1
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Lu Q, Xu Y, Zhang Z, Li S, Zhang Z. Primary hypertrophic osteoarthropathy: genetics, clinical features and management. Front Endocrinol (Lausanne) 2023; 14:1235040. [PMID: 37705574 PMCID: PMC10497106 DOI: 10.3389/fendo.2023.1235040] [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] [Received: 06/05/2023] [Accepted: 07/31/2023] [Indexed: 09/15/2023] Open
Abstract
Primary hypertrophic osteoarthropathy (PHO) is a genetic disorder mainly characterized by clubbing fingers, pachydermia and periostosis. Mutations in the HPGD or SLCO2A1 gene lead to impaired prostaglandin E2 (PGE2) degradation, thus elevating PGE2 levels. The identification of the causative genes has provided a better understanding of the underlying mechanisms. PHO can be divided into three subtypes according to its pathogenic gene and inheritance patterns. The onset age, sex ratio and clinical features differ among subtypes. The synthesis and signaling pathways of PGE2 are outlined in this review. Cyclooxygenase-2 (COX-2) is the key enzyme that acts as the rate-limiting step for prostaglandin production, thus COX-2 inhibitors have been used to treat this disease. Although this treatment showed effective results, it has side effects that restrain its use. Here, we reviewed the genetics, clinical features, differential diagnosis and current treatment options of PHO according to our many years of clinical research on the disease. We also discussed probable treatment that may be an option in the future.
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Affiliation(s)
- Qi Lu
- Shanghai Clinical Research Center of Bone Disease, Department of Osteoporosis and Bone Diseases, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, China
| | - Yang Xu
- Shanghai Clinical Research Center of Bone Disease, Department of Osteoporosis and Bone Diseases, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, China
| | - Zeng Zhang
- Department of Orthopedic Surgery, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, China
| | - Shanshan Li
- Shanghai Clinical Research Center of Bone Disease, Department of Osteoporosis and Bone Diseases, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, China
| | - Zhenlin Zhang
- Shanghai Clinical Research Center of Bone Disease, Department of Osteoporosis and Bone Diseases, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, China
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2
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Puzio I, Graboś D, Bieńko M, Radzki RP, Nowakiewicz A, Kosior-Korzecka U. Camelina Oil Supplementation Improves Bone Parameters in Ovariectomized Rats. ANIMALS : AN OPEN ACCESS JOURNAL FROM MDPI 2021; 11:ani11051343. [PMID: 34065038 PMCID: PMC8150831 DOI: 10.3390/ani11051343] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 04/28/2021] [Accepted: 05/03/2021] [Indexed: 02/07/2023]
Abstract
The aim of the present study was to determine the effect of administration of Camelina sativa oil (CO) as a source of polyunsaturated fatty acids (PUFA) on bone parameters in ovariectomized rats (OVX). Overall, 40 10-week-old healthy female Wistar rats were divided into 4 groups with 10 animals in each. Rats in the control group (SHO) were subjected to a sham operation, whereas experimental rats (OVX) were ovariectomized. After a 7-day recovery period, the SHO the rats received orally 1 mL of physiological saline for the next 6 weeks. The OVX rats received orally 1 mL of physiological saline (OVX-PhS), 5 g/kg BW (OVX-CO5), or 9 g/kg BW (OVX-CO9) of camelina oil. The use of camelina oil had a significant effect on body weight, lean mass, and fat mass. The camelina oil administration suppressed the decrease in the values of some densitometric, tomographic, and mechanical parameters of femur caused by estrogen deficiency. The CO treatment increased significantly the serum level of osteocalcin and decreased the serum level of C-terminal telopeptide of type I collagen in the OVX rats. In conclusion, camelina oil exerts a positive osteotropic effect by inhibiting ovariectomy-induced adverse changes in bones. Camelina oil supplementation can be used as an efficient method for improving bone health in a disturbed state. However, further research must be carried out on other animal species supplemented with the oil.
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Affiliation(s)
- Iwona Puzio
- Department of Animal Physiology, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Akademicka St. 12, 20-950 Lublin, Poland; (D.G.); (M.B.); (R.P.R.)
- Correspondence:
| | - Dorota Graboś
- Department of Animal Physiology, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Akademicka St. 12, 20-950 Lublin, Poland; (D.G.); (M.B.); (R.P.R.)
| | - Marek Bieńko
- Department of Animal Physiology, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Akademicka St. 12, 20-950 Lublin, Poland; (D.G.); (M.B.); (R.P.R.)
| | - Radosław P. Radzki
- Department of Animal Physiology, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Akademicka St. 12, 20-950 Lublin, Poland; (D.G.); (M.B.); (R.P.R.)
| | - Aneta Nowakiewicz
- Department of Preclinical Veterinary Sciences, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Akademicka St. 12, 20-950 Lublin, Poland; (A.N.); (U.K.-K.)
| | - Urszula Kosior-Korzecka
- Department of Preclinical Veterinary Sciences, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Akademicka St. 12, 20-950 Lublin, Poland; (A.N.); (U.K.-K.)
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3
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Cheng W, Yao M, Liu F. Bitter Taste Receptor as a Therapeutic Target in Orthopaedic Disorders. Drug Des Devel Ther 2021; 15:895-903. [PMID: 33679130 PMCID: PMC7926036 DOI: 10.2147/dddt.s289614] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 02/10/2021] [Indexed: 12/11/2022] Open
Abstract
Non-gustatory, extraoral bitter taste receptors (T2Rs) are G-protein coupled receptors that are expressed throughout the body and have various functional responses when stimulated by bitter agonists. Presently, T2Rs have been found to be expressed in osteoclasts and osteocytes where osteoclasts were capable of detecting bacterial quorum-sensing molecules through the T2R38 isoform. In the innate immune system, stimulating T2Rs induces anti-inflammatory and anti-pathogenic effects through the phospholipase C/inositol triphosphate pathway, which leads to intracellular calcium release from the endoplasmic reticulum. The immune cells with functional responses to T2R activation also play a role in bone inflammation and orthopaedic disorders. Furthermore, increasing intracellular calcium levels in bone cells through T2R activation can potentially influence bone formation and resorption. With recent studies finding T2R expression in bone cells, we examine the potential of targeting this receptor to treat bone inflammation and to promote bone anabolism.
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Affiliation(s)
- Weyland Cheng
- Department of Orthopaedic Surgery, Children’s Hospital Affiliated to Zhengzhou University, Henan Children’s Hospital, Zhengzhou Children’s Hospital, Zhengzhou, Henan, People’s Republic of China
- Henan Provincial Key Laboratory of Children’s Genetics and Metabolic Diseases, Children’s Hospital Affiliated to Zhengzhou University, Henan Children’s Hospital, Zhengzhou Children’s Hospital, Zhengzhou, Henan, People’s Republic of China
| | - Manye Yao
- Department of Orthopaedic Surgery, Children’s Hospital Affiliated to Zhengzhou University, Henan Children’s Hospital, Zhengzhou Children’s Hospital, Zhengzhou, Henan, People’s Republic of China
| | - Fangna Liu
- Department of Orthopaedic Surgery, Children’s Hospital Affiliated to Zhengzhou University, Henan Children’s Hospital, Zhengzhou Children’s Hospital, Zhengzhou, Henan, People’s Republic of China
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4
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Zippelius T, Hoff P, Strube P, Schiffner R, Maslaris A, Matziolis G, Röhner E. Effects of iloprost on human mature osteoblasts in vitro. J Back Musculoskelet Rehabil 2020; 32:897-903. [PMID: 30958330 DOI: 10.3233/bmr-171043] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND AND OBJECTIVES Bone marrow oedema is a multifactorial conditioned illness. Alongside any strain relief of an affected joint, treatment with Iloprost also belongs to the choice of cures. In past studies, a modulatory effect on bone could be shown. The hypothesis of the present work is that Iloprost has a growth-stimulating effect on osteoblasts in vitro. METHODS Human osteoblasts were isolated and cultivated. Subsequently, the cells were treated with Iloprost in bioavailable concentrations. Alterations of the cell structure were examined by means of light microscopy. A regulation of the number of vital cells was carried out by using a CASY cell counter. Possible cell impairment after Iloprost treatment was analysed by means of XTT Elisa as well as FDA and PI staining via fluorescence microscopy. RESULTS Using light microscopy, no changes in cell structure could be observed. With the CASY cell counter, no increase in the numbers of osteoblasts appeared after Iloprost treatment. Also, XTT Elisas and fluorescence microscopy did not reveal any cell impairment due to Iloprost. CONCLUSION Our results could not confirm a modulatory effect in mature osteoblasts. On the basis of the present work we could not verify any growth-stimulating effect by Iloprost in mature osteoblasts in vitro. Admittedly, effects had been shown previously during osteogenesis, but we do exclude an effect on mature osteoblasts which have already differentiated.
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Affiliation(s)
- Timo Zippelius
- Orthopaedic Department of the Waldkliniken Eisenberg, Orthopaedic Professorship of the University Hospital Jena, Eisenberg, Germany
| | - Paula Hoff
- Orthopaedic Department of the Waldkliniken Eisenberg, Orthopaedic Professorship of the University Hospital Jena, Eisenberg, Germany.,Endokrinologikum Berlin, Berlin, Germany.,Department of Rheumatology and Clinical Immunology, Charité University Hospital, Berlin, Germany
| | - Patrick Strube
- Orthopaedic Department of the Waldkliniken Eisenberg, Orthopaedic Professorship of the University Hospital Jena, Eisenberg, Germany
| | - René Schiffner
- Orthopaedic Department of the Waldkliniken Eisenberg, Orthopaedic Professorship of the University Hospital Jena, Eisenberg, Germany
| | - Alexander Maslaris
- Orthopaedic Department of the Waldkliniken Eisenberg, Orthopaedic Professorship of the University Hospital Jena, Eisenberg, Germany
| | - Georg Matziolis
- Orthopaedic Department of the Waldkliniken Eisenberg, Orthopaedic Professorship of the University Hospital Jena, Eisenberg, Germany
| | - Eric Röhner
- Orthopaedic Department of the Waldkliniken Eisenberg, Orthopaedic Professorship of the University Hospital Jena, Eisenberg, Germany
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5
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Bao M, Zhang K, Wei Y, Hua W, Gao Y, Li X, Ye L. Therapeutic potentials and modulatory mechanisms of fatty acids in bone. Cell Prolif 2020; 53:e12735. [PMID: 31797479 PMCID: PMC7046483 DOI: 10.1111/cpr.12735] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 11/02/2019] [Accepted: 11/05/2019] [Indexed: 02/05/2023] Open
Abstract
Bone metabolism is a lifelong process that includes bone formation and resorption. Osteoblasts and osteoclasts are the predominant cell types associated with bone metabolism, which is facilitated by other cells such as bone marrow mesenchymal stem cells (BMMSCs), osteocytes and chondrocytes. As an important component in our daily diet, fatty acids are mainly categorized as long-chain fatty acids including polyunsaturated fatty acids (LCPUFAs), monounsaturated fatty acids (LCMUFAs), saturated fatty acids (LCSFAs), medium-/short-chain fatty acids (MCFAs/SCFAs) as well as their metabolites. Fatty acids are closely associated with bone metabolism and associated bone disorders. In this review, we summarized the important roles and potential therapeutic implications of fatty acids in multiple bone disorders, reviewed the diverse range of critical effects displayed by fatty acids on bone metabolism, and elucidated their modulatory roles and mechanisms on specific bone cell types. The evidence supporting close implications of fatty acids in bone metabolism and disorders suggests fatty acids as potential therapeutic and nutritional agents for the treatment and prevention of metabolic bone diseases.
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Affiliation(s)
- Minyue Bao
- State Key Laboratory of Oral DiseasesNational Clinical Research Center for Oral DiseasesWest China Hospital of StomatologySichuan UniversityChengduChina
| | - Kaiwen Zhang
- State Key Laboratory of Oral DiseasesNational Clinical Research Center for Oral DiseasesWest China Hospital of StomatologySichuan UniversityChengduChina
| | - Yangyini Wei
- State Key Laboratory of Oral DiseasesNational Clinical Research Center for Oral DiseasesWest China Hospital of StomatologySichuan UniversityChengduChina
| | - Weihan Hua
- State Key Laboratory of Oral DiseasesNational Clinical Research Center for Oral DiseasesWest China Hospital of StomatologySichuan UniversityChengduChina
| | - Yanzi Gao
- State Key Laboratory of Oral DiseasesNational Clinical Research Center for Oral DiseasesWest China Hospital of StomatologySichuan UniversityChengduChina
| | - Xin Li
- State Key Laboratory of Oral DiseasesNational Clinical Research Center for Oral DiseasesWest China Hospital of StomatologySichuan UniversityChengduChina
| | - Ling Ye
- State Key Laboratory of Oral DiseasesNational Clinical Research Center for Oral DiseasesWest China Hospital of StomatologySichuan UniversityChengduChina
- State Key Laboratory of Oral DiseasesNational Clinical Research Center for Oral DiseasesDepartment of Cariology and EndodonticsWest China Hospital of StomatologySichuan UniversityChengduChina
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6
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Ern C, Frasheri I, Berger T, Kirchner HG, Heym R, Hickel R, Folwaczny M. Effects of prostaglandin E 2 and D 2 on cell proliferation and osteogenic capacity of human mesenchymal stem cells. Prostaglandins Leukot Essent Fatty Acids 2019; 151:1-7. [PMID: 31589940 DOI: 10.1016/j.plefa.2019.09.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 09/11/2019] [Accepted: 09/12/2019] [Indexed: 12/19/2022]
Abstract
The manifestation of periodontitis-related inflammatory reaction is inevitably bound to the production of prostaglandins E2 and D2 which have been suggested to mediate osteoclastic and osteogenic effects within the affected tissue. We demonstrated the presence of PGE2 and PGD2 receptors on hMSCs on RNA level and with immunofluorescence. For each Prostaglandin, three concentrations were studied: 0.1; 0.5 or 1.0 µg/ml. A lower expression of EP1 and EP4 (PGE2 receptors 1 and 4) after stimulation with PGE2 was shown, thus a tendency to compromise osteogenic differentiation and metabolism. PGE2 induced a higher growth-rate during the first week, while a continuous inflammatory challenge determined a decrease of the proliferation of hMSCs. PGD2 inhibited cell growth irrespective of the duration of the stimulation. PGE2 and PGD2 have also negative effects on calcium deposition osteogenic, thus on differentiation of hMSCs. PGE2 and PGD2 seem to induce bone resorption also having indirectly a negative impact on the osteogenic differentiation of hMSCs. Thus, inhibitors of PGE2 and PGD2 can be used as adjunct to mechanical periodontal treatment.
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Affiliation(s)
- C Ern
- Department of Conservative Dentistry and Periodontology, University Hospital, LMU Munich, Goethestr. 70, Munich D-80336, Germany
| | - I Frasheri
- Department of Conservative Dentistry and Periodontology, University Hospital, LMU Munich, Goethestr. 70, Munich D-80336, Germany
| | - T Berger
- Department of Conservative Dentistry and Periodontology, University Hospital, LMU Munich, Goethestr. 70, Munich D-80336, Germany
| | - H G Kirchner
- Department of Conservative Dentistry and Periodontology, University Hospital, LMU Munich, Goethestr. 70, Munich D-80336, Germany
| | - R Heym
- Department of Conservative Dentistry and Periodontology, University Hospital, LMU Munich, Goethestr. 70, Munich D-80336, Germany
| | - R Hickel
- Department of Conservative Dentistry and Periodontology, University Hospital, LMU Munich, Goethestr. 70, Munich D-80336, Germany
| | - M Folwaczny
- Department of Conservative Dentistry and Periodontology, University Hospital, LMU Munich, Goethestr. 70, Munich D-80336, Germany.
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7
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Sheikh Z, Chen G, Al-Jaf F, Thévenin M, Banks K, Glogauer M, Young RN, Grynpas MD. In Vivo Bone Effects of a Novel Bisphosphonate-EP4a Conjugate Drug (C3) for Reversing Osteoporotic Bone Loss in an Ovariectomized Rat Model. JBMR Plus 2019; 3:e10237. [PMID: 31844825 PMCID: PMC6894726 DOI: 10.1002/jbm4.10237] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 08/15/2019] [Accepted: 09/06/2019] [Indexed: 01/30/2023] Open
Abstract
Pathological bone loss is a regular feature of postmenopausal osteoporosis, and the microstructural changes along with the bone loss make the individual prone to getting hip, spine, and wrist fractures. We have developed a new conjugate drug named C3, which has a synthetic, stable EP4 agonist (EP4a) covalently linked to an inactive alendronate (ALN) that binds to bone and allows physiological remodeling. After losing bone for 12 weeks, seven groups of rats were treated for 8 weeks via tail‐vein injection. The groups were: C3 conjugate at low and high doses, vehicle‐treated ovariectomy (OVX) and sham, C1 (a similar conjugate, but with active ALN at high dose), inactive ALN alone, and a mixture of unconjugated ALN and EP4a to evaluate the conjugation effects. Bone turnover was determined by dynamic and static histomorphometry; μCT was employed to determine bone microarchitecture; and bone mechanical properties were evaluated via biomechanical testing. Treatment with C3 significantly increased trabecular bone volume and vertebral BMD versus OVX controls. There was also significant improvement in the vertebral load‐bearing abilities and stimulation of bone formation in femurs after C3 treatment. This preclinical research revealed that C3 resulted in significant anabolic effects on trabecular bone, and EP4a and ALN conjugation components are vital to conjugate anabolic efficacy. A combined therapy using an EP4 selective agonist anabolic agent linked to an inactive ALN is presented here that produces significant anabolic effects, allows bone remodeling, and has the potential for treating postmenopausal osteoporosis or other diseases where bone strengthening would be beneficial. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Zeeshan Sheikh
- Lunenfeld-Tanenbaum Research Institute Mount Sinai Hospital Toronto Ontario Canada.,Department of Laboratory Medicine and Pathology University of Toronto Toronto Ontario Canada.,Faculty of Dentistry University of Toronto Toronto Ontario Canada.,Faculty of Dentistry Dalhousie University Halifax Nova Scotia Canada
| | - Gang Chen
- Department of Chemistry Simon Fraser University Burnaby British Columbia Canada
| | - Faik Al-Jaf
- Faculty of Dentistry University of Toronto Toronto Ontario Canada
| | - Marion Thévenin
- Department of Chemistry Simon Fraser University Burnaby British Columbia Canada
| | - Kate Banks
- Division of Comparative Medicine University of Toronto Toronto Ontario Canada.,Department of Physiology University of Toronto Toronto Ontario Canada
| | - Michael Glogauer
- Faculty of Dentistry University of Toronto Toronto Ontario Canada.,Department of Dental Oncology and Maxillofacial Prosthetics Princess Margaret Cancer Centre Toronto Ontario Canada
| | - Robert N Young
- Department of Chemistry Simon Fraser University Burnaby British Columbia Canada
| | - Marc D Grynpas
- Lunenfeld-Tanenbaum Research Institute Mount Sinai Hospital Toronto Ontario Canada.,Department of Laboratory Medicine and Pathology University of Toronto Toronto Ontario Canada.,Institute of Biomaterials and Biomedical Engineering University of Toronto Toronto Ontario Canada
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8
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Ern C, Berger T, Frasheri I, Heym R, Hickel R, Folwaczny M. Differentiation of hMSC and hPDLSC induced by PGE2 or BMP-7 in 3D models. Prostaglandins Leukot Essent Fatty Acids 2017; 122:30-37. [PMID: 28735626 DOI: 10.1016/j.plefa.2017.06.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 04/06/2017] [Accepted: 06/12/2017] [Indexed: 01/14/2023]
Abstract
Regenerative therapies of pathogenic tissue defects are gaining increasing importance in periodontology. Among others, the osteogenic effect of BMP-7 seems to play a major role in the development of teeth and alveolar bone. Human periodontal ligament stem cells (hPDLSC), as well as human mesenchymal stem cells (hMSC), show the ability to differentiate into various types of tissues. Regarding prostaglandin E2, many studies have confirmed that it is involved in the inflammation associated to periodontitis stimulating osteoclasts, which ultimately leads to resorption of tooth supporting bone. Herein, we aimed to investigate how PGE2 influences regenerative processes. The influence of PGE2 and BMP-7 on the osteogenic differentiation of hMSC and hPDLSC was determined in a 3D cell culture model using qRT-PCR, immunocytochemistry and REM. BMP-7 enhanced the expression of osteogenic markers in hMSC and lowered it in hPDLSC-TERT. BMP-7 had a lower osteogenic effect on hPDLSC-hTERT than on hMSC, while PGE2 decreases the osteogenic differentiation in both cell types, thus, inhibiting anabolic processes. Both cell types presented good proliferation and adhesion onto the scaffolds. The well-developed structural morphology and the support of osteogenic differentiation suggest that the scaffolds are potential candidate materials for bone regeneration. The positivity for Cap in hPDLSC and more in hMSC immunostaining samples indicates the initiation of neocementogenesis as part of periodontal regeneration. In conclusion, BMP7, in particular combined with MSC, seems to have a favourable application also in periodontal regeneration. Our results show that inflammation plays an important role in periodontal regeneration. PGE2 is a key mediator, which stimulates bone resorption also via a mechanism involving the inhibition of osteogenic differentiation of MSC as well as PDLSC. Therefore, regenerative approaches should always be conducted in combination with anti-inflammatory measures oriented to control inflammation.
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Affiliation(s)
- Christina Ern
- Department of Operative Dentistry and Periodontology, University Hospital, Ludwig-Maximilians-Universität München, Germany.
| | - Tamara Berger
- Department of Operative Dentistry and Periodontology, University Hospital, Ludwig-Maximilians-Universität München, Germany; Max Planck Institute of Psychiatry, Munich, Germany.
| | - Iris Frasheri
- Department of Operative Dentistry and Periodontology, University Hospital, Ludwig-Maximilians-Universität München, Germany.
| | - Richard Heym
- Department of Operative Dentistry and Periodontology, University Hospital, Ludwig-Maximilians-Universität München, Germany.
| | - Reinhard Hickel
- Department of Operative Dentistry and Periodontology, University Hospital, Ludwig-Maximilians-Universität München, Germany.
| | - Matthias Folwaczny
- Department of Operative Dentistry and Periodontology, University Hospital, Ludwig-Maximilians-Universität München, Germany.
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9
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Prostaglandin E 2 inhibits matrix mineralization by human bone marrow stromal cell-derived osteoblasts via Epac-dependent cAMP signaling. Sci Rep 2017; 7:2243. [PMID: 28533546 PMCID: PMC5440379 DOI: 10.1038/s41598-017-02650-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 04/20/2017] [Indexed: 02/06/2023] Open
Abstract
The osteoinductive properties of prostaglandin E2 (PGE2) and its signaling pathways have led to suggestions that it may serve as a potential therapeutic strategy for bone loss. However, the prominence of PGE2 as an inducer of bone formation is attributed primarily to findings from studies using rodent models. In the current study, we investigated the effects of PGE2 on human bone marrow stromal cell (hBMSC) lineage commitment and determined its mode of action. We demonstrated that PGE2 treatment of hBMSCs significantly altered the expression profile of several genes associated with osteoblast differentiation (RUNX2 and ALP) and maturation (BGLAP and MGP). This was attributed to the activation of specific PGE2 receptors, and was associated with increases in cAMP production and sustained AKT phosphorylation. Pharmacological inhibition of exchange protein directly activated by cAMP (Epac), but not protein kinase A (PKA), recovered the mineralization functions of hBMSC-derived osteoblasts treated with PGE2 and restored AKT phosphorylation, along with the expression levels of RUNX2, ALP, BGLAP and MGP. Our findings therefore provide insights into how PGE2 influences hBMSC-mediated matrix mineralization, and should be taken into account when evaluating the role of PGE2 in human bone metabolism.
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10
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van Zoelen EJ, Duarte I, Hendriks JM, van der Woning SP. TGFβ-induced switch from adipogenic to osteogenic differentiation of human mesenchymal stem cells: identification of drug targets for prevention of fat cell differentiation. Stem Cell Res Ther 2016; 7:123. [PMID: 27562730 PMCID: PMC5000485 DOI: 10.1186/s13287-016-0375-3] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 07/12/2016] [Accepted: 07/25/2016] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Patients suffering from osteoporosis show an increased number of adipocytes in their bone marrow, concomitant with a reduction in the pool of human mesenchymal stem cells (hMSCs) that are able to differentiate into osteoblasts, thus leading to suppressed osteogenesis. METHODS In order to be able to interfere with this process, we have investigated in-vitro culture conditions whereby adipogenic differentiation of hMSCs is impaired and osteogenic differentiation is promoted. By means of gene expression microarray analysis, we have investigated genes which are potential targets for prevention of fat cell differentiation. RESULTS Our data show that BMP2 promotes both adipogenic and osteogenic differentiation of hMSCs, while transforming growth factor beta (TGFβ) inhibits differentiation into both lineages. However, when cells are cultured under adipogenic differentiation conditions, which contain cAMP-enhancing agents such as IBMX of PGE2, TGFβ promotes osteogenic differentiation, while at the same time inhibiting adipogenic differentiation. Gene expression and immunoblot analysis indicated that IBMX-induced suppression of HDAC5 levels plays an important role in the inhibitory effect of TGFβ on osteogenic differentiation. By means of gene expression microarray analysis, we have investigated genes which are downregulated by TGFβ under adipogenic differentiation conditions and may therefore be potential targets for prevention of fat cell differentiation. We thus identified nine genes for which FDA-approved drugs are available. Our results show that drugs directed against the nuclear hormone receptor PPARG, the metalloproteinase ADAMTS5, and the aldo-keto reductase AKR1B10 inhibit adipogenic differentiation in a dose-dependent manner, although in contrast to TGFβ they do not appear to promote osteogenic differentiation. CONCLUSIONS The approach chosen in this study has resulted in the identification of new targets for inhibition of fat cell differentiation, which may not only be relevant for prevention of osteoporosis, but also of obesity.
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Affiliation(s)
- Everardus J van Zoelen
- Department of Cell and Applied Biology, Faculty of Science, Radboud University Nijmegen, PO Box 9010, 6500 GL, Nijmegen, The Netherlands. .,Present Address: Department of Cell and Applied Biology, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands.
| | - Isabel Duarte
- Department of Cell and Applied Biology, Faculty of Science, Radboud University Nijmegen, PO Box 9010, 6500 GL, Nijmegen, The Netherlands.,Present Address: Department of Cell and Applied Biology, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands.,Present Address: Systems Biology and Bioinformatics Laboratory (SysBioLab), University of Algarve, Faro, Portugal
| | - José M Hendriks
- Department of Cell and Applied Biology, Faculty of Science, Radboud University Nijmegen, PO Box 9010, 6500 GL, Nijmegen, The Netherlands.,Present Address: Department of Cell and Applied Biology, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands.,Present Address: Department of Physical Organic Chemistry, Radboud University Nijmegen, Nijmegen, The Netherlands
| | - Sebastian P van der Woning
- Department of Cell and Applied Biology, Faculty of Science, Radboud University Nijmegen, PO Box 9010, 6500 GL, Nijmegen, The Netherlands.,Present Address: Department of Cell and Applied Biology, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands.,Present Address: ARGENX BVBA, Technologiepark 30, B-9052, Zwijnaarde, Belgium
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11
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Hu S, Liu CC, Chen G, Willett T, Young RN, Grynpas MD. In vivo effects of two novel ALN-EP4a conjugate drugs on bone in the ovariectomized rat model for reversing postmenopausal bone loss. Osteoporos Int 2016; 27:797-808. [PMID: 26272313 DOI: 10.1007/s00198-015-3284-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 08/05/2015] [Indexed: 12/18/2022]
Abstract
UNLABELLED Two alendronate-EP4 agonist (ALN-EP4a) conjugate drugs, C1 and C2, which differ in structure by a short linker molecule, were evaluated in ovariectomized (OVX) rats for their anabolic effects. We showed that C1 led to significant anabolic effects on cortical and trabecular bone while anabolic effects associated with C2 were minimal. INTRODUCTION EP4as were covalently linked to ALN to create ALN-EP4a conjugate anabolic bone drugs, C1 and C2, which differ in structure by a short linker molecule in C1. When administered systemically, C1 and C2 are delivered to bone through targeted binding of ALN, where local hydrolytic enzymes liberate EP4a from ALN to exert anabolic effects. Here, we compare effects of C1 to C2 in a curative in vivo study. METHODS Three-month-old female Sprague Dawley rats were OVX or sham operated and allowed to lose bone for 3 months. Animals were then treated via tail vein injections for 3 months and sacrificed. Treatment groups were as follows: C1L (5 mg/kg biweekly), C1H (5 mg/kg weekly), C2L (15 mg/kg monthly), C2H (15 mg/kg biweekly), OVX and sham control (phosphate-buffered saline (PBS) biweekly), and ALN/EP4a-unconjugated mixture (0.75 mg/kg each biweekly). RESULTS MicroCT analysis showed that C1H treatment significantly increased vertebral bone mineral density (vBMD) and trabecular bone volume versus OVX controls while C2 treatments did not. Biomechanical testing showed that C1H treatment but not C2 treatments led to significant improvement in the load bearing abilities of the vertebrae compared to OVX controls. C1 stimulated endocortical bone formation and increased load bearing in femurs, while C2 did not. CONCLUSIONS We showed that C1 led to significant anabolic effects on cortical and trabecular bone while anabolic effects associated with C2 were minimal. These results led us to hypothesize a mode of action by which presence of a linker is crucial in facilitating the anabolic effects of EP4a when dosed as a prodrug with ALN.
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MESH Headings
- Alendronate/therapeutic use
- Animals
- Bone Density/drug effects
- Bone Density Conservation Agents/therapeutic use
- Bone Remodeling/drug effects
- Disease Models, Animal
- Drug Combinations
- Drug Evaluation, Preclinical/methods
- Female
- Humans
- Lumbar Vertebrae/drug effects
- Lumbar Vertebrae/physiopathology
- Osteoporosis, Postmenopausal/drug therapy
- Osteoporosis, Postmenopausal/physiopathology
- Ovariectomy
- Rats, Sprague-Dawley
- Receptors, Prostaglandin E, EP4 Subtype/agonists
- Receptors, Prostaglandin E, EP4 Subtype/chemistry
- Receptors, Prostaglandin E, EP4 Subtype/therapeutic use
- Structure-Activity Relationship
- Weight-Bearing/physiology
- X-Ray Microtomography/methods
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Affiliation(s)
- S Hu
- Department of Laboratory Medicine and Pathology, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada
| | - C C Liu
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, M5S 3G9, Canada
| | - G Chen
- Department of Chemistry, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada
| | - T Willett
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, M5S 3G9, Canada
| | - R N Young
- Department of Chemistry, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada
| | - M D Grynpas
- Department of Laboratory Medicine and Pathology, University of Toronto, Toronto, ON, M5S 1A8, Canada.
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada.
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, M5S 3G9, Canada.
- , 25 Orde St., Suite 417, Toronto, ON, M5T 3H7, Canada.
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12
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Gao C, Fu Y, Li Y, Zhang X, Zhang L, Yu F, Xu SS, Xu Q, Zhu Y, Guan Y, Wang X, Kong W. Microsomal Prostaglandin E Synthase-1-Derived PGE2 Inhibits Vascular Smooth Muscle Cell Calcification. Arterioscler Thromb Vasc Biol 2015; 36:108-21. [PMID: 26543101 DOI: 10.1161/atvbaha.115.306642] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2015] [Accepted: 10/15/2015] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Chronic administration of selective cyclooxygenase-2 (COX-2) inhibitors leads to an increased risk of adverse cardiovascular events, including myocardial infarction and stroke. Vascular smooth muscle cell (VSMC) calcification, a common complication of chronic kidney disease, is directly related to cardiovascular morbidity and mortality. Here, we tested whether specific COX-2 inhibition affects vascular calcification during chronic renal failure. APPROACH AND RESULTS The COX-2-specific inhibitors NS398 and SC236 significantly increased high-phosphate (Pi)-induced VSMC calcification. Similarly, COX-2(-/-) VSMCs, COX-2(-/-) aortas rings treated with high Pi and adenine diet-induced COX-2(-/-) chronic renal failure mice displayed enhanced calcium deposition. Metabolomic analysis revealed the differential suppression of PGE2 production by COX-1- and COX-2-specific inhibitors in high-Pi-stimulated VSMCs, indicating the involvement of PGE2 during COX-2 inhibition-aggravated vascular calcification. Indeed, exogenous PGE2 reduced alkaline phosphatase activity, osteogenic transdifferentiation, apoptosis, and calcification of VSMCs. In accordance, downregulation of microsomal prostaglandin E synthase (mPGES)-1 in VSMCs, mPGES-1(-/-) aorta with high-Pi stimulation and mPGES-1(-/-) chronic renal failure mice resulted in enhanced vascular mineralization. Further applications of RNAi and specific antagonists for PGE2 receptors indicated EP4 may mediate PGE2-inhibited vascular calcification. CONCLUSIONS Our data revealed the pivotal role of COX-2-mPGES-1-PGE2 axis in vascular calcification. The selective inhibition of COX-2 or mPGES-1 may increase the risk of calcification and subsequent adverse cardiovascular events during chronic renal failure.
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Affiliation(s)
- Cheng Gao
- From the Department of Physiology and Pathophysiology (C.G., Y.F., X.Z., L.Z., F.Y., Y.Z., Y.G., X.W., W.K.) and Institute of Cardiovascular Sciences (Y.L.), School of Basic Medical Sciences, Peking University, Beijing, P.R. China; Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, P.R. China (C.G., Y.F., Y.L., X.Z., L.Z., F.Y., Y.Z., Y.G., X.W., W.K.); Gonville and Caius College, University of Cambridge, Cambridge, United Kingdom (S.S.X.); and Cardiovascular Division, King's College London BHF Centre, London, United Kingdom (Q.X.)
| | - Yi Fu
- From the Department of Physiology and Pathophysiology (C.G., Y.F., X.Z., L.Z., F.Y., Y.Z., Y.G., X.W., W.K.) and Institute of Cardiovascular Sciences (Y.L.), School of Basic Medical Sciences, Peking University, Beijing, P.R. China; Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing, P.R. China (C.G., Y.F., Y.L., X.Z., L.Z., F.Y., Y.Z., Y.G., X.W., W.K.); Gonville and Caius College, University of Cambridge, Cambridge, United Kingdom (S.S.X.); and Cardiovascular Division, King's College London BHF Centre, London, United Kingdom (Q.X.)
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13
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Riquelme MA, Burra S, Kar R, Lampe PD, Jiang JX. Mitogen-activated Protein Kinase (MAPK) Activated by Prostaglandin E2 Phosphorylates Connexin 43 and Closes Osteocytic Hemichannels in Response to Continuous Flow Shear Stress. J Biol Chem 2015; 290:28321-28328. [PMID: 26442583 DOI: 10.1074/jbc.m115.683417] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Indexed: 01/04/2023] Open
Abstract
Cx43 hemichannels serve as a portal for the release of prostaglandins, a critical process in mediating biological responses of mechanical loading on bone formation and remodeling. We have previously observed that fluid flow shear stress (FFSS) opens hemichannels; however, sustained FFSS results in hemichannel closure, as continuous opening of hemichannels is detrimental to cell viability and bone remodeling. However, the mechanism that regulates the closure of the hemichannels is unknown. Here, we show that activation of p44/42 ERK upon continuous FFSS leads to Cx43 phosphorylation at Ser(279)-Ser(282), sites known to be phosphorylated sites by p44/42 MAPK. Incubation of osteocytic MLO-Y4 cells with conditioned media (CM) collected after continuous FFSS increased MAPK-dependent phosphorylation of Cx43. CM treatment inhibited hemichannel opening and this inhibition was reversed when cells were pretreated with the MAPK pathway inhibitor. We found that prostaglandin E2 (PGE2) accumulates in the CM in a time-dependent manner. Treatment with PGE2 increased phospho-p44/42 ERK levels and also Cx43 phosphorylation at Ser(279)-Ser(282) sites. Depletion of PGE2 from CM, and pre-treatment with a p44/42 ERK pathway-specific inhibitor, resulted in a complete inhibition of ERK-dependent Cx43 phosphorylation and attenuated the inhibition of hemichannels by CM and PGE2. Consistently, the opening of hemichannels by FFSS was blocked by PGE2 and CM and this blockage was reversed by U0126 and the CM depleted of PGE2. A similar observation was also obtained in isolated primary osteocytes. Together, results from this study suggest that extracellular PGE2 accumulated after continuous FFSS is responsible for activation of p44/42 ERK signaling and subsequently, direct Cx43 phosphorylation by activated ERK leads to hemichannel closure.
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Affiliation(s)
- Manuel A Riquelme
- Department of Biochemistry, University of Texas Health Science Center, San Antonio, Texas 78229-3900
| | - Sirisha Burra
- Department of Biochemistry, University of Texas Health Science Center, San Antonio, Texas 78229-3900
| | - Rekha Kar
- Department of Biochemistry, University of Texas Health Science Center, San Antonio, Texas 78229-3900
| | - Paul D Lampe
- Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109
| | - Jean X Jiang
- Department of Biochemistry, University of Texas Health Science Center, San Antonio, Texas 78229-3900.
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Huang KC, Huang TW, Yang TY, Lee MS. Chronic NSAIDs Use Increases the Risk of a Second Hip Fracture in Patients After Hip Fracture Surgery: Evidence From a STROBE-Compliant Population-Based Study. Medicine (Baltimore) 2015; 94:e1566. [PMID: 26402817 PMCID: PMC4635757 DOI: 10.1097/md.0000000000001566] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Nonsteroidal anti-inflammatory drugs (NSAIDs) control musculoskeletal pain, but they also cause adverse side effects. The aim of this study is to explore the impact of chronic NSAIDs use on the risk of a second hip fracture (SHFx) after hip fracture surgery. This population-based case-cohort study used the Taiwan National Health Insurance Research Database (NHIRD), which contains data from >99% of the population. From a random sample of 1 million enrollees, we identified 34,725 patients ≥40 years who sustained a first hip fracture and underwent hip fracture surgery between 1999 and 2009. Chronic NSAIDs use is defined as taking NSAIDs for at least 14 days a month for at least 3 months. The main outcome measure is an SHFx. Propensity-score matching was used to control for confounding. Our results revealed that chronic NSAIDs use was a significant risk factor for an SHFx in patients after hip fracture surgery and for adverse side effects that might last for 12 months. Compared with the nonchronic-use cohort (n = 29,764), the adjusted hazard ratio of an SHFx was 2.15 (95% CI: 2.07-2.33) for the chronic-use cohort (n = 4961). The 10-year Kaplan-Meier survival analyses showed that chronic NSAIDs use presented a positive year-postsurgery-dependency effect on the risk of an SHFx in all the selected subgroups of patients (all P ≤ 0.011). In conclusion, chronic NSAIDs use increases the risk of an SHFx after hip fracture surgery. Avoiding chronic NSAIDs use must be emphasized in clinical practice.
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Affiliation(s)
- Kuo-Chin Huang
- From the College of Medicine, Chang Gung University, Taoyuan, Taiwan (KCH, TWH, MSL); Department of Orthopaedic Surgery, Chang Gung Memorial Hospital, Chiayi, Taiwan (KCH, TWH, TYY); and Department of Orthopaedic Surgery, Chang Gung Memorial Hospital, Kaohsiung, Taiwan (MSL)
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15
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Liu CC, Hu S, Chen G, Georgiou J, Arns S, Kumar NS, Young RN, Grynpas MD. Novel EP4 receptor agonist-bisphosphonate conjugate drug (C1) promotes bone formation and improves vertebral mechanical properties in the ovariectomized rat model of postmenopausal bone loss. J Bone Miner Res 2015; 30:670-80. [PMID: 25284325 DOI: 10.1002/jbmr.2382] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 08/29/2014] [Accepted: 09/11/2014] [Indexed: 11/12/2022]
Abstract
Current treatments for postmenopausal osteoporosis aim to either promote bone formation or inhibit bone resorption. The C1 conjugate drug represents a new treatment approach by chemically linking the antiresorptive compound alendronate (ALN) with the anabolic agent prostanoid EP4 receptor agonist (EP4a) through a linker molecule (LK) to form a conjugate compound. This enables the bone-targeting ability of ALN to deliver EP4a to bone sites and mitigate the systemic side effects of EP4a, while also facilitating dual antiresorptive and anabolic effects. In vivo hydrolysis is required to release the EP4a and ALN components for pharmacological activity. Our study investigated the in vivo efficacy of this drug in treating established bone loss using an ovariectomized (OVX) rat model of postmenopausal osteopenia. In a curative experiment, 3-month-old female Sprague-Dawley rats were OVX, allowed to lose bone for 7 weeks, then treated for 6 weeks. Treatment groups consisted of C1 conjugate at low and high doses, vehicle-treated OVX and sham, prostaglandin E2 (PGE2 ), and mixture of unconjugated ALN-LK and EP4a to assess the effect of conjugation. Results showed that weekly administration of C1 conjugate dose-dependently increased bone volume in trabecular bone, which partially or completely reversed OVX-induced bone loss in the lumbar vertebra and improved vertebral mechanical strength. The conjugate also dose-dependently stimulated endocortical woven bone formation and intracortical resorption in cortical bone, with high-dose treatment increasing the mechanical strength but compromising the material properties. Conjugation between the EP4a and ALN-LK components was crucial to the drug's anabolic efficacy. To our knowledge, the C1 conjugate represents the first time that a combined therapy using an anabolic agent and the antiresorptive compound ALN has shown significant anabolic effects which reversed established osteopenia.
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Affiliation(s)
- Careesa C Liu
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
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16
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Choudhary S, Canalis E, Estus T, Adams D, Pilbeam C. Cyclooxygenase-2 suppresses the anabolic response to PTH infusion in mice. PLoS One 2015; 10:e0120164. [PMID: 25781979 PMCID: PMC4363701 DOI: 10.1371/journal.pone.0120164] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 02/03/2015] [Indexed: 11/29/2022] Open
Abstract
We previously reported that the ability of continuously elevated PTH to stimulate osteoblastic differentiation in bone marrow stromal cell cultures was abrogated by an osteoclastic factor secreted in response to cyclooxygenase-2 (Cox2)-produced prostaglandin E2. We now examine the impact of Cox2 (Ptgs2) knockout (KO) on the anabolic response to continuously elevated PTH in vivo. PTH (40 μg/kg/d) or vehicle was infused for 12 or 21 days in 3-mo-old male wild type (WT) and KO mice in the outbred CD-1 background. Changes in bone phenotype were assessed by bone mineral density (BMD), μCT and histomorphometry. PTH infusion for both 12 and 21 days increased femoral BMD in Cox2 KO mice and decreased BMD in WT mice. Femoral and vertebral trabecular bone volume fractions were increased in KO mice, but not in WT mice, by PTH infusion. In the femoral diaphysis, PTH infusion increased cortical area in Cox2 KO, but not WT, femurs. PTH infusion markedly increased trabecular bone formation rate in the femur, serum markers of bone formation, and expression of bone formation-related genes, growth factors, and Wnt target genes in KO mice relative to WT mice, and decreased gene expression of Wnt antagonists only in KO mice. In contrast to the differential effects of PTH on anabolic factors in WT and KO mice, PTH infusion increased serum markers of resorption, expression of resorption-related genes, and the percent bone surface covered by osteoclasts similarly in both WT and KO mice. We conclude that Cox2 inhibits the anabolic, but not the catabolic, effects of continuous PTH. These data suggest that the bone loss with continuously infused PTH in mice is due largely to suppression of bone formation and that this suppression is mediated by Cox2.
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Affiliation(s)
- Shilpa Choudhary
- New England Musculoskeletal Institute, University of Connecticut Health Center, Farmington, Connecticut, United States of America
- Department of Medicine, University of Connecticut Health Center, Farmington, Connecticut, United States of America
| | - Ernesto Canalis
- New England Musculoskeletal Institute, University of Connecticut Health Center, Farmington, Connecticut, United States of America
| | - Thomas Estus
- New England Musculoskeletal Institute, University of Connecticut Health Center, Farmington, Connecticut, United States of America
| | - Douglas Adams
- New England Musculoskeletal Institute, University of Connecticut Health Center, Farmington, Connecticut, United States of America
| | - Carol Pilbeam
- New England Musculoskeletal Institute, University of Connecticut Health Center, Farmington, Connecticut, United States of America
- Department of Medicine, University of Connecticut Health Center, Farmington, Connecticut, United States of America
- * E-mail:
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Hardaway AL, Herroon MK, Rajagurubandara E, Podgorski I. Bone marrow fat: linking adipocyte-induced inflammation with skeletal metastases. Cancer Metastasis Rev 2014; 33:527-43. [PMID: 24398857 PMCID: PMC4154371 DOI: 10.1007/s10555-013-9484-y] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Adipocytes are important but underappreciated components of bone marrow microenvironment, and their numbers greatly increase with age, obesity, and associated metabolic pathologies. Age and obesity are also significant risk factors for development of metastatic prostate cancer. Adipocytes are metabolically active cells that secrete adipokines, growth factors, and inflammatory mediators; influence behavior and function of neighboring cells; and have a potential to disturb local milleu and dysregulate normal bone homeostasis. Increased marrow adiposity has been linked to bone marrow inflammation and osteoporosis of the bone, but its effects on growth and progression of prostate tumors that have metastasized to the skeleton are currently not known. This review focuses on fat-bone relationship in a context of normal bone homeostasis and metastatic tumor growth in bone. We discuss effects of marrow fat cells on bone metabolism, hematopoiesis, and inflammation. Special attention is given to CCL2- and COX-2-driven pathways and their potential as therapeutic targets for bone metastatic disease.
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Affiliation(s)
- Aimalie L. Hardaway
- Department of Pharmacology, Wayne State University School of, Medicine, 540 E. Canfield, Rm 6304, Detroit, MI 48201, USA
- Karmanos Cancer Institute, Wayne State University School of, Medicine, Detroit, MI 48201, USA
| | - Mackenzie K. Herroon
- Department of Pharmacology, Wayne State University School of, Medicine, 540 E. Canfield, Rm 6304, Detroit, MI 48201, USA
| | - Erandi Rajagurubandara
- Department of Pharmacology, Wayne State University School of, Medicine, 540 E. Canfield, Rm 6304, Detroit, MI 48201, USA
| | - Izabela Podgorski
- Department of Pharmacology, Wayne State University School of, Medicine, 540 E. Canfield, Rm 6304, Detroit, MI 48201, USA
- Karmanos Cancer Institute, Wayne State University School of, Medicine, Detroit, MI 48201, USA
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Allard-Chamard H, Dufort P, Haroun S, de Brum-Fernandes AJ. Cytosolic phospholipase A2 and eicosanoids modulate life, death and function of human osteoclasts in vitro. Prostaglandins Leukot Essent Fatty Acids 2014; 90:117-23. [PMID: 24508380 DOI: 10.1016/j.plefa.2013.12.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Revised: 12/16/2013] [Accepted: 12/17/2013] [Indexed: 11/18/2022]
Abstract
INTRODUCTION Eicosanoids are important in bone physiology but the specific function of phopholipase enzymes has not been determined in osteoclasts. The objective of this is study was to determine the presence of cPLA2 in human in vitro-differentiated osteoclasts as well as osteoclasts in situ from bone biopsies. MATERIALS AND METHODS Osteoclastogenesis, apoptosis, bone resorption and the modulation of actin cytoskeleton assays were performed on osteoclasts differentiated in vitro. Immunohistochemistry was done in differentiated osteoclasts as well as on bone biopsies. RESULTS Human osteoclasts from normal, fetal, osteoarthritic, osteoporotic and Pagetic bone biopsies express cPLA2 and stimulation with RANKL increases cPLA2 phosphorylation in vitro. Inhibition of cPLA2 increased osteoclastogenesis and decreased apoptosis but decreased the capacity of osteoclasts to generate actin rings and to resorb bone. DISCUSSION AND CONCLUSIONS These results suggest that cPLA2 modulates osteoclast functions and could be a useful target in bone diseases with hyperactivated osteoclasts.
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Affiliation(s)
- Hugues Allard-Chamard
- Division of Rheumatology, Faculté de médecine et des sciences de la santé de l' Université de Sherbrooke et Centre de Recherche Clinique Étienne-Le Bel, Sherbrooke, Québec, Canada.
| | - Philippe Dufort
- Division of Rheumatology, Faculté de médecine et des sciences de la santé de l' Université de Sherbrooke et Centre de Recherche Clinique Étienne-Le Bel, Sherbrooke, Québec, Canada.
| | - Sonia Haroun
- Division of Rheumatology, Faculté de médecine et des sciences de la santé de l' Université de Sherbrooke et Centre de Recherche Clinique Étienne-Le Bel, Sherbrooke, Québec, Canada.
| | - Artur J de Brum-Fernandes
- Division of Rheumatology, Faculté de médecine et des sciences de la santé de l' Université de Sherbrooke et Centre de Recherche Clinique Étienne-Le Bel, Sherbrooke, Québec, Canada.
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19
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Gong X, Yang W, Wang L, Duncan RL, Pan J. Prostaglandin E2 modulates F-actin stress fiber in FSS-stimulated MC3T3-E1 cells in a PKA-dependent manner. Acta Biochim Biophys Sin (Shanghai) 2014; 46:40-7. [PMID: 24296051 DOI: 10.1093/abbs/gmt126] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The effect of prostaglandin E2 (PGE2) on bone mass has been well-established in vivo. Previous studies have showed that PGE2 increases differentiation, proliferation, and regulates cell morphology through F-actin stress fiber in statically cultured osteoblasts. However, the effect of PGE2 on osteoblasts in the presence of fluid shear stress (FSS), which could better uncover the anabolic effect of PGE2 in vivo, has yet to be examined. Here, we hypothesized that PGE2 modulates F-actin stress fiber in FSS-stimulated MC3T3-E1 osteoblastic cells through protein kinase A (PKA) pathway. Furthermore, this PGE2-induced F-actin remodeling was associated with the recovery of cellular mechanosensitivity. Our data showed that treatment with 10 nM dmPGE2 for 15 min significantly suppressed the F-actin stress fiber intensity in FSS-stimulated cells in a PKA-dependent manner. In addition, dmPGE2 treatment enhanced the cells' calcium peak magnitude and the percentage of responding cells in the second FSS stimulation, though these effects were abolished and attenuated by co-treatment with phalloidin. Our results demonstrated that 10 nM dmPGE2 was able to accelerate the 'reset' process of F-actin stress fiber to its pre-stimulated level partially through PKA pathway, and thus promoted the recovery of cellular mechanosensitivity. Our finding provided a novel cellular mechanism by which PGE2 increased bone formation as shown in vivo, suggesting that PGE2 could be a potential target for treatments of bone formation-related diseases.
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Affiliation(s)
- Xiaoyuan Gong
- Key Laboratory for Biorheological Science and Technology of Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044, China
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20
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Marenzana M, Arnett TR. The Key Role of the Blood Supply to Bone. Bone Res 2013; 1:203-15. [PMID: 26273504 DOI: 10.4248/br201303001] [Citation(s) in RCA: 197] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Accepted: 07/22/2013] [Indexed: 12/16/2022] Open
Abstract
The importance of the vascular supply for bone is well-known to orthopaedists but is still rather overlooked within the wider field of skeletal research. Blood supplies oxygen, nutrients and regulatory factors to tissues, as well as removing metabolic waste products such as carbon dioxide and acid. Bone receives up to about 10% of cardiac output, and this blood supply permits a much higher degree of cellularity, remodelling and repair than is possible in cartilage, which is avascular. The blood supply to bone is delivered to the endosteal cavity by nutrient arteries, then flows through marrow sinusoids before exiting via numerous small vessels that ramify through the cortex. The marrow cavity affords a range of vascular niches that are thought to regulate the growth and differentiation of hematopoietic and stromal cells, in part via gradients of oxygen tension. The quality of vascular supply to bone tends to decline with age and may be compromised in common pathological settings, including diabetes, anaemias, chronic airway diseases and immobility, as well as by tumours. Reductions in vascular supply are associated with bone loss. This may be due in part to the direct effects of hypoxia, which blocks osteoblast function and bone formation but causes reciprocal increases in osteoclastogenesis and bone resorption. Common regulatory factors such as parathyroid hormone or nitrates, both of which are potent vasodilators, might exert their osteogenic effects on bone via the vasculature. These observations suggest that the bone vasculature will be a fruitful area for future research.
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Affiliation(s)
- Massimo Marenzana
- Department of Bioengineering, Imperial College London and Kennedy Institute of Rheumatology, University of Oxford , UK
| | - Timothy R Arnett
- Department of Cell and Developmental Biology, University College London , UK
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22
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Choudhary S, Blackwell K, Voznesensky O, Roy AD, Pilbeam C. Prostaglandin E2 acts via bone marrow macrophages to block PTH-stimulated osteoblast differentiation in vitro. Bone 2013; 56:31-41. [PMID: 23639875 PMCID: PMC4073290 DOI: 10.1016/j.bone.2013.04.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 04/19/2013] [Accepted: 04/20/2013] [Indexed: 12/26/2022]
Abstract
Intermittent PTH is the major anabolic therapy for osteoporosis while continuous PTH causes bone loss. PTH acts on the osteoblast (OB) lineage to regulate bone resorption and formation. PTH also induces cyclooxygenase-2 (COX-2), producing prostaglandin E2 (PGE(2)) that can act on both OBs and osteoclasts (OCs). Because intermittent PTH is more anabolic in Cox-2 knockout (KO) than wild type (WT) mice, we hypothesized COX-2 might contribute to the effects of continuous PTH by suppressing PTH-stimulated differentiation of mesenchymal stem cells into OBs. We compared effects of continuous PTH on bone marrow stromal cells (BMSCs) and primary OBs (POBs) from Cox-2 KO mice, mice with deletion of PGE(2) receptors (Ptger(4) and Ptger(2) KO mice), and WT controls. PTH increased OB differentiation in BMSCs only in the absence of COX-2 expression or activity. In the absence of COX-2, PTH stimulated differentiation if added during the first week of culture. In Cox-2 KO BMSCs, PTH-stimulated differentiation was prevented by adding PGE(2) to cultures. Co-culture of POBs with M-CSF-expanded bone marrow macrophages (BMMs) showed that the inhibition of PTH-stimulated OB differentiation required not only COX-2 or PGE(2) but also BMMs. Sufficient PGE(2) to mediate the inhibitory effect was made by either WT POBs or WT BMMs. The inhibitory effect mediated by COX-2/PGE(2) was transferred by conditioned media from RANKL-treated BMMs and could be blocked by osteoprotegerin, which interferes with RANKL binding to its receptor on OC lineage cells. Deletion of Ptger(4), but not Ptger(2), in BMMs prevented the inhibition of PTH-stimulated OB differentiation. As expected, PGE(2) also stimulated OB differentiation, but when given in combination with PTH, the stimulatory effects of both were abrogated. These data suggest that PGE(2), acting via EP4R on BMMs committed to the OC lineage, stimulated secretion of a factor or factors that acted to suppress PTH-stimulated OB differentiation. This suppression of OB differentiation could contribute to the bone loss seen with continuous PTH in vivo.
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MESH Headings
- Adipogenesis/drug effects
- Adipogenesis/genetics
- Animals
- Bone Marrow Cells/cytology
- Bone Marrow Cells/drug effects
- Bone Marrow Cells/metabolism
- Cattle
- Cell Differentiation/drug effects
- Cell Differentiation/genetics
- Cells, Cultured
- Culture Media, Conditioned/pharmacology
- Cyclooxygenase 2/metabolism
- Dinoprostone/pharmacology
- Gene Expression Regulation/drug effects
- Hematopoietic System/cytology
- Macrophages/cytology
- Macrophages/drug effects
- Macrophages/metabolism
- Mice
- Mice, Knockout
- Osteoblasts/cytology
- Osteoblasts/drug effects
- Osteoblasts/enzymology
- Osteocalcin/genetics
- Osteocalcin/metabolism
- Parathyroid Hormone/pharmacology
- RANK Ligand/pharmacology
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Prostaglandin E, EP2 Subtype/deficiency
- Receptors, Prostaglandin E, EP2 Subtype/metabolism
- Receptors, Prostaglandin E, EP4 Subtype/deficiency
- Receptors, Prostaglandin E, EP4 Subtype/metabolism
- Stromal Cells/cytology
- Stromal Cells/drug effects
- Stromal Cells/enzymology
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Affiliation(s)
| | | | | | | | - Carol Pilbeam
- Corresponding author at: University of Connecticut Health Center, 263 Farmington Avenue, MC5456, Farmington, CT 06030, USA. Fax: +1 860 679 1932. (C. Pilbeam)
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23
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The growing role of eicosanoids in tissue regeneration, repair, and wound healing. Prostaglandins Other Lipid Mediat 2013; 104-105:130-8. [PMID: 23727457 DOI: 10.1016/j.prostaglandins.2013.05.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2013] [Revised: 04/14/2013] [Accepted: 05/08/2013] [Indexed: 11/21/2022]
Abstract
Tissue repair and regeneration are essential processes in maintaining tissue homeostasis, especially in response to injury or stress. Eicosanoids are ubiquitous mediators of cell proliferation, differentiation, and angiogenesis, all of which are important for tissue growth. Eicosanoids regulate the induction and resolution of inflammation that accompany the tissue response to injury. In this review, we describe how this diverse group of molecules is a key regulator of tissue repair and regeneration in multiple organ systems and biologic contexts.
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24
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Shinozaki Y, Yanagi T, Yamaguchi Y, Kido H, Fukushima T. Osteogenic Evaluation of DNA/Protamine Complex Paste in Rat Cranial Defects. J HARD TISSUE BIOL 2013. [DOI: 10.2485/jhtb.22.401] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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25
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Le P, Kawai M, Bornstein S, DeMambro VE, Horowitz MC, Rosen CJ. A high-fat diet induces bone loss in mice lacking the Alox5 gene. Endocrinology 2012; 153:6-16. [PMID: 22128029 PMCID: PMC3249675 DOI: 10.1210/en.2011-0082] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
5-Lipoxygenase catalyzes leukotriene generation from arachidonic acid. The gene that encodes 5-lipoxygenase, Alox5, has been identified in genome-wide association and mouse Quantitative Trait Locus studies as a candidate gene for obesity and low bone mass. Thus, we tested the hypothesis that Alox5(-/-) mice would exhibit metabolic and skeletal changes when challenged by a high-fat diet (HFD). On a regular diet, Alox5(-/-) mice did not differ in total body weight, percent fat mass, or bone mineral density compared with wild-type (WT) controls (P < 0.05). However, when placed on a HFD, Alox5(-/-) gained more fat mass and lost greater areal bone mass vs. WT (P < 0.05). Microarchitectural analyses revealed that on a HFD, WT showed increases in cortical area (P < 0.01) and trabecular thickness (P < 0.01), whereas Alox5(-/-) showed no change in cortical parameters but a decrease in trabecular number (P < 0.05) and bone volume fraction compared with WT controls (P < 0.05). By histomorphometry, a HFD did not change bone formation rates of either strain but produced an increase in osteoclast number per bone perimeter in Alox5(-/-) mice (P < 0.03). In vitro, osteoclastogenesis of marrow stromal cells was enhanced in mutant but not WT mice fed a HFD. Gene expression for Rankl, Pparg, and Cox-2 was greater in the femur of Alox5(-/-) than WT mice on a HFD (P < 0.01), but these increases were suppressed in the Alox5(-/-) mice after 8 wk of treatment with celecoxib, a cyclooxygenase-2 inhibitor. In sum, there is a strong gene by environmental interaction for bone mass when mice lacking the Alox5 gene are fed a HFD.
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Affiliation(s)
- Phuong Le
- Center for Clinical and Translational Research, Maine Medical Center Research Institute, 81 Research Drive, Scarborough, Maine 04074-7205, USA
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26
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Di Francesco S, Castellan P, Manco R, Tenaglia RL. Reciprocal cross-talk between Prostaglandin E2 and bone in prostate cancer: a current review. Cent European J Urol 2011; 64:201-4. [PMID: 24578893 PMCID: PMC3921745 DOI: 10.5173/ceju.2011.04.art2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Revised: 08/10/2011] [Accepted: 08/16/2011] [Indexed: 01/08/2023] Open
Abstract
In this review we analyzed the role of PGE2 as a possible regulator of bone metabolism and bone metastases in prostate cancer. Published studies were identified by searching computerized bibliographic systems from January 1st, 2000 to July 1st, 2011. PGE2 represents a key factor in the modulation of bone metabolism and bone metastatic disease in prostate cancer interacting with bone regulatory signals including the RANK/RANKL/OPG system and Wnt pathways. A high concentration of PGE2 exerts a prevalent stimulatory effect on osteoclastogenesis via OPG/RANK/RANKL axis activation and a inhibitory effect on osteoblastogenesis trough inhibition of Wnt pathway. An inversely low level of PGE2 exerts a stimulatory effect on osteoblastogenesis via activation of the Wnt pathway. Our finding suggests that PGE2 acts as a regulator in maintaining normal bone mass and indicate a mechanism whereby chemical manipulation of PGE2 levels or signaling may be therapeutically beneficial for prostate cancer treatment.
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Affiliation(s)
- Simona Di Francesco
- Department of Medicine and Aging Science, Section of Clinical Urology, ''G. D'Annunzio'' University, Chieti, Italy
| | - Pietro Castellan
- Department of Medicine and Aging Science, Section of Clinical Urology, ''G. D'Annunzio'' University, Chieti, Italy
| | - Rossella Manco
- Department of Medicine and Aging Science, Section of Clinical Urology, ''G. D'Annunzio'' University, Chieti, Italy
| | - Raffaele L Tenaglia
- Department of Medicine and Aging Science, Section of Clinical Urology, ''G. D'Annunzio'' University, Chieti, Italy
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27
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Burra S, Jiang JX. Connexin 43 hemichannel opening associated with Prostaglandin E(2) release is adaptively regulated by mechanical stimulation. Commun Integr Biol 2011; 2:239-40. [PMID: 19641742 DOI: 10.4161/cib.2.3.8154] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2009] [Accepted: 02/07/2009] [Indexed: 11/19/2022] Open
Abstract
Osteocytes present in the bone are known to be the major mechanosensory cells. Their involvement in mechanoregulation of bone remodeling is not yet clear. Osteocytes are connected with each other through gap junctions formed by Connexin 43 (Cx43). Apart from forming gap junctions, Cx43 in osteocytes is also present in the form of hemichannels. Recently, we have developed a unique antibody that specifically blocks hemichannels and does not have any effect on gap junctions. Cx43 hemichannels present in osteocytes of the bone are mechanosensory in nature as they open when subjected to mechanical stimulation in the form of fluid flow shear stress (FFSS). Opening of Cx43 hemichannels results in the release of molecules like Prostaglandin E(2) (PGE(2)) that are involved in bone remodeling. Our recent report shows that the opening of Cx43 hemichannels depends on the magnitude and duration of shear stress. When osteocytes are subjected to FFSS followed by a brief rest and reapplication of FFSS, it led to further increase in opening of Cx43 hemichannels. Application of continuous FFSS for longer periods of time (24 hrs) results in decreased opening of hemichannels. These results show that Cx43 hemichannels are adaptive in response to mechanical stimulation, possibly to regulate the release PGE(2) during bone remodeling.
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Affiliation(s)
- Sirisha Burra
- Department of Biochemistry; University of Texas Health Science Center at San Antonio; San Antonio, TX USA
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28
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Phosphatidylserine-Containing Liposomes: Potential Pharmacological Interventions Against Inflammatory and Immune Diseases Through the Production of Prostaglandin E2 After Uptake by Myeloid Derived Phagocytes. Arch Immunol Ther Exp (Warsz) 2011; 59:195-201. [DOI: 10.1007/s00005-011-0123-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Accepted: 11/05/2010] [Indexed: 10/18/2022]
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29
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Abstract
SummaryThe essential polyunsaturated fatty acids (PUFAs) are divided into two classes, n-3 (ω-3) and n-6 (ω-6) and their dietary precursors are α-linolenic (ALA) and linoleic acid (LA), respectively. PUFAs are precursors of a wide range of metabolites, for example eicosanoids like prostaglandins and leukotrienes, which play critical roles in the regulation of a variety of biological processes, including bone metabolism.A large body of evidence supports an effect of PUFA on bone metabolism which may be mediated by regulation of osteoblastogenesis and osteoclast activity, change of membrane function, decrease in inflammatory cytokines, such as interleukin-1 (IL-1), interleukin-6 (IL-6), and tumour necrosis factor alpha (TNF-α), modulation of peroxisome proliferators-activated receptor γ (PPARγ) and influence in NO secretion and NO synthase.Animal studies have shown that a higher dietary omega-3/omega-6 fatty acids ratio is associated with beneficial effects on bone health. Human studies conducted in elderly subjects suggest that omega-3 instead of omega-6 has a positive effect on bone metabolism. In spite of increasing evidence, studies conducted in humans do not allow us to draw a definitive conclusion on the usefulness of PUFAs in clinical practice.
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30
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Kruger M, Coetzee M, Haag M, Weiler H. Long-chain polyunsaturated fatty acids: Selected mechanisms of action on bone. Prog Lipid Res 2010; 49:438-49. [DOI: 10.1016/j.plipres.2010.06.002] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Indexed: 01/11/2023]
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31
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Blackwell KA, Raisz LG, Pilbeam CC. Prostaglandins in bone: bad cop, good cop? Trends Endocrinol Metab 2010; 21:294-301. [PMID: 20079660 PMCID: PMC2862787 DOI: 10.1016/j.tem.2009.12.004] [Citation(s) in RCA: 200] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2009] [Revised: 12/10/2009] [Accepted: 12/11/2009] [Indexed: 02/01/2023]
Abstract
Prostaglandins (PGs) are multifunctional regulators of bone metabolism that stimulate both bone resorption and formation. PGs have been implicated in bone resorption associated with inflammation and metastatic bone disease, and also in bone formation associated with fracture healing and heterotopic ossification. Recent studies have identified roles for inducible cyclooxygenase (COX)-2 and PGE(2) receptors in these processes. Although the effects of PGs have been most often associated with cAMP production and protein kinase A activation, PGs can engage an extensive G-protein signaling network. Further analysis of COX-2 and PG receptors and their downstream G-protein signaling in bone could provide important clues to the regulation of skeletal cell growth in both health and disease.
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Affiliation(s)
- Katherine A Blackwell
- New England Musculoskeletal Institute, University of Connecticut Health Center, 263 Farmington Ave, Farmington, CT, USA
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32
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Liu C, Zhao Y, Cheung WY, Gandhi R, Wang L, You L. Effects of cyclic hydraulic pressure on osteocytes. Bone 2010; 46:1449-56. [PMID: 20149907 PMCID: PMC3417308 DOI: 10.1016/j.bone.2010.02.006] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Revised: 02/02/2010] [Accepted: 02/03/2010] [Indexed: 11/17/2022]
Abstract
Bone is able to adapt its composition and structure in order to suit its mechanical environment. Osteocytes, bone cells embedded in the calcified matrix, are believed to be the mechanosensors and responsible for orchestrating the bone remodeling process. Recent in vitro studies have shown that osteocytes are able to sense and respond to substrate strain and fluid shear. However the capacity of osteocytes to sense cyclic hydraulic pressure (CHP) associated with physiological mechanical loading is not well understood. In this study, we subjected osteocyte-like MLO-Y4 cells to controlled CHP of 68 kPa at 0.5 Hz, and investigated the effects of CHP on intracellular calcium concentration, cytoskeleton organization, mRNA expression of genes related to bone remodeling, and osteocyte apoptosis. We found that osteocytes were able to sense CHP and respond by increased intracellular calcium concentration, altered microtubule organization, a time-dependent increase in COX-2 mRNA level and RANKL/OPG mRNA ratio, and decreased apoptosis. These findings support the hypothesis that loading induced cyclic hydraulic pressure in bone serves as a mechanical stimulus to osteocytes and may play a role in regulating bone remodeling in vivo.
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Affiliation(s)
- Chao Liu
- Department of Mechanical and Industrial Engineering, University of Toronto, ON, Canada
| | - Yan Zhao
- Institute of Biomaterials & Biomedical Engineering, University of Toronto, ON, Canada
| | - Wing-Yee Cheung
- Institute of Biomaterials & Biomedical Engineering, University of Toronto, ON, Canada
| | - Ronak Gandhi
- Division of Engineering Science, University of Toronto, ON, Canada
| | - Liyun Wang
- Center for Biomedical Engineering Research, Department of Mechanical Engineering, University of Delaware, Newark, DE 19716, USA
| | - Lidan You
- Department of Mechanical and Industrial Engineering, University of Toronto, ON, Canada
- Institute of Biomaterials & Biomedical Engineering, University of Toronto, ON, Canada
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33
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Noh ALSM, Yang M, Lee JM, Park H, Lee DS, Yim M. Phosphodiesterase 3 and 4 negatively regulate receptor activator of nuclear factor-kappaB ligand-mediated osteoclast formation by prostaglandin E2. Biol Pharm Bull 2010; 32:1844-8. [PMID: 19881295 DOI: 10.1248/bpb.32.1844] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Prostaglandin E2 (PGE2) stimulates osteoclast formation by increasing receptor activator of nuclear factor (NF)-kappaB ligand (RANKL) mRNA expression via cAMP-protein kinase A (PKA) pathways in osteoblasts. Since phosphodiesterases (PDEs) balance the concentration of intracellular cAMP stimulated by PGE2, we investigated the role of PDEs in PGE2-mediated osteoclast formation using various cAMP-specific PDEs inhibitors. In the presence of PGE(2), PDE3 and 4 inhibitors were shown to dose-dependently increase the osteoclast formation in cocultures of mouse bone marrow cells and calvarial osteoblasts. In agreement with this finding, they stimulated PGE2-induced cAMP production followed by increased RANKL mRNA expression in osteoblasts, suggesting that PDE3 and 4 negatively regulate PGE2-mediated RANKL expression in osteoblasts. RT-PCR analysis revealed that PDE3A, 3B, 4A, 4B and 4D are expressed in osteoblasts. The PDE8 inhibitor did not increase osteoclast formation, although it stimulated PGE2-induced RANKL mRNA expression in osteoblasts. The four subtypes of PGE receptors are designated EP1, EP2, EP3, and EP4. PDE3 and 4 inhibitors were found to increase EP1/3, EP4 and/or EP2 agonist-stimulated RANKL expression, indicating that PDE3 and PDE4 negatively regulate PGE2-induced RANKL mRNA expression through four EPs. Taken together, these data suggest that PDE3 and PDE4 could have important pharmacological and clinical implications in bone-related diseases.
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Affiliation(s)
- A Long Sae Mi Noh
- College of Pharmacy, Sookmyung Women's University, Hyochangwongil 52, Yongsan-ku, Seoul 140-742, Republic ofKorea
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34
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Wu Y, Tai HH, Cho H. Synthesis and SAR of thiazolidinedione derivatives as 15-PGDH inhibitors. Bioorg Med Chem 2010; 18:1428-33. [DOI: 10.1016/j.bmc.2010.01.016] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2009] [Revised: 01/06/2010] [Accepted: 01/07/2010] [Indexed: 12/31/2022]
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35
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Chen JH, Liu C, You L, Simmons CA. Boning up on Wolff's Law: mechanical regulation of the cells that make and maintain bone. J Biomech 2009; 43:108-18. [PMID: 19818443 DOI: 10.1016/j.jbiomech.2009.09.016] [Citation(s) in RCA: 204] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/21/2009] [Indexed: 12/31/2022]
Abstract
Bone tissue forms and is remodeled in response to the mechanical forces that it experiences, a phenomenon described by Wolff's Law. Mechanically induced formation and adaptation of bone tissue is mediated by bone cells that sense and respond to local mechanical cues. In this review, the forces experienced by bone cells, the mechanotransduction pathways involved, and the responses elicited are considered. Particular attention is given to two cell types that have emerged as key players in bone mechanobiology: osteocytes, the putative primary mechanosensors in intact bone; and osteoprogenitors, the cells responsible for bone formation and recently implicated in ectopic calcification of cardiovascular tissues. Mechanoregulation of bone involves a complex interplay between these cells, their microenvironments, and other cell types. Thus, dissection of the role of mechanics in regulating bone cell fate and function, and translation of that knowledge to improved therapies, requires identification of relevant cues, multifactorial experimental approaches, and advanced model systems that mimic the mechanobiological environment.
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Affiliation(s)
- Jan-Hung Chen
- Department of Mechanical & Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, ON, Canada M5S 3G8
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36
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Gao Q, Xu M, Alander CB, Choudhary S, Pilbeam CC, Raisz LG. Effects of prostaglandin E2 on bone in mice in vivo. Prostaglandins Other Lipid Mediat 2009; 89:20-5. [DOI: 10.1016/j.prostaglandins.2009.03.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2009] [Revised: 03/11/2009] [Accepted: 03/14/2009] [Indexed: 12/01/2022]
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37
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Abstract
Cyclooxygenase (COX) catalyzes the conversion of arachidonic acid into prostaglandins (PGs), which play a significant role in health and disease in the gastrointestinal tract (GI) and in the renal, skeletal, and ocular systems. COX-1 is constitutively expressed and found in most normal tissues, whereas COX-2 can be expressed at low levels in normal tissues and is highly induced by pro-inflammatory mediators. Inhibitors of COX activity include: (1) conventional nonselective, nonsteroidal anti-inflammatory drugs (ns-NSAIDs) and (2) COX-2 selective nonsteroidal anti-inflammatory drugs (COX-2 s-NSAIDs). Inhibition of COX-1 often elicits GI toxicity in animals and humans. Therefore, COX-2 s-NSAIDs were developed to provide a selective COX-2 agent, while minimizing the attendant COX-1-mediated GI toxicities. Rats and dogs overpredict COX inhibition for renal effects such as renal handling of electrolytes in humans. COX inhibitors are shown to have both beneficial and detrimental effects, such as on healing of ligament or tendon tears, on the skeletal system in animal models. Certain ophthalmic conditions such as glaucoma and keratitis are associated with increased COX-2 expression, suggesting a potential role in their pathophysiology.
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Affiliation(s)
- Zaher A Radi
- Pfizer Global R&D, Drug Safety R&D, St. Louis, Missouri 63017, USA.
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