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Costa S, Fairfield H, Reagan MR. Inverse correlation between trabecular bone volume and bone marrow adipose tissue in rats treated with osteoanabolic agents. Bone 2019; 123:211-223. [PMID: 30954729 PMCID: PMC6559822 DOI: 10.1016/j.bone.2019.03.038] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 03/26/2019] [Accepted: 03/28/2019] [Indexed: 12/28/2022]
Abstract
There is currently an unmet clinical need for improved treatments for skeletal diseases such as osteoporosis and cancer-induced bone disease. This is due in part to a paucity of novel targets and an incomplete understanding of the mechanisms of action for established therapies. We defined the effects of anabolic treatments on bone and the bone marrow adipocyte (BMA). Sclerostin-neutralizing antibodies (Scl-Ab), romosozumab, human parathyroid hormone (hPTH, 1-34), and hPTH/hPTHrP analogues (e.g. teriparatide and abaloparatide) stimulate bone formation and have been studied in clinical trials for severe osteoporosis. In this study, eight-week-old male and female rats were administered vehicle, Scl-Ab (3 mg/kg or 50 mg/kg) weekly, or hPTH (1-34) (75 μg/kg) daily for 4 or 26 weeks. Histological analyses of distal femura were performed using a novel ImageJ method for trabecular bone and bone marrow adipose tissue (BMAT). Adipocyte number, circumference, and total adipose area were compared within the tissue area (T.Ar) or the marrow area (Ma.Ar), (defined as the T.Ar minus the trabecular bone area). After 26 weeks of treatment, a significant inverse correlation between bone and tissue adiposity (total adipocyte area divided by T.Ar) were observed in males and females (p < 0.0001). However, there were no significant correlations between bone and marrow adiposity (total adipocyte area divided by Ma.Ar) for either sex after 26 weeks of treatments. Scl-Ab treatments also resulted in no effect on adipocytes based on marrow adiposity for either sex after 26 weeks. However, chronic hPTH treatments significantly reduced adipocyte number and adiposity within the T.Ar and within the Ma.Ar in males. Overall, our data suggest that with long-term treatment, Scl-Abs decrease total tissue adiposity mainly by increasing trabecular bone, resulting in an overall reduction in the space in which adipocytes can reside. These findings were determined by developing and comparing two different methods of assessment of the marrow cavity, defined to either include or exclude trabecular bone. Thus, researchers should consider which adiposity measurement is more informative and relevant for their studies. Overall, our findings should help design improved therapies or combination treatments to target a potential new contributor to bone diseases: the bone marrow adipocyte.
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Affiliation(s)
- Samantha Costa
- Maine Medical Center Research Institute, Scarborough, ME, USA; University of Maine Graduate School of Biomedical Science and Engineering, Orono, ME, USA; Tufts University School of Medicine, Boston, MA, USA
| | - Heather Fairfield
- Maine Medical Center Research Institute, Scarborough, ME, USA; University of Maine Graduate School of Biomedical Science and Engineering, Orono, ME, USA; Tufts University School of Medicine, Boston, MA, USA
| | - Michaela R Reagan
- Maine Medical Center Research Institute, Scarborough, ME, USA; University of Maine Graduate School of Biomedical Science and Engineering, Orono, ME, USA; Tufts University School of Medicine, Boston, MA, USA.
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Tabacco G, Bilezikian JP. Osteoanabolic and dual action drugs. Br J Clin Pharmacol 2019; 85:1084-1094. [PMID: 30218587 DOI: 10.1111/bcp.13766] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 09/06/2018] [Accepted: 09/07/2018] [Indexed: 01/02/2023] Open
Abstract
Teriparatide (TPTD) and abaloparatide (ABL) are the only osteoanabolic drugs available, at this time, for treatment of osteoporosis. TPTD is a 34-amino acid fragment that is identical in its primary sequence to the 34 amino acids of full-length human parathyroid hormone [hPTH(1-84)]. ABL is identical to parathyroid hormone-related peptide (PTHrP) through the first 22 residues with significantly different amino acids inserted thereafter, between residues 22 and 34. The osteoanabolic actions of PTH are due directly to its effects on cells of the osteoblast lineage and indirectly by stimulating IGF-I synthesis and suppressing sclerostin and associated enhancement of Wnt signalling. Both TPTD and ABL are ligands that bind to and activate the PTH receptor type 1 (PTHR1) receptor but they appear to do so differently: ABL favours the transient, more anabolic configuration of the receptor. Both TPTD and ABL reduce the risk of vertebral fractures and non-vertebral fractures. Both drugs are administered for a maximum of 24 months, and should be followed by an antiresorptive agent to maintain gains in bone mineral density (BMD). Romosozumab, a monoclonal antibody that binds to and inhibits sclerostin, appears to have dual actions by stimulating bone formation and reducing bone resorption. In the pivotal clinical trial, romosozumab, administered as a 210 mg monthly subcutaneous dose, significantly reduced new vertebral fractures and in a subsequent study reduced both vertebral and non-vertebral fractures.
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Affiliation(s)
- Gaia Tabacco
- Division of Endocrinology, Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY, 10032, USA.,Unit of Endocrinology and Diabetes, Department of Medicine, Campus Bio-Medico University of Rome, Italy
| | - John P Bilezikian
- Division of Endocrinology, Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY, 10032, USA
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Lewiecki EM, Dinavahi RV, Lazaretti-Castro M, Ebeling PR, Adachi JD, Miyauchi A, Gielen E, Milmont CE, Libanati C, Grauer A. One Year of Romosozumab Followed by Two Years of Denosumab Maintains Fracture Risk Reductions: Results of the FRAME Extension Study. J Bone Miner Res 2019; 34:419-428. [PMID: 30508316 DOI: 10.1002/jbmr.3622] [Citation(s) in RCA: 110] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 10/16/2018] [Accepted: 10/28/2018] [Indexed: 12/29/2022]
Abstract
Romosozumab, a humanized monoclonal antibody that binds and inhibits sclerostin, has the dual effect of increasing bone formation and decreasing bone resorption. As previously reported in the pivotal FRActure study in postmenopausal woMen with ostEoporosis (FRAME), women with a T-score of ≤ -2.5 at the total hip or femoral neck received subcutaneous placebo or romosozumab once monthly for 12 months, followed by open-label subcutaneous denosumab every 6 months for an additional 12 months. Upon completion of the 24-month primary analysis period, eligible women entered the extension phase and received denosumab for an additional 12 months. Here, we report the final analysis results through 36 months, including efficacy assessments of new vertebral, clinical, and nonvertebral fracture; bone mineral density (BMD); and safety assessments. Of 7180 women enrolled, 5743 (80%) completed the 36-month study (2851 romosozumab-to-denosumab; 2892 placebo-to-denosumab). Through 36 months, fracture risk was reduced in subjects receiving romosozumab versus placebo for 12 months followed by 24 months of denosumab for both groups: new vertebral fracture (relative risk reduction [RRR], 66%; incidence, 1.0% versus 2.8%; p < 0.001), clinical fracture (RRR, 27%; incidence, 4.0% versus 5.5%; p = 0.004), and nonvertebral fracture (RRR, 21%; incidence, 3.9% versus 4.9%; p = 0.039). BMD continued to increase for the 2 years with denosumab treatment in both arms. The substantial difference in BMD achieved through 12 months of romosozumab treatment versus placebo was maintained through the follow-up period when both treatment arms received denosumab. Subject incidence of adverse events, including positively adjudicated serious cardiovascular adverse events, were overall balanced between groups. In conclusion, in postmenopausal women with osteoporosis, 12 months of romosozumab led to persistent fracture reduction benefit and ongoing BMD gains when followed by 24 months of denosumab. The sequence of romosozumab followed by denosumab may be a promising regimen for the treatment of osteoporosis. © 2018 American Society for Bone and Mineral Research.
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Affiliation(s)
- E Michael Lewiecki
- New Mexico Clinical Research & Osteoporosis Center, Albuquerque, NM, USA
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Rachner TD, Hofbauer LC, Göbel A, Tsourdi E. Novel therapies in osteoporosis: PTH-related peptide analogs and inhibitors of sclerostin. J Mol Endocrinol 2019; 62:R145-R154. [PMID: 30389901 DOI: 10.1530/jme-18-0173] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 09/12/2018] [Indexed: 01/03/2023]
Abstract
Bone-forming approaches to treat patients with severe osteoporosis are effective, but treatment options are limited, and there is an unmet clinical need for additional drugs. This review discusses two novel and advanced anabolic therapeutic concepts that have successfully completed phase 3 trials. Romosozumab is a monoclonal antibody that targets the Wnt inhibitor sclerostin. Two phase 3 trials (FRAME and ARCH) of romosozumab for the treatment of postmenopausal osteoporosis have been completed. Both trials successfully reached their primary endpoint by reducing vertebral fractures by 75% compared to placebo (FRAME trial) and 48% compared to alendronate (ARCH trial), respectively. Abaloparatide is a PTH-related protein (PTHrP) analog that has displayed bone anabolic activity. In the phase 3 ACTIVE trial, abaloparatide was compared to placebo and teriparatide for 18 months in postmenopausal women who had already experienced an osteoporotic fracture. Abaloparatide successfully reduced the rate of new vertebral fractures by 86% compared to placebo. Furthermore, abaloparatide achieved greater BMD increases at all measured sites compared to both placebo and teriparatide. Based on these results, abaloparatide was FDA approved in April 2017. This review discusses available data of both agents with regard to efficacy and safety as well as their possible future application.
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Affiliation(s)
- Tilman D Rachner
- Department of Medicine III, Technische Universität Dresden Medical Center, Dresden, Germany
- Center for Healthy Aging, Technische Universität Dresden Medical Center, Dresden, Germany
- German Cancer Consortium (DKTK), partner site Dresden and German Cancer Research Center (DKFZ), Dresden, Germany
| | - Lorenz C Hofbauer
- Department of Medicine III, Technische Universität Dresden Medical Center, Dresden, Germany
- Center for Healthy Aging, Technische Universität Dresden Medical Center, Dresden, Germany
- German Cancer Consortium (DKTK), partner site Dresden and German Cancer Research Center (DKFZ), Dresden, Germany
- Center for Regenerative Therapies Dresden, Technische Universität Dresden, Dresden, Germany
| | - Andy Göbel
- Department of Medicine III, Technische Universität Dresden Medical Center, Dresden, Germany
- German Cancer Consortium (DKTK), partner site Dresden and German Cancer Research Center (DKFZ), Dresden, Germany
| | - Elena Tsourdi
- Department of Medicine III, Technische Universität Dresden Medical Center, Dresden, Germany
- Center for Healthy Aging, Technische Universität Dresden Medical Center, Dresden, Germany
- German Cancer Consortium (DKTK), partner site Dresden and German Cancer Research Center (DKFZ), Dresden, Germany
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Holdsworth G, Roberts SJ, Ke HZ. Novel actions of sclerostin on bone. J Mol Endocrinol 2019; 62:R167-R185. [PMID: 30532996 DOI: 10.1530/jme-18-0176] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 10/17/2018] [Indexed: 12/11/2022]
Abstract
The discovery that two rare autosomal recessive high bone mass conditions were caused by the loss of sclerostin expression prompted studies into its role in bone homeostasis. In this article, we aim to bring together the wealth of information relating to sclerostin in bone though discussion of rare human disorders in which sclerostin is reduced or absent, sclerostin manipulation via genetic approaches and treatment with antibodies that neutralise sclerostin in animal models and in human. Together, these findings demonstrate the importance of sclerostin as a regulator of bone homeostasis and provide valuable insights into its biological mechanism of action. We summarise the current state of knowledge in the field, including the current understanding of the direct effects of sclerostin on the canonical WNT signalling pathway and the actions of sclerostin as an inhibitor of bone formation. We review the effects of sclerostin, and its inhibition, on bone at the cellular and tissue level and discuss new findings that suggest that sclerostin may also regulate adipose tissue. Finally, we highlight areas in which future research is expected to yield additional insights into the biology of sclerostin.
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Affiliation(s)
| | | | - Hua Zhu Ke
- Bone Therapeutic Area, UCB Pharma, Slough, United Kingdom
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56
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Li S, Huang B, Jiang B, Gu M, Yang X, Yin Y. Sclerostin Antibody Mitigates Estrogen Deficiency-Inducted Marrow Lipid Accumulation Assessed by Proton MR Spectroscopy. Front Endocrinol (Lausanne) 2019; 10:159. [PMID: 30949129 PMCID: PMC6436376 DOI: 10.3389/fendo.2019.00159] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 02/25/2019] [Indexed: 11/25/2022] Open
Abstract
Sclerostin knock-out mice or sclerostin antibody (Scl-Ab) treated wild-type mice displayed decreased marrow adiposity. But the effects of Scl-Ab on estrogen deficiency-induced marrow fat expansion remain elusive. In this work, 45 female New Zealand rabbits were equally divided into sham-operation, ovariectomy controls, and ovariectomy treated with Scl-Ab for 5 months. MR spectroscopy was performed to longitudinally assess marrow fat fraction at baseline conditions, 2.5 and 5 months post-operatively, respectively. We evaluated bone mineral density (BMD), bone structural parameters, serum bone biomarkers, and quantitative parameters of marrow adipocytes. Ovariectomized rabbits markedly exhibited expansion of marrow fat in a time-dependent manner, with a variation of marrow fat fraction (+17.8%) at 2.5 months relative to baseline and it was maintained until 5 months (+30.4%, all P < 0.001), which was accompanied by diminished BMD and deterioration of trabecular microstructure. Compared to sham controls, adipocyte mean diameter, adipocyte density and adipocytes area percentage was increased by 42.9, 68.3, and 108.6% in ovariectomized rabbits, respectively. Scl-Ab treatment increased serum bone formation marker and alleviated the ovariectomy escalation of serum bone resorption marker. It remarkably lessened the ovariectomy-mediated deterioration of BMD, and morphometric characteristics of trabecular bone. Marrow fat fraction was decreased significantly with Scl-Ab to levels matching that of sham-operated controls and correlated positively with reductions in adipocyte mean diameter, percentage adipocyte volume per marrow volume, and adipocyte density. Taken together, early Scl-Ab treatment reverts marrow fat expansion seen in ovariectomized rabbits in addition to having a beneficial effect on bone mass and microstructural properties.
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Affiliation(s)
- Shaojun Li
- Department of Radiology, The Second Military Medical University Affiliated Gongli Hospital, Shanghai, China
- *Correspondence: Shaojun Li
| | - Bingcang Huang
- Department of Radiology, The Second Military Medical University Affiliated Gongli Hospital, Shanghai, China
| | - Bo Jiang
- Department of Radiology, The Second Military Medical University Affiliated Gongli Hospital, Shanghai, China
| | - Mingjun Gu
- Department of Endocrinology, The Second Military Medical University Affiliated Gongli Hospital, Shanghai, China
| | - Xiaodan Yang
- Department of Endocrinology, The Second Military Medical University Affiliated Gongli Hospital, Shanghai, China
| | - Ying Yin
- Department of Endocrinology, The Second Military Medical University Affiliated Gongli Hospital, Shanghai, China
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57
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Costa S, Reagan MR. Therapeutic Irradiation: Consequences for Bone and Bone Marrow Adipose Tissue. Front Endocrinol (Lausanne) 2019; 10:587. [PMID: 31555210 PMCID: PMC6727661 DOI: 10.3389/fendo.2019.00587] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 08/09/2019] [Indexed: 12/28/2022] Open
Abstract
Radiotherapy continues to be one of the most accepted medical treatments for cancer. Localized irradiation is the most common treatment for prostate, pancreatic, rectal, cervical and endometrial malignancies. Conventional localized fractions are total doses of 30-62Gy at 1.8-2Gy per fraction, with administration of ~60Gy often used for tumor ablation. However, even the lowest dose of localized irradiation exposure can result in adverse complications to adjacent organs, tissues, and vessels, which absorb a portion of the treatment. Skeletal complications are common amongst cancer patients undergoing these localized treatments. Irradiation exposure causes deterioration to the overall quantity and quality of bone by interfering with the trabecular architecture through increased osteoclast activity and decreased osteoblast activity. Irradiation-induced bone damage parallels adipocyte infiltration of the bone marrow (BM) resulting in compositional alterations of the microenvironment that may further affect bone quality and disease state. There may also be direct effects of irradiation on the BM adipocyte/pre-adipocyte, although in vitro findings do not always agree and cellular response is dependent on irradiation dosage. Hematopoietic cells also become apoptotic upon irradiation, which causes a range of skeletal effects. Bone loss leaves patients at a greater risk for osteopenia, osteoporosis, osteonecrosis, and skeletal fractures that drastically reduce quality of life. Osteoanabolic agents stimulate bone formation and reduce fracture risk in patients with low bone density; thus, osteoanabolic or anti-resorptive agents may be useful co-treatments with irradiation. This review discusses these topics and proposes further research directions using novel or combination therapies to enhance bone health during irradiation.
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Affiliation(s)
- Samantha Costa
- Center for Clinical and Translational Research, Maine Medical Center Research Institute, Scarborough, ME, United States
- University of Maine Graduate School of Biomedical Science and Engineering, Orono, ME, United States
- Tufts University School of Medicine, Boston, MA, United States
| | - Michaela R. Reagan
- Center for Clinical and Translational Research, Maine Medical Center Research Institute, Scarborough, ME, United States
- University of Maine Graduate School of Biomedical Science and Engineering, Orono, ME, United States
- Tufts University School of Medicine, Boston, MA, United States
- *Correspondence: Michaela R. Reagan
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58
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Hadaya D, Gkouveris I, Soundia A, Bezouglaia O, Boyce RW, Stolina M, Dwyer D, Dry SM, Pirih FQ, Aghaloo TL, Tetradis S. Clinically Relevant Doses of Sclerostin Antibody Do Not Induce Osteonecrosis of the Jaw (ONJ) in Rats with Experimental Periodontitis. J Bone Miner Res 2019; 34:171-181. [PMID: 30184271 PMCID: PMC6448152 DOI: 10.1002/jbmr.3581] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 08/13/2018] [Accepted: 08/25/2018] [Indexed: 12/31/2022]
Abstract
Antiresorptive agents, such as bisphosphonates and denosumab, are frequently used for the management of osteoporosis. Indeed, both medications decrease the risk of osteoporotic fractures; however, these medications are associated with rare but potentially severe side effects, such as osteonecrosis of the jaw (ONJ). ONJ, defined as an area of exposed bone in the maxillofacial region that lasts for 8 weeks, often presents with significant pain and infection and can lead to serious complications. Interestingly, other treatments for osteoporosis have been developed, such as antibodies against the osteocyte-secreted protein, sclerostin. Sclerostin functions to inhibit the Wnt signaling cascade, leading to inhibition of bone formation. In clinical trials, a sclerostin antibody (romosozumab, Amgen Inc., UCB Brussels) increases bone formation and lowers the risk of osteoporotic fractures. However, in conjunction with increased osteoblastic activity, a reduction in bone resorption markers is observed. This antiresorptive effect raises the concern of possible ONJ development in patients treated with sclerostin antibodies. Here, utilizing ligature-induced experimental periodontitis (EP), we evaluated the effects of sclerostin inhibition on the development of ONJ-like lesions in ovariectomized rats. Beginning 8 weeks post-ovariectomy, rats were treated for 22 weeks with weekly injections of vehicle (Veh), 200 μg/kg zoledronic acid (ZA), a potent bisphosphonate at 100-fold the osteoporosis dose, or 5 mg/kg sclerostin antibody (Scl-Ab) at the osteoporotic dose. EP was initiated at week 12 and maintained for the remainder of the study. Scl-Ab treatment transiently increased serum P1NP, a bone formation marker, increased BV/TV, and decreased eroded surfaces in lumbar vertebrae. ZA-treated rats developed histologic features of ONJ, whereas Veh-treated controls did not. Scl-Ab animals lost less periodontal bone in sites with EP. However, these animals presented with no histologic signs of ONJ. In conclusion, sclerostin inhibition enhanced structural bone parameters, without inducing ONJ-like lesions, in ovariectomized rats with EP. © 2018 American Society for Bone and Mineral Research.
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Affiliation(s)
- Danny Hadaya
- Division of Diagnostic and Surgical Sciences, UCLA School of Dentistry, Los Angeles, CA, USA
| | - Ioannis Gkouveris
- Division of Diagnostic and Surgical Sciences, UCLA School of Dentistry, Los Angeles, CA, USA
| | - Akrivoula Soundia
- Division of Diagnostic and Surgical Sciences, UCLA School of Dentistry, Los Angeles, CA, USA
| | - Olga Bezouglaia
- Division of Diagnostic and Surgical Sciences, UCLA School of Dentistry, Los Angeles, CA, USA
| | - Rogely W Boyce
- Comparative Biology and Safety Sciences, Amgen Inc., Thousand Oaks, CA, USA
| | - Marina Stolina
- Discovery Research Department, Amgen Inc., Thousand Oaks, CA, USA
| | - Denise Dwyer
- Discovery Research Department, Amgen Inc., Thousand Oaks, CA, USA
| | - Sarah M Dry
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Flavia Q Pirih
- Division of Constitutive and Regenerative Sciences, UCLA School of Dentistry, Los Angeles, CA, USA
| | - Tara L Aghaloo
- Division of Diagnostic and Surgical Sciences, UCLA School of Dentistry, Los Angeles, CA, USA
| | - Sotirios Tetradis
- Division of Diagnostic and Surgical Sciences, UCLA School of Dentistry, Los Angeles, CA, USA
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Toscani D, Bolzoni M, Ferretti M, Palumbo C, Giuliani N. Role of Osteocytes in Myeloma Bone Disease: Anti-sclerostin Antibody as New Therapeutic Strategy. Front Immunol 2018; 9:2467. [PMID: 30410490 PMCID: PMC6209728 DOI: 10.3389/fimmu.2018.02467] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 10/05/2018] [Indexed: 11/16/2022] Open
Abstract
Osteocytes are terminally differentiated cells of the osteoblast lineage. They are involved in the regulation of bone remodeling by increasing osteoclast formation or decreasing bone formation by the secretion of the osteoblast inhibitor sclerostin. Monoclonal antibody anti-sclerostin, Romosozumab, has been developed and tested in clinical trials in patients with osteoporosis. In the last years, the role of osteocytes in the development of osteolytic bone lesions that occurs in multiple myeloma, have been underlined. Myeloma cells increase osteocyte death through the up-regulation of both apoptosis and autophagy that, in turn, triggers osteoclast formation, and activity. When compared to healthy controls, myeloma patients with bone disease have higher osteocyte cell death, but the treatment with proteasome inhibitor bortezomib has been shown to maintain osteocyte viability. In preclinical mouse models of multiple myeloma, treatment with blocking anti-sclerostin antibody increased osteoblast numbers and bone formation rate reducing osteolytic bone lesions. Moreover, the combination of anti-sclerostin antibody and the osteoclast inhibitor zoledronic acid increased bone mass and fracture resistance synergistically. However, anti-sclerostin antibody did not affect tumor burden in vivo or the efficacy of anti-myeloma drugs in vitro. Nevertheless, the combination therapy of anti-sclerostin antibody and the proteasome inhibitor carfilzomib, displayed potent anti-myeloma activity as well as positive effects on bone disease in vivo. In conclusion, all these data suggest that osteocytes are involved in myeloma bone disease and may be considered a novel target for the use of antibody-mediated anti-sclerostin therapy also in multiple myeloma patients.
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Affiliation(s)
- Denise Toscani
- Department Medicine and Surgery, University of Parma, Parma, Italy
| | - Marina Bolzoni
- Department Medicine and Surgery, University of Parma, Parma, Italy
| | - Marzia Ferretti
- Department of Biomedical, Metabolic and Neural Sciences, Human Morphology Section, University of Modena and Reggio Emilia, Modena, Italy
| | - Carla Palumbo
- Department of Biomedical, Metabolic and Neural Sciences, Human Morphology Section, University of Modena and Reggio Emilia, Modena, Italy
| | - Nicola Giuliani
- Department Medicine and Surgery, University of Parma, Parma, Italy
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Appelman-Dijkstra NM, Papapoulos SE. Clinical advantages and disadvantages of anabolic bone therapies targeting the WNT pathway. Nat Rev Endocrinol 2018; 14:605-623. [PMID: 30181608 DOI: 10.1038/s41574-018-0087-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The WNT signalling pathway is a key regulator of bone metabolism, particularly bone formation, which has helped to define the role of osteocytes - the most abundant bone cells - as orchestrators of bone remodelling. Several molecules involved in the control of the WNT signalling pathway have been identified as potential targets for the development of bone-building therapeutics for patients with osteoporosis. Several of these molecules have been investigated in animal models, but only inhibitors of sclerostin (which is produced by osteocytes) have been investigated in phase III clinical studies. Here, we review the rationale for these developments and the specificity and potential off-target actions of WNT-based therapeutics. We also describe the available preclinical and clinical studies and discuss the benefits and risks of using sclerostin inhibitors for the management of patients with osteoporosis.
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Rausch V, Seybold D, Königshausen M, Köller M, Schildhauer TA, Geßmann J. [Basic principles of fracture healing]. DER ORTHOPADE 2018; 46:640-647. [PMID: 28718007 DOI: 10.1007/s00132-017-3449-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND In contrast to other tissues, bone has the remarkable ability to heal without scarring. After union of the fracture, the remodeled bone ideally does not differ from the original bone, especially in terms of biomechanical properties. The healing of a fracture resembles the embryonic development of bone. Depending on the biomechanical properties of the fracture, bone heals directly or indirectly, which refers to the formation of cartilage as a step before new bone appears. Currently, treatment of the patient is often limited to anatomical reduction and optimization of the fracture environment with respect to biomechanics. PROSPECTS Future treatment strategies, however, could include systemic medication that could be especially beneficial for patients at risk of complications in fracture healing. The aim of this review is to provide an overview on the process of fracture healing and to depict possibilities for current and future treatment strategies.
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Affiliation(s)
- Valentin Rausch
- Chirurgische Universitätsklinik und Poliklinik, Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil, Bürkle-de-la-Camp-Platz 1, 44789, Bochum, Deutschland
| | - Dominik Seybold
- Chirurgische Universitätsklinik und Poliklinik, Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil, Bürkle-de-la-Camp-Platz 1, 44789, Bochum, Deutschland.
| | - Matthias Königshausen
- Chirurgische Universitätsklinik und Poliklinik, Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil, Bürkle-de-la-Camp-Platz 1, 44789, Bochum, Deutschland
| | - Manfred Köller
- Chirurgische Universitätsklinik und Poliklinik, Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil, Bürkle-de-la-Camp-Platz 1, 44789, Bochum, Deutschland
| | - Thomas A Schildhauer
- Chirurgische Universitätsklinik und Poliklinik, Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil, Bürkle-de-la-Camp-Platz 1, 44789, Bochum, Deutschland
| | - Jan Geßmann
- Chirurgische Universitätsklinik und Poliklinik, Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil, Bürkle-de-la-Camp-Platz 1, 44789, Bochum, Deutschland
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Yang K, Miron RJ, Bian Z, Zhang YF. A bone-targeting drug-delivery system based on Semaphorin 3A gene therapy ameliorates bone loss in osteoporotic ovariectomized mice. Bone 2018; 114:40-49. [PMID: 29883786 DOI: 10.1016/j.bone.2018.06.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Revised: 06/01/2018] [Accepted: 06/04/2018] [Indexed: 12/15/2022]
Abstract
Osteoporosis is a serious health problem worldwide. Semaphorins (Sema) have been described as key molecules involved in the cross-talk between bone cells (osteoblasts/osteoclasts). In this study, we investigated whether plasmid containing Sema3a could ameliorate bone loss in an ovariectomized (OVX) mouse model via (AspSerSer)6, a selectively bone-targeting moiety. Plasmid pcDNA3.1(+)-Sema3a-GFP was fabricated and transfected cells with the plasmid demonstrated statistically higher levels of Sema3A in vitro (p < 0.001). Mice were ovariectomized and injected twice weekly with (AspSerSer)6-(STR-R8)+pcDNA3.1(+)-Sema3a-GFP for four weeks. The aim of the study was twofold: firstly to design an effective bone-targeting drug-delivery system (AspSerSer)6. Secondly, the effects of Sem3A gene therapy on bone loss was investigated. Here, the targeting selectivity of pcDNA3.1(+)-Sema3a-GFP via (AspSerSer)6 to the trabecular bone surface was firstly verified by histological observation of frozen sections and immunofluorescence staining. Then, bone microstructure analysis by Micro-CT indicated significantly less bone loss in mice treated with (AspSerSer)6-(STR-R8)+pcDNA3.1(+)-Sema3a-GFP compared to the control group (p < 0.05). Furthermore,H&E staining and Safranin O staining of the decalcified sections demonstrated statistically significantly higher bone area/total area in the mice that were injected with (AspSerSer)6-(STR-R8)+pcDNA3.1(+)-Sema3a-GFP (p < 0.001, p < 0.01,respectively). TRAP staining and immunohistochemistry staining of COL I demonstrated lower numbers of osteoclasts and significantly increased numbers of osteoblasts in the bone-targeting moiety delivering pcDNA3.1(+)-Sema3a-GFP group, when compared to the control group (p < 0.01, p < 0.001,respectively). Together, our findings have identified that, (AspSerSer)6, a bone-targeting drug-delivery system based on semaphorin3A gene therapy, ameliorated bone loss in osteoporotic ovariectomized mice, by suppressing osteoclastic bone resorption and simultaneously increasing osteoblastic bone formation. Gene therapy by local site-specific Sema3A overexpression might be a potential new strategy for treating osteoporosis and bone defects.
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Affiliation(s)
- K Yang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - R J Miron
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China; Department of Periodontology, Cell Therapy Institute, College of Dental Medicine, Nova Southeastern University, Fort Lauderdale, Florida, USA
| | - Z Bian
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China; Department of Endodontics, School and Hospital of Stomatology, Wuhan University, Wuhan, China.
| | - Y F Zhang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China; Department of Dental Implantology, School and Hospital of Stomatology, Wuhan University, Wuhan, China.
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Abstract
Most current treatments for osteoporosis inhibit bone resorption and reduce total fracture numbers by about one-quarter. The identification of the osteocytic protein sclerostin as a potent regulator of bone turnover and bone density has led to the development of a new therapeutic class-agents that inhibit sclerostin activity, resulting in increased bone formation and reduced bone resorption. Romosozumab and blosozumab are monoclonal antibodies that bind to sclerostin, reducing its inhibition of Wnt signaling. They have comparable activities in phase I and II studies, doubling formation markers, halving resorption indices, and increasing spine bone density by >10% over 12 months. Only romosozumab has progressed to phase III, where the first study showed a 73% reduction in vertebral fracture risk and a 36% reduction in clinical fractures at 1 year. It was well-tolerated. A further phase III study will conclude in 2017. Romosozumab is a very promising medication in the management of established osteoporosis, but much remains to be done to determine its optimal duration and sequence of administration.
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Differential time-dependent transcriptional changes in the osteoblast lineage in cortical bone associated with sclerostin antibody treatment in ovariectomized rats. Bone Rep 2018; 8:95-103. [PMID: 29955627 PMCID: PMC6020117 DOI: 10.1016/j.bonr.2018.03.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 02/15/2018] [Accepted: 03/13/2018] [Indexed: 12/13/2022] Open
Abstract
Inhibition of sclerostin with sclerostin antibody (Scl-Ab) results in stimulation of bone formation on cancellous (Cn), endocortical (Ec), and periosteal (Ps) surfaces in rodents and non-human primates. With long-term dosing of Scl-Ab, the increase in bone formation is not sustained, attenuating first on Cn surfaces and later on Ec and Ps surfaces. In Cn bone, the attenuation in bone formation (self-regulation) is associated with transcriptional changes in the osteocyte (OCy) that would limit mitogenesis and are sustained with continued dosing. The expression changes in Cn OCy occur coincident with a decrease in osteoprogenitor (OP) numbers that may directly or indirectly be a consequence of the transcriptional changes in the OCy to limit OP proliferation. To characterize the Scl-Ab–mediated changes in cortical (Ct) bone and compare these changes to Cn bone, densitometric, histomorphometric, and transcriptional analyses were performed on femur diaphyses from aged ovariectomized rats. Animals were administered 50 mg/kg/wk of Scl-Ab or vehicle for up to 6 months (183 days), followed by a treatment-free period (up to 126 days). Scl-Ab increased Ct mass and area through day 183, which declined slightly when treatment was discontinued. Ps and Ec bone formation was sustained through the dosing on both Ct surfaces, with evidence of a decline in bone formation only at day 183 on the Ec surface. This is in contrast to Cn bone, where reduced bone formation was observed after day 29. TaqMan analysis of 60 genes with functional roles in the bone using mRNA isolated from laser capture micro-dissection samples enriched for Ec osteoblasts and Ct OCy suggest a pattern of gene expression in Ct bone that differed from Cn, especially in the OCy, and that corresponded to observed differences in the timing of phenotypic changes. Notable with Scl-Ab treatment was a “transcriptional switch” in Ct OCy at day 183, coincident with the initial decline in bone formation on the endocortex. A consistent sustained increase of expression for most genes in response to Scl-Ab was observed from day 8 through day 85 at the times of maximal bone formation on both Ct surfaces; however, at day 183, this increase was reversed, with expression of these genes generally returning to control values or decreasing compared to vehicle. Genes exhibiting this pattern included Wnt inhibitors Sost and Dkk1, though both had been up-regulated until the end of dosing in Cn OCy. Changes in cell cycle genes such as Cdkn1a and Ndrg1 in Ct OCy suggested up-regulation of p53 signaling, as observed in Cn OCy; however, unlike in Cn bone, p53 signaling was not associated with decreased bone formation and was absent at day 183, when bone formation began to decline on the Ec surface. These data demonstrate involvement of similar molecular pathways in Ct and Cn bone in response to Scl-Ab but with a different temporal relationship to bone formation and suggest that the specific mechanism underlying self-regulation of Scl-Ab–induced bone formation may be different between Cn and Ct bone. Sclerostin antibody stimulates bone formation that attenuates over time. Attenuation (self-regulation) is delayed in cortical versus cancellous bone. Self-regulation coincides with transcriptional changes in cortical osteocytes. Response of Wnt inhibitors differs between cortical and cancellous bone. Results suggest a distinct mechanism for self-regulation in cortical bone.
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Key Words
- ANOVA, analysis of variance
- Anabolics
- BMC, bone mineral content
- BMP, bone morphogenetic protein
- BS, bone surface
- Bone
- Cn, cancellous
- Ct, cortical
- Ec, endocortical
- Ec.Pm, endocortical perimeter
- LC, lining cells
- LCM, laser capture micro-dissection
- MS/BS, mineralizing surface
- OB, osteoblast(s)
- OCy, osteocyte(s)
- OP, osteoprogenitor(s)
- OPG, osteoprotegerin
- OVX, ovariectomized
- Osteoporosis
- Ps, periosteal
- Ps.Pm, periosteal perimeter
- RANKL, receptor activator of nuclear factor kappa-B ligand
- Scl-Ab, sclerostin antibody
- Scl-AbVI, 50 mg/kg of a Scl-Ab
- TFP, treatment-free period
- TGF, transforming growth factor
- TP, treatment period
- Therapeutics
- VEH, vehicle
- Wnt signaling
- pQCT, peripheral quantitative computed tomography
- s.c., subcutaneous
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Boyce RW, Brown D, Felx M, Mellal N, Locher K, Pyrah I, Ominsky MS, Taylor S. Decreased osteoprogenitor proliferation precedes attenuation of cancellous bone formation in ovariectomized rats treated with sclerostin antibody. Bone Rep 2018; 8:90-94. [PMID: 29955626 PMCID: PMC6020110 DOI: 10.1016/j.bonr.2018.03.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 02/15/2018] [Accepted: 03/02/2018] [Indexed: 02/03/2023] Open
Abstract
Sclerostin antibody (Scl-Ab) stimulates bone formation, which with long-term treatment, attenuates over time. The cellular and molecular mechanisms responsible for the attenuation of bone formation are not well understood, but in aged ovariectomized (OVX) rats, the reduction in vertebral cancellous bone formation is preceded by a reduction in osteoprogenitor (OP) number and significant induction of signaling pathways known to suppress mitogenesis and cell cycle progression in the osteocyte (OCy) (Taylor et al., 2016). To determine if the reduction in OP number is associated with a decrease in proliferation, aged OVX rats were administered vehicle or Scl-Ab for 9 or 29 days and implanted with continuous-delivery 5-bromo-2′-deoxyuridine (BrdU) mini-osmotic pumps 5 days prior to necropsy. The total number of BrdU-labeled osteoblasts (OB) was quantified in vertebral cancellous bone to indirectly assess the effects of Scl-Ab treatment on OP proliferation at the time of activation of modeling-based bone formation at day 9 and at the time of maximal mineralizing surface, initial decrease in OP number, and transcriptional changes in the OCy at day 29. Compared with vehicle, Scl-Ab resulted in an increase in the total number of BrdU-positive OB (+260%) at day 9 that decreased with continued treatment (+50%) at day 29. These differences in proliferation occurred at time points when the increase in total OB number was significant and similar in magnitude. These findings suggest that reduced OP proliferation contributes to the decrease in OP numbers, an effect that would limit the OB pool and contribute to the attenuation of bone formation that occurs with long-term Scl-Ab treatment. Sclerostin antibody stimulates bone formation (BF) that attenuates over time. Osteoprogenitor (OP) proliferation increases early with treatment. Attenuation of BF is preceded by a decrease in OP proliferation. Decrease is coincident with molecular signaling consistent with cell cycle arrest. Decreased OP proliferation contributes to the attenuation of BF.
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Key Words
- ANOVA, analysis of variance
- Anabolics
- Bone
- BrdU, 5-bromo-2′-deoxyuridine
- CDKN1A, cyclin-dependent kinase inhibitor 1A
- CDKN2A, CDKN inhibitor 2A
- CE, coefficient of error
- CV, coefficient of variation
- Cell signaling
- D, day
- E2F1, E2F transcription factor 1
- FOXM1, Forkhead box protein M1
- MS/BS, mineralizing surface per bone surface
- MYC, v-myc avian myelocytomatosis viral oncogene homolog
- MYCN, MYC neuroblastoma-derived homolog
- OB, osteoblast(s)
- OCy, osteocyte(s)
- OP, osteoprogenitor(s)
- OVX, ovariectomized
- Ob.N, OB number
- Osteoporosis
- Osteoprogenitors
- PROBE, precision range of an optimally balanced estimator
- RB1, retinoblastoma protein 1
- RUNX2, Runt-related transcription factor 2
- SURS, systematic uniform random sampling
- Scl-Ab, sclerostin antibody
- Scl-AbVI, 50 mg/kg of a Scl-Ab
- TP53, tumor protein p53
- VEH, vehicle
- Wnt signaling
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Affiliation(s)
- Rogely Waite Boyce
- Department of Comparative Biology and Safety Sciences, Amgen Inc., One Amgen Center Drive, Thousand Oaks, CA 91320, United States
| | - Danielle Brown
- Charles River Laboratories, 4025 Stirrup Creek Drive, Suite 150, Durham, NC 27703, United States
| | - Melanie Felx
- Charles River Laboratories, 22022 Transcanadienne, Senneville, QC H9X 3R3, Canada
| | - Nacera Mellal
- Charles River Laboratories, 22022 Transcanadienne, Senneville, QC H9X 3R3, Canada
| | - Kathrin Locher
- Department of Comparative Biology and Safety Sciences, Amgen Inc., One Amgen Center Drive, Thousand Oaks, CA 91320, United States
| | - Ian Pyrah
- Department of Comparative Biology and Safety Sciences, Amgen Inc., One Amgen Center Drive, Thousand Oaks, CA 91320, United States
| | - Michael S Ominsky
- Department of CardioMetabolic Disorders, Amgen Inc., One Amgen Center Drive, Thousand Oaks, CA 91320, United States
| | - Scott Taylor
- Department of Comparative Biology and Safety Sciences, Amgen Inc., One Amgen Center Drive, Thousand Oaks, CA 91320, United States
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66
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Zhang S, Zhang Q, Zhang D, Wang C, Yan C. Anti-osteoporosis activity of a novel Achyranthes bidentata polysaccharide via stimulating bone formation. Carbohydr Polym 2018; 184:288-298. [DOI: 10.1016/j.carbpol.2017.12.070] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 12/05/2017] [Accepted: 12/27/2017] [Indexed: 02/06/2023]
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Ye W, Wang Y, Mei B, Hou S, Liu X, Wu G, Qin L, Zhao K, Huang Q. Computational and functional characterization of four SNPs in the SOST locus associated with osteoporosis. Bone 2018; 108:132-144. [PMID: 29307778 DOI: 10.1016/j.bone.2018.01.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 12/29/2017] [Accepted: 01/02/2018] [Indexed: 01/19/2023]
Abstract
The SOST gene encodes sclerostin, a C-terminal cysteine knot-like domain containing key negative regulator of osteoblastic bone formation that inhibits LRP5/6-mediated canonical Wnt signaling. Numerous single nucleotide polymorphisms (SNPs) in the SOST locus are firmly associated with bone mineral density (BMD) and fracture in genome-wide association studies (GWAS) and candidate gene association studies. However, the validation and mechanistic elucidation of causal genetic variants, especially for SNPs located beyond the promoter-proximal region, remain largely unresolved. By employing computational and experimental approaches, here we identify four SNPs rs1230399, rs7220711, rs1107748 and rs75901553 as functional variants which display allelic variation in SOST gene expression. The osteoporosis associated SNP rs1230399 in the SOST distal upstream regulatory region shows FOXA1 binding activity with subsequent transinactivation in a T allele-specific manner. The BMD GWAS lead SNPs rs7220711 and rs1107748 both reside in the 52-kb regulatory element deletion 35-kb downstream of the SOST gene which leads to Van Buchem disease. The rs7220711-A has a higher affinity for the transcriptional repressors MAFF or MAFK homodimers than rs7220711-G, while rs1107748 confers C allele specific transcriptional enhancer activity via a CTCF binding element. The variant rs75901553 C>T located in a conserved site of the SOST 3' UTR abolishes a target binding site for miR-98-5p which is negatively responsive to parathyroid hormone or 17β-estradiol in osteoblastic cell lines. Our findings uncover the biological consequences of four independent genetic variants in the SOST region and their important roles in SOST expression via diverse mechanisms, providing new insights into the genetics and molecular pathogenesis of osteoporosis.
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Affiliation(s)
- Weiyuan Ye
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China
| | - Ya Wang
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China
| | - Bing Mei
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China
| | - Sasa Hou
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China
| | - Xinhong Liu
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China
| | - Guiju Wu
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China
| | - Longjuan Qin
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China
| | - Kehui Zhao
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China
| | - Qingyang Huang
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China.
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68
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McClung MR. Romosozumab for the treatment of osteoporosis. Osteoporos Sarcopenia 2018; 4:11-15. [PMID: 30775535 PMCID: PMC6362945 DOI: 10.1016/j.afos.2018.03.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 03/07/2018] [Accepted: 03/10/2018] [Indexed: 11/17/2022] Open
Abstract
Romosozumab, a specific inhibitor of sclerostin, is a unique approach to therapy for postmenopausal osteoporosis and related disorders. The elucidation of sclerostin deficiency as the molecular defect of syndromes of high bone mass with normal quality, and the pivotal role of sclerostin as a mediator of osteoblastic activity and bone formation, provided the platform for the evaluation of inhibitors of sclerostin to activate bone formation. An extensive preclinical program and 2 large fracture endpoint trials with romosozumab, a sclerostin-binding antibody, have been completed. This review will highlight the results of those studies and describe the current status of romosozumab as a potential therapy for osteoporosis.
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69
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Nicol L, Wang Y, Smith R, Sloan J, Nagamani SC, Shapiro J, Lee B, Orwoll E. Serum Sclerostin Levels in Adults With Osteogenesis Imperfecta: Comparison With Normal Individuals and Response to Teriparatide Therapy. J Bone Miner Res 2018; 33:307-315. [PMID: 29044725 DOI: 10.1002/jbmr.3312] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 10/10/2017] [Accepted: 10/16/2017] [Indexed: 11/12/2022]
Abstract
Sclerostin (SOST), a glycoprotein primarily derived from osteocytes, is an important regulator of bone remodeling. Osteogenesis imperfecta (OI) is a heritable disorder of bone characterized by low bone mass, bone fragility, recurrent fractures, and bone deformities. Altered SOST-mediated signaling may have a role in pathogenesis of type I collagen-related OI; however, this has not been evaluated in humans. We measured serum SOST levels in adults with OI who were enrolled in a randomized, placebo-controlled clinical trial that evaluated the effects of osteoanabolic therapy with teriparatide. Compared with age- and sex-matched control participants, mean SOST levels were lower in those with type I or types III/VI OI (p < 0.0001). Receiver operating curve analysis revealed that sclerostin alone or sclerostin plus bone mineral content discriminated patients with OI from controls (area under the curve 0.80 and 0.87, respectively). SOST levels increased in the group of patients with type I OI during therapy with teriparatide (compared with placebo, p = 0.01). The increase was significant at 6, 12, and 24 months of therapy (p ≤ 0.02) and was apparent as early as 3 months (p = 0.06). The magnitude of increases in SOST levels during therapy was inversely correlated with increases in vertebral volumetric bone mineral density (vBMD). Overall, these results suggest that: 1) SOST regulation is fundamentally altered in osteogenesis imperfecta; 2) serum SOST levels could be a biomarker of OI in adults; and 3) alterations in SOST may help predict the response to anabolic therapies in OI. © 2017 American Society for Bone and Mineral Research.
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Affiliation(s)
- Lindsey Nicol
- Department of Pediatrics, Division of Endocrinology, Oregon Health & Sciences University, Portland, OR, USA
| | - Ying Wang
- Department of Medicine, Division of Biostatistics, Oregon Health & Sciences University, Portland, OR, USA
| | | | - John Sloan
- Lilly Research Laboratories, Indianapolis, IN, USA
| | - Sandesh Cs Nagamani
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Texas Children's Hospital, Houston, TX, USA
| | - Jay Shapiro
- Department of Bone and Osteogenesis Imperfecta, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Brendan Lee
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Texas Children's Hospital, Houston, TX, USA
| | - Eric Orwoll
- Department of Medicine, Division of Endocrinology, Oregon Health & Sciences University, Portland, OR, USA
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Holdsworth G, Greenslade K, Jose J, Stencel Z, Kirby H, Moore A, Ke HZ, Robinson MK. Dampening of the bone formation response following repeat dosing with sclerostin antibody in mice is associated with up-regulation of Wnt antagonists. Bone 2018; 107:93-103. [PMID: 29129759 DOI: 10.1016/j.bone.2017.11.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 10/03/2017] [Accepted: 11/05/2017] [Indexed: 01/08/2023]
Abstract
Administration of antibodies to sclerostin (Scl-Ab) has been shown to increase bone mass, bone mineral density (BMD) and bone strength by increasing bone formation and decreasing bone resorption in both animal studies and human clinical trials. In these studies, the magnitude and rate of increase in bone formation markers is attenuated upon repeat dosing with Scl-Ab despite a continuous and progressive increase in BMD. Here, we investigated whether the attenuation in the bone formation response following repeated administration of Scl-Ab was associated with increased expression of secreted antagonists of Wnt signalling and determined how the circulating marker of bone formation, P1NP, responded to single, or multiple doses, of Scl-Ab four days post-dosing. Female Balb/c mice were treated with Scl-Ab and we demonstrated that the large increase in serum P1NP observed following the first dose was reduced following administration of multiple doses of Scl-Ab. This dampening of the P1NP response was not due to a change in the kinetics of the bone formation marker response, or differences in exposure to the drug. The abundance of transcripts encoding several secreted Wnt antagonists was determined in femurs collected from mice following one or six doses of Scl-Ab, or vehicle treatment. Compared with vehicle controls, expression of SOST, SOST-DC1, DKK1, DKK2, SFRP1, SFRP2, FRZB, SFRP4 and WIF1 transcripts was significantly increased (approximately 1.5-4.2 fold) following a single dose of Scl-Ab. With the exception of SFRP1, these changes were maintained or further increased following six doses of Scl-Ab and the abundance of SFRP5 was also increased. Up-regulation of these Wnt antagonists may exert a negative feedback to increased Wnt signalling induced by repeated administration of Scl-Ab and could contribute to self-regulation of the bone formation response over time. After an antibody-free period of four weeks or more, the P1NP response was comparable to the naïve response, and a second phase of treatment with Scl-Ab following an antibody-free period elicited additional gains in BMD. Together, these data demonstrate that the rapid dampening of the bone formation response in the immediate post-dose period which occurs after repeat dosing of Scl-Ab is associated with increased expression of Wnt antagonists, and a treatment-free period can restore the full bone formation response to Scl-Ab.
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Affiliation(s)
| | | | | | | | - Hishani Kirby
- UCB Pharma, Slough, UK; Hishani Kirby Associates Ltd, Reading, UK
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71
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Li X, Ominsky MS, Villasenor KS, Niu QT, Asuncion FJ, Xia X, Grisanti M, Wronski TJ, Simonet WS, Ke HZ. Sclerostin Antibody Reverses Bone Loss by Increasing Bone Formation and Decreasing Bone Resorption in a Rat Model of Male Osteoporosis. Endocrinology 2018; 159:260-271. [PMID: 29069393 DOI: 10.1210/en.2017-00794] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 10/17/2017] [Indexed: 12/31/2022]
Abstract
Sclerostin antibody (Scl-Ab) restored bone mass and strength in the ovariectomized rat model of postmenopausal osteoporosis. Increased bone mineral density (BMD) and decreased skeletal fragility fracture risk have been reported in postmenopausal osteoporotic women receiving Scl-Ab. In males, loss of androgen leads to rapid decreases in BMD and an increased risk of fragility fractures. We hypothesized that Scl-Ab could reverse the loss of bone mass and strength caused by androgen ablation in the orchiectomized (ORX) rat model of male osteoporosis. We treated 9-month-old ORX Sprague Dawley rats (3 months after ORX) subcutaneously twice weekly with vehicle or Scl-Ab (5 or 25 mg/kg) for 6 weeks (n = 10 per group). Both doses of Scl-Ab fully reversed the BMD deficit in the lumbar spine and femur and tibia in ORX rats. Microcomputed tomography showed that the bone mass in the fifth lumbar vertebral body, femur diaphysis, and femoral neck were dose-dependently restored by Scl-Ab. The bone strength at these sites increased significantly with Scl-Ab to levels matching those of sham-operated controls and correlated positively with improvements in bone mineral content, demonstrating bone quality maintenance. Dynamic histomorphometry of the tibial diaphysis and second lumbar vertebral body demonstrated that Scl-Ab significantly increased bone formation on periosteal, endocortical, and trabecular surfaces and significantly decreased bone resorption on endocortical and trabecular surfaces. The effects of Scl-Ab on increasing bone formation and decreasing bone resorption led to restoration of bone mass and strength in androgen-deficient rats. These findings support the ongoing evaluation of Scl-Ab as a potential therapeutic agent for osteoporosis in men.
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Affiliation(s)
| | | | | | | | | | - Xuechun Xia
- Department of Physiological Sciences, University of Florida, Gainesville, Florida
| | | | - Thomas J Wronski
- Department of Physiological Sciences, University of Florida, Gainesville, Florida
| | | | - Hua Zhu Ke
- UCB Pharma, Slough, Berkshire, United Kingdom
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Bisson SK, Ung RV, Mac-Way F. Role of the Wnt/ β-Catenin Pathway in Renal Osteodystrophy. Int J Endocrinol 2018; 2018:5893514. [PMID: 29808090 PMCID: PMC5901476 DOI: 10.1155/2018/5893514] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 03/08/2018] [Indexed: 12/17/2022] Open
Abstract
Vascular calcification and bone fragility are common and interrelated health problems that affect chronic kidney disease (CKD) patients. Bone fragility, which leads to higher risk of fracture and mortality, arises from the abnormal bone remodeling and mineralization that are seen in chronic kidney disease. Recently, sclerostin and Dickkopf-related protein 1 were suggested to play a significant role in CKD-related bone disease as they are known inhibitors of the Wnt pathway, thus preventing bone formation. This review focuses on new knowledge about the Wnt pathway in bone, how its function is affected by chronic kidney disease and how this affects bone structure. Expression of components and inhibitors of the Wnt pathway has been shown to be affected by the loss of kidney function, and a better understanding of the bone effects of Wnt pathway inhibitors could allow the development of new therapies to prevent bone fragility in this population.
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Affiliation(s)
- Sarah-Kim Bisson
- Faculty and Department of Medicine, CHU de Québec Research Center, L'Hôtel-Dieu de Québec Hospital, Endocrinology and Nephrology Axis, Université Laval, Quebec, Canada
| | - Roth-Visal Ung
- Faculty and Department of Medicine, CHU de Québec Research Center, L'Hôtel-Dieu de Québec Hospital, Endocrinology and Nephrology Axis, Université Laval, Quebec, Canada
| | - Fabrice Mac-Way
- Faculty and Department of Medicine, CHU de Québec Research Center, L'Hôtel-Dieu de Québec Hospital, Endocrinology and Nephrology Axis, Université Laval, Quebec, Canada
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Abstract
PURPOSE OF REVIEW This review provides a summary of the current knowledge on Sost/sclerostin in cancers targeting the bone, discusses novel observations regarding its potential as a therapeutic approach to treat cancer-induced bone loss, and proposes future research needed to fully understand the potential of therapeutic approaches that modulate sclerostin function. RECENT FINDINGS Accumulating evidence shows that sclerostin expression is dysregulated in a number of cancers that target the bone. Further, new findings demonstrate that pharmacological inhibition of sclerostin in preclinical models of multiple myeloma results in a robust prevention of bone loss and preservation of bone strength, without apparent effects on tumor growth. These data raise the possibility of targeting sclerostin for the treatment of cancer patients with bone metastasis. Sclerostin is emerging as a valuable target to prevent the bone destruction that accompanies the growth of cancer cells in the bone. Further studies will focus on combining anti-sclerostin therapy with tumor-targeted agents to achieve both beneficial skeletal outcomes and inhibition of tumor progression.
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Affiliation(s)
- Michelle M McDonald
- The Garvan Institute of Medical Research, Sydney, Australia
- St. Vincent's School of Medicine, University of New South Wales, Sydney, Australia
| | - Jesus Delgado-Calle
- Division of Hematology/Oncology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA.
- Melvin and Bren Simon Cancer Center, Indianapolis, IN, USA.
- Indiana Center for Musculoskeletal Health, Indianapolis, IN, USA.
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74
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Kanis JA, Cooper C, Rizzoli R, Abrahamsen B, Al-Daghri NM, Brandi ML, Cannata-Andia J, Cortet B, Dimai HP, Ferrari S, Hadji P, Harvey NC, Kraenzlin M, Kurth A, McCloskey E, Minisola S, Thomas T, Reginster JY. Identification and management of patients at increased risk of osteoporotic fracture: outcomes of an ESCEO expert consensus meeting. Osteoporos Int 2017; 28:2023-2034. [PMID: 28451733 PMCID: PMC5483332 DOI: 10.1007/s00198-017-4009-0] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 03/10/2017] [Indexed: 12/21/2022]
Abstract
Osteoporosis represents a significant and increasing healthcare burden in Europe, but most patients at increased risk of fracture do not receive medication, resulting in a large treatment gap. Identification of patients who are at particularly high risk will help clinicians target appropriate treatment more precisely and cost-effectively, and should be the focus of future research. INTRODUCTION The purpose of the study was to review data on the identification and treatment of patients with osteoporosis at increased risk of fracture. METHODS A working group convened by the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis met to review current data on the epidemiology and burden of osteoporosis and the patterns of medical management throughout Europe. RESULTS In Europe in 2010, the cost of managing osteoporosis was estimated at €37 billion and notably the costs of treatment and long-term care of patients with fractures were considerably higher than the costs for pharmacological prevention. Despite the availability of effective treatments, the uptake of osteoporosis therapy is low and declining, in particular for secondary fracture prevention where the risk of a subsequent fracture following a first fracture is high. Consequently, there is a significant treatment gap between those who would benefit from treatment and those who receive it, which urgently needs to be addressed so that the burden of disease can be reduced. CONCLUSIONS Implementation of global fracture prevention strategies is a critical need. Future research should focus on identifying specific risk factors for imminent fractures, periods of high fracture risk, patients who are at increased risk of fracture and therapies that are most suited to such high-risk patients and optimal implementation strategies in primary, secondary and tertiary care.
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Affiliation(s)
- J A Kanis
- Centre for Metabolic Bone Diseases, University of Sheffield Medical School, Beech Hill Road, Sheffield, S10 2RX, UK.
- Institute for Health and Ageing, Catholic University of Australia, Melbourne, Australia.
| | - C Cooper
- MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK
- NIHR Musculoskeletal Biomedical Research Unit, University of Oxford, Oxford, UK
| | - R Rizzoli
- Service of Bone Diseases, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland
| | - B Abrahamsen
- Institute of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - N M Al-Daghri
- Prince Mutaib Chair for Biomarkers of Osteoporosis, Biochemistry Department, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - M L Brandi
- Department of Surgery and Translational Medicine, Unit of Bone and Mineral Diseases, University of Florence, Florence, Italy
| | - J Cannata-Andia
- Bone and Mineral Research Unit, Instituto "Reina Sofía" de Investigación, REDinREN ISCIII, Hospital Universitario Central de Asturias, Universidad de Oviedo, Asturias, Spain
| | - B Cortet
- Department of Rheumatology, Lille University Hospital, Lille, France
| | - H P Dimai
- Department of Internal Medicine, Division of Endocrinology and Diabetology, Medical University of Graz, Graz, Austria
| | - S Ferrari
- Service of Bone Diseases, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland
| | - P Hadji
- Department of Bone Oncology, Endocrinology and Reproductive Medicine, Krankenhaus Nordwest, Frankfurt, Germany
| | - N C Harvey
- MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK
| | - M Kraenzlin
- Endonet, Endocrine Clinic and Laboratory, Basel, Switzerland
| | - A Kurth
- Department of Orthopaedic Surgery and Osteology, Klinikum Frankfurt, Frankfurt, Germany
- Mayor Teaching Hospital, Charitè Medical School, Berlin, Germany
| | - E McCloskey
- Centre for Metabolic Bone Diseases, University of Sheffield Medical School, Beech Hill Road, Sheffield, S10 2RX, UK
- MRC and Arthritis Research UK Centre for Integrated Research in Musculoskeletal Ageing, Mellanby Centre for Bone Research, University of Sheffield, Sheffield, UK
| | - S Minisola
- Department of Internal Medicine and Medical Disciplines, "Sapienza" Università di Roma, Rome, Italy
| | - T Thomas
- INSERM U1059, Laboratoire Biologie Intégrée du Tissu Osseux, Rheumatology Department, CHU Saint-Etienne, Université de Lyon, Saint-Etienne, France
| | - J-Y Reginster
- Department of Public Health, Epidemiology and Health Economics, University of Liège, Liège, Belgium
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Fairfield H, Falank C, Harris E, Demambro V, McDonald M, Pettitt JA, Mohanty ST, Croucher P, Kramer I, Kneissel M, Rosen CJ, Reagan MR. The skeletal cell-derived molecule sclerostin drives bone marrow adipogenesis. J Cell Physiol 2017; 233:1156-1167. [PMID: 28460416 DOI: 10.1002/jcp.25976] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 04/27/2017] [Indexed: 01/13/2023]
Abstract
The bone marrow niche is a dynamic and complex microenvironment that can both regulate, and be regulated by the bone matrix. Within the bone marrow (BM), mesenchymal stromal cell (MSC) precursors reside in a multi-potent state and retain the capacity to differentiate down osteoblastic, adipogenic, or chondrogenic lineages in response to numerous biochemical cues. These signals can be altered in various pathological states including, but not limited to, osteoporotic-induced fracture, systemic adiposity, and the presence of bone-homing cancers. Herein we provide evidence that signals from the bone matrix (osteocytes) determine marrow adiposity by regulating adipogenesis in the bone marrow. Specifically, we found that physiologically relevant levels of Sclerostin (SOST), which is a Wnt-inhibitory molecule secreted from bone matrix-embedded osteocytes, can induce adipogenesis in 3T3-L1 cells, mouse ear- and BM-derived MSCs, and human BM-derived MSCs. We demonstrate that the mechanism of SOST induction of adipogenesis is through inhibition of Wnt signaling in pre-adipocytes. We also demonstrate that a decrease of sclerostin in vivo, via both genetic and pharmaceutical methods, significantly decreases bone marrow adipose tissue (BMAT) formation. Overall, this work demonstrates a direct role for SOST in regulating fate determination of BM-adipocyte progenitors. This provides a novel mechanism for which BMAT is governed by the local bone microenvironment, which may prove relevant in the pathogenesis of certain diseases involving marrow adipose. Importantly, with anti-sclerostin therapy at the forefront of osteoporosis treatment and a greater recognition of the role of BMAT in disease, these data are likely to have important clinical implications.
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Affiliation(s)
- Heather Fairfield
- Center for Clinical and Translational Research, Maine Medical Center Research Institute, Scarborough, Maine.,University of Maine Graduate School of Biomedical Science and Engineering, Orono, Maine.,Tufts University School of Medicine, Boston, Massachusetts
| | - Carolyne Falank
- Center for Clinical and Translational Research, Maine Medical Center Research Institute, Scarborough, Maine.,University of Maine Graduate School of Biomedical Science and Engineering, Orono, Maine.,Tufts University School of Medicine, Boston, Massachusetts
| | - Elizabeth Harris
- Center for Clinical and Translational Research, Maine Medical Center Research Institute, Scarborough, Maine.,University of Maine Graduate School of Biomedical Science and Engineering, Orono, Maine.,Tufts University School of Medicine, Boston, Massachusetts
| | - Victoria Demambro
- Center for Clinical and Translational Research, Maine Medical Center Research Institute, Scarborough, Maine.,University of Maine Graduate School of Biomedical Science and Engineering, Orono, Maine.,Tufts University School of Medicine, Boston, Massachusetts
| | | | | | - Sindhu T Mohanty
- The Garvan Institute of Medical Research, Sydney, NSW, Australia
| | - Peter Croucher
- The Garvan Institute of Medical Research, Sydney, NSW, Australia
| | - Ina Kramer
- Novartis Institutes for BioMedical Research, Basel, Switzerland
| | | | - Clifford J Rosen
- Center for Clinical and Translational Research, Maine Medical Center Research Institute, Scarborough, Maine.,University of Maine Graduate School of Biomedical Science and Engineering, Orono, Maine.,Tufts University School of Medicine, Boston, Massachusetts
| | - Michaela R Reagan
- Center for Clinical and Translational Research, Maine Medical Center Research Institute, Scarborough, Maine.,University of Maine Graduate School of Biomedical Science and Engineering, Orono, Maine.,Tufts University School of Medicine, Boston, Massachusetts
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76
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Delgado-Calle J, Anderson J, Cregor MD, Condon KW, Kuhstoss SA, Plotkin LI, Bellido T, Roodman GD. Genetic deletion of Sost or pharmacological inhibition of sclerostin prevent multiple myeloma-induced bone disease without affecting tumor growth. Leukemia 2017; 31:2686-2694. [PMID: 28529307 PMCID: PMC5699973 DOI: 10.1038/leu.2017.152] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 04/26/2017] [Accepted: 05/04/2017] [Indexed: 12/28/2022]
Abstract
Multiple myeloma (MM) causes lytic bone lesions due to increased bone
resorption and concomitant marked suppression of bone formation. Sclerostin
(Scl) levels, an osteocyte-derived inhibitor of Wnt/β-catenin signaling,
are elevated in MM patient sera and are increased in osteocytes in MM-bearing
mice. We show here that genetic deletion of Sost, the gene encoding Scl,
prevented MM-induced bone disease in an immune-deficient mouse model of early
MM, and that administration of anti-Scl antibody (Scl-Ab) increased bone mass
and decreases osteolysis in immune-competent mice with established MM. Sost/Scl
inhibition increased osteoblast numbers, stimulated new bone formation and
decreased osteoclast number in MM-colonized bone. Further, Sost/Scl inhibition
did not affect tumor growth in vivo or anti-myeloma drug
efficacy in vitro. These results identify the osteocyte as a
major contributor to the deleterious effects of MM in bone and osteocyte-derived
Scl as a promising target for the treatment of established MM-induced bone
disease. Further, Scl did not interfere with efficacy of chemotherapy for MM
suggesting that combined treatment with anti-myeloma drugs and Scl-Ab should
effectively control MM growth and bone disease, providing new avenues to
effectively control MM and bone disease in patients with active MM.
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Affiliation(s)
- J Delgado-Calle
- Department of Anatomy and Cell Biology, Indiana University, Indianapolis, IN, USA.,Roudebush Veterans Administration Medical Center, Indianapolis, IN, USA
| | - J Anderson
- Division of Hematology/Oncology, Department of Medicine, Indiana University, Indianapolis, IN, USA
| | - M D Cregor
- Department of Anatomy and Cell Biology, Indiana University, Indianapolis, IN, USA
| | - K W Condon
- Department of Anatomy and Cell Biology, Indiana University, Indianapolis, IN, USA
| | - S A Kuhstoss
- Lilly Research Laboratories, Indianapolis, Indiana, USA
| | - L I Plotkin
- Department of Anatomy and Cell Biology, Indiana University, Indianapolis, IN, USA.,Roudebush Veterans Administration Medical Center, Indianapolis, IN, USA
| | - T Bellido
- Department of Anatomy and Cell Biology, Indiana University, Indianapolis, IN, USA.,Roudebush Veterans Administration Medical Center, Indianapolis, IN, USA.,Division of Endocrinology, Department of Medicine, Indiana University School of Medicine, Indiana University, Indianapolis, IN, USA
| | - G D Roodman
- Roudebush Veterans Administration Medical Center, Indianapolis, IN, USA.,Division of Hematology/Oncology, Department of Medicine, Indiana University, Indianapolis, IN, USA
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77
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Inhibiting the osteocyte-specific protein sclerostin increases bone mass and fracture resistance in multiple myeloma. Blood 2017; 129:3452-3464. [PMID: 28515094 DOI: 10.1182/blood-2017-03-773341] [Citation(s) in RCA: 122] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 05/02/2017] [Indexed: 12/15/2022] Open
Abstract
Multiple myeloma (MM) is a plasma cell cancer that develops in the skeleton causing profound bone destruction and fractures. The bone disease is mediated by increased osteoclastic bone resorption and suppressed bone formation. Bisphosphonates used for treatment inhibit bone resorption and prevent bone loss but fail to influence bone formation and do not replace lost bone, so patients continue to fracture. Stimulating bone formation to increase bone mass and fracture resistance is a priority; however, targeting tumor-derived modulators of bone formation has had limited success. Sclerostin is an osteocyte-specific Wnt antagonist that inhibits bone formation. We hypothesized that inhibiting sclerostin would prevent development of bone disease and increase resistance to fracture in MM. Sclerostin was expressed in osteocytes from bones from naive and myeloma-bearing mice. In contrast, sclerostin was not expressed by plasma cells from 630 patients with myeloma or 54 myeloma cell lines. Mice injected with 5TGM1-eGFP, 5T2MM, or MM1.S myeloma cells demonstrated significant bone loss, which was associated with a decrease in fracture resistance in the vertebrae. Treatment with anti-sclerostin antibody increased osteoblast numbers and bone formation rate but did not inhibit bone resorption or reduce tumor burden. Treatment with anti-sclerostin antibody prevented myeloma-induced bone loss, reduced osteolytic bone lesions, and increased fracture resistance. Treatment with anti-sclerostin antibody and zoledronic acid combined increased bone mass and fracture resistance when compared with treatment with zoledronic acid alone. This study defines a therapeutic strategy superior to the current standard of care that will reduce fractures for patients with MM.
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79
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Delgado-Calle J, Bellido T. New Insights Into the Local and Systemic Functions of Sclerostin: Regulation of Quiescent Bone Lining Cells and Beige Adipogenesis in Peripheral Fat Depots. J Bone Miner Res 2017; 32:889-891. [PMID: 28370281 PMCID: PMC5489913 DOI: 10.1002/jbmr.3141] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 03/27/2017] [Indexed: 12/25/2022]
Affiliation(s)
- Jesus Delgado-Calle
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Roudebush Veterans Administration Medical Center, Indianapolis, Indiana, USA
| | - Teresita Bellido
- Department of Anatomy & Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Department of Medicine, Division of Endocrinology, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Roudebush Veterans Administration Medical Center, Indianapolis, Indiana, USA
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80
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Lim SY, Bolster MB. Profile of romosozumab and its potential in the management of osteoporosis. Drug Des Devel Ther 2017; 11:1221-1231. [PMID: 28458516 PMCID: PMC5402913 DOI: 10.2147/dddt.s127568] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Increased understanding of bone biology has led to the discovery of several unique signaling pathways that regulate bone formation and resorption. The Wnt signaling pathway plays a significant role in skeletal development, adult skeletal homeostasis, and bone remodeling. Sclerostin is an inhibitor of the Wnt signaling pathway. Romosozumab, a humanized monoclonal antibody that binds to sclerostin, prevents sclerostin from exerting this inhibitory effect. Therefore, in the presence of romosozumab, the Wnt signaling pathway is activated leading to bone formation and bone mineral density gain. Clinical studies of romosozumab have shown that this agent is one of the most potent bone anabolic agents in development to date. Romosozumab does not act solely as an anabolic agent, but rather, it has effects on increasing bone formation as well as reducing bone resorption. In the clinical studies, patients tolerated romosozumab well with no major safety signals reported. In a Phase III study, romosozumab as compared to placebo has been shown to reduce vertebral fractures by 73% after 1 year of treatment. Sequential therapy with romosozumab for 1 year followed by denosumab in the second year reduced vertebral fractures by 75% as compared to the group that received placebo for 1 year and denosumab in the second year. Romosozumab holds significant potential, by a novel mechanism of action, to expand our ability to treat osteoporosis. More studies are needed to determine the ideal setting in which romosozumab may be used to optimize osteoporosis treatment.
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Affiliation(s)
- Sian Yik Lim
- Straub Bone & Joint Center, Straub Medical Center, Honolulu, HI
| | - Marcy B Bolster
- Division of Rheumatology, Allergy & Immunology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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81
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