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Gavila P, Ajrithirong P, Chumnanprai S, Kalpongnukul N, Pisitkun T, Chantarangsu S, Sriwattanapong K, Tagami J, Porntaveetus T. Salivary proteomic signatures in severe dental fluorosis. Sci Rep 2024; 14:18372. [PMID: 39112609 PMCID: PMC11306554 DOI: 10.1038/s41598-024-69409-0] [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: 02/25/2024] [Accepted: 08/05/2024] [Indexed: 08/10/2024] Open
Abstract
The relationship between dental fluorosis and alterations in the salivary proteome remains inadequately elucidated. This study aimed to investigate the salivary proteome and fluoride concentrations in urine and drinking water among Thai individuals afflicted with severe dental fluorosis. Thirty-seven Thai schoolchildren, aged 6-16, were stratified based on Thylstrup and Fejerskov fluorosis index scores: 10 with scores ranging from 5 to 9 (SF) and 27 with a score of 0 (NF). Urinary and water fluoride levels were determined using an ion-selective fluoride electrode. Salivary proteomic profiling was conducted via LC-MS/MS, followed by comprehensive bioinformatic analysis. Results revealed significantly elevated urinary fluoride levels in the SF group (p = 0.007), whereas water fluoride levels did not significantly differ between the two cohorts. Both groups exhibited 104 detectable salivary proteins. The NF group demonstrated notable upregulation of LENG9, whereas the SF group displayed upregulation of LDHA, UBA1, S100A9, H4C3, and LCP1, all associated with the CFTR ion channel. Moreover, the NF group uniquely expressed 36 proteins, and Gene Ontology and pathway analyses suggested a link with various aspects of immune defense. In summary, the study hypothesized that the CFTR ion channel might play a predominant role in severe fluorosis and highlighted the depletion of immune-related salivary proteins, suggesting compromised immune defense in severe fluorosis. The utility of urinary fluoride might be a reliable indicator for assessing excessive fluoride exposure.
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Affiliation(s)
- Patcharaporn Gavila
- Center of Excellence in Genomics and Precision Dentistry, Department of Physiology, Faculty of Dentistry, Chulalongkorn University, Bangkok, 10330, Thailand
- Intercountry Centre for Oral Health, Department of Health, Ministry of Public Health, Chiangmai, 50000, Thailand
- Graduate Program in Geriatric and Special Patients Care, Clinical Research Center, Faculty of Dentistry, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Penpitcha Ajrithirong
- Center of Excellence in Genomics and Precision Dentistry, Department of Physiology, Faculty of Dentistry, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Supoj Chumnanprai
- Intercountry Centre for Oral Health, Department of Health, Ministry of Public Health, Chiangmai, 50000, Thailand
| | - Nuttiya Kalpongnukul
- Center of Excellence in Systems Biology, Research Affairs, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Trairak Pisitkun
- Center of Excellence in Systems Biology, Research Affairs, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand
- Research Affairs, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Soranun Chantarangsu
- Department of Oral Pathology, Faculty of Dentistry, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Kanokwan Sriwattanapong
- Center of Excellence in Genomics and Precision Dentistry, Department of Physiology, Faculty of Dentistry, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Junji Tagami
- Faculty of Dentistry, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Thantrira Porntaveetus
- Center of Excellence in Genomics and Precision Dentistry, Department of Physiology, Faculty of Dentistry, Chulalongkorn University, Bangkok, 10330, Thailand.
- Graduate Program in Geriatric and Special Patients Care, Clinical Research Center, Faculty of Dentistry, Chulalongkorn University, Bangkok, 10330, Thailand.
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2
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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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3
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Fonseca Ó, Gomes MS, Amorim MA, Gomes AC. Cystic Fibrosis Bone Disease: The Interplay between CFTR Dysfunction and Chronic Inflammation. Biomolecules 2023; 13:425. [PMID: 36979360 PMCID: PMC10046889 DOI: 10.3390/biom13030425] [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: 01/19/2023] [Revised: 02/19/2023] [Accepted: 02/22/2023] [Indexed: 03/30/2023] Open
Abstract
Cystic fibrosis is a monogenic disease with a multisystemic phenotype, ranging from predisposition to chronic lung infection and inflammation to reduced bone mass. The exact mechanisms unbalancing the maintenance of an optimal bone mass in cystic fibrosis patients remain unknown. Multiple factors may contribute to severe bone mass reduction that, in turn, have devastating consequences in the patients' quality of life and longevity. Here, we will review the existing evidence linking the CFTR dysfunction and cell-intrinsic bone defects. Additionally, we will also address how the proinflammatory environment due to CFTR dysfunction in immune cells and chronic infection impairs the maintenance of an adequate bone mass in CF patients.
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Affiliation(s)
- Óscar Fonseca
- i3S–Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
| | - Maria Salomé Gomes
- i3S–Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- ICBAS–Instuto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, 4030-313 Porto, Portugal
| | | | - Ana Cordeiro Gomes
- i3S–Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- IBMC–Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
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4
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Pawlaczyk-Kamieńska T, Borysewicz-Lewicka M, Batura-Gabryel H, Cofta S. Oral Care Recommendation for Cystic Fibrosis Patients-Recommendation for Dentists. J Clin Med 2022; 11:2756. [PMID: 35628882 PMCID: PMC9146407 DOI: 10.3390/jcm11102756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Revised: 05/06/2022] [Accepted: 05/10/2022] [Indexed: 11/16/2022] Open
Abstract
Cystic fibrosis (CF) is a genetic disease that is caused by a defect in the gene coding for the transmembrane cystic fibrosis transmembrane conductance regulator (CFTR). Research papers published so far point out that despite the numerous dental treatment needs of CF patients, there are no oral care guidelines for this group of patients. The aim of the article is to propose standards of dental prophylactic and therapeutic procedures for CF patients in different age groups. Regardless of the CF patient's age, dental check-ups should be scheduled at least every 6 months. However, taking into account the actual condition of the individual CF patients, therapeutic visits may be scheduled for earlier dates, to provide well-fitting treatment, considering the level of risk of oral diseases. The described management standards may be helpful and may improve the quality of dental care provided to CF patients.
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Affiliation(s)
- Tamara Pawlaczyk-Kamieńska
- Department of Risk Group Dentistry, Chair of Pediatric Dentistry, Poznan University of Medical Sciences, 61-701 Poznan, Poland;
| | - Maria Borysewicz-Lewicka
- Department of Risk Group Dentistry, Chair of Pediatric Dentistry, Poznan University of Medical Sciences, 61-701 Poznan, Poland;
| | - Halina Batura-Gabryel
- Department of Pulmonology, Allergology and Respiratory Oncology, Poznan University of Medical Sciences, 60-569 Poznan, Poland; (H.B.-G.); (S.C.)
| | - Szczepan Cofta
- Department of Pulmonology, Allergology and Respiratory Oncology, Poznan University of Medical Sciences, 60-569 Poznan, Poland; (H.B.-G.); (S.C.)
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5
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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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6
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Ji M, Duan X, Han X, Sun J, Zhang D. Exogenous transforming growth factor-β1 prevents the inflow of fluoride to ameleoblasts through regulation of voltage-gated chloride channels 5 and 7. Exp Ther Med 2021; 21:615. [PMID: 33936272 PMCID: PMC8082615 DOI: 10.3892/etm.2021.10047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Accepted: 03/15/2021] [Indexed: 02/07/2023] Open
Abstract
Dental fluorosis is a global issue. Although there are multiple causes of dental fluorosis, the precise mechanism remains controversial. Previous studies have demonstrated that extracellular fluoride may promote an accumulation of fluoride ions in ameloblasts, which may induce oxidative and endoplasmic reticulum stresses, leading to dental fluorosis. However, the exact process by which fluoride ions enter cells has not been determined. In the present study, intracellular fluoride concentration was determined using a newly developed specific fluorescent probe called probe 1. Under high extracellular fluoride concentrations, the fluorescence intensity of the ameloblasts increased, however, exogenous transforming growth factor-β1 (TGF-β1) was able to inhibit the increase. Furthermore, changes in the expression of the voltage-gated chloride channels 5 and 7 (ClC5 and ClC-7), which are responsible for the transport of fluoride were investigated. The results indicated that fluoride reduced the expression of endogenous TGF-β1 and increased the expression of ClC-5 and ClC-7. Additionally, exogenous TGF-β1 reduced the expression of ClC-5 and ClC-7. The results of the present study indicate that exogenous TGF-β1 may prevent accumulation of fluoride in ameloblasts through the regulation of ClC-5 and ClC-7 under high extracellular fluoride concentrations.
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Affiliation(s)
- Mei Ji
- Department of Stomatology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Xuejing Duan
- Department of Stomatology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Xiaohui Han
- Department of Stomatology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Jing Sun
- Department of Stomatology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Dongsheng Zhang
- Department of Stomatology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
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7
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Willis JR, Saus E, Iraola-Guzmán S, Cabello-Yeves E, Ksiezopolska E, Cozzuto L, Bejarano LA, Andreu-Somavilla N, Alloza-Trabado M, Blanco A, Puig-Sola A, Broglio E, Carolis C, Ponomarenko J, Hecht J, Gabaldón T. Citizen-science based study of the oral microbiome in Cystic fibrosis and matched controls reveals major differences in diversity and abundance of bacterial and fungal species. J Oral Microbiol 2021; 13:1897328. [PMID: 34104346 PMCID: PMC8143623 DOI: 10.1080/20002297.2021.1897328] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Introduction: Cystic fibrosis (CF) is an autosomal genetic disease, associated with the production of excessively thick mucosa and with life-threatening chronic lung infections. The microbiota of the oral cavity can act as a reservoir or as a barrier for infectious microorganisms that can colonize the lungs. However, the specific composition of the oral microbiome in CF is poorly understood.Methods: In collaboration with CF associations in Spain, we collected oral rinse samples from 31 CF persons (age range 7-47) and matched controls, and then performed 16S rRNA metabarcoding and high-throughput sequencing, combined with culture and proteomics-based identification of fungi to survey the bacterial and fungal oral microbiome.Results: We found that CF is associated with less diverse oral microbiomes, which were characterized by higher prevalence of Candida albicans and differential abundances of a number of bacterial taxa that have implications in both the connection to lung infections in CF, as well as potential oral health concerns, particularly periodontitis and dental caries.Conclusion: Overall, our study provides a first global snapshot of the oral microbiome in CF. Future studies are required to establish the relationships between the composition of the oral and lung microbiomes in CF.
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Affiliation(s)
- Jesse R Willis
- Centre for Genomic Regulation (CRG), the Barcelona Institute of Science and Technology, Barcelona, Spain.,Life Sciences Programme, Barcelona Supercomputing Centre (BSC-CNS) Jordi Girona, Barcelona, Spain.,Mechanisms of Disease Programme, Institute for Research in Biomedicine (IRB), the Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Ester Saus
- Centre for Genomic Regulation (CRG), the Barcelona Institute of Science and Technology, Barcelona, Spain.,Life Sciences Programme, Barcelona Supercomputing Centre (BSC-CNS) Jordi Girona, Barcelona, Spain.,Mechanisms of Disease Programme, Institute for Research in Biomedicine (IRB), the Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Susana Iraola-Guzmán
- Centre for Genomic Regulation (CRG), the Barcelona Institute of Science and Technology, Barcelona, Spain.,Life Sciences Programme, Barcelona Supercomputing Centre (BSC-CNS) Jordi Girona, Barcelona, Spain.,Mechanisms of Disease Programme, Institute for Research in Biomedicine (IRB), the Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Elena Cabello-Yeves
- Life Sciences Programme, Barcelona Supercomputing Centre (BSC-CNS) Jordi Girona, Barcelona, Spain.,Mechanisms of Disease Programme, Institute for Research in Biomedicine (IRB), the Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Ewa Ksiezopolska
- Centre for Genomic Regulation (CRG), the Barcelona Institute of Science and Technology, Barcelona, Spain.,Life Sciences Programme, Barcelona Supercomputing Centre (BSC-CNS) Jordi Girona, Barcelona, Spain.,Mechanisms of Disease Programme, Institute for Research in Biomedicine (IRB), the Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Luca Cozzuto
- Centre for Genomic Regulation (CRG), the Barcelona Institute of Science and Technology, Barcelona, Spain.,Experimental and Health Sciences Department, Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Luis A Bejarano
- Centre for Genomic Regulation (CRG), the Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Nuria Andreu-Somavilla
- Centre for Genomic Regulation (CRG), the Barcelona Institute of Science and Technology, Barcelona, Spain.,Experimental and Health Sciences Department, Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Miriam Alloza-Trabado
- Centre for Genomic Regulation (CRG), the Barcelona Institute of Science and Technology, Barcelona, Spain.,Experimental and Health Sciences Department, Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Andrea Blanco
- Centre for Genomic Regulation (CRG), the Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Anna Puig-Sola
- Centre for Genomic Regulation (CRG), the Barcelona Institute of Science and Technology, Barcelona, Spain.,Experimental and Health Sciences Department, Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Elisabetta Broglio
- Centre for Genomic Regulation (CRG), the Barcelona Institute of Science and Technology, Barcelona, Spain.,Experimental and Health Sciences Department, Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Carlo Carolis
- Centre for Genomic Regulation (CRG), the Barcelona Institute of Science and Technology, Barcelona, Spain.,Experimental and Health Sciences Department, Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Julia Ponomarenko
- Centre for Genomic Regulation (CRG), the Barcelona Institute of Science and Technology, Barcelona, Spain.,Experimental and Health Sciences Department, Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Jochen Hecht
- Centre for Genomic Regulation (CRG), the Barcelona Institute of Science and Technology, Barcelona, Spain.,Experimental and Health Sciences Department, Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Toni Gabaldón
- Centre for Genomic Regulation (CRG), the Barcelona Institute of Science and Technology, Barcelona, Spain.,Life Sciences Programme, Barcelona Supercomputing Centre (BSC-CNS) Jordi Girona, Barcelona, Spain.,Mechanisms of Disease Programme, Institute for Research in Biomedicine (IRB), the Barcelona Institute of Science and Technology, Barcelona, Spain.,Experimental and Health Sciences Department, Universitat Pompeu Fabra (UPF), Barcelona, Spain.,Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain
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8
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Masi L, Ferrari S, Javaid MK, Papapoulos S, Pierroz DD, Brandi ML. Bone fragility in patients affected by congenital diseases non skeletal in origin. Orphanet J Rare Dis 2021; 16:11. [PMID: 33407701 PMCID: PMC7789665 DOI: 10.1186/s13023-020-01611-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 11/10/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Bone tissue represents a large systemic compartment of the human body, with an active metabolism, that controls mineral deposition and removal, and where several factors may play a role. For these reasons, several non-skeletal diseases may influence bone metabolism. It is of a crucial importance to classify these disorders in order to facilitate diagnosis and clinical management. This article reports a taxonomic classification of non-skeletal rare congenital disorders, which have an impact on bone metabolism METHODS: The International Osteoporosis Foundation (IOF) Skeletal Rare Diseases Working Group (SRD-WG), comprised of basic and clinical scientists, has decided to review the taxonomy of non-skeletal rare disorders that may alter bone physiology. RESULTS The taxonomy of non-skeletal rare congenital disorders which impact bone comprises a total of 6 groups of disorders that may influence the activity of bone cells or the characteristics of bone matrix. CONCLUSIONS This paper provides the first comprehensive taxonomy of non-skeletal rare congenital disorders with impact on bone physiology.
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Affiliation(s)
- L Masi
- Metabolic Bone Diseases Unit, University Hospital of Florence, AOU-Careggi, Florence, Italy
| | - S Ferrari
- Division of Bone Diseases, Faculty of Medicine, Geneva University Hospital, Geneva, Switzerland
| | - M K Javaid
- Oxford NIHR Musculoskeletal Biomedical Research Unit, University of Oxford, Oxford, UK
| | - S Papapoulos
- Center for Bone Quality, Leiden University Medical Center, Leiden, The Netherlands
| | - D D Pierroz
- International Osteoporosis Foundation (IOF), Rue Juste-Olivier 9, 1260, Nyon, Switzerland
| | - M L Brandi
- Fondazione Italiana Ricerca sulle Malattie dell'Osso, Florence, Italy.
- Department of Biomedical, Experimental and Clinical Sciences, University of Florence, Florence, Italy.
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9
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Orlando V, Morin G, Laffont A, Lénart D, Solórzano Barrera C, Mustafy T, Sankhe S, Villemure I, Mailhot G. CFTR deletion affects mouse osteoblasts in a gender-specific manner. J Cell Physiol 2020; 235:6736-6753. [PMID: 31985038 DOI: 10.1002/jcp.29568] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 01/10/2020] [Indexed: 12/24/2022]
Abstract
Advancements in research and care have contributed to increase life expectancy of individuals with cystic fibrosis (CF). With increasing age comes a greater likelihood of developing CF bone disease, a comorbidity characterized by a low bone mass and impaired bone quality, which displays gender differences in severity. However, pathophysiological mechanisms underlying this gender difference have never been thoroughly investigated. We used bone marrow-derived osteoblasts and osteoclasts from Cftr+/+ and Cftr-/- mice to examine whether the impact of CF transmembrane conductance regulator (CFTR) deletion on cellular differentiation and functions differed between genders. To determine whether in vitro findings translated into in vivo observations, we used imaging techniques and three-point bending testing. In vitro studies revealed no osteoclast-autonomous defect but impairment of osteoblast differentiation and functions and aberrant responses to various stimuli in cells isolated from Cftr-/- females only. Compared with wild-type controls, knockout mice exhibited a trabecular osteopenic phenotype that was more pronounced in Cftr-/- males than Cftr-/- females. Bone strength was reduced to a similar extent in knockout mice of both genders. In conclusion, we find a trabecular bone phenotype in Cftr-/- mice that was slightly more pronounced in males than females, which is reminiscent of the situation found in patients. However, at the osteoblast level, the pathophysiological mechanisms underlying this phenotype differ between males and females, which may underlie gender differences in the way bone marrow-derived osteoblasts behave in absence of CFTR.
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Affiliation(s)
- Valérie Orlando
- Research Centre, CHU Sainte-Justine, Montreal, Montreal, Quebec, Canada
| | - Geneviève Morin
- Research Centre, CHU Sainte-Justine, Montreal, Montreal, Quebec, Canada
| | - Alisson Laffont
- Research Centre, CHU Sainte-Justine, Montreal, Montreal, Quebec, Canada
| | - Déborah Lénart
- Research Centre, CHU Sainte-Justine, Montreal, Montreal, Quebec, Canada
| | - Carolina Solórzano Barrera
- Research Centre, CHU Sainte-Justine, Montreal, Montreal, Quebec, Canada.,Department of Mechanical Engineering, École Polytechnique of Montréal, Station Centre-Ville, Montréal, Quebec, Canada
| | - Tanvir Mustafy
- Research Centre, CHU Sainte-Justine, Montreal, Montreal, Quebec, Canada.,Department of Mechanical Engineering, École Polytechnique of Montréal, Station Centre-Ville, Montréal, Quebec, Canada
| | - Safiétou Sankhe
- Research Centre, CHU Sainte-Justine, Montreal, Montreal, Quebec, Canada
| | - Isabelle Villemure
- Research Centre, CHU Sainte-Justine, Montreal, Montreal, Quebec, Canada.,Department of Mechanical Engineering, École Polytechnique of Montréal, Station Centre-Ville, Montréal, Quebec, Canada
| | - Geneviève Mailhot
- Research Centre, CHU Sainte-Justine, Montreal, Montreal, Quebec, Canada.,Department of Nutrition, Faculty of Medicine, Université de Montreal, Montreal, Quebec, Canada
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10
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The CFTR gene variants in Japanese children with idiopathic pancreatitis. Hum Genome Var 2019; 6:17. [PMID: 30992994 PMCID: PMC6459923 DOI: 10.1038/s41439-019-0049-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Revised: 02/15/2019] [Accepted: 02/18/2019] [Indexed: 12/15/2022] Open
Abstract
The cystic fibrosis transmembrane conductance regulator (CFTR) gene has been reported as one of the pancreatitis susceptibility genes. Although many variants of CFTR have been reported in Caucasian patients, there are few data in Japanese patients. We aimed to survey CFTR variants in Japanese children with idiopathic pancreatitis. Twenty-eight Japanese paediatric patients with idiopathic pancreatitis were enroled, who were not previously diagnosed by genetic analysis of PRSS1 and SPINK1. The entire CFTR gene was sequenced in the patients by combining LA-PCR and next-generation sequencing analysis. To determine a splice-affecting variant, CFTR expression was investigated in the nasal epithelial cells by RT-PCR. One (3.6%) and 15 (53.6%) of 28 patients had pathogenic and functionally affected variants in the CFTR gene, respectively. Two variants, p.Arg352Gln and p.Arg1453Trp, were found more frequently in the patients compared with one in Japanese healthy controls (p = 0.0078 and 0.044, respectively). We confirmed skipping of exon 10 in the nasal epithelial cells in one patient having a splice-affecting variant (c.1210-12 T(5)) in intron 9. Functionally affected variants of the CFTR gene are not so rare in Japanese paediatric patients with idiopathic pancreatitis. Surveying CFTR gene variants in a Japanese sample could help identify pancreatitis risk in these children. Mutations in a cystic fibrosis-related gene could help identify Japanese children at risk of developing pancreatic inflammation. Tadashi Kaname, of Tokyo’s National Center for Child Health and Development, and colleagues sequenced the cystic fibrosis transmembrane conductance regulator gene (CFTR) in 28 Japanese children with pancreatitis of unknown origin. The gene is involved in the development of cystic fibrosis and has been reported to be associated with pancreatitis but little is known about its role in idiopathic pancreatitis in Asian populations. The team found CFTR gene mutations in 16 out of the 28 children. Cystic fibrosis is uncommon among Japanese, so CFTR mutations were also thought to be rare. The study suggests, however, that mutations might not be so rare in Japanese children with idiopathic pancreatitis and could help identify those at risk of developing the condition.
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11
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Dental and periodontal manifestations in patients with cystic fibrosis - A systematic review. J Cyst Fibros 2018; 18:762-771. [PMID: 30473190 DOI: 10.1016/j.jcf.2018.11.007] [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: 08/05/2018] [Revised: 11/12/2018] [Accepted: 11/12/2018] [Indexed: 11/20/2022]
Abstract
BACKGROUND The oral cavity is an important reservoir of microorganisms and can be a potential source of infection of the respiratory tract in CF patients. The literature on the oral health does not explicitly determine dental problems in these patients. The aim of the study was to systematically review the studies relating to oral status in CF patients. METHODS A systematic review of papers published from 1997 to 2018 regarding oral status in CF children and adults, carried out in accordance with the Cochrane Collaboration guidelines. RESULTS The search resulted in 143 studies. Thirteen publications were included in the systematic review. CONCLUSIONS
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12
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Ji M, Xiao L, Xu L, Huang S, Zhang D. How pH is regulated during amelogenesis in dental fluorosis. Exp Ther Med 2018; 16:3759-3765. [PMID: 30402142 DOI: 10.3892/etm.2018.6728] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 12/01/2017] [Indexed: 12/14/2022] Open
Abstract
Amelogenesis is a complicated process that concerns the interaction between growing hydroxyapatite crystals and extracellular proteins, which requires the tight regulation of pH. In dental fluorosis, the balance of pH regulation is broken, leading to abnormal mineralization. The current review focuses on the electrolyte transport processes associated with pH homeostasis, particularly regarding the changes in ion transporters that occur during amelogenesis, following exposure to excessive fluoride. Furthermore, the possible mechanism of fluorosis is discussed on the basis of acid hypothesis. There are two main methods by which F- accelerates crystal formation in ameloblasts. Firstly, it induces the release of protons, lowering the pH of the cell microenvironment. The decreased pH stimulates the upregulation of ion transporters, which attenuates further declines in the pH. Secondly, F- triggers an unknown signaling pathway, causing changes in the transcription of ion transporters and upregulating the expression of bicarbonate transporters. This results in the release of a large amount of bicarbonate from ameloblasts, which may neutralize the pH to form a microenvironment that favors crystal nucleation. The decreased pH stimulates the diffusion of F- into the cytoplasm of amelobalsts along the concentration gradient formed by the release of protons. The retention of F- causes a series of pathological changes, including oxidative and endoplasmic reticulum stress. If the buffering capacity of ameloblasts facing F- toxicity holds, normal mineralization occurs; however, if F- levels are high enough to overwhelm the buffering capacity of ameloblasts, abnormal mineralization occurs, leading to dental fluorosis.
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Affiliation(s)
- Mei Ji
- Department of Stomatology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Lili Xiao
- Department of Stomatology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Le Xu
- Department of Stomatology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Shengyun Huang
- Department of Stomatology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Dongsheng Zhang
- Department of Stomatology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
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13
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Al-Ansari S, Jalali R, Plotkin LI, Bronckers ALJJ, DenBesten P, Zhang Y, Raber-Durlacher JE, de Lange J, Rozema FR. The Importance of Connexin 43 in Enamel Development and Mineralization. Front Physiol 2018; 9:750. [PMID: 30013481 PMCID: PMC6036266 DOI: 10.3389/fphys.2018.00750] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 05/28/2018] [Indexed: 11/13/2022] Open
Abstract
During enamel development, formation of hydroxyapatite crystals and regulation of pH in the enamel matrix require massive transport of ions. Both ameloblasts and adjacent dental epithelial cells in the stellate reticulum co-express several transmembrane cotransporters/ion-exchangers for transport of ions across plasma membranes. Gap junctions (GJs) enable intercellular exchanges of ions between neighboring cells. This suggests that the ameloblasts and other cell layers of the enamel organ, form a functional unit. During the bell stage of tooth formation, the non-ameloblast dental epithelium highly expresses the Na-K-Cl cotransporter (Nkcc1). Nkcc1-null mice are associated with enamel hypomineralization and increased expression of GJ protein connexin 43 (Cx43), suggesting that reduced ion transport in the Nkcc1-null mouse is in part compensated by increased intercellular ion transport through GJs. To understand the role of GJs in ion transport and its effect on pH regulation, we examined in a mouse strain in which Cx43 was ablated selectively in DMP1 expressing cells (Cx43flox/flox mice crossed with DMP1-8kb-Cre mice), including ameloblasts. Micro-CT analysis showed that the mineral density at late maturation stage incisal enamel of the Cx43-null mice was 10% less than in controls, whereas that in dentin was unchanged. Maturation stage ameloblasts of mice lacking the pH regulating sodium/bicarbonate transporter NBCe1 (Nbce1-null), or chloride channel Cftr (Cftr-null) were found to have increased Cx43-immunostaining. These results support the possibility that GJs in the ameloblast-papillary complex at the maturation stage contribute to ion transport by enabling passage of ions directly from cells of the papillary layer into ameloblast layer. Increasing the number of GJs may partly compensate the reduction of ion-cotransporters and ion exchangers in dental epithelium.
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Affiliation(s)
- Sali Al-Ansari
- Department of Oral Medicine, Academic Center for Dentistry, Amsterdam, Netherlands
| | - Rozita Jalali
- Department of Orofacial Sciences, School of Dentistry, University of California, San Francisco, San Francisco, CA, United States
| | - Lilian I Plotkin
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, United States.,Roudebush Veterans Administration Medical Center, Indianapolis, IN, United States.,Indiana Center for Musculoskeletal Health, Indianapolis, IN, United States
| | | | - Pamela DenBesten
- Department of Orofacial Sciences, School of Dentistry, University of California, San Francisco, San Francisco, CA, United States
| | - Yan Zhang
- Department of Orofacial Sciences, School of Dentistry, University of California, San Francisco, San Francisco, CA, United States
| | - Judith E Raber-Durlacher
- Department of Oral Medicine, Academic Center for Dentistry, Amsterdam, Netherlands.,Department of Oral and Maxillofacial Surgery, Amsterdam Medical Centre, University of Amsterdam, Amsterdam, Netherlands
| | - Jan de Lange
- Department of Oral and Maxillofacial Surgery, Amsterdam Medical Centre, University of Amsterdam, Amsterdam, Netherlands
| | - Frederik R Rozema
- Department of Oral Medicine, Academic Center for Dentistry, Amsterdam, Netherlands.,Department of Oral and Maxillofacial Surgery, Amsterdam Medical Centre, University of Amsterdam, Amsterdam, Netherlands
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14
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Abstract
Amelogenesis (tooth enamel formation) is a biomineralization process consisting primarily of two stages (secretory stage and maturation stage) with unique features. During the secretory stage, the inner epithelium of the enamel organ (i.e., the ameloblast cells) synthesizes and secretes enamel matrix proteins (EMPs) into the enamel space. The protein-rich enamel matrix forms a highly organized architecture in a pH-neutral microenvironment. As amelogenesis transitions to maturation stage, EMPs are degraded and internalized by ameloblasts through endosomal-lysosomal pathways. Enamel crystallite formation is initiated early in the secretory stage, however, during maturation stage the more rapid deposition of calcium and phosphate into the enamel space results in a rapid expansion of crystallite length and mineral volume. During maturation-stage amelogenesis, the pH value of enamel varies considerably from slightly above neutral to acidic. Extracellular acid-base balance during enamel maturation is tightly controlled by ameloblast-mediated regulatory networks, which include significant synthesis and movement of bicarbonate ions from both the enamel papillary layer cells and ameloblasts. In this review we summarize the carbonic anhydrases and the carbonate transporters/exchangers involved in pH regulation in maturation-stage amelogenesis. Proteins that have been shown to be instrumental in this process include CA2, CA6, CFTR, AE2, NBCe1, SLC26A1/SAT1, SLC26A3/DRA, SLC26A4/PDS, SLC26A6/PAT1, and SLC26A7/SUT2. In addition, we discuss the association of miRNA regulation with bicarbonate transport in tooth enamel formation.
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Affiliation(s)
- Kaifeng Yin
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, 2250 Alcazar Street, CSA103, Los Angeles, CA, 90033, USA
- Department of Orthodontics, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA
| | - Michael L Paine
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, 2250 Alcazar Street, CSA103, Los Angeles, CA, 90033, USA.
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15
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Varga G, DenBesten P, Rácz R, Zsembery Á. Importance of bicarbonate transport in pH control during amelogenesis - need for functional studies. Oral Dis 2017; 24:879-890. [PMID: 28834043 DOI: 10.1111/odi.12738] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 08/13/2017] [Indexed: 12/27/2022]
Abstract
Dental enamel, the hardest mammalian tissue, is produced by ameloblasts. Ameloblasts show many similarities to other transporting epithelia although their secretory product, the enamel matrix, is quite different. Ameloblasts direct the formation of hydroxyapatite crystals, which liberate large quantities of protons that then need to be buffered to allow mineralization to proceed. Buffering requires a tight pH regulation and secretion of bicarbonate by ameloblasts. Many investigations have used immunohistochemical and knockout studies to determine the effects of these genes on enamel formation, but up till recently very little functional data were available for mineral ion transport. To address this, we developed a novel 2D in vitro model using HAT-7 ameloblast cells. HAT-7 cells can be polarized and develop functional tight junctions. Furthermore, they are able to accumulate bicarbonate ions from the basolateral to the apical fluid spaces. We propose that in the future, the HAT-7 2D system along with similar cellular models will be useful to functionally model ion transport processes during amelogenesis. Additionally, we also suggest that similar approaches will allow a better understanding of the regulation of the cycling process in maturation-stage ameloblasts, and the pH sensory mechanisms, which are required to develop sound, healthy enamel.
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Affiliation(s)
- G Varga
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | - P DenBesten
- Department of Orofacial Sciences, University of California, San Francisco, CA, USA
| | - R Rácz
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | - Á Zsembery
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
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16
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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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17
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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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18
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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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19
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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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20
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Yin K, Guo J, Lin W, Robertson SYT, Soleimani M, Paine ML. Deletion of Slc26a1 and Slc26a7 Delays Enamel Mineralization in Mice. Front Physiol 2017; 8:307. [PMID: 28559854 PMCID: PMC5432648 DOI: 10.3389/fphys.2017.00307] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 04/28/2017] [Indexed: 12/12/2022] Open
Abstract
Amelogenesis features two major developmental stages—secretory and maturation. During maturation stage, hydroxyapatite deposition and matrix turnover require delicate pH regulatory mechanisms mediated by multiple ion transporters. Several members of the Slc26 gene family (Slc26a1, Slc26a3, Slc26a4, Slc26a6, and Slc26a7), which exhibit bicarbonate transport activities, have been suggested by previous studies to be involved in maturation-stage amelogenesis, especially the key process of pH regulation. However, details regarding the functional role of these genes in enamel formation are yet to be clarified, as none of the separate mutant animal lines demonstrates any discernible enamel defects. Continuing with our previous investigation of Slc26a1−/− and Slc26a7−/− animal models, we generated a double-mutant animal line with the absence of both Slc26a1 and Slc26a7. We showed in the present study that the double-mutant enamel density was significantly lower in the regions that represent late maturation-, maturation- and secretory-stage enamel development in wild-type mandibular incisors. However, the “maturation” and “secretory” enamel microstructures in double-mutant animals resembled those observed in wild-type secretory and/or pre-secretory stages. Elemental composition analysis revealed a lack of mineral deposition and an accumulation of carbon and chloride in double-mutant enamel. Deletion of Slc26a1 and Slc26a7 did not affect the stage-specific morphology of the enamel organ. Finally, compensatory expression of pH regulator genes and ion transporters was detected in maturation-stage enamel organs of double-mutant animals when compared to wild-type. Combined with the findings from our previous study, these data indicate the involvement of SLC26A1and SLC26A7 as key ion transporters in the pH regulatory network during enamel maturation.
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Affiliation(s)
- Kaifeng Yin
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry of University of Southern CaliforniaLos Angeles, CA, USA.,Department of Orthodontics, Herman Ostrow School of Dentistry of University of Southern CaliforniaLos Angeles, CA, USA
| | - Jing Guo
- Department of Endodontics, Herman Ostrow School of Dentistry of University of Southern CaliforniaLos Angeles, CA, USA
| | - Wenting Lin
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry of University of Southern CaliforniaLos Angeles, CA, USA
| | - Sarah Y T Robertson
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry of University of Southern CaliforniaLos Angeles, CA, USA
| | - Manoocher Soleimani
- Department of Medicine, University of Cincinnati, Research Services, Veterans Affairs Medical CenterCincinnati, OH, USA
| | - Michael L Paine
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry of University of Southern CaliforniaLos Angeles, CA, USA
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21
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Vardenafil reduces macrophage pro-inflammatory overresponses in cystic fibrosis through PDE5- and CFTR-dependent mechanisms. Clin Sci (Lond) 2017; 131:1107-1121. [PMID: 28196856 DOI: 10.1042/cs20160749] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 02/13/2017] [Accepted: 02/14/2017] [Indexed: 02/07/2023]
Abstract
Chronic inflammation that progressively disrupts the lung tissue is a hallmark of cystic fibrosis (CF). In mice, vardenafil, an inhibitor of phosphodiesterase type 5 (PDE5), restores transepithelial ion transport and corrects mislocalization of the most common CF mutation, F508del-CFTR. It also reduces lung pro-inflammatory responses in mice and in patients with CF. To test the hypothesis that macrophages are target effector cells of the immunomo-dulatory effect of vardenafil, we isolated lung macrophages from mice homozygous for the F508del mutation or invalidated for the cftr gene and from their corresponding wild-type (WT) littermates. We then evaluated the effect of vardenafil on the classical M1 polarization, mirroring release of pro-inflammatory cytokines. We confirmed that macrophages from different body compartments express CF transmembrane conductance regulator (CFTR) and showed that vardenafil targets the cells through PDE5- and CFTR-dependent mechanisms. In the presence of the F508del mutation, vardenafil down-regulated overresponses of the M1 markers, tumour necrosis factor (TNF)-α and inducible nitric oxide synthase (NOS)-2. Our study identifies lung macrophages as target cells of the anti-inflammatory effect of vardenafil in CF and supports the view that the drug is potentially beneficial for treating CF as it combines rescue of CFTR protein and anti-inflammatory properties.
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Duchesneau P, Besla R, Derouet MF, Guo L, Karoubi G, Silberberg A, Wong AP, Waddell TK. Partial Restoration of CFTR Function in cftr-Null Mice following Targeted Cell Replacement Therapy. Mol Ther 2017; 25:654-665. [PMID: 28187947 DOI: 10.1016/j.ymthe.2016.11.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 11/10/2016] [Accepted: 11/27/2016] [Indexed: 01/22/2023] Open
Abstract
Cystic fibrosis (CF) is a fatal recessive genetic disorder caused by a mutation in the gene encoding CF transmembrane conductance regulator (CFTR) protein. Alteration in CFTR leads to thick airway mucus and bacterial infection. Cell therapy has been proposed for CFTR restoration, but efficacy has been limited by low engraftment levels. In our previous studies, we have shown that using a pre-conditioning regimen in combination with optimization of cell number and time of delivery, we could obtain greater bone marrow cell (BMC) retention in the lung. Here, we found that optimized delivery of wild-type (WT) BMC contributed to apical CFTR expression in airway epithelium and restoration of select ceramide species and fatty acids in CFTR-/- mice. Importantly, WT BMC delivery delayed Pseudomonas aeruginosa lung infection and increased survival of CFTR-/- recipients. Only WT BMCs had a beneficial effect beyond 6 months, suggesting a dual mechanism of BMC benefit: a non-specific effect early after cell delivery, possibly due to the recruitment of macrophages and neutrophils, and a late beneficial effect dependent on long-term CFTR expression. Taken together, our results suggest that BMC can improve overall lung function and may have potential therapeutic benefit for the treatment of CF.
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Affiliation(s)
- Pascal Duchesneau
- Latner Thoracic Surgery Research Laboratories and McEwen Centre for Regenerative Medicine, Toronto General Hospital Research Institute, University of Toronto, Toronto, ON M5G 2C4, Canada
| | - Rickvinder Besla
- Latner Thoracic Surgery Research Laboratories and McEwen Centre for Regenerative Medicine, Toronto General Hospital Research Institute, University of Toronto, Toronto, ON M5G 2C4, Canada
| | - Mathieu F Derouet
- Latner Thoracic Surgery Research Laboratories and McEwen Centre for Regenerative Medicine, Toronto General Hospital Research Institute, University of Toronto, Toronto, ON M5G 2C4, Canada
| | - Li Guo
- Latner Thoracic Surgery Research Laboratories and McEwen Centre for Regenerative Medicine, Toronto General Hospital Research Institute, University of Toronto, Toronto, ON M5G 2C4, Canada
| | - Golnaz Karoubi
- Latner Thoracic Surgery Research Laboratories and McEwen Centre for Regenerative Medicine, Toronto General Hospital Research Institute, University of Toronto, Toronto, ON M5G 2C4, Canada
| | - Amanda Silberberg
- Latner Thoracic Surgery Research Laboratories and McEwen Centre for Regenerative Medicine, Toronto General Hospital Research Institute, University of Toronto, Toronto, ON M5G 2C4, Canada
| | - Amy P Wong
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Thomas K Waddell
- Latner Thoracic Surgery Research Laboratories and McEwen Centre for Regenerative Medicine, Toronto General Hospital Research Institute, University of Toronto, Toronto, ON M5G 2C4, Canada.
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23
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Bronckers AL, Lyaruu DM. Magnesium, pH regulation and modulation by mouse ameloblasts exposed to fluoride. Bone 2017; 94:56-64. [PMID: 27744011 DOI: 10.1016/j.bone.2016.10.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 10/05/2016] [Accepted: 10/10/2016] [Indexed: 12/25/2022]
Abstract
Supraoptimal intake of fluoride (F) induces structural defects in forming enamel, dentin and bone and increases the risk of bone fractures. In comparison to bone and dentin is formation of enamel most sensitive to low levels of F and the degree of enamel fluorosis depends on the mouse strain. What molecular mechanism is responsible for these differences in sensitivity is unclear. Maturation ameloblasts transport bicarbonates into enamel in exchange for Cl- to buffer protons released by forming apatites. We proposed that F-enhanced mineral deposition releases excess of protons that will affect mineralization in forming enamel. In this study we tested the hypothesis that increased sensitivity to F is associated with a reduced capacity of ameloblasts to buffer acids. Quantified electron probe microanalysis showed that enamel of F-sensitive C57Bl mice contained the same levels of Cl- as enamel of F-resistant FVB mice. Enamel of C57Bl mice was less mineral dense, contained less Ca but more Mg and K. Ameloblast modulation was much more impaired than in FVB mice. In enamel of FVB mice the levels of Mg correlated negative with Ca (r=-0.57, p=0.01) and with the Ca/P molar ratio (r=-0.32, p=0.53). In moderate and high acidic enamel the correlations between Mg and Ca/P ratio were strong (r=-0.75, p=0.08) to very strong negative (r=-0.98, p=0.0020), respectively. Correlations in enamel between F and Ca were (weak) negative but between F and Ca/P very high positive (r=+0.95, p=0.003) in high acidic enamel and less positive (r=0.45, p=0.27) in moderate acidic fluorotic enamel (r=0.45, p=0.27). Similar correlations between Mg and Ca/P or F and Ca/P were found in dentin and bone of fluorotic and Cftr null mice. These data are consistent with the concept that Mg delays but F increases maturation of crystals particularly when enamel is acidic. The sensitivity of forming enamel to F likely is due to the sensitivity of pH cycling to acidification of enamel associated with F-induced release of protons.
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Affiliation(s)
- Antonius Ljj Bronckers
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, MOVE Research Institute, Amsterdam, The Netherlands.
| | - Donacian M Lyaruu
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, MOVE Research Institute, Amsterdam, The Netherlands
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24
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Abstract
Hypomineralization of developing enamel is associated with changes in ameloblast modulation during the maturation stage. Modulation (or pH cycling) involves the cyclic transformation of ruffle-ended (RE) ameloblasts facing slightly acidic enamel into smooth-ended (SE) ameloblasts near pH-neutral enamel. The mechanism of ameloblast modulation is not clear. Failure of ameloblasts of Cftr-null and anion exchanger 2 ( Ae2)-null mice to transport Cl- into enamel acidifies enamel, prevents modulation, and reduces mineralization. It suggests that pH regulation is critical for modulation and for completion of enamel mineralization. This report presents a review of the major types of transmembrane molecules that ameloblasts express to transport calcium to form crystals and bicarbonates to regulate pH. The type of transporter depends on the developmental stage. Modulation is proposed to be driven by the pH of enamel fluid and the compositional and/or physicochemical changes that result from increased acidity, which may turn RE ameloblasts into SE mode. Amelogenins delay outgrowth of crystals and keep the intercrystalline space open for diffusion of mineral ions into complete depth of enamel. Modulation enables stepwise removal of amelogenins from the crystal surface, their degradation, and removal from the enamel. Removal of matrix allows slow expansion of crystals. Modulation also reduces the stress that ameloblasts experience when exposed to high acid levels generated by mineral formation or by increased intracellular Ca2+. By cyclically interrupting Ca2+ transport by RE ameloblasts and their transformation into SE ameloblasts, proton production ceases shortly and enables the ameloblasts to recover. Modulation also improves enamel crystal quality by selectively dissolving immature Ca2+-poor crystals, removing impurities as Mg2+ and carbonates, and recrystallizing into more acid-resistant crystals.
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Affiliation(s)
- A L J J Bronckers
- 1 Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, MOVE Research Institute, Amsterdam, Netherlands
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25
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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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26
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Braun C, Bacchetta J, Reix P. [Insights into cystic fibrosis-related bone disease]. Arch Pediatr 2016; 23:857-66. [PMID: 27345551 DOI: 10.1016/j.arcped.2016.05.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 03/17/2016] [Accepted: 05/11/2016] [Indexed: 02/04/2023]
Abstract
With the increasing life expectancy of patients with cystic fibrosis (CF), prevalence of late complications such as CF-related bone disease (CFBD) has increased. It was initially described in 24% of the adult population with CF and has also been reported in the pediatric population. CFBD is multifactorial and progresses in different steps. Both decreased bone formation and increased bone resorption (in different amounts) are observed. CFBD is likely primitive (directly related to the CFTR defect itself), but is also worsened by acquired secondary factors such as lung infections, chronic inflammation, denutrition, vitamin deficiency, and decreased physical activity. CFBD may be clinically apparent (i.e., mainly vertebral and costal fractures), or clinically asymptomatic (therefore corresponding to abnormalities in bone density and architecture). CFBD management mainly aims to prevent the occurrence of fractures. Prevention and regular monitoring of bone disease as early as 8 years of age is of the utmost importance, as is the control of possible secondary deleterious CFBD factors. New radiological tools, such as high-resolution peripheral quantitative computed tomography, allow an accurate evaluation of cortical and trabecular bone micro-architecture in addition to compartmental density; as such, they will likely improve the assessment of the bone fracture threat in CF patients in the near future.
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Affiliation(s)
- C Braun
- Université Claude-Bernard Lyon 1, 43, boulevard du 11-Novembre-1918, 69100 Villeurbanne, France
| | - J Bacchetta
- Université Claude-Bernard Lyon 1, 43, boulevard du 11-Novembre-1918, 69100 Villeurbanne, France; Centre de référence des maladies rénales rares, hôpital femme mère enfant, 69500 Bron, France; Inserm 1033 LYOS, prévention des maladies osseuses, 69008 Lyon, France
| | - P Reix
- Université Claude-Bernard Lyon 1, 43, boulevard du 11-Novembre-1918, 69100 Villeurbanne, France; Centre de ressources et de compétences de la mucoviscidose, hôpital femme mère enfant, 69500 Bron, France; UMR 5558, équipe EMET, 43, boulevard du 11-Novembre-1918, 69100 Villeurbanne, France.
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27
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Cook DP, Rector MV, Bouzek DC, Michalski AS, Gansemer ND, Reznikov LR, Li X, Stroik MR, Ostedgaard LS, Abou Alaiwa MH, Thompson MA, Prakash YS, Krishnan R, Meyerholz DK, Seow CY, Stoltz DA. Cystic Fibrosis Transmembrane Conductance Regulator in Sarcoplasmic Reticulum of Airway Smooth Muscle. Implications for Airway Contractility. Am J Respir Crit Care Med 2016; 193:417-26. [PMID: 26488271 DOI: 10.1164/rccm.201508-1562oc] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE An asthma-like airway phenotype has been described in people with cystic fibrosis (CF). Whether these findings are directly caused by loss of CF transmembrane conductance regulator (CFTR) function or secondary to chronic airway infection and/or inflammation has been difficult to determine. OBJECTIVES Airway contractility is primarily determined by airway smooth muscle. We tested the hypothesis that CFTR is expressed in airway smooth muscle and directly affects airway smooth muscle contractility. METHODS Newborn pigs, both wild type and with CF (before the onset of airway infection and inflammation), were used in this study. High-resolution immunofluorescence was used to identify the subcellular localization of CFTR in airway smooth muscle. Airway smooth muscle function was determined with tissue myography, intracellular calcium measurements, and regulatory myosin light chain phosphorylation status. Precision-cut lung slices were used to investigate the therapeutic potential of CFTR modulation on airway reactivity. MEASUREMENTS AND MAIN RESULTS We found that CFTR localizes to the sarcoplasmic reticulum compartment of airway smooth muscle and regulates airway smooth muscle tone. Loss of CFTR function led to delayed calcium reuptake following cholinergic stimulation and increased myosin light chain phosphorylation. CFTR potentiation with ivacaftor decreased airway reactivity in precision-cut lung slices following cholinergic stimulation. CONCLUSIONS Loss of CFTR alters porcine airway smooth muscle function and may contribute to the airflow obstruction phenotype observed in human CF. Airway smooth muscle CFTR may represent a therapeutic target in CF and other diseases of airway narrowing.
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Affiliation(s)
- Daniel P Cook
- 1 Department of Internal Medicine.,2 Department of Molecular Physiology and Biophysics
| | | | | | | | | | | | | | | | | | | | - Michael A Thompson
- 3 Department of Anesthesiology and.,4 Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
| | - Y S Prakash
- 3 Department of Anesthesiology and.,4 Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
| | - Ramaswamy Krishnan
- 5 Department of Emergency Medicine, Center for Vascular Biology Research, Beth Israel Deaconess Medical Center, Boston, Massachusetts; and
| | | | - Chun Y Seow
- 7 Department of Pathology and Laboratory Medicine, James Hogg Research Centre/St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - David A Stoltz
- 1 Department of Internal Medicine.,2 Department of Molecular Physiology and Biophysics.,8 Department of Biomedical Engineering, and.,9 Pappajohn Biomedical Institute, University of Iowa, Iowa City, Iowa
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28
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Le Henaff C, Faria Da Cunha M, Hatton A, Tondelier D, Marty C, Collet C, Zarka M, Geoffroy V, Zatloukal K, Laplantine E, Edelman A, Sermet-Gaudelus I, Marie PJ. Genetic deletion of keratin 8 corrects the altered bone formation and osteopenia in a mouse model of cystic fibrosis. Hum Mol Genet 2016; 25:1281-93. [PMID: 26769674 DOI: 10.1093/hmg/ddw009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 01/06/2016] [Indexed: 12/23/2022] Open
Abstract
Patients with cystic fibrosis (CF) display low bone mass and alterations in bone formation. Mice carrying the F508del genetic mutation in the cystic fibrosis conductance regulator (Cftr) gene display reduced bone formation and decreased bone mass. However, the underlying molecular mechanisms leading to these skeletal defects are unknown, which precludes the development of an efficient anti-osteoporotic therapeutic strategy. Here we report a key role for the intermediate filament protein keratin 8 (Krt8), in the osteoblast dysfunctions in F508del-Cftr mice. We found that murine and human osteoblasts express Cftr and Krt8 at low levels. Genetic studies showed that Krt8 deletion (Krt8(-/-)) in F508del-Cftr mice increased the levels of circulating markers of bone formation, corrected the expression of osteoblast phenotypic genes, promoted trabecular bone formation and improved bone mass and microarchitecture. Mechanistically, Krt8 deletion in F508del-Cftr mice corrected overactive NF-κB signaling and decreased Wnt-β-catenin signaling induced by the F508del-Cftr mutation in osteoblasts. In vitro, treatment with compound 407, which specifically disrupts the Krt8-F508del-Cftr interaction in epithelial cells, corrected the abnormal NF-κB and Wnt-β-catenin signaling and the altered phenotypic gene expression in F508del-Cftr osteoblasts. In vivo, short-term treatment with 407 corrected the altered Wnt-β-catenin signaling and bone formation in F508del-Cftr mice. Collectively, the results show that genetic or pharmacologic targeting of Krt8 leads to correction of osteoblast dysfunctions, altered bone formation and osteopenia in F508del-Cftr mice, providing a therapeutic strategy targeting the Krt8-F508del-CFTR interaction to correct the abnormal bone formation and bone loss in cystic fibrosis.
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Affiliation(s)
- Carole Le Henaff
- INSERM UMR-1132, Paris, France, University Paris Diderot, Sorbonne Paris Cité, Paris, France
| | | | - Aurélie Hatton
- INSERM U-1151, Team 2, University Paris Descartes, Paris, France
| | | | - Caroline Marty
- INSERM UMR-1132, Paris, France, University Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Corinne Collet
- INSERM UMR-1132, Paris, France, University Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Mylène Zarka
- INSERM UMR-1132, Paris, France, University Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Valérie Geoffroy
- INSERM UMR-1132, Paris, France, University Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Kurt Zatloukal
- Institute of Pathology, Medical University of Graz, Graz, Austria and
| | - Emmanuel Laplantine
- Laboratoire de Signalisation et Pathogenèse, Institut Pasteur, Paris, France
| | | | | | - Pierre J Marie
- INSERM UMR-1132, Paris, France, University Paris Diderot, Sorbonne Paris Cité, Paris, France,
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Yin K, Lei Y, Wen X, Lacruz RS, Soleimani M, Kurtz I, Snead ML, White SN, Paine ML. SLC26A Gene Family Participate in pH Regulation during Enamel Maturation. PLoS One 2015; 10:e0144703. [PMID: 26671068 PMCID: PMC4679777 DOI: 10.1371/journal.pone.0144703] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 11/23/2015] [Indexed: 12/15/2022] Open
Abstract
The bicarbonate transport activities of Slc26a1, Slc26a6 and Slc26a7 are essential to physiological processes in multiple organs. Although mutations of Slc26a1, Slc26a6 and Slc26a7 have not been linked to any human diseases, disruption of Slc26a1, Slc26a6 or Slc26a7 expression in animals causes severe dysregulation of acid-base balance and disorder of anion homeostasis. Amelogenesis, especially the enamel formation during maturation stage, requires complex pH regulation mechanisms based on ion transport. The disruption of stage-specific ion transporters frequently results in enamel pathosis in animals. Here we present evidence that Slc26a1, Slc26a6 and Slc26a7 are highly expressed in rodent incisor ameloblasts during maturation-stage tooth development. In maturation-stage ameloblasts, Slc26a1, Slc26a6 and Slc26a7 show a similar cellular distribution as the cystic fibrosis transmembrane conductance regulator (Cftr) to the apical region of cytoplasmic membrane, and the distribution of Slc26a7 is also seen in the cytoplasmic/subapical region, presumably on the lysosomal membrane. We have also examined Slc26a1 and Slc26a7 null mice, and although no overt abnormal enamel phenotypes were observed in Slc26a1-/- or Slc26a7-/- animals, absence of Slc26a1 or Slc26a7 results in up-regulation of Cftr, Ca2, Slc4a4, Slc4a9 and Slc26a9, all of which are involved in pH homeostasis, indicating that this might be a compensatory mechanism used by ameloblasts cells in the absence of Slc26 genes. Together, our data show that Slc26a1, Slc26a6 and Slc26a7 are novel participants in the extracellular transport of bicarbonate during enamel maturation, and that their functional roles may be achieved by forming interaction units with Cftr.
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Affiliation(s)
- Kaifeng Yin
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry of University of Southern California, Los Angeles, California, United States of America
| | - Yuejuan Lei
- Department of Operative and Endodontics, The Affiliated Stomatological Hospital, Guangxi Medical University, Nanning, Guangxi, China
| | - Xin Wen
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry of University of Southern California, Los Angeles, California, United States of America
| | - Rodrigo S. Lacruz
- Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, New York, United States of America
| | - Manoocher Soleimani
- Department of Medicine, University of Cincinnati, Research Services, Veterans Affairs Medical Center, Cincinnati, Ohio, United States of America
| | - Ira Kurtz
- Division of Nephrology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, United States of America
| | - Malcolm L. Snead
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry of University of Southern California, Los Angeles, California, United States of America
| | - Shane N. White
- School of Dentistry, University of California Los Angeles, Los Angeles, California, United States of America
| | - Michael L. Paine
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry of University of Southern California, Los Angeles, California, United States of America
- * E-mail:
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30
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V-type ATPase proton pump expression during enamel formation. Matrix Biol 2015; 52-54:234-245. [PMID: 26586472 DOI: 10.1016/j.matbio.2015.11.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 10/29/2015] [Accepted: 11/09/2015] [Indexed: 01/12/2023]
Abstract
Several diseases such as proximal and distal renal tubular acidosis and osteoporosis are related to intracellular pH dysregulation resulting from mutations in genes coding for ion channels, including proteins comprising the proton-pumping V-type ATPase. V-type ATPase is a multi-subunit protein complex expressed in enamel forming cells. V-type ATPase plays a key role in enamel development, specifically lysosomal acidification, yet our understanding of the relationship between the endocytotic activities and dental health and disease is limited. The objective of this study is to better understand the ameloblast-associated pH regulatory networks essential for amelogenesis. Quantitative RT-PCR was performed on tissues from secretory-stage and maturation-stage enamel organs to determine which of the V-type ATPase subunits are most highly upregulated during maturation-stage amelogenesis: a time when ameloblast endocytotic activity is highest. Western blot analyses, using specific antibodies to four of the V-type ATPase subunits (Atp6v0d2, Atp6v1b2, Atp6v1c1 and Atp6v1e1), were then applied to validate much of the qPCR data. Immunohistochemistry using these same four antibodies was also performed to identify the spatiotemporal expression profiles of individual V-type ATPase subunits. Our data show that cytoplasmic V-type ATPase is significantly upregulated in enamel organ cells during maturation-stage when compared to secretory-stage. These data likely relate to the higher endocytotic activities, and the greater need for lysosomal acidification, during maturation-stage amelogenesis. It is also apparent from our immunolocalization data, using antibodies against two of the V-type ATPase subunits (Atp6v1c1 and Atp6v1e1), that significant expression is seen at the apical membrane of maturation-stage ameloblasts. Others have also identified this V-type ATPase expression profile at the apical membrane of maturation ameloblasts. Collectively, these data better define the expression and role of the V-type ATPase proton pump in the enamel organ during amelogenesis.
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31
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Jalali R, Zandieh-Doulabi B, DenBesten PK, Seidler U, Riederer B, Wedenoja S, Micha D, Bronckers ALJJ. Slc26a3/Dra and Slc26a6 in Murine Ameloblasts. J Dent Res 2015; 94:1732-9. [PMID: 26394631 DOI: 10.1177/0022034515606873] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Formation of apatite crystals during enamel development generates protons. To sustain mineral accretion, maturation ameloblasts need to buffer these protons. The presence of cytosolic carbonic anhydrases, the basolateral Na(+) bicarbonate cotransporter Nbce1, and the basolateral anion exchanger Ae2a,b in maturation ameloblasts suggests that these cells secrete bicarbonates into the forming enamel, but it is unknown by which mechanism. Solute carrier (Slc) family 26A encodes different anion exchangers that exchange Cl(-)/HCO3 (-), including Slc26a3/Dra, Slc26a6/Pat-1, and Slc26a4/pendrin. Previously, we showed that pendrin is expressed in ameloblasts but is not critical for enamel formation. In this study, we tested the hypothesis that maturation ameloblasts express Dra and Slc26a6 to secrete bicarbonate into the enamel space in exchange for Cl(-). Real-time polymerase chain reaction detected mRNA transcripts for Dra and Slc26a6 in mouse incisor enamel organs, and Western blotting confirmed their translation into protein. Both isoforms were immunolocalized in ameloblasts, principally at maturation stage. Mice with null mutation of either Dra or Slc26a6 had a normal dental or skeletal phenotype without changes in mineral density, as measured by micro-computed tomography. In enamel organs of Slc26a6-null mice, Dra and pendrin protein levels were both elevated by 52% and 55%, respectively. The amount of Slc26a6 protein was unchanged in enamel organs of Ae2a,b- and Cftr-null mice but reduced in Dra-null mice by 36%. Our data show that ameloblasts express Dra, pendrin, or Slc26a6 but each of these separately is not critical for formation of dental enamel. The data suggest that in ameloblasts, Slc26a isoforms can functionally compensate for one another.
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Affiliation(s)
- R Jalali
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam, University of Amsterdam, and MOVE Research Institute, VU University Amsterdam, Amsterdam, Netherlands
| | - B Zandieh-Doulabi
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam, University of Amsterdam, and MOVE Research Institute, VU University Amsterdam, Amsterdam, Netherlands
| | - P K DenBesten
- Department of Oral Sciences, University of California, San Francisco, CA, USA
| | - U Seidler
- Abteilung Gastroenterologie, Hepatologie und Endokrinologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - B Riederer
- Abteilung Gastroenterologie, Hepatologie und Endokrinologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - S Wedenoja
- Department of Medical Genetics, Biomedicum Helsinki, University of Helsinki, Finland
| | - D Micha
- Department of Clinical Genetics, Vrije Universiteit Medical Center, Amsterdam, Netherlands
| | - A L J J Bronckers
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam, University of Amsterdam, and MOVE Research Institute, VU University Amsterdam, Amsterdam, Netherlands
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Guo J, Bervoets TJM, Henriksen K, Everts V, Bronckers ALJJ. Null mutation of chloride channel 7 (Clcn7) impairs dental root formation but does not affect enamel mineralization. Cell Tissue Res 2015; 363:361-70. [PMID: 26346547 PMCID: PMC4735262 DOI: 10.1007/s00441-015-2263-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 07/29/2015] [Indexed: 12/23/2022]
Abstract
ClC-7, located in late endosomes and lysosomes, is critical for the function of osteoclasts. Secretion of Cl(-) by the ruffled border of osteoclasts enables H(+) secretion by v-H(+)-ATPases to dissolve bone mineral. Mice lacking ClC-7 show altered lysosomal function that leads to severe lysosomal storage. Maturation ameloblasts are epithelial cells with a ruffled border that secrete Cl(-) as well as endocytose and digest large quantities of enamel matrix proteins during formation of dental enamel. We tested the hypothesis that ClC-7 in maturation ameloblasts is required for intracellular digestion of matrix fragments to complete enamel mineralization. Craniofacial bones and developing teeth in Clcn7(-/-) mice were examined by micro-CT, immunohistochemistry, quantified histomorphometry and electron microscopy. Osteoclasts and ameloblasts in wild-type mice stained intensely with anti-ClC-7 antibody but not in Clcn7(-/-) mice. Craniofacial bones in Clcn7(-/-) mice were severely osteopetrotic and contained 1.4- to 1.6-fold more bone volume, which was less mineralized than the wild-type littermates. In Clcn7(-/-) mice maturation ameloblasts and osteoclasts highly expressed Ae2 as in wild-type mice. However, teeth failed to erupt, incisors were much shorter and roots were disfigured. Molars formed a normal dental crown. In compacted teeth, dentin was slightly less mineralized, enamel did not retain a matrix and mineralized fairly normal. We concluded that ClC-7 is essential for osteoclasts to resorb craniofacial bones to enable tooth eruption and root development. Disruption of Clcn7 reduces bone and dentin mineral density but does not affect enamel mineralization.
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Affiliation(s)
- Jing Guo
- Department Oral Cell Biology, Academic Center of Dentistry Amsterdam (ACTA), University of Amsterdam and VU-University of Amsterdam, MOVE Research Institute, Gustav Mahlerlaan 3004, 1081 LA, Amsterdam, The Netherlands. .,School of Stomatology/Dental Clinic, Zhejiang Chinese Medical University, Mailbox 97, Binwen Road 548, Binjiang District, 310053, Hangzhou, China.
| | - Theodore J M Bervoets
- Department Oral Cell Biology, Academic Center of Dentistry Amsterdam (ACTA), University of Amsterdam and VU-University of Amsterdam, MOVE Research Institute, Gustav Mahlerlaan 3004, 1081 LA, Amsterdam, The Netherlands
| | - Kim Henriksen
- Nordic Bioscience Biomarkers and Research A/S, Hovedgade 207, 2730, Herlev, Denmark
| | - Vincent Everts
- Department Oral Cell Biology, Academic Center of Dentistry Amsterdam (ACTA), University of Amsterdam and VU-University of Amsterdam, MOVE Research Institute, Gustav Mahlerlaan 3004, 1081 LA, Amsterdam, The Netherlands
| | - Antonius L J J Bronckers
- Department Oral Cell Biology, Academic Center of Dentistry Amsterdam (ACTA), University of Amsterdam and VU-University of Amsterdam, MOVE Research Institute, Gustav Mahlerlaan 3004, 1081 LA, Amsterdam, The Netherlands
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33
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Zheng L, Zinn V, Lefkelidou A, Taqi N, Chatzistavrou X, Balam T, Nervina J, Papagerakis S, Papagerakis P. Orai1 expression pattern in tooth and craniofacial ectodermal tissues and potential functions during ameloblast differentiation. Dev Dyn 2015; 244:1249-58. [PMID: 26178077 DOI: 10.1002/dvdy.24307] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 06/24/2015] [Accepted: 07/01/2015] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Orai1 is a plasma membrane protein that forms the pore of the calcium release activated calcium channel. Humans with mutated Orai1 present with hereditary combined immunodeficiency, congenital myopathy and anhidrotic ectodermal dysplasia. Consistent with the ectodermal dysplasia phenotype, enamel formation and mineralization is also abnormal in Orai1 deficient patients. The expression pattern and potential functions of Orai1 in enamel formation remains unclear. To contribute toward understanding the role of Orai1 in amelogenesis we characterized ORAI1 protein developmental pattern in comparison with other ectodermal organs. We also examined the effects of Orai1 down-regulation in ameloblast cell proliferation and differentiation. RESULTS Our data show strong expression of ORAI1 protein during the ameloblast secretory stage, which weans at the end of the maturation stage. In salivary glands, ORAI1 is expressed mainly in acini cells. ORAI1 expression is also found in hair follicle and oral epithelium. Knockdown of Orai1 expression decreases cell proliferation and results in RNA expression levels changes of key ameloblast genes regulating enamel thickness and mineralization. CONCLUSIONS This study provides insights in the anhidrotic ectodermal dysplasia phenotype due to Orai1 mutation and highlights the importance of calcium signaling in controlling ameloblast differentiation and maturation during tooth development.
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Affiliation(s)
- Li Zheng
- Department of Orthodontics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, Michigan.,Department of Otolaryngology, School of Medicine, University of Michigan, Ann Arbor, Michigan
| | - Vina Zinn
- Department of Orthodontics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, Michigan
| | - Anna Lefkelidou
- Department of Orthodontics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, Michigan
| | - Nawar Taqi
- Department of Orthodontics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, Michigan
| | - Xanthippi Chatzistavrou
- Department of Orthodontics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, Michigan
| | - Tarek Balam
- Department of Orthodontics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, Michigan
| | - Jeanne Nervina
- Department of Orthodontics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, Michigan
| | - Silvana Papagerakis
- Department of Otolaryngology, School of Medicine, University of Michigan, Ann Arbor, Michigan.,Department of Periodontology and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, Michigan
| | - Petros Papagerakis
- Department of Orthodontics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, Michigan.,Center for Organogenesis, School of Medicine, University of Michigan, Ann Arbor, Michigan.,Center for Computational Medicine and Bioinformatics, School of Medicine, University of Michigan, Ann Arbor, Michigan
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Varga G, Kerémi B, Bori E, Földes A. Function and repair of dental enamel - Potential role of epithelial transport processes of ameloblasts. Pancreatology 2015; 15:S55-60. [PMID: 25747281 DOI: 10.1016/j.pan.2015.01.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 01/28/2015] [Indexed: 12/11/2022]
Abstract
The hardest mammalian tissue, dental enamel is produced by ameloblasts, which are electrolyte-transporting epithelial cells. Although the end product is very different, they show many similarities to transporting epithelia of the pancreas, salivary glands and kidney. Enamel is produced in a multi-step epithelial secretory process that features biomineralization which is an interplay of secreted ameloblast specific proteins and the time-specific transport of minerals, protons and bicarbonate. First, "secretory" ameloblasts form the entire thickness of the enamel layer, but with low mineral content. Then they differentiate into "maturation" ameloblasts, which remove organic matrix from the enamel and in turn further build up hydroxyapatite crystals. The protons generated by hydroxyapatite formation need to be buffered, otherwise enamel will not attain full mineralization. Buffering requires a tight pH regulation and secretion of bicarbonate by ameloblasts. The whole process has been the focus of many immunohistochemical and gene knock-out studies, but, perhaps surprisingly, no functional data existed for mineral ion transport by ameloblasts. However, recent studies including ours provided a better insight for molecular mechanism of mineral formation. The secretory regulation is not completely known as yet, but its significance is crucial. Impairing regulation retards or prevents completion of enamel mineralization and results in the development of hypomineralized enamel that easily erodes after dental eruption. Factors that impair this function are fluoride and disruption of pH regulators. Revealing these factors may eventually lead to the treatment of enamel hypomineralization related to genetic or environmentally induced malformation.
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Affiliation(s)
- Gábor Varga
- Department of Oral Biology, Semmelweis University, Budapest, Hungary.
| | - Beáta Kerémi
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | - Erzsébet Bori
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | - Anna Földes
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
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Le Henaff C, Mansouri R, Modrowski D, Zarka M, Geoffroy V, Marty C, Tarantino N, Laplantine E, Marie PJ. Increased NF-κB Activity and Decreased Wnt/β-Catenin Signaling Mediate Reduced Osteoblast Differentiation and Function in ΔF508 Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Mice. J Biol Chem 2015; 290:18009-18017. [PMID: 26060255 DOI: 10.1074/jbc.m115.646208] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Indexed: 01/11/2023] Open
Abstract
The prevalent human ΔF508 mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) is associated with reduced bone formation and bone loss in mice. The molecular mechanisms by which the ΔF508-CFTR mutation causes alterations in bone formation are poorly known. In this study, we analyzed the osteoblast phenotype in ΔF508-CFTR mice and characterized the signaling mechanisms underlying this phenotype. Ex vivo studies showed that the ΔF508-CFTR mutation negatively impacted the differentiation of bone marrow stromal cells into osteoblasts and the activity of osteoblasts, demonstrating that the ΔF508-CFTR mutation alters both osteoblast differentiation and function. Treatment with a CFTR corrector rescued the abnormal collagen gene expression in ΔF508-CFTR osteoblasts. Mechanistic analysis revealed that NF-κB signaling and transcriptional activity were increased in mutant osteoblasts. Functional studies showed that the activation of NF-κB transcriptional activity in mutant osteoblasts resulted in increased β-catenin phosphorylation, reduced osteoblast β-catenin expression, and altered expression of Wnt/β-catenin target genes. Pharmacological inhibition of NF-κB activity or activation of canonical Wnt signaling rescued Wnt target gene expression and corrected osteoblast differentiation and function in bone marrow stromal cells and osteoblasts from ΔF508-CFTR mice. Overall, the results show that the ΔF508-CFTR mutation impairs osteoblast differentiation and function as a result of overactive NF-κB and reduced Wnt/β-catenin signaling. Moreover, the data indicate that pharmacological inhibition of NF-κB or activation of Wnt/β-catenin signaling can rescue the abnormal osteoblast differentiation and function induced by the prevalent ΔF508-CFTR mutation, suggesting novel therapeutic strategies to correct the osteoblast dysfunctions in cystic fibrosis.
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Affiliation(s)
- Carole Le Henaff
- UMR-1132 INSERM, 75475 Paris; Université Paris Diderot, Sorbonne Paris Cité, 75013 Paris
| | - Rafik Mansouri
- UMR-1132 INSERM, 75475 Paris; Université Paris Diderot, Sorbonne Paris Cité, 75013 Paris
| | - Dominique Modrowski
- UMR-1132 INSERM, 75475 Paris; Université Paris Diderot, Sorbonne Paris Cité, 75013 Paris
| | - Mylène Zarka
- UMR-1132 INSERM, 75475 Paris; Université Paris Diderot, Sorbonne Paris Cité, 75013 Paris
| | - Valérie Geoffroy
- UMR-1132 INSERM, 75475 Paris; Université Paris Diderot, Sorbonne Paris Cité, 75013 Paris
| | - Caroline Marty
- UMR-1132 INSERM, 75475 Paris; Université Paris Diderot, Sorbonne Paris Cité, 75013 Paris
| | - Nadine Tarantino
- Laboratoire de Signalisation et Pathogenèse, Institut Pasteur, 75015 Paris, France
| | - Emmanuel Laplantine
- Laboratoire de Signalisation et Pathogenèse, Institut Pasteur, 75015 Paris, France
| | - Pierre J Marie
- UMR-1132 INSERM, 75475 Paris; Université Paris Diderot, Sorbonne Paris Cité, 75013 Paris.
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Melin L, Lundgren J, Malmberg P, Norén JG, Taube F, Cornell DH. XRMA and ToF-SIMS Analysis of Normal and Hypomineralized Enamel. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2015; 21:407-421. [PMID: 25674916 DOI: 10.1017/s1431927615000033] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Molar incisor hypomineralization (MIH) is a developmental disturbance of the enamel. This study presents analyses of hypomineralized and normal enamel in first molar teeth diagnosed with MIH, utilizing time-of-flight secondary ion mass spectrometry area analyses and X-ray microanalysis of area and spot profiles in uncoated samples between gold lines which provide electrical conductivity. Statistical analysis of mean values allows discrimination of normal from MIH enamel, which has higher Mg and lower Na and P. Inductive analysis using complete data sets for profiles from the enamel surface to the enamel-dentin junction found that Mg, Cl and position in the profile provide useful discrimination criteria. Element profiles provide a visual complement to the inductive analysis and several elements also provide insight into the development of both normal and MIH enamel. The higher Mg content and different Cl profiles of hypomineralized enamel compared with normal enamel are probably related to a relatively short period during the development of ameloblasts between birth and the 1st year of life.
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Affiliation(s)
- Lisa Melin
- 1Department of Pediatric Dentistry,Institute of Odontology at the Sahlgrenska Academy,University of Gothenburg,P.O. Box 450,SE 405 30 Gothenburg,Sweden
| | - Jesper Lundgren
- 2Department of Psychology,University of Gothenburg,P.O. Box 500,SE 405 30 Gothenburg,Sweden
| | - Per Malmberg
- 3Department of Chemical and Biological Engineering,Chalmers University of Technology,Kemivägen 10,412 96 Gothenburg,Sweden
| | - Jörgen G Norén
- 1Department of Pediatric Dentistry,Institute of Odontology at the Sahlgrenska Academy,University of Gothenburg,P.O. Box 450,SE 405 30 Gothenburg,Sweden
| | - Fabian Taube
- 4Department of Occupational and Environmental Medicine,Sahlgrenska University Hospital,P.O. Box 414,SE 405 30 Gothenburg,Sweden
| | - David H Cornell
- 5Department of Earth Sciences,University of Gothenburg,P.O. Box 460,SE 405 30 Gothenburg,Sweden
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Ousingsawat J, Wanitchakool P, Schreiber R, Wuelling M, Vortkamp A, Kunzelmann K. Anoctamin-6 controls bone mineralization by activating the calcium transporter NCX1. J Biol Chem 2015; 290:6270-80. [PMID: 25589784 DOI: 10.1074/jbc.m114.602979] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Anoctamin-6 (Ano6, TMEM16F) belongs to a family of putative Ca(2+)-activated Cl(-) channels and operates as membrane phospholipid scramblase. Deletion of Ano6 leads to reduced skeleton size, skeletal deformities, and mineralization defects in mice. However, it remains entirely unclear how a lack of Ano6 leads to a delay in bone mineralization by osteoblasts. The Na(+)/Ca(2+) exchanger NCX1 was found to interact with Ano6 in a two-hybrid split-ubiquitin screen. Using human osteoblasts and osteoblasts from Ano6(-/-) and WT mice, we demonstrate that NCX1 requires Ano6 to efficiently translocate Ca(2+) out of osteoblasts into the calcifying bone matrix. Ca(2+)-activated anion currents are missing in primary osteoblasts isolated from Ano6 null mice. Our findings demonstrate the importance of NCX1 for bone mineralization and explain why deletion of an ion channel leads to the observed mineralization defect: Ano6 Cl(-) currents are probably required to operate as a Cl(-) bypass channel, thereby compensating net Na(+) charge movement by NCX1.
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Affiliation(s)
- Jiraporn Ousingsawat
- From the Institut für Physiologie, Universität Regensburg, D-93053 Regensburg and
| | | | - Rainer Schreiber
- From the Institut für Physiologie, Universität Regensburg, D-93053 Regensburg and
| | - Manuela Wuelling
- the Department Entwicklungsbiologie, Fakultät für Biologie, Universität Duisburg-Essen, 45141 Essen, Germany
| | - Andrea Vortkamp
- the Department Entwicklungsbiologie, Fakultät für Biologie, Universität Duisburg-Essen, 45141 Essen, Germany
| | - Karl Kunzelmann
- From the Institut für Physiologie, Universität Regensburg, D-93053 Regensburg and
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38
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Bronckers ALJJ, Lyaruu DM, Guo J, Bijvelds MJC, Bervoets TJM, Zandieh-Doulabi B, Medina JF, Li Z, Zhang Y, DenBesten PK. Composition of mineralizing incisor enamel in cystic fibrosis transmembrane conductance regulator-deficient mice. Eur J Oral Sci 2014; 123:9-16. [PMID: 25557910 DOI: 10.1111/eos.12163] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/28/2014] [Indexed: 12/25/2022]
Abstract
Formation of crystals in the enamel space releases protons that need to be buffered to sustain mineral accretion. We hypothesized that apical cystic fibrosis transmembrane conductance regulator (CFTR) in maturation ameloblasts transduces chloride into forming enamel as a critical step to secrete bicarbonates. We tested this by determining the calcium, chloride, and fluoride levels in developing enamel of Cftr-null mice by quantitative electron probe microanalysis. Maturation-stage enamel from Cftr-null mice contained less chloride and calcium than did wild-type enamel, was more acidic when stained with pH dyes ex vivo, and formed no fluorescent modulation bands after in vivo injection of the mice with calcein. To acidify the enamel further we exposed Cftr-null mice to fluoride in drinking water to stimulate proton release during formation of hypermineralized lines. In Cftr-deficient mice, fluoride further lowered enamel calcium without further reducing chloride levels. The data support the view that apical CFTR in maturation ameloblasts tranduces chloride into developing enamel as part of the machinery to buffer protons released during mineral accretion.
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Affiliation(s)
- Antonius L J J Bronckers
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam (ACTA), MOVE Research Institute, University of Amsterdam and VU University Amsterdam, Amsterdam, the Netherlands
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39
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Yin K, Hacia JG, Zhong Z, Paine ML. Genome-wide analysis of miRNA and mRNA transcriptomes during amelogenesis. BMC Genomics 2014; 15:998. [PMID: 25406666 PMCID: PMC4254193 DOI: 10.1186/1471-2164-15-998] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2014] [Accepted: 10/23/2014] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND In the rodent incisor during amelogenesis, as ameloblast cells transition from secretory stage to maturation stage, their morphology and transcriptome profiles change dramatically. Prior whole genome transcriptome analysis has given a broad picture of the molecular activities dominating both stages of amelogenesis, but this type of analysis has not included miRNA transcript profiling. In this study, we set out to document which miRNAs and corresponding target genes change significantly as ameloblasts transition from secretory- to maturation-stage amelogenesis. RESULTS Total RNA samples from both secretory- and maturation-stage rat enamel organs were subjected to genome-wide miRNA and mRNA transcript profiling. We identified 59 miRNAs that were differentially expressed at the maturation stage relative to the secretory stage of enamel development (False Discovery Rate (FDR)<0.05, fold change (FC)≥1.8). In parallel, transcriptome profiling experiments identified 1,729 mRNA transcripts that were differentially expressed in the maturation stage compared to the secretory stage (FDR<0.05, FC≥1.8). Based on bioinformatics analyses, 5.8% (629 total) of these differentially expressed genes (DEGS) were highlighted as being the potential targets of 59 miRNAs that were differentially expressed in the opposite direction, in the same tissue samples. Although the number of predicted target DEGs was not higher than baseline expectations generated by examination of stably expressed miRNAs, Gene Ontology (GO) analysis showed that these 629 DEGS were enriched for ion transport, pH regulation, calcium handling, endocytotic, and apoptotic activities. Seven differentially expressed miRNAs (miR-21, miR-31, miR-488, miR-153, miR-135b, miR-135a and miR298) in secretory- and/or maturation-stage enamel organs were confirmed by in situ hybridization. Further, we used luciferase reporter assays to provide evidence that two of these differentially expressed miRNAs, miR-153 and miR-31, are potential regulators for their predicated target mRNAs, Lamp1 (miR-153) and Tfrc (miR-31). CONCLUSIONS In conclusion, these data indicate that miRNAs exhibit a dynamic expression pattern during the transition from secretory-stage to maturation-stage tooth enamel formation. Although they represent only one of numerous mechanisms influencing gene activities, miRNAs specific to the maturation stage could be involved in regulating several key processes of enamel maturation by influencing mRNA stability and translation.
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Affiliation(s)
- Kaifeng Yin
- />Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, 2250 Alcazar Street, CSA103, Los Angeles, CA 90033 USA
| | - Joseph G Hacia
- />Department of Biochemistry and Molecular Biology, Keck School of Medicine, University of Southern California, 2250 Alcazar Street, CSA140, Los Angeles, CA 90033 USA
| | - Zhe Zhong
- />Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, 2250 Alcazar Street, CSA103, Los Angeles, CA 90033 USA
| | - Michael L Paine
- />Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, 2250 Alcazar Street, CSA103, Los Angeles, CA 90033 USA
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40
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Pfister S, Weber T, Härtig W, Schwerdel C, Elsaesser R, Knuesel I, Fritschy JM. Novel role of cystic fibrosis transmembrane conductance regulator in maintaining adult mouse olfactory neuronal homeostasis. J Comp Neurol 2014; 523:406-30. [PMID: 25271146 DOI: 10.1002/cne.23686] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 09/25/2014] [Accepted: 09/26/2014] [Indexed: 02/03/2023]
Abstract
The olfactory epithelium (OE) of mice deficient in cystic fibrosis transmembrane conductance regulator (CFTR) exhibits ion transport deficiencies reported in human CF airways, as well as progressive neuronal loss, suggesting defects in olfactory neuron homeostasis. Microvillar cells, a specialized OE cell-subtype, have been implicated in maintaining tissue homeostasis. These cells are endowed with a PLCβ2/IP3 R3/TRPC6 signal transduction pathway modulating release of neuropeptide Y (NPY), which stimulates OE stem cell activity. It is unknown, however, whether microvillar cells also mediate the deficits observed in CFTR-null mice. Here we show that Cftr mRNA in mouse OE is exclusively localized in microvillar cells and CFTR immunofluorescence is coassociated with the scaffolding protein NHERF-1 and PLCβ2 in microvilli. In CFTR-null mice, PLCβ2 was undetectable, NHERF-1 mislocalized, and IP3 R3 more intensely stained, along with increased levels of NPY, suggesting profound alteration of the PLCβ2/IP3 R3 signaling pathway. In addition, basal olfactory neuron homeostasis was altered, shown by increased progenitor cell proliferation, differentiation, and apoptosis and by reduced regenerative capacity following methimazole-induced neurodegeneration. The importance of CFTR in microvillar cells was further underscored by decreased thickness of the OE mucus layer and increased numbers of immune cells within this tissue in CFTR-KO mice. Finally, we observed enhanced immune responses to an acute viral-like infection, as well as hyper-responsiveness to chemical and physical stimuli applied intranasally. Taken together, these data strengthen the notion that microvillar cells in the OE play a key role in maintaining tissue homeostasis and identify several mechanisms underlying this regulation through the multiple functions of CFTR.
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Affiliation(s)
- Sandra Pfister
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland; Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
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Jalali R, Guo J, Zandieh-Doulabi B, Bervoets TJM, Paine ML, Boron WF, Parker MD, Bijvelds MJC, Medina JF, DenBesten PK, Bronckers ALJJ. NBCe1 (SLC4A4) a potential pH regulator in enamel organ cells during enamel development in the mouse. Cell Tissue Res 2014; 358:433-42. [PMID: 25012520 DOI: 10.1007/s00441-014-1935-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 05/23/2014] [Indexed: 12/11/2022]
Abstract
During the formation of dental enamel, maturation-stage ameloblasts express ion-transporting transmembrane proteins. The SLC4 family of ion-transporters regulates intra- and extracellular pH in eukaryotic cells by cotransporting HCO3 (-) with Na(+). Mutation in SLC4A4 (coding for the sodium-bicarbonate cotransporter NBCe1) induces developmental defects in human and murine enamel. We have hypothesized that NBCe1 in dental epithelium is engaged in neutralizing protons released during crystal formation in the enamel space. We immunolocalized NBCe1 protein in wild-type dental epithelium and examined the effect of the NBCe1-null mutation on enamel formation in mice. Ameloblasts expressed gene transcripts for NBCe1 isoforms B/D/C/E. In wild-type mice, weak to moderate immunostaining for NBCe1 with antibodies that recognized isoforms A/B/D/E and isoform C was seen in ameloblasts at the secretory stage, with no or low staining in the early maturation stage but moderate to high staining in the late maturation stage. The papillary layer showed the opposite pattern being immunostained prominently at the early maturation stage but with gradually less staining at the mid- and late maturation stages. In NBCe1 (-/-) mice, the ameloblasts were disorganized, the enamel being thin and severely hypomineralized. Enamel organs of CFTR (-/-) and AE2a,b (-/-) mice (CFTR and AE2 are believed to be pH regulators in ameloblasts) contained higher levels of NBCe1 protein than wild-type mice. Thus, the expression of NBCe1 in ameloblasts and the papillary layer cell depends on the developmental stage and possibly responds to pH changes.
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Affiliation(s)
- R Jalali
- Department of Oral Cell Biology, Academic Centre for Dentistry at Amsterdam (ACTA), Vrije Universiteit, Gustav Mahlerlaan 3004, 1081 LA, Amsterdam, The Netherlands,
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42
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Damkier HH, Josephsen K, Takano Y, Zahn D, Fejerskov O, Frische S. Fluctuations in surface pH of maturing rat incisor enamel are a result of cycles of H(+)-secretion by ameloblasts and variations in enamel buffer characteristics. Bone 2014; 60:227-34. [PMID: 24373736 DOI: 10.1016/j.bone.2013.12.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 11/18/2013] [Accepted: 12/16/2013] [Indexed: 12/15/2022]
Abstract
It is disputed if ameloblasts in the maturation zone of the enamel organ mainly buffer protons released by hydroxyapatite (HA) crystal growth or if they periodically secrete protons to create alternating acidic and alkaline conditions. The latter hypothesis predicts alternating pH regimes in maturing enamel, which would be affected by pharmacological interference with ameloblast H(+)-secretion. This study tests these predictions. Colorimetric pH-indicators and ratiometric fluorometry were used to measure surface pH in maturation zone enamel of rat incisors. Alternating acidic (down to pH6.24±0.06) and alkaline zones (up to pH7.34±0.08) were found along the tooth coinciding with ameloblast morphological cycles. Underlying the cyclic pattern, a gradual decrease in pH towards the incisal edge was seen. Vinblastine or FR167356 (H(+)-ATPase-inhibitor) disturbed ameloblast acid-secretion, especially in the early parts of acidic zones. Enamel surface pH reflects the titration state of surface PO4(3-)-ions. At the pH-values observed, PO4(3-) would be protonated (pKa>12) and HA dissolved. However, by molecular dynamics simulations we estimate the pKa of HPO4(2-) at an ideal HA surface to be 4.3. The acidic pH measured at the enamel surface may thus only dissolve non-perfect domains of HA crystals in which PO4(3-) is less electrostatically shielded. During repeated alkaline/acidic cycles, near-perfect HA-domains may therefore gradually replace less perfect HA-domains resulting in near-perfect HA-crystals. In conclusion, cyclic changes in ameloblast H(+)-secretion and the degree of enamel maturation determine enamel surface pH. This is in accordance with a hypothesis implicating H(+)-ATPase mediated acid-secretion by ameloblasts.
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Affiliation(s)
| | | | - Yoshiro Takano
- Section of Biostructural Science, Graduate School of Tokyo Medical and Dental University, Japan
| | - Dirk Zahn
- Lehrstuhl für Theoretische Chemie/Computer Chemie Centrum, Friedrich-Alexander Universität Erlangen-Nürnberg, Germany
| | - Ole Fejerskov
- Department of Biomedicine, Aarhus University, Denmark
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Stalvey MS, Clines KL, Havasi V, McKibbin CR, Dunn LK, Chung WJ, Clines GA. Osteoblast CFTR inactivation reduces differentiation and osteoprotegerin expression in a mouse model of cystic fibrosis-related bone disease. PLoS One 2013; 8:e80098. [PMID: 24236172 PMCID: PMC3827431 DOI: 10.1371/journal.pone.0080098] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Accepted: 09/30/2013] [Indexed: 11/18/2022] Open
Abstract
Low bone mass and increased fracture risk are recognized complications of cystic fibrosis (CF). CF-related bone disease (CFBD) is characterized by uncoupled bone turnover—impaired osteoblastic bone formation and enhanced osteoclastic bone resorption. Intestinal malabsorption, vitamin D deficiency and inflammatory cytokines contribute to CFBD. However, epidemiological investigations and animal models also support a direct causal link between inactivation of skeletal cystic fibrosis transmembrane regulator (CFTR), the gene that when mutated causes CF, and CFBD. The objective of this study was to examine the direct actions of CFTR on bone. Expression analyses revealed that CFTR mRNA and protein were expressed in murine osteoblasts, but not in osteoclasts. Functional studies were then performed to investigate the direct actions of CFTR on osteoblasts using a CFTR knockout (Cftr−/−) mouse model. In the murine calvarial organ culture assay, Cftr−/− calvariae displayed significantly less bone formation and osteoblast numbers than calvariae harvested from wildtype (Cftr+/+) littermates. CFTR inactivation also reduced alkaline phosphatase expression in cultured murine calvarial osteoblasts. Although CFTR was not expressed in murine osteoclasts, significantly more osteoclasts formed in Cftr−/− compared to Cftr+/+ bone marrow cultures. Indirect regulation of osteoclastogenesis by the osteoblast through RANK/RANKL/OPG signaling was next examined. Although no difference in receptor activator of NF-κB ligand (Rankl) mRNA was detected, significantly less osteoprotegerin (Opg) was expressed in Cftr−/− compared to Cftr+/+ osteoblasts. Together, the Rankl:Opg ratio was significantly higher in Cftr−/− murine calvarial osteoblasts contributing to a higher osteoclastogenesis potential. The combined findings of reduced osteoblast differentiation and lower Opg expression suggested a possible defect in canonical Wnt signaling. In fact, Wnt3a and PTH-stimulated canonical Wnt signaling was defective in Cftr−/− murine calvarial osteoblasts. These results support that genetic inactivation of CFTR in osteoblasts contributes to low bone mass and that targeting osteoblasts may represent an effective strategy to treat CFBD.
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Affiliation(s)
- Michael S. Stalvey
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Katrina L. Clines
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Viktoria Havasi
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Christopher R. McKibbin
- Department of Medicine, University of Virginia, Charlottesville, Virginia, United States of America
| | - Lauren K. Dunn
- Department of Medicine, University of Virginia, Charlottesville, Virginia, United States of America
| | - W. Joon Chung
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Gregory A. Clines
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Veterans Administration Medical Center, Birmingham, Alabama, United States of America
- * E-mail:
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44
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Abstract
The biological functions of ion channels in tooth development vary according to the nature of their gating, the species of ions passing through those gates, the number of gates, localization of channels, tissue expressing the channel, and interactions between cells and microenvironment. Ion channels feature unique and specific ion flux in ameloblasts, odontoblasts, and other tooth-specific cell lineages. Both enamel and dentin have active chemical systems orchestrating a variety of ion exchanges and demineralization and remineralization processes in a stage-dependent manner. An important role for ion channels is to regulate and maintain the calcium and pH homeostasis that are critical for proper enamel and dentin biomineralization. Specific functions of chloride channels, TRPVs, calcium channels, potassium channels, and solute carrier superfamily members in tooth formation have been gradually clarified in recent years. Mutations in these ion channels or transporters often result in disastrous changes in tooth development. The channelopathies of tooth include altered eruption (CLCN7, KCNJ2, TRPV3), root dysplasia (CLCN7, KCNJ2), amelogenesis imperfecta (KCNJ1, CFTR, AE2, CACNA1C, GJA1), dentin dysplasia (CLCN5), small teeth (CACNA1C, GJA1), tooth agenesis (CLCN7), and other impairments. The mechanisms leading to tooth channelopathies are primarily related to pH regulation, calcium homeostasis, or other alterations of the niche for tooth eruption and development.
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Affiliation(s)
- X Duan
- Department of Oral Biology, Clinic of Oral Rare Diseases and Genetic Diseases, School of Stomatology, The Fourth Military Medical University, Xi'an, 710032, P.R. China
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45
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Lacruz RS, Smith CE, Kurtz I, Hubbard MJ, Paine ML. New paradigms on the transport functions of maturation-stage ameloblasts. J Dent Res 2012; 92:122-9. [PMID: 23242231 DOI: 10.1177/0022034512470954] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Fully matured dental enamel is an architecturally and mechanically complex hydroxyapatite-based bioceramic devoid of most of the organic material that was essential in its making. Enamel formation is a staged process principally involving secretory and maturation stages, each associated with major changes in gene expression and cellular function. Cellular activities that define the maturation stage of amelogenesis include ion (e.g., calcium and phosphate) transport and storage, control of intracellular and extracellular pH (e.g., bicarbonate and hydrogen ion movements), and endocytosis. Recent studies on rodent amelogenesis have identified a multitude of gene products that appear to be linked to these cellular activities. This review describes the main cellular activities of these genes during the maturation stage of amelogenesis.
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Affiliation(s)
- R S Lacruz
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA.
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46
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Bronckers ALJJ, Guo J, Lyaruu DM, DenBesten P, Zandieh-Doulabi B. Immunolocalization and western blotting of the anion exchanger pendrin in ameloblasts. Eur J Oral Sci 2012. [DOI: 10.1111/j.1600-0722.2012.00978.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- ALJJ Bronckers
- Department of Oral Cell Biology; ACTA University of Amsterdam; VU-University of Amsterdam; the Netherlands
| | - J Guo
- Department of Oral Cell Biology; ACTA University of Amsterdam; VU-University of Amsterdam; the Netherlands
| | - DM Lyaruu
- Department of Oral Cell Biology; ACTA University of Amsterdam; VU-University of Amsterdam; the Netherlands
| | - P DenBesten
- Department of Orofacial Sciences; University of California-San Francisco; CA USA
| | - B Zandieh-Doulabi
- Department of Oral Cell Biology; ACTA University of Amsterdam; VU-University of Amsterdam; the Netherlands
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47
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Bronckers ALJJ, Guo J, Zandieh-Doulabi B, Bervoets TJ, Lyaruu DM, Li X, Wangemann P, DenBesten P. Developmental expression of solute carrier family 26A member 4 (SLC26A4/pendrin) during amelogenesis in developing rodent teeth. Eur J Oral Sci 2012; 119 Suppl 1:185-92. [PMID: 22243245 DOI: 10.1111/j.1600-0722.2011.00901.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Ameloblasts need to regulate pH during the formation of enamel crystals, a process that generates protons. Solute carrier family 26A member 4 (SLC26A4, or pendrin) is an anion exchanger for chloride, bicarbonate, iodine, and formate. It is expressed in apical membranes of ion-transporting epithelia in kidney, inner ear, and thyroid where it regulates luminal pH and fluid transport. We hypothesized that maturation ameloblasts express SLC26A4 to neutralize acidification of enamel fluid in forming enamel. In rodents, secretory and maturation ameloblasts were immunopositive for SLC26A4. Staining was particularly strong in apical membranes of maturation ameloblasts facing forming enamel. RT-PCR confirmed the presence of mRNA transcripts for Slc26a4 in enamel organs. SLC26A4 immunostaining was also found in mineralizing connective tissues, including odontoblasts, osteoblasts, osteocytes, osteoclasts, bone lining cells, cellular cementoblasts, and cementocytes. However, Slc26a4-null mutant mice had no overt dental phenotype. The presence of SLC26A4 in apical plasma membranes of maturation ameloblasts is consistent with a potential function as a pH regulator. SLC26A4 does not appear to be critical for ameloblast function and is probably compensated by other pH regulators.
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Affiliation(s)
- Antonius L J J Bronckers
- Department of Oral Cell Biology ACTA, University of Amsterdam and VU-University of Amsterdam, Research Institute MOVE, Amsterdam, the Netherlands.
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48
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Bakouh N, Chérif-Zahar B, Hulin P, Prié D, Friedlander G, Edelman A, Planelles G. Functional interaction between CFTR and the sodium-phosphate co-transport type 2a in Xenopus laevis oocytes. PLoS One 2012; 7:e34879. [PMID: 22514683 PMCID: PMC3325942 DOI: 10.1371/journal.pone.0034879] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Accepted: 03/09/2012] [Indexed: 11/25/2022] Open
Abstract
Background A growing number of proteins, including ion transporters, have been shown to interact with Cystic Fibrosis Transmembrane conductance Regulator (CFTR). CFTR is an epithelial chloride channel that is involved in Cystic Fibrosis (CF) when mutated; thus a better knowledge of its functional interactome may help to understand the pathophysiology of this complex disease. In the present study, we investigated if CFTR and the sodium-phosphate co-transporter type 2a (NPT2a) functionally interact after heterologous expression of both proteins in Xenopus laevis oocytes. Methodology/Findings NPT2a was expressed alone or in combination with CFTR in X. laevis oocytes. Using the two-electrode voltage-clamp technique, the inorganic phosphate-induced current (IPi) was measured and taken as an index of NPT2a activity. The maximal IPi for NPT2a substrates was reduced when CFTR was co-expressed with NPT2a, suggesting a decrease in its expression at the oolemna. This was consistent with Western blot analysis showing reduced NPT2a plasma membrane expression in oocytes co-expressing both proteins, whereas NPT2a protein level in total cell lysate was the same in NPT2a- and NPT2a+CFTR-oocytes. In NPT2a+CFTR- but not in NPT2a-oocytes, IPi and NPT2a surface expression were increased upon PKA stimulation, whereas stimulation of Exchange Protein directly Activated by cAMP (EPAC) had no effect. When NPT2a-oocytes were injected with NEG2, a short amino-acid sequence from the CFTR regulatory domain that regulates PKA-dependent CFTR trafficking to the plasma membrane, IPi values and NPT2a membrane expression were diminished, and could be enhanced by PKA stimulation, thereby mimicking the effects of CFTR co-expression. Conclusion/Perspectives We conclude that when both CFTR and NPT2a are expressed in X. laevis oocytes, CFTR confers to NPT2a a cAMPi-dependent trafficking to the membrane. This functional interaction raises the hypothesis that CFTR may play a role in phosphate homeostasis.
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Affiliation(s)
- Naziha Bakouh
- Inserm UMRS-845, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine Paris Descartes, Paris, France
| | - Baya Chérif-Zahar
- Inserm UMRS-845, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine Paris Descartes, Paris, France
| | - Philippe Hulin
- Inserm UMRS-845, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine Paris Descartes, Paris, France
| | - Dominique Prié
- Inserm UMRS-845, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine Paris Descartes, Paris, France
| | - Gérard Friedlander
- Inserm UMRS-845, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine Paris Descartes, Paris, France
| | - Aleksander Edelman
- Inserm UMRS-845, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine Paris Descartes, Paris, France
| | - Gabrielle Planelles
- Inserm UMRS-845, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine Paris Descartes, Paris, France
- * E-mail:
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49
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Lacruz RS, Smith CE, Bringas P, Chen YB, Smith SM, Snead ML, Kurtz I, Hacia JG, Hubbard MJ, Paine ML. Identification of novel candidate genes involved in mineralization of dental enamel by genome-wide transcript profiling. J Cell Physiol 2012; 227:2264-75. [PMID: 21809343 DOI: 10.1002/jcp.22965] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The gene repertoire regulating vertebrate biomineralization is poorly understood. Dental enamel, the most highly mineralized tissue in mammals, differs from other calcifying systems in that the formative cells (ameloblasts) lack remodeling activity and largely degrade and resorb the initial extracellular matrix. Enamel mineralization requires that ameloblasts undergo a profound functional switch from matrix-secreting to maturational (calcium transport, protein resorption) roles as mineralization progresses. During the maturation stage, extracellular pH decreases markedly, placing high demands on ameloblasts to regulate acidic environments present around the growing hydroxyapatite crystals. To identify the genetic events driving enamel mineralization, we conducted genome-wide transcript profiling of the developing enamel organ from rat incisors and highlight over 300 genes differentially expressed during maturation. Using multiple bioinformatics analyses, we identified groups of maturation-associated genes whose functions are linked to key mineralization processes including pH regulation, calcium handling, and matrix turnover. Subsequent qPCR and Western blot analyses revealed that a number of solute carrier (SLC) gene family members were up-regulated during maturation, including the novel protein Slc24a4 involved in calcium handling as well as other proteins of similar function (Stim1). By providing the first global overview of the cellular machinery required for enamel maturation, this study provide a strong foundation for improving basic understanding of biomineralization and its practical applications in healthcare.
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Affiliation(s)
- Rodrigo S Lacruz
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, California, USA.
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50
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Bronckers ALJJ, Lyaruu DM, Bervoets TJ, Medina JF, DenBesten P, Richter J, Everts V. Murine ameloblasts are immunonegative for Tcirg1, the v-H-ATPase subunit essential for the osteoclast plasma proton pump. Bone 2012; 50:901-8. [PMID: 22245629 PMCID: PMC3345336 DOI: 10.1016/j.bone.2011.12.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Revised: 12/23/2011] [Accepted: 12/26/2011] [Indexed: 12/14/2022]
Abstract
Maturation stage ameloblasts of rodents express vacuolar type-H-ATPase in the ruffled border of their plasma membrane in contact with forming dental enamel, similar to osteoclasts that resorb bone. It has been proposed that in ameloblasts this v-H-ATPase acts as proton pump to acidify the enamel space, required to complete enamel mineralization. To examine whether this v-H-ATPase in mouse ameloblasts is a proton pump, we determined whether these cells express the lysosomal, T-cell, immune regulator 1 (Tcirg1, v-H-Atp6v(0)a(3)), which is an essential part of the plasma membrane proton pump that is present in osteoclasts. Mutation of this subunit in Tcirg1 null (or oc/oc) mice leads to severe osteopetrosis. No immunohistochemically detectable Tcirg1 was seen in mouse maturation stage ameloblasts. Strong positive staining in secretory and maturation stage ameloblasts however was found for another subunit of v-H-ATPase, subunit b, brain isoform (v-H-Atp6v(1)b(2)). Mouse osteoclasts and renal tubular epithelium stained strongly for both Tcirg1 and v-H-Atp6v(1)b(2). In Tcirg1 null mice osteoclasts and renal epithelium were negative for Tcirg1 but remained positive for v-H-Atp6v(1)b(2). The bone in these mutant mice was osteopetrotic, tooth eruption was inhibited or delayed, and teeth were often morphologically disfigured. However, enamel formation in these mutant mice was normal, ameloblasts structurally unaffected and the mineral content of enamel similar to that of wild type mice. We concluded that Tcirg1, which is essential for osteoclasts to pump protons into the bone, is not appreciably expressed in maturation stage mouse ameloblasts. Our data suggest that the reported v-H-ATPase in maturation stage ameloblasts is not the typical osteoclast-type plasma membrane associated proton pump which acidifies the extracellular space, but rather a v-H-ATPase potentially involved in intracellular acidification.
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Affiliation(s)
- Antonius L J J Bronckers
- Dept of Oral Cell Biology ACTA, University of Amsterdam and VU University Amsterdam, Research Institute MOVE, Gustav Mahlerlaan 3004, Amsterdam, The Netherlands.
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