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Bi R, Sun Y, Xiang L, Xu Z, Ye X, Tian Y, Lin Y, Yang C, Gao Y. TGF-β1/Smad3 Signaling Is Required to Alleviate Fluoride-Induced Enamel Hypomineralization. Biol Trace Elem Res 2024; 202:569-579. [PMID: 37140770 DOI: 10.1007/s12011-023-03688-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 04/28/2023] [Indexed: 05/05/2023]
Abstract
Excessive fluoride intake during enamel development can affect enamel mineralization, leading to dental fluorosis. However, its potential mechanisms remain largely unexplored. In the present study, we aimed to investigate the impact of fluoride on the expressions of RUNX2 and ALPL during mineralization and the effect of TGF-β1 administration on fluoride treatment. A dental fluorosis model of newborn mice and an ameloblast cell line ALC were both used in the present study. The mice of the NaF group, including the mothers and newborns, were fed with water containing 150 ppm NaF after delivery to induce dental fluorosis. The mandibular incisors and molars showed significant abrasion in the NaF group. Immunostaining, qRT-PCR, and Western blotting analysis indicated that exposure to fluoride markedly down-regulated RUNX2 and ALPL in mouse ameloblasts and ALCs. Besides, fluoride treatment significantly decreased the mineralization level detected by ALP staining. Furthermore, exogenous TGF-β1 up-regulated RUNX2 and ALPL and promoted mineralization, while the addition of SIS3 could block such TGF-β1-induced up-regulation. In TGF-β1 conditional knockout mice, the immunostaining of RUNX2 and ALPL was weaker compared with wild-type mice. Exposure to fluoride inhibited the expressions of TGF-β1 and Smad3. Co-treatment of TGF-β1 and fluoride up-regulated RUNX2 and ALPL compared with the fluoride alone treatment, promoting mineralization. Collectively, our data indicated that TGF-β1/Smad3 signaling pathway was necessary for the regulatory effects of fluoride on RUNX2 and ALPL, and the fluoride-induced suppression of ameloblast mineralization was mitigated by activating TGF-β1/Smad3 signaling pathway.
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Affiliation(s)
- Ruonan Bi
- Department of Pediatrics and Preventive Dentistry, Binzhou Medical University Hospital, Shandong, 256600, Binzhou, China
| | - Yiqun Sun
- Department of Pediatrics and Preventive Dentistry, Binzhou Medical University Hospital, Shandong, 256600, Binzhou, China
| | - Lili Xiang
- Department of Pediatrics and Preventive Dentistry, Binzhou Medical University Hospital, Shandong, 256600, Binzhou, China
| | - Zhenzhen Xu
- Department of Pediatrics and Preventive Dentistry, Binzhou Medical University Hospital, Shandong, 256600, Binzhou, China
| | - Xiaoyuan Ye
- Department of Pediatrics and Preventive Dentistry, Binzhou Medical University Hospital, Shandong, 256600, Binzhou, China
| | - Yanying Tian
- Department of Pediatrics and Preventive Dentistry, Binzhou Medical University Hospital, Shandong, 256600, Binzhou, China
| | - Yao Lin
- Department of Pediatrics and Preventive Dentistry, Binzhou Medical University Hospital, Shandong, 256600, Binzhou, China
| | - Chunyan Yang
- Institute of Stomatology, Binzhou Medical University, Shandong, 264003, Yantai, China.
| | - Yuguang Gao
- Department of Pediatrics and Preventive Dentistry, Binzhou Medical University Hospital, Shandong, 256600, Binzhou, China.
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Yang Y, Zhu J, Chiba Y, Fukumoto S, Qin M, Wang X. Enamel defects of Axenfeld-Rieger syndrome and the role of PITX2 in its pathogenesis. Oral Dis 2023; 29:3654-3664. [PMID: 35836351 DOI: 10.1111/odi.14315] [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: 12/28/2021] [Revised: 06/09/2022] [Accepted: 07/06/2022] [Indexed: 11/27/2022]
Abstract
OBJECTIVES To investigate the detailed ultrastructural patterns of dental abnormalities affected by Axenfeld-Rieger syndrome (ARS) with a heterozygous microdeletion involving paired-like homeodomain 2 (PITX2) and explored the underlying molecular mechanisms driving enamel defects. SUBJECTS AND METHODS Sanger sequencing, genomic quantitative PCR analysis, and chromosomal microarray analysis (CMA) were used to screen the disease-causing mutation in one ARS proband. An exfoliated tooth from an ARS patient was analyzed with scanning electron microscopy and micro-computerized tomography. A stable Pitx2 knockdown cell line was generated to simulate PITX2 haploinsufficiency. Cell proliferation and ameloblast differentiation were analyzed, and the role of the Wnt/β-catenin pathway in proliferation of ameloblast precursor cells was investigated. RESULTS An approximately 0.216 Mb novel deletion encompassing PITX2 was identified. The affected tooth displayed a thinner and broken layer of enamel and abnormal enamel biomineralization. PITX2 downregulation inhibited the proliferation and differentiation of inner enamel epithelial cells, and LiCl stifmulation partially reversed the proliferation ability after Pitx2 knockdown. CONCLUSIONS Enamel formation is disturbed in some patients with ARS. Pitx2 knockdown can influence the proliferation and ameloblast differentiation of inner enamel epithelial cells, and PITX2 may regulate cell proliferation via Wnt/β-catenin signaling pathway.
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Affiliation(s)
- Yi Yang
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, China
| | - Junxia Zhu
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, China
| | - Yuta Chiba
- Division of Oral Health, Section of Oral Medicine for Children, Growth and Development, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Satoshi Fukumoto
- Division of Oral Health, Section of Oral Medicine for Children, Growth and Development, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
- Division of Pediatric Dentistry, Department of Oral Health and Development Sciences, Tohoku University Graduate School of Dentistry, Sendai, Japan
| | - Man Qin
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, China
| | - Xin Wang
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, China
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Wölfel EM, von Kroge S, Matthies L, Koehne T, Petz K, Beikler T, Schmid-Herrmann CU, Kahl-Nieke B, Tsiakas K, Santer R, Muschol NM, Herrmann J, Busse B, Amling M, Rolvien T, Jandl NM, Barvencik F. Effects of Infantile Hypophosphatasia on Human Dental Tissue. Calcif Tissue Int 2023; 112:308-319. [PMID: 36414794 PMCID: PMC9968273 DOI: 10.1007/s00223-022-01041-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 11/02/2022] [Indexed: 11/23/2022]
Abstract
Hypophosphatasia (HPP) is an inherited, systemic disorder, caused by loss-of-function variants of the ALPL gene encoding the enzyme tissue non-specific alkaline phosphatase (TNSALP). HPP is characterized by low serum TNSALP concentrations associated with defective bone mineralization and increased fracture risk. Dental manifestations have been reported as the exclusive feature (odontohypophosphatasia) and in combination with skeletal complications. Enzyme replacement therapy (asfotase alfa) has been shown to improve respiratory insufficiency and skeletal complications in HPP patients, while its effects on dental status have been understudied to date. In this study, quantitative backscattered electron imaging (qBEI) and histological analysis were performed on teeth from two patients with infantile HPP before and during asfotase alfa treatment and compared to matched healthy control teeth. qBEI and histological methods revealed varying mineralization patterns in cementum and dentin with lower mineralization in HPP. Furthermore, a significantly higher repair cementum thickness was observed in HPP compared to control teeth. Comparison before and during treatment showed minor improvements in mineralization and histological parameters in the patient when normalized to matched control teeth. HPP induces heterogeneous effects on mineralization and morphology of the dental status. Short treatment with asfotase alfa slightly affects mineralization in cementum and dentin. Despite HPP being a rare disease, its mild form occurs at higher prevalence. This study is of high clinical relevance as it expands our knowledge of HPP and dental involvement. Furthermore, it contributes to the understanding of dental tissue treatment, which has hardly been studied so far.
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Affiliation(s)
- Eva Maria Wölfel
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 59, 22529, Hamburg, Germany
- Interdisciplinary Competence Center for Interface Research (ICCIR), Lottestr. 55A, Hamburg, Germany
| | - Simon von Kroge
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 59, 22529, Hamburg, Germany
| | - Levi Matthies
- Department of Oral and Maxillofacial Surgery, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Till Koehne
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 59, 22529, Hamburg, Germany
- Department of Orthodontics, Center for Dental and Oral Medicine, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Karin Petz
- Department of Periodontics, Preventive and Restorative Dentistry, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Thomas Beikler
- Department of Periodontics, Preventive and Restorative Dentistry, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Carmen Ulrike Schmid-Herrmann
- Department of Orthodontics, Center for Dental and Oral Medicine, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Bärbel Kahl-Nieke
- Department of Orthodontics, Center for Dental and Oral Medicine, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Konstantinos Tsiakas
- Department of Pediatrics, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - René Santer
- Department of Pediatrics, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Nicole Maria Muschol
- Department of Pediatrics, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Jochen Herrmann
- Department of Diagnostic and Interventional Radiology and Nuclear Medicine, Section of Pediatric Radiology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Björn Busse
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 59, 22529, Hamburg, Germany
- Interdisciplinary Competence Center for Interface Research (ICCIR), Lottestr. 55A, Hamburg, Germany
| | - Michael Amling
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 59, 22529, Hamburg, Germany
| | - Tim Rolvien
- Division of Orthopaedics, Department of Trauma and Orthopaedic Surgery, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Nico Maximilian Jandl
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 59, 22529, Hamburg, Germany
- Division of Orthopaedics, Department of Trauma and Orthopaedic Surgery, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Florian Barvencik
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 59, 22529, Hamburg, Germany.
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Amadeu de Oliveira F, Mohamed FF, Kinoshita Y, Narisawa S, Farquharson C, Miyake K, Foster BL, Millan JL. Gene Therapy Using Recombinant AAV Type 8 Vector Encoding TNAP-D 10 Improves the Skeletal Phenotypes in Murine Models of Osteomalacia. JBMR Plus 2023; 7:e10709. [PMID: 36699639 PMCID: PMC9850441 DOI: 10.1002/jbm4.10709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Revised: 10/25/2022] [Accepted: 11/08/2022] [Indexed: 12/05/2022] Open
Abstract
Hypophosphatasia (HPP), caused by loss-of-function mutations in the ALPL gene encoding tissue-nonspecific alkaline phosphatase (TNAP), is characterized by skeletal and dental hypomineralization that can vary in severity from life-threatening to milder manifestations only in adulthood. PHOSPHO1 deficiency leads to early-onset scoliosis, osteomalacia, and fractures that mimic pseudo-HPP. Asfotase alfa, a life-saving enzyme replacement therapy approved for pediatric-onset HPP, requires subcutaneous injections 3 to 6 times per week. We recently showed that a single injection of an adeno-associated virus vector serotype 8 harboring TNAP-D10 (AAV8-TNAP-D10) effectively prevented skeletal disease and prolonged life in Alpl -/- mice phenocopying infantile HPP. Here, we aimed to determine the efficacy of AAV8-TNAP-D10 in improving the skeletal and dental phenotype in the Alpl Prx1/Prx1 and Phospho1 -/- mouse models of late-onset (adult) HPP and pseudo-HPP, respectively. A single dose of 3 × 1011 vector genomes per body (vg/b) was injected intramuscularly into 8-week-old Alpl Prx1/Prx1 and wild-type (WT) littermates, or into 3-day-old Phospho1 -/- and WT mice, and treatment efficacy was evaluated after 60 days for late-onset HPP mice and after 90 days for Phospho1 -/- mice. Biochemical analysis showed sustained serum alkaline phosphatase activity and reduced plasma PPi levels, and radiographic images, micro-computed tomography (micro-CT) analysis, and hematoxylin and eosin (H&E) staining showed improvements in the long bones in the late-onset HPP mice and corrected scoliosis in the Phospho1 -/- mice. Micro-CT analysis of the dentoalveolar complex did not reveal significant changes in the phenotype of late-onset HPP and pseudo-HPP models. Moreover, alizarin red staining analysis showed that AAV8-TNAP-D10 treatment did not promote ectopic calcification of soft organs in adult HPP mice after 60 days of treatment, even after inducing chronic kidney disease. Overall, the AAV8-TNAP-D10 treatment improved the skeletal phenotype in both the adult HPP and pseudo-HPP mouse models. This preclinical study will contribute to the advancement of gene therapy for the improvement of skeletal disease in patients with heritable forms of osteomalacia. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
| | - Fatma F. Mohamed
- Division of Biosciences, College of DentistryThe Ohio State UniversityColumbusOHUSA
| | - Yuka Kinoshita
- Human Genetics ProgramSanford Burnham Prebys Medical Discovery InstituteLa JollaCAUSA
| | - Sonoko Narisawa
- Human Genetics ProgramSanford Burnham Prebys Medical Discovery InstituteLa JollaCAUSA
| | - Colin Farquharson
- The Royal (Dick) School of Veterinary Studies (RDSVS), The Roslin InstituteUniversity of EdinburghEdinburghUK
| | - Koichi Miyake
- Department of Gene TherapyNippon Medical SchoolTokyoJapan
| | - Brian L Foster
- Division of Biosciences, College of DentistryThe Ohio State UniversityColumbusOHUSA
| | - Jose Luis Millan
- Human Genetics ProgramSanford Burnham Prebys Medical Discovery InstituteLa JollaCAUSA
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Mu H, Dong Z, Wang Y, Chu Q, Gao Y, Wang A, Wang Y, Liu X, Gao Y. Odontogenesis-Associated Phosphoprotein (ODAPH) Overexpression in Ameloblasts Disrupts Enamel Formation via Inducing Abnormal Mineralization of Enamel in Secretory Stage. Calcif Tissue Int 2022; 111:611-621. [PMID: 36163390 DOI: 10.1007/s00223-022-01023-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Accepted: 09/05/2022] [Indexed: 11/02/2022]
Abstract
Odontogenesis-associated phosphoprotein (ODAPH) is a recently discovered enamel matrix protein. Our previous study demonstrated that knockouting out Odaph in mice resulted in enamel hypomineralization. To further investigate the effect of Odaph on enamel mineralization, we constructed an Odaph overexpression mouse model, controlled by an amelogenin promoter. Our histological analysis of OdaphTg mice revealed that the enamel layer was thinner than in WT mice. An uneven, thinner enamel layer was confirmed using micro-computed tomography (uCT). It was subsequently found that the Tomes' processes lost their normal morphology, resulting in the loss of the enamel prism structure. These results indicate that Odaph overexpression in ameloblasts led to enamel dysplasia. In conjunction with this, Odaph overexpression hindered Amelx secretion, and may result in endoplasmic reticulum stress. Interestingly, uCT revealed that enamel had higher mineral density at the secretory stage; due to this, we did the histological staining for the mineralization-related proteins Alkaline phosphatase (ALPL) and Runt-related transcription factor 2 (RUNX2). It was observed that these proteins were up-regulated in OdaphTg mice versus WT mice, indicating that Odaph overexpression led to abnormal enamel mineralization. To confirm this, we transfected ameloblast-like cell line (ALC) with Odaph overexpression lentivirus in vitro and identified that both Alpl and Runx2 were strikingly upregulated in OE-mus-Odaph versus OE-NC cells. We concluded that the ectopic overexpression of Odaph in ameloblasts led to abnormal enamel mineralization. In summary, Odaph profoundly influences amelogenesis by participating in enamel mineralization.
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Affiliation(s)
- Haiyu Mu
- Department of Pediatrics and Preventive Dentistry, Binzhou Medical University Hospital, Binzhou, 256600, Shandong, China
| | - Zhiheng Dong
- Department of Pediatrics and Preventive Dentistry, Binzhou Medical University Hospital, Binzhou, 256600, Shandong, China.
| | - Yumin Wang
- Institute of Stomatology, Binzhou Medical University, Yantai, 264003, Shandong, China
| | - Qing Chu
- Department of Pediatrics and Preventive Dentistry, Binzhou Medical University Hospital, Binzhou, 256600, Shandong, China
| | - Yan Gao
- Department of Pediatrics and Preventive Dentistry, Binzhou Medical University Hospital, Binzhou, 256600, Shandong, China
| | - Aiqin Wang
- Department of Periodontics, Binzhou Medical University Hospital, Binzhou, 256600, Shandong, China
| | - Yu Wang
- Institute of Stomatology, Binzhou Medical University, Yantai, 264003, Shandong, China
| | - Xiaoying Liu
- Department of Cell Biology, College of Life Science and Technology, Weifang Medical University, Weifang, 261053, Shandong, China
| | - Yuguang Gao
- Department of Pediatrics and Preventive Dentistry, Binzhou Medical University Hospital, Binzhou, 256600, Shandong, China.
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Okawa R, Nakano K. Dental manifestation and management of hypophosphatasia. JAPANESE DENTAL SCIENCE REVIEW 2022; 58:208-216. [PMID: 35814738 PMCID: PMC9260292 DOI: 10.1016/j.jdsr.2022.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 06/22/2022] [Accepted: 06/26/2022] [Indexed: 11/24/2022] Open
Abstract
Hypophosphatasia is an inherited metabolic disorder characterized by defective mineralization of bones and teeth with a wide variety of manifestations, ranging from stillbirth to dental symptoms alone. Recently, the prognosis of severe hypophosphatasia patients has been greatly improved by the introduction of enzyme replacement therapy. The typical dental manifestation is early exfoliation of primary teeth due to disturbed cementum formation, so dentures are recommended to ensure that important oral functions are acquired. Some studies have shown that enzyme replacement therapy improves dental mineralization, resulting in the stabilization of periodontal tissues and better growth of tooth roots. A nationwide Japanese survey revealed the common genetic and dental manifestations of patients with mild hypophosphatasia, which markedly differ from those of the severe forms. There may be many undiagnosed mild patients, so dentists should contribute to the early diagnosis by screening possible cases based on the typical finding of early exfoliation of primary teeth. Early diagnosis is important for patients to receive early intervention in both medical and dental fields. The establishment of fundamental dental therapy to solve the dental problems is still underway and is eagerly anticipated.
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7
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Andras NL, Mohamed FF, Chu EY, Foster BL. Between a rock and a hard place: Regulation of mineralization in the periodontium. Genesis 2022; 60:e23474. [PMID: 35460154 PMCID: PMC9492628 DOI: 10.1002/dvg.23474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 04/08/2022] [Accepted: 04/09/2022] [Indexed: 12/30/2022]
Abstract
The periodontium supports and attaches teeth via mineralized and nonmineralized tissues. It consists of two, unique mineralized tissues, cementum and alveolar bone. In between these tissues, lies an unmineralized, fibrous periodontal ligament (PDL), which distributes occlusal forces, nourishes and invests teeth, and harbors progenitor cells for dentoalveolar repair. Many unanswered questions remain regarding periodontal biology. This review will focus on recent research providing insights into one enduring mystery: the precise regulation of the hard-soft tissue borders in the periodontium which define the interfaces of the cementum-PDL-alveolar bone structure. We will focus on advances in understanding the molecular mechanisms that maintain the unmineralized PDL "between a rock and a hard place" by regulating the mineralization of cementum and alveolar bone.
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Affiliation(s)
- Natalie L. Andras
- Biosciences Division, College of DentistryThe Ohio State UniversityColumbusOhioUSA
| | - Fatma F. Mohamed
- Biosciences Division, College of DentistryThe Ohio State UniversityColumbusOhioUSA
| | - Emily Y. Chu
- Division of Operative Dentistry, Department of General Dentistry, School of DentistryUniversity of MarylandBaltimoreMarylandUSA
| | - Brian L. Foster
- Biosciences Division, College of DentistryThe Ohio State UniversityColumbusOhioUSA
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8
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Figueredo CA, Abdelhay N, Gibson MP. The Roles of SIBLING Proteins in Dental, Periodontal and Craniofacial Development. FRONTIERS IN DENTAL MEDICINE 2022. [DOI: 10.3389/fdmed.2022.898802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The majority of dental, periodontal, and craniofacial tissues are derived from the neural crest cells and ectoderm. Neural crest stem cells are pluripotent, capable of differentiating into a variety of cells. These cells can include osteoblasts, odontoblasts, cementoblasts, chondroblasts, and fibroblasts which are responsible for forming some of the tissues of the oral and craniofacial complex. The hard tissue forming cells deposit a matrix composed of collagen and non-collagenous proteins (NCPs) that later undergoes mineralization. The NCPs play a role in the mineralization of collagen. One such category of NCPs is the small integrin-binding ligand, N-linked glycoprotein (SIBLING) family of proteins. This family is composed of dentin sialophosphosprotein (DSPP), osteopontin (OPN), dentin matrix protein 1 (DMP1), bone sialoprotein (BSP), and matrix extracellular phosphoglycoprotein (MEPE). The SIBLING family is known to have regulatory effects in the mineralization process of collagen fibers and the maturation of hydroxyapatite crystals. It is well established that SIBLING proteins have critical roles in tooth development. Recent literature has described the expression and role of SIBLING proteins in other areas of the oral and craniofacial complex as well. The objective of the present literature review is to summarize and discuss the different roles the SIBLING proteins play in the development of dental, periodontal, and craniofacial tissues.
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9
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Loss of BMP2 and BMP4 Signaling in the Dental Epithelium Causes Defective Enamel Maturation and Aberrant Development of Ameloblasts. Int J Mol Sci 2022; 23:ijms23116095. [PMID: 35682776 PMCID: PMC9180982 DOI: 10.3390/ijms23116095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/18/2022] [Accepted: 05/25/2022] [Indexed: 12/10/2022] Open
Abstract
BMP signaling is crucial for differentiation of secretory ameloblasts, the cells that secrete enamel matrix. However, whether BMP signaling is required for differentiation of maturation-stage ameloblasts (MA), which are instrumental for enamel maturation into hard tissue, is hitherto unknown. To address this, we used an in vivo genetic approach which revealed that combined deactivation of the Bmp2 and Bmp4 genes in the murine dental epithelium causes development of dysmorphic and dysfunctional MA. These fail to exhibit a ruffled apical plasma membrane and to reabsorb enamel matrix proteins, leading to enamel defects mimicking hypomaturation amelogenesis imperfecta. Furthermore, subsets of mutant MA underwent pathological single or collective cell migration away from the ameloblast layer, forming cysts and/or exuberant tumor-like and gland-like structures. Massive apoptosis in the adjacent stratum intermedium and the abnormal cell-cell contacts and cell-matrix adhesion of MA may contribute to this aberrant behavior. The mutant MA also exhibited severely diminished tissue non-specific alkaline phosphatase activity, revealing that this enzyme’s activity in MA crucially depends on BMP2 and BMP4 inputs. Our findings show that combined BMP2 and BMP4 signaling is crucial for survival of the stratum intermedium and for proper development and function of MA to ensure normal enamel maturation.
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10
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Mohamed FF, Chavez MB, de Oliveira FA, Narisawa S, Farquharson C, Millán JL, Foster BL. Perspective on Dentoalveolar Manifestations Resulting From PHOSPHO1 Loss-of-Function: A Form of Pseudohypophosphatasia? FRONTIERS IN DENTAL MEDICINE 2022; 3:826387. [PMID: 36185572 PMCID: PMC9521815 DOI: 10.3389/fdmed.2022.826387] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Mineralization of the skeleton occurs by several physicochemical and biochemical processes and mechanisms that facilitate the deposition of hydroxyapatite (HA) in specific areas of the extracellular matrix (ECM). Two key phosphatases, phosphatase, orphan 1 (PHOSPHO1) and tissue-non-specific alkaline phosphatase (TNAP), play complementary roles in the mineralization process. The actions of PHOSPHO1 on phosphocholine and phosphoethanolamine in matrix vesicles (MVs) produce inorganic phosphate (Pi) for the initiation of HA mineral formation within MVs. TNAP hydrolyzes adenosine triphosphate (ATP) and the mineralization inhibitor, inorganic pyrophosphate (PPi), to generate Pi that is incorporated into MVs. Genetic mutations in the ALPL gene-encoding TNAP lead to hypophosphatasia (HPP), characterized by low circulating TNAP levels (ALP), rickets in children and/or osteomalacia in adults, and a spectrum of dentoalveolar defects, the most prevalent being lack of acellular cementum leading to premature tooth loss. Given that the skeletal manifestations of genetic ablation of the Phospho1 gene in mice resemble many of the manifestations of HPP, we propose that Phospho1 gene mutations may underlie some cases of "pseudo-HPP" where ALP may be normal to subnormal, but ALPL mutation(s) have not been identified. The goal of this perspective article is to compare and contrast the loss-of-function effects of TNAP and PHOSPHO1 on the dentoalveolar complex to predict the likely dental phenotype in humans that may result from PHOSPHO1 mutations. Potential cases of pseudo-HPP associated with PHOSPHO1 mutations may resist diagnosis, and the dental manifestations could be a key criterion for consideration.
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Affiliation(s)
- Fatma F. Mohamed
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, United States
| | - Michael B. Chavez
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, United States
| | - Flavia Amadeu de Oliveira
- Sanford Children’s Health Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, United States
| | - Sonoko Narisawa
- Sanford Children’s Health Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, United States
| | - Colin Farquharson
- The Royal (Dick) School of Veterinary Studies (RDSVS), The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - José Luis Millán
- Sanford Children’s Health Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, United States
| | - Brian L. Foster
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, United States,,Correspondence: Brian L. Foster,
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11
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Goettsch C, Strzelecka-Kiliszek A, Bessueille L, Quillard T, Mechtouff L, Pikula S, Canet-Soulas E, Luis MJ, Fonta C, Magne D. TNAP as a therapeutic target for cardiovascular calcification: a discussion of its pleiotropic functions in the body. Cardiovasc Res 2022; 118:84-96. [PMID: 33070177 PMCID: PMC8752354 DOI: 10.1093/cvr/cvaa299] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 09/11/2020] [Accepted: 10/06/2020] [Indexed: 12/15/2022] Open
Abstract
Cardiovascular calcification (CVC) is associated with increased morbidity and mortality. It develops in several diseases and locations, such as in the tunica intima in atherosclerosis plaques, in the tunica media in type 2 diabetes and chronic kidney disease, and in aortic valves. In spite of the wide occurrence of CVC and its detrimental effects on cardiovascular diseases (CVD), no treatment is yet available. Most of CVC involve mechanisms similar to those occurring during endochondral and/or intramembranous ossification. Logically, since tissue-nonspecific alkaline phosphatase (TNAP) is the key-enzyme responsible for skeletal/dental mineralization, it is a promising target to limit CVC. Tools have recently been developed to inhibit its activity and preclinical studies conducted in animal models of vascular calcification already provided promising results. Nevertheless, as its name indicates, TNAP is ubiquitous and recent data indicate that it dephosphorylates different substrates in vivo to participate in other important physiological functions besides mineralization. For instance, TNAP is involved in the metabolism of pyridoxal phosphate and the production of neurotransmitters. TNAP has also been described as an anti-inflammatory enzyme able to dephosphorylate adenosine nucleotides and lipopolysaccharide. A better understanding of the full spectrum of TNAP's functions is needed to better characterize the effects of TNAP inhibition in diseases associated with CVC. In this review, after a brief description of the different types of CVC, we describe the newly uncovered additional functions of TNAP and discuss the expected consequences of its systemic inhibition in vivo.
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Affiliation(s)
- Claudia Goettsch
- Department of Internal Medicine I, Cardiology, Medical Faculty, RWTH Aachen
University, Aachen, Germany
| | - Agnieszka Strzelecka-Kiliszek
- Laboratory of Biochemistry of Lipids, Nencki Institute of Experimental
Biology, 3 Pasteur Street, 02-093 Warsaw, Poland
| | - Laurence Bessueille
- Institute of Molecular and Supramolecular Chemistry and Biochemistry
(ICBMS), UMR CNRS 5246, Université Claude Bernard Lyon 1, Bâtiment
Raulin, 43 Bd du 11 novembre 1918, Lyon 69622 Villeurbanne Cedex, France
| | - Thibaut Quillard
- PHY-OS Laboratory, UMR 1238 INSERM, Université de Nantes, CHU
de Nantes, France
| | - Laura Mechtouff
- Stroke Department, Hospices Civils de Lyon, France
- CREATIS Laboratory, CNRS UMR 5220, Inserm U1044, Université Claude Bernard
Lyon 1, Lyon, France
| | - Slawomir Pikula
- Laboratory of Biochemistry of Lipids, Nencki Institute of Experimental
Biology, 3 Pasteur Street, 02-093 Warsaw, Poland
| | - Emmanuelle Canet-Soulas
- CarMeN Laboratory, Univ Lyon, INSERM, INRA, INSA Lyon, Université Claude
Bernard Lyon 1, Lyon, France
| | - Millan Jose Luis
- Human Genetics Program, Sanford Burnham Prebys Medical Discovery
Institute, La Jolla, CA 92037, USA
| | - Caroline Fonta
- Brain and Cognition Research Center CerCo, CNRS UMR5549, Université de
Toulouse, France
| | - David Magne
- Institute of Molecular and Supramolecular Chemistry and Biochemistry
(ICBMS), UMR CNRS 5246, Université Claude Bernard Lyon 1, Bâtiment
Raulin, 43 Bd du 11 novembre 1918, Lyon 69622 Villeurbanne Cedex, France
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12
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Inoue A, Kiyoshima T, Yoshizaki K, Nakatomi C, Nakatomi M, Ohshima H, Shin M, Gao J, Tsuru K, Okabe K, Nakamura I, Honda H, Matsuda M, Takahashi I, Jimi E. Deletion of epithelial cell-specific p130Cas impairs the maturation stage of amelogenesis. Bone 2022; 154:116210. [PMID: 34592494 DOI: 10.1016/j.bone.2021.116210] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 09/17/2021] [Accepted: 09/18/2021] [Indexed: 11/02/2022]
Abstract
Amelogenesis consists of secretory, transition, maturation, and post-maturation stages, and the morphological changes of ameloblasts at each stage are closely related to their function. p130 Crk-associated substrate (Cas) is a scaffold protein that modulates essential cellular processes, including cell adhesion, cytoskeletal changes, and polarization. The expression of p130Cas was observed from the secretory stage to the maturation stage in ameloblasts. Epithelial cell-specific p130Cas-deficient (p130CasΔepi-) mice exhibited enamel hypomineralization with chalk-like white mandibular incisors in young mice and attrition in aged mouse molars. A micro-computed tomography analysis and Vickers micro-hardness testing showed thinner enamel, lower enamel mineral density and hardness in p130CasΔepi- mice in comparison to p130Casflox/flox mice. Scanning electron microscopy, and an energy dispersive X-ray spectroscopy analysis indicated the disturbance of the enamel rod structure and lower Ca and P contents in p130CasΔepi- mice, respectively. The disorganized arrangement of ameloblasts, especially in the maturation stage, was observed in p130CasΔepi- mice. Furthermore, expression levels of enamel matrix proteins, such as amelogenin and ameloblastin in the secretory stage, and functional markers, such as alkaline phosphatase and iron accumulation, and Na+/Ca2++K+-exchanger in the maturation stage were reduced in p130CasΔepi- mice. These findings suggest that p130Cas plays important roles in amelogenesis (197 words).
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Affiliation(s)
- Akane Inoue
- Laboratory of Molecular and Cellular Biochemistry, Division of Oral Biological Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan; Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth and Development, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Tamotsu Kiyoshima
- Laboratory of Oral Pathology, Division of Maxillofacial Diagnostic and Surgical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Keigo Yoshizaki
- Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth and Development, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Chihiro Nakatomi
- Division of Physiology, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu 803-8580, Japan
| | - Mitsushiro Nakatomi
- Department of Human, Information and Life Sciences, School of Health Sciences, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan
| | - Hayato Ohshima
- Division of Anatomy and Cell Biology of the Hard Tissue, Department of Tissue Regeneration and Reconstruction, Niigata University Graduate School of Medical and Dental Sciences, 2-5274 Gakkocho-dori, Chuo-ku, Niigata 951-8514, Japan
| | - Masashi Shin
- Department of Physiological Sciences and Molecular Biology, Fukuoka Dental College, 2-5-1 Tamura, Sawara-ku, Fukuoka 814-0175, Japan; Oral Medicine Center, Fukuoka Dental College, 2-5-1 Tamura, Sawara-ku, Fukuoka 814-0175, Japan
| | - Jing Gao
- Laboratory of Molecular and Cellular Biochemistry, Division of Oral Biological Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Kanji Tsuru
- Section of Bioengineering, Fukuoka Dental College, 2-5-1 Tamura, Sawara-ku, Fukuoka 814-0175, Japan
| | - Koji Okabe
- Department of Physiological Sciences and Molecular Biology, Fukuoka Dental College, 2-5-1 Tamura, Sawara-ku, Fukuoka 814-0175, Japan
| | - Ichiro Nakamura
- Department of Rehabilitation, Yugawara Hospital, Japan Community Health Care Organization, 2-21-6 Chuo, Yugawara, Ashigara-shimo, Kanagawa 259-0396, Japan
| | - Hiroaki Honda
- Field of Human Disease Models, Major in Advanced Life Sciences and Medicine, Institute of Laboratory Animals, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan
| | - Miho Matsuda
- Laboratory of Molecular and Cellular Biochemistry, Division of Oral Biological Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Ichiro Takahashi
- Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth and Development, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Eijiro Jimi
- Laboratory of Molecular and Cellular Biochemistry, Division of Oral Biological Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan; Oral Health/Brain Health/Total Health Research Center, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
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Schroth RJ, Long C, Lee VHK, Alai-Towfigh H, Rockman-Greenberg C. Dental outcomes for children receiving asfotase alfa for hypophosphatasia. Bone 2021; 152:116089. [PMID: 34175501 DOI: 10.1016/j.bone.2021.116089] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 06/01/2021] [Accepted: 06/22/2021] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Hypophosphatasia, a genetic disease impeding development of teeth and bones, is associated with premature exfoliation of primary teeth. Hypophosphatasia is caused by mutations in the ALPL gene, which encodes the tissue non-specific form of alkaline phosphatase. Asfotase alfa (Strensiq®) is a human recombinant bone-targeted alkaline phosphatase. OBJECTIVES To review development and exfoliation patterns of primary/permanent teeth in a cohort of patients with hypophosphatasia enrolled in an open-label clinical trial of enzyme replacement therapy (ERT) with asfotase alfa. METHODS Data were collected from existing study files of a cohort of patients ≤5 years of age with infantile hypophosphatasia. Children were recruited at the Winnipeg site of a global clinical trial and were treated with ERT. Dental information, including the exfoliation/eruption patterns, were recorded at each visit. RESULTS Eleven children (7 females, 4 males) participated. Participants enrolled as infants (5 infants; mean age 3.0 ± 2.3 months) prematurely lost significantly fewer teeth to hypophosphatasia than patients recruited as preschoolers (6 preschoolers; mean age 52.5 ± 11.3 months), who started on asfotase alfa at a later age. Conclusion The oral health of children with early onset infantile hypophosphatasia may be improved with early and continued administration of ERT, compared to institution of therapy later in childhood.
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Affiliation(s)
- Robert J Schroth
- Rady Faculty of Health Sciences, University of Manitoba, Canada; Children's Hospital Research Institute of Manitoba, Canada; Section of Pediatric Dentistry, Winnipeg Regional Health Authority, Canada; Shared Health Manitoba, Canada.
| | - Catherine Long
- Rady Faculty of Health Sciences, University of Manitoba, Canada
| | - Victor H K Lee
- Rady Faculty of Health Sciences, University of Manitoba, Canada; Children's Hospital Research Institute of Manitoba, Canada
| | | | - Cheryl Rockman-Greenberg
- Rady Faculty of Health Sciences, University of Manitoba, Canada; Children's Hospital Research Institute of Manitoba, Canada; Shared Health Manitoba, Canada
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14
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Kinoshita Y, Mohamed FF, Amadeu de Oliveira F, Narisawa S, Miyake K, Foster BL, Millán JL. Gene Therapy Using Adeno-Associated Virus Serotype 8 Encoding TNAP-D 10 Improves the Skeletal and Dentoalveolar Phenotypes in Alpl -/- Mice. J Bone Miner Res 2021; 36:1835-1849. [PMID: 34076297 PMCID: PMC8446309 DOI: 10.1002/jbmr.4382] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 05/25/2021] [Accepted: 05/28/2021] [Indexed: 12/26/2022]
Abstract
Hypophosphatasia (HPP) is caused by loss-of-function mutations in the ALPL gene that encodes tissue-nonspecific alkaline phosphatase (TNAP), whose deficiency results in the accumulation of extracellular inorganic pyrophosphate (PPi ), a potent mineralization inhibitor. Skeletal and dental hypomineralization characterizes HPP, with disease severity varying from life-threatening perinatal or infantile forms to milder forms that manifest in adulthood or only affect the dentition. Enzyme replacement therapy (ERT) using mineral-targeted recombinant TNAP (Strensiq/asfotase alfa) markedly improves the life span, skeletal phenotype, motor function, and quality of life of patients with HPP, though limitations of ERT include frequent injections due to a short elimination half-life of 2.28 days and injection site reactions. We tested the efficacy of a single intramuscular administration of adeno-associated virus 8 (AAV8) encoding TNAP-D10 to increase the life span and improve the skeletal and dentoalveolar phenotypes in TNAP knockout (Alpl-/- ) mice, a murine model for severe infantile HPP. Alpl-/- mice received 3 × 1011 vector genomes/body of AAV8-TNAP-D10 within 5 days postnatal (dpn). AAV8-TNAP-D10 elevated serum ALP activity and suppressed plasma PPi . Treatment extended life span of Alpl-/- mice, and no ectopic calcifications were observed in the kidneys, aorta, coronary arteries, or brain in the 70 dpn observational window. Treated Alpl-/- mice did not show signs of rickets, including bowing of long bones, enlargement of epiphyses, or fractures. Bone microstructure of treated Alpl-/- mice was similar to wild type, with a few persistent small cortical and trabecular defects. Histology showed no measurable osteoid accumulation but reduced bone volume fraction in treated Alpl-/- mice versus controls. Treated Alpl-/- mice featured normal molar and incisor dentoalveolar tissues, with the exceptions of slightly reduced molar enamel and alveolar bone density. Histology showed the presence of cementum and normal periodontal ligament attachment. These results support gene therapy as a promising alternative to ERT for the treatment of HPP. © 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)
- Yuka Kinoshita
- Sanford Children's Health Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Fatma F Mohamed
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - Flavia Amadeu de Oliveira
- Sanford Children's Health Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Sonoko Narisawa
- Sanford Children's Health Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Koichi Miyake
- Department of Biochemistry and Molecular Biology, Nippon Medical School, Tokyo, Japan
| | - Brian L Foster
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - José Luis Millán
- Sanford Children's Health Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
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15
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Kramer K, Chavez MB, Tran AT, Farah F, Tan MH, Kolli TN, Dos Santos EJL, Wimer HF, Millán JL, Suva LJ, Gaddy D, Foster BL. Dental defects in the primary dentition associated with hypophosphatasia from biallelic ALPL mutations. Bone 2021; 143:115732. [PMID: 33160095 PMCID: PMC7769999 DOI: 10.1016/j.bone.2020.115732] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 10/29/2020] [Accepted: 11/02/2020] [Indexed: 12/12/2022]
Abstract
ALPL encodes tissue-nonspecific alkaline phosphatase (TNAP), an enzyme expressed in bone, teeth, liver, and kidney. ALPL loss-of-function mutations cause hypophosphatasia (HPP), an inborn error-of-metabolism that produces skeletal and dental mineralization defects. Case reports describe widely varying dental phenotypes, making it unclear how HPP comparatively affects the three unique dental mineralized tissues: enamel, dentin, and cementum. We hypothesized that HPP affected all dental mineralized tissues and aimed to establish quantitative measurements of dental tissues in a subject with HPP. The female proband was diagnosed with HPP during childhood based on reduced alkaline phosphatase activity (ALP), mild rachitic skeletal effects, and premature primary tooth loss. The diagnosis was subsequently confirmed genetically by the presence of compound heterozygous ALPL mutations (exon 5: c.346G>A, p.A116T; exon 10: c.1077C>G, p.I359M). Dental defects in 8 prematurely exfoliated primary teeth were analyzed by high resolution micro-computed tomography (micro-CT) and histology. Similarities to the Alpl-/- mouse model of HPP were identified by additional analyses of murine dentoalveolar tissues. Primary teeth from the proband exhibited substantial remaining root structure compared to healthy control teeth. Enamel and dentin densities were not adversely affected in HPP vs. control teeth. However, analysis of discrete dentin regions revealed an approximate 10% reduction in the density of outer mantle dentin of HPP vs. control teeth. All 4 incisors and the molar lacked acellular cementum by micro-CT and histology, but surprisingly, 2 of 3 prematurely exfoliated canines exhibited apparently normal acellular cementum. Based on dentin findings in the proband's teeth, we examined dentoalveolar tissues in a mouse model of HPP, revealing that the delayed initiation of mineralization in the incisor mantle dentin was associated with a broader lack of circumpulpal dentin mineralization. This study describes a quantitative approach to measure effects of HPP on dental tissues. This approach has uncovered a previously unrecognized novel mantle dentin defect in HPP, as well as a surprising and variable cementum phenotype within the teeth from the same HPP subject.
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Affiliation(s)
- K Kramer
- Division of Orthodontics, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - M B Chavez
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - A T Tran
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - F Farah
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - M H Tan
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - T N Kolli
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - E J Lira Dos Santos
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA; Department of Prosthodontics and Periodontics, Division of Periodontics, Piracicaba Dental School, University of Campinas-UNICAMP, Piracicaba, SP, Brazil
| | - H F Wimer
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA; National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - J L Millán
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - L J Suva
- Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - D Gaddy
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - B L Foster
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA.
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16
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TNAP as a New Player in Chronic Inflammatory Conditions and Metabolism. Int J Mol Sci 2021; 22:ijms22020919. [PMID: 33477631 PMCID: PMC7831495 DOI: 10.3390/ijms22020919] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/14/2021] [Accepted: 01/14/2021] [Indexed: 12/19/2022] Open
Abstract
This review summarizes important information on the ectoenzyme tissue-nonspecific alkaline phosphatase (TNAP) and gives a brief insight into the symptoms, diagnostics, and treatment of the rare disease Hypophosphatasia (HPP), which is resulting from mutations in the TNAP encoding ALPL gene. We emphasize the role of TNAP beyond its well-known contribution to mineralization processes. Therefore, above all, the impact of the enzyme on central molecular processes in the nervous system and on inflammation is presented here.
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17
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Tissue-Nonspecific Alkaline Phosphatase-A Gatekeeper of Physiological Conditions in Health and a Modulator of Biological Environments in Disease. Biomolecules 2020; 10:biom10121648. [PMID: 33302551 PMCID: PMC7763311 DOI: 10.3390/biom10121648] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 11/30/2020] [Accepted: 12/05/2020] [Indexed: 12/15/2022] Open
Abstract
Tissue-nonspecific alkaline phosphatase (TNAP) is a ubiquitously expressed enzyme that is best known for its role during mineralization processes in bones and skeleton. The enzyme metabolizes phosphate compounds like inorganic pyrophosphate and pyridoxal-5′-phosphate to provide, among others, inorganic phosphate for the mineralization and transportable vitamin B6 molecules. Patients with inherited loss of function mutations in the ALPL gene and consequently altered TNAP activity are suffering from the rare metabolic disease hypophosphatasia (HPP). This systemic disease is mainly characterized by impaired bone and dental mineralization but may also be accompanied by neurological symptoms, like anxiety disorders, seizures, and depression. HPP characteristically affects all ages and shows a wide range of clinical symptoms and disease severity, which results in the classification into different clinical subtypes. This review describes the molecular function of TNAP during the mineralization of bones and teeth, further discusses the current knowledge on the enzyme’s role in the nervous system and in sensory perception. An additional focus is set on the molecular role of TNAP in health and on functional observations reported in common laboratory vertebrate disease models, like rodents and zebrafish.
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18
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Yoshizaki K, Fukumoto S, Bikle DD, Oda Y. Transcriptional Regulation of Dental Epithelial Cell Fate. Int J Mol Sci 2020; 21:ijms21238952. [PMID: 33255698 PMCID: PMC7728066 DOI: 10.3390/ijms21238952] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 11/10/2020] [Accepted: 11/12/2020] [Indexed: 12/28/2022] Open
Abstract
Dental enamel is hardest tissue in the body and is produced by dental epithelial cells residing in the tooth. Their cell fates are tightly controlled by transcriptional programs that are facilitated by fate determining transcription factors and chromatin regulators. Understanding the transcriptional program controlling dental cell fate is critical for our efforts to build and repair teeth. In this review, we describe the current understanding of these regulators essential for regeneration of dental epithelial stem cells and progeny, which are identified through transgenic mouse models. We first describe the development and morphogenesis of mouse dental epithelium in which different subpopulations of epithelia such as ameloblasts contribute to enamel formation. Then, we describe the function of critical factors in stem cells or progeny to drive enamel lineages. We also show that gene mutations of these factors are associated with dental anomalies in craniofacial diseases in humans. We also describe the function of the master regulators to govern dental lineages, in which the genetic removal of each factor switches dental cell fate to that generating hair. The distinct and related mechanisms responsible for the lineage plasticity are discussed. This knowledge will lead us to develop a potential tool for bioengineering new teeth.
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Affiliation(s)
- Keigo Yoshizaki
- Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth and Development, Kyushu University Faculty of Dental Science, Fukuoka 812-8582, Japan;
| | - Satoshi Fukumoto
- Section of Pediatric Dentistry, Division of Oral Health, Growth and Development, Kyushu University Faculty of Dental Science, Fukuoka 812-8582, Japan;
- Division of Pediatric Dentistry, Department of Oral Health and Development Sciences, Tohoku University Graduate School of Dentistry, Sendai 980-8575, Japan
| | - Daniel D. Bikle
- Departments of Medicine and Endocrinology, University of California San Francisco and Veterans Affairs Medical Center, San Francisco, CA 94158, USA;
| | - Yuko Oda
- Departments of Medicine and Endocrinology, University of California San Francisco and Veterans Affairs Medical Center, San Francisco, CA 94158, USA;
- Correspondence:
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19
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Amadeu de Oliveira F, Narisawa S, Bottini M, Millán JL. Visualization of Mineral-Targeted Alkaline Phosphatase Binding to Sites of Calcification In Vivo. J Bone Miner Res 2020; 35:1765-1771. [PMID: 32343017 PMCID: PMC8383212 DOI: 10.1002/jbmr.4038] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 04/01/2020] [Accepted: 04/20/2020] [Indexed: 02/02/2023]
Abstract
A mineral-targeted form of recombinant tissue-nonspecific alkaline phosphatase (TNAP), asfotase alfa, was approved multinationally as an enzyme replacement therapy for hypophosphatasia in 2015. Two reports to date have shown evidence of binding of this drug to mineralizing tissues using histochemistry and immunohistochemistry. Here, we sought to expand on those earlier studies by directly visualizing the in vivo binding of asfotase alfa conjugated with AnaTag HiLyte Fluor 750 or Alexa Fluor 647 fluorescent dye to sites of skeletal/dental mineralization and ectopic calcification. We utilized 40-day-old Tagln-Cre; HprtALPL/Y mice, a model of severe medial vascular calcification; Tie2-Cre; HprtALPL/Y mice, a model of severe intimal calcification; and sibling WT HprtALPL/Y mice, devoid of soft-tissue calcification. A single dose of 8 mg/kg labeled asfotase alfa was injected via the retro-orbital route. Skeletal tissues and soft organs were imaged ex vivo 2 days after the injection. Strong fluorescence signal was observed in all skeletal tissues (calvaria, vertebra, long bones, jaw, and mandibles) from mutant and WT mice. Fluorescence analysis of histological sections from bones revealed strong binding of asfotase alfa. Asfotase alfa binding to sites of ectopic calcification in the heart, aorta, and renal artery were found in both the Tagln-Cre; HprtALPL/Y and Tie2-Cre; HprtALPL/Y mice but not in WT mice. In addition, asfotase alfa binding was also found in the kidney stroma and brain of the Tie2-Cre; HprtALPL/Y mice. Our results show that fluorescence-labeled asfotase alfa administered in vivo binds not only to sites of skeletal and dental mineralization but also to sites of ectopic calcification in these animal models. © 2020 American Society for Bone and Mineral Research.
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Affiliation(s)
| | - Sonoko Narisawa
- Human Genetics Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Massimo Bottini
- Human Genetics Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - José Luis Millán
- Human Genetics Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
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20
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Ukarapong S, Seeherunvong T, Berkovitz G. Current and Emerging Therapies for Pediatric Bone Diseases. Clin Rev Bone Miner Metab 2020. [DOI: 10.1007/s12018-020-09272-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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21
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Insights into dental mineralization from three heritable mineralization disorders. J Struct Biol 2020; 212:107597. [PMID: 32758526 DOI: 10.1016/j.jsb.2020.107597] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 07/27/2020] [Accepted: 07/30/2020] [Indexed: 12/19/2022]
Abstract
Teeth are comprised of three unique mineralized tissues, enamel, dentin, and cementum, that are susceptible to developmental defects similar to those affecting bone. X-linked hypophosphatemia (XLH), caused by PHEX mutations, leads to increased fibroblast growth factor 23 (FGF23)-driven hypophosphatemia and local extracellular matrix disturbances. Hypophosphatasia (HPP), caused by ALPL mutations, results in increased levels of inorganic pyrophosphate (PPi), a mineralization inhibitor. Generalized arterial calcification in infancy (GACI), caused by ENPP1 mutations, results in vascular calcification due to decreased PPi, later compounded by FGF23-driven hypophosphatemia. In this perspective, we compare and contrast dental defects in primary teeth associated with XLH, HPP, and GACI, briefly reviewing genetic and biochemical features of these disorders and findings of clinical and preclinical studies to date, including some of our own recent observations. The distinct dental defects associated with the three heritable mineralization disorders reflect unique processes of the respective dental hard tissues, revealing insights into their development and clues about pathological mechanisms underlying such disorders.
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22
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Machiya A, Tsukamoto S, Ohte S, Kuratani M, Suda N, Katagiri T. Smad4-dependent transforming growth factor-β family signaling regulates the differentiation of dental epithelial cells in adult mouse incisors. Bone 2020; 137:115456. [PMID: 32473314 DOI: 10.1016/j.bone.2020.115456] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 05/22/2020] [Accepted: 05/25/2020] [Indexed: 01/22/2023]
Abstract
Teeth consist of two major tissues, enamel and dentin, which are formed during development by epithelial and mesenchymal cells, respectively. Rodent incisors are useful experimental models for studying the molecular mechanisms of tooth formation because they are simultaneously growing in not only embryos but also adults. Members of the transforming growth factor-β (TGF-β) family regulate epithelial-mesenchymal interactions through an essential coactivator, Smad4. In the present study, we established Smad4 conditional knockout (cKO) mice and examined phenotypes in adult incisors. Smad4 cKO mice died with severe anemia within one month. Phosphorylated Smad1/5/9 and Smad2/3 were detected in epithelial cells in both control and Smad4 cKO mice. Disorganized and hypoplastic epithelial cells, such as ameloblasts, were observed in Smad4 cKO mice. Moreover, alkaline phosphatase expression and iron accumulation were reduced in dental epithelial cells in Smad4 cKO mice. These findings suggest that TGF-β family signaling through Smad4 is required for the differentiation and functions of dental epithelial cells in adult mouse incisors.
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Affiliation(s)
- Aiko Machiya
- Division of Biomedical Sciences, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan; Division of Orthodontics, Department of Human Development and Fostering, Meikai University School of Dentistry, Saitama, Japan; Division of Oral Rehabilitation of Sciences, Department of Restorative and Biomaterials Sciences, Meikai University School of Dentistry, Saitama, Japan
| | - Sho Tsukamoto
- Division of Biomedical Sciences, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan
| | - Satoshi Ohte
- Division of Biomedical Sciences, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan; Microbial Chemistry Laboratory, Graduate School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan
| | - Mai Kuratani
- Division of Biomedical Sciences, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan
| | - Naoto Suda
- Division of Orthodontics, Department of Human Development and Fostering, Meikai University School of Dentistry, Saitama, Japan
| | - Takenobu Katagiri
- Division of Biomedical Sciences, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan.
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23
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Chu EY, Vo TD, Chavez MB, Nagasaki A, Mertz EL, Nociti FH, Aitken SF, Kavanagh D, Zimmerman K, Li X, Stabach PR, Braddock DT, Millán JL, Foster BL, Somerman MJ. Genetic and pharmacologic modulation of cementogenesis via pyrophosphate regulators. Bone 2020; 136:115329. [PMID: 32224162 PMCID: PMC7482720 DOI: 10.1016/j.bone.2020.115329] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 03/19/2020] [Accepted: 03/20/2020] [Indexed: 11/27/2022]
Abstract
Pyrophosphate (PPi) serves as a potent and physiologically important regulator of mineralization, with systemic and local concentrations determined by several key regulators, including: tissue-nonspecific alkaline phosphatase (ALPL gene; TNAP protein), the progressive ankylosis protein (ANKH; ANK), and ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1; ENPP1). Results to date have indicated important roles for PPi in cementum formation, and we addressed several gaps in knowledge by employing genetically edited mouse models where PPi metabolism was disrupted and pharmacologically modulating PPi in a PPi-deficient mouse model. We demonstrate that acellular cementum growth is inversely proportional to PPi levels, with reduced cementum in Alpl KO (increased PPi levels) mice and excess cementum in Ank KO mice (decreased PPi levels). Moreover, simultaneous ablation of Alpl and Ank results in reestablishment of functional cementum in dKO mice. Additional reduction of PPi by dual deletion of Ank and Enpp1 does not further increase cementogenesis, and PDL space is maintained in part through bone modeling/remodeling by osteoclasts. Our results provide insights into cementum formation and expand our knowledge of how PPi regulates cementum. We also demonstrate for the first time that pharmacologic manipulation of PPi through an ENPP1-Fc fusion protein can regulate cementum growth, supporting therapeutic interventions targeting PPi metabolism.
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Affiliation(s)
- E Y Chu
- National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA.
| | - T D Vo
- National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA
| | - M B Chavez
- Biosciences Division, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - A Nagasaki
- National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA
| | - E L Mertz
- National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
| | - F H Nociti
- Department of Prosthodontics & Periodontics, State University of Campinas, Piracicaba Dental School, Piracicaba, São Paulo, Brazil
| | - S F Aitken
- National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA
| | - D Kavanagh
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - K Zimmerman
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - X Li
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - P R Stabach
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - D T Braddock
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - J L Millán
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - B L Foster
- Biosciences Division, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - M J Somerman
- National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA
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24
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Michigami T, Tachikawa K, Yamazaki M, Kawai M, Kubota T, Ozono K. Hypophosphatasia in Japan: ALPL Mutation Analysis in 98 Unrelated Patients. Calcif Tissue Int 2020; 106:221-231. [PMID: 31707452 DOI: 10.1007/s00223-019-00626-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 10/24/2019] [Indexed: 12/19/2022]
Abstract
Hypophosphatasia (HPP) is highly variable in clinical expression and is generally classified into six subtypes. Although it would be beneficial to be able to predict the clinical course from the ALPL genotype, studies on this issue are limited. Here, we aimed to clarify the features of Japanese HPP and the relationships between genotype and clinical manifestations. We analyzed 98 unrelated Japanese patients to investigate the percentage of each clinical form, frequently detected mutations, and the relationship between the genotype and phenotype. Some of the identified mutants were characterized by transfection experiments. Perinatal severe form was the most frequent (45.9%), followed by perinatal benign form (22.4%). Among the 196 alleles, p.Leu520ArgfsX86 (c.1559delT) was detected in 89 alleles, and p.Phe327Leu (c.979T>C) was identified in 23 alleles. All of the homozygotes for p.Leu520ArgfsX86 were classified into perinatal severe form, and patients carrying p.Phe327Leu in one of the alleles were classified into perinatal benign or odonto HPP. Twenty of the 22 patients with perinatal benign HPP were compound heterozygous for p.Phe327Leu and another mutation. Most patients with odonto HPP were found to be monoallelic heterozygotes for dominant-negative mutations or compound heterozygotes with mutants having residual activity. The high prevalence of p.Leu520ArgfsX86 and p.Phe327Leu mutations might underlie the high rate of perinatal severe and perinatal benign forms, respectively, in Japanese HPP. Although ALPL genotyping would be beneficial for predicting the clinical course to an extent, the observed phenotypical variability among patients sharing the same genotypes suggests the presence of modifiers.
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Affiliation(s)
- Toshimi Michigami
- Department of Bone and Mineral Research, Research Institute, Osaka Women's and Children's Hospital, Osaka Prefectural Hospital Organization, 840 Murodo-cho, Izumi, 594-1101, Osaka, Japan.
| | - Kanako Tachikawa
- Department of Bone and Mineral Research, Research Institute, Osaka Women's and Children's Hospital, Osaka Prefectural Hospital Organization, 840 Murodo-cho, Izumi, 594-1101, Osaka, Japan
| | - Miwa Yamazaki
- Department of Bone and Mineral Research, Research Institute, Osaka Women's and Children's Hospital, Osaka Prefectural Hospital Organization, 840 Murodo-cho, Izumi, 594-1101, Osaka, Japan
| | - Masanobu Kawai
- Department of Bone and Mineral Research, Research Institute, Osaka Women's and Children's Hospital, Osaka Prefectural Hospital Organization, 840 Murodo-cho, Izumi, 594-1101, Osaka, Japan
| | - Takuo Kubota
- Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, 565-0871, Osaka, Japan
| | - Keiichi Ozono
- Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, 565-0871, Osaka, Japan
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25
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Abstract
Understanding the "code of life" and mapping the human genome have been monumental and era-defining scientific landmarks-analogous to setting foot on the moon. The last century has been characterized by exponential advances in our understanding of the biological and specifically molecular basis of health and disease. The early part of the 20th century was marked by fundamental theoretical and scientific advances in understanding heredity, the identification of the DNA molecule and genes, and the elucidation of the central dogma of biology. The second half was characterized by experimental and increasingly molecular investigations, including clinical and population applications. The completion of the Human Genome Project in 2003 and the continuous technological advances have democratized access to this information and the ability to generate health and disease association data; however, the realization of genomic and precision medicine, to practically improve people's health, has lagged. The oral health domain has made great strides and substantially benefited from the last century of advances in genetics and genomics. Observations regarding a hereditary component of dental caries were reported as early as the 1920s. Subsequent breakthroughs were made in the discovery of genetic causes of rare diseases, such as ectodermal dysplasias, orofacial clefts, and other craniofacial and dental anomalies. More recently, genome-wide investigations have been conducted and reported for several diseases and traits, including periodontal disease, dental caries, tooth agenesis, cancers of the head and neck, orofacial pain, temporomandibular disorders, and craniofacial morphometrics. Gene therapies and gene editing with CRISPR/Cas represent the latest frontier surpassed in the era of genomic medicine. Amid rapid genomics progress, several challenges and opportunities lie ahead. Importantly, systematic efforts supported by implementation science are needed to realize the full potential of genomics, including the improvement of public and practitioner genomics literacy, the promotion of individual and population oral health, and the reduction of disparities.
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Affiliation(s)
- K. Divaris
- Department of Pediatric Dentistry, School of Dentistry, University of North Carolina–Chapel Hill, Chapel Hill, NC, USA
- Department of Epidemiology, Gillings School of Global Health, University of North Carolina–Chapel Hill, Chapel Hill, NC, USA
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26
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Bowden SA, Foster BL. Alkaline Phosphatase Replacement Therapy for Hypophosphatasia in Development and Practice. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1148:279-322. [PMID: 31482504 DOI: 10.1007/978-981-13-7709-9_13] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Hypophosphatasia (HPP) is an inherited disorder that affects bone and tooth mineralization characterized by low serum alkaline phosphatase. HPP is caused by loss-of-function mutations in the ALPL gene encoding the protein, tissue-nonspecific alkaline phosphatase (TNSALP). TNSALP is expressed by mineralizing cells of the skeleton and dentition and is associated with the mineralization process. Generalized reduction of activity of the TNSALP leads to accumulation of its substrates, including inorganic pyrophosphate (PPi) that inhibits physiological mineralization. This leads to defective skeletal mineralization, with manifestations including rickets, osteomalacia, fractures, and bone pain, all of which can result in multi-systemic complications with significant morbidity, as well as mortality in severe cases. Dental manifestations are nearly universal among affected individuals and feature most prominently premature loss of deciduous teeth. Management of HPP has been limited to supportive care until the introduction of a TNSALP enzyme replacement therapy (ERT), asfotase alfa (AA). AA ERT has proven to be transformative, improving survival in severely affected infants and increasing overall quality of life in children and adults with HPP. This chapter provides an overview of TNSALP expression and functions, summarizes HPP clinical types and pathologies, discusses early attempts at therapies for HPP, summarizes development of HPP mouse models, reviews design and validation of AA ERT, and provides up-to-date accounts of AA ERT efficacy in clinical trials and case reports, including therapeutic response, adverse effects, limitations, and potential future directions in therapy.
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Affiliation(s)
- S A Bowden
- Division of Endocrinology, Department of Pediatrics, Nationwide Children's Hospital/The Ohio State University College of Medicine, Columbus, OH, USA.
| | - B L Foster
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
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27
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Williams DK, Pinzón C, Huggins S, Pryor JH, Falck A, Herman F, Oldeschulte J, Chavez MB, Foster BL, White SH, Westhusin ME, Suva LJ, Long CR, Gaddy D. Genetic engineering a large animal model of human hypophosphatasia in sheep. Sci Rep 2018; 8:16945. [PMID: 30446691 PMCID: PMC6240114 DOI: 10.1038/s41598-018-35079-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 10/24/2018] [Indexed: 12/02/2022] Open
Abstract
The availability of tools to accurately replicate the clinical phenotype of rare human diseases is a key step toward improved understanding of disease progression and the development of more effective therapeutics. We successfully generated the first large animal model of a rare human bone disease, hypophosphatasia (HPP) using CRISPR/Cas9 to introduce a single point mutation in the tissue nonspecific alkaline phosphatase (TNSALP) gene (ALPL) (1077 C > G) in sheep. HPP is a rare inherited disorder of mineral metabolism that affects bone and tooth development, and is associated with muscle weakness. Compared to wild-type (WT) controls, HPP sheep have reduced serum alkaline phosphatase activity, decreased tail vertebral bone size, and metaphyseal flaring, consistent with the mineralization deficits observed in human HPP patients. Computed tomography revealed short roots and thin dentin in incisors, and reduced mandibular bone in HPP vs. WT sheep, accurately replicating odonto-HPP. Skeletal muscle biopsies revealed aberrant fiber size and disorganized mitochondrial cristae structure in HPP vs. WT sheep. These genetically engineered sheep accurately phenocopy human HPP and provide a novel large animal platform for the longitudinal study of HPP progression, as well as other rare human bone diseases.
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Affiliation(s)
- Diarra K Williams
- Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - Carlos Pinzón
- Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - Shannon Huggins
- Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - Jane H Pryor
- Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - Alyssa Falck
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - Forrest Herman
- Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - James Oldeschulte
- Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - Michael B Chavez
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, 43210, USA
| | - Brian L Foster
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, 43210, USA
| | - Sarah H White
- Department of Animal Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - Mark E Westhusin
- Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - Larry J Suva
- Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - Charles R Long
- Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - Dana Gaddy
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, 43210, USA.
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28
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Abstract
Dental anomalies exist in every subtype of hypophosphatasia (HPP), from the most severe to the most moderate, called odontohypophosphatasia. The forms are defined by the age at onset of the initial symptoms. These anomalies affect all dental mineralized tissues from enamel, dentin and cementum to alveolar bone in a gradient proportional to the severity of the disease. Early loss of the deciduous teeth, before 3 years of age, and then possibly of the permanent teeth, is due to an abnormality of the cementum, the tissue attaching the teeth to alveolar bone, and is the most frequent abnormality. Tooth loss is a very important diagnostic sign and needs to be recognized. Patients with HPP need specialized oral and dental care in coordination with the reference and expert centers. The oral and dental signs and their treatment remain poorly known. The recording of the abnormalities and their treatment in a registry is indispensable in order to enhance patient management and oral and dental health.
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29
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Bowden SA, Foster BL. Profile of asfotase alfa in the treatment of hypophosphatasia: design, development, and place in therapy. Drug Des Devel Ther 2018; 12:3147-3161. [PMID: 30288020 PMCID: PMC6161731 DOI: 10.2147/dddt.s154922] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Hypophosphatasia (HPP) is a multi-systemic metabolic disorder caused by loss-of-function mutations in the ALPL gene that encodes the mineralization-associated enzyme, tissue-nonspecific alkaline phosphatase (TNSALP). HPP is characterized by defective bone and dental mineralization, leading to skeletal abnormalities with complications resulting in significant morbidity and mortality. Management of HPP has been limited to supportive care until the introduction of a recently approved enzyme replacement therapy employing bone-targeted recombinant human TNSALP, asfotase alfa (AA). This new therapy has been transformative as it improves survival in severely affected infants, and overall quality of life in children and adults with HPP. This review provides an overview of HPP, focusing on important steps in the development of AA enzyme replacement therapy, including the drug design, preclinical studies in the HPP mouse model, and outcomes from clinical trials and case report publications to date, with special attention given to response to therapy of skeletal manifestations, biochemical features, and other clinical manifestations. The limitations, adverse effects, and outcomes of AA are outlined and the place in therapy for individuals with HPP is discussed.
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Affiliation(s)
- Sasigarn A Bowden
- Division of Endocrinology, Department of Pediatrics, Nationwide Children's Hospital/The Ohio State University College of Medicine, Columbus, OH 43205, USA,
| | - Brian L Foster
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH 43205, USA
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30
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Ikeue R, Nakamura-Takahashi A, Nitahara-Kasahara Y, Watanabe A, Muramatsu T, Sato T, Okada T. Bone-Targeted Alkaline Phosphatase Treatment of Mandibular Bone and Teeth in Lethal Hypophosphatasia via an scAAV8 Vector. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2018; 10:361-370. [PMID: 30202773 PMCID: PMC6129726 DOI: 10.1016/j.omtm.2018.08.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 08/13/2018] [Indexed: 12/16/2022]
Abstract
Hypophosphatasia is an inherited disease caused by mutations in the gene encoding tissue-nonspecific alkaline phosphatase (TNALP), the major symptom of which is hypomineralization of the bones and teeth. We had recently demonstrated that TNALP-deficient (Akp2−/−) mice, which mimic the phenotype of the severe infantile form of hypophosphatasia, can be treated by intramuscular injection of a self-complementary (sc) type 8 recombinant adeno-associated virus (rAAV8) vector expressing bone-targeted TNALP with deca-aspartates at the C terminus (TNALP-D10) via the muscle creatine kinase (MCK) promoter. In this study, we focused on the efficacy of this scAAV8-MCK-TNALP-D10 treatment on the mandibular bone and teeth in neonatal Akp2−/− mice. Upon scAAV8-MCK-TNALP-D10 injection, an improvement of mandibular growth was observed by X-ray analysis. Micro-computed tomography analysis revealed progressive mineralization of the molar root in the treated Akp2−/− mice, and morphometric parameters of the alveolar bone were improved. These results suggest that the mandibular bones and teeth of hypophosphatasia were effectively treated by muscle directed rAAV-mediated TNALP-D10 transduction. Our strategy would be promising for future hypophosphatasia gene therapy because it induces dentoalveolar mineralization and reduces the risk of tooth exfoliation.
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Affiliation(s)
- Ryo Ikeue
- Department of Fixed Prosthodontics, Tokyo Dental College, Tokyo, Japan
| | - Aki Nakamura-Takahashi
- Department of Pharmacology, Tokyo Dental College, Tokyo, Japan.,Department of Biochemistry and Molecular Biology, Nippon Medical School, Tokyo, Japan
| | | | - Atsushi Watanabe
- Department of Biochemistry and Molecular Biology, Nippon Medical School, Tokyo, Japan.,Division of Clinical Genetics, Nippon Medical School Hospital, Tokyo, Japan
| | - Takashi Muramatsu
- Department of Operative Dentistry, Tokyo Dental College, Tokyo, Japan
| | - Toru Sato
- Department of Fixed Prosthodontics, Tokyo Dental College, Tokyo, Japan
| | - Takashi Okada
- Department of Biochemistry and Molecular Biology, Nippon Medical School, Tokyo, Japan
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31
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Liu X, Wang Y, Zhang L, Xu Z, Chu Q, Xu C, Sun Y, Gao Y. Combination of Runx2 and Cbfβ upregulates Amelotin gene expression in ameloblasts by directly interacting with cis‑enhancers during amelogenesis. Mol Med Rep 2018; 17:6068-6076. [PMID: 29436627 DOI: 10.3892/mmr.2018.8564] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 01/05/2018] [Indexed: 11/05/2022] Open
Abstract
Amelotin (Amtn) is a recently identified enamel protein secreted by ameloblasts at late stage of enamel development. Runt‑related transcription factor 2 (Runx2) in combination with the coactivator core‑binding factor β (Cbfβ) regulates the early stages of tooth development. The aim of the present study was to investigate the role of Runx2 in the regulation of Amtn gene expression in ameloblasts. Immunohistochemistry was performed and the results revealed that Runx2 protein was predominantly expressed in the nuclei of ameloblasts during the transition stage and the maturation stage of enamel development, whereas Cbfβ was expressed in ameloblasts from the secretory stage to the maturation stage. Reverse transcription‑quantitative polymerase chain reaction results demonstrated that Runx2 knockdown decreased Amtn expression in ameloblast‑lineage cells and co‑expression of Runx2 and Cbfβ in ameloblast lineage cells induced an upregulation in Amtn gene expression. Two putative Runx2‑binding sites within the Amtn promoter were identified using bioinformatics analysis. Results of an electrophoretic mobility shift assay and chromatin immunoprecipitation indicated that Runx2/Cbfβ bound to specific DNA sequences. Site‑directed mutagenesis of the Runx2 binding sites within the Amtn promoter resulted in decreased basal promoter activity and did not affect the overexpressed Runx2/Cbfβ. The results of the present study suggest that Runx2 upregulates Amtn gene expression via binding directly to Runx2 sites within the Amtn promoter during amelogenesis.
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Affiliation(s)
- Xiaoying Liu
- Department of Oral Biology, Weifang Medical University, Weifang, Shandong 261053, P.R. China
| | - Yumin Wang
- Department of Pediatric Dentistry, Binzhou Medical University, Yantai, Shandong 264003, P.R. China
| | - Li Zhang
- Department of Pediatric Dentistry, Binzhou Medical University, Yantai, Shandong 264003, P.R. China
| | - Zhenzhen Xu
- Department of Pediatric Dentistry, Binzhou Medical University, Yantai, Shandong 264003, P.R. China
| | - Qing Chu
- Department of Pediatric Dentistry, Binzhou Medical University, Yantai, Shandong 264003, P.R. China
| | - Chang Xu
- Department of Pediatric Dentistry, Binzhou Medical University, Yantai, Shandong 264003, P.R. China
| | - Yan Sun
- Department of Oral Biology, Weifang Medical University, Weifang, Shandong 261053, P.R. China
| | - Yuguang Gao
- Department of Oral Biology, Weifang Medical University, Weifang, Shandong 261053, P.R. China
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32
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Ao M, Chavez MB, Chu EY, Hemstreet KC, Yin Y, Yadav MC, Millán JL, Fisher LW, Goldberg HA, Somerman MJ, Foster BL. Overlapping functions of bone sialoprotein and pyrophosphate regulators in directing cementogenesis. Bone 2017; 105:134-147. [PMID: 28866368 PMCID: PMC5730356 DOI: 10.1016/j.bone.2017.08.027] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 08/24/2017] [Accepted: 08/28/2017] [Indexed: 12/19/2022]
Abstract
Although acellular cementum is essential for tooth attachment, factors directing its development and regeneration remain poorly understood. Inorganic pyrophosphate (PPi), a mineralization inhibitor, is a key regulator of cementum formation: tissue-nonspecific alkaline phosphatase (Alpl/TNAP) null mice (increased PPi) feature deficient cementum, while progressive ankylosis protein (Ank/ANK) null mice (decreased PPi) feature increased cementum. Bone sialoprotein (Bsp/BSP) and osteopontin (Spp1/OPN) are multifunctional extracellular matrix components of cementum proposed to have direct and indirect effects on cell activities and mineralization. Studies on dentoalveolar development of Bsp knockout (Bsp-/-) mice revealed severely reduced acellular cementum, however underlying mechanisms remain unclear. The similarity in defective cementum phenotypes between Bsp-/- mice and Alpl-/- mice (the latter featuring elevated PPi and OPN), prompted us to examine whether BSP is operating by modulating PPi-associated genes. Genetic ablation of Bsp caused a 2-fold increase in circulating PPi, altered mRNA expression of Alpl, Spp1, and Ank, and increased OPN protein in the periodontia. Generation of a Bsp knock-out (KO) cementoblast cell line revealed significantly decreased mineralization capacity, 50% increased PPi in culture media, and increased Spp1 and Ank mRNA expression. While addition of 2μg/ml recombinant BSP altered Spp1, Ank, and Enpp1 expression in cementoblasts, changes resulting from this dose were not dependent on the integrin-binding RGD motif or MAPK/ERK signaling pathway. Decreasing PPi by genetic ablation of Ank on the Bsp-/- mouse background reestablished cementum formation, allowing >3-fold increased acellular cementum volume compared to wild-type (WT). However, deleting Ank did not fully compensate for the absence of BSP. Bsp-/-; Ank-/- double-deficient mice exhibited mean 20-27% reduced cementum thickness and volume compared to Ank-/- mice. From these data, we conclude that the perturbations in PPi metabolism are not solely driving the cementum pathology in Bsp-/- mice, and that PPi is more potent than BSP as a cementum regulator, as shown by the ability to override loss of BSP by lowering PPi. We propose that BSP and PPi work in concert to direct mineralization in cementum and likely other mineralized tissues.
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Affiliation(s)
- M Ao
- National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA
| | - M B Chavez
- Biosciences Division, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - E Y Chu
- National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA
| | - K C Hemstreet
- National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Y Yin
- National Institute of Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Bethesda, MD, USA
| | - M C Yadav
- Sanford Children's Health Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - J L Millán
- Sanford Children's Health Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - L W Fisher
- National Institute of Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Bethesda, MD, USA
| | - H A Goldberg
- Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada
| | - M J Somerman
- National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, MD, USA
| | - B L Foster
- Biosciences Division, College of Dentistry, The Ohio State University, Columbus, OH, USA.
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Oral findings in patient with lethal hypophosphatasia treated with enzyme replacement therapy. PEDIATRIC DENTAL JOURNAL 2017. [DOI: 10.1016/j.pdj.2017.04.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Pandya M, Rosene L, Farquharson C, Millán JL, Diekwisch TGH. Intravesicular Phosphatase PHOSPHO1 Function in Enamel Mineralization and Prism Formation. Front Physiol 2017; 8:805. [PMID: 29089903 PMCID: PMC5651051 DOI: 10.3389/fphys.2017.00805] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 09/29/2017] [Indexed: 11/13/2022] Open
Abstract
The transport of mineral ions from the enamel organ-associated blood vessels to the developing enamel crystals involves complex cargo packaging and carriage mechanisms across several cell layers, including the ameloblast layer and the stratum intermedium. Previous studies have established PHOSPHO1 as a matrix vesicle membrane-associated phosphatase that interacts with matrix vesicles molecules phosphoethanolamine and phosphocholine to initiate apatite crystal formation inside of matrix vesicles in bone. In the present study, we sought to determine the function of Phospho1 during amelogenesis. PHOSPHO1 protein localization during amelogenesis was verified using immunohistochemistry, with positive signals in the enamel layer, ameloblast Tomes' processes, and in the walls of ameloblast secretory vesicles. These ameloblast secretory vesicle walls were also labeled for amelogenin and the exosomal protein marker HSP70 using immunohistochemistry. Furthermore, PHOSPHO1 presence in the enamel organ was confirmed by Western blot. Phospho1−/− mice lacked sharp incisal tips, featured a significant 25% increase in total enamel volume, and demonstrated a significant 2-fold reduction in silver grain density of von Kossa stained ground sections indicative of reduced mineralization in the enamel layer when compared to wild-type mice (p < 0.001). Scanning electron micrographs of Phospho1−/− mouse enamel revealed a loss of the prominent enamel prism “picket fence” structure, a loss of parallel crystal organization within prisms, and a 1.56-fold increase in enamel prism width (p < 0.0001). Finally, EDS elemental analysis demonstrated a significant decrease in phosphate incorporation in the enamel layer when compared to controls (p < 0.05). Together, these data establish that the matrix vesicle membrane-associated phosphatase PHOSPHO1 is essential for physiological enamel mineralization. Our findings also suggest that intracellular ameloblast secretory vesicles have unexpected compositional similarities with the extracellular matrix vesicles of bone, dentin, and cementum in terms of vesicle membrane composition and intravesicular ion assembly.
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Affiliation(s)
- Mirali Pandya
- Department of Periodontics, Texas A&M College of Dentistry, Dallas, TX, United States.,Center for Craniofacial Research and Diagnosis, Texas A&M College of Dentistry, Dallas, TX, United States
| | - Lauren Rosene
- Department of Periodontics, Texas A&M College of Dentistry, Dallas, TX, United States.,Center for Craniofacial Research and Diagnosis, Texas A&M College of Dentistry, Dallas, TX, United States
| | - Colin Farquharson
- Division of Developmental Biology, The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom
| | - José L Millán
- Sanford Children's Health Research Center, Sanford-Burnham Institute for Medical Research, La Jolla, CA, United States
| | - Thomas G H Diekwisch
- Department of Periodontics, Texas A&M College of Dentistry, Dallas, TX, United States.,Center for Craniofacial Research and Diagnosis, Texas A&M College of Dentistry, Dallas, TX, United States
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Yoshizaki K, Hu L, Nguyen T, Sakai K, Ishikawa M, Takahashi I, Fukumoto S, DenBesten PK, Bikle DD, Oda Y, Yamada Y. Mediator 1 contributes to enamel mineralization as a coactivator for Notch1 signaling and stimulates transcription of the alkaline phosphatase gene. J Biol Chem 2017; 292:13531-13540. [PMID: 28673966 DOI: 10.1074/jbc.m117.780866] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 06/17/2017] [Indexed: 12/21/2022] Open
Abstract
Tooth enamel is mineralized through the differentiation of multiple dental epithelia including ameloblasts and the stratum intermedium (SI), and this differentiation is controlled by several signaling pathways. Previously, we demonstrated that the transcriptional coactivator Mediator 1 (MED1) plays a critical role in enamel formation. For instance, conditional ablation of Med1 in dental epithelia causes functional changes in incisor-specific dental epithelial stem cells, resulting in mineralization defects in the adult incisors. However, the molecular mechanism by which Med1 deficiency causes these abnormalities is not clear. Here, we demonstrated that Med1 ablation causes early SI differentiation defects resulting in enamel hypoplasia of the Med1-deficient molars. Med1 deletion prevented Notch1-mediated differentiation of the SI cells resulting in decreased alkaline phosphatase (ALPL), which is essential for mineralization. However, it does not affect the ability of ameloblasts to produce enamel matrix proteins. Using the dental epithelial SF2 cell line, we demonstrated that MED1 directly activates transcription of the Alpl gene through the stimulation of Notch1 signaling by forming a complex with cleaved Notch1-RBP-Jk on the Alpl promoter. These results suggest that MED1 may be essential for enamel matrix mineralization by serving as a coactivator for Notch1 signaling regulating transcription of the Alpl gene.
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Affiliation(s)
- Keigo Yoshizaki
- From the Laboratory of Cell and Developmental Biology, NIDCR, National Institutes of Health, Bethesda, Maryland 20892.,the Division of Oral Health, Growth, and Development, Kyushu University Faculty of Dental Science, Fukuoka 812-8582, Japan
| | - Lizhi Hu
- the Departments of Medicine and Dermatology, the University of California San Francisco and the Veterans Affairs Medical Center, San Francisco, California 94158
| | - Thai Nguyen
- the Departments of Medicine and Dermatology, the University of California San Francisco and the Veterans Affairs Medical Center, San Francisco, California 94158
| | - Kiyoshi Sakai
- From the Laboratory of Cell and Developmental Biology, NIDCR, National Institutes of Health, Bethesda, Maryland 20892
| | - Masaki Ishikawa
- From the Laboratory of Cell and Developmental Biology, NIDCR, National Institutes of Health, Bethesda, Maryland 20892
| | - Ichiro Takahashi
- the Division of Oral Health, Growth, and Development, Kyushu University Faculty of Dental Science, Fukuoka 812-8582, Japan
| | - Satoshi Fukumoto
- the Division of Pediatric Dentistry, Department of Oral Health and Development Sciences, Tohoku University Graduate School of Dentistry, Sendai 980-8575, Japan, and
| | - Pamela K DenBesten
- the University of California San Francisco School of Dentistry, San Francisco, California 94143
| | - Daniel D Bikle
- the Departments of Medicine and Dermatology, the University of California San Francisco and the Veterans Affairs Medical Center, San Francisco, California 94158
| | - Yuko Oda
- the Departments of Medicine and Dermatology, the University of California San Francisco and the Veterans Affairs Medical Center, San Francisco, California 94158,
| | - Yoshihiko Yamada
- From the Laboratory of Cell and Developmental Biology, NIDCR, National Institutes of Health, Bethesda, Maryland 20892,
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Abstract
BACKGROUND Hypophosphatasia (HPP) is a rare inherited metabolic disease in which mutations in the ALPL gene (encoding tissue-nonspecific alkaline phosphatase) result in varying degrees of enzyme deficiency. HPP manifests in a spectrum of symptoms, including early primary tooth loss (root intact) and alveolar bone mineralisation defects. OBJECTIVE To provide an overview of HPP for dental professionals to help recognise and differentially diagnose patients for appropriate referral to a specialist team. METHODS A non-systematic review of publications on HPP was performed. RESULTS Different forms of HPP are described, along with characteristic symptoms and laboratory findings. Diagnosis is challenging due to the rareness and variable presentation of symptoms. Low alkaline phosphatase levels are a signature of HPP, but reference ranges vary according to gender and age. Key features are defined and management strategies discussed, focusing on enzyme replacement therapy. Finally, a patient registry aimed at better defining the prevalence of HPP and raising awareness is described. CONCLUSIONS HPP is a rare disease with a wide spectrum of manifestations, with orodental symptoms featuring prominently in the natural history. Dental professionals may be positioned at the beginning of the diagnostic pathway; thus, recognition of HPP features for timely referral and optimal disease management is important.
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Affiliation(s)
- Agnès Bloch-Zupan
- Faculté de Chirurgie Dentaire, Université de Strasbourg, Strasbourg, France.
- Hôpitaux Universitaires de Strasbourg, Pôle de Médecine et Chirurgie Bucco-Dentaires, Centre de référence des manifestations odontologiques des maladies rares (CRMR), Reference Centre for Orodental Manifestations of Rare Diseases, Strasbourg, France.
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS-UdS UMR7104, Université de Strasbourg, Illkirch, France.
- Eastman Dental Institute, University College London, London, UK.
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37
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Scott LJ. Asfotase Alfa in Perinatal/Infantile-Onset and Juvenile-Onset Hypophosphatasia: A Guide to Its Use in the USA. BioDrugs 2016; 30:41-8. [PMID: 26832358 DOI: 10.1007/s40259-016-0161-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Subcutaneous asfotase alfa (Strensiq™), a first-in-class bone-targeted human recombinant tissue-nonspecific alkaline phosphatase (TNSALP) replacement therapy, is approved in the USA for the treatment of patients with perinatal/infantile- or juvenile-onset hypophosphatasia (HPP). In clinical trials, asfotase alfa was an effective and generally well tolerated treatment for perinatal/infantile- and juvenile onset-HPP through at least 3 and 5 years' treatment, respectively. Relative to untreated age-matched, juvenile-onset-HPP historical control cohorts, survival and ventilation-free survival were significantly prolonged in asfotase alfa-treated patients, consequent to preceding improvements in bone mineralization.
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Affiliation(s)
- Lesley J Scott
- Springer, Private Bag 65901, Mairangi Bay, 0754, Auckland, New Zealand.
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38
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Abstract
Hypophosphatasia (HPP) is a rare inheritable disease that results from loss-of-function mutations in the ALPL gene encoding tissue-nonspecific alkaline phosphatase (TNSALP). Therapeutic options for treating the underlying pathophysiology of the disease have been lacking, with the mainstay of treatment being management of symptoms and supportive care. HPP is associated with significant morbidity and mortality in paediatric patients, with mortality rates as high as 100 % in perinatal-onset HPP and 50 % in infantile-onset HPP. Subcutaneous asfotase alfa (Strensiq(®)), a first-in-class bone-targeted human recombinant TNSALP replacement therapy, is approved in the EU for long-term therapy in patients with paediatric-onset HPP to treat bone manifestations of the disease. In noncomparative clinical trials in infants and children with paediatric-onset HPP, asfotase alfa rapidly improved radiographically-assessed rickets severity scores at 24 weeks (primary timepoint) as reflected in improvements in bone mineralization, with these benefits sustained after more than 3 years of treatment. Furthermore, patients typically experienced improvements in respiratory function, gross motor function, fine motor function, cognitive development, muscle strength (normalization) and ability to perform activities of daily living, and catch-up height-gain. In life-threatening perinatal and infantile HPP, asfotase alfa also improved overall survival. Asfotase alfa was generally well tolerated in clinical trials, with relatively few patients discontinuing treatment and most treatment-related adverse events being of mild to moderate intensity. Thus, subcutaneous asfotase alfa is a valuable emerging therapy for the treatment of bone manifestations in patients with paediatric-onset HPP.
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Affiliation(s)
- Lesley J Scott
- Springer, Private Bag 65901, Mairangi Bay, Auckland, 0754, New Zealand.
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39
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Foster BL, Kuss P, Yadav MC, Kolli TN, Narisawa S, Lukashova L, Cory E, Sah RL, Somerman MJ, Millán JL. Conditional Alpl Ablation Phenocopies Dental Defects of Hypophosphatasia. J Dent Res 2016; 96:81-91. [PMID: 27582029 DOI: 10.1177/0022034516663633] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Loss-of-function mutations in ALPL result in hypophosphatasia (HPP), an inborn error of metabolism that causes defective skeletal and dental mineralization. ALPL encodes tissue-nonspecific alkaline phosphatase, an enzyme expressed in bone, teeth, liver, and kidney that hydrolyzes the mineralization inhibitor inorganic pyrophosphate. As Alpl-null mice die before weaning, we aimed to generate mouse models of late-onset HPP with extended life spans by engineering a floxed Alpl allele, allowing for conditional gene ablation (conditional knockout [cKO]) when crossed with Cre recombinase transgenic mice. The authors hypothesized that targeted deletion of Alpl in osteoblasts and selected dental cells ( Col1a1-cKO) or deletion in chondrocytes, osteoblasts, and craniofacial mesenchyme ( Prx1-cKO) would phenocopy skeletal and dental manifestations of late-onset HPP. Col1a1-cKO and Prx1-cKO mice were viable and fertile, and they did not manifest the epileptic seizures characteristic of the Alpl-/- model of severe infantile HPP. Both cKO models featured normal postnatal body weight but significant reduction as compared with wild type mice by 8 to 12 wk. Plasma alkaline phosphatase for both cKO models at 24 wk was reduced by approximately 75% as compared with controls. Radiography revealed profound skeletal defects in cKO mice, including rachitic changes, hypomineralized long bones, deformations, and signs of fractures. Microcomputed tomography confirmed quantitative differences in cortical and trabecular bone, including decreased cortical thickness and mineral density. Col1a1-cKO mice exhibited classic signs of HPP dentoalveolar disease, including short molar roots with thin dentin, lack of acellular cementum, and osteoid accumulation in alveolar bone. Prx1-cKO mice exhibited the same array of periodontal defects but featured less affected molar dentin. Both cKO models exhibited reduced alveolar bone height and 4-fold increased numbers of osteoclast-like cells versus wild type at 24 wk, consistent with HPP-associated periodontal disease. These novel models of late-onset HPP can inform on long-term skeletal and dental manifestations and will provide essential tools to further studies of etiopathologies and therapeutic interventions.
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Affiliation(s)
- B L Foster
- 1 Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - P Kuss
- 2 Sanford Children's Health Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - M C Yadav
- 2 Sanford Children's Health Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - T N Kolli
- 1 Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - S Narisawa
- 2 Sanford Children's Health Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - L Lukashova
- 3 Hospital for Special Surgery, New York, NY, USA
| | - E Cory
- 4 Department of Bioengineering, University of California-San Diego, La Jolla, CA, USA.,5 Center for Musculoskeletal Research, University of California-San Diego, La Jolla, CA, USA
| | - R L Sah
- 4 Department of Bioengineering, University of California-San Diego, La Jolla, CA, USA.,5 Center for Musculoskeletal Research, University of California-San Diego, La Jolla, CA, USA.,6 Department of Orthopaedic Surgery, University of California-San Diego, La Jolla, CA, USA
| | - M J Somerman
- 7 National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - J L Millán
- 2 Sanford Children's Health Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
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40
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Okawa R, Iijima O, Kishino M, Okawa H, Toyosawa S, Sugano-Tajima H, Shimada T, Okada T, Ozono K, Ooshima T, Nakano K. Gene therapy improves dental manifestations in hypophosphatasia model mice. J Periodontal Res 2016; 52:471-478. [PMID: 27561677 DOI: 10.1111/jre.12412] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/07/2016] [Indexed: 01/31/2023]
Abstract
BACKGROUND AND OBJECTIVE Hypophosphatasia is a rare inherited skeletal disorder characterized by defective bone mineralization and deficiency of tissue non-specific alkaline phosphatase (TNSALP) activity. The disease is caused by mutations in the liver/bone/kidney alkaline phosphatase gene (ALPL) encoding TNSALP. Early exfoliation of primary teeth owing to disturbed cementum formation, periodontal ligament weakness and alveolar bone resorption are major complications encountered in oral findings, and discovery of early loss of primary teeth in a dental examination often leads to early diagnosis of hypophosphatasia. Although there are no known fundamental treatments or effective dental approaches to prevent early exfoliation of primary teeth in affected patients, several possible treatments have recently been described, including gene therapy. Gene therapy has also been applied to TNSALP knockout mice (Alpl-/- ), which phenocopy the infantile form of hypophosphatasia, and improved their systemic condition. In the present study, we investigated whether gene therapy improved the dental condition of Alpl-/- mice. MATERIAL AND METHODS Following sublethal irradiation (4 Gy) at the age of 2 d, Alpl-/- mice underwent gene therapy using bone marrow cells transduced with a lentiviral vector expressing a bone-targeted form of TNSALP injected into the jugular vein (n = 3). Wild-type (Alpl+/+ ), heterozygous mice (Alpl+/- ) and Alpl-/- mice were analyzed at 9 d of age (n = 3 of each), while Alpl+/+ mice and treated or untreated Alpl-/- mice were analyzed at 1 mo of age (n = 3 of each), and Alpl+/- mice and Alpl-/- mice with gene therapy were analyzed at 3 mo of age (n = 3 of each). A single mandibular hemi-section obtained at 1 mo of age was analyzed using a small animal computed tomography machine to assess alveolar bone formation. Other mandibular hemi-sections obtained at 9 d, 1 mo and 3 mo of age were subjected to hematoxylin and eosin staining and immunohistochemical analysis of osteopontin, a marker of cementum. RESULTS Immunohistochemical analysis of osteopontin, a marker of acellular cementum, revealed that Alpl-/- mice displayed impaired formation of cementum and alveolar bone, similar to the human dental phenotype. Cementum formation was clearly present in Alpl-/- mice that underwent gene therapy, but did not recover to the same level as that in wild-type (Alpl+/+ ) mice. Micro-computed tomography examination showed that gene therapy improved alveolar bone mineral density in Alpl-/- mice to a similar level to that in Alpl+/+ mice. CONCLUSIONS Our results suggest that gene therapy can improve the general condition of Alpl-/- mice, and induce significant alveolar bone formation and moderate improvement of cementum formation, which may contribute to inhibition of early spontaneous tooth exfoliation.
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Affiliation(s)
- R Okawa
- Osaka University Graduate School of Dentistry, Osaka, Japan
| | - O Iijima
- Nippon Medical School, Tokyo, Japan
| | - M Kishino
- Osaka University Graduate School of Dentistry, Osaka, Japan
| | - H Okawa
- Osaka University Graduate School of Dentistry, Osaka, Japan
| | - S Toyosawa
- Osaka University Graduate School of Dentistry, Osaka, Japan
| | | | | | - T Okada
- Nippon Medical School, Tokyo, Japan
| | - K Ozono
- Osaka University Graduate School of Medicine, Osaka, Japan
| | - T Ooshima
- Osaka University Graduate School of Dentistry, Osaka, Japan
| | - K Nakano
- Osaka University Graduate School of Dentistry, Osaka, Japan
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41
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Cui L, Houston DA, Farquharson C, MacRae VE. Characterisation of matrix vesicles in skeletal and soft tissue mineralisation. Bone 2016; 87:147-58. [PMID: 27072517 DOI: 10.1016/j.bone.2016.04.007] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 03/25/2016] [Accepted: 04/06/2016] [Indexed: 12/16/2022]
Abstract
The importance of matrix vesicles (MVs) has been repeatedly highlighted in the formation of cartilage, bone, and dentin since their discovery in 1967. These nano-vesicular structures, which are found in the extracellular matrix, are believed to be one of the sites of mineral nucleation that occurs in the organic matrix of the skeletal tissues. In the more recent years, there have been numerous reports on the observation of MV-like particles in calcified vascular tissues that could be playing a similar role. Therefore, here, we review the characteristics MVs possess that enable them to participate in mineral deposition. Additionally, we outline the content of skeletal tissue- and soft tissue-derived MVs, and discuss their key mineralisation mediators that could be targeted for future therapeutic use.
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Affiliation(s)
- L Cui
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, The University of Edinburgh Easter Bush Campus, Edinburgh, Midlothian, EH25 9RG, UK.
| | - D A Houston
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, The University of Edinburgh Easter Bush Campus, Edinburgh, Midlothian, EH25 9RG, UK
| | - C Farquharson
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, The University of Edinburgh Easter Bush Campus, Edinburgh, Midlothian, EH25 9RG, UK
| | - V E MacRae
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, The University of Edinburgh Easter Bush Campus, Edinburgh, Midlothian, EH25 9RG, UK
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42
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Abstract
Hypophosphatasia (HPP) results from ALPL mutations leading to deficient activity of the tissue-non-specific alkaline phosphatase isozyme (TNAP) and thereby extracellular accumulation of inorganic pyrophosphate (PPi), a natural substrate of TNAP and potent inhibitor of mineralization. Thus, HPP features rickets or osteomalacia and hypomineralization of teeth. Enzyme replacement using mineral-targeted TNAP from birth prevented severe HPP in TNAP-knockout mice and was then shown to rescue and substantially treat infants and young children with life-threatening HPP. Clinical trials are revealing aspects of HPP pathophysiology not yet fully understood, such as craniosynostosis and muscle weakness when HPP is severe. New treatment approaches are under development to improve patient care.
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Affiliation(s)
- José Luis Millán
- Sanford Children's Health Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA.
| | - Michael P Whyte
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospital for Children, St. Louis, MO, 63110, USA
- Division of Bone and Mineral Diseases, Washington University School of Medicine at Barnes-Jewish Hospital, St. Louis, MO, 63110, USA
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43
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Yin K, Lei Y, Wen X, Lacruz RS, Soleimani M, Kurtz I, Snead ML, White SN, Paine ML. SLC26A Gene Family Participate in pH Regulation during Enamel Maturation. PLoS One 2015; 10:e0144703. [PMID: 26671068 PMCID: PMC4679777 DOI: 10.1371/journal.pone.0144703] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 11/23/2015] [Indexed: 12/15/2022] Open
Abstract
The bicarbonate transport activities of Slc26a1, Slc26a6 and Slc26a7 are essential to physiological processes in multiple organs. Although mutations of Slc26a1, Slc26a6 and Slc26a7 have not been linked to any human diseases, disruption of Slc26a1, Slc26a6 or Slc26a7 expression in animals causes severe dysregulation of acid-base balance and disorder of anion homeostasis. Amelogenesis, especially the enamel formation during maturation stage, requires complex pH regulation mechanisms based on ion transport. The disruption of stage-specific ion transporters frequently results in enamel pathosis in animals. Here we present evidence that Slc26a1, Slc26a6 and Slc26a7 are highly expressed in rodent incisor ameloblasts during maturation-stage tooth development. In maturation-stage ameloblasts, Slc26a1, Slc26a6 and Slc26a7 show a similar cellular distribution as the cystic fibrosis transmembrane conductance regulator (Cftr) to the apical region of cytoplasmic membrane, and the distribution of Slc26a7 is also seen in the cytoplasmic/subapical region, presumably on the lysosomal membrane. We have also examined Slc26a1 and Slc26a7 null mice, and although no overt abnormal enamel phenotypes were observed in Slc26a1-/- or Slc26a7-/- animals, absence of Slc26a1 or Slc26a7 results in up-regulation of Cftr, Ca2, Slc4a4, Slc4a9 and Slc26a9, all of which are involved in pH homeostasis, indicating that this might be a compensatory mechanism used by ameloblasts cells in the absence of Slc26 genes. Together, our data show that Slc26a1, Slc26a6 and Slc26a7 are novel participants in the extracellular transport of bicarbonate during enamel maturation, and that their functional roles may be achieved by forming interaction units with Cftr.
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Affiliation(s)
- Kaifeng Yin
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry of University of Southern California, Los Angeles, California, United States of America
| | - Yuejuan Lei
- Department of Operative and Endodontics, The Affiliated Stomatological Hospital, Guangxi Medical University, Nanning, Guangxi, China
| | - Xin Wen
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry of University of Southern California, Los Angeles, California, United States of America
| | - Rodrigo S. Lacruz
- Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, New York, United States of America
| | - Manoocher Soleimani
- Department of Medicine, University of Cincinnati, Research Services, Veterans Affairs Medical Center, Cincinnati, Ohio, United States of America
| | - Ira Kurtz
- Division of Nephrology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, United States of America
| | - Malcolm L. Snead
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry of University of Southern California, Los Angeles, California, United States of America
| | - Shane N. White
- School of Dentistry, University of California Los Angeles, Los Angeles, California, United States of America
| | - Michael L. Paine
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry of University of Southern California, Los Angeles, California, United States of America
- * E-mail:
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Soenjaya Y, Foster BL, Nociti FH, Ao M, Holdsworth DW, Hunter GK, Somerman MJ, Goldberg HA. Mechanical Forces Exacerbate Periodontal Defects in Bsp-null Mice. J Dent Res 2015; 94:1276-85. [PMID: 26130257 DOI: 10.1177/0022034515592581] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Bone sialoprotein (BSP) is an acidic phosphoprotein with collagen-binding, cell attachment, and hydroxyapatite-nucleating properties. BSP expression in mineralized tissues is upregulated at onset of mineralization. Bsp-null (Bsp(-/-)) mice exhibit reductions in bone mineral density, bone turnover, osteoclast activation, and impaired bone healing. Furthermore, Bsp(-/-) mice have marked periodontal tissue breakdown, with a lack of acellular cementum leading to periodontal ligament detachment, extensive alveolar bone and tooth root resorption, and incisor malocclusion. We hypothesized that altered mechanical stress from mastication contributes to periodontal destruction observed in Bsp(-/-) mice. This hypothesis was tested by comparing Bsp(-/-) and wild-type mice fed with standard hard pellet diet or soft powder diet. Dentoalveolar tissues were analyzed using histology and micro-computed tomography. By 8 wk of age, Bsp(-/-) mice exhibited molar and incisor malocclusion regardless of diet. Bsp(-/-) mice with hard pellet diet exhibited high incidence (30%) of severe incisor malocclusion, 10% lower body weight, 3% reduced femur length, and 30% elevated serum alkaline phosphatase activity compared to wild type. Soft powder diet reduced severe incisor malocclusion incidence to 3% in Bsp(-/-) mice, supporting the hypothesis that occlusal loading contributed to the malocclusion phenotype. Furthermore, Bsp(-/-) mice in the soft powder diet group featured normal body weight, long bone length, and serum alkaline phosphatase activity, suggesting that tooth dysfunction and malnutrition contribute to growth and skeletal defects reported in Bsp(-/-) mice. Bsp(-/-) incisors also erupt at a slower rate, which likely leads to the observed thickened dentin and enhanced mineralization of dentin and enamel toward the apical end. We propose that the decrease in eruption rate is due to a lack of acellular cementum and associated defective periodontal attachment. These data demonstrate the importance of BSP in maintaining proper periodontal function and alveolar bone remodeling and point to dental dysfunction as causative factor of skeletal defects observed in Bsp(-/-) mice.
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Affiliation(s)
- Y Soenjaya
- Biomedical Engineering Program, University of Western Ontario, London, Canada School of Dentistry, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Canada
| | - B L Foster
- National Institute for Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - F H Nociti
- National Institute for Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA Department of Prosthodontics and Periodontics, Division of Periodontics, School of Dentistry, Campinas State University, Piracicaba, Brazil
| | - M Ao
- National Institute for Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - D W Holdsworth
- Biomedical Engineering Program, University of Western Ontario, London, Canada School of Dentistry, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Canada Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, Canada
| | - G K Hunter
- Biomedical Engineering Program, University of Western Ontario, London, Canada School of Dentistry, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Canada Deparment of Biochemistry, University of Western Ontario, London, Canada
| | - M J Somerman
- National Institute for Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - H A Goldberg
- Biomedical Engineering Program, University of Western Ontario, London, Canada School of Dentistry, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Canada Deparment of Biochemistry, University of Western Ontario, London, Canada
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Counter-regulatory phosphatases TNAP and NPP1 temporally regulate tooth root cementogenesis. Int J Oral Sci 2015; 7:27-41. [PMID: 25504209 PMCID: PMC4817535 DOI: 10.1038/ijos.2014.62] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/06/2014] [Indexed: 12/29/2022] Open
Abstract
Cementum is critical for anchoring the insertion of periodontal ligament fibers to the tooth root. Several aspects of cementogenesis remain unclear, including differences between acellular cementum and cellular cementum, and between cementum and bone. Biomineralization is regulated by the ratio of inorganic phosphate (Pi) to mineral inhibitor pyrophosphate (PPi), where local Pi and PPi concentrations are controlled by phosphatases including tissue-nonspecific alkaline phosphatase (TNAP) and ectonucleotide pyrophosphatase/phosphodiesterase 1 (NPP1). The focus of this study was to define the roles of these phosphatases in cementogenesis. TNAP was associated with earliest cementoblasts near forming acellular and cellular cementum. With loss of TNAP in the Alpl null mouse, acellular cementum was inhibited, while cellular cementum production increased, albeit as hypomineralized cementoid. In contrast, NPP1 was detected in cementoblasts after acellular cementum formation, and at low levels around cellular cementum. Loss of NPP1 in the Enpp1 null mouse increased acellular cementum, with little effect on cellular cementum. Developmental patterns were recapitulated in a mouse model for acellular cementum regeneration, with early TNAP expression and later NPP1 expression. In vitro, cementoblasts expressed Alpl gene/protein early, whereas Enpp1 gene/protein expression was significantly induced only under mineralization conditions. These patterns were confirmed in human teeth, including widespread TNAP, and NPP1 restricted to cementoblasts lining acellular cementum. These studies suggest that early TNAP expression creates a low PPi environment promoting acellular cementum initiation, while later NPP1 expression increases PPi, restricting acellular cementum apposition. Alterations in PPi have little effect on cellular cementum formation, though matrix mineralization is affected.
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Gasque KCS, Foster BL, Kuss P, Yadav MC, Liu J, Kiffer-Moreira T, van Elsas A, Hatch N, Somerman MJ, Millán JL. Improvement of the skeletal and dental hypophosphatasia phenotype in Alpl-/- mice by administration of soluble (non-targeted) chimeric alkaline phosphatase. Bone 2015; 72:137-47. [PMID: 25433339 PMCID: PMC4283789 DOI: 10.1016/j.bone.2014.11.017] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 11/16/2014] [Accepted: 11/19/2014] [Indexed: 12/13/2022]
Abstract
Hypophosphatasia (HPP) results from ALPL gene mutations, which lead to a deficiency of tissue-nonspecific alkaline phosphatase (TNAP), and accumulation of inorganic pyrophosphate, a potent inhibitor of mineralization that is also a natural substrate of TNAP, in the extracellular space. HPP causes mineralization disorders including soft bones (rickets or osteomalacia) and defects in teeth and periodontal tissues. Enzyme replacement therapy using mineral-targeting recombinant TNAP has proven effective in preventing skeletal and dental defects in TNAP knockout (Alpl(-/-)) mice, a model for life-threatening HPP. Here, we show that the administration of a soluble, intestinal-like chimeric alkaline phosphatase (ChimAP) improves the manifestations of HPP in Alpl(-/-) mice. Mice received daily subcutaneous injections of ChimAP at doses of 1, 8 or 16 mg/kg, from birth for up to 53 days. Lifespan and body weight of Alpl(-/-) mice were normalized, and vitamin B6-associated seizures were absent with 16 mg/kg/day of ChimAP. Radiographs, μCT and histological analyses documented improved mineralization in cortical and trabecular bone and secondary ossification centers in long bones of ChimAP16-treated mice. There was no evidence of craniosynostosis in the ChimAP16-treated mice and we did not detect ectopic calcification by radiography and histology in the aortas, stomachs, kidneys or lungs in any of the treatment groups. Molar tooth development and function improved with the highest ChimAP dose, including enamel, dentin, and tooth morphology. Cementum remained deficient and alveolar bone mineralization was reduced compared to controls, though ChimAP-treated Alpl(-/-) mice featured periodontal attachment and retained teeth. This study provides the first evidence for the pharmacological efficacy of ChimAP for use in the treatment of skeletal and dental manifestations of HPP.
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Affiliation(s)
- Kellen C S Gasque
- Sanford Children's Health Research Center, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - Brian L Foster
- Laboratory of Oral Connective Tissue Biology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Pia Kuss
- Sanford Children's Health Research Center, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - Manisha C Yadav
- Sanford Children's Health Research Center, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - Jin Liu
- Department of Orthodontics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| | - Tina Kiffer-Moreira
- Sanford Children's Health Research Center, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | | | - Nan Hatch
- Department of Orthodontics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| | - Martha J Somerman
- Laboratory of Oral Connective Tissue Biology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - José Luis Millán
- Sanford Children's Health Research Center, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA.
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Foster BL, Sheen CR, Hatch NE, Liu J, Cory E, Narisawa S, Kiffer-Moreira T, Sah RL, Whyte MP, Somerman MJ, Millán JL. Periodontal Defects in the A116T Knock-in Murine Model of Odontohypophosphatasia. J Dent Res 2015; 94:706-14. [PMID: 25716980 DOI: 10.1177/0022034515573273] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Mutations in ALPL result in hypophosphatasia (HPP), a disease causing defective skeletal mineralization. ALPL encodes tissue nonspecific alkaline phosphatase (ALP), an enzyme that promotes mineralization by reducing inorganic pyrophosphate, a mineralization inhibitor. In addition to skeletal defects, HPP causes dental defects, and a mild clinical form of HPP, odontohypophosphatasia, features only a dental phenotype. The Alpl knockout (Alpl (-/-)) mouse phenocopies severe infantile HPP, including profound skeletal and dental defects. However, the severity of disease in Alpl (-/-) mice prevents analysis at advanced ages, including studies to target rescue of dental tissues. We aimed to generate a knock-in mouse model of odontohypophosphatasia with a primarily dental phenotype, based on a mutation (c.346G>A) identified in a human kindred with autosomal dominant odontohypophosphatasia. Biochemical, skeletal, and dental analyses were performed on the resulting Alpl(+/A116T) mice to validate this model. Alpl(+/A116T) mice featured 50% reduction in plasma ALP activity compared with wild-type controls. No differences in litter size, survival, or body weight were observed in Alpl(+/A116T) versus wild-type mice. The postcranial skeleton of Alpl(+/A116T) mice was normal by radiography, with no differences in femur length, cortical/trabecular structure or mineral density, or mechanical properties. Parietal bone trabecular compartment was mildly altered. Alpl(+/A116T) mice featured alterations in the alveolar bone, including radiolucencies and resorptive lesions, osteoid accumulation on the alveolar bone crest, and significant differences in several bone properties measured by micro-computed tomography. Nonsignificant changes in acellular cementum did not appear to affect periodontal attachment or function, although circulating ALP activity was correlated significantly with incisor cementum thickness. The Alpl(+/A116T) mouse is the first model of odontohypophosphatasia, providing insights on dentoalveolar development and function under reduced ALP, bringing attention to direct effects of HPP on alveolar bone, and offering a new model for testing potential dental-targeted therapies in future studies.
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Affiliation(s)
- B L Foster
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - C R Sheen
- Sanford Children's Health Research Center, Sanford-Burnham Medical Research Institute, La Jolla, CA, USA
| | - N E Hatch
- Department of Orthodontics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| | - J Liu
- Department of Orthodontics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| | - E Cory
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA
| | - S Narisawa
- Sanford Children's Health Research Center, Sanford-Burnham Medical Research Institute, La Jolla, CA, USA
| | - T Kiffer-Moreira
- Sanford Children's Health Research Center, Sanford-Burnham Medical Research Institute, La Jolla, CA, USA
| | - R L Sah
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA
| | - M P Whyte
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospital for Children, St. Louis, MO, USA Division of Bone and Mineral Diseases, Washington University School of Medicine, St. Louis, MO, USA
| | - M J Somerman
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - J L Millán
- Sanford Children's Health Research Center, Sanford-Burnham Medical Research Institute, La Jolla, CA, USA
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Abstract
Hypophosphatasia (HPP) is due to mutations of the tissue non-specific alkaline phosphatase (TNAP) gene expressed in the liver, kidney, and bone. TNAP substrates include inorganic pyrophosphate cleaved into inorganic phosphate (Pi) in bone, pyridoxal-5'-phosphate (PLP), the circulating form of vitamin B6, and phosphoethanolamine (PEA). As an autosomal recessive or dominant disease, HPP results in a range of clinical forms. Its hallmarks are low alkaline phosphatase (AP) and elevated PLP and PEA levels. Perinatal HPP may cause early death with respiratory insufficiency and hypomineralization resulting in deformed limbs and sometimes near-absence of bones and skull. Infantile HPP is diagnosed before 6 months of life. Respiratory failure, rib fractures and seizures due to vitamin B6 deficiency in the brain indicate poor prognosis. Craniosynostosis is frequent. Unlike in other forms of rickets, calcium and phosphorus are not decreased, resulting in hypercalciuria and nephrocalcinosis. Hypercalcemic crisis may occur. Failure to thrive and growth retardation are concerns. In infantile and adult forms of HPP, non-traumatic fractures may be the prominent manifestation, with otherwise unexplained chronic pain. Progressive myopathy has been described. Dental manifestations with early loss of teeth are usual in HPP and in a specific form, odontohypophosphatasia. HPP has been studied in knock-out mice models which mimic its severe form. Animal models have made a major contribution to the development of an original enzyme therapy for human infantile HPP, which is however essentially targeted at mineralized tissues. Better knowledge of its extraskeletal manifestations, including pain and neurological symptoms, is therefore required.
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Affiliation(s)
- Jean Pierre Salles
- Unité d'Endocrinologie Maladies Osseuses, Hôpital Des Enfants, CHU de Toulouse and Inserm UMR 1043 UPS, Toulouse Cedex, France,
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49
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Abstract
Genetically modified mice are powerful tools for understanding the functions of genes and proteins and often serve as models of human disease. Here, several knockout and transgenic mouse lines related to tissue-nonspecific alkaline phosphatase (TNAP) are described. Conventional TNAP knockout mice die before weaning and show vitamin B6 dependent epilepsy and impaired bone mineralization, mimicking infantile hypophosphatasia. Administration of recombinant human TNAP rescues the lethal phenotype and improves bone mineralization in the null knockout mice, and this enzyme replacement therapy has been successfully applied to the treatment of human patients. Transgenic expression of human TNAP also rescues the TNAP knockout mice. Studies of the TNAP knockout mice and their double knockouts with ectonucleotide pyrophosphatase/phosphodiesterase 1 or progressive ankylosis protein revealed that pyridoxal phosphate and inorganic pyrophosphate are natural substrates of TNAP. Bone osteopontin from TNAP knockout mice is highly phosphorylated, whereas osteopontin from TNAP knockout mice expressing human TNAP is de-phosphorylated, similar to that in wild type mice, indicating that osteopontin is also a natural substrate of TNAP and that phosphorylated osteopontin contributes the impaired bone mineralization in TNAP knockout mice. Conditional TNAP knockout mice and TNAP mutants produced by ENU (N-ethyl-N-nitrosourea) mutagenesis show milder hypophosphatasia and are expected to be useful models of adult hypophosphatasia.
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50
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Liu J, Nam HK, Campbell C, Gasque KCDS, Millán JL, Hatch NE. Tissue-nonspecific alkaline phosphatase deficiency causes abnormal craniofacial bone development in the Alpl(-/-) mouse model of infantile hypophosphatasia. Bone 2014; 67:81-94. [PMID: 25014884 PMCID: PMC4149826 DOI: 10.1016/j.bone.2014.06.040] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Revised: 06/09/2014] [Accepted: 06/30/2014] [Indexed: 12/27/2022]
Abstract
UNLABELLED Tissue-nonspecific alkaline phosphatase (TNAP) is an enzyme present on the surface of mineralizing cells and their derived matrix vesicles that promotes hydroxyapatite crystal growth. Hypophosphatasia (HPP) is an inborn-error-of-metabolism that, dependent upon age of onset, features rickets or osteomalacia due to loss-of function mutations in the gene (Alpl) encoding TNAP. Craniosynostosis is prevalent in infants with HPP and other forms of rachitic disease but how craniosynostosis develops in these disorders is unknown. OBJECTIVES Because craniosynostosis carries high morbidity, we are investigating craniofacial skeletal abnormalities in Alpl(-/-) mice to establish these mice as a model of HPP-associated craniosynostosis and determine mechanisms by which TNAP influences craniofacial skeletal development. METHODS Cranial bone, cranial suture and cranial base abnormalities were analyzed by micro-CT and histology. Craniofacial shape abnormalities were quantified using digital calipers. TNAP expression was suppressed in MC3T3E1(C4) calvarial cells by TNAP-specific shRNA. Cells were analyzed for changes in mineralization, gene expression, proliferation, apoptosis, matrix deposition and cell adhesion. RESULTS Alpl(-/-) mice feature craniofacial shape abnormalities suggestive of limited anterior-posterior growth. Craniosynostosis in the form of bony coronal suture fusion is present by three weeks after birth. Alpl(-/-) mice also exhibit marked histologic abnormalities of calvarial bones and the cranial base involving growth plates, cortical and trabecular bone within two weeks of birth. Analysis of calvarial cells in which TNAP expression was suppressed by shRNA indicates that TNAP deficiency promotes aberrant osteoblastic gene expression, diminished matrix deposition, diminished proliferation, increased apoptosis and increased cell adhesion. CONCLUSIONS These findings demonstrate that Alpl(-/-) mice exhibit a craniofacial skeletal phenotype similar to that seen in infants with HPP, including true bony craniosynostosis in the context of severely diminished bone mineralization. Future studies will be required to determine if TNAP deficiency and other forms of rickets promote craniosynostosis directly through abnormal calvarial cell behavior, or indirectly due to deficient growth of the cranial base.
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Affiliation(s)
- Jin Liu
- Department of Orthodontics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| | - Hwa Kyung Nam
- Department of Orthodontics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| | - Cassie Campbell
- Department of Orthodontics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| | | | | | - Nan E Hatch
- Department of Orthodontics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, MI, USA.
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