1
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Srot V, Houari S, Kapun G, Bussmann B, Predel F, Pokorny B, Bužan E, Salzberger U, Fenk B, Kelsch M, van Aken PA. Ingenious Architecture and Coloration Generation in Enamel of Rodent Teeth. ACS NANO 2024; 18:11270-11283. [PMID: 38629732 PMCID: PMC11064225 DOI: 10.1021/acsnano.4c00578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Revised: 03/13/2024] [Accepted: 03/19/2024] [Indexed: 05/01/2024]
Abstract
Teeth exemplify architectures comprising an interplay of inorganic and organic constituents, resulting in sophisticated natural composites. Rodents (Rodentia) showcase extraordinary adaptations, with their continuously growing incisors surpassing human teeth in functional and structural optimizations. In this study, employing state-of-the-art direct atomic-scale imaging and nanoscale spectroscopies, we present compelling evidence that the release of material from ameloblasts and the subsequent formation of iron-rich enamel and surface layers in the constantly growing incisors of rodents are complex orchestrated processes, intricately regulated and independent of environmental factors. The synergistic fusion of three-dimensional tomography and imaging techniques of etched rodent́s enamel unveils a direct correlation between the presence of pockets infused with ferrihydrite-like material and the acid resistant properties exhibited by the iron-rich enamel, fortifying it as an efficient protective shield. Moreover, observations using optical microscopy shed light on the role of iron-rich enamel as a microstructural element that acts as a path for color transmission, although the native color remains indistinguishable from that of regular enamel, challenging the prevailing paradigms. The redefinition of "pigmented enamel" to encompass ferrihydrite-like infusion in rodent incisors reshapes our perception of incisor microstructure and color generation. The functional significance of acid-resistant iron-rich enamel and the understanding of the underlying coloration mechanism in rodent incisors have far-reaching implications for human health, development of potentially groundbreaking dental materials, and restorative dentistry. These findings enable the creation of an entirely different class of dental biomaterials with enhanced properties, inspired by the ingenious designs found in nature.
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Affiliation(s)
- Vesna Srot
- Max
Planck Institute for Solid State Research, Stuttgart 70569, Germany
| | - Sophia Houari
- Unité
de Formation et de Recherche d’Odontologie, Université Paris Cité, Paris 75006, France
- UR2496,
Biomedical Research in Odontology, Université
Paris Cité, Montrouge 92120, France
| | - Gregor Kapun
- National
Institute of Chemistry, Ljubljana 1000, Slovenia
- Centre
of Excellence on Nanoscience and Nanotechnology−Nanocenter, Ljubljana 1000, Slovenia
| | - Birgit Bussmann
- Max
Planck Institute for Solid State Research, Stuttgart 70569, Germany
| | - Felicitas Predel
- Max
Planck Institute for Solid State Research, Stuttgart 70569, Germany
| | - Boštjan Pokorny
- Faculty
of Environmental Protection, Velenje 3320, Slovenia
- Slovenian
Forestry Institute, Ljubljana 1000, Slovenia
| | - Elena Bužan
- Faculty
of Environmental Protection, Velenje 3320, Slovenia
- Faculty
of Mathematics, Natural Sciences and Information Technologies, University of Primorska, Koper 6000, Slovenia
| | - Ute Salzberger
- Max
Planck Institute for Solid State Research, Stuttgart 70569, Germany
| | - Bernhard Fenk
- Max
Planck Institute for Solid State Research, Stuttgart 70569, Germany
| | - Marion Kelsch
- Max
Planck Institute for Solid State Research, Stuttgart 70569, Germany
| | - Peter A. van Aken
- Max
Planck Institute for Solid State Research, Stuttgart 70569, Germany
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2
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Marsico C, Grimm JR, Renteria C, Guillen DP, Tang K, Nikitin V, Arola DD. Characterizing the microstructures of mammalian enamel by synchrotron phase contrast microCT. Acta Biomater 2024; 178:208-220. [PMID: 38428512 DOI: 10.1016/j.actbio.2024.02.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 02/08/2024] [Accepted: 02/23/2024] [Indexed: 03/03/2024]
Abstract
The enamel of mammalian teeth is a highly mineralized tissue that must endure a lifetime of cyclic contact and is inspiring the development of next-generation engineering materials. Attempts to implement enamel-inspired structures in synthetic materials have had limited success, largely due to the absence of a detailed understanding of its microstructure. The present work used synchrotron phase-contrast microCT imaging to evaluate the three-dimensional microstructure of enamel from four mammals including Lion, Gray Wolf, Snow Leopard, and Black Bear. Quantitative results of image analysis revealed that the decussation pattern of enamel consists of discrete diazone (D) and parazone (P) bands of rods organized with stacking arrangement of D+/P/D-/P in all mammals evaluated; the D+ and D- refer to distinct diazone bands with juxtaposed rod orientations from the reference plane. Furthermore, the rod orientations in the bands can be described in terms of two principal angles, defined here as the pitch and yaw. While the pitch angle increases from the outer enamel to a maximum (up to ≈ 40°) near the dentin enamel junction, minimal spatial variations are observed in yaw across the enamel thickness. There are clear differences in the decussation parameters of enamel across species that are interpreted here with respect to the structural demands placed on their teeth. The rod pitch and band width of enamel are identified as important design parameters and appear to be correlated with the bite force quotient of the four mammals evaluated. STATEMENT OF SIGNIFICANCE: The multi-functionality of tooth enamel requires both hardness and resistance to fracture, properties that are generally mutually exclusive. Ubiquitous to all mammalian teeth, the enamel is expected to have undergone adaptations in microstructure to accommodate the differences in diet, body size and bite force across animals. For the first time, we compare the complex three-dimensional microstructure of enamel from teeth of multiple mammalian species using synchrotron micro-computed tomography. The findings provide new understanding of the "design" of mammalian enamel microstructures, as well as how specific parameters associated with the decussation of rods appear to be engineered to modulate its fracture resistance.
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Affiliation(s)
- C Marsico
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA; Materials Science and Engineering Department, Idaho National Laboratory, Idaho Falls, ID, USA
| | - J R Grimm
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA; Physical and Computational Science Directorate, Pacific Northwest National Laboratory, Richland, WA, USA
| | - C Renteria
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA; Department of Oral Health Sciences, University of Washington, Seattle, WA, USA
| | - D P Guillen
- Materials Science and Engineering Department, Idaho National Laboratory, Idaho Falls, ID, USA
| | - K Tang
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA
| | - V Nikitin
- Department of Chemistry, Argonne National Laboratory, Lemond, IL, USA
| | - D D Arola
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA; Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, WA, USA; Department of Mechanical Engineering, University of Washington, Seattle, WA, USA.
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Gonzalez Lopez M, Huteckova B, Lavicky J, Zezula N, Rakultsev V, Fridrichova V, Tuaima H, Nottmeier C, Petersen J, Kavkova M, Zikmund T, Kaiser J, Lav R, Star H, Bryja V, Henyš P, Vořechovský M, Tucker AS, Harnos J, Buchtova M, Krivanek J. Spatiotemporal monitoring of hard tissue development reveals unknown features of tooth and bone development. SCIENCE ADVANCES 2023; 9:eadi0482. [PMID: 37531427 PMCID: PMC10396306 DOI: 10.1126/sciadv.adi0482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 06/28/2023] [Indexed: 08/04/2023]
Abstract
Mineralized tissues, such as bones or teeth, are essential structures of all vertebrates. They enable rapid movement, protection, and food processing, in addition to providing physiological functions. Although the development, regeneration, and pathogenesis of teeth and bones have been intensely studied, there is currently no tool to accurately follow the dynamics of growth and healing of these vital tissues in space and time. Here, we present the BEE-ST (Bones and tEEth Spatio-Temporal growth monitoring) approach, which allows precise quantification of development, regeneration, remodeling, and healing in any type of calcified tissue across different species. Using mouse teeth as model the turnover rate of continuously growing incisors was quantified, and role of hard/soft diet on molar root growth was shown. Furthermore, the dynamics of bones and teeth growth in lizards, frogs, birds, and zebrafish was uncovered. This approach represents an effective, highly reproducible, and versatile tool that opens up diverse possibilities in developmental biology, bone and tooth healing, tissue engineering, and disease modeling.
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Affiliation(s)
- Marcos Gonzalez Lopez
- Department of Histology and Embryology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Barbora Huteckova
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
- Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Brno, Czech Republic
| | - Josef Lavicky
- Department of Histology and Embryology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Nikodem Zezula
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Vladislav Rakultsev
- Department of Histology and Embryology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Vendula Fridrichova
- Department of Histology and Embryology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Haneen Tuaima
- Department of Histology and Embryology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Cita Nottmeier
- Department of Orthodontics, University of Leipzig Medical Center, Leipzig, Germany
| | - Julian Petersen
- Department of Orthodontics, University of Leipzig Medical Center, Leipzig, Germany
| | - Michaela Kavkova
- Department of Histology and Embryology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
- Central European Institute of Technology, Brno University of Technology, Brno, Czech Republic
| | - Tomas Zikmund
- Central European Institute of Technology, Brno University of Technology, Brno, Czech Republic
| | - Jozef Kaiser
- Central European Institute of Technology, Brno University of Technology, Brno, Czech Republic
| | - Rupali Lav
- Centre for Craniofacial and Regenerative Biology, King’s College London, London, UK
| | - Haza Star
- Centre for Craniofacial and Regenerative Biology, King’s College London, London, UK
| | - Vítězslav Bryja
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Petr Henyš
- Institute of New Technologies and Applied Informatics, Faculty of Mechatronics, Informatics and Interdisciplinary Studies, Technical University of Liberec, Liberec, Czech Republic
| | - Miroslav Vořechovský
- Institute of Structural Mechanics, Faculty of Civil Engineering, Brno University of Technology, Czech Republic
| | - Abigail S. Tucker
- Centre for Craniofacial and Regenerative Biology, King’s College London, London, UK
- Institute of Histology and Embryology, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Jakub Harnos
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Marcela Buchtova
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
- Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Brno, Czech Republic
| | - Jan Krivanek
- Department of Histology and Embryology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
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Shah FA. High-resolution Raman spectroscopy reveals compositional differences between pigmented incisor enamel and unpigmented molar enamel in Rattus norvegicus. Sci Rep 2023; 13:12301. [PMID: 37516744 PMCID: PMC10387050 DOI: 10.1038/s41598-023-38792-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 07/14/2023] [Indexed: 07/31/2023] Open
Abstract
Dental enamel is a peculiar biological tissue devoid of any self-renewal capacity as opposed to bone. Thus, a thorough understanding of enamel composition is essential to develop novel strategies for dental enamel repair. While the mineral found in bone and dental enamel is generally viewed as the biologically-produced equivalent of hydroxy(l)apatite, the formation of these bioapatites is controlled by different organic matrix frameworks-mainly type-I collagen in bone and amelogenin in enamel. In lower vertebrates, such as rodents, two distinct types of enamel are produced. Iron-containing pigmented enamel protects the continuously growing incisor teeth while magnesium-rich unpigmented enamel covers the molar teeth. Using high-resolution Raman spectroscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy, this work explores the differences in acid phosphate (HPO42-), carbonate (CO32-), hydroxyl (OH-), iron, and magnesium content of pigmented incisor enamel and unpigmented molar enamel of Sprague Dawley rats. Bundles of hydroxy(l)apatite nanowires comprise the enamel prisms, where prisms in pigmented enamel are wider and longer than those in unpigmented molars. In contrast to magnesium-rich unpigmented enamel, higher mineral crystallinity, and higher HPO42- and OH- levels are hallmark features of iron-rich pigmented enamel. Furthermore, the apparent absence of iron oxides or oxy(hydroxides) indicates that iron is introduced into the apatite lattice at the expense of calcium, albeit in amounts that do not alter the Raman signatures of the PO43- internal modes. Compositional idiosyncrasies of iron-rich pigmented and nominally iron-free unpigmented enamel offer new insights into enamel biomineralisation supporting the notion that, in rodents, ameloblast function differs significantly between the incisors and the molars.
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Affiliation(s)
- Furqan A Shah
- Department of Biomaterials, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
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5
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Moussa MS, Goldsmith M, Komarova SV. Craniofacial Bones and Teeth in Spacefarers: Systematic Review and Meta-analysis. JDR Clin Trans Res 2023; 8:113-122. [PMID: 35311413 PMCID: PMC10026165 DOI: 10.1177/23800844221084985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
INTRODUCTION Estimating the risk of dental problems in long-duration space missions to the Moon and Mars is critical for avoiding dental emergencies in an environment that does not support proper treatment. Previous risk estimates were constructed based on the experience in short-duration space missions and isolated environments on Earth. However, previous estimates did not account for potential changes in dental structures due to space travel, even though bone loss is a known problem for long-duration spaceflights. The objective of this study was to systematically analyze the changes in hard tissues of the craniofacial complex during spaceflights. METHODS Comprehensive search of Medline, Embase, Scopus, the NASA Technical Report Server, and other sources identified 1,585 potentially relevant studies. After screening, 32 articles that presented quantitative data for skull in humans (6/32) and for calvariae, mandible, and lower incisors in rats (20/32) and mice (6/32) were selected. RESULTS Skull bone mineral density showed a significant increase in spacefaring humans. In spacefaring rodents, calvariae bone volume to tissue volume (BV/TV) demonstrated a trend toward increasing that did not reach statistical significance, while in mandibles, there was a significant decrease in BV/TV. Dentin thickness and incisor volume of rodent incisors were not significantly different between spaceflight and ground controls. DISCUSSION Our study demonstrates significant knowledge gaps regarding many structures of the craniofacial complex such as the maxilla, molar, premolar, and canine teeth, as well as small sample sizes for the studies of mandible and incisors. Understanding the effects of microgravity on craniofacial structures is important for estimating risks during long-duration spaceflight and for formulating proper protocols to prevent dental emergencies. KNOWLEDGE TRANSFER STATEMENT Avoiding dental emergencies in long-duration spaceflights is critical since this environment does not support proper treatment. Prior risk estimates did not account for changes in dental structures due to space travel. We reviewed and synthesized the literature for changes in craniofacial complex associated with spaceflight. The results of our study will help clinicians and scientists to better prepare to mitigate potential oral health issues in space travelers on long-duration missions.
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Affiliation(s)
- M S Moussa
- Faculty of Dental Medicine and Oral Health Sciences, McGill University, Montreal, Quebec, Canada
- Shriners Hospital for Children-Canada, Montreal, Quebec, Canada
| | - M Goldsmith
- Faculty of Dental Medicine and Oral Health Sciences, McGill University, Montreal, Quebec, Canada
- Shriners Hospital for Children-Canada, Montreal, Quebec, Canada
| | - S V Komarova
- Faculty of Dental Medicine and Oral Health Sciences, McGill University, Montreal, Quebec, Canada
- Shriners Hospital for Children-Canada, Montreal, Quebec, Canada
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Kunarti S, Eka Juniarti D, Kartini Sunur Y, Kurnia Ariani M. The different effects of low-level laser therapy before and after overinstrumentation on the expression of substance P and interleukin-10. Saudi Dent J 2023; 35:317-321. [DOI: 10.1016/j.sdentj.2023.03.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 03/25/2023] [Accepted: 03/27/2023] [Indexed: 04/03/2023] Open
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Möhring S, Cieplik F, Hiller KA, Ebensberger H, Ferstl G, Hermens J, Zaparty M, Witzgall R, Mansfeld U, Buchalla W, Scholz KJ. Elemental Compositions of Enamel or Dentin in Human and Bovine Teeth Differ from Murine Teeth. MATERIALS (BASEL, SWITZERLAND) 2023; 16:1514. [PMID: 36837152 PMCID: PMC9965556 DOI: 10.3390/ma16041514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 02/03/2023] [Accepted: 02/08/2023] [Indexed: 06/18/2023]
Abstract
Teeth with different chemical compositions can show vastly different physical properties, so knowledge of elemental composition is required to use animal teeth as substitutes for human teeth in research. In vitro, energy dispersive X-ray spectroscopy (EDX), improved by calibration standards and Si3N4-window material, enables determining local elemental compositions of inorganic and organic compounds without sample destruction. Six human molars, bovine incisors, murine incisors, and murine molars were analyzed. EDX-field scans and line scans were analyzed for elements Ca, P, O, C, N, F, Na, Mg, Fe, Cl, and S. Furthermore, Ca/P- and Ca/N-Ratios were calculated. The presence of iron in murine incisor enamel was investigated using additional wavelength dispersive X-ray spectroscopy measurements (WDX) near the enamel surface. Bovine and human enamel and dentin revealed close similarities regarding elemental composition. The median (25-75% percentiles) of At%Ca was 21.1 (20.8-21.3) in human enamel, 21.0 (20.7-21.2) in bovine enamel, and in murine enamel, 18.3 (17.85-18.88) for molars and 18.35 (18.00-18.75) for incisors. In dentin, murine teeth revealed a higher At%Ca compared to human and bovine teeth. Significant differences between human and bovine teeth were found for nitrogen in dentin, with a median of 4.5 (3.3-5) At%N for human dentin and 2.7 (2.3-3.2) At%N for bovine dentin. The Ca/P-Ratio was the highest in human and bovine enamel, which did not differ significantly. Enamel from murine molars had a higher Ca/P-Ratio than murine incisors and the highest Ca/P-Ratio in dentin was observed for human teeth and murine molars (1.49). WDX revealed iron in the outer 10 µm of pre- and post-eruptive enamel of murine incisors. Pre- and post-eruptive enamel on murine incisors only differed significantly in At%Ca (p = 0.041) and At%P (p = 0.026) with both At% higher in the pre-eruptive enamel. Murine teeth differ significantly from human and bovine teeth in terms of the elemental composition of enamel and dentin.
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Affiliation(s)
- Steffen Möhring
- Department of Conservative Dentistry and Periodontology, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg, Germany
| | - Fabian Cieplik
- Department of Conservative Dentistry and Periodontology, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg, Germany
| | - Karl-Anton Hiller
- Department of Conservative Dentistry and Periodontology, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg, Germany
| | - Helga Ebensberger
- Department of Conservative Dentistry and Periodontology, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg, Germany
| | - Gerlinde Ferstl
- Department of Conservative Dentistry and Periodontology, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg, Germany
| | - Joshua Hermens
- Institute for Molecular and Cellular Anatomy, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Melanie Zaparty
- Institute for Molecular and Cellular Anatomy, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Ralph Witzgall
- Institute for Molecular and Cellular Anatomy, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Ulrich Mansfeld
- Bavarian Polymer Institute (BPI), University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany
| | - Wolfgang Buchalla
- Department of Conservative Dentistry and Periodontology, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg, Germany
| | - Konstantin Johannes Scholz
- Department of Conservative Dentistry and Periodontology, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg, Germany
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Said R, Mortazavi H, Cooper D, Ovens K, McQuillan I, Papagerakis S, Papagerakis P. Deciphering the functions of Stromal Interaction Molecule-1 in amelogenesis using AmelX-iCre mice. Front Physiol 2023; 14:1100714. [PMID: 36935757 PMCID: PMC10014868 DOI: 10.3389/fphys.2023.1100714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 02/17/2023] [Indexed: 03/05/2023] Open
Abstract
Introduction: The intracellular Ca2+ sensor stromal interaction molecule 1 (STIM1) is thought to play a critical role in enamel development, as its mutations cause Amelogenesis Imperfecta (AI). We recently established an ameloblast-specific (AmelX-iCre) Stim1 conditional deletion mouse model to investigate the role of STIM1 in controlling ameloblast function and differentiation in vivo (Stim1 cKO). Our pilot data (Said et al., J. Dent. Res., 2019, 98, 1002-1010) support our hypothesis for a broad role of Stim1 in amelogenesis. This paper aims to provide an in-depth characterization of the enamel phenotype observed in our Stim1 cKO model. Methods: We crossed AmelX-iCre mice with Stim1-floxed animals to develop ameloblast-specific Stim1 cKO mice. Scanning electron microscopy, energy dispersive spectroscopy, and micro- CT were used to study the enamel phenotype. RNAseq and RT-qPCR were utilized to evaluate changes in the gene expression of several key ameloblast genes. Immunohistochemistry was used to detect the amelogenin, matrix metalloprotease 20 and kallikrein 4 proteins in ameloblasts. Results: Stim1 cKO animals exhibited a hypomineralized AI phenotype, with reduced enamel volume, diminished mineral density, and lower calcium content. The mutant enamel phenotype was more severe in older Stim1 cKO mice compared to younger ones and changes in enamel volume and mineral content were more pronounced in incisors compared to molars. Exploratory RNAseq analysis of incisors' ameloblasts suggested that ablation of Stim1 altered the expression levels of several genes encoding enamel matrix proteins which were confirmed by subsequent RT-qPCR. On the other hand, RT-qPCR analysis of molars' ameloblasts showed non-significant differences in the expression levels of enamel matrix genes between control and Stim1-deficient cells. Moreover, gene expression analysis of incisors' and molars' ameloblasts showed that Stim1 ablation caused changes in the expression levels of several genes associated with calcium transport and mitochondrial kinetics. Conclusions: Collectively, these findings suggest that the loss of Stim1 in ameloblasts may impact enamel mineralization and ameloblast gene expression.
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Affiliation(s)
- Raed Said
- College of Dentistry, University of Saskatchewan, Saskatoon, SK, Canada
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Helyasadat Mortazavi
- College of Dentistry, University of Saskatchewan, Saskatoon, SK, Canada
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - David Cooper
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Katie Ovens
- Department of Computer Science, University of Calgary, Calgary, AB, Canada
| | - Ian McQuillan
- Department of Computer Sciences, College of Arts and Sciences, University of Saskatchewan, Saskatoon, SK, Canada
| | - Silvana Papagerakis
- Department of Surgery, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
- Department of Otolaryngology-Head and Neck Surgery, School of Medicine, University of Michigan, Ann Arbor, MI, United States
| | - Petros Papagerakis
- College of Dentistry, University of Saskatchewan, Saskatoon, SK, Canada
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
- *Correspondence: Petros Papagerakis,
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Lancaster PE, Carmichael FA, Clerehugh V, Brettle DS. Emissivity evaluation of human enamel and dentin. Front Physiol 2022; 13:993674. [DOI: 10.3389/fphys.2022.993674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 09/20/2022] [Indexed: 11/13/2022] Open
Abstract
Background: Human enamel and dentin temperatures have been assessed with non-contact infrared imaging devices for safety and diagnostic capacity and require an emissivity parameter to enable absolute temperature measurements. Emissivity is a ratio of thermal energy emitted from an object of interest, compared to a perfect emitter at a given temperature and wavelength, being dependent on tissue composition, structure, and surface texture. Evaluating the emissivity of human enamel and dentin is varied in the literature and warrants review. The primary aim of this study was to evaluate the emissivity of the external and internal surface of human enamel and dentin, free from acquired or developmental defects, against a known reference point. The secondary aim was to assess the emissivity value of natural caries in enamel and dentin.Method: Fourteen whole human molar teeth were paired within a thermally stable chamber at 30°C. Two additional teeth (one sound and one with natural occlusal caries–ICDAS caries score 4 and radiographic score RB4) were sliced and prepared as 1-mm-thick slices and placed on a hot plate at 30°C within the chamber. A 3M Scotch Super 33 + Black Vinyl Electrical Tape was used for the known emissivity reference-point of 0.96. All samples were allowed to reach thermal equilibrium, and a FLIR SC305 infrared camera recorded the warming sequence. Emissivity values were calculated using the Tape reference point and thermal camera software.Results: The external enamel surface mean emissivity value was 0.96 (SD 0.01, 95% CI 0.96–0.97), whereas the internal enamel surface value was 0.97 (SD 0.01, 95% CI 0.96–0.98). The internal crown-dentin mean emissivity value was 0.94 (SD 0.02, 95% CI 0.92–0.95), whereas the internal root-dentin value was 0.93 (SD 0.02, 95% CI 0.91–0.94) and the surface root-dentin had a value of 0.84 (SD 0.04, 95% CI 0.77–0.91). The mean emissivity value of the internal enamel surface with caries was 0.82 (SD 0.05, 95% CI 0.38–1.25), and the value of the internal crown-dentin with caries was 0.73 (SD 0.08, 95% CI 0.54–0.92).Conclusion: The emissivity values of sound enamel, both internal and external, were similar and higher than those of all sound dentin types in this study. Sound dentin emissivity values diminished from the crown to the root and root surface. The lowest emissivity values were recorded in caries lesions of both tissues. This methodology can improve emissivity acquisition for comparison of absolute temperatures between studies which evaluate thermal safety concerns during dental procedures and may offer a caries diagnostic aid.
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Surface and Structural Studies of Age-Related Changes in Dental Enamel: An Animal Model. MATERIALS 2022; 15:ma15113993. [PMID: 35683290 PMCID: PMC9182525 DOI: 10.3390/ma15113993] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 05/26/2022] [Accepted: 06/01/2022] [Indexed: 01/28/2023]
Abstract
In the animal kingdom, continuously erupting incisors provided an attractive model for studying the enamel matrix and mineral composition of teeth during development. Enamel, the hardest mineral tissue in the vertebrates, is a tissue sensitive to external conditions, reflecting various disturbances in its structure. The developing dental enamel was monitored in a series of incisor samples extending the first four weeks of postnatal life in the spiny mouse. The age-dependent changes in enamel surface morphology in the micrometre and nanometre-scale and a qualitative assessment of its mechanical features were examined by applying scanning electron microscopy (SEM) and atomic force microscopy (AFM). At the same time, structural studies using XRD and vibrational spectroscopy made it possible to assess crystallinity and carbonate content in enamel mineral composition. Finally, a model for predicting the maturation based on chemical composition and structural factors was constructed using artificial neural networks (ANNs). The research presented here can extend the existing knowledge by proposing a pattern of enamel development that could be used as a comparative material in environmental, nutritional, and pharmaceutical research.
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11
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Aminu N, Yam MF, Chan SY, Bello I, Umar NM, Nuhu T, Toh SM. The evaluation of healing effect of triclosan and flurbiprofen-loaded nanogels in experimental periodontitis in rats by morphometric analysis. Saudi Dent J 2021; 33:554-559. [PMID: 34803300 PMCID: PMC8589614 DOI: 10.1016/j.sdentj.2020.08.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 08/18/2020] [Accepted: 08/23/2020] [Indexed: 10/24/2022] Open
Abstract
Purpose To evaluate therapeutic effectiveness of antibacterial triclosan (TCS) and anti-inflammatory flurbiprofen (FLB)-loaded nanogels system in ligature-induced experimental periodontitis in rats. Methodology A total of 72 Sprague-Dawley rats were used in this study. Four groups (n = 18 each) were randomly created: Group 1 - neither subjected to experimental periodontitis nor to any treatment; Group 2 - subjected to experimental periodontitis but not treated; Group 3 - subjected to experimental periodontitis and then treated with the developed nanogels; Group 4 - subjected to experimental periodontitis and then placed on a mixture of pure TCS and FLB treatment. The experimental periodontitis was induced on the lower incisors by applying a ligature which was kept for 14 days. Treatment was done for 7 days, and sampling was done at 7, 14, and 28 day of the post-induction experimental period. Morphometric analysis was conducted to assess the clinical outcomes and healing effect. Results The morphometric findings showed that the group treated with the developed TCS and FLB-loaded nanogels recovered better and faster than a mixture of pure TCS and FLB. At 28 day of the experimental period, there was no significant difference (p > 0.05) between the baseline control group and the nanogels treated group. Conclusions The developed TCS and FLB-loaded nanogels was found to be effective in the treatment of experimental periodontitis in rats. The used experimental periodontitis model was found to be simple and easily reproducible.
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Affiliation(s)
- Nafiu Aminu
- Department of Pharmaceutics and Pharmaceutical Microbiology, Faculty of Pharmaceutical Sciences, Usmanu Danfodiyo University, Sokoto, P.M.B. 2346, Sokoto, Nigeria
| | - Mun-Fei Yam
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 USM Penang, Malaysia
| | - Siok-Yee Chan
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 USM Penang, Malaysia
| | - Idris Bello
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 USM Penang, Malaysia
| | - Nura Muhammad Umar
- Department of Pharmaceutics and Pharmaceutical Microbiology, Faculty of Pharmaceutical Sciences, Usmanu Danfodiyo University, Sokoto, P.M.B. 2346, Sokoto, Nigeria.,School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 USM Penang, Malaysia
| | - Tanko Nuhu
- Department of Pharmaceutics and Pharmaceutical Microbiology, Faculty of Pharmaceutical Sciences, Usmanu Danfodiyo University, Sokoto, P.M.B. 2346, Sokoto, Nigeria
| | - Seok-Ming Toh
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 USM Penang, Malaysia
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12
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Manno SHC, Manno FAM, Tian L, Khan MS, Ahmed I, Liu Y, Li VWT, Xu S, Xie F, Hung TF, Ma V, Cho W, Aldape B, Cheng SH, Lau C. Spectroscopic and microscopic examination of teeth exposed to green tea at different temperatures. PLoS One 2020; 15:e0244542. [PMID: 33378409 PMCID: PMC7773275 DOI: 10.1371/journal.pone.0244542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 12/14/2020] [Indexed: 11/18/2022] Open
Abstract
Tea is a popular beverage consumed at different temperatures. The effect of tea on teeth at different temperatures has not been studied previously. The present study used an in vitro green tea immersed tooth model at different tea temperatures (hot and cold) compared to an in vivo tea administration model allowing rats to drink tea over the course of a week. The elements present in tea leaves were identified by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and compared to the elements in teeth (enamel surface) using Laser-Induced Breakdown Spectroscopy (LIBS). Here, LIBS demonstrated in vivo and in vitro green tea treatments resulted in a significant increase in the mineral elements found in enamel. For the in vitro assessment, elements in enamel varied based on cold-tea and hot-tea treatment; however, hot water reduced the elements in enamel. Atomic force microscopy found the in vivo tea group had a higher roughness average (RA) compared with the in vivo water group. Cold tea and hot tea in vitro groups demonstrated lower RA than in vitro water controls. Scanning electron microscopy found hot water induced cracks more than 1.3μm in enamel while cold tea and hot tea promoted the adhering of extrinsic matter to teeth. Overall, teeth treated to high temperature lost the mineral phase leading to demineralization. Our results indicate that green tea protects enamel, but its protective action in dental structures is enhanced at cold temperature.
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Affiliation(s)
- Sinai H. C. Manno
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong SAR, China
- State Key Laboratory of Marine Pollution (SKLMP), City University of Hong Kong, Hong Kong SAR, China
- Department of Physics, City University of Hong Kong, Hong Kong SAR, China
| | - Francis A. M. Manno
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong SAR, China
- Department of Physics, City University of Hong Kong, Hong Kong SAR, China
| | - Li Tian
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong SAR, China
- State Key Laboratory of Marine Pollution (SKLMP), City University of Hong Kong, Hong Kong SAR, China
| | - Muhammad S. Khan
- Department of Physics, City University of Hong Kong, Hong Kong SAR, China
| | - Irfan Ahmed
- Department of Physics, City University of Hong Kong, Hong Kong SAR, China
- Department of Electrical Engineering, Sukkur IBA University, Sukkur, Sindh, Pakistan
| | - Yuanchao Liu
- Department of Physics, City University of Hong Kong, Hong Kong SAR, China
| | - Vincent W. T. Li
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong SAR, China
| | - Shisan Xu
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong SAR, China
| | - Fangjing Xie
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong SAR, China
| | - Tak Fu Hung
- Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Victor Ma
- Department of Clinical Oncology, Queen Elizabeth Hospital, Hong Kong, Hong Kong SAR, China
| | - William Cho
- Department of Clinical Oncology, Queen Elizabeth Hospital, Hong Kong, Hong Kong SAR, China
| | - Beatriz Aldape
- División de Estudios de Posgrado e Investigación, Facultad de Odontología, Portal de la Universidad Nacional Autónoma de México, México, D.F., México
| | - Shuk Han Cheng
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong SAR, China
- State Key Laboratory of Marine Pollution (SKLMP), City University of Hong Kong, Hong Kong SAR, China
- Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Condon Lau
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong SAR, China
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13
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Świetlicka I, Kuc D, Świetlicki M, Arczewska M, Muszyński S, Tomaszewska E, Prószyński A, Gołacki K, Błaszczak J, Cieślak K, Kamiński D, Mielnik-Błaszczak M. Near-Surface Studies of the Changes to the Structure and Mechanical Properties of Human Enamel under the Action of Fluoride Varnish Containing CPP-ACP Compound. Biomolecules 2020; 10:biom10050765. [PMID: 32422985 PMCID: PMC7277937 DOI: 10.3390/biom10050765] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 04/30/2020] [Accepted: 05/11/2020] [Indexed: 12/03/2022] Open
Abstract
Changes to the features of the enamel surface submitted to induced demineralisation and subsequent remineralisation were studied. The in vitro examination was conducted on polished slices of human molar teeth, divided in four groups: the untreated control (n = 20), challenged by a demineralisation with orthophosphoric acid (H3PO4) (n = 20), and challenged by a demineralisation following remineralisation with fluoride (F) varnish containing casein phosphopeptides (CPP) and amorphous calcium phosphate (ACP) compounds (n = 20). The specimens’ enamel surfaces were subjected to analysis of structure, molecular arrangement, mechanical features, chemical composition, and crystalline organization of apatite crystals. Specimens treated with acid showed a significant decrease in crystallinity, calcium, and phosphorus levels as well as mechanical parameters, with an increase in enamel surface roughness and degree of carbonates when compared to the control group. Treatment with fluoride CPP–ACP varnish provided great improvements in enamel arrangement, as the destroyed hydroxyapatite structure was largely rebuilt and the resulting enamel surface was characterised by greater regularity, higher molecular and structural organisation, and a smoother surface compared to the demineralised one. In conclusion, this in vitro study showed that fluoride CPP–ACP varnish, by improving enamel hardness and initiating the deposition of a new crystal layer, can be an effective remineralising agent for the treatment of damaged enamel.
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Affiliation(s)
- Izabela Świetlicka
- Department of Biophysics, Faculty of Environmental Biology, University of Life Sciences in Lublin, 20-950 Lublin, Poland;
- Correspondence: (I.Ś.); (M.A.)
| | - Damian Kuc
- Chair and Department of Paediatric Dentistry, Medical University of Lublin, 20-059 Lublin, Poland; (D.K.); (M.M.-B.)
| | - Michał Świetlicki
- Department of Applied Physics, Faculty of Mechanical Engineering, Lublin University of Technology, 20-618 Lublin, Poland; (M.Ś.); (A.P.)
| | - Marta Arczewska
- Department of Biophysics, Faculty of Environmental Biology, University of Life Sciences in Lublin, 20-950 Lublin, Poland;
- Correspondence: (I.Ś.); (M.A.)
| | - Siemowit Muszyński
- Department of Biophysics, Faculty of Environmental Biology, University of Life Sciences in Lublin, 20-950 Lublin, Poland;
| | - Ewa Tomaszewska
- Department of Animal Physiology, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, 20-950 Lublin, Poland;
| | - Adam Prószyński
- Department of Applied Physics, Faculty of Mechanical Engineering, Lublin University of Technology, 20-618 Lublin, Poland; (M.Ś.); (A.P.)
| | - Krzysztof Gołacki
- Department of Mechanical Engineering and Automatics, Faculty of Production Engineering, University of Life Sciences in Lublin, 20-612 Lublin, Poland;
| | | | - Krystian Cieślak
- Institute of Renewable Energy Engineering, Faculty of Environmental Engineering, Lublin University of Technology, 20-618 Lublin, Poland;
| | - Daniel Kamiński
- Department of Crystallography, Faculty of Chemistry, Maria Curie-Sklodowska University, 20-031 Lublin, Poland;
| | - Maria Mielnik-Błaszczak
- Chair and Department of Paediatric Dentistry, Medical University of Lublin, 20-059 Lublin, Poland; (D.K.); (M.M.-B.)
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Davis KA, Mountain RV, Pickett OR, Den Besten PK, Bidlack FB, Dunn EC. Teeth as Potential New Tools to Measure Early-Life Adversity and Subsequent Mental Health Risk: An Interdisciplinary Review and Conceptual Model. Biol Psychiatry 2020; 87:502-513. [PMID: 31858984 PMCID: PMC7822497 DOI: 10.1016/j.biopsych.2019.09.030] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 09/04/2019] [Accepted: 09/11/2019] [Indexed: 12/18/2022]
Abstract
Early-life adversity affects nearly half of all youths in the United States and is a known risk factor for psychiatric disorders across the life course. One strategy to prevent mental illness may be to target interventions toward children who are exposed to adversity, particularly during sensitive periods when these adversities may have even more enduring effects. However, a major obstacle impeding progress in this area is the lack of tools to reliably and validly measure the existence and timing of early-life adversity. In this review, we summarize empirical work across dentistry, anthropology, and archaeology on human tooth development and discuss how teeth preserve a time-resolved record of our life experiences. Specifically, we articulate how teeth have been examined in these fields as biological fossils in which the history of an individual's early-life experiences is permanently imprinted; this area of research is related to, but distinct from, studies of oral health. We then integrate these insights with knowledge about the role of psychosocial adversity in shaping psychopathology risk to present a working conceptual model, which proposes that teeth may be an understudied yet suggestive new tool to identify individuals at risk for mental health problems following early-life psychosocial stress exposure. We end by presenting a research agenda and discussion of future directions for rigorously testing this possibility and with a call to action for interdisciplinary research to meet the urgent need for new biomarkers of adversity and psychiatric outcomes.
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15
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Świetlicka I, Arczewska M, Muszyński S, Tomaszewska E, Świetlicki M, Kuc D, Mielnik-Błaszczak M, Gołacki K, Cieślak K. Surface analysis of etched enamel modified during the prenatal period. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2019; 222:117271. [PMID: 31226619 DOI: 10.1016/j.saa.2019.117271] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Revised: 05/27/2019] [Accepted: 06/11/2019] [Indexed: 06/09/2023]
Abstract
Structural changes in the enamel surface subjected to induced demineralization and assessment of the influence of prenatal administration of β-hydroxy β-methylbutyrate (HMB) on enamel resistance were investigated. The examination was conducted on five sets of teeth from one-day-old spiny mice (Acomys cahirinus), one from the control and four from the experimental groups. Surface structure, molecular arrangement and crystalline organization of offspring's enamel both before and after etching were studied. Obtained results revealed that the physical and molecular arrangements of enamel were altered after the prenatal supplementation, and significantly affected its final structure and resistance against acid action. The enamel of incisors from the offspring which mothers were supplemented with HMB in a high dose (0.2 g/kgbw) and in the late period of gestation (26th-39th day) showed the highest endurance against acid treatment demonstrating only vestigial changes in their surface structure after acid action. Comparing to the remaining experimental groups, it was characterized by a reduced roughness and fractal dimension, significantly lower degree of demineralization and simultaneous lack of notable differences in the Raman spectra before and after acid etching. The results suggest that an increased enamel resiliency was the effect of a relatively high degree of mineralization and higher organization of the surface.
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Affiliation(s)
- Izabela Świetlicka
- Department of Biophysics, Faculty of Production Engineering, University of Life Sciences in Lublin, Lublin, Poland
| | - Marta Arczewska
- Department of Biophysics, Faculty of Production Engineering, University of Life Sciences in Lublin, Lublin, Poland.
| | - Siemowit Muszyński
- Department of Biophysics, Faculty of Production Engineering, University of Life Sciences in Lublin, Lublin, Poland
| | - Ewa Tomaszewska
- Department of Animal Physiology, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Lublin, Poland
| | - Michał Świetlicki
- Department of Applied Physics, Faculty of Mechanical Engineering, Lublin University of Technology, Lublin, Poland
| | - Damian Kuc
- Department of Paedodontics, Medical University of Lublin, Lublin, Poland
| | | | - Krzysztof Gołacki
- Department of Mechanical Engineering and Automatics, Faculty of Production Engineering, University of Life Sciences in Lublin, Lublin, Poland
| | - Krystian Cieślak
- Institute of Renewable Energy Engineering, Faculty of Environmental Engineering, Lublin University of Technology, Lublin, Poland
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16
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Smith CE, Hu Y, Hu JCC, Simmer JP. Characteristics of the transverse 2D uniserial arrangement of rows of decussating enamel rods in the inner enamel layer of mouse mandibular incisors. J Anat 2019; 235:912-930. [PMID: 31402450 PMCID: PMC6794213 DOI: 10.1111/joa.13053] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/06/2019] [Indexed: 12/16/2022] Open
Abstract
The 2D arrangement of rows of enamel rods with alternating (decussating) tilt angles across the thickness of the inner layer in rat and mouse incisor enamel is well known and assumed to occur in a uniform and repetitive pattern. Some irregularities in the arrangement of rows have been reported, but no detailed investigation of row structure across the entire inner enamel layer currently exists. This investigation was undertaken to determine if the global row pattern in mouse mandibular incisor enamel is predominately regular in nature with only occasional anomalies or if rows of enamel rods have more spatial complexity than previously suspected. The data from this investigation indicate that rows of enamel rods are highly variable in length and have complex transverse arrangements across the width and thickness of the inner enamel layer. The majority of rows are short or medium in length, with 87% having < 100 rods per row. The remaining 13% are long rows (with 100-233 rods per row) that contain 46% of all enamel rods seen in transverse sections. Variable numbers of rows were associated with the lateral, central and mesial regions of the enamel layer. Each region contained different ratios of short, medium and long rows. A variety of relationships was found along the transverse length of rows in each region, including uniform associations of alternating rod tilts between neighboring rows, and instances where two rows having the same rod tilt were paired for variable distances then moved apart to accommodate rows of opposite tilt. Sometimes a row appeared to branch into two rows with the same tilt, or conversely where two rows merged into one row depending upon the mesial-to-lateral direction in which the row was viewed. Some rows showed both pairing and branching/merging along their length. These tended to be among the longest rows identified, and they often crossed the central region with extensions into the lateral and mesial regions. The most frequent row arrangement was a row of petite length nestled at the side of another row having the same rod tilt (30% of all rows). These were termed 'focal stacks' and may relate to the evolution of uniserial rat and mouse incisor enamel from a multilayered ancestor. The mesial and lateral endpoints of rows also showed complex arrangements with the dentinoenamel junction (DEJ), the inner enamel layer itself, and the boundary area to the outer enamel layer. It was concluded that the diversity in row lengths and various spatial arrangements both within and between rows across the transverse plane provides a method to interlock the enamel layer across each region and keep the enamel layer compact relative to the curving DEJ surface. The uniserial pattern for rows in mouse mandibular incisors is not uniform, but diverse and very complex.
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Affiliation(s)
- Charles E Smith
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, USA.,Department of Anatomy & Cell Biology, Faculty of Medicine, McGill University, Montreal, QC, Canada
| | - Yuanyuan Hu
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Jan C-C Hu
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - James P Simmer
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, USA
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17
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Sellers KC, Schmiegelow AB, Holliday CM. The significance of enamel thickness in the teeth of
Alligator mississippiensis
and its diversity among crocodyliforms. J Zool (1987) 2019. [DOI: 10.1111/jzo.12707] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- K. C. Sellers
- Department of Pathology and Anatomical Sciences University of Missouri Columbia MO USA
| | - A. B. Schmiegelow
- School of Dentistry University of Missouri, Kansas City Kansas City MO USA
| | - C. M. Holliday
- Department of Pathology and Anatomical Sciences University of Missouri Columbia MO USA
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18
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Wang SK, Hu Y, Smith CE, Yang J, Zeng C, Kim JW, Hu JCC, Simmer JP. The Enamel Phenotype in Homozygous Fam83h Truncation Mice. Mol Genet Genomic Med 2019; 7:e724. [PMID: 31060110 PMCID: PMC6565571 DOI: 10.1002/mgg3.724] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 03/14/2019] [Accepted: 04/08/2019] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Truncation FAM83H mutations cause human autosomal dominant hypocalcified amelogenesis imperfecta (ADHCAI), an inherited disorder characterized by severe hardness defects in dental enamel. No enamel defects were observed in Fam83h null mice suggesting that Fam83h truncation mice would better replicate human mutations. METHODS We generated and characterized a mouse model (Fam83hTr/Tr ) expressing a truncated FAM83H protein (amino acids 1-296), which recapitulated the ADHCAI-causing human FAM83H p.Tyr297* mutation. RESULTS Day 14 and 7-week Fam83hTr/Tr molars exhibited rough enamel surfaces and slender cusps resulting from hypoplastic enamel defects. The lateral third of the Fam83hTr/Tr incisor enamel layer was thinner, with surface roughness and altered enamel rod orientation, suggesting disturbed enamel matrix secretion. Regular electron density in mandibular incisor enamel indicated normal enamel maturation. Only mildly increased posteruption attrition of Fam83hTr/Tr molar enamel was observed at 7-weeks. Histologically, the Fam83hTr/Tr enamel organ, including ameloblasts, and enamel matrices at sequential stages of amelogenesis exhibited comparable morphology without overt abnormalities, except irregular and less evident ameloblast Tomes' processes in specific areas. CONCLUSIONS Considering Fam83h-/- mice showed no enamel phenotype, while Fam83hTr/Tr (p.Tyr297*) mice displayed obvious enamel malformations, we conclude that FAM83H truncation mutations causing ADHCAI in humans disturb amelogenesis through a neomorphic mechanism, rather than haploinsufficiency.
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Affiliation(s)
- Shih-Kai Wang
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, Michigan
| | - Yuanyuan Hu
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, Michigan
| | - Charles E Smith
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, Michigan.,Department of Anatomy and Cell Biology, McGill University, Quebec, Canada
| | - Jie Yang
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, Michigan
| | - Chunhua Zeng
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, Michigan
| | - Jung-Wook Kim
- Department of Pediatric Dentistry & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Korea
| | - Jan C-C Hu
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, Michigan
| | - James P Simmer
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, Michigan
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19
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Saghiri MA, Asatourian A, Sorenson CM, Sheibani N. Mice dental pulp and periodontal ligament endothelial cells exhibit different proangiogenic properties. Tissue Cell 2017; 50:31-36. [PMID: 29429515 DOI: 10.1016/j.tice.2017.11.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Revised: 11/22/2017] [Accepted: 11/30/2017] [Indexed: 02/06/2023]
Abstract
Dental pulp is a highly vascularized tissue with a high regenerative capacity. This is attributed to its unique blood supply and the presence of progenitor or postnatal dental pulp stem cells. Here we aimed to isolate and compare the angiogenic properties of endothelial cells (EC) prepared from mouse dental pulp and periodontal ligament (PDL). EC were isolated from 4-week-old wild type immorto mice. Mice were sacrificed and after mandible isolation, the molar and incisor teeth and the PDL from molar teeth were dissected. EC were prepared by collagenase digestion of tissues and affinity purification using magnetic beads coated with platelet/endothelial cell adhesion molecule-1 (PECAM-1/CD31) antibody. EC prepared from incisor and molar pulps and PDL were examined for expression of appropriate markers by fluorescence-activated cell sorting (FACS) analysis. The proliferation, migration, and capillary morphogenesis of EC were evaluated. Ex vivo sprouting angiogenesis from various tissues was also compared. Data were analyzed at the level of significance of P<0.05. Pulp EC prepared from incisors proliferated and migrated significantly faster than molar and PDL EC (P<0.05). In addition, molar and PDL EC formed a more extensive capillary network when plated on Matrigel. This is consistent with the lower proliferative and migratory characteristics of these cells compared with incisor EC (P<0.05). However, PDL tissue showed significantly more sprouting area than molar and incisor pulp tissues (P<0.05). Thus, pulp EC from molar and incisor and PDL EC present different proangiogenic properties. Collectively our results suggest that EC from different tooth tissue have unique characteristics related to their target tissue and function.
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Affiliation(s)
- Mohammad Ali Saghiri
- Departments of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; Departments of Biomedical Engineering, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States.
| | - Armen Asatourian
- Sector of Angiogenesis Regenerative Medicine, Dr. H. Afsar Lajevardi Research Cluster, Shiraz, Iran
| | - Christine M Sorenson
- Department of Pediatircs, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States
| | - Nader Sheibani
- Departments of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; Departments of Biomedical Engineering, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States
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20
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Savi FM, Brierly GI, Baldwin J, Theodoropoulos C, Woodruff MA. Comparison of Different Decalcification Methods Using Rat Mandibles as a Model. J Histochem Cytochem 2017; 65:705-722. [PMID: 28958188 DOI: 10.1369/0022155417733708] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Selection of decalcification agents is an essential consideration when processing mineralized tissues because the integrity and immunohistochemical characteristics of the tissues may be affected. Here, we report results obtained from the decalcification of rat mandibles using 10% ethylenediaminetetraacetic acid (EDTA) at room temperature (RT), 10% EDTA at 37C, 5% nitric acid, and 10% formic acid at RT. Decalcification endpoints were determined by microcomputed tomography. Morphological preservation and antigenicity were evaluated by hematoxylin and eosin staining and immunohistochemistry. Decalcification of the anterior and posterior portions of the mandible took 220 and 191 hr in 10% EDTA RT, 102 and 73 hr in 10% EDTA 37C, 13.5 and 4.3 hr in 5% nitric acid, and 140 and 36 hr in 10% formic acid, respectively. Decalcification in 10% EDTA at 37C was accelerated, but 10% EDTA at RT provided optimal results for immunohistochemistry and cellular and structural details. Decalcification using 5% nitric acid was accomplished in the shortest time and exhibited good cellular and architectural morphology, whereas 10% formic acid was suboptimal with respect to tissue and cellular morphology. Despite being the slowest method, EDTA at RT is still the recommended method for decalcifying mineralized tissues; however, if rapid decalcification is needed, 5% nitric acid is the best option, yielding acceptable tissue integrity and speed.
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Affiliation(s)
- Flavia M Savi
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Gary I Brierly
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Jeremy Baldwin
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Christina Theodoropoulos
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Maria A Woodruff
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
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Lacruz RS, Habelitz S, Wright JT, Paine ML. DENTAL ENAMEL FORMATION AND IMPLICATIONS FOR ORAL HEALTH AND DISEASE. Physiol Rev 2017; 97:939-993. [PMID: 28468833 DOI: 10.1152/physrev.00030.2016] [Citation(s) in RCA: 221] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 01/10/2017] [Accepted: 01/10/2017] [Indexed: 12/16/2022] Open
Abstract
Dental enamel is the hardest and most mineralized tissue in extinct and extant vertebrate species and provides maximum durability that allows teeth to function as weapons and/or tools as well as for food processing. Enamel development and mineralization is an intricate process tightly regulated by cells of the enamel organ called ameloblasts. These heavily polarized cells form a monolayer around the developing enamel tissue and move as a single forming front in specified directions as they lay down a proteinaceous matrix that serves as a template for crystal growth. Ameloblasts maintain intercellular connections creating a semi-permeable barrier that at one end (basal/proximal) receives nutrients and ions from blood vessels, and at the opposite end (secretory/apical/distal) forms extracellular crystals within specified pH conditions. In this unique environment, ameloblasts orchestrate crystal growth via multiple cellular activities including modulating the transport of minerals and ions, pH regulation, proteolysis, and endocytosis. In many vertebrates, the bulk of the enamel tissue volume is first formed and subsequently mineralized by these same cells as they retransform their morphology and function. Cell death by apoptosis and regression are the fates of many ameloblasts following enamel maturation, and what cells remain of the enamel organ are shed during tooth eruption, or are incorporated into the tooth's epithelial attachment to the oral gingiva. In this review, we examine key aspects of dental enamel formation, from its developmental genesis to the ever-increasing wealth of data on the mechanisms mediating ionic transport, as well as the clinical outcomes resulting from abnormal ameloblast function.
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Affiliation(s)
- Rodrigo S Lacruz
- Department of Basic Science and Craniofacial Biology, College of Dentistry, New York University, New York, New York; Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, San Francisco, California; Department of Pediatric Dentistry, School of Dentistry, University of North Carolina, Chapel Hill, North Carolina; Herman Ostrow School of Dentistry, Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, California
| | - Stefan Habelitz
- Department of Basic Science and Craniofacial Biology, College of Dentistry, New York University, New York, New York; Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, San Francisco, California; Department of Pediatric Dentistry, School of Dentistry, University of North Carolina, Chapel Hill, North Carolina; Herman Ostrow School of Dentistry, Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, California
| | - J Timothy Wright
- Department of Basic Science and Craniofacial Biology, College of Dentistry, New York University, New York, New York; Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, San Francisco, California; Department of Pediatric Dentistry, School of Dentistry, University of North Carolina, Chapel Hill, North Carolina; Herman Ostrow School of Dentistry, Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, California
| | - Michael L Paine
- Department of Basic Science and Craniofacial Biology, College of Dentistry, New York University, New York, New York; Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, San Francisco, California; Department of Pediatric Dentistry, School of Dentistry, University of North Carolina, Chapel Hill, North Carolina; Herman Ostrow School of Dentistry, Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, California
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22
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Yachuan Z, Xuedong Z, Liwei Z. [Expression and function of microRNAs in enamel development]. HUA XI KOU QIANG YI XUE ZA ZHI = HUAXI KOUQIANG YIXUE ZAZHI = WEST CHINA JOURNAL OF STOMATOLOGY 2017; 35:328-333. [PMID: 28675021 DOI: 10.7518/hxkq.2017.03.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
microRNAs (miRNAs) are endogenous short, noncoding RNAs that can negatively regulate gene expression post-transcriptionally. miRNAs are involved in multiple developmental events in various tissues and organs, including dental enamel development. Any disruption during enamel development may result in inherited enamel malformations. This article reviews the expression and function of miRNAs in enamel development.
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Affiliation(s)
- Zhou Yachuan
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Zhou Xuedong
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Zheng Liwei
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
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23
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Structural and Morphometric Comparison of Lower Incisors in PACAP-Deficient and Wild-Type Mice. J Mol Neurosci 2016; 59:300-8. [PMID: 27154515 DOI: 10.1007/s12031-016-0765-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 04/27/2016] [Indexed: 10/21/2022]
Abstract
Pituitary adenylate cyclase activating polypeptide (PACAP) is a neuropeptide with widespread distribution. PACAP plays an important role in the development of the nervous system, it has a trophic and protective effect, and it is also implicated in the regulation of various physiological functions. Teeth are originated from the mesenchyme of the neural crest and the ectoderm of the first branchial arch, suggesting similarities with the development of the nervous system. Earlier PACAP-immunoreactive fibers have been found in the odontoblastic and subodontoblastic layers of the dental pulp. Our previous examinations have shown that PACAP deficiency causes alterations in the morphology and structure of the developing molars of 7-day-old mice. In our present study, morphometric and structural comparison was performed on the incisors of 1-year-old wild-type and PACAP-deficient mice. Hard tissue density measurements and morphometric comparison were carried out on the mandibles and the lower incisors with micro-CT. For structural examination, Raman microscopy was applied on frontal thin sections of the mandible. With micro-CT morphometrical measurements, the size of the incisors and the relative volume of the pulp to dentin were significantly smaller in the PACAP-deficient group compared to the wild-type animals. The density of calcium hydroxyapatite in the dentin was reduced in the PACAP-deficient mice. No structural differences could be observed in the enamel with Raman microscopy. Significant differences were found in the dentin of PACAP-deficient mice with Raman microscopy, where increased carbonate/phosphate ratio indicates higher intracrystalline disordering. The evaluation of amide III bands in the dentin revealed higher structural diversity in wild-type mice. Based upon our present and previous results, it is obvious that PACAP plays an important role in tooth development with the regulation of morphogenesis, dentin, and enamel mineralization. Further studies are required to clarify the molecular background of the effects of PACAP on tooth development.
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Guo F, Feng J, Wang F, Li W, Gao Q, Chen Z, Shoff L, Donly KJ, Gluhak-Heinrich J, Chun YHP, Harris SE, MacDougall M, Chen S. Bmp2 deletion causes an amelogenesis imperfecta phenotype via regulating enamel gene expression. J Cell Physiol 2015; 230:1871-82. [PMID: 25545831 DOI: 10.1002/jcp.24915] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 12/09/2014] [Accepted: 12/18/2014] [Indexed: 01/16/2023]
Abstract
Although Bmp2 is essential for tooth formation, the role of Bmp2 during enamel formation remains unknown in vivo. In this study, the role of Bmp2 in regulation of enamel formation was investigated by the Bmp2 conditional knock out (Bmp2 cKO) mice. Teeth of Bmp2 cKO mice displayed severe and profound phenotypes with asymmetric and misshaped incisors as well as abrasion of incisors and molars. Scanning electron microscopy analysis showed that the enamel layer was hypoplastic and enamel lacked a typical prismatic pattern. Teeth from null mice were much more brittle as tested by shear and compressive moduli. Expression of enamel matrix protein genes, amelogenin, enamelin, and enamel-processing proteases, Mmp-20 and Klk4 was reduced in the Bmp2 cKO teeth as reflected in a reduced enamel formation. Exogenous Bmp2 up-regulated those gene expressions in mouse enamel organ epithelial cells. This result for the first time indicates Bmp2 signaling is essential for proper enamel development and mineralization in vivo.
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Affiliation(s)
- Feng Guo
- Department of Stomatology, Xiangya Hospital, Central South University, Changsha, China; Department of Developmental Dentistry, The University of Texas Health Science Center at San Antonio, Floyd Curl Drive, San Antonio, Texas
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