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Yavuz GY, Keskinruzgar A, Bozdag Z, Bayazit S. Investigation of the Effect of Local and Systemic Preoperative Dexamethasone Application on Bone Tissue Healing in Mandibular Bone Defects. J Craniofac Surg 2024:00001665-990000000-01759. [PMID: 38980035 DOI: 10.1097/scs.0000000000010412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Accepted: 05/19/2024] [Indexed: 07/10/2024] Open
Abstract
OBJECTIVES The aim of this study was to investigate the effect of locally and systemically delivered single-dose corticosteroid injections on bone tissue. STUDY DESIGN A total of 84 Wistar albino rats were divided into 2 groups as local and systemic injection groups, and 2 groups as control and experiment among themselves. Before the procedure, dexamethasone was given to the experimental group and physiological saline was given to the control group. A defect was created in the jawbone. It was sacrificed on the third, seventh, and 40th days. The mandible bones of the sacrificed rats were removed and the healing of the bone tissue was examined histopathologically. RESULTS No significant difference was observed in the tissue sections of the subjects sacrificed after 40 days. However, the increase in fibroblastic connective tissue and the number of osteoblasts were less in the experimental local groups that were sacrificed after 7 days compared with the control groups (P=0.040 and 0.041). Again, it was determined that there was a statistically significant decrease in the experimental local group compared with the experimental systemic group (P=0.040 and 0.004). CONCLUSIONS It can be said that single-dose corticosteroid applications cause a delay in bone healing in the early period.
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Affiliation(s)
- Gunay Yapici Yavuz
- Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Adiyaman University, Adiyaman
| | - Aydin Keskinruzgar
- Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Adiyaman University, Adiyaman
| | - Zehra Bozdag
- Department of Patology, Faculty of Medicine, İnönü University, Malatya, Turkey
| | - Seyma Bayazit
- Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Adiyaman University, Adiyaman
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Genetic factors contributing to late adverse musculoskeletal effects in childhood acute lymphoblastic leukemia survivors. THE PHARMACOGENOMICS JOURNAL 2022; 22:19-24. [PMID: 34446917 DOI: 10.1038/s41397-021-00252-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 08/11/2021] [Accepted: 08/17/2021] [Indexed: 02/07/2023]
Abstract
BACKGROUND A substantial number of survivors of childhood acute lymphoblastic leukemia (ALL) suffer from treatment-related late adverse effects. While multiple studies have identified the effects of chemotherapeutics and radiation therapy on musculoskeletal outcomes, few have investigated their associations with genetic factors. METHODS Here we analyzed musculoskeletal complications in relation to common and rare genetic variants derived through whole-exome sequencing of the PETALE cohort. Top-ranking associations were further assessed through stratified and multivariate analyses. RESULTS DUOX2 variant was associated with skeletal muscle function deficit, as defined by peak muscle power Z score ≤ -2 SD (P = 4.5 × 10-5 for genotyping model). Upon risk stratification analysis, common variants in the APOL3, COL12A1, and LY75 genes were associated with Z score ≤ -2 SD at the cross-sectional area (CSA) at 4% radial length and lumbar bone mineral density (BMD) in high-risk patients (P ≤ 0.01). The modulation of the effect by risk group was driven by the interaction of the genotype with cumulative glucocorticoid dose. Identified variants remained significant throughout multivariate analyses incorporating non-genetic factors of the studied cohort. CONCLUSION This exploratory study identified novel genetic variants associated with long-term musculoskeletal impairments in childhood ALL survivors. Replication in an independent cohort is needed to confirm the association found in this study.
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Wofford KL, Singh BS, Cullen DK, Spiller KL. Biomaterial-mediated reprogramming of monocytes via microparticle phagocytosis for sustained modulation of macrophage phenotype. Acta Biomater 2020; 101:237-248. [PMID: 31731024 PMCID: PMC6960335 DOI: 10.1016/j.actbio.2019.11.021] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 10/14/2019] [Accepted: 11/08/2019] [Indexed: 12/15/2022]
Abstract
Monocyte-derived macrophages orchestrate tissue regeneration by homing to sites of injury, phagocytosing pathological debris, and stimulating other cell types to repair the tissue. Accordingly, monocytes have been investigated as a translational and potent source for cell therapy, but their utility has been hampered by their rapid acquisition of a pro-inflammatory phenotype in response to the inflammatory injury microenvironment. To overcome this problem, we designed a cell therapy strategy where monocytes are exogenously reprogrammed by intracellularly loading the cells with biodegradable microparticles containing an anti-inflammatory drug in order to modulate and maintain an anti-inflammatory phenotype over time. To test this concept, poly(lactic-co-glycolic) acid microparticles were loaded with the anti-inflammatory drug dexamethasone (Dex) and administered to primary human monocytes for four hours to facilitate phagocytic uptake. After removal of non-phagocytosed microparticles, microparticle-loaded monocytes differentiated into macrophages and stored the microparticles intracellularly for several weeks in vitro, releasing drug into the extracellular environment over time. Cells loaded with intracellular Dex microparticles showed decreased expression and secretion of inflammatory factors even in the presence of pro-inflammatory stimuli up to 7 days after microparticle uptake compared to untreated cells or cells loaded with blank microparticles, without interfering with phagocytosis of tissue debris. This study represents a new strategy for long-term maintenance of anti-inflammatory macrophage phenotype using a translational monocyte-based cell therapy strategy without the use of genetic modification. Because of the ubiquitous nature of monocyte-derived macrophage involvement in pathology and regeneration, this strategy holds potential as a treatment for a vast number of diseases and disorders. STATEMENT OF SIGNIFICANCE: We report a unique and translational strategy to overcome the challenges associated with monocyte- and macrophage-based cell therapies, in which the cells rapidly take on inflammatory phenotypes when administered to sites of injury. By intracellularly loading monocytes with drug-loaded microparticles prior to administration via phagocytosis, we were able to inhibit inflammation while preserving functional behaviors of human primary macrophages derived from those monocytes up to seven days later. To our knowledge, this study represents the first report of reprogramming macrophages to an anti-inflammatory phenotype without the use of genetic modification.
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Affiliation(s)
- Kathryn L Wofford
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA 19104, United States; Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA 19104, United States; Departments of Neurosurgery & Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Bhavani S Singh
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA 19104, United States
| | - D Kacy Cullen
- Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA 19104, United States; Departments of Neurosurgery & Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Kara L Spiller
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA 19104, United States.
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Effects of different pre-operative doses of dexamethasone on alveolar repair in rats. Arch Oral Biol 2019; 110:104624. [PMID: 31841964 DOI: 10.1016/j.archoralbio.2019.104624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 11/08/2019] [Accepted: 11/24/2019] [Indexed: 11/22/2022]
Abstract
Dexamethasone has been widly used in oral and maxillofacial surgery for controlling of postoperative surgical inflammation. Despite its clinical effectiveness, several studies have demonstrated the negative impact of this drug on the healing of soft and hard tissues. This study aimed to assess the effects of different pre-operative doses of dexamethasone on alveolar repair. Sixty rats were divided into four groups of 15 animals each. Single pre-operative doses of dexamethasone equivalent to human doses of 4 mg (Group 4 mg), 8 mg (Group 8 mg), and 12 mg (Group 12 mg), calculated by allometric dose extrapolation, were administered; and rats in the Control Group were injected with saline solution. The animals were anesthetized, and their left mandibular first molars (M1) were removed. After three, seven, and 40 days, 5 animals from each group were euthanized, and bone samples of M1 alveolus were collected for radipgraphic, histomorphological and histometric evaluation of the early and late phases of alveolar healing. At three days, Group 12 mg presented reduced radiographic density, percentage of collagen, and connective matrix compared with the Control Group. At 7 days, the percentage of bone was increased in the Control Group compared to Groups 8 mg and 12 mg (P < 0.05). It can be concluded that a single pre-operative dose of 12 mg of dexamethasone affected the early stages of alveolar repair in rats.
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Wofford KL, Cullen DK, Spiller KL. Modulation of macrophage phenotype via phagocytosis of drug-loaded microparticles. J Biomed Mater Res A 2019; 107:1213-1224. [PMID: 30672109 PMCID: PMC6499658 DOI: 10.1002/jbm.a.36617] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Accepted: 01/09/2019] [Indexed: 12/17/2022]
Abstract
Monocyte-derived macrophages play a critical role in directing wound pathology following injury. Depending on their phenotype, macrophages also promote tissue regeneration. However, the therapeutic administration of macrophages with a controlled phenotype is challenging because macrophages are highly plastic and quickly revert to a detrimental, inflammatory phenotype in response to the environment of a damaged tissue. To address this issue, we developed a novel strategy to modulate macrophage phenotype intracellularly through phagocytosis of drug-loaded microparticles. Poly(lactic-co-glycolic acid) microparticles loaded with the anti-inflammatory drug dexamethasone (Dex) were phagocytosed by monocytes and stored intracellularly for at least 5 days. After differentiation into macrophages, cell phenotype was characterized over time with high-throughput gene expression analysis via NanoString. We found that the microparticles modulated macrophage phenotype for up to 7 days after microparticle uptake, with decreases in inflammation-related genes at early timepoints and upregulation of homing- and phagocytosis-related genes at multiple timepoints in a manner similar to cells treated with continuous free Dex. These data suggest that intracellularly loading macrophages with Dex microparticles via phagocytosis could be a unique methodology to selectively modulate macrophage phenotype over time. This strategy would allow therapeutic administration of macrophages for the treatment of a number of inflammatory disease and disorders. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1213-1224, 2019.
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Affiliation(s)
- Kathryn L Wofford
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, Pennsylvania
- Center for Neurotrauma, Neurodegeneration and Restoration, CMC VA Medical Center, Philadelphia, Pennsylvania
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania
| | - D Kacy Cullen
- Center for Neurotrauma, Neurodegeneration and Restoration, CMC VA Medical Center, Philadelphia, Pennsylvania
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Kara L Spiller
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, Pennsylvania
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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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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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Faia-Torres AB, Charnley M, Goren T, Guimond-Lischer S, Rottmar M, Maniura-Weber K, Spencer ND, Reis RL, Textor M, Neves NM. Osteogenic differentiation of human mesenchymal stem cells in the absence of osteogenic supplements: A surface-roughness gradient study. Acta Biomater 2015; 28:64-75. [PMID: 26432440 DOI: 10.1016/j.actbio.2015.09.028] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Revised: 09/17/2015] [Accepted: 09/23/2015] [Indexed: 12/22/2022]
Abstract
The use of biomaterials to direct osteogenic differentiation of human mesenchymal stem cells (hMSCs) in the absence of osteogenic supplements is thought to be part of the next generation of orthopedic implants. We previously engineered surface-roughness gradients of average roughness (Ra) varying from the sub-micron to the micrometer range (∼0.5-4.7 μm), and mean distance between peaks (RSm) gradually varying from ∼214 μm to 33 μm. Here we have screened the ability of such surface-gradients of polycaprolactone to influence the expression of alkaline phosphatase (ALP), collagen type 1 (COL1) and mineralization by hMSCs cultured in dexamethasone (Dex)-deprived osteogenic induction medium (OIM) and in basal growth medium (BGM). Ra∼1.53 μm/RSm∼79 μm in Dex-deprived OI medium, and Ra∼0.93 μm/RSm∼135 μm in BGM consistently showed higher effectiveness at supporting the expression of the osteogenic markers ALP, COL1 and mineralization, compared to the tissue culture polystyrene (TCP) control in complete OIM. The superior effectiveness of specific surface-roughness revealed that this strategy may be used as a compelling alternative to soluble osteogenic inducers in orthopedic applications featuring the clinically relevant biodegradable polymer polycaprolactone. STATEMENT OF SIGNIFICANCE Biodegradable polymers, such as polycaprolactone (PCL), are promising materials in the field of tissue engineering and regenerative medicine, which aims at creating viable options to replace permanent orthopedic implants. The material, cells, and growth-stimulating factors are often referred to as the key components of engineered tissues. In this article, we studied the hypothesis of specific surface modification of PCL being capable of inducing mesenchymal stem cell differentiation in bone cells in the absence of cell-differentiating factors. The systematic investigation of the linearly varying surface-roughness gradient showed that an average PCL roughness of 0.93 μm alone can serve as a compelling alternative to soluble osteogenic inducers in orthopedic applications featuring the clinically relevant biodegradable polymer polycaprolactone.
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Santo VE, Ratanavaraporn J, Sato K, Gomes ME, Mano JF, Reis RL, Tabata Y. Cell engineering by the internalization of bioinstructive micelles for enhanced bone regeneration. Nanomedicine (Lond) 2015; 10:1707-21. [DOI: 10.2217/nnm.15.11] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aim: To direct precursor cells toward the osteoblastic lineage, by using an intracellular nanocarrier releasing dexamethasone. Materials & methods: Biodegradable gelatin-based micelles entrapped dexamethasone (dex-micelles). Internalization efficiency and biocompatibility of dex-micelles and their potency for in vitro osteogenic differentiation and in vivo bone regeneration were assessed. Results: Dex-micelles were internalized by rat bone marrow mesenchymal stem cells and demonstrated a pH-responsive release profile and an enhancement of 2D and 3D in vitro osteogenic differentiation. In vivo implantation of gelatin scaffolds seeded with rat bone marrow mesenchymal stem cells precultured for 24 h with dex-micelles promoted a significant enhancement of de novo bone formation in a rat ulna defect, in a dose-dependent manner. Conclusion: The proposed intracellular delivery system is a powerful tool to promote bone regeneration.
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Affiliation(s)
- Vítor E Santo
- Department of Biomaterials, Field of Tissue Engineering, Institute for Frontier Medical Sciences, Kyoto University, Sakyo Ku, Kyoto 6068507, Japan
- 3B's Research Group – Biomaterials, Biodegradables & Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering & Regenerative Medicine, AvePark, 4806–909 Taipas, Guimarães, Portugal
- ICVS/3B's – PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Juthamas Ratanavaraporn
- Department of Biomaterials, Field of Tissue Engineering, Institute for Frontier Medical Sciences, Kyoto University, Sakyo Ku, Kyoto 6068507, Japan
| | - Keisuke Sato
- Department of Biomaterials, Field of Tissue Engineering, Institute for Frontier Medical Sciences, Kyoto University, Sakyo Ku, Kyoto 6068507, Japan
| | - Manuela E Gomes
- 3B's Research Group – Biomaterials, Biodegradables & Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering & Regenerative Medicine, AvePark, 4806–909 Taipas, Guimarães, Portugal
- ICVS/3B's – PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - João F Mano
- 3B's Research Group – Biomaterials, Biodegradables & Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering & Regenerative Medicine, AvePark, 4806–909 Taipas, Guimarães, Portugal
- ICVS/3B's – PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Rui L Reis
- 3B's Research Group – Biomaterials, Biodegradables & Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering & Regenerative Medicine, AvePark, 4806–909 Taipas, Guimarães, Portugal
- ICVS/3B's – PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Yasuhiko Tabata
- Department of Biomaterials, Field of Tissue Engineering, Institute for Frontier Medical Sciences, Kyoto University, Sakyo Ku, Kyoto 6068507, Japan
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Kim J, Lee H, Kang KS, Chun KH, Hwang GS. Protective effect of Korean Red Ginseng against glucocorticoid-induced osteoporosis in vitro and in vivo. J Ginseng Res 2014; 39:46-53. [PMID: 25535476 PMCID: PMC4268568 DOI: 10.1016/j.jgr.2014.06.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 06/08/2014] [Indexed: 11/25/2022] Open
Abstract
Background Glucocorticoids (GCs) are commonly used in many chemotherapeutic protocols and play an important role in the normal regulation of bone remodeling. However, the prolonged use of GCs results in osteoporosis, which is partially due to apoptosis of osteoblasts and osteocytes. In this study, effects of Korean Red Ginseng (KRG) on GC-treated murine osteoblastic MC3T3-E1 cells and a GC-induced osteoporosis mouse model were investigated. Methods MC3T3-E1 cells were exposed to dexamethasone (Dex) with or without KRG and cell viability was measured by the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Real-time polymerase chain reaction was performed to evaluate the apoptotic gene expression; osteogenic gene expression and alkaline phosphatase (ALP) activity were also measured. Western blotting was performed to evaluate the mitogen-activated protein kinase (MAPK) proteins. A GC-induced osteoporosis animal model was used for in vivo study. Results and conclusion The MTT assay revealed that Korean Red Ginseng (KRG) prevents loss of cell viability caused by Dex-induced apoptosis in MC3T3E1 cells. Real-time polymerase chain reaction data showed that groups treated with both Dex and KRG exhibited lower mRNA levels of caspase-3 and -9, whereas the mRNA levels of Bcl2, IAPs, and XIAP increased. Moreover, groups treated with both Dex and KRG demonstrated increased mRNA levels of ALP, RUNX2, and bone morphogenic proteins as well as increased ALP activity in MC3T3-E1 cells, compared to cells treated with Dex only. In addition, KRG increased protein kinase B (AKT) phosphorylation and decreased c-Jun N-terminal kinase (JNK) phosphorylation. Moreover, microcomputed tomography analysis of the femurs showed that GC implantation caused trabecular bone loss. However, a significant reduction of bone loss was observed in the KRG-treated group. These results suggest that the molecular mechanism of KRG in the GC-induced apoptosis may lead to the development of therapeutic strategies to prevent and/or delay osteoporosis.
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Affiliation(s)
- Jinhee Kim
- Laboratory of Cell Differentiation Research, College of Korean Medicine, Gachon University, Seongnam, Korea
| | - Hyejin Lee
- Laboratory of Cell Differentiation Research, College of Korean Medicine, Gachon University, Seongnam, Korea
| | - Ki Sung Kang
- College of Korean Medicine, Gachon University, Seongnam, Korea
| | - Kwang-Hoon Chun
- Gachon Institute of Pharmaceutical Sciences, College of Pharmacy, Gachon University, Incheon, Korea
| | - Gwi Seo Hwang
- Laboratory of Cell Differentiation Research, College of Korean Medicine, Gachon University, Seongnam, Korea
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Fleuren WWM, Toonen EJM, Verhoeven S, Frijters R, Hulsen T, Rullmann T, van Schaik R, de Vlieg J, Alkema W. Identification of new biomarker candidates for glucocorticoid induced insulin resistance using literature mining. BioData Min 2013; 6:2. [PMID: 23379763 PMCID: PMC3577498 DOI: 10.1186/1756-0381-6-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Accepted: 01/02/2013] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Glucocorticoids are potent anti-inflammatory agents used for the treatment of diseases such as rheumatoid arthritis, asthma, inflammatory bowel disease and psoriasis. Unfortunately, usage is limited because of metabolic side-effects, e.g. insulin resistance, glucose intolerance and diabetes. To gain more insight into the mechanisms behind glucocorticoid induced insulin resistance, it is important to understand which genes play a role in the development of insulin resistance and which genes are affected by glucocorticoids.Medline abstracts contain many studies about insulin resistance and the molecular effects of glucocorticoids and thus are a good resource to study these effects. RESULTS We developed CoPubGene a method to automatically identify gene-disease associations in Medline abstracts. We used this method to create a literature network of genes related to insulin resistance and to evaluate the importance of the genes in this network for glucocorticoid induced metabolic side effects and anti-inflammatory processes.With this approach we found several genes that already are considered markers of GC induced IR, such as phosphoenolpyruvate carboxykinase (PCK) and glucose-6-phosphatase, catalytic subunit (G6PC). In addition, we found genes involved in steroid synthesis that have not yet been recognized as mediators of GC induced IR. CONCLUSIONS With this approach we are able to construct a robust informative literature network of insulin resistance related genes that gave new insights to better understand the mechanisms behind GC induced IR. The method has been set up in a generic way so it can be applied to a wide variety of disease networks.
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Affiliation(s)
- Wilco WM Fleuren
- Computational Drug Discovery (CDD), CMBI, NCMLS, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
- Netherlands Bioinformatics Centre (NBIC), P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Erik JM Toonen
- Department of Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | | | - Raoul Frijters
- Computational Drug Discovery (CDD), CMBI, NCMLS, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
- Present address: Rijk Zwaan Nederland BV, Fijnaart, The Netherlands
| | - Tim Hulsen
- Computational Drug Discovery (CDD), CMBI, NCMLS, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
- Present address: Philips Research Europe, Eindhoven, The Netherlands
| | | | | | - Jacob de Vlieg
- Computational Drug Discovery (CDD), CMBI, NCMLS, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
- Netherlands eScience Center, Amsterdam, The Netherlands
| | - Wynand Alkema
- Computational Drug Discovery (CDD), CMBI, NCMLS, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
- Present address: NIZO Food Research BV, Ede, The Netherlands
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Hakala M, Kröger H, Valleala H, Hienonen-Kempas T, Lehtonen-Veromaa M, Heikkinen J, Tuomiranta T, Hannonen P, Paimela L. Once-monthly oral ibandronate provides significant improvement in bone mineral density in postmenopausal women treated with glucocorticoids for inflammatory rheumatic diseases: a 12-month, randomized, double-blind, placebo-controlled trial. Scand J Rheumatol 2013; 41:260-6. [PMID: 22803768 DOI: 10.3109/03009742.2012.664647] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
OBJECTIVES To study the efficacy and safety of once-monthly oral ibandronate in the prevention of glucocorticoid (GC)-induced osteoporosis (GIOP) in postmenopausal women with inflammatory rheumatic diseases. METHOD A randomized, double-blind, placebo-controlled, parallel-group study of 140 postmenopausal women was conducted. At baseline, the mean lumbar spine (LS) (L1-L4) bone mineral density (BMD) was normal or osteopaenic (T-score ≥ -2.0) and the patients were receiving treatment with 5-15 mg/day of prednisone equivalent. Patients were randomized 1:1 to receive either monthly oral ibandronate 150 mg or placebo for 12 months. All patients received vitamin D and calcium supplements. The primary endpoint was the relative change in mean LS BMD from baseline to 12 months. RESULTS Mean LS BMD increased significantly by 2.6% and 3.2% from baseline to 6 and 12 months with ibandronate compared to 0.3% and -0.1% with placebo, respectively (p < 0.001). Comparable significant mean increases were also found in trochanter, femoral neck and total hip BMDs at 12 months. Reductions in the serum levels of bone turnover markers C-terminal telopeptide of type I collagen (sCTX), N-terminal propeptide of type I procollagen (P1NP), and tartrate-resistant acid phosphatase (TRACP) were significantly more marked in the ibandronate group than in the placebo group at 1, 6, and 12 months. Adverse events (AEs) were reported at a similar frequency in both groups. A higher proportion of serious AEs (SAEs) were reported in the ibandronate group without emergence of any single SAE. CONCLUSIONS Once-monthly oral ibandronate provides a significant increase in LS and total hip BMD with an acceptable safety profile in postmenopausal women treated with low-dose GCs for inflammatory rheumatic diseases.
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Affiliation(s)
- M Hakala
- Department of Musculoskeletal Medicine and Rehabilitation, Medical School, University of Tampere, Tampere, Finland.
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Wu L, Qi H, Zhong Y, Lv S, Yu J, Liu J, Wang L, Bi J, Kong X, Di W, Zha J, Liu F, Ding G. 11β-Hydroxysteroid dehydrogenase type 1 selective inhibitor BVT.2733 protects osteoblasts against endogenous glucocorticoid induced dysfunction. Endocr J 2013; 60:1047-58. [PMID: 23759754 DOI: 10.1507/endocrj.ej12-0376] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Pharmacologic glucocorticoids (GCs) inhibit osteoblast function and induce osteoporosis. 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) may play a role in osteoporosis as it regulates GC action at a pre-receptor level by converting inactive GC to its active form. Further, 11β-HSD1 was found increasingly expressed in bone with age. In spite of these observations, its function in senile osteoporosis remains uncertain. In this study we constructed a lentiviral vector overexpressing mouse 11β-HSD1 and then MC3T3-E1 preosteoblast cells were infected by the negative control lentivirus and 11β-HSD1-overexpressing lentivirus, respectively. The mRNA and protein levels of 11β-HSD1 were significantly increased in MC3T3-E1 cells that were infected by 11β-HSD1-overexpressing lentivirus compared to the cells infected by the negative control lentivirus. The osteogenic differentiation of MC3T3-E1 preosteoblast cells was dramatically suppressed by 11β-HSD1 overexpression under the reductase substrate dehydrocorticosterone (DHC). The inhibition effect was similar to the inhibition of osteogenesis by over-dose GCs, including ALP activity, the ultimate calcium nodus formation as well as the expression of the osteogenic genes such as ALP, BSP, OPN and OCN. However, with addition of BVT.2733, a selective inhibitor of 11β-HSD1, all of the above osteogenic repression effects by 11β-HSD1 overexpression were reversed. Furthermore, a GC receptor antagonist RU486 also showed the similar effect, preventing inhibition of osteogenesis by 11β-HSD1 overexpression. These results demonstrated that the specific 11β-HSD1 inhibitor BVT.2733 can reverse the suppression effect towards osteogenic differentiation in 11β-HSD1 overexpressed MC3T3-E1 cells. Inhibition of 11β-HSD1 can be a new therapeutic strategy for senile osteoporosis.
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Affiliation(s)
- Lin Wu
- Department of Geratology, the First Hospital Affiliated to Nanjing Medical University, Nanjing, Jiangsu Province, People's Republic of China
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14
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Li J, Wang X, Zhou C, Liu L, Wu Y, Wang D, Jiang H. Perioperative glucocorticosteroid treatment delays early healing of a mandible wound by inhibiting osteogenic differentiation. Injury 2012; 43:1284-9. [PMID: 22658419 DOI: 10.1016/j.injury.2012.04.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2011] [Revised: 04/05/2012] [Accepted: 04/16/2012] [Indexed: 02/02/2023]
Abstract
AIM The purpose of this study is to investigate the effects of dexamethasone on repair of a critical size defect of the mandible in male Sprague-Dawley rats. MATERIALS AND METHODS Fifty rats were divided into 2 groups: saline control and dexamethasone-treated groups. A 1 mm × 3 mm full-thickness bone defect was created at the inferior border of the mandible. Saline or dexamethasone was administered once a day for 5 days after postoperative palinesthesia. On days 1, 3, 6, 10 and 17, after cessation of drug administration, 5 samples from each group were analysed. The bone defect healing process was examined and analysed by stereology, radiology, histology and histochemical staining for total collagen, tartrate-resistant acid phosphatase staining for osteoclasts and immunohistochemical staining for the COX-2, RUNX2 and osteocalcin antigens. RESULTS The dexamethasone-treated rats exhibited significantly lower radiopacity properties compared to the control rats. Histological staining revealed that the osteogenic differentiation and maturation of a callus in the defect region was significantly delayed from day 1 to day 10 in the dexamethasone group after cessation of drug administration compared to the control group. Consistent with the histological data, the level of total collagen protein was significantly lower in the dexamethasone group than in the control group. However, there was no significant difference between the 2 groups at day 17. Immunohistochemical analysis of COX-2, RUNX2 and osteocalcin expression showed that, at day 1, COX-2 and RUNX2 expression in the dexamethasone group was significantly lower than in the control group. There was no significant difference in osteocalcin expression between the two groups at each time point. There was no significant difference in the number of osteoclasts between the two groups. CONCLUSION In a model of bone healing of a mandible defect, dexamethasone-treated rats exhibited impaired osteogenic differentiation and maturation due to the inhibition of COX-2, osteogenic gene, RUNX2 and collagen protein expression, which resulted in delayed bone repair. Although perioperative short-term therapy did not exhibit long-term effects on wound healing of the maxillofacial bone, the application of glucocorticoids should be cautiously considered in the clinic.
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Affiliation(s)
- Jun Li
- Department of Oral and Maxillofacial Surgery, School of Stomatology, Nanjing Medical University, Nanjing, Jiangsu 210029, PR China
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15
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Abstract
BACKGROUND Glucocorticoid-induced osteoporosis (GIO) refers to a clinical condition in which a class of corticosteroids increases the susceptibility of bones to fracture. Numerous recent studies have improved our understanding of the underlying biology of this condition, whereas data from randomized controlled trials have provided clinicians with more options for prevention of GIO. OBJECTIVE To review the pathophysiology and epidemiology of GIO, as well as current pharmacologic treatment and prevention modalities available. To review the state of healthcare provider concordance with GIO prevention guidelines. METHODS Representative examples of various cellular and molecular processes underlying GIO were included, with an emphasis towards more recent discoveries. The data used to describe the epidemiology of GIO were derived from both randomized controlled studies and observational studies, framed through a discussion of known osteoporosis risk factors. RESULTS/CONCLUSION Progress has been made in clarifying the pathophysiologic mechanisms that result in GIO. Although the options for preventions and treatment of GIO continue to expand, provider compliance with preventive measures remains suboptimal.
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Affiliation(s)
- Liron Caplan
- University of Colorado Denver, Denver Veterans Affairs Medical Center, PO Box 6511, B115, Colorado 80045, Denver, USA.
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16
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Jeong KS, Lee J, Jeong W, Noh DH, Do SH, Kim YK. Measurement of estrogen effect on bone turnover by 2H2O labeling. Calcif Tissue Int 2005; 76:365-70. [PMID: 15742235 DOI: 10.1007/s00223-004-1103-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2004] [Accepted: 10/06/2004] [Indexed: 10/25/2022]
Abstract
Estrogen loss has been known to increase bone turnover through accelerated bone resorption coupled by increased bone formation. In the present study, we measured estrogen effect on bone turnover by incorporation of 2H from 2H2O into amino acids. At 6 weeks of age, rats were either sham-operated (sham) or ovariectomized (ovx). Two weeks after surgery, 17beta-estradiol (est) was implanted subcutaneously to ovx rats. At 9 weeks of age, 2H2O labeling started by administration of 4% 2H2O to rats for 4 or 7 weeks in drinking water after a single intraperitonial bolus injection with 99.9% 2H2O. Body 2H2O enrichments were stable at approximately 3.0% over labeling period. Fractional replacements (f) of the midshaft femur were higher in the sham group (40.36 +/- 4.89% vs 42.47 +/- 11.22%) than the ovx (28.57 +/- 9.67% vs 37.47 +/- 8.34%) and est (26.57 +/- 4.00% vs 30.35 +/- 5.34%) groups 4 and 7 weeks after labeling, respectively. Ovariectomy-induced bone loss was observed in the trabecular bone along with a significantly increased number of osteoclasts, all of which were normalized after estradiol treatment. Taken together, our results indicate that estrogen deficiency significantly reduces the proportion of newly synthesized bone matrix as well as the total amount of bone matrix. The reduced portion of new matrix in ovx rats, presumably caused by activated osteoclastic degradation, was compensated rapidly with time. In addition, estradiol treatment protected the bone matrix by decreasing bone turnover rate.
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Affiliation(s)
- K S Jeong
- Department of Veterinary Pathology, College of Veterinary Medicine, Kyungpook National University, South Korea
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17
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Lee JA, Kim YK. Measurement of Age-Related Changes in Bone Matrix Using 2H 2O Labeling. Prev Nutr Food Sci 2005. [DOI: 10.3746/jfn.2005.10.1.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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18
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Centrella M, Christakos S, McCarthy TL. Skeletal hormones and the C/EBP and Runx transcription factors: interactions that integrate and redefine gene expression. Gene 2005; 342:13-24. [PMID: 15527960 DOI: 10.1016/j.gene.2004.06.036] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2004] [Revised: 05/27/2004] [Accepted: 06/17/2004] [Indexed: 11/27/2022]
Abstract
Systemic hormones and local growth factors have significant and often complex roles in normal tissue development, growth, remodeling, and repair. Early efforts in skeletal tissue attempted to define active panels of these agents and their direct effects on cell proliferation, matrix production, and secretion of other soluble mediators of differentiated cell function. Initial results resolved many of these questions and began to unveil functional interactions between specific hormones and growth factors. More recent evidence suggests that interactions between individual hormone systems also occur in less anticipated but probably not less meaningful ways. In some cases, these interactions may help to define a spectrum of effects on gene expression by focusing, refocusing, or integrating the activity of previously recognized transcription regulators. Other studies in isolated osteoblasts predict that certain steroid hormones have distinctive effects on specific transcription factors with important roles in bone growth and repair. In this review, we focus on studies that define functional and physical interactions between molecular mediators of hormone activity that could directly effect skeletal growth factor biology.
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Affiliation(s)
- Michael Centrella
- Department of Surgery, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520-8041, USA.
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19
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Sher LB, Woitge HW, Adams DJ, Gronowicz GA, Krozowski Z, Harrison JR, Kream BE. Transgenic expression of 11beta-hydroxysteroid dehydrogenase type 2 in osteoblasts reveals an anabolic role for endogenous glucocorticoids in bone. Endocrinology 2004; 145:922-9. [PMID: 14617568 DOI: 10.1210/en.2003-0655] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Glucocorticoid excess leads to bone loss, primarily by decreasing bone formation. However, a variety of in vitro models show that glucocorticoids can promote osteogenesis. To elucidate the role of endogenous glucocorticoids in bone metabolism, we developed transgenic (TG) mice in which a 2.3-kb Col1a1 promoter fragment drives 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) expression in mature osteoblasts. 11beta-HSD2 should metabolically inactivate endogenous glucocorticoids in the targeted cells, thereby reducing glucocorticoid signaling. The inhibitory effect of 300 nm hydrocortisone on percent collagen synthesis was blunted in TG calvariae, demonstrating that the transgene was active. Collagen synthesis rates were lower in TG calvarial organ cultures compared with wild-type. Trabecular bone parameters measured by microcomputed tomography were reduced in L3 vertebrae, but not femurs, of 7- and 24-wk-old TG females. These changes were also not seen in males. In addition, histomorphometry showed that osteoid surface was increased in TG female vertebrae, suggesting that mineralization may be impaired. Our data demonstrate that endogenous glucocorticoid signaling is required for normal vertebral trabecular bone volume and architecture in female mice.
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Affiliation(s)
- Lorin B Sher
- Department of Medicine, MC-1850, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 06030, USA
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20
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Ng PC, Lam CWK, Wong GWK, Lee CH, Cheng PS, Fok TF, Chan IHS, Wong E, Cheung K, Lee SY. Changes in markers of bone metabolism during dexamethasone treatment for chronic lung disease in preterm infants. Arch Dis Child Fetal Neonatal Ed 2002; 86:F49-54. [PMID: 11815549 PMCID: PMC1721351 DOI: 10.1136/fn.86.1.f49] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIM To characterise the change in serum and urinary bone markers in the early postnatal period, and to assess the effect of systemic corticosteroid on bone metabolism in preterm infants. METHODS Bone formation was quantified by measurement of serum concentrations of bone specific alkaline phosphatase (BALP) and osteocalcin. Bone resorption was measured by monitoring creatinine adjusted urinary deoxypyridinoline (Dpd) concentration. Blood and urinary samples were collected from corticosteroid treated infants (n = 19) immediately before the start (T(d-pre)), three weeks after the start (T(d-end)), and two (T(d-post2)) and four weeks (T(d-post4)) after the end of the dexamethasone course. Untreated patients (n = 30) had specimens taken at week 3 (T(wk-3)), 6 (T(wk-6)), 8 (T(wk-8)), and 10 (T(wk-10)) of postnatal age. RESULTS Serum concentrations of BALP and osteocalcin at T(d-end) were significantly lower than pretreatment levels and the levels at the corresponding time point (T(wk-6)) of the non-treatment group. In contrast, urinary Dpd concentration at T(d-end) was not significantly decreased compared with the pretreatment level. However, it was significantly lower than the urinary Dpd concentration at T(wk-6) of the non-treatment group. The rate of increase in lower leg length was significantly higher in the non-treatment group between weeks 3 and 6 than in the corresponding period during dexamethasone treatment in the corticosteroid group. CONCLUSION Systemic corticosteroid causes appreciable suppression of serum BALP and osteocalcin and, to a lesser extent, urinary Dpd. The results suggest that corticosteroid inhibits bone growth mainly by decreasing bone formation.
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Affiliation(s)
- P C Ng
- Department of Paediatrics, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong.
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21
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Walsh S, Jordan GR, Jefferiss C, Stewart K, Beresford JN. High concentrations of dexamethasone suppress the proliferation but not the differentiation or further maturation of human osteoblast precursors in vitro: relevance to glucocorticoid-induced osteoporosis. Rheumatology (Oxford) 2001; 40:74-83. [PMID: 11157145 DOI: 10.1093/rheumatology/40.1.74] [Citation(s) in RCA: 141] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVE The use of glucocorticoids (GCs) in the treatment of RA is a frequent cause of bone loss. In vitro, however, this same class of steroids has been shown to promote the recruitment and/or maturation of primitive osteogenic precursors present in the colony forming unit-fibroblastic (CFU-F) fraction of human bone and marrow. In an effort to reconcile these conflicting observations, we investigated the effects of the synthetic GC dexamethasone (Dx) on parameters of growth and osteogenic differentiation in cultures of bone marrow stromal cells derived from a large cohort of adult human donors (n=30). METHODS Marrow suspensions were cultured in the absence and presence of Dx at concentrations between 10 pm and 1 microm. After 28 days we determined the number and diameter of colonies formed, the total number of cells, the surface expression of receptors for selected growth factors and extracellular matrix proteins and, based on the expression of the developmental markers alkaline phosphatase (AP) and the antigen recognized by the STRO-1 monoclonal antibody, the proportion of cells undergoing osteogenic differentiation and their extent of maturation. RESULTS At a physiologically equivalent concentration, Dx had no effect on the adhesion of CFU-F or on their subsequent proliferation, but did promote their osteogenic differentiation and further maturation. These effects were independent of changes in the expression of the receptors for fibroblast growth factors, insulin-like growth factor 1, nerve growth factor, platelet-derived growth factors and parathyroid hormone/parathyroid hormone-related protein, but were associated with changes in the number of cells expressing the alpha(2) and alpha(4), but not beta(1), integrin subunits. At supraphysiological concentrations, the effects of Dx on the osteogenic recruitment and maturation of CFU-F and their progeny were maintained but at the expense of a decrease in cell number. CONCLUSIONS A decrease in the proliferation of osteogenic precursors, but not in their differentiation or maturation, is likely to be a key factor in the genesis of GC-induced bone loss.
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Affiliation(s)
- S Walsh
- Bone Research Group, Department of Pharmacy and Pharmacology, 7 West, University of Bath, Claverton Down, Bath BA2 7AY, UK
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22
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23
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Woitge HW, Kream BE. Calvariae from fetal mice with a disrupted Igf1 gene have reduced rates of collagen synthesis but maintain responsiveness to glucocorticoids. J Bone Miner Res 2000; 15:1956-64. [PMID: 11028448 DOI: 10.1359/jbmr.2000.15.10.1956] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The goals of this study were to examine the role of insulin-like growth factor I (IGF-I) on bone formation and to test the hypothesis that the inhibitory effects of glucocorticoids on bone formation are independent of the IGF-I pathway. In serum-free organ cultures of 18-day fetal mouse calvariae derived from Igf1 null mice (Igf1-/-) and their wild-type (Igf1+/+) and heterozygous (Igf1+/-) littermates, we measured the incorporation of [3H]proline into collagenase-digestible protein (CDP) and noncollagen protein (NCP), percent collagen synthesis (PCS), the incorporation of [3H]thymidine into DNA, and messenger RNA (mRNA) levels of osteoblast markers in the presence or absence of dexamethasone. After 24 h of culture, calvariae of all genotypes had similar levels of PCS. However, after 48-96 h of culture, PCS was significantly lower in Igf1-/- calvariae compared with Igf1+/+ calvariae. Treatment of calvariae with 100 nM of dexamethasone for 48-96 h decreased PCS in all genotypes. After 72 h of culture, [3H]thymidine incorporation was similar in all genotypes and 100 nM dexamethasone caused a significant reduction in [3H]thymidine incorporation in all genotypes. Dexamethasone at 100 nM decreased alpha1(I)-collagen (Colla1) mRNA and increased alkaline phosphatase, bone sialoprotein, and osteopontin mRNA in all genotypes after 72 h of culture. Type I IGF receptor mRNA levels were highest in Igf1-/- calvarial cultures. Dexamethasone at 100 nM increased Igf2 and type I IGF receptor mRNA levels in all genotypes. We conclude that one intact allele for Igf1 is sufficient to maintain normal rates of collagen synthesis in fetal mouse calvarial cultures. Moreover, the inhibitory effects of glucocorticoids on collagen synthesis and cell replication are at least partially independent of the IGF-I pathway in this model.
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Affiliation(s)
- H W Woitge
- Department of Medicine, University of Connecticut Health Center, Farmington 06030, USA
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24
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Abu EO, Horner A, Kusec V, Triffitt JT, Compston JE. The localization of the functional glucocorticoid receptor alpha in human bone. J Clin Endocrinol Metab 2000; 85:883-9. [PMID: 10690906 DOI: 10.1210/jcem.85.2.6365] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Glucocorticoids have well-documented effects on the skeleton, although their mechanism of action is still poorly understood. The actions of glucocorticoids on bone cells are mediated, in part, directly via specific receptors. The presence of these receptors has been demonstrated in both rodent and human osteoblastic cells in vitro, but their presence in human bone in vivo has not been reported. In this study, we have used specific affinity purified polyclonal antibodies to the functional glucocorticoid receptor alpha (GRalpha) to investigate its expression in both developing and adult human bone using sections of neonatal rib, calvarial, and vertebral bones, tibial growth plates from adolescents, and iliac crest biopsies from adults who were to undergo liver transplantation. In the tibial growth plates, GRalpha was predominantly expressed in the hypertrophic chondrocytes within the cartilage. In the primary spongiosa, the receptor was highly expressed by osteoblasts at sites of bone modeling. Within the bone marrow, receptors were also detected in mononuclear cells and in endothelial cells of blood vessels. In the neonatal rib and vertebrae, GRalpha was widely distributed at sites of endochondral bone formation in resting, proliferating, mature, and hypertrophic chondrocytes. They were also highly expressed in osteoblasts at sites of bone modeling. At sites of intramembranous ossification in neonatal calvarial bone and rib periosteum, GRa was widely expressed in cells within the fibrous tissue and in osteoblasts at both the bone-forming surface and at modeling sites. In the iliac crests from adults, GRalpha was predominantly expressed in osteocytes. The receptors were not detected in osteoclasts. Our results show for the first time the presence of the functional GRalpha in human bone in situ and suggest that the actions of glucocorticoids on bone may be mediated, in part, directly via the GR at different stages of life. The absence of receptor expression in osteoclasts also suggests that the effects of glucocorticoids on bone resorption may be mediated indirectly.
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Affiliation(s)
- E O Abu
- Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrookes Hospital, United Kingdom.
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25
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Goldstein MF, Fallon JJ, Harning R. Chronic glucocorticoid therapy-induced osteoporosis in patients with obstructive lung disease. Chest 1999; 116:1733-49. [PMID: 10593801 DOI: 10.1378/chest.116.6.1733] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Long-term glucocorticoid (GC) therapy has been instrumental in decreasing morbidity and mortality in a variety of chronic inflammatory diseases, including persistent asthma. Long-term GC therapy is also widely prescribed for COPD. One of the important and often unrecognized side effects of chronic GC therapy is secondary osteoporosis. The risk of GC-induced bone loss is roughly correlated with daily dose, duration, and total cumulative lifetime dose of GC treatment. Oral prednisone increases the risk of bone loss and fracture. High doses of inhaled GCs may also increase the risk of osteopenia/osteoporosis, but the risk appears to be less than that associated with oral GCs. Hormone replacement therapy, oral and parenteral bisphosphonates, supplemental calcium and vitamin D, calcitonin, and fluoride compounds have been used, experimentally, in the management of GC-induced bone loss. Asthma and COPD specialists are key prescribers of oral and inhaled steroids and are likely to encounter patients with significant bone loss. Despite known risk factors and the availability of reliable diagnostic tools to recognize bone loss, the opportunity to slow, reverse, and treat bone loss is often missed. We present a review of the current literature regarding the incidence, treatment, and prevention of osteopenia/osteoporosis secondary to chronic GC therapy in adult asthma and COPD patients. Guidelines are presented regarding the identification of patients at risk for developing GC-induced secondary bone loss, and therapeutic alternatives are discussed.
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26
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Gohel A, McCarthy MB, Gronowicz G. Estrogen prevents glucocorticoid-induced apoptosis in osteoblasts in vivo and in vitro. Endocrinology 1999; 140:5339-47. [PMID: 10537165 DOI: 10.1210/endo.140.11.7135] [Citation(s) in RCA: 139] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The ability of estrogen to prevent glucocorticoid-induced apoptosis in osteoblasts was studied both in vitro and in vivo. Glucocorticoid treatment for 72 h produced a dose-dependent increase in the number of apoptotic cells, determined by acridine orange/ethidium bromide staining, with a maximal response of 31+/-2% and 26+/-3% with 100 nM corticosterone in primary rat and mouse osteoblasts, respectively. Simultaneous administration of varying concentrations of 17beta-estradiol and 100 nM corticosterone decreased apoptotic osteoblasts in a dose-dependent manner, with a maximal decrease of 70% with 0.01 nM 17beta-estradiol. Terminal deoxynucleotidyltransferase-mediated deoxy-UTP-biotin nick end labeling also demonstrated glucocorticoid-induced DNA fragmentation that was inhibited by estrogen. Estrogen was shown to inhibit apoptosis induced by lipopolysaccharide treatment. As early as 6 h, Western blots demonstrated a dose-dependent decrease in the Bcl-2/Bax ratio, which reached a minimum of 0.18 in osteoblasts treated with 1000 nM corticosterone for 72 h. This reduction in Bcl-2/Bax was abolished by treating osteoblasts simultaneously with 17beta-estradiol, but not with 17alpha-estradiol. In 7-day-old mice, administration of varying concentrations of dexamethasone for 72 h resulted in a dose-dependent increase in the number of apoptotic osteoblasts as demonstrated by in situ terminal deoxynucleotidyltransferase-mediated deoxy-UTP-biotin nick end labeling staining of calvaria. A maximum of 22+/-1% apoptotic osteoblasts on the bone surface was found with 1 mg/kg BW dexamethasone compared with 2+/-1% in vehicle-treated mice. Injection of varying concentrations of 17beta-estradiol (0.5-5 mg/kg BW), but not 17alpha-estradiol, with 1 mg/kg dexamethasone produced a dose-dependent decrease in the number of apoptotic osteoblasts to 5+/-1% with 5 mg/kg 17beta-estradiol. Thus, glucocorticoid-induced apoptosis of osteoblasts may be prevented at least in part by 17beta-estradiol.
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Affiliation(s)
- A Gohel
- Division of Oral and Maxillofacial Radiology, University of Connecticut Health Center, Farmington 06032, USA
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