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Kuliczkowska-Płaksej J, Zdrojowy-Wełna A, Jawiarczyk-Przybyłowska A, Gojny Ł, Bolanowski M. Diagnosis and therapeutic approach to bone health in patients with hypopituitarism. Rev Endocr Metab Disord 2024; 25:513-539. [PMID: 38565758 DOI: 10.1007/s11154-024-09878-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/17/2024] [Indexed: 04/04/2024]
Abstract
The results of many studies in recent years indicate a significant impact of pituitary function on bone health. The proper function of the pituitary gland has a significant impact on the growth of the skeleton and the appearance of sexual dimorphism. It is also responsible for achieving peak bone mass, which protects against the development of osteoporosis and fractures later in life. It is also liable for the proper remodeling of the skeleton, which is a physiological mechanism managing the proper mechanical resistance of bones and the possibility of its regeneration after injuries. Pituitary diseases causing hypofunction and deficiency of tropic hormones, and thus deficiency of key hormones of effector organs, have a negative impact on the skeleton, resulting in reduced bone mass and susceptibility to pathological fractures. The early appearance of pituitary dysfunction, i.e. in the pre-pubertal period, is responsible for failure to achieve peak bone mass, and thus the risk of developing osteoporosis in later years. This argues for the need for a thorough assessment of patients with hypopituitarism, not only in terms of metabolic disorders, but also in terms of bone disorders. Early and properly performed treatment may prevent patients from developing the bone complications that are so common in this pathology. The aim of this review is to discuss the physiological, pathophysiological, and clinical insights of bone involvement in pituitary disease.
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Affiliation(s)
- Justyna Kuliczkowska-Płaksej
- Department and Clinic of Endocrinology, Diabetes and Isotope Therapy, Wroclaw Medical University, Wybrzeże Pasteura 4, Wrocław, 50-367, Poland
| | - Aleksandra Zdrojowy-Wełna
- Department and Clinic of Endocrinology, Diabetes and Isotope Therapy, Wroclaw Medical University, Wybrzeże Pasteura 4, Wrocław, 50-367, Poland
| | - Aleksandra Jawiarczyk-Przybyłowska
- Department and Clinic of Endocrinology, Diabetes and Isotope Therapy, Wroclaw Medical University, Wybrzeże Pasteura 4, Wrocław, 50-367, Poland.
| | - Łukasz Gojny
- Department and Clinic of Endocrinology, Diabetes and Isotope Therapy, Wroclaw Medical University, Wybrzeże Pasteura 4, Wrocław, 50-367, Poland
| | - Marek Bolanowski
- Department and Clinic of Endocrinology, Diabetes and Isotope Therapy, Wroclaw Medical University, Wybrzeże Pasteura 4, Wrocław, 50-367, Poland
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2
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Pofi R, Caratti G, Ray DW, Tomlinson JW. Treating the Side Effects of Exogenous Glucocorticoids; Can We Separate the Good From the Bad? Endocr Rev 2023; 44:975-1011. [PMID: 37253115 PMCID: PMC10638606 DOI: 10.1210/endrev/bnad016] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 04/25/2023] [Accepted: 05/26/2023] [Indexed: 06/01/2023]
Abstract
It is estimated that 2% to 3% of the population are currently prescribed systemic or topical glucocorticoid treatment. The potent anti-inflammatory action of glucocorticoids to deliver therapeutic benefit is not in doubt. However, the side effects associated with their use, including central weight gain, hypertension, insulin resistance, type 2 diabetes (T2D), and osteoporosis, often collectively termed iatrogenic Cushing's syndrome, are associated with a significant health and economic burden. The precise cellular mechanisms underpinning the differential action of glucocorticoids to drive the desirable and undesirable effects are still not completely understood. Faced with the unmet clinical need to limit glucocorticoid-induced adverse effects alongside ensuring the preservation of anti-inflammatory actions, several strategies have been pursued. The coprescription of existing licensed drugs to treat incident adverse effects can be effective, but data examining the prevention of adverse effects are limited. Novel selective glucocorticoid receptor agonists and selective glucocorticoid receptor modulators have been designed that aim to specifically and selectively activate anti-inflammatory responses based upon their interaction with the glucocorticoid receptor. Several of these compounds are currently in clinical trials to evaluate their efficacy. More recently, strategies exploiting tissue-specific glucocorticoid metabolism through the isoforms of 11β-hydroxysteroid dehydrogenase has shown early potential, although data from clinical trials are limited. The aim of any treatment is to maximize benefit while minimizing risk, and within this review we define the adverse effect profile associated with glucocorticoid use and evaluate current and developing strategies that aim to limit side effects but preserve desirable therapeutic efficacy.
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Affiliation(s)
- Riccardo Pofi
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford OX3 7LE, UK
| | - Giorgio Caratti
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford OX3 7LE, UK
| | - David W Ray
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford OX3 7LE, UK
- NIHR Oxford Biomedical Research Centre, John Radcliffe Hospital, Oxford OX3 9DU, UK
- Oxford Kavli Centre for Nanoscience Discovery, University of Oxford, Oxford OX37LE, UK
| | - Jeremy W Tomlinson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford OX3 7LE, UK
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3
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Bensreti H, Alhamad DW, Gonzalez AM, Pizarro-Mondesir M, Bollag WB, Isales CM, McGee-Lawrence ME. Update on the Role of Glucocorticoid Signaling in Osteoblasts and Bone Marrow Adipocytes During Aging. Curr Osteoporos Rep 2023; 21:32-44. [PMID: 36564571 PMCID: PMC9936962 DOI: 10.1007/s11914-022-00772-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/15/2022] [Indexed: 12/25/2022]
Abstract
PURPOSE OF REVIEW Bone marrow adipose tissue (BMAT) in the skeleton likely plays a variety of physiological and pathophysiological roles that are not yet fully understood. In elucidating the complex relationship between bone and BMAT, glucocorticoids (GCs) are positioned to play a key role, as they have been implicated in the differentiation of bone marrow mesenchymal stem cells (BMSCs) between osteogenic and adipogenic lineages. The purpose of this review is to illuminate aspects of both endogenous and exogenous GC signaling, including the influence of GC receptors, in mechanisms of bone aging including relationships to BMAT. RECENT FINDINGS Harmful effects of GCs on bone mass involve several cellular pathways and events that can include BMSC differentiation bias toward adipogenesis and the influence of mature BMAT on bone remodeling through crosstalk. Interestingly, BMAT involvement remains poorly explored in GC-induced osteoporosis and warrants further investigation. This review provides an update on the current understanding of the role of glucocorticoids in the biology of osteoblasts and bone marrow adipocytes (BMAds).
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Affiliation(s)
- Husam Bensreti
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Dima W Alhamad
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Alejandro Marrero Gonzalez
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Manuel Pizarro-Mondesir
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Wendy B Bollag
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, GA, USA
- Charlie Norwood VA Medical Center, Augusta, GA, USA
| | - Carlos M Isales
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, USA
- Department of Orthopaedic Surgery, Medical College of Georgia, Augusta University, Augusta, GA, USA
- Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Meghan E McGee-Lawrence
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA.
- Department of Orthopaedic Surgery, Medical College of Georgia, Augusta University, Augusta, GA, USA.
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4
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Gado M, Baschant U, Hofbauer LC, Henneicke H. Bad to the Bone: The Effects of Therapeutic Glucocorticoids on Osteoblasts and Osteocytes. Front Endocrinol (Lausanne) 2022; 13:835720. [PMID: 35432217 PMCID: PMC9008133 DOI: 10.3389/fendo.2022.835720] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 02/10/2022] [Indexed: 02/06/2023] Open
Abstract
Despite the continued development of specialized immunosuppressive therapies in the form of monoclonal antibodies, glucocorticoids remain a mainstay in the treatment of rheumatological and auto-inflammatory disorders. Therapeutic glucocorticoids are unmatched in the breadth of their immunosuppressive properties and deliver their anti-inflammatory effects at unparalleled speed. However, long-term exposure to therapeutic doses of glucocorticoids decreases bone mass and increases the risk of fractures - particularly in the spine - thus limiting their clinical use. Due to the abundant expression of glucocorticoid receptors across all skeletal cell populations and their respective progenitors, therapeutic glucocorticoids affect skeletal quality through a plethora of cellular targets and molecular mechanisms. However, recent evidence from rodent studies, supported by clinical data, highlights the considerable role of cells of the osteoblast lineage in the pathogenesis of glucocorticoid-induced osteoporosis: it is now appreciated that cells of the osteoblast lineage are key targets of therapeutic glucocorticoids and have an outsized role in mediating their undesirable skeletal effects. As part of this article, we review the molecular mechanisms underpinning the detrimental effects of supraphysiological levels of glucocorticoids on cells of the osteoblast lineage including osteocytes and highlight the clinical implications of recent discoveries in the field.
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Affiliation(s)
- Manuel Gado
- Center for Regenerative Therapies TU Dresden, Technische Universität Dresden, Dresden, Germany
| | - Ulrike Baschant
- Department of Medicine III, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
- Center for Healthy Aging, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Lorenz C. Hofbauer
- Center for Regenerative Therapies TU Dresden, Technische Universität Dresden, Dresden, Germany
- Department of Medicine III, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
- Center for Healthy Aging, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Holger Henneicke
- Center for Regenerative Therapies TU Dresden, Technische Universität Dresden, Dresden, Germany
- Department of Medicine III, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
- Center for Healthy Aging, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
- *Correspondence: Holger Henneicke,
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Kim S, Henneicke H, Cavanagh LL, Macfarlane E, Thai LJ, Foong D, Gasparini SJ, Fong-Yee C, Swarbrick MM, Seibel MJ, Zhou H. Osteoblastic glucocorticoid signaling exacerbates high-fat-diet- induced bone loss and obesity. Bone Res 2021; 9:40. [PMID: 34465731 PMCID: PMC8408138 DOI: 10.1038/s41413-021-00159-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 04/21/2021] [Accepted: 05/19/2021] [Indexed: 12/22/2022] Open
Abstract
Chronic high-fat diet (HFD) consumption not only promotes obesity and insulin resistance, but also causes bone loss through mechanisms that are not well understood. Here, we fed wild-type CD-1 mice either chow or a HFD (43% of energy from fat) for 18 weeks; HFD-fed mice exhibited decreased trabecular volume (-28%) and cortical thickness (-14%) compared to chow-fed mice. In HFD-fed mice, bone loss was due to reduced bone formation and mineral apposition, without obvious effects on bone resorption. HFD feeding also increased skeletal expression of sclerostin and caused deterioration of the osteocyte lacunocanalicular network (LCN). In mice fed HFD, skeletal glucocorticoid signaling was activated relative to chow-fed mice, independent of serum corticosterone concentrations. We therefore examined whether skeletal glucocorticoid signaling was necessary for HFD-induced bone loss, using transgenic mice lacking glucocorticoid signaling in osteoblasts and osteocytes (HSD2OB/OCY-tg mice). In HSD2OB/OCY-tg mice, bone formation and mineral apposition rates were not suppressed by HFD, and bone loss was significantly attenuated. Interestingly, in HSD2OB/OCY-tg mice fed HFD, both Wnt signaling (less sclerostin induction, increased β-catenin expression) and glucose uptake were significantly increased, relative to diet- and genotype-matched controls. The osteocyte LCN remained intact in HFD-fed HSD2OB/OCY-tg mice. When fed a HFD, HSD2OB/OCY-tg mice also increased their energy expenditure and were protected against obesity, insulin resistance, and dyslipidemia. Therefore, glucocorticoid signaling in osteoblasts and osteocytes contributes to the suppression of bone formation in HFD-fed mice. Skeletal glucocorticoid signaling is also an important determinant of glucose uptake in bone, which influences the whole-body metabolic response to HFD.
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Affiliation(s)
- Sarah Kim
- Bone Research Program, ANZAC Research Institute, The University of Sydney, Sydney, NSW, Australia.,Concord Clinical School, The University of Sydney, Sydney, NSW, Australia
| | - Holger Henneicke
- Bone Research Program, ANZAC Research Institute, The University of Sydney, Sydney, NSW, Australia.,Department of Medicine III, Technische University Dresden Medical Center, Dresden, Germany.,Center for Healthy Aging, Technische Universität Dresden Medical Center, Dresden, Germany.,Center for Regenerative Therapies Dresden, Technische University Dresden, Dresden, Germany
| | - Lauryn L Cavanagh
- Bone Research Program, ANZAC Research Institute, The University of Sydney, Sydney, NSW, Australia
| | - Eugenie Macfarlane
- Bone Research Program, ANZAC Research Institute, The University of Sydney, Sydney, NSW, Australia
| | - Lee Joanne Thai
- Bone Research Program, ANZAC Research Institute, The University of Sydney, Sydney, NSW, Australia
| | - Daphne Foong
- Bone Research Program, ANZAC Research Institute, The University of Sydney, Sydney, NSW, Australia
| | - Sylvia J Gasparini
- Bone Research Program, ANZAC Research Institute, The University of Sydney, Sydney, NSW, Australia
| | - Colette Fong-Yee
- Bone Research Program, ANZAC Research Institute, The University of Sydney, Sydney, NSW, Australia
| | - Michael M Swarbrick
- Bone Research Program, ANZAC Research Institute, The University of Sydney, Sydney, NSW, Australia.,Concord Clinical School, The University of Sydney, Sydney, NSW, Australia
| | - Markus J Seibel
- Bone Research Program, ANZAC Research Institute, The University of Sydney, Sydney, NSW, Australia.,Concord Clinical School, The University of Sydney, Sydney, NSW, Australia.,Department of Endocrinology and Metabolism, Concord Repatriation General Hospital, The University of Sydney, Sydney, NSW, Australia
| | - Hong Zhou
- Bone Research Program, ANZAC Research Institute, The University of Sydney, Sydney, NSW, Australia. .,Concord Clinical School, The University of Sydney, Sydney, NSW, Australia.
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6
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Peng CH, Lin WY, Yeh KT, Chen IH, Wu WT, Lin MD. The molecular etiology and treatment of glucocorticoid-induced osteoporosis. Tzu Chi Med J 2021; 33:212-223. [PMID: 34386357 PMCID: PMC8323641 DOI: 10.4103/tcmj.tcmj_233_20] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 11/19/2020] [Accepted: 12/30/2020] [Indexed: 12/30/2022] Open
Abstract
Glucocorticoid-induced osteoporosis (GIOP) is the most common form of secondary osteoporosis, accounting for 20% of osteoporosis diagnoses. Using glucocorticoids for >6 months leads to osteoporosis in 50% of patients, resulting in an increased risk of fracture and death. Osteoblasts, osteocytes, and osteoclasts work together to maintain bone homeostasis. When bone formation and resorption are out of balance, abnormalities in bone structure or function may occur. Excess glucocorticoids disrupt the bone homeostasis by promoting osteoclast formation and prolonging osteoclasts' lifespan, leading to an increase in bone resorption. On the other hand, glucocorticoids inhibit osteoblasts' formation and facilitate apoptosis of osteoblasts and osteocytes, resulting in a reduction of bone formation. Several signaling pathways, signaling modulators, endocrines, and cytokines are involved in the molecular etiology of GIOP. Clinically, adults ≥40 years of age using glucocorticoids chronically with a high fracture risk are considered to have medical intervention. In addition to vitamin D and calcium tablet supplementations, the major therapeutic options approved for GIOP treatment include antiresorption drug bisphosphonates, parathyroid hormone N-terminal fragment teriparatide, and the monoclonal antibody denosumab. The selective estrogen receptor modulator can only be used under specific condition for postmenopausal women who have GIOP but fail to the regular GIOP treatment or have specific therapeutic contraindications. In this review, we focus on the molecular etiology of GIOP and the molecular pharmacology of the therapeutic drugs used for GIOP treatment.
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Affiliation(s)
- Cheng-Huan Peng
- Department of Orthopedics, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan.,Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan.,School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Wen-Ying Lin
- Department of Orthopedics, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan
| | - Kuang-Ting Yeh
- Department of Orthopedics, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan.,School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Ing-Ho Chen
- Department of Orthopedics, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan.,School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Wen-Tien Wu
- Department of Orthopedics, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan.,Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan.,School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Ming-Der Lin
- Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan.,Department of Molecular Biology and Human Genetics, Tzu Chi University, Hualien, Taiwan
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7
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Fuchs M, Kirchhoff F, Reichel H, Perka C, Faschingbauer M, Gwinner C. Variation of synovial fluid leucocyte cell count and polymorphonuclear percentage in patients with aseptic revision total knee arthroplasty. Bone Jt Open 2021; 2:566-572. [PMID: 34337971 PMCID: PMC8384436 DOI: 10.1302/2633-1462.28.bjo-2021-0109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
AIMS Current guidelines consider analyses of joint aspirates, including leucocyte cell count (LC) and polymorphonuclear percentage (PMN%) as a diagnostic mainstay of periprosthetic joint infection (PJI). It is unclear if these parameters are subject to a certain degree of variability over time. Therefore, the aim of this study was to evaluate the variation of LC and PMN% in patients with aseptic revision total knee arthroplasty (TKA). METHODS We conducted a prospective, double-centre study of 40 patients with 40 knee joints. Patients underwent joint aspiration at two different time points with a maximum period of 120 days in between these interventions and without any events such as other joint aspirations or surgeries. The main indications for TKA revision surgery were aseptic implant loosening (n = 24) and joint instability (n = 11). RESULTS Overall, 80 synovial fluid samples of 40 patients were analyzed. The average time period between the joint aspirations was 50 days (SD 32). There was a significantly higher percentage change in LC when compared to PMN% (44.1% (SD 28.6%) vs 27.3% (SD 23.7%); p = 0.003). When applying standard definition criteria, LC counts were found to skip back and forth between the two time points with exceeding the thresholds in up to 20% of cases, which was significantly more compared to PMN% for the European Bone and Joint Infection Society (EBJIS) criteria (p = 0.001), as well as for Musculoskeletal Infection Society (MSIS) (p = 0.029). CONCLUSION LC and PMN% are subject to considerable variation. According to its higher interindividual variance, LC evaluation might contribute to false-positive or false-negative results in PJI assessment. Single LC testing prior to TKA revision surgery seems to be insufficient to exclude PJI. On the basis of the obtained results, PMN% analyses overrule LC measurements with regard to a conclusive diagnostic algorithm. Cite this article: Bone Jt Open 2021;2(8):566-572.
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Affiliation(s)
- Michael Fuchs
- RKU Department of Orthopaedic Surgery, University Ulm Medical Centre, Ulm, Baden-Württemberg, Germany
| | - Felix Kirchhoff
- RKU Department of Orthopaedic Surgery, University Ulm Medical Centre, Ulm, Baden-Württemberg, Germany
| | - Heiko Reichel
- RKU Department of Orthopaedic Surgery, University Ulm Medical Centre, Ulm, Baden-Württemberg, Germany
| | - Carsten Perka
- Department of Orthopaedic Surgery, Charite Universitatsmedizin Berlin, Berlin, Berlin, Germany
| | - Martin Faschingbauer
- RKU Department of Orthopaedic Surgery, University Ulm Medical Centre, Ulm, Baden-Württemberg, Germany
| | - Clemens Gwinner
- Department of Orthopaedic Surgery, Charite Universitatsmedizin Berlin, Berlin, Berlin, Germany
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8
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Hachemi Y, Rapp AE, Lee S, Dorn AK, Krüger BT, Kaiser K, Ignatius A, Tuckermann J. Intact Glucocorticoid Receptor Dimerization Is Deleterious in Trauma-Induced Impaired Fracture Healing. Front Immunol 2021; 11:628287. [PMID: 33679723 PMCID: PMC7927427 DOI: 10.3389/fimmu.2020.628287] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 12/29/2020] [Indexed: 11/13/2022] Open
Abstract
Following severe trauma, fracture healing is impaired because of overwhelming systemic and local inflammation. Glucocorticoids (GCs), acting via the glucocorticoid receptor (GR), influence fracture healing by modulating the trauma-induced immune response. GR dimerization-dependent gene regulation is essential for the anti-inflammatory effects of GCs. Therefore, we investigated in a murine trauma model of combined femur fracture and thoracic trauma, whether effective GR dimerization influences the pathomechanisms of trauma-induced compromised fracture healing. To this end, we used mice with decreased GR dimerization ability (GRdim). The healing process was analyzed by cytokine/chemokine multiplex analysis, flow cytometry, gene-expression analysis, histomorphometry, micro-computed tomography, and biomechanical testing. GRdim mice did not display a systemic or local hyper-inflammation upon combined fracture and thorax trauma. Strikingly, we discovered that GRdim mice were protected from fracture healing impairment induced by the additional thorax trauma. Collectively and in contrast to previous studies describing the beneficial effects of intact GR dimerization in inflammatory models, we report here an adverse role of intact GR dimerization in trauma-induced compromised fracture healing.
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Affiliation(s)
- Yasmine Hachemi
- Institute of Comparative Molecular Endocrinology, Ulm University, Ulm, Germany
| | - Anna E Rapp
- Institute of Orthopedic Research and Biomechanics, Ulm University Medical Center, Ulm, Germany
| | - Sooyeon Lee
- Institute of Comparative Molecular Endocrinology, Ulm University, Ulm, Germany
| | - Ann-Kristin Dorn
- Institute of Comparative Molecular Endocrinology, Ulm University, Ulm, Germany
| | - Benjamin T Krüger
- Institute of Orthopedic Research and Biomechanics, Ulm University Medical Center, Ulm, Germany
| | - Kathrin Kaiser
- Institute of Orthopedic Research and Biomechanics, Ulm University Medical Center, Ulm, Germany
| | - Anita Ignatius
- Institute of Orthopedic Research and Biomechanics, Ulm University Medical Center, Ulm, Germany
| | - Jan Tuckermann
- Institute of Comparative Molecular Endocrinology, Ulm University, Ulm, Germany
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9
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Martin CS, Cooper MS, Hardy RS. Endogenous Glucocorticoid Metabolism in Bone: Friend or Foe. Front Endocrinol (Lausanne) 2021; 12:733611. [PMID: 34512556 PMCID: PMC8429897 DOI: 10.3389/fendo.2021.733611] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 08/09/2021] [Indexed: 02/02/2023] Open
Abstract
The role of tissue specific metabolism of endogenous glucocorticoids (GCs) in the pathogenesis of human disease has been a field of intense interest over the last 20 years, fuelling clinical trials of metabolism inhibitors in the treatment of an array of metabolic diseases. Localised pre-receptor metabolism of endogenous and therapeutic GCs by the 11β-hydroxysteroid dehydrogenase (11β-HSD) enzymes (which interconvert endogenous GCs between their inactive and active forms) are increasingly recognised as being critical in mediating both their positive and negative actions on bone homeostasis. In this review we explore the roles of endogenous and therapeutic GC metabolism by the 11β-HSD enzymes in the context of bone metabolism and bone cell function, and consider future strategies aimed at modulating this system in order to manage and treat various bone diseases.
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Affiliation(s)
- Claire S. Martin
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom
| | - Mark S. Cooper
- Australian and New Zealand Army Corps (ANZAC) Research Institute, University of Sydney, Sydney, NSW, Australia
| | - Rowan S. Hardy
- Arthritis Research United Kingdom (UK) Career Development Fellow, University of Birmingham, Birmingham, United Kingdom
- Institute of Clinical Sciences, University of Birmingham, Birmingham, United Kingdom
- *Correspondence: Rowan S. Hardy,
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10
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Lee S, Krüger BT, Ignatius A, Tuckermann J. Distinct Glucocorticoid Receptor Actions in Bone Homeostasis and Bone Diseases. Front Endocrinol (Lausanne) 2021; 12:815386. [PMID: 35082759 PMCID: PMC8784516 DOI: 10.3389/fendo.2021.815386] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 12/16/2021] [Indexed: 12/29/2022] Open
Abstract
Glucocorticoids (GCs) are steroid hormones that respond to stress and the circadian rhythm. Pharmacological GCs are widely used to treat autoimmune and chronic inflammatory diseases despite their adverse effects on bone after long-term therapy. GCs regulate bone homeostasis in a cell-type specific manner, affecting osteoblasts, osteoclasts, and osteocytes. Endogenous physiological and exogenous/excessive GCs act via nuclear receptors, mainly via the GC receptor (GR). Endogenous GCs have anabolic effects on bone mass regulation, while excessive or exogenous GCs can cause detrimental effects on bone. GC-induced osteoporosis (GIO) is a common adverse effect after GC therapy, which increases the risk of fractures. Exogenous GC treatment impairs osteoblastogenesis, survival of the osteoblasts/osteocytes and prolongs the longevity of osteoclasts. Under normal physiological conditions, endogenous GCs are regulated by the circadian rhythm and circadian genes display oscillatory rhythmicity in bone cells. However, exogenous GCs treatment disturbs the circadian rhythm. Recent evidence suggests that the disturbed circadian rhythm by continuous exogenous GCs treatment can in itself hamper bone integrity. GC signaling is also important for fracture healing and rheumatoid arthritis, where crosstalk among several cell types including macrophages and stromal cells is indispensable. This review summarizes the complexity of GC actions via GR in bone cells at cellular and molecular levels, including the effect on circadian rhythmicity, and outlines new therapeutic possibilities for the treatment of their adverse effects.
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Affiliation(s)
- Sooyeon Lee
- Institute for Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany
| | - Benjamin Thilo Krüger
- Institute of Orthopedic Research and Biomechanics, Trauma Research Center Ulm, Ulm University Medical Center, Ulm, Germany
| | - Anita Ignatius
- Institute of Orthopedic Research and Biomechanics, Trauma Research Center Ulm, Ulm University Medical Center, Ulm, Germany
| | - Jan Tuckermann
- Institute for Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany
- *Correspondence: Jan Tuckermann,
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11
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Skeletal glucocorticoid signalling determines leptin resistance and obesity in aging mice. Mol Metab 2020; 42:101098. [PMID: 33045434 PMCID: PMC7596342 DOI: 10.1016/j.molmet.2020.101098] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 09/28/2020] [Accepted: 10/06/2020] [Indexed: 11/23/2022] Open
Abstract
Objective Aging and chronic glucocorticoid excess share a number of critical features, including the development of central obesity, insulin resistance and osteoporosis. Previous studies have shown that skeletal glucocorticoid signalling increases with aging and that osteoblasts mediate the detrimental skeletal and metabolic effects of chronic glucocorticoid excess. Here, we investigated whether endogenous glucocorticoid action in the skeleton contributes to metabolic dysfunction during normal aging. Methods Mice lacking glucocorticoid signalling in osteoblasts and osteocytes (HSD2OB/OCY-tg mice) and their wild-type littermates were studied until 3, 6, 12 and 18 months of age. Body composition, adipose tissue morphology, skeletal gene expression and glucose/insulin tolerance were assessed at each timepoint. Leptin sensitivity was assessed by arcuate nucleus STAT3 phosphorylation and inhibition of feeding following leptin administration. Tissue-specific glucose uptake and adipose tissue oxygen consumption rate were also measured. Results As they aged, wild-type mice became obese and insulin-resistant. In contrast, HSD2OB/OCY-tg mice remained lean and insulin-sensitive during aging. Obesity in wild-type mice was due to leptin resistance, evidenced by an impaired ability of exogenous leptin to suppress food intake and phosphorylate hypothalamic STAT3, from 6 months of age onwards. In contrast, HSD2OB/OCY-tg mice remained leptin-sensitive throughout the study. Compared to HSD2OB/OCY-tg mice, leptin-resistant wild-type mice displayed attenuated sympathetic outflow, with reduced tyrosine hydroxylase expression in both the hypothalamus and thermogenic adipose tissues. Adipose tissue oxygen consumption rate declined progressively in aging wild-type mice but was maintained in HSD2OB/OCY-tg mice. At 18 months of age, adipose tissue glucose uptake was increased 3.7-fold in HSD2OB/OCY-tg mice, compared to wild-type mice. Conclusions Skeletal glucocorticoid signalling is critical for the development of leptin resistance, obesity and insulin resistance during aging. These findings underscore the skeleton's importance in the regulation of body weight and implicate osteoblastic/osteocytic glucocorticoid signalling in the aetiology of aging-related obesity and metabolic disease. As they aged, wild-type CD1 mice became hyperphagic, obese and insulin-resistant. Mice lacking skeletal glucocorticoid signalling (HSD2OB/OCY-tg) were lean and healthy. Unlike wild-type mice, HSD2OB/OCY-tg mice remained leptin-sensitive during aging. Adipose tissue sympathetic outflow was maintained in aging HSD2OB/OCY-tg mice.
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12
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Arthritis and the role of endogenous glucocorticoids. Bone Res 2020; 8:33. [PMID: 32963891 PMCID: PMC7478967 DOI: 10.1038/s41413-020-00112-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 07/09/2020] [Accepted: 07/27/2020] [Indexed: 12/17/2022] Open
Abstract
Rheumatoid arthritis and osteoarthritis, the most common forms of arthritis, are chronic, painful, and disabling conditions. Although both diseases differ in etiology, they manifest in progressive joint destruction characterized by pathological changes in the articular cartilage, bone, and synovium. While the potent anti-inflammatory properties of therapeutic (i.e., exogenous) glucocorticoids have been heavily researched and are widely used in clinical practice, the role of endogenous glucocorticoids in arthritis susceptibility and disease progression remains poorly understood. Current evidence from mouse models suggests that local endogenous glucocorticoid signaling is upregulated by the pro-inflammatory microenvironment in rheumatoid arthritis and by aging-related mechanisms in osteoarthritis. Furthermore, these models indicate that endogenous glucocorticoid signaling in macrophages, mast cells, and chondrocytes has anti-inflammatory effects, while signaling in fibroblast-like synoviocytes, myocytes, osteoblasts, and osteocytes has pro-inflammatory actions in rheumatoid arthritis. Conversely, in osteoarthritis, endogenous glucocorticoid signaling in both osteoblasts and chondrocytes has destructive actions. Together these studies provide insights into the role of endogenous glucocorticoids in the pathogenesis of both inflammatory and degenerative joint disease.
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13
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The shift in the balance between osteoblastogenesis and adipogenesis of mesenchymal stem cells mediated by glucocorticoid receptor. Stem Cell Res Ther 2019; 10:377. [PMID: 31805987 PMCID: PMC6896503 DOI: 10.1186/s13287-019-1498-0] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Revised: 11/09/2019] [Accepted: 11/18/2019] [Indexed: 12/31/2022] Open
Abstract
Mesenchymal stem cells (MSCs) are multipotent cells capable of differentiating into several tissues, such as bone, cartilage, and fat. Glucocorticoids affect a variety of biological processes such as proliferation, differentiation, and apoptosis of various cell types, including osteoblasts, adipocytes, or chondrocytes. Glucocorticoids exert their function by binding to the glucocorticoid receptor (GR). Physiological concentrations of glucocorticoids stimulate osteoblast proliferation and promote osteogenic differentiation of MSCs. However, pharmacological concentrations of glucocorticoids can not only induce apoptosis of osteoblasts and osteocytes but can also reduce proliferation and inhibit the differentiation of osteoprogenitor cells. Several signaling pathways, including the Wnt, TGFβ/BMP superfamily and Notch signaling pathways, transcription factors, post-transcriptional regulators, and other regulators, regulate osteoblastogenesis and adipogenesis of MSCs mediated by GR. These signaling pathways target key transcription factors, such as Runx2 and TAZ for osteogenesis and PPARγ and C/EBPs for adipogenesis. Glucocorticoid-induced osteonecrosis and osteoporosis are caused by various factors including dysfunction of bone marrow MSCs. Transplantation of MSCs is valuable in regenerative medicine for the treatment of osteonecrosis of the femoral head, osteoporosis, osteogenesis imperfecta, and other skeletal disorders. However, the mechanism of inducing MSCs to differentiate toward the osteogenic lineage is the key to an efficient treatment. Thus, a better understanding of the molecular mechanisms behind the imbalance between GR-mediated osteoblastogenesis and adipogenesis of MSCs would not only help us to identify the pathogenic causes of glucocorticoid-induced osteonecrosis and osteoporosis but also promote future clinical applications for stem cell-based tissue engineering and regenerative medicine. Here, we primarily review the signaling mechanisms involved in adipogenesis and osteogenesis mediated by GR and discuss the factors that control the adipo-osteogenic balance.
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14
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Ahmad M, Hachemi Y, Paxian K, Mengele F, Koenen M, Tuckermann J. A Jack of All Trades: Impact of Glucocorticoids on Cellular Cross-Talk in Osteoimmunology. Front Immunol 2019; 10:2460. [PMID: 31681333 PMCID: PMC6811614 DOI: 10.3389/fimmu.2019.02460] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 10/02/2019] [Indexed: 12/13/2022] Open
Abstract
Glucocorticoids (GCs) are known to have a strong impact on the immune system, metabolism, and bone homeostasis. While these functions have been long investigated separately in immunology, metabolism, or bone biology, the understanding of how GCs regulate the cellular cross-talk between innate immune cells, mesenchymal cells, and other stromal cells has been garnering attention rather recently. Here we review the recent findings of GC action in osteoporosis, inflammatory bone diseases (rheumatoid and osteoarthritis), and bone regeneration during fracture healing. We focus on studies of pre-clinical animal models that enable dissecting the role of GC actions in innate immune cells, stromal cells, and bone cells using conditional and function-selective mutant mice of the GC receptor (GR), or mice with impaired GC signaling. Importantly, GCs do not only directly affect cellular functions, but also influence the cross-talk between mesenchymal and immune cells, contributing to both beneficial and adverse effects of GCs. Given the importance of endogenous GCs as stress hormones and the wide prescription of pharmaceutical GCs, an improved understanding of GC action is decisive for tackling inflammatory bone diseases, osteoporosis, and aging.
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Affiliation(s)
- Mubashir Ahmad
- Institute of Comparative Molecular Endocrinology (CME), University of Ulm, Ulm, Germany
| | - Yasmine Hachemi
- Institute of Comparative Molecular Endocrinology (CME), University of Ulm, Ulm, Germany
| | - Kevin Paxian
- Institute of Comparative Molecular Endocrinology (CME), University of Ulm, Ulm, Germany
| | - Florian Mengele
- Institute of Comparative Molecular Endocrinology (CME), University of Ulm, Ulm, Germany
- Praxisklinik für Orthopädie, Unfall- und Neurochirurgie Prof. Bischoff/ Dr. Spies/ Dr. Mengele, Neu-Ulm, Germany
| | - Mascha Koenen
- Institute of Comparative Molecular Endocrinology (CME), University of Ulm, Ulm, Germany
- Department of Immunobiology, Yale School of Medicine, New Haven, CT, United States
| | - Jan Tuckermann
- Institute of Comparative Molecular Endocrinology (CME), University of Ulm, Ulm, Germany
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15
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Fenton CG, Doig CL, Fareed S, Naylor A, Morrell AP, Addison O, Wehmeyer C, Buckley CD, Cooper MS, Lavery GG, Raza K, Hardy RS. 11β-HSD1 plays a critical role in trabecular bone loss associated with systemic glucocorticoid therapy. Arthritis Res Ther 2019; 21:188. [PMID: 31420008 PMCID: PMC6698000 DOI: 10.1186/s13075-019-1972-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 08/07/2019] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Despite their efficacy in the treatment of chronic inflammation, the prolonged application of therapeutic glucocorticoids (GCs) is limited by significant systemic side effects including glucocorticoid-induced osteoporosis (GIOP). 11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) is a bi-directional enzyme that primarily activates GCs in vivo, regulating tissue-specific exposure to active GC. We aimed to determine the contribution of 11β-HSD1 to GIOP. METHODS Wild type (WT) and 11β-HSD1 knockout (KO) mice were treated with corticosterone (100 μg/ml, 0.66% ethanol) or vehicle (0.66% ethanol) in drinking water over 4 weeks (six animals per group). Bone parameters were assessed by micro-CT, sub-micron absorption tomography and serum markers of bone metabolism. Osteoblast and osteoclast gene expression was assessed by quantitative RT-PCR. RESULTS Wild type mice receiving corticosterone developed marked trabecular bone loss with reduced bone volume to tissue volume (BV/TV), trabecular thickness (Tb.Th) and trabecular number (Tb.N). Histomorphometric analysis revealed a dramatic reduction in osteoblast numbers. This was matched by a significant reduction in the serum marker of osteoblast bone formation P1NP and gene expression of the osteoblast markers Alp and Bglap. In contrast, 11β-HSD1 KO mice receiving corticosterone demonstrated almost complete protection from trabecular bone loss, with partial protection from the decrease in osteoblast numbers and markers of bone formation relative to WT counterparts receiving corticosterone. CONCLUSIONS This study demonstrates that 11β-HSD1 plays a critical role in GIOP, mediating GC suppression of anabolic bone formation and reduced bone volume secondary to a decrease in osteoblast numbers. This raises the intriguing possibility that therapeutic inhibitors of 11β-HSD1 may be effective in preventing GIOP in patients receiving therapeutic steroids.
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Affiliation(s)
- C. G. Fenton
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, UK
| | - C. L. Doig
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
| | - S. Fareed
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, UK
| | - A. Naylor
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
| | - A. P. Morrell
- Aston Institute of Materials Research, Aston University, Birmingham, UK
| | - O. Addison
- Institute of Clinical Sciences, University of Birmingham, Birmingham, UK
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
| | - C. Wehmeyer
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
| | - C. D. Buckley
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
| | - M. S. Cooper
- ANZAC Research Institute, University of Sydney, Sydney, Australia
| | - G. G. Lavery
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, UK
| | - K. Raza
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
- Sandwell and West Birmingham Hospitals NHS Trust, Birmingham, UK
| | - R. S. Hardy
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, UK
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16
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Klotho prevents DEX-induced apoptosis in MC3T3-E1 osteoblasts through the NF-κB signaling pathway. Biochem Biophys Res Commun 2018; 507:355-361. [PMID: 30442365 DOI: 10.1016/j.bbrc.2018.11.040] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 11/06/2018] [Indexed: 12/25/2022]
Abstract
Dexamethasone (DEX) is a commonly used anti-inflammatory drug and an immunosuppressive drug used in clinical practice to treat a variety of diseases. Glucocorticoid-induced osteoporosis (GIOP) is a consequence of high dose, or a long-term low dose use of glucocorticoids (GCs). These treatment regimens can cause a variety of bone-related adverse effects, leading to increased osteoblast and bone cell apoptosis. Evidence suggests that klotho (KL) can inhibit GIOP. It is unknown whether KL attenuates DEX-induced apoptosis in MC3T3-E1 cells or the underlying mechanisms involved. In the present study, we found that MC3T3-E1 cells pretreated with DEX led to the up-regulation of cleaved-caspase-3, and down-regulation of caspase-3, which were inhibited by KL transfection. Furthermore, flow cytometry and western blot analysis revealed that the NFκB inhibitor pyrrolidine dithiocarbamate (PDTC) could restore the DEX-induced caspase-3 decrease and inhibit the DEX-induced cleaved caspase-3 increase. We observed that DEX stimulated the degradation of IκBα(NFκB inhibitor α) and the translocation of NFκB, which were suppressed by KL transfection. These findings therefore, indicate a protective role for KL against osteoblastic cell apoptosis induced by DEX, via the NF-κB signaling pathway.
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17
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Wang L, Heckmann BL, Yang X, Long H. Osteoblast autophagy in glucocorticoid-induced osteoporosis. J Cell Physiol 2018; 234:3207-3215. [PMID: 30417506 DOI: 10.1002/jcp.27335] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 08/10/2018] [Indexed: 02/05/2023]
Abstract
Administration of glucocorticoids is an effective strategy for treating many inflammatory and autoimmune diseases. However, glucocorticoid treatment can have adverse effects on bone, leading to glucocorticoid-induced osteoporosis (GIO), the most common form of secondary osteoporosis. Although the pathogenesis of GIO has been studied for decades, over the past ten years the autophagy machinery has been implicated as a novel mechanism. Autophagy in osteoblasts, osteocytes, and osteoclasts plays a critical role in the maintenance of bone homeostasis. Herein, we specifically discuss how osteoblast autophagy responds to glucocorticoids and its role in the development of GIO.
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Affiliation(s)
- Lufei Wang
- Oral and Craniofacial Biomedicine Program, School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Bradlee L Heckmann
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Xianrui Yang
- Department of Orthodontics, State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,Department of Developmental Biology, Harvard School of Dental Medicine, Boston, Massachusetts
| | - Hu Long
- Department of Orthodontics, State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
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18
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Hardy RS, Zhou H, Seibel MJ, Cooper MS. Glucocorticoids and Bone: Consequences of Endogenous and Exogenous Excess and Replacement Therapy. Endocr Rev 2018; 39:519-548. [PMID: 29905835 DOI: 10.1210/er.2018-00097] [Citation(s) in RCA: 136] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 06/08/2018] [Indexed: 02/02/2023]
Abstract
Osteoporosis associated with long-term glucocorticoid therapy remains a common and serious bone disease. Additionally, in recent years it has become clear that more subtle states of endogenous glucocorticoid excess may have a major impact on bone health. Adverse effects can be seen with mild systemic glucocorticoid excess, but there is also evidence of tissue-specific regulation of glucocorticoid action within bone as a mechanism of disease. This review article examines (1) the role of endogenous glucocorticoids in normal bone physiology, (2) the skeletal effects of endogenous glucocorticoid excess in the context of endocrine conditions such as Cushing disease/syndrome and autonomous cortisol secretion (subclinical Cushing syndrome), and (3) the actions of therapeutic (exogenous) glucocorticoids on bone. We review the extent to which the effect of glucocorticoids on bone is influenced by variations in tissue metabolizing enzymes and glucocorticoid receptor expression and sensitivity. We consider how the effects of therapeutic glucocorticoids on bone are complicated by the effects of the underlying inflammatory disease being treated. We also examine the impact that glucocorticoid replacement regimens have on bone in the context of primary and secondary adrenal insufficiency. We conclude that even subtle excess of endogenous or moderate doses of therapeutic glucocorticoids are detrimental to bone. However, in patients with inflammatory disorders there is a complex interplay between glucocorticoid treatment and underlying inflammation, with the underlying condition frequently representing the major component underpinning bone damage.
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Affiliation(s)
- Rowan S Hardy
- University of Birmingham, Birmingham, United Kingdom
| | - Hong Zhou
- Bone Research Program, ANZAC Research Institute, Sydney, New South Wales, Australia
| | - Markus J Seibel
- Bone Research Program, ANZAC Research Institute, Sydney, New South Wales, Australia.,Department of Endocrinology and Metabolism, Concord Repatriation General Hospital, Sydney, New South Wales, Australia.,Concord Clinical School, University of Sydney, Sydney, New South Wales, Australia
| | - Mark S Cooper
- Department of Endocrinology and Metabolism, Concord Repatriation General Hospital, Sydney, New South Wales, Australia.,Concord Clinical School, University of Sydney, Sydney, New South Wales, Australia.,Adrenal Steroid Laboratory, ANZAC Research Institute, Sydney, New South Wales, Australia
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19
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Hachemi Y, Rapp AE, Picke AK, Weidinger G, Ignatius A, Tuckermann J. Molecular mechanisms of glucocorticoids on skeleton and bone regeneration after fracture. J Mol Endocrinol 2018; 61:R75-R90. [PMID: 29588427 PMCID: PMC5976078 DOI: 10.1530/jme-18-0024] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 03/27/2018] [Indexed: 12/29/2022]
Abstract
Glucocorticoid hormones (GCs) have profound effects on bone metabolism. Via their nuclear hormone receptor - the GR - they act locally within bone cells and modulate their proliferation, differentiation, and cell death. Consequently, high glucocorticoid levels - as present during steroid therapy or stress - impair bone growth and integrity, leading to retarded growth and glucocorticoid-induced osteoporosis, respectively. Because of their profound impact on the immune system and bone cell differentiation, GCs also affect bone regeneration and fracture healing. The use of conditional-mutant mouse strains in recent research provided insights into the cell-type-specific actions of the GR. However, despite recent advances in system biology approaches addressing GR genomics in general, little is still known about the molecular mechanisms of GCs and GR in bone cells. Here, we review the most recent findings on the molecular mechanisms of the GR in general and the known cell-type-specific actions of the GR in mesenchymal cells and their derivatives as well as in osteoclasts during bone homeostasis, GC excess, bone regeneration and fracture healing.
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Affiliation(s)
- Yasmine Hachemi
- Institute of Comparative Molecular EndocrinologyUlm University, Ulm, Germany
| | - Anna E Rapp
- Institute of Orthopaedic Research and BiomechanicsUlm University Medical Centre, Ulm, Germany
| | - Ann-Kristin Picke
- Institute of Comparative Molecular EndocrinologyUlm University, Ulm, Germany
| | - Gilbert Weidinger
- Institute of Biochemistry and Molecular BiologyUlm University, Ulm, Germany
| | - Anita Ignatius
- Institute of Orthopaedic Research and BiomechanicsUlm University Medical Centre, Ulm, Germany
| | - Jan Tuckermann
- Institute of Comparative Molecular EndocrinologyUlm University, Ulm, Germany
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20
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Ohlsson C, Nilsson KH, Henning P, Wu J, Gustafsson KL, Poutanen M, Lerner UH, Movérare-Skrtic S. WNT16 overexpression partly protects against glucocorticoid-induced bone loss. Am J Physiol Endocrinol Metab 2018; 314:E597-E604. [PMID: 29406783 DOI: 10.1152/ajpendo.00292.2017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Therapeutic use of glucocorticoids (GCs) is a major cause of secondary osteoporosis, but the molecular mechanisms responsible for the deleterious effects of GCs in bone are only partially understood. WNT16 is a crucial physiological regulator of bone mass and fracture susceptibility, and we hypothesize that disturbed WNT16 activity might be involved in the deleterious effects of GC in bone. Twelve-week-old female Obl-Wnt16 mice (WNT16 expression driven by the rat procollagen type I α1 promoter) and wild-type (WT) littermates were treated with prednisolone (7.6 mg·kg-1·day-1) or vehicle for 4 wk. We first observed that GC treatment decreased the Wnt16 mRNA levels in bone of female mice (-56.4 ± 6.1% compared with vehicle, P < 0.001). We next evaluated if WNT16 overexpression protects against GC-induced bone loss. Dual-energy X-ray absorptiometry analyses revealed that GC treatment decreased total body bone mineral density in WT mice (-3.9 ± 1.2%, P = 0.028) but not in Obl-Wnt16 mice (+1.3 ± 1.4%, nonsignificant). Microcomputed tomography analyses showed that GC treatment decreased trabecular bone volume fraction (BV/TV) of the femur in WT mice ( P = 0.019) but not in Obl-Wnt16 mice. Serum levels of the bone formation marker procollagen type I N-terminal propeptide were substantially reduced by GC treatment in WT mice (-50.3 ± 7.0%, P = 0.008) but not in Obl-Wnt16 mice (-3.8 ± 21.2%, nonsignificant). However, the cortical bone thickness in femur was reduced by GC treatment in both WT mice and Obl-Wnt16 mice. In conclusion, GC treatment decreases Wnt16 mRNA levels in bone and WNT16 overexpression partly protects against GC-induced bone loss.
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Affiliation(s)
- Claes Ohlsson
- Centre for Bone and Arthritis Research at Institute of Medicine, Sahlgrenska Academy at University of Gothenburg , Gothenburg , Sweden
| | - Karin H Nilsson
- Centre for Bone and Arthritis Research at Institute of Medicine, Sahlgrenska Academy at University of Gothenburg , Gothenburg , Sweden
| | - Petra Henning
- Centre for Bone and Arthritis Research at Institute of Medicine, Sahlgrenska Academy at University of Gothenburg , Gothenburg , Sweden
| | - Jianyao Wu
- Centre for Bone and Arthritis Research at Institute of Medicine, Sahlgrenska Academy at University of Gothenburg , Gothenburg , Sweden
| | - Karin L Gustafsson
- Centre for Bone and Arthritis Research at Institute of Medicine, Sahlgrenska Academy at University of Gothenburg , Gothenburg , Sweden
| | - Matti Poutanen
- Centre for Bone and Arthritis Research at Institute of Medicine, Sahlgrenska Academy at University of Gothenburg , Gothenburg , Sweden
- Institute of Biomedicine and Turku Center for Disease Modeling, University of Turku , Turku , Finland
| | - Ulf H Lerner
- Centre for Bone and Arthritis Research at Institute of Medicine, Sahlgrenska Academy at University of Gothenburg , Gothenburg , Sweden
| | - Sofia Movérare-Skrtic
- Centre for Bone and Arthritis Research at Institute of Medicine, Sahlgrenska Academy at University of Gothenburg , Gothenburg , Sweden
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Abstract
Glucocorticoids (GC), produced and released by the adrenal glands, regulate numerous physiological processes in a wide range of tissues. Because of their profound immunosuppressive and anti-inflammatory actions, GC are extensively used for the treatment of immune and inflammatory conditions, the management of organ transplantation, and as a component of chemotherapy regimens for cancers. However, both pathologic endogenous elevation and long-term use of exogenous GC are associated with severe adverse effects. In particular, excess GC has devastating effects on the musculoskeletal system. GC increase bone resorption and decrease formation leading to bone loss, microarchitectural deterioration and fracture. GC also induce loss of muscle mass and strength leading to an increased incidence of falls. The combined effects on bone and muscle account for the increased fracture risk with GC. This review summarizes the advance in knowledge in the last two decades about the mechanisms of action of GC in bone and muscle and the attempts to interfere with the damaging actions of GC in these tissues with the goal of developing more effective therapeutic strategies.
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Affiliation(s)
- Amy Y Sato
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana, 46202
| | - Munro Peacock
- Department of Medicine, Division of Endocrinology, Indiana University School of Medicine, Indianapolis, Indiana, 46202
| | - Teresita Bellido
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana, 46202.,Department of Medicine, Division of Endocrinology, Indiana University School of Medicine, Indianapolis, Indiana, 46202.,Roudebush Veterans Administration Medical Center, Indianapolis, Indiana, 46202
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22
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Liu S, Fang T, Yang L, Chen Z, Mu S, Fu Q. Gastrodin protects MC3T3-E1 osteoblasts from dexamethasone-induced cellular dysfunction and promotes bone formation via induction of the NRF2 signaling pathway. Int J Mol Med 2018; 41:2059-2069. [PMID: 29393365 PMCID: PMC5810206 DOI: 10.3892/ijmm.2018.3414] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 01/09/2018] [Indexed: 12/31/2022] Open
Abstract
Glucocorticoid (GC)-induced osteoporosis (GIO) is one of the most common secondary and iatrogenic forms of osteoporosis. GCs are widely used in clinical therapy and play a key role in the normal regulation of bone remodeling. However, the prolonged and high-dose administration of GCs results in the occurrence of osteoporosis, which is partially due to the dysfunction and apoptosis of osteoblasts and osteocytes. The aim of the present study was to investigate the effects of gastrodin, a natural bioactive compound isolated from the traditional Chinese herbal agent Gastrodia elata, on GC-treated MC3T3‑E1 murine osteoblastic cells. MC3T3‑E1 cells were exposed to dexamethasone (DEX), with or without gastrodin pretreatment, and cell viability was measured by the cell counting kit-8 (CCK-8) assay. Quantitative polymerase chain reaction analysis was performed to evaluate osteogenic gene expression, and cellular alkaline phosphatase (ALP) activity was measured as well. Alizarin Red staining of calcium deposits was found to reflect the degree of osteoblast maturity. Western blotting was performed to determine the expression of osteogenic and adipogenic differentiation key proteins, as well as nuclear factor-like 2 (NRF2) pathway‑related proteins. Annexin V-fluorescein isothiocyanate̸propidium iodide flow cytometric analysis was performed to determine osteoblast apoptosis. JC-1 staining was used to detect the changes of the mitochondrial membrane potential in cells. The results revealed that gastrodin prevented the decrease in cell viability caused by DEX-induced MC3T3‑E1 cell dysfunction, and that groups pretreated with gastrodin exhibited higher mRNA levels of osteogenic genes, such as Runx2, osterix, bone morphogenetic protein-2 and osteocalcin. Furthermore, treatment with both DEX and gastrodin was associated with increased ALP activity in MC3T3-E1 cells, as well as more calcium deposits, compared with cells treated with DEX alone. In addition, gastrodin increased osteogenic key marker protein Runx2 while activating NRF2 and downstream effector protein expression. Therefore, gastrodin may have the potential to reduce DEX-induced cell apoptosis and increase the mitochondrial membrane potential against DEX. These results demonstrated that gastrodin was able to prevent and/or delay DEX‑induced osteoporosis by improving osteoblast function, and these protective effects were verified in an animal model.
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Affiliation(s)
- Shengye Liu
- Department of Spine and Joint Surgery, The Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Tao Fang
- Department of Spine and Joint Surgery, The Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Liyu Yang
- Department of Spine and Joint Surgery, The Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Zhiguang Chen
- Emergency Department, The Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Shuai Mu
- Department of Spine and Joint Surgery, The Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Qin Fu
- Department of Spine and Joint Surgery, The Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
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Zhang S, Liu Y, Liang Q. Low-dose dexamethasone affects osteoblast viability by inducing autophagy via intracellular ROS. Mol Med Rep 2018; 17:4307-4316. [PMID: 29363725 PMCID: PMC5802204 DOI: 10.3892/mmr.2018.8461] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 12/18/2017] [Indexed: 12/11/2022] Open
Abstract
Glucocorticoids (GCs) are closely associated with the progression of GC-induced osteoporosis (GIOP) by inhibiting osteoblast viability. However, endogenous GCs are important for bone development. In addition, previous studies have demonstrated that GCs could induce autophagy, a cytoprotective process that is protective against various stressors. In the present study, the aim is to explore whether osteoblasts exhibited dose-dependent viability in the presence of GCs due to autophagy. hFOB 1.19 osteoblasts were treated with various doses of dexamethasone (DEX; 10−8-10−4 M) for 0, 24, 48 and 72 h. The results revealed a biphasic effect of DEX on the viability of hFOB 1.19 cells; a high dose of DEX (≥10−6 M) accelerated cell apoptosis, while a low dose of DEX (10−8 M) increased cell viability. Furthermore, significantly increased autophagy was observed in the low dose DEX treatment group, as indicated by the expression of the autophagy-associated proteins beclin 1 and microtubule-associated protein light chain 3, and the detection of autophagosomes. Another finding was that DEX upregulated intracellular reactive oxygen species (ROS), which was decreased by the autophagy agonist rapamycin. The increase in autophagy and cell viability associated with low-dose DEX (10−8 M) was suppressed by the ROS scavenger catalase and the autophagy inhibitor 3-methyladenine. In conclusion, the results revealed that GCs affected osteoblast viability in a dose-dependent manner. A low dose of GCs increased osteoblast viability by inducing autophagy via intracellular ROS. The results indicate that autophagy may be a novel mechanism by which osteoblasts survive GC exposure and provide a potential therapeutic target for treating GIOP.
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Affiliation(s)
- Shaokun Zhang
- Department of Orthopedics, The First Hospital of China Medical University, Shenyang, Liaoning 110000, P.R. China
| | - Yongyi Liu
- Department of Orthopedics, The First Hospital of China Medical University, Shenyang, Liaoning 110000, P.R. China
| | - Qingwei Liang
- Department of Sports Medicine, The First Hospital of China Medical University, Shenyang, Liaoning 110000, P.R. China
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Rapp AE, Hachemi Y, Kemmler J, Koenen M, Tuckermann J, Ignatius A. Induced global deletion of glucocorticoid receptor impairs fracture healing. FASEB J 2018; 32:2235-2245. [PMID: 29217668 PMCID: PMC5893166 DOI: 10.1096/fj.201700459rr] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Although endogenous glucocorticoids (GCs) are important regulators of bone integrity and the immune system, their role in bone repair after fracture-a process highly dependent on inflammation and bone formation-is unclear. Because most effects of GCs are mediated by the glucocorticoid receptor (GR), we used an inducible global GR knockout (GRgtROSACreERT2) mouse model to eliminate endogenous GC action in all cells contributing to bone repair. The healing process was analyzed by cytokine/chemokine multiplex analysis, flow cytometry, histology, gene-expression analysis, microcomputed tomography, and biomechanical analysis. We observed increased early systemic and local inflammatory responses, as well as a significantly higher number of T cells infiltrating the fracture callus. Later in the healing process, we found impaired endochondral ossification in the absence of the GR, leading to persistent cartilage in the calli of the GRgtROSACreERT2 mice, decreased bending stiffness, and a significantly lower proportion of healed bones. Collectively, our data show that the absence of the GR significantly impairs fracture healing associated with a defective cartilage-to-bone transition, underscoring an important role of GCs during fracture healing.-Rapp, A. E., Hachemi, Y., Kemmler, J., Koenen, M., Tuckermann, J., Ignatius, A. Induced global deletion of glucocorticoid receptor impairs fracture healing.
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Affiliation(s)
- Anna E Rapp
- Institute of Orthopaedic Research and Biomechanics, Centre for Trauma Research Ulm, Ulm University Medical Centre
| | - Yasmine Hachemi
- Institute of Comparative Molecular Endocrinology, Ulm University, Ulm, Germany
| | - Julia Kemmler
- Institute of Orthopaedic Research and Biomechanics, Centre for Trauma Research Ulm, Ulm University Medical Centre
| | - Mascha Koenen
- Institute of Comparative Molecular Endocrinology, Ulm University, Ulm, Germany
| | - Jan Tuckermann
- Institute of Comparative Molecular Endocrinology, Ulm University, Ulm, Germany
| | - Anita Ignatius
- Institute of Orthopaedic Research and Biomechanics, Centre for Trauma Research Ulm, Ulm University Medical Centre
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Suarez-Bregua P, Guerreiro PM, Rotllant J. Stress, Glucocorticoids and Bone: A Review From Mammals and Fish. Front Endocrinol (Lausanne) 2018; 9:526. [PMID: 30250453 PMCID: PMC6139303 DOI: 10.3389/fendo.2018.00526] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 08/21/2018] [Indexed: 12/13/2022] Open
Abstract
Glucocorticoids (GCs) are the final effector products of a neuroendocrine HPA/HPI axis governing energy balance and stress response in vertebrates. From a physiological point of view, basal GC levels are essential for intermediary metabolism and participate in the development and homeostasis of a wide range of body tissues, including the skeleton. Numerous mammalian studies have demonstrated that GC hormones exert a positive role during bone modeling and remodeling as they promote osteoblastogenesis to maintain the bone architecture. Although the pharmacological effect of the so-called stress hormones has been widely reported, the role of endogenous GCs on bone mineral metabolism as result of the endocrine stress response has been largely overlooked across vertebrates. In addition, stress responses are variable depending on the stressor (e.g., starvation, predation, and environmental change), life cycle events (e.g., migration and aging), and differ among vertebrate lineages, which react differently according to their biological, social and cognitive complexity (e.g., mineral demands, physical, and psychological stress). This review intends to summarize the endogenous GCs action on bone metabolism of mammals and fish under a variety of challenging circumstances. Particular emphasis will be given to the regulatory loop between GCs and the parathyroid hormone (PTH) family peptides, and other key regulators of mineral homeostasis and bone remodeling in vertebrates.
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Affiliation(s)
- Paula Suarez-Bregua
- Institute of Marine Research, Spanish National Research Council (IIM-CSIC), Vigo, Spain
| | | | - Josep Rotllant
- Institute of Marine Research, Spanish National Research Council (IIM-CSIC), Vigo, Spain
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Abstract
PURPOSE OF REVIEW The aim of this study is to summarize monitoring, prevention and treatment options of glucocorticoid-induced osteoporosis for patients on chronic glucocorticoid therapy. RECENT FINDINGS Recent meta-analyses highlight the efficacy of bisphosphonate use in improving bone mineral density and in reducing vertebral fractures in the setting of long-term glucocorticoid use. A new study has now shown that alendronate also reduces the risk of hip fracture in glucocorticoid use. Emerging data indicate that teriparatide and denosumab also reduce the risk of osteoporotic fracture in glucocorticoid-induced osteoporosis. SUMMARY Glucocorticoid use is a leading cause of secondary osteoporosis; however, patients at risk of glucocorticoid-induced osteoporosis are often not evaluated or treated in a timely manner. Patients on a dose equivalent of 2.5 mg prednisone or greater for 3 months or longer duration should have their fracture risk assessed. Those at moderate or high risk should start bisphosphonate therapy, or if contraindicated, a second-line agent such as teriparatide or denosumab.
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Affiliation(s)
- Emory Hsu
- Emory University School of Medicine, Atlanta, Georgia, USA
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Zhou M, Li J, Wu J, Yang Y, Zeng X, Lv X, Cui L, Yao W, Liu Y. Preventive effects of Polygonum multiflorum on glucocorticoid-induced osteoporosis in rats. Exp Ther Med 2017; 14:2445-2460. [PMID: 28962180 PMCID: PMC5609219 DOI: 10.3892/etm.2017.4802] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Accepted: 03/10/2017] [Indexed: 11/29/2022] Open
Abstract
In Traditional Chinese Medicine, Polygonum multiflorum (PM) is known for its anti-aging properties. A previous study by our group showed that extracts of PM were able to prevent and treat bone loss in vivo, and the active components emodin and 2,3,5,4,-tetrahydroxystilbene-2-O-β-glucoside (TSG) promoted the osteogenic differentiation of mesenchymal stem cells in vitro. The aim of the present study was to investigate the preventive effects of PM on glucocorticoid-induced osteoporosis (GIO) in rats. A crude extract of PM was prepared with 75% ethanol, purified and enriched using a D-101 macroresin column and elution with 30% ethanol, and the material obtained was assessed by high-performance liquid chromatography. Male or female Sprague Dawley rats (n=180) were randomly divided into nine groups: Control, prednisone, prednisone plus calcitriol (CAL), prednisone plus 30% ethanolic eluate of PM [high (H), medium (M) and low (L) dose] and prednisone plus crude extract of PM (H, M and L dose). Prednisone was orally administered to the osteoporosis model rats for 21 weeks, alongside which they received PM extracts. The weight of the viscera, anterior tibial muscle and other tissues was recorded at the end of the experiment. The femur and lumbar vertebra were collected for the measurement of three-dimensional microarchitecture by micro-computed tomography scanning, assessment of biomechanical properties and determination of bone mineral density (BMD). In the 30% ethanolic eluate of the PM extract, the content of TSG and combined anthraquinone was 9.20 and 0.15%, respectively, and that in the crude extract of PM was 2.23 and 0.03%, respectively. Over 6 weeks, the weight of the rats the in prednisone group decreased (P<0.05), while the weight of rats treated with M and H doses of 30% ethanolic eluate was increased compared with that in the prednisone group (P<0.05). Rats exposed to prednisone exhibited a deteriorated bone microarchitecture, low BMD, decreased bone volume/total volume and poor biomechanical properties. Furthermore, the weight of the adrenal gland and the anterior tibial muscle was decreased. 30% ethanolic eluate of PM at M and L doses and crude extract of PM at the H dose counteracted the alterations of skeletal and other characteristics induced by prednisone in rats, as did CAL. In conclusion, extracts of PM exerted a protective effect on bone tissue in GIO rats.
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Affiliation(s)
- Manru Zhou
- Department of Pharmacology, Guangdong Medical University, Zhanjiang, Guangdong 524023, P.R. China
- Department of Pharmacy, Xinhua College of Sun Yat-sen University, Guangzhou, Guangdong 510520, P.R. China
| | - Jin Li
- Department of Pharmacology, Guangdong Medical University, Zhanjiang, Guangdong 524023, P.R. China
| | - Jingkai Wu
- Department of Pharmacology, Guangdong Medical University, Zhanjiang, Guangdong 524023, P.R. China
| | - Yajun Yang
- Department of Pharmacology, Guangdong Medical University, Zhanjiang, Guangdong 524023, P.R. China
| | - Xiaobing Zeng
- Guangdong Key Laboratory for Research and Development of Natural Drugs, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong 524023, P.R. China
| | - Xiaohua Lv
- Department of Pharmacology, Guangdong Medical University, Zhanjiang, Guangdong 524023, P.R. China
| | - Liao Cui
- Department of Pharmacology, Guangdong Medical University, Zhanjiang, Guangdong 524023, P.R. China
- Guangdong Key Laboratory for Research and Development of Natural Drugs, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong 524023, P.R. China
| | - Weimin Yao
- Department of Respiratory Medicine, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong 524023, P.R. China
| | - Yuyu Liu
- Department of Pharmacology, Guangdong Medical University, Zhanjiang, Guangdong 524023, P.R. China
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Chen H, Xing J, Hu X, Chen L, Lv H, Xu C, Hong D, Wu X. Inhibition of heat shock protein 90 rescues glucocorticoid-induced bone loss through enhancing bone formation. J Steroid Biochem Mol Biol 2017; 171:236-246. [PMID: 28408351 DOI: 10.1016/j.jsbmb.2017.04.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Revised: 04/07/2017] [Accepted: 04/07/2017] [Indexed: 01/05/2023]
Abstract
Endogenous glucocorticoids (GCs) support normal bone development and bone mass maintenance, whereas long-term exposure to pharmacological dosages of GCs uncouples bone formation and resorption, resulting in GC-induced osteoporosis (GIOP). Heat shock protein 90 (HSP90) chaperoning glucocorticoid receptor (GR) signaling prompts us to speculate that HSP90 plays critical roles in GC-mediated bone formation and GIOP. In the present study, inhibition of HSP90 activity by 17-Demethoxy-17-allyaminogeldanmycin (17-AAG) or knockdown of HSP90 expression by siRNAs attenuated dexamethasone(Dex)-induced GR nuclear accumulation and transcriptional output of GR signaling, whereas overexpression of HSP90α or HSP90β enhanced GR transactivity in C3H10T1/2 cells. Though 17-AAG itself enhanced osteoblastic differentiation, it restored the Dex(10-8M)-induced and Dex(10-6M)-negated osteoblastic differentiation in C3H10T1/2 cells and primary calvarial osteoblasts. Moreover, systemic administration of 17-AAG to mice induced not only osteoclastogenesis but also osteoblastogenesis, whereas bone formation possibly exceeded bone resorption, eventually leading to the increased bone masses. Likewise, systemic administration of 17-AAG to mice restored GC-negated osteoblastogenesis and enhanced GC-induced osteoclastogenesis, similarly, 17-AAG-induced bone formation possibly exceeded both 17-AAG- and GC-induced bone resorption, eventually resulting in rescue of GIOP. Together, the present study has revealed that inhibition of HSP90 restores GIOP through enhancing bone formation, and our findings may help to shed light on the pathogenesis of GIOP and provide targets for the therapeutic intervention of the disease.
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Affiliation(s)
- Haixiao Chen
- Department of Orthopedics, the Affiliated Taizhou Hospital, Wenzhou Medical University, Linhai City, 317000, China
| | - Ji Xing
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Xinhua Hu
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Lihua Chen
- Department of Orthopedics, the Affiliated Taizhou Hospital, Wenzhou Medical University, Linhai City, 317000, China
| | - Haiyan Lv
- Department of Orthopedics, the Affiliated Taizhou Hospital, Wenzhou Medical University, Linhai City, 317000, China
| | - Chengyun Xu
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Dun Hong
- Department of Orthopedics, the Affiliated Taizhou Hospital, Wenzhou Medical University, Linhai City, 317000, China.
| | - Ximei Wu
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou, 310058, China.
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29
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Henneicke H, Li J, Kim S, Gasparini SJ, Seibel MJ, Zhou H. Chronic Mild Stress Causes Bone Loss via an Osteoblast-Specific Glucocorticoid-Dependent Mechanism. Endocrinology 2017; 158:1939-1950. [PMID: 28368468 DOI: 10.1210/en.2016-1658] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 02/16/2017] [Indexed: 12/26/2022]
Abstract
Chronic stress and depression are associated with alterations in the hypothalamic-pituitary-adrenal signaling cascade and considered a risk factor for bone loss and fractures. However, the mechanisms underlying the association between stress and poor bone health are unclear. Using a transgenic (tg) mouse model in which glucocorticoid signaling is selectively disrupted in mature osteoblasts and osteocytes [11β-hydroxysteroid-dehydrogenase type 2 (HSD2)OB-tg mice], the present study examines the impact of chronic stress on skeletal metabolism and structure. Eight-week-old male and female HSD2OB-tg mice and their wild-type (WT) littermates were exposed to chronic mild stress (CMS) for the duration of 4 weeks. At the endpoint, L3 vertebrae and tibiae were analyzed by micro-computed tomography and histomorphometry, and bone turnover was measured biochemically. Compared with nonstressed controls, exposure to CMS caused an approximately threefold increase in serum corticosterone concentrations in WT and HSD2OB-tg mice of both genders. Compared with controls, CMS resulted in loss of vertebral trabecular bone mass in male WT mice but not in male HSD2OB-tg littermates. Furthermore, both tibial cortical area and area fraction were reduced in stressed WT but not in stressed HSD2OB-tg male mice. Osteoclast activity and bone resorption marker were increased in WT males following CMS, features absent in HSD2OB-tg males. Interestingly, CMS had little effect on vertebral and long-bone structural parameters in female mice. We conclude that in male mice, bone loss during CMS is mediated via enhanced glucocorticoid signaling in osteoblasts (and osteocytes) and subsequent activation of osteoclasts. Female mice appear resistant to the skeletal effects of CMS.
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Affiliation(s)
- Holger Henneicke
- Bone Research Program, ANZAC Research Institute, University of Sydney, Sydney, New South Wales 2139, Australia
| | - Jingbao Li
- Bone Research Program, ANZAC Research Institute, University of Sydney, Sydney, New South Wales 2139, Australia
- Key Laboratory for Space Bioscience and Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, Shaanxi 710000, China
| | - Sarah Kim
- Bone Research Program, ANZAC Research Institute, University of Sydney, Sydney, New South Wales 2139, Australia
| | - Sylvia J Gasparini
- Bone Research Program, ANZAC Research Institute, University of Sydney, Sydney, New South Wales 2139, Australia
| | - Markus J Seibel
- Bone Research Program, ANZAC Research Institute, University of Sydney, Sydney, New South Wales 2139, Australia
- Department of Endocrinology and Metabolism, Concord Hospital, University of Sydney, Sydney, New South Wales 2139, Australia
| | - Hong Zhou
- Bone Research Program, ANZAC Research Institute, University of Sydney, Sydney, New South Wales 2139, Australia
- Department of Endocrinology and Metabolism, Concord Hospital, University of Sydney, Sydney, New South Wales 2139, Australia
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30
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Abstract
Objective: To review the recent developments in the mechanisms of epithelium sodium channels (ENaCs) induced bone formation and regulation. Data Sources: Studies written in English or Chinese were searched using Medline, PubMed and the index of Chinese-language literature with time restriction from 2005 to 2014. Keywords included ENaC, bone, bone formation, osteonecrosis, estrogen, and osteoporosis. Data from published articles about the structure of ENaC, mechanism of ENaC in bone formation in recent domestic and foreign literature were selected. Study Selection: Abstract and full text of all studies were required to obtain. Studies those were not accessible and those did not focus on the keywords were excluded. Results: ENaCs are tripolymer ion channels which are assembled from homologous α, β, and γ subunits. Crystal structure of ENaCs suggests that ENaC has a central ion-channel located in the central symmetry axis of the three subunits. ENaCs are protease sensitive channels whose iron-channel activity is regulated by the proteolytic reaction. Channel opening probability of ENaCs is regulated by proteinases, mechanical force, and shear stress. Several molecules are involved in regulation of ENaCs in bone formation, including nitride oxide synthases, voltage-sensitive calcium channels, and cyclooxygenase-2. Conclusion: The pathway of ENaC involved in shear stress has an effect on stimulating osteoblasts even bone formation by estrogen interference.
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Affiliation(s)
| | | | - Wei-Hua Xu
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, China
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31
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Hartmann K, Koenen M, Schauer S, Wittig-Blaich S, Ahmad M, Baschant U, Tuckermann JP. Molecular Actions of Glucocorticoids in Cartilage and Bone During Health, Disease, and Steroid Therapy. Physiol Rev 2016; 96:409-47. [PMID: 26842265 DOI: 10.1152/physrev.00011.2015] [Citation(s) in RCA: 141] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Cartilage and bone are severely affected by glucocorticoids (GCs), steroid hormones that are frequently used to treat inflammatory diseases. Major complications associated with long-term steroid therapy include impairment of cartilaginous bone growth and GC-induced osteoporosis. Particularly in arthritis, GC application can increase joint and bone damage. Contrarily, endogenous GC release supports cartilage and bone integrity. In the last decade, substantial progress in the understanding of the molecular mechanisms of GC action has been gained through genome-wide binding studies of the GC receptor. These genomic approaches have revolutionized our understanding of gene regulation by ligand-induced transcription factors in general. Furthermore, specific inactivation of GC signaling and the GC receptor in bone and cartilage cells of rodent models has enabled the cell-specific effects of GCs in normal tissue homeostasis, inflammatory bone diseases, and GC-induced osteoporosis to be dissected. In this review, we summarize the current view of GC action in cartilage and bone. We further discuss future research directions in the context of new concepts for optimized steroid therapies with less detrimental effects on bone.
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Affiliation(s)
- Kerstin Hartmann
- Institute for Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany; and Division of Endocrinology, Diabetes, and Bone Diseases, Department of Medicine III, Technische Universität Dresden, Dresden, Germany
| | - Mascha Koenen
- Institute for Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany; and Division of Endocrinology, Diabetes, and Bone Diseases, Department of Medicine III, Technische Universität Dresden, Dresden, Germany
| | - Sebastian Schauer
- Institute for Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany; and Division of Endocrinology, Diabetes, and Bone Diseases, Department of Medicine III, Technische Universität Dresden, Dresden, Germany
| | - Stephanie Wittig-Blaich
- Institute for Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany; and Division of Endocrinology, Diabetes, and Bone Diseases, Department of Medicine III, Technische Universität Dresden, Dresden, Germany
| | - Mubashir Ahmad
- Institute for Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany; and Division of Endocrinology, Diabetes, and Bone Diseases, Department of Medicine III, Technische Universität Dresden, Dresden, Germany
| | - Ulrike Baschant
- Institute for Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany; and Division of Endocrinology, Diabetes, and Bone Diseases, Department of Medicine III, Technische Universität Dresden, Dresden, Germany
| | - Jan P Tuckermann
- Institute for Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany; and Division of Endocrinology, Diabetes, and Bone Diseases, Department of Medicine III, Technische Universität Dresden, Dresden, Germany
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Song M, Zhao D, Wei S, Liu C, Liu Y, Wang B, Zhao W, Yang K, Yang Y, Wu H. The effect of electromagnetic fields on the proliferation and the osteogenic or adipogenic differentiation of mesenchymal stem cells modulated by dexamethasone. Bioelectromagnetics 2014; 35:479-90. [PMID: 25145543 DOI: 10.1002/bem.21867] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2013] [Accepted: 05/17/2014] [Indexed: 01/29/2023]
Affiliation(s)
- Mingyu Song
- Department of Orthopedics; Tongji Hospital; Tongji Medical College, Huazhong University of Science and Technology; Wuhan Hubei China
| | - Dongming Zhao
- Department of Orthopedics; Tongji Hospital; Tongji Medical College, Huazhong University of Science and Technology; Wuhan Hubei China
| | - Sheng Wei
- Department of Orthopedics; Tongji Hospital; Tongji Medical College, Huazhong University of Science and Technology; Wuhan Hubei China
| | - Chaoxu Liu
- Department of Orthopedics; Tongji Hospital; Tongji Medical College, Huazhong University of Science and Technology; Wuhan Hubei China
| | - Yang Liu
- Department of Orthopedics; Tongji Hospital; Tongji Medical College, Huazhong University of Science and Technology; Wuhan Hubei China
| | - Bo Wang
- Department of Orthopedics; Tongji Hospital; Tongji Medical College, Huazhong University of Science and Technology; Wuhan Hubei China
| | - Wenchun Zhao
- Navy University of Engineering; Wuhan Hubei China
| | - Kaixiang Yang
- Department of Orthopedics; Tongji Hospital; Tongji Medical College, Huazhong University of Science and Technology; Wuhan Hubei China
| | - Yong Yang
- Department of Orthopedics; Tongji Hospital; Tongji Medical College, Huazhong University of Science and Technology; Wuhan Hubei China
| | - Hua Wu
- Department of Orthopedics; Tongji Hospital; Tongji Medical College, Huazhong University of Science and Technology; Wuhan Hubei China
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Leung VY, Aladin DM, Lv F, Tam V, Sun Y, Lau RY, Hung SC, Ngan AH, Tang B, Lim CT, Wu EX, Luk KD, Lu WW, Masuda K, Chan D, Cheung KM. Mesenchymal Stem Cells Reduce Intervertebral Disc Fibrosis and Facilitate Repair. Stem Cells 2014; 32:2164-77. [DOI: 10.1002/stem.1717] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 03/01/2014] [Accepted: 03/20/2014] [Indexed: 02/06/2023]
Affiliation(s)
- Victor Y.L. Leung
- Department of Orthopaedics & Traumatology; The University of Hong Kong; Hong Kong SAR People's Republic of China
- Department of Biochemistry; The University of Hong Kong; Hong Kong SAR People's Republic of China
- Centre for Reproduction, Development, and Growth; The University of Hong Kong; Hong Kong SAR People's Republic of China
| | - Darwesh M.K. Aladin
- Department of Orthopaedics & Traumatology; The University of Hong Kong; Hong Kong SAR People's Republic of China
- Mechanobiology Institute; National University of Singapore; Singapore
| | - Fengjuan Lv
- Department of Orthopaedics & Traumatology; The University of Hong Kong; Hong Kong SAR People's Republic of China
| | - Vivian Tam
- Department of Orthopaedics & Traumatology; The University of Hong Kong; Hong Kong SAR People's Republic of China
| | - Yi Sun
- Department of Orthopaedics & Traumatology; The University of Hong Kong; Hong Kong SAR People's Republic of China
| | - Roy Y.C. Lau
- Department of Orthopaedics & Traumatology; The University of Hong Kong; Hong Kong SAR People's Republic of China
| | - Siu-Chun Hung
- Department of Orthopaedics & Traumatology; The University of Hong Kong; Hong Kong SAR People's Republic of China
| | - Alfonso H.W. Ngan
- Department of Mechanical Engineering; The University of Hong Kong; Hong Kong SAR People's Republic of China
| | - Bin Tang
- Department of Micro-nano Materials and Devices; South University of Science and Technology of China; Guangzhou People's Republic of China
| | - Chwee Teck Lim
- Mechanobiology Institute; National University of Singapore; Singapore
- Department of Bioengineering; National University of Singapore; Singapore
- Department of Mechanical Engineering; National University of Singapore; Singapore
| | - Ed X. Wu
- Department of Electrical & Electronic Engineering; The University of Hong Kong; Hong Kong SAR People's Republic of China
| | - Keith D.K. Luk
- Department of Orthopaedics & Traumatology; The University of Hong Kong; Hong Kong SAR People's Republic of China
| | - William W. Lu
- Department of Orthopaedics & Traumatology; The University of Hong Kong; Hong Kong SAR People's Republic of China
| | - Koichi Masuda
- Department of Orthopaedic Surgery; University of California; San Diego California USA
| | - Danny Chan
- Department of Biochemistry; The University of Hong Kong; Hong Kong SAR People's Republic of China
- Centre for Reproduction, Development, and Growth; The University of Hong Kong; Hong Kong SAR People's Republic of China
| | - Kenneth M.C. Cheung
- Department of Orthopaedics & Traumatology; The University of Hong Kong; Hong Kong SAR People's Republic of China
- Centre for Reproduction, Development, and Growth; The University of Hong Kong; Hong Kong SAR People's Republic of China
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34
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Henneicke H, Gasparini SJ, Brennan-Speranza TC, Zhou H, Seibel MJ. Glucocorticoids and bone: local effects and systemic implications. Trends Endocrinol Metab 2014; 25:197-211. [PMID: 24418120 DOI: 10.1016/j.tem.2013.12.006] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Revised: 12/11/2013] [Accepted: 12/11/2013] [Indexed: 01/19/2023]
Abstract
Glucocorticoids (GCs) are highly effective in the treatment of inflammatory and autoimmune conditions but their therapeutic use is limited by numerous adverse effects. Recent insights into the mechanisms of action of both endogenous and exogenous GCs on bone cells have unlocked new approaches to the development of effective strategies for the prevention and treatment of GC-induced osteoporosis. Furthermore, topical studies in rodents indicate that the osteoblast-derived peptide, osteocalcin, plays a central role in the pathogenesis of GC-induced diabetes and obesity. These exciting findings mechanistically link the detrimental effects of GCs on bone and energy metabolism. In this article we review the physiology and pathophysiology of GC action on bone cells, and discuss current and emerging concepts regarding the molecular mechanisms underlying adverse effects of GCs such as osteoporosis and diabetes.
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Affiliation(s)
- Holger Henneicke
- Bone Research Program, The Australian and New Zealand Army Corps (ANZAC) Research Institute, The University of Sydney, Sydney, Australia
| | - Sylvia J Gasparini
- Bone Research Program, The Australian and New Zealand Army Corps (ANZAC) Research Institute, The University of Sydney, Sydney, Australia
| | - Tara C Brennan-Speranza
- Bone Research Program, The Australian and New Zealand Army Corps (ANZAC) Research Institute, The University of Sydney, Sydney, Australia
| | - Hong Zhou
- Bone Research Program, The Australian and New Zealand Army Corps (ANZAC) Research Institute, The University of Sydney, Sydney, Australia
| | - Markus J Seibel
- Bone Research Program, The Australian and New Zealand Army Corps (ANZAC) Research Institute, The University of Sydney, Sydney, Australia; Department of Endocrinology and Metabolism, Concord Hospital, The University of Sydney, Sydney, Australia.
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Spies CM, Wiebe E, Tu J, Li A, Gaber T, Huscher D, Seibel MJ, Zhou H, Buttgereit F. Acute murine antigen-induced arthritis is not affected by disruption of osteoblastic glucocorticoid signalling. BMC Musculoskelet Disord 2014; 15:31. [PMID: 24491163 PMCID: PMC3922092 DOI: 10.1186/1471-2474-15-31] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Accepted: 01/29/2014] [Indexed: 01/04/2023] Open
Abstract
Background The role of endogenous glucocorticoids (GC) in the initiation and maintenance of rheumatoid arthritis (RA) remains unclear. We demonstrated previously that disruption of GC signalling in osteoblasts results in a profound attenuation of K/BxN serum-induced arthritis, a mouse model of RA. To determine whether or not the modulation of the inflammatory response by osteoblasts involves T cells, we studied the effects of disrupted osteoblastic GC-signalling in the T cell-dependent model of antigen-induced arthritis (AIA). Methods Acute arthritis was induced in pre-immunised 11-week-old male 11β-hydroxysteroid dehydrogenase type 2 transgenic (tg) mice and their wild-type (WT) littermates by intra-articular injection of methylated bovine serum albumine (mBSA) into one knee joint. Knee diameter was measured every 1–2 days until euthanasia on day 14 post injection. In a separate experiment, arthritis was maintained for 28 days by weekly reinjections of mBSA. Tissues were analysed by histology, histomorphometry and microfocal-computed tomography. Serum cytokines levels were determined by multiplex suspension array. Results In both short and long term experiments, arthritis developed in tg and WT mice with no significant difference between both groups. Histological indices of inflammation, cartilage damage and bone erosion were similar in tg and WT mice. Bone volume and turnover at the contralateral tibia and systemic cytokine levels were not different. Conclusions Acute murine AIA is not affected by a disruption in osteoblastic GC signalling. These data indicate that osteoblasts do not modulate the T cell-mediated inflammatory response via a GC-dependent pathway.
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Affiliation(s)
- Cornelia M Spies
- Department of Rheumatology and Clinical Immunology, Charité - Universitätsmedizin Berlin, Charitéplatz 1, D-10117 Berlin, Germany.
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Baschant U, Culemann S, Tuckermann J. Molecular determinants of glucocorticoid actions in inflammatory joint diseases. Mol Cell Endocrinol 2013; 380:108-18. [PMID: 23769823 DOI: 10.1016/j.mce.2013.06.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 06/07/2013] [Indexed: 12/31/2022]
Abstract
Since their discovery in 1948, glucocorticoids have been widely used clinically to treat inflammatory disorders like rheumatoid arthritis. However, their usefulness, especially in rheumatoid arthritis therapy, is hampered by severe side effects on bone leading to glucocorticoid-induced osteoporosis. The molecular and cellular mechanisms mediating the beneficial and adverse effects remain poorly understood. Nevertheless, advanced molecular biological analyses and in vivo approaches using conditional mutant mice have helped to unravel in part the underlying mechanisms of immunosuppression and side effects of glucocorticoid therapy in arthritis, thereby contributing to an improved understanding of these therapeutically important hormones.
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Affiliation(s)
- Ulrike Baschant
- Institute of General Zoology and Endocrinology, University of Ulm, Zentrum für Biomedizinische Forschung, Helmholtzstraße 8/1, D-89081 Ulm, Germany
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Li J, Zhang N, Huang X, Xu J, Fernandes JC, Dai K, Zhang X. Dexamethasone shifts bone marrow stromal cells from osteoblasts to adipocytes by C/EBPalpha promoter methylation. Cell Death Dis 2013; 4:e832. [PMID: 24091675 PMCID: PMC3824658 DOI: 10.1038/cddis.2013.348] [Citation(s) in RCA: 130] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Revised: 08/01/2013] [Accepted: 08/12/2013] [Indexed: 01/09/2023]
Abstract
Dexamethasone (Dex)-induced osteoporosis has been described as the most severe side effect in long-term glucocorticoid therapy. The decreased bone mass and the increased marrow fat suggest that Dex possibly shifts the differentiation of bone marrow stromal cells (BMSCs) to favor adipocyte over osteoblast, but the underlying mechanisms are still unknown. In this paper, we established a Dex-induced osteoporotic mouse model, and found that BMSCs from Dex-treated mice are more likely to differentiate into adipocyte than those from control mice, even under the induction of bone morphogenetic protein-2 (BMP2). We also discovered both in vitro and in vivo that the expression level of adipocyte regulator CCAAT/enhancer-binding protein alpha (C/EBPalpha) is significantly upregulated in Dex-induced osteoporotic BMSCs during osteoblastogenesis by a mechanism that involves inhibited DNA hypermethylation of its promoter. Knockdown of C/EBPalpha in Dex-induced osteoporotic cells rescues their differentiation potential, suggesting that Dex shifts BMSC differentiation by inhibiting C/EBPalpha promoter methylation and upregulating its expression level. We further found that the Wnt/beta-catenin pathway is involved in Dex-induced osteoporosis and C/EBPalpha promoter methylation, and its activation by LiCl rescues the effect of Dex on C/EBPalpha promoter methylation and osteoblast/adipocyte balance. This study revealed the C/EBPalpha promoter methylation mechanism and evaluated the function of Wnt/beta-catenin pathway in Dex-induced osteoporosis, providing a useful therapeutic target for this type of osteoporosis.
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Affiliation(s)
- J Li
- The Key Laboratory of Stem Cell Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences (SIBS), Chinese Academy of Sciences (CAS), Shanghai Jiao Tong University School of Medicine (SJTUSM), China
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Seibel MJ, Cooper MS, Zhou H. Glucocorticoid-induced osteoporosis: mechanisms, management, and future perspectives. Lancet Diabetes Endocrinol 2013; 1:59-70. [PMID: 24622268 DOI: 10.1016/s2213-8587(13)70045-7] [Citation(s) in RCA: 129] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Glucocorticoids are widely used for their unsurpassed anti-inflammatory and immunomodulatory effects. However, the therapeutic use of glucocorticoids is almost always limited by substantial adverse outcomes such as osteoporosis, diabetes, and obesity. These unwanted outcomes are a major dilemma for clinicians because improvements in the primary disorder seem to be achievable only by accepting substantial adverse effects that are often difficult to prevent or treat. To understand the pathogenesis of glucocorticoid-induced osteoporosis, it is necessary to consider that the actions of glucocorticoids on bone and mineral metabolism are strongly dose and time dependent. At physiological concentrations, endogenous glucocorticoids are key regulators of mesenchymal cell differentiation and bone development, with additional regulatory roles in renal and intestinal calcium handling. However, at supraphysiological concentrations, glucocorticoids affect the same systems in different and often unfavourable ways. For many years, these anabolic and catabolic actions of glucocorticoids on bone were deemed paradoxical. In this Review, we highlight recent advances in our understanding of the mechanisms underlying the physiology and pathophysiology of glucocorticoid action on the skeleton and discuss present and future management strategies for glucocorticoid-induced osteoporosis.
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Affiliation(s)
- Markus J Seibel
- Bone Research Program, Concord Hospital, Concord, Sydney, NSW, Australia; ANZAC Research Institute, Concord Hospital, Concord, Sydney, NSW, Australia; Department of Endocrinology and Metabolism, Concord Hospital, Concord, Sydney, NSW, Australia; Concord Clinical School, Concord Hospital, Concord, Sydney, NSW, Australia.
| | - Mark S Cooper
- Adrenal Steroid Laboratory, Concord Hospital, Concord, Sydney, NSW, Australia; ANZAC Research Institute, Concord Hospital, Concord, Sydney, NSW, Australia; Department of Endocrinology and Metabolism, Concord Hospital, Concord, Sydney, NSW, Australia; Concord Clinical School, Concord Hospital, Concord, Sydney, NSW, Australia
| | - Hong Zhou
- Bone Research Program, Concord Hospital, Concord, Sydney, NSW, Australia; Concord Clinical School, Concord Hospital, Concord, Sydney, NSW, Australia
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Zhou H, Cooper MS, Seibel MJ. Endogenous Glucocorticoids and Bone. Bone Res 2013; 1:107-19. [PMID: 26273496 DOI: 10.4248/br201302001] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Accepted: 04/20/2013] [Indexed: 01/28/2023] Open
Abstract
While the adverse effects of glucocorticoids on bone are well described, positive effects of glucocorticoids on the differentiation of osteoblasts are also observed. These paradoxical effects of glucocorticoids are dose dependent. At both physiologicaland supraphysiological levels of glucocorticoids, osteoblasts and osteocytes are the major glucocorticoid target cells. However, the response of the osteoblasts to each of these is quite distinct. At physiology levels, glucocorticoids direct mesenchymal progenitor cells to differentiate towards osteoblasts and thus increase bone formation in a positive way. In contrast with ageing, the excess production of glucocorticoids, at both systemic and intracellular levels, appear to impact on osteoblast and osteocytes in a negative way in a similar fashion to that seen with therapeutic glucocorticoids. This review will focus on therole of glucocorticoids in normal bone physiology, with particular emphasis on the mechanism by which endogenous glucocorticoids impact on bone and its constituent cells.
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Affiliation(s)
- Hong Zhou
- Bone Research Program, ANZAC Research Institute , Sydney, Australia ; Concord Clinical School, The University of Sydney , Sydney, Australia
| | - Mark S Cooper
- Concord Clinical School, The University of Sydney , Sydney, Australia ; Department of Endocrinology & Metabolism, Concord Hospital , Sydney, Australia
| | - Markus J Seibel
- Bone Research Program, ANZAC Research Institute , Sydney, Australia ; Concord Clinical School, The University of Sydney , Sydney, Australia ; Department of Endocrinology & Metabolism, Concord Hospital , Sydney, Australia
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Brennan-Speranza TC, Henneicke H, Gasparini SJ, Blankenstein KI, Heinevetter U, Cogger VC, Svistounov D, Zhang Y, Cooney GJ, Buttgereit F, Dunstan CR, Gundberg C, Zhou H, Seibel MJ. Osteoblasts mediate the adverse effects of glucocorticoids on fuel metabolism. J Clin Invest 2012; 122:4172-89. [PMID: 23093779 DOI: 10.1172/jci63377] [Citation(s) in RCA: 135] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 08/23/2012] [Indexed: 12/11/2022] Open
Abstract
Long-term glucocorticoid treatment is associated with numerous adverse outcomes, including weight gain, insulin resistance, and diabetes; however, the pathogenesis of these side effects remains obscure. Glucocorticoids also suppress osteoblast function, including osteocalcin synthesis. Osteocalcin is an osteoblast-specific peptide that is reported to be involved in normal murine fuel metabolism. We now demonstrate that osteoblasts play a pivotal role in the pathogenesis of glucocorticoid-induced dysmetabolism. Osteoblast-targeted disruption of glucocorticoid signaling significantly attenuated the suppression of osteocalcin synthesis and prevented the development of insulin resistance, glucose intolerance, and abnormal weight gain in corticosterone-treated mice. Nearly identical effects were observed in glucocorticoid-treated animals following heterotopic (hepatic) expression of both carboxylated and uncarboxylated osteocalcin through gene therapy, which additionally led to a reduction in hepatic lipid deposition and improved phosphorylation of the insulin receptor. These data suggest that the effects of exogenous high-dose glucocorticoids on insulin target tissues and systemic energy metabolism are mediated, at least in part, through the skeleton.
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Joyce NC, Hache LP, Clemens PR. Bone health and associated metabolic complications in neuromuscular diseases. Phys Med Rehabil Clin N Am 2012; 23:773-99. [PMID: 23137737 DOI: 10.1016/j.pmr.2012.08.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This article reviews the recent literature regarding bone health as it relates to the patient living with neuromuscular disease (NMD). Studies defining the scope of bone-related disease in NMD are scant. The available evidence is discussed, focusing on abnormal calcium metabolism, increased fracture risk, and the prevalence of both scoliosis and hypovitaminosis D in Duchenne muscular dystrophy, amyotrophic lateral sclerosis, and spinal muscular atrophy. Future directions are discussed, including the urgent need for studies both to determine the nature and extent of poor bone health, and to evaluate the therapeutic effect of available osteoporosis treatments in patients with NMD.
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Affiliation(s)
- Nanette C Joyce
- Department of Rehabilitation Medicine, University of California, Davis, Sacramento, CA 95817, USA.
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The epithelial sodium channel is involved in dexamethasone-induced osteoblast differentiation and mineralization. Cell Biol Toxicol 2012; 28:279-89. [DOI: 10.1007/s10565-012-9222-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2012] [Accepted: 05/28/2012] [Indexed: 01/09/2023]
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Madsen SH, Andreassen KV, Christensen ST, Karsdal MA, Sverdrup FM, Bay-Jensen AC, Henriksen K. Glucocorticoids exert context-dependent effects on cells of the joint in vitro. Steroids 2011; 76:1474-82. [PMID: 21855558 DOI: 10.1016/j.steroids.2011.07.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Revised: 07/27/2011] [Accepted: 07/28/2011] [Indexed: 01/20/2023]
Abstract
INTRODUCTION Glucocorticoids are known to attenuate bone formation in vivo leading to decreased bone volume and increased risk of fractures, whereas effects on the joint tissue are less characterized. However, glucocorticoids appear to have a reducing effect on inflammation and pain in osteoarthritis. This study aimed at characterizing the effect of glucocorticoids on chondrocytes, osteoclasts, and osteoblasts. EXPERIMENTAL We used four model systems to investigate how glucocorticoids affect the cells of the joint; two intact tissues (femoral head- and cartilage-explants), and two separate cell cultures of osteoblasts (2T3-pre-osteoblasts) and osteoclasts (CD14(+)-monocytes). The model systems were cultured in the presence of two glucocorticoids; prednisolone or dexamethasone. To induce anabolic and catabolic conditions, cultures were activated by insulin-like growth factor I/bone morphogenetic protein 2 and oncostatin M/tumor necrosis factor-α, respectively. Histology and markers of bone- and cartilage-turnover were used to evaluate effects of glucocorticoid treatment. RESULTS Prednisolone treatment decreased collagen type-II degradation in immature cartilage, whereas glucocorticoids did not affect collagen type-II in mature cartilage. Glucocorticoids had an anti-catabolic effect on catabolic-activated cartilage from a bovine stifle joint and murine femoral heads. Glucocorticoids decreased viability of all bone cells, leading to a reduction in osteoclastogenesis and bone resorption; however, bone morphogenetic protein 2-stimulated osteoblasts increased bone formation, as opposed to non-stimulated osteoblasts. CONCLUSIONS Using highly robust in vitro models of bone and cartilage turnover, we suggest that effects of glucocorticoids highly depend on the activation and differential stage of the cell targeted in the joint. Present data indicated that glucocorticoid treatment may be beneficial for articular cartilage, although detrimental effects on bone should be taken into account.
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Affiliation(s)
- Suzi H Madsen
- Cartilage Biology and Biomarkers, Nordic Bioscience A/S, Herlev Hovedgade 207, DK-2730 Herlev, Denmark.
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Henneicke H, Herrmann M, Kalak R, Brennan-Speranza TC, Heinevetter U, Bertollo N, Day RE, Huscher D, Buttgereit F, Dunstan CR, Seibel MJ, Zhou H. Corticosterone selectively targets endo-cortical surfaces by an osteoblast-dependent mechanism. Bone 2011; 49:733-42. [PMID: 21722764 DOI: 10.1016/j.bone.2011.06.013] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Revised: 06/01/2011] [Accepted: 06/13/2011] [Indexed: 11/29/2022]
Abstract
BACKGROUND The pathogenesis of glucocorticoid-induced osteoporosis remains ill defined. In this study, we examined the role of the osteoblast in mediating the effects of exogenous glucocorticoids on cortical and trabecular bone, employing the Col2.3-11βHSD2 transgenic mouse model of osteoblast-targeted disruption of glucocorticoid signalling. METHODS Eight week-old male transgenic (tg) and wild-type (WT) mice (n=20-23/group) were treated with either 1.5 mg corticosterone (CS) or placebo for 4 weeks. Serum tartrate-resistant acid phosphatase 5b (TRAP5b) and osteocalcin (OCN) were measured throughout the study. Tibiae and lumbar vertebrae were analysed by micro-CT and histomorphometry at endpoint. RESULTS CS suppressed serum OCN levels in WT and tg mice, although they remained higher in tg animals at all time points (p<0.05). Serum TRAP5b levels increased in WT mice only. The effect of CS on cortical bone differed by site: At the endosteal surface, exposure to CS significantly increased bone resorption and reduced bone formation, resulting in a larger bone marrow cavity cross-sectional area (p<0.01). In contrast, at the pericortical surface bone resorption was significantly decreased accompanied with a significant increase in pericortical cross-sectional area (p<0.05) while bone formation remained unaffected. Vertebral cortical thickness and area were reduced in CS treatment mice. Tg mice were partially protected from the effects of exogenous CS, both on a cellular and structural level. At the CS doses used in this study, trabecular bone remained largely unaffected. CONCLUSION Endocortical osteoblasts appear to be particularly sensitive to the detrimental actions of exogenous glucocorticoids. The increase in tibial pericortical cross-sectional area and the according changes in pericortical circumference suggest an anabolic bone response to GC treatment at this site. The protection of tg mice from these effects indicates that both catabolic and anabolic action of glucocorticoids are, at least in part, mediated by osteoblasts.
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Affiliation(s)
- Holger Henneicke
- Bone Research Program, ANZAC Research Institute, The University of Sydney, Sydney, Australia
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Rauch A, Gossye V, Bracke D, Gevaert E, Jacques P, Van Beneden K, Vandooren B, Rauner M, Hofbauer LC, Haegeman G, Elewaut D, Tuckermann JP, De Bosscher K. An anti-inflammatory selective glucocorticoid receptor modulator preserves osteoblast differentiation. FASEB J 2011; 25:1323-32. [PMID: 21233489 DOI: 10.1096/fj.10-173393] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Glucocorticoids (GCs) are in widespread use to treat inflammatory bone diseases, such as rheumatoid arthritis (RA). Their anti-inflammatory efficacy, however, is accompanied by deleterious effects on bone, leading to GC-induced osteoporosis (GIO). These effects include up-regulation of the receptor activator of NF-κB ligand/osteoprotegerin (RANKL/OPG) ratio to promote bone-resorbing osteoclasts and include inhibition of bone-forming osteoblasts. We previously identified suppression of osteoblast differentiation by the monomer glucocorticoid receptor (GR) via the inhibition of Il11 expression as a crucial mechanism for GIO. Here we show that the GR-modulating substance compound A (CpdA), which does not induce GR dimerization, still suppresses proinflammatory cytokines in fibroblast-like synovial cells from patients with RA and in osteoblasts. In contrast to the full GR agonist dexamethasone, it does not unfavorably alter the RANKL/OPG ratio and does not affect Il11 expression and subsequent STAT3 phosphorylation in these cells. Notably, while dexamethasone inhibits osteoblast differentiation, CpdA does not affect osteoblast differentiation in vitro and in vivo. We describe here for the first time that selective GR modulators can act against inflammation, while not impairing osteoblast differentiation.
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Affiliation(s)
- Alexander Rauch
- Group of Tissue-Specific Hormone Action, Fritz Lipmann Institute, Leibniz Institute for Age Research, Jena, Germany
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Malik AK, Khaldoyanidi S, Auci DL, Miller SC, Ahlem CN, Reading CL, Page T, Frincke JM. 5-Androstene-3β,7β,17β-triol (β-AET) slows thermal injury induced osteopenia in mice: relation to aging and osteoporosis. PLoS One 2010; 5:e13566. [PMID: 21042414 PMCID: PMC2958849 DOI: 10.1371/journal.pone.0013566] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Accepted: 09/24/2010] [Indexed: 01/06/2023] Open
Abstract
5-androstene-3β,7β,17β-triol (β-AET), an active metabolite of dehydroepiandrosterone (DHEA), reversed glucocorticoid (GC)-induced suppression of IL-6, IL-8 and osteoprotegerin production by human osteoblast-like MG-63 cells and promoted osteoblast differentiation of human mesenchymal stem cells (MSCs). In a murine thermal injury model that includes glucocorticoid-induced osteopenia, β-AET significantly (p<0.05) preserved bone mineral content, restored whole body bone mineral content and endochondral growth, suggesting reversal of GC-mediated decreases in chondrocyte proliferation, maturation and osteogenesis in the growth plate. In men and women, levels of β-AET decline with age, consistent with a role for β-AET relevant to diseases associated with aging. β-AET, related compounds or synthetic derivatives may be part of effective therapeutic strategies to accelerate tissue regeneration and prevent or treat diseases associated with aging such as osteoporosis.
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Affiliation(s)
- Ajay K. Malik
- Harbor Biosciences, Inc., San Diego, California, United States of America
| | - Sophia Khaldoyanidi
- Torrey Pines Institute for Molecular Studies, San Diego, California, United States of America
| | - Dominick L. Auci
- Harbor Biosciences, Inc., San Diego, California, United States of America
- * E-mail:
| | - Scott C. Miller
- Radiobiology Division, University of Utah, Salt Lake City, Utah, United States of America
| | - Clarence N. Ahlem
- Harbor Biosciences, Inc., San Diego, California, United States of America
| | | | - Theodore Page
- Harbor Biosciences, Inc., San Diego, California, United States of America
| | - James M. Frincke
- Harbor Biosciences, Inc., San Diego, California, United States of America
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Rauch A, Seitz S, Baschant U, Schilling AF, Illing A, Stride B, Kirilov M, Mandic V, Takacz A, Schmidt-Ullrich R, Ostermay S, Schinke T, Spanbroek R, Zaiss MM, Angel PE, Lerner UH, David JP, Reichardt HM, Amling M, Schütz G, Tuckermann JP. Glucocorticoids suppress bone formation by attenuating osteoblast differentiation via the monomeric glucocorticoid receptor. Cell Metab 2010; 11:517-31. [PMID: 20519123 DOI: 10.1016/j.cmet.2010.05.005] [Citation(s) in RCA: 305] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2009] [Revised: 12/25/2009] [Accepted: 05/04/2010] [Indexed: 01/10/2023]
Abstract
Development of osteoporosis severely complicates long-term glucocorticoid (GC) therapy. Using a Cre-transgenic mouse line, we now demonstrate that GCs are unable to repress bone formation in the absence of glucocorticoid receptor (GR) expression in osteoblasts as they become refractory to hormone-induced apoptosis, inhibition of proliferation, and differentiation. In contrast, GC treatment still reduces bone formation in mice carrying a mutation that only disrupts GR dimerization, resulting in bone loss in vivo, enhanced apoptosis, and suppressed differentiation in vitro. The inhibitory GC effects on osteoblasts can be explained by a mechanism involving suppression of cytokines, such as interleukin 11, via interaction of the monomeric GR with AP-1, but not NF-kappaB. Thus, GCs inhibit cytokines independent of GR dimerization and thereby attenuate osteoblast differentiation, which accounts, in part, for bone loss during GC therapy.
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Affiliation(s)
- Alexander Rauch
- Tissue-specific hormone action, Leibniz Institute for Age Research, Fritz Lipmann Institute, 07745 Jena, Germany
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Weber AJ, Li G, Kalak R, Street J, Buttgereit F, Dunstan CR, Seibel MJ, Zhou H. Osteoblast-targeted disruption of glucocorticoid signalling does not delay intramembranous bone healing. Steroids 2010; 75:282-6. [PMID: 20096296 DOI: 10.1016/j.steroids.2010.01.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2009] [Revised: 01/06/2010] [Accepted: 01/07/2010] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Glucocorticoids at pharmacological doses have been shown to interfere with fracture repair. The role of endogenous glucocorticoids in fracture healing is not well understood. We examined whether endogenous glucocorticoids affect bone healing in an in vivo model of cortical defect repair. METHODS Experiments were performed using a well characterised mouse model in which intracellular glucocorticoid signalling was disrupted in osteoblasts through transgenic overexpression of 11beta-hydroxysteroid-dehydrogenase type 2 (11beta-HSD2) under the control of a collagen type I promoter (Col2.3-11beta-HSD2). Unicortical bone defects (ø 0.8mm) were created in the tibiae of 7-week-old male transgenic mice and their wild-type littermates. Repair was assessed via histomorphometry, immunohistochemistry and microcomputed tomography (micro-CT) analysis at 1-3 weeks after defect creation. RESULTS At week 1, micro-CT images of the defect demonstrated formation of mineralized intramembranous bone which increased in volume and density by week 2. At week 3, healing of the defect was nearly complete in all animals. Analysis by histomorphometry and micro-CT revealed that repair of the bony defect was similar in Col2.3-11beta-HSD2 transgenic animals and their wild-type littermates at all time-points. CONCLUSION Disrupting endogenous glucocorticoid signalling in mature osteoblasts did not affect intramembranous fracture healing in a tibia defect repair model. It remains to be shown whether glucocorticoid signalling has a role in endochondral fracture healing.
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Affiliation(s)
- Agnes J Weber
- Bone Research Program, ANZAC Research Institute, The University of Sydney, Hospital Road, Concord NSW 2139, Sydney, Australia
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Mak W, Shao X, Dunstan CR, Seibel MJ, Zhou H. Biphasic glucocorticoid-dependent regulation of Wnt expression and its inhibitors in mature osteoblastic cells. Calcif Tissue Int 2009; 85:538-45. [PMID: 19876584 DOI: 10.1007/s00223-009-9303-1] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2009] [Accepted: 09/30/2009] [Indexed: 11/26/2022]
Abstract
Glucocorticoids exert both anabolic and catabolic effects on bone. Previously, we reported that endogenous glucocorticoids control mesenchymal lineage commitment and osteoblastogenesis through regulation of Wnt signaling in osteoblasts. Here, we investigated the effects of glucocorticoids on Wnt expression in mature osteoblasts. Mature osteoblasts and their immature progenitors were separately isolated from Col2.3-GFP transgenic mice in which mature osteoblasts are identifiable through GFP expression. mRNA levels of Wnt2, Wnt2b, Wnt4, Wnt5a, Wnt10b, and Wnt11 were 4- to 12-fold higher in osteoblasts compared to their progenitors (P < 0.05). Expression of Wnt7b and Wnt10b in osteoblasts was modulated by corticosterone (CS), in a biphasic fashion with 3- to 3.5-fold upregulation at 10 nM CS (P < 0.01) and 50% downregulation at 100 nM CS (P < 0.05). CS 100 nM also increased expression of the Wnt inhibitors sFRP-1 and DKK-1 two- to threefold (P < 0.05). We conclude that the contrasting anabolic and catabolic effects of glucocorticoids on bone are, at least in part, mediated through the regulation of Wnt expression and its inhibitors in mature osteoblasts.
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Affiliation(s)
- Wendy Mak
- Bone Research Program, ANZAC Research Institute, The University of Sydney, Hospital Road, Concord, 2139, Sydney, NSW, Australia
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