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Zhang X, Luo Y, Hao H, Krahn JM, Su G, Dutcher R, Xu Y, Liu J, Pedersen LC, Xu D. Heparan sulfate selectively inhibits the collagenase activity of cathepsin K. Matrix Biol 2024; 129:15-28. [PMID: 38548090 DOI: 10.1016/j.matbio.2024.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 03/18/2024] [Accepted: 03/25/2024] [Indexed: 04/09/2024]
Abstract
Cathepsin K (CtsK) is a cysteine protease with potent collagenase activity. CtsK is highly expressed by bone-resorbing osteoclasts and plays an essential role in resorption of bone matrix. Although CtsK is known to bind heparan sulfate (HS), the structural details of the interaction, and how HS regulates the biological functions of CtsK, remains largely unknown. In this report, we discovered that HS is a multifaceted regulator of the structure and function of CtsK. Structurally, HS forms a highly stable complex with CtsK and induces its dimerization. Co-crystal structures of CtsK with bound HS oligosaccharides reveal the location of the HS binding site and suggest how HS may support dimerization. Functionally, HS plays a dual role in regulating the enzymatic activity of CtsK. While it preserves the peptidase activity of CtsK by stabilizing its active conformation, it inhibits the collagenase activity of CtsK in a sulfation level-dependent manner. These opposing effects can be explained by our finding that the HS binding site is remote from the active site, which allows HS to specifically inhibit the collagenase activity without affecting the peptidase activity. At last, we show that structurally defined HS oligosaccharides effectively block osteoclast resorption of bone in vitro without inhibiting osteoclast differentiation, which suggests that HS-based oligosaccharide might be explored as a new class of selective CtsK inhibitor for many diseases involving exaggerated bone resorption.
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Affiliation(s)
- Xiaoxiao Zhang
- Department of Oral Biology, School of Dental Medicine, University at Buffalo, the State University of New York, Buffalo, NY 14214, USA
| | - Yin Luo
- Department of Oral Biology, School of Dental Medicine, University at Buffalo, the State University of New York, Buffalo, NY 14214, USA
| | - Huanmeng Hao
- Department of Oral Biology, School of Dental Medicine, University at Buffalo, the State University of New York, Buffalo, NY 14214, USA
| | - Juno M Krahn
- Macromolecular Structure Group, Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Guowei Su
- Glycan Therapeutics Corp, 617 Hutton Street, Raleigh, NC 27606, USA
| | - Robert Dutcher
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Yongmei Xu
- Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
| | - Jian Liu
- Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
| | - Lars C Pedersen
- Macromolecular Structure Group, Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Ding Xu
- Department of Oral Biology, School of Dental Medicine, University at Buffalo, the State University of New York, Buffalo, NY 14214, USA.
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Zhang X, Luo Y, Hao H, Krahn JM, Su G, Dutcher R, Xu Y, Liu J, Pedersen LC, Xu D. Heparan sulfate selectively inhibits the collagenase activity of cathepsin K. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.05.574350. [PMID: 38260317 PMCID: PMC10802503 DOI: 10.1101/2024.01.05.574350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Cathepsin K (CtsK) is a cysteine protease with potent collagenase activity. CtsK is highly expressed by bone-resorbing osteoclasts and plays an essential role in bone remodeling. Although CtsK is known to bind heparan sulfate (HS), the structural details of the interaction, and how HS ultimately regulates the biological functions of CtsK, remains largely unknown. In this report, we determined that CtsK preferably binds to larger HS oligosaccharides, such as dodecasaccharides (12mer), and that the12mer can induce monomeric CtsK to form a stable dimer in solution. Interestingly, while HS has no effect on the peptidase activity of CtsK, it greatly inhibits the collagenase activity of CtsK in a manner dependent on sulfation level. By forming a complex with CtsK, HS was able to preserve the full peptidase activity of CtsK for prolonged periods, likely by stabilizing its active conformation. Crystal structures of Ctsk with a bound 12mer, alone and in the presence of the endogenous inhibitor cystatin-C reveal the location of HS binding is remote from the active site. Mutagenesis based on these complex structures identified 6 basic residues of Ctsk that play essential roles in mediating HS-binding. At last, we show that HS 12mers can effectively block osteoclast resorption of bone in vitro. Combined, we have shown that HS can function as a multifaceted regulator of CtsK and that HS-based oligosaccharide might be explored as a new class of selective CtsK inhibitor in many diseases that involve exaggerated bone resorption.
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Affiliation(s)
- Xiaoxiao Zhang
- Department of Oral Biology, School of Dental Medicine, University at Buffalo, the State University of New York, Buffalo, NY 14214, USA
| | - Yin Luo
- Department of Oral Biology, School of Dental Medicine, University at Buffalo, the State University of New York, Buffalo, NY 14214, USA
- These authors contributed equally to this work
| | - Huanmeng Hao
- Department of Oral Biology, School of Dental Medicine, University at Buffalo, the State University of New York, Buffalo, NY 14214, USA
- These authors contributed equally to this work
| | - Juno M. Krahn
- Macromolecular Structure Group, Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Guowei Su
- Glycan Therapeutics Corp, 617 Hutton Street, Raleigh, NC 27606
| | - Robert Dutcher
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Yongmei Xu
- Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Jian Liu
- Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Lars C. Pedersen
- Macromolecular Structure Group, Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Ding Xu
- Department of Oral Biology, School of Dental Medicine, University at Buffalo, the State University of New York, Buffalo, NY 14214, USA
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Samakkarnthai P, Saul D, Zhang L, Aversa Z, Doolittle ML, Sfeir JG, Kaur J, Atkinson EJ, Edwards JR, Russell GG, Pignolo RJ, Kirkland JL, Tchkonia T, Niedernhofer LJ, Monroe DG, Lebrasseur NK, Farr JN, Robbins PD, Khosla S. In vitro and in vivo effects of zoledronic acid on senescence and senescence-associated secretory phenotype markers. Aging (Albany NY) 2023; 15:3331-3355. [PMID: 37154858 PMCID: PMC10449299 DOI: 10.18632/aging.204701] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 04/18/2023] [Indexed: 05/10/2023]
Abstract
In addition to reducing fracture risk, zoledronic acid has been found in some studies to decrease mortality in humans and extend lifespan and healthspan in animals. Because senescent cells accumulate with aging and contribute to multiple co-morbidities, the non-skeletal actions of zoledronic acid could be due to senolytic (killing of senescent cells) or senomorphic (inhibition of the secretion of the senescence-associated secretory phenotype [SASP]) actions. To test this, we first performed in vitro senescence assays using human lung fibroblasts and DNA repair-deficient mouse embryonic fibroblasts, which demonstrated that zoledronic acid killed senescent cells with minimal effects on non-senescent cells. Next, in aged mice treated with zoledronic acid or vehicle for 8 weeks, zoledronic acid significantly reduced circulating SASP factors, including CCL7, IL-1β, TNFRSF1A, and TGFβ1 and improved grip strength. Analysis of publicly available RNAseq data from CD115+ (CSF1R/c-fms+) pre-osteoclastic cells isolated from mice treated with zoledronic acid demonstrated a significant downregulation of senescence/SASP genes (SenMayo). To establish that these cells are potential senolytic/senomorphic targets of zoledronic acid, we used single cell proteomic analysis (cytometry by time of flight [CyTOF]) and demonstrated that zoledronic acid significantly reduced the number of pre-osteoclastic (CD115+/CD3e-/Ly6G-/CD45R-) cells and decreased protein levels of p16, p21, and SASP markers in these cells without affecting other immune cell populations. Collectively, our findings demonstrate that zoledronic acid has senolytic effects in vitro and modulates senescence/SASP biomarkers in vivo. These data point to the need for additional studies testing zoledronic acid and/or other bisphosphonate derivatives for senotherapeutic efficacy.
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Affiliation(s)
- Parinya Samakkarnthai
- Division of Endocrinology, Mayo Clinic, Rochester, MN 55905, USA
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN 55905, USA
- Division of Endocrinology, Phramongkutklao Hospital and College of Medicine, Bangkok 10400, Thailand
| | - Dominik Saul
- Division of Endocrinology, Mayo Clinic, Rochester, MN 55905, USA
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN 55905, USA
- Department of Trauma and Reconstructive Surgery, Eberhard Karls University Tübingen, BG Trauma Center Tübingen, Tübingen 72076, Germany
| | - Lei Zhang
- Institute on the Biology of Aging and Metabolism, Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Zaira Aversa
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN 55905, USA
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN 55905, USA
| | - Madison L. Doolittle
- Division of Endocrinology, Mayo Clinic, Rochester, MN 55905, USA
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN 55905, USA
| | - Jad G. Sfeir
- Division of Endocrinology, Mayo Clinic, Rochester, MN 55905, USA
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN 55905, USA
| | - Japneet Kaur
- Division of Endocrinology, Mayo Clinic, Rochester, MN 55905, USA
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN 55905, USA
| | | | - James R. Edwards
- Botnar Research Centre, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, OX3 7FY, UK
| | - Graham G. Russell
- Botnar Research Centre, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, OX3 7FY, UK
- Mellanby Centre for Musculoskeletal Research, University of Sheffield, Sheffield, S10 2RX, UK
| | - Robert J. Pignolo
- Division of Endocrinology, Mayo Clinic, Rochester, MN 55905, USA
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN 55905, USA
- Division of Hospital Internal Medicine, Mayo Clinic, Rochester, MN 55905, USA
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN 55905, USA
| | - James L. Kirkland
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN 55905, USA
- Division of General Internal Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | - Tamar Tchkonia
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN 55905, USA
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN 55905, USA
- Division of General Internal Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | - Laura J. Niedernhofer
- Institute on the Biology of Aging and Metabolism, Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - David G. Monroe
- Division of Endocrinology, Mayo Clinic, Rochester, MN 55905, USA
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN 55905, USA
| | - Nathan K. Lebrasseur
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN 55905, USA
- Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN 55905, USA
| | - Joshua N. Farr
- Division of Endocrinology, Mayo Clinic, Rochester, MN 55905, USA
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN 55905, USA
| | - Paul D. Robbins
- Institute on the Biology of Aging and Metabolism, Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Sundeep Khosla
- Division of Endocrinology, Mayo Clinic, Rochester, MN 55905, USA
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN 55905, USA
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4
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Samakkarnthai P, Saul D, Zhang L, Aversa Z, Doolittle ML, Sfeir JG, Kaur J, Atkinson EJ, Edwards JR, Russell RGG, Pignolo RJ, Kirkland JL, Tchkonia T, Niedernhofer LJ, Monroe DG, LeBrasseur NK, Farr JN, Robbins PD, Khosla S. In vitro and in vivo effects of zoledronate on senescence and senescence-associated secretory phenotype markers. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.23.529777. [PMID: 36865244 PMCID: PMC9980119 DOI: 10.1101/2023.02.23.529777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
In addition to reducing fracture risk, zoledronate has been found in some studies to decrease mortality in humans and extend lifespan and healthspan in animals. Because senescent cells accumulate with aging and contribute to multiple co-morbidities, the non-skeletal actions of zoledronate could be due to senolytic (killing of senescent cells) or senomorphic (inhibition of the secretion of the senescence-associated secretory phenotype [SASP]) actions. To test this, we first performed in vitro senescence assays using human lung fibroblasts and DNA repair-deficient mouse embryonic fibroblasts, which demonstrated that zoledronate killed senescent cells with minimal effects on non-senescent cells. Next, in aged mice treated with zoledronate or vehicle for 8 weeks, zoledronate significantly reduced circulating SASP factors, including CCL7, IL-1β, TNFRSF1A, and TGFβ1 and improved grip strength. Analysis of publicly available RNAseq data from CD115+ (CSF1R/c-fms+) pre-osteoclastic cells isolated from mice treated with zoledronate demonstrated a significant downregulation of senescence/SASP genes (SenMayo). To establish that these cells are potential senolytic/senomorphic targets of zoledronate, we used single cell proteomic analysis (cytometry by time of flight [CyTOF]) and demonstrated that zoledronate significantly reduced the number of pre-osteoclastic (CD115+/CD3e-/Ly6G-/CD45R-) cells and decreased protein levels of p16, p21, and SASP markers in these cells without affecting other immune cell populations. Collectively, our findings demonstrate that zoledronate has senolytic effects in vitro and modulates senescence/SASP biomarkers in vivo . These data point to the need for additional studies testing zoledronate and/or other bisphosphonate derivatives for senotherapeutic efficacy.
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5
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The Senolytic Drug Fisetin Attenuates Bone Degeneration in the Zmpste24 -/- Progeria Mouse Model. J Osteoporos 2023; 2023:5572754. [PMID: 36875869 PMCID: PMC9977556 DOI: 10.1155/2023/5572754] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 08/26/2022] [Accepted: 01/21/2023] [Indexed: 03/07/2023] Open
Abstract
Aging leads to several geriatric conditions including osteoporosis (OP) and associated frailty syndrome. Treatments for these conditions are limited and none target fundamental drivers of pathology, and thus identifying strategies to delay progressive loss of tissue homeostasis and functional reserve will significantly improve quality of life in elderly individuals. A fundamental property of aging is the accumulation of senescent cells. Senescence is a cell state defined by loss of proliferative capacity, resistance to apoptosis, and the release of a proinflammatory and anti-regenerative senescence-associated secretory phenotype (SASP). The accumulation of senescent cells and SASP factors is thought to significantly contribute to systemic aging. Senolytics-compounds which selectively target and kill senescent cells-have been characterized to target and inhibit anti-apoptotic pathways that are upregulated during senescence, which can elicit apoptosis in senescent cells and relieve SASP production. Senescent cells have been linked to several age-related pathologies including bone density loss and osteoarthritis in mice. Previous studies in murine models of OP have demonstrated that targeting senescent cells pharmacologically with senolytic drugs can reduce symptomology of the disease. Here, we demonstrate the efficacy of senolytic drugs (dasatinib, quercetin, and fisetin) to improve age-associated degeneration in bone using the Zmpste24-/- (Z24-/-) progeria murine system for Hutchinson-Gilford progeria syndrome (HGPS). We found that the combination of dasatinib plus quercetin could not significantly mitigate trabecular bone loss although fisetin administration could reduce bone density loss in the accelerated aging Z24-/- model. Furthermore, the overt bone density loss observed in the Z24-/- model reported herein highlights the Z24 model as a translational model to recapitulate alterations in bone density associated with advanced age. Consistent with the "geroscience hypothesis," these data demonstrate the utility of targeting a fundamental driver of systemic aging (senescent cell accumulation) to alleviate a common condition with age, bone deterioration.
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Babu LK, Ghosh D. Looking at Mountains: Role of Sustained Hypoxia in Regulating Bone Mineral Homeostasis in Relation to Wnt Pathway and Estrogen. Clin Rev Bone Miner Metab 2022. [DOI: 10.1007/s12018-022-09283-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Karsenty G, Khosla S. The crosstalk between bone remodeling and energy metabolism: A translational perspective. Cell Metab 2022; 34:805-817. [PMID: 35545088 PMCID: PMC9535690 DOI: 10.1016/j.cmet.2022.04.010] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 03/30/2022] [Accepted: 04/20/2022] [Indexed: 12/15/2022]
Abstract
Genetics in model organisms has progressively broken down walls that previously separated different disciplines of biology. One example of this holistic evolution is the recognition of the complex relationship that exists between the control of bone mass (bone remodeling) and energy metabolism in mammals. Numerous hormones orchestrate this crosstalk. In particular, the study of the leptin-mediated regulation of bone mass has not only revealed the existence of a central control of bone mass but has also led to the realization that sympathetic innervation is a major regulator of bone remodeling. This happened at a time when the use of drugs aiming at treating osteoporosis, the most frequent bone disease, has dwindled. This review will highlight the main aspects of the leptin-mediated regulation of bone mass and how this led to the realization that β-blockers, which block the effects of the sympathetic nervous system, may be a viable option to prevent osteoporosis.
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Affiliation(s)
- Gerard Karsenty
- Department of Genetics and Development, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA.
| | - Sundeep Khosla
- Kogod Center of Aging and Division of Endocrinology and Metabolism, Mayo Clinic College of Medicine and Science, Rochester, MN, USA.
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8
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Khosla S, Farr JN, Monroe DG. Cellular senescence and the skeleton: pathophysiology and therapeutic implications. J Clin Invest 2022; 132:154888. [PMID: 35104801 PMCID: PMC8803328 DOI: 10.1172/jci154888] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Cellular senescence is a fundamental aging mechanism that is currently the focus of considerable interest as a pathway that could be targeted to ameliorate aging across multiple tissues, including the skeleton. There is now substantial evidence that senescent cells accumulate in the bone microenvironment with aging and that targeting these cells prevents age-related bone loss, at least in mice. Cellular senescence also plays important roles in mediating the skeletal fragility associated with diabetes mellitus, radiation, and chemotherapy. As such, there are ongoing efforts to develop "senolytic" drugs that kill senescent cells by targeting key survival mechanisms in these cells without affecting normal cells. Because senescent cells accumulate across tissues with aging, senolytics offer the attractive possibility of treating multiple age-related comorbidities simultaneously.
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9
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Zhang S, Xie D, Zhang Q. Mesenchymal stem cells plus bone repair materials as a therapeutic strategy for abnormal bone metabolism: Evidence of clinical efficacy and mechanisms of action implied. Pharmacol Res 2021; 172:105851. [PMID: 34450314 DOI: 10.1016/j.phrs.2021.105851] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Revised: 08/06/2021] [Accepted: 08/22/2021] [Indexed: 12/18/2022]
Abstract
The regeneration process of human bones is very complicated, the management and treatment of bone damage caused by diseases are the main problems faced by clinicians worldwide. It is known that cell-based stem cell therapy together with biomaterials is a fast-developing method of tissue regeneration. This review focuses on the different types and main characteristics of scaffolds and stem cells suitable for bone regeneration, and aims to provide a state-of-the-art description of the current treatment of common bone metabolism related diseases such as osteoarthritis, osteoporosis and osteosarcoma and the strategies based on stem cell biological scaffolds used in bone tissue engineering. This method may provide a new treatment option for the treatment of common bone metabolism-related diseases that cannot be cured by ordinary and routine applications. Three databases (PubMed, CNKI and Web of Science) search terms used to write this review are: "arthritis", "osteoporosis", "osteosarcoma", "bone tissue engineering", "mesenchymal stem cells", "materials", "bioactive scaffolds" and their combinations, and the most relevant studies are selected. As a conclusion, it needs to be emphasized that despite the encouraging results, further development is needed due to the need for more in-depth research, standardization of stem cell manufacturing processes, large-scale development of clinical methods for bone tissue engineering, and market regulatory approval. Although the research and application of tissue regeneration technology and stem cells are still in their infancy, the application prospect is broad and it is expected to solve the current clinical problems.
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Affiliation(s)
- Shuqin Zhang
- Office of Clinical Trial of Drug, Guangdong Provincial Key Laboratory of Bone and Joint Degeneration Diseases, The Third Affiliated Hospital of Southern Medical University, China
| | - Denghui Xie
- Guangdong Provincial Key Laboratory of Bone and Joint Degeneration Diseases, The Third Affiliated Hospital of Southern Medical University, 183 West Zhongshan Avenue, Guangzhou 510000, China.
| | - Qun Zhang
- Office of Clinical Trial of Drug, Guangdong Provincial Key Laboratory of Bone and Joint Degeneration Diseases, The Third Affiliated Hospital of Southern Medical University, 183 West Zhongshan Avenue, Guangzhou 510000, China.
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10
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Khosla S, Farr JN, Tchkonia T, Kirkland JL. The role of cellular senescence in ageing and endocrine disease. Nat Rev Endocrinol 2020; 16:263-275. [PMID: 32161396 PMCID: PMC7227781 DOI: 10.1038/s41574-020-0335-y] [Citation(s) in RCA: 268] [Impact Index Per Article: 67.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/14/2020] [Indexed: 12/19/2022]
Abstract
With the ageing of the global population, interest is growing in the 'geroscience hypothesis', which posits that manipulation of fundamental ageing mechanisms will delay (in parallel) the appearance or severity of multiple chronic, non-communicable diseases, as these diseases share the same underlying risk factor - namely, ageing. In this context, cellular senescence has received considerable attention as a potential target in preventing or treating multiple age-related diseases and increasing healthspan. Here we review mechanisms of cellular senescence and approaches to target this pathway therapeutically using 'senolytic' drugs that kill senescent cells or inhibitors of the senescence-associated secretory phenotype (SASP). Furthermore, we highlight the evidence that cellular senescence has a causative role in multiple diseases associated with ageing. Finally, we focus on the role of cellular senescence in a number of endocrine diseases, including osteoporosis, metabolic syndrome and type 2 diabetes mellitus, as well as other endocrine conditions. Although much remains to be done, considerable preclinical evidence is now leading to the initiation of proof-of-concept clinical trials using senolytics for several endocrine and non-endocrine diseases.
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Affiliation(s)
- Sundeep Khosla
- Division of Endocrinology, Mayo Clinic, Rochester, MN, USA.
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, USA.
| | - Joshua N Farr
- Division of Endocrinology, Mayo Clinic, Rochester, MN, USA
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, USA
| | - Tamara Tchkonia
- Division of Endocrinology, Mayo Clinic, Rochester, MN, USA
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, USA
| | - James L Kirkland
- Division of Endocrinology, Mayo Clinic, Rochester, MN, USA.
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, USA.
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11
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Friend or Foe? Essential Roles of Osteoclast in Maintaining Skeletal Health. BIOMED RESEARCH INTERNATIONAL 2020; 2020:4791786. [PMID: 32190665 PMCID: PMC7073503 DOI: 10.1155/2020/4791786] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Accepted: 01/27/2020] [Indexed: 02/08/2023]
Abstract
Heightened activity of osteoclast is considered to be the culprit in breaking the balance during bone remodeling in pathological conditions, such as osteoporosis. As a “foe” of skeletal health, many antiosteoporosis therapies aim to inhibit osteoclastogenesis. However, bone remodeling is a dynamic process that requires the subtle coordination of osteoclasts and osteoblasts. Severe suppression of osteoclast differentiation will impair bone formation because of the coupling effect. Thus, understanding the complex roles of osteoclast in maintaining proper bone remodeling is highly warranted to develop better management of osteoporosis. This review aimed to determine the varied roles of osteoclasts in maintaining skeletal health and to highlight the positive roles of osteoclasts in maintaining normal bone remodeling. Generally, osteoclasts interact with osteocytes to initiate targeted bone remodeling and have crosstalk with mesenchymal stem cells and osteoblasts via secreted factors or cell-cell contact to promote bone formation. We believe that a better outcome of bone remodeling disorders will be achieved when proper strategies are made to coordinate osteoclasts and osteoblasts in managing such disorders.
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12
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Abstract
Cellular senescence refers to a process induced by various types of stress that causes irreversible cell cycle arrest and distinct cellular alterations, including profound changes in gene expression, metabolism, and chromatin organization as well as activation/reinforcement of anti-apoptotic pathways and development of a pro-inflammatory secretome or senescence-associated secretory phenotype (SASP). However, because of challenges and technical limitations in identifying and characterizing senescent cells in living organisms, only recently have some of the diverse in vivo roles of these unique cells been discovered. New findings indicate that senescent cells and their SASP can have acute beneficial functions, such as in tissue regeneration and wound healing. However, in contrast, when senescent cells accumulate in excess chronically at sites of pathology or in old tissues they drive multiple age-associated chronic diseases. Senotherapeutics that selectively eliminate senescent cells ("senolytics") or inhibit their detrimental SASP ("senomorphics") have been developed and tested in aged preclinical models. These studies have established that targeting senescence is a powerful anti-aging strategy to improve "healthspan" - i.e., the healthy period of life free of chronic disease. The roles of senescence in mediating age-related bone loss have been a recent focus of rigorous investigation. Studies in mice and humans demonstrate that with aging, at least a subset of most cell types in the bone microenvironment become senescent and develop a heterogeneous SASP. Furthermore, age-related bone loss can be alleviated in old mice, with apparent advantages over anti-resorptive therapy, by reducing the senescent cell burden genetically or pharmacologically with the first class of senolytics or a senomorphic. Collectively, these findings point to targeting senescence as a transformational strategy to extend healthspan, therefore providing strong rationale for identifying and optimizing senotherapeutics to alleviate multiple chronic diseases of aging, including osteoporosis, and set the stage for translating senotherapeutics to humans, with clinical trials currently ongoing.
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Affiliation(s)
- Joshua N Farr
- Division of Endocrinology and Metabolism and Kogod Center on Aging, Mayo Clinic, Rochester, MN, USA.
| | - Sundeep Khosla
- Division of Endocrinology and Metabolism and Kogod Center on Aging, Mayo Clinic, Rochester, MN, USA.
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13
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Lewiecki EM, Bilezikian JP, Giangregorio L, Greenspan SL, Khosla S, Kostenuik P, Krohn K, McClung MR, Miller PD, Pacifici R. Proceedings of the 2018 Santa Fe Bone Symposium: Advances in the Management of Osteoporosis. J Clin Densitom 2019; 22:1-19. [PMID: 30366683 DOI: 10.1016/j.jocd.2018.09.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Accepted: 09/19/2018] [Indexed: 12/16/2022]
Abstract
The Santa Fe Bone Symposium is an annual meeting devoted to clinical applications of recent advances in skeletal research. The 19th Santa Fe Bone Symposium convened August 3-4, 2018, in Santa Fe, New Mexico, USA. Attendees included physicians of many specialties, fellows in training, advanced practice providers, clinical researchers, and bone density technologists. The format consisted of lectures, case presentations by endocrinology fellows, and panel discussions, with all involving extensive interactive discussions. Topics were diverse, including an evolutionary history of calcium homeostasis, osteoporosis treatment in the very old, optimizing outcomes with orthopedic surgery, microbiome and bone, new strategies for combination and sequential therapy of osteoporosis, exercise as medicine, manifestations of parathyroid hormone excess and deficiency, parathyroid hormone as a therapeutic agent, cell senescence and bone health, and managing patients outside clinical practice guidelines. The National Bone Health Alliance conducted a premeeting on development of fracture liaison services. A workshop was devoted to Bone Health TeleECHO (Bone Health Extension for Community Healthcare Outcomes), a strategy of ongoing medical education for healthcare professions to expand capacity to deliver best practice skeletal healthcare in underserved communities and reduce the osteoporosis treatment gap.
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Affiliation(s)
- E Michael Lewiecki
- New Mexico Clinical Research & Osteoporosis Center, Albuquerque, NM, USA.
| | - John P Bilezikian
- Columbia University College of Physicians and Surgeons, NYC, NY, USA
| | - Lora Giangregorio
- University of Waterloo and Schlegel-UW Research Institute for Aging, Waterloo, Ontario, Canada
| | | | | | | | | | - Michael R McClung
- Oregon Osteoporosis Center, Portland, OR, USA; MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC, Australia
| | - Paul D Miller
- University of Colorado Health Sciences Center, Denver, CO, USA
| | - Roberto Pacifici
- Division of Endocrinology, Metabolism and Lipids, Department of Medicine, Emory University, Atlanta, GA, USA
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Aghebati‐Maleki L, Dolati S, Zandi R, Fotouhi A, Ahmadi M, Aghebati A, Nouri M, Kazem Shakouri S, Yousefi M. Prospect of mesenchymal stem cells in therapy of osteoporosis: A review. J Cell Physiol 2018; 234:8570-8578. [DOI: 10.1002/jcp.27833] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Accepted: 11/07/2018] [Indexed: 12/18/2022]
Affiliation(s)
- Leili Aghebati‐Maleki
- Immunology Research Center, Tabriz University of Medical Sciences Tabriz Iran
- Department of Immunology Faculty of Medicine, Tabriz University of Medical Sciences Tabriz Iran
| | - Sanam Dolati
- Aging Research Institute, Tabriz University of Medical Sciences Tabriz Iran
- Student Research Committee, Tabriz University of Medical Sciences Tabriz Iran
| | - Reza Zandi
- Department of Orthopedic Surgery Faculty of Medicine, Shahid Beheshti University of Medical Sciences Tehran Iran
| | - Ali Fotouhi
- Department of Orthopedic Surgery Faculty of Medicine, Shahid Beheshti University of Medical Sciences Tehran Iran
| | - Majid Ahmadi
- Department of Reproductive Biology Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences Tabriz Iran
| | - Ali Aghebati
- Immunology Research Center, Tabriz University of Medical Sciences Tabriz Iran
| | - Mohammad Nouri
- Department of Reproductive Biology Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences Tabriz Iran
| | - Seyed Kazem Shakouri
- Physical Medicine and Rehabilitation Research Centre, Tabriz University of Medical Sciences Tabriz Iran
| | - Mehdi Yousefi
- Stem Cell Research Center, Tabriz University of Medical Sciences Tabriz Iran
- Department of Immunology Faculty of Medicine, Tabriz University of Medical Sciences Tabriz Iran
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15
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Khosla S, Drake MT, Volkman TL, Thicke BS, Achenbach SJ, Atkinson EJ, Joyner MJ, Rosen CJ, Monroe DG, Farr JN. Sympathetic β1-adrenergic signaling contributes to regulation of human bone metabolism. J Clin Invest 2018; 128:4832-4842. [PMID: 30153111 DOI: 10.1172/jci122151] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 08/23/2018] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Evidence from rodent studies indicates that the sympathetic nervous system (SNS) regulates bone metabolism, principally via β2-adrenergic receptors (β2-ARs). Given the conflicting human data, we used multiple approaches to evaluate the role of the SNS in regulating human bone metabolism. METHODS Bone biopsies were obtained from 19 young and 19 elderly women for assessment of ADRB1, ADRB2, and ADRB3 mRNA expression. We examined the relationship of β-blocker use to bone microarchitecture by high-resolution peripheral quantitative CT in a population sample of 248 subjects. A total of 155 postmenopausal women were randomized to 1 of 5 treatment groups for 20 weeks: placebo; propranolol, 20 mg b.i.d.; propranolol, 40 mg b.i.d.; atenolol, 50 mg/day; or nebivolol, 5 mg/day. We took advantage of the β1-AR selectivity gradient of these drugs (propranolol [nonselective] << atenolol [relatively β1-AR selective] < nebivolol [highly β1-AR selective]) to define the β-AR selectivity for SNS effects on bone. RESULTS ADRB1 and ADRB2, but not ADRB3, were expressed in human bone; patients treated clinically with β1-AR-selective blockers had better bone microarchitecture than did nonusers, and relative to placebo, atenolol and nebivolol, but not propranolol, reduced the bone resorption marker serum C-telopeptide of type I collagen (by 19.5% and 20.6%, respectively; P < 0.01) and increased bone mineral density of the ultradistal radius (by 3.6% and 2.9%; P < 0.01 and P < 0.05, respectively). CONCLUSIONS These 3 independent lines of evidence strongly support a role for adrenergic signaling in the regulation of bone metabolism in humans, principally via β1-ARs. TRIAL REGISTRATION ClinicalTrials.gov NCT02467400. FUNDING This research was supported by the NIH (AG004875 and AR027065) and a Mayo Clinic Clinical and Translational Science Award (CTSA) (UL1 TR002377).
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Affiliation(s)
- Sundeep Khosla
- Robert and Arlene Kogod Center on Aging and Division of Endocrinology
| | - Matthew T Drake
- Robert and Arlene Kogod Center on Aging and Division of Endocrinology
| | - Tammie L Volkman
- Robert and Arlene Kogod Center on Aging and Division of Endocrinology
| | - Brianne S Thicke
- Robert and Arlene Kogod Center on Aging and Division of Endocrinology
| | | | | | - Michael J Joyner
- Department of Anesthesia, Mayo Clinic College of Medicine and Science, Rochester, Minnesota, USA
| | - Clifford J Rosen
- Maine Medical Center Research Institute, Scarborough, Maine, USA
| | - David G Monroe
- Robert and Arlene Kogod Center on Aging and Division of Endocrinology
| | - Joshua N Farr
- Robert and Arlene Kogod Center on Aging and Division of Endocrinology
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16
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Khosla S, Farr JN, Kirkland JL. Inhibiting Cellular Senescence: A New Therapeutic Paradigm for Age-Related Osteoporosis. J Clin Endocrinol Metab 2018; 103:1282-1290. [PMID: 29425296 PMCID: PMC6276719 DOI: 10.1210/jc.2017-02694] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 02/02/2018] [Indexed: 12/31/2022]
Abstract
Context With the aging of the population and projected increase in osteoporotic fractures coupled with the declining use of osteoporosis medications, there is a compelling need for new approaches to treat osteoporosis. Given that age-related osteoporosis generally coexists with multiple other comorbidities (e.g., atherosclerosis, diabetes, frailty) that share aging as the leading risk factor, there is growing interest in the "Geroscience Hypothesis," which posits that manipulation of fundamental aging mechanisms will delay the appearance or severity of multiple chronic diseases because these diseases share aging as the underlying risk factor. In this context, one fundamental aging mechanism that has received considerable attention recently as contributing to multiple age-related morbidities is cellular senescence. This mini-review provides an overview on cellular senescence with a focus on its role in mediating age-related bone loss. Methods This summary is based on the authors' knowledge of the field supplemented by a PubMed search using the terms "senescence," "aging," and "bone." Results There is compelling evidence from preclinical models and supportive human data demonstrating an increase in senescent cells in the bone microenvironment with aging. These cells produce a proinflammatory secretome that leads to increased bone resorption and decreased bone formation, and approaches that either eliminate senescent cells or impair the production of their proinflammatory secretome have been shown to prevent age-related bone loss in mice. Conclusions Targeting cellular senescence represents a novel therapeutic strategy to prevent not only bone loss but potentially multiple age-related diseases simultaneously.
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Affiliation(s)
- Sundeep Khosla
- Division of Endocrinology and Metabolism and Kogod Center on Aging, Mayo
Clinic, Rochester, Minnesota 55905
| | - Joshua N Farr
- Division of Endocrinology and Metabolism and Kogod Center on Aging, Mayo
Clinic, Rochester, Minnesota 55905
| | - James L Kirkland
- Division of Endocrinology and Metabolism and Kogod Center on Aging, Mayo
Clinic, Rochester, Minnesota 55905
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17
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Farr JN, Weivoda MM, Nicks KM, Fraser DG, Negley BA, Onken JL, Thicke BS, Ruan M, Liu H, Forrest D, Hawse JR, Khosla S, Monroe DG. Osteoprotection Through the Deletion of the Transcription Factor Rorβ in Mice. J Bone Miner Res 2018; 33:720-731. [PMID: 29206307 PMCID: PMC5925424 DOI: 10.1002/jbmr.3351] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 11/13/2017] [Accepted: 11/25/2017] [Indexed: 01/01/2023]
Abstract
There is a clinical need to identify new molecular targets for the treatment of osteoporosis, particularly those that simultaneously inhibit bone resorption while stimulating bone formation. We have previously shown in overexpression studies that retinoic acid receptor-related orphan receptor β (Rorβ) suppresses in vitro osteoblast differentiation. In addition, the expression of Rorβ is markedly increased in bone marrow-derived mesenchymal stromal cells with aging in both mice and humans. Here we establish a critical role for Rorβ in regulating bone metabolism using a combination of in vitro and in vivo studies. We used Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas9 gene editing to demonstrate that loss of Rorβ in osteoblasts enhances Wnt signaling, specifically through increased recruitment of β-catenin to T-cell factor/lymphoid enhancer factor (Tcf/Lef) DNA binding sites in the promoters of the Wnt target genes Tcf7 and Opg. This resulted in increased osteogenic gene expression and suppressed osteoclast formation through increased osteoprotegerin (OPG) secretion in Rorβ-deficient cells. Consistent with our in vitro data, genetic deletion of Rorβ in both female and male mice resulted in preserved bone mass and microarchitecture with advancing age due to increased bone formation with a concomitant decrease in resorption. The improved skeletal phenotype in the Rorβ-/- mice was also associated with increased bone protein levels of TCF7 and OPG. These data demonstrate that loss of Rorβ has beneficial skeletal effects by increasing bone formation and decreasing bone resorption, at least in part through β-catenin-dependent activation of the Wnt pathway. Thus, inhibition of Rorβ represents a novel approach to potentially prevent or reverse osteoporosis. © 2017 American Society for Bone and Mineral Research.
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Affiliation(s)
- Joshua N Farr
- Department of Medicine, Division of Endocrinology, Mayo Clinic College of Medicine, Rochester, MN, USA
- Robert and Arlene Kogod Center on Aging, Rochester, MN, USA
| | - Megan M Weivoda
- Department of Medicine, Division of Endocrinology, Mayo Clinic College of Medicine, Rochester, MN, USA
- Robert and Arlene Kogod Center on Aging, Rochester, MN, USA
| | - Kristy M Nicks
- Department of Medicine, Division of Endocrinology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Daniel G Fraser
- Department of Medicine, Division of Endocrinology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Brittany A Negley
- Department of Medicine, Division of Endocrinology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Jennifer L Onken
- Department of Medicine, Division of Endocrinology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Brianne S Thicke
- Department of Medicine, Division of Endocrinology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Ming Ruan
- Department of Medicine, Division of Endocrinology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Hong Liu
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Douglas Forrest
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), Bethesda, MD, USA
| | - John R Hawse
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Sundeep Khosla
- Department of Medicine, Division of Endocrinology, Mayo Clinic College of Medicine, Rochester, MN, USA
- Robert and Arlene Kogod Center on Aging, Rochester, MN, USA
| | - David G Monroe
- Department of Medicine, Division of Endocrinology, Mayo Clinic College of Medicine, Rochester, MN, USA
- Robert and Arlene Kogod Center on Aging, Rochester, MN, USA
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18
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Khosla S, Monroe DG. Regulation of Bone Metabolism by Sex Steroids. Cold Spring Harb Perspect Med 2018; 8:cshperspect.a031211. [PMID: 28710257 DOI: 10.1101/cshperspect.a031211] [Citation(s) in RCA: 146] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Osteoporosis is a significant public health problem, and a major cause of the disease is estrogen deficiency following menopause in women. In addition, considerable evidence now shows that estrogen is also a major regulator of bone metabolism in men. Since the original description of the effects of estrogen deficiency on bone by Fuller Albright more than 70 years ago, there has been enormous progress in understanding the mechanisms of estrogen and testosterone action on bone using human and mouse models. Although we understand more about the effects of estrogen on bone as compared with testosterone, both sex steroids do play important roles, perhaps in a somewhat compartment-specific (i.e., cancellous vs. cortical bone) manner. This review summarizes our current knowledge of sex steroid action on bone based on human and mouse studies, identifies both agreements and potential discrepancies between these studies, and suggests directions for future research in this important area.
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Affiliation(s)
- Sundeep Khosla
- Robert and Arlene Kogod Center on Aging and Endocrine Research Unit, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - David G Monroe
- Robert and Arlene Kogod Center on Aging and Endocrine Research Unit, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
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19
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Khosla S, Hofbauer LC. Osteoporosis treatment: recent developments and ongoing challenges. Lancet Diabetes Endocrinol 2017; 5:898-907. [PMID: 28689769 PMCID: PMC5798872 DOI: 10.1016/s2213-8587(17)30188-2] [Citation(s) in RCA: 567] [Impact Index Per Article: 81.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Revised: 05/16/2017] [Accepted: 05/19/2017] [Indexed: 02/07/2023]
Abstract
Osteoporosis is an enormous and growing public health problem. Once considered an inevitable consequence of ageing, it is now eminently preventable and treatable. Ironically, despite tremendous therapeutic advances, there is an increasing treatment gap for patients at high fracture risk. In this Series paper, we trace the evolution of drug therapy for osteoporosis, which began in the 1940s with the demonstration by Fuller Albright that treatment with oestrogen could reverse the negative calcium balance that developed in women after menopause or oophorectomy. We note a watershed in osteoporosis drug discovery around the year 2000, when the approach to developing novel therapeutics shifted from one driven by discoveries in animal studies and clinical observations (eg, oestrogen, calcitonin, and teriparatide) or opportunistic repurposing of existing compounds (eg, bisphosphonates) to one driven by advances in fundamental bone biology (eg, denosumab) coupled with clues from patients with rare bone diseases (eg, romosozumab, odanacatib). Despite these remarkable advances, concerns about rare side-effects of anti-resorptive drugs, particularly bisphosphonates, and the absence of clear evidence in support of their long-term efficacy is leading many patients who could benefit from drug therapy to not take these drugs. As such, there remains an important clinical need to develop ways to enhance patient acceptance and compliance with these effective drugs, and to continue to develop new drugs that do not cause these side-effects and have prolonged anabolic effects on bone. Such changes could lead to a true reversal of this potentially devastating disease of ageing.
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Affiliation(s)
- Sundeep Khosla
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, USA; Endocrine Research Unit, Mayo Clinic College of Medicine and Science, Mayo Clinic, Rochester, MN, USA.
| | - Lorenz C Hofbauer
- Division of Endocrinology, Diabetes, and Bone Diseases, Carl Gustav Carus University Hospital, Dresden Technical University, Dresden, Germany; Centre for Healthy Aging, Carl Gustav Carus University Hospital, Dresden Technical University, Dresden, Germany
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20
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Targeting cellular senescence prevents age-related bone loss in mice. Nat Med 2017; 23:1072-1079. [PMID: 28825716 PMCID: PMC5657592 DOI: 10.1038/nm.4385] [Citation(s) in RCA: 766] [Impact Index Per Article: 109.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 07/13/2017] [Indexed: 11/08/2022]
Abstract
Aging is associated with increased cellular senescence, which is hypothesized to drive the eventual development of multiple comorbidities. Here we investigate a role for senescent cells in age-related bone loss through multiple approaches. In particular, we used either genetic (i.e., the INK-ATTAC 'suicide' transgene encoding an inducible caspase 8 expressed specifically in senescent cells) or pharmacological (i.e., 'senolytic' compounds) means to eliminate senescent cells. We also inhibited the production of the proinflammatory secretome of senescent cells using a JAK inhibitor (JAKi). In aged (20- to 22-month-old) mice with established bone loss, activation of the INK-ATTAC caspase 8 in senescent cells or treatment with senolytics or the JAKi for 2-4 months resulted in higher bone mass and strength and better bone microarchitecture than in vehicle-treated mice. The beneficial effects of targeting senescent cells were due to lower bone resorption with either maintained (trabecular) or higher (cortical) bone formation as compared to vehicle-treated mice. In vitro studies demonstrated that senescent-cell conditioned medium impaired osteoblast mineralization and enhanced osteoclast-progenitor survival, leading to increased osteoclastogenesis. Collectively, these data establish a causal role for senescent cells in bone loss with aging, and demonstrate that targeting these cells has both anti-resorptive and anabolic effects on bone. Given that eliminating senescent cells and/or inhibiting their proinflammatory secretome also improves cardiovascular function, enhances insulin sensitivity, and reduces frailty, targeting this fundamental mechanism to prevent age-related bone loss suggests a novel treatment strategy not only for osteoporosis, but also for multiple age-related comorbidities.
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21
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Drake MT, Clarke BL, Oursler MJ, Khosla S. Cathepsin K Inhibitors for Osteoporosis: Biology, Potential Clinical Utility, and Lessons Learned. Endocr Rev 2017; 38:325-350. [PMID: 28651365 PMCID: PMC5546879 DOI: 10.1210/er.2015-1114] [Citation(s) in RCA: 162] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 06/20/2017] [Indexed: 12/24/2022]
Abstract
Cathepsin K is a cysteine protease member of the cathepsin lysosomal protease family. Although cathepsin K is highly expressed in osteoclasts, lower levels of cathepsin K are also found in a variety of other tissues. Secretion of cathepsin K from the osteoclast into the sealed osteoclast-bone cell interface results in efficient degradation of type I collagen. The absence of cathepsin K activity in humans results in pycnodysostosis, characterized by increased bone mineral density and fractures. Pharmacologic cathepsin K inhibition leads to continuous increases in bone mineral density for ≤5 years of treatment and improves bone strength at the spine and hip. Compared with other antiresorptive agents, cathepsin K inhibition is nearly equally efficacious for reducing biochemical markers of bone resorption but comparatively less active for reducing bone formation markers. Despite multiple efforts to develop cathepsin K inhibitors, potential concerns related to off-target effects of the inhibitors against other cathepsins and cathepsin K inhibition at nonbone sites, including skin and perhaps cardiovascular and cerebrovascular sites, prolonged the regulatory approval process. A large multinational randomized, double-blind phase III study of odanacatib in postmenopausal women with osteoporosis was recently completed. Although that study demonstrated clinically relevant reductions in fractures at multiple sites, odanacatib was ultimately withdrawn from the regulatory approval process after it was found to be associated with an increased risk of cerebrovascular accidents. Nonetheless, the underlying biology and clinical effects of cathepsin K inhibition remain of considerable interest and could guide future therapeutic approaches for osteoporosis.
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Affiliation(s)
- Matthew T. Drake
- Division of Endocrinology and Kogod Center on Aging, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - Bart L. Clarke
- Division of Endocrinology and Kogod Center on Aging, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - Merry Jo Oursler
- Division of Endocrinology and Kogod Center on Aging, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - Sundeep Khosla
- Division of Endocrinology and Kogod Center on Aging, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
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22
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Abstract
The Wnt/β-catenin signaling pathway plays an essential role in osteoblast biology. Sclerostin is a soluble antagonist of Wnt/β-catenin signaling secreted primarily by osteocytes. Current evidence indicates that sclerostin likely functions as a local/paracrine regulator of bone metabolism rather than as an endocrine hormone. Nonetheless, circulating sclerostin levels in humans often reflect changes in the bone microenvironment, although there may be exceptions to this observation. Using existing assays, circulating sclerostin levels have been shown to be altered in response to both hormonal stimuli and across a variety of normal physiological and pathophysiological conditions. In both rodents and humans, parathyroid hormone provided either intermittently or continuously suppresses sclerostin levels. Likewise, most evidence from both human and animal studies supports a suppressive effect of estrogen on sclerostin levels. Efforts to examine non-hormonal/systemic regulation of sclerostin have in general shown less consistent findings or have provided associations rather than direct interventional information, with the exception of mechanosensory studies which have consistently demonstrated increased sclerostin levels with skeletal unloading, and conversely decreases in sclerostin with enhanced skeletal loading. Herein, we will review the existent literature on both hormonal and non-hormonal/systemic factors which have been studied for their impact on sclerostin regulation.
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Affiliation(s)
- Matthew T Drake
- Department of Endocrinology, Kogod Center on Aging, Mayo Clinic College of Medicine, Rochester, MN, USA.
| | - Sundeep Khosla
- Department of Endocrinology, Kogod Center on Aging, Mayo Clinic College of Medicine, Rochester, MN, USA
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23
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Bahuguna R, Jain A, Khan SA, Arvind MS. Role of odanacatib in reducing bone loss due to endodontic disease: An overview. J Int Soc Prev Community Dent 2017; 6:S175-S181. [PMID: 28217533 PMCID: PMC5285591 DOI: 10.4103/2231-0762.197183] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Aims and Objectives: Through a comprehensive literature review, this article provides an overview of the potential role of odanacatib (ODN) in reducing bone loss due to endodontic disease. Materials and Methods: A literature review was performed in PubMed Central, MEDLINE, Cochrane Library, and EBSCO databases. The articles identified included those published between 2002 and 2016. Based on the predetermined inclusion and exclusion criteria, out of 237 articles found, 50 were selected for this review. Results: Cathepsin K (CstK), which is indispensible to the immune system, also plays an important role in osteoclastic bone resorption. ODN, which is an orally active, selective, and effective inhibitor of CstK, decreases bone resorption by selectively inhibiting proteolysis of matrix proteins by CstK, without affecting other osteoclastic activity or osteoblast viability. Conclusion: The goal of endodontic treatment is to achieve a clinically asymptomatic state along with formation of reparative bone. This process could take 6 months or longer, hence, an earlier reversal of the resorption process could lead to faster healing and resolution of the periapical lesion. Use of ODN can be of help in achieving this goal.
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Affiliation(s)
- Rachana Bahuguna
- Department of Pedodontics, RKDF Dental College and Research Centre, Bhopal, Madhya Pradesh, India
| | - Atul Jain
- Department of Conservative Dentistry and Endodontics, RKDF Dental College and Research Centre, Bhopal, Madhya Pradesh, India
| | - Suleman Abbas Khan
- Department of Pedodontics, RKDF Dental College and Research Centre, Bhopal, Madhya Pradesh, India
| | - M S Arvind
- Department of Conservative Dentistry and Endodontics, RKDF Dental College and Research Centre, Bhopal, Madhya Pradesh, India
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24
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Khan A, Fortier M. Ostéoporose pendant la ménopause. JOURNAL OF OBSTETRICS AND GYNAECOLOGY CANADA 2016; 38:S465-S483. [DOI: 10.1016/j.jogc.2016.09.057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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25
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Choi HJ. New antiresorptive therapies for postmenopausal osteoporosis. J Menopausal Med 2015; 21:1-11. [PMID: 26046031 PMCID: PMC4452807 DOI: 10.6118/jmm.2015.21.1.1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2015] [Revised: 03/19/2015] [Accepted: 03/25/2015] [Indexed: 12/18/2022] Open
Abstract
Osteoporosis is a systemic skeletal disease whose risk increases with age and it is common among postmenopausal women. Currently, almost all pharmacological agents for osteoporosis target the bone resorption component of bone remodeling activity. Current antiresorptive agents are effective, but the effectiveness of some agents is limited by real or perceived intolerance, longterm adverse events (AEs), coexisting comorbidities, and inadequate long-term adherence. New antiresorptive therapies that may expand options for the prevention and treatment of osteoporosis include denosumab, combination of conjugated estrogen/bazedoxifene and cathepsin K inhibitors. However, the long-term efficacy and AEs of these antiresorptive therapies need to be confirmed in studies with a longer follow-up period.
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Affiliation(s)
- Hee-Jeong Choi
- Department of Family Medicine, Eulji University School of Medicine, Daejeon, Korea
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26
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Gajic-Veljanoski O, Tomlinson G, Srighanthan J, Adachi JD, Josse R, Brown JP, Cheung AM. Effect of odanacatib on BMD and fractures: estimates from Bayesian univariate and bivariate meta-analyses. J Clin Endocrinol Metab 2014; 99:3070-9. [PMID: 24823462 DOI: 10.1210/jc.2014-1162] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
CONTEXT Odanacatib (ODN), a selective cathepsin-K inhibitor, was found to increase bone mineral density (BMD); the effect on fractures is based on adverse event reports. OBJECTIVE To estimate current effects and predict future effects of ODN on BMD and fractures. DATA SOURCES Electronic databases (Medline, EMBASE, Cochrane Library), conference proceedings, and bibliographies. STUDY SELECTION Trials that compared ODN 50 mg/wk to placebo for at least 1 year and reported changes in BMD or fractures. Meta-analysis: Two bone outcomes were pooled as independent and as joint outcomes in Bayesian univariate and bivariate random-effects models. DATA SYNTHESIS Of 32 potentially eligible articles, six citations describing four trials (993 patients) were included. ODN for 3 years increased mean BMD at the lumbar spine by 5.0% (95% credible interval [CrI], 2.7, 7.5), total hip by 3.6% (95% CrI, 1.6, 5.9), and femoral neck (FN) by 3.6% (95% CrI, 1.6, 5.7). In a future trial of 3-year duration, the predicted mean increase in BMD, adjusted for the effect on fractures, was 4.9% for lumbar spine (95% CrI, 2.5, 7.4), 3.4% for total hip (95% CrI, 1.7, 5.2), and 3.5% for FN (95% CrI, 1.8, 5.3). After accounting for the effect on FN BMD, ODN for 3 years was associated with a population odds ratio of 0.38 (95% CrI, 0.1, 0.8). In a future trial, the odds ratio was 0.41 (95% CrI, 0.1, 1.1). The probability of benefit on fractures was 96-99%. The estimates remained robust in sensitivity analyses. CONCLUSIONS Our analyses suggest that ODN will increase BMD and decrease all fractures in the fracture outcome trial; however, direct demonstration of this antifracture efficacy is needed.
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Affiliation(s)
- Olga Gajic-Veljanoski
- Osteoporosis Program (O.G.-V., J.S., A.M.C.), University Health Network/Mt Sinai Hospital, Toronto, ON M5G 2C4, Canada; Institute of Health Policy, Management and Evaluation (G.T., A.M.C.), and Department of Medicine (G.T., R.J., A.M.C.), University of Toronto, Toronto, ON M5T 3M6, Canada; St Joseph's Healthcare and McMaster University (J.D.A.), Hamilton, ON L8N 1Y2, Canada; St Michael's Hospital (R.J.), Toronto, ON M5C 2T2, Canada; and Centre Hospitalier Universitaire de Québec Research Centre and Laval University (J.P.B.), Quebec, QC G1V 4G2, Canada
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Affiliation(s)
- Dennis M Black
- Department of Epidemiology and Biostatistics, University of California, San Francisco, CA, USA
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Takeshita S, Fumoto T, Matsuoka K, Park KA, Aburatani H, Kato S, Ito M, Ikeda K. Osteoclast-secreted CTHRC1 in the coupling of bone resorption to formation. J Clin Invest 2013; 123:3914-24. [PMID: 23908115 DOI: 10.1172/jci69493] [Citation(s) in RCA: 164] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Accepted: 05/31/2013] [Indexed: 12/18/2022] Open
Abstract
Bone remodeling is characterized by the sequential, local tethering of osteoclasts and osteoblasts and is key to the maintenance of bone integrity. While bone matrix-mobilized growth factors, such as TGF-β, are proposed to regulate remodeling, no in vivo evidence exists that an osteoclast-produced molecule serves as a coupling factor for bone resorption to formation. We found that CTHRC1, a protein secreted by mature bone-resorbing osteoclasts, targets stromal cells to stimulate osteogenesis. Cthrc1 expression was robustly induced when mature osteoclasts were placed on dentin or hydroxyapatite, and also by increasing extracellular calcium. Cthrc1 expression in bone increased in a high-turnover state (such as that induced by RANKL injections in vivo), but decreased in conditions associated with suppressed bone turnover (such as with aging and after alendronate treatment). Targeted deletion of Cthrc1 in mice eliminated Cthrc1 expression in bone, whereas its deficiency in osteoblasts did not exert any significant effect. Osteoclast-specific deletion of Cthrc1 resulted in osteopenia due to reduced bone formation and impaired the coupling process after resorption induced by RANKL injections, impairing bone mass recovery. These data demonstrate that CTHRC1 is an osteoclast-secreted coupling factor that regulates bone remodeling.
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Affiliation(s)
- Sunao Takeshita
- Department of Bone and Joint Disease, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan.
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Langdahl B, Binkley N, Bone H, Gilchrist N, Resch H, Rodriguez Portales J, Denker A, Lombardi A, Le Bailly De Tilleghem C, Dasilva C, Rosenberg E, Leung A. Odanacatib in the treatment of postmenopausal women with low bone mineral density: five years of continued therapy in a phase 2 study. J Bone Miner Res 2012; 27:2251-8. [PMID: 22777865 DOI: 10.1002/jbmr.1695] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Odanacatib (ODN) is a selective inhibitor of the collagenase cathepsin K that is highly expressed by osteoclasts. In this 2-year, phase 2, dose-ranging trial, postmenopausal women with bone mineral density (BMD) T-scores -2.0 to -3.5 at spine or hip were randomized to weekly placebo or ODN 3, 10, 25, or 50 mg plus vitamin D(3) and calcium. Prespecified trial-extensions continued through 5 years. In year 3, all women were re-randomized to ODN 50 mg or placebo. For years 4 and 5, women who received placebo or ODN 3 mg in years 1 and 2 and placebo in year 3 received ODN 50 mg; others continued year 3 treatments. Endpoints included lumbar spine (primary), hip, 1/3 radius, and total body BMD; markers of bone metabolism; and safety. Women in the year 4 to 5 extension receiving placebo (n = 41) or ODN 50 mg (n = 100) had similar baseline characteristics. For women who received ODN (10-50 mg) for 5 years, spine and hip BMD increased over time. With ODN 50 mg continually for 5 years (n = 13), mean lumbar spine BMD percent change from baseline (95% confidence interval [CI]) was 11.9% (7.2% to 16.5%) versus -0.4% (-3.1% to 2.3%) for women who were switched from ODN 50 mg to placebo after 2 years (n = 14). In pooled results of women receiving continuous ODN (10-50 mg, n = 26-29), year 5 geometric mean percent changes from baseline in bone resorption markers cross-linked N-telopeptide of type I collagen (NTX)/creatinine and cross-linked C-telopeptide (CTX) were approximately -55%, but near baseline for bone formation markers bone-specific alkaline phosphatase (BSAP) and amino-terminal propeptide of type I procollagen (P1NP). In women switched from ODN 10 to 50 mg to placebo after 2 years (n = 25), bone turnover markers were near baseline. In summary, women receiving combinations of ODN (10-50 mg) for 5 years had gains in spine and hip BMD and showed larger reductions in bone resorption than bone formation markers. Discontinuation of ODN resulted in reversal of treatment effects. Treatment with ODN for up to 5 years was generally well-tolerated.
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Affiliation(s)
- Bente Langdahl
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark.
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Abstract
Cathepsin K is a key enzyme involved in the degradation of organic bone matrix by osteoclasts. Inhibition of bone resorption observed in human and animal models deficient for cathepsin K has identified this enzyme as a suitable target for intervention by small molecules with the potential to be used as therapeutic agents in the treatment of osteoporosis. Odanacatib (ODN) is a nonbasic selective cathepsin K inhibitor with good pharmacokinetic parameters such as minimal in vitro metabolism, long half-life, and oral bioavailability. In preclinical studies, ovariectomized monkeys and rabbits treated with ODN showed substantial inhibition of bone resorption markers along with increases in bone mineral density (BMD). Significant differences were observed in the effects of ODN treatment compared with those of other antiresorptive agents such as bisphosphonates and denosumab. ODN displayed compartment-specific effects on trabecular versus cortical bone formation, with treatment resulting in marked increases in periosteal bone formation and cortical thickness in ovariectomized monkeys whereas trabecular bone formation was reduced. Furthermore, osteoclasts remained viable. Phase I and II studies conducted in postmenopausal women showed ODN to be safe and well tolerated. After 5 years, women who received ODN 50 mg weekly continuously from year 1 (n = 13), showed BMD increases from baseline of 11.9% at the lumbar spine, 9.8% at the femoral neck, 10.9% at the hip trochanter, and 8.5% at the total hip. Additionally, these subjects maintained a low level of the urine bone resorption marker N-terminal telopeptide/creatinine (−67.4% from baseline) through 5 years of treatment, while levels of serum bone-specific alkaline phosphatase remained only slightly reduced relative to baseline (−15.3%). In women who were switched from ODN to placebo after 2 years, bone turnover markers were transiently increased and BMD gains reversed after 12 months off medication. Adverse experiences in the ODN-treated group were not significantly different from the placebo group. In conclusion, available data suggests that cathepsin K inhibition could be a promising intervention with which to treat osteoporosis. Ongoing studies are expected to provide information on the long-term efficacy in fracture reduction and safety of prolonged treatment with ODN.
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Affiliation(s)
- Kong Wah Ng
- Department of Endocrinology and Diabetes and St Vincent's Institute, St Vincent's Hospital, Fitzroy, Victoria, Australia.
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