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Yan M, Wang J, Wang H, Zhou J, Qi H, Naji Y, Zhao L, Tang Y, Dai Y. Knockdown of NR3C1 inhibits the proliferation and migration of clear cell renal cell carcinoma through activating endoplasmic reticulum stress-mitophagy. J Transl Med 2023; 21:701. [PMID: 37807060 PMCID: PMC10560440 DOI: 10.1186/s12967-023-04560-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 09/22/2023] [Indexed: 10/10/2023] Open
Abstract
BACKGROUND Clear cell renal cell carcinoma (ccRCC) is closely associated with steroid hormones and their receptors affected by lipid metabolism. Recently, there has been growing interest in the carcinogenic role of NR3C1, the sole gene responsible for encoding glucocorticoid receptor. However, the specific role of NR3C1 in ccRCC remains unclear. The present study was thus developed to explore the underlying mechanism of NR3C1's carcinogenic effects in ccRCC. METHODS Expression of NR3C1 was verified by various tumor databases and assessed using RT-qPCR and western blot. Stable transfected cell lines of ccRCC with NR3C1 knockdown were constructed, and a range of in vitro and in vivo experiments were performed to examine the effects of NR3C1 on ccRCC proliferation and migration. Transcriptomics and lipidomics sequencing were then conducted on ACHN cells, which were divided into control and sh-NR3C1 group. Finally, the sequencing results were validated using transmission electron microscopy, mitochondrial membrane potential assay, immunofluorescence co-localization, cell immunofluorescent staining, and Western blot. The rescue experiments were designed to investigate the relationship between endoplasmic reticulum stress (ER stress) and mitophagy in ccRCC cells after NR3C1 knockdown, as well as the regulation of their intrinsic signaling pathways. RESULTS The expression of NR3C1 in ccRCC cells and tissues was significantly elevated. The sh-NR3C1 group, which had lower levels of NR3C1, exhibited a lower proliferation and migration capacity of ccRCC than that of the control group (P < 0.05). Then, lipidomic and transcriptomic sequencing showed that lipid metabolism disorders, ER stress, and mitophagy genes were enriched in the sh-NR3C1 group. Finally, compared to the control group, ER stress and mitophagy were observed in the sh-NR3C1 group, while the expression of ATF6, CHOP, PINK1, and BNIP3 was also up-regulated (P < 0.05). Furthermore, Ceapin-A7, an inhibitor of ATF6, significantly down-regulated the expression of PINK1 and BNIP3 (P < 0.05), and significantly increased the proliferation and migration of ccRCC cells (P < 0.05). CONCLUSIONS This study confirms that knockdown of NR3C1 activates ER stress and induces mitophagy through the ATF6-PINK1/BNIP3 pathway, resulting in reduced proliferation and migration of ccRCC. These findings indicate potential novel targets for clinical treatment of ccRCC.
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Affiliation(s)
- Minbo Yan
- Department of Urology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, Guangdong, China
- Guangdong Provincial Key Laboratory of Biomedical Imaging, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, Guangdong, China
| | - Jinhua Wang
- Department of Urology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, Guangdong, China
- Guangdong Provincial Key Laboratory of Biomedical Imaging, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, Guangdong, China
| | - Haojie Wang
- Department of Urology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, Guangdong, China
- Guangdong Provincial Key Laboratory of Biomedical Imaging, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, Guangdong, China
| | - Jun Zhou
- Department of Urology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, Guangdong, China
- Guangdong Provincial Key Laboratory of Biomedical Imaging, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, Guangdong, China
| | - Hao Qi
- Department of Urology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, Guangdong, China
- Guangdong Provincial Key Laboratory of Biomedical Imaging, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, Guangdong, China
| | - Yaser Naji
- Department of Urology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, Guangdong, China
| | - Liangyu Zhao
- Department of Urology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, Guangdong, China.
- Guangdong Provincial Key Laboratory of Biomedical Imaging, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, Guangdong, China.
| | - Yuxin Tang
- Department of Urology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, Guangdong, China.
- Guangdong Provincial Key Laboratory of Biomedical Imaging, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, Guangdong, China.
| | - Yingbo Dai
- Department of Urology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, Guangdong, China.
- Guangdong Provincial Key Laboratory of Biomedical Imaging, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, Guangdong, China.
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Boeddrich A, Haenig C, Neuendorf N, Blanc E, Ivanov A, Kirchner M, Schleumann P, Bayraktaroğlu I, Richter M, Molenda CM, Sporbert A, Zenkner M, Schnoegl S, Suenkel C, Schneider LS, Rybak-Wolf A, Kochnowsky B, Byrne LM, Wild EJ, Nielsen JE, Dittmar G, Peters O, Beule D, Wanker EE. A proteomics analysis of 5xFAD mouse brain regions reveals the lysosome-associated protein Arl8b as a candidate biomarker for Alzheimer's disease. Genome Med 2023; 15:50. [PMID: 37468900 PMCID: PMC10357615 DOI: 10.1186/s13073-023-01206-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 06/22/2023] [Indexed: 07/21/2023] Open
Abstract
BACKGROUND Alzheimer's disease (AD) is characterized by the intra- and extracellular accumulation of amyloid-β (Aβ) peptides. How Aβ aggregates perturb the proteome in brains of patients and AD transgenic mouse models, remains largely unclear. State-of-the-art mass spectrometry (MS) methods can comprehensively detect proteomic alterations, providing relevant insights unobtainable with transcriptomics investigations. Analyses of the relationship between progressive Aβ aggregation and protein abundance changes in brains of 5xFAD transgenic mice have not been reported previously. METHODS We quantified progressive Aβ aggregation in hippocampus and cortex of 5xFAD mice and controls with immunohistochemistry and membrane filter assays. Protein changes in different mouse tissues were analyzed by MS-based proteomics using label-free quantification; resulting MS data were processed using an established pipeline. Results were contrasted with existing proteomic data sets from postmortem AD patient brains. Finally, abundance changes in the candidate marker Arl8b were validated in cerebrospinal fluid (CSF) from AD patients and controls using ELISAs. RESULTS Experiments revealed faster accumulation of Aβ42 peptides in hippocampus than in cortex of 5xFAD mice, with more protein abundance changes in hippocampus, indicating that Aβ42 aggregate deposition is associated with brain region-specific proteome perturbations. Generating time-resolved data sets, we defined Aβ aggregate-correlated and anticorrelated proteome changes, a fraction of which was conserved in postmortem AD patient brain tissue, suggesting that proteome changes in 5xFAD mice mimic disease-relevant changes in human AD. We detected a positive correlation between Aβ42 aggregate deposition in the hippocampus of 5xFAD mice and the abundance of the lysosome-associated small GTPase Arl8b, which accumulated together with axonal lysosomal membranes in close proximity of extracellular Aβ plaques in 5xFAD brains. Abnormal aggregation of Arl8b was observed in human AD brain tissue. Arl8b protein levels were significantly increased in CSF of AD patients. CONCLUSIONS We report a comprehensive biochemical and proteomic investigation of hippocampal and cortical brain tissue derived from 5xFAD transgenic mice, providing a valuable resource to the neuroscientific community. We identified Arl8b, with significant abundance changes in 5xFAD and AD patient brains. Arl8b might enable the measurement of progressive lysosome accumulation in AD patients and have clinical utility as a candidate biomarker.
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Affiliation(s)
- Annett Boeddrich
- Neuroproteomics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125, Berlin, Germany
| | - Christian Haenig
- Neuroproteomics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125, Berlin, Germany
| | - Nancy Neuendorf
- Neuroproteomics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125, Berlin, Germany
| | - Eric Blanc
- Core Unit Bioinformatics, Berlin Institute of Health at Charité - University Medicine Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Andranik Ivanov
- Core Unit Bioinformatics, Berlin Institute of Health at Charité - University Medicine Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Marieluise Kirchner
- Core Unit Proteomics, Berlin Institute of Health at Charité - University Medicine Berlin, Lindenberger Weg 80, 13125, Berlin, Germany
| | - Philipp Schleumann
- Neuroproteomics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125, Berlin, Germany
| | - Irem Bayraktaroğlu
- Neuroproteomics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125, Berlin, Germany
| | - Matthias Richter
- Advanced Light Microscopy, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125, Berlin, Germany
| | - Christine Mirjam Molenda
- Advanced Light Microscopy, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125, Berlin, Germany
| | - Anje Sporbert
- Advanced Light Microscopy, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125, Berlin, Germany
| | - Martina Zenkner
- Neuroproteomics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125, Berlin, Germany
| | - Sigrid Schnoegl
- Neuroproteomics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125, Berlin, Germany
| | - Christin Suenkel
- Systems Biology of Gene Regulatory Elements, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125, Berlin, Germany
| | - Luisa-Sophie Schneider
- Department of Psychiatry, Charité - University Medicine Berlin, Hindenburgdamm 30, 12203, Berlin, Germany
| | - Agnieszka Rybak-Wolf
- Systems Biology of Gene Regulatory Elements, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125, Berlin, Germany
| | - Bianca Kochnowsky
- Department of Psychiatry, Charité - University Medicine Berlin, Hindenburgdamm 30, 12203, Berlin, Germany
| | - Lauren M Byrne
- UCL Huntington's Disease Centre, UCL Queen Square Institute of Neurology, Queen Square, London, WC1N 3BG, UK
| | - Edward J Wild
- UCL Huntington's Disease Centre, UCL Queen Square Institute of Neurology, Queen Square, London, WC1N 3BG, UK
- National Hospital for Neurology & Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Jørgen E Nielsen
- Neurogenetics Clinic & Research Lab, Danish Dementia Research Centre, Rigshospitalet, University of Copenhagen, Section 8008, Inge Lehmanns Vej 8, 2100, Copenhagen, Denmark
| | - Gunnar Dittmar
- Core Unit Proteomics, Berlin Institute of Health at Charité - University Medicine Berlin, Lindenberger Weg 80, 13125, Berlin, Germany
- Proteomics of Cellular Signalling, Luxembourg Institute of Health, 1a Rue Thomas Edison, 1445, Strassen, Luxembourg
| | - Oliver Peters
- Department of Psychiatry, Charité - University Medicine Berlin, Hindenburgdamm 30, 12203, Berlin, Germany
- German Center for Neurodegenerative Diseases (DZNE), Charitéplatz 1, 10117, Berlin, Germany
| | - Dieter Beule
- Core Unit Bioinformatics, Berlin Institute of Health at Charité - University Medicine Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Erich E Wanker
- Neuroproteomics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125, Berlin, Germany.
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3
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Chan CT, Fenn AM, Harder NK, Mindur JE, McAlpine CS, Patel J, Valet C, Rattik S, Iwamoto Y, He S, Anzai A, Kahles F, Poller WC, Janssen H, Wong LP, Fernandez-Hernando C, Koolbergen DR, van der Laan AM, Yvan-Charvet L, Sadreyev RI, Nahrendorf M, Westerterp M, Tall AR, Gustafsson JA, Swirski FK. Liver X receptors are required for thymic resilience and T cell output. J Exp Med 2021; 217:151978. [PMID: 32716519 PMCID: PMC7537384 DOI: 10.1084/jem.20200318] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 05/07/2020] [Accepted: 06/16/2020] [Indexed: 02/06/2023] Open
Abstract
The thymus is a primary lymphoid organ necessary for optimal T cell development. Here, we show that liver X receptors (LXRs)—a class of nuclear receptors and transcription factors with diverse functions in metabolism and immunity—critically contribute to thymic integrity and function. LXRαβ-deficient mice develop a fatty, rapidly involuting thymus and acquire a shrunken and prematurely immunoinhibitory peripheral T cell repertoire. LXRαβ’s functions are cell specific, and the resulting phenotypes are mutually independent. Although thymic macrophages require LXRαβ for cholesterol efflux, thymic epithelial cells (TECs) use LXRαβ for self-renewal and thymocytes for negative selection. Consequently, TEC-derived LXRαβ protects against homeostatic premature involution and orchestrates thymic regeneration following stress, while thymocyte-derived LXRαβ limits cell disposal during negative selection and confers heightened sensitivity to experimental autoimmune encephalomyelitis. These results identify three distinct but complementary mechanisms by which LXRαβ governs T lymphocyte education and illuminate LXRαβ’s indispensable roles in adaptive immunity.
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Affiliation(s)
- Christopher T Chan
- Center for Systems Biology and Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Ashley M Fenn
- Center for Systems Biology and Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Nina K Harder
- Center for Systems Biology and Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - John E Mindur
- Center for Systems Biology and Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Cameron S McAlpine
- Center for Systems Biology and Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Jyoti Patel
- Center for Systems Biology and Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Colin Valet
- Center for Systems Biology and Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Sara Rattik
- Center for Systems Biology and Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Yoshiko Iwamoto
- Center for Systems Biology and Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Shun He
- Center for Systems Biology and Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Atsushi Anzai
- Center for Systems Biology and Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Florian Kahles
- Center for Systems Biology and Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Wolfram C Poller
- Center for Systems Biology and Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Henrike Janssen
- Center for Systems Biology and Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Lai Ping Wong
- Department of Molecular Biology, Massachusetts General Hospital and Department of Genetics, Harvard Medical School, Boston, MA
| | - Carlos Fernandez-Hernando
- Vascular Biology and Therapeutics Program, Department of Comparative Medicine and Pathology, Yale University School of Medicine, New Haven, CT
| | - David R Koolbergen
- Heart Center, Department of Cardiothoracic Surgery, Amsterdam Universitair Medische Centra, University of Amsterdam, Amsterdam, Netherlands
| | - Anja M van der Laan
- Heart Center, Department of Cardiology, Amsterdam Universitair Medische Centra, University of Amsterdam, Amsterdam, Netherlands
| | - Laurent Yvan-Charvet
- Institut National de la Santé et de la Recherche Médicale, Université Côte d'Azur, Centre Méditerranéen de Médecine Moléculaire, Atip-Avenir, Fédération Hospitalo-Universitaire Oncoage, Nice, France.,Division of Molecular Medicine, Department of Medicine, Columbia University, New York, NY
| | - Ruslan I Sadreyev
- Department of Molecular Biology and Department of Pathology, Massachusetts General Hospital, and Harvard Medical School, Boston, MA
| | - Matthias Nahrendorf
- Center for Systems Biology and Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Marit Westerterp
- Division of Molecular Medicine, Department of Medicine, Columbia University, New York, NY.,Department of Pediatrics, Section Molecular Genetics, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Alan R Tall
- Division of Molecular Medicine, Department of Medicine, Columbia University, New York, NY
| | - Jan-Ake Gustafsson
- Center for Nuclear Receptors and Cell Signaling, University of Houston, Houston, TX
| | - Filip K Swirski
- Center for Systems Biology and Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA
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4
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Præstholm SM, Correia CM, Grøntved L. Multifaceted Control of GR Signaling and Its Impact on Hepatic Transcriptional Networks and Metabolism. Front Endocrinol (Lausanne) 2020; 11:572981. [PMID: 33133019 PMCID: PMC7578419 DOI: 10.3389/fendo.2020.572981] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 09/03/2020] [Indexed: 12/14/2022] Open
Abstract
Glucocorticoids (GCs) and the glucocorticoid receptor (GR) are important regulators of development, inflammation, stress response and metabolism, demonstrated in various diseases including Addison's disease, Cushing's syndrome and by the many side effects of prolonged clinical administration of GCs. These conditions include severe metabolic challenges in key metabolic organs like the liver. In the liver, GR is known to regulate the transcription of key enzymes in glucose and lipid metabolism and contribute to the regulation of circadian-expressed genes. Insights to the modes of GR regulation and the underlying functional mechanisms are key for understanding diseases and for the development of improved clinical uses of GCs. The activity and function of GR is regulated at numerous levels including ligand availability, interaction with heat shock protein (HSP) complexes, expression of GR isoforms and posttranslational modifications. Moreover, recent genomics studies show functional interaction with multiple transcription factors (TF) and coregulators in complex transcriptional networks controlling cell type-specific gene expression by GCs. In this review we describe the different regulatory steps important for GR activity and discuss how different TF interaction partners of GR selectively control hepatic gene transcription and metabolism.
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Affiliation(s)
| | | | - Lars Grøntved
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
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5
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Acevedo A, Berthel A, DuBois D, Almon RR, Jusko WJ, Androulakis IP. Pathway-Based Analysis of the Liver Response to Intravenous Methylprednisolone Administration in Rats: Acute Versus Chronic Dosing. GENE REGULATION AND SYSTEMS BIOLOGY 2019; 13:1177625019840282. [PMID: 31019365 PMCID: PMC6466473 DOI: 10.1177/1177625019840282] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 03/05/2019] [Indexed: 12/25/2022]
Abstract
Pharmacological time-series data, from comparative dosing studies, are critical to characterizing drug effects. Reconciling the data from multiple studies is inevitably difficult; multiple in vivo high-throughput -omics studies are necessary to capture the global and temporal effects of the drug, but these experiments, though analogous, differ in (microarray or other) platforms, time-scales, and dosing regimens and thus cannot be directly combined or compared. This investigation addresses this reconciliation issue with a meta-analysis technique aimed at assessing the intrinsic activity at the pathway level. The purpose of this is to characterize the dosing effects of methylprednisolone (MPL), a widely used anti-inflammatory and immunosuppressive corticosteroid (CS), within the liver. A multivariate decomposition approach is applied to analyze acute and chronic MPL dosing in male adrenalectomized rats and characterize the dosing-dependent differences in the dynamic response of MPL-responsive signaling and metabolic pathways. We demonstrate how to deconstruct signaling and metabolic pathways into their constituent pathway activities, activities which are scored for intrinsic pathway activity. Dosing-induced changes in the dynamics of pathway activities are compared using a model-based assessment of pathway dynamics, extending the principles of pharmacokinetics/pharmacodynamics (PKPD) to describe pathway activities. The model-based approach enabled us to hypothesize on the likely emergence (or disappearance) of indirect dosing-dependent regulatory interactions, pointing to likely mechanistic implications of dosing of MPL transcriptional regulation. Both acute and chronic MPL administration induced a strong core of activity within pathway families including the following: lipid metabolism, amino acid metabolism, carbohydrate metabolism, metabolism of cofactors and vitamins, regulation of essential organelles, and xenobiotic metabolism pathway families. Pathway activities alter between acute and chronic dosing, indicating that MPL response is dosing dependent. Furthermore, because multiple pathway activities are dominant within a single pathway, we observe that pathways cannot be defined by a single response. Instead, pathways are defined by multiple, complex, and temporally related activities corresponding to different subgroups of genes within each pathway.
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Affiliation(s)
- Alison Acevedo
- Department of Biomedical Engineering,
Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey,
Piscataway, NJ, USA
| | - Ana Berthel
- Department of Biochemistry, Mount
Holyoke College, South Hadley, MA, USA
| | - Debra DuBois
- Department of Pharmaceutical Sciences,
School of Pharmacy and Pharmaceutical Sciences, The State University of New York at
Buffalo, Buffalo, NY, USA
- Department of Biological Sciences, The
State University of New York at Buffalo, Buffalo, NY, USA
| | - Richard R Almon
- Department of Pharmaceutical Sciences,
School of Pharmacy and Pharmaceutical Sciences, The State University of New York at
Buffalo, Buffalo, NY, USA
- Department of Biological Sciences, The
State University of New York at Buffalo, Buffalo, NY, USA
| | - William J Jusko
- Department of Pharmaceutical Sciences,
School of Pharmacy and Pharmaceutical Sciences, The State University of New York at
Buffalo, Buffalo, NY, USA
- Department of Biological Sciences, The
State University of New York at Buffalo, Buffalo, NY, USA
| | - Ioannis P Androulakis
- Department of Biomedical Engineering,
Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey,
Piscataway, NJ, USA
- Department of Chemical and Biochemical
Engineering, Robert Wood Johnson Medical School, Rutgers, The State University of
New Jersey, Piscataway, NJ, USA
- Department of Surgery, Robert Wood
Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ,
USA
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6
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Suzuki S, Iben JR, Coon SL, Kino T. SIRT1 is a transcriptional enhancer of the glucocorticoid receptor acting independently to its deacetylase activity. Mol Cell Endocrinol 2018; 461:178-187. [PMID: 28923345 PMCID: PMC5756502 DOI: 10.1016/j.mce.2017.09.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 09/10/2017] [Accepted: 09/13/2017] [Indexed: 12/21/2022]
Abstract
Glucocorticoids have strong effects on diverse human activities through the glucocorticoid receptor (GR). Sirtuin 1 (SIRT1) is a NAD+-dependent histone deacetylase and promotes longevity by influencing intermediary metabolism and other regulatory activities including mitochondrial function. In this study, we examined the effects of SIRT1 on GR-mediated transcriptional activity. We found that SIRT1 enhanced GR-induced transcriptional activity on endogenous and exogenous glucocorticoid-responsive genes, whereas knockdown of SIRT1 attenuated it. This effect of SIRT1 was independent to its deacetylase activity, as the SIRT1 mutant defective in this activity (H363Y) enhanced GR transcriptional activity, and the compounds inhibiting or activating the SIRT1 deacetylase activity did not influence it. RNA-seq analysis revealed that SIRT1 knockdown influenced ∼30% of the glucocorticoid-responsive transcriptome for most of which it acted as an enhancer for positive/negative effects of this hormone. SIRT1 physically interacted with GR, and was attracted to GR-bound glucocorticoid response elements in a glucocorticoid-dependent fashion. SIRT1 cooperatively activated GR transcriptional activity with the PPARγ coactivator-1α also in its deacetylase activity-independent fashion. Thus, SIRT1 is a novel transcriptional enhancer of GR-induced transcriptional activity possibly by functioning as a scaffold for the transcriptional complex formed on GR.
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Affiliation(s)
- Shigeru Suzuki
- Program in Reproductive and Adult Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA; Department of Pediatrics, Asahikawa Medical University, Asahikawa 078-8510, Japan.
| | - James R Iben
- Molecular Genomics Core, Eunice Kennedy Shriver National Institutes of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Steven L Coon
- Molecular Genomics Core, Eunice Kennedy Shriver National Institutes of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Tomoshige Kino
- Program in Reproductive and Adult Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA; Division of Translational Medicine, Sidra Medical and Research Center, Doha 26999, Qatar.
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7
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Morris J, Moseley VR, Cabang AB, Coleman K, Wei W, Garrett-Mayer E, Wargovich MJ. Reduction in promotor methylation utilizing EGCG (epigallocatechin-3-gallate) restores RXRα expression in human colon cancer cells. Oncotarget 2018; 7:35313-26. [PMID: 27167203 PMCID: PMC5085231 DOI: 10.18632/oncotarget.9204] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 04/16/2016] [Indexed: 12/16/2022] Open
Abstract
Silencing of regulatory genes through hypermethylation of CpG islands is an important mechanism in tumorigenesis. In colon cancer, RXRα, an important dimerization partner with other nuclear transcription factors, is silenced through this mechanism. We previously found that colon tumors in ApcMin/+ mice had diminished levels of RXRα protein and expression levels of this gene were restored by treatment with a green tea intervention, due to reduced promoter methylation of RXRα. We hypothesized that CIMP+ cell lines, which epigenetically silence key regulatory genes would also evidence silencing of RXRα and EGCG treatment would restore its expression. We indeed found EGCG to restore RXRα activity levels in the human cell lines, in a dose dependent manner and reduced RXRα promoter methylation. EGCG induced methylation changes in several other colon cancer related genes but did not cause a decrease in global methylation. Numerous epidemiological reports have shown the benefits of green tea consumption in reducing colon cancer risk but to date no studies have shown that the risk reduction may be related to the epigenetic restoration by tea polyphenols. Our results show that EGCG modulates the reversal of gene silencing involved in colon carcinogenesis providing a possible avenue for colon cancer prevention and treatment.
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Affiliation(s)
- Jay Morris
- Department of Molecular Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Vondina R Moseley
- Department of Cell & Molecular Pharmacology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - April B Cabang
- Department of Molecular Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Katie Coleman
- Department of Cell & Molecular Pharmacology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Wei Wei
- Department of Public Health Science, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Elizabeth Garrett-Mayer
- Department of Biostatistics & Epidemiology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Michael J Wargovich
- Department of Molecular Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
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8
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Scaroni C, Zilio M, Foti M, Boscaro M. Glucose Metabolism Abnormalities in Cushing Syndrome: From Molecular Basis to Clinical Management. Endocr Rev 2017; 38:189-219. [PMID: 28368467 DOI: 10.1210/er.2016-1105] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 03/15/2017] [Indexed: 12/13/2022]
Abstract
An impaired glucose metabolism, which often leads to the onset of diabetes mellitus (DM), is a common complication of chronic exposure to exogenous and endogenous glucocorticoid (GC) excess and plays an important part in contributing to morbidity and mortality in patients with Cushing syndrome (CS). This article reviews the pathogenesis, epidemiology, diagnosis, and management of changes in glucose metabolism associated with hypercortisolism, addressing both the pathophysiological aspects and the clinical and therapeutic implications. Chronic hypercortisolism may have pleiotropic effects on all major peripheral tissues governing glucose homeostasis. Adding further complexity, both genomic and nongenomic mechanisms are directly induced by GCs in a context-specific and cell-/organ-dependent manner. In this paper, the discussion focuses on established and potential pathologic molecular mechanisms that are induced by chronically excessive circulating levels of GCs and affect glucose homeostasis in various tissues. The management of patients with CS and DM includes treating their hyperglycemia and correcting their GC excess. The effects on glycemic control of various medical therapies for CS are reviewed in this paper. The association between DM and subclinical CS and the role of screening for CS in diabetic patients are also discussed.
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Affiliation(s)
- Carla Scaroni
- Endocrinology Unit, Department of Medicine, DIMED, University of Padova, Via Ospedale 105, 35128 Padua, Italy
| | - Marialuisa Zilio
- Endocrinology Unit, Department of Medicine, DIMED, University of Padova, Via Ospedale 105, 35128 Padua, Italy
| | - Michelangelo Foti
- Department of Cell Physiology & Metabolism, Centre Médical Universitaire, 1 Rue Michel Servet, 1211 Genèva, Switzerland
| | - Marco Boscaro
- Endocrinology Unit, Department of Medicine, DIMED, University of Padova, Via Ospedale 105, 35128 Padua, Italy
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9
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Dendoncker K, Libert C. Glucocorticoid resistance as a major drive in sepsis pathology. Cytokine Growth Factor Rev 2017; 35:85-96. [DOI: 10.1016/j.cytogfr.2017.04.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 04/07/2017] [Accepted: 04/19/2017] [Indexed: 01/07/2023]
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10
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Patel R, Magomedova L, Tsai R, Angers S, Orellana A, Cummins CL. Separating the Anti-Inflammatory and Diabetogenic Effects of Glucocorticoids Through LXRβ Antagonism. Endocrinology 2017; 158:1034-1047. [PMID: 28324010 DOI: 10.1210/en.2017-00094] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Accepted: 01/23/2017] [Indexed: 11/19/2022]
Abstract
Synthetic glucocorticoids (GCs), including dexamethasone (DEX), are powerful anti-inflammatory drugs. Long-term use of GCs, however, can result in metabolic side effects such as hyperglycemia, hepatosteatosis, and insulin resistance. The GC receptor (GR) and liver X receptors (LXRα and LXRβ) regulate overlapping genes involved in gluconeogenesis and inflammation. We have previously shown that Lxrβ-/- mice are resistant to the diabetogenic effects of DEX but still sensitive to its immunosuppressive actions. To determine whether this finding could be exploited for therapeutic intervention, we treated mice with GSK2033, a pan-LXR antagonist, alone or combined with DEX. GSK2033 suppressed GC-induced gluconeogenic gene expression without affecting immune-responsive GR target genes. The suppressive effect of GSK2033 on DEX-induced gluconeogenic genes was specific to LXRβ, was liver cell autonomous, and occurred in a target gene-specific manner. Compared with DEX treatment alone, the coadministration of GSK2033 with DEX decreased the recruitment of GR and its accessory factors MED1 and C/EBPβ to the phosphoenolpyruvate carboxykinase promoter. However, GSK2033 had no effect on DEX-mediated suppression of inflammatory genes expressed in the liver or in mouse primary macrophages stimulated with lipopolysaccharides. In conclusion, our study provides evidence that the gluconeogenic and immunosuppressive actions of GR activation can be mechanistically dissociated by pharmacological antagonism of LXRβ. Treatment with an LXRβ antagonist could allow the safer use of existing GC drugs in patients requiring chronic dosing of anti-inflammatory agents for the treatment of diseases such as rheumatoid arthritis and inflammatory bowel disease.
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Affiliation(s)
- Rucha Patel
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, Ontario M5S 3M2, Canada
| | - Lilia Magomedova
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, Ontario M5S 3M2, Canada
| | - Ricky Tsai
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, Ontario M5S 3M2, Canada
| | - Stéphane Angers
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, Ontario M5S 3M2, Canada
| | - Arturo Orellana
- Department of Chemistry, York University, Toronto, Ontario M3J 1P3, Canada
| | - Carolyn L Cummins
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, Ontario M5S 3M2, Canada
- Banting and Best Diabetes Centre, University of Toronto, Toronto, Ontario M5G 2C4, Canada
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11
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Bian X, Zhong H, Li F, Cai Y, Li X, Wang L, Fan X. LXR agonist rescued the deficit in the proliferation of the cerebellar granule cells induced by dexamethasone. Biochem Biophys Res Commun 2016; 477:826-833. [PMID: 27369072 DOI: 10.1016/j.bbrc.2016.06.142] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Accepted: 06/27/2016] [Indexed: 12/16/2022]
Abstract
Dexamethasone (DEX) exposure during early postnatal life produces permanent neuromotor and intellectual deficits and stunts cerebellar growth. The liver X receptor (LXR) plays important roles in CNS development. However, the effects of LXR on the DEX-mediated impairment of cerebellar development remain undetermined. Thus, mice were pretreated with LXR agonist TO901317 (TO) and were later exposed to DEX to evaluate its protective effects on DEX-mediated deficit during cerebellar development. The results showed that an acute exposure of DEX on postnatal day 7 resulted in a significant impairment in cerebellar development and decreased the proliferation of granule neuron precursors in the external granule layer of cerebellum. This effect was attenuated by pretreatment with TO. We further found that the decrease in the proliferation caused by DEX occurred via up-regulation of glucocorticoid receptor and p27kip1, which could be partially prevented by LXR agonist pretreatment. Overall, our results suggest that LXR agonist pretreatment could protect against DEX-induced deficits in cerebellar development in postnatal mice and may thus be perspective recruited to counteract such GC side effects.
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Affiliation(s)
- Xuting Bian
- Department of Developmental Neuropsychology, School of Psychology, Third Military Medical University, Chongqing, 400038, China
| | - Hongyu Zhong
- Department of Developmental Neuropsychology, School of Psychology, Third Military Medical University, Chongqing, 400038, China
| | - Fen Li
- Department of Developmental Neuropsychology, School of Psychology, Third Military Medical University, Chongqing, 400038, China
| | - Yulong Cai
- Department of Developmental Neuropsychology, School of Psychology, Third Military Medical University, Chongqing, 400038, China
| | - Xin Li
- Department of Developmental Neuropsychology, School of Psychology, Third Military Medical University, Chongqing, 400038, China
| | - Lian Wang
- Department of Developmental Neuropsychology, School of Psychology, Third Military Medical University, Chongqing, 400038, China
| | - Xiaotang Fan
- Department of Developmental Neuropsychology, School of Psychology, Third Military Medical University, Chongqing, 400038, China.
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12
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Impact of Glucocorticoid Excess on Glucose Tolerance: Clinical and Preclinical Evidence. Metabolites 2016; 6:metabo6030024. [PMID: 27527232 PMCID: PMC5041123 DOI: 10.3390/metabo6030024] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 07/28/2016] [Accepted: 07/29/2016] [Indexed: 12/28/2022] Open
Abstract
Glucocorticoids (GCs) are steroid hormones that exert important physiological actions on metabolism. Given that GCs also exert potent immunosuppressive and anti-inflammatory actions, synthetic GCs such as prednisolone and dexamethasone were developed for the treatment of autoimmune- and inflammatory-related diseases. The synthetic GCs are undoubtedly efficient in terms of their therapeutic effects, but are accompanied by significant adverse effects on metabolism, specifically glucose metabolism. Glucose intolerance and reductions in insulin sensitivity are among the major concerns related to GC metabolic side effects, which may ultimately progress to type 2 diabetes mellitus. A number of pre-clinical and clinical studies have aimed to understand the repercussions of GCs on glucose metabolism and the possible mechanisms of GC action. This review intends to summarize the main alterations that occur in liver, skeletal muscle, adipose tissue, and pancreatic islets in the context of GC-induced glucose intolerance. For this, both experimental (animals) and clinical studies were selected and, whenever possible, the main cellular mechanisms involved in such GC-side effects were discussed.
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The Interactome of the Glucocorticoid Receptor and Its Influence on the Actions of Glucocorticoids in Combatting Inflammatory and Infectious Diseases. Microbiol Mol Biol Rev 2016; 80:495-522. [PMID: 27169854 DOI: 10.1128/mmbr.00064-15] [Citation(s) in RCA: 126] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Glucocorticoids (GCs) have been widely used for decades as a first-line treatment for inflammatory and autoimmune diseases. However, their use is often hampered by the onset of adverse effects or resistance. GCs mediate their effects via binding to glucocorticoid receptor (GR), a transcription factor belonging to the family of nuclear receptors. An important aspect of GR's actions, including its anti-inflammatory capacity, involves its interactions with various proteins, such as transcription factors, cofactors, and modifying enzymes, which codetermine receptor functionality. In this review, we provide a state-of-the-art overview of the protein-protein interactions (PPIs) of GR that positively or negatively affect its anti-inflammatory properties, along with mechanistic insights, if known. Emphasis is placed on the interactions that affect its anti-inflammatory effects in the presence of inflammatory and microbial diseases.
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14
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Feillet C, Guérin S, Lonchampt M, Dacquet C, Gustafsson JÅ, Delaunay F, Teboul M. Sexual Dimorphism in Circadian Physiology Is Altered in LXRα Deficient Mice. PLoS One 2016; 11:e0150665. [PMID: 26938655 PMCID: PMC4777295 DOI: 10.1371/journal.pone.0150665] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 02/16/2016] [Indexed: 11/28/2022] Open
Abstract
The mammalian circadian timing system coordinates key molecular, cellular and physiological processes along the 24-h cycle. Accumulating evidence suggests that many clock-controlled processes display a sexual dimorphism. In mammals this is well exemplified by the difference between the male and female circadian patterns of glucocorticoid hormone secretion and clock gene expression. Here we show that the non-circadian nuclear receptor and metabolic sensor Liver X Receptor alpha (LXRα) which is known to regulate glucocorticoid production in mice modulates the sex specific circadian pattern of plasma corticosterone. Lxrα-/- males display a blunted corticosterone profile while females show higher amplitude as compared to wild type animals. Wild type males are significantly slower than females to resynchronize their locomotor activity rhythm after an 8 h phase advance but this difference is abrogated in Lxrα-/- males which display a female-like phenotype. We also show that circadian expression patterns of liver 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) and Phosphoenolpyruvate carboxykinase (Pepck) differ between sexes and are differentially altered in Lxrα-/- animals. These changes are associated with a damped profile of plasma glucose oscillation in males but not in females. Sex specific alteration of the insulin and leptin circadian profiles were observed in Lxα-/- females and could be explained by the change in corticosterone profile. Together this data indicates that LXRα is a determinant of sexually dimorphic circadian patterns of key physiological parameters. The discovery of this unanticipated role for LXRα in circadian physiology underscores the importance of addressing sex differences in chronobiology studies and future LXRα targeted therapies.
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Affiliation(s)
- Céline Feillet
- University Nice Sophia Antipolis, Institute of Biology Valrose, 06108, Nice, France
- CNRS UMR 7277, 06108, Nice, France
- INSERM UMR 1091, 06108, Nice, France
| | - Sophie Guérin
- University Nice Sophia Antipolis, Institute of Biology Valrose, 06108, Nice, France
- CNRS UMR 7277, 06108, Nice, France
- INSERM UMR 1091, 06108, Nice, France
| | - Michel Lonchampt
- Metabolic Diseases Research, Institut de Recherches Servier, 92284, Suresnes, France
| | - Catherine Dacquet
- Metabolic Diseases Research, Institut de Recherches Servier, 92284, Suresnes, France
| | - Jan-Åke Gustafsson
- Center for Nuclear Receptors and Cell Signaling, Department of Biology and Biochemistry, University of Houston, Houston, Texas, 77204–5056, United States of America
| | - Franck Delaunay
- University Nice Sophia Antipolis, Institute of Biology Valrose, 06108, Nice, France
- CNRS UMR 7277, 06108, Nice, France
- INSERM UMR 1091, 06108, Nice, France
| | - Michèle Teboul
- University Nice Sophia Antipolis, Institute of Biology Valrose, 06108, Nice, France
- CNRS UMR 7277, 06108, Nice, France
- INSERM UMR 1091, 06108, Nice, France
- * E-mail:
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15
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DHEA-induced modulation of renal gluconeogenesis, insulin sensitivity and plasma lipid profile in the control- and dexamethasone-treated rabbits. Metabolic studies. Biochimie 2016; 121:87-101. [DOI: 10.1016/j.biochi.2015.11.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 11/19/2015] [Indexed: 12/13/2022]
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16
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Abstract
In response to stress, the central nervous system initiates a signaling cascade, which leads to the production of glucocorticoids (GCs). GCs act through the glucocorticoid receptor (GR) to coordinate the appropriate cellular response with the primary goal of mobilizing the storage forms of carbon precursors to generate a continuous glucose supply for the brain. Although GCs are critical for maintaining energy homeostasis, excessive GC stimulation leads to a number of undesirable side effects, including hyperglycemia, insulin resistance, fatty liver, obesity, and muscle wasting leading to severe metabolic dysfunction. Summarized below are the diverse metabolic roles of glucocorticoids in energy homeostasis and dysregulation, focusing specifically on glucose, lipid, and protein metabolism.
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Affiliation(s)
- Lilia Magomedova
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, M5S 3M2, Canada
| | - Carolyn L Cummins
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, M5S 3M2, Canada.
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17
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Hill MJ, Suzuki S, Segars JH, Kino T. CRTC2 Is a Coactivator of GR and Couples GR and CREB in the Regulation of Hepatic Gluconeogenesis. Mol Endocrinol 2016; 30:104-17. [PMID: 26652733 PMCID: PMC4695631 DOI: 10.1210/me.2015-1237] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 11/25/2015] [Indexed: 12/22/2022] Open
Abstract
Glucocorticoid hormones play essential roles in the regulation of gluconeogenesis in the liver, an adaptive response that is required for the maintenance of circulating glucose levels during fasting. Glucocorticoids do this by cooperating with glucagon, which is secreted from pancreatic islets to activate the cAMP-signaling pathway in hepatocytes. The cAMP-response element-binding protein (CREB)-regulated transcription coactivator 2 (CRTC2) is a coactivator known to be specific to CREB and plays a central role in the glucagon-mediated activation of gluconeogenesis in the early phase of fasting. We show here that CRTC2 also functions as a coactivator for the glucocorticoid receptor (GR). CRTC2 strongly enhances GR-induced transcriptional activity of glucocorticoid-responsive genes. CRTC2 physically interacts with the ligand-binding domain of the GR through a region spanning amino acids 561-693. Further, CRTC2 is required for the glucocorticoid-associated cooperative mRNA expression of the glucose-6-phosphatase, a rate-limiting enzyme for hepatic gluconeogenesis, by facilitating the attraction of GR and itself to its promoter region already occupied by CREB. CRTC2 is required for the maintenance of blood glucose levels during fasting in mice by enhancing the GR transcriptional activity on both the G6p and phosphoenolpyruvate carboxykinase (Pepck) genes. Finally, CRTC2 modulates the transcriptional activity of the progesterone receptor, indicating that it may influence the transcriptional activity of other steroid/nuclear receptors. Taken together, these results reveal that CRTC2 plays an essential role in the regulation of hepatic gluconeogenesis through coordinated regulation of the glucocorticoid/GR- and glucagon/CREB-signaling pathways on the key genes G6P and PEPCK.
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Affiliation(s)
- Micah J Hill
- Program in Reproductive and Adult Endocrinology (M.J.H., S.S., J.H.S., T.K.), Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892; Division of Reproductive Endocrinology and Infertility (M.J.H.), Walter Reed National Military Medical Center, Bethesda, Maryland 20889; Department of Pediatrics (S.S.), Asahikawa Medical University, Asahikawa 078-8510, Japan; Division of Reproductive Sciences and Women's Health Research (J.H.S.), Department of Gynecology and Obstetrics, Johns Hopkins School of Medicine, Baltimore, Maryland 21205; and Department of Experimental Therapeutics (T.K.), Division of Experimental Biology, Sidra Medical and Research Center, Doha 26999, Qatar
| | - Shigeru Suzuki
- Program in Reproductive and Adult Endocrinology (M.J.H., S.S., J.H.S., T.K.), Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892; Division of Reproductive Endocrinology and Infertility (M.J.H.), Walter Reed National Military Medical Center, Bethesda, Maryland 20889; Department of Pediatrics (S.S.), Asahikawa Medical University, Asahikawa 078-8510, Japan; Division of Reproductive Sciences and Women's Health Research (J.H.S.), Department of Gynecology and Obstetrics, Johns Hopkins School of Medicine, Baltimore, Maryland 21205; and Department of Experimental Therapeutics (T.K.), Division of Experimental Biology, Sidra Medical and Research Center, Doha 26999, Qatar
| | - James H Segars
- Program in Reproductive and Adult Endocrinology (M.J.H., S.S., J.H.S., T.K.), Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892; Division of Reproductive Endocrinology and Infertility (M.J.H.), Walter Reed National Military Medical Center, Bethesda, Maryland 20889; Department of Pediatrics (S.S.), Asahikawa Medical University, Asahikawa 078-8510, Japan; Division of Reproductive Sciences and Women's Health Research (J.H.S.), Department of Gynecology and Obstetrics, Johns Hopkins School of Medicine, Baltimore, Maryland 21205; and Department of Experimental Therapeutics (T.K.), Division of Experimental Biology, Sidra Medical and Research Center, Doha 26999, Qatar
| | - Tomoshige Kino
- Program in Reproductive and Adult Endocrinology (M.J.H., S.S., J.H.S., T.K.), Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892; Division of Reproductive Endocrinology and Infertility (M.J.H.), Walter Reed National Military Medical Center, Bethesda, Maryland 20889; Department of Pediatrics (S.S.), Asahikawa Medical University, Asahikawa 078-8510, Japan; Division of Reproductive Sciences and Women's Health Research (J.H.S.), Department of Gynecology and Obstetrics, Johns Hopkins School of Medicine, Baltimore, Maryland 21205; and Department of Experimental Therapeutics (T.K.), Division of Experimental Biology, Sidra Medical and Research Center, Doha 26999, Qatar
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Regulation of Glucose Homeostasis by Glucocorticoids. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015. [PMID: 26215992 DOI: 10.1007/978-1-4939-2895-8_5] [Citation(s) in RCA: 357] [Impact Index Per Article: 39.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Glucocorticoids are steroid hormones that regulate multiple aspects of glucose homeostasis. Glucocorticoids promote gluconeogenesis in liver, whereas in skeletal muscle and white adipose tissue they decrease glucose uptake and utilization by antagonizing insulin response. Therefore, excess glucocorticoid exposure causes hyperglycemia and insulin resistance. Glucocorticoids also regulate glycogen metabolism. In liver, glucocorticoids increase glycogen storage, whereas in skeletal muscle they play a permissive role for catecholamine-induced glycogenolysis and/or inhibit insulin-stimulated glycogen synthesis. Moreover, glucocorticoids modulate the function of pancreatic α and β cells to regulate the secretion of glucagon and insulin, two hormones that play a pivotal role in the regulation of blood glucose levels. Overall, the major glucocorticoid effect on glucose homeostasis is to preserve plasma glucose for brain during stress, as transiently raising blood glucose is important to promote maximal brain function. In this chapter we will discuss the current understanding of the mechanisms underlying different aspects of glucocorticoid-regulated mammalian glucose homeostasis.
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Ferraù F, Korbonits M. Metabolic comorbidities in Cushing's syndrome. Eur J Endocrinol 2015; 173:M133-57. [PMID: 26060052 DOI: 10.1530/eje-15-0354] [Citation(s) in RCA: 110] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 06/09/2015] [Indexed: 12/12/2022]
Abstract
Cushing's syndrome (CS) patients have increased mortality primarily due to cardiovascular events induced by glucocorticoid (GC) excess-related severe metabolic changes. Glucose metabolism abnormalities are common in CS due to increased gluconeogenesis, disruption of insulin signalling with reduced glucose uptake and disposal of glucose and altered insulin secretion, consequent to the combination of GCs effects on liver, muscle, adipose tissue and pancreas. Dyslipidaemia is a frequent feature in CS as a result of GC-induced increased lipolysis, lipid mobilisation, liponeogenesis and adipogenesis. Protein metabolism is severely affected by GC excess via complex direct and indirect stimulation of protein breakdown and inhibition of protein synthesis, which can lead to muscle loss. CS patients show changes in body composition, with fat redistribution resulting in accumulation of central adipose tissue. Metabolic changes, altered adipokine release, GC-induced heart and vasculature abnormalities, hypertension and atherosclerosis contribute to the increased cardiovascular morbidity and mortality. In paediatric CS patients, the interplay between GC and the GH/IGF1 axis affects growth and body composition, while in adults it further contributes to the metabolic derangement. GC excess has a myriad of deleterious effects and here we attempt to summarise the metabolic comorbidities related to CS and their management in the perspective of reducing the cardiovascular risk and mortality overall.
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Affiliation(s)
- Francesco Ferraù
- Centre for Endocrinology William Harvey Research Institute, Barts and the London School of Medicine, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Márta Korbonits
- Centre for Endocrinology William Harvey Research Institute, Barts and the London School of Medicine, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
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20
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Tsui KH, Chung LC, Feng TH, Lee TY, Chang PL, Chen WT, Juang HH. Divergent effect of liver X receptor agonists on prostate-specific antigen expression is dependent on androgen receptor in prostate carcinoma cells. Prostate 2015; 75:603-15. [PMID: 25560459 DOI: 10.1002/pros.22944] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 11/17/2014] [Indexed: 11/09/2022]
Abstract
BACKGROUND Liver X receptor (LXR) isoforms, LXRα and LXRβ, have similar protein structures and ligands, but diverse tissue distribution. We used two synthetic, non-steroidal LXR agonists, T0901317 and GW3965, to investigate the effects of LXR agonist modulation on prostate specific antigen (PSA) via the expressions of androgen receptors (AR), LXRα, or LXRβ, in prostate carcinoma cells. METHODS LXRα- or LXRβ-knockdown cells were transduced with specific shRNA lentiviral particles. LXRα and LXRβ expressions were assessed by immunoblotting and RT-qPCR assays. Cell proliferation was determined by (3) H-thymidine incorporation assays. The effects of LXR agonists and epigallocatechin gallate (EGCG) on PSA expression were determined by ELISA, immunoblotting, or transient gene expression assays. RESULTS Treatment with either T0901317 or GW3965 significantly attenuated cell proliferation of LNCaP cells. T0901317 treatment suppressed PSA expression while GW3965 treatment enhanced PSA expression. The increase of PSA promoter activity by GW3965 was dependent on the expression of AR. Either LXRα- or LXRβ-knockdown did not affect the activation of androgen on PSA gene expression. However, as compared with mock knockdown-LNCaP cells, the LXRα-knockdown but not the LXRβ-knockdown attenuated the effects of T0901317 and GW3965 on PSA expressions. The effect of GW3965 on PSA expression was blocked by the addition of EGCG. CONCLUSIONS Our results indicate that T0901317 and GW3965 have divergent effects on PSA expressions. The effects of LXR agonists on PSA expression are LXRα-dependent and AR-dependent. EGCG blocks the inducing effect of GW3965 on PSA expression.
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Affiliation(s)
- Ke-Hung Tsui
- Department of Urology, Chang Gung Memorial Hospital-Linko, Kwei-Shan, Tao-Yuan, Taiwan; Department of Anatomy, College of Medicine, Chang Gung University, Kwei-Shan, Tao-Yuan, Taiwan
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Abstract
Glucocorticoids (GCs) and their cognate, intracellular receptor, the glucocorticoid receptor (GR) have been characterized as critical checkpoints in the hormonal control of energy homeostasis in mammals. Whereas physiological levels of GCs are required for proper metabolic control, aberrant GC action has been linked to a variety of severe metabolic diseases, including type 2 diabetes and obesity. As a member of the nuclear receptor superfamily of transcription factors, the GR translocates into the cell nucleus upon GC binding where it serves as a transcriptional regulator of distinct GC-responsive target genes that are in many cases associated with lipid regulatory pathways and thereby intricately control both physiological and pathophysiological systemic lipid homeostasis. Thus, this chapter focuses on the current knowledge of GC/GR function in lipid handling and its implications for systemic metabolic dysfunction.
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Abstract
The liver is an essential metabolic organ, and its metabolic function is controlled by insulin and other metabolic hormones. Glucose is converted into pyruvate through glycolysis in the cytoplasm, and pyruvate is subsequently oxidized in the mitochondria to generate ATP through the TCA cycle and oxidative phosphorylation. In the fed state, glycolytic products are used to synthesize fatty acids through de novo lipogenesis. Long-chain fatty acids are incorporated into triacylglycerol, phospholipids, and/or cholesterol esters in hepatocytes. These complex lipids are stored in lipid droplets and membrane structures, or secreted into the circulation as very low-density lipoprotein particles. In the fasted state, the liver secretes glucose through both glycogenolysis and gluconeogenesis. During pronged fasting, hepatic gluconeogenesis is the primary source for endogenous glucose production. Fasting also promotes lipolysis in adipose tissue, resulting in release of nonesterified fatty acids which are converted into ketone bodies in hepatic mitochondria though β-oxidation and ketogenesis. Ketone bodies provide a metabolic fuel for extrahepatic tissues. Liver energy metabolism is tightly regulated by neuronal and hormonal signals. The sympathetic system stimulates, whereas the parasympathetic system suppresses, hepatic gluconeogenesis. Insulin stimulates glycolysis and lipogenesis but suppresses gluconeogenesis, and glucagon counteracts insulin action. Numerous transcription factors and coactivators, including CREB, FOXO1, ChREBP, SREBP, PGC-1α, and CRTC2, control the expression of the enzymes which catalyze key steps of metabolic pathways, thus controlling liver energy metabolism. Aberrant energy metabolism in the liver promotes insulin resistance, diabetes, and nonalcoholic fatty liver diseases.
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Affiliation(s)
- Liangyou Rui
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan
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Liu X, Pan L. Detection of driver metabolites in the human liver metabolic network using structural controllability analysis. BMC SYSTEMS BIOLOGY 2014; 8:51. [PMID: 24885538 PMCID: PMC4024020 DOI: 10.1186/1752-0509-8-51] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Accepted: 04/28/2014] [Indexed: 12/20/2022]
Abstract
Background Abnormal states in human liver metabolism are major causes of human liver diseases ranging from hepatitis to hepatic tumor. The accumulation in relevant data makes it feasible to derive a large-scale human liver metabolic network (HLMN) and to discover important biological principles or drug-targets based on network analysis. Some studies have shown that interesting biological phenomenon and drug-targets could be discovered by applying structural controllability analysis (which is a newly prevailed concept in networks) to biological networks. The exploration on the connections between structural controllability theory and the HLMN could be used to uncover valuable information on the human liver metabolism from a fresh perspective. Results We applied structural controllability analysis to the HLMN and detected driver metabolites. The driver metabolites tend to have strong ability to influence the states of other metabolites and weak susceptibility to be influenced by the states of others. In addition, the metabolites were classified into three classes: critical, high-frequency and low-frequency driver metabolites. Among the identified 36 critical driver metabolites, 27 metabolites were found to be essential; the high-frequency driver metabolites tend to participate in different metabolic pathways, which are important in regulating the whole metabolic systems. Moreover, we explored some other possible connections between the structural controllability theory and the HLMN, and find that transport reactions and the environment play important roles in the human liver metabolism. Conclusion There are interesting connections between the structural controllability theory and the human liver metabolism: driver metabolites have essential biological functions; the crucial role of extracellular metabolites and transport reactions in controlling the HLMN highlights the importance of the environment in the health of human liver metabolism.
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Affiliation(s)
| | - Linqiang Pan
- Key Laboratory of Image Information Processing and Intelligent Control, School of Automation, Huazhong University of Science and Technology, Luoyu Road 1037, 430074 Wuhan, China.
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Patel R, Williams-Dautovich J, Cummins CL. Minireview: new molecular mediators of glucocorticoid receptor activity in metabolic tissues. Mol Endocrinol 2014; 28:999-1011. [PMID: 24766141 DOI: 10.1210/me.2014-1062] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The glucocorticoid receptor (GR) was one of the first nuclear hormone receptors cloned and represents one of the most effective drug targets available today for the treatment of severe inflammation. The physiologic consequences of endogenous or exogenous glucocorticoid excess are well established and include hyperglycemia, insulin resistance, fatty liver, obesity, and muscle wasting. However, at the molecular and tissue-specific level, there are still many unknown protein mediators of glucocorticoid response and thus, much remains to be uncovered that will help determine whether activation of the GR can be tailored to improve therapeutic efficacy while minimizing unwanted side effects. This review summarizes recent discoveries of tissue-selective modulators of glucocorticoid signaling that are important in mediating the unwanted side effects of therapeutic glucocorticoid use, emphasizing the downstream molecular effects of GR activation in the liver, adipose tissue, muscle, and pancreas.
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Affiliation(s)
- Rucha Patel
- Department of Pharmaceutical Sciences (R.P., J.W-D., C.L.C.), University of Toronto, Toronto, Ontario, M5S 3M2, Canada; and Banting and Best Diabetes Centre (C.L.C.), Toronto, Ontario M5G 2C4 Canada
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Rose AJ, Herzig S. Metabolic control through glucocorticoid hormones: an update. Mol Cell Endocrinol 2013; 380:65-78. [PMID: 23523966 DOI: 10.1016/j.mce.2013.03.007] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Revised: 02/21/2013] [Accepted: 03/08/2013] [Indexed: 01/28/2023]
Abstract
In the past decades, glucocorticoid (GC) hormones and their cognate, intracellular receptor, the glucocorticoid receptor (GR), have been well established as critical checkpoints in mammalian energy homeostasis. Whereas many aspects in healthy nutrient metabolism require physiological levels and/or action of GC, aberrant GC/GR signalling has been linked to severe metabolic dysfunction, including obesity, insulin resistance and type 2 diabetes. Consequently, studies of the molecular mechanisms within the GC signalling axis have become a major focus in biomedical research, up-to-date particularly focusing on systemic glucose and lipid handling. However, with the availability of novel high throughput technologies and more sophisticated metabolic phenotyping capabilities, as-yet non-appreciated, metabolic functions of GC have been recently discovered, including regulatory roles of the GC/GR axis in protein and bile acid homeostasis as well as metabolic inter-organ communication. Therefore, this review summarises recent advances in GC/GR biology, and summarises findings relevant for basic and translational metabolic research.
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Affiliation(s)
- Adam J Rose
- Joint Research Division, Molecular Metabolic Control, German Cancer Research Center (DKFZ) Heidelberg, Center for Molecular Biology (ZMBH), Heidelberg University, Network Aging Research, University Hospital Heidelberg, Germany
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Ng SSM, Li A, Pavlakis GN, Ozato K, Kino T. Viral infection increases glucocorticoid-induced interleukin-10 production through ERK-mediated phosphorylation of the glucocorticoid receptor in dendritic cells: potential clinical implications. PLoS One 2013; 8:e63587. [PMID: 23667643 PMCID: PMC3648469 DOI: 10.1371/journal.pone.0063587] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Accepted: 04/03/2013] [Indexed: 12/16/2022] Open
Abstract
The hypothalamic-pituitary-adrenal axis plays a central role in the adaptive response to stress including infection of pathogens through glucocorticoids. Physical and/or mental stress alter susceptibility to viral infection possibly by affecting this regulatory system, thus we explored potential cellular targets and mechanisms that underlie this phenomenon in key immune components dendritic cells (DCs). Dexamethasone (DEX) treatment and subsequent Newcastle disease virus (NDV) infection most significantly and cooperatively stimulated mRNA expression of the interleukin (IL)-10 in murine bone marrow-derived DCs among 89 genes involved in the Toll-like receptor signaling pathways. NDV increased DEX-induced IL-10 mRNA and protein expression by 7- and 3-fold, respectively, which was observed from 3 hours after infection. Conventional DCs (cDCs), but not plasmacytoid DCs (pDCs) were major sources of IL-10 in bone marrow-derived DCs treated with DEX and/or infected with NDV. Murine cytomegalovirus and DEX increased serum IL-10 cooperatively in female mice. Pre-treatment of DCs with the extracellular signal-regulated kinase (ERK) inhibitor U0126 abolished cooperative induction of IL-10 by DEX and NDV. Further, ERK overexpression increased IL-10 promoter activity stimulated by wild-type human GR but not by its mutant defective in serine 203, whereas ERK knockdown abolished NDV/DEX cooperation on IL-10 mRNA and phosphorylation of the mouse GR at serine 213. NDV also increased DEX-induced mRNA expression of three known glucocorticoid-responsive genes unrelated to the Toll-like receptor signaling pathways in DCs. These results indicate that virus and glucocorticoids cooperatively increase production of anti-inflammatory cytokine IL-10 by potentiating the transcriptional activity of GR in DCs, through which virus appears to facilitate its own propagation in infected hosts. The results may further underlie in part known exacerbation of IL-10/T helper-2-related allergic disorders by stress and viral infection.
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Affiliation(s)
- Sinnie Sin Man Ng
- Unit on Molecular Hormone Action, Program in Reproductive and Adult Endocrinology, Eunice Kennedy Shriver National Institutes of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, United States of America
- School of Biomedical Science, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong Special Administrative Region, China
- Human Retrovirus Pathogenesis Section, Vaccine Branch, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, United States of America
| | - Andrew Li
- Unit on Molecular Hormone Action, Program in Reproductive and Adult Endocrinology, Eunice Kennedy Shriver National Institutes of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, United States of America
| | - George N. Pavlakis
- Human Retrovirus Pathogenesis Section, Vaccine Branch, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, United States of America
| | - Keiko Ozato
- Laboratory of Molecular Growth and Regulation, Eunice Kennedy Shriver National Institutes of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Tomoshige Kino
- Unit on Molecular Hormone Action, Program in Reproductive and Adult Endocrinology, Eunice Kennedy Shriver National Institutes of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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Soodvilai S, Jia Z, Fongsupa S, Chatsudthipong V, Yang T. Liver X receptor agonists decrease ENaC-mediated sodium transport in collecting duct cells. Am J Physiol Renal Physiol 2012; 303:F1610-6. [PMID: 23077096 DOI: 10.1152/ajprenal.00283.2012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Liver X receptors (LXRs) are nuclear receptors that regulate cholesterol, fatty acid, and glucose metabolism in various tissues. However, the renal action of LXRs is not well understood. Here we investigated the effects of LXR-activating ligands on modulation of epithelial sodium channel (ENaC)-mediated sodium transport in collecting duct cells. Exposure of the M1 cells to the synthetic LXR agonists T0901317 and GW3965 or the natural ligand 22R-hydroxycholesterol for 24 h decreased amiloride-sensitive sodium transport, corresponding with an increase of transepithelial resistance. The inhibition of amiloride-sensitive sodium transport after incubation with T0901317 or GW3965 was not mediated by a reduction of Na(+)/K(+)-ATPase-mediated basolateral sodium transport. On the other hand, T0901317 and GW3965 decreased mRNA abundance and membrane expression of ENaC. Preincubation the monolayer with GW3965 attenuated aldosterone-induced stimulation sodium transport. In primary cultures of collecting duct cells, T0901317 and GW3965 similarly inhibited ENaC transport function as in M1 cells. This is the first evidence showing LXR-activating ligands modulate ENaC-mediated sodium transport in collecting duct cells. These results suggest that LXRs may represent a novel therapeutic target for treatment of conditions with dysregulation of ENaC such as hypertension.
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Wang JC, Gray NE, Kuo T, Harris CA. Regulation of triglyceride metabolism by glucocorticoid receptor. Cell Biosci 2012; 2:19. [PMID: 22640645 PMCID: PMC3419133 DOI: 10.1186/2045-3701-2-19] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Accepted: 05/28/2012] [Indexed: 12/11/2022] Open
Abstract
Glucocorticoids are steroid hormones that play critical and complex roles in the regulation of triglyceride (TG) homeostasis. Depending on physiological states, glucocorticoids can modulate both TG synthesis and hydrolysis. More intriguingly, glucocorticoids can concurrently affect these two processes in adipocytes. The metabolic effects of glucocorticoids are conferred by intracellular glucocorticoid receptors (GR). GR is a transcription factor that, upon binding to glucocorticoids, regulates the transcriptional rate of specific genes. These GR primary target genes further initiate the physiological and pathological responses of glucocorticoids. In this article, we overview glucocorticoid-regulated genes, especially those potential GR primary target genes, involved in glucocorticoid-regulated TG metabolism. We also discuss transcriptional regulators that could act with GR to participate in these processes. This knowledge is not only important for the fundamental understanding of steroid hormone actions, but also are essential for future therapeutic interventions against metabolic diseases associated with aberrant glucocorticoid signaling, such as insulin resistance, dyslipidemia, central obesity and hepatic steatosis.
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Affiliation(s)
- Jen-Chywan Wang
- Department of Nutritional Science & Toxicology, University of California at Berkeley, Berkeley, CA, 94720, USA.
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