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Allbritton-King JD, Maity J, Patel A, Colbert RA, Navid F, Bhattacharyya T. VEGF Secretion Drives Bone Formation in Classical MAP2K1+ Melorheostosis. J Bone Miner Res 2023; 38:1834-1845. [PMID: 37737377 PMCID: PMC10872821 DOI: 10.1002/jbmr.4915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 09/11/2023] [Accepted: 09/17/2023] [Indexed: 09/23/2023]
Abstract
Patients with classical melorheostosis exhibit exuberant bone overgrowth in the appendicular skeleton, resulting in pain and deformity with no known treatment. Most patients have somatic, mosaic mutations in MAP2K1 (encoding the MEK1 protein) in osteoblasts and overlying skin. As with most rare bone diseases, lack of affected tissue has limited the opportunity to understand how the mutation results in excess bone formation. The aim of this study was to create a cellular model to study melorheostosis. We obtained patient skin cells bearing the MAP2K1 mutation (affected cells), and along with isogenic control normal fibroblasts reprogrammed them using the Sendai virus method into induced pluripotent stem cells (iPSCs). Pluripotency was validated by marker staining and embryoid body formation. iPSCs were then differentiated to mesenchymal stem cells (iMSCs) and validated by flow cytometry. We confirmed retention of the MAP2K1 mutation in iMSCs with polymerase chain reaction (PCR) and confirmed elevated MEK1 activity by immunofluorescence staining. Mutation-bearing iMSCs showed significantly elevated vascular endothelial growth factor (VEGF) secretion, proliferation and collagen I and IV secretion. iMSCs were then differentiated into osteoblasts, which showed increased mineralization at 21 days and increased VEGF secretion at 14 and 21 days of differentiation. Administration of VEGF to unaffected iMSCs during osteogenic differentiation was sufficient to increase mineralization. Blockade of VEGF by bevacizumab reduced mineralization in iMSC-derived affected osteoblasts and in affected primary patient-derived osteoblasts. These data indicate that patient-derived induced pluripotent stem cells recreate the elevated MEK1 activity, increased mineralization, and increased proliferation seen in melorheostosis patients. The increased bone formation is driven, in part, by abundant VEGF secretion. Modifying the activity of VEGF (a known stimulator of osteoblastogenesis) represents a promising treatment pathway to explore. iPSCs may have wide applications to other rare bone diseases. © 2023 American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Jules D Allbritton-King
- Clinical and Investigative Orthopedics Surgery Unit, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Jyotirindra Maity
- Clinical and Investigative Orthopedics Surgery Unit, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Amit Patel
- Clinical and Investigative Orthopedics Surgery Unit, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Robert A Colbert
- Pediatric Translational Research Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Fatemeh Navid
- Pediatric Translational Research Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Timothy Bhattacharyya
- Clinical and Investigative Orthopedics Surgery Unit, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
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2
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Visconti RJ, Kolaja K, Cottrell JA. A functional three-dimensional microphysiological human model of myeloma bone disease. J Bone Miner Res 2021; 36:1914-1930. [PMID: 34173283 DOI: 10.1002/jbmr.4404] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 06/09/2021] [Accepted: 06/22/2021] [Indexed: 12/12/2022]
Abstract
Human myeloma bone disease (MBD) occurs when malignant plasma cells migrate to the bone marrow and commence inimical interactions with stromal cells, disrupting the skeletal remodeling process. The myeloma cells simultaneously suppress osteoblastic bone formation while promoting excessive osteoclastic resorption. This bone metabolism imbalance produces osteolytic lesions that cause chronic bone pain and reduce trabecular and cortical bone structural integrity, and often culminate in pathological fractures. Few bone models exist that enable scientists to study MBD and the effect therapies have on restoring the bone metabolism imbalance. The purpose of this research was to develop a well characterized three-dimensional (3D) bone organoid that could be used to study MBD and current or potential treatment options. First, bone marrow stromal cell-derived osteoblasts (OBs) mineralized an endosteal-like extracellular matrix (ECM) over 21 days. Multiple analyses confirmed the generation of hydroxyapatite (HA)-rich bone-like tissue fragments that were abundant in alkaline phosphatase, calcium, and markers of osteoblastic gene expression. On day 22, bone marrow macrophage (BMM)-derived osteoclasts (OCs) were introduced to enhance the resorptive capability of the model and recapitulate the balanced homeostatic nature of skeletal remodeling. Tartrate-resistant acid phosphatase 5b (TRAcP-5b), type I collagen C-telopeptide (CTX-1), and gene expression analysis confirmed OC activity in the normal 3D organoid (3D in vitro model of normal bonelike fragments [3D-NBF]). On day 30, a human multiple myeloma (MM)-derived plasmacytoma cell line was introduced to the 3D-NBF to generate the 3D-myeloma bone disease organoid (3D-MBD). After 12 days, the 3D-MBD had significantly reduced total HA, increased TRAcP-5b levels, increases levels of CTX-1, and decreased expression of osteoblastic genes. Therapeutic intervention with pharmaceutical agents including an immunomodulatory drug, a bisphosphonate, and monoclonal restored HA content and reduced free CTX-1 in a dose-dependent manner. This osteogenically functional model of MBD provides a novel tool to study biological mechanisms guiding the disease and to screen potential therapeutics. © 2021 American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Richard J Visconti
- Department of Biological Sciences, Seton Hall University, South Orange, New Jersey, USA.,Investigative Toxicology, Nonclinical Research and Development, Bristol Myers Squibb, Summit, New Jersey, USA
| | - Kyle Kolaja
- Investigative Toxicology, Nonclinical Research and Development, Bristol Myers Squibb, Summit, New Jersey, USA
| | - Jessica A Cottrell
- Department of Biological Sciences, Seton Hall University, South Orange, New Jersey, USA
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3
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Indermaur M, Casari D, Kochetkova T, Peruzzi C, Zimmermann E, Rauch F, Willie B, Michler J, Schwiedrzik J, Zysset P. Compressive Strength of Iliac Bone ECM Is Not Reduced in Osteogenesis Imperfecta and Increases With Mineralization. J Bone Miner Res 2021; 36:1364-1375. [PMID: 33740286 PMCID: PMC8359849 DOI: 10.1002/jbmr.4286] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 03/03/2021] [Accepted: 03/07/2021] [Indexed: 01/13/2023]
Abstract
Osteogenesis imperfecta (OI) is an inheritable, genetic, and collagen-related disorder leading to an increase in bone fragility, but the origin of its "brittle behavior" is unclear. Because of its complex hierarchical structure, bone behaves differently at various length scales. This study aims to compare mechanical properties of human OI bone with healthy control bone at the extracellular matrix (ECM) level and to quantify the influence of the degree of mineralization. Degree of mineralization and mechanical properties were analyzed under dry conditions in 12 fixed and embedded transiliac crest biopsies (control n = 6, OI type I n = 3, OI type IV n = 2, and OI type III n = 1). Mean degree of mineralization was measured by microcomputed tomography at the biopsy level and the mineral-to-matrix ratio was assessed by Raman spectroscopy at the ECM level. Both methods revealed that the degree of mineralization is higher for OI bone compared with healthy control. Micropillar compression is a novel technique for quantifying post-yield properties of bone at the ECM level. Micropillars (d = 5 μm, h = 10 μm) were fabricated using focused ion beam milling and quasi-statically compressed to capture key post-yield properties such as ultimate strength. The qualitative inspection of the stress-strain curves showed that both OI and healthy control bone have a ductile response at the ECM level. The quantitative results showed that compressive strength is not reduced in OI bone and is increasing with OI severity. Nanoindentation measurements revealed that OI bone tends to have a higher Young's modulus, hardness, and dissipated energy compared with healthy bone. Micropillar strength and indentation modulus increased linearly and significantly (p < .0001) with mineral-to-matrix ratio. In conclusion, this study indicates that compressive mechanical properties of dry OI bone at the iliac crest are not inferior to healthy control at the ECM level and increase with mineralization. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Michael Indermaur
- ARTORG Center for Biomedical Engineering ResearchUniversity of BernBernSwitzerland
| | - Daniele Casari
- Swiss Federal Laboratories for Material Science and Technology, EmpaThunSwitzerland
| | - Tatiana Kochetkova
- Swiss Federal Laboratories for Material Science and Technology, EmpaThunSwitzerland
| | - Cinzia Peruzzi
- Swiss Federal Laboratories for Material Science and Technology, EmpaThunSwitzerland
| | | | - Frank Rauch
- Shriners Hospital for ChildrenMontrealCanada
- McGill UniversityMontrealCanada
| | - Bettina Willie
- Shriners Hospital for ChildrenMontrealCanada
- McGill UniversityMontrealCanada
| | - Johann Michler
- Swiss Federal Laboratories for Material Science and Technology, EmpaThunSwitzerland
| | - Jakob Schwiedrzik
- Swiss Federal Laboratories for Material Science and Technology, EmpaThunSwitzerland
| | - Philippe Zysset
- ARTORG Center for Biomedical Engineering ResearchUniversity of BernBernSwitzerland
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4
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Ross RD, Anderson K, Davison R, El-Masri BM, Andreasen CM, Andersen TL, Sumner DR. Osteoporosis Treatments Affect Bone Matrix Maturation in a Rat Model of Induced Cortical Remodeling. JBMR Plus 2020; 4:e10344. [PMID: 32258964 PMCID: PMC7117844 DOI: 10.1002/jbm4.10344] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 01/19/2020] [Indexed: 11/20/2022] Open
Abstract
To test how osteoporosis drugs affect bone matrix maturation during cortical bone remodeling, 72 pregnant rats were switched from a 0.4% to a 0.01% calcium diet at parturition for a 23‐day lactation period. At weaning, eight dams were sacrificed to establish baseline values, while the remaining dams were returned to 0.4% calcium and treated with vehicle (saline), sodium fluoride (NaF), zoledronic acid (ZA), or sclerostin antibody (Scl‐Ab) for either 7 or 28 days (eight animals per group per time point). Femora were examined by μCT, dynamic histomorphometry, Fourier transform infrared imaging, and three‐point bending of notched specimens. Cortical porosity decreased in all groups from baseline to day 28. Intracortical mineralizing surface (MS/BS) and mineral apposition rate (MAR), as well as the mineral‐to‐matrix ratio were unaffected by treatment, but intracortical crystallinity was increased in the ZA group at day 10 compared with vehicle. Cortical area increased in all groups over 28 days mainly because of an addition of bone at the endocortical surface. Endocortical MS/BS did not vary among the groups, but endocortical MAR was suppressed in the NaF group at day 2 and elevated in the Scl‐Ab group at day 4 compared with vehicle. Endocortical mineral‐to‐matrix ratio was increased at days 5 and 10 following NaF treatment and endocortical crystallinity was increased at day 5 following ZA treatment compared with vehicle. Fracture toughness did not differ among the groups. Thus, the treatments affected matrix maturation more strongly at the endocortical then intracortical envelope. In this model of induced remodeling, the bone formation phase is synchronized at multiple sites, facilitating study of the effects of drugs or other bone‐targeting agents on matrix maturation independent of their effects on the initiation of remodeling. © 2020 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Ryan D Ross
- Department of Cell & Molecular Medicine Rush University Medical Center Chicago IL USA.,Department of Orthopedic Surgery Rush University Medical Center Chicago IL USA
| | - Kyle Anderson
- Department of Cell & Molecular Medicine Rush University Medical Center Chicago IL USA
| | - Reid Davison
- Department of Cell & Molecular Medicine Rush University Medical Center Chicago IL USA
| | - Bilal M El-Masri
- Clinical Cell Biology, Research Unit of Pathology, Department of Clinical Research University of Southern Denmark, and Department of Pathology, Odense University Hospital Odense Denmark.,Department of Molecular Medicine University of Southern Denmark Odense Denmark
| | - Christina M Andreasen
- Clinical Cell Biology, Research Unit of Pathology, Department of Clinical Research University of Southern Denmark, and Department of Pathology, Odense University Hospital Odense Denmark.,Department of Molecular Medicine University of Southern Denmark Odense Denmark
| | - Thomas L Andersen
- Clinical Cell Biology, Research Unit of Pathology, Department of Clinical Research University of Southern Denmark, and Department of Pathology, Odense University Hospital Odense Denmark.,Department of Molecular Medicine University of Southern Denmark Odense Denmark
| | - Dale R Sumner
- Department of Cell & Molecular Medicine Rush University Medical Center Chicago IL USA.,Department of Orthopedic Surgery Rush University Medical Center Chicago IL USA
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5
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Yajima A, Tsuchiya K, Burr DB, Wallace JM, Damrath JD, Inaba M, Tominaga Y, Satoh S, Nakayama T, Tanizawa T, Ogawa H, Ito A, Nitta K. The Importance of Biologically Active Vitamin D for Mineralization by Osteocytes After Parathyroidectomy for Renal Hyperparathyroidism. JBMR Plus 2019; 3:e10234. [PMID: 31768492 PMCID: PMC6874232 DOI: 10.1002/jbm4.10234] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 08/20/2019] [Accepted: 08/26/2019] [Indexed: 11/10/2022] Open
Abstract
Hypomineralized matrix is a factor determining bone mineral density. Increased perilacunar hypomineralized bone area is caused by reduced mineralization by osteocytes. The importance of vitamin D in the mineralization by osteocytes was investigated in hemodialysis patients who underwent total parathyroidectomy (PTX) with immediate autotransplantation of diffuse hyperplastic parathyroid tissue. No previous reports on this subject exist. The study was conducted in 19 patients with renal hyperparathyroidism treated with PTX. In 15 patients, the serum calcium levels were maintained by subsequent administration of alfacalcidol (2.0 μg/day), i.v. calcium gluconate, and oral calcium carbonate for 4 weeks after PTX (group I). This was followed in a subset of 4 patients in group I by a reduced dose of 0.5 μg/day until 1 year following PTX; this was defined as group II. In the remaining 4 patients, who were not in group I, the serum calcium (Ca) levels were maintained without subsequent administration of alfacalcidol (group III). Transiliac bone biopsy specimens were obtained in all groups before and 3 or 4 weeks after PTX to evaluate the change of the hypomineralized bone area. In addition, patients from group II underwent a third bone biopsy 1 year following PTX. A significant decrease of perilacunar hypomineralized bone area was observed 3 or 4 weeks after PTX in all group I and II patients. The area was increased again in the group II patients 1 year following PTX. In group III patients, an increase of the hypomineralized bone area was observed 4 weeks after PTX. The maintenance of a proper dose of vitamin D is necessary for mineralization by osteocytes, which is important to increase bone mineral density after PTX for renal hyperparathyroidism. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Aiji Yajima
- Department of Anatomy and Cell Biology Indiana University School of Medicine Indianapolis IN USA.,Department of Medicine, Kidney Center Tokyo Women's Medical University Shinjuku-ku, Tokyo Japan
| | - Ken Tsuchiya
- Department of Blood Purification, Kidney Center Tokyo Women's Medical University, Shinjuku-ku Tokyo Japan
| | - David B Burr
- Department of Anatomy and Cell Biology Indiana University School of Medicine Indianapolis IN USA
| | - Joseph M Wallace
- Department of Biomedical Engineering Indiana University, Purdue University Indianapolis IN USA
| | - John D Damrath
- Department of Biomedical Engineering Indiana University, Purdue University Indianapolis IN USA
| | - Masaaki Inaba
- Department of Metabolism, Endocrinology and Molecular Medicine Osaka City University Graduate School of Medicine Osaka Japan
| | - Yoshihiro Tominaga
- Department of Transplant Surgery Nagoya Second Red Cross Hospital Nagoya, Aichi Japan
| | - Shigeru Satoh
- Center for Kidney Disease and Transplantation Akita University Hospital Akita Japan
| | - Takashi Nakayama
- Department of Orthopedic Surgery Towa Hospital Adachi-ku, Tokyo Japan
| | | | - Hajime Ogawa
- Department of Medicine, Division of Nephrology Ogawa Clinic Shinagawa-ku, Tokyo Japan
| | - Akemi Ito
- Ito Bone Histomorphometry Institute Niigata Japan
| | - Kosaku Nitta
- Department of Medicine, Kidney Center Tokyo Women's Medical University Shinjuku-ku, Tokyo Japan
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6
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Wang K, Le L, Chun BM, Tiede-Lewis LM, Shiflett LA, Prideaux M, Campos RS, Veno PA, Xie Y, Dusevich V, Bonewald LF, Dallas SL. A Novel Osteogenic Cell Line That Differentiates Into GFP-Tagged Osteocytes and Forms Mineral With a Bone-Like Lacunocanalicular Structure. J Bone Miner Res 2019; 34:979-995. [PMID: 30882939 PMCID: PMC7350928 DOI: 10.1002/jbmr.3720] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 02/15/2019] [Accepted: 02/22/2019] [Indexed: 01/20/2023]
Abstract
Osteocytes, the most abundant cells in bone, were once thought to be inactive, but are now known to have multifunctional roles in bone, including in mechanotransduction, regulation of osteoblast and osteoclast function and phosphate homeostasis. Because osteocytes are embedded in a mineralized matrix and are challenging to study, there is a need for new tools and cell models to understand their biology. We have generated two clonal osteogenic cell lines, OmGFP66 and OmGFP10, by immortalization of primary bone cells from mice expressing a membrane-targeted GFP driven by the Dmp1-promoter. One of these clones, OmGFP66, has unique properties compared with previous osteogenic and osteocyte cell models and forms 3-dimensional mineralized bone-like structures, containing highly dendritic GFP-positive osteocytes, embedded in clearly defined lacunae. Confocal and electron microscopy showed that structurally and morphologically, these bone-like structures resemble bone in vivo, even mimicking the lacunocanalicular ultrastructure and 3D spacing of in vivo osteocytes. In osteogenic conditions, OmGFP66 cells express alkaline phosphatase (ALP), produce a mineralized type I collagen matrix, and constitutively express the early osteocyte marker, E11/gp38. With differentiation they express osteocyte markers, Dmp1, Phex, Mepe, Fgf23, and the mature osteocyte marker, Sost. They also express RankL, Opg, and Hif1α, and show expected osteocyte responses to PTH, including downregulation of Sost, Dmp1, and Opg and upregulation of RankL and E11/gp38. Live cell imaging revealed the dynamic process by which OmGFP66 bone-like structures form, the motile properties of embedding osteocytes and the integration of osteocyte differentiation with mineralization. The OmGFP10 clone showed an osteocyte gene expression profile similar to OmGFP66, but formed less organized bone nodule-like mineral, similar to other osteogenic cell models. Not only do these cell lines provide useful new tools for mechanistic and dynamic studies of osteocyte differentiation, function, and biomineralization, but OmGFP66 cells have the unique property of modeling osteocytes in their natural bone microenvironment. © 2019 American Society for Bone and Mineral Research.
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Affiliation(s)
- Kun Wang
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri, Kansas City, Kansas City, MO, USA
| | - Lisa Le
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri, Kansas City, Kansas City, MO, USA
| | - Brad M Chun
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri, Kansas City, Kansas City, MO, USA
| | - LeAnn M Tiede-Lewis
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri, Kansas City, Kansas City, MO, USA
| | - Lora A Shiflett
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri, Kansas City, Kansas City, MO, USA
| | - Matthew Prideaux
- Department of Anatomy and Cell Biology, School of Medicine, Indiana University, Indianapolis, IN, USA
| | - Richard S Campos
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri, Kansas City, Kansas City, MO, USA
| | - Patricia A Veno
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri, Kansas City, Kansas City, MO, USA
| | - Yixia Xie
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri, Kansas City, Kansas City, MO, USA
| | - Vladimir Dusevich
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri, Kansas City, Kansas City, MO, USA
| | - Lynda F Bonewald
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri, Kansas City, Kansas City, MO, USA.,Department of Anatomy and Cell Biology, School of Medicine, Indiana University, Indianapolis, IN, USA.,Department of Orthopaedic Surgery, Indiana University, Indianapolis, IN, USA
| | - Sarah L Dallas
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri, Kansas City, Kansas City, MO, USA
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7
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Ryan BA, Alhani K, Sellars KB, Kirby BJ, St-Arnaud R, Kaufmann M, Jones G, Kovacs CS. Mineral Homeostasis in Murine Fetuses Is Sensitive to Maternal Calcitriol but Not to Absence of Fetal Calcitriol. J Bone Miner Res 2019; 34:669-680. [PMID: 30508318 DOI: 10.1002/jbmr.3642] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 11/13/2018] [Accepted: 11/14/2018] [Indexed: 12/14/2022]
Abstract
Vitamin D receptor (VDR) null fetuses have normal serum minerals, parathyroid hormone (PTH), skeletal morphology, and mineralization but increased serum calcitriol, placental calcium transport, and placental expression of Pthrp, Trpv6, and (as reported in this study) Pdia3. We examined Cyp27b1 null fetal mice, which do not make calcitriol, to determine if loss of calcitriol has the same consequences as loss of VDR. Cyp27b1 null and wild-type (WT) females were mated to Cyp27b1+/- males, which generated Cyp27b1 null and Cyp27b1+/- fetuses from Cyp27b1 null mothers, and Cyp27b1+/- and WT fetuses from WT mothers. Cyp27b1 null fetuses had undetectable calcitriol but normal serum calcium and phosphorus, PTH, fibroblast growth factor 23 (FGF23), skeletal mineral content, tibial lengths and morphology, placental calcium transport, and expression of Trpv6 and Pthrp; conversely, placental Pdia3 was downregulated. However, although Cyp27b1+/- and null fetuses of Cyp27b1 null mothers were indistinguishable, they had higher serum and amniotic fluid calcium, lower amniotic fluid phosphorus, lower FGF23, and higher 25-hydroxyvitamin D and 24,25-dihydroxyvitamin D than in WT and Cyp27b1+/- fetuses of WT mothers. In summary, loss of fetal calcitriol did not alter mineral or bone homeostasis, but Cyp27b1 null mothers altered mineral homeostasis in their fetuses independent of fetal genotype. Cyp27b1 null fetuses differ from Vdr null fetuses, possibly through high levels of calcitriol acting on Pdia3 in Vdr nulls to upregulate placental calcium transport and expression of Trpv6 and Pthrp. In conclusion, maternal calcitriol influences fetal mineral metabolism, whereas loss of fetal calcitriol does not. © 2018 American Society for Bone and Mineral Research.
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Affiliation(s)
- Brittany A Ryan
- Faculty of Medicine-Endocrinology, Memorial University of Newfoundland, St. John's, Canada
| | - Kamal Alhani
- Faculty of Medicine-Endocrinology, Memorial University of Newfoundland, St. John's, Canada
| | - K Berit Sellars
- Faculty of Medicine-Endocrinology, Memorial University of Newfoundland, St. John's, Canada
| | - Beth J Kirby
- Faculty of Medicine-Endocrinology, Memorial University of Newfoundland, St. John's, Canada
| | - René St-Arnaud
- Shriners Hospitals for Children-Canada and McGill University, Montréal, Canada
| | | | | | - Christopher S Kovacs
- Faculty of Medicine-Endocrinology, Memorial University of Newfoundland, St. John's, Canada
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8
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Zheng H, Ramnaraign D, Anderson BA, Tycksen E, Nunley R, McAlinden A. MicroRNA-138 Inhibits Osteogenic Differentiation and Mineralization of Human Dedifferentiated Chondrocytes by Regulating RhoC and the Actin Cytoskeleton. JBMR Plus 2018; 3:e10071. [PMID: 30828688 PMCID: PMC6383697 DOI: 10.1002/jbm4.10071] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 06/22/2018] [Accepted: 06/26/2018] [Indexed: 01/03/2023] Open
Abstract
MicroRNAs (miRNAs) are known to play critical roles in many cellular processes including those regulating skeletal development and homeostasis. A previous study from our group identified differentially expressed miRNAs in the developing human growth plate. Among those more highly expressed in hypertrophic chondrocytes compared to progenitor chondrocytes was miR‐138, therefore suggesting a possible role for this miRNA in regulating chondrogenesis and/or endochondral ossification. The goal of this study was to determine the function of miR‐ 138 in regulating osteogenesis by using human osteoarthritic dedifferentiated chondrocytes (DDCs) as source of inducible cells. We show that over‐expression of miR‐138 inhibited osteogenic differentiation of DDCs in vitro. Moreover, cell shape was altered and cell proliferation and possibly migration was also suppressed by miR‐138. Given alterations in cell shape, closer analysis revealed that F‐actin polymerization was also inhibited by miR‐138. Computational approaches showed that the small GTPase, RhoC, is a potential miR‐138 target gene. We pursued RhoC further given its function in regulating cell proliferation and migration in cancer cells. Indeed, miR‐138 over‐expression in DDCs resulted in decreased RhoC protein levels. A series of rescue experiments showed that RhoC over‐expression could attenuate the inhibitory actions of miR‐138 on DDC proliferation, F‐actin polymerization and osteogenic differentiation. Bone formation was also found to be enhanced within human demineralized bone scaffolds seeded with DDCs expressing both miR‐138 and RhoC. In conclusion, we have discovered a new mechanism in DDCs whereby miR‐138 functions to suppress RhoC which subsequently inhibits proliferation, F‐actin polymerization and osteogenic differentiation. To date, there are no published reports on the importance of RhoC in regulating osteogenesis. This opens up new avenues of research involving miR‐138 and RhoC pathways to better understand mechanisms regulating bone formation in addition to the potential use of DDCs as a cell source for bone tissue engineering. © 2018 The Authors. JBMR Plus is published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research.
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Affiliation(s)
- Hongjun Zheng
- Department of Orthopaedic SurgeryWashington University School of MedicineSt LouisMOUSA
| | | | - Britta A Anderson
- Department of Orthopaedic SurgeryWashington University School of MedicineSt LouisMOUSA
| | - Eric Tycksen
- Genome Technology Access CenterWashington University School of MedicineSt LouisMOUSA
| | - Ryan Nunley
- Department of Orthopaedic SurgeryWashington University School of MedicineSt LouisMOUSA
| | - Audrey McAlinden
- Department of Orthopaedic SurgeryWashington University School of MedicineSt LouisMOUSA
- Department of Cell BiologyWashington University School of MedicineSt LouisMOUSA
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9
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Whyte MP, Fujita KP, Moseley S, Thompson DD, McAlister WH. Validation of a Novel Scoring System for Changes in Skeletal Manifestations of Hypophosphatasia in Newborns, Infants, and Children: The Radiographic Global Impression of Change Scale. J Bone Miner Res 2018; 33:868-874. [PMID: 29297597 DOI: 10.1002/jbmr.3377] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 12/12/2017] [Accepted: 12/26/2017] [Indexed: 11/10/2022]
Abstract
Hypophosphatasia (HPP) is the heritable metabolic disease characterized by impaired skeletal mineralization due to low activity of the tissue-nonspecific isoenzyme of alkaline phosphatase. Although HPP during growth often manifests with distinctive radiographic skeletal features, no validated method was available to quantify them, including changes over time. We created the Radiographic Global Impression of Change (RGI-C) scale to assess changes in the skeletal burden of pediatric HPP. Site-specific pairs of radiographs of newborns, infants, and children with HPP from three clinical studies of asfotase alfa, an enzyme replacement therapy for HPP, were obtained at baseline and during treatment. Each pair was scored by three pediatric radiologists ("raters"), with nine raters across the three studies. Intrarater and interrater agreement was determined by weighted Kappa coefficients. Interrater reliability was assessed using intraclass correlation coefficients (ICCs) and by two-way random effects analysis of variance (ANOVA) and a mixed-model repeated measures ANOVA. Pearson correlation coefficients evaluated relationships of the RGI-C to the Rickets Severity Scale (RSS), Pediatric Outcomes Data Collection Instrument Global Function Parent Normative Score, Childhood Health Assessment Questionnaire Disability Index, 6-Minute Walk Test percent predicted, and Z-score for height in patients aged 6 to 12 years at baseline. Eighty-nine percent (8/9) of raters showed substantial or almost perfect intrarater agreement of sequential RGI-C scores (weighted Kappa coefficients, 0.72 to 0.93) and moderate or substantial interrater agreement (weighted Kappa coefficients, 0.53 to 0.71) in patients aged 0 to 12 years at baseline. Moderate-to-good interrater reliability was observed (ICC, 0.57 to 0.65). RGI-C scores were significantly (p ≤ 0.0065) correlated with the RSS and with measures of global function, disability, endurance, and growth in the patients aged 6 to 12 years at baseline. Thus, the RGI-C is valid and reliable for detecting clinically important changes in skeletal manifestations of severe HPP in newborns, infants, and children, including during asfotase alfa treatment. © 2018 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc.
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Affiliation(s)
- Michael P Whyte
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospital for Children, St. Louis, MO, USA.,Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine at Barnes-Jewish Hospital, St. Louis, MO, USA
| | | | | | | | - William H McAlister
- Mallinckrodt Institute of Radiology, Washington University School of Medicine at St. Louis Children's Hospital, St. Louis, MO, USA
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10
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Siller AF, Whyte MP. Alkaline Phosphatase: Discovery and Naming of Our Favorite Enzyme. J Bone Miner Res 2018; 33:362-364. [PMID: 28727174 DOI: 10.1002/jbmr.3225] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 07/10/2017] [Accepted: 07/12/2017] [Indexed: 12/11/2022]
Abstract
Alkaline phosphatase can be considered "our favorite enzyme" for reasons apparent to those who diagnose and treat metabolic bone diseases or who study skeletal biology. Few might know, however, that alkaline phosphatase likely represents the most frequently assayed enzyme in all of medicine. Elevated activity in the circulation is universally recognized as a marker for skeletal or hepatobiliary disease. Nevertheless, the assay conditions in many ways are nonphysiological. The term alkaline phosphatase emerged when it became necessary to distinguish "bone phosphatase" from the phosphatase in the prostate that features an acidic pH optimum. Beginning in 1948, studies of the inborn-error-of-metabolism hypophosphatasia would identify the natural substrates and establish the physiological role of alkaline phosphatase, including in biomineralization. Here, we recount the discovery in 1923 and then eventual naming of this enzyme that remains paramount in our field. © 2017 American Society for Bone and Mineral Research.
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Affiliation(s)
- Alejandro F Siller
- Washington University School of Medicine, St. Louis, MO, USA.,Shriners Hospital for Children, St. Louis, MO, USA
| | - Michael P Whyte
- Washington University School of Medicine, St. Louis, MO, USA.,Shriners Hospital for Children, St. Louis, MO, USA
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11
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Worton LE, Shi YC, Smith EJ, Barry SC, Gonda TJ, Whitehead JP, Gardiner EM. Ectodermal-Neural Cortex 1 Isoforms Have Contrasting Effects on MC3T3-E1 Osteoblast Mineralization and Gene Expression. J Cell Biochem 2017; 118:2141-2150. [PMID: 27996212 DOI: 10.1002/jcb.25851] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 12/19/2016] [Indexed: 01/01/2023]
Abstract
The importance of Wnt pathway signaling in development of bone has been well established. Here we investigated the role of a known Wnt target, ENC1 (ectodermal-neural cortex 1; NRP/B), in osteoblast differentiation. Enc1 expression was detected in mouse osteoblasts, chondrocytes, and osteocytes by in situ hybridization, and osteoblastic expression was verified in differentiating primary cultures and MC3T3-E1 pre-osteoblast cells, with 57 kDa and 67 kDa ENC1 protein isoforms detected throughout differentiation. Induced knockdown of both ENC1 isoforms reduced alkaline phosphatase staining and virtually abolished MC3T3-E1 mineralization. At culture confluence, Alpl (alkaline phosphatase liver/bone/kidney) expression was markedly reduced compared with control cells, and there was significant and coordinated alteration of other genes involved in cellular phosphate biochemistry. In contrast, with 67 kDa-selective knockdown mineralized nodule formation was enhanced and there was a two-fold increase in Alpl expression at confluence. There was enhanced expression of Wnt/β-catenin target genes with knockdown of both isoforms at this time-point and a five-fold increase in Frzb (Frizzled related protein) with 67 kDa-selective knockdown at mineralization, indicating possible ENC1 interactions with Wnt signaling in osteoblasts. These results are the first to demonstrate a role for ENC1 in the control of osteoblast differentiation. Additionally, the contrasting mineralization phenotypes and transcriptional patterns seen with coordinate knockdown of both ENC1 isoforms vs selective knockdown of 67 kDa ENC1 suggest opposing roles for the isoforms in regulation of osteoblastic differentiation, through effects on Alpl expression and phosphate cellular biochemistry. This study is the first to report differential roles for the ENC1 isoforms in any cell lineage. J. Cell. Biochem. 118: 2141-2150, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Leah E Worton
- The University of Queensland, Brisbane, Queensland, Australia.,Department of Orthopaedics and Sports Medicine, University of Washington, Seattle, Washington
| | - Yan-Chuan Shi
- Garvan Institute of Medical Research, Sydney, New South Wales, Australia.,Faculty of Medicine, University of New South Wales, New South Wales, Australia
| | - Elisabeth J Smith
- Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - Simon C Barry
- The University of Adelaide, Adelaide, South Australia, Australia
| | - Thomas J Gonda
- The University of Queensland, Brisbane, Queensland, Australia
| | | | - Edith M Gardiner
- The University of Queensland, Brisbane, Queensland, Australia.,Department of Orthopaedics and Sports Medicine, University of Washington, Seattle, Washington
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12
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Whyte MP. Hypophosphatasia: Enzyme Replacement Therapy Brings New Opportunities and New Challenges. J Bone Miner Res 2017; 32:667-675. [PMID: 28084648 DOI: 10.1002/jbmr.3075] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 12/09/2016] [Accepted: 12/26/2016] [Indexed: 11/11/2022]
Abstract
Hypophosphatasia (HPP) is caused by loss-of-function mutation(s) of the gene that encodes the tissue-nonspecific isoenzyme of alkaline phosphatase (TNSALP). Autosomal inheritance (dominant or recessive) from among more than 300 predominantly missense defects of TNSALP (ALPL) explains HPP's broad-ranging severity, the greatest of all skeletal diseases. In health, TNSALP is linked to cell surfaces and richly expressed in the skeleton and developing teeth. In HPP,TNSALP substrates accumulate extracellularly, including inorganic pyrophosphate (PPi), an inhibitor of mineralization. The PPi excess can cause tooth loss, rickets or osteomalacia, calcific arthropathies, and perhaps muscle weakness. Severely affected infants may seize from insufficient hydrolysis of pyridoxal 5'-phosphate (PLP), the major extracellular vitamin B6 . Now, significant successes are documented for newborns, infants, and children severely affected by HPP given asfotase alfa, a hydroxyapatite-targeted recombinant TNSALP. Since fall 2015, this biologic is approved by regulatory agencies multinationally typically for pediatric-onset HPP. Safe and effective treatment is now possible for this last rickets to have a medical therapy, but a number of challenges involving diagnosis, understanding prognosis, and providing this treatment are reviewed herein. © 2017 American Society for Bone and Mineral Research.
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Affiliation(s)
- Michael P Whyte
- Department of Internal Medicine, Division of Bone and Mineral Diseases, Washington University School of Medicine, and Center for Metabolic Bone Disease and Molecular Research, Shriners Hospital for Children, St. Louis, MO, USA
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13
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Whyte MP, McAlister WH, Fallon MD, Pierpont ME, Bijanki VN, Duan S, Otaify GA, Sly WS, Mumm S. Raine Syndrome (OMIM #259775), Caused By FAM20C Mutation, Is Congenital Sclerosing Osteomalacia With Cerebral Calcification (OMIM 259660). J Bone Miner Res 2017; 32:757-769. [PMID: 27862258 DOI: 10.1002/jbmr.3034] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 10/06/2016] [Accepted: 10/30/2016] [Indexed: 12/12/2022]
Abstract
In 1985, we briefly reported infant sisters with a unique, lethal, autosomal recessive disorder designated congenital sclerosing osteomalacia with cerebral calcification. In 1986, this condition was entered into Mendelian Inheritance In Man (MIM) as osteomalacia, sclerosing, with cerebral calcification (MIM 259660). However, no attestations followed. Instead, in 1989 Raine and colleagues published an affected neonate considering unprecedented the striking clinical and radiographic features. In 1992, "Raine syndrome" entered MIM formally as osteosclerotic bone dysplasia, lethal (MIM #259775). In 2007, the etiology emerged as loss-of-function mutation of FAM20C that encodes family with sequence similarity 20, member C. FAM20C is highly expressed in embryonic calcified tissues and encodes a kinase (dentin matrix protein 4) for most of the secreted phosphoproteome including FGF23, osteopontin, and other regulators of skeletal mineralization. Herein, we detail the clinical, radiological, biochemical, histopathological, and FAM20C findings of our patients. Following premortem tetracycline labeling, the proposita's non-decalcified skeletal histopathology after autopsy indicated no rickets but documented severe osteomalacia. Archival DNA revealed the sisters were compound heterozygotes for a unique missense mutation and a novel deletion in FAM20C. Individuals heterozygous for the missense mutation seemed to prematurely fuse their metopic suture and develop a metopic ridge sometimes including trigonocephaly. Our findings clarify FAM20C's role in hard tissue formation and mineralization, and show that Raine syndrome is congenital sclerosing osteomalacia with cerebral calcification. © 2016 American Society for Bone and Mineral Research.
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Affiliation(s)
- Michael P Whyte
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospital for Children, St. Louis, MO, USA.,Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine at Barnes-Jewish Hospital, St. Louis, MO, USA
| | - William H McAlister
- Department of Pediatric Radiology, Mallinckrodt Institute of Radiology, Washington University School of Medicine at St. Louis Children's Hospital, St. Louis, MO, USA
| | - Michael D Fallon
- Department of Surgical Pathology, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - Mary Ella Pierpont
- Department of Pediatrics, University of Minnesota School of Medicine, and Children's Hospitals and Clinics of Minnesota, Minneapolis, MN, USA
| | - Vinieth N Bijanki
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospital for Children, St. Louis, MO, USA
| | - Shenghui Duan
- Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine at Barnes-Jewish Hospital, St. Louis, MO, USA
| | - Ghada A Otaify
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospital for Children, St. Louis, MO, USA.,Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine at Barnes-Jewish Hospital, St. Louis, MO, USA.,Department of Clinical Genetics, Division of Human Genetics and Genome Research, Centre of Excellence of Human Genetics, National Research Centre, Cairo, Egypt
| | - William S Sly
- E.A. Doisey Department of Biochemistry, St. Louis University School of Medicine, St. Louis, MO, USA
| | - Steven Mumm
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospital for Children, St. Louis, MO, USA.,Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine at Barnes-Jewish Hospital, St. Louis, MO, USA
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14
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Yuan G, Hua B, Yang Y, Xu L, Cai T, Sun N, Yan Z, Lu C, Qian R. The Circadian Gene Clock Regulates Bone Formation Via PDIA3. J Bone Miner Res 2017; 32:861-871. [PMID: 27883226 DOI: 10.1002/jbmr.3046] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 11/11/2016] [Accepted: 11/19/2016] [Indexed: 11/10/2022]
Abstract
The expression patterns of clock-controlled genes (ccgs) are regulated by circadian rhythm, which is a major regulatory and physiological mechanism tied to the solar day. Disruptions in circadian rhythm contribute to the development of cardiovascular diseases, cancer, metabolic syndromes, and aging. It has been reported that bone remodeling is also regulated by circadian rhythm. However, the molecular mechanism by which the circadian gene Clock regulates bone remodeling has yet to be elucidated. Here, we show that Clock mutant mice exhibit a significant reduction in bone density as well as increased apoptosis. Protein disulfide isomerase family A member 3 (PDIA3) is a 1,25-dihydroxy-vitamin D3 [1α,25(OH)2D3] receptor that can regulate bone formation and apoptosis. Using luciferase and ChIP assays, we confirmed that Pdia3 is a ccg. Clock activates Pdia3 transcription by binding the E-box promoter, and transcription is decreased in ClockΔ19 mutant mice. Forced expression of Pdia3 or of Clock completely rescues the osteogenic disorders found in the mutant background and inhibits apoptosis in vivo and in vitro. Furthermore, ablation of PDIA3 via RNA interference completely blocks the compensatory effect of forced expression of Clock in osteoblasts. Our results demonstrate that the core circadian gene Clock regulates bone formation via transcriptional control of 1,2,5(OH)2D3 receptor PDIA3. © 2016 American Society for Bone and Mineral Research.
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Affiliation(s)
- Gongsheng Yuan
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai, China.,Research Center on Aging and Medicine, Fudan University, Shanghai, China
| | - Bingxuan Hua
- Department of Orthopedics, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yang Yang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Lirong Xu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Tingting Cai
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Ning Sun
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai, China.,Research Center on Aging and Medicine, Fudan University, Shanghai, China.,State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, China
| | - Zuoqin Yan
- Department of Orthopedics, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Chao Lu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai, China.,Research Center on Aging and Medicine, Fudan University, Shanghai, China
| | - Ruizhe Qian
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Fudan University, Shanghai, China.,Research Center on Aging and Medicine, Fudan University, Shanghai, China
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15
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Jedeon K, Houari S, Loiodice S, Thuy TT, Le Normand M, Berdal A, Babajko S. Chronic Exposure to Bisphenol A Exacerbates Dental Fluorosis in Growing Rats. J Bone Miner Res 2016; 31:1955-1966. [PMID: 27257137 DOI: 10.1002/jbmr.2879] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 05/16/2016] [Accepted: 06/01/2016] [Indexed: 01/27/2023]
Abstract
Enamel defects resulting from environmental conditions and way of life are public health concerns because of their high prevalence. Because their etiology is unclear, the aim of this study was to analyze the various forms of enamel hypomineralization, and to characterize the genes involved in this process to determine the mechanisms involved in disruptions of amelogenesis. We used bisphenol A (BPA) and fluoride as models; both are commonly encountered in human populations and utilized in dentistry. Wistar rats were chronically exposed to 5 μg/kg/day BPA from day 1 of gestation to day 65 after birth (P65) and 5 mM fluoride from P21 to P65. Resulting enamel defects were comparable to the human enamel pathologies molar incisor hypomineralization (MIH) and dental fluorosis (DF) respectively, and were more severe in rats exposed to both agents than to each agent alone. Large-scale transcriptomic analysis of dental epithelium showed a small group of genes the expression of which was affected by exposure to BPA or NaF. Among the most modulated, many are directly involved in amelogenesis (Amelx, Enam, Klk4, Mmp12, Slc26a4, and Slc5a8), and can be regrouped as forming the "hypomineralization enameloma." Each of these gene expression perturbations may contribute to enamel defects. Exposure to BPA weakens enamel, making it more prone to generate frequent mineralization defects MIH and DF. Our study identifies hypomineralization genes that may enable the use of dental enamel as an early marker of exposure to environmental toxicants because of its unique ability to retrospectively record ameloblast pathophysiology. © 2016 American Society for Bone and Mineral Research.
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Affiliation(s)
- Katia Jedeon
- Cordeliers Research Centre Inserm UMRS 1138, Paris-Diderot University, Paris-Descartes University, Pierre & Marie Curie-Paris University, Laboratory of Molecular Oral Pathophysiology, Paris, France.,Paris-Diderot University, Faculty of Dentistry, Paris, France.,Centre de Référence des maladies rares de la face et de la cavité buccale MAFACE hôpital Rothschild, Paris, France
| | - Sophia Houari
- Cordeliers Research Centre Inserm UMRS 1138, Paris-Diderot University, Paris-Descartes University, Pierre & Marie Curie-Paris University, Laboratory of Molecular Oral Pathophysiology, Paris, France.,Paris-Diderot University, Faculty of Dentistry, Paris, France.,Groupe Hospitalier La Pitié Salpêtrière-Charles Foix, Paris, France
| | - Sophia Loiodice
- Cordeliers Research Centre Inserm UMRS 1138, Paris-Diderot University, Paris-Descartes University, Pierre & Marie Curie-Paris University, Laboratory of Molecular Oral Pathophysiology, Paris, France.,Paris-Diderot University, Faculty of Dentistry, Paris, France
| | - Tran Thu Thuy
- Cordeliers Research Centre Inserm UMRS 1138, Paris-Diderot University, Paris-Descartes University, Pierre & Marie Curie-Paris University, Laboratory of Molecular Oral Pathophysiology, Paris, France.,Paris-Diderot University, Faculty of Dentistry, Paris, France.,Faculty of Odonto-Stomatology, Ho Chi Minh University of Medicine and Pharmacology, Ho Chi Minh-Ville, Vietnam
| | - Manon Le Normand
- Cordeliers Research Centre Inserm UMRS 1138, Paris-Diderot University, Paris-Descartes University, Pierre & Marie Curie-Paris University, Laboratory of Molecular Oral Pathophysiology, Paris, France
| | - Ariane Berdal
- Cordeliers Research Centre Inserm UMRS 1138, Paris-Diderot University, Paris-Descartes University, Pierre & Marie Curie-Paris University, Laboratory of Molecular Oral Pathophysiology, Paris, France.,Paris-Diderot University, Faculty of Dentistry, Paris, France.,Centre de Référence des maladies rares de la face et de la cavité buccale MAFACE hôpital Rothschild, Paris, France
| | - Sylvie Babajko
- Cordeliers Research Centre Inserm UMRS 1138, Paris-Diderot University, Paris-Descartes University, Pierre & Marie Curie-Paris University, Laboratory of Molecular Oral Pathophysiology, Paris, France.,Paris-Diderot University, Faculty of Dentistry, Paris, France
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16
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Farlay D, Armas LAG, Gineyts E, Akhter MP, Recker RR, Boivin G. Nonenzymatic Glycation and Degree of Mineralization Are Higher in Bone From Fractured Patients With Type 1 Diabetes Mellitus. J Bone Miner Res 2016; 31:190-5. [PMID: 26234180 PMCID: PMC4876148 DOI: 10.1002/jbmr.2607] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 07/21/2015] [Accepted: 07/28/2015] [Indexed: 01/22/2023]
Abstract
Low-energy fractures are frequent complications in type 1 diabetes mellitus patients (T1DM). Modifications of bone intrinsic composition might be a potential cause of fragility observed in diabetic subjects. Advanced glycation end products (AGEs) were found in numerous connective tissues from T1DM patients. However, whether AGEs are present at high levels in bone matrix from diabetic subjects is unknown. Moreover, whether elevated AGEs in the bone matrix impair mineralization has not been addressed in humans. The purposes of this study were 1) to determine whether bone matrix from fracturing and nonfracturing T1DM contained more AGEs than bone from healthy patients (CTL), and 2) to compare the degree of mineralization of bone and hardness between fracturing and nonfracturing T1DM versus CTL. We analyzed iliac crest bone biopsies from 5 fracturing T1DM patients, 5 nonfracturing T1DM patients, and 5 healthy subjects, all age- and sex-matched. AGEs (pentosidine) in bone matrix was measured by high-performance liquid chromatography separately in trabecular and cortical bone. The degree of mineralization of bone (DMB) was assessed by digitized microradiography, and mechanical properties by micro- and nanohardness tests. Trabecular bone from fracturing T1DM exhibited significantly higher levels of pentosidine than CTL (p = 0.04) and was more mineralized than nonfracturing T1DM (p = 0.04) and CTL (p = 0.04). Trabecular bone was not significantly different in pentosidine between nonfracturing T1DM and CTL. Cortical bone from nonfracturing T1DM was not significantly different from CTL. Positive correlations were found between HbA1c and pentosidine (r' = 0.79, p < 0.003) and between HbA1c and DMB (r' = 0.64, p < 0.02). Both modifications could lead to less flexible bone (reduced modulus of elasticity) and a tendency toward low-energy fractures in T1DM patients.
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Affiliation(s)
- Delphine Farlay
- INSERM, UMR 1033, Lyon, France.,Université de Lyon, Lyon, France
| | - Laura A G Armas
- Osteoporosis Research Center, School of Medicine, Creighton University, Omaha, NE, USA
| | - Evelyne Gineyts
- INSERM, UMR 1033, Lyon, France.,Université de Lyon, Lyon, France
| | - Mohammed P Akhter
- Osteoporosis Research Center, School of Medicine, Creighton University, Omaha, NE, USA
| | - Robert R Recker
- Osteoporosis Research Center, School of Medicine, Creighton University, Omaha, NE, USA
| | - Georges Boivin
- INSERM, UMR 1033, Lyon, France.,Université de Lyon, Lyon, France
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17
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Eleniste PP, Patel V, Posritong S, Zero O, Largura H, Cheng YH, Himes ER, Hamilton M, Ekwealor JTB, Kacena MA, Bruzzaniti A. Pyk2 and Megakaryocytes Regulate Osteoblast Differentiation and Migration Via Distinct and Overlapping Mechanisms. J Cell Biochem 2015; 117:1396-406. [PMID: 26552846 DOI: 10.1002/jcb.25430] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 11/09/2015] [Indexed: 01/08/2023]
Abstract
Osteoblast differentiation and migration are necessary for bone formation during bone remodeling. Mice lacking the proline-rich tyrosine kinase Pyk2 (Pyk2-KO) have increased bone mass, in part due to increased osteoblast proliferation. Megakaryocytes (MKs), the platelet-producing cells, also promote osteoblast proliferation in vitro and bone-formation in vivo via a pathway that involves Pyk2. In the current study, we examined the mechanism of action of Pyk2, and the role of MKs, on osteoblast differentiation and migration. We found that Pyk2-KO osteoblasts express elevated alkaline phosphatase (ALP), type I collagen and osteocalcin mRNA levels as well as increased ALP activity, and mineralization, confirming that Pyk2 negatively regulates osteoblast function. Since Pyk2 Y402 phosphorylation is important for its catalytic activity and for its protein-scaffolding functions, we expressed the phosphorylation-mutant (Pyk2(Y402F) ) and kinase-mutant (Pyk2(K457A) ) in Pyk2-KO osteoblasts. Both Pyk2(Y402F) and Pyk2(K457A) reduced ALP activity, whereas only kinase-inactive Pyk2(K457A) inhibited Pyk2-KO osteoblast migration. Consistent with a role for Pyk2 on ALP activity, co-culture of MKs with osteoblasts led to a decrease in the level of phosphorylated Pyk2 (pY402) as well as a decrease in ALP activity. Although, Pyk2-KO osteoblasts exhibited increased migration compared to wild-type osteoblasts, Pyk2 expression was not required necessary for the ability of MKs to stimulate osteoblast migration. Together, these data suggest that osteoblast differentiation and migration are inversely regulated by MKs via distinct Pyk2-dependent and independent signaling pathways. Novel drugs that distinguish between the kinase-dependent or protein-scaffolding functions of Pyk2 may provide therapeutic specificity for the control of bone-related diseases.
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Affiliation(s)
- Pierre P Eleniste
- Department of Biomedical and Applied Sciences, Indiana University School of Dentistry, Indianapolis, Indiana
| | - Vruti Patel
- Department of Biomedical and Applied Sciences, Indiana University School of Dentistry, Indianapolis, Indiana
| | - Sumana Posritong
- Department of Biomedical and Applied Sciences, Indiana University School of Dentistry, Indianapolis, Indiana
| | - Odette Zero
- Department of Biomedical and Applied Sciences, Indiana University School of Dentistry, Indianapolis, Indiana
| | - Heather Largura
- Department of Biomedical and Applied Sciences, Indiana University School of Dentistry, Indianapolis, Indiana
| | - Ying-Hua Cheng
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Evan R Himes
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Matthew Hamilton
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Jenna T B Ekwealor
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Melissa A Kacena
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Angela Bruzzaniti
- Department of Biomedical and Applied Sciences, Indiana University School of Dentistry, Indianapolis, Indiana
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18
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Ariganello MB, Omelon S, Variola F, Wazen RM, Moffatt P, Nanci A. Osteogenic cell cultures cannot utilize exogenous sources of synthetic polyphosphate for mineralization. J Cell Biochem 2015; 115:2089-102. [PMID: 25043819 DOI: 10.1002/jcb.24886] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2013] [Accepted: 07/10/2014] [Indexed: 11/08/2022]
Abstract
Phosphate is critical for mineralization and deficiencies in the regulation of free phosphate lead to disease. Inorganic polyphosphates (polyPs) may represent a physiological source of phosphate because they can be hydrolyzed by biological phosphatases. To investigate whether exogenous polyP could be utilized for mineral formation, mineralization was evaluated in two osteogenic cell lines, Saos-2 and MC3T3, expressing different levels of tissue non-specific alkaline phosphatase (tnALP). The role of tnALP was further explored by lentiviral-mediated overexpression in MC3T3 cells. When cells were cultured in the presence of three different phosphate sources, there was a strong mineralization response with β-glycerophosphate (βGP) and orthophosphate (Pi) but none of the cultures sustained mineralization in the presence of polyP (neither chain length 17-Pi nor 42-Pi). Even in the presence of mineralizing levels of phosphate, low concentrations of polyP (50 μM) were sufficient to inhibit mineral formation. Energy-dispersive X-ray spectroscopy confirmed the presence of apatite-like mineral deposits in MC3T3 cultures supplemented with βGP, but not in those with polyP. While von Kossa staining was consistent with the presence or absence of mineral, an unusual Alizarin staining was obtained in polyP-treated MC3T3 cultures. This staining pattern combined with low Ca:P ratios suggests the persistence of Ca-polyP complexes, even with high residual ALP activity. In conclusion, under standard culture conditions, exogenous polyP does not promote mineral deposition. This is not due to a lack of active ALP, and unless conditions that favor significant processing of polyP are achieved, its mineral inhibitory capacity predominates.
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Affiliation(s)
- Marianne B Ariganello
- Department of Stomatology, Faculty of Dentistry, Université de Montréal, P.O. Box 6128 Station Centre-Ville, Montréal Québec, Canada, H3C 3J7
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Fahiminiya S, Majewski J, Al-Jallad H, Moffatt P, Mort J, Glorieux FH, Roschger P, Klaushofer K, Rauch F. Osteoporosis caused by mutations in PLS3: clinical and bone tissue characteristics. J Bone Miner Res 2014; 29:1805-14. [PMID: 24616189 DOI: 10.1002/jbmr.2208] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Revised: 01/20/2014] [Accepted: 02/09/2014] [Indexed: 11/06/2022]
Abstract
Mutations in PLS3 have been identified as a cause of bone fragility in children, but the bone phenotype associated with PLS3 mutations has not been reported in detail. PLS3 is located on the X chromosome and encodes the actin-binding protein plastin 3. Here we describe skeletal findings in 4 boys from 2 families with mutations in PLS3 (c.994_995delGA; p.Asp332* in family 1; c.1433T > C; p.Leu478Pro in family 2). When first evaluated between 4 and 8 years of age, these boys had a history of one to four long-bone fractures. Mild vertebral compression fractures were identified in each boy. No obvious extraskeletal disease manifestations were present. Lumbar spine areal bone mineral density (LS-aBMD) Z-scores ranged from -1.7 to -3.5, but height was normal. Iliac bone histomorphometry in 2 patients showed low trabecular bone volume and a low osteoid maturation time but normal bone formation rate and osteoclast surface. Quantitative backscattered electron imaging (qBEI) did not reveal a major abnormality in bone mineralization density distribution. The 2 boys from family 1 received oral alendronate for 6 years, which normalized LS-aBMD. The mothers of the 4 boys did not have a history of fractures and had normal LS-aBMD. However, one of these mothers had low bone mass at the distal radius, as measured by peripheral quantitative computed tomography (pQCT). In conclusion, hemizygous mutations in PLS3 are associated with osteoporosis and bone fragility in childhood, but in contrast to bone fragility caused by mutations in collagen type I encoding genes, there is no hypermineralization of mineralized bone matrix.
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Affiliation(s)
- Somayyeh Fahiminiya
- Department of Human Genetics, Faculty of Medicine, McGill University and Genome Quebec Innovation Center, Montreal, Quebec, Canada
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Ross RD, Edwards LH, Acerbo AS, Ominsky MS, Virdi AS, Sena K, Miller LM, Sumner DR. Bone matrix quality after sclerostin antibody treatment. J Bone Miner Res 2014; 29:1597-607. [PMID: 24470143 DOI: 10.1002/jbmr.2188] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 01/21/2014] [Accepted: 01/22/2014] [Indexed: 11/10/2022]
Abstract
Sclerostin antibody (Scl-Ab) is a novel bone-forming agent that is currently undergoing preclinical and clinical testing. Scl-Ab treatment is known to dramatically increase bone mass, but little is known about the quality of the bone formed during treatment. In the current study, global mineralization of bone matrix in rats and nonhuman primates treated with vehicle or Scl-Ab was assayed by backscattered scanning electron microscopy (bSEM) to quantify the bone mineral density distribution (BMDD). Additionally, fluorochrome labeling allowed tissue age-specific measurements to be made in the primate model with Fourier-transform infrared microspectroscopy to determine the kinetics of mineralization, carbonate substitution, crystallinity, and collagen cross-linking. Despite up to 54% increases in the bone volume after Scl-Ab treatment, the mean global mineralization of trabecular and cortical bone was unaffected in both animal models investigated. However, there were two subtle changes in the BMDD after Scl-Ab treatment in the primate trabecular bone, including an increase in the number of pixels with a low mineralization value (Z5) and a decrease in the standard deviation of the distribution. Tissue age-specific measurements in the primate model showed that Scl-Ab treatment did not affect the mineral-to-matrix ratio, crystallinity, or collagen cross-linking in the endocortical, intracortical, or trabecular compartments. Scl-Ab treatment was associated with a nonsignificant trend toward accelerated mineralization intracortically and a nearly 10% increase in carbonate substitution for tissue older than 2 weeks in the trabecular compartment (p < 0.001). These findings suggest that Scl-Ab treatment does not negatively impact bone matrix quality.
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Affiliation(s)
- Ryan D Ross
- Department of Anatomy and Cell Biology, Rush University Medical Center, Chicago, IL, USA
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Chen F, Guo R, Itoh S, Moreno L, Rosenthal E, Zappitelli T, Zirngibl RA, Flenniken A, Cole W, Grynpas M, Osborne LR, Vogel W, Adamson L, Rossant J, Aubin JE. First mouse model for combined osteogenesis imperfecta and Ehlers-Danlos syndrome. J Bone Miner Res 2014; 29:1412-23. [PMID: 24443344 DOI: 10.1002/jbmr.2177] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Revised: 01/11/2014] [Accepted: 01/17/2014] [Indexed: 11/08/2022]
Abstract
By using a genome-wide N-ethyl-N-nitrosourea (ENU)-induced dominant mutagenesis screen in mice, a founder with low bone mineral density (BMD) was identified. Mapping and sequencing revealed a T to C transition in a splice donor of the collagen alpha1 type I (Col1a1) gene, resulting in the skipping of exon 9 and a predicted 18-amino acid deletion within the N-terminal region of the triple helical domain of Col1a1. Col1a1(Jrt) /+ mice were smaller in size, had lower BMD associated with decreased bone volume/tissue volume (BV/TV) and reduced trabecular number, and furthermore exhibited mechanically weak, brittle, fracture-prone bones, a hallmark of osteogenesis imperfecta (OI). Several markers of osteoblast differentiation were upregulated in mutant bone, and histomorphometry showed that the proportion of trabecular bone surfaces covered by activated osteoblasts (Ob.S/BS and N.Ob/BS) was elevated, but bone surfaces undergoing resorption (Oc.S/BS and N.Oc/BS) were not. The number of bone marrow stromal osteoprogenitors (CFU-ALP) was unaffected, but mineralization was decreased in cultures from young Col1a1(Jrt) /+ versus +/+ mice. Total collagen and type I collagen content of matrices deposited by Col1a1(Jrt) /+ dermal fibroblasts in culture was ∼40% and 30%, respectively, that of +/+ cells, suggesting that mutant collagen chains exerted a dominant negative effect on type I collagen biosynthesis. Mutant collagen fibrils were also markedly smaller in diameter than +/+ fibrils in bone, tendon, and extracellular matrices deposited by dermal fibroblasts in vitro. Col1a1(Jrt) /+ mice also exhibited traits associated with Ehlers-Danlos syndrome (EDS): Their skin had reduced tensile properties, tail tendon appeared more frayed, and a third of the young adult mice had noticeable curvature of the spine. Col1a1(Jrt) /+ is the first reported model of combined OI/EDS and will be useful for exploring aspects of OI and EDS pathophysiology and treatment.
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Affiliation(s)
- Frieda Chen
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
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Guañabens N, Mumm S, Möller I, González-Roca E, Peris P, Demertzis JL, Whyte MP. Calcific periarthritis as the only clinical manifestation of hypophosphatasia in middle-aged sisters. J Bone Miner Res 2014; 29:929-34. [PMID: 24123110 DOI: 10.1002/jbmr.2110] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 09/08/2013] [Accepted: 09/26/2013] [Indexed: 11/07/2022]
Abstract
Hypophosphatasia (HPP) is the inborn error of metabolism that features low serum alkaline phosphatase (ALP) activity caused by loss-of-function mutation(s) within the gene for the tissue nonspecific isoenzyme of ALP (TNSALP). In HPP, extracellular accumulation of inorganic pyrophosphate (PPi), a TNSALP substrate and inhibitor of mineralization, leads frequently to premature tooth loss and often to rickets or osteomalacia. In affected adults, the excess PPi sometimes also causes calcium pyrophosphate dihydrate (CPPD) deposition, PPi arthropathy, or pseudogout, or seemingly paradoxical deposition of hydroxyapatite crystals in ligaments or around joints when the condition is called calcific periarthritis (CP). We report three middle-aged sisters with CP as the only clinical manifestation of HPP. Each presented during early adult life with recurrent episodes of pain principally around the shoulders, elbows, wrists, hips, or Achilles tendon. Otherwise, they were in good health, including no history of unusual dental disease, fractures, or pseudofractures. Calcific deposits were identified in symptomatic areas principally by ultrasonographic assessment but also confirmed radiographically. All three sisters had low serum levels of total and bone-specific ALP, hyperphosphatemia, and increased serum concentrations of the TNSALP substrate pyridoxal 5'-phosphate together characteristic of HPP. Mutation analysis revealed that each carried a single unique 18-bp duplication within TNSALP (c.188_205dup18, p.Gly63_Thr68dup) as did two of their healthy sons and their mother, who was without signs of CPPD deposition or CP but had knee osteoarthritis. We find that CP can be the only complication of HPP in adults. Thus, multiple juxta-articular deposits of hydroxyapatite causing CP may be a useful sign of HPP, especially when the CP is familial.
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Affiliation(s)
- Núria Guañabens
- Metabolic Bone Diseases Unit, Department of Rheumatology, Hospital Clinic, IDIBAPS, CIBERehd, University of Barcelona, Barcelona, Spain
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McElderry JDP, Zhao G, Khmaladze A, Wilson CG, Franceschi RT, Morris MD. Tracking circadian rhythms of bone mineral deposition in murine calvarial organ cultures. J Bone Miner Res 2013; 28:1846-54. [PMID: 23505073 PMCID: PMC3720727 DOI: 10.1002/jbmr.1924] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 02/18/2013] [Accepted: 03/06/2013] [Indexed: 01/23/2023]
Abstract
Osteoblasts, which orchestrate the deposition of small apatite crystals through the expression of nucleating proteins, have been shown to also express clock genes associated with the circadian signaling pathway. We hypothesized that protein-mediated bone mineralization may be linked to circadian oscillator mechanisms functioning in peripheral bone tissue. In this study, Per1 expression in ex vivo neonatal murine calvaria organ cultures was monitored for 6 days using a Per1-luciferase transgene as a bioluminescent indicator of clock function. Fluctuations in Per1 expression had a period of 25 ± 4 hours (n = 14) with early expression at CT09:59 ± 03:37 (CT = circadian time). We also established the kinetics of mineral deposition in developing bone by using noninvasive Raman microscopy to track mineral accumulation in calvarial tissue. The content and quality of newly deposited mineral was continually examined at the interparietal bone/fontanel boundary for a period of 6 days with 1-hour temporal resolution. Using this approach, mineralization over time exhibited bursts of mineral deposition followed by little or no deposition, which was recurrent with a periodicity of 26.8 ± 9.6 hours. As many as six near-daily mineralization events were observed in the calvaria before deposition ceased. Earliest mineralization events occurred at CT16:51 ± 03:45, which is 6 hours behind Per1 expression. These findings are consistent with the hypothesis that mineralization in developing bone tissue is regulated by a local circadian oscillator mechanism.
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