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Patel GC, Millar JC, Clark AF. Glucocorticoid Receptor Transactivation Is Required for Glucocorticoid-Induced Ocular Hypertension and Glaucoma. Invest Ophthalmol Vis Sci 2019; 60:1967-1978. [PMID: 31050723 PMCID: PMC6890434 DOI: 10.1167/iovs.18-26383] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Purpose Glucocorticoid (GC)–induced ocular hypertension (GC-OHT) is a serious side effect of prolonged GC therapy that can lead to glaucoma and permanent vision loss. GCs cause a plethora of changes in the trabecular meshwork (TM), an ocular tissue that regulates intraocular pressure (IOP). GCs act through the glucocorticoid receptor (GR), and the GR regulates transcription both through transactivation and transrepression. Many of the anti-inflammatory properties of GCs are mediated by GR transrepression, while GR transactivation largely accounts for GC metabolic effects and side effects of GC therapy. There is no evidence showing which of the two mechanisms plays a role in GC-OHT. Methods GRdim transgenic mice (which have active transrepression and impaired transactivation) and wild-type (WT) C57BL/6J mice received weekly periocular dexamethasone acetate (DEX-Ac) injections. IOP, outflow facilities, and biochemical changes to the TM were determined. Results GRdim mice did not develop GC-OHT after continued DEX treatment, while WT mice had significantly increased IOP and decreased outflow facilities. Both TM tissue in eyes of DEX-treated GRdim mice and cultured TM cells isolated from GRdim mice had reduced or no change in the expression of fibronectin, myocilin, collagen type I, and α-smooth muscle actin (α-SMA). GRdim mouse TM (MTM) cells also had a significant reduction in DEX-induced cytoskeletal changes, which was clearly seen in WT MTM cells. Conclusions We provide the first evidence for the role of GR transactivation in regulating GC-mediated gene expression in the TM and in the development of GC-OHT. This discovery suggests a novel therapeutic approach for treating ocular inflammation without causing GC-OHT and glaucoma.
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Affiliation(s)
- Gaurang C Patel
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - J Cameron Millar
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Abbot F Clark
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas, United States
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Desgeorges T, Caratti G, Mounier R, Tuckermann J, Chazaud B. Glucocorticoids Shape Macrophage Phenotype for Tissue Repair. Front Immunol 2019; 10:1591. [PMID: 31354730 PMCID: PMC6632423 DOI: 10.3389/fimmu.2019.01591] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 06/25/2019] [Indexed: 12/16/2022] Open
Abstract
Inflammation is a complex process which is highly conserved among species. Inflammation occurs in response to injury, infection, and cancer, as an allostatic mechanism to return the tissue and to return the organism back to health and homeostasis. Excessive, or chronic inflammation is associated with numerous diseases, and thus strategies to combat run-away inflammation is required. Anti-inflammatory drugs were therefore developed to switch inflammation off. However, the inflammatory response may be beneficial for the organism, in particular in the case of sterile tissue injury. The inflammatory response can be divided into several parts. The first step is the mounting of the inflammatory reaction itself, characterized by the presence of pro-inflammatory cytokines, and the infiltration of immune cells into the injured area. The second step is the resolution phase, where immune cells move toward an anti-inflammatory phenotype and decrease the secretion of pro-inflammatory cytokines. The last stage of inflammation is the regeneration process, where the tissue is rebuilt. Innate immune cells are major actors in the inflammatory response, of which, macrophages play an important role. Macrophages are highly sensitive to a large number of environmental stimuli, and can adapt their phenotype and function on demand. This change in phenotype in response to the environment allow macrophages to be involved in all steps of inflammation, from the first mounting of the pro-inflammatory response to the post-damage tissue repair.
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Affiliation(s)
- Thibaut Desgeorges
- Institut NeuroMyoGène, Université Claude Bernard Lyon 1, Univ Lyon, CNRS UMR 5310, INSERM U1217, Lyon, France
| | - Giorgio Caratti
- Institute of Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany
| | - Rémi Mounier
- Institut NeuroMyoGène, Université Claude Bernard Lyon 1, Univ Lyon, CNRS UMR 5310, INSERM U1217, Lyon, France
| | - Jan Tuckermann
- Institute of Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany
| | - Bénédicte Chazaud
- Institut NeuroMyoGène, Université Claude Bernard Lyon 1, Univ Lyon, CNRS UMR 5310, INSERM U1217, Lyon, France
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Frenkel B, White W, Tuckermann J. Glucocorticoid-Induced Osteoporosis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015. [PMID: 26215995 DOI: 10.1007/978-1-4939-2895-8_8] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Osteoporosis is among the most devastating side effects of glucocorticoid (GC) therapy for the management of inflammatory and auto-immune diseases. Evidence from both humans and mice indicate deleterious skeletal effects within weeks of pharmacological GC administration, both related and unrelated to a decrease in bone mineral density (BMD). Osteoclast numbers and bone resorption are also rapidly increased, and together with osteoblast inactivation and decreased bone formation, these changes lead the fastest loss in BMD during the initial disease phase. Bone resorption then decreases to sub-physiological levels, but persistent and severe inhibition of bone formation leads to further bone loss and progressively increased fracture risk, up to an order of magnitude higher than that observed in untreated individuals. Bone forming osteoblasts are thus considered the main culprits in GC-induced osteoporosis (GIO). Accordingly, we focus this review primarily on deleterious effects on osteoblasts: inhibition of cell replication and function and acceleration of apoptosis. Mediating these adverse effects, GCs target pivotal regulatory mechanisms that govern osteoblast growth, differentiation and survival. Specifically, GCs inhibit growth factor pathways, including Insulin Growth Factors, Growth Hormone, Hepatocyte Growth/Scatter Factor and IL6-type cytokines. They also inhibit downstream kinases, including PI3-kinase and the MAP kinase ERK, the latter attributable in part to direct transcriptional stimulation of MAP kinase phosphatase 1. Most importantly, however, GCs inhibit the Wnt signaling pathway, which plays a pivotal role in osteoblast replication, function and survival. They transcriptionally stimulate expression of Wnt inhibitors of both the Dkk and Sfrp families, and they induce reactive oxygen species (ROS), which result in loss of ß-catenin to ROS-activated FoxO transcription factors. Identification of dissociated GCs, which would suppress the immune system without causing osteoporosis, is proving more challenging than initially thought, and GIO is currently managed by co-treatment with bisphosphonates or PTH. These drugs, however, are not ideally suited for GIO. Future therapeutic approaches may aim at GC targets such as those mentioned above, or newly identified targets including the Notch pathway, the AP-1/Il11 axis and the osteoblast master regulator RUNX2.
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Affiliation(s)
- Baruch Frenkel
- Department of Orthopaedic Surgery, Keck School of Medicine, Institute for Genetic Medicine, University of Southern California, 2250 Alcazar Street, CSC-240, Los Angeles, CA, 90033, USA,
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Hochberg I, Harvey I, Tran QT, Stephenson EJ, Barkan AL, Saltiel AR, Chandler WF, Bridges D. Gene expression changes in subcutaneous adipose tissue due to Cushing's disease. J Mol Endocrinol 2015; 55:81-94. [PMID: 26150553 PMCID: PMC4543687 DOI: 10.1530/jme-15-0119] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/06/2015] [Indexed: 01/15/2023]
Abstract
Glucocorticoids have major effects on adipose tissue metabolism. To study tissue mRNA expression changes induced by chronic elevated endogenous glucocorticoids, we performed RNA sequencing on the subcutaneous adipose tissue from patients with Cushing's disease (n=5) compared to patients with nonfunctioning pituitary adenomas (n=11). We found a higher expression of transcripts involved in several metabolic pathways, including lipogenesis, proteolysis and glucose oxidation as well as a decreased expression of transcripts involved in inflammation and protein synthesis. To further study this in a model system, we subjected mice to dexamethasone treatment for 12 weeks and analyzed their inguinal (subcutaneous) fat pads, which led to similar findings. Additionally, mice treated with dexamethasone showed drastic decreases in lean body mass as well as increased fat mass, further supporting the human transcriptomic data. These data provide insight to transcriptional changes that may be responsible for the comorbidities associated with chronic elevations of glucocorticoids.
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Affiliation(s)
- Irit Hochberg
- Institute of EndocrinologyDiabetes and Metabolism, Rambam Health Care Campus, Haifa, IsraelLife Science InstituteUniversity of Michigan, Ann Arbor, MI, USAPhysiologyUTHSC, Memphis, TN, USAPreventive MedicineUTHSC, Memphis, TN, USAInternal MedicineUniversity of Michigan, Ann Arbor, MI USANeurosurgeryUniversity of Michigan, Ann Arbor, MI USAPediatricsUTHSC, Memphis, TN, USA Institute of EndocrinologyDiabetes and Metabolism, Rambam Health Care Campus, Haifa, IsraelLife Science InstituteUniversity of Michigan, Ann Arbor, MI, USAPhysiologyUTHSC, Memphis, TN, USAPreventive MedicineUTHSC, Memphis, TN, USAInternal MedicineUniversity of Michigan, Ann Arbor, MI USANeurosurgeryUniversity of Michigan, Ann Arbor, MI USAPediatricsUTHSC, Memphis, TN, USA
| | - Innocence Harvey
- Institute of EndocrinologyDiabetes and Metabolism, Rambam Health Care Campus, Haifa, IsraelLife Science InstituteUniversity of Michigan, Ann Arbor, MI, USAPhysiologyUTHSC, Memphis, TN, USAPreventive MedicineUTHSC, Memphis, TN, USAInternal MedicineUniversity of Michigan, Ann Arbor, MI USANeurosurgeryUniversity of Michigan, Ann Arbor, MI USAPediatricsUTHSC, Memphis, TN, USA
| | - Quynh T Tran
- Institute of EndocrinologyDiabetes and Metabolism, Rambam Health Care Campus, Haifa, IsraelLife Science InstituteUniversity of Michigan, Ann Arbor, MI, USAPhysiologyUTHSC, Memphis, TN, USAPreventive MedicineUTHSC, Memphis, TN, USAInternal MedicineUniversity of Michigan, Ann Arbor, MI USANeurosurgeryUniversity of Michigan, Ann Arbor, MI USAPediatricsUTHSC, Memphis, TN, USA
| | - Erin J Stephenson
- Institute of EndocrinologyDiabetes and Metabolism, Rambam Health Care Campus, Haifa, IsraelLife Science InstituteUniversity of Michigan, Ann Arbor, MI, USAPhysiologyUTHSC, Memphis, TN, USAPreventive MedicineUTHSC, Memphis, TN, USAInternal MedicineUniversity of Michigan, Ann Arbor, MI USANeurosurgeryUniversity of Michigan, Ann Arbor, MI USAPediatricsUTHSC, Memphis, TN, USA
| | - Ariel L Barkan
- Institute of EndocrinologyDiabetes and Metabolism, Rambam Health Care Campus, Haifa, IsraelLife Science InstituteUniversity of Michigan, Ann Arbor, MI, USAPhysiologyUTHSC, Memphis, TN, USAPreventive MedicineUTHSC, Memphis, TN, USAInternal MedicineUniversity of Michigan, Ann Arbor, MI USANeurosurgeryUniversity of Michigan, Ann Arbor, MI USAPediatricsUTHSC, Memphis, TN, USA
| | - Alan R Saltiel
- Institute of EndocrinologyDiabetes and Metabolism, Rambam Health Care Campus, Haifa, IsraelLife Science InstituteUniversity of Michigan, Ann Arbor, MI, USAPhysiologyUTHSC, Memphis, TN, USAPreventive MedicineUTHSC, Memphis, TN, USAInternal MedicineUniversity of Michigan, Ann Arbor, MI USANeurosurgeryUniversity of Michigan, Ann Arbor, MI USAPediatricsUTHSC, Memphis, TN, USA
| | - William F Chandler
- Institute of EndocrinologyDiabetes and Metabolism, Rambam Health Care Campus, Haifa, IsraelLife Science InstituteUniversity of Michigan, Ann Arbor, MI, USAPhysiologyUTHSC, Memphis, TN, USAPreventive MedicineUTHSC, Memphis, TN, USAInternal MedicineUniversity of Michigan, Ann Arbor, MI USANeurosurgeryUniversity of Michigan, Ann Arbor, MI USAPediatricsUTHSC, Memphis, TN, USA
| | - Dave Bridges
- Institute of EndocrinologyDiabetes and Metabolism, Rambam Health Care Campus, Haifa, IsraelLife Science InstituteUniversity of Michigan, Ann Arbor, MI, USAPhysiologyUTHSC, Memphis, TN, USAPreventive MedicineUTHSC, Memphis, TN, USAInternal MedicineUniversity of Michigan, Ann Arbor, MI USANeurosurgeryUniversity of Michigan, Ann Arbor, MI USAPediatricsUTHSC, Memphis, TN, USA Institute of EndocrinologyDiabetes and Metabolism, Rambam Health Care Campus, Haifa, IsraelLife Science InstituteUniversity of Michigan, Ann Arbor, MI, USAPhysiologyUTHSC, Memphis, TN, USAPreventive MedicineUTHSC, Memphis, TN, USAInternal MedicineUniversity of Michigan, Ann Arbor, MI USANeurosurgeryUniversity of Michigan, Ann Arbor, MI USAPediatricsUTHSC, Memphis, TN, USA Institute of EndocrinologyDiabetes and Metabolism, Rambam Health Care Campus, Haifa, IsraelLife Science InstituteUniversity of Michigan, Ann Arbor, MI, USAPhysiologyUTHSC, Memphis, TN, USAPreventive MedicineUTHSC, Memphis, TN, USAInternal MedicineUniversity of Michigan, Ann Arbor, MI USANeurosurgeryUniversity of Michigan, Ann Arbor, MI USAPediatricsUTHSC, Memphis, TN, USA
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