affiliation(s)
- Arman Nayebosadri
- Department of Biomedical Engineering, Indiana University Purdue University Indianapolis, Indiana University Purdue University Indianapolis, Indianapolis, Indiana, USA
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Robertson S, Rohwer JM, Hapgood JP, Louw A. Impact of glucocorticoid receptor density on ligand-independent dimerization, cooperative ligand-binding and basal priming of transactivation: a cell culture model. PLoS One 2013; 8:e64831. [PMID: 23717665 PMCID: PMC3661511 DOI: 10.1371/journal.pone.0064831] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 04/18/2013] [Indexed: 11/26/2022] Open
Abstract
Glucocorticoid receptor (GR) levels vary between tissues and individuals and are altered by physiological and pharmacological effectors. However, the effects and implications of differences in GR concentration have not been fully elucidated. Using three statistically different GR concentrations in transiently transfected COS-1 cells, we demonstrate, using co-immunoprecipitation (CoIP) and fluorescent resonance energy transfer (FRET), that high levels of wild type GR (wtGR), but not of dimerization deficient GR (GRdim), display ligand-independent dimerization. Whole-cell saturation ligand-binding experiments furthermore establish that positive cooperative ligand-binding, with a concomitant increased ligand-binding affinity, is facilitated by ligand-independent dimerization at high concentrations of wtGR, but not GRdim. The down-stream consequences of ligand-independent dimerization at high concentrations of wtGR, but not GRdim, are shown to include basal priming of the system as witnessed by ligand-independent transactivation of both a GRE-containing promoter-reporter and the endogenous glucocorticoid (GC)-responsive gene, GILZ, as well as ligand-independent loading of GR onto the GILZ promoter. Pursuant to the basal priming of the system, addition of ligand results in a significantly greater modulation of transactivation potency than would be expected solely from the increase in ligand-binding affinity. Thus ligand-independent dimerization of the GR at high concentrations primes the system, through ligand-independent DNA loading and transactivation, which together with positive cooperative ligand-binding increases the potency of GR agonists and shifts the bio-character of partial GR agonists. Clearly GR-levels are a major factor in determining the sensitivity to GCs and a critical factor regulating transcriptional programs.
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Affiliation(s)
- Steven Robertson
- Department of Biochemistry, University of Stellenbosch, Matieland, Stellenbosch, Republic of South Africa
| | - Johann M. Rohwer
- Department of Biochemistry, University of Stellenbosch, Matieland, Stellenbosch, Republic of South Africa
| | - Janet P. Hapgood
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, Republic of South Africa
| | - Ann Louw
- Department of Biochemistry, University of Stellenbosch, Matieland, Stellenbosch, Republic of South Africa
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Trebble PJ, Woolven JM, Saunders KA, Simpson KD, Farrow SN, Matthews LC, Ray DW. A ligand-specific kinetic switch regulates glucocorticoid receptor trafficking and function. J Cell Sci 2013; 126:3159-69. [PMID: 23687373 DOI: 10.1242/jcs.124784] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The ubiquitously expressed glucocorticoid receptor (GR) is a major drug target for inflammatory disease, but issues of specificity and target tissue sensitivity remain. We now identify high potency, non-steroidal GR ligands, GSK47867A and GSK47869A, which induce a novel conformation of the GR ligand-binding domain (LBD) and augment the efficacy of cellular action. Despite their high potency, GSK47867A and GSK47869A both induce surprisingly slow GR nuclear translocation, followed by prolonged nuclear GR retention, and transcriptional activity following washout. We reveal that GSK47867A and GSK47869A specifically alter the GR LBD structure at the HSP90-binding site. The alteration in the HSP90-binding site was accompanied by resistance to HSP90 antagonism, with persisting transactivation seen after geldanamycin treatment. Taken together, our studies reveal a new mechanism governing GR intracellular trafficking regulated by ligand binding that relies on a specific surface charge patch within the LBD. This conformational change permits extended GR action, probably because of altered GR-HSP90 interaction. This chemical series may offer anti-inflammatory drugs with prolonged duration of action due to altered pharmacodynamics rather than altered pharmacokinetics.
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Affiliation(s)
- Peter J Trebble
- Manchester Centre for Nuclear Hormone Research in Disease, University of Manchester, Oxford Road, Manchester M13 9PT, UK
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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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