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Hess MK, Mersha A, Ference SS, Nafziger SR, Keane JA, Fuller AM, Kurz SG, Sutton CM, Spangler ML, Petersen JL, Cupp AS. Puberty classifications in beef heifers are moderately to highly heritable and associated with candidate genes related to cyclicity and timing of puberty. Front Genet 2024; 15:1405456. [PMID: 38939530 PMCID: PMC11208629 DOI: 10.3389/fgene.2024.1405456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Accepted: 05/23/2024] [Indexed: 06/29/2024] Open
Abstract
Introduction: Pubertal attainment is critical to reproductive longevity in heifers. Previously, four heifer pubertal classifications were identified according to attainment of blood plasma progesterone concentrations > 1 ng/ml: 1) Early; 2) Typical; 3) Start-Stop; and 4) Non-Cycling. Early and Typical heifers initiated and maintained cyclicity, Start-Stop started and then stopped cyclicity and Non-Cycling never initiated cyclicity. Start-Stop heifers segregated into Start-Stop-Discontinuous (SSD) or Start-Stop-Start (SSS), with SSD having similar phenotypes to Non-Cycling and SSS to Typical heifers. We hypothesized that these pubertal classifications are heritable, and loci associated with pubertal classifications could be identified by genome wide association studies (GWAS). Methods: Heifers (n = 532; 2017 - 2022) genotyped on the Illumina Bovine SNP50 v2 or GGP Bovine 100K SNP panels were used for variant component estimation and GWAS. Heritability was estimated using a univariate Bayesian animal model. Results: When considering pubertal classifications: Early, Typical, SSS, SSD, and Non-Cycling, pubertal class was moderately heritable (0.38 ± 0.08). However, when heifers who initiated and maintained cyclicity were compared to those that did not cycle (Early+Typical vs. SSD+Non-Cycling) heritability was greater (0.59 ± 0.19). A GWAS did not identify single nucleotide polymorphisms (SNPs) significantly associated with pubertal classifications, indicating puberty is a polygenic trait. A candidate gene approach was used, which fitted SNPs within or nearby a set of 71 candidate genes previously associated with puberty, PCOS, cyclicity, regulation of hormone secretion, signal transduction, and methylation. Eight genes/regions were associated with pubertal classifications, and twenty-two genes/regions were associated with whether puberty was attained during the trial. Additionally, whole genome sequencing (WGS) data on 33 heifers were aligned to the reference genome (ARS-UCD1.2) to identify variants in FSHR, a gene critical to pubertal attainment. Fisher's exact test determined if FSHR SNPs segregated by pubertal classification. Two FSHR SNPs that were not on the bovine SNP panel were selected for additional genotyping and analysis, and one was associated with pubertal classifications and whether they cycled during the trial. Discussion: In summary, these pubertal classifications are moderately to highly heritable and polygenic. Consequently, genomic tools to inform selection/management of replacement heifers would be useful if informed by SNPs associated with cyclicity and early pubertal attainment.
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Affiliation(s)
- Melanie K. Hess
- Department of Animal Science, University of Nebraska–Lincoln, Lincoln, NE, United States
| | | | | | | | | | | | | | | | | | | | - Andrea S. Cupp
- Department of Animal Science, University of Nebraska–Lincoln, Lincoln, NE, United States
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Wang Y, Sarnowski C, Lin H, Pitsillides AN, Heard‐Costa NL, Choi SH, Wang D, Bis JC, Blue EE, Boerwinkle E, De Jager PL, Fornage M, Wijsman EM, Seshadri S, Dupuis J, Peloso GM, DeStefano AL. Key variants via the Alzheimer's Disease Sequencing Project whole genome sequence data. Alzheimers Dement 2024; 20:3290-3304. [PMID: 38511601 PMCID: PMC11095439 DOI: 10.1002/alz.13705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 12/08/2023] [Accepted: 12/21/2023] [Indexed: 03/22/2024]
Abstract
INTRODUCTION Genome-wide association studies (GWAS) have identified loci associated with Alzheimer's disease (AD) but did not identify specific causal genes or variants within those loci. Analysis of whole genome sequence (WGS) data, which interrogates the entire genome and captures rare variations, may identify causal variants within GWAS loci. METHODS We performed single common variant association analysis and rare variant aggregate analyses in the pooled population (N cases = 2184, N controls = 2383) and targeted analyses in subpopulations using WGS data from the Alzheimer's Disease Sequencing Project (ADSP). The analyses were restricted to variants within 100 kb of 83 previously identified GWAS lead variants. RESULTS Seventeen variants were significantly associated with AD within five genomic regions implicating the genes OARD1/NFYA/TREML1, JAZF1, FERMT2, and SLC24A4. KAT8 was implicated by both single variant and rare variant aggregate analyses. DISCUSSION This study demonstrates the utility of leveraging WGS to gain insights into AD loci identified via GWAS.
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Affiliation(s)
- Yanbing Wang
- Department of BiostatisticsBoston University, School of Public HealthBostonMassachusettsUSA
| | - Chloé Sarnowski
- Department of BiostatisticsBoston University, School of Public HealthBostonMassachusettsUSA
- Human Genetics CenterDepartment of EpidemiologySchool of Public HealthThe University of Texas Health Science Center at HoustonHoustonTexasUSA
| | - Honghuang Lin
- Department of MedicineUniversity of Massachusetts Chan Medical SchoolWorcesterMassachusettsUSA
| | | | - Nancy L. Heard‐Costa
- Department of BiostatisticsBoston University, School of Public HealthBostonMassachusettsUSA
- The Framingham Heart StudyFraminghamMassachusettsUSA
| | - Seung Hoan Choi
- Department of BiostatisticsBoston University, School of Public HealthBostonMassachusettsUSA
| | - Dongyu Wang
- Department of BiostatisticsBoston University, School of Public HealthBostonMassachusettsUSA
| | - Joshua C. Bis
- Cardiovascular Health Research UnitDepartment of MedicineUniversity of WashingtonSeattleWashingtonUSA
| | - Elizabeth E. Blue
- Department of MedicineDivision of Medical GeneticsUniversity of WashingtonSeattleWashingtonUSA
- Brotman Baty InstituteSeattleWashingtonUSA
| | | | - Eric Boerwinkle
- Human Genetics CenterDepartment of EpidemiologySchool of Public HealthThe University of Texas Health Science Center at HoustonHoustonTexasUSA
| | - Philip L. De Jager
- Center for Translational & Computational NeuroimmunologyDepartment of NeurologyColumbia University Irving Medical CenterNew YorkNew YorkUSA
- Taub Institute for Research on Alzheimer's Disease and the Aging BrainColumbia University Irving Medical CenterNew YorkNew YorkUSA
| | - Myriam Fornage
- Human Genetics CenterDepartment of EpidemiologySchool of Public HealthThe University of Texas Health Science Center at HoustonHoustonTexasUSA
- Brown Foundation Institute of Molecular MedicineMcGovern Medical SchoolUniversity of Texas Health Science Center at HoustonHoustonTexasUSA
| | - Ellen M. Wijsman
- Division of Medical Genetics and Department Biostatistics Statistical Genetics LabUniversity of WashingtonHans Rosling Center for Population HealthSeattleWashingtonUSA
| | - Sudha Seshadri
- The Framingham Heart StudyFraminghamMassachusettsUSA
- Glenn Biggs Institute for Alzheimer's & Neurodegenerative DiseasesThe University of Texas Health Science Center at San AntonioSan AntonioTexasUSA
- Department of NeurologyBoston University School of MedicineBostonMassachusettsUSA
| | - Josée Dupuis
- Department of BiostatisticsBoston University, School of Public HealthBostonMassachusettsUSA
- Department of Epidemiology, Biostatistics and Occupational HealthSchool of Population and Global HealthMcGill UniversityMontrealQuebecCanada
| | - Gina M. Peloso
- Department of BiostatisticsBoston University, School of Public HealthBostonMassachusettsUSA
| | - Anita L. DeStefano
- Department of BiostatisticsBoston University, School of Public HealthBostonMassachusettsUSA
- The Framingham Heart StudyFraminghamMassachusettsUSA
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Yang Y, Qin M, Zhao Y, Wang X. Digenic inheritance accounts for phenotypic variability in amelogenesis imperfecta. Clin Genet 2024; 105:243-253. [PMID: 37937686 DOI: 10.1111/cge.14449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 10/17/2023] [Accepted: 10/18/2023] [Indexed: 11/09/2023]
Abstract
Amelogenesis imperfecta (AI) represents a group of clinically and genetically heterogeneous disorders that affect enamel formation and mineralization. Although AI is commonly considered a monogenic disorder, digenic inheritance is rarely reported. In this study, we recruited two nonconsanguineous Chinese families exhibiting diverse phenotypes of enamel defects among affected family members. Digenic variants were discovered in both probands. In family 1, the proband inherited a paternal frameshift variant in LAMA3 (NM_198129.4:c.3712dup) and a maternal deletion encompassing the entire AMELX gene. This resulted in a combined hypoplastic and hypomineralized AI phenotype, which was distinct from the parents' manifestations. In family 2, whole-exome sequencing analysis revealed the proband carried a maternal heterozygous splicing variant in COL17A1 (NC_000010.11 (NM_000494.3): c.4156 + 2dup) and compound heterozygous variants in RELT (paternal: NM_032871.4:c.260A > T; maternal: NM_032871.4:c.521 T > G). These genetic changes caused the abundant irregular enamel defects observed in the proband, whereas other affected family members carrying heterozygous variants in both COL17A1 and RELT displayed only horizontal grooves as their phenotype. The pathogenicity of the novel COL17A1 splice site variant was confirmed through RT-PCR and minigene assay. This study enhances our understanding by highlighting the potential association between the co-occurrence of variants in two genes and variable phenotypes observed in AI patients.
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Affiliation(s)
- Yi Yang
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, People's Republic of China
| | - Man Qin
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, People's Republic of China
| | - Yuming Zhao
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, People's Republic of China
| | - Xin Wang
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, People's Republic of China
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Souza Bomfim GH, Mitaishvili E, Schnetkamp PP, Lacruz RS. Na+/Ca2+ exchange in enamel cells is dominated by the K+-dependent NCKX exchanger. J Gen Physiol 2024; 156:e202313372. [PMID: 37947795 PMCID: PMC10637953 DOI: 10.1085/jgp.202313372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 08/15/2023] [Accepted: 10/31/2023] [Indexed: 11/12/2023] Open
Abstract
Calcium (Ca2+) extrusion is an essential function of the enamel-forming ameloblasts, providing Ca2+ for extracellular mineralization. The plasma membrane Ca2+ ATPases (PMCAs) remove cytosolic Ca2+ (cCa2+) and were recently shown to be efficient when ameloblasts experienced low cCa2+ elevation. Sodium-calcium (Na+/Ca2+) exchange has higher capacity to extrude cCa2+, but there is limited evidence on the function of the two main families of Na+/Ca2+ exchangers in enamel formation. The purpose of this study was to analyze the function of the NCX (coded by SLC8) and the K+-dependent NCKX (coded by SLC24) exchangers in rat ameloblasts and to compare their efficacy in the two main stages of enamel formation: the enamel forming secretory stage and the mineralizing or maturation stage. mRNA expression profiling confirmed the expression of Slc8 and Slc24 genes in enamel cells, Slc24a4 being the most highly upregulated transcript during the maturation stage, when Ca2+ transport increases. Na+/Ca2+ exchange was analyzed in the Ca2+ influx mode in Fura-2 AM-loaded ameloblasts. We show that maturation-stage ameloblasts have a higher Na+/Ca2+ exchange capacity than secretory-stage cells. We also show that Na+/Ca2+ exchange in both stages is dominated by NCKX over NCX. The importance of NCKX function in ameloblasts may partly explain why mutations in the SLC24A4 gene, but not in SLC8 genes, result in enamel disease. Our results demonstrate that Na+/Ca2+ exchangers are fully operational in ameloblasts and that their contribution to Ca2+ homeostasis increases in the maturation stage, when Ca2+ transport need is higher.
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Affiliation(s)
| | - Erna Mitaishvili
- Department of Chemistry, Herbert H. Lehman College, City University of New York. PhD Program in Biology, The Graduate Center of The City University of New York, New York, NY, USA
| | - Paul P.M. Schnetkamp
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Rodrigo S. Lacruz
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, NY, USA
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Wang SK, Lee ZH, Aref P, Chu KY. A novel ODAPH mutation causing amelogenesis imperfecta and its expression in human dental tissues. J Dent Sci 2024; 19:524-531. [PMID: 38303846 PMCID: PMC10829723 DOI: 10.1016/j.jds.2023.09.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Revised: 09/18/2023] [Indexed: 02/03/2024] Open
Abstract
Background/purpose Amelogenesis imperfecta (AI), an assemblage of genetic diseases with dental enamel malformations, is generally grouped into hypoplastic, hypomaturation, and hypocalcified types. This study aimed to identify the genetic etiology for a consanguineous Iranian family with autosomal recessive hypocalcified AI. Materials and methods Dental defects were characterized, and whole exome analysis conducted to search for disease-causing mutations. Minigene assay and RT-PCR were performed to evaluate molecular consequences of the identified mutation and expression of the causative gene in human dental tissues. Results The defective enamel of erupted teeth showed extensive post-eruptive failure and discoloration. Partial enamel hypoplasia and indistinct dentino-enamel junction were evident on unerupted teeth, resembling hypocalcified AI. A novel homozygous ODAPH (previously designated C4orf26) mutation of single-nucleotide deletion (NG_032974.1:g.5103del, NM_178497.5:c.67+1del) was identified to be disease-causing. The mutation would cause a frameshift to different ODAPH transcript variant (TV) products: p.(Ala23Hisfs∗29) for TV1 and p.(Gly23Aspfs∗140) for TV2. Both dental pulps of developing and exfoliating primary teeth expressed ODAPH TV2. Conclusion Loss-of-function ODAPH mutations can cause AI type IIIB (the hypocalcified, autosomal recessive type), rather than type IIA4 (the hypomaturation, pigmented autosomal recessive type). This study supports a hypothesis that the product of ODAPH TV2 is the single dominant ODAPH protein isoform critical for dental enamel formation and may also play an unappreciated role in development and homeostasis of dentin-pulp complex. Due to genetic heterogeneity and a nonideal genotype-phenotype correlation of AI, it is essential to perform genetic testing for patients with inherited enamel defects to make a definitive diagnosis.
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Affiliation(s)
- Shih-Kai Wang
- Department of Dentistry, National Taiwan University School of Dentistry, Taipei, Taiwan
- Department of Pediatric Dentistry, National Taiwan University Children's Hospital, Taipei, Taiwan
| | - Zhe-Hao Lee
- Department of Dentistry, National Taiwan University School of Dentistry, Taipei, Taiwan
| | - Parissa Aref
- Department of Pediatric Dentistry, Islamic Azad University Dental Branch of Tehran, Tehran, Iran
| | - Kuan-Yu Chu
- Department of Pediatric Dentistry, National Taiwan University Children's Hospital, Taipei, Taiwan
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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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7
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Wang Y, Sarnowski C, Lin H, Pitsillides AN, Heard-Costa NL, Choi SH, Wang D, Bis JC, Blue EE, Boerwinkle E, De Jager PL, Fornage M, Wijsman EM, Seshadri S, Dupuis J, Peloso GM, DeStefano AL. Key variants via Alzheimer's Disease Sequencing Project whole genome sequence data. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.08.28.23294631. [PMID: 37693453 PMCID: PMC10491364 DOI: 10.1101/2023.08.28.23294631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
INTRODUCTION Genome-wide association studies (GWAS) have identified loci associated with Alzheimer's disease (AD) but did not identify specific causal genes or variants within those loci. Analysis of whole genome sequence (WGS) data, which interrogates the entire genome and captures rare variations, may identify causal variants within GWAS loci. METHODS We performed single common variant association analysis and rare variant aggregate analyses in the pooled population (N cases=2,184, N controls=2,383) and targeted analyses in sub-populations using WGS data from the Alzheimer's Disease Sequencing Project (ADSP). The analyses were restricted to variants within 100 kb of 83 previously identified GWAS lead variants. RESULTS Seventeen variants were significantly associated with AD within five genomic regions implicating the genes OARD1/NFYA/TREML1, JAZF1, FERMT2, and SLC24A4. KAT8 was implicated by both single variant and rare variant aggregate analyses. DISCUSSION This study demonstrates the utility of leveraging WGS to gain insights into AD loci identified via GWAS.
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Affiliation(s)
- Yanbing Wang
- Department of Biostatistics, Boston University, School of Public Health, Boston, MA, USA
| | - Chloé Sarnowski
- Department of Biostatistics, Boston University, School of Public Health, Boston, MA, USA
- Human Genetics Center, Department of Epidemiology, Human Genetics, and Environmental Sciences, School of Public Health, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Honghuang Lin
- Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | | | - Nancy L Heard-Costa
- Department of Biostatistics, Boston University, School of Public Health, Boston, MA, USA
- The Framingham Heart Study, Framingham, MA, USA
| | - Seung Hoan Choi
- Department of Biostatistics, Boston University, School of Public Health, Boston, MA, USA
| | - Dongyu Wang
- Department of Biostatistics, Boston University, School of Public Health, Boston, MA, USA
| | - Joshua C Bis
- Cardiovascular Health Research Unit, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Elizabeth E Blue
- Department of Medicine, Division of Medical Genetics, University of Washington, Seattle, WA, USA
- Brotman Baty Institute, Seattle, WA, USA
| | | | - Eric Boerwinkle
- Human Genetics Center, Department of Epidemiology, Human Genetics, and Environmental Sciences, School of Public Health, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Philip L De Jager
- Center for Translational & Computational Neuroimmunology, Department of Neurology, Columbia University Irving Medical Center, New York, NY, USA
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY, USA
| | - Myriam Fornage
- Human Genetics Center, Department of Epidemiology, Human Genetics, and Environmental Sciences, School of Public Health, The University of Texas Health Science Center at Houston, Houston, TX, USA
- Brown Foundation Institute of Molecular Medicine, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Ellen M Wijsman
- Div. of Medical Genetics and Dept. Biostatistics Statistical Genetics Lab, University of Washington, Seattle, WA, USA
| | - Sudha Seshadri
- The Framingham Heart Study, Framingham, MA, USA
- Glenn Biggs Institute for Alzheimer’s & Neurodegenerative Diseases, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
- Boston University School of Medicine, Department of Neurology, Boston, MA, USA
| | - Josée Dupuis
- Department of Biostatistics, Boston University, School of Public Health, Boston, MA, USA
- Department of Epidemiology, Biostatistics and Occupational Health, School of Population and Global Health, McGill University, Montreal, Canada
| | - Gina M Peloso
- Department of Biostatistics, Boston University, School of Public Health, Boston, MA, USA
| | - Anita L DeStefano
- Department of Biostatistics, Boston University, School of Public Health, Boston, MA, USA
- The Framingham Heart Study, Framingham, MA, USA
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Bloch-Zupan A, Rey T, Jimenez-Armijo A, Kawczynski M, Kharouf N, Dure-Molla MDL, Noirrit E, Hernandez M, Joseph-Beaudin C, Lopez S, Tardieu C, Thivichon-Prince B, Dostalova T, Macek M, Alloussi ME, Qebibo L, Morkmued S, Pungchanchaikul P, Orellana BU, Manière MC, Gérard B, Bugueno IM, Laugel-Haushalter V. Amelogenesis imperfecta: Next-generation sequencing sheds light on Witkop's classification. Front Physiol 2023; 14:1130175. [PMID: 37228816 PMCID: PMC10205041 DOI: 10.3389/fphys.2023.1130175] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 03/06/2023] [Indexed: 05/27/2023] Open
Abstract
Amelogenesis imperfecta (AI) is a heterogeneous group of genetic rare diseases disrupting enamel development (Smith et al., Front Physiol, 2017a, 8, 333). The clinical enamel phenotypes can be described as hypoplastic, hypomineralized or hypomature and serve as a basis, together with the mode of inheritance, to Witkop's classification (Witkop, J Oral Pathol, 1988, 17, 547-553). AI can be described in isolation or associated with others symptoms in syndromes. Its occurrence was estimated to range from 1/700 to 1/14,000. More than 70 genes have currently been identified as causative. Objectives: We analyzed using next-generation sequencing (NGS) a heterogeneous cohort of AI patients in order to determine the molecular etiology of AI and to improve diagnosis and disease management. Methods: Individuals presenting with so called "isolated" or syndromic AI were enrolled and examined at the Reference Centre for Rare Oral and Dental Diseases (O-Rares) using D4/phenodent protocol (www.phenodent.org). Families gave written informed consents for both phenotyping and molecular analysis and diagnosis using a dedicated NGS panel named GenoDENT. This panel explores currently simultaneously 567 genes. The study is registered under NCT01746121 and NCT02397824 (https://clinicaltrials.gov/). Results: GenoDENT obtained a 60% diagnostic rate. We reported genetics results for 221 persons divided between 115 AI index cases and their 106 associated relatives from a total of 111 families. From this index cohort, 73% were diagnosed with non-syndromic amelogenesis imperfecta and 27% with syndromic amelogenesis imperfecta. Each individual was classified according to the AI phenotype. Type I hypoplastic AI represented 61 individuals (53%), Type II hypomature AI affected 31 individuals (27%), Type III hypomineralized AI was diagnosed in 18 individuals (16%) and Type IV hypoplastic-hypomature AI with taurodontism concerned 5 individuals (4%). We validated the genetic diagnosis, with class 4 (likely pathogenic) or class 5 (pathogenic) variants, for 81% of the cohort, and identified candidate variants (variant of uncertain significance or VUS) for 19% of index cases. Among the 151 sequenced variants, 47 are newly reported and classified as class 4 or 5. The most frequently discovered genotypes were associated with MMP20 and FAM83H for isolated AI. FAM20A and LTBP3 genes were the most frequent genes identified for syndromic AI. Patients negative to the panel were resolved with exome sequencing elucidating for example the gene involved ie ACP4 or digenic inheritance. Conclusion: NGS GenoDENT panel is a validated and cost-efficient technique offering new perspectives to understand underlying molecular mechanisms of AI. Discovering variants in genes involved in syndromic AI (CNNM4, WDR72, FAM20A … ) transformed patient overall care. Unravelling the genetic basis of AI sheds light on Witkop's AI classification.
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Affiliation(s)
- Agnes Bloch-Zupan
- Université de Strasbourg, Faculté de Chirurgie Dentaire, Strasbourg, France
- Université de Strasbourg, Institut d’études avancées (USIAS), Strasbourg, France
- Hôpitaux Universitaires de Strasbourg (HUS), Pôle de Médecine et Chirurgie Bucco-dentaires, Hôpital Civil, Centre de référence des maladies rares orales et dentaires, O-Rares, Filiére Santé Maladies rares TETE COU, European Reference Network ERN CRANIO, Strasbourg, France
- Université de Strasbourg, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), IN-SERM U1258, CNRS- UMR7104, Illkirch, France
- Eastman Dental Institute, University College London, London, United Kingdom
| | - Tristan Rey
- Université de Strasbourg, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), IN-SERM U1258, CNRS- UMR7104, Illkirch, France
- Hôpitaux Universitaires de Strasbourg, Laboratoires de diagnostic génétique, Institut de Génétique Médicale d’Alsace, Strasbourg, France
| | - Alexandra Jimenez-Armijo
- Université de Strasbourg, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), IN-SERM U1258, CNRS- UMR7104, Illkirch, France
| | - Marzena Kawczynski
- Hôpitaux Universitaires de Strasbourg (HUS), Pôle de Médecine et Chirurgie Bucco-dentaires, Hôpital Civil, Centre de référence des maladies rares orales et dentaires, O-Rares, Filiére Santé Maladies rares TETE COU, European Reference Network ERN CRANIO, Strasbourg, France
| | - Naji Kharouf
- Université de Strasbourg, Laboratoire de Biomatériaux et Bioingénierie, Inserm UMR_S 1121, Strasbourg, France
| | | | - Muriel de La Dure-Molla
- Rothschild Hospital, Public Assistance-Paris Hospitals (AP-HP), Reference Center for Rare Oral and Den-tal Diseases (O-Rares), Paris, France
| | - Emmanuelle Noirrit
- Centre Hospitalier Universitaire (CHU) Rangueil, Toulouse, Competence Center for Rare Oral and Den-tal Diseases, Toulouse, France
| | - Magali Hernandez
- Centre Hospitalier Régional Universitaire de Nancy, Université de Lorraine, Competence Center for Rare Oral and Dental Diseases, Nancy, France
| | - Clara Joseph-Beaudin
- Centre Hospitalier Universitaire de Nice, Competence Center for Rare Oral and Dental Diseases, Nice, France
| | - Serena Lopez
- Centre Hospitalier Universitaire de Nantes, Competence Center for Rare Oral and Dental Diseases, Nantes, France
| | - Corinne Tardieu
- APHM, Hôpitaux Universitaires de Marseille, Hôpital Timone, Competence Center for Rare Oral and Dental Diseases, Marseille, France
| | - Béatrice Thivichon-Prince
- Centre Hospitalier Universitaire de Lyon, Competence Center for Rare Oral and Dental Diseases, Lyon, France
| | | | - Tatjana Dostalova
- Department of Stomatology (TD) and Department of Biology and Medical Genetics (MM) Charles University 2nd Faculty of Medicine and Motol University Hospital, Prague, Czechia
| | - Milan Macek
- Department of Stomatology (TD) and Department of Biology and Medical Genetics (MM) Charles University 2nd Faculty of Medicine and Motol University Hospital, Prague, Czechia
| | | | - Mustapha El Alloussi
- Faculty of Dentistry, International University of Rabat, CReSS Centre de recherche en Sciences de la Santé, Rabat, Morocco
| | - Leila Qebibo
- Unité de génétique médicale et d’oncogénétique, CHU Hassan II, Fes, Morocco
| | | | | | - Blanca Urzúa Orellana
- Instituto de Investigación en Ciencias Odontológicas, Facultad de Odontología, Universidad de Chile, Santiago, Chile
| | - Marie-Cécile Manière
- Université de Strasbourg, Faculté de Chirurgie Dentaire, Strasbourg, France
- Hôpitaux Universitaires de Strasbourg (HUS), Pôle de Médecine et Chirurgie Bucco-dentaires, Hôpital Civil, Centre de référence des maladies rares orales et dentaires, O-Rares, Filiére Santé Maladies rares TETE COU, European Reference Network ERN CRANIO, Strasbourg, France
| | - Bénédicte Gérard
- Hôpitaux Universitaires de Strasbourg, Laboratoires de diagnostic génétique, Institut de Génétique Médicale d’Alsace, Strasbourg, France
| | - Isaac Maximiliano Bugueno
- Université de Strasbourg, Faculté de Chirurgie Dentaire, Strasbourg, France
- Hôpitaux Universitaires de Strasbourg (HUS), Pôle de Médecine et Chirurgie Bucco-dentaires, Hôpital Civil, Centre de référence des maladies rares orales et dentaires, O-Rares, Filiére Santé Maladies rares TETE COU, European Reference Network ERN CRANIO, Strasbourg, France
- Université de Strasbourg, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), IN-SERM U1258, CNRS- UMR7104, Illkirch, France
| | - Virginie Laugel-Haushalter
- Université de Strasbourg, Faculté de Chirurgie Dentaire, Strasbourg, France
- Université de Strasbourg, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), IN-SERM U1258, CNRS- UMR7104, Illkirch, France
- Hôpitaux Universitaires de Strasbourg, Laboratoires de diagnostic génétique, Institut de Génétique Médicale d’Alsace, Strasbourg, France
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9
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Shin M, Matsushima A, Kajiya H, Okamoto F, Ogata K, Oka K, Ohshima H, Bartlett JD, Okabe K. Conditional knockout of transient receptor potential melastatin 7 in the enamel epithelium: Effects on enamel formation. Eur J Oral Sci 2023; 131:e12920. [PMID: 36794562 DOI: 10.1111/eos.12920] [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: 07/18/2022] [Accepted: 01/21/2023] [Indexed: 02/17/2023]
Abstract
Transient receptor potential melastatin 7 (TRPM7) is a unique ion channel connected to a kinase domain. We previously demonstrated that Trpm7 expression is high in mouse ameloblasts and odontoblasts, and that amelogenesis is impaired in TRPM7 kinase-dead mice. Here, we analyzed TRPM7 function during amelogenesis in Keratin 14-Cre;Trpm7fl/fl conditional knockout (cKO) mice and Trpm7 knockdown cell lines. cKO mice showed lesser tooth pigmentation than control mice and broken incisor tips. Enamel calcification and microhardness were lower in cKO mice. Electron probe microanalysis (EPMA) showed that the calcium and phosphorus contents in the enamel were lower in cKO mouse than in control mice. The ameloblast layer in cKO mice showed ameloblast dysplasia at the maturation stage. The morphological defects were observed in rat SF2 cells with Trpm7 knockdown. Compared with mock transfectants, the Trpm7 knockdown cell lines showed lower levels of calcification with Alizarin Red-positive staining and an impaired intercellular adhesion structures. These findings suggest that TRPM7 is a critical ion channel in enamel calcification for the effective morphogenesis of ameloblasts during amelogenesis.
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Affiliation(s)
- Masashi Shin
- Section of Cellular Physiology, Department of Physiological Science and Molecular Biology, Fukuoka Dental College, Fukuoka, Japan
- Oral Medicine Research Center, Fukuoka Dental College, Fukuoka, Japan
| | - Aya Matsushima
- Section of Cellular Physiology, Department of Physiological Science and Molecular Biology, Fukuoka Dental College, Fukuoka, Japan
| | - Hiroshi Kajiya
- Section of Cellular Physiology, Department of Physiological Science and Molecular Biology, Fukuoka Dental College, Fukuoka, Japan
- Oral Medicine Research Center, Fukuoka Dental College, Fukuoka, Japan
| | - Fujio Okamoto
- Section of Cellular Physiology, Department of Physiological Science and Molecular Biology, Fukuoka Dental College, Fukuoka, Japan
| | - Kayoko Ogata
- Oral Medicine Research Center, Fukuoka Dental College, Fukuoka, Japan
- Section of Functional Structure, Department of Morphological Biology, Fukuoka Dental College, Fukuoka, Japan
| | - Kyoko Oka
- Oral Medicine Research Center, Fukuoka Dental College, Fukuoka, Japan
- Section of Pediatric Dentistry, Department of Oral Growth and development, Fukuoka Dental College, Fukuoka, Japan
| | - Hayato Ohshima
- Division of Anatomy and Cell Biology of the Hard Tissue, Department of Tissue Regeneration and Reconstruction, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - John D Bartlett
- Division of Biosciences, Ohio State University, College of Dentistry, Columbus, Ohio, USA
| | - Koji Okabe
- Section of Cellular Physiology, Department of Physiological Science and Molecular Biology, Fukuoka Dental College, Fukuoka, Japan
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10
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Kim YJ, Zhang H, Lee Y, Seymen F, Koruyucu M, Kasimoglu Y, Simmer JP, Hu JCC, Kim JW. Novel WDR72 Mutations Causing Hypomaturation Amelogenesis Imperfecta. J Pers Med 2023; 13:326. [PMID: 36836560 PMCID: PMC9965932 DOI: 10.3390/jpm13020326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 02/10/2023] [Accepted: 02/11/2023] [Indexed: 02/16/2023] Open
Abstract
Amelogenesis imperfecta (AI) is a heterogeneous collection of hereditary enamel defects. The affected enamel can be classified as hypoplastic, hypomaturation, or hypocalcified in form. A better understanding of normal amelogenesis and improvements in our ability to diagnose AI through genetic testing can be realized through more complete knowledge of the genes and disease-causing variants that cause AI. In this study, mutational analysis was performed with whole exome sequencing (WES) to identify genetic etiology underlying the hypomaturation AI condition in affected families. Mutational analyses identified biallelic WDR72 mutations in four hypomaturation AI families. Novel mutations include a homozygous deletion and insertion mutation (NM_182758.4: c.2680_2699delinsACTATAGTT, p.(Ser894Thrfs*15)), compound heterozygous mutations (paternal c.2332dupA, p.(Met778Asnfs*4)) and (maternal c.1287_1289del, p.(Ile430del)) and a homozygous 3694 bp deletion that includes exon 14 (NG_017034.2:g.96472_100165del). A homozygous recurrent mutation variant (c.1467_1468delAT, p.(Val491Aspfs*8)) was also identified. Current ideas on WDR72 structure and function are discussed. These cases expand the mutational spectrum of WDR72 mutations causing hypomaturation AI and improve the possibility of genetic testing to accurately diagnose AI caused by WDR72 defects.
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Affiliation(s)
- Youn Jung Kim
- Department of Pediatric Dentistry & DRI, School of Dentistry, Seoul National University, Seoul 03080, Republic of Korea
| | - Hong Zhang
- Department of Biologic and Materials Sciences & Prosthodontics, School of Dentistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Yejin Lee
- Department of Pediatric Dentistry & DRI, School of Dentistry, Seoul National University, Seoul 03080, Republic of Korea
| | - Figen Seymen
- Department of Paediatric Dentistry, Faculty of Dentistry, Altinbas University, Istanbul 34147, Turkey
| | - Mine Koruyucu
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul 34116, Turkey
| | - Yelda Kasimoglu
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul 34116, Turkey
| | - James P. Simmer
- Department of Biologic and Materials Sciences & Prosthodontics, School of Dentistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jan C.-C. Hu
- Department of Biologic and Materials Sciences & Prosthodontics, School of Dentistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jung-Wook Kim
- Department of Pediatric Dentistry & DRI, School of Dentistry, Seoul National University, Seoul 03080, Republic of Korea
- Department of Molecular Genetics & DRI, School of Dentistry, Seoul National University, Seoul 03080, Republic of Korea
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11
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Ngu J, Bronckers ALJJ, Katsura K, Zhang Y, Den Besten PK. Na + and K + transport and maturation stage ameloblast modulation. Front Physiol 2023; 14:1124444. [PMID: 36814472 PMCID: PMC9939811 DOI: 10.3389/fphys.2023.1124444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 01/13/2023] [Indexed: 02/08/2023] Open
Abstract
Introduction: Enamel mineralization requires calcium transport into the extracellular matrix for the synthesis of hydroxyapatite (HA) crystals. Formation of HA releases protons into the matrix, which are then neutralized when ameloblasts modulate from cells with apical invaginations, the so-called ruffle-ended ameloblasts (RE), to smooth-ended ameloblasts (SE). Ameloblast modulation is associated with the translocation of the calcium exchanger Nckx4 to the apical border of RE, to remove Na+ from the enamel matrix in exchange for Ca2+ and K+. As enamel matures, Na+ and K+ in the matrix progressively decrease. However, the transporter to remove K+ from mineralizing enamel has not been identified. Methods: Expression of K+ exchangers and channels in secretory and maturation stage of enamel organs were compared following an RNA-seq analysis. Kcnj15, which encodes the Kir4.2 inwardly rectifying K+ channel, was found to be the most upregulated internalizing K+ transporter in maturation stage of enamel organs. Kir4.2 was immunolocalized in wt, Nckx4-/-, Wdr72-/-, and fluorosed ameloblasts. Regulation of Wdr72 expression by pH was characterized in vitro and in vivo. Results: Kir4.2 immunolocalized to the apical border of wild type (wt) mouse RE and cytosol of SE, a spatial distribution pattern shared by NCKX4. In Nckx4-/- ameloblasts, Kir4.2 also localized to the apical surface of RE and cytosol of SE. However, in fluorosed and Wdr72-/- ameloblasts, in which vesicle trafficking is disrupted, Kir4.2 remained in the cytosol. In vitro, Wdr72 was upregulated in LS8 cells cultured in medium with a pH 6.2, which is the pH of the enamel matrix underlying RE, as compared to pH 7.2 under SE. Conclusion: Taken together these results suggest that Kir4.2 participates in K+ uptake by maturation ameloblasts, and that K+ and Na+ uptake by Kir4.2 and Nckx4, respectively, may be regulated by pH through WDR72-mediated endocytosis and membrane trafficking.
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Affiliation(s)
- Jake Ngu
- Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA, United States
| | - 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, Netherlands
| | - Kaitlin Katsura
- Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA, United States
| | - Yan Zhang
- Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA, United States
| | - Pamela K. Den Besten
- Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA, United States
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12
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Chan B, Cheng IC, Rozita J, Gorshteyn I, Huang Y, Shaffer I, Chang C, Li W, Lytton J, Den Besten P, Zhang Y. Sodium/(calcium + potassium) exchanger NCKX4 optimizes KLK4 activity in the enamel matrix microenvironment to regulate ECM modeling. Front Physiol 2023; 14:1116091. [PMID: 36814474 PMCID: PMC9939835 DOI: 10.3389/fphys.2023.1116091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 01/16/2023] [Indexed: 02/09/2023] Open
Abstract
Enamel development is a process in which extracellular matrix models from a soft proteinaceous matrix to the most mineralized tissue in vertebrates. Patients with mutant NCKX4, a gene encoding a K+-dependent Na+/Ca2+-exchanger, develop a hypomineralized and hypomature enamel. How NCKX4 regulates enamel protein removal to achieve an almost protein-free enamel is unknown. We characterized the upregulation pattern of Nckx4 in the progressively differentiating enamel-forming ameloblasts by qPCR, and as well as confirmed NCKX4 protein to primarily localize at the apical surface of wild-type ruffle-ended maturation ameloblasts by immunostaining of the continuously growing mouse incisors, posing the entire developmental trajectory of enamel. In contrast to the normal mature enamel, where ECM proteins are hydrolyzed and removed, we found significant protein retention in the maturation stage of Nckx4 -/- mouse enamel. The Nckx4 -/- enamel held less Ca2+ and K+ but more Na+ than the Nckx4 +/+ enamel did, as measured by EDX. The alternating acidic and neutral pH zones at the surface of mineralizing Nckx4 +/+ enamel were replaced by a largely neutral pH matrix in the Nckx4 -/- enamel. In situ zymography revealed a reduced kallikrein-related peptidase 4 (KLK4) activity in the Nckx4 -/- enamel. We showed that KLK4 took on 90% of proteinase activity in the maturation stage of normal enamel, and that recombinant KLK4 as well as native mouse enamel KLK4 both performed less effectively in a buffer with increased [Na+] and pH, conditions found in the Nckx4 -/- developing enamel. This study, for the first time to our knowledge, provides evidence demonstrating the impaired in situ KLK4 activity in Nckx4 -/- enamel and suggests a novel function of NCKX4 in facilitating KLK4-mediated hydrolysis and removal of ECM proteins, warranting the completion of enamel matrix modeling.
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Affiliation(s)
- Barry Chan
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Ieong Cheng Cheng
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Jalali Rozita
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Ida Gorshteyn
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Yulei Huang
- Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Sun-Yat-sen University, Guangzhou, China
| | - Ida Shaffer
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Chih Chang
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Wu Li
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Jonathan Lytton
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, AB, Canada
| | - Pamela Den Besten
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Yan Zhang
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
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13
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Said R, Mortazavi H, Cooper D, Ovens K, McQuillan I, Papagerakis S, Papagerakis P. Deciphering the functions of Stromal Interaction Molecule-1 in amelogenesis using AmelX-iCre mice. Front Physiol 2023; 14:1100714. [PMID: 36935757 PMCID: PMC10014868 DOI: 10.3389/fphys.2023.1100714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 02/17/2023] [Indexed: 03/05/2023] Open
Abstract
Introduction: The intracellular Ca2+ sensor stromal interaction molecule 1 (STIM1) is thought to play a critical role in enamel development, as its mutations cause Amelogenesis Imperfecta (AI). We recently established an ameloblast-specific (AmelX-iCre) Stim1 conditional deletion mouse model to investigate the role of STIM1 in controlling ameloblast function and differentiation in vivo (Stim1 cKO). Our pilot data (Said et al., J. Dent. Res., 2019, 98, 1002-1010) support our hypothesis for a broad role of Stim1 in amelogenesis. This paper aims to provide an in-depth characterization of the enamel phenotype observed in our Stim1 cKO model. Methods: We crossed AmelX-iCre mice with Stim1-floxed animals to develop ameloblast-specific Stim1 cKO mice. Scanning electron microscopy, energy dispersive spectroscopy, and micro- CT were used to study the enamel phenotype. RNAseq and RT-qPCR were utilized to evaluate changes in the gene expression of several key ameloblast genes. Immunohistochemistry was used to detect the amelogenin, matrix metalloprotease 20 and kallikrein 4 proteins in ameloblasts. Results: Stim1 cKO animals exhibited a hypomineralized AI phenotype, with reduced enamel volume, diminished mineral density, and lower calcium content. The mutant enamel phenotype was more severe in older Stim1 cKO mice compared to younger ones and changes in enamel volume and mineral content were more pronounced in incisors compared to molars. Exploratory RNAseq analysis of incisors' ameloblasts suggested that ablation of Stim1 altered the expression levels of several genes encoding enamel matrix proteins which were confirmed by subsequent RT-qPCR. On the other hand, RT-qPCR analysis of molars' ameloblasts showed non-significant differences in the expression levels of enamel matrix genes between control and Stim1-deficient cells. Moreover, gene expression analysis of incisors' and molars' ameloblasts showed that Stim1 ablation caused changes in the expression levels of several genes associated with calcium transport and mitochondrial kinetics. Conclusions: Collectively, these findings suggest that the loss of Stim1 in ameloblasts may impact enamel mineralization and ameloblast gene expression.
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Affiliation(s)
- Raed Said
- College of Dentistry, University of Saskatchewan, Saskatoon, SK, Canada
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Helyasadat Mortazavi
- College of Dentistry, University of Saskatchewan, Saskatoon, SK, Canada
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - David Cooper
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Katie Ovens
- Department of Computer Science, University of Calgary, Calgary, AB, Canada
| | - Ian McQuillan
- Department of Computer Sciences, College of Arts and Sciences, University of Saskatchewan, Saskatoon, SK, Canada
| | - Silvana Papagerakis
- Department of Surgery, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
- Department of Otolaryngology-Head and Neck Surgery, School of Medicine, University of Michigan, Ann Arbor, MI, United States
| | - Petros Papagerakis
- College of Dentistry, University of Saskatchewan, Saskatoon, SK, Canada
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
- *Correspondence: Petros Papagerakis,
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14
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Al-Khannaq M, Lytton J. Regulation of K +-Dependent Na +/Ca 2+-Exchangers (NCKX). Int J Mol Sci 2022; 24:ijms24010598. [PMID: 36614039 PMCID: PMC9820825 DOI: 10.3390/ijms24010598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 12/23/2022] [Accepted: 12/24/2022] [Indexed: 12/31/2022] Open
Abstract
Potassium-dependent sodium-calcium exchangers (NCKX) have emerged as key determinants of calcium (Ca2+) signaling and homeostasis, especially in environments where ion concentrations undergo large changes, such as excitatory cells and transport epithelia. The regulation of NCKX transporters enables them to respond to the changing cellular environment thereby helping to shape the extent and kinetics of Ca2+ signals. This review examines the current knowledge of the different ways in which NCKX activity can be modulated. These include (i) cellular and dynamic subcellular location (ii); changes in protein expression mediated at the gene, transcript, or protein level (iii); genetic changes resulting in altered protein structure or expression (iv); regulation via changes in substrate concentration (v); and post-translational modification, partner protein interactions, and allosteric regulation. Detailed mechanistic understanding of NCKX regulation is an emerging area of research with the potential to provide important new insights into transporter function, the control of Ca2+ signals, and possible interventions for dysregulated Ca2+ homeostasis.
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15
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ATM rules neurodevelopment and glutamatergic transmission in the hippocampus but not in the cortex. Cell Death Dis 2022; 13:616. [PMID: 35842432 PMCID: PMC9288428 DOI: 10.1038/s41419-022-05038-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 06/14/2022] [Accepted: 06/27/2022] [Indexed: 01/21/2023]
Abstract
Interest in the function of ataxia-telangiectasia-mutated protein (ATM) is extensively growing as evidenced by preclinical studies that continuously link ATM with new intracellular pathways. Here, we exploited Atm+/- and Atm-/- mice and demonstrate that cognitive defects are rescued by the delivery of the antidepressant Fluoxetine (Fluox). Fluox increases levels of the chloride intruder NKCC1 exclusively at hippocampal level suggesting an ATM context-specificity. A deeper investigation of synaptic composition unveils increased Gluk-1 and Gluk-5 subunit-containing kainate receptors (KARs) levels in the hippocampus, but not in the cortex, of Atm+/- and Atm-/- mice. Analysis of postsynaptic fractions and confocal studies indicates that KARs are presynaptic while in vitro and ex vivo electrophysiology that are fully active. These changes are (i) linked to KCC2 activity, as the KCC2 blockade in Atm+/- developing neurons results in reduced KARs levels and (ii) developmental regulated. Indeed, the pharmacological inhibition of ATM kinase in adults produces different changes as identified by RNA-seq investigation. Our data display how ATM affects both inhibitory and excitatory neurotransmission, extending its role to a variety of neurological and psychiatric disorders.
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16
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Hossain MA, Al Amin M, Hasan MI, Sohel M, Ahammed MA, Mahmud SH, Rahman MR, Rahman MH. Bioinformatics and system biology approaches to identify molecular pathogenesis of polycystic ovarian syndrome, type 2 diabetes, obesity, and cardiovascular disease that are linked to the progression of female infertility. INFORMATICS IN MEDICINE UNLOCKED 2022. [DOI: 10.1016/j.imu.2022.100960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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17
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Suzuki A, Yoshioka H, Liu T, Gull A, Singh N, Le T, Zhao Z, Iwata J. Crucial Roles of microRNA-16-5p and microRNA-27b-3p in Ameloblast Differentiation Through Regulation of Genes Associated With Amelogenesis Imperfecta. Front Genet 2022; 13:788259. [PMID: 35401675 PMCID: PMC8990915 DOI: 10.3389/fgene.2022.788259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 03/11/2022] [Indexed: 11/13/2022] Open
Abstract
Amelogenesis imperfecta is a congenital disorder within a heterogeneous group of conditions characterized by enamel hypoplasia. Patients suffer from early tooth loss, social embarrassment, eating difficulties, and pain due to an abnormally thin, soft, fragile, and discolored enamel with poor aesthetics and functionality. The etiology of amelogenesis imperfecta is complicated by genetic interactions. To identify mouse amelogenesis imperfecta-related genes (mAIGenes) and their respective phenotypes, we conducted a systematic literature review and database search and found and curated 70 mAIGenes across all of the databases. Our pathway enrichment analysis indicated that these genes were enriched in tooth development-associated pathways, forming four distinct groups. To explore how these genes are regulated and affect the phenotype, we predicted microRNA (miRNA)-gene interaction pairs using our bioinformatics pipeline. Our miRNA regulatory network analysis pinpointed that miR-16-5p, miR-27b-3p, and miR-23a/b-3p were hub miRNAs. The function of these hub miRNAs was evaluated through ameloblast differentiation assays with/without the candidate miRNA mimics using cultured mouse ameloblast cells. Our results revealed that overexpression of miR-16-5p and miR-27b-3p, but not miR-23a/b-3p, significantly inhibited ameloblast differentiation through regulation of mAIGenes. Thus, our study shows that miR-16-5p and miR-27b-3p are candidate pathogenic miRNAs for amelogenesis imperfecta.
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Affiliation(s)
- Akiko Suzuki
- Department of Diagnostic and Biomedical Sciences, School of Dentistry, The University of Texas Health Science Center at Houston, Houston, TX, United States
- Center for Craniofacial Research, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Hiroki Yoshioka
- Department of Diagnostic and Biomedical Sciences, School of Dentistry, The University of Texas Health Science Center at Houston, Houston, TX, United States
- Center for Craniofacial Research, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Teng Liu
- Center for Precision Health, School of Biomedical Informatics, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Aania Gull
- Department of Diagnostic and Biomedical Sciences, School of Dentistry, The University of Texas Health Science Center at Houston, Houston, TX, United States
- Center for Craniofacial Research, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Naina Singh
- Center for Craniofacial Research, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Thanh Le
- Department of Diagnostic and Biomedical Sciences, School of Dentistry, The University of Texas Health Science Center at Houston, Houston, TX, United States
- Center for Craniofacial Research, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Zhongming Zhao
- Center for Precision Health, School of Biomedical Informatics, The University of Texas Health Science Center at Houston, Houston, TX, United States
- Human Genetics Center, School of Public Health, The University of Texas Health Science Center at Houston, Houston, TX, United States
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX, United States
| | - Junichi Iwata
- Department of Diagnostic and Biomedical Sciences, School of Dentistry, The University of Texas Health Science Center at Houston, Houston, TX, United States
- Center for Craniofacial Research, The University of Texas Health Science Center at Houston, Houston, TX, United States
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX, United States
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18
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Husein D, Alamoudi A, Ohyama Y, Mochida H, Ritter B, Mochida Y. Identification of the C-terminal region in Amelogenesis Imperfecta causative protein WDR72 required for Golgi localization. Sci Rep 2022; 12:4640. [PMID: 35301423 PMCID: PMC8930991 DOI: 10.1038/s41598-022-08719-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 02/28/2022] [Indexed: 11/22/2022] Open
Abstract
Amelogenesis Imperfecta (AI) represents a group of hereditary conditions that manifest tooth enamel defects. Several causative mutations in the WDR72 gene have been identified and patients with WDR72 mutations have brown (or orange-brown) discolored enamel, rough enamel surface, early loss of enamel after tooth eruption, and severe attrition. Although the molecular function of WDR72 is not yet fully understood, a recent study suggested that WDR72 could be a facilitator of endocytic vesicle trafficking, which appears inconsistent with the previously reported cytoplasmic localization of WDR72. Therefore, the aims of our study were to investigate the tissues and cell lines in which WDR72 was expressed and to further determine the sub-cellular localization of WDR72. The expression of Wdr72 gene was investigated in mouse tissues and cell lines. Endogenous WDR72 protein was detected in the membranous fraction of ameloblast cell lines in addition to the cytosolic fraction. Sub-cellular localization studies supported our fractionation data, showing WDR72 at the Golgi apparatus, and to a lesser extent, in the cytoplasmic area. In contrast, a WDR72 AI mutant form that lacks its C-terminal region was exclusively detected in the cytoplasm. In addition, our studies identified a putative prenylation/CAAX motif within the last four amino acids of human WDR72 and generated a WDR72 variant, called CS mutant, in which the putative motif was ablated by a point mutation. Interestingly, mutation of the putative CAAX motif impaired WDR72 recruitment to the Golgi. Cell fractionation assays confirmed subcellular distribution of wild-type WDR72 in both cytosolic and membranous fractions, while the WDR72 AI mutant and CS mutant forms were predominantly detected in the cytosolic fraction. Our studies provide new insights into the subcellular localization of WDR72 and demonstrate a critical role for the C-terminal CAAX motif in regulating WDR72 recruitment to the Golgi. In accordance with structural modelling studies that classified WDR72 as a potential vesicle transport protein, our findings suggest a role for WDR72 in vesicular Golgi transport that may be key to understanding the underlying cause of AI.
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Affiliation(s)
- Dina Husein
- Department of Molecular and Cell Biology, Henry M. Goldman School of Dental Medicine, Boston University, Boston, MA, USA
| | - Ahmed Alamoudi
- Department of Molecular and Cell Biology, Henry M. Goldman School of Dental Medicine, Boston University, Boston, MA, USA
- Oral Biology Department, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Yoshio Ohyama
- Department of Molecular and Cell Biology, Henry M. Goldman School of Dental Medicine, Boston University, Boston, MA, USA
| | - Hanna Mochida
- Department of Molecular and Cell Biology, Henry M. Goldman School of Dental Medicine, Boston University, Boston, MA, USA
| | - Brigitte Ritter
- Department of Biochemistry, School of Medicine, Boston University, Boston, MA, USA
| | - Yoshiyuki Mochida
- Department of Molecular and Cell Biology, Henry M. Goldman School of Dental Medicine, Boston University, Boston, MA, USA.
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19
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Lee Y, Zhang H, Seymen F, Kim YJ, Kasimoglu Y, Koruyucu M, Simmer JP, Hu JCC, Kim JW. Novel KLK4 Mutations Cause Hypomaturation Amelogenesis Imperfecta. J Pers Med 2022; 12:jpm12020150. [PMID: 35207639 PMCID: PMC8878363 DOI: 10.3390/jpm12020150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/18/2022] [Accepted: 01/20/2022] [Indexed: 12/02/2022] Open
Abstract
Amelogenesis imperfecta (AI) is a group of rare genetic diseases affecting the tooth enamel. AI is characterized by an inadequate quantity and/or quality of tooth enamel and can be divided into three major categories: hypoplastic, hypocalcified and hypomaturation types. Even though there are some overlapping phenotypes, hypomaturation AI enamel typically has a yellow to brown discoloration with a dull appearance but a normal thickness indicating a less mineralized enamel matrix. In this study, we recruited four Turkish families with hypomaturation AI and performed mutational analysis using whole exome sequencing. These analyses revealed two novel homozygous mutations in the KLK4 gene: a nonsense mutation in exon 3 (NM_004917.4:c.170C>A, p.(Ser57*)) was found in families 1, 2 and 3 and a missense mutation in exon 6 (c.637T>C, p.(Cys213Arg)) in family 4. Functional analysis showed that the missense mutation transcript could not translate the mutant protein efficiently or generated an unstable protein that lacked functional activity. The two novel inactivating KLK4 mutations we identified caused a hypomaturation AI phenotype similar to those caused by the four previously described KLK4 nonsense and frameshift mutations. This study improves our understanding of the normal and pathologic mechanisms of enamel formation.
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Affiliation(s)
- Yejin Lee
- Department of Pediatric Dentistry, School of Dentistry & DRI, Seoul National University, Seoul 03080, Korea; (Y.L.); (Y.J.K.)
| | - Hong Zhang
- Department of Biologic and Materials Sciences & Prosthodontics, School of Dentistry, University of Michigan, Ann Arbor, MI 48109, USA; (H.Z.); (J.P.S.); (J.C.-C.H.)
| | - Figen Seymen
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul 34116, Turkey; (F.S.); (Y.K.); (M.K.)
| | - Youn Jung Kim
- Department of Pediatric Dentistry, School of Dentistry & DRI, Seoul National University, Seoul 03080, Korea; (Y.L.); (Y.J.K.)
| | - Yelda Kasimoglu
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul 34116, Turkey; (F.S.); (Y.K.); (M.K.)
| | - Mine Koruyucu
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul 34116, Turkey; (F.S.); (Y.K.); (M.K.)
| | - James P. Simmer
- Department of Biologic and Materials Sciences & Prosthodontics, School of Dentistry, University of Michigan, Ann Arbor, MI 48109, USA; (H.Z.); (J.P.S.); (J.C.-C.H.)
| | - Jan C.-C. Hu
- Department of Biologic and Materials Sciences & Prosthodontics, School of Dentistry, University of Michigan, Ann Arbor, MI 48109, USA; (H.Z.); (J.P.S.); (J.C.-C.H.)
| | - Jung-Wook Kim
- Department of Pediatric Dentistry, School of Dentistry & DRI, Seoul National University, Seoul 03080, Korea; (Y.L.); (Y.J.K.)
- Department of Molecular Genetics, School of Dentistry & DRI, Seoul National University, Seoul 03080, Korea
- Correspondence:
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20
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Inoue A, Kiyoshima T, Yoshizaki K, Nakatomi C, Nakatomi M, Ohshima H, Shin M, Gao J, Tsuru K, Okabe K, Nakamura I, Honda H, Matsuda M, Takahashi I, Jimi E. Deletion of epithelial cell-specific p130Cas impairs the maturation stage of amelogenesis. Bone 2022; 154:116210. [PMID: 34592494 DOI: 10.1016/j.bone.2021.116210] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 09/17/2021] [Accepted: 09/18/2021] [Indexed: 11/02/2022]
Abstract
Amelogenesis consists of secretory, transition, maturation, and post-maturation stages, and the morphological changes of ameloblasts at each stage are closely related to their function. p130 Crk-associated substrate (Cas) is a scaffold protein that modulates essential cellular processes, including cell adhesion, cytoskeletal changes, and polarization. The expression of p130Cas was observed from the secretory stage to the maturation stage in ameloblasts. Epithelial cell-specific p130Cas-deficient (p130CasΔepi-) mice exhibited enamel hypomineralization with chalk-like white mandibular incisors in young mice and attrition in aged mouse molars. A micro-computed tomography analysis and Vickers micro-hardness testing showed thinner enamel, lower enamel mineral density and hardness in p130CasΔepi- mice in comparison to p130Casflox/flox mice. Scanning electron microscopy, and an energy dispersive X-ray spectroscopy analysis indicated the disturbance of the enamel rod structure and lower Ca and P contents in p130CasΔepi- mice, respectively. The disorganized arrangement of ameloblasts, especially in the maturation stage, was observed in p130CasΔepi- mice. Furthermore, expression levels of enamel matrix proteins, such as amelogenin and ameloblastin in the secretory stage, and functional markers, such as alkaline phosphatase and iron accumulation, and Na+/Ca2++K+-exchanger in the maturation stage were reduced in p130CasΔepi- mice. These findings suggest that p130Cas plays important roles in amelogenesis (197 words).
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Affiliation(s)
- Akane Inoue
- Laboratory of Molecular and Cellular Biochemistry, Division of Oral Biological Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan; Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth and Development, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Tamotsu Kiyoshima
- Laboratory of Oral Pathology, Division of Maxillofacial Diagnostic and Surgical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Keigo Yoshizaki
- Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth and Development, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Chihiro Nakatomi
- Division of Physiology, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu 803-8580, Japan
| | - Mitsushiro Nakatomi
- Department of Human, Information and Life Sciences, School of Health Sciences, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan
| | - Hayato Ohshima
- Division of Anatomy and Cell Biology of the Hard Tissue, Department of Tissue Regeneration and Reconstruction, Niigata University Graduate School of Medical and Dental Sciences, 2-5274 Gakkocho-dori, Chuo-ku, Niigata 951-8514, Japan
| | - Masashi Shin
- Department of Physiological Sciences and Molecular Biology, Fukuoka Dental College, 2-5-1 Tamura, Sawara-ku, Fukuoka 814-0175, Japan; Oral Medicine Center, Fukuoka Dental College, 2-5-1 Tamura, Sawara-ku, Fukuoka 814-0175, Japan
| | - Jing Gao
- Laboratory of Molecular and Cellular Biochemistry, Division of Oral Biological Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Kanji Tsuru
- Section of Bioengineering, Fukuoka Dental College, 2-5-1 Tamura, Sawara-ku, Fukuoka 814-0175, Japan
| | - Koji Okabe
- Department of Physiological Sciences and Molecular Biology, Fukuoka Dental College, 2-5-1 Tamura, Sawara-ku, Fukuoka 814-0175, Japan
| | - Ichiro Nakamura
- Department of Rehabilitation, Yugawara Hospital, Japan Community Health Care Organization, 2-21-6 Chuo, Yugawara, Ashigara-shimo, Kanagawa 259-0396, Japan
| | - Hiroaki Honda
- Field of Human Disease Models, Major in Advanced Life Sciences and Medicine, Institute of Laboratory Animals, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan
| | - Miho Matsuda
- Laboratory of Molecular and Cellular Biochemistry, Division of Oral Biological Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Ichiro Takahashi
- Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth and Development, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Eijiro Jimi
- Laboratory of Molecular and Cellular Biochemistry, Division of Oral Biological Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan; Oral Health/Brain Health/Total Health Research Center, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
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21
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Kim Y, Lee Y, Kasimoglu Y, Seymen F, Simmer J, Hu JC, Cho ES, Kim JW. Recessive Mutations in ACP4 Cause Amelogenesis Imperfecta. J Dent Res 2022; 101:37-45. [PMID: 34036831 PMCID: PMC8721729 DOI: 10.1177/00220345211015119] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Amelogenesis imperfecta (AI) is an innate disorder that affects the formation and mineralization of the tooth enamel. When diagnosed with AI, one's teeth can be hypoplastic (thin enamel), hypomature (normal enamel thickness but discolored and softer than normal enamel), hypocalcified (normal enamel thickness but extremely weak), or mixed conditions of the above. Numerous studies have revealed the genes that are involved in causing AI. Recently, ACP4 (acid phosphatase 4) was newly found as a gene causing hypoplastic AI, and it was suggested that mutant forms of ACP4 might affect access to the catalytic core or the ability to form a homodimer. In this study, a Korean and a Turkish family with hypoplastic AI were recruited, and their exome sequences were analyzed. Biallelic mutations were revealed in ACP4: paternal (NM_033068: c.419C>T, p.(Pro140Leu)) and maternal (c.262C>A, p.(Arg88Ser)) mutations in family 1 and a paternal (c.713C>T, p.(Ser238Leu)) mutation and de novo (c.350A>G, p.(Gln117Arg)) mutation in the maternal allele in family 2. Mutations were analyzed by cloning, mutagenesis, immunofluorescence, immunoprecipitation, and acid phosphatase activity test. Comparison between the wild-type and mutant ACP4s showed a decreased amount of protein expression from the mutant forms, a decreased ability to form a homodimer, and a decreased acid phosphatase activity level. We believe that these findings will not only expand the mutational spectrum of ACP4 but also increase our understanding of the mechanism of ACP4 function during normal and pathologic amelogenesis.
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Affiliation(s)
- Y.J. Kim
- Department of Molecular Genetics and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - Y. Lee
- Department of Pediatric Dentistry and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - Y. Kasimoglu
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul, Turkey
| | - F. Seymen
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul, Turkey
| | - J.P. Simmer
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| | - J.C.-C. Hu
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| | - E.-S. Cho
- Cluster for Craniofacial Development and Regeneration Research, Institute of Oral Biosciences, Jeonbuk National University School of Dentistry, Jeonju, Republic of Korea
| | - J.-W. Kim
- Department of Molecular Genetics and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea,Department of Pediatric Dentistry and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea,J.W. Kim, Department of Molecular Genetics, Department of Pediatric Dentistry and Dental Research Institute, School of Dentistry, Seoul National University, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.
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22
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Seymen F, Zhang H, Kasimoglu Y, Koruyucu M, Simmer JP, Hu JCC, Kim JW. Novel Mutations in GPR68 and SLC24A4 Cause Hypomaturation Amelogenesis Imperfecta. J Pers Med 2021; 12:jpm12010013. [PMID: 35055328 PMCID: PMC8781920 DOI: 10.3390/jpm12010013] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 12/15/2021] [Accepted: 12/20/2021] [Indexed: 11/16/2022] Open
Abstract
Amelogenesis imperfecta (AI) is a rare genetic condition affecting the quantity and/or quality of tooth enamel. Hypomaturation AI is characterized by brownish-yellow discoloration with increased opacity and poorly mineralized enamel prone to fracture and attrition. We recruited three families affected by hypomaturation AI and performed whole exome sequencing with selected individuals in each family. Bioinformatic analysis and Sanger sequencing identified and confirmed mutations and segregation in the families. Family 1 had a novel homozygous frameshift mutation in GPR68 gene (NM_003485.3:c.78_83delinsC, p.(Val27Cysfs*146)). Family 2 had a novel homozygous nonsense mutation in SLC24A4 gene (NM_153646.4:c.613C>T, NP_705932.2:p.(Arg205*)). Family 3 also had a homozygous missense mutation in SLC24A4 gene which was reported previously (c.437C>T, p.(Ala146Val)). This report not only expands the mutational spectrum of the AI-causing genes but also improves our understanding of normal and pathologic amelogenesis.
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Affiliation(s)
- Figen Seymen
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul 34116, Turkey; (F.S.); (Y.K.); (M.K.)
| | - Hong Zhang
- Department of Biologic and Materials Sciences & Prosthodontics, School of Dentistry, University of Michigan, Ann Arbor, MI 48109, USA; (H.Z.); (J.P.S.); (J.C.-C.H.)
| | - Yelda Kasimoglu
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul 34116, Turkey; (F.S.); (Y.K.); (M.K.)
| | - Mine Koruyucu
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul 34116, Turkey; (F.S.); (Y.K.); (M.K.)
| | - James P. Simmer
- Department of Biologic and Materials Sciences & Prosthodontics, School of Dentistry, University of Michigan, Ann Arbor, MI 48109, USA; (H.Z.); (J.P.S.); (J.C.-C.H.)
| | - Jan C.-C. Hu
- Department of Biologic and Materials Sciences & Prosthodontics, School of Dentistry, University of Michigan, Ann Arbor, MI 48109, USA; (H.Z.); (J.P.S.); (J.C.-C.H.)
| | - Jung-Wook Kim
- Department of Pediatric Dentistry, School of Dentistry & DRI, Seoul National University, Seoul 03080, Korea
- Department of Molecular Genetics, School of Dentistry & DRI, Seoul National University, Seoul 03080, Korea
- Correspondence:
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23
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Costiniti V, Bomfim GH, Mitaishvili E, Son GY, Li Y, Lacruz RS. Calcium Transport in Specialized Dental Epithelia and Its Modulation by Fluoride. Front Endocrinol (Lausanne) 2021; 12:730913. [PMID: 34456880 PMCID: PMC8385142 DOI: 10.3389/fendo.2021.730913] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 07/26/2021] [Indexed: 11/25/2022] Open
Abstract
Most cells use calcium (Ca2+) as a second messenger to convey signals that affect a multitude of biological processes. The ability of Ca2+ to bind to proteins to alter their charge and conformation is essential to achieve its signaling role. Cytosolic Ca2+ (cCa2+) concentration is maintained low at ~100 nM so that the impact of elevations in cCa2+ is readily sensed and transduced by cells. However, such elevations in cCa2+ must be transient to prevent detrimental effects. Cells have developed a variety of systems to rapidly clear the excess of cCa2+ including Ca2+ pumps, exchangers and sequestering Ca2+ within intracellular organelles. This Ca2+ signaling toolkit is evolutionarily adapted so that each cell, tissue, and organ can fulfill its biological function optimally. One of the most specialized cells in mammals are the enamel forming cells, the ameloblasts, which also handle large quantities of Ca2+. The end goal of ameloblasts is to synthesize, secrete and mineralize a unique proteinaceous matrix without the benefit of remodeling or repair mechanisms. Ca2+ uptake into ameloblasts is mainly regulated by the store operated Ca2+ entry (SOCE) before it is transported across the polarized ameloblasts to reach the insulated enamel space. Here we review the ameloblasts Ca2+ signaling toolkit and address how the common electronegative non-metal fluoride can alter its function, potentially addressing the biology of dental fluorosis.
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Affiliation(s)
| | | | | | | | | | - Rodrigo S. Lacruz
- Department Molecular Pathobiology, College of Dentistry, New York University, New York, NY, United States
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24
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Thibodeau S, Yang W, Sharma S, Lytton J. Calmodulin binds and modulates K +-dependent Na +/Ca 2+-exchanger isoform 4, NCKX4. J Biol Chem 2021; 296:100092. [PMID: 33199372 PMCID: PMC7949085 DOI: 10.1074/jbc.ra120.015037] [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: 06/29/2020] [Revised: 10/25/2020] [Accepted: 11/16/2020] [Indexed: 11/06/2022] Open
Abstract
The family of K+-dependent Na+/Ca2+-exchangers, NCKX, are important mediators of cellular Ca2+ efflux, particularly in neurons associated with sensory transduction. The NCKX family comprises five proteins, NCKX1-5, each being the product of a different SLC24 gene. NCKX4 (SLC24A4) has been found to have a critical role in termination and adaptation of visual and olfactory signals, melanocortin-dependent satiety signaling, and the maturation of dental enamel. To explore mechanisms that might influence the temporal control of NCKX4 activity, a yeast two-hybrid system was used to search for protein interaction partners. We identified calmodulin as a partner for NCKX4 and confirmed the interaction using glutathione-S-transferase fusion pull-down. Calmodulin binding to NCKX4 was demonstrated in extracts from mouse brain and in transfected HEK293 cells. Calmodulin bound in a Ca2+-dependent manner to a motif present in the central cytosolic loop of NCKX4 and was abolished by the double-mutant I328D/F334D. When cotransfected in HEK293 cells, calmodulin bound to NCKX4 under basal conditions and induced a ∼2.5-fold increase in NCKX4 abundance, but did not influence either cellular location or basal activity. When purinergic stimulation of NCKX4 was examined in these cells, coexpression of wild-type calmodulin, but not a Ca2+ binding-deficient calmodulin mutant, suppressed NCKX4 activation in a time-dependent manner. We propose that Ca2+ binding to calmodulin prepositioned on NCKX4 induces a slow conformational rearrangement that interferes with purinergic stimulation of the exchanger, possibly by obscuring T331, a previously identified potential protein kinase C site.
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Affiliation(s)
- Stephanie Thibodeau
- Department of Biochemistry & Molecular Biology, Libin Cardiovascular Institute and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Weidong Yang
- Department of Biochemistry & Molecular Biology, Libin Cardiovascular Institute and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Sunita Sharma
- Department of Biochemistry & Molecular Biology, Libin Cardiovascular Institute and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Jonathan Lytton
- Department of Biochemistry & Molecular Biology, Libin Cardiovascular Institute and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
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25
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Khan SA, Khan MA, Muhammad N, Bashir H, Khan N, Muhammad N, Yilmaz R, Khan S, Wasif N. A novel nonsense variant in SLC24A4 causing a rare form of amelogenesis imperfecta in a Pakistani family. BMC MEDICAL GENETICS 2020; 21:97. [PMID: 32380970 PMCID: PMC7206816 DOI: 10.1186/s12881-020-01038-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 04/28/2020] [Indexed: 02/07/2023]
Abstract
Background Amelogenesis imperfecta (AI) is a highly heterogeneous group of hereditary developmental abnormalities which mainly affects the dental enamel during tooth development in terms of its thickness, structure, and composition. It appears both in syndromic as well as non-syndromic forms. In the affected individuals, the enamel is usually thin, soft, rough, brittle, pitted, chipped, and abraded, having reduced functional ability and aesthetics. It leads to severe complications in the patient, like early tooth loss, severe discomfort, pain, dental caries, chewing difficulties, and discoloration of teeth from yellow to yellowish-brown or creamy type. The study aimed to identify the disease-causing variant in a consanguineous family. Methods We recruited a consanguineous Pashtun family of Pakistani origin. Exome sequencing analysis was followed by Sanger sequencing to identify the pathogenic variant in this family. Results Clinical analysis revealed hypomaturation AI having generalized yellow-brown or creamy type of discoloration in affected members. We identified a novel nonsense sequence variant c.1192C > T (p.Gln398*) in exon-12 of SLC24A4 by using exome sequencing. Later, its co-segregation within the family was confirmed by Sanger sequencing. The human gene mutation database (HGMD, 2019) has a record of five pathogenic variants in SLC24A4, causing AI phenotype. Conclusion This nonsense sequence variant c.1192C > T (p.Gln398*) is the sixth disease-causing variant in SLC24A4, which extends its mutation spectrum and confirms the role of this gene in the morphogenesis of human tooth enamel. The identified variant highlights the critical role of SLC24A4 in causing a rare AI type in humans.
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Affiliation(s)
- Sher Alam Khan
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology (KUST), Kohat, Pakistan
| | - Muhammad Adnan Khan
- Dental Material, Institute of Basic Medical Sciences, Khyber Medical University Peshawar, Peshawar, Pakistan
| | - Nazif Muhammad
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology (KUST), Kohat, Pakistan
| | - Hina Bashir
- Department of Biochemistry, Sharif Medical and Dental College, Lahore, Pakistan
| | - Niamat Khan
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology (KUST), Kohat, Pakistan
| | - Noor Muhammad
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology (KUST), Kohat, Pakistan
| | - Rüstem Yilmaz
- Department of Neurology, University of Ulm, Ulm, Germany
| | - Saadullah Khan
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology (KUST), Kohat, Pakistan.
| | - Naveed Wasif
- Institute of Molecular Biology and Biotechnology (IMBB), Center for Research in Molecular Medicine (CRiMM), The University of Lahore, Lahore, Pakistan. .,Department of Human Genetics, University of Ulm, Ulm, Germany. .,Institute of Human Genetics, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany.
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26
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Hassan MT, Lytton J. Potassium-dependent sodium-calcium exchanger (NCKX) isoforms and neuronal function. Cell Calcium 2020; 86:102135. [DOI: 10.1016/j.ceca.2019.102135] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 11/25/2019] [Accepted: 11/26/2019] [Indexed: 12/16/2022]
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Lepperdinger U, Maurer E, Witsch-Baumgartner M, Stigler R, Zschocke J, Lussi A, Kapferer-Seebacher I. Expanding the phenotype of hypomaturation amelogenesis imperfecta due to a novel SLC24A4 variant. Clin Oral Investig 2020; 24:3519-3525. [PMID: 32034543 DOI: 10.1007/s00784-020-03222-7] [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: 03/11/2019] [Accepted: 01/23/2020] [Indexed: 10/24/2022]
Abstract
OBJECTIVES Biallelic variants in solute carrier family 24 member 4 (SLC24A4) have been previously reported to cause non-syndromic autosomal recessive amelogenesis imperfecta (AI) of the pigmented hypomaturation type (MIM #615887). We here describe a novel variant in SLC24A4 causing mild enamel hypomaturation defects also in heterozygous individuals. MATERIALS AND METHODS In the present pedigree analysis, a large consanguineous Syrian family with AI of the hypomaturation type was investigated by clinical and dental evaluation, and exome and Sanger sequencing. Dental histological investigations of seven primary and two permanent teeth were performed. RESULTS Homozygous variants in SLC24A4 (c.1604G>A; p.Gly535Asp) were identified in five individuals with brown discolorations and irregular pits and grooves of the teeth. Severe attritions, occlusal abfractions, and the radiological lack of contrast between enamel and dentin point out a mineralization defect. Histological dental investigations confirmed the clinical diagnosis of AI of the hypomaturation type. In two heterozygous individuals, a mild hypomaturation defect was present with white and light brown enamel discolorations. CONCLUSIONS This is the first report of heterozygous SLC24A4 variants causing mild hypomaturation defects, providing confirmatory evidence that the function of SLC24A4 in calcium transport has a crucial role in the maturation stage of amelogenesis. CLINICAL RELEVANCE The present report is expanding the clinical phenotype of SLC24A4 variants to more severe forms of amelogenesis imperfecta. An autosomal-dominant inheritance pattern with mild clinical phenotypes in heterozygotes has to be considered.
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Affiliation(s)
- Ulrike Lepperdinger
- Department of Operative and Restorative Dentistry, Medical University of Innsbruck, Anichstraße 35, A-6020, Innsbruck, Austria
| | - Elisabeth Maurer
- Division of Human Genetics, Medical University Innsbruck, Innsbruck, Austria
| | | | - Robert Stigler
- Department of Oral and Maxillofacial Surgery, Medical University Innsbruck, Innsbruck, Austria
| | - Johannes Zschocke
- Division of Human Genetics, Medical University Innsbruck, Innsbruck, Austria
| | - Adrian Lussi
- Department of Operative Dentistry and Periodontology, Faculty of Dentistry, University Medical Centre, Freiburg, Germany
| | - Ines Kapferer-Seebacher
- Department of Operative and Restorative Dentistry, Medical University of Innsbruck, Anichstraße 35, A-6020, Innsbruck, Austria.
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28
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Structure-function relationships of K +-dependent Na +/Ca 2+ exchangers (NCKX). Cell Calcium 2019; 86:102153. [PMID: 31927187 DOI: 10.1016/j.ceca.2019.102153] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 12/15/2019] [Accepted: 12/16/2019] [Indexed: 01/13/2023]
Abstract
K+-dependent Na+/Ca2+ exchanger proteins (NCKX1-5) of the SLC24 gene family play important roles in a wide range of biological processes including but not limited to rod and cone photoreceptor vision, olfaction, enamel formation and skin pigmentation. NCKX proteins are also widely expressed throughout the brain and NCKX2 and NCKX4 knockouts in mice have specific phenotypes. Here we review our work on structure-function relationships of NCKX proteins. We discuss membrane topology, domains critical to transport function, and residues critical to cation binding and transport function, all in the context of crystal structures that were obtained for the archaeal Na+/Ca2+ exchanger NCX_Mj.
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29
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Racz R, Nagy A, Rakonczay Z, Dunavari EK, Gerber G, Varga G. Defense Mechanisms Against Acid Exposure by Dental Enamel Formation, Saliva and Pancreatic Juice Production. Curr Pharm Des 2019; 24:2012-2022. [PMID: 29769002 PMCID: PMC6225347 DOI: 10.2174/1381612824666180515125654] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 04/30/2018] [Accepted: 05/08/2018] [Indexed: 12/16/2022]
Abstract
The pancreas, the salivary glands and the dental enamel producing ameloblasts have marked developmental, structural and functional similarities. One of the most striking similarities is their bicarbonate-rich secretory product, serving acid neutralization. An important difference between them is that while pancreatic juice and saliva are delivered into a lumen where they can be collected and analyzed, ameloblasts produce locally precipitating hydroxyapatite which cannot be easily studied. Interestingly, the ion and protein secretion by the pancreas, the salivary glands, and maturation ameloblasts are all two-step processes, of course with significant differences too. As they all have to defend against acid exposure by producing extremely large quantities of bicarbonate, the failure of this function leads to deteriorating consequences. The aim of the present review is to describe and characterize the defense mechanisms of the pancreas, the salivary glands and enamel-producing ameloblasts against acid exposure and to compare their functional capabilities to do this by producing bicarbonate.
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Affiliation(s)
- Robert Racz
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | - Akos Nagy
- Department of Dentistry, Oral and Maxillofacial Surgery, University of Pecs, Pecs, Hungary
| | - Zoltan Rakonczay
- Department of Pathophysiology, University of Szeged, Szeged, Hungary
| | - Erika Katalin Dunavari
- Department of Dentistry, Oral and Maxillofacial Surgery, University of Pecs, Pecs, Hungary
| | - Gabor Gerber
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
| | - Gabor Varga
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
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30
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Kim YJ, Seymen F, Kang J, Koruyucu M, Tuloglu N, Bayrak S, Tuna EB, Lee ZH, Shin TJ, Hyun HK, Kim YJ, Lee SH, Hu J, Simmer J, Kim JW. Candidate gene sequencing reveals mutations causing hypoplastic amelogenesis imperfecta. Clin Oral Investig 2019; 23:1481-1487. [PMID: 30120606 PMCID: PMC6378126 DOI: 10.1007/s00784-018-2577-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 08/14/2018] [Indexed: 01/28/2023]
Abstract
OBJECTIVE Amelogenesis imperfecta (AI) is a rare hereditary disorder affecting the quality and quantity of the tooth enamel. The purpose of this study was to identify the genetic etiology of hypoplastic AI families based on the candidate gene approach. MATERIALS AND METHODS We recruited three Turkish families with hypoplastic AI and performed a candidate gene screening based on the characteristic clinical feature to find the pathogenic genetic etiology. RESULTS The candidate gene sequencing of the LAMB3 gene for family 1 revealed a heterozygous nonsense mutation in the last exon [c.3431C > A, p.(Ser1144*)]. FAM20A gene sequencing for families 2 and 3 identified a homozygous deletion [c.34_35delCT, p.(Leu12Alafs*67)] and a homozygous deletion-insertion (c.1109 + 3_1109 + 7delinsTGGTC) mutation, respectively. CONCLUSION The candidate gene approach can be successfully used to identify the genetic etiology of the AI in some cases with characteristic clinical features. CLINICAL RELEVANCE Identification of the genetic etiology of the AI will help both the family members and dentist understand the nature of the disorder. Characteristic clinical feature can suggest possible genetic causes.
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Affiliation(s)
- Youn Jung Kim
- Department of Molecular Genetics & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, South Korea
| | - Figen Seymen
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul, Turkey
| | - Jenny Kang
- Department of Pediatric Dentistry & Dental Research Institute, School of Dentistry, Seoul National University, 275-1 Yongon-dong, Seoul, Chongno-gu, 110-768, South Korea
| | - Mine Koruyucu
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul, Turkey
| | - Nuray Tuloglu
- Department of Pedodontics, Faculty of Dentistry, Eskisehir Osmangazi University, Eskisehir, Turkey
| | - Sule Bayrak
- Department of Pedodontics, Faculty of Dentistry, Eskisehir Osmangazi University, Eskisehir, Turkey
| | - Elif Bahar Tuna
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul, Turkey
| | - Zang Hee Lee
- Department of Cell and Developmental Biology & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, South Korea
| | - Teo Jeon Shin
- Department of Pediatric Dentistry & Dental Research Institute, School of Dentistry, Seoul National University, 275-1 Yongon-dong, Seoul, Chongno-gu, 110-768, South Korea
| | - Hong-Keun Hyun
- Department of Pediatric Dentistry & Dental Research Institute, School of Dentistry, Seoul National University, 275-1 Yongon-dong, Seoul, Chongno-gu, 110-768, South Korea
| | - Young-Jae Kim
- Department of Pediatric Dentistry & Dental Research Institute, School of Dentistry, Seoul National University, 275-1 Yongon-dong, Seoul, Chongno-gu, 110-768, South Korea
| | - Sang-Hoon Lee
- Department of Pediatric Dentistry & Dental Research Institute, School of Dentistry, Seoul National University, 275-1 Yongon-dong, Seoul, Chongno-gu, 110-768, South Korea
| | - Jan Hu
- Department of Biologic and Materials Sciences, University of Michigan Dental Research Lab, 1210 Eisenhower Place, Ann Arbor, MI, 48108, USA
| | - James Simmer
- Department of Biologic and Materials Sciences, University of Michigan Dental Research Lab, 1210 Eisenhower Place, Ann Arbor, MI, 48108, USA
| | - Jung-Wook Kim
- Department of Molecular Genetics & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, South Korea.
- Department of Pediatric Dentistry & Dental Research Institute, School of Dentistry, Seoul National University, 275-1 Yongon-dong, Seoul, Chongno-gu, 110-768, South Korea.
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31
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Yang Q, Chen K, Zhang H, Zhang W, Gong C, Zhang Q, Liu P, Sun T, Xu Y, Qian X, Qiu W, Ma C. Correlations Between Single Nucleotide Polymorphisms, Cognitive Dysfunction, and Postmortem Brain Pathology in Alzheimer's Disease Among Han Chinese. Neurosci Bull 2019; 35:193-204. [PMID: 30783964 DOI: 10.1007/s12264-019-00343-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 11/01/2018] [Indexed: 12/14/2022] Open
Abstract
In this study, the distribution of five Alzheimer's disease (AD)-related single nucleotide polymorphisms (SNPs) in the Han population was examined in combination with the evaluation of clinical cognition and brain pathological analysis. The associations among SNPs, clinical daily cognitive states, and postmortem neuropathological changes were analyzed in 110 human brains from the Chinese Academy of Medical Sciences/Peking Union Medical College (CAMS/PUMC) Human Brain Bank. APOE ε4 (OR = 4.482, P = 0.004), the RS2305421 GG genotype (adjusted OR = 4.397, P = 0.015), and the RS10498633 GT genotype (adjusted OR = 2.375, P = 0.028) were associated with a higher score on the ABC (Aβ plaque score, Braak NFT stage, and CERAD neuritic plaque score) dementia scale. These results advance our understanding of the pathogenesis of AD, the relationship between pathological diagnosis and clinical diagnosis, and the SNPs in the Han population for future research.
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Affiliation(s)
- Qian Yang
- Institute of Basic Medical Sciences, Department of Human Anatomy, Histology and Embryology, Neuroscience Center, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China.,Joint Laboratory of Anesthesia and Pain, Peking Union Medical College, Beijing, 100005, China
| | - Kang Chen
- Joint Laboratory of Anesthesia and Pain, Peking Union Medical College, Beijing, 100005, China.,Eight-Year MD Program, Peking Union Medical College, Beijing, 100730, China
| | - Hanlin Zhang
- Joint Laboratory of Anesthesia and Pain, Peking Union Medical College, Beijing, 100005, China.,Eight-Year MD Program, Peking Union Medical College, Beijing, 100730, China
| | - Wanying Zhang
- Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, USA
| | - Changlin Gong
- Joint Laboratory of Anesthesia and Pain, Peking Union Medical College, Beijing, 100005, China.,Eight-Year MD Program, Peking Union Medical College, Beijing, 100730, China
| | - Qing Zhang
- Institute of Basic Medical Sciences, Department of Human Anatomy, Histology and Embryology, Neuroscience Center, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China.,Joint Laboratory of Anesthesia and Pain, Peking Union Medical College, Beijing, 100005, China
| | - Pan Liu
- Institute of Basic Medical Sciences, Department of Human Anatomy, Histology and Embryology, Neuroscience Center, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China.,Joint Laboratory of Anesthesia and Pain, Peking Union Medical College, Beijing, 100005, China
| | - Tianyi Sun
- Institute of Basic Medical Sciences, Department of Human Anatomy, Histology and Embryology, Neuroscience Center, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China.,Joint Laboratory of Anesthesia and Pain, Peking Union Medical College, Beijing, 100005, China
| | - Yuanyuan Xu
- National Experimental Teaching Demonstration Center of Basic Medicine, Peking Union Medical College, Beijing, 100005, China
| | - Xiaojing Qian
- Institute of Basic Medical Sciences, Department of Human Anatomy, Histology and Embryology, Neuroscience Center, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China
| | - Wenying Qiu
- Institute of Basic Medical Sciences, Department of Human Anatomy, Histology and Embryology, Neuroscience Center, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China.
| | - Chao Ma
- Institute of Basic Medical Sciences, Department of Human Anatomy, Histology and Embryology, Neuroscience Center, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China.
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Daneshmandpour Y, Darvish H, Pashazadeh F, Emamalizadeh B. Features, genetics and their correlation in Jalili syndrome: a systematic review. J Med Genet 2019; 56:358-369. [DOI: 10.1136/jmedgenet-2018-105716] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 01/02/2019] [Accepted: 01/09/2019] [Indexed: 11/03/2022]
Abstract
Jalili syndrome is a rare genetic disorder first identified by Jalili in Gaza. Amelogenesis imperfecta and cone-rode dystrophy are simultaneously seen in Jalili syndrome patients as the main and primary manifestations. Molecular analysis has revealed that theCNNM4gene is responsible for this rare syndrome. Jalili syndrome has been observed in many countries around the world, especially in the Middle East and North Africa. In the current scoping systematic review we searched electronic databases to find studies related to Jalili syndrome. In this review we summarise the reported clinical symptoms,CNNM4gene and protein structure,CNNM4mutations, attempts to reach a genotype-phenotype correlation, the functional role ofCNNM4mutations, and epidemiological aspects of Jalili syndrome. In addition, we have analysed the reported mutations in mutation effect prediction databases in order to gain a better understanding of the mutation’s outcomes.
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33
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Eckstein M, Lacruz RS. CRAC channels in dental enamel cells. Cell Calcium 2018; 75:14-20. [PMID: 30114531 PMCID: PMC6435299 DOI: 10.1016/j.ceca.2018.07.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 07/31/2018] [Accepted: 07/31/2018] [Indexed: 01/09/2023]
Abstract
Enamel mineralization relies on Ca2+ availability provided by Ca2+ release activated Ca2+ (CRAC) channels. CRAC channels are modulated by the endoplasmic reticulum Ca2+ sensor STIM1 which gates the pore subunit of the channel known as ORAI1, found the in plasma membrane, to enable sustained Ca2+ influx. Mutations in the STIM1 and ORAI1 genes result in CRAC channelopathy, an ensemble of diseases including immunodeficiency, muscular hypotonia, ectodermal dysplasia with defects in sweat gland function and abnormal enamel mineralization similar to amelogenesis imperfecta (AI). In some reports, the chief medical complain has been the patient's dental health, highlighting the direct and important link between CRAC channels and enamel. The reported enamel defects are apparent in both the deciduous and in permanent teeth and often require extensive dental treatment to provide the patient with a functional dentition. Among the dental phenotypes observed in the patients, discoloration, increased wear, hypoplasias (thinning of enamel) and chipping has been reported. These findings are not universal in all patients. Here we review the mutations in STIM1 and ORAI1 causing AI-like phenotype, and evaluate the enamel defects in CRAC channel deficient mice. We also provide a brief overview of the role of CRAC channels in other mineralizing systems such as dentine and bone.
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Affiliation(s)
- M Eckstein
- Dept. Basic Science and Craniofacial Biology, New York University College of Dentistry, 345 East 24th Street, New York 10010, USA
| | - R S Lacruz
- Dept. Basic Science and Craniofacial Biology, New York University College of Dentistry, 345 East 24th Street, New York 10010, USA.
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34
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Lu T, Li M, Xu X, Xiong J, Huang C, Zhang X, Hu A, Peng L, Cai D, Zhang L, Wu B, Xiong F. Whole exome sequencing identifies an AMBN missense mutation causing severe autosomal-dominant amelogenesis imperfecta and dentin disorders. Int J Oral Sci 2018; 10:26. [PMID: 30174330 PMCID: PMC6119682 DOI: 10.1038/s41368-018-0027-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 05/15/2018] [Accepted: 05/18/2018] [Indexed: 11/25/2022] Open
Abstract
Tooth development is a complex process that involves precise and time-dependent orchestration of multiple genetic, molecular, and cellular interactions. Ameloblastin (AMBN, also named “amelin” or “sheathlin”) is the second most abundant enamel matrix protein known to have a key role in amelogenesis. Amelogenesis imperfecta (AI [MIM: 104500]) refers to a genetically and phenotypically heterogeneous group of conditions characterized by inherited developmental enamel defects. The hereditary dentin disorders comprise a variety of autosomal-dominant genetic symptoms characterized by abnormal dentin structure affecting either the primary or both the primary and secondary teeth. The vital role of Ambn in amelogenesis has been confirmed experimentally using mouse models. Only two cases have been reported of mutations of AMBN associated with non-syndromic human AI. However, no AMBN missense mutations have been reported to be associated with both human AI and dentin disorders. We recruited one kindred with autosomal-dominant amelogenesis imperfecta (ADAI) and dentinogenesis imperfecta/dysplasia characterized by generalized severe enamel and dentin defects. Whole exome sequencing of the proband identified a novel heterozygous C-T point mutation at nucleotide position 1069 of the AMBN gene, causing a Pro to Ser mutation at the conserved amino acid position 357 of the protein. Exfoliated third molar teeth from the affected family members were found to have enamel and dentin of lower mineral density than control teeth, with thinner and easily fractured enamel, short and thick roots, and pulp obliteration. This study demonstrates, for the first time, that an AMBN missense mutation causes non-syndromic human AI and dentin disorders. A mutation on a gene involved in healthy tooth development may cause both enamel and dentin disorders. The ameloblastin enamel protein, and its associated gene, AMBN, play vital roles in enamel formation and tooth remodelling. Mutations on AMBN can cause amelogenesis imperfecta (AI), a genetic and hereditory condition resulting in enamel defects and severe tooth decay. Now, Fu Xiong and Bu-Ling Wu at Southern Medical University in Guangzhou, China, and co-workers have identified an AMBN mutation found in both enamel and dentin defect disorders. The researchers analyzed extracted teeth from a Chinese patient with both AI and a severe dentin disorder, along with teeth from affected and non-affected members of the same family, and compared the results with a control group. They identified a rare mutation on AMBN common to all affected individuals.
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Affiliation(s)
- Ting Lu
- Department of Stomatology, Nanfang Hospital, College of Stomatology, Southern Medical University, Guangzhou, Guangdong, China.,Department of Medical Genetics, School of Basic Medicine Sciences, Southern Medical University, Guangzhou, Guangdong, China
| | - Meiyi Li
- Department of Medical Genetics, School of Basic Medicine Sciences, Southern Medical University, Guangzhou, Guangdong, China
| | - Xiangmin Xu
- Department of Medical Genetics, School of Basic Medicine Sciences, Southern Medical University, Guangzhou, Guangdong, China.,Guangdong Key Laboratory of Biological Chip, Guangzhou, Guangdong, China
| | - Jun Xiong
- Department of Laboratory Medicine, ZhuJiang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Cheng Huang
- Department of Medical Genetics, School of Basic Medicine Sciences, Southern Medical University, Guangzhou, Guangdong, China
| | - Xuelian Zhang
- Department of Medical Genetics, School of Basic Medicine Sciences, Southern Medical University, Guangzhou, Guangdong, China
| | - Aiqin Hu
- Department of Medical Genetics, School of Basic Medicine Sciences, Southern Medical University, Guangzhou, Guangdong, China
| | - Ling Peng
- Department of Stomatology, Nanfang Hospital, College of Stomatology, Southern Medical University, Guangzhou, Guangdong, China
| | - Decheng Cai
- Department of Medical Genetics, School of Basic Medicine Sciences, Southern Medical University, Guangzhou, Guangdong, China
| | - Leitao Zhang
- Department of Stomatology, Nanfang Hospital, College of Stomatology, Southern Medical University, Guangzhou, Guangdong, China
| | - Buling Wu
- Department of Stomatology, Nanfang Hospital, College of Stomatology, Southern Medical University, Guangzhou, Guangdong, China.
| | - Fu Xiong
- Department of Medical Genetics, School of Basic Medicine Sciences, Southern Medical University, Guangzhou, Guangdong, China. .,Guangdong Key Laboratory of Biological Chip, Guangzhou, Guangdong, China.
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35
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Jalloul AH, Liu G, Szerencsei RT, Schnetkamp PP. Residues important for Ca2+ ion transport in the neuronal K+-dependent Na+-Ca2+ exchanger (NCKX2). Cell Calcium 2018; 74:187-197. [DOI: 10.1016/j.ceca.2018.06.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Revised: 06/07/2018] [Accepted: 06/14/2018] [Indexed: 12/18/2022]
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36
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Koruyucu M, Kang J, Kim Y, Seymen F, Kasimoglu Y, Lee Z, Shin T, Hyun H, Kim Y, Lee S, Hu J, Simmer J, Kim J. Hypoplastic AI with Highly Variable Expressivity Caused by ENAM Mutations. J Dent Res 2018; 97:1064-1069. [PMID: 29554435 PMCID: PMC6055254 DOI: 10.1177/0022034518763152] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Tooth enamel, the hardest tissue in the human body, is formed after a complex series of interactions between dental epithelial tissue and the underlying ectomesenchyme. Nonsyndromic amelogenesis imperfecta (AI) is a rare genetic disorder affecting tooth enamel without other nonoral symptoms. In this study, we identified 2 novel ENAM mutations in 2 families with hypoplastic AI by whole exome sequencing. Family 1 had a heterozygous splicing donor site mutation in intron 4, NM_031889; c.123+2T>G. Affected individuals had hypoplastic enamel with or without the characteristic horizontal hypoplastic grooves in some teeth. Family 2 had a nonsense mutation in the last exon, c.1842C>G, p.(Tyr614*), that was predicted to truncate the protein by 500 amino acids. Participating individuals had at least 1 mutant allele, while the proband had a homozygous mutation. Most interestingly, the clinical phenotype of the individuals harboring the heterozygous mutation varied from a lack of penetrance to a mild hypoplastic enamel defect. We believe that these findings will broaden our understanding of the clinical phenotype of AI caused by ENAM mutations.
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Affiliation(s)
- M. Koruyucu
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul, Turkey
| | - J. Kang
- Department of Pediatric Dentistry and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - Y.J. Kim
- Department of Molecular Genetics and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - F. Seymen
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul, Turkey
| | - Y. Kasimoglu
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul, Turkey
| | - Z.H. Lee
- Department of Cell and Developmental Biology and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - T.J. Shin
- Department of Pediatric Dentistry and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - H.K. Hyun
- Department of Pediatric Dentistry and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - Y.J. Kim
- Department of Pediatric Dentistry and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - S.H. Lee
- Department of Pediatric Dentistry and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - J.C.C. Hu
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| | - J.P. Simmer
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| | - J.W. Kim
- Department of Pediatric Dentistry and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
- Department of Molecular Genetics and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
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37
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Eckstein M, Aulestia FJ, Nurbaeva MK, Lacruz RS. Altered Ca 2+ signaling in enamelopathies. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1865:1778-1785. [PMID: 29750989 DOI: 10.1016/j.bbamcr.2018.04.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 04/26/2018] [Accepted: 04/30/2018] [Indexed: 10/16/2022]
Abstract
Biomineralization requires the controlled movement of ions across cell barriers to reach the sites of crystal growth. Mineral precipitation occurs in aqueous phases as fluids become supersaturated with specific ionic compositions. In the biological world, biomineralization is dominated by the presence of calcium (Ca2+) in crystal lattices. Ca2+ channels are intrinsic modulators of this process, facilitating the availability of Ca2+ within cells in a tightly regulated manner in time and space. Unequivocally, the most mineralized tissue produced by vertebrates, past and present, is dental enamel. With some of the longest carbonated hydroxyapatite (Hap) crystals known, dental enamel formation is fully coordinated by specialized epithelial cells of ectodermal origin known as ameloblasts. These cells form enamel in two main developmental stages: a) secretory; and b) maturation. The secretory stage is marked by volumetric growth of the tissue with limited mineralization, and the opposite is found in the maturation stage, as enamel crystals expand in width concomitant with increased ion transport. Disruptions in the formation and/or mineralization stages result, in most cases, in permanent alterations in the crystal assembly. This introduces weaknesses in the material properties affecting enamel's hardness and durability, thus limiting its efficacy as a biting, chewing tool and increasing the possibility of pathology. Here, we briefly review enamel development and discuss key properties of ameloblasts and their Ca2+-handling machinery, and how alterations in this toolkit result in enamelopathies.
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Affiliation(s)
- Miriam Eckstein
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, United States
| | - Francisco J Aulestia
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, United States
| | - Meerim K Nurbaeva
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, United States
| | - Rodrigo S Lacruz
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, United States.
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38
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Koruyucu M, Seymen F, Gencay G, Gencay K, Tuna E, Shin T, Hyun HK, Kim YJ, Kim JW. Nephrocalcinosis in Amelogenesis Imperfecta Caused by the FAM20A Mutation. Nephron Clin Pract 2018; 139:189-196. [DOI: 10.1159/000486607] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 12/27/2017] [Indexed: 01/03/2023] Open
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39
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Emerling CA, Widjaja AD, Nguyen NN, Springer MS. Their loss is our gain: regressive evolution in vertebrates provides genomic models for uncovering human disease loci. J Med Genet 2017; 54:787-794. [PMID: 28814606 DOI: 10.1136/jmedgenet-2017-104837] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Revised: 07/07/2017] [Accepted: 07/10/2017] [Indexed: 12/20/2022]
Abstract
Throughout Earth's history, evolution's numerous natural 'experiments' have resulted in a diverse range of phenotypes. Though de novo phenotypes receive widespread attention, degeneration of traits inherited from an ancestor is a very common, yet frequently neglected, evolutionary path. The latter phenomenon, known as regressive evolution, often results in vertebrates with phenotypes that mimic inherited disease states in humans. Regressive evolution of anatomical and/or physiological traits is typically accompanied by inactivating mutations underlying these traits, which frequently occur at loci identical to those implicated in human diseases. Here we discuss the potential utility of examining the genomes of vertebrates that have experienced regressive evolution to inform human medical genetics. This approach is low cost and high throughput, giving it the potential to rapidly improve knowledge of disease genetics. We discuss two well-described examples, rod monochromacy (congenital achromatopsia) and amelogenesis imperfecta, to demonstrate the utility of this approach, and then suggest methods to equip non-experts with the ability to corroborate candidate genes and uncover new disease loci.
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Affiliation(s)
- Christopher A Emerling
- Museum of Vertebrate Zoology, University of California, Berkeley, California, USA
- Department of Biology, University of California, Riverside, California, USA
| | - Andrew D Widjaja
- Department of Biochemistry, University of California, Riverside, California, USA
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, California, USA
| | - Nancy N Nguyen
- Department of Bioengineering, University of California, Riverside, California, USA
- Department of Bioengineering, University of California, Los Angeles, California, USA
| | - Mark S Springer
- Department of Biology, University of California, Riverside, California, USA
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40
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Pedersen NC, Shope B, Liu H. An autosomal recessive mutation in SCL24A4 causing enamel hypoplasia in Samoyed and its relationship to breed-wide genetic diversity. Canine Genet Epidemiol 2017; 4:11. [PMID: 29201383 PMCID: PMC5699110 DOI: 10.1186/s40575-017-0049-1] [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: 04/26/2017] [Accepted: 09/17/2017] [Indexed: 01/29/2023] Open
Abstract
Background Pure breeding of dogs has led to over 700 heritable disorders, of which almost 300 are Mendelian in nature. Seventy percent of the characterized mutations have an autosomal recessive mode of inheritance, indicative of positive selection during bouts of inbreeding primarily for new desired conformational traits. Samoyed suffer from several common complex genetic disorders, but up to this time only two X-linked and one autosomal dominant disorder have been identified. Previous studies based on pedigrees and SNP arrays have concluded that Samoyed breeders have done a good job in maintaining genetic diversity and avoiding excessive inbreeding. This may explain why autosomal recessive disorders have not occurred to the extent observed in many other breeds. However, an enamel hypoplasia analogous to a form of autosomal recessive amelogenesis imperfecta (ARAI) in humans has been recently characterized in Samoyed, although the causative mutation appears to have existed for three or more decades. The rise of such a mutation indicates that bouts of inbreeding for desired conformational traits are still occurring despite an old and well-defined breed standard. Therefore, the present study has two objectives: 1) measure genetic diversity in the breed using DNA and short tandem repeats (STR), and 2) identify the exact mutation responsible for enamel hypoplasia in the breed, possible explanations for its recent spread, and the effect of eliminating the mutation on existing genetic diversity. Results The recent discovery of an autosomal recessive amelogenesis imperfecta (ARAI) in Samoyed provides an opportunity to study the mutation as well as genetic factors that favored its occurrence and subsequent spread. The first step in the study was to use 33 short tandem repeat (STR) loci on 25/38 autosomes and seven STRs across the dog leukocyte antigen (DLA) class I and II regions on CFA12 to determine the DNA-based genetic profile of 182 individuals from North America, Europe and Australia. Samoyed from the three continents constituted a single breed with only slight genetic differences. Breed-wide genetic diversity was low, most likely from a small founder population and subsequent artificial genetic bottlenecks. Two alleles at each autosome locus occurred in 70–95% of the dogs and 54% of alleles were homozygous. The number of DLA class I and II haplotypes was also low and three class I and two class II haplotypes occurred in 80–90% of individuals. Therefore, most Samoyed belong to two lines, with most dogs possessing a minority of existing genetic diversity and a minority of dogs containing a majority of diversity. Although contemporary Samoyed lack genetic diversity, the bulk of parents are as unrelated as possible with smaller subpopulations either more inbred or outbred than the total population. A familial disorder manifested by hypocalcification of enamel has been recently identified. A genome wide association study (GWAS) on seven affected and five unrelated healthy dogs pointed to a region of extended homozygosity on Canis familiaris autosome 8 (CFA8). The region contained a gene in the solute carrier 24 family (SCL24A4) that encodes a protein involved in potassium dependent sodium/calcium exchange and transport. Mutations in this gene were recently found to cause a similar type of enamel hypoplasia in people. Sequencing of this candidate gene revealed a 21 bp duplication in exon 17. A test for the duplication was in concordance with the disease phenotype. The exact incidence of affected dogs is unknown, but 12% of the 168 healthy dogs tested were heterozygous for the mutation. This population was biased toward close relatives, so a liberal estimate of the incidence of affected dogs in the breed would be around 3.6/1000. Theoretical calculations based on the comparison of the whole population with a population devoid of carriers indicated that eliminating the trait would not affect existing genetic diversity at this time. Conclusions The contemporary Samoyed, like many other breeds, has retained only a small portion of the genetic diversity that exists among all dogs. This limited genetic diversity along with positive genetic selection for desirable traits has led to at least three simple non-recessive genetic disorders and a low incidence of complex genetic traits such as autoimmune disease and hip dysplasia. Unlike many other pure breeds, the Samoyed has been spared the spate of deleterious autosomal recessive traits that have plagued many other pure breeds. However, ARAI due to a mutation in the SCL24A4 gene has apparently existed in the breed for several decades but is being increasingly diagnosed. The increase in diseased dogs is most likely due to a period of intensified positive selection for some desired conformational trait. A genetic test has been developed for identifying the mutation carriers which will enable the breeders to eliminate enamel hypoplasia in Samoyed by selective breeding and it appears that this mutation can be eliminated now without loss of genetic diversity.
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Affiliation(s)
- Niels C Pedersen
- Center for Companion Animal Health, University of California, One Shields Avenue, Davis, CA 95616 USA
| | - Bonnie Shope
- Veterinary Dental Services, LLC, 530 Massachusetts Ave, Boxborough, MA 01719 USA
| | - Hongwei Liu
- Department of Veterinary Pathology, Microbiology and Immunology, University of California, One Shields Avenue, Davis, CA 65616 USA
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Jalali R, Lodder JC, Zandieh-Doulabi B, Micha D, Melvin JE, Catalan MA, Mansvelder HD, DenBesten P, Bronckers A. The Role of Na:K:2Cl Cotransporter 1 (NKCC1/SLC12A2) in Dental Epithelium during Enamel Formation in Mice. Front Physiol 2017; 8:924. [PMID: 29209227 PMCID: PMC5702478 DOI: 10.3389/fphys.2017.00924] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 10/31/2017] [Indexed: 12/21/2022] Open
Abstract
Na+:K+:2Cl− cotransporters (NKCCs) belong to the SLC12A family of cation-coupled Cl− transporters. We investigated whether enamel-producing mouse ameloblasts express NKCCs. Transcripts for Nkcc1 were identified in the mouse dental epithelium by RT-qPCR and NKCC1 protein was immunolocalized in outer enamel epithelium and in the papillary layer but not the ameloblast layer. In incisors of Nkcc1-null mice late maturation ameloblasts were disorganized, shorter and the mineral density of the enamel was reduced by 10% compared to wild-type controls. Protein levels of gap junction protein connexin 43, Na+-dependent bicarbonate cotransporter e1 (NBCe1), and the Cl−-dependent bicarbonate exchangers SLC26A3 and SLC26A6 were upregulated in Nkcc1-null enamel organs while the level of NCKX4/SLC24A4, the major K+, Na+ dependent Ca2+ transporter in maturation ameloblasts, was slightly downregulated. Whole-cell voltage clamp studies on rat ameloblast-like HAT-7 cells indicated that bumetanide increased ion-channel activity conducting outward currents. Bumetanide also reduced cell volume of HAT-7 cells. We concluded that non-ameloblast dental epithelium expresses NKCC1 to regulate cell volume in enamel organ and provide ameloblasts with Na+, K+ and Cl− ions required for the transport of mineral- and bicarbonate-ions into enamel. Absence of functional Nkcc1 likely is compensated by other types of ion channels and ion transporters. The increased amount of Cx43 in enamel organ cells in Nkcc1-null mice suggests that these cells display a higher number of gap junctions to increase intercellular communication.
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Affiliation(s)
- Rozita Jalali
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam Movement Sciences, University of Amsterdam, VU University Amsterdam, Amsterdam, Netherlands.,Department of Functional Anatomy, Academic Centre for Dentistry Amsterdam (ACTA), MOVE Research Institute Amsterdam, University of Amsterdam, VU University Amsterdam, Amsterdam, Netherlands
| | - Johannes C Lodder
- Department Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, Netherlands
| | - Behrouz Zandieh-Doulabi
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam Movement Sciences, University of Amsterdam, VU University Amsterdam, Amsterdam, Netherlands
| | - Dimitra Micha
- Department of Clinical Genetics, VU University Medical Center, Amsterdam Movement Sciences, Netherlands
| | - James E Melvin
- Secretory Mechanisms and Dysfunction Section, NIDCR/NIH, Bethesda, MD, United States
| | - Marcelo A Catalan
- Secretory Mechanisms and Dysfunction Section, NIDCR/NIH, Bethesda, MD, United States.,Departamento de Ciencias Químicas y Farmaceúticas, Facultad de Ciencias de la Salud, Universidad Arturo Prat, Iquique, Chile
| | - Huibert D Mansvelder
- Department Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, Netherlands
| | - Pamela DenBesten
- Department of Orofacial Sciences, School of Dentistry, University of California, San Francisco, San Francisco, CA, United States
| | - Antonius Bronckers
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam Movement Sciences, University of Amsterdam, VU University Amsterdam, Amsterdam, Netherlands
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Brookes SJ, Barron MJ, Smith CEL, Poulter JA, Mighell AJ, Inglehearn CF, Brown CJ, Rodd H, Kirkham J, Dixon MJ. Amelogenesis imperfecta caused by N-terminal enamelin point mutations in mice and men is driven by endoplasmic reticulum stress. Hum Mol Genet 2017; 26:1863-1876. [PMID: 28334996 PMCID: PMC5411757 DOI: 10.1093/hmg/ddx090] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 03/02/2017] [Indexed: 12/30/2022] Open
Abstract
‘Amelogenesis imperfecta’ (AI) describes a group of inherited diseases of dental enamel that have major clinical impact. Here, we identify the aetiology driving AI in mice carrying a p.S55I mutation in enamelin; one of the most commonly mutated proteins underlying AI in humans. Our data indicate that the mutation inhibits the ameloblast secretory pathway leading to ER stress and an activated unfolded protein response (UPR). Initially, with the support of the UPR acting in pro-survival mode, Enamp.S55I heterozygous mice secreted structurally normal enamel. However, enamel secreted thereafter was structurally abnormal; presumably due to the UPR modulating ameloblast behaviour and function in an attempt to relieve ER stress. Homozygous mutant mice failed to produce enamel. We also identified a novel heterozygous ENAMp.L31R mutation causing AI in humans. We hypothesize that ER stress is the aetiological factor in this case of human AI as it shared the characteristic phenotype described above for the Enamp.S55I mouse. We previously demonstrated that AI in mice carrying the Amelxp.Y64H mutation is a proteinopathy. The current data indicate that AI in Enamp.S55I mice is also a proteinopathy, and based on comparative phenotypic analysis, we suggest that human AI resulting from the ENAMp.L31R mutation is another proteinopathic disease. Identifying a common aetiology for AI resulting from mutations in two different genes opens the way for developing pharmaceutical interventions designed to relieve ER stress or modulate the UPR during enamel development to ameliorate the clinical phenotype.
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Affiliation(s)
- Steven J Brookes
- Department of Oral Biology, School of Dentistry, Wellcome Trust Brenner Building University Of Leeds, St James's University Hospital, Leeds LS9 7TF, UK
| | - Martin J Barron
- Faculty of Biology, Medicine & Health, Manchester Academic Health Sciences Centre, University of Manchester, Michael Smith Building, Manchester M13 9PT, UK
| | - Claire E L Smith
- Department of Oral Medicine, School of Dentistry, University of Leeds, Leeds, UK
| | - James A Poulter
- Department of Oral Medicine, School of Dentistry, University of Leeds, Leeds, UK
| | - Alan J Mighell
- Leeds Institute of Biomedical and Clinical Sciences, St James's University Hospital, University of Leeds, Leeds LS9 7TF, UK
| | - Chris F Inglehearn
- Department of Oral Medicine, School of Dentistry, University of Leeds, Leeds, UK
| | - Catriona J Brown
- Birmingham Dental Hospital and School of Dentistry, Birmingham B5 7EG, UK
| | - Helen Rodd
- Unit of Oral Health and Development, School of Clinical Dentistry, University of Sheffield, Sheffield, UK
| | - Jennifer Kirkham
- Department of Oral Biology, School of Dentistry, Wellcome Trust Brenner Building University Of Leeds, St James's University Hospital, Leeds LS9 7TF, UK
| | - Michael J Dixon
- Faculty of Biology, Medicine & Health, Manchester Academic Health Sciences Centre, University of Manchester, Michael Smith Building, Manchester M13 9PT, UK
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43
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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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44
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Huang W, Yang M, Wang C, Song Y. Evolutionary analysis of FAM83H in vertebrates. PLoS One 2017; 12:e0180360. [PMID: 28683132 PMCID: PMC5500323 DOI: 10.1371/journal.pone.0180360] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 06/14/2017] [Indexed: 01/08/2023] Open
Abstract
Amelogenesis imperfecta is a group of disorders causing abnormalities in enamel formation in various phenotypes. Many mutations in the FAM83H gene have been identified to result in autosomal dominant hypocalcified amelogenesis imperfecta in different populations. However, the structure and function of FAM83H and its pathological mechanism have yet to be further explored. Evolutionary analysis is an alternative for revealing residues or motifs that are important for protein function. In the present study, we chose 50 vertebrate species in public databases representative of approximately 230 million years of evolution, including 1 amphibian, 2 fishes, 7 sauropsidas and 40 mammals, and we performed evolutionary analysis on the FAM83H protein. By sequence alignment, conserved residues and motifs were indicated, and the loss of important residues and motifs of five special species (Malayan pangolin, platypus, minke whale, nine-banded armadillo and aardvark) was discovered. A phylogenetic time tree showed the FAM83H divergent process. Positive selection sites in the C-terminus suggested that the C-terminus of FAM83H played certain adaptive roles during evolution. The results confirmed some important motifs reported in previous findings and identified some new highly conserved residues and motifs that need further investigation. The results suggest that the C-terminus of FAM83H contain key conserved regions critical to enamel formation and calcification.
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Affiliation(s)
- Wushuang Huang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Mei Yang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Changning Wang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Yaling Song
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China
- * E-mail:
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45
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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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46
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Smith CEL, Poulter JA, Antanaviciute A, Kirkham J, Brookes SJ, Inglehearn CF, Mighell AJ. Amelogenesis Imperfecta; Genes, Proteins, and Pathways. Front Physiol 2017; 8:435. [PMID: 28694781 PMCID: PMC5483479 DOI: 10.3389/fphys.2017.00435] [Citation(s) in RCA: 157] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 06/08/2017] [Indexed: 01/11/2023] Open
Abstract
Amelogenesis imperfecta (AI) is the name given to a heterogeneous group of conditions characterized by inherited developmental enamel defects. AI enamel is abnormally thin, soft, fragile, pitted and/or badly discolored, with poor function and aesthetics, causing patients problems such as early tooth loss, severe embarrassment, eating difficulties, and pain. It was first described separately from diseases of dentine nearly 80 years ago, but the underlying genetic and mechanistic basis of the condition is only now coming to light. Mutations in the gene AMELX, encoding an extracellular matrix protein secreted by ameloblasts during enamel formation, were first identified as a cause of AI in 1991. Since then, mutations in at least eighteen genes have been shown to cause AI presenting in isolation of other health problems, with many more implicated in syndromic AI. Some of the encoded proteins have well documented roles in amelogenesis, acting as enamel matrix proteins or the proteases that degrade them, cell adhesion molecules or regulators of calcium homeostasis. However, for others, function is less clear and further research is needed to understand the pathways and processes essential for the development of healthy enamel. Here, we review the genes and mutations underlying AI presenting in isolation of other health problems, the proteins they encode and knowledge of their roles in amelogenesis, combining evidence from human phenotypes, inheritance patterns, mouse models, and in vitro studies. An LOVD resource (http://dna2.leeds.ac.uk/LOVD/) containing all published gene mutations for AI presenting in isolation of other health problems is described. We use this resource to identify trends in the genes and mutations reported to cause AI in the 270 families for which molecular diagnoses have been reported by 23rd May 2017. Finally we discuss the potential value of the translation of AI genetics to clinical care with improved patient pathways and speculate on the possibility of novel treatments and prevention strategies for AI.
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Affiliation(s)
- Claire E L Smith
- Division of Oral Biology, School of Dentistry, St. James's University Hospital, University of LeedsLeeds, United Kingdom.,Section of Ophthalmology and Neuroscience, St. James's University Hospital, University of LeedsLeeds, United Kingdom
| | - James A Poulter
- Section of Ophthalmology and Neuroscience, St. James's University Hospital, University of LeedsLeeds, United Kingdom
| | - Agne Antanaviciute
- Section of Genetics, School of Medicine, St. James's University Hospital, University of LeedsLeeds, United Kingdom
| | - Jennifer Kirkham
- Division of Oral Biology, School of Dentistry, St. James's University Hospital, University of LeedsLeeds, United Kingdom
| | - Steven J Brookes
- Division of Oral Biology, School of Dentistry, St. James's University Hospital, University of LeedsLeeds, United Kingdom
| | - Chris F Inglehearn
- Section of Ophthalmology and Neuroscience, St. James's University Hospital, University of LeedsLeeds, United Kingdom
| | - Alan J Mighell
- Section of Ophthalmology and Neuroscience, St. James's University Hospital, University of LeedsLeeds, United Kingdom.,Oral Medicine, School of Dentistry, University of LeedsLeeds, United Kingdom
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47
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Vinberg F, Wang T, De Maria A, Zhao H, Bassnett S, Chen J, Kefalov VJ. The Na +/Ca 2+, K + exchanger NCKX4 is required for efficient cone-mediated vision. eLife 2017; 6:e24550. [PMID: 28650316 PMCID: PMC5515578 DOI: 10.7554/elife.24550] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 06/23/2017] [Indexed: 12/24/2022] Open
Abstract
Calcium (Ca2+) plays an important role in the function and health of neurons. In vertebrate cone photoreceptors, Ca2+ controls photoresponse sensitivity, kinetics, and light adaptation. Despite the critical role of Ca2+ in supporting the function and survival of cones, the mechanism for its extrusion from cone outer segments is not well understood. Here, we show that the Na+/Ca2+, K+ exchanger NCKX4 is expressed in zebrafish, mouse, and primate cones. Functional analysis of NCKX4-deficient mouse cones revealed that this exchanger is essential for the wide operating range and high temporal resolution of cone-mediated vision. We show that NCKX4 shapes the cone photoresponse together with the cone-specific NCKX2: NCKX4 acts early to limit response amplitude, while NCKX2 acts late to further accelerate response recovery. The regulation of Ca2+ by NCKX4 in cones is a novel mechanism that supports their ability to function as daytime photoreceptors and promotes their survival.
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Affiliation(s)
- Frans Vinberg
- Department of Ophthalmology and Visual Sciences, Washington University, St. Louis, United States
| | - Tian Wang
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, United States
- Department of Cell and Neurobiology, Keck School of Medicine, University of Southern California, Los Angeles, United States
- Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, United States
| | - Alicia De Maria
- Department of Ophthalmology and Visual Sciences, Washington University, St. Louis, United States
| | - Haiqing Zhao
- Department of Biology, Johns Hopkins University, Baltimore, United States
| | - Steven Bassnett
- Department of Ophthalmology and Visual Sciences, Washington University, St. Louis, United States
| | - Jeannie Chen
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, United States
- Department of Cell and Neurobiology, Keck School of Medicine, University of Southern California, Los Angeles, United States
- Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, United States
| | - Vladimir J Kefalov
- Department of Ophthalmology and Visual Sciences, Washington University, St. Louis, United States
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48
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Lencer ES, Warren WC, Harrison R, McCune AR. The Cyprinodon variegatus genome reveals gene expression changes underlying differences in skull morphology among closely related species. BMC Genomics 2017; 18:424. [PMID: 28558659 PMCID: PMC5450241 DOI: 10.1186/s12864-017-3810-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 05/22/2017] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Understanding the genetic and developmental origins of phenotypic novelty is central to the study of biological diversity. In this study we identify modifications to the expression of genes at four developmental stages that may underlie jaw morphological differences among three closely related species of pupfish (genus Cyprinodon) from San Salvador Island, Bahamas. Pupfishes on San Salvador Island are trophically differentiated and include two endemic species that have evolved jaw morphologies unlike that of any other species in the genus Cyprinodon. RESULTS We find that gene expression differs significantly across recently diverged species of pupfish. Genes such as Bmp4 and calmodulin, previously implicated in jaw diversification in African cichlid fishes and Galapagos finches, were not found to be differentially expressed among species of pupfish. Instead we find multiple growth factors and cytokine/chemokine genes to be differentially expressed among these pupfish taxa. These include both genes and pathways known to affect craniofacial development, such as Wnt signaling, as well as novel genes and pathways not previously implicated in craniofacial development. These data highlight both shared and potentially unique sources of jaw diversity in pupfish and those identified in other evolutionary model systems such as Galapagos finches and African cichlids. CONCLUSIONS We identify modifications to the expression of genes involved in Wnt signaling, Igf signaling, and the inflammation response as promising avenues for future research. Our project provides insight into the magnitude of gene expression changes contributing to the evolution of morphological novelties, such as jaw structure, in recently diverged pupfish species.
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Affiliation(s)
- Ezra S Lencer
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14850, USA.
| | - Wesley C Warren
- McDonnell Genome Institute, Washington University School of Medicine, St Louis, MO, 63108, USA
| | - Richard Harrison
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14850, USA
| | - Amy R McCune
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14850, USA
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49
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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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Nurbaeva MK, Eckstein M, Feske S, Lacruz RS. Ca 2+ transport and signalling in enamel cells. J Physiol 2017; 595:3015-3039. [PMID: 27510811 PMCID: PMC5430215 DOI: 10.1113/jp272775] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 07/21/2016] [Indexed: 01/02/2023] Open
Abstract
Dental enamel is one of the most remarkable examples of matrix-mediated biomineralization. Enamel crystals form de novo in a rich extracellular environment in a stage-dependent manner producing complex microstructural patterns that are visually stunning. This process is orchestrated by specialized epithelial cells known as ameloblasts which themselves undergo striking morphological changes, switching function from a secretory role to a cell primarily engaged in ionic transport. Ameloblasts are supported by a host of cell types which combined represent the enamel organ. Fully mineralized enamel is the hardest tissue found in vertebrates owing its properties partly to the unique mixture of ionic species represented and their highly organized assembly in the crystal lattice. Among the main elements found in enamel, Ca2+ is the most abundant ion, yet how ameloblasts modulate Ca2+ dynamics remains poorly known. This review describes previously proposed models for passive and active Ca2+ transport, the intracellular Ca2+ buffering systems expressed in ameloblasts and provides an up-dated view of current models concerning Ca2+ influx and extrusion mechanisms, where most of the recent advances have been made. We also advance a new model for Ca2+ transport by the enamel organ.
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Affiliation(s)
- Meerim K. Nurbaeva
- Department of Basic Science and Craniofacial BiologyNew York University College of DentistryNew YorkUSA
| | - Miriam Eckstein
- Department of Basic Science and Craniofacial BiologyNew York University College of DentistryNew YorkUSA
| | - Stefan Feske
- Department of PathologyNew York University School of MedicineNew YorkNY10016USA
| | - Rodrigo S. Lacruz
- Department of Basic Science and Craniofacial BiologyNew York University College of DentistryNew YorkUSA
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