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Jha SS. Biologics: Teriparatide and Newer Anabolics. Indian J Orthop 2023; 57:135-146. [PMID: 38107803 PMCID: PMC10721587 DOI: 10.1007/s43465-023-01063-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 11/14/2023] [Indexed: 12/19/2023]
Abstract
The landscape of osteoporosis management has evolved significantly over the years, witnessing a paradigm shift from conventional therapies to the emergence of biologic agents. This chapter delves into the intricate mechanisms, potential applications, and future directions of biologic interventions in osteoporosis care. Biologic agents, with their targeted approach to bone health, have revolutionized the field by offering precision-driven strategies that address the underlying mechanisms of bone fragility. This chapter explores the mechanisms of action of various biologics, including Receptor Activator of Nuclear Factor Kappa-B Ligand (RANKL) inhibitors, monoclonal antibodies targeting sclerostin, parathyroid hormone (PTH) analogues, and cathepsin K inhibitors. It discusses their potential benefits, limitations, and safety considerations, while shedding light on the promise of combination therapies that merge biologic agents with traditional approaches. Furthermore, the chapter delves into the potential applications of biologic agents in specific patient populations, the role of biomarkers in predicting treatment responses, and the influence of emerging biological targets. It also explores the advancements in novel targets and drug delivery systems that aim to enhance treatment convenience and effectiveness. By tailoring treatments based on patient characteristics and exploring novel therapeutic targets, the chapter envisions a future of precision medicine in osteoporosis care. As research continues to evolve, the chapter anticipates a transformative impact on bone health outcomes, fracture prevention, and overall quality of life for individuals at risk of osteoporosis-related fractures. Through comprehensive insights into the mechanisms, applications, and future directions of biologic agents, this chapter offers a holistic perspective on the evolving landscape of osteoporosis management.
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Affiliation(s)
- Shiva Shankar Jha
- Harishchandra Institute of Orthopaedics & Research, Allahabad, India
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Zhang X, Chang M, Wang B, Liu X, Zhang Z, Han G. YAP/WNT5A/FZD4 axis regulates osteogenic differentiation of human periodontal ligament cells under cyclic stretch. J Periodontal Res 2023; 58:907-918. [PMID: 37340863 DOI: 10.1111/jre.13143] [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: 12/08/2022] [Revised: 05/07/2023] [Accepted: 05/15/2023] [Indexed: 06/22/2023]
Abstract
OBJECTIVE To verify the role of YAP/WNT5A/FZD4 axis in stretch-induced osteogenic differentiation of hPDLCs. BACKGROUND During orthodontic tooth movement, differentiation of human periodontal ligament cells (hPDLCs) at the tension side of the periodontal ligament mediates new bone formation. WNT5A promotes osteogenesis and its regulator Yes-associated protein (YAP) is responsive to mechanical stimulation in hPDLCs. However, the mechanisms of YAP and WNT5A in alveolar bone remodeling remain unclear. METHODS Cyclic stretch was applied to hPDLCs to mimic the orthodontic stretching force. Osteogenic differentiation was determined by alkaline phosphatase (ALP) activity, Alizarin Red staining, qRT-PCR and western blotting. To detect activation of YAP and expression of WNT5A and its receptor Frizzled-4 (FZD4), western blotting, immunofluorescence, qRT-PCR and ELISA were performed. Verteporfin, Lats-IN-1, small interfering RNAs and recombinant protein were used to explore the relationship of YAP, WNT5A and FZD4, and the effect of their relationship on stretch-induced osteogenesis of hPDLCs. RESULTS WNT5A, FZD4 and nuclear localization of YAP were upregulated by cyclic stretch. YAP positively regulated WNT5A and FZD4 expression and osteogenic differentiation of hPDLCs under cyclic stretch by YAP inhibition or activation assay. Knockdown of WNT5A and FZD4 attenuated YAP-induced and stretch-induced osteogenic differentiation. Recombinant WNT5A rescued the suppressed osteogenic differentiation by YAP inhibitor in hPDLCs, whereas knockdown of FZD4 weakened the effect of WNT5A and amplified the suppression. CONCLUSIONS WNT5A/FZD4 could be positively regulated by YAP and the YAP/WNT5A/FZD4 axis mediated osteogenic differentiation of hPDLCs under cyclic stretch. This study provided further insight into the biological mechanism of orthodontic tooth movement.
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Affiliation(s)
- Xiaocen 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
| | - Maolin Chang
- 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
- Orthodontic Department Division II, School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Beike Wang
- 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
- Orthodontic Department Division II, School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Xiaoyu Liu
- 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
| | - Zhen 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
- Orthodontic Department Division II, School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Guangli Han
- 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
- Orthodontic Department Division II, School & Hospital of Stomatology, Wuhan University, Wuhan, China
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Ahmadi A, Mazloomnejad R, Kasravi M, Gholamine B, Bahrami S, Sarzaeem MM, Niknejad H. Recent advances on small molecules in osteogenic differentiation of stem cells and the underlying signaling pathways. Stem Cell Res Ther 2022; 13:518. [PMID: 36371202 PMCID: PMC9652959 DOI: 10.1186/s13287-022-03204-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 10/09/2022] [Indexed: 11/15/2022] Open
Abstract
Bone-related diseases are major contributors to morbidity and mortality in elderly people and the current treatments result in insufficient healing and several complications. One of the promising areas of research for healing bone fractures and skeletal defects is regenerative medicine using stem cells. Differentiating stem cells using agents that shift cell development towards the preferred lineage requires activation of certain intracellular signaling pathways, many of which are known to induce osteogenesis during embryological stages. Imitating embryological bone formation through activation of these signaling pathways has been the focus of many osteogenic studies. Activation of osteogenic signaling can be done by using small molecules. Several of these agents, e.g., statins, metformin, adenosine, and dexamethasone have other clinical uses but have also shown osteogenic capacities. On the other hand, some other molecules such as T63 and tetrahydroquinolines are not as well recognized in the clinic. Osteogenic small molecules exert their effects through the activation of signaling pathways known to be related to osteogenesis. These pathways include more well-known pathways including BMP/Smad, Wnt, and Hedgehog as well as ancillary pathways including estrogen signaling and neuropeptide signaling. In this paper, we review the recent data on small molecule-mediated osteogenic differentiation, possible adjunctive agents with these molecules, and the signaling pathways through which each small molecule exerts its effects.
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Affiliation(s)
- Armin Ahmadi
- Department of Pharmacology, School of Medicine, Shahid Beheshti University of Medical Sciences, P.O. Box: 1985711151, Tehran, Iran
| | - Radman Mazloomnejad
- Department of Pharmacology, School of Medicine, Shahid Beheshti University of Medical Sciences, P.O. Box: 1985711151, Tehran, Iran
| | - Mohammadreza Kasravi
- Department of Pharmacology, School of Medicine, Shahid Beheshti University of Medical Sciences, P.O. Box: 1985711151, Tehran, Iran
| | - Babak Gholamine
- Department of Pharmacology, School of Medicine, Shahid Beheshti University of Medical Sciences, P.O. Box: 1985711151, Tehran, Iran
| | - Soheyl Bahrami
- Ludwig Boltzmann Institute for Experimental and Clinical Traumatology in AUVA Research Center, Vienna, Austria
| | - Mohammad Mahdi Sarzaeem
- Department of Orthopedic Surgery, Imam Hossein Medical Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hassan Niknejad
- Department of Pharmacology, School of Medicine, Shahid Beheshti University of Medical Sciences, P.O. Box: 1985711151, Tehran, Iran.
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Yao W, Wei X, Guo H, Cheng D, Li H, Sun L, Wang S, Guo D, Yang Y, Si J. Tributyltin reduces bone mineral density by reprograming bone marrow mesenchymal stem cells in rat. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2020; 73:103271. [PMID: 31627035 DOI: 10.1016/j.etap.2019.103271] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 10/03/2019] [Accepted: 10/04/2019] [Indexed: 06/10/2023]
Abstract
Tributyltin (TBT), a proven endocrine disrupter, was widely used in industry and agriculture. Previous research showed that TBT could alter the balance between osteogenesis and adipogenesis, which may have significant consequences for bone health. Herein, we exposed male rats to TBT chloride (TBTCl) to evaluate the deleterious effects of TBT on bone. Exposure to 50 μg kg-1 TBT resulted in a significant decrease in bone mineral density (BMD) at the femur diaphysis region in the rat. A dose-dependent increase in lipid accumulation and adipocyte number was observed in the bone marrow (BM) of the femur. Meanwhile, TBTCl treatment significantly enhanced the expression of PPARγ and attenuated the expression of Runx2 and β-catenin in BM. In addition, serum ALP activity of TBT-exposed rats also showed a dose-dependent decrease. These results suggest that TBT could reduce BMD via inhibition of the Wnt/β-catenin pathway and skew the adipo-osteogenic balance in the BM of rats.
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Affiliation(s)
- Wenhuan Yao
- Institute of Preventive Medicine, Shandong University, Jinan, China; Department of Toxicology, Shandong Center for Disease Control and Prevention, Jinan, China
| | - Xinglong Wei
- Institute of Preventive Medicine, Shandong University, Jinan, China; Department of Environmental Health, School of Public Health, Shandong University, Jinan, China
| | - Hao Guo
- Institute of Preventive Medicine, Shandong University, Jinan, China; Department of Environmental Health, School of Public Health, Shandong University, Jinan, China
| | - Dong Cheng
- Institute of Preventive Medicine, Shandong University, Jinan, China; Department of Toxicology, Shandong Center for Disease Control and Prevention, Jinan, China
| | - Hui Li
- Institute of Preventive Medicine, Shandong University, Jinan, China; Department of Toxicology, Shandong Center for Disease Control and Prevention, Jinan, China
| | - Limin Sun
- Orthopedics Department, Shandong Provincial Third Hospital, Jinan, China
| | - Shu'e Wang
- Institute of Preventive Medicine, Shandong University, Jinan, China; Department of Environmental Health, School of Public Health, Shandong University, Jinan, China
| | - Dongmei Guo
- Institute of Preventive Medicine, Shandong University, Jinan, China; Department of Environmental Health, School of Public Health, Shandong University, Jinan, China
| | - Yanli Yang
- Department of Environmental Health, School of Public Health, Shandong University, Jinan, China
| | - Jiliang Si
- Institute of Preventive Medicine, Shandong University, Jinan, China; Department of Environmental Health, School of Public Health, Shandong University, Jinan, China.
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George EL, Truesdell SL, Magyar AL, Saunders MM. The effects of mechanically loaded osteocytes and inflammation on bone remodeling in a bisphosphonate-induced environment. Bone 2019; 127:460-473. [PMID: 31301402 DOI: 10.1016/j.bone.2019.07.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 07/03/2019] [Accepted: 07/08/2019] [Indexed: 12/23/2022]
Abstract
Bisphosphonate-related osteonecrosis of the jaw is a disease appearing after tooth removal in patients undergoing bisphosphonate treatment for metastasizing cancers and osteoporosis. The complexity of the condition requires a multicellular model to address the net effects of two key risk factors: mechanical trauma (pathologic overload) and inflammation. In this work, a system comprised of a polydimethylsiloxane chip and mechanical loading device is used to expose bisphosphonate-treated osteocytes to mechanical trauma. Specifically, osteocytes are treated with the potent nitrogen-containing bisphosphonate, zoledronic acid, and exposed to short-term pathologic overload via substrate stretch. During bone remodeling, osteocyte apoptosis plays a role in attracting pre-osteoclasts to sites of damage; as such, lactate dehydrogenase activity, cell death and protein expression are evaluated as functions of load. Additionally, the effects of osteocyte soluble factors on osteoclast and osteoblast functional activity are quantified. Osteoclast activity and bone resorption are quantified in the presence and absence of inflammatory components, lipopolysaccharide and interferon gamma. Results suggest that inflammation associated with bacterial infection may hinder bone resorption by osteoclasts. In addition, osteocytes may respond to overload by altering expression of soluble signals that act on osteoblasts to attenuate bone formation. These findings give insight into the multicellular interactions implicated in bisphosphonate-related osteonecrosis of the jaw.
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Affiliation(s)
- Estee L George
- The University of Akron, Olson Research Center 319, 302 E. Buchtel Ave., Akron, OH 44325-0302, USA.
| | - Sharon L Truesdell
- The University of Akron, Olson Research Center 319, 302 E. Buchtel Ave., Akron, OH 44325-0302, USA.
| | - Alexandria L Magyar
- The University of Akron, Olson Research Center 319, 302 E. Buchtel Ave., Akron, OH 44325-0302, USA.
| | - Marnie M Saunders
- The University of Akron, Olson Research Center 319, 302 E. Buchtel Ave., Akron, OH 44325-0302, USA.
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Exendin-4 regulates Wnt and NF-κB signaling in lipopolysaccharide-induced human periodontal ligament stem cells to promote osteogenic differentiation. Int Immunopharmacol 2019; 75:105801. [PMID: 31401384 DOI: 10.1016/j.intimp.2019.105801] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 07/12/2019] [Accepted: 07/31/2019] [Indexed: 11/24/2022]
Abstract
A major feature of chronic periodontitis (CP) is the damage and destruction of alveolar bone. Periodontal ligament stem cells (PDLSCs) can differentiate into bone and improve CP. Exendin-4 (Ex-4) has been shown to have anti-inflammatory mechanisms and can promote bone regeneration. However, the effects of Ex-4 on the osteogenic differentiation of PDLSCs in the inflammatory microenvironment remains uncharacterized. In this study, we assessed the effects of Ex-4 on PDLSCs stimulated with lipopolysaccharide (LPS) to mimic the inflammatory environment. PDLSCs proliferation was assessed through CCK-8 assays and osteogenic differentiation was measured using Alizarin Red staining. The anti-inflammatory and osteogenic mechanisms of Ex-4 were assessed by western blot, RT-PCR, ELISA and immunofluorescence. We found that LPS treatment promoted the proliferative capacity of PDLSCs and inhibited their osteogenic differentiation. However, Ex-4 reversed these effects through suppressing PDLSCs proliferation and promoting osteogenic differentiation. Ex-4 increased Runx2, ALP, and Osx levels and decreased TNF-α and IL-6 expression. Ex-4 also reduced the expression of IκBα and p-IκBα, and inhibited the nuclear translocation of NF-κB/p65. The expression of β-catenin decreased in nucleus after co-treatment of Ex-4 with LPS. Taken together, these data demonstrate that Ex-4 promotes PDLSCs osteogenic differentiation in the inflammatory microenvironment through regulating NF-κB and Wnt signaling.
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7
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Higher Sclerostin/SOST expression is associated with lower percentage of circulatory blasts and better prognosis in patients with myelofibrosis. Ann Hematol 2018. [DOI: 10.1007/s00277-018-3294-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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8
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Luo G, Liu H, Lu H. Glucagon-like peptide-1(GLP-1) receptor agonists: potential to reduce fracture risk in diabetic patients? Br J Clin Pharmacol 2016; 81:78-88. [PMID: 27099876 DOI: 10.1111/bcp.12777] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
This review summarizes current knowledge about glucagon-like peptide 1 receptor agonists (GLP-1 RA) and their effects on bone metabolism and fracture risk. Recent in vivo and in vitro experiments indicated that GLP-1 RA could improve bone metabolism. GLP-1 could affect the fat-bone axis by promoting osteogenic differentiation and inhibiting adipogenic differentiation of bone mesenchymal precursor cells (BMSCs), which express the GLP-1 receptor. GLP-1 RA may also influence the balance between osteoclasts and osteoblasts, thus leading to more bone formation and less bone resorption. Wnt/β-catenin signalling is involved in this process. Mature osteocytes, which also express the GLP-1 receptor, produce sclerostin which inhibits Wnt/β-catenin signalling by binding to low density lipoprotein receptor-related protein (LRP) 5 and preventing the binding of Wnt. GLP-1 RA also decreases the expression of sclerostin (SOST) and circulating levels of SOST. In addition, GLP-1 receptors are expressed in thyroid C cells, where GLP-1 induces calcitonin release and thus indirectly inhibits bone resorption. Furthermore, GLP-1 RA influences the osteoprotegerin(OPG)/receptor activator of nuclear factor-κB ligand (RANKL)/receptor activator of nuclear factor-κB (RANK) system by increasing OPG gene expression, and thus reverses the decreased bone mass in rats models. However, a recent meta-analysis and a cohort study did not show a significant relationship between GLP-RA use and fracture risk. Future clinical trials will be necessary to investigate thoroughly the relationship between GLP-1 RA use and fracture risk in diabetic patients.
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Yao W, Dai W, Jiang L, Lay EYA, Zhong Z, Ritchie RO, Li X, Ke H, Lane NE. Sclerostin-antibody treatment of glucocorticoid-induced osteoporosis maintained bone mass and strength. Osteoporos Int 2016; 27:283-294. [PMID: 26384674 PMCID: PMC4958115 DOI: 10.1007/s00198-015-3308-6] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 08/25/2015] [Indexed: 12/18/2022]
Abstract
UNLABELLED This study was to determine if antibody against sclerostin (Scl-Ab) could prevent glucocorticoid (GC)-induced osteoporosis in mice. We found that Scl-Ab prevented GC-induced reduction in bone mass and bone strength and that the anabolic effects of Scl-Ab might be partially achieved through the preservation of osteoblast activity through autophagy. INTRODUCTION Glucocorticoids (GCs) inhibit bone formation by altering osteoblast and osteocyte cell activity and lifespan. A monoclonal antibody against sclerostin, Scl-Ab, increased bone mass in both preclinical animal and clinical studies in subjects with low bone mass. The objectives of this study were to determine if treatment with the Scl-Ab could prevent loss of bone mass and strength in a mouse model of GC excess and to elucidate if Scl-Ab modulated bone cell activity through autophagy. METHODS We generated reporter mice that globally expressed dsRed fused to LC3, a protein marker for autophagosomes, and evaluated the dose-dependent effects of GCs (0, 0.8, 2.8, and 4 mg/kg/day) and Scl-Ab on autophagic osteoblasts, bone mass, and bone strength. RESULTS GC treatment at 2.8 and 4 mg/kg/day of methylprednisolone significantly lowered trabecular bone volume (Tb-BV/TV) at the lumbar vertebrae and distal femurs, cortical bone mass at the mid-shaft femur (FS), and cortical bone strength compared to placebo (PL). In mice treated with GC and Scl-Ab, Tb-BV/TV increased by 60-125 %, apparent bone strength of the lumbar vertebrae by 30-70 %, FS-BV by 10-18 %, and FS-apparent strength by 13-15 %, as compared to GC vehicle-treated mice. GC treatment at 4 mg/kg/day reduced the number of autophagic osteoblasts by 70 % on the vertebral trabecular bone surface compared to the placebo group (PL, GC 0 mg), and GC + Scl-Ab treatment. CONCLUSIONS Treatment with Scl-Ab prevented GC-induced reduction in both trabecular and cortical bone mass and strength and appeared to maintain osteoblast activity through autophagy.
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Affiliation(s)
- W. Yao
- Center for Musculoskeletal Health, Internal Medicine, University of California at Davis Medical Center, Sacramento, CA 95817, USA
| | - W. Dai
- Center for Musculoskeletal Health, Internal Medicine, University of California at Davis Medical Center, Sacramento, CA 95817, USA
- Science and Technology Experimental Center, Integrative Medicine Discipline, Longhua Hospital Shanghai University of Traditional Chinese Medicine, Shanghai 200032, China
| | - L. Jiang
- Center for Musculoskeletal Health, Internal Medicine, University of California at Davis Medical Center, Sacramento, CA 95817, USA
| | - E. Y.-A. Lay
- Center for Musculoskeletal Health, Internal Medicine, University of California at Davis Medical Center, Sacramento, CA 95817, USA
| | - Z. Zhong
- Center for Musculoskeletal Health, Internal Medicine, University of California at Davis Medical Center, Sacramento, CA 95817, USA
| | - R. O. Ritchie
- Department of Materials Science and Engineering, University of California at Berkeley, Berkeley, CA 94720, USA
| | - X. Li
- Department of Metabolic Disorders, Amgen Inc., Thousand Oaks, CA, USA
| | - H. Ke
- Department of Metabolic Disorders, Amgen Inc., Thousand Oaks, CA, USA
| | - N. E. Lane
- Center for Musculoskeletal Health, Internal Medicine, University of California at Davis Medical Center, Sacramento, CA 95817, USA
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Beier EE, Maher JR, Sheu TJ, Cory-Slechta DA, Berger AJ, Zuscik MJ, Puzas JE. Heavy metal lead exposure, osteoporotic-like phenotype in an animal model, and depression of Wnt signaling. ENVIRONMENTAL HEALTH PERSPECTIVES 2013; 121:97-104. [PMID: 23086611 PMCID: PMC3552813 DOI: 10.1289/ehp.1205374] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2012] [Accepted: 10/19/2012] [Indexed: 05/21/2023]
Abstract
BACKGROUND Exposure to lead (Pb) from environmental and industrial sources remains an overlooked serious public health risk. Elucidating the effect of Pb on bone cell function is therefore critical for understanding its risk associated with diseases of low bone mass. OBJECTIVES We tested the hypothesis that Pb negatively affects bone mass. We also assessed the underlying mechanisms of Pb on bone signaling pathways. METHODS We used a model of low-level Pb exposure in a rodent beginning before conception and continuing over 18 months. We characterized the effect of Pb on bone quality using dual-energy X-ray absorptiometry (DXA), micro-computed tomography, Raman spectroscopy, and histology. We assessed the effect of Pb on bone and adipocyte formation by mineral deposition, lipid droplet formation, and Western blot and RNA analysis. RESULTS Pb-exposed animals had decreased bone mass that resulted in bones that were more susceptible to fracture. Pb decreased osteoblastic cell number leading to a depression of bone formation. Accompanying this, Pb exposure elevated sclerostin protein levels in the skeleton, and correspondingly reduced levels of β-catenin and Runx2 in stromal precursor cells. Pb also increased skeletal expression of peroxisome proliferator-activated receptor-γ (PPAR-γ). These results indicate a shift in mesenchymal differentiation wherein Pb promoted enhanced adipogenesis and decreased osteoblastogenesis. Substantial differences in bone marrow composition were observed, highlighted by an increase in adipocytes. CONCLUSIONS The disruption Pb has on bone mass and bone homeostasis is principally explained by inhibition of the Wnt/β-catenin pathway, which may provide a molecular basis for novel therapeutic strategies to combat Pb-induced bone pathologies.
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Affiliation(s)
- Eric E Beier
- Center for Musculoskeletal Research, University of Rochester, School of Medicine and Dentistry, Rochester, New York, USA
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Assar R, Leisewitz AV, Garcia A, Inestrosa NC, Montecino MA, Sherman DJ. Reusing and composing models of cell fate regulation of human bone precursor cells. Biosystems 2012; 108:63-72. [PMID: 22309764 DOI: 10.1016/j.biosystems.2012.01.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Revised: 12/28/2011] [Accepted: 01/19/2012] [Indexed: 01/22/2023]
Abstract
In order to treat osteoporosis and other bone mass disorders it is necessary to understand the regulatory processes that control the cell fate decisions responsible for going from bone precursor cells to bone tissue. Many processes interact to regulate cell division, differentiation and apoptosis. There are models for these basic processes, but not for their interactions. In this work we use the theory of switched systems, reuse and composition of validated models to describe the cell fate decisions leading to bone and fat formation. We describe the differentiation of osteo-adipo progenitor cells by composing its model with differentiation stimuli. We use the activation of the Wnt pathway as stimulus to osteoblast lineage, including regulation of cell division and apoptosis. This model is our first step to simulate physiological responses in silico to treatments for bone mass disorders.
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Affiliation(s)
- Rodrigo Assar
- INRIA Bordeaux Sud-Ouest, Project-team (EPC) MAGNOME common to INRIA, CNRS, Talence, France.
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Salari Sharif P, Abdollahi M, Larijani B. Current, new and future treatments of osteoporosis. Rheumatol Int 2010; 31:289-300. [PMID: 20676643 DOI: 10.1007/s00296-010-1586-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2010] [Accepted: 07/14/2010] [Indexed: 11/24/2022]
Abstract
Osteoporosis as a common chronic disease is challenging human health. Although different therapeutic options are routinely used for prevention/treatment of osteoporosis, their side effects and benefits are under question. Increasing our knowledge about signaling pathways in bone and osteocytes as well as osteoblasts and osteoclasts will help us in designing new therapeutic modalities for osteoporosis. In the present study, all new therapeutic measures of osteoporosis have been reviewed. For this purpose, search engines like Pubmed, Web of Science, Scopus, Google Scholar were searched and all relevant articles were found. The study was limited to the year 1998-2010. Bisphosphonates are the cornerstone of osteoporosis treatment, but there are not enough relevant studies that investigated their equivalencies in comparison with each other or the other medications. Therefore, medication selection is empirical and subjective. Furthermore, no eminent study has compared certain combinations. There are new hopes for treatment of osteoporosis, which are more specific with less harm. Our results show that new and emerging therapies are more potent and target specified which more individualize osteoporosis treatment; however, more investigations on their safety and efficacy in comparison with current medications are highly recommended.
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Affiliation(s)
- Pooneh Salari Sharif
- Medical Ethics and History of Medicine Research Center, Tehran University of Medical Sciences, 3rd floor, 21# 16 Azar Ave, Tehran, Iran.
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Haussler MR, Haussler CA, Whitfield GK, Hsieh JC, Thompson PD, Barthel TK, Bartik L, Egan JB, Wu Y, Kubicek JL, Lowmiller CL, Moffet EW, Forster RE, Jurutka PW. The nuclear vitamin D receptor controls the expression of genes encoding factors which feed the "Fountain of Youth" to mediate healthful aging. J Steroid Biochem Mol Biol 2010; 121:88-97. [PMID: 20227497 PMCID: PMC2906618 DOI: 10.1016/j.jsbmb.2010.03.019] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2010] [Accepted: 03/08/2010] [Indexed: 12/13/2022]
Abstract
The nuclear vitamin D receptor (VDR) binds 1,25-dihydroxyvitamin D3 (1,25D), its high affinity renal endocrine ligand, to signal intestinal calcium and phosphate absorption plus bone remodeling, generating a mineralized skeleton free of rickets/osteomalacia with a reduced risk of osteoporotic fractures. 1,25D/VDR signaling regulates the expression of TRPV6, BGP, SPP1, LRP5, RANKL and OPG, while achieving feedback control of mineral ions to prevent age-related ectopic calcification by governing CYP24A1, PTH, FGF23, PHEX, and klotho transcription. Vitamin D also elicits numerous intracrine actions when circulating 25-hydroxyvitamin D3, the metabolite reflecting vitamin D status, is converted to 1,25D locally by extrarenal CYP27B1, and binds VDR to promote immunoregulation, antimicrobial defense, xenobiotic detoxification, anti-inflammatory/anticancer actions and cardiovascular benefits. VDR also affects Wnt signaling through direct interaction with beta-catenin, ligand-dependently blunting beta-catenin mediated transcription in colon cancer cells to attenuate growth, while potentiating beta-catenin signaling via VDR ligand-independent mechanisms in osteoblasts and keratinocytes to function osteogenically and as a pro-hair cycling receptor, respectively. Finally, VDR also drives the mammalian hair cycle in conjunction with the hairless corepressor by repressing SOSTDC1, S100A8/S100A9, and PTHrP. Hair provides a shield against UV-induced skin damage and cancer in terrestrial mammals, illuminating another function of VDR that facilitates healthful aging.
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Affiliation(s)
- Mark R Haussler
- Department of Basic Medical Sciences, The University of Arizona, College of Medicine-Phoenix in partnership with Arizona State University, Phoenix, AZ 85004-2157, United States.
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Abstract
Mechanical loading is of pivotal importance in the maintenance of skeletal homeostasis, but the players involved in the transduction of mechanical stimuli to promote bone maintenance have long remained elusive. Osteocytes, the most abundant cells in bone, possess mechanosensing appendices stretching through a system of bone canaliculi. Mechanical stimulation plays an important role in osteocyte survival and hence in the preservation of bone mechanical properties, through the maintenance of bone hydratation. Osteocytes can also control the osteoblastic differentiation of mesenchymal precursors in response to mechanical loading by modulating WNT signaling pathways, essential regulators of cell fate and commitment, through the protein sclerostin. Mutations of Sost, the sclerostin-encoding gene, have dramatic effects on the skeleton, indicating that osteocytes may act as master regulators of bone formation and localized bone remodeling. Moreover, the development of sclerostin inhibitors is opening new possibilities for bone regeneration in orthopedics and the dental field.
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Girdlestone J, Limbani VA, Cutler AJ, Navarrete CV. Efficient expansion of mesenchymal stromal cells from umbilical cord under low serum conditions. Cytotherapy 2010; 11:738-48. [PMID: 19878060 DOI: 10.3109/14653240903079401] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Mesenchymal stromal cells (MSC) are of clinical interest for their potential use in regenerative medicine and immunotherapy. Originally derived from bone marrow (BM), MSC have now been isolated from most tissues, including umbilical cord (UC) and UC blood (UCB). If MSC from UC are biologically equivalent to those from BM, they would be attractive as a readily available and non-invasive source for cellular therapies. METHODS Sections of UC were separated into vascular and Wharton's jelly (WJ) fractions, which were then digested individually to release MSC that were isolated by plastic adherence in a 10% fetal calf serum (FCS) medium, or a low serum medium designed for multipotent adult progenitor cells (MAPC). The resulting perivascular (PV) and WJ MSC lines were assayed for expression of characteristic markers and differentiation and immunosuppressive properties. RESULTS MSC lines were readily derived from most UC tested. Cells grown in MAPC medium (MM) tended to be smaller and more elongated and expressed more nestin, but did not differ substantially in their growth rate, expression of other markers and differentiation capacity. All UC lines tested were adipogenic but poorly osteogenic, and were equivalent in their ability to suppress T-cell proliferation induced by phytohemagglutinin (PHA), activation beads and allostimulation. CONCLUSIONS UC is a convenient, efficient source of MSC that can be expanded under low serum conditions for application on future studies of tissue regeneration and immunosuppression.
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Affiliation(s)
- John Girdlestone
- National Health Service Blood and Transplant, Histocompatibility and Immunogenetics Research Group, Colindale Centre, London, UK.
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16
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Pelletier JC, Lundquist JT, Gilbert AM, Alon N, Bex FJ, Bhat BM, Bursavich MG, Coleburn VE, Felix LA, Green DM, Green P, Hauze DB, Kharode YP, Lam HS, Lockhead SR, Magolda RL, Matteo JJ, Mehlmann JF, Milligan C, Murrills RJ, Pirrello J, Selim S, Sharp MC, Unwalla RJ, Vera MD, Wrobel JE, Yaworsky P, Bodine PVN. (1-(4-(Naphthalen-2-yl)pyrimidin-2-yl)piperidin-4-yl)methanamine: A Wingless β-Catenin Agonist That Increases Bone Formation Rate. J Med Chem 2009; 52:6962-5. [DOI: 10.1021/jm9014197] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
| | | | - Adam M. Gilbert
- Chemical Sciences, Wyeth Research, 401 N. Middletown Road, Pearl River, New York 10965
| | - Nipa Alon
- Chemical Sciences, Wyeth Research, 401 N. Middletown Road, Pearl River, New York 10965
| | | | | | - Mattew G. Bursavich
- Chemical Sciences, Wyeth Research, 401 N. Middletown Road, Pearl River, New York 10965
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Johnson ML, Lara N, Kamel MA. How genomics has informed our understanding of the pathogenesis of osteoporosis. Genome Med 2009; 1:84. [PMID: 19735586 PMCID: PMC2768991 DOI: 10.1186/gm84] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Osteoporosis is a skeletal disorder characterized by compromised bone strength that predisposes a person to an increased risk of fracture. Osteoporosis is a complex trait that involves multiple genes, environmental factors, and gene-gene and gene-environment interactions. Twin and family studies have indicated that between 25% and 85% of the variation in bone mass and other skeletal phenotypes is heritable, but our knowledge of the underlying genes is limited. Bone mineral density is the most common assessment for diagnosing osteoporosis and is the most often used quantitative value in the design of genetic studies. In recent years, our understanding of the pathophysiology of osteoporosis has been greatly facilitated by advances brought about by the Human Genome Project. Genetic approaches ranging from family studies of monogenic traits to association studies with candidate genes, to whole-genome scans in both humans and animals have identified a small number of genes that contribute to the heritability of bone mass. Studies with transgenic and knockout mouse models have revealed major new insights into the biology of many of these identified genes, but much more needs to be learned. Ultimately, we hope that by revealing the underlying genetics and biology driving the pathophysiology of osteoporosis, new and effective treatment can be developed to combat and possibly cure this devastating disease. Here we review the rapidly evolving field of the genomics of osteoporosis with a focus on important gene discoveries, new biological/physiological paradigms that are emerging, and many of the unanswered questions and hurdles yet to be overcome in the field.
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Affiliation(s)
- Mark L Johnson
- Department of Oral Biology, University of Missouri - Kansas City School of Dentistry, 650 East 25th Street, Kansas City, MO 64108, USA.
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Abstract
During the past 10 years we have experienced very significant developments in our understanding of bone biology, and this has improved our abilities to both diagnose and treat patients with osteoporosis. This review covers some of the significant discoveries in bone biology that have led to a better understanding of osteoporosis, including a few of the discoveries that have been translated into new therapies to treat patients with osteoporosis and the structural deterioration of patients with inflammatory arthritis.
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Affiliation(s)
- Nancy E Lane
- Aging Center, Medicine and Rheumatology, Department of Medicine, University of California at Davis Medical School, Sacramento, CA 95817, USA
| | - Wei Yao
- Aging Center, Medicine and Rheumatology, Department of Medicine, University of California at Davis Medical School, Sacramento, CA 95817, USA
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