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Renostro-Souza A, Fonseca-Souza G, Küchler EC, Vasconcelos KRF, Feltrin-Souza J, Kirschneck C, Matsumoto MAN, Lepri CP, Oliveira MAHDM, Thedei G. Association of defects of enamel with polymorphisms in the vitamin D receptor and parathyroid hormone genes. Braz Dent J 2024; 35:e245900. [PMID: 38922252 PMCID: PMC11196029 DOI: 10.1590/0103-6440202405900] [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: 01/15/2024] [Accepted: 02/28/2024] [Indexed: 06/27/2024] Open
Abstract
This cross-sectional study aimed to investigate the association between developmental defects of enamel (DDE) and single nucleotide polymorphisms (SNPs) in the genes encoding the vitamin D receptor (VDR) and parathyroid hormone (PTH). Orthodontic patients receiving treatment at a dental school were selected through convenience sampling. Intra-oral photographs were used to assess DDE, which were classified according to the criteria proposed by Ghanim et al. (2015) by a single calibrated examiner (Kappa>0.80). Enamel hypoplasia, molar-incisor hypomineralization (MIH), hypomimineralized second primary molar (HSPM), and non-MIH/HSPM demarcated opacities were considered for the analysis. Genomic DNA was extracted from buccal cells. The SNPs in VDR (rs7975232) and PHT (rs694, rs6256, and rs307247) were genotyped using real-time polymerase chain reactions (PCR). Statistical analyses were performed using the PLINK software (version 1.03, designed by Shaun Purcell, EUA). Chi-square or Fisher's exact tests were performed at a significance level of 5%. Ninety-one (n=91) patients (49 females and 42 males) (mean age of 14.1±5.8 years) were included. The frequency of DDE was 38.5% (35 patients). Genotype distributions were in Hardy-Weinberg equilibrium. No significant statistical association was found between DDE and the SNPs evaluated. A borderline association (p=0.09) was observed between DDE and the CC haplotype for SNP rs7975232 in VDR. In conclusion, the selected SNPs in VDR and PTH genes were not associated with DDE in the studied samples.
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Affiliation(s)
| | | | | | | | | | | | - Mírian Aiko Nakane Matsumoto
- Department of Pediatric Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | | | | | - Geraldo Thedei
- Department of Biomaterials, University of Uberaba, Uberaba, MG, Brazil
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Park SY, Jeong SJ, Han JH, Shin JE, Lee JH, Kang CM. Natal factors affecting developmental defects of enamel in preterm infants: a prospective cohort study. Sci Rep 2024; 14:2089. [PMID: 38267499 PMCID: PMC10808204 DOI: 10.1038/s41598-024-52525-2] [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: 10/05/2023] [Accepted: 01/19/2024] [Indexed: 01/26/2024] Open
Abstract
This study investigated natal factors influencing developmental defects of enamel (DDE) in premature infants using a newly refined preterm developmental defects of enamel (PDDE) index. Dental examinations were conducted on a cohort of 118 preterm infants (average age 3.5 ± 1.4 years) to record PDDE scores, while reviewing their medical records to examine natal factors. According to the logistic regression analysis, factors related to DDE prevalence were advanced maternal age, gestational age < 28 weeks, birth weight < 1000 g, 1 min APGAR score < 7, and hospitalization period > 2 months, which were significantly higher by 2.91, 5.53, 7.63, 10.02, and 4.0 times, respectively. According to regression analysis with generalized linear models, the PDDE scores were approximately 7.65, 4.96, and 15.0 points higher in premature children diagnosed with bronchopulmonary dysplasia, intraventricular hemorrhage, and necrotizing enterocolitis, respectively. When endotracheal intubation was performed, the PDDE score was 5.06 points higher. The prevalence of PDDE was primarily observed bilaterally in the maxillary anterior teeth. Extremely preterm infants showed significantly delayed tooth eruption, suggesting that the influence of gestational age on dental development rates. Identifying the factors related to DDE in premature children can inform early dental interventions to support the oral health of high-risk children.
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Affiliation(s)
- Shang-Yon Park
- Department of Pediatric Dentistry, Yonsei University College of Dentistry, Seoul, Republic of Korea
| | - Su Jin Jeong
- Statistics Support Part, Medical Science Research Institute, Kyung Hee University Medical Center, Seoul, Republic of Korea
| | - Jung Ho Han
- Department of Pediatrics, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Jeong Eun Shin
- Department of Pediatrics, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Jae-Ho Lee
- Department of Pediatric Dentistry, Yonsei University College of Dentistry, Seoul, Republic of Korea
- Oral Science Research Center, Yonsei University College of Dentistry, Seoul, Republic of Korea
| | - Chung-Min Kang
- Department of Pediatric Dentistry, Yonsei University College of Dentistry, Seoul, Republic of Korea.
- Oral Science Research Center, Yonsei University College of Dentistry, Seoul, Republic of Korea.
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3
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Souza Bomfim GH, Mitaishvili E, Schnetkamp PP, Lacruz RS. Na+/Ca2+ exchange in enamel cells is dominated by the K+-dependent NCKX exchanger. J Gen Physiol 2024; 156:e202313372. [PMID: 37947795 PMCID: PMC10637953 DOI: 10.1085/jgp.202313372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 08/15/2023] [Accepted: 10/31/2023] [Indexed: 11/12/2023] Open
Abstract
Calcium (Ca2+) extrusion is an essential function of the enamel-forming ameloblasts, providing Ca2+ for extracellular mineralization. The plasma membrane Ca2+ ATPases (PMCAs) remove cytosolic Ca2+ (cCa2+) and were recently shown to be efficient when ameloblasts experienced low cCa2+ elevation. Sodium-calcium (Na+/Ca2+) exchange has higher capacity to extrude cCa2+, but there is limited evidence on the function of the two main families of Na+/Ca2+ exchangers in enamel formation. The purpose of this study was to analyze the function of the NCX (coded by SLC8) and the K+-dependent NCKX (coded by SLC24) exchangers in rat ameloblasts and to compare their efficacy in the two main stages of enamel formation: the enamel forming secretory stage and the mineralizing or maturation stage. mRNA expression profiling confirmed the expression of Slc8 and Slc24 genes in enamel cells, Slc24a4 being the most highly upregulated transcript during the maturation stage, when Ca2+ transport increases. Na+/Ca2+ exchange was analyzed in the Ca2+ influx mode in Fura-2 AM-loaded ameloblasts. We show that maturation-stage ameloblasts have a higher Na+/Ca2+ exchange capacity than secretory-stage cells. We also show that Na+/Ca2+ exchange in both stages is dominated by NCKX over NCX. The importance of NCKX function in ameloblasts may partly explain why mutations in the SLC24A4 gene, but not in SLC8 genes, result in enamel disease. Our results demonstrate that Na+/Ca2+ exchangers are fully operational in ameloblasts and that their contribution to Ca2+ homeostasis increases in the maturation stage, when Ca2+ transport need is higher.
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Affiliation(s)
| | - Erna Mitaishvili
- Department of Chemistry, Herbert H. Lehman College, City University of New York. PhD Program in Biology, The Graduate Center of The City University of New York, New York, NY, USA
| | - Paul P.M. Schnetkamp
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Rodrigo S. Lacruz
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, NY, USA
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Kim KH, Kim EJ, Kim HY, Li S, Jung HS. Fabrication of functional ameloblasts from hiPSCs for dental application. Front Cell Dev Biol 2023; 11:1164811. [PMID: 37457296 PMCID: PMC10339106 DOI: 10.3389/fcell.2023.1164811] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 06/15/2023] [Indexed: 07/18/2023] Open
Abstract
Tooth formation relies on two types of dental cell populations, namely, the dental epithelium and dental mesenchyme, and the interactions between these cell populations are important during tooth development. Although human-induced pluripotent stem cells (hiPSCs) can differentiate into dental epithelial and mesenchymal cells, organoid research on tooth development has not been established yet. This study focused on the hiPSC-derived human ameloblast organoid (hAO) using a three-dimensional (3D) culture system. hAOs had similar properties to ameloblasts, forming enamel in response to calcium and mineralization by interaction with the dental mesenchyme. hAOs simultaneously had osteogenic and odontogenic differentiation potential. Furthermore, hAOs demonstrated tooth regenerative potential upon interaction with the mouse dental mesenchyme. Our findings provide new insights into a suitable hiPSC-derived dental source and demonstrate that hAOs can be beneficial not only for tooth regeneration but also for the study of various dental diseases for which treatment has not been developed yet.
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Affiliation(s)
- Ka-Hwa Kim
- Division in Anatomy and Developmental Biology, Department of Oral Biology, Taste Research Center, Oral Science Research Center, BK21 FOUR Project, Yonsei University College of Dentistry, Seoul, Republic of Korea
| | - Eun-Jung Kim
- Division in Anatomy and Developmental Biology, Department of Oral Biology, Taste Research Center, Oral Science Research Center, BK21 FOUR Project, Yonsei University College of Dentistry, Seoul, Republic of Korea
| | | | - Shujin Li
- Division in Anatomy and Developmental Biology, Department of Oral Biology, Taste Research Center, Oral Science Research Center, BK21 FOUR Project, Yonsei University College of Dentistry, Seoul, Republic of Korea
| | - Han-Sung Jung
- Division in Anatomy and Developmental Biology, Department of Oral Biology, Taste Research Center, Oral Science Research Center, BK21 FOUR Project, Yonsei University College of Dentistry, Seoul, Republic of Korea
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Chan B, Cheng IC, Rozita J, Gorshteyn I, Huang Y, Shaffer I, Chang C, Li W, Lytton J, Den Besten P, Zhang Y. Sodium/(calcium + potassium) exchanger NCKX4 optimizes KLK4 activity in the enamel matrix microenvironment to regulate ECM modeling. Front Physiol 2023; 14:1116091. [PMID: 36814474 PMCID: PMC9939835 DOI: 10.3389/fphys.2023.1116091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 01/16/2023] [Indexed: 02/09/2023] Open
Abstract
Enamel development is a process in which extracellular matrix models from a soft proteinaceous matrix to the most mineralized tissue in vertebrates. Patients with mutant NCKX4, a gene encoding a K+-dependent Na+/Ca2+-exchanger, develop a hypomineralized and hypomature enamel. How NCKX4 regulates enamel protein removal to achieve an almost protein-free enamel is unknown. We characterized the upregulation pattern of Nckx4 in the progressively differentiating enamel-forming ameloblasts by qPCR, and as well as confirmed NCKX4 protein to primarily localize at the apical surface of wild-type ruffle-ended maturation ameloblasts by immunostaining of the continuously growing mouse incisors, posing the entire developmental trajectory of enamel. In contrast to the normal mature enamel, where ECM proteins are hydrolyzed and removed, we found significant protein retention in the maturation stage of Nckx4 -/- mouse enamel. The Nckx4 -/- enamel held less Ca2+ and K+ but more Na+ than the Nckx4 +/+ enamel did, as measured by EDX. The alternating acidic and neutral pH zones at the surface of mineralizing Nckx4 +/+ enamel were replaced by a largely neutral pH matrix in the Nckx4 -/- enamel. In situ zymography revealed a reduced kallikrein-related peptidase 4 (KLK4) activity in the Nckx4 -/- enamel. We showed that KLK4 took on 90% of proteinase activity in the maturation stage of normal enamel, and that recombinant KLK4 as well as native mouse enamel KLK4 both performed less effectively in a buffer with increased [Na+] and pH, conditions found in the Nckx4 -/- developing enamel. This study, for the first time to our knowledge, provides evidence demonstrating the impaired in situ KLK4 activity in Nckx4 -/- enamel and suggests a novel function of NCKX4 in facilitating KLK4-mediated hydrolysis and removal of ECM proteins, warranting the completion of enamel matrix modeling.
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Affiliation(s)
- Barry Chan
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Ieong Cheng Cheng
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Jalali Rozita
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Ida Gorshteyn
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Yulei Huang
- Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Sun-Yat-sen University, Guangzhou, China
| | - Ida Shaffer
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Chih Chang
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Wu Li
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Jonathan Lytton
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, AB, Canada
| | - Pamela Den Besten
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Yan Zhang
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
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Said R, Mortazavi H, Cooper D, Ovens K, McQuillan I, Papagerakis S, Papagerakis P. Deciphering the functions of Stromal Interaction Molecule-1 in amelogenesis using AmelX-iCre mice. Front Physiol 2023; 14:1100714. [PMID: 36935757 PMCID: PMC10014868 DOI: 10.3389/fphys.2023.1100714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 02/17/2023] [Indexed: 03/05/2023] Open
Abstract
Introduction: The intracellular Ca2+ sensor stromal interaction molecule 1 (STIM1) is thought to play a critical role in enamel development, as its mutations cause Amelogenesis Imperfecta (AI). We recently established an ameloblast-specific (AmelX-iCre) Stim1 conditional deletion mouse model to investigate the role of STIM1 in controlling ameloblast function and differentiation in vivo (Stim1 cKO). Our pilot data (Said et al., J. Dent. Res., 2019, 98, 1002-1010) support our hypothesis for a broad role of Stim1 in amelogenesis. This paper aims to provide an in-depth characterization of the enamel phenotype observed in our Stim1 cKO model. Methods: We crossed AmelX-iCre mice with Stim1-floxed animals to develop ameloblast-specific Stim1 cKO mice. Scanning electron microscopy, energy dispersive spectroscopy, and micro- CT were used to study the enamel phenotype. RNAseq and RT-qPCR were utilized to evaluate changes in the gene expression of several key ameloblast genes. Immunohistochemistry was used to detect the amelogenin, matrix metalloprotease 20 and kallikrein 4 proteins in ameloblasts. Results: Stim1 cKO animals exhibited a hypomineralized AI phenotype, with reduced enamel volume, diminished mineral density, and lower calcium content. The mutant enamel phenotype was more severe in older Stim1 cKO mice compared to younger ones and changes in enamel volume and mineral content were more pronounced in incisors compared to molars. Exploratory RNAseq analysis of incisors' ameloblasts suggested that ablation of Stim1 altered the expression levels of several genes encoding enamel matrix proteins which were confirmed by subsequent RT-qPCR. On the other hand, RT-qPCR analysis of molars' ameloblasts showed non-significant differences in the expression levels of enamel matrix genes between control and Stim1-deficient cells. Moreover, gene expression analysis of incisors' and molars' ameloblasts showed that Stim1 ablation caused changes in the expression levels of several genes associated with calcium transport and mitochondrial kinetics. Conclusions: Collectively, these findings suggest that the loss of Stim1 in ameloblasts may impact enamel mineralization and ameloblast gene expression.
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Affiliation(s)
- Raed Said
- College of Dentistry, University of Saskatchewan, Saskatoon, SK, Canada
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Helyasadat Mortazavi
- College of Dentistry, University of Saskatchewan, Saskatoon, SK, Canada
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - David Cooper
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Katie Ovens
- Department of Computer Science, University of Calgary, Calgary, AB, Canada
| | - Ian McQuillan
- Department of Computer Sciences, College of Arts and Sciences, University of Saskatchewan, Saskatoon, SK, Canada
| | - Silvana Papagerakis
- Department of Surgery, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
- Department of Otolaryngology-Head and Neck Surgery, School of Medicine, University of Michigan, Ann Arbor, MI, United States
| | - Petros Papagerakis
- College of Dentistry, University of Saskatchewan, Saskatoon, SK, Canada
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
- *Correspondence: Petros Papagerakis,
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Masunova N, Tereschenko M, Alexandrov G, Spirina L, Tarasenko N. Crucial Role of microRNAs as New Targets for Amelogenesis Disorders Detection. Curr Drug Targets 2023; 24:1139-1149. [PMID: 37936447 DOI: 10.2174/0113894501257011231030161427] [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: 04/19/2023] [Revised: 09/21/2023] [Accepted: 10/19/2023] [Indexed: 11/09/2023]
Abstract
INTRODUCTION Amelogenesis imperfecta (AI) refers to a heterogeneous group of conditions with multiple factors which contribute to the hypomineralisation of enamel. Preventive measures are necessary to predict this pathology. Prospects for preventive medicine are closely related to the search for new informative methods for diagnosing a human disease. MicroRNAs are prominent for the non-invasive diagnostic platform. THE AIM OF THE STUDY The aim of the review is to review the heterogeneous factors involved in amelogenesis and to select the microRNA panel associated with the AI type. METHODS We used DIANA Tools (algorithms, databases and software) for interpreting and archiving data in a systematic framework ranging from the analysis of expression regulation from deep sequencing data to the annotation of miRNA regulatory elements and targets (https://dianalab. e-ce.uth.gr/). In our study, based on a gene panel associated with the AI types, twenty-four miRNAs were identified for the hypoplastic type (supplement), thirty-five for hypocalcified and forty-- nine for hypomaturation AI. The selection strategy included the microRNA search with multiple targets using the AI type's gene panel. RESULTS Key proteins, calcium-dependent and genetic factors were analysed to reveal their role in amelogenesis. The role of extracellular non-coding RNA sequences with multiple regulatory functions seems to be the most attractive. We chose the list of microRNAs associated with the AI genes. We found four microRNAs (hsa-miR-27a-3p, hsa-miR-375, hsa-miR-16-5p and hsamiR- 146a-5p) for the gene panel, associated with the hypoplastic type of AI; five microRNAs (hsa- miR-29c-3p, hsa-miR-124-3p, hsa-miR-1343-3p, hsa-miR-335-5p, and hsa-miR-16-5p - for hypocalcified type of AI, and seven ones (hsa-miR-124-3p, hsa-miR-147a, hsa-miR-16-5p, hsamiR- 429, hsa-let-7b-5p, hsa-miR-146a-5p, hsa-miR-335-5p) - for hypomaturation. It was revealed that hsa-miR-16-5p is included in three panels specific for both hypoplastic, hypocalcified, and hypomaturation types. Hsa-miR-146a-5p is associated with hypoplastic and hypomaturation type of AI, which is associated with the peculiarities of the inflammatory response immune response. In turn, hsa-miR-335-5p associated with hypocalcified and hypomaturation type of AI. CONCLUSION Liquid biopsy approaches are a promising way to reduce the economic cost of treatment for these patients in modern healthcare. Unique data exist about the role of microRNA in regulating amelogenesis. The list of microRNAs that are associated with AI genes and classified by AI types has been uncovered. The target gene analysis showed the variety of functions of selected microRNAs, which explains the multiple heterogeneous mechanisms in amelogenesis. Predisposition to mineralisation problems is a programmed event. Many factors determine the manifestation of this problem. Additionally, it is necessary to remember the variable nature of the changes, which reduces the prediction accuracy. Therefore, models based on liquid biopsy and microRNAs make it possible to take into account these factors and their influence on the mineralisation. The found data needs further investigation.
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Affiliation(s)
- Nadezhda Masunova
- Siberian State Medical University of the Ministry of Health of Russia, 634050, Tomsk, Russia
| | - Maria Tereschenko
- Siberian State Medical University of the Ministry of Health of Russia, 634050, Tomsk, Russia
| | - Georgy Alexandrov
- Siberian State Medical University of the Ministry of Health of Russia, 634050, Tomsk, Russia
| | - Liudmila Spirina
- Siberian State Medical University of the Ministry of Health of Russia, 634050, Tomsk, Russia
- Cancer Research Institute, Tomsk National Research Medical Center of the Russian Academy of Sciences, Tomsk, Russia
| | - Natalia Tarasenko
- Siberian State Medical University of the Ministry of Health of Russia, 634050, Tomsk, Russia
- Research Institute of Medical Genetics, Tomsk National Research Medical Center of the Russian Academy of Sciences, Tomsk, Russia
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Souza Bomfim GH, Giacomello M, Lacruz RS. PMCA Ca 2+ clearance in dental enamel cells depends on the magnitude of cytosolic Ca 2. FASEB J 2023; 37:e22679. [PMID: 36515675 PMCID: PMC11006021 DOI: 10.1096/fj.202201291r] [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: 08/08/2022] [Revised: 10/31/2022] [Accepted: 11/21/2022] [Indexed: 12/15/2022]
Abstract
Enamel formation (amelogenesis) is a two-step process whereby crystals partially grow during the secretory stage followed by a significant growth expansion during the maturation stage concurrent with an increase in vectorial Ca2+ transport. This requires tight regulation of cytosolic Ca2+ (c Ca2+ ) concentration in the enamel forming ameloblasts by controlling Ca2+ influx (entry) and Ca2+ extrusion (clearance). Gene and protein expression studies suggest that the plasma membrane Ca2+ -ATPases (PMCA1-4) are likely involved in c Ca2+ extrusion in ameloblasts, yet no functional analysis of these pumps has been reported nor whether their activity changes across amelogenesis. PMCAs have high Ca2+ affinity and low Ca2+ clearance which may be a limiting factor in their contribution to enamel formation as maturation stage ameloblasts handle high Ca2+ loads. We analyzed PMCA function in rat secretory and maturation ameloblasts by blocking or potentiating these pumps. Low/moderate elevations in c Ca2+ measured using the Ca2+ probe Fura-2-AM show that secretory ameloblasts clear Ca2+ faster than maturation stage cells through PMCAs. This process was completely inhibited by an external alkaline (pH 9.0) solution or was significantly delayed by the PMCA blockers vanadate and caloxin 1b1. Eliciting higher c Ca2+ transients via the activation of the ORAI1 Ca2+ channel showed that the PMCAs of maturation ameloblasts were more efficient. Inhibiting PMCAs decreased the rate of Ca2+ influx via ORAI1 but potentiation with forskolin had no effect. Our findings suggest that PMCAs are functional Ca2+ pumps during amelogenesis regulating c Ca2+ upon low and/or moderate Ca2+ stimulus in secretory stage, thus participating in amelogenesis.
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Affiliation(s)
| | - Marta Giacomello
- Department of Biology, University of Padova, Padua, Italy
- Department of Biomedical Sciences, University of Padova, Padua, Italy
| | - Rodrigo S. Lacruz
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, New York, USA
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9
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Elzein R, Abdel-Sater F, Mehawej C, Jalkh N, Ayoub F, Chouery E. Identification by whole-exome sequencing of new single-nucleotide polymorphisms associated with molar-incisor hypomineralisation among the Lebanese population. Eur Arch Paediatr Dent 2022; 23:919-928. [PMID: 35986881 DOI: 10.1007/s40368-022-00738-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Accepted: 07/21/2022] [Indexed: 12/24/2022]
Abstract
OBJECTIVE Molar-incisor hypomineralization (MIH) is a developmental qualitative enamel defect, causing a worldwide challenging dental problem. The etiology of this defect remains unclear. Here we identify by whole-exome sequencing (WES) new single-nucleotide polymorphisms (SNPs) in genes expressed during enamel mineralization and in those modulating prenatal, natal and postnatal risk factors among the Lebanese MIH children: immune system and xenobiotic detoxification. DESIGN Dental examination for MIH was performed based on the MIH index for diagnostic criteria. Saliva samples were collected from 37 non-related, MIH-diagnosed subjects for DNA extraction. WES was performed on the Illumina HiSeq2000 platform. The χ2 test and Fisher's exact test were used to determine relationship between SNPs frequencies and MIH. OR and its 95% CI were used to report the strength of association. The significance threshold was set at 0.05. RESULTS Among the Lebanese population, 37 SNPs presented a significant association with MIH in the following genes: AMTN, MMP-20, STIM1, STIM2, ORAI1, SLC34A2, SLC34A3, VDR, PVALB, HSP90B1, TRPM7, SLC24A4, CA6, SLC4A2, TNFRSF11A, IL10RB, ARNT, ESR1 and CYP1B1. CONCLUSION This is the first WES study conducted in patients with MIH. Yet, interactions between polymorphisms in different gene categories are to be investigated for a better assessment of MIH susceptibility.
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Affiliation(s)
- R Elzein
- Department of Pediatric Dentistry and Public Dental Health, Faculty of Dental Medicine, Lebanese University, Beirut, Lebanon. .,Medical Genetics Unit, Faculty of Medicine, Saint-Joseph University, Beirut, Lebanon.
| | - F Abdel-Sater
- Laboratory of Cancer Biology and Cellular Immunology, Department of Biological Sciences, Faculty of Sciences, Lebanese University, Beirut, Lebanon
| | - C Mehawej
- Department of Human Genetics, Gilbert and Rose-Marie Chagoury School of Medicine, Lebanese American University, Byblos, Lebanon
| | - N Jalkh
- Medical Genetics Unit, Faculty of Medicine, Saint-Joseph University, Beirut, Lebanon
| | - F Ayoub
- Department of Forensic Odontology, Human Identification and Anthropology, Faculty of Dental Medicine, Lebanese University, Beirut, Lebanon
| | - E Chouery
- Department of Human Genetics, Gilbert and Rose-Marie Chagoury School of Medicine, Lebanese American University, Byblos, Lebanon
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10
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Arai H, Inaba A, Ikezaki S, Kumakami-Sakano M, Azumane M, Ohshima H, Morikawa K, Harada H, Otsu K. Energy metabolic shift contributes to the phenotype modulation of maturation stage ameloblasts. Front Physiol 2022; 13:1062042. [PMID: 36523561 PMCID: PMC9745043 DOI: 10.3389/fphys.2022.1062042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 11/15/2022] [Indexed: 12/13/2023] Open
Abstract
Maturation stage ameloblasts (M-ABs) are responsible for terminal enamel mineralization in teeth and undergo characteristic cyclic changes in both morphology and function between ruffle-ended ameloblasts (RA) and smooth-ended ameloblasts (SA). Energy metabolism has recently emerged as a potential regulator of cell differentiation and fate decisions; however, its implication in M-ABs remains unclear. To elucidate the relationship between M-ABs and energy metabolism, we examined the expression pattern of energy metabolic enzymes in M-ABs of mouse incisors. Further, using the HAT7 cell line with M-AB characteristics, we designed experiments to induce an energy metabolic shift by changes in oxygen concentration. We revealed that RA preferentially utilizes oxidative phosphorylation, whereas SA depends on glycolysis-dominant energy metabolism in mouse incisors. In HAT7 cells, hypoxia induced an energy metabolic shift toward a more glycolytic-dominant state, and the energy metabolic shift reduced alkaline phosphatase (ALP) activity and calcium transport and deposition with a change in calcium-related gene expression, implying a phenotype shift from RA to SA. Taken together, these results indicate that the energy metabolic state is an important determinant of the RA/SA phenotype in M-ABs. This study sheds light on the biological significance of energy metabolism in governing M-ABs, providing a novel molecular basis for understanding enamel mineralization and elucidating the pathogenesis of enamel hypomineralization.
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Affiliation(s)
- Haruno Arai
- Division of Developmental Biology and Regenerative Medicine, Department of Anatomy, Iwate Medical University, Yahaba, Japan
- Division of Pediatric and Special Care Dentistry, Department of Oral Health Science, School of Dentistry, Iwate Medical University, Morioka, Japan
| | - Akira Inaba
- Division of Developmental Biology and Regenerative Medicine, Department of Anatomy, Iwate Medical University, Yahaba, Japan
- Division of Pediatric and Special Care Dentistry, Department of Oral Health Science, School of Dentistry, Iwate Medical University, Morioka, Japan
| | - Shojiro Ikezaki
- Division of Developmental Biology and Regenerative Medicine, Department of Anatomy, Iwate Medical University, Yahaba, Japan
| | - Mika Kumakami-Sakano
- Division of Developmental Biology and Regenerative Medicine, Department of Anatomy, Iwate Medical University, Yahaba, Japan
| | - Marii Azumane
- Division of Developmental Biology and Regenerative Medicine, Department of Anatomy, Iwate Medical University, Yahaba, Japan
- Division of Oral and Maxillofacial Surgery, Department of Reconstructive Oral and Maxillofacial Surgery, Iwate Medical University, Morioka, Japan
| | - Hayato Ohshima
- Division of Anatomy and Cell Biology of the Hard Tissue, Department of Tissue Regeneration and Reconstruction, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Kazumasa Morikawa
- Division of Pediatric and Special Care Dentistry, Department of Oral Health Science, School of Dentistry, Iwate Medical University, Morioka, Japan
| | - Hidemitsu Harada
- Division of Developmental Biology and Regenerative Medicine, Department of Anatomy, Iwate Medical University, Yahaba, Japan
| | - Keishi Otsu
- Division of Developmental Biology and Regenerative Medicine, Department of Anatomy, Iwate Medical University, Yahaba, Japan
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11
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Organoids from human tooth showing epithelial stemness phenotype and differentiation potential. Cell Mol Life Sci 2022; 79:153. [PMID: 35217915 PMCID: PMC8881251 DOI: 10.1007/s00018-022-04183-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 01/27/2022] [Accepted: 02/01/2022] [Indexed: 01/09/2023]
Abstract
Insight into human tooth epithelial stem cells and their biology is sparse. Tissue-derived organoid models typically replicate the tissue’s epithelial stem cell compartment. Here, we developed a first-in-time epithelial organoid model starting from human tooth. Dental follicle (DF) tissue, isolated from unerupted wisdom teeth, efficiently generated epithelial organoids that were long-term expandable. The organoids displayed a tooth epithelial stemness phenotype similar to the DF’s epithelial cell rests of Malassez (ERM), a compartment containing dental epithelial stem cells. Single-cell transcriptomics reinforced this organoid-ERM congruence, and uncovered novel, mouse-mirroring stem cell features. Exposure of the organoids to epidermal growth factor induced transient proliferation and eventual epithelial-mesenchymal transition, highly mimicking events taking place in the ERM in vivo. Moreover, the ERM stemness organoids were able to unfold an ameloblast differentiation process, further enhanced by transforming growth factor-β (TGFβ) and abrogated by TGFβ receptor inhibition, thereby reproducing TGFβ's known key position in amelogenesis. Interestingly, by creating a mesenchymal-epithelial composite organoid (assembloid) model, we demonstrated that the presence of dental mesenchymal cells (i.e. pulp stem cells) triggered ameloblast differentiation in the epithelial stem cells, thus replicating the known importance of mesenchyme-epithelium interaction in tooth development and amelogenesis. Also here, differentiation was abrogated by TGFβ receptor inhibition. Together, we developed novel organoid models empowering the exploration of human tooth epithelial stem cell biology and function as well as their interplay with dental mesenchyme, all at present only poorly defined in humans. Moreover, the new models may pave the way to future tooth-regenerative perspectives.
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12
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Costiniti V, Bomfim GHS, Neginskaya M, Son GY, Mitaishvili E, Giacomello M, Pavlov E, Lacruz RS. Mitochondria modulate ameloblast Ca 2+ signaling. FASEB J 2022; 36:e22169. [PMID: 35084775 PMCID: PMC8852362 DOI: 10.1096/fj.202100602r] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 12/22/2021] [Accepted: 01/07/2022] [Indexed: 02/03/2023]
Abstract
The role of mitochondria in enamel, the most mineralized tissue in the body, is poorly defined. Enamel is formed by ameloblast cells in two main sequential stages known as secretory and maturation. Defining the physiological features of each stage is essential to understand mineralization. Here, we analyzed functional features of mitochondria in rat primary secretory and maturation-stage ameloblasts focusing on their role in Ca2+ signaling. Quantification of the Ca2+ stored in the mitochondria by trifluoromethoxy carbonylcyanide phenylhydrazone stimulation was comparable in both stages. The release of endoplasmic reticulum Ca2+ pools by adenosine triphosphate in rhod2AM-loaded cells showed similar mitochondrial Ca2+ (m Ca2+ ) uptake. However, m Ca2+ extrusion via Na+ -Li+ -Ca2+ exchanger was more prominent in maturation. To address if m Ca2+ uptake via the mitochondrial Ca2+ uniporter (MCU) played a role in cytosolic Ca2+ (c Ca2+ ) buffering, we stimulated Ca2+ influx via the store-operated Ca2+ entry (SOCE) and blocked MCU with the inhibitor Ru265. This inhibitor was first tested using the enamel cell line LS8 cells. Ru265 prevented c Ca2+ clearance in permeabilized LS8 cells like ruthenium red, and it did not affect ΔΨm in intact cells. In primary ameloblasts, SOCE stimulation elicited a significantly higher m Ca2+ uptake in maturation ameloblasts. The uptake of Ca2+ into the mitochondria was dramatically decreased in the presence of Ru265. Combined, these results suggest an increased mitochondrial Ca2+ handling in maturation but only upon stimulation of Ca2+ influx via SOCE. These functional studies provide insights not only on the role of mitochondria in ameloblast Ca2+ physiology, but also advance the concept that SOCE and m Ca2+ uptake are complementary processes in biological mineralization.
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Affiliation(s)
- Veronica Costiniti
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, USA
| | - Guilherme H. S. Bomfim
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, USA
| | - Maria Neginskaya
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, USA
| | - Ga-Yeon Son
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, USA
| | - Erna Mitaishvili
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, USA
| | - Marta Giacomello
- Department of Biology, University of Padova, Padua, Italy,Department of Biomedical Sciences, University of Padova, Padua, Italy
| | - Evgeny Pavlov
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, USA
| | - Rodrigo S. Lacruz
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, USA
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13
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Mahdee AF, Ali AH, Gillespie JI. Structural and functional relations between the connective tissue and epithelium of enamel organ and their role during enamel maturation. J Mol Histol 2021; 52:975-989. [PMID: 34100179 DOI: 10.1007/s10735-021-09992-y] [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: 01/21/2021] [Accepted: 06/02/2021] [Indexed: 10/21/2022]
Abstract
The morphological and possible functional interactions between the connective tissue and enamel organ cells were examined during the maturation phase of enamel formation, using immunohistochemical techniques. Decalcified mandibular sections (10 µm) including incisors were used from Wistar rats ages 10-12 weeks. Sections were incubated with one or two primary antibodies targeting cell cytoskeleton (vimentin, α-actin, α-tubulin), dendritic marker (OX6), gap junctions (cx-43), enzymes (nitric-oxide synthase (nos1) and cyclooxygenase (cox1)), and the ion transporters (Na+/H+ exchanger (NHE1) and Na+/Ca2+ exchanger (NCX)) for 24 h, before incubation with the appropriate conjugated fluorescent secondary antibodies. Sections were examined by fluorescence microscopy. Haematoxylin-eosin slides were also employed. Cellular heterogeneity and morphological modulations were identified within enamel organ cells and connective tissue covering suggesting complex cellular interactions and indicating a new functional concept and possible complementary role during enamel maturation. Also, some ion transportation activity, and nos1 and cox1 signalling pathways have been identified, indicating intercellular communication between these regions. A hypothesis is suggested, to explain the morphological modulation of ameloblasts and papillary cells during enamel maturation which functions to increase the transporting membrane surface area to accomplish faster and bulker ion transportation to achieve controlled pH and to direct Ca2+ towards enamel.
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Affiliation(s)
- Anas F Mahdee
- Department of Restorative and Aesthetic Dentistry, College of Dentistry, University of Baghdad, Baghdad, Iraq.
| | - Ahmed H Ali
- Department of Restorative and Aesthetic Dentistry, College of Dentistry, University of Baghdad, Baghdad, Iraq
| | - James I Gillespie
- Department of Urology, Campus Drie Eiken, University of Antwerp, Antwerp, Belgium
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14
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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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15
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Costiniti V, Bomfim GH, Mitaishvili E, Son GY, Li Y, Lacruz RS. Calcium Transport in Specialized Dental Epithelia and Its Modulation by Fluoride. Front Endocrinol (Lausanne) 2021; 12:730913. [PMID: 34456880 PMCID: PMC8385142 DOI: 10.3389/fendo.2021.730913] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 07/26/2021] [Indexed: 11/25/2022] Open
Abstract
Most cells use calcium (Ca2+) as a second messenger to convey signals that affect a multitude of biological processes. The ability of Ca2+ to bind to proteins to alter their charge and conformation is essential to achieve its signaling role. Cytosolic Ca2+ (cCa2+) concentration is maintained low at ~100 nM so that the impact of elevations in cCa2+ is readily sensed and transduced by cells. However, such elevations in cCa2+ must be transient to prevent detrimental effects. Cells have developed a variety of systems to rapidly clear the excess of cCa2+ including Ca2+ pumps, exchangers and sequestering Ca2+ within intracellular organelles. This Ca2+ signaling toolkit is evolutionarily adapted so that each cell, tissue, and organ can fulfill its biological function optimally. One of the most specialized cells in mammals are the enamel forming cells, the ameloblasts, which also handle large quantities of Ca2+. The end goal of ameloblasts is to synthesize, secrete and mineralize a unique proteinaceous matrix without the benefit of remodeling or repair mechanisms. Ca2+ uptake into ameloblasts is mainly regulated by the store operated Ca2+ entry (SOCE) before it is transported across the polarized ameloblasts to reach the insulated enamel space. Here we review the ameloblasts Ca2+ signaling toolkit and address how the common electronegative non-metal fluoride can alter its function, potentially addressing the biology of dental fluorosis.
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Affiliation(s)
| | | | | | | | | | - Rodrigo S. Lacruz
- Department Molecular Pathobiology, College of Dentistry, New York University, New York, NY, United States
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16
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Földes A, Sang-Ngoen T, Kádár K, Rácz R, Zsembery Á, DenBesten P, Steward MC, Varga G. Three-Dimensional Culture of Ameloblast-Originated HAT-7 Cells for Functional Modeling of Defective Tooth Enamel Formation. Front Pharmacol 2021; 12:682654. [PMID: 34149428 PMCID: PMC8206558 DOI: 10.3389/fphar.2021.682654] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 05/19/2021] [Indexed: 01/04/2023] Open
Abstract
Background: Amelogenesis, the formation of dental enamel, is well understood at the histomorphological level but the underlying molecular mechanisms are poorly characterized. Ameloblasts secrete enamel matrix proteins and Ca2+, and also regulate extracellular pH as the formation of hydroxyapatite crystals generates large quantities of protons. Genetic or environmental impairment of transport and regulatory processes (e.g. dental fluorosis) leads to the development of enamel defects such as hypomineralization. Aims: Our aims were to optimize the culture conditions for the three-dimensional growth of ameloblast-derived HAT-7 cells and to test the effects of fluoride exposure on HAT-7 spheroid formation. Methods: To generate 3D HAT-7 structures, cells were dispersed and plated within a Matrigel extracellular matrix scaffold and incubated in three different culture media. Spheroid formation was then monitored over a two-week period. Ion transporter and tight-junction protein expression was investigated by RT-qPCR. Intracellular Ca2+ and pH changes were measured by microfluorometry using the fluorescent dyes fura-2 and BCECF. Results: A combination of Hepato-STIM epithelial cell differentiation medium and Matrigel induced the expansion and formation of 3D HAT-7 spheroids. The cells retained their epithelial cell morphology and continued to express both ameloblast-specific and ion transport-specific marker genes. Furthermore, like two-dimensional HAT-7 monolayers, the HAT-7 spheroids were able to regulate their intracellular pH and to show intracellular calcium responses to extracellular stimulation. Finally, we demonstrated that HAT-7 spheroids may serve as a disease model for studying the effects of fluoride exposure during amelogenesis. Conclusion: In conclusion, HAT-7 cells cultivated within a Matrigel extracellular matrix form three-dimensional, multi-cellular, spheroidal structures that retain their functional capacity for pH regulation and intracellular Ca2+ signaling. This new 3D model will allow us to gain a better understanding of the molecular mechanisms involved in amelogenesis, not only in health but also in disorders of enamel formation, such as those resulting from fluoride exposure.
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Affiliation(s)
- Anna Földes
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | | | - Kristóf Kádár
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | - Róbert Rácz
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | - Ákos Zsembery
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | - Pamela DenBesten
- Department of Orofacial Sciences, University of California San Francisco, San Francisco, CA, United States
| | - Martin C Steward
- Department of Oral Biology, Semmelweis University, Budapest, Hungary.,School of Medical Sciences, University of Manchester, Manchester, United Kingdom
| | - Gábor Varga
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
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17
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TRPM7-Mediated Calcium Transport in HAT-7 Ameloblasts. Int J Mol Sci 2021; 22:ijms22083992. [PMID: 33924361 PMCID: PMC8069123 DOI: 10.3390/ijms22083992] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 04/05/2021] [Accepted: 04/08/2021] [Indexed: 02/06/2023] Open
Abstract
TRPM7 plays an important role in cellular Ca2+, Zn2+ and Mg2+ homeostasis. TRPM7 channels are abundantly expressed in ameloblasts and, in the absence of TRPM7, dental enamel is hypomineralized. The potential role of TRPM7 channels in Ca2+ transport during amelogenesis was investigated in the HAT-7 rat ameloblast cell line. The cells showed strong TRPM7 mRNA and protein expression. Characteristic TRPM7 transmembrane currents were observed, which increased in the absence of intracellular Mg2+ ([Mg2+]i), were reduced by elevated [Mg2+]i, and were inhibited by the TRPM7 inhibitors NS8593 and FTY720. Mibefradil evoked similar currents, which were suppressed by elevated [Mg2+]i, reducing extracellular pH stimulated transmembrane currents, which were inhibited by FTY720. Naltriben and mibefradil both evoked Ca2+ influx, which was further enhanced by the acidic intracellular conditions. The SOCE inhibitor BTP2 blocked Ca2+ entry induced by naltriben but not by mibefradil. Thus, in HAT-7 cells, TRPM7 may serves both as a potential modulator of Orai-dependent Ca2+ uptake and as an independent Ca2+ entry pathway sensitive to pH. Therefore, TRPM7 may contribute directly to transepithelial Ca2+ transport in amelogenesis.
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18
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Epithelial loss of mitochondrial oxidative phosphorylation leads to disturbed enamel and impaired dentin matrix formation in postnatal developed mouse incisor. Sci Rep 2020; 10:22037. [PMID: 33328493 PMCID: PMC7744519 DOI: 10.1038/s41598-020-77954-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 11/12/2020] [Indexed: 12/03/2022] Open
Abstract
The formation of dentin and enamel matrix depends on reciprocal interactions between epithelial-mesenchymal cells. To assess the role of mitochondrial function in amelogenesis and dentinogenesis, we studied postnatal incisor development in K320E-TwinkleEpi mice. In these mice, a loss of mitochondrial DNA (mtDNA), followed by a severe defect in the oxidative phosphorylation system is induced specifically in Keratin 14 (K14+) expressing epithelial cells. Histochemical staining showed severe reduction of cytochrome c oxidase activity only in K14+ epithelial cells. In mutant incisors, H&E staining showed severe defects in the ameloblasts, in the epithelial cells of the stratum intermedium and the papillary cell layer, but also a disturbed odontoblast layer. The lack of amelogenin in the enamel matrix of K320E-TwinkleEpi mice indicated that defective ameloblasts are not able to form extracellular enamel matrix proteins. In comparison to control incisors, von Kossa staining showed enamel biomineralization defects and dentin matrix impairment. In mutant incisor, TUNEL staining and ultrastructural analyses revealed differentiation defects, while in hair follicle cells apoptosis is prevalent. We concluded that mitochondrial oxidative phosphorylation in epithelial cells of the developed incisor is required for Ca2+ homeostasis to regulate the formation of enamel matrix and induce the differentiation of ectomesenchymal cells into odontoblasts.
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19
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Said R, Lobanova L, Papagerakis S, Papagerakis P. Calcium Sets the Clock in Ameloblasts. Front Physiol 2020; 11:920. [PMID: 32848861 PMCID: PMC7411184 DOI: 10.3389/fphys.2020.00920] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 07/09/2020] [Indexed: 01/22/2023] Open
Abstract
Background Stromal interaction molecule 1 (STIM1) is one of the main components of the store operated Ca2+ entry (SOCE) signaling pathway. Individuals with mutated STIM1 present severely hypomineralized enamel characterized as amelogenesis imperfecta (AI) but the downstream molecular mechanisms involved remain unclear. Circadian clock signaling plays a key role in regulating the enamel thickness and mineralization, but the effects of STIM1-mediated AI on circadian clock are unknown. Objectives The aim of this study is to examine the potential links between SOCE and the circadian clock during amelogenesis. Methods We have generated mice with ameloblast-specific deletion of Stim1 (Stim1fl/fl/Amelx-iCre+/+, Stim1 cKO) and analyzed circadian gene expression profile in Stim1 cKO compared to control (Stim1fl/fl/Amelx-iCre–/–) using ameloblast micro-dissection and RNA micro-array of 84 circadian genes. Expression level changes were validated by qRT-PCR and immunohistochemistry. Results Stim1 deletion has resulted in significant upregulation of the core circadian activator gene Brain and Muscle Aryl Hydrocarbon Receptor Nuclear Translocation 1 (Bmal1) and downregulation of the circadian inhibitor Period 2 (Per2). Our analyses also revealed that SOCE disruption results in dysregulation of two additional circadian regulators; p38α mitogen-activated protein kinase (MAPK14) and transforming growth factor-beta1 (TGF-β1). Both MAPK14 and TGF-β1 pathways are known to play major roles in enamel secretion and their dysregulation has been previously implicated in the development of AI phenotype. Conclusion These data indicate that disruption of SOCE significantly affects the ameloblasts molecular circadian clock, suggesting that alteration of the circadian clock may be partly involved in the development of STIM1-mediated AI.
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Affiliation(s)
- Raed Said
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada.,College of Dentistry, University of Saskatchewan, Saskatoon, SK, Canada
| | - Liubov Lobanova
- College of Dentistry, University of Saskatchewan, Saskatoon, SK, Canada
| | - Silvana Papagerakis
- Department of Surgery, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Petros Papagerakis
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada.,College of Dentistry, University of Saskatchewan, Saskatoon, SK, Canada
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20
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Reibring CG, Hallberg K, Linde A, Gritli-Linde A. Distinct and Overlapping Expression Patterns of the Homer Family of Scaffolding Proteins and Their Encoding Genes in Developing Murine Cephalic Tissues. Int J Mol Sci 2020; 21:ijms21041264. [PMID: 32070057 PMCID: PMC7072945 DOI: 10.3390/ijms21041264] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Revised: 02/08/2020] [Accepted: 02/10/2020] [Indexed: 02/06/2023] Open
Abstract
In mammals Homer1, Homer2 and Homer3 constitute a family of scaffolding proteins with key roles in Ca2+ signaling and Ca2+ transport. In rodents, Homer proteins and mRNAs have been shown to be expressed in various postnatal tissues and to be enriched in brain. However, whether the Homers are expressed in developing tissues is hitherto largely unknown. In this work, we used immunohistochemistry and in situ hybridization to analyze the expression patterns of Homer1, Homer2 and Homer3 in developing cephalic structures. Our study revealed that the three Homer proteins and their encoding genes are expressed in a wide range of developing tissues and organs, including the brain, tooth, eye, cochlea, salivary glands, olfactory and respiratory mucosae, bone and taste buds. We show that although overall the three Homers exhibit overlapping distribution patterns, the proteins localize at distinct subcellular domains in several cell types, that in both undifferentiated and differentiated cells Homer proteins are concentrated in puncta and that the vascular endothelium is enriched with Homer3 mRNA and protein. Our findings suggest that Homer proteins may have differential and overlapping functions and are expected to be of value for future research aiming at deciphering the roles of Homer proteins during embryonic development.
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Affiliation(s)
- Claes-Göran Reibring
- Department of Oral Biochemistry, Institute of Odontology, Sahlgrenska Academy at the University of Gothenburg, SE-40530 Göteborg, Sweden; (C.-G.R.); (K.H.); (A.L.)
- Public Dental Service, Region Västra Götaland, SE-45131 Uddevalla, Sweden
| | - Kristina Hallberg
- Department of Oral Biochemistry, Institute of Odontology, Sahlgrenska Academy at the University of Gothenburg, SE-40530 Göteborg, Sweden; (C.-G.R.); (K.H.); (A.L.)
| | - Anders Linde
- Department of Oral Biochemistry, Institute of Odontology, Sahlgrenska Academy at the University of Gothenburg, SE-40530 Göteborg, Sweden; (C.-G.R.); (K.H.); (A.L.)
| | - Amel Gritli-Linde
- Department of Oral Biochemistry, Institute of Odontology, Sahlgrenska Academy at the University of Gothenburg, SE-40530 Göteborg, Sweden; (C.-G.R.); (K.H.); (A.L.)
- Correspondence: ; Tel.: +46-31-7863392
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21
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Eckstein M, Vaeth M, Aulestia FJ, Costiniti V, Kassam SN, Bromage TG, Pedersen P, Issekutz T, Idaghdour Y, Moursi AM, Feske S, Lacruz RS. Differential regulation of Ca 2+ influx by ORAI channels mediates enamel mineralization. Sci Signal 2019; 12:12/578/eaav4663. [PMID: 31015290 DOI: 10.1126/scisignal.aav4663] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Store-operated Ca2+ entry (SOCE) channels are highly selective Ca2+ channels activated by the endoplasmic reticulum (ER) sensors STIM1 and STIM2. Their direct interaction with the pore-forming plasma membrane ORAI proteins (ORAI1, ORAI2, and ORAI3) leads to sustained Ca2+ fluxes that are critical for many cellular functions. Mutations in the human ORAI1 gene result in immunodeficiency, anhidrotic ectodermal dysplasia, and enamel defects. In our investigation of the role of ORAI proteins in enamel, we identified enamel defects in a patient with an ORAI1 null mutation. Targeted deletion of the Orai1 gene in mice showed enamel defects and reduced SOCE in isolated enamel cells. However, Orai2-/- mice showed normal enamel despite having increased SOCE in the enamel cells. Knockdown experiments in the enamel cell line LS8 suggested that ORAI2 and ORAI3 modulated ORAI1 function, with ORAI1 and ORAI2 being the main contributors to SOCE. ORAI1-deficient LS8 cells showed altered mitochondrial respiration with increased oxygen consumption rate and ATP, which was associated with altered redox status and enhanced ER Ca2+ uptake, likely due to S-glutathionylation of SERCA pumps. Our findings demonstrate an important role of ORAI1 in Ca2+ influx in enamel cells and establish a link between SOCE, mitochondrial function, and redox homeostasis.
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Affiliation(s)
- Miriam Eckstein
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, NY 10010, USA
| | - Martin Vaeth
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - Francisco J Aulestia
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, NY 10010, USA
| | - Veronica Costiniti
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, NY 10010, USA
| | - Serena N Kassam
- Department of Pediatric Dentistry, New York University College of Dentistry, New York, NY 10010, USA
| | - Timothy G Bromage
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, NY 10010, USA.,Department of Biomaterials, New York University College of Dentistry, New York, NY 10010, USA
| | - Pal Pedersen
- Carl Zeiss Microscopy, LLC, Thornwood, NY 10594, USA
| | - Thomas Issekutz
- Department of Pediatrics, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Youssef Idaghdour
- Biology Program, Division of Science and Mathematics, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Amr M Moursi
- Department of Pediatric Dentistry, New York University College of Dentistry, New York, NY 10010, USA
| | - Stefan Feske
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - Rodrigo S Lacruz
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, NY 10010, USA.
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22
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Fleig A, Parekh AB. New insights into Ca 2+ channel function in health and disease. J Physiol 2019; 595:2997-2998. [PMID: 28503825 DOI: 10.1113/jp274289] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Affiliation(s)
- Andrea Fleig
- The Queen's Medical Center and John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, USA
| | - Anant B Parekh
- Department of Physiology, Anatomy and Genetics, Parks Road, Oxford, OX1 3PT, UK
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23
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Eckstein M, Lacruz RS. CRAC channels in dental enamel cells. Cell Calcium 2018; 75:14-20. [PMID: 30114531 PMCID: PMC6435299 DOI: 10.1016/j.ceca.2018.07.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 07/31/2018] [Accepted: 07/31/2018] [Indexed: 01/09/2023]
Abstract
Enamel mineralization relies on Ca2+ availability provided by Ca2+ release activated Ca2+ (CRAC) channels. CRAC channels are modulated by the endoplasmic reticulum Ca2+ sensor STIM1 which gates the pore subunit of the channel known as ORAI1, found the in plasma membrane, to enable sustained Ca2+ influx. Mutations in the STIM1 and ORAI1 genes result in CRAC channelopathy, an ensemble of diseases including immunodeficiency, muscular hypotonia, ectodermal dysplasia with defects in sweat gland function and abnormal enamel mineralization similar to amelogenesis imperfecta (AI). In some reports, the chief medical complain has been the patient's dental health, highlighting the direct and important link between CRAC channels and enamel. The reported enamel defects are apparent in both the deciduous and in permanent teeth and often require extensive dental treatment to provide the patient with a functional dentition. Among the dental phenotypes observed in the patients, discoloration, increased wear, hypoplasias (thinning of enamel) and chipping has been reported. These findings are not universal in all patients. Here we review the mutations in STIM1 and ORAI1 causing AI-like phenotype, and evaluate the enamel defects in CRAC channel deficient mice. We also provide a brief overview of the role of CRAC channels in other mineralizing systems such as dentine and bone.
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Affiliation(s)
- M Eckstein
- Dept. Basic Science and Craniofacial Biology, New York University College of Dentistry, 345 East 24th Street, New York 10010, USA
| | - R S Lacruz
- Dept. Basic Science and Craniofacial Biology, New York University College of Dentistry, 345 East 24th Street, New York 10010, USA.
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24
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An S. The emerging role of extracellular Ca
2+
in osteo/odontogenic differentiation and the involvement of intracellular Ca
2+
signaling: From osteoblastic cells to dental pulp cells and odontoblasts. J Cell Physiol 2018; 234:2169-2193. [DOI: 10.1002/jcp.27068] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 06/25/2018] [Indexed: 12/15/2022]
Affiliation(s)
- Shaofeng An
- Department of Operative Dentistry and EndodonticsGuanghua School of Stomatology, Hospital of Stomatology, Sun Yat‐sen UniversityGuangzhou China
- Guangdong Province Key Laboratory of StomatologySun Yat‐Sen UniversityGuangzhou China
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25
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Eckstein M, Aulestia FJ, Nurbaeva MK, Lacruz RS. Altered Ca 2+ signaling in enamelopathies. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1865:1778-1785. [PMID: 29750989 DOI: 10.1016/j.bbamcr.2018.04.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 04/26/2018] [Accepted: 04/30/2018] [Indexed: 10/16/2022]
Abstract
Biomineralization requires the controlled movement of ions across cell barriers to reach the sites of crystal growth. Mineral precipitation occurs in aqueous phases as fluids become supersaturated with specific ionic compositions. In the biological world, biomineralization is dominated by the presence of calcium (Ca2+) in crystal lattices. Ca2+ channels are intrinsic modulators of this process, facilitating the availability of Ca2+ within cells in a tightly regulated manner in time and space. Unequivocally, the most mineralized tissue produced by vertebrates, past and present, is dental enamel. With some of the longest carbonated hydroxyapatite (Hap) crystals known, dental enamel formation is fully coordinated by specialized epithelial cells of ectodermal origin known as ameloblasts. These cells form enamel in two main developmental stages: a) secretory; and b) maturation. The secretory stage is marked by volumetric growth of the tissue with limited mineralization, and the opposite is found in the maturation stage, as enamel crystals expand in width concomitant with increased ion transport. Disruptions in the formation and/or mineralization stages result, in most cases, in permanent alterations in the crystal assembly. This introduces weaknesses in the material properties affecting enamel's hardness and durability, thus limiting its efficacy as a biting, chewing tool and increasing the possibility of pathology. Here, we briefly review enamel development and discuss key properties of ameloblasts and their Ca2+-handling machinery, and how alterations in this toolkit result in enamelopathies.
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Affiliation(s)
- Miriam Eckstein
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, United States
| | - Francisco J Aulestia
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, United States
| | - Meerim K Nurbaeva
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, United States
| | - Rodrigo S Lacruz
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, United States.
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26
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Lacruz RS, Habelitz S, Wright JT, Paine ML. DENTAL ENAMEL FORMATION AND IMPLICATIONS FOR ORAL HEALTH AND DISEASE. Physiol Rev 2017; 97:939-993. [PMID: 28468833 DOI: 10.1152/physrev.00030.2016] [Citation(s) in RCA: 223] [Impact Index Per Article: 31.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 01/10/2017] [Accepted: 01/10/2017] [Indexed: 12/16/2022] Open
Abstract
Dental enamel is the hardest and most mineralized tissue in extinct and extant vertebrate species and provides maximum durability that allows teeth to function as weapons and/or tools as well as for food processing. Enamel development and mineralization is an intricate process tightly regulated by cells of the enamel organ called ameloblasts. These heavily polarized cells form a monolayer around the developing enamel tissue and move as a single forming front in specified directions as they lay down a proteinaceous matrix that serves as a template for crystal growth. Ameloblasts maintain intercellular connections creating a semi-permeable barrier that at one end (basal/proximal) receives nutrients and ions from blood vessels, and at the opposite end (secretory/apical/distal) forms extracellular crystals within specified pH conditions. In this unique environment, ameloblasts orchestrate crystal growth via multiple cellular activities including modulating the transport of minerals and ions, pH regulation, proteolysis, and endocytosis. In many vertebrates, the bulk of the enamel tissue volume is first formed and subsequently mineralized by these same cells as they retransform their morphology and function. Cell death by apoptosis and regression are the fates of many ameloblasts following enamel maturation, and what cells remain of the enamel organ are shed during tooth eruption, or are incorporated into the tooth's epithelial attachment to the oral gingiva. In this review, we examine key aspects of dental enamel formation, from its developmental genesis to the ever-increasing wealth of data on the mechanisms mediating ionic transport, as well as the clinical outcomes resulting from abnormal ameloblast function.
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Affiliation(s)
- Rodrigo S Lacruz
- Department of Basic Science and Craniofacial Biology, College of Dentistry, New York University, New York, New York; Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, San Francisco, California; Department of Pediatric Dentistry, School of Dentistry, University of North Carolina, Chapel Hill, North Carolina; Herman Ostrow School of Dentistry, Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, California
| | - Stefan Habelitz
- Department of Basic Science and Craniofacial Biology, College of Dentistry, New York University, New York, New York; Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, San Francisco, California; Department of Pediatric Dentistry, School of Dentistry, University of North Carolina, Chapel Hill, North Carolina; Herman Ostrow School of Dentistry, Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, California
| | - J Timothy Wright
- Department of Basic Science and Craniofacial Biology, College of Dentistry, New York University, New York, New York; Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, San Francisco, California; Department of Pediatric Dentistry, School of Dentistry, University of North Carolina, Chapel Hill, North Carolina; Herman Ostrow School of Dentistry, Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, California
| | - Michael L Paine
- Department of Basic Science and Craniofacial Biology, College of Dentistry, New York University, New York, New York; Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, San Francisco, California; Department of Pediatric Dentistry, School of Dentistry, University of North Carolina, Chapel Hill, North Carolina; Herman Ostrow School of Dentistry, Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, California
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27
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Furukawa Y, Haruyama N, Nikaido M, Nakanishi M, Ryu N, Oh-Hora M, Kuremoto K, Yoshizaki K, Takano Y, Takahashi I. Stim1 Regulates Enamel Mineralization and Ameloblast Modulation. J Dent Res 2017; 96:1422-1429. [PMID: 28732182 DOI: 10.1177/0022034517719872] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Loss-of-function mutations in the Ca2+ release-activated Ca2+ channel genes ORAI1 and STIM1 abolish store-operated Ca2+ entry (SOCE) and result in ectodermal dysplasia with amelogenesis imperfecta. However, because of the limited availability of patient tissue, analyses of enamel mineralization or possible changes in ameloblast function or morphology have not been possible. Here, we generated mice with ectodermal tissue-specific deletion of Stim1 ( Stim1 cKO [conditional knockout]), Stim2 ( Stim2 cKO), and Stim1 and Stim2 ( Stim1/2 cKO) and analyzed their enamel phenotypes as compared with those of control ( Stim1/2fl/fl) animals. Ablation of Stim1 and Stim1/2 but not Stim2 expression resulted in chalky enamel and severe attrition at the incisor tips and molar cusps. Stim1 and Stim1/2 cKO, but not Stim2 cKO, demonstrated inferior enamel mineralization with impaired structural integrity, whereas the shape of the teeth and enamel thickness appeared to be normal in all animals. The gene expression levels of the enamel matrix proteins Amelx and Ambn and the enamel matrix proteases Mmp20 and Klk4 were not altered by the abrogation of SOCE in Stim1/2 cKO mice. The morphology of ameloblasts during the secretory and maturation stages was not significantly altered in either the incisors or molars of the cKO animals. However, in Stim1 and Stim1/2 cKO incisors, the alternating modulation of maturation-stage ameloblasts between the smooth- and ruffle-ended cell types continued beyond the regular cycle and extended to the areas corresponding to the zone of postmodulation ameloblasts in the teeth of control animals. These results indicate that SOCE is essential for proper enamel mineralization, in which Stim1 plays a critical role during the maturation process.
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Affiliation(s)
- Y Furukawa
- 1 Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth, and Development, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.,2 Institute of Decision Science Program for Sustainable Society, Kyushu University, Fukuoka, Japan
| | - N Haruyama
- 1 Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth, and Development, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - M Nikaido
- 1 Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth, and Development, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - M Nakanishi
- 1 Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth, and Development, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - N Ryu
- 1 Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth, and Development, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - M Oh-Hora
- 3 Division of Molecular Immunology, Research Center for Infectious Diseases, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - K Kuremoto
- 4 Department of Advanced Prosthodontics, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - K Yoshizaki
- 1 Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth, and Development, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Y Takano
- 5 Department of Cell Biology and Neuroscience, School of Medicine, Juntendo University, Tokyo, Japan
| | - I Takahashi
- 1 Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth, and Development, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
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28
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Lacruz RS. Enamel: Molecular identity of its transepithelial ion transport system. Cell Calcium 2017; 65:1-7. [PMID: 28389033 PMCID: PMC5944837 DOI: 10.1016/j.ceca.2017.03.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 03/27/2017] [Accepted: 03/27/2017] [Indexed: 12/14/2022]
Abstract
Enamel is the most calcified tissue in vertebrates. It differs from bone in a number of characteristics including its origin from ectodermal epithelium, lack of remodeling capacity by the enamel forming cells, and absence of collagen. The enamel-forming cells known as ameloblasts, choreograph first the synthesis of a unique protein-rich matrix, followed by the mineralization of this matrix into a tissue that is ∼95% mineral. To do this, ameloblasts arrange the coordinated movement of ions across a cell barrier while removing matrix proteins and monitoring extracellular pH using a variety of buffering systems to enable the growth of carbonated apatite crystals. Although our knowledge of these processes and the molecular identity of the proteins involved in transepithelial ion transport has increased in the last decade, it remains limited compared to other cells. Here we present an overview of the evolution and development of enamel, its differences with bone, and describe the ion transport systems associated with ameloblasts.
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Affiliation(s)
- Rodrigo S Lacruz
- Dept. Basic Science and Craniofacial Biology, New York University College of Dentistry, 345 East 24th Street, New York, NY 10010, United States.
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29
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Robertson SYT, Wen X, Yin K, Chen J, Smith CE, Paine ML. Multiple Calcium Export Exchangers and Pumps Are a Prominent Feature of Enamel Organ Cells. Front Physiol 2017; 8:336. [PMID: 28588505 PMCID: PMC5440769 DOI: 10.3389/fphys.2017.00336] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 05/08/2017] [Indexed: 12/11/2022] Open
Abstract
Calcium export is a key function for the enamel organ during all stages of amelogenesis. Expression of a number of ATPase calcium transporting, plasma membrane genes (ATP2B1-4/PMCA1-4), solute carrier SLC8A genes (sodium/calcium exchanger or NCX1-3), and SLC24A gene family members (sodium/potassium/calcium exchanger or NCKX1-6) have been investigated in the developing enamel organ in earlier studies. This paper reviews the calcium export pathways that have been described and adds novel insights to the spatiotemporal expression patterns of PMCA1, PMCA4, and NCKX3 during amelogenesis. New data are presented to show the mRNA expression profiles for the four Atp2b1-4 gene family members (PMCA1-4) in secretory-stage and maturation-stage rat enamel organs. These data are compared to expression profiles for all Slc8a and Slc24a gene family members. PMCA1, PMCA4, and NCKX3 immunolocalization data is also presented. Gene expression profiles quantitated by real time PCR show that: (1) PMCA1, 3, and 4, and NCKX3 are most highly expressed during secretory-stage amelogenesis; (2) NCX1 and 3, and NCKX6 are expressed during secretory and maturation stages; (3) NCKX4 is most highly expressed during maturation-stage amelogenesis; and (4) expression levels of PMCA2, NCX2, NCKX1, NCKX2, and NCKX5 are negligible throughout amelogenesis. In the enamel organ PMCA1 localizes to the basolateral membrane of both secretory and maturation ameloblasts; PMCA4 expression is seen in the basolateral membrane of secretory and maturation ameloblasts, and also cells of the stratum intermedium and papillary layer; while NCKX3 expression is limited to Tomes' processes, and the apical membrane of maturation-stage ameloblasts. These new findings are discussed in the perspective of data already present in the literature, and highlight the multiplicity of calcium export systems in the enamel organ needed to regulate biomineralization.
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Affiliation(s)
- Sarah Y T Robertson
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern CaliforniaLos Angeles, CA, United States
| | - Xin Wen
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern CaliforniaLos Angeles, CA, United States
| | - Kaifeng Yin
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern CaliforniaLos Angeles, CA, United States
| | - Junjun Chen
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern CaliforniaLos Angeles, CA, United States.,Department of Oral Medicine, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of MedicineShanghai, China.,Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Department of Biochemistry and Molecular Cell Biology, Shanghai Jiao Tong University School of MedicineShanghai, China
| | - Charles E Smith
- Department of Anatomy and Cell Biology, Faculty of Medicine, McGill UniversityMontreal, QC, Canada
| | - Michael L Paine
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern CaliforniaLos Angeles, CA, United States
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30
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Eckstein M, Vaeth M, Fornai C, Vinu M, Bromage TG, Nurbaeva MK, Sorge JL, Coelho PG, Idaghdour Y, Feske S, Lacruz RS. Store-operated Ca 2+ entry controls ameloblast cell function and enamel development. JCI Insight 2017; 2:e91166. [PMID: 28352661 DOI: 10.1172/jci.insight.91166] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Loss-of-function mutations in stromal interaction molecule 1 (STIM1) impair the activation of Ca2+ release-activated Ca2+ (CRAC) channels and store-operated Ca2+ entry (SOCE), resulting in a disease syndrome called CRAC channelopathy that is characterized by severe dental enamel defects. The cause of these enamel defects has remained unclear given a lack of animal models. We generated Stim1/2K14cre mice to delete STIM1 and its homolog STIM2 in enamel cells. These mice showed impaired SOCE in enamel cells. Enamel in Stim1/2K14cre mice was hypomineralized with decreased Ca content, mechanically weak, and thinner. The morphology of SOCE-deficient ameloblasts was altered, showing loss of the typical ruffled border, resulting in mislocalized mitochondria. Global gene expression analysis of SOCE-deficient ameloblasts revealed strong dysregulation of several pathways. ER stress genes associated with the unfolded protein response were increased in Stim1/2-deficient cells, whereas the expression of components of the glutathione system were decreased. Consistent with increased oxidative stress, we found increased ROS production, decreased mitochondrial function, and abnormal mitochondrial morphology in ameloblasts of Stim1/2K14cre mice. Collectively, these data show that loss of SOCE in enamel cells has substantial detrimental effects on gene expression, cell function, and the mineralization of dental enamel.
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Affiliation(s)
- Miriam Eckstein
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, New York, USA
| | - Martin Vaeth
- Department of Pathology, New York University School of Medicine, New York, New York, USA
| | - Cinzia Fornai
- Department of Anthropology, University of Vienna, Vienna, Austria.,Department of Evolutionary Medicine, University of Zurich, Zurich, Switzerland
| | - Manikandan Vinu
- Biology Program, Division of Science and Mathematics, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Timothy G Bromage
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, New York, USA.,Department of Biomaterials and Biomimetics, New York University College of Dentistry, New York, New York, USA
| | - Meerim K Nurbaeva
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, New York, USA
| | - Jessica L Sorge
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, New York, USA
| | - Paulo G Coelho
- Department of Biomaterials and Biomimetics, New York University College of Dentistry, New York, New York, USA
| | - Youssef Idaghdour
- Biology Program, Division of Science and Mathematics, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Stefan Feske
- Department of Pathology, New York University School of Medicine, New York, New York, USA
| | - Rodrigo S Lacruz
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, New York, USA
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