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Qiu T, Hutečková B, Seppala M, Cobourne MT, Chen Z, Hovořáková M, Buchtová M, Tucker AS. Molecular profiling of the vestibular lamina highlights a key role for Hedgehog signalling. Development 2023; 150:297306. [PMID: 36971701 DOI: 10.1242/dev.201464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Accepted: 03/13/2023] [Indexed: 03/29/2023]
Abstract
The vestibular lamina (VL) forms the oral vestibule, creating a gap between the teeth, lips and cheeks. In a number of ciliopathies, formation of the vestibule is defective, leading to the creation of multiple frenula. In contrast to the neighbouring dental lamina, which forms the teeth, little is known about the genes that pattern the VL. Here we establish a molecular signature for the usually non-odontogenic VL and highlight several genes and signalling pathways that may play a role in its development. For one of these, the Sonic hedgehog (Shh) pathway, we show that co-receptors Gas1, Cdon and Boc are highly expressed in the VL and act to enhance the Shh signal from the forming incisor region. In Gas1 mutant mice, expression of Gli1 was disrupted and the VL epithelium failed to extend due to a loss of proliferation. This defect was exacerbated in Boc/Gas1 double mutants and could be phenocopied using cyclopamine in culture. Signals from the forming teeth, therefore, control development of the vestibular lamina, coordinating the development of the dentition and the oral cavity.
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Affiliation(s)
- Tengyang Qiu
- Centre for Craniofacial & Regenerative Biology, Faculty of Dentistry, Oral & Craniofacial Sciences , King's College London, London, SE1 9RT United Kingdom
- The State Key Laboratory Breeding Base of Basic Science of Stomatology & Key Laboratory of Oral Biomedicine , Ministry of Education (Hubei-MOST KLOS & KLOBM), School and Hospital of Stomatology, Wuhan University, 430079 Wuhan, China
| | - Barbora Hutečková
- Department of Experimental Biology, Faculty of Science, Masaryk University, 625 00 Brno, Czech Republic
- Laboratory of Molecular Morphogenesis, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, 602 00 Brno, Czech Republic
| | - Maisa Seppala
- Centre for Craniofacial & Regenerative Biology, Faculty of Dentistry, Oral & Craniofacial Sciences , King's College London, London, SE1 9RT United Kingdom
- Department of Orthodontics, Faculty of Dentistry, Oral & Craniofacial Sciences, King's College London, London, SE1 9RT UK
| | - Martyn T Cobourne
- Centre for Craniofacial & Regenerative Biology, Faculty of Dentistry, Oral & Craniofacial Sciences , King's College London, London, SE1 9RT United Kingdom
- Department of Orthodontics, Faculty of Dentistry, Oral & Craniofacial Sciences, King's College London, London, SE1 9RT UK
| | - Zhi Chen
- The State Key Laboratory Breeding Base of Basic Science of Stomatology & Key Laboratory of Oral Biomedicine , Ministry of Education (Hubei-MOST KLOS & KLOBM), School and Hospital of Stomatology, Wuhan University, 430079 Wuhan, China
| | - Mária Hovořáková
- Institute of Histology and Embryology, First Faculty of Medicine, Charles University, Albertov 4, 128 00 Praha 2, Czech Republic
| | - Marcela Buchtová
- Department of Experimental Biology, Faculty of Science, Masaryk University, 625 00 Brno, Czech Republic
- Laboratory of Molecular Morphogenesis, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, 602 00 Brno, Czech Republic
| | - Abigail S Tucker
- Centre for Craniofacial & Regenerative Biology, Faculty of Dentistry, Oral & Craniofacial Sciences , King's College London, London, SE1 9RT United Kingdom
- Institute of Histology and Embryology, First Faculty of Medicine, Charles University, Albertov 4, 128 00 Praha 2, Czech Republic
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2
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Joshi P, Vijaykumar A, Enkhmandakh B, Shin DG, Mina M, Bayarsaihan D. The chromatin accessibility landscape in the dental pulp of mouse molars and incisors. Acta Biochim Pol 2022; 69:131-138. [PMID: 35226446 DOI: 10.18388/abp.2020_5771] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 01/04/2022] [Indexed: 11/10/2022]
Abstract
The dental pulp is a promising source of progenitor cells for regenerative medicine. The natural function of dental pulp is to produce odontoblasts to generate reparative dentin. Stem cells within the pulp tissue originate from the migrating neural crest cells and possess mesenchymal stem cell properties with the ability to differentiate into multiple lineages. To elucidate the transcriptional control mechanisms underlying cell fate determination, we compared the transcriptome and chromatin accessibility in primary dental pulp tissue derived from 5-6-day-old mice. Using RNA sequencing and assay for transposase-accessible chromatin using sequencing (ATAC-seq), we correlated gene expression with chromatin accessibility. We found that the majority of ATAC-seq peaks were concentrated at genes associated with development and cell differentiation. Most of these genes were highly expressed in the mouse dental pulp. Surprisingly, we uncovered a group of genes encoding master transcription factors that were not expressed in the dental pulp but retained open chromatin states. Within this group, we identified key developmental genes important for specification of the neural crest, adipocyte, neural, myoblast, osteoblast and hepatocyte lineages. Collectively, our results uncover a complex relationship between gene expression and the chromatin accessibility landscape in the mouse dental pulp.
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Affiliation(s)
- Pujan Joshi
- Computer Science and Engineering Department, University of Connecticut, Storrs, CT 06269, USA
| | - Anushree Vijaykumar
- Department of Craniofacial Sciences, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Badam Enkhmandakh
- Center for Regenerative Medicine and Skeletal Development, Department of Reconstructive Sciences, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Dong-Guk Shin
- Computer Science and Engineering Department, University of Connecticut, Storrs, CT 06269, USA
| | - Mina Mina
- Department of Craniofacial Sciences, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Dashzeveg Bayarsaihan
- 3Center for Regenerative Medicine and Skeletal Development, Department of Reconstructive Sciences, University of Connecticut Health Center, Farmington, CT 06030, USA; 4Institute for System Genomics, University of Connecticut, Storrs, CT 06269, USA
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3
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Li D, Wang X, Yao L, Jing H, Qin T, Li M, Zhang S, Chen Z, Zhang L. Sox2 controls asymmetric patterning of ameloblast lineage commitment by regulation of FGF signaling in the mouse incisor. J Mol Histol 2021; 52:1035-1042. [PMID: 34279757 DOI: 10.1007/s10735-021-10005-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 07/12/2021] [Indexed: 10/20/2022]
Abstract
Mouse incisors are covered by enamel only on the labial side and the lingual side is covered by dentin without enamel. This asymmetric distribution of enamel makes it possible to be abrased on the lingual side, generating the sharp cutting edge of incisor on the labial side. The abrasion of mouse incisors is compensated by the continuous growth throughout life. Epithelium stem cells responsible for its continuous growth are reported to localize within the labial cervical loop. The transcription factor Sox2 plays important roles in the maintenance of stem cell pluripotency and organ formation. We previously found that Sox2 mainly expressed in the dental epithelium. Besides, Sox2 has been reported to be a dental epithelium stem cell marker in the incisor. However, the exact mechanism of Sox2 controlling amelogenesis is still not quite clearly elucidated. Here we report that conditional deletion of Sox2 in the dental epithelium using Shhcre caused impaired ameloblast differentiation in the labial side and induced ectopic ameloblast-like cell differentiation on the lingual side. Abnormal FGF gene expression was detected by RNAscope in situ hybridization in the mutant incisor. Collectively, we speculate that asymmetric ameloblast lineage commitment of mouse incisor might be regulated by Sox2 through FGF signaling.
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Affiliation(s)
- Dan Li
- Department of Stomatology, Yantai Affiliated Hospital of Binzhou Medical University, No. 717 Jinbu Street, Yantai, 264100, Shandong, China
- Binzhou Medical University, No. 346 Guanhai Street, Yantai, 264003, Shandong, China
| | - Xiaofei Wang
- Binzhou Medical University, No. 346 Guanhai Street, Yantai, 264003, Shandong, China
- Department of Stomatology, Binzhou Affiliated Hospital of Binzhou Medical University, Binzhou, 256600, Shandong, China
| | - Liping Yao
- Department of Cariology and Endodontology, Yantai Stomatological Hospital, Yantai, 264008, Shandong, China
| | - Huaixiang Jing
- Department of Stomatology, Yantai Affiliated Hospital of Binzhou Medical University, No. 717 Jinbu Street, Yantai, 264100, Shandong, China
| | - Tiantian Qin
- Department of Stomatology, Yantai Affiliated Hospital of Binzhou Medical University, No. 717 Jinbu Street, Yantai, 264100, Shandong, China
| | - Mingyue Li
- Binzhou Medical University, No. 346 Guanhai Street, Yantai, 264003, Shandong, China
| | - Shuyu Zhang
- Binzhou Medical University, No. 346 Guanhai Street, Yantai, 264003, Shandong, China
| | - Zhi Chen
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory for Oral Biomedicine of Ministry of Education (KLOBM), School and Hospital of Stomatology, Wuhan University, Wuhan, 430079, China.
| | - Li Zhang
- Department of Stomatology, Yantai Affiliated Hospital of Binzhou Medical University, No. 717 Jinbu Street, Yantai, 264100, Shandong, China.
- Binzhou Medical University, No. 346 Guanhai Street, Yantai, 264003, Shandong, China.
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4
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Deng S, Fan L, Wang Y, Zhang Q. Constitutive activation of β-catenin in odontoblasts induces aberrant pulp calcification in mouse incisors. J Mol Histol 2021; 52:567-576. [PMID: 33689044 DOI: 10.1007/s10735-021-09965-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 02/17/2021] [Indexed: 10/21/2022]
Abstract
During dentin formation, odontoblast polarization ensures that odontoblasts directionally secrete dentin matrix protein, leading to tubular dentin formation; however, little is known about the major features and regulatory mechanisms of odontoblast polarization. In a study of epithelial cell polarization, β-catenin was shown to serve as a structural component of cadherin-based adherens junctions to initiate cell polarity. However, the role of β-catenin in odontoblast polarization has not been well investigated. In this study, we explored whether β-catenin participated in odontoblast polarization to regulate the secretion of mineralization proteins. We established Col1-CreErt2; β-catenin exon3fl/fl (CA-β-catenin) mice, which constitutively activate β-catenin in odontoblasts. CA-β-catenin mice exhibited disorganization and depolarization of incisor odontoblasts. Moreover, the incisor dentin was hypomineralized, and ectopic calcification was found in mouse incisor pulp. In addition, by constitutive activation of β-catenin, the expression levels of the core polarity molecule Cdc42 and its downstream polarity protein complex Par3-Par6-aPKC were decreased in the incisors of CA-β-catenin mice. These findings suggest that β-catenin plays an essential role in dentin formation by regulating odontoblast polarization.
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Affiliation(s)
- Shijian Deng
- Department of Endodontics, School and Hospital of Stomatology, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Tongji University, No.399 Yanchang Road, Shanghai, 200072, China
| | - Linlin Fan
- Department of Endodontics, School and Hospital of Stomatology, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Tongji University, No.399 Yanchang Road, Shanghai, 200072, China
- Department of Pediatric Dentistry, Wuxi Stomatology Hospital, Jiangsu, China
| | - Yunfei Wang
- Department of Endodontics, School and Hospital of Stomatology, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Tongji University, No.399 Yanchang Road, Shanghai, 200072, China
- Department of Endodontics, Shanghai Xuhui District Dental Center, Shanghai, China
| | - Qi Zhang
- Department of Endodontics, School and Hospital of Stomatology, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Tongji University, No.399 Yanchang Road, Shanghai, 200072, China.
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5
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Abstract
Dentin Sialoprotein (DSP) and phosphophoryn (PP) are two most dominant non-collagenous proteins in dentin, which are the cleavage products of the DSPP (dentin sialophosphoprotein) precursor protein. The absence of the DSPP gene in DSPP knock-out (KO) mice results in characteristics that are consistent with dentinogenesis imperfecta type III in humans. Symptoms include thin dentin, bigger pulp chamber with frequent pulp exposure as well as abnormal epithelial-mesenchymal interactions, and the appearance of chondrocyte-like cells in dental pulp. To better understand how DSPP influences tooth development and dentin formation, we used a bacterial artificial chromosome transgene construct (BAC-DSPP) that contained the complete DSPP gene and promoter to generate BAC-DSPP transgenic mice directly in a mouse DSPP KO background. Two BAC-DSPP transgenic mouse strains were generated and characterized. DSPP mRNA expression in BAC-DSPP Strain A incisors was similar to that from wild-type (wt) mice. DSPP mRNA expression in BAC-DSPP Strain B animals was only 10% that of wt mice. PP protein content in Strain A incisors was 25% of that found in wt mice, which was sufficient to completely rescue the DSPP KO defect in mineral density, since microCT dentin mineral density analysis in 21-day postnatal animal molars showed essentially identical mineral density in both strain A and wt mice. Strain B mouse incisors, with 5% PP expression, only partially rescued the DSPP KO defect in mineral density, as microCT scans of 21-day postnatal animal molars indicated a reduced dentin mineral density compared to wt mice, though the mineral density was still increased over that of DSPP KO. Furthermore, our findings showed that DSPP dosage in Strain A was sufficient to rescue the DSPP KO defect in terms of epithelial-mesenchymal interactions, odontoblast lineage maintenance, along with normal dentin thickness and normal mineral density while DSPP gene dosage in Strain B only partially rescued the aforementioned DSPP KO defect.
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Affiliation(s)
- Dandrich Lim
- Department of Cariology, Restorative Sciences and Endodontics, University of Michigan School of Dentistry, Ann Arbor, Michigan, United States of America
| | - Ko-Chien Wu
- Department of Cariology, Restorative Sciences and Endodontics, University of Michigan School of Dentistry, Ann Arbor, Michigan, United States of America
| | - Arthur Lee
- Department of Cariology, Restorative Sciences and Endodontics, University of Michigan School of Dentistry, Ann Arbor, Michigan, United States of America
| | - Thomas L. Saunders
- Division of Medical Medicine and Genetics, Department of Internal Medicine, Transgenic Animal Model Core, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Helena H. Ritchie
- Department of Cariology, Restorative Sciences and Endodontics, University of Michigan School of Dentistry, Ann Arbor, Michigan, United States of America
- * E-mail:
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6
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Woodruff ED, Gutierrez GC, Van Otterloo E, Williams T, Cohn MJ. Anomalous incisor morphology indicates tissue-specific roles for Tfap2a and Tfap2b in tooth development. Dev Biol 2021; 472:67-74. [PMID: 33460639 PMCID: PMC8018193 DOI: 10.1016/j.ydbio.2020.12.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 12/17/2020] [Accepted: 12/21/2020] [Indexed: 01/13/2023]
Abstract
Mice possess two types of teeth that differ in their cusp patterns; incisors have one cusp and molars have multiple cusps. The patterning of these two types of teeth relies on fine-tuning of the reciprocal molecular signaling between dental epithelial and mesenchymal tissues during embryonic development. The AP-2 transcription factors, particularly Tfap2a and Tfap2b, are essential components of such epithelial-mesenchymal signaling interactions that coordinate craniofacial development in mice and other vertebrates, but little is known about their roles in the regulation of tooth development and shape. Here we demonstrate that incisors and molars differ in their temporal and spatial expression of Tfap2a and Tfap2b. At the bud stage, Tfap2a is expressed in both the epithelium and mesenchyme of the incisors and molars, but Tfap2b expression is restricted to the molar mesenchyme, only later appearing in the incisor epithelium. Tissue-specific deletions show that loss of the epithelial domain of Tfap2a and Tfap2b affects the number and spatial arrangement of the incisors, notably resulting in duplicated lower incisors. In contrast, deletion of these two genes in the mesenchymal domain has little effect on tooth development. Collectively these results implicate epithelial expression of Tfap2a and Tfap2b in regulating the extent of the dental lamina associated with patterning the incisors and suggest that these genes contribute to morphological differences between anterior (incisor) and posterior (molar) teeth within the mammalian dentition.
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Affiliation(s)
- Emily D Woodruff
- Department of Biology, University of Florida, Gainesville, FL, USA.
| | | | - Eric Van Otterloo
- Department of Craniofacial Biology, University of Colorado Anschutz Medical Campus, Denver, CO, USA
| | - Trevor Williams
- Department of Craniofacial Biology, University of Colorado Anschutz Medical Campus, Denver, CO, USA
| | - Martin J Cohn
- Department of Biology, University of Florida, Gainesville, FL, USA; Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, USA.
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7
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Imhof T, Balic A, Heilig J, Chiquet-Ehrismann R, Chiquet M, Niehoff A, Brachvogel B, Thesleff I, Koch M. Pivotal Role of Tenascin-W (-N) in Postnatal Incisor Growth and Periodontal Ligament Remodeling. Front Immunol 2021; 11:608223. [PMID: 33552067 PMCID: PMC7862723 DOI: 10.3389/fimmu.2020.608223] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Accepted: 12/07/2020] [Indexed: 12/19/2022] Open
Abstract
The continuously growing mouse incisor provides a fascinating model for studying stem cell regulation and organ renewal. In the incisor, epithelial and mesenchymal stem cells assure lifelong tooth growth. The epithelial stem cells reside in a niche known as the cervical loop. Mesenchymal stem cells are located in the nearby apical neurovascular bundle and in the neural plexus. So far, little is known about extracellular cues that are controlling incisor stem cell renewal and guidance. The extracellular matrix protein tenascin-W, also known as tenascin-N (TNN), is expressed in the mesenchyme of the pulp and of the periodontal ligament of the incisor, and is closely associated with collagen 3 fibers. Here, we report for the first time the phenotype of tenascin-W/TNN deficient mice, which in a C57BL/6N background exhibit a reduced body weight and lifespan. We found major defects in the alveolar bone and periodontal ligament of the growing rodent incisors, whereas molars were not affected. The alveolar bone around the incisor was replaced by a dense scar-like connective tissue, enriched with newly formed nerve fibers likely leading to periodontal pain, less food intake and reduced body weight. Using soft food to reduce mechanical load on the incisor partially rescued the phenotype. In situ hybridization and Gli1 reporter mouse experiments revealed decreased hedgehog signaling in the incisor mesenchymal stem cell compartment, which coordinates the development of mesenchymal stem cell niche. These results indicate that TNN deficiency in mice affects periodontal remodeling and increases nerve fiber branching. Through periodontal pain the food intake is reduced and the incisor renewal and the neurovascular sonic hedgehog secretion rate are reduced. In conclusion, tenascin-W/TNN seems to have a primary function in rapid periodontal tissue remodeling and a secondary function in mechanosensation.
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Affiliation(s)
- Thomas Imhof
- Faculty of Medicine and University Hospital Cologne, Institute for Dental Research and Oral Musculoskeletal Biology, University of Cologne, Cologne, Germany
- Center for Biochemistry, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Anamaria Balic
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Juliane Heilig
- Center for Biochemistry, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Cologne Center for Musculoskeletal Biomechanics, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Ruth Chiquet-Ehrismann
- Friedrich Miescher Institute for Biomedical Research, Novartis Res. Foundation, Basel, Switzerland
| | - Matthias Chiquet
- Department of Orthodontics and Dentofacial Orthopedics, School of Dental Medicine, University of Bern, Bern, Switzerland
| | - Anja Niehoff
- Cologne Center for Musculoskeletal Biomechanics, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Institute of Biomechanics and Orthopaedics, German Sport University Cologne, Cologne, Germany
| | - Bent Brachvogel
- Center for Biochemistry, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Department of Pediatrics and Adolescent Medicine, Experimental Neonatology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Irma Thesleff
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Manuel Koch
- Faculty of Medicine and University Hospital Cologne, Institute for Dental Research and Oral Musculoskeletal Biology, University of Cologne, Cologne, Germany
- Center for Biochemistry, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
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8
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Bekes K, Mitulović G, Meißner N, Resch U, Gruber R. Saliva proteomic patterns in patients with molar incisor hypomineralization. Sci Rep 2020; 10:7560. [PMID: 32371984 PMCID: PMC7200701 DOI: 10.1038/s41598-020-64614-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 04/16/2020] [Indexed: 12/12/2022] Open
Abstract
Molar incisor hypomineralization (MIH) is an endemic pediatric disease with an unclear pathogenesis. Considering that saliva controls enamel remineralization and that MIH is associated with higher saliva flow rate, we hypothesized that the protein composition of saliva is linked to disease. To test this, we enrolled 5 children aged 6-14 years with MIH showing at least one hypersensitive molar and 5 caries-free children without hypomineralization. Saliva samples were subjected to proteomic analysis followed by protein classification in to biological pathways. Among 618 salivary proteins identified with high confidence, 88 proteins were identified exclusively in MIH patients and 16 proteins in healthy controls only. Biological pathway analysis classified these 88 patient-only proteins to neutrophil-mediated adaptive immunity, the activation of the classical pathway of complement activation, extracellular matrix degradation, heme scavenging as well as glutathione -and drug metabolism. The 16 controls-only proteins were associated with adaptive immunity related to platelet degranulation and the lysosome. This report suggests that the proteaneous composition of saliva is affected in MIH patients, reflecting a catabolic environment which is linked to inflammation.
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Affiliation(s)
- K Bekes
- Department of Paediatric Dentistry, School of Dentistry, Medical University of Vienna, Vienna, Austria.
| | - G Mitulović
- Proteomics Core Facility, Clinical Institute of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | | | - U Resch
- Department of Vascular Biology and Thrombosis Research, Medical University of Vienna, Vienna, Austria
| | - R Gruber
- Department of Oral Biology, School of Dentistry, Medical University of Vienna, Vienna, Austria
- Department of Periodontology, School of Dental Medicine, University of Bern, Bern, Switzerland
- Austrian Cluster for Tissue Regeneration, Vienna, Austria
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9
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Fujihara H, Nozaki T, Tsutsumi M, Isumi M, Shimoda S, Hamada Y, Masutani M. Spontaneous Development of Dental Dysplasia in Aged Parp-1 Knockout Mice. Cells 2019; 8:cells8101157. [PMID: 31569682 PMCID: PMC6829344 DOI: 10.3390/cells8101157] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 09/16/2019] [Accepted: 09/17/2019] [Indexed: 01/14/2023] Open
Abstract
Poly(ADP-ribose) polymerase (Parp)-1 catalyzes polyADP-ribosylation using NAD+ and is involved in the DNA damage response, genome stability, and transcription. In this study, we demonstrated that aged Parp-1-/- mouse incisors showed more frequent dental dysplasia in both ICR/129Sv mixed background and C57BL/6 strain compared to aged Parp-1+/+ incisors, suggesting that Parp-1 deficiency could be involved in development of dental dysplasia at an advanced age. Computed tomography images confirmed that dental dysplasia was observed at significantly higher incidences in Parp-1-/- mice. The relative calcification levels of Parp-1-/- incisors were higher in both enamel and dentin (p < 0.05). Immunohistochemical analysis revealed (1) Parp-1 positivity in ameloblasts and odontoblasts in Parp-1+/+ incisor, (2) weaker dentin sialoprotein positivity in dentin of Parp-1-/- incisor, and (3) bone sialoprotein positivity in dentin of Parp-1-/- incisor, suggesting ectopic osteogenic formation in dentin of Parp-1-/- incisor. These results indicate that Parp-1 deficiency promotes odontogenic failure in incisors at an advanced age. Parp-1 deficiency did not affect dentinogenesis during the development of mice, suggesting that Parp-1 is not essential in dentinogenesis during development but is possibly involved in the regulation of continuous dentinogenesis in the incisors at an advanced age.
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Affiliation(s)
- Hisako Fujihara
- Biochemistry Division, National Cancer Center Research Institute 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan.
- Department of Oral and Maxillofacial Surgery, School of Dental Medicine, Tsurumi University 2-1-3 Tsurumi, Tsurumi-ku, Yokohama, Kanagawa 230-8501, Japan.
| | - Tadashige Nozaki
- Biochemistry Division, National Cancer Center Research Institute 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan.
- Department of Pharmacology, Faculty of Dentistry, Osaka Dental University 8-1, Kuzuhahanazono-cho, Hirakata, Osaka 573-1121, Japan.
| | - Masahiro Tsutsumi
- Department of Pathology, Saiseikai Chuwa Hospital 323 Oaza Abe, Sakurai City, Nara 633-0054, Japan.
| | - Mayu Isumi
- Department of Frontier Life Sciences, Graduate School of Biochemical Science, Nagasaki University 1-7-1 Sakamoto, Nagasaki 852-8588, Japan.
| | - Shinji Shimoda
- Department of Oral Anatomy-1, School of Dental Medicine, Tsurumi University 2-1-3 Tsurumi, Tsurumi-ku, Yokohama, Kanagawa 230-8501, Japan.
| | - Yoshiki Hamada
- Department of Oral and Maxillofacial Surgery, School of Dental Medicine, Tsurumi University 2-1-3 Tsurumi, Tsurumi-ku, Yokohama, Kanagawa 230-8501, Japan.
| | - Mitsuko Masutani
- Biochemistry Division, National Cancer Center Research Institute 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan.
- Department of Frontier Life Sciences, Graduate School of Biochemical Science, Nagasaki University 1-7-1 Sakamoto, Nagasaki 852-8588, Japan.
- Division of Cellular Signaling, National Cancer Center Research Institute 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan.
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10
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Al-Mosawi M, Davis GR, Bushby A, Montgomery J, Beaumont J, Al-Jawad M. Crystallographic texture and mineral concentration quantification of developing and mature human incisal enamel. Sci Rep 2018; 8:14449. [PMID: 30262903 PMCID: PMC6160435 DOI: 10.1038/s41598-018-32425-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 08/30/2018] [Indexed: 11/08/2022] Open
Abstract
For human dental enamel, what is the precise mineralization progression spatially and the precise timing of mineralization? This is an important question in the fundamental understanding of matrix-mediated biomineralization events, but in particular because we can use our understanding of this natural tissue growth in humans to develop biomimetic approaches to repair and replace lost enamel tissue. It is important to understand human tissues in particular since different species have quite distinct spatial and temporal progression of mineralization. In this study, five human central incisors at different stages of enamel maturation/mineralization were spatially mapped using synchrotron X-ray diffraction and X-ray microtomography techniques. From the earliest developmental stage, two crystallite-orientation populations coexist with angular separations between the crystallite populations of approximately 40° varying as a function of position within the tooth crown. In general, one population had significantly lower texture magnitude and contributed a higher percentage to the overall crystalline structure, compared to the other population which contributed only 20-30% but had significantly higher texture magnitude. This quantitative analysis allows us to understand the complex and co-operative structure-function relationship between two populations of crystallites within human enamel. There was an increase in the mineral concentration from the enamel-dentin junction peripherally and from the incisal tip cervically as a function of maturation time. Quantitative backscattered-electron analyses showed that mineralization of prism cores precedes that of prism boundaries. These results provide new insights into the precise understanding of the natural growth of human enamel.
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Affiliation(s)
- Mohammed Al-Mosawi
- Institute of Dentistry, Barts and the London School of Medicine and Dentistry, Queen Mary, University of London, London, E1 4NS, United Kingdom
| | - Graham Roy Davis
- Institute of Dentistry, Barts and the London School of Medicine and Dentistry, Queen Mary, University of London, London, E1 4NS, United Kingdom
| | - Andy Bushby
- School of Engineering and Materials Science, Queen Mary University of London, London, E1 4NS, United Kingdom
| | - Janet Montgomery
- Department of Archaeology, Durham University, South Road, Durham, DH1 3LE, United Kingdom
| | - Julia Beaumont
- School of Archaeological and Forensic Sciences, University of Bradford, Bradford, BD7 1DP, United Kingdom
| | - Maisoon Al-Jawad
- Institute of Dentistry, Barts and the London School of Medicine and Dentistry, Queen Mary, University of London, London, E1 4NS, United Kingdom.
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11
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Luo PP, Xu HS. [Effect of overdose fluoride on the expression of TGF-β3 in rat incisor]. Shanghai Kou Qiang Yi Xue 2018; 27:22-24. [PMID: 29946635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
PURPOSE To observe the effect of overdose fluoride on the expression of TGF-β3 in rat incisor and to explore the possible mechanism of dental fluorosis. METHODS: Twenty Wistar rats were randomly divided into 2 groups. The animals were maintained in standard environmental conditions with free access to food and water (control group) or water added with 100mg/L F (experimental group). The rats were killed at the end of 8th week. The expression of TGF-β3 was detected by immunohistochemical staining. Statistical analysis was performed using SPSS12.0 software package. RESULTS The expression of TGF-β3 in ameloblasts was significantly inhibited in the experimental of group II(P<0.01). The gray value of the control group and the fluorine group were 85.89±7.90, 116.76±8.04, respectively. CONCLUSIONS Fluoride might disturb the signal transduction between the epithelia and mesenchyma by inhibiting the expression of TGF-β3 in ameloblasts, which in turn may inhibit the differentiation and function of the tooth-forming cells.
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Affiliation(s)
- Ping-Ping Luo
- Department of Stomatology, Shanghai No.8 People's Hospital. Shanghai 201500, China. E-mail:
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12
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An Z, Sabalic M, Bloomquist RF, Fowler TE, Streelman T, Sharpe PT. A quiescent cell population replenishes mesenchymal stem cells to drive accelerated growth in mouse incisors. Nat Commun 2018; 9:378. [PMID: 29371677 PMCID: PMC5785476 DOI: 10.1038/s41467-017-02785-6] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 12/28/2017] [Indexed: 01/06/2023] Open
Abstract
The extent to which heterogeneity within mesenchymal stem cell (MSC) populations is related to function is not understood. Using the archetypal MSC in vitro surface marker, CD90/Thy1, here we show that 30% of the MSCs in the continuously growing mouse incisor express CD90/Thy1 and these cells give rise to 30% of the differentiated cell progeny during postnatal development. In adulthood, when growth rate homeostasis is established, the CD90/Thy1+ MSCs decrease dramatically in number. When adult incisors are cut, the growth rate increases to rapidly re-establish tooth length and homeostasis. This accelerated growth rate correlates with the re-appearance of CD90/Thy+ MSCs and re-establishment of their contribution to cell differentiation. A population of Celsr1+ quiescent cells becomes mitotic following clipping and replenishes the CD90/Thy1 population. A sub-population of MSCs thus exists in the mouse incisor, distinguished by expression of CD90/Thy1 that plays a specific role only during periods of increased growth rate.
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Affiliation(s)
- Zhengwen An
- Centre for Craniofacial and Regenerative Biology, Dental Institute, Kings College London, London, SE1 9RT, UK
| | - Maja Sabalic
- Centre for Craniofacial and Regenerative Biology, Dental Institute, Kings College London, London, SE1 9RT, UK
| | - Ryan F Bloomquist
- Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, USA
| | - Teresa E Fowler
- Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, USA
| | - Todd Streelman
- Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, USA
| | - Paul T Sharpe
- Centre for Craniofacial and Regenerative Biology, Dental Institute, Kings College London, London, SE1 9RT, UK.
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13
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Sun Z, Yu W, Sanz Navarro M, Sweat M, Eliason S, Sharp T, Liu H, Seidel K, Zhang L, Moreno M, Lynch T, Holton NE, Rogers L, Neff T, Goodheart MJ, Michon F, Klein OD, Chai Y, Dupuy A, Engelhardt JF, Chen Z, Amendt BA. Sox2 and Lef-1 interact with Pitx2 to regulate incisor development and stem cell renewal. Development 2016; 143:4115-4126. [PMID: 27660324 PMCID: PMC5117215 DOI: 10.1242/dev.138883] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 09/06/2016] [Indexed: 12/26/2022]
Abstract
Sox2 marks dental epithelial stem cells (DESCs) in both mammals and reptiles, and in this article we demonstrate several Sox2 transcriptional mechanisms that regulate dental stem cell fate and incisor growth. Conditional Sox2 deletion in the oral and dental epithelium results in severe craniofacial defects, including impaired dental stem cell proliferation, arrested incisor development and abnormal molar development. The murine incisor develops initially but is absorbed independently of apoptosis owing to a lack of progenitor cell proliferation and differentiation. Tamoxifen-induced inactivation of Sox2 demonstrates the requirement of Sox2 for maintenance of the DESCs in adult mice. Conditional overexpression of Lef-1 in mice increases DESC proliferation and creates a new labial cervical loop stem cell compartment, which produces rapidly growing long tusk-like incisors, and Lef-1 epithelial overexpression partially rescues the tooth arrest in Sox2 conditional knockout mice. Mechanistically, Pitx2 and Sox2 interact physically and regulate Lef-1, Pitx2 and Sox2 expression during development. Thus, we have uncovered a Pitx2-Sox2-Lef-1 transcriptional mechanism that regulates DESC homeostasis and dental development.
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Affiliation(s)
- Zhao Sun
- Department of Anatomy and Cell Biology, and the Craniofacial Anomalies Research Center, The University of Iowa, Iowa City, IA 52242, USA
| | - Wenjie Yu
- Department of Anatomy and Cell Biology, and the Craniofacial Anomalies Research Center, The University of Iowa, Iowa City, IA 52242, USA
| | - Maria Sanz Navarro
- Developmental Biology Program, Institute of Biotechnology, University of Helsinki, 00790 Helsinki, Finland
| | - Mason Sweat
- Department of Anatomy and Cell Biology, and the Craniofacial Anomalies Research Center, The University of Iowa, Iowa City, IA 52242, USA
| | - Steven Eliason
- Department of Anatomy and Cell Biology, and the Craniofacial Anomalies Research Center, The University of Iowa, Iowa City, IA 52242, USA
| | - Thad Sharp
- Department of Anatomy and Cell Biology, and the Craniofacial Anomalies Research Center, The University of Iowa, Iowa City, IA 52242, USA
| | - Huan Liu
- Department of Anatomy and Cell Biology, and the Craniofacial Anomalies Research Center, The University of Iowa, Iowa City, IA 52242, USA
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory for Oral Biomedicine of Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan 430079, P.R.China
| | - Kerstin Seidel
- Department of Orofacial Sciences and Program in Craniofacial Biology, UCSF, San Francisco, CA 94143-0442, USA
| | - Li Zhang
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory for Oral Biomedicine of Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan 430079, P.R.China
| | - Myriam Moreno
- Department of Anatomy and Cell Biology, and the Craniofacial Anomalies Research Center, The University of Iowa, Iowa City, IA 52242, USA
| | - Thomas Lynch
- Department of Anatomy and Cell Biology, and the Craniofacial Anomalies Research Center, The University of Iowa, Iowa City, IA 52242, USA
| | - Nathan E Holton
- Iowa Institute for Oral Health Research, College of Dentistry, The University of Iowa, Iowa City, IA 52242, USA
| | - Laura Rogers
- Department of Anatomy and Cell Biology, and the Craniofacial Anomalies Research Center, The University of Iowa, Iowa City, IA 52242, USA
| | - Traci Neff
- Department of Anatomy and Cell Biology, and the Craniofacial Anomalies Research Center, The University of Iowa, Iowa City, IA 52242, USA
| | - Michael J Goodheart
- Department of Obstetrics and Gynecology, The University of Iowa, Iowa City, IA 52242, USA
| | - Frederic Michon
- Developmental Biology Program, Institute of Biotechnology, University of Helsinki, 00790 Helsinki, Finland
| | - Ophir D Klein
- Department of Orofacial Sciences and Program in Craniofacial Biology, UCSF, San Francisco, CA 94143-0442, USA
| | - Yang Chai
- Center for Craniofacial Molecular Biology, Ostrow School of Dentistry, University of Southern California, Los Angeles, CA 90033, USA
| | - Adam Dupuy
- Department of Anatomy and Cell Biology, and the Craniofacial Anomalies Research Center, The University of Iowa, Iowa City, IA 52242, USA
| | - John F Engelhardt
- Department of Anatomy and Cell Biology, and the Craniofacial Anomalies Research Center, The University of Iowa, Iowa City, IA 52242, USA
| | - Zhi Chen
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory for Oral Biomedicine of Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan 430079, P.R.China
| | - Brad A Amendt
- Department of Anatomy and Cell Biology, and the Craniofacial Anomalies Research Center, The University of Iowa, Iowa City, IA 52242, USA
- Iowa Institute for Oral Health Research, College of Dentistry, The University of Iowa, Iowa City, IA 52242, USA
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14
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Hovorakova M, Lochovska K, Zahradnicek O, Domonkosova Tibenska K, Dornhoferova M, Horakova-Smrckova L, Bodorikova S. One Odontogenic Cell-Population Contributes to the Development of the Mouse Incisors and of the Oral Vestibule. PLoS One 2016; 11:e0162523. [PMID: 27611193 PMCID: PMC5017683 DOI: 10.1371/journal.pone.0162523] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 08/24/2016] [Indexed: 11/18/2022] Open
Abstract
The area of the oral vestibule is often a place where pathologies appear (e.g., peripheral odontomas). The origin of these pathologies is not fully understood. In the present study, we traced a cell population expressing Sonic hedgehog (Shh) from the beginning of tooth development using Cre-LoxP system in the lower jaw of wild-type (WT) mice. We focused on Shh expression in the area of the early appearing rudimentary incisor germs located anteriorly to the prospective incisors. The localization of the labelled cells in the incisor germs and also in the inner epithelial layer of the vestibular anlage showed that the first very early developmental events in the lower incisor area are common to the vestibulum oris and the prospective incisor primordia in mice. Scanning electron microscopic analysis of human historical tooth-like structures found in the vestibular area of jaws confirmed their relation to teeth and thus the capability of the vestibular tissue to form teeth. The location of labelled cells descendant of the early appearing Shh expression domain related to the rudimentary incisor anlage not only in the rudimentary and functional incisor germs but also in the externally located anlage of the oral vestibule documented the odontogenic potential of the vestibular epithelium. This potential can be awakened under pathological conditions and become a source of pathologies in the vestibular area.
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Affiliation(s)
- Maria Hovorakova
- Department of Teratology, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, 14220, Prague 4, Czech Republic
- * E-mail:
| | - Katerina Lochovska
- Department of Teratology, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, 14220, Prague 4, Czech Republic
- Department of Anthropology and Human Genetics, Faculty of Science, Charles University, Prague, Czech Republic
| | - Oldrich Zahradnicek
- Department of Teratology, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, 14220, Prague 4, Czech Republic
| | - Kristina Domonkosova Tibenska
- Department of Anthropology, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Slovak Republic
| | - Michaela Dornhoferova
- Department of Anthropology, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Slovak Republic
| | - Lucie Horakova-Smrckova
- Department of Teratology, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, 14220, Prague 4, Czech Republic
- Department of Cell Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Silvia Bodorikova
- Department of Anthropology, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Slovak Republic
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15
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Togo Y, Takahashi K, Saito K, Kiso H, Tsukamoto H, Huang B, Yanagita M, Sugai M, Harada H, Komori T, Shimizu A, MacDougall M, Bessho K. Antagonistic Functions of USAG-1 and RUNX2 during Tooth Development. PLoS One 2016; 11:e0161067. [PMID: 27518316 PMCID: PMC4982599 DOI: 10.1371/journal.pone.0161067] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 07/30/2016] [Indexed: 12/02/2022] Open
Abstract
Supernumerary teeth and tooth agenesis are common morphological anomalies in humans. We previously obtained evidence that supernumerary maxillary incisors form as a result of the successive development of the rudimentary maxillary incisor tooth germ in Usag-1 null mice. The development of tooth germs is arrested in Runx2 null mice, and such mice also exhibit lingual epithelial buds associated with the upper molars and incisors. The aim of this study is to investigate the potential crosstalk between Usag-1 and Runx2 during tooth development. In the present study, three interesting phenomena were observed in double null Usag-1-/-/Runx2-/- mice: the prevalence of supernumerary teeth was lower than in Usag-1 null mice; tooth development progressed further compared than in Runx2 null mice; and the frequency of molar lingual buds was lower than in Runx2 null mice. Therefore, we suggest that RUNX2 and USAG-1 act in an antagonistic manner. The lingual bud was completely filled with odontogenic epithelial Sox2-positive cells in the Usag-1+/+/Runx2-/- mice, whereas almost no odontogenic epithelial Sox2-positive cells contributed to supernumerary tooth formation in the rudimentary maxillary incisors of the Usag-1-/-/Runx2+/+ mice. Our findings suggest that RUNX2 directly or indirectly prevents the differentiation and/or proliferation of odontogenic epithelial Sox2-positive cells. We hypothesize that RUNX2 inhibits the bone morphogenetic protein (BMP) and/or Wnt signaling pathways regulated by USAG-1, whereas RUNX2 expression is induced by BMP signaling independently of USAG-1.
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Affiliation(s)
- Yumiko Togo
- Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawahara-cho, Sakyo-ku, 606–8507, Kyoto, Japan
| | - Katsu Takahashi
- Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawahara-cho, Sakyo-ku, 606–8507, Kyoto, Japan
- * E-mail:
| | - Kazuyuki Saito
- Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawahara-cho, Sakyo-ku, 606–8507, Kyoto, Japan
| | - Honoka Kiso
- Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawahara-cho, Sakyo-ku, 606–8507, Kyoto, Japan
| | - Hiroko Tsukamoto
- Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawahara-cho, Sakyo-ku, 606–8507, Kyoto, Japan
| | - Boyen Huang
- School of Dentistry and Health Sciences, Faculty of Science, Charles Sturt University, Orange, NSW, 2800, Australia
| | - Motoko Yanagita
- Department of Nephrology, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawahara-cho, Sakyo-ku, 606–8507, Kyoto, Japan
| | - Manabu Sugai
- Department of Molecular Genetics, Division of Medicine, Faculty of Medical Sciences, University of Fukui, Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910–1193, Japan
| | - Hidemitsu Harada
- Division of Developmental Biology and Regenerative Medicine, Department of Anatomy, Iwate Medical University, 2-1-1, Nishitokuta, Yahaba, Iwate, 028–3694, Japan
| | - Toshihisa Komori
- Department of Cell Biology, Unit of Basic Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki, 852–8588, Japan
| | - Akira Shimizu
- Department of Experimental Therapeutics, Institute for Advancement of Clinical and Translational Science, Kyoto University Hospital, 54 Shogoin-Kawahara-cho, Sakyo-ku, 606–8507, Kyoto, Japan
| | - Mary MacDougall
- Institute of Oral Health Research, Department of Oral and Maxillofacial Surgery, School of Dentistry, University of Alabama, Birmingham, Alabama, United States of America
| | - Kazuhisa Bessho
- Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawahara-cho, Sakyo-ku, 606–8507, Kyoto, Japan
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16
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Aberg T, Cavender A, Gaikwad JS, Bronckers ALJJ, Wang X, Waltimo-Sirén J, Thesleff I, D'Souza RN. Phenotypic Changes in Dentition of Runx2 Homozygote-null Mutant Mice. J Histochem Cytochem 2016; 52:131-9. [PMID: 14688224 DOI: 10.1177/002215540405200113] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Genetic and molecular studies in humans and mice indicate that Runx2 (Cbfa1) is a critical transcriptional regulator of bone and tooth formation. Heterozygous mutations in Runx2 cause cleidocranial dysplasia (CCD), an inherited disorder in humans and mice characterized by skeletal defects, supernumerary teeth, and delayed eruption. Mice lacking the Runx2 gene die at birth and lack bone and tooth development. Our extended phenotypic studies of Runx2 mutants showed that developing teeth fail to advance beyond the bud stage and that mandibular molar organs were more severely affected than maxillary molar organs. Runx2 (−/−) tooth organs, when transplanted beneath the kidney capsules of nude mice, failed to progress in development. Tooth epithelial-mesenchymal recombinations using Runx2 (+/+) and (−/−) tissues indicate that the defect in mesenchyme cannot be rescued by normal dental epithelium. Finally, our molecular analyses showed differential effects of the absence of Runx2 on tooth extracellular matrix (ECM) gene expression. These data support the hypothesis that Runx2 is one of the key mesenchymal factors that influences tooth morphogenesis and the subsequent differentiation of ameloblasts and odontoblasts.
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Affiliation(s)
- Thomas Aberg
- Institute of Biotechnology, Viikki Biocenter, University of Helsinki, Finland
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Yamamoto T, Oida S, Inage T. Gene Expression and Localization of Insulin-like Growth Factors and Their Receptors throughout Amelogenesis in Rat Incisors. J Histochem Cytochem 2016; 54:243-52. [PMID: 16260589 DOI: 10.1369/jhc.5a6821.2005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Insulin-like growth factors (IGFs) are expressed in many tissues and control cell differentiation, proliferation, and apoptosis. In teeth, the temporo-spatial pattern of expression IGFs and their receptors has not been fully characterized. The purpose of this study was to obtain a comprehensive profile of their expression throughout the life cycle of ameloblasts, using the continuously erupting rat incisor model. Upper incisors of young male rats were fixed by perfusion, decalcified, and embedded in paraffin. Sections were processed for in situ hybridization and immunohistochemistry. mRNA and protein expression profiles IGF-I, IGF-II, IGF-IR, and IGF-IIR mRNA were essentially identical. At the apical loop of the incisor, very strong signals were seen in the outer enamel epithelium while the inner enamel epithelium showed a moderate reaction. In the region of ameloblasts facing pulp, inner enamel epithelium cells were still moderately reactive while signals over the outer enamel epithelium were slightly reduced. In the region of ameloblasts facing dentin and the initial portion of the secretory zone, signals in ameloblasts were weak while those over the outer enamel epithelium were strong. In the region of postsecretory transition, signals in both ameloblasts and papillary layer cells gradually increased. In maturation proper, signals in ameloblasts appeared as alternating bands of strong and weak reactivities, which corresponded to the regions of ruffle-ended and smooth-ended ameloblasts, respectively. Papillary layer cells also showed alternations in signal intensity that matched those in ameloblasts. These results suggest that the IGF family may act as an autocrine/paracrine system that influences not only cell differentiation but also the physiological activity of ameloblasts.
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Affiliation(s)
- Tatsuya Yamamoto
- Department of Anatomy, School of Dentistry, Nihon University, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo, Japan.
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Abstract
Parathyroid hormone related peptide (PTHrP) was discovered as a causative factor of humoral hypercalcemia of malignancy (HHM). In the present study using HHM model rats, the time course of odontoblastic response to PTHrP and its relation to incisal fracture were elicited. Nude rats were implanted with PTHrP-expressing tumor (LC-6) cells, mandibular incisors were collected at several time points. Microscopically 3 distinctive types of odontoblastic/dentin lesions were observed. Hypercalcfied dentin, which was reported as hypercalcemia-induced lesion in previous reports, observed in all areas of the dentin from week 5–10 samplings. Dentin niche, observed solely in week-10 sampling point, exhibited a nature identical to that of reparative odontoblast reported in the literatures of various cytotoxic agents. Since cytotoxicites were neither observed prior to the lesions nor reported as a role of PTHrP, the reparative response may have derived from highly sustained levels of PTHrP. Loss of columnar odontoblasts height was initially observed at week-5 time point in the middle section of the incisor. This primary loss of cell height prior to incisor fracture was considered to be the earliest response to the increased PTHrP levels of this model.
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Affiliation(s)
- Atsuhiko Kato
- Toxicology Laboratory, Chugai Pharmaceutical Co., Ltd., Gotemba-shi, Shizuoka 412-8513, Japan.
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Ibrahim M, Mohan S, Xing MJ, Kesavan C. Conditional Knockout of the MicroRNA 17-92 Cluster in Type-I Collagen-Expressing Cells Decreases Alveolar Bone Size and Incisor Tooth Mechanical Properties. Folia Biol (Praha) 2016; 62:175-179. [PMID: 27643583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
To test the role of the miR17-92 (miR) cluster in dental bones, we evaluated the incisor tooth phenotype by micro-CT in 5- and 12-week-old conditional knockout (CKO) mice deficient in the miR17-92 cluster in type-I collagen-expressing cells and bone strength by finite element analysis. The incisor teeth of CKO mice showed a 23-30 % reduction in tissue volume and bone volume. Accordingly, the stiffness and failure load of incisor teeth assessed by finite element analysis showed an 18-40 % decrease in CKO compared to wild-type mice. A positive correlation between bone parameters and strength data suggests that the decreased mechanical properties of incisor teeth are due to decreased tissue volume and bone volume. Subsequently, we found that the width of alveolar bone was reduced by 25 % with a 16 % increase in periodontal ligament space, suggesting that the CKO mice are more susceptible to tooth movement. Since alveolar bone is populated primarily by osteoblast lineage cells, it is likely that the reduction in periosteal expansion of alveolar bone in the lower jaw of CKO mice results from decreased periosteal bone formation. Overall, our phenotype analysis demonstrates that the miR17-92 cluster is essential for development and maintenance of tooth strength by regulating its tooth size.
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Affiliation(s)
- M Ibrahim
- Musculoskeletal Disease Center, VA Loma Linda Healthcare System, Loma Linda, CA, USA
| | - S Mohan
- Musculoskeletal Disease Center, VA Loma Linda Healthcare System, Loma Linda, CA, USA
| | - M J Xing
- Musculoskeletal Disease Center, VA Loma Linda Healthcare System, Loma Linda, CA, USA
| | - C Kesavan
- Musculoskeletal Disease Center, VA Loma Linda Healthcare System, Loma Linda, CA, USA
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20
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Poelmans S, Kawamoto T, Cristofoli F, Politis C, Vermeesch J, Bailleul-Forestier I, Hens G, Devriendt K, Verdonck A, Carels C. Genotypic and phenotypic variation in six patients with solitary median maxillary central incisor syndrome. Am J Med Genet A 2015; 167A:2451-8. [PMID: 26080100 DOI: 10.1002/ajmg.a.37207] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 06/03/2015] [Indexed: 11/09/2022]
Abstract
Solitary Median Maxillary Central Incisor occurs in 1 of 50,000 live births. It is the mildest manifestation of the holoprosencephaly spectrum and is genetically heterogeneous. Here we report six patients with solitary median maxillary central incisor, and a range of other phenotypic anomalies with different degrees of severity, varying from mild signs of holoprosencephaly to associated intellectual disability, and with different genetic background. Using array comparative genomic hybridization, pathogenic copy number variants were found in three of the six patients. Two patients had a deletion at the 18p11 chromosomal region that includes TGIF1 while the other patient had a deletion at 7q36, including the SHH gene. In one patient, a mutation in SIX3 was detected with exome sequencing, while in the two remaining patients all known holoprosencephaly genes were excluded using multiplex ligation-dependent probe amplification and sequencing, and remain unsolved. One of the two latter patients had isolated solitary median maxillary central incisor without other visible dentofacial anomalies, while the other had clinical features not part of the known holoprosencephaly spectrum.
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Affiliation(s)
- Simon Poelmans
- Department of Oral Health Sciences-Orthodontics, KU Leuven and Dentistry, University Hospitals Leuven, Leuven, Belgium
| | - Tatsuro Kawamoto
- Department of Orthodontics and Craniofacial Biology, College of Dentistry, Radboudumc, Nijmegen, The Netherlands
- Department of Maxillofacial Reconstruction and Function, Maxillofacial Orthognathics, Division of Maxillofacial/Neck Reconstruction, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan
| | - Francesca Cristofoli
- Department of Human Genetics, KU Leuven and Centre for Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Constantinus Politis
- Department of Oral and Maxillofacial Surgery, KU Leuven and University Hospitals Leuven, Leuven, Belgium
| | - Joris Vermeesch
- Department of Human Genetics, KU Leuven and Centre for Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Isabelle Bailleul-Forestier
- Department of Oral Health Sciences-Paediatric Dentistry and Special Care, KU Leuven and Dentistry, University Hospitals Leuven, Leuven, Belgium
- Department of Paediatric Dentistry, Paul Sabatier University, Hôpitaux de Toulouse, France
| | - Greet Hens
- Department of Otorhinolaryngology, Head and Neck Surgery, KU Leuven and University Hospitals Leuven, Leuven, Belgium
| | - Koenraad Devriendt
- Department of Human Genetics, KU Leuven and Centre for Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Anna Verdonck
- Department of Oral Health Sciences-Orthodontics, KU Leuven and Dentistry, University Hospitals Leuven, Leuven, Belgium
| | - Carine Carels
- Department of Oral Health Sciences-Orthodontics, KU Leuven and Dentistry, University Hospitals Leuven, Leuven, Belgium
- Department of Orthodontics and Craniofacial Biology, College of Dentistry, Radboudumc, Nijmegen, The Netherlands
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21
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Maciejewska K, Drzazga Z, Kaszuba M. The changes in bone organic and inorganic matrix in newborn rats after maternal application of antiretroviral agents: Indinavir and zidovudine. Biofactors 2015; 41:198-208. [PMID: 26040542 DOI: 10.1002/biof.1215] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2015] [Accepted: 04/29/2015] [Indexed: 01/31/2023]
Abstract
This work presents results concerning influence of indinavir (protease inhibitor, PI(1)) and zidovudine (nucleoside and nucleotide inhibitor of reverse transcriptase, NRTI) administered to pregnant Wistar rat females on organic and mineral constituents of bones and teeth (mandibles, skulls, tibiae, femurs, and incisors) of their offspring at the age of: 7, 14, and 28 days studied by means of induced laser and X-ray fluorescence spectroscopy supported by digital radiography. Influence of indinavir administered to pregnant female rats on bone of their offspring revealed mainly in changes of mineral concentration: lowered Ca concentration and disturbances of trace elements. Zidovudine influenced organic matter more than inorganic matrix which was seen in enhancement of LIF fluorescence. However, there was also an unexpected increase of bone density for rats from zidovudine group, unlike indinavir group, observed. Our studies suggest that studied antiretroviral agents given to pregnant women, may have different destructive impact on bone state of their offspring in the first period of life. Maternal administration of zidovudine may delay development of organic matrix, while indinavir may have adverse effects on inorganic structure.
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Affiliation(s)
- Karina Maciejewska
- Department of Medical Physics, Institute of Physics, University of Silesia, Katowice, Poland
- Silesian Center for Education and Interdisciplinary Research, Chorzow, Poland
| | - Zofia Drzazga
- Department of Medical Physics, Institute of Physics, University of Silesia, Katowice, Poland
- Silesian Center for Education and Interdisciplinary Research, Chorzow, Poland
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22
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Çiftçi ZZ, Kırzıoğlu Z, Nazıroğlu M, Özmen Ö. Effects of prenatal and postnatal exposure of Wi-Fi on development of teeth and changes in teeth element concentration in rats. [corrected]. Biol Trace Elem Res 2015; 163:193-201. [PMID: 25395122 DOI: 10.1007/s12011-014-0175-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 11/03/2014] [Indexed: 01/16/2023]
Abstract
The present study determined the effects of prenatal and postnatal exposure to Wi-Fi (2.45 GHz)-induced electromagnetic radiation (EMR) on tooth and surrounding tissue development as well as the element levels in growing rats. Twenty-four rats and their offspring were equally divided into two separate groups identified as experiment and control. The experiment group was exposed to 2.45 GHz EMR for 2 h/day during the periods of pregnancy (21 days) and lactation (21 days). The offspring of these dams were also exposed to EMR up to decapitation. The control group was exposed to cage stress for 2 h per day using the same protocol established for the experimental group. On the 7th, 14th, and 21st days after birth, 8 male offspring rats from each of the two groups were decapitated, and the jaws were taken for histological and immunohistochemical examination. Caspase-3 (1/50 dilution) was used in the immunohistochemical examination for apoptotic activity. On the last day of the experiment, the rats' incisors were also collected. In samples that were histologically and immunohistochemically examined, there was an increase in apoptosis and caspase-3 in both the control and the Wi-Fi groups during the development of the teeth. However, no significant difference was observed between the two groups in terms of development and apoptotic activity. Results from the elemental analysis showed that iron and strontium concentrations were increased in the Wi-Fi group, whereas boron, copper, and zinc concentrations were decreased. There were no statistically significant differences in calcium, cadmium, potassium, magnesium, sodium, or phosphorus values between the groups. Histological and immunohistochemical examinations between the experimental and control groups showed that exposure to 2.45 GHz EMR for 2 h per day does not interfere with the development of teeth and surrounding tissues. However, there were alterations in the elemental composition of the teeth, especially affecting such oxidative stress-related elements as copper, zinc, and iron, suggesting that short-term exposure to Wi-Fi-induced EMR may cause an imbalance in the oxidative stress condition in the teeth of growing rats.
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Affiliation(s)
- Zülfikar Zahit Çiftçi
- Department of Pedodontics, Faculty of Dentistry, Süleyman Demirel University, Isparta, Turkey
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23
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Shekaran A, Shoemaker JT, Kavanaugh TE, Lin AS, LaPlaca MC, Fan Y, Guldberg RE, García AJ. The effect of conditional inactivation of beta 1 integrins using twist 2 Cre, Osterix Cre and osteocalcin Cre lines on skeletal phenotype. Bone 2014; 68:131-41. [PMID: 25183373 PMCID: PMC4189988 DOI: 10.1016/j.bone.2014.08.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2014] [Revised: 08/13/2014] [Accepted: 08/16/2014] [Indexed: 11/27/2022]
Abstract
Skeletal development and growth are complex processes regulated by multiple microenvironmental cues, including integrin-ECM interactions. The β1 sub-family of integrins is the largest integrin sub-family and constitutes the main integrin binding partners of collagen I, the major ECM component of bone. As complete β1 integrin knockout results in embryonic lethality, studies of β1 integrin function in vivo rely on tissue-specific gene deletions. While multiple in vitro studies indicate that β1 integrins are crucial regulators of osteogenesis and mineralization, in vivo osteoblast-specific perturbations of β1 integrins have resulted in mild and sometimes contradictory skeletal phenotypes. To further investigate the role of β1 integrins on skeletal phenotype, we used the Twist2-Cre, Osterix-Cre and osteocalcin-Cre lines to generate conditional β1 integrin deletions, where Cre is expressed primarily in mesenchymal condensation, pre-osteoblast, and mature osteoblast lineage cells respectively within these lines. Mice with Twist2-specific β1 integrin disruption were smaller, had impaired skeletal development, especially in the craniofacial and vertebral tissues at E19.5, and did not survive beyond birth. Osterix-specific β1 integrin deficiency resulted in viable mice which were normal at birth but displayed early defects in calvarial ossification, incisor eruption and growth as well as femoral bone mineral density, structure, and mechanical properties. Although these defects persisted into adulthood, they became milder with age. Finally, a lack of β1 integrins in mature osteoblasts and osteocytes resulted in minor alterations to femur structure but had no effect on mineral density, biomechanics or fracture healing. Taken together, our data indicate that β1 integrin expression in early mesenchymal condensations play an important role in skeletal ossification, while β1 integrin-ECM interactions in pre-osteoblast, odontoblast- and hypertrophic chondryocyte-lineage cells regulate incisor eruption and perinatal bone formation in both intramembranously and endochondrally formed bones in young, rapidly growing mice. In contrast, the osteocalcin-specific β1 integrin deletion had only minor effects on skeletal phenotype.
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Affiliation(s)
- Asha Shekaran
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Drive, Atlanta, GA 30332, USA; Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, 315 Ferst Drive, Atlanta, GA 30332, USA
| | - James T Shoemaker
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Drive, Atlanta, GA 30332, USA
| | - Taylor E Kavanaugh
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Drive, Atlanta, GA 30332, USA
| | - Angela S Lin
- Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, 315 Ferst Drive, Atlanta, GA 30332, USA; School of Mechanical Engineering, Georgia Institute of Technology, 801 Ferst Drive, Atlanta, GA 30332, USA
| | - Michelle C LaPlaca
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Drive, Atlanta, GA 30332, USA
| | - Yuhong Fan
- Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, 315 Ferst Drive, Atlanta, GA 30332, USA; School of Biology, Georgia Institute of Technology, 310 Ferst Drive, Atlanta, GA 30332, USA
| | - Robert E Guldberg
- Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, 315 Ferst Drive, Atlanta, GA 30332, USA; School of Mechanical Engineering, Georgia Institute of Technology, 801 Ferst Drive, Atlanta, GA 30332, USA
| | - Andrés J García
- Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, 315 Ferst Drive, Atlanta, GA 30332, USA; School of Mechanical Engineering, Georgia Institute of Technology, 801 Ferst Drive, Atlanta, GA 30332, USA.
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24
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Sharp T, Wang J, Li X, Cao H, Gao S, Moreno M, Amendt BA. A pituitary homeobox 2 (Pitx2):microRNA-200a-3p:β-catenin pathway converts mesenchymal cells to amelogenin-expressing dental epithelial cells. J Biol Chem 2014; 289:27327-27341. [PMID: 25122764 PMCID: PMC4175363 DOI: 10.1074/jbc.m114.575654] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Revised: 08/12/2014] [Indexed: 12/21/2022] Open
Abstract
Pitx2, Wnt/β-catenin signaling, and microRNAs (miRs) play a critical role in the regulation of dental stem cells during embryonic development. In this report, we have identified a Pitx2:β-catenin regulatory pathway involved in epithelial cell differentiation and conversion of mesenchymal cells to amelogenin expressing epithelial cells via miR-200a. Pitx2 and β-catenin are expressed in the labial incisor cervical loop or epithelial stem cell niche, with decreased expression in the differentiating ameloblast cells of the mouse lower incisor. Bioinformatics analyses reveal that miR-200a-3p expression is activated in the pre-ameloblast cells to enhance epithelial cell differentiation. We demonstrate that Pitx2 activates miR-200a-3p expression and miR-200a-3p reciprocally represses Pitx2 and β-catenin expression. Pitx2 and β-catenin interact to synergistically activate gene expression during odontogenesis and miR-200a-3p attenuates their expression and directs differentiation. To understand how this mechanism controls cell differentiation and cell fate, oral epithelial and odontoblast mesenchymal cells were reprogrammed by a two-step induction method using Pitx2 and miR-200a-3p. Conversion to amelogenin expressing dental epithelial cells involved an up-regulation of the stem cell marker Sox2 and proliferation genes and decreased expression of mesenchymal markers. E-cadherin expression was increased as well as ameloblast specific factors. The combination of Pitx2, a regulator of dental stem cells and miR-200a converts mesenchymal cells to a fully differentiated dental epithelial cell type. This pathway and reprogramming can be used to reprogram mesenchymal or oral epithelial cells to dental epithelial (ameloblast) cells, which can be used in tissue repair and regeneration studies.
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Affiliation(s)
- Thad Sharp
- Department of Anatomy and Cell Biology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Jianbo Wang
- Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas 77030, and
| | - Xiao Li
- Department of Anatomy and Cell Biology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Huojun Cao
- Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas 77030, and
| | - Shan Gao
- Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas 77030, and
| | - Myriam Moreno
- Department of Anatomy and Cell Biology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Brad A Amendt
- Department of Anatomy and Cell Biology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242,; Craniofacial Anomalies Research Center, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242.
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25
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Damkier HH, Josephsen K, Takano Y, Zahn D, Fejerskov O, Frische S. Fluctuations in surface pH of maturing rat incisor enamel are a result of cycles of H(+)-secretion by ameloblasts and variations in enamel buffer characteristics. Bone 2014; 60:227-34. [PMID: 24373736 DOI: 10.1016/j.bone.2013.12.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 11/18/2013] [Accepted: 12/16/2013] [Indexed: 12/15/2022]
Abstract
It is disputed if ameloblasts in the maturation zone of the enamel organ mainly buffer protons released by hydroxyapatite (HA) crystal growth or if they periodically secrete protons to create alternating acidic and alkaline conditions. The latter hypothesis predicts alternating pH regimes in maturing enamel, which would be affected by pharmacological interference with ameloblast H(+)-secretion. This study tests these predictions. Colorimetric pH-indicators and ratiometric fluorometry were used to measure surface pH in maturation zone enamel of rat incisors. Alternating acidic (down to pH6.24±0.06) and alkaline zones (up to pH7.34±0.08) were found along the tooth coinciding with ameloblast morphological cycles. Underlying the cyclic pattern, a gradual decrease in pH towards the incisal edge was seen. Vinblastine or FR167356 (H(+)-ATPase-inhibitor) disturbed ameloblast acid-secretion, especially in the early parts of acidic zones. Enamel surface pH reflects the titration state of surface PO4(3-)-ions. At the pH-values observed, PO4(3-) would be protonated (pKa>12) and HA dissolved. However, by molecular dynamics simulations we estimate the pKa of HPO4(2-) at an ideal HA surface to be 4.3. The acidic pH measured at the enamel surface may thus only dissolve non-perfect domains of HA crystals in which PO4(3-) is less electrostatically shielded. During repeated alkaline/acidic cycles, near-perfect HA-domains may therefore gradually replace less perfect HA-domains resulting in near-perfect HA-crystals. In conclusion, cyclic changes in ameloblast H(+)-secretion and the degree of enamel maturation determine enamel surface pH. This is in accordance with a hypothesis implicating H(+)-ATPase mediated acid-secretion by ameloblasts.
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Affiliation(s)
| | | | - Yoshiro Takano
- Section of Biostructural Science, Graduate School of Tokyo Medical and Dental University, Japan
| | - Dirk Zahn
- Lehrstuhl für Theoretische Chemie/Computer Chemie Centrum, Friedrich-Alexander Universität Erlangen-Nürnberg, Germany
| | - Ole Fejerskov
- Department of Biomedicine, Aarhus University, Denmark
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26
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Li X, Venugopalan SR, Cao H, Pinho FO, Paine ML, Snead ML, Semina EV, Amendt BA. A model for the molecular underpinnings of tooth defects in Axenfeld-Rieger syndrome. Hum Mol Genet 2014; 23:194-208. [PMID: 23975681 PMCID: PMC3857954 DOI: 10.1093/hmg/ddt411] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 08/19/2013] [Indexed: 12/18/2022] Open
Abstract
Patients with Axenfeld-Rieger Syndrome (ARS) present various dental abnormalities, including hypodontia, and enamel hypoplasia. ARS is genetically associated with mutations in the PITX2 gene, which encodes one of the earliest transcription factors to initiate tooth development. Thus, Pitx2 has long been considered as an upstream regulator of the transcriptional hierarchy in early tooth development. However, because Pitx2 is also a major regulator of later stages of tooth development, especially during amelogenesis, it is unclear how mutant forms cause ARS dental anomalies. In this report, we outline the transcriptional mechanism that is defective in ARS. We demonstrate that during normal tooth development Pitx2 activates Amelogenin (Amel) expression, whose product is required for enamel formation, and that this regulation is perturbed by missense PITX2 mutations found in ARS patients. We further show that Pitx2-mediated Amel activation is controlled by chromatin-associated factor Hmgn2, and that Hmgn2 prevents Pitx2 from efficiently binding to and activating the Amel promoter. Consistent with a physiological significance to this interaction, we show that K14-Hmgn2 transgenic mice display a severe loss of Amel expression on the labial side of the lower incisors, as well as enamel hypoplasia-consistent with the human ARS phenotype. Collectively, these findings define transcriptional mechanisms involved in normal tooth development and shed light on the molecular underpinnings of the enamel defect observed in ARS patients who carry PITX2 mutations. Moreover, our findings validate the etiology of the enamel defect in a novel mouse model of ARS.
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Affiliation(s)
- Xiao Li
- Department of Anatomy and Cell Biology and Craniofacial Anomalies Research Center, The University of Iowa, Iowa City, IA 52244, USA
| | - Shankar R. Venugopalan
- Department of Anatomy and Cell Biology and Craniofacial Anomalies Research Center, The University of Iowa, Iowa City, IA 52244, USA
| | - Huojun Cao
- Department of Anatomy and Cell Biology and Craniofacial Anomalies Research Center, The University of Iowa, Iowa City, IA 52244, USA
| | - Flavia O. Pinho
- Department of Anatomy and Cell Biology and Craniofacial Anomalies Research Center, The University of Iowa, Iowa City, IA 52244, USA
| | - Michael L. Paine
- Center for Craniofacial Molecular Biology, Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA and
| | - Malcolm L. Snead
- Center for Craniofacial Molecular Biology, Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA and
| | - Elena V. Semina
- Division of Developmental Biology, Department of Pediatrics, The Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Brad A. Amendt
- Department of Anatomy and Cell Biology and Craniofacial Anomalies Research Center, The University of Iowa, Iowa City, IA 52244, USA
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27
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Muica Nagy-Bota MC, Pap Z, Denes L, Ghizdavăţ A, Brînzaniuc K, Lup Coşarcă AS, Chibelean Cireş-Mărginean M, Păcurar M, Pávai Z. Immunohistochemical study of Ki67, CD34 and p53 expression in human tooth buds. Rom J Morphol Embryol 2014; 55:43-48. [PMID: 24715164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
AIM OF THE STUDY Establishment of Ki67, p53 and CD34 expression in human tooth buds of different stages of odontogenetic development. MATERIALS AND METHODS Tissue samples containing tooth buds were removed from the incisor areas of human fetuses in different stages of development (weeks 9-10, 12-13, 13-16, 21-24), and from the canine and molar areas of 21-24 weeks fetuses. The tissue fragments were fixed using formalin and were processed using common histological techniques with paraffin embedding. Immunostaining for Ki67, p53 and CD34 has been performed using the dextran method and moist heat antigen retrieval (except for CD34). The resulting slides were photographed and quantitatively evaluated. RESULTS Ki67 immunoexpression decreases with advancement of the developmental stage of the tooth bud: in the inner enamel epithelium, between weeks 9 and 16 (IEE), in the preameloblasts (PB) between weeks 13 and 16, in the ameloblasts (AB) between weeks 21 and 24; outer enamel epithelium (OEE); stratum intermedium (SI); in the dental papilla: between weeks 9 and 10 in the dental papilla (DP), between weeks 13 and 16 in the outer layer of the dental papilla (DP1) and in the central layer of the dental papilla (DP2). Likewise, we noted Ki67 expression in the odontoblast layer (O) and pulp (P), between weeks 21 and 24. Concerning CD34 expression, we observed a decrease from weeks 9-10 until weeks 13-16, followed by an increase until weeks 21-24 of intrauterine life. From weeks 9-10, we observed a constant decrease of expression until weeks 13-16, followed by an increase during weeks 21-24. CONCLUSIONS All Ki67, p53 and CD34 have been identified in the tooth bud. Ki67 expression gradually decreases with the embryonic development of the tooth, while p53 and CD34 expression decreases from weeks 9-10 to weeks 13-16 of intrauterine life, followed by an increase until weeks 21-24.
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28
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Wang SK, Samann AC, Hu JCC, Simmer JP. FAM20C functions intracellularly within both ameloblasts and odontoblasts in vivo. J Bone Miner Res 2013; 28:2508-11. [PMID: 23703840 PMCID: PMC3836880 DOI: 10.1002/jbmr.1990] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 05/07/2013] [Accepted: 05/10/2013] [Indexed: 12/21/2022]
Abstract
FAM20C, also known as Golgi casein kinase (G-CK), is proposed to be the archetype for a family of secreted kinases that phosphorylate target proteins in the Golgi and in extracellular matrices, but FAM20C serving an extracellular function is controversial. FAM20C phosphorylates secretory calcium-binding phosphoproteins (SCPPs), which are associated with the evolution of biomineralization in vertebrates. Current models of biomineralization assume SCPP proteins are secreted as phosphoproteins and their phosphates are essential for protein conformation and function. It would be a radical departure from current theories if proteins in mineralizing matrices were dephosphorylated as part of the mineralization mechanism and rephosphorylated in the extracellular milieu by FAM20C using ATP. To see if such mechanisms are possible in the formation of dental enamel, we tested the hypothesis that FAM20C is secreted by ameloblasts and accumulates in the enamel extracellular matrix during tooth development. FAM20C localization was determined by immunohistochemistry in day 5 mouse incisors and molars and by Western blot analyses of proteins extracted from pig enamel organ epithelia (EOE) and enamel shavings. FAM20C localized intracellularly within ameloblasts and odontoblasts in a pattern consistent with Golgi localization. Western blots detected FAM20C in the EOE extracts but not in the enamel matrix. We conclude that FAM20C is not a constituent of the enamel extracellular matrix and functions intracellularly within ameloblasts.
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Affiliation(s)
- Shih-Kai Wang
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, 48108 USA
| | - Andrew C. Samann
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, 48108 USA
| | - Jan C-C. Hu
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, 48108 USA
| | - James P. Simmer
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, 48108 USA
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29
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Yue SC, Bai YX, Yang Y, Li LX. [Effect of orthodontic force on expression of Asporin after tooth auto-transplantation: an experimental study in Beagle dogs]. Zhonghua Kou Qiang Yi Xue Za Zhi 2013; 48:745-749. [PMID: 24495726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
OBJECTIVE To evaluate the effect of orthodontic light force on the expression of Asporin, bone morphogenetic proteins-2 (BMP-2) and alkaline phosphatase (ALP) after auto-transplantation. METHODS Thirty-two maxillary and mandibular incisors in four 13 month-old male Beagle dogs were auto-transplanted to the other side of the same jaw. The teeth were all endodontically treated and divided into four groups, control (group 1) and three experimental groups (groups 2, 3 and 4).In control group, the teeth were unloaded. In the other three experimental groups, continuous force was applied in the 1st week (group 2), 2nd week (group 3) and 4th week (group 4) after auto-transplantation, respectively. The dogs were sacrificed in the 8th week. The mRNA expressions of Asporin,BMP-2 and ALP were examined by real time PCR. The expression of periodontal ligament associated protein-1 (PLAP-1) was examined by Western blotting. The data were statistically analyzed using SPSS 17.0 and one-way analysis of variance (ANOVA). RESULTS In group 3, the expression of Asporin mRNA (2.047 ± 0.281) was higher than that in the other three groups, while the expression of BMP-2 (1.358 ± 0.095) was lower than that in group 2 and control group (P < 0.05). The expression of PLAP-1 (1.054 ± 0.113) in group 3 was higher than other groups, while significant difference was found between any two groups. CONCLUSIONS Orthodontic force could stimulate the expression of Asporin and PLAP-1. The orthodontic force applied in the 2nd week after the tooth auto-transplantation, the expression of Asporin and PLAP-1 reached the highest level.
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Affiliation(s)
- Shi-chao Yue
- Department of Orthodontics, Capital Medical University School of Stomatology, Beijing 100050, China
| | - Yu-xing Bai
- Department of Orthodontics, Capital Medical University School of Stomatology, Beijing 100050, China.
| | - Yun Yang
- Department of Orthodontics, Capital Medical University School of Stomatology, Beijing 100050, China
| | - Li-xuan Li
- Department of Orthodontics, Capital Medical University School of Stomatology, Beijing 100050, China
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30
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Cao H, Jheon A, Li X, Sun Z, Wang J, Florez S, Zhang Z, McManus MT, Klein OD, Amendt BA. The Pitx2:miR-200c/141:noggin pathway regulates Bmp signaling and ameloblast differentiation. Development 2013; 140:3348-59. [PMID: 23863486 PMCID: PMC3737717 DOI: 10.1242/dev.089193] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/10/2013] [Indexed: 02/06/2023]
Abstract
The mouse incisor is a remarkable tooth that grows throughout the animal's lifetime. This continuous renewal is fueled by adult epithelial stem cells that give rise to ameloblasts, which generate enamel, and little is known about the function of microRNAs in this process. Here, we describe the role of a novel Pitx2:miR-200c/141:noggin regulatory pathway in dental epithelial cell differentiation. miR-200c repressed noggin, an antagonist of Bmp signaling. Pitx2 expression caused an upregulation of miR-200c and chromatin immunoprecipitation assays revealed endogenous Pitx2 binding to the miR-200c/141 promoter. A positive-feedback loop was discovered between miR-200c and Bmp signaling. miR-200c/141 induced expression of E-cadherin and the dental epithelial cell differentiation marker amelogenin. In addition, miR-203 expression was activated by endogenous Pitx2 and targeted the Bmp antagonist Bmper to further regulate Bmp signaling. miR-200c/141 knockout mice showed defects in enamel formation, with decreased E-cadherin and amelogenin expression and increased noggin expression. Our in vivo and in vitro studies reveal a multistep transcriptional program involving the Pitx2:miR-200c/141:noggin regulatory pathway that is important in epithelial cell differentiation and tooth development.
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Affiliation(s)
- Huojun Cao
- Department of Anatomy and Cell Biology, The University of Iowa, Iowa City, IA 52242, USA
| | - Andrew Jheon
- Department of Orofacial Sciences and Program in Craniofacial and Mesenchymal Biology, UCSF, San Francisco, CA 94143-0442, USA
| | - Xiao Li
- Department of Anatomy and Cell Biology, The University of Iowa, Iowa City, IA 52242, USA
| | - Zhao Sun
- Department of Anatomy and Cell Biology, The University of Iowa, Iowa City, IA 52242, USA
| | - Jianbo Wang
- Department of Anatomy and Cell Biology, The University of Iowa, Iowa City, IA 52242, USA
| | - Sergio Florez
- Department of Anatomy and Cell Biology, The University of Iowa, Iowa City, IA 52242, USA
| | - Zichao Zhang
- Department of Anatomy and Cell Biology, The University of Iowa, Iowa City, IA 52242, USA
| | - Michael T. McManus
- Department of Microbiology and Immunology and Diabetes Center, UCSF, San Francisco, CA 94143-0442, USA
| | - Ophir D. Klein
- Department of Orofacial Sciences and Program in Craniofacial and Mesenchymal Biology, UCSF, San Francisco, CA 94143-0442, USA
- Department of Pediatrics and Institute for Human Genetics, UCSF, San Francisco, CA 94143-0442, USA
| | - Brad A. Amendt
- Department of Anatomy and Cell Biology, The University of Iowa, Iowa City, IA 52242, USA
- Craniofacial Anomalies Research Center, University of Iowa, Iowa City, IA 52242, USA
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Włodarski KH, Szczęsny G, Kuzaka B, Włodarski PK. Long-term preservation of Bone Morphogenetic Activity in stored demineralized murine incisors. Pol Orthop Traumatol 2013; 78:97-100. [PMID: 23563912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Demineralized bone or dentine implanted intramuscularly induce endochondral bone formation. This phenomenon, termed "bone induction" is triggered by non-collagenous signal molecules, named "Bone Morphogenetic Proteins" (BMPs), released from bone or dentine. Demineralization of bone/dentine prior their implantation facilitates the release of BMPs from the extracellular matrix allowing to reach a BMP threshold level needed to initiate the process of differentiation of mesenchymal cells towards an osteogenic/chondrogenic lineage. Unprocessed, mineralized tissues usually fail to induce cartilage/bone. Isolated BMPs are commercially available, and in clinical practice are an alternative for demineralized tissues, however, in many cases demineralized bone has advantages over soluble BMPs, as it combines both bone inducing principles and mechanical properties, a feature important for bridging bone fracture and filling bone defects. Demineralized bones are an inexpensive source of bone forming agents for bone-fracture healing or filling bone defects. In this report we demonstrated that storage of lyophilized demineralized murine incisors for 30 months does not deteriorate its osteoinductive potency and colonizing induced bone by bone marrow. Lyophylized incisors, stored for 0-30 months at refrigator were implanted intramuscularly and recovered, together with surrounding tissues at various time intervals ranging 10-450 days. Bone closely associated with implant was observed in about 87% of cases, regardless the storage duration. It is concluded that storage of demineralized and lyophilized incisor matrices for at least 30 months does not change their osteoinductive potency.
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Affiliation(s)
- Krzysztof H Włodarski
- Department of Histology and Embryology, Medical University of Warsaw, Warsaw, Poland.
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Jumlongras D, Lachke SA, O’Connell DJ, Aboukhalil A, Li X, Choe SE, Ho JWK, Turbe-Doan A, Robertson EA, Olsen BR, Bulyk ML, Amendt BA, Maas RL. An evolutionarily conserved enhancer regulates Bmp4 expression in developing incisor and limb bud. PLoS One 2012; 7:e38568. [PMID: 22701669 PMCID: PMC3373496 DOI: 10.1371/journal.pone.0038568] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 05/07/2012] [Indexed: 12/02/2022] Open
Abstract
To elucidate the transcriptional regulation of Bmp4 expression during organogenesis, we used phylogenetic footprinting and transgenic reporter analyses to identify Bmp4 cis-regulatory modules (CRMs). These analyses identified a regulatory region located ∼46 kb upstream of the mouse Bmp4 transcription start site that had previously been shown to direct expression in lateral plate mesoderm. We refined this regulatory region to a 396-bp minimal enhancer, and show that it recapitulates features of endogenous Bmp4 expression in developing mandibular arch ectoderm and incisor epithelium during the initiation-stage of tooth development. In addition, this enhancer directs expression in the apical ectodermal ridge (AER) of the developing limb and in anterior and posterior limb mesenchyme. Transcript profiling of E11.5 mouse incisor dental lamina, together with protein binding microarray (PBM) analyses, allowed identification of a conserved DNA binding motif in the Bmp4 enhancer for Pitx homeoproteins, which are also expressed in the developing mandibular and incisor epithelium. In vitro electrophoretic mobility shift assays (EMSA) and in vivo transgenic reporter mutational analyses revealed that this site supports Pitx binding and that the site is necessary to recapitulate aspects of endogenous Bmp4 expression in developing craniofacial and limb tissues. Finally, Pitx2 chromatin immunoprecipitation (ChIP) demonstrated direct binding of Pitx2 to this Bmp4 enhancer site in a dental epithelial cell line. These results establish a direct molecular regulatory link between Pitx family members and Bmp4 gene expression in developing incisor epithelium.
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Affiliation(s)
- Dolrudee Jumlongras
- Division of Genetics, Department of Medicine, Harvard Medical School, Brigham and Women’s Hospital, Boston Massachusetts, United States of America
- Department of Developmental Biology, Harvard School of Dental Medicine, Boston, Massachusetts, United States of America
| | - Salil A. Lachke
- Department of Biological Sciences, Center for Bioinformatics and Computational Biology, University of Delaware, Newark, Delaware, United States of America
| | - Daniel J. O’Connell
- Division of Genetics, Department of Medicine, Harvard Medical School, Brigham and Women’s Hospital, Boston Massachusetts, United States of America
| | - Anton Aboukhalil
- Division of Genetics, Department of Medicine, Harvard Medical School, Brigham and Women’s Hospital, Boston Massachusetts, United States of America
- Department of Aeronautics and Astronautics, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts, United States of America
| | - Xiao Li
- Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas, United States of America
| | - Sung E. Choe
- Division of Genetics, Department of Medicine, Harvard Medical School, Brigham and Women’s Hospital, Boston Massachusetts, United States of America
| | - Joshua W. K. Ho
- Division of Genetics, Department of Medicine, Harvard Medical School, Brigham and Women’s Hospital, Boston Massachusetts, United States of America
- Center for Biomedical Informatics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Annick Turbe-Doan
- Division of Genetics, Department of Medicine, Harvard Medical School, Brigham and Women’s Hospital, Boston Massachusetts, United States of America
| | - Erin A. Robertson
- Division of Genetics, Department of Medicine, Harvard Medical School, Brigham and Women’s Hospital, Boston Massachusetts, United States of America
| | - Bjorn R. Olsen
- Department of Developmental Biology, Harvard School of Dental Medicine, Boston, Massachusetts, United States of America
| | - Martha L. Bulyk
- Division of Genetics, Department of Medicine, Harvard Medical School, Brigham and Women’s Hospital, Boston Massachusetts, United States of America
- Department of Pathology, Harvard Medical School, Brigham and Women’s Hospital, Boston, Massachusetts, United States of America
- Harvard-MIT Division of Health Sciences and Technology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Brad A. Amendt
- Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas, United States of America
| | - Richard L. Maas
- Division of Genetics, Department of Medicine, Harvard Medical School, Brigham and Women’s Hospital, Boston Massachusetts, United States of America
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Moe K, Shrestha A, Kvinnsland IH, Luukko K, Kettunen P. Developmentally regulated expression of Sema3A chemorepellant in the developing mouse incisor. Acta Odontol Scand 2012; 70:184-9. [PMID: 21793640 DOI: 10.3109/00016357.2011.600717] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE Semaphorin 3A (Sema3A) is an essential chemorepellant controlling peripheral axon pathfinding and patterning, but also serves non-neuronal cellular functions. Incisors of rodent are distinctive from molars as they erupt continuously, have only one root and enamel is present only on the labial side. The aim of this study is to address putative regulatory roles of Sema3A chemorepellant in the development of incisor innervation and formation. MATERIALS AND METHODS This study analyzed expression of Sema3A mRNAs during embryonic and early post-natal stages of mouse mandibular incisor using sectional radioactive in situ hybridization. RESULTS Although Sema3A mRNAs were observed in condensed dental mesenchyme during the early bud stage, they were absent in dental papilla or pulp at later stages. Sema3A mRNAs were observed in the dental epithelium including the cervical loops and a prominent expression was also seen in alveolar bone. Interestingly, transcripts were absent from the mesenchymal dental follicle target area (future periodontal ligament) throughout the studied stages. CONCLUSION The expression patterns of Sema3A indicate that it may control the timing and patterning of the incisor innervation. In particular, Sema3A appears to regulate innervation of the periodontal ligament, while nerve penetration into the incisor dental pulp appears not to be dependent on Sema3A. Moreover, Sema3A may regulate the functions of cervical loops and the development of alveolar bone. Future study with Sema3A deficient mice will help to elucidate the putative neuronal and non-neuronal functions of Sema3A in incisor tooth development.
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Affiliation(s)
- Kyaw Moe
- Department of Biomedicine, University of Bergen, Norway
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Bronckers ALJJ, Lyaruu DM, Bervoets TJ, Medina JF, DenBesten P, Richter J, Everts V. Murine ameloblasts are immunonegative for Tcirg1, the v-H-ATPase subunit essential for the osteoclast plasma proton pump. Bone 2012; 50:901-8. [PMID: 22245629 PMCID: PMC3345336 DOI: 10.1016/j.bone.2011.12.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Revised: 12/23/2011] [Accepted: 12/26/2011] [Indexed: 12/14/2022]
Abstract
Maturation stage ameloblasts of rodents express vacuolar type-H-ATPase in the ruffled border of their plasma membrane in contact with forming dental enamel, similar to osteoclasts that resorb bone. It has been proposed that in ameloblasts this v-H-ATPase acts as proton pump to acidify the enamel space, required to complete enamel mineralization. To examine whether this v-H-ATPase in mouse ameloblasts is a proton pump, we determined whether these cells express the lysosomal, T-cell, immune regulator 1 (Tcirg1, v-H-Atp6v(0)a(3)), which is an essential part of the plasma membrane proton pump that is present in osteoclasts. Mutation of this subunit in Tcirg1 null (or oc/oc) mice leads to severe osteopetrosis. No immunohistochemically detectable Tcirg1 was seen in mouse maturation stage ameloblasts. Strong positive staining in secretory and maturation stage ameloblasts however was found for another subunit of v-H-ATPase, subunit b, brain isoform (v-H-Atp6v(1)b(2)). Mouse osteoclasts and renal tubular epithelium stained strongly for both Tcirg1 and v-H-Atp6v(1)b(2). In Tcirg1 null mice osteoclasts and renal epithelium were negative for Tcirg1 but remained positive for v-H-Atp6v(1)b(2). The bone in these mutant mice was osteopetrotic, tooth eruption was inhibited or delayed, and teeth were often morphologically disfigured. However, enamel formation in these mutant mice was normal, ameloblasts structurally unaffected and the mineral content of enamel similar to that of wild type mice. We concluded that Tcirg1, which is essential for osteoclasts to pump protons into the bone, is not appreciably expressed in maturation stage mouse ameloblasts. Our data suggest that the reported v-H-ATPase in maturation stage ameloblasts is not the typical osteoclast-type plasma membrane associated proton pump which acidifies the extracellular space, but rather a v-H-ATPase potentially involved in intracellular acidification.
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Affiliation(s)
- Antonius L J J Bronckers
- Dept of Oral Cell Biology ACTA, University of Amsterdam and VU University Amsterdam, Research Institute MOVE, Gustav Mahlerlaan 3004, Amsterdam, The Netherlands.
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Abstract
The mouse incisor is a valuable but under-utilized model organ for studying the behavior of adult stem cells. This remarkable tooth grows continuously throughout the animal's lifetime and houses two distinct epithelial stem cell niches called the labial and lingual cervical loop (laCL and liCL, respectively). These stem cells produce progeny that undergo a series of well-defined differentiation events en route to becoming enamel-producing ameloblasts. During this differentiation process, the progeny move out of the stem cell niche and migrate toward the distal tip of the tooth. Although the molecular pathways involved in tooth development are well documented, little is known about the roles of miRNAs in this process. We used microarray technology to compare the expression of miRNAs in three regions of the adult mouse incisor: the laCL, liCL, and ameloblasts. We identified 26 and 35 differentially expressed miRNAs from laCL/liCL and laCL/ameloblast comparisons, respectively. Out of 10 miRNAs selected for validation by qPCR, all transcripts were confirmed to be differentially expressed. In situ hybridization and target prediction analyses further supported the reliability of our microarray results. These studies point to miRNAs that likely play a role in the renewal and differentiation of adult stem cells during stem cell-fueled incisor growth.
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Affiliation(s)
- Andrew H. Jheon
- Program in Craniofacial and Mesenchymal Biology, Department of Orofacial Sciences, University of California San Francisco, San Francisco, United States of America
| | - Chun-Ying Li
- Program in Craniofacial and Mesenchymal Biology, Department of Orofacial Sciences, University of California San Francisco, San Francisco, United States of America
| | - Timothy Wen
- Program in Craniofacial and Mesenchymal Biology, Department of Orofacial Sciences, University of California San Francisco, San Francisco, United States of America
| | - Frederic Michon
- Developmental Biology Program, Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Ophir D. Klein
- Program in Craniofacial and Mesenchymal Biology, Department of Orofacial Sciences, University of California San Francisco, San Francisco, United States of America
- Department of Pediatrics and Institute for Human Genetics, University of California San Francisco, San Francisco, United States of America
- * E-mail:
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Yoshioka H, Yoshiko Y, Minamizaki T, Suzuki S, Koma Y, Nobukiyo A, Sotomaru Y, Suzuki A, Itoh M, Maeda N. Incisor enamel formation is impaired in transgenic rats overexpressing the type III NaPi transporter Slc20a1. Calcif Tissue Int 2011; 89:192-202. [PMID: 21643723 DOI: 10.1007/s00223-011-9506-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2010] [Accepted: 05/11/2011] [Indexed: 12/14/2022]
Abstract
Inorganic phosphate (Pi) is required in many biological processes, including signaling cascades, skeletal development, tooth mineralization, and nucleic acid synthesis. Recently, we showed that Pi transport in osteoblasts, mediated by Slc20a1, a member of the type III sodium-dependent phosphate transporter family, is indispensable for osteoid mineralization in rapidly growing rat bone. In addition, we found that bone mineral density decreased slightly with dysfunction of Pi homeostasis in aged transgenic rats overexpressing mouse Slc20a1 (Slc20a1-Tg). Bone and tooth share certain common molecular features, and thus, we focused on tooth development in Slc20a1-Tg mandibular incisors in order to determine the role of Slc20a1 in tooth mineralization. Around the time of weaning, there were no significant differences in serologic parameters between wild-type and Slc20a1-Tg rats. However, histological analysis showed that Slc20a1-Tg ameloblasts formed clusters in the papillary layer during the maturation stage as early as 4 weeks of age. These pathologies became more severe with age and included the formation of cyst-like or multilayer ameloblast structures, accompanied by a chalky white appearance with abnormal attrition and fracture. Hyperphosphatemia was also observed in aging Slc20a1-Tg rats. Micro-computed tomography and electron probe microanalysis revealed impairments in enamel, such as delayed mineralization and hypomineralization. Our results suggest that enamel formation is sensitive to imbalances in Pit1-mediated cellular function as seen in bone, although these processes are under the control of systemic Pi homeostasis.
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Affiliation(s)
- Hirotaka Yoshioka
- Department of Oral Growth and Developmental Biology, Hiroshima University Graduate School of Biomedical Sciences, Kasumi, Minamiku, Japan
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Abstract
BACKGROUND The enamel layerof kallikrein 4 (Klk4)-null mice has a normal thickness and a decussating pattern of enamel rods, but it contains residual enamel proteins, is less highly mineralized, and fractures in its deepest part just above the dentino-enamel junction (DEJ). The plane of fracture is puzzling because the deepest enamel is deposited earliest and, through the action of the secretory stage enamel protease (Mmp20), is the most mature part of the enamel layer at the time of the onset of Klk4 expression. OBJECTIVES To characterize the planes of fracture in Mmp20- and Klk4-null mice and to localize Klk4 expression in developing teeth. METHODS Klk4- and Mmp20-null mice were sacrificed at 7 weeks and their mandibular incisors were characterized by scanning electron microscopy. Klk4(+/)(lac)(Z) mice were mated with Klk4(+/)(lac)(Z) mice. Offspring were genotyped by polymerase chain reaction. Klk4(+/)(+), Klk4(+/)(lac)(Z), and Klk4(lac)(Z/)(lac)(Z) (null) littermates on postnatal days 5, 8, 11, and 14 were processed for β-galactosidase histochemistry. RESULTS The enamel layer fractures at the DEJ in Mmp20-null mice, and fractures occur in enamel above the DEJ in Klk4-null mice. Klk4 is not expressed by secretory-stage ameloblasts, murine odontoblasts beneath the secretory stage, or maturation-stage ameloblasts. Klk4 is specifically expressed by transition and maturation-stage ameloblasts. CONCLUSIONS The breakage of enamel near the DEJ in Klk4-null mice is not due to a failure of odontoblasts to express Klk4, but it relates to a progressive hypomineralization of enamel with depth.
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Affiliation(s)
- James P. Simmer
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, Mich
| | - Yuanyuan Hu
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, Mich
| | - Amelia S. Richardson
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, Mich
| | - John D. Bartlett
- Department of Cytokine Biology, The Forsyth Institute, Cambridge, Mass., USA
| | - Jan C.-C. Hu
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, Mich
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Zheng L, Papagerakis S, Schnell SD, Hoogerwerf WA, Papagerakis P. Expression of clock proteins in developing tooth. Gene Expr Patterns 2011; 11:202-6. [PMID: 21156215 PMCID: PMC3073654 DOI: 10.1016/j.gep.2010.12.002] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Revised: 11/29/2010] [Accepted: 12/07/2010] [Indexed: 11/16/2022]
Abstract
Morphological and functional changes during ameloblast and odontoblast differentiation suggest that enamel and dentin formation is under circadian control. Circadian rhythms are endogenous self-sustained oscillations with periods of 24h that control diverse physiological and metabolic processes. Mammalian clock genes play a key role in synchronizing circadian functions in many organs. However, close to nothing is known on clock genes expression during tooth development. In this work, we investigated the expression of four clock genes during tooth development. Our results showed that circadian clock genes Bmal1, clock, per1, and per2 mRNAs were detected in teeth by RT-PCR. Immunohistochemistry showed that clock protein expression was first detected in teeth at the bell stage (E17), being expressed in EOE and dental papilla cells. At post-natal day four (PN4), all four clock proteins continued to be expressed in teeth but with different intensities, being strongly expressed within the nucleus of ameloblasts and odontoblasts and down-regulated in dental pulp cells. Interestingly, at PN21 incisor, expression of clock proteins was down-regulated in odontoblasts of the crown-analogue side but expression was persisting in root-analogue side odontoblasts. In contrast, both crown and root odontoblasts were strongly stained for all four clock proteins in first molars at PN21. Within the periodontal ligament (PDL) space, epithelial rests of Malassez (ERM) showed the strongest expression among other PDL cells. Our data suggests that clock genes might be involved in the regulation of ameloblast and odontoblast functions, such as enamel and dentin protein secretion and matrix mineralization.
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Affiliation(s)
- Li Zheng
- Department of Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| | - Silvana Papagerakis
- Department of Otorhinolaryngology, Medical School, University of Michigan, Ann Arbor, MI, USA
| | - Santiago D. Schnell
- Brehm Center for Type 1 Diabetes & Analysis, University of Michigan, Ann Arbor, MI, USA
| | | | - Petros Papagerakis
- Department of Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
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Ahmad M, Iseki H, Abduweli D, Baba O, Tabata MJ, Takano Y. Ultrastructural and histochemical evaluation of appositional mineralization of circumpulpal dentin at the crown- and root-analog portions of rat incisors. J Electron Microsc (Tokyo) 2010; 60:79-87. [PMID: 21030417 DOI: 10.1093/jmicro/dfq075] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Mineralization of circumpulpal dentin has been interpreted in such a way that predentin matrix is abruptly converted to almost fully mineralized dentin at the mineralization front. A group of investigators pointed out the existence of intermediary layer along the mineralization front of rat incisor dentin and claimed that dentin mineralization is a rather transient process. Owing to a paucity of information, however, the entity of transient mineralization of dentin has remained elusive. Here we confirmed the existence of a lightly mineralized layer (LL) along the mineralization front of rat incisor dentin, recognizable by both light and electron microscopy, in routinely processed specimens. LL less than 3 µm thick was shown to be located along the mineralization front of crown-analog dentin and tapered out toward the root analog of the incisor. Electron microscopy revealed that mineral deposition first occurred in the non-collagenous matrix of LL and that mineralization of collagen fibers took place sometime later at the conventional mineralization front. Microscopic appearance of the mineral phase of LL varied considerably depending on the histological processing of ultrathin sections, thus explaining the inconsistent interpretation of dentin mineralization in previous studies. These data suggest that mineralization of circumpulpal dentin in rat incisors proceeds in a stepwise or a transient manner, initiated by crystal deposition in the non-collagenous matrix followed by massive mineral deposition in collagen fibers at the mineralization front. The thickness of LL where only the non-collagenous matrix is mineralized may vary in relation to differences in the local non-collagenous matrix and also the rate of collagen mineralization in the respective portions of circumpulpal dentin.
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Affiliation(s)
- Masud Ahmad
- Section of Biostructural Science, Department of Hard Tissue Engineering, Graduate School of Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
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Bronckers A, Kalogeraki L, Jorna HJN, Wilke M, Bervoets TJ, Lyaruu DM, Zandieh-Doulabi B, Denbesten P, de Jonge H. The cystic fibrosis transmembrane conductance regulator (CFTR) is expressed in maturation stage ameloblasts, odontoblasts and bone cells. Bone 2010; 46:1188-96. [PMID: 20004757 PMCID: PMC2842452 DOI: 10.1016/j.bone.2009.12.002] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2009] [Revised: 11/29/2009] [Accepted: 12/02/2009] [Indexed: 02/05/2023]
Abstract
Patients with cystic fibrosis (CF) have mild defects in dental enamel. The gene mutated in these patients is CFTR, a Cl(-) channel involved in transepithelial salt and water transport and bicarbonate secretion. We tested the hypothesis that Cftr channels are present and operating in the plasma membranes of mouse ameloblasts. Tissue sections of young mouse jaws and fetal human jaws were immunostained with various anti-Cftr antibodies. Specificity of the antibodies was validated in Cftr-deficient murine and human tissues. Immunostaining for Cftr was obtained in the apical plasma membranes of mouse maturation ameloblasts of both incisor and molar tooth germs. A granular intracellular immunostaining of variable intensity was also noted in bone cells and odontoblasts. In Cftr-deficient mice the incisors were chalky white and eroded much faster than in wild type mice. Histologically, only maturation ameloblasts of incisors were structurally affected in Cftr-deficient mice. Some antibody species gave also a positive cytosolic staining in Cftr-deficient cells. Transcripts of Cftr were found in maturation ameloblasts, odontoblasts and bone cells. Similar data were obtained in forming human dentin and bone. We conclude that Cftr protein locates in the apical plasma membranes of mouse maturation ameloblasts. In mouse incisors Cftr is critical for completion of enamel mineralization and conceivably functions as a regulator of pH during rapid crystal growth. Osteopenia found in CF patients as well as in Cftr-deficient mice is likely associated with defective Cftr operating in bone cells.
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Affiliation(s)
- Antonius Bronckers
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam (ACTA), Research Institute MOVE , University of Amsterdam and VU University Amsterdam, The Netherlands.
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Simon S, Smith AJ, Lumley PJ, Berdal A, Smith G, Finney S, Cooper PR. Molecular characterization of young and mature odontoblasts. Bone 2009; 45:693-703. [PMID: 19555781 DOI: 10.1016/j.bone.2009.06.018] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2009] [Revised: 06/02/2009] [Accepted: 06/13/2009] [Indexed: 01/22/2023]
Abstract
UNLABELLED The odontoblast is the secretory cell responsible for primary, secondary and tertiary reactionary dentinogenesis. We provide evidence that the changes in secretory activity of odontoblasts reflect differential transcriptional control and that common regulatory processes may exist between dentine and bone. INTRODUCTION Based on the hypothesis that differential dentine secretion (primary and secondary dentinogenesis) is associated with changes in the transcriptional control within the cell, we have investigated the transcriptome of odontoblasts at young and mature stages and subsequently used this information to identify key regulatory intracellular pathways involved in this process. MATERIALS AND METHODS We used microarray analysis to compare the transcriptome of early stage (primary dentinogenesis) and late stage (secondary dentinogenesis) odontoblasts from 30 month old bovine teeth. Secondarily, we used post-array sqRT-PCR to confirm the differential expression of 23 genes in both populations of odontoblasts. Finally, immunohistochemistry was performed on bovine and murine tissues with antibodies to DMP1 and anti-phospho p38 proteins. RESULTS DMP-1 and osteocalcin gene expression were up-regulated in the mature odontoblasts, whereas collagen I, DSPP, TGF-beta1 and TGF-beta1R gene expression were down-regulated. Microarray analysis highlighted 574 differentially regulated genes (fold change>2 - p<0.05). This study supports further existing similarities between pulp cells and bone cells. Using post-array Sq-RT-PCR we characterized transcript levels of genes involved in the p38 MAP kinase pathway (PTPRR, NTRKK2, MAPK13, MAP2K6, MKK3). Differential p38 gene activation was confirmed by immunohistochemistry for p38 protein in murine teeth. Finally, immunohistochemistry for DMP1 indicated that odontoblasts involved in primary and secondary dentinogenesis may coexist in the same tooth. CONCLUSION As established in bone cells, the transcriptome of the odontoblast was shown here to evolve with their stage and functional maturity. Identification of the involved signalling pathways, as highlighted for p38, will enable the deciphering of physiology and pathology of mineralised tissue formation.
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Affiliation(s)
- S Simon
- INSERM, UMR S 872, Centre de Recherche des Cordeliers, Paris, France.
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Maruyama Y, Harada F, Jabbar S, Saito I, Aita M, Kawano Y, Suzuki A, Nozawa-Inoue K, Maeda T. Neurotrophin-4/5-depletion induces a delay in maturation of the periodontal Ruffini endings in mice. ACTA ACUST UNITED AC 2009; 68:267-88. [PMID: 16477147 DOI: 10.1679/aohc.68.267] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Neurotrophin-4/5 (NT-4/5) - a member of the neurotrophic factors - is a ligand for TrkB, which has been reported to be expressed in the mechanoreceptive Ruffini endings of the periodontal ligament. The present study examined developmental changes in the terminal morphology and neural density in homozygous mice with a targeted disruption of the nt-4/5 gene and wild-type mice by immunohistochemistry for protein gene product 9.5 (PGP 9.5), a general neuronal marker, and by quantitative analysis using an image analyzer. Postnatal development of terminal Schwann cells was also investigated by enzymatic histochemistry for non-specific cholinesterase activity (ChE). Furthermore, the immuno-expression of TrkB and low affinity nerve growth factor receptor (p75-NGFR) was surveyed in the periodontal Ruffini endings as well as trigeminal ganglion. At postnatal 1 week, the lingual periodontal ligament of both types of mice contained PGP 9.5-positive nerve fibers showing a tree-like ramification with axonal swellings in their course. In both types of mice at 2 weeks of age, comparatively thick nerve fibers with a smooth outline increased in number, and frequently ramified to form nerve terminals with dendritic profiles. However, no typical Ruffini endings with irregular outlines observed in the adult wild-type mice were found in the periodontal ligament at this stage. At postnatal 3 weeks, typical Ruffini endings with irregular outlines were discernable in the periodontal ligament of the wild-type mice while the dendritic endings showing smooth outlines were restricted to the homozygous mice. After postnatal 8 weeks, both types of mice showed an increase in the number of Ruffini endings, but the morphology differed between the wild-type and NT-4/5 homozygous mice. In the wild-type mice, a major population of the Ruffini endings expanded their axonal branches and developed many microprojections, resulting in a reduction of endings with smooth outlines. In contrast, we failed to find such typical Ruffini endings in the periodontal ligament of the homozygous mice: A majority of the periodontal Ruffini endings continued to show smooth outlines at postnatal 12 weeks. Quantitative analysis on neural density demonstrated a reduction in the homozygous mice with a significant difference by postnatal 8 weeks. Enzymatic histochemistry for non-specific ChE did not exhibit a distinct difference in the distribution and density of terminal Schwann cells between wild-type and homozygous mice. Furthermore, TrkB and p75-NGFR mRNA and proteins did not differ in the trigeminal ganglion between the two types. The periodontal Ruffini endings also displayed immunoreactivities for TrkB and p75- NGFR in both phenotypes. These findings suggest that the nt-4/5 gene depletion caused a delay in the formation and maturation of the periodontal Ruffini endings in the mice by inhibiting the growth of the periodontal nerves at an early stage, and indicate that multiple neurotrophins such as NT- 4/5 and BDNF might play roles in the development and/or maturation of the periodontal Ruffini endings.
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Affiliation(s)
- Yuko Maruyama
- Divisions of Oral Anatomy, Department of Oral Biological Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
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Abstract
We previously reported expression of a protein by enamel organ (EO) cells in rat incisors, originally isolated from the amyloid of Pindborg odontogenic tumors called Apin. The aim of the present study was to further characterize the Apin gene and its protein in various species, assess tissue specificity, and clarify its localization within the EO. Northern blotting and RT-PCR revealed that expression of Apin was highest in the EO and gingiva, moderate in nasal and salivary glands, and lowest in the epididymis. The protein sequences deduced from the cloned cDNA for rat, mouse, pig, and human were aligned together with those obtained from four other mammal genomes. Apin is highly conserved in mammals but is absent in fish, birds, and amphibians. Comparative SDS-PAGE analyses of the protein obtained from bacteria, transfected cells, and extracted from EOs all indicated that Apin is post-translationally modified, a finding consistent with the presence of predicted sites for phosphorylation and O-linked glycosylation. In rodent incisors, Apin was detected only in the ameloblast layer of the EO, starting at post-secretory transition and extending throughout the maturation stage. Intense labeling was visible over the Golgi region as well as on the apices of ameloblasts abutting the enamel matrix. Apin was also immunodetected in epithelial cells of the gingiva which bind it to the tooth surface (junctional epithelium). The presence of Apin at cell-tooth interfaces suggests involvement in adhesive mechanisms active at these sites, but its presence among other epithelial tissues indicates Apin likely possesses broader physiological roles.
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Affiliation(s)
- Pierre Moffatt
- Genetics Unit, Shriners Hospital for Children, Montréal, Québec, Canada H3G 1A6
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Zhang X, Rahemtulla FG, MacDougall MJ, Thomas HF. Vitamin D receptor deficiency affects dentin maturation in mice. Arch Oral Biol 2007; 52:1172-9. [PMID: 17707333 DOI: 10.1016/j.archoralbio.2007.06.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2007] [Revised: 05/01/2007] [Accepted: 06/20/2007] [Indexed: 10/22/2022]
Abstract
Mutation of vitamin D receptors (vdr) results in resistance to the vitamin's normal effects which may compromise dentin formation. The objective of this study was to investigate the effect of vdr deficiency on post-natal dentin maturation in mice. The dentin in mandibular incisors of 70.5-day-old vdr wild-type and vdr knockout mice was compared at different levels along the long axis. Expression of biglycan and decorin was detected by immunolocalisation. Scanning electron microscopy was used to observe the ultrastructure of the dentin, and micro-computerised tomography was used to determine the degree of dentin mineralisation density. In the vdr knockout mice, the pulp chamber was larger and the dentin wall was thinner compared with the wild-type mice. In addition, the pre-dentin layer was thickened with an irregular front line and diffuse expression of biglycan and decorin. Fewer tubules, lower mineralisation density and pore-like defects were observed in the dentin at the eruptive region and level with the first molar. In conclusion, vdr deficiency compromises dentin maturation.
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Affiliation(s)
- Xueming Zhang
- Department of Prosthodontics, School of Dentistry, University of Alabama at Birmingham, USA.
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Bennett CN, Ouyang H, Ma YL, Zeng Q, Gerin I, Sousa KM, Lane TF, Krishnan V, Hankenson KD, MacDougald OA. Wnt10b increases postnatal bone formation by enhancing osteoblast differentiation. J Bone Miner Res 2007; 22:1924-32. [PMID: 17708715 DOI: 10.1359/jbmr.070810] [Citation(s) in RCA: 208] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
UNLABELLED Overexpression of Wnt10b from the osteocalcin promoter in transgenic mice increases postnatal bone mass. Increases in osteoblast perimeter, mineralizing surface, and bone formation rate without detectable changes in pre-osteoblast proliferation, osteoblast apoptosis, or osteoclast number and activity suggest that, in this animal model, Wnt10b primarily increases bone mass by stimulating osteoblastogenesis. INTRODUCTION Wnt signaling regulates many aspects of development including postnatal accrual of bone. Potential mechanisms for how Wnt signaling increases bone mass include regulation of osteoblast and/or osteoclast number and activity. To help differentiate between these possibilities, we studied mice in which Wnt10b is expressed specifically in osteoblast lineage cells or in mice devoid of Wnt10b. MATERIALS AND METHODS Transgenic mice, in which mouse Wnt10b is expressed from the human osteocalcin promoter (Oc-Wnt10b), were generated in C57BL/6 mice. Transgene expression was evaluated by RNase protection assay. Quantitative assessment of bone variables was done by radiography, muCT, and static and dynamic histomorphometry. Mechanisms of bone homeostasis were evaluated with assays for BrdU, TUNEL, and TRACP5b activity, as well as serum levels of C-terminal telopeptide of type I collagen (CTX). The endogenous role of Wnt10b in bone was assessed by dynamic histomorphometry in Wnt10b(-/-) mice. RESULTS Oc-Wnt10b mice have increased mandibular bone and impaired eruption of incisors during postnatal development. Analyses of femoral distal metaphyses show significantly higher BMD, bone volume fraction, and trabecular number. Increased bone formation is caused by increases in number of osteoblasts per bone surface, rate of mineral apposition, and percent mineralizing surface. Although number of osteoclasts per bone surface is not altered, Oc-Wnt10b mice have increased total osteoclast activity because of higher bone mass. In Wnt10b(-/-) mice, changes in mineralizing variables and osteoblast perimeter in femoral distal metaphyses were not observed; however, bone formation rate is reduced because of decreased total bone volume and trabecular number. CONCLUSIONS High bone mass in Oc-Wnt10b mice is primarily caused by increased osteoblastogenesis, with a minor contribution from elevated mineralizing activity of osteoblasts.
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Affiliation(s)
- Christina N Bennett
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, USA
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Muto T, Miyoshi K, Munesue S, Nakada H, Okayama M, Matsuo T, Noma T. Differential expression of syndecan isoforms during mouse incisor amelogenesis. J Med Invest 2007; 54:331-9. [PMID: 17878683 DOI: 10.2152/jmi.54.331] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Syndecans are transmembranous heparan sulfate proteoglycans (HSPGs) with covalently attached glycosaminoglycan side-chains located on the cell surface. The mammalian syndecan family is composed of four types of syndecans (syndecan-1 to -4). Syndecans interact with the intracellular cytoskeleton through the cytoplasmic domains of their core proteins and membrane proteins, extracellular enzymes, growth factors, and matrix components, through their heparan-sulfate chains, to regulate developmental processes.Here, as a first step to assess the possible roles of syndecan proteins in amelogenesis, we examined the expression patterns of all syndecan isoforms in continuously growing mouse incisors, in which we can overview major differentiation stages of amelogenesis at a glance. Understanding the expression domain of each syndecan isoform during specific developmental stages seems useful for investigating their physiological roles in amelogenesis. Immunohistochemical analysis of syndecan core proteins in the lower incisors from postnatal day 1 mice revealed spatially and temporally specific expression patterns, with syndecan-1 expressed in undifferentiated epithelial and mesenchymal cells, and syndecan-2, -3, and -4 in more differentiated cells. These findings suggest that each syndecan isoform functions distinctly during the amelogenesis of the incisors of mice.
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Affiliation(s)
- Taro Muto
- Department of Molecular Biology, The University of Tokushima Graduate School, Tokushima, Japan
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Amen M, Liu X, Vadlamudi U, Elizondo G, Diamond E, Engelhardt JF, Amendt BA. PITX2 and beta-catenin interactions regulate Lef-1 isoform expression. Mol Cell Biol 2007; 27:7560-73. [PMID: 17785445 PMCID: PMC2169058 DOI: 10.1128/mcb.00315-07] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2007] [Revised: 05/09/2007] [Accepted: 08/20/2007] [Indexed: 11/20/2022] Open
Abstract
Lef-1 and PITX2 function in the Wnt signaling pathway by recruiting and interacting with beta-catenin to activate target genes. Chromatin immunoprecipitation (ChIP) assays identified the Lef-1 promoter as a PITX2 downstream target. Transgenic mice expressing LacZ driven by the 2.5-kb LEF-1 promoter demonstrated expression in the tooth epithelium correlated with endogenous Lef-1 FL epithelial expression. PITX2 isoforms regulate the LEF-1 promoter, and beta-catenin synergistically enhanced activation of the LEF-1 promoter in combination with PITX2 and Lef-1 isoforms. PITX2 enhances endogenous expression of the full-length beta-catenin-dependent Lef-1 isoform (Lef-1 FL) while decreasing expression of the N-terminally truncated beta-catenin-independent isoform. Our research revealed a novel interaction between PITX2, Lef-1, and beta-catenin in which the Lef-1 beta-catenin binding domain is dispensable for its interaction with PITX2. PITX2 interacts with two sites within the Lef-1 protein. Furthermore, beta-catenin interacts with the PITX2 homeodomain and Lef-1 interacts with the PITX2 C-terminal tail. Lef-1 and beta-catenin interact simultaneously and independently with PITX2 through two different sites to regulate PITX2 transcriptional activity. These data support a role for PITX2 in cell proliferation, migration, and cell division through differential Lef-1 isoform expression and interactions with Lef-1 and beta-catenin.
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Affiliation(s)
- Melanie Amen
- Texas A&M Health Science Center, Institute of Biosciences and Technology, 2121 W. Holcombe Boulevard, Houston, TX 77030, USA
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Abe K, Miyoshi K, Muto T, Ruspita I, Horiguchi T, Nagata T, Noma T. Establishment and characterization of rat dental epithelial derived ameloblast-lineage clones. J Biosci Bioeng 2007; 103:479-85. [PMID: 17609165 DOI: 10.1263/jbb.103.479] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2007] [Accepted: 02/20/2007] [Indexed: 01/21/2023]
Abstract
Teeth are the hardest tissues covered with enamel produced by ameloblasts. The ameloblast differentiation is controlled by sequential epithelial-mesenchymal interactions during tooth morphogenesis. However, the molecular mechanism of ameloblast differentiation remains unclear. To address this question, we developed an in vitro assay system to evaluate the molecular mechanism of amelogenesis. First, we established dental epithelium-derived clones from 6-day-old rat incisors and established that cells of the clone SRE-G5 were the largest producers of amelogenin mRNA. Next, we analyzed the effects of several chemicals on the amelogenin expression in SRE-G5 cells. Only mitogen-activated protein kinase (MAPK) activators enhanced amelogenin mRNA expression. This finding corresponded to the immunohistochemical data showing the presence of phosphorylated forms of p38, c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK) during ameloblast differentiation. To examine the roles of MAPK signals, we compared the effects of anisomycin and sodium salicylate on the expression of tooth-related differentiation markers. Both anisomycin and sodium salicylate induced amelogenin, Abcg2, and Bmp4 mRNA and down-regulated p75NGFR mRNA. On the other hand, ALP, ectodin, Bmp2 and Fgf8 mRNA were up-regulated only by anisomycin. These results indicate that MAPK signaling functions, at least in part, as the inducer of ameloblast differentiation.
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Affiliation(s)
- Kaori Abe
- Department of Molecular Biology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan
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Murashima-Suginami A, Takahashi K, Kawabata T, Sakata T, Tsukamoto H, Sugai M, Yanagita M, Shimizu A, Sakurai T, Slavkin HC, Bessho K. Rudiment incisors survive and erupt as supernumerary teeth as a result of USAG-1 abrogation. Biochem Biophys Res Commun 2007; 359:549-55. [PMID: 17555714 DOI: 10.1016/j.bbrc.2007.05.148] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2007] [Accepted: 05/21/2007] [Indexed: 11/21/2022]
Abstract
The term "supernumerary teeth" describes production of more than the normal number of teeth in the primary or permanent dentitions. Their aetiology is not understood. Uterine sensitization associated gene-1 (USAG-1) is a BMP antagonist that plays important roles in the local regulation of BMP signaling by binding and neutralizing BMP activities, and also serves as a modulator of Wnt signaling. We report here that USAG-1 deficient mice have supernumerary teeth. The supernumerary maxillary incisor appears to form as a result of the successive development of the rudimentary upper incisor tooth. We confirmed that the USAG-1 expression is localized to the epithelium and mesenchyme of the rudimentary maxillary incisor tooth organ formation. USAG-1 abrogation rescued apoptotic elimination of odontogenic mesenchymal cells. Based upon these results, we conclude that USAG-1 controls the number of teeth in the maxillary incisor region by regulating apoptosis.
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Affiliation(s)
- Akiko Murashima-Suginami
- Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
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Liu H, Wang Q, Zhu F, Luo PP, Liu TL, Wei XL. [Effect of fluorosis on the expression of basic fibroblast growth factor in rat incisors]. Zhonghua Kou Qiang Yi Xue Za Zhi 2007; 42:242-4. [PMID: 17683676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
OBJECTIVE To investigate the effects of overdose fluoride on the expression of basic fibroblast growth factor (bFGF) in rat incisors. METHODS Twenty Wistar rats were randomly divided into 2 groups: group I (control group) distilled water was given; group II (experimental group) 100 mg/L NaF was given. The rats were killed at the end of 8 th week. Immunohistochemical staining was used to study the expression of bFGF in rat incisors. RESULTS Immunohistochemical results demonstrated the presence of bFGF in ameloblasts, odontoblasts of rat incisors. The expression of bFGF was reduced in group II (P < 0.01). CONCLUSIONS Overdose fluoride inhibits the expression of bFGF and affects the interaction between dental epithelium and dental mesenchyme, which leads to the enamel demineralization.
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Affiliation(s)
- Hui Liu
- Department of Cariology and Endodontology, School of Stomatology, Tongji University, Shanghai 200072, China
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