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Jimenez-Armijo A, Morkmued S, Ahumada JT, Kharouf N, de Feraudy Y, Gogl G, Riet F, Niederreither K, Laporte J, Birling MC, Selloum M, Herault Y, Hernandez M, Bloch-Zupan A. The Rogdi knockout mouse is a model for Kohlschütter-Tönz syndrome. Sci Rep 2024; 14:445. [PMID: 38172607 PMCID: PMC10764811 DOI: 10.1038/s41598-023-50870-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 12/27/2023] [Indexed: 01/05/2024] Open
Abstract
Kohlschütter-Tönz syndrome (KTS) is a rare autosomal recessive disorder characterized by severe intellectual disability, early-onset epileptic seizures, and amelogenesis imperfecta. Here, we present a novel Rogdi mutant mouse deleting exons 6-11- a mutation found in KTS patients disabling ROGDI function. This Rogdi-/- mutant model recapitulates most KTS symptoms. Mutants displayed pentylenetetrazol-induced seizures, confirming epilepsy susceptibility. Spontaneous locomotion and circadian activity tests demonstrate Rogdi mutant hyperactivity mirroring patient spasticity. Object recognition impairment indicates memory deficits. Rogdi-/- mutant enamel was markedly less mature. Scanning electron microscopy confirmed its hypomineralized/hypomature crystallization, as well as its low mineral content. Transcriptomic RNA sequencing of postnatal day 5 lower incisors showed downregulated enamel matrix proteins Enam, Amelx, and Ambn. Enamel crystallization appears highly pH-dependent, cycling between an acidic and neutral pH during enamel maturation. Rogdi-/- teeth exhibit no signs of cyclic dental acidification. Additionally, expression changes in Wdr72, Slc9a3r2, and Atp6v0c were identified as potential contributors to these tooth acidification abnormalities. These proteins interact through the acidifying V-ATPase complex. Here, we present the Rogdi-/- mutant as a novel model to partially decipher KTS pathophysiology. Rogdi-/- mutant defects in acidification might explain the unusual combination of enamel and rare neurological disease symptoms.
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Affiliation(s)
- Alexandra Jimenez-Armijo
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U1258, CNRS- UMR7104, Université de Strasbourg, Illkirch, France
| | - Supawich Morkmued
- Pediatrics Division, Department of Preventive Dentistry, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
| | - José Tomás Ahumada
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U1258, CNRS- UMR7104, Université de Strasbourg, Illkirch, France
| | - Naji Kharouf
- Laboratoire de Biomatériaux et Bioingénierie, Inserm UMR_S 1121, Université de Strasbourg, Strasbourg, France
| | - Yvan de Feraudy
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U1258, CNRS- UMR7104, Université de Strasbourg, Illkirch, France
- Department of Neuropediatrics, Strasbourg University Hospital, Strasbourg, France
| | - Gergo Gogl
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U1258, CNRS- UMR7104, Université de Strasbourg, Illkirch, France
| | - Fabrice Riet
- CNRS, INSERM, CELPHEDIA, PHENOMIN, Institut Clinique de la Souris (ICS), Université de Strasbourg, Illkirch, France
| | - Karen Niederreither
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U1258, CNRS- UMR7104, Université de Strasbourg, Illkirch, France
| | - Jocelyn Laporte
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U1258, CNRS- UMR7104, Université de Strasbourg, Illkirch, France
| | - Marie Christine Birling
- CNRS, INSERM, CELPHEDIA, PHENOMIN, Institut Clinique de la Souris (ICS), Université de Strasbourg, Illkirch, France
| | - Mohammed Selloum
- CNRS, INSERM, CELPHEDIA, PHENOMIN, Institut Clinique de la Souris (ICS), Université de Strasbourg, Illkirch, France
| | - Yann Herault
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U1258, CNRS- UMR7104, Université de Strasbourg, Illkirch, France
- CNRS, INSERM, CELPHEDIA, PHENOMIN, Institut Clinique de la Souris (ICS), Université de Strasbourg, Illkirch, France
| | - Magali Hernandez
- Centre Hospitalier Régional Universitaire de Nancy, Competence Center for Rare Oral and Dental Diseases, Université de Lorraine, Nancy, France
| | - Agnès Bloch-Zupan
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U1258, CNRS- UMR7104, Université de Strasbourg, Illkirch, France.
- Faculté de Chirurgie Dentaire, Université de Strasbourg, Strasbourg, France.
- Institut d'études Avancées (USIAS), Université de Strasbourg, Strasbourg, France.
- Pôle de Médecine et Chirurgie Bucco-Dentaires, Hôpital Civil, Centre de Référence des Maladies Rares Orales et Dentaires, O-Rares, Filière Santé Maladies Rares TETE COU, European Reference Network ERN CRANIO, Hôpitaux Universitaires de Strasbourg (HUS), Strasbourg, France.
- Eastman Dental Institute, University College London, London, UK.
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Nasseri S, Parsa S, Vahabzadeh Z, Baban B, Khademerfan MB, Nikkhoo B, Rastegar Khosravi M, Bahrami S, Fathi F. CRISPR/Cas9-Induced Fam83h Knock-out Leads to Impaired Wnt/β-Catenin Pathway and Altered Expression of Tooth Mineralization Genes in Mice. IRANIAN JOURNAL OF BIOTECHNOLOGY 2023; 21:e3673. [PMID: 38269199 PMCID: PMC10804060 DOI: 10.30498/ijb.2023.391902.3673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 08/19/2023] [Indexed: 01/26/2024]
Abstract
Background Dental enamel formation is a complex process that is regulated by various genes. One such gene, Family With Sequence Similarity 83 Member H (Fam83h), has been identified as an essential factor for dental enamel formation. Additionally, Fam83h has been found to be potentially linked to the Wnt/β-catenin pathway. Objectives This study aimed to investigate the effects of the Fam83h knockout gene on mineralization and formation of teeth, along with mediators of the Wnt/β-catenin pathway as a development aspect in mice. Materials and Methods To confirm the Fam83h-KnockOut mice, both Sanger sequencing and Western blot methods were used. then used qPCR to measure the expression levels of genes related to tooth mineralization and formation of dental root, including Fam20a, Dspp, Dmp1, Enam, Ambn, Sppl2a, Mmp20, and Wnt/β-catenin pathway mediators, in both the Fam83h-Knockout and wild-type mice at 5, 11 and 18 days of age. also the expression level of Fgf10 and mediators of the Wnt/β-catenin pathway was measured in the skin of both Knockout and wild-type mice using qPCR. A histological assessment was then performed to further investigate the results. Results A significant reduction in the expression levels of Ambn, Mmp20, Dspp, and Fgf10 in the dental root of Fam83h-Knockout mice compared to their wild-type counterparts was demonstrated by our results, indicating potential disruptions in tooth development. Significant down-regulation of CK1a, CK1e, and β-catenin in the dental root of Fam83h-Knockout mice was associated with a reduction in mineralization and formation-related gene. Additionally, the skin analysis of Fam83h-Knockout mice revealed reduced levels of Fgf10, CK1a, CK1e, and β-catenin. Further histological assessment confirmed that the concurrent reduction of Fgf10 expression level and Wnt/β-catenin genes were associated with alterations in hair follicle maturation. Conclusions The concurrent reduction in the expression level of both Wnt/β-catenin mediators and mineralization-related genes, resulting in the disruption of dental mineralization and formation, was caused by the deficiency of Fam83h. Our findings suggest a cumulative effect and multi-factorial interplay between Fam83h, Wnt/Β-Catenin signaling, and dental mineralization-related genes subsequently, during the dental formation process.
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Affiliation(s)
- Sherko Nasseri
- Cellular and Molecular Research Center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Sanandaj, Iran
- Department of Molecular Medicine and Medical biotechnology, Faculty of Medicine, Kurdistan University of Medical Sciences, Sanandaj, Iran
| | - Sara Parsa
- Cellular and Molecular Research Center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Sanandaj, Iran
| | - Zakaria Vahabzadeh
- Liver and Digestive Research Center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Sanandaj, Iran
- Department of Biochemistry, Faculty of Medicine, Kurdistan University of Medical Sciences, Sanandaj, Iran
| | - Babak Baban
- Department of Oral Biology and Diagnostic Sciences, Dental College of Georgia, Augusta University, Augusta, Georgia
| | - Mohammad Bagher Khademerfan
- Cellular and Molecular Research Center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Sanandaj, Iran
- Department of Molecular Medicine and Medical biotechnology, Faculty of Medicine, Kurdistan University of Medical Sciences, Sanandaj, Iran
| | - Bahram Nikkhoo
- Department of Pathology, Faculty of Medicine, Kurdistan University of Medical Sciences, Sanandaj, Iran
| | - Mohammad Rastegar Khosravi
- Department of Endodontics, Faculty of Dentistry, Kurdistan University of Medical Sciences, Sanandaj, Iran
| | - Saman Bahrami
- Cellular and Molecular Research Center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Sanandaj, Iran
| | - Fardin Fathi
- Cellular and Molecular Research Center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Sanandaj, Iran
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Dong J, Ruan W, Duan X. Molecular-based phenotype variations in amelogenesis imperfecta. Oral Dis 2023; 29:2334-2365. [PMID: 37154292 DOI: 10.1111/odi.14599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 04/03/2023] [Accepted: 04/15/2023] [Indexed: 05/10/2023]
Abstract
Amelogenesis imperfecta (AI) is one of the typical dental genetic diseases in human. It can occur isolatedly or as part of a syndrome. Previous reports have mainly clarified the types and mechanisms of nonsyndromic AI. This review aimed to compare the phenotypic differences among the hereditary enamel defects with or without syndromes and their underlying pathogenic genes. We searched the articles in PubMed with different strategies or keywords including but not limited to amelogenesis imperfecta, enamel defects, hypoplastic/hypomaturation/hypocalcified, syndrome, or specific syndrome name. The articles with detailed clinical information about the enamel and other phenotypes and clear genetic background were used for the analysis. We totally summarized and compared enamel phenotypes of 18 nonsyndromic AI with 17 causative genes and 19 syndromic AI with 26 causative genes. According to the clinical features, radiographic or ultrastructural changes in enamel, the enamel defects were basically divided into hypoplastic and hypomineralized (hypomaturated and hypocalcified) and presented a higher heterogeneity which were closely related to the involved pathogenic genes, types of mutation, hereditary pattern, X chromosome inactivation, incomplete penetrance, and other mechanisms.The gene-specific enamel phenotypes could be an important indicator for diagnosing nonsyndromic and syndromic AI.
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Affiliation(s)
- Jing Dong
- State Key Laboratory of Military Stomatology, Shaanxi Key Laboratory of Stomatology, Department of Oral Biology & Clinic of Oral Rare Diseases and Genetic Diseases, School of Stomatology, National Clinical Research Center for Oral Disease, The Fourth Military Medical University, Xi'an, China
- College of Life Sciences, Northwest University, Xi'an, China
| | - Wenyan Ruan
- State Key Laboratory of Military Stomatology, Shaanxi Key Laboratory of Stomatology, Department of Oral Biology & Clinic of Oral Rare Diseases and Genetic Diseases, School of Stomatology, National Clinical Research Center for Oral Disease, The Fourth Military Medical University, Xi'an, China
| | - Xiaohong Duan
- State Key Laboratory of Military Stomatology, Shaanxi Key Laboratory of Stomatology, Department of Oral Biology & Clinic of Oral Rare Diseases and Genetic Diseases, School of Stomatology, National Clinical Research Center for Oral Disease, The Fourth Military Medical University, Xi'an, China
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Li Y, Zhang L, Cen W, Yuan Y. Association of KLK4 rs2235091 polymorphism with susceptibility to dental caries: a systematic review and meta-analysis. Front Pediatr 2023; 11:1236000. [PMID: 37711595 PMCID: PMC10498278 DOI: 10.3389/fped.2023.1236000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 08/14/2023] [Indexed: 09/16/2023] Open
Abstract
Objective To investigate the association between Kallikrein-related peptidase-4 (KLK4) rs2235091 polymorphism and susceptibility to dental caries (DC) by a method of systematic review and meta-analysis. Methods Four English databases were searched for studies on the correlation between KLK4 rs2235091 polymorphism and susceptibility to DC from inception to April 1, 2023. Data analysis was processed by Stata 15.0 software. Results Four articles were eligible, including 848 individuals with caries and 463 controls. The results of pooled analysis showed no significant differences in the five gene models (G vs. A: odds ratio (OR) = 1.14, 95% CI: 0.73-1.79, P = 0.567; GG + GA vs. AA: OR = 1.01, 95% CI: 0.77-1.32, P = 0.489; GG vs. GA + AA: OR = 0.84, 95% CI: 0.57-1.23, P = 0.368; GA vs. AA: OR = 1.06, 95% CI: 0.80-1.41, P = 0.681; GG vs. AA: OR = 1.15, 95% CI: 0.57-2.31, P = 0.690). However, subgroup analysis indicated a statistically significant difference in the dominant (GG + GA vs. AA: OR = 1.74, 95% CI: 1.02-2.96, P = 0.042) gene model in primary dentition, but no significance in allelic, recessive, homozygous and heterozygous models. Besides, in permanent dentition, no significant differences were found among the five genetic models (all P > 0.05). Conclusion KLK4 rs2235091 polymorphism may be associated with susceptibility to DC of pediatric primary dentition, but not with the risk of caries of permanent dentition. Genotype GG + GA may increase susceptibility to DC of pediatric primary dentition. However, considering the limited records enrolled in this review, more trials with larger sample sizes and more rigorous designs are needed to verify the conclusions of this meta-analysis in the future. Systematic Review Registration https://inplasy.com/, identifier INPLASY202380014.
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Affiliation(s)
| | | | | | - Yongping Yuan
- Department of Stomatology, Ningbo College of Health Sciences, Ningbo, ZJ, China
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Wald T, Verma A, Cooley V, Marangoni P, Cazares O, Sharir A, Sandoval EJ, Sung D, Najibi H, Drennon TY, Bush JO, Joester D, Klein OD. A Suite of Mouse Reagents for Studying Amelogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.30.534992. [PMID: 37034814 PMCID: PMC10081212 DOI: 10.1101/2023.03.30.534992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Amelogenesis, the formation of dental enamel, is driven by specialized epithelial cells called ameloblasts, which undergo successive stages of differentiation. Ameloblasts secrete enamel matrix proteins (EMPs), proteases, calcium, and phosphate ions in a stage-specific manner to form mature tooth enamel. Developmental defects in tooth enamel are common in humans, and they can greatly impact the well-being of affected individuals. Our understanding of amelogenesis and developmental pathologies is rooted in past studies using epithelial Cre driver and knockout alleles. However, the available mouse models are limited, as most do not allow targeting different ameloblast sub-populations, and constitutive loss of EMPs often results in severe phenotype in the mineral, making it difficult to interpret defect mechanisms. Herein, we report on the design and verification of a toolkit of twelve mouse alleles that include ameloblast-stage specific Cre recombinases, fluorescent reporter alleles, and conditional flox alleles for the major EMPs. We show how these models may be used for applications such as sorting of live stage specific ameloblasts, whole mount imaging, and experiments with incisor explants. The full list of new alleles is available at https://dev.facebase.org/enamelatlas/mouse-models/ .
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Chiba Y, Yoshizaki K, Sato H, Ikeuchi T, Rhodes C, Chiba M, Saito K, Nakamura T, Iwamoto T, Yamada A, Yamada Y, Fukumoto S. Deficiency of G protein-coupled receptor Gpr111/Adgrf2 causes enamel hypomineralization in mice by alteration of the expression of kallikrein-related peptidase 4 (Klk4) during pH cycling process. FASEB J 2023; 37:e22861. [PMID: 36929047 DOI: 10.1096/fj.202202053r] [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: 12/07/2022] [Revised: 02/21/2023] [Accepted: 02/23/2023] [Indexed: 03/18/2023]
Abstract
Enamel is formed by the repetitive secretion of a tooth-specific extracellular matrix and its decomposition. Calcification of the enamel matrix via hydroxyapatite (HAP) maturation requires pH cycling to be tightly regulated through the neutralization of protons released during HAP synthesis. We found that Gpr115, which responds to changes in extracellular pH, plays an important role in enamel formation. Gpr115-deficient mice show partial enamel hypomineralization, suggesting that other pH-responsive molecules may be involved. In this study, we focused on the role of Gpr111/Adgrf2, a duplicate gene of Gpr115, in tooth development. Gpr111 was highly expressed in mature ameloblasts. Gpr111-KO mice showed enamel hypomineralization. Dysplasia of enamel rods and high carbon content seen in Gpr111-deficient mice suggested the presence of residual enamel matrices in enamel. Depletion of Gpr111 in dental epithelial cells induced the expression of ameloblast-specific protease, kallikrein-related peptidase 4 (Klk4), suggesting that Gpr111 may act as a suppressor of Klk4 expression. Moreover, reduction of extracellular pH to 6.8 suppressed the expression of Gpr111, while the converse increased Klk4 expression. Such induction of Klk4 was synergistically enhanced by Gpr111 knockdown, suggesting that proper enamel mineralization may be linked to the modulation of Klk4 expression by Gpr111. Furthermore, our in vitro suppression of Gpr111 and Gpr115 expression indicated that their suppressive effect on calcification was additive. These results suggest that both Gpr111 and Gpr115 respond to extracellular pH, contribute to the expression of proteolytic enzymes, and regulate the pH cycle, thereby playing important roles in enamel formation.
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Affiliation(s)
- Yuta Chiba
- Section of Pediatric Dentistry, Division of Oral Health, Growth and Development, Kyushu University Faculty of Dental Science, Fukuoka, Japan
- Division of Pediatric Dentistry, Department of Community Social Dentistry, Tohoku University Graduate School of Dentistry, Sendai, Japan
| | - Keigo Yoshizaki
- Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth, and Development, Kyushu University Faculty of Dental Science, Fukuoka, Japan
| | - Hiroshi Sato
- Section of Pediatric Dentistry, Division of Oral Health, Growth and Development, Kyushu University Faculty of Dental Science, Fukuoka, Japan
| | - Tomoko Ikeuchi
- Division of Pediatric Dentistry, Laboratory of Cell and Developmental Biology, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland, USA
| | - Craig Rhodes
- Division of Pediatric Dentistry, Laboratory of Cell and Developmental Biology, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland, USA
| | - Mitsuki Chiba
- Division of Pediatric Dentistry, Department of Community Social Dentistry, Tohoku University Graduate School of Dentistry, Sendai, Japan
| | - Kan Saito
- Division of Pediatric Dentistry, Department of Community Social Dentistry, Tohoku University Graduate School of Dentistry, Sendai, Japan
| | - Takashi Nakamura
- Division of Molecular Pharmacology and Cell Biophysics, Department of Disease Management Dentistry, Tohoku University Graduate School of Dentistry, Sendai, Japan
| | - Tsutomu Iwamoto
- Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Department of Pediatric Dentistry/Special Needs Dentistry, Tokyo Medical and Dental University, Tokyo, Japan
| | - Aya Yamada
- Division of Pediatric Dentistry, Department of Community Social Dentistry, Tohoku University Graduate School of Dentistry, Sendai, Japan
| | - Yoshihiko Yamada
- Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth, and Development, Kyushu University Faculty of Dental Science, Fukuoka, Japan
| | - Satoshi Fukumoto
- Section of Pediatric Dentistry, Division of Oral Health, Growth and Development, Kyushu University Faculty of Dental Science, Fukuoka, Japan
- Division of Pediatric Dentistry, Department of Community Social Dentistry, Tohoku University Graduate School of Dentistry, Sendai, Japan
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Zheng X, Huang W, He Z, Li Y, Li S, Song Y. Effects of Fam83h truncation mutation on enamel developmental defects in male C57/BL6J mice. Bone 2023; 166:116595. [PMID: 36272714 DOI: 10.1016/j.bone.2022.116595] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 10/10/2022] [Accepted: 10/17/2022] [Indexed: 11/05/2022]
Abstract
Truncation mutations in family with sequence similarity, member H (FAM83H) gene are considered the main cause of autosomal dominant hypocalcified amelogenesis imperfecta (ADHCAI); however, its pathogenic mechanism in amelogenesis remains poorly characterized. This study aimed to investigate the effects of truncated FAM83H on developmental defects in enamel. CRISPR/Cas9 technology was used to develop a novel Fam83h c.1186C > T (p.Q396*) knock-in mouse strain, homologous to the human FAM83H c.1192C > T mutation in ADHCAI. The Fam83hQ396⁎/Q396⁎ mice showed poor growth, a sparse and scruffy coat, scaly skin and early mortality compared to control mice. Moreover, the forelimbs of homozygous mice were swollen, exhibiting a significant inflammatory response. Incisors of Fam83hQ396⁎/Q396⁎ mice appeared chalky white, shorter, and less sharp than those of control mice, and energy dispersive X-ray spectroscopy (EDS) analysis and Prussian blue staining helped identify decreased iron and increased calcium (Ca) and phosphorus (P) levels, with an unchanged Ca/P ratio. The expression of iron transportation proteins, transferrin receptor (TFRC) and solute carrier family 40 member 1 (SLC40A1), was decreased in Fam83h-mutated ameloblasts. Micro-computed tomography revealed enamel defects in Fam83hQ396⁎/Q396⁎ mice. Fam83hQ396⁎/Q396⁎ enamel showed decreased Vickers hardness and distorted enamel rod structure and ameloblast arrangement. mRNA sequencing showed that the cell adhesion pathway was most notably clustered in LS8-Fam83h-mutated cells. Immunofluorescence analysis further revealed decreased protein expression of desmoglein 3, a component of desmosomes, in Fam83h-mutated ameloblasts. The FAM83H-casein kinase 1α (CK1α)-keratin 14 (K14)-amelogenin (AMELX) interaction was detected in ameloblasts. And K14 and AMELX were disintegrated from the tetramer in Fam83h-mutated ameloblasts in vitro and in vivo. In secretory stage ameloblasts of Fam83hQ396⁎/Q396⁎ mice, AMELX secretion exhibited obvious retention in the cytoplasm. In conclusion, truncated FAM83H exerted dominant-negative effects on gross development, amelogenesis, and enamel biomineralization by disturbing iron transportation, influencing the transportation and secretion of AMELX, and interfering with cell-cell adhesion in ameloblasts.
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Affiliation(s)
- Xueqing Zheng
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei_MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Wushuang Huang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei_MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Zhenru He
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei_MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Yang Li
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei_MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Shiyu Li
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei_MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Yaling Song
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei_MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China.
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Mu H, Dong Z, Wang Y, Chu Q, Gao Y, Wang A, Wang Y, Liu X, Gao Y. Odontogenesis-Associated Phosphoprotein (ODAPH) Overexpression in Ameloblasts Disrupts Enamel Formation via Inducing Abnormal Mineralization of Enamel in Secretory Stage. Calcif Tissue Int 2022; 111:611-621. [PMID: 36163390 DOI: 10.1007/s00223-022-01023-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Accepted: 09/05/2022] [Indexed: 11/02/2022]
Abstract
Odontogenesis-associated phosphoprotein (ODAPH) is a recently discovered enamel matrix protein. Our previous study demonstrated that knockouting out Odaph in mice resulted in enamel hypomineralization. To further investigate the effect of Odaph on enamel mineralization, we constructed an Odaph overexpression mouse model, controlled by an amelogenin promoter. Our histological analysis of OdaphTg mice revealed that the enamel layer was thinner than in WT mice. An uneven, thinner enamel layer was confirmed using micro-computed tomography (uCT). It was subsequently found that the Tomes' processes lost their normal morphology, resulting in the loss of the enamel prism structure. These results indicate that Odaph overexpression in ameloblasts led to enamel dysplasia. In conjunction with this, Odaph overexpression hindered Amelx secretion, and may result in endoplasmic reticulum stress. Interestingly, uCT revealed that enamel had higher mineral density at the secretory stage; due to this, we did the histological staining for the mineralization-related proteins Alkaline phosphatase (ALPL) and Runt-related transcription factor 2 (RUNX2). It was observed that these proteins were up-regulated in OdaphTg mice versus WT mice, indicating that Odaph overexpression led to abnormal enamel mineralization. To confirm this, we transfected ameloblast-like cell line (ALC) with Odaph overexpression lentivirus in vitro and identified that both Alpl and Runx2 were strikingly upregulated in OE-mus-Odaph versus OE-NC cells. We concluded that the ectopic overexpression of Odaph in ameloblasts led to abnormal enamel mineralization. In summary, Odaph profoundly influences amelogenesis by participating in enamel mineralization.
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Affiliation(s)
- Haiyu Mu
- Department of Pediatrics and Preventive Dentistry, Binzhou Medical University Hospital, Binzhou, 256600, Shandong, China
| | - Zhiheng Dong
- Department of Pediatrics and Preventive Dentistry, Binzhou Medical University Hospital, Binzhou, 256600, Shandong, China.
| | - Yumin Wang
- Institute of Stomatology, Binzhou Medical University, Yantai, 264003, Shandong, China
| | - Qing Chu
- Department of Pediatrics and Preventive Dentistry, Binzhou Medical University Hospital, Binzhou, 256600, Shandong, China
| | - Yan Gao
- Department of Pediatrics and Preventive Dentistry, Binzhou Medical University Hospital, Binzhou, 256600, Shandong, China
| | - Aiqin Wang
- Department of Periodontics, Binzhou Medical University Hospital, Binzhou, 256600, Shandong, China
| | - Yu Wang
- Institute of Stomatology, Binzhou Medical University, Yantai, 264003, Shandong, China
| | - Xiaoying Liu
- Department of Cell Biology, College of Life Science and Technology, Weifang Medical University, Weifang, 261053, Shandong, China
| | - Yuguang Gao
- Department of Pediatrics and Preventive Dentistry, Binzhou Medical University Hospital, Binzhou, 256600, Shandong, China.
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Liang T, Wang SK, Smith C, Zhang H, Hu Y, Seymen F, Koruyucu M, Kasimoglu Y, Kim JW, Zhang C, Saunders TL, Simmer JP, Hu JCC. Enamel defects in Acp4 R110C/R110C mice and human ACP4 mutations. Sci Rep 2022; 12:16477. [PMID: 36183038 PMCID: PMC9526733 DOI: 10.1038/s41598-022-20684-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 09/16/2022] [Indexed: 11/13/2022] Open
Abstract
Human ACP4 (OMIM*606362) encodes a transmembrane protein that belongs to histidine acid phosphatase (ACP) family. Recessive mutations in ACP4 cause non-syndromic hypoplastic amelogenesis imperfecta (AI1J, OMIM#617297). While ACP activity has long been detected in developing teeth, its functions during tooth development and the pathogenesis of ACP4-associated AI remain largely unknown. Here, we characterized 2 AI1J families and identified a novel ACP4 disease-causing mutation: c.774_775del, p.Gly260Aspfs*29. To investigate the role of ACP4 during amelogenesis, we generated and characterized Acp4R110C mice that carry the p.(Arg110Cys) loss-of-function mutation. Mouse Acp4 expression was the strongest at secretory stage ameloblasts, and the protein localized primarily at Tomes' processes. While Acp4 heterozygous (Acp4+/R110C) mice showed no phenotypes, incisors and molars of homozygous (Acp4R110C/R110C) mice exhibited a thin layer of aplastic enamel with numerous ectopic mineralized nodules. Acp4R110C/R110C ameloblasts appeared normal initially but underwent pathology at mid-way of secretory stage. Ultrastructurally, sporadic enamel ribbons grew on mineralized dentin but failed to elongate, and aberrant needle-like crystals formed instead. Globs of organic matrix accumulated by the distal membranes of defective Tomes' processes. These results demonstrated a critical role for ACP4 in appositional growth of dental enamel probably by processing and regulating enamel matrix proteins around mineralization front apparatus.
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Affiliation(s)
- Tian Liang
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1011 N University Ave, Ann Arbor, MI, 48109, USA
| | - Shih-Kai Wang
- Department of Dentistry, National Taiwan University School of Dentistry, No. 1, Changde St., Zhongzheng Dist., Taipei City, 100, Taiwan
- Department of Pediatric Dentistry, National Taiwan University Children's Hospital, No. 8, Zhongshan S. Rd., Zhongzheng Dist., Taipei City, 100, Taiwan
| | - Charles Smith
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1011 N University Ave, Ann Arbor, MI, 48109, USA
- Department of Anatomy & Cell Biology, Faculty of Medicine & Health Sciences, McGill University, Montreal, QC, Canada
| | - Hong Zhang
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1011 N University Ave, Ann Arbor, MI, 48109, USA
| | - Yuanyuan Hu
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1011 N University Ave, Ann Arbor, MI, 48109, USA
| | - Figen Seymen
- Department of Pedodontics, Faculty of Dentistry, Altinbas University, 34147, Istanbul, Turkey
| | - Mine Koruyucu
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, 34116, Istanbul, Turkey
| | - Yelda Kasimoglu
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, 34116, Istanbul, Turkey
| | - Jung-Wook Kim
- Department of Molecular Genetics & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, 03080, Republic of Korea
- Department of Pediatric Dentistry & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, 03080, Republic of Korea
| | - Chuhua Zhang
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1011 N University Ave, Ann Arbor, MI, 48109, USA
| | - Thomas L Saunders
- Division of Molecular, Medicine and Genetics, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - James P Simmer
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1011 N University Ave, Ann Arbor, MI, 48109, USA.
| | - Jan C-C Hu
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1011 N University Ave, Ann Arbor, MI, 48109, USA
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10
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Mohabatpour F, Al-Dulaymi M, Lobanova L, Scutchings B, Papagerakis S, Badea I, Chen X, Papagerakis P. Gemini surfactant-based nanoparticles T-box1 gene delivery as a novel approach to promote epithelial stem cells differentiation and dental enamel formation. BIOMATERIALS ADVANCES 2022; 137:212844. [PMID: 35929273 DOI: 10.1016/j.bioadv.2022.212844] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 04/14/2022] [Accepted: 05/04/2022] [Indexed: 06/15/2023]
Abstract
Enamel is the highest mineralized tissue in the body protecting teeth from external stimuli, infections, and injuries. Enamel lacks the ability to self-repair due to the absence of enamel-producing cells in the erupted teeth. Here, we reported a novel approach to promote enamel-like tissue formation via the delivery of a key ameloblast inducer, T-box1 gene, into a rat dental epithelial stem cell line, HAT-7, using non-viral gene delivery systems based on cationic lipids. We comparatively assessed the lipoplexes prepared from glycyl-lysine-modified gemini surfactants and commercially available 1,2-dioleoyl-3-trimethylammonium-propane lipids at three nitrogen-to phosphate (N/P) ratios of 2.5, 5 and 10. Our findings revealed that physico-chemical characteristics and biological activities of the gemini surfactant-based lipoplexes with a N/P ratio of 5 provide the most optimal outcomes among those examined. HAT-7 cells were transfected with T-box1 gene using the optimal formulation then cultured in conventional 2D cell culture systems. Ameloblast differentiation, mineralization, bio-enamel interface and structure were assessed at different time points over 28 days. Our results showed that our gemini transfection system provides superior gene expression compared to the benchmark agent, while keeping low cytotoxicity levels. T-box1-transfected HAT-7 cells strongly expressed markers of secretory and maturation stages of the ameloblasts, deposited minerals, and produced enamel-like crystals when compared to control cells. Taken together, our gemini surfactant-based T-box1 gene delivery system is effective to accelerate and guide ameloblastic differentiation of dental epithelial stem cells and promote enamel-like tissue formation. This study would represent a significant advance towards the tissue engineering and regeneration of dental enamel.
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Affiliation(s)
- Fatemeh Mohabatpour
- Division of Biomedical Engineering, University of Saskatchewan, 57 Campus Dr., S7N 5A9 SK, Canada; College of Dentistry, University of Saskatchewan, 105 Wiggins Rd, S7N 5E4, SK, Canada
| | - Mays Al-Dulaymi
- College of Pharmacy and Nutrition, University of Saskatchewan, 107 Wiggins Rd, S7N 5E5, SK, Canada
| | - Liubov Lobanova
- College of Dentistry, University of Saskatchewan, 105 Wiggins Rd, S7N 5E4, SK, Canada
| | - Brittany Scutchings
- College of Pharmacy and Nutrition, University of Saskatchewan, 107 Wiggins Rd, S7N 5E5, SK, Canada
| | - Silvana Papagerakis
- Division of Biomedical Engineering, University of Saskatchewan, 57 Campus Dr., S7N 5A9 SK, Canada; Department of Surgery, College of Medicine, University of Saskatchewan, 107 Wiggins Rd B419, S7N 0W8, SK, Canada; Department of Otolaryngology, College of Medicine, University of Michigan, Ann Arbor, MI, USA.
| | - Ildiko Badea
- College of Pharmacy and Nutrition, University of Saskatchewan, 107 Wiggins Rd, S7N 5E5, SK, Canada
| | - Xiongbiao Chen
- Division of Biomedical Engineering, University of Saskatchewan, 57 Campus Dr., S7N 5A9 SK, Canada; Department of Mechanical Engineering, University of Saskatchewan, 57 Campus Dr., S7N 5A9 SK, Canada.
| | - Petros Papagerakis
- Division of Biomedical Engineering, University of Saskatchewan, 57 Campus Dr., S7N 5A9 SK, Canada; College of Dentistry, University of Saskatchewan, 105 Wiggins Rd, S7N 5E4, SK, Canada.
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11
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Loss of BMP2 and BMP4 Signaling in the Dental Epithelium Causes Defective Enamel Maturation and Aberrant Development of Ameloblasts. Int J Mol Sci 2022; 23:ijms23116095. [PMID: 35682776 PMCID: PMC9180982 DOI: 10.3390/ijms23116095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/18/2022] [Accepted: 05/25/2022] [Indexed: 12/10/2022] Open
Abstract
BMP signaling is crucial for differentiation of secretory ameloblasts, the cells that secrete enamel matrix. However, whether BMP signaling is required for differentiation of maturation-stage ameloblasts (MA), which are instrumental for enamel maturation into hard tissue, is hitherto unknown. To address this, we used an in vivo genetic approach which revealed that combined deactivation of the Bmp2 and Bmp4 genes in the murine dental epithelium causes development of dysmorphic and dysfunctional MA. These fail to exhibit a ruffled apical plasma membrane and to reabsorb enamel matrix proteins, leading to enamel defects mimicking hypomaturation amelogenesis imperfecta. Furthermore, subsets of mutant MA underwent pathological single or collective cell migration away from the ameloblast layer, forming cysts and/or exuberant tumor-like and gland-like structures. Massive apoptosis in the adjacent stratum intermedium and the abnormal cell-cell contacts and cell-matrix adhesion of MA may contribute to this aberrant behavior. The mutant MA also exhibited severely diminished tissue non-specific alkaline phosphatase activity, revealing that this enzyme’s activity in MA crucially depends on BMP2 and BMP4 inputs. Our findings show that combined BMP2 and BMP4 signaling is crucial for survival of the stratum intermedium and for proper development and function of MA to ensure normal enamel maturation.
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12
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Val P, Lyons NJ, Gasparini N, Willenbring JK, Albert JS. Landscape Evolution as a Diversification Driver in Freshwater Fishes. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2021.788328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The exceptional concentration of vertebrate diversity in continental freshwaters has been termed the “freshwater fish paradox,” with > 15,000 fish species representing more than 20% of all vertebrate species compressed into tiny fractions of the Earth’s land surface area (<0.5%) or total aquatic habitat volume (<0.001%). This study asks if the fish species richness of the world’s river basins is explainable in terms of river captures using topographic metrics as proxies. The River Capture Hypothesis posits that drainage-network rearrangements have accelerated biotic diversification through their combined effects on dispersal, speciation, and extinction. Yet rates of river capture are poorly constrained at the basin scale worldwide. Here we assess correlations between fish species density (data for 14,953 obligate freshwater fish species) and basin-wide metrics of landscape evolution (data for 3,119 river basins), including: topography (elevation, average relief, slope, drainage area) and climate (average rainfall and air temperature). We assess the results in the context of both static landscapes (e.g., species-area and habitat heterogeneity relationships) and transient landscapes (e.g., river capture, tectonic activity, landscape disequilibrium). We also relax assumptions of functional neutrality of basins (tropical vs. extratropical, tectonically stable vs. active terrains). We found a disproportionate number of freshwater species in large, lowland river basins of tropical South America, Africa, and Southeast Asia, under predictable conditions of large geographic area, tropical climate, low topographic relief, and high habitat volume (i.e., high rainfall rates). However, our results show that these conditions are only necessary, but not fully sufficient, to explain the basins with the highest diversity. Basins with highest diversity are all located on tectonically stable regions, places where river capture is predicted to be most conducive to the formation of high fish species richness over evolutionary timescales. Our results are consistent with predictions of several landscape evolution models, including the River Capture Hypothesis, Mega Capture Hypothesis, and Intermediate Capture Rate Hypothesis, and support conclusions of numerical modeling studies indicating landscape transience as a mechanistic driver of net diversification in riverine and riparian organisms with widespread continental distributions.
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13
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Qin W, Wan QQ, Ma YX, Wang CY, Wan MC, Ma S, Wang YR, Wang WR, Gu JT, Tay FR, Niu LN. Manifestation and Mechanisms of Abnormal Mineralization in Teeth. ACS Biomater Sci Eng 2021; 9:1733-1756. [PMID: 34436861 DOI: 10.1021/acsbiomaterials.1c00592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Tooth biomineralization is a dynamic and complicated process influenced by local and systemic factors. Abnormal mineralization in teeth occurs when factors related to physiologic mineralization are altered during tooth formation and after tooth maturation, resulting in microscopic and macroscopic manifestations. The present Review provides timely information on the mechanisms and structural alterations of different forms of pathological tooth mineralization. A comprehensive study of these alterations benefits diagnosis and biomimetic treatment of abnormal mineralization in patients.
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Affiliation(s)
- Wen Qin
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P. R. China
| | - Qian-Qian Wan
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P. R. China
| | - Yu-Xuan Ma
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P. R. China
| | - Chen-Yu Wang
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P. R. China
| | - Mei-Chen Wan
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P. R. China
| | - Sai Ma
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P. R. China
| | - Yi-Rong Wang
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P. R. China
| | - Wan-Rong Wang
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P. R. China
| | - Jun-Ting Gu
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P. R. China
| | - Franklin R Tay
- College of Graduate Studies, Augusta University, Augusta, Georgia 30912, United States
| | - Li-Na Niu
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P. R. China
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14
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Bartlett JD, Smith CE, Hu Y, Ikeda A, Strauss M, Liang T, Hsu YH, Trout AH, McComb DW, Freeman RC, Simmer JP, Hu JCC. MMP20-generated amelogenin cleavage products prevent formation of fan-shaped enamel malformations. Sci Rep 2021; 11:10570. [PMID: 34012043 PMCID: PMC8134442 DOI: 10.1038/s41598-021-90005-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 04/27/2021] [Indexed: 11/09/2022] Open
Abstract
Dental enamel forms extracellularly as thin ribbons of amorphous calcium phosphate (ACP) that initiate on dentin mineral in close proximity to the ameloblast distal membrane. Secreted proteins are critical for this process. Enam-/- and Ambn-/- mice fail to form enamel. We characterize enamel ribbon formation in wild-type (WT), Amelx-/- and Mmp20-/- mouse mandibular incisors using focused ion beam scanning electron microscopy (FIB-SEM) in inverted backscatter mode. In Amelx-/- mice, initial enamel mineral ribbons extending from dentin are similar in form to those of WT mice. As early enamel development progresses, the Amelx-/- mineral ribbons develop multiple branches, resembling the staves of a Japanese fan. These striking fan-shaped structures cease growing after attaining ~ 20 µm of enamel thickness (WT is ~ 120 µm). The initial enamel mineral ribbons in Mmp20-/- mice, like those of the Amelx-/- and WT, extend from the dentin surface to the ameloblast membrane, but appear to be fewer in number and coated on their sides with organic material. Remarkably, Mmp20-/- mineral ribbons also form fan-like structures that extend to ~ 20 µm from the dentin surface. However, these fans are subsequently capped with a hard, disorganized outer mineral layer. Amelogenin cleavage products are the only matrix components absent in both Amelx-/- and Mmp20-/- mice. We conclude that MMP20 and amelogenin are not critical for enamel mineral ribbon initiation, orientation, or initial shape. The pathological fan-like plates in these mice may form from the lack of amelogenin cleavage products, which appear necessary to form ordered hydroxyapatite.
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Affiliation(s)
- John D Bartlett
- Division of Biosciences, Ohio State University College of Dentistry, Columbus, OH, USA
| | - Charles E Smith
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1210 Eisenhower Pl, Ann Arbor, MI, 48108, USA
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada
| | - Yuanyuan Hu
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1210 Eisenhower Pl, Ann Arbor, MI, 48108, USA
| | - Atsushi Ikeda
- Division of Biosciences, Ohio State University College of Dentistry, Columbus, OH, USA
| | - Mike Strauss
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada
| | - Tian Liang
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1210 Eisenhower Pl, Ann Arbor, MI, 48108, USA
| | - Ya-Hsiang Hsu
- Department of Materials Science and Engineering, Ohio State University College of Engineering, Columbus, OH, USA
- Center for Electron Microscopy and Analysis, Ohio State University, Columbus, OH, USA
| | - Amanda H Trout
- Department of Materials Science and Engineering, Ohio State University College of Engineering, Columbus, OH, USA
- Center for Electron Microscopy and Analysis, Ohio State University, Columbus, OH, USA
| | - David W McComb
- Department of Materials Science and Engineering, Ohio State University College of Engineering, Columbus, OH, USA
- Center for Electron Microscopy and Analysis, Ohio State University, Columbus, OH, USA
| | - Rebecca C Freeman
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1210 Eisenhower Pl, Ann Arbor, MI, 48108, USA
| | - James P Simmer
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1210 Eisenhower Pl, Ann Arbor, MI, 48108, USA.
| | - Jan C-C Hu
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1210 Eisenhower Pl, Ann Arbor, MI, 48108, USA
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15
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Habelitz S, Bai Y. Mechanisms of Enamel Mineralization Guided by Amelogenin Nanoribbons. J Dent Res 2021; 100:1434-1443. [PMID: 34009057 DOI: 10.1177/00220345211012925] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The nanofibrous nature and its intricate structural organization are the basis for the extraordinary ability of sound enamel to outlive masticatory forces at minimal failure rates. Apatite nanofibers of several hundreds of micrometers to possibly millimeters in length originate during the secretory stage of amelogenesis as 2-nm-thin and 15-nm-wide ribbons that develop and grow in length under the guidance of a dynamic mixture of specialized proteins, the developing enamel matrix (DEM). A critical role in the unidirectional and oriented growth of enamel mineral ribbons has been attributed to amelogenin, the major constituent of the DEM. This review elaborates on recent studies on the ability of ribbon-like assemblies of amelogenin to template the formation of an amorphous calcium phosphate precursor that transforms into apatite mineral ribbons similar to the ones observed in developing enamel. A mechanistic model of the biological processes that drive biomineralization in enamel is presented in the context of a comparative analysis of enamel mouse models and earlier structural data of the DEM emphasizing a regulatory role of the matrix metalloproteinase 20 in mineral deposition and the involvement of a process-directing agent for the templated mineral growth directed by amelogenin nanoribbons.
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Affiliation(s)
- S Habelitz
- Department of Preventative and Restorative Dental Sciences, School of Dentistry, University of California, San Francisco, CA, USA
| | - Y Bai
- Department of Preventative and Restorative Dental Sciences, School of Dentistry, University of California, San Francisco, CA, USA
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16
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Schwarze UY, Ni Y, Zhou Y, Terlecki-Zaniewicz L, Schosserer M, Hackl M, Grillari J, Gruber R. Size changes in miR‑21 knockout mice: Geometric morphometrics on teeth, alveolar bone and mandible. Mol Med Rep 2021; 23:285. [PMID: 33604680 PMCID: PMC7905328 DOI: 10.3892/mmr.2021.11924] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 10/27/2020] [Indexed: 01/07/2023] Open
Abstract
MicroRNA‑21 (miR‑21) is a small non‑coding RNA that is differentially expressed during tooth development, particularly during amelogenesis. Although orthodontic tooth movement and the innate immune response are impaired, miR‑21 knockout mice demonstrate no obvious skeletal phenotype. However, the consequence of miR‑21 knockout on tooth phenotype and corresponding alveolar bone is unknown. The current study utilized landmark‑based geometric morphometrics to identify anatomical dissimilarities of the three lower and upper molars, and the corresponding alveolar bone, in miR‑21 knockout and wild‑type control mice. The anatomical structures were visualized by microcomputer tomography. A total of 36 and 38 landmarks were placed on mandibular and maxillary molars, respectively. For the alveolar bone, 16 landmarks were selected on both anatomical sites. General Procrustes analysis revealed significantly smaller molars and dimensions of the alveolar bone in the mandible of the miR‑21 knockout mice when compared with wild‑type controls (P=0.03 and P=0.04, respectively). The overall dimension of the mandible was reduced by the lack of miR‑21 (P=0.02). In the maxilla, the dimension of the alveolar bone was significant (P=0.02); however, this was not observed in the molars (P=0.36). Based on principal component analysis, no changes in shape for any of the anatomical sites were observed. Dental and skeletal jaw length were calculated and no prognathism was identified. However, the fluctuating asymmetry of the molars in the mandible and the maxilla was reduced in the miR‑21 knockout mice by 38 and 27%, respectively. Taken together, the results of the present study revealed that the molars in the mandible and the dimension of the respective alveolar bone were smaller in miR‑21 mice compared with wild‑type littermates, suggesting that miR‑21 influences tooth development.
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Affiliation(s)
- Uwe Yacine Schwarze
- Department of Oral Biology, School of Dentistry, Medical University of Vienna, A-1090 Vienna, Austria
- Department of Orthopaedics and Trauma, Medical University of Graz, A-8010 Graz, Austria
- Department of Dental Medicine and Oral Health, Medical University of Graz, A-8010 Graz, Austria
- Austrian Cluster for Tissue Regeneration, A-1200 Vienna, Austria
| | - Yuxin Ni
- Department of Oral Biology, School of Dentistry, Medical University of Vienna, A-1090 Vienna, Austria
- Department of Stomatology, Union Shenzhen Hospital, Huazhong University of Science and Technology, Shenzhen, Guangdong 518051, P.R. China
| | - Yanmin Zhou
- Department of Stomatology, Union Shenzhen Hospital, Huazhong University of Science and Technology, Shenzhen, Guangdong 518051, P.R. China
| | - Lucia Terlecki-Zaniewicz
- Institute of Molecular Biotechnology, Department of Biotechnology, University of Natural Resources and Life Sciences, A-1190 Vienna, Austria
| | - Markus Schosserer
- Austrian Cluster for Tissue Regeneration, A-1200 Vienna, Austria
- Institute of Molecular Biotechnology, Department of Biotechnology, University of Natural Resources and Life Sciences, A-1190 Vienna, Austria
| | - Matthias Hackl
- Austrian Cluster for Tissue Regeneration, A-1200 Vienna, Austria
- TAmiRNA GmbH, A-1110 Vienna, Austria
| | - Johannes Grillari
- Austrian Cluster for Tissue Regeneration, A-1200 Vienna, Austria
- Institute of Molecular Biotechnology, Department of Biotechnology, University of Natural Resources and Life Sciences, A-1190 Vienna, Austria
- Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, A-1200 Vienna, Austria
| | - Reinhard Gruber
- Department of Oral Biology, School of Dentistry, Medical University of Vienna, A-1090 Vienna, Austria
- Austrian Cluster for Tissue Regeneration, A-1200 Vienna, Austria
- Department of Periodontology, School of Dental Medicine, University of Bern, 3010 Bern, Switzerland
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17
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Chavez MB, Chu EY, Kram V, de Castro LF, Somerman MJ, Foster BL. Guidelines for Micro-Computed Tomography Analysis of Rodent Dentoalveolar Tissues. JBMR Plus 2021; 5:e10474. [PMID: 33778330 PMCID: PMC7990153 DOI: 10.1002/jbm4.10474] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 01/16/2021] [Accepted: 02/09/2021] [Indexed: 12/21/2022] Open
Abstract
Micro–computed tomography (μCT) has become essential for analysis of mineralized as well as nonmineralized tissues and is therefore widely applicable in the life sciences. However, lack of standardized approaches and protocols for scanning, analyzing, and reporting data often makes it difficult to understand exactly how analyses were performed, how to interpret results, and if findings can be broadly compared with other models and studies. This problem is compounded in analysis of the dentoalveolar complex by the presence of four distinct mineralized tissues: enamel, dentin, cementum, and alveolar bone. Furthermore, these hard tissues interface with adjacent soft tissues, the dental pulp and periodontal ligament (PDL), making for a complex organ. Drawing on others' and our own experience analyzing rodent dentoalveolar tissues by μCT, we introduce techniques to successfully analyze dentoalveolar tissues with similar or disparate compositions, densities, and morphological characteristics. Our goal is to provide practical guidelines for μCT analysis of rodent dentoalveolar tissues, including approaches to optimize scan parameters (filters, voltage, voxel size, and integration time), reproducibly orient samples, define regions and volumes of interest, segment and subdivide tissues, interpret findings, and report methods and results. We include illustrative examples of analyses performed on genetically engineered mouse models with phenotypes in enamel, dentin, cementum, and alveolar bone. The recommendations are designed to increase transparency and reproducibility, promote best practices, and provide a basic framework to apply μCT analysis to the dentoalveolar complex that can also be extrapolated to a variety of other tissues of the body. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Michael B Chavez
- Division of Biosciences, College of Dentistry The Ohio State University Columbus OH USA
| | - Emily Y Chu
- National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) National Institutes of Health (NIH) Bethesda MD USA
| | - Vardit Kram
- National Institute of Dental and Craniofacial Research (NIDCR)National Institutes of Health (NIH) Bethesda MD USA
| | - Luis F de Castro
- National Institute of Dental and Craniofacial Research (NIDCR)National Institutes of Health (NIH) Bethesda MD USA
| | - Martha J Somerman
- National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) National Institutes of Health (NIH) Bethesda MD USA
| | - Brian L Foster
- Division of Biosciences, College of Dentistry The Ohio State University Columbus OH USA
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18
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Stifler CA, Jakes JE, North JD, Green DR, Weaver JC, Gilbert PUPA. Crystal misorientation correlates with hardness in tooth enamels. Acta Biomater 2021; 120:124-134. [PMID: 32711081 DOI: 10.1016/j.actbio.2020.07.037] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 07/14/2020] [Accepted: 07/17/2020] [Indexed: 01/31/2023]
Abstract
The multi-scale hierarchical structure of tooth enamel enables it to withstand a lifetime of damage without catastrophic failure. While many previous studies have investigated structure-function relationships in enamel, the effects of crystal misorientation on mechanical performance have not been assessed. To address this issue, in the present study, we review previously published polarization-dependent imaging contrast (PIC) maps of mouse and human enamel, and parrotfish enameloid, in which crystal orientations were measured and displayed in every 60-nm-pixel. By combining those previous results with the PIC maps of sheep enamel presented here we discovered that, in all enamel(oid)s, adjacent crystals are slightly misoriented, with misorientation angles in the 0°-30° range, and mean 2°-8°. Within this limited range, misorientation is positively correlated with literature hardness values, demonstrating an important structure-property relation, not previously identified. At greater misorientation angles 8°30°, this correlation is expected to reverse direction, but data from different non-enamel systems, with more diverse crystal misorientations, are required to determine if and where this occurs. STATEMENT OF SIGNIFICANCE: We identify a structure-function relationship in tooth enamels from different species: crystal misorientation correlates with hardness, contributing to the remarkable mechanical properties of enamel in diverse animals.
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Affiliation(s)
- Cayla A Stifler
- Department of Physics, University of Wisconsin, Madison, WI 53706, United States
| | - Joseph E Jakes
- Forest Biopolymers Science and Engineering, USDA Forest Service, Forest Products Laboratory, Madison, WI 53726, United States
| | - Jamie D North
- Department of Chemistry, Carleton College, Northfield, MN 55057, United States
| | - Daniel R Green
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA 02138, United States
| | - James C Weaver
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA 02138, United States
| | - Pupa U P A Gilbert
- Department of Physics, University of Wisconsin, Madison, WI 53706, United States; Departments of Chemistry, Geoscience, Materials Science, University of Wisconsin, Madison, WI 53706, United States.
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Odontogenesis-associated phosphoprotein truncation blocks ameloblast transition into maturation in Odaph C41*/C41* mice. Sci Rep 2021; 11:1132. [PMID: 33441959 PMCID: PMC7807025 DOI: 10.1038/s41598-020-80912-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 12/21/2020] [Indexed: 01/29/2023] Open
Abstract
Mutations of Odontogenesis-Associated Phosphoprotein (ODAPH, OMIM *614829) cause autosomal recessive amelogenesis imperfecta, however, the function of ODAPH during amelogenesis is unknown. Here we characterized normal Odaph expression by in situ hybridization, generated Odaph truncation mice using CRISPR/Cas9 to replace the TGC codon encoding Cys41 into a TGA translation termination codon, and characterized and compared molar and incisor tooth formation in Odaph+/+, Odaph+/C41*, and OdaphC41*/C41* mice. We also searched genomes to determine when Odaph first appeared phylogenetically. We determined that tooth development in Odaph+/+ and Odaph+/C41* mice was indistinguishable in all respects, so the condition in mice is inherited in a recessive pattern, as it is in humans. Odaph is specifically expressed by ameloblasts starting with the onset of post-secretory transition and continues until mid-maturation. Based upon histological and ultrastructural analyses, we determined that the secretory stage of amelogenesis is not affected in OdaphC41*/C41* mice. The enamel layer achieves a normal shape and contour, normal thickness, and normal rod decussation. The fundamental problem in OdaphC41*/C41* mice starts during post-secretory transition, which fails to generate maturation stage ameloblasts. At the onset of what should be enamel maturation, a cyst forms that separates flattened ameloblasts from the enamel surface. The maturation stage fails completely.
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Gil-Bona A, Bidlack FB. Tooth Enamel and its Dynamic Protein Matrix. Int J Mol Sci 2020; 21:ijms21124458. [PMID: 32585904 PMCID: PMC7352428 DOI: 10.3390/ijms21124458] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 06/19/2020] [Accepted: 06/20/2020] [Indexed: 12/12/2022] Open
Abstract
Tooth enamel is the outer covering of tooth crowns, the hardest material in the mammalian body, yet fracture resistant. The extremely high content of 95 wt% calcium phosphate in healthy adult teeth is achieved through mineralization of a proteinaceous matrix that changes in abundance and composition. Enamel-specific proteins and proteases are known to be critical for proper enamel formation. Recent proteomics analyses revealed many other proteins with their roles in enamel formation yet to be unraveled. Although the exact protein composition of healthy tooth enamel is still unknown, it is apparent that compromised enamel deviates in amount and composition of its organic material. Why these differences affect both the mineralization process before tooth eruption and the properties of erupted teeth will become apparent as proteomics protocols are adjusted to the variability between species, tooth size, sample size and ephemeral organic content of forming teeth. This review summarizes the current knowledge and published proteomics data of healthy and diseased tooth enamel, including advancements in forensic applications and disease models in animals. A summary and discussion of the status quo highlights how recent proteomics findings advance our understating of the complexity and temporal changes of extracellular matrix composition during tooth enamel formation.
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Affiliation(s)
- Ana Gil-Bona
- The Forsyth Institute, Cambridge, MA 02142, USA
- Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA 02115, USA
- Correspondence: (A.G.-B.); (F.B.B.)
| | - Felicitas B. Bidlack
- The Forsyth Institute, Cambridge, MA 02142, USA
- Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA 02115, USA
- Correspondence: (A.G.-B.); (F.B.B.)
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21
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Wang SK, Zhang H, Chavez MB, Hu Y, Seymen F, Koruyucu M, Kasimoglu Y, Colvin CD, Kolli TN, Tan MH, Wang YL, Lu PY, Kim JW, Foster BL, Bartlett JD, Simmer JP, Hu JCC. Dental malformations associated with biallelic MMP20 mutations. Mol Genet Genomic Med 2020; 8:e1307. [PMID: 32495503 PMCID: PMC7434610 DOI: 10.1002/mgg3.1307] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 04/07/2020] [Accepted: 04/08/2020] [Indexed: 12/30/2022] Open
Abstract
Background Matrix metallopeptidase 20 (MMP20) is an evolutionarily conserved protease that is essential for processing enamel matrix proteins during dental enamel formation. MMP20 mutations cause human autosomal recessive pigmented hypomaturation‐type amelogenesis imperfecta (AI2A2; OMIM #612529). MMP20 is expressed in both odontoblasts and ameloblasts, but its function during dentinogenesis is unclear. Methods We characterized 10 AI kindreds with MMP20 defects, characterized human third molars and/or Mmp20−/− mice by histology, Backscattered Scanning Electron Microscopy (bSEM), µCT, and nanohardness testing. Results We identified six novel MMP20 disease‐causing mutations. Four pathogenic variants were associated with exons encoding the MMP20 hemopexin‐like (PEX) domain, suggesting a necessary regulatory function. Mutant human enamel hardness was softest (13% of normal) midway between the dentinoenamel junction (DEJ) and the enamel surface. bSEM and µCT analyses of the third molars revealed reduced mineral density in both enamel and dentin. Dentin close to the DEJ showed an average hardness number 62%–69% of control. Characterization of Mmp20−/− mouse dentin revealed a significant reduction in dentin thickness and mineral density and a transient increase in predentin thickness, indicating disturbances in dentin matrix secretion and mineralization. Conclusion These results expand the spectrum of MMP20 disease‐causing mutations and provide the first evidence for MMP20 function during dentin formation.
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Affiliation(s)
- Shih-Kai Wang
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, USA.,Department of Pediatric Dentistry, National Taiwan University School of Dentistry, Taipei City, Taiwan R.O.C
| | - Hong Zhang
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Michael B Chavez
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - Yuanyuan Hu
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Figen Seymen
- Department of Pedodontics, Istanbul University Faculty of Dentistry, Istanbul, Turkey
| | - Mine Koruyucu
- Department of Pedodontics, Istanbul University Faculty of Dentistry, Istanbul, Turkey
| | - Yelda Kasimoglu
- Department of Pedodontics, Istanbul University Faculty of Dentistry, Istanbul, Turkey
| | - Connor D Colvin
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - Tamara N Kolli
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - Michelle H Tan
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - Yin-Lin Wang
- Department of Pediatric Dentistry, National Taiwan University School of Dentistry, Taipei City, Taiwan R.O.C
| | - Pei-Ying Lu
- Department of Pediatric Dentistry, National Taiwan University School of Dentistry, Taipei City, Taiwan R.O.C
| | - Jung-Wook Kim
- Department of Pediatric Dentistry & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea.,Department of Molecular Genetics & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - Brian L Foster
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - John D Bartlett
- Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - James P Simmer
- 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
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22
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Kim Y, Kang J, Seymen F, Koruyucu M, Zhang H, Kasimoglu Y, Bayram M, Tuna-Ince E, Bayrak S, Tuloglu N, Hu JC, Simmer J, Kim JW. Alteration of Exon Definition Causes Amelogenesis Imperfecta. J Dent Res 2020; 99:410-418. [PMID: 31999931 PMCID: PMC7088207 DOI: 10.1177/0022034520901708] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Amelogenesis imperfecta (AI) is a collection of genetic disorders affecting the quality and/or quantity of tooth enamel. More than 20 genes are, so far, known to be responsible for this condition. In this study, we recruited 3 Turkish families with hypomaturation AI. Whole-exome sequence analyses identified disease-causing mutations in each proband, and these mutations cosegregated with the AI phenotype in all recruited members of each family. The AI-causing mutations in family 1 were a novel AMELX mutation [NM_182680.1:c.143T>C, p.(Leu48Ser)] in the proband and a novel homozygous MMP20 mutation [NM_004771.3:c.616G>A, p.(Asp206Asn)] in the mother of the proband. Previously reported compound heterozygous MMP20 mutations [NM_004771.3:c.103A>C, p.(Arg35=) and c.389C>T, p.(Thr130Ile)] caused the AI in family 2 and family 3. Minigene splicing analyses revealed that the AMELX missense mutation increased exonic definition of exon 4 and the MMP20 synonymous mutation decreased exonic definition of exon 1. These mutations would trigger an alteration of exon usage during RNA splicing, causing the enamel malformations. These results broaden our understanding of molecular genetic pathology of tooth enamel formation.
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Affiliation(s)
- Y.J. Kim
- Department of Molecular Genetics & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - J. Kang
- Department of Pediatric Dentistry & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - F. Seymen
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul, Turkey
| | - M. Koruyucu
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul, Turkey
| | - H. Zhang
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| | - Y. Kasimoglu
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul, Turkey
| | - M. Bayram
- Department of Pedodontics, Faculty of Dentistry, Istanbul Medipol University, Istanbul, Turkey
| | - E.B. Tuna-Ince
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul, Turkey
| | - S. Bayrak
- Department of Pediatric Dentistry, Faculty of Dentistry, University of Eskisehir Osmangazi, Eskisehir, Turkey
| | - N. Tuloglu
- Department of Pediatric Dentistry, Faculty of Dentistry, University of Eskisehir Osmangazi, Eskisehir, Turkey
| | - J.C.-C. Hu
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| | - J.P. Simmer
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| | - J.-W. Kim
- Department of Molecular Genetics & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
- Department of Pediatric Dentistry & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
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23
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Kelly AM, Kallistova A, Küchler EC, Romanos HF, Lips A, Costa MC, Modesto A, Vieira AR. Measuring the Microscopic Structures of Human Dental Enamel Can Predict Caries Experience. J Pers Med 2020; 10:jpm10010005. [PMID: 32024259 PMCID: PMC7151622 DOI: 10.3390/jpm10010005] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 01/28/2020] [Accepted: 01/28/2020] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVES The hierarchical structure of enamel gives insight on the properties of enamel and can influence its strength and ultimately caries experience. Currently, past caries experience is quantified using the decayed, missing, filled teeth/decayed, missing, filled surface (DMFT/DMFS for permanent teeth; dmft/dmfs for primary teeth), or international caries detection and assessment system (ICDAS) scores. By analyzing the structure of enamel, a new measurement can be utilized clinically to predict susceptibility to future caries experience based on a patient's individual's biomarkers. The purpose of this study was to test the hypothesis that number of prisms by square millimeter in enamel and average gap distance between prisms and interprismatic areas, influence caries experience through genetic variation of the genes involved in enamel formation. MATERIALS AND METHODS Scanning electron microscopy (SEM) images of enamel from primary teeth were used to measure (i) number of prisms by square millimeter and interprismatic spaces, (ii) prism density, and (iii) gap distances between prisms in the enamel samples. The measurements were tested to explore a genetic association with variants of selected genes and correlations with caries experience based on the individual's DMFT+ dmft score and enamel microhardness at baseline, after an artificial lesion was created and after the artificial lesion was treated with fluoride. RESULTS Associations were found between variants of genes including ameloblastin, amelogenin, enamelin, tuftelin, tuftelin interactive protein 11, beta defensin 1, matrix metallopeptidase 20 and enamel structure variables measured (number of prisms by square millimeter in enamel and average gap distance between prisms and interprismatic areas). Significant correlations were found between caries experience and microhardness and enamel structure. Negative correlations were found between number of prisms by square millimeter and high caries experience (r value= -0.71), gap distance between prisms and the enamel microhardness after an artificial lesion was created (r value= -0.70), and gap distance between prisms and the enamel microhardness after an artificial lesion was created and then treated with fluoride (r value= -0.81). There was a positive correlation between number of prisms by square millimeter and prism density of the enamel (r value = 0.82). CONCLUSIONS Our data support that genetic variation may impact enamel formation, and therefore influence susceptibility to dental caries and future caries experience. CLINICAL RELEVANCE The evaluation of enamel structure that may impact caries experience allows for hypothesizing that the identification of individuals at higher risk for dental caries and implementation of personalized preventative treatments may one day become a reality.
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Affiliation(s)
- Ariana M. Kelly
- Department of Oral Biology, School of Dental Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA; (A.M.K.); (E.C.K.)
| | - Anna Kallistova
- Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University, Albertov 6, Prague 2, Czech;
- Institute of Geology of the CAS, v.v.i., Rozvojová 269, Prague 6, Czech
| | - Erika C. Küchler
- Department of Oral Biology, School of Dental Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA; (A.M.K.); (E.C.K.)
- Department of Pediatric Dentistry and Orthodontics, Federal University of Rio de Janeiro, Rio de Janeiro, RJ 21941-901, Brazil; (H.F.R.); (M.C.C.)
| | - Helena F. Romanos
- Department of Pediatric Dentistry and Orthodontics, Federal University of Rio de Janeiro, Rio de Janeiro, RJ 21941-901, Brazil; (H.F.R.); (M.C.C.)
| | - Andrea Lips
- Clinical Research Unit, Fluminense Federal University, Niteról 24020, Brazil;
| | - Marcelo C. Costa
- Department of Pediatric Dentistry and Orthodontics, Federal University of Rio de Janeiro, Rio de Janeiro, RJ 21941-901, Brazil; (H.F.R.); (M.C.C.)
| | - Adriana Modesto
- Department of Pediatric Dentistry, School of Dental Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA;
| | - Alexandre R. Vieira
- Department of Oral Biology, School of Dental Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA; (A.M.K.); (E.C.K.)
- Correspondence:
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24
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Zhang H, Hu Y, Seymen F, Koruyucu M, Kasimoglu Y, Wang S, Wright JT, Havel MW, Zhang C, Kim J, Simmer JP, Hu JC. ENAM mutations and digenic inheritance. Mol Genet Genomic Med 2019; 7:e00928. [PMID: 31478359 PMCID: PMC6785452 DOI: 10.1002/mgg3.928] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 07/25/2019] [Accepted: 07/26/2019] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND ENAM mutations cause autosomal dominant or recessive amelogenesis imperfecta (AI) and show a dose effect: enamel malformations are more severe or only penetrant when both ENAM alleles are defective. METHODS Whole exome sequences of recruited AI probands were initially screened for mutations in known AI candidate genes. Sanger sequencing was used to confirm sequence variations and their segregation with the disease phenotype. The co-occurrence of ENAM and LAMA3 mutations in one family raised the possibility of digenic inheritance. Enamel formed in Enam+/+ Ambn+/+ , Enam+/- , Ambn+/- , and Enam+/- Ambn+/- mice was characterized by dissection and backscattered scanning electron microscopy (bSEM). RESULTS ENAM mutations segregating with AI in five families were identified. Two novel ENAM frameshift mutations were identified. A single-nucleotide duplication (c.395dupA/p.Pro133Alafs*13) replaced amino acids 133-1142 with a 12 amino acid (ATTKAAFEAAIT*) sequence, and a single-nucleotide deletion (c.2763delT/p.Asp921Glufs*32) replaced amino acids 921-1142 with 31 amino acids (ESSPQQASYQAKETAQRRGKAKTLLEMMCPR*). Three families were heterozygous for a previously reported single-nucleotide ENAM deletion (c.588+1delG/p.Asn197Ilefs*81). One of these families also harbored a heterozygous LAMA3 mutation (c.1559G>A/p.Cys520Tyr) that cosegregated with both the AI phenotype and the ENAM mutation. In mice, Ambn+/- maxillary incisors were normal. Ambn+/- molars were also normal, except for minor surface roughness. Ambn+/- mandibular incisors were sometimes chalky and showed minor chipping. Enam+/- incisor enamel was thinner than normal with ectopic mineral deposited laterally. Enam+/- molars were sometimes chalky and rough surfaced. Enam+/- Ambn+/- enamel was thin and rough, in part due to ectopic mineralization, but also underwent accelerated attrition. CONCLUSION Novel ENAM mutations causing AI were identified, raising to 22 the number of ENAM variations known to cause AI. The severity of the enamel phenotype in Enam+/- Ambn+/- double heterozygous mice is caused by composite digenic effects. Digenic inheritance should be explored as a cause of AI in humans.
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Affiliation(s)
- Hong Zhang
- Department of Biologic and Materials SciencesUniversity of Michigan School of DentistryAnn ArborMIUSA
| | - Yuanyuan Hu
- Department of Biologic and Materials SciencesUniversity of Michigan School of DentistryAnn ArborMIUSA
| | - Figen Seymen
- Department of Pedodontics, Faculty of DentistryIstanbul UniversityIstanbulTurkey
| | - Mine Koruyucu
- Department of Pedodontics, Faculty of DentistryIstanbul UniversityIstanbulTurkey
| | - Yelda Kasimoglu
- Department of Pedodontics, Faculty of DentistryIstanbul UniversityIstanbulTurkey
| | - Shih‐Kai Wang
- Department of Biologic and Materials SciencesUniversity of Michigan School of DentistryAnn ArborMIUSA
- Department of DentistryNational Taiwan University School of DentistryTaipei CityTaiwan R.O.C.
| | - John Timothy Wright
- Department of Pediatric DentistryUniversity of North Carolina School of DentistryChapel HillNCUSA
| | - Michael W. Havel
- Department of Biologic and Materials SciencesUniversity of Michigan School of DentistryAnn ArborMIUSA
| | - Chuhua Zhang
- Department of Biologic and Materials SciencesUniversity of Michigan School of DentistryAnn ArborMIUSA
| | - Jung‐Wook Kim
- Department of Molecular Genetics and Department of Pediatric Dentistry and Dental Research Institute, School of DentistrySeoul National UniversitySeoulKorea
| | - James P. Simmer
- Department of Biologic and Materials SciencesUniversity of Michigan School of DentistryAnn ArborMIUSA
| | - Jan C.‐C. Hu
- Department of Biologic and Materials SciencesUniversity of Michigan School of DentistryAnn ArborMIUSA
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25
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Green DR, Schulte F, Lee KH, Pugach MK, Hardt M, Bidlack FB. Mapping the Tooth Enamel Proteome and Amelogenin Phosphorylation Onto Mineralizing Porcine Tooth Crowns. Front Physiol 2019; 10:925. [PMID: 31417410 PMCID: PMC6682599 DOI: 10.3389/fphys.2019.00925] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 07/09/2019] [Indexed: 01/13/2023] Open
Abstract
Tooth enamel forms in an ephemeral protein matrix where changes in protein abundance, composition and posttranslational modifications are critical to achieve healthy enamel properties. Amelogenin (AMELX) with its splice variants is the most abundant enamel matrix protein, with only one known phosphorylation site at serine 16 shown in vitro to be critical for regulating mineralization. The phosphorylated form of AMELX stabilizes amorphous calcium phosphate, while crystalline hydroxyapatite forms in the presence of the unphosphorylated protein. While AMELX regulates mineral transitions over space and time, it is unknown whether and when un-phosphorylated amelogenin occurs during enamel mineralization. This study aims to reveal the spatiotemporal distribution of the cleavage products of the most abundant AMLEX splice variants including the full length P173, the shorter leucine-rich amelogenin protein (LRAP), and the exon 4-containing P190 in forming enamel, all within the context of the changing enamel matrix proteome during mineralization. We microsampled permanent pig molars, capturing known stages of enamel formation from both crown surface and inner enamel. Nano-LC-MS/MS proteomic analyses after tryptic digestion rendered more than 500 unique protein identifications in enamel, dentin, and bone. We mapped collagens, keratins, and proteolytic enzymes (CTSL, MMP2, MMP10) and determined distributions of P173, LRAP, and P190 products, the enamel proteins enamelin (ENAM) and ameloblastin (AMBN), and matrix-metalloprotease-20 (MMP20) and kallikrein-4 (KLK4). All enamel proteins and KLK4 were near-exclusive to enamel and in excellent agreement with published abundance levels. Phosphorylated P173 and LRAP products decreased in abundance from recently deposited matrix toward older enamel, mirrored by increasing abundances of testicular acid phosphatase (ACPT). Our results showed that hierarchical clustering analysis of secretory enamel links closely matching distributions of unphosphorylated P173 and LRAP products with ACPT and non-traditional amelogenesis proteins, many associated with enamel defects. We report higher protein diversity than previously published and Gene Ontology (GO)-defined protein functions related to the regulation of mineral formation in secretory enamel (e.g., casein α-S1, CSN1S1), immune response in erupted enamel (e.g., peptidoglycan recognition protein, PGRP), and phosphorylation. This study presents a novel approach to characterize and study functional relationships through spatiotemporal mapping of the ephemeral extracellular matrix proteome.
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Affiliation(s)
- Daniel R Green
- The Forsyth Institute, Cambridge, MA, United States.,Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, United States
| | | | - Kyu-Ha Lee
- The Forsyth Institute, Cambridge, MA, United States.,Department of Oral Health Policy and Epidemiology, Harvard School of Dental Medicine, Boston, MA, United States
| | - Megan K Pugach
- The Forsyth Institute, Cambridge, MA, United States.,Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA, United States
| | - Markus Hardt
- The Forsyth Institute, Cambridge, MA, United States.,Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA, United States
| | - Felicitas B Bidlack
- The Forsyth Institute, Cambridge, MA, United States.,Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA, United States
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26
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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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Yamazaki H, Tran B, Beniash E, Kwak SY, Margolis HC. Proteolysis by MMP20 Prevents Aberrant Mineralization in Secretory Enamel. J Dent Res 2019; 98:468-475. [PMID: 30744480 DOI: 10.1177/0022034518823537] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The present study was conducted to investigate the role of proteolysis by matrix metalloproteinase 20 (MMP20) in regulating the initial formation of the enamel mineral structure during the secretory stage of amelogenesis, utilizing Mmp20-null mice that lack this essential protease. Ultrathin sagittal sections of maxillary incisors from 8-wk-old wild-type (WT), Mmp20-null (KO), and heterozygous (HET) littermates were prepared. Secretory-stage enamel ultrastructures from each genotype as a function of development were compared using transmission electron microscopy, selected area electron diffraction, and Raman microspectroscopy. Characteristic rod structures observed in WT enamel exhibited amorphous features in newly deposited enamel, which subsequently transformed into apatite-like crystals in older enamel. Surprisingly, initial mineral formation in KO enamel was found to proceed in the same manner as in the WT. However, soon after a rod structure began to form, large plate-like crystals appeared randomly within the developing KO enamel layer. As development continued, observed plate-like crystals became dominant and obscured the appearance of the enamel rod structure. Upon formation of these plate-like crystals, the KO enamel layer stopped growing in thickness, unlike WT and HET enamel layers that continued to grow at the same rate. Raman results indicated that Mmp20-KO enamel contains a significant portion of octacalcium phosphate, unlike WT enamel. Although normal in all other respects, large, randomly dispersed mineral crystals were observed in secretory HET enamel, although to a lesser extent than that seen in KO enamel, indicating that the level of MMP20 expression has a proportional effect on suppressing aberrant mineral formation. In conclusion, we found that proteolysis of extracellular enamel matrix proteins by MMP20 is not required for the initial development of the enamel rod structure during the early secretory stage of amelogenesis. Proteolysis by MMP20, however, is essential for the prevention of abnormal crystal formation during amelogenesis.
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Affiliation(s)
- H Yamazaki
- 1 The Forsyth Institute, Cambridge, MA, USA.,2 Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA, USA
| | - B Tran
- 3 Simmons College, Boston, MA, USA
| | - E Beniash
- 4 Center for Craniofacial Regeneration, Department of Oral Biology, University of Pittsburgh School of Dental Medicine, Pittsburgh, PA, USA
| | - S Y Kwak
- 1 The Forsyth Institute, Cambridge, MA, USA.,2 Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA, USA
| | - H C Margolis
- 1 The Forsyth Institute, Cambridge, MA, USA.,2 Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA, USA
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Pandya M, Diekwisch TGH. Enamel biomimetics-fiction or future of dentistry. Int J Oral Sci 2019. [PMID: 30610185 DOI: 10.1038/s41368-018-0038-6,1-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2023] Open
Abstract
Tooth enamel is a complex mineralized tissue consisting of long and parallel apatite crystals configured into decussating enamel rods. In recent years, multiple approaches have been introduced to generate or regenerate this highly attractive biomaterial characterized by great mechanical strength paired with relative resilience and tissue compatibility. In the present review, we discuss five pathways toward enamel tissue engineering, (i) enamel synthesis using physico-chemical means, (ii) protein matrix-guided enamel crystal growth, (iii) enamel surface remineralization, (iv) cell-based enamel engineering, and (v) biological enamel regeneration based on de novo induction of tooth morphogenesis. So far, physical synthesis approaches using extreme environmental conditions such as pH, heat and pressure have resulted in the formation of enamel-like crystal assemblies. Biochemical methods relying on enamel proteins as templating matrices have aided the growth of elongated calcium phosphate crystals. To illustrate the validity of this biochemical approach we have successfully grown enamel-like apatite crystals organized into decussating enamel rods using an organic enamel protein matrix. Other studies reviewed here have employed amelogenin-derived peptides or self-assembling dendrimers to re-mineralize mineral-depleted white lesions on tooth surfaces. So far, cell-based enamel tissue engineering has been hampered by the limitations of presently existing ameloblast cell lines. Going forward, these limitations may be overcome by new cell culture technologies. Finally, whole-tooth regeneration through reactivation of the signaling pathways triggered during natural enamel development represents a biological avenue toward faithful enamel regeneration. In the present review we have summarized the state of the art in enamel tissue engineering and provided novel insights into future opportunities to regenerate this arguably most fascinating of all dental tissues.
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Affiliation(s)
- Mirali Pandya
- Center for Craniofacial Research and Diagnosis, Texas A&M College of Dentistry, Dallas, TX, USA
| | - Thomas G H Diekwisch
- Center for Craniofacial Research and Diagnosis, Texas A&M College of Dentistry, Dallas, TX, USA.
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29
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Abstract
Tooth enamel is a complex mineralized tissue consisting of long and parallel apatite crystals configured into decussating enamel rods. In recent years, multiple approaches have been introduced to generate or regenerate this highly attractive biomaterial characterized by great mechanical strength paired with relative resilience and tissue compatibility. In the present review, we discuss five pathways toward enamel tissue engineering, (i) enamel synthesis using physico-chemical means, (ii) protein matrix-guided enamel crystal growth, (iii) enamel surface remineralization, (iv) cell-based enamel engineering, and (v) biological enamel regeneration based on de novo induction of tooth morphogenesis. So far, physical synthesis approaches using extreme environmental conditions such as pH, heat and pressure have resulted in the formation of enamel-like crystal assemblies. Biochemical methods relying on enamel proteins as templating matrices have aided the growth of elongated calcium phosphate crystals. To illustrate the validity of this biochemical approach we have successfully grown enamel-like apatite crystals organized into decussating enamel rods using an organic enamel protein matrix. Other studies reviewed here have employed amelogenin-derived peptides or self-assembling dendrimers to re-mineralize mineral-depleted white lesions on tooth surfaces. So far, cell-based enamel tissue engineering has been hampered by the limitations of presently existing ameloblast cell lines. Going forward, these limitations may be overcome by new cell culture technologies. Finally, whole-tooth regeneration through reactivation of the signaling pathways triggered during natural enamel development represents a biological avenue toward faithful enamel regeneration. In the present review we have summarized the state of the art in enamel tissue engineering and provided novel insights into future opportunities to regenerate this arguably most fascinating of all dental tissues. Five pathways for tooth enamel engineering hold great promise for developing new technologies, leading to novel biomaterials and biotechnologies to regenerate enamel tissue. Tooth enamel is a unique tissue-specific biomaterial with exceptional structural and mechanical properties. In recent years, many approaches have been adopted to generate or regenerate this complex tissue; Mirali Pandya and Thomas Diekwisch of Texas A&M College of Dentistry, USA conducted a review of the current state and future directions of enamel tissue engineering. In their review, the authors focused on five pathways for enamel tissue engineering: (1) physical synthesis of enamel; (2) biochemical enamel engineering; (3) in situ enamel engineering; (4) cell-based enamel engineering; and (5) whole tooth regeneration. The authors conclude that those five approaches will help identify the biological mechanisms that lead to the generation of tooth enamel.
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Song W, Wang Y, Chu Q, Qi C, Gao Y, Gao Y, Xiang L, Zhenzhen X, Gao Y. Loss of transforming growth factor-β1 in epithelium cells affects enamel formation in mice. Arch Oral Biol 2018; 96:146-154. [PMID: 30243146 DOI: 10.1016/j.archoralbio.2018.09.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 09/07/2018] [Accepted: 09/08/2018] [Indexed: 01/23/2023]
Abstract
OBJECTIVES In order to understand the specific in vivo function of transforming growth factor-beta1 (TGF-β1), we successfully established aTGF-β1 deficient mouse model using a conditional knockout method. In the present study, we aimed to further understand the potential role of TGF-β1 in enamel formation. DESIGN Transgenic mice withoutTGF-β1 in epithelial cells were generated. Scanning electron microscopy and micro-computed tomography analysis were used to detect the dental appearance, enamel microstructure and tooth density. Histological analysis was used to examine the residual organic matrix of enamel. Quantitative real-time polymerase chain reaction was used to analyze the expressions of enamel matrix proteins at the mRNA level. RESULTS The enamel of mandibular molars and incisors inTGF-β1 conditional knockout mice displayed severe attrition and lower density compared with the wild-type littermates. A slender microstructure of enamel rod was observed, and enamel matrix proteins were retained in the enamel space at the maturation stage in conditional knockout mice. Moreover, the expressions of enamel matrix protein-encoding genes, such as amelogenin (Amelx), ameloblastin (Ambn), Enamelin (Enam) and matrix metalloproteinase-20 (Mmp-20), were increased in enamel organs of conditional knockout mice. On the other hand, the expressions of Amelotin (Amtn), kallikrein-related peptidase-4 (Klk4), C4orf26 and WD repeat-containing protein 72 (Wdr72) were dramatically decreased at the transition and maturation stages. CONCLUSIONS TGF-β1 played an important role in enamel mineralization through decreasing synthesis ofAmelx, Ambn and Enam and increasing synthesis of Klk4, Amtn, Corf26 and Wdr72.
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Affiliation(s)
- Wenying Song
- Department of Stomatology, Hospital Affiliated to Binzhou Medical University, Binzhou City, Shandong Province, 256603, People's Republic of China
| | - Yanli Wang
- Binzhou People's Hospital of Shandong Province, Shandong Binzhou 2566610, People's Republic of China
| | - Qing Chu
- Department of Stomatology, Hospital Affiliated to Binzhou Medical University, Binzhou City, Shandong Province, 256603, People's Republic of China
| | - Congcong Qi
- Institute of Stomatology, Binzhou Medical University, Yantai, Shandong Province 264003, People's Republic of China
| | - Yuehua Gao
- Institute of Stomatology, Binzhou Medical University, Yantai, Shandong Province 264003, People's Republic of China
| | - Yan Gao
- Department of Stomatology, Hospital Affiliated to Binzhou Medical University, Binzhou City, Shandong Province, 256603, People's Republic of China
| | - Lili Xiang
- Department of Stomatology, Hospital Affiliated to Binzhou Medical University, Binzhou City, Shandong Province, 256603, People's Republic of China
| | - Xu Zhenzhen
- Department of Stomatology, Hospital Affiliated to Binzhou Medical University, Binzhou City, Shandong Province, 256603, People's Republic of China
| | - Yuguang Gao
- Department of Stomatology, Hospital Affiliated to Binzhou Medical University, Binzhou City, Shandong Province, 256603, People's Republic of China.
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31
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Fan L, Deng S, Sui X, Liu M, Cheng S, Wang Y, Gao Y, Chu CH, Zhang Q. Constitutive activation of β-catenin in ameloblasts leads to incisor enamel hypomineralization. J Mol Histol 2018; 49:499-507. [PMID: 30066216 DOI: 10.1007/s10735-018-9788-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Accepted: 07/25/2018] [Indexed: 12/13/2022]
Abstract
Enamel is the hardest tissue with the highest degree of mineralization protecting the dental pulp from injury in vertebrates. The ameloblasts differentiated from ectoderm-derived epithelial cells are a single cell layer and are important for the enamel formation and mineralization. Wnt/β-catenin signaling has been proven to exert an important role in the mineralization of bone, dentin and cementum. Little was known about the regulatory mechanism of Wnt/β-catenin signaling pathway in ameloblasts during amelogenesis, especially in the mineralization of enamel. To investigate the role of β-catenin in ameloblasts, we established Amelx-Cre; β-catenin∆ex3fl/fl (CA-β-catenin) mice, which could constitutive activate β-catenin in ameloblasts. It showed the delayed mineralization and eventual hypomineralization in the incisor enamel of CA-β-catenin mice. Meanwhile, the amelogenesis-related proteinases Mmp20 and Klk4 were decreased in the incisors of CA-β-catenin mice. These data indicated that β-catenin plays an essential role in differentiation and function of ameloblasts during amelogenesis.
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Affiliation(s)
- Linlin Fan
- Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Shanghai, China
| | - Shijian Deng
- Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Shanghai, China
| | - Xin Sui
- Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Shanghai, China
| | - Mengmeng Liu
- Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Shanghai, China
| | - Shuhua Cheng
- Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Shanghai, China
| | - Yunfei Wang
- Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Shanghai, China
| | - Yuguang Gao
- Department of Stomatology, Hospital Affiliated to Binzhou Medical University, Binzhou, Shandong, China
| | - Chun-Hung Chu
- Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - Qi Zhang
- Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Shanghai, China. .,Department of Endodontics, School of Stomatology, Tongji University, Shanghai, China.
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32
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Shin M, Chavez MB, Ikeda A, Foster BL, Bartlett JD. MMP20 Overexpression Disrupts Molar Ameloblast Polarity and Migration. J Dent Res 2018; 97:820-827. [PMID: 29481294 DOI: 10.1177/0022034518758657] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Ameloblasts responsible for enamel formation express matrix metalloproteinase 20 (MMP20), an enzyme that cleaves enamel matrix proteins, including amelogenin (AMELX) and ameloblastin (AMBN). Previously, we showed that continuously erupting incisors from transgenic mice overexpressing active MMP20 had a massive cell infiltrate present within their enamel space, leading to enamel mineralization defects. However, effects of MMP20 overexpression on mouse molars were not analyzed, although these teeth more accurately represent human odontogenesis. Therefore, MMP20-overexpressing mice ( Mmp20+/+Tg+) were assessed by multiscale analyses, combining several approaches from high-resolution micro-computed tomography to enamel organ immunoblots. During the secretory stage at postnatal day 6 (P6), Mmp20+/+Tg+ mice had a discontinuous ameloblast layer and, unlike incisors, molar P12 maturation stage ameloblasts abnormally migrated away from the enamel layer into the stratum intermedium/stellate reticulum. TOPflash assays performed in vitro demonstrated that MMP20 expression promoted β-catenin nuclear localization and that MMP20 expression promoted invasion through Matrigel-coated filters. However, for both assays, significant differences were eliminated in the presence of the β-catenin inhibitor ICG-001. This suggests that MMP20 activity promotes cell migration via the Wnt pathway. In vivo, the unique molar migration of amelogenin-expressing ameloblasts was associated with abnormal deposition of ectopic calcified nodules surrounding the adherent enamel layer. Enamel content was assessed just prior to eruption at P15. Compared to wild-type, Mmp20+/+Tg+ molars exhibited significant reductions in enamel thickness (70%), volume (60%), and mineral density (40%), and MMP20 overexpression resulted in premature cleavage of AMBN, which likely contributed to the severe defects in enamel mineralization. In addition, Mmp20+/+Tg+ mouse molar enamel organs had increased levels of inactive p-cofilin, a protein that regulates cell polarity. These data demonstrate that increased MMP20 activity in molars causes premature degradation of ameloblastin and inactivation of cofilin, which may contribute to pathological Wnt-mediated cell migration away from the enamel layer.
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Affiliation(s)
- M Shin
- 1 Fukuoka Dental College, Sawara-ku, Fukuoka, Japan
| | - M B Chavez
- 2 Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - A Ikeda
- 2 Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - B L Foster
- 2 Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - J D Bartlett
- 2 Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
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33
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Pandya M, Rosene L, Farquharson C, Millán JL, Diekwisch TGH. Intravesicular Phosphatase PHOSPHO1 Function in Enamel Mineralization and Prism Formation. Front Physiol 2017; 8:805. [PMID: 29089903 PMCID: PMC5651051 DOI: 10.3389/fphys.2017.00805] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 09/29/2017] [Indexed: 11/13/2022] Open
Abstract
The transport of mineral ions from the enamel organ-associated blood vessels to the developing enamel crystals involves complex cargo packaging and carriage mechanisms across several cell layers, including the ameloblast layer and the stratum intermedium. Previous studies have established PHOSPHO1 as a matrix vesicle membrane-associated phosphatase that interacts with matrix vesicles molecules phosphoethanolamine and phosphocholine to initiate apatite crystal formation inside of matrix vesicles in bone. In the present study, we sought to determine the function of Phospho1 during amelogenesis. PHOSPHO1 protein localization during amelogenesis was verified using immunohistochemistry, with positive signals in the enamel layer, ameloblast Tomes' processes, and in the walls of ameloblast secretory vesicles. These ameloblast secretory vesicle walls were also labeled for amelogenin and the exosomal protein marker HSP70 using immunohistochemistry. Furthermore, PHOSPHO1 presence in the enamel organ was confirmed by Western blot. Phospho1−/− mice lacked sharp incisal tips, featured a significant 25% increase in total enamel volume, and demonstrated a significant 2-fold reduction in silver grain density of von Kossa stained ground sections indicative of reduced mineralization in the enamel layer when compared to wild-type mice (p < 0.001). Scanning electron micrographs of Phospho1−/− mouse enamel revealed a loss of the prominent enamel prism “picket fence” structure, a loss of parallel crystal organization within prisms, and a 1.56-fold increase in enamel prism width (p < 0.0001). Finally, EDS elemental analysis demonstrated a significant decrease in phosphate incorporation in the enamel layer when compared to controls (p < 0.05). Together, these data establish that the matrix vesicle membrane-associated phosphatase PHOSPHO1 is essential for physiological enamel mineralization. Our findings also suggest that intracellular ameloblast secretory vesicles have unexpected compositional similarities with the extracellular matrix vesicles of bone, dentin, and cementum in terms of vesicle membrane composition and intravesicular ion assembly.
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Affiliation(s)
- Mirali Pandya
- Department of Periodontics, Texas A&M College of Dentistry, Dallas, TX, United States.,Center for Craniofacial Research and Diagnosis, Texas A&M College of Dentistry, Dallas, TX, United States
| | - Lauren Rosene
- Department of Periodontics, Texas A&M College of Dentistry, Dallas, TX, United States.,Center for Craniofacial Research and Diagnosis, Texas A&M College of Dentistry, Dallas, TX, United States
| | - Colin Farquharson
- Division of Developmental Biology, The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom
| | - José L Millán
- Sanford Children's Health Research Center, Sanford-Burnham Institute for Medical Research, La Jolla, CA, United States
| | - Thomas G H Diekwisch
- Department of Periodontics, Texas A&M College of Dentistry, Dallas, TX, United States.,Center for Craniofacial Research and Diagnosis, Texas A&M College of Dentistry, Dallas, TX, United States
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Bronckers ALJJ, Lyaruu DM, Jalali R, DenBesten PK. Buffering of protons released by mineral formation during amelogenesis in mice. Eur J Oral Sci 2016; 124:415-425. [PMID: 27422589 DOI: 10.1111/eos.12287] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/01/2016] [Indexed: 12/17/2022]
Abstract
Regulation of pH by ameloblasts during amelogenesis is critical for enamel mineralization. We examined the effects of reduced bicarbonate secretion and the presence or absence of amelogenins on ameloblast modulation and enamel mineralization. To that end, the composition of fluorotic and non-fluorotic enamel of several different mouse mutants, including enamel of cystic fibrosis transmembrane conductance regulator-deficient (Cftr null), anion exchanger-2-deficient (Ae2a,b null), and amelogenin-deficient (Amelx null) mice, was determined by quantitative X-ray microanalysis. Correlation analysis was carried out to compare the effects of changes in the levels of sulfated-matrix (S) and chlorine (Cl; for bicarbonate secretion) on mineralization and modulation. The chloride (Cl- ) levels in forming enamel determined the ability of ameloblasts to modulate, remove matrix, and mineralize enamel. In general, the lower the Cl- content, the stronger the negative effects. In Amelx-null mice, modulation was essentially normal and the calcium content was reduced least. Retention of amelogenins in enamel of kallikrein-4-deficient (Klk4-null) mice resulted in decreased mineralization and reduced the length of the first acid modulation band without changing the total length of all acidic bands. These data suggest that buffering by bicarbonates is critical for modulation, matrix removal and enamel mineralization. Amelogenins also act as a buffer but are not critical for modulation.
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Affiliation(s)
- Antonius L J J Bronckers
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam, Amsterdam, the Netherlands. .,VU University Amsterdam, MOVE Research Institute, Amsterdam, the Netherlands.
| | - Don M Lyaruu
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam, Amsterdam, the Netherlands
| | - Rozita Jalali
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam, Amsterdam, the Netherlands
| | - Pamela K DenBesten
- Department of Oral Sciences, University of California in San Francisco, CA, USA
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