1
|
Yu S, Liu D, Yan C, Yuan C, Zhang C, Zheng S. A novel mutation in GPR68 causes hypomaturation amelogenesis imperfecta. Arch Oral Biol 2024; 164:105991. [PMID: 38761453 DOI: 10.1016/j.archoralbio.2024.105991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Revised: 05/01/2024] [Accepted: 05/03/2024] [Indexed: 05/20/2024]
Abstract
OBJECTIVES To identify the genetic cause of a Chinese family with hypomaturation amelogenesis imperfecta (AI) and to characterize the structure of GPR68 mutated enamel in order to develop a deeper understanding of the role of the GPR68 protein during the intricate process of amelogenesis. DESIGN One Chinese family with generalized hypomaturation AI was recruited. Two of the third molars from the proband were subjected to scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Whole exome sequencing (WES) was performed, and the identified mutation was confirmed by Sanger sequencing. Bioinformatics studies were further conducted to analyze the potential deleterious effects of the mutation. RESULTS The proband presented with a hypomaturation AI phenotype, characterized by fragile and discolored enamel surface. The AI enamel showed prismatic structure, which was sporadically obscured by areas of amorphous material and porous structure. EDX analysis showed the proband's enamel demonstrated a significant decrease in calcium and phosphorus content and a significant increase in oxygen compared with normal enamel. A novel homozygous mutation of G protein-coupled receptor 68 (GPR68) (c .149 T > A, p.Ile50Asn) was identified in the proband. Bioinformatics analysis indicated that the mutation site displayed a high level of evolutionary conservation among species, and the mutation might impact the stability and conformation of the protein. CONCLUSION The novel homozygous GPR68 mutation resulted in hypomaturation AI. We first described the effect of GPR68 mutation on enamel structure. Our results provide new genetic evidence that mutations involved in GPR68 contribute to hypomaturation AI.
Collapse
Affiliation(s)
- Shunlan Yu
- Department of Preventive Dentistry, Peking University School and Hospital of Stomatology & National Center for Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research Center of Oral Biomaterials and Digital Medical Devices & Beijing Key Laboratory of Digital Stomatology & NHC Key Laboratory of Digital Stomatology & NMPA Key Laboratory for Dental Materials, Beijing, PR China
| | - Dandan Liu
- Department of Preventive Dentistry, Peking University School and Hospital of Stomatology & National Center for Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research Center of Oral Biomaterials and Digital Medical Devices & Beijing Key Laboratory of Digital Stomatology & NHC Key Laboratory of Digital Stomatology & NMPA Key Laboratory for Dental Materials, Beijing, PR China
| | - Changqing Yan
- Department of Preventive Dentistry, Peking University School and Hospital of Stomatology & National Center for Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research Center of Oral Biomaterials and Digital Medical Devices & Beijing Key Laboratory of Digital Stomatology & NHC Key Laboratory of Digital Stomatology & NMPA Key Laboratory for Dental Materials, Beijing, PR China
| | - Chao Yuan
- Department of Preventive Dentistry, Peking University School and Hospital of Stomatology & National Center for Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research Center of Oral Biomaterials and Digital Medical Devices & Beijing Key Laboratory of Digital Stomatology & NHC Key Laboratory of Digital Stomatology & NMPA Key Laboratory for Dental Materials, Beijing, PR China
| | - Chenying Zhang
- Department of Preventive Dentistry, Peking University School and Hospital of Stomatology & National Center for Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research Center of Oral Biomaterials and Digital Medical Devices & Beijing Key Laboratory of Digital Stomatology & NHC Key Laboratory of Digital Stomatology & NMPA Key Laboratory for Dental Materials, Beijing, PR China.
| | - Shuguo Zheng
- Department of Preventive Dentistry, Peking University School and Hospital of Stomatology & National Center for Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research Center of Oral Biomaterials and Digital Medical Devices & Beijing Key Laboratory of Digital Stomatology & NHC Key Laboratory of Digital Stomatology & NMPA Key Laboratory for Dental Materials, Beijing, PR China.
| |
Collapse
|
2
|
Hermans F, Hasevoets S, Vankelecom H, Bronckaers A, Lambrichts I. From Pluripotent Stem Cells to Organoids and Bioprinting: Recent Advances in Dental Epithelium and Ameloblast Models to Study Tooth Biology and Regeneration. Stem Cell Rev Rep 2024; 20:1184-1199. [PMID: 38498295 PMCID: PMC11222197 DOI: 10.1007/s12015-024-10702-w] [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] [Accepted: 02/20/2024] [Indexed: 03/20/2024]
Abstract
Ameloblasts are the specialized dental epithelial cell type responsible for enamel formation. Following completion of enamel development in humans, ameloblasts are lost and biological repair or regeneration of enamel is not possible. In the past, in vitro models to study dental epithelium and ameloblast biology were limited to freshly isolated primary cells or immortalized cell lines, both with limited translational potential. In recent years, large strides have been made with the development of induced pluripotent stem cell and organoid models of this essential dental lineage - both enabling modeling of human dental epithelium. Upon induction with several different signaling factors (such as transforming growth factor and bone morphogenetic proteins) these models display elevated expression of ameloblast markers and enamel matrix proteins. The advent of 3D bioprinting, and its potential combination with these advanced cellular tools, is poised to revolutionize the field - and its potential for tissue engineering, regenerative and personalized medicine. As the advancements in these technologies are rapidly evolving, we evaluate the current state-of-the-art regarding in vitro cell culture models of dental epithelium and ameloblast lineage with a particular focus toward their applicability for translational tissue engineering and regenerative/personalized medicine.
Collapse
Affiliation(s)
- Florian Hermans
- Department of Cardiology and Organ Systems (COS), Biomedical Research Institute (BIOMED), Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, 3590, Belgium.
| | - Steffie Hasevoets
- Department of Cardiology and Organ Systems (COS), Biomedical Research Institute (BIOMED), Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, 3590, Belgium
| | - Hugo Vankelecom
- Laboratory of Tissue Plasticity in Health and Disease, Cluster of Stem Cell and Developmental Biology, Department of Development and Regeneration, KU Leuven, Leuven, 3000, Belgium
| | - Annelies Bronckaers
- Department of Cardiology and Organ Systems (COS), Biomedical Research Institute (BIOMED), Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, 3590, Belgium
| | - Ivo Lambrichts
- Department of Cardiology and Organ Systems (COS), Biomedical Research Institute (BIOMED), Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, 3590, Belgium.
| |
Collapse
|
3
|
Reibring CG, El Shahawy M, Hallberg K, Harfe BD, Linde A, Gritli-Linde A. Loss of BMP2 and BMP4 Signaling in the Dental Epithelium Causes Defective Enamel Maturation and Aberrant Development of Ameloblasts. Int J Mol Sci 2022; 23:6095. [PMID: 35682776 PMCID: PMC9180982 DOI: 10.3390/ijms23116095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/18/2022] [Accepted: 05/25/2022] [Indexed: 12/10/2022] Open
Abstract
BMP signaling is crucial for differentiation of secretory ameloblasts, the cells that secrete enamel matrix. However, whether BMP signaling is required for differentiation of maturation-stage ameloblasts (MA), which are instrumental for enamel maturation into hard tissue, is hitherto unknown. To address this, we used an in vivo genetic approach which revealed that combined deactivation of the Bmp2 and Bmp4 genes in the murine dental epithelium causes development of dysmorphic and dysfunctional MA. These fail to exhibit a ruffled apical plasma membrane and to reabsorb enamel matrix proteins, leading to enamel defects mimicking hypomaturation amelogenesis imperfecta. Furthermore, subsets of mutant MA underwent pathological single or collective cell migration away from the ameloblast layer, forming cysts and/or exuberant tumor-like and gland-like structures. Massive apoptosis in the adjacent stratum intermedium and the abnormal cell-cell contacts and cell-matrix adhesion of MA may contribute to this aberrant behavior. The mutant MA also exhibited severely diminished tissue non-specific alkaline phosphatase activity, revealing that this enzyme's activity in MA crucially depends on BMP2 and BMP4 inputs. Our findings show that combined BMP2 and BMP4 signaling is crucial for survival of the stratum intermedium and for proper development and function of MA to ensure normal enamel maturation.
Collapse
Affiliation(s)
- Claes-Göran Reibring
- Department of Oral Biochemistry, Institute of Odontology, Sahlgrenska Academy at the University of Gothenburg, SE-40530 Göteborg, Sweden; (C.-G.R.); (M.E.S.); (K.H.); (A.L.)
| | - Maha El Shahawy
- Department of Oral Biochemistry, Institute of Odontology, Sahlgrenska Academy at the University of Gothenburg, SE-40530 Göteborg, Sweden; (C.-G.R.); (M.E.S.); (K.H.); (A.L.)
- Department of Oral Biology, Faculty of Dentistry, Minia University, Minia 61511, Egypt
| | - Kristina Hallberg
- Department of Oral Biochemistry, Institute of Odontology, Sahlgrenska Academy at the University of Gothenburg, SE-40530 Göteborg, Sweden; (C.-G.R.); (M.E.S.); (K.H.); (A.L.)
| | - Brian D. Harfe
- Department of Molecular Genetics and Microbiology Genetics Institute, College of Medicine, University of Florida, Gainesville, FL 32610, USA;
| | - Anders Linde
- Department of Oral Biochemistry, Institute of Odontology, Sahlgrenska Academy at the University of Gothenburg, SE-40530 Göteborg, Sweden; (C.-G.R.); (M.E.S.); (K.H.); (A.L.)
| | - Amel Gritli-Linde
- Department of Oral Biochemistry, Institute of Odontology, Sahlgrenska Academy at the University of Gothenburg, SE-40530 Göteborg, Sweden; (C.-G.R.); (M.E.S.); (K.H.); (A.L.)
| |
Collapse
|
4
|
Bussaneli DG, Vieira AR, Santos-Pinto L, Restrepo M. Molar-incisor hypomineralisation: an updated view for aetiology 20 years later. Eur Arch Paediatr Dent 2022; 23:193-198. [PMID: 34392496 DOI: 10.1007/s40368-021-00659-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 08/11/2021] [Indexed: 12/16/2022]
Abstract
BACKGROUND The term Molar-Incisor Hypomineralisation (MIH) was introduced in 2001 by Weerheijm, Jälevik and Alaluusua, and describes a defect of systemic origin that affects one to four first permanent molars, often associated with permanent incisors. In the past 20 years, this definition dictated the work regarding MIH prevalence, associated risk factors, association with dental caries, impact on quality of life, and therapeutic options. PURPOSE In this report, we offer an updated and comprehensive view of MIH centred on the patient and the tooth. CONCLUSION MIH today is globally recognized as a potential public health problem and it is not a defect of purely systemic origin but rather a condition with complex aetiology that in some instances may be the result of gene-environmental interactions.
Collapse
Affiliation(s)
- D G Bussaneli
- Department of Morphology, Genetics, Orthodontics and Pediatric Dentistry, São Paulo State University (Unesp), Araraquara School of Dentistry, Araraquara, São Paulo, Brazil
| | - A R Vieira
- Department of Oral Biology, School of Dental Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - L Santos-Pinto
- Department of Morphology, Genetics, Orthodontics and Pediatric Dentistry, São Paulo State University (Unesp), Araraquara School of Dentistry, Araraquara, São Paulo, Brazil
| | - M Restrepo
- Basic and Clinical Research Group in Dentistry, School of Dentistry, CES University, Medellín, Colombia.
| |
Collapse
|
5
|
Ren Q, Pan J, Chen Y, Shen Z, Yang Z, Kwon K, Guo Y, Wang Y, Ji F. Melatonin-Medicated Neural JNK3 Up-Regulation Promotes Ameloblastic Mineralization. Front Cell Dev Biol 2022; 9:749642. [PMID: 35004671 PMCID: PMC8740296 DOI: 10.3389/fcell.2021.749642] [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: 08/12/2021] [Accepted: 11/05/2021] [Indexed: 11/13/2022] Open
Abstract
Introduction: Melatonin, an endogenous neurohormone, modulates the biological circadian rhythms of vertebrates. It functions have been reported in previous stomatological studies as anti-inflammation, antioxidant, osseointegration of dental implants and stimulation to dental pulp stem cells differentiation, but its role in ameloblastic differentiation and mineralization has been rarely studied. Objective: To reveal the effects of melatonin on the mineralization of ameloblast lineage cells (ALCs), and to identify the change in gene expression and the potential mechanism based on ribonucleic acid sequencing (RNA-seq) analysis. Method: ALCs were induced in melatonin-conditioned medium. After 7-days culture, Western blot, real-time PCR, alkaline phosphatase (ALP) activity test, RNA-seq were accordingly used to detect the change in molecular level. After 1-month odontogenic induction in melatonin medium, Alizarin Red-S (ARS) staining showed the changes of mineral nodules. Differentially expressed genes (DEGs), enrichment of functions and signaling pathways analysis based on Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) database were performed. The JNK3 antagonist (JNK3 inhibitor IX, SR3576) and β-arrestin1 (Arrb1) overexpression were applied to confirm the fluctuation of melatonin-medicated JNK3 and Arrb1 expression. Results: In this study, we found out melatonin contributed to the ameloblastic mineralization, from which we can observed the elevated expression of enamel matrix protein, and increased ALP activity and mineralized nodules formation. RNA-seq analysis showed the up-regulation of neural JNK3 and down-regulation of Arrb1 in ALCs. Meanwhile, phosphorylated JNK3 deficiency (phosphorylated JNK3 inhibitor---SR3576 added to culture medium) led to mineralization delay, and Arrb1 overexpression proved Arrb1 takes bridge between melatonin receptors (MTNR) and JNK3 in MAPK signaling pathway.
Collapse
Affiliation(s)
- Qianhui Ren
- Shanghai Key Laboratory of Stomatology, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Department of Orthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
| | - Jing Pan
- Shanghai Key Laboratory of Stomatology, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Department of Orthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
| | - Yunshuo Chen
- State Key Laboratory of Medical Genomics, National Research Center for Translational Medicine at Shanghai, Rui Jin Hospital, Shanghai Institute of Hematology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhecheng Shen
- Shanghai Key Laboratory of Stomatology, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Department of Orthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
| | - Zhao Yang
- Shanghai Key Laboratory of Stomatology, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Department of Orthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
| | - Kubin Kwon
- Shanghai Key Laboratory of Stomatology, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Department of Orthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
| | - Ying Guo
- Shanghai Key Laboratory of Stomatology, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Department of Orthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
| | - Yueying Wang
- State Key Laboratory of Medical Genomics, National Research Center for Translational Medicine at Shanghai, Rui Jin Hospital, Shanghai Institute of Hematology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Fang Ji
- Shanghai Key Laboratory of Stomatology, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Department of Orthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
| |
Collapse
|
6
|
Vagner VD, Korshunov AS, Kuryatnikov KN, Rogachev EA, Belskaya LV, Sarf EA, Maksimenko KA. [The nature of metabolic processes in human dental hard tissues depending on their morphological structure]. STOMATOLOGIIA 2022; 101:7-13. [PMID: 36562360 DOI: 10.17116/stomat20221010617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
THE STUDY OBJECTIVE Was to give a comparative assessment of the movement of enamel and dentin fluid depending on the morphological structure of different sections of human dental hard tissues. MATERIALS AND METHODS The research involved 140 female subjects aged 21-30 years. Sizes, form, surface of enamel-dentin junction, enamel prisms and their crystals in superficial, middle and deep sections, width, tortuosity, facing of dentin tubules of tested teeth were analyzed by scanning electron microscope Jeol JCM-5700 and atomic force microscope NTEGRA Prima. The biochemical study examined the quantitative content of water in the samples of enamel, dentin, enamel-dentin junction by weighing sample weights before and after drying. The data obtained were processed by methods of variation statistics using standard packages Microsoft Excel 2008, Statistica 12.0. RESULTS The enamel-dentine junction of large-fastened type is characterized by zones of dentin integration into enamel at the distance of more than 10 mm, with regular arrangement of enamel prisms and wide dentine tubules of 3.55 to 4.70 μm in diameter; no water content reduction was found. The small-fastened type has less pronounced spots of dentin interference with enamel from 2 to 10 μm, the dentinal tubules are slightly curved with a diameter of 2.90 to 3.60 μm, the water content in dentin is reduced. In microfastened type, a linear structure with interpenetration zones up to 2 μm, enamel prisms slightly ordered, dentin tubules narrowed and curved in diameter from 1.30 to 1.95 μm, water content in enamel and dentin is reduced. CONCLUSION At microfastened type of enamel-dentin junction, chaotic arrangement of enamel prisms and narrow dentin tubules water movement is broken and metabolic processes are reduced that determines high probability of exposure of dental hard tissue diseases.
Collapse
Affiliation(s)
- V D Vagner
- Central Research Institute of Dentistry and Maxillofacial Surgery, Moscow, Russia
| | | | | | | | | | - E A Sarf
- Omsk State Pedagogical University, Omsk, Russia
| | | |
Collapse
|
7
|
Mahdee AF, Ali AH, Gillespie JI. Structural and functional relations between the connective tissue and epithelium of enamel organ and their role during enamel maturation. J Mol Histol 2021; 52:975-989. [PMID: 34100179 DOI: 10.1007/s10735-021-09992-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 06/02/2021] [Indexed: 10/21/2022]
Abstract
The morphological and possible functional interactions between the connective tissue and enamel organ cells were examined during the maturation phase of enamel formation, using immunohistochemical techniques. Decalcified mandibular sections (10 µm) including incisors were used from Wistar rats ages 10-12 weeks. Sections were incubated with one or two primary antibodies targeting cell cytoskeleton (vimentin, α-actin, α-tubulin), dendritic marker (OX6), gap junctions (cx-43), enzymes (nitric-oxide synthase (nos1) and cyclooxygenase (cox1)), and the ion transporters (Na+/H+ exchanger (NHE1) and Na+/Ca2+ exchanger (NCX)) for 24 h, before incubation with the appropriate conjugated fluorescent secondary antibodies. Sections were examined by fluorescence microscopy. Haematoxylin-eosin slides were also employed. Cellular heterogeneity and morphological modulations were identified within enamel organ cells and connective tissue covering suggesting complex cellular interactions and indicating a new functional concept and possible complementary role during enamel maturation. Also, some ion transportation activity, and nos1 and cox1 signalling pathways have been identified, indicating intercellular communication between these regions. A hypothesis is suggested, to explain the morphological modulation of ameloblasts and papillary cells during enamel maturation which functions to increase the transporting membrane surface area to accomplish faster and bulker ion transportation to achieve controlled pH and to direct Ca2+ towards enamel.
Collapse
Affiliation(s)
- Anas F Mahdee
- Department of Restorative and Aesthetic Dentistry, College of Dentistry, University of Baghdad, Baghdad, Iraq.
| | - Ahmed H Ali
- Department of Restorative and Aesthetic Dentistry, College of Dentistry, University of Baghdad, Baghdad, Iraq
| | - James I Gillespie
- Department of Urology, Campus Drie Eiken, University of Antwerp, Antwerp, Belgium
| |
Collapse
|
8
|
Jie YK, Cheng CH, Wang LC, Ma HL, Deng YQ, Liu GX, Feng J, Guo ZX, Ye LT. Hypoxia-induced oxidative stress and transcriptome changes in the mud crab (Scylla paramamosain). Comp Biochem Physiol C Toxicol Pharmacol 2021; 245:109039. [PMID: 33785424 DOI: 10.1016/j.cbpc.2021.109039] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 03/04/2021] [Accepted: 03/20/2021] [Indexed: 02/08/2023]
Abstract
Mud crab (Scylla paramamosain) is an economically important cultured species in China. Hypoxia is a major environmental stressor during mud crab culture. In the present study, we investigated the oxidative stress and transcriptome changes in the gills of mud crab after intermediate hypoxia stress with dissolved oxygen (DO) 3.0 ± 0.2 mg/L (named as "DO3") and acute hypoxia stress with DO 1.0 ± 0.2 mg/L (named as "DO1") for 0, 3, 6, 12 and 24 h. The superoxide dismutase (SOD) activity of DO1 increased significantly at 3, 6 and 24 h after hypoxia stress, while SOD activity of DO3 increased significantly at 6 and 24 h. The total antioxidant capacity (T-AOC) increased significantly at 6, 12 and 24 h after hypoxia stress. The malondialdehyde (MDA) concentration of DO1 increased significantly at 6, 12 and 24 h after hypoxia stress, while MDA concentration of DO3 only increased significantly at 6 h. The lactate dehydrogenase (LDH) activity of DO1 increased significantly at 3, 6, 12 and 24 h after hypoxia stress, while LDH activity of DO3 increased significantly at 12 and 24 h. Transcriptomic analysis was conducted at 24 h of gill tissues after hypoxia stress. A total of 1052 differentially expressed genes (DEGs) were obtained, including 394 DEGs between DO1 and DO3, 481 DEGs between DO1 and control group, 177 DEGs between DO3 and control group. DEGs were enriched in the pathways related to metabolism, immune functions, ion transport, and signal transduction. Transcriptional analysis showed that glycolysis and tricarboxylic acid cycle genes were the key factors in regulating the adaptation of mud crab to hypoxia stress.
Collapse
Affiliation(s)
- Yu-Kun Jie
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Engineering Research Center of Aquaculture, Shanghai Ocean University, Shanghai 201306, China; Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, China
| | - Chang-Hong Cheng
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, China.
| | - Li-Cang Wang
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, China
| | - Hong-Ling Ma
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, China
| | - Yi-Qin Deng
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, China
| | - Guang-Xin Liu
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, China
| | - Juan Feng
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, China
| | - Zhi-Xun Guo
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, China.
| | - Ling-Tong Ye
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, China
| |
Collapse
|
9
|
Ohki R, Matsuki-Fukushima M, Fujikawa K, Mayahara M, Matsuyama K, Nakamura M. In the absence of a basal lamina, ameloblasts absorb enamel in a serumless and chemically defined organ culture system. J Oral Biosci 2021; 63:66-73. [PMID: 33493674 DOI: 10.1016/j.job.2020.12.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 12/23/2020] [Accepted: 12/17/2020] [Indexed: 11/30/2022]
Abstract
OBJECTIVES Tooth organ development was examined in a serumless, chemically defined organ culture system to determine whether morphological and functional development was identical to that in in vivo and serum-supplemented organ cultures. METHODS Mouse mandibular first molar tooth organs at 16 days of gestation were cultured for up to 28 days in a Tronwell culture system using a serum-supplemented or serumless, chemically defined medium. After culture, specimens were processed for assessing tooth development using ultrastructural, immunohistochemical, and mRNA expression analyses. RESULTS In serum-supplemented conditions, inner enamel epithelial cells differentiated into secretory-stage ameloblasts, which formed enamel and reached the maturation stage after 14 and 21 days of culture, respectively. Ameloblasts deposited a basal lamina on immature enamel. Conversely, in serumless conditions, ameloblasts formed enamel on mineralized dentin after 21 days. Moreover, maturation-stage ameloblasts did not form basal lamina and directly absorbed mineralized enamel after 28 days of culture. RT-PCR analysis indicated that tooth organs, cultured in serumless conditions for 28 days, had significantly reduced expression levels of ODAM, amelotin, and laminin-322. CONCLUSIONS These results indicate that several differences were detected compared to the development in serum-supplemented conditions, such as delayed enamel and dentin formation and the failure of maturation-stage ameloblasts to form basal laminae. Therefore, our results suggest that some factors might be required for the steady formation of mineralized dentin, enamel, and a basal lamina. Additionally, our results indicate that a basal lamina is necessary for enamel maturation.
Collapse
Affiliation(s)
- Retsu Ohki
- Department of Oral Anatomy and Developmental Biology, Showa University School of Dentistry, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 4142-8555, Japan
| | - M Matsuki-Fukushima
- Department of Oral Anatomy and Developmental Biology, Showa University School of Dentistry, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 4142-8555, Japan
| | - K Fujikawa
- Department of Oral Anatomy and Developmental Biology, Showa University School of Dentistry, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 4142-8555, Japan
| | - Mitsuori Mayahara
- Department of Oral Anatomy and Developmental Biology, Showa University School of Dentistry, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 4142-8555, Japan
| | - Kayo Matsuyama
- Department of Oral Anatomy and Developmental Biology, Showa University School of Dentistry, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 4142-8555, Japan
| | - Masanori Nakamura
- Department of Oral Anatomy and Developmental Biology, Showa University School of Dentistry, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 4142-8555, Japan.
| |
Collapse
|
10
|
Epithelial loss of mitochondrial oxidative phosphorylation leads to disturbed enamel and impaired dentin matrix formation in postnatal developed mouse incisor. Sci Rep 2020; 10:22037. [PMID: 33328493 PMCID: PMC7744519 DOI: 10.1038/s41598-020-77954-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 11/12/2020] [Indexed: 12/03/2022] Open
Abstract
The formation of dentin and enamel matrix depends on reciprocal interactions between epithelial-mesenchymal cells. To assess the role of mitochondrial function in amelogenesis and dentinogenesis, we studied postnatal incisor development in K320E-TwinkleEpi mice. In these mice, a loss of mitochondrial DNA (mtDNA), followed by a severe defect in the oxidative phosphorylation system is induced specifically in Keratin 14 (K14+) expressing epithelial cells. Histochemical staining showed severe reduction of cytochrome c oxidase activity only in K14+ epithelial cells. In mutant incisors, H&E staining showed severe defects in the ameloblasts, in the epithelial cells of the stratum intermedium and the papillary cell layer, but also a disturbed odontoblast layer. The lack of amelogenin in the enamel matrix of K320E-TwinkleEpi mice indicated that defective ameloblasts are not able to form extracellular enamel matrix proteins. In comparison to control incisors, von Kossa staining showed enamel biomineralization defects and dentin matrix impairment. In mutant incisor, TUNEL staining and ultrastructural analyses revealed differentiation defects, while in hair follicle cells apoptosis is prevalent. We concluded that mitochondrial oxidative phosphorylation in epithelial cells of the developed incisor is required for Ca2+ homeostasis to regulate the formation of enamel matrix and induce the differentiation of ectomesenchymal cells into odontoblasts.
Collapse
|
11
|
Ida-Yonemochi H, Otsu K, Harada H, Ohshima H. Functional Expression of Sodium-Dependent Glucose Transporter in Amelogenesis. J Dent Res 2020; 99:977-986. [PMID: 32345094 DOI: 10.1177/0022034520916130] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Glucose is an essential source of energy for mammalian cells and is transported into the cells by glucose transporters. There are 2 types of glucose transporters: one is a passive glucose transporter, GLUT (SLC2A), and the other is a sodium-dependent active glucose transporter, SGLT (SLC5A). We previously reported that the expression of GLUTs during tooth development is precisely and spatiotemporally controlled and that the glucose uptake mediated by GLUT1 plays a crucial role in early tooth morphogenesis and tooth size determination. This study aimed to clarify the localization and roles of SGLT1 and SGLT2 in murine ameloblast differentiation by using immunohistochemistry, immunoelectron microscopy, an in vitro tooth organ culture experiment, and in vivo administration of an inhibitor of SGLT1/2, phloridzin. SGLT1, which has high affinity with glucose, was immunolocalized in the early secretory ameloblasts and the ruffle-ended ameloblasts in the maturation stage. However, SGLT2, which has high glucose transport capacity, was observed in the stratum intermedium, papillary layer, and ameloblasts at the maturation stage and colocalized with Na+-K+-ATPase. The inhibition of SGLT1/2 by phloridzin in the tooth germs induced the disturbance of ameloblast differentiation and enamel matrix formation both in vitro (organ culture) and in vivo (mouse model). The expression of SGLT1 and SGLT2 was significantly upregulated in hypoxic conditions in the ameloblast-lineage cells. These findings suggest that the active glucose uptake mediated by SGLT1 and SGLT2 is strictly regulated and dependent on the intra- and extracellular microenvironments during tooth morphogenesis and that the appropriate passive and active glucose transport is an essential event in amelogenesis.
Collapse
Affiliation(s)
- H Ida-Yonemochi
- Division of Anatomy and Cell Biology of the Hard Tissue, Department of Tissue Regeneration and Reconstruction, Graduate School of Medical and Dental Sciences, Niigata University, Chuo-ku, Japan
| | - K Otsu
- Division of Developmental Biology and Regenerative Medicine, Department of Anatomy, Iwate Medical University, Shiwa-gun, Japan
| | - H Harada
- Division of Developmental Biology and Regenerative Medicine, Department of Anatomy, Iwate Medical University, Shiwa-gun, Japan
| | - H Ohshima
- Division of Anatomy and Cell Biology of the Hard Tissue, Department of Tissue Regeneration and Reconstruction, Graduate School of Medical and Dental Sciences, Niigata University, Chuo-ku, Japan
| |
Collapse
|
12
|
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.
Collapse
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
| |
Collapse
|
13
|
Potential function of TGF-β isoforms in maturation-stage ameloblasts. J Oral Biosci 2019; 61:43-54. [PMID: 30929801 DOI: 10.1016/j.job.2018.12.002] [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: 11/19/2018] [Revised: 12/18/2018] [Accepted: 12/19/2018] [Indexed: 12/19/2022]
Abstract
OBJECTIVES To investigate potential functions of transforming growth factor-beta (TGF-β) isoforms in maturation-stage ameloblasts during amelogenesis. METHODS In vivo activation of TGF-β was characterized by using matrix metalloproteinase 20 null (Mmp20-/-) and wild-type (Mmp20+/+) mice. Using mHAT9d cells cultured in the presence of each TGF-β isoform, (1) cell proliferation was determined by MTS assay, (2) immunostaining with anti-cleaved caspase-3 monoclonal antibody was performed and apoptotic indices were measured, (3) gene expression was analyzed by RT-qPCR, and (4) the uptake of amelogenin into mHAT9d cells was directly observed using a fluorescence microscope. RESULTS TGF-β1 and TGF-β3 were present in the enamel matrix of developing teeth which were activated by MMP20 in vivo. A genetic study revealed that the three TGF-β isoforms upregulate kallikrein 4 (KLK4) mRNA levels but downregulate carbonic anhydrase II. Moreover, TGF-β1 and TGF-β2 significantly upregulated the mRNA level of amelotin, whereas TGF-β3 dramatically downregulated the mRNA levels of odontogenic ameloblast-associated protein (ODAM), family with sequence similarity 83 member H (FAM83H), and alkaline phosphatase (ALP). Immunostaining analysis showed that the apoptosis of mHAT9d cells is induced by three TGF-β isoforms, with TGF-β3 being most effective. Both TGF-β1 and TGF-β3 induced endocytosis of amelogenin. CONCLUSIONS We propose that TGF-β is regulated in an isoform-specific manner to perform multiple biological functions such as gene expression related to the structure of basal lamina/ameloblasts, mineral ion transport, apoptosis, and endocytosis in maturation-stage ameloblasts.
Collapse
|
14
|
Ji M, Xiao L, Xu L, Huang S, Zhang D. How pH is regulated during amelogenesis in dental fluorosis. Exp Ther Med 2018; 16:3759-3765. [PMID: 30402142 DOI: 10.3892/etm.2018.6728] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 12/01/2017] [Indexed: 12/14/2022] Open
Abstract
Amelogenesis is a complicated process that concerns the interaction between growing hydroxyapatite crystals and extracellular proteins, which requires the tight regulation of pH. In dental fluorosis, the balance of pH regulation is broken, leading to abnormal mineralization. The current review focuses on the electrolyte transport processes associated with pH homeostasis, particularly regarding the changes in ion transporters that occur during amelogenesis, following exposure to excessive fluoride. Furthermore, the possible mechanism of fluorosis is discussed on the basis of acid hypothesis. There are two main methods by which F- accelerates crystal formation in ameloblasts. Firstly, it induces the release of protons, lowering the pH of the cell microenvironment. The decreased pH stimulates the upregulation of ion transporters, which attenuates further declines in the pH. Secondly, F- triggers an unknown signaling pathway, causing changes in the transcription of ion transporters and upregulating the expression of bicarbonate transporters. This results in the release of a large amount of bicarbonate from ameloblasts, which may neutralize the pH to form a microenvironment that favors crystal nucleation. The decreased pH stimulates the diffusion of F- into the cytoplasm of amelobalsts along the concentration gradient formed by the release of protons. The retention of F- causes a series of pathological changes, including oxidative and endoplasmic reticulum stress. If the buffering capacity of ameloblasts facing F- toxicity holds, normal mineralization occurs; however, if F- levels are high enough to overwhelm the buffering capacity of ameloblasts, abnormal mineralization occurs, leading to dental fluorosis.
Collapse
Affiliation(s)
- Mei Ji
- Department of Stomatology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Lili Xiao
- Department of Stomatology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Le Xu
- Department of Stomatology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Shengyun Huang
- Department of Stomatology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| | - Dongsheng Zhang
- Department of Stomatology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China
| |
Collapse
|
15
|
Kim HE, Hong JH. The overview of channels, transporters, and calcium signaling molecules during amelogenesis. Arch Oral Biol 2018; 93:47-55. [PMID: 29803993 DOI: 10.1016/j.archoralbio.2018.05.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 05/18/2018] [Accepted: 05/19/2018] [Indexed: 01/02/2023]
Abstract
Enamel is a highly calcified tissue. Its formation requires a progressive and dynamic system for the regulation of electrolyte concentration by enamel epithelia. A critical function of enamel epithelial cells, ameloblasts, is the secretion and movement of electrolytes via various channels and transporters to develop the enamel tissue. Enamel formation generates protons, which need to be neutralised. Thus, ameloblasts possess a buffering system to sustain mineral accretion. Normal tooth formation involves stage-dependent net fluctuations in pH during amelogenesis. To date, all of our information about ion transporters in dental enamel tissue is based solely on immunostaining-expression techniques. This review critically evaluates the current understanding and recent discoveries and physiological role of ion channels and transporters, Mg2+ transporters, and Ca2+ regulatory proteins during amelogenesis in enamel formation. The ways in which ameloblasts modulate ions are discussed in the context of current research for developing a novel morphologic-functional model of enamel maturation.
Collapse
Affiliation(s)
- Hee-Eun Kim
- Department of Dental Hygiene, College of Health Science, Gachon University, 191 Hambangmoe-ro, Yeonsu-gu, Incheon, 21936, South Korea
| | - Jeong Hee Hong
- Department of Physiology, College of Medicine, Lee Gil Ya Cancer and Diabetes Institute, GAIHST, Gachon University, Incheon, 21999, South Korea.
| |
Collapse
|
16
|
Ogata K, Tsumuraya T, Oka K, Shin M, Okamoto F, Kajiya H, Katagiri C, Ozaki M, Matsushita M, Okabe K. The crucial role of the TRPM7 kinase domain in the early stage of amelogenesis. Sci Rep 2017; 7:18099. [PMID: 29273814 PMCID: PMC5741708 DOI: 10.1038/s41598-017-18291-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 12/07/2017] [Indexed: 12/15/2022] Open
Abstract
Transient receptor potential melastatin-7 (TRPM7) is a bi-functional protein containing a kinase domain fused to an ion channel. TRPM7 is highly expressed in ameloblasts during tooth development. Here we show that TRPM7 kinase-inactive knock-in mutant mice (TRPM7 KR mice) exhibited small enamel volume with opaque white-colored incisors. The TRPM7 channel function of ameloblast-lineage cells from TRPM7 KR mice was normal. Interestingly, phosphorylation of intracellular molecules including Smad1/5/9, p38 and cAMP response element binding protein (CREB) was inhibited in ameloblasts from TRPM7 KR mice at the pre-secretory stage. An immunoprecipitation assay showed that CREB was bound to TRPM7, suggesting that direct phosphorylation of CREB by TRPM7 was inhibited in ameloblast-lineage cells from TRPM7 KR mice. These results indicate that the function of the TRPM7 kinase domain plays an important role in ameloblast differentiation, independent of TRPM7 channel activity, via phosphorylation of CREB.
Collapse
Affiliation(s)
- Kayoko Ogata
- Section of Cellular Physiology, Department of Physiological Sciences and Molecular Biology, Fukuoka Dental College, Fukuoka, Japan.,Section of Pediatric Dentistry, Department of Oral Growth and Development, Fukuoka Dental College, Fukuoka, Japan
| | - Tomoyuki Tsumuraya
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan
| | - Kyoko Oka
- Section of Pediatric Dentistry, Department of Oral Growth and Development, Fukuoka Dental College, Fukuoka, Japan.
| | - Masashi Shin
- Section of Cellular Physiology, Department of Physiological Sciences and Molecular Biology, Fukuoka Dental College, Fukuoka, Japan
| | - Fujio Okamoto
- Section of Cellular Physiology, Department of Physiological Sciences and Molecular Biology, Fukuoka Dental College, Fukuoka, Japan
| | - Hiroshi Kajiya
- Section of Cellular Physiology, Department of Physiological Sciences and Molecular Biology, Fukuoka Dental College, Fukuoka, Japan
| | - Chiaki Katagiri
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan
| | - Masao Ozaki
- Section of Pediatric Dentistry, Department of Oral Growth and Development, Fukuoka Dental College, Fukuoka, Japan
| | - Masayuki Matsushita
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan
| | - Koji Okabe
- Section of Cellular Physiology, Department of Physiological Sciences and Molecular Biology, Fukuoka Dental College, Fukuoka, Japan
| |
Collapse
|
17
|
Rácz R, Földes A, Bori E, Zsembery Á, Harada H, Steward MC, DenBesten P, Bronckers ALJJ, Gerber G, Varga G. No Change in Bicarbonate Transport but Tight-Junction Formation Is Delayed by Fluoride in a Novel Ameloblast Model. Front Physiol 2017; 8:940. [PMID: 29375389 PMCID: PMC5770627 DOI: 10.3389/fphys.2017.00940] [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: 06/16/2017] [Accepted: 11/06/2017] [Indexed: 01/17/2023] Open
Abstract
We have recently developed a novel in vitro model using HAT-7 rat ameloblast cells to functionally study epithelial ion transport during amelogenesis. Our present aims were to identify key transporters of bicarbonate in HAT-7 cells and also to examine the effects of fluoride exposure on vectorial bicarbonate transport, cell viability, and the development of transepithelial resistance. To obtain monolayers, the HAT-7 cells were cultured on Transwell permeable filters. We monitored transepithelial resistance (TER) as an indicator of tight junction formation and polarization. We evaluated intracellular pH changes by microfluorometry using the fluorescent indicator BCECF. Activities of ion transporters were tested by withdrawal of various ions from the bathing medium, by using transporter specific inhibitors, and by activation of transporters with forskolin and ATP. Cell survival was estimated by alamarBlue assay. Changes in gene expression were monitored by qPCR. We identified the activity of several ion transporters, NBCe1, NHE1, NKCC1, and AE2, which are involved in intracellular pH regulation and vectorial bicarbonate and chloride transport. Bicarbonate secretion by HAT-7 cells was not affected by acute fluoride exposure over a wide range of concentrations. However, tight-junction formation was inhibited by 1 mM fluoride, a concentration which did not substantially reduce cell viability, suggesting an effect of fluoride on paracellular permeability and tight-junction formation. Cell viability was only reduced by prolonged exposure to fluoride concentrations greater than 1 mM. In conclusion, cultured HAT-7 cells are functionally polarized and are able to transport bicarbonate ions from the basolateral to the apical fluid spaces. Exposure to 1 mM fluoride has little effect on bicarbonate secretion or cell viability but delays tight-junction formation, suggesting a novel mechanism that may contribute to dental fluorosis.
Collapse
Affiliation(s)
- Róbert Rácz
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | - Anna Földes
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | - Erzsébet Bori
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | - Ákos Zsembery
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | | | - Martin C Steward
- School of Medical Sciences, University of Manchester, Manchester, United Kingdom
| | - Pamela DenBesten
- 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), Amsterdam, Netherlands
| | - Gábor Gerber
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
| | - Gábor Varga
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| |
Collapse
|
18
|
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.
Collapse
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
| |
Collapse
|
19
|
Abstract
Amelogenesis (tooth enamel formation) is a biomineralization process consisting primarily of two stages (secretory stage and maturation stage) with unique features. During the secretory stage, the inner epithelium of the enamel organ (i.e., the ameloblast cells) synthesizes and secretes enamel matrix proteins (EMPs) into the enamel space. The protein-rich enamel matrix forms a highly organized architecture in a pH-neutral microenvironment. As amelogenesis transitions to maturation stage, EMPs are degraded and internalized by ameloblasts through endosomal-lysosomal pathways. Enamel crystallite formation is initiated early in the secretory stage, however, during maturation stage the more rapid deposition of calcium and phosphate into the enamel space results in a rapid expansion of crystallite length and mineral volume. During maturation-stage amelogenesis, the pH value of enamel varies considerably from slightly above neutral to acidic. Extracellular acid-base balance during enamel maturation is tightly controlled by ameloblast-mediated regulatory networks, which include significant synthesis and movement of bicarbonate ions from both the enamel papillary layer cells and ameloblasts. In this review we summarize the carbonic anhydrases and the carbonate transporters/exchangers involved in pH regulation in maturation-stage amelogenesis. Proteins that have been shown to be instrumental in this process include CA2, CA6, CFTR, AE2, NBCe1, SLC26A1/SAT1, SLC26A3/DRA, SLC26A4/PDS, SLC26A6/PAT1, and SLC26A7/SUT2. In addition, we discuss the association of miRNA regulation with bicarbonate transport in tooth enamel formation.
Collapse
Affiliation(s)
- Kaifeng Yin
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, 2250 Alcazar Street, CSA103, Los Angeles, CA, 90033, USA
- Department of Orthodontics, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA
| | - Michael L Paine
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, 2250 Alcazar Street, CSA103, Los Angeles, CA, 90033, USA.
| |
Collapse
|
20
|
Green DR, Green GM, Colman AS, Bidlack FB, Tafforeau P, Smith TM. Synchrotron imaging and Markov Chain Monte Carlo reveal tooth mineralization patterns. PLoS One 2017; 12:e0186391. [PMID: 29049333 PMCID: PMC5648163 DOI: 10.1371/journal.pone.0186391] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 09/29/2017] [Indexed: 11/29/2022] Open
Abstract
The progressive character of tooth formation records aspects of mammalian life history, diet, seasonal behavior and climate. Tooth mineralization occurs in two stages: secretion and maturation, which overlap to some degree. Despite decades of study, the spatial and temporal pattern of elemental incorporation during enamel mineralization remains poorly characterized. Here we use synchrotron X-ray microtomography and Markov Chain Monte Carlo sampling to estimate mineralization patterns from an ontogenetic series of sheep molars (n = 45 M1s, 18 M2s). We adopt a Bayesian approach that posits a general pattern of maturation estimated from individual- and population-level mineral density variation over time. This approach converts static images of mineral density into a dynamic model of mineralization, and demonstrates that enamel secretion and maturation waves advance at nonlinear rates with distinct geometries. While enamel secretion is ordered, maturation geometry varies within a population and appears to be driven by diffusive processes. Our model yields concrete expectations for the integration of physiological and environmental signals, which is of particular significance for paleoseasonality research. This study also provides an avenue for characterizing mineralization patterns in other taxa. Our synchrotron imaging data and model are available for application to multiple disciplines, including health, material science, and paleontological research.
Collapse
Affiliation(s)
- Daniel R. Green
- Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts, United States of America
- Forsyth Institute, Cambridge, Massachusetts, United States of America
- * E-mail:
| | - Gregory M. Green
- Physics Department, Stanford University, Palo Alto, California, United States of America
- Kavli Institute for Particle Physics and Cosmology, Stanford University, Palo Alto, California, United States of America
| | - Albert S. Colman
- Department of the Geophysical Sciences, University of Chicago, Chicago, Illinois, United States of America
| | | | - Paul Tafforeau
- European Synchrotron Radiation Facility, Grenoble, France
| | - Tanya M. Smith
- Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts, United States of America
- Australian Research Center for Human Evolution, Griffith University, Brisbane, Australia
| |
Collapse
|
21
|
Mahdee A, Eastham J, Whitworth JM, Gillespie JI. Evidence for programmed odontoblast process retraction after dentine exposure in the rat incisor. Arch Oral Biol 2017; 85:130-141. [PMID: 29073561 DOI: 10.1016/j.archoralbio.2017.10.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 09/26/2017] [Accepted: 10/02/2017] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To re-examine the morphology and potential functions of odontoblasts in intact rat incisors and after cavity preparation into dentine. DESIGN Intact incisors were fixed, decalcified, snap frozen and sectioned (10μm), before staining with rhodamine phalloidin or antibodies for cyto-skeletal proteins: vimentin and actin, ion transporter: NaK-ATPase, and dendritic cell marker: OX6. Samples with cavity were processed similarly and stained for actin and vimentin before comparing the lengths of odontoblast processes (OP) at baseline, 3h and 24h (n=5 for each group). RESULTS Actin was expressed through the full length of OP, while vimentin immunoreactivity was not uniform, with 4 distinct regions. OP showed morphological complexity with fine branches emanating within different regions of dentine. Novel actin-positive tree-like OP were identified within predentine which reduced in intensity and length toward the incisal portion of the tooth. Specimens with cavities showed time-dependant pulpal retraction of OP. CONCLUSIONS Differences in structural antibody expression suggest functional variations in OP within different regions of dentine. The role of actin positive OP in predentine is not known, but could be related to dentine deposition, cellular stability or sensing mechanisms. Cavity preparation into dentine was followed by programmed retraction of OP which could be controlled either mechanically by the spatial limitation of the OP within dentinal tubules or structurally by the presence of vimentin, in addition to actin, in the mid-dentine.
Collapse
Affiliation(s)
- A Mahdee
- Centre for Oral Health Research, UK; Institute of Cellular Medicine, UK; School of Dental Sciences Newcastle University, UK; University of Baghdad College of Dentistry, Iraq.
| | - J Eastham
- School of Dental Sciences Newcastle University, UK.
| | - J M Whitworth
- Centre for Oral Health Research, UK; School of Dental Sciences Newcastle University, UK.
| | - J I Gillespie
- Urology and Urological Rehabilitation Antwerp University, Belgium.
| |
Collapse
|
22
|
Varga G, DenBesten P, Rácz R, Zsembery Á. Importance of bicarbonate transport in pH control during amelogenesis - need for functional studies. Oral Dis 2017; 24:879-890. [PMID: 28834043 DOI: 10.1111/odi.12738] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 08/13/2017] [Indexed: 12/27/2022]
Abstract
Dental enamel, the hardest mammalian tissue, is produced by ameloblasts. Ameloblasts show many similarities to other transporting epithelia although their secretory product, the enamel matrix, is quite different. Ameloblasts direct the formation of hydroxyapatite crystals, which liberate large quantities of protons that then need to be buffered to allow mineralization to proceed. Buffering requires a tight pH regulation and secretion of bicarbonate by ameloblasts. Many investigations have used immunohistochemical and knockout studies to determine the effects of these genes on enamel formation, but up till recently very little functional data were available for mineral ion transport. To address this, we developed a novel 2D in vitro model using HAT-7 ameloblast cells. HAT-7 cells can be polarized and develop functional tight junctions. Furthermore, they are able to accumulate bicarbonate ions from the basolateral to the apical fluid spaces. We propose that in the future, the HAT-7 2D system along with similar cellular models will be useful to functionally model ion transport processes during amelogenesis. Additionally, we also suggest that similar approaches will allow a better understanding of the regulation of the cycling process in maturation-stage ameloblasts, and the pH sensory mechanisms, which are required to develop sound, healthy enamel.
Collapse
Affiliation(s)
- G Varga
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | - P DenBesten
- Department of Orofacial Sciences, University of California, San Francisco, CA, USA
| | - R Rácz
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | - Á Zsembery
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| |
Collapse
|
23
|
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.
Collapse
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
| |
Collapse
|
24
|
Oka S, Sasagawa I, Ishiyama M. Histochemical and immunohistochemical examination of odontoblasts (petroblasts) in petrodentine formation of lungfish. Arch Oral Biol 2017; 83:222-229. [PMID: 28810187 DOI: 10.1016/j.archoralbio.2017.07.025] [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: 04/03/2017] [Revised: 07/28/2017] [Accepted: 07/28/2017] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Petrodentine, the core of the lungfish tooth plate, is a well-mineralized tissue similar to mammalian enamel and analogous to enameloid in fish teeth. Petrodentine is formed solely by petroblasts, which are specialized odontoblasts, whereas enameloid is a composite tissue produced by both odontoblasts and dental epithelial cells. To clarify the details of petrodentine formation, petroblasts were investigated using histochemical and immunohistochemical techniques. METHODS Extant lungfish (Lepidosiren paradoxa) were used in this study. Tooth plates during the stage of petrodentine formation were observed by means of histochemistry and immunohistochemistry. Commercial kits were used to detect enzyme activity. Correlative sections were immunostained using antibodies against selected peptides. Routine staining such as periodic acid-Schiff (PAS) reaction to identify glycogen and Elastica van Gieson staining for the detection of elastic fibers in histological sections were performed. In addition, conventional transmission electron microscopy was used for observing the fine structure. RESULTS Petroblasts showed marked acid and alkaline phosphatase activities, and positive immunoreactivities against anti-nestin, anti-V-ATPase, and anti-Ca2+-ATPase, during the maturation stage, but in the matrix formation stage, reactions were much weaker than that of the maturation stage. During the maturation stage, petroblasts showed intense PAS reactivity, and glycogen particles were observed in petroblasts by transmission electron microscopy. Glucose transporter 1-immunoreactivity was observed in petroblasts in the matrix formation stage and the initial to mid part of the maturation stage. CONCLUSIONS The results in this study suggested that petroblasts have two functional stages, matrix formation and maturation, and glycogen plays an important role in the modulation of petroblasts.
Collapse
Affiliation(s)
- Shunya Oka
- Department of Biology, School of Life Dentistry at Niigata, The Nippon Dental University, Niigata, Japan.
| | - Ichiro Sasagawa
- Advanced Research Center, School of Life Dentistry at Niigata, The Nippon Dental University, Niigata, Japan
| | - Mikio Ishiyama
- Department of Histology, School of Life Dentistry at Niigata, The Nippon Dental University, Niigata, Japan
| |
Collapse
|
25
|
Furukawa Y, Haruyama N, Nikaido M, Nakanishi M, Ryu N, Oh-Hora M, Kuremoto K, Yoshizaki K, Takano Y, Takahashi I. Stim1 Regulates Enamel Mineralization and Ameloblast Modulation. J Dent Res 2017; 96:1422-1429. [PMID: 28732182 DOI: 10.1177/0022034517719872] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Loss-of-function mutations in the Ca2+ release-activated Ca2+ channel genes ORAI1 and STIM1 abolish store-operated Ca2+ entry (SOCE) and result in ectodermal dysplasia with amelogenesis imperfecta. However, because of the limited availability of patient tissue, analyses of enamel mineralization or possible changes in ameloblast function or morphology have not been possible. Here, we generated mice with ectodermal tissue-specific deletion of Stim1 ( Stim1 cKO [conditional knockout]), Stim2 ( Stim2 cKO), and Stim1 and Stim2 ( Stim1/2 cKO) and analyzed their enamel phenotypes as compared with those of control ( Stim1/2fl/fl) animals. Ablation of Stim1 and Stim1/2 but not Stim2 expression resulted in chalky enamel and severe attrition at the incisor tips and molar cusps. Stim1 and Stim1/2 cKO, but not Stim2 cKO, demonstrated inferior enamel mineralization with impaired structural integrity, whereas the shape of the teeth and enamel thickness appeared to be normal in all animals. The gene expression levels of the enamel matrix proteins Amelx and Ambn and the enamel matrix proteases Mmp20 and Klk4 were not altered by the abrogation of SOCE in Stim1/2 cKO mice. The morphology of ameloblasts during the secretory and maturation stages was not significantly altered in either the incisors or molars of the cKO animals. However, in Stim1 and Stim1/2 cKO incisors, the alternating modulation of maturation-stage ameloblasts between the smooth- and ruffle-ended cell types continued beyond the regular cycle and extended to the areas corresponding to the zone of postmodulation ameloblasts in the teeth of control animals. These results indicate that SOCE is essential for proper enamel mineralization, in which Stim1 plays a critical role during the maturation process.
Collapse
Affiliation(s)
- Y Furukawa
- 1 Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth, and Development, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.,2 Institute of Decision Science Program for Sustainable Society, Kyushu University, Fukuoka, Japan
| | - N Haruyama
- 1 Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth, and Development, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - M Nikaido
- 1 Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth, and Development, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - M Nakanishi
- 1 Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth, and Development, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - N Ryu
- 1 Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth, and Development, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - M Oh-Hora
- 3 Division of Molecular Immunology, Research Center for Infectious Diseases, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - K Kuremoto
- 4 Department of Advanced Prosthodontics, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - K Yoshizaki
- 1 Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth, and Development, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Y Takano
- 5 Department of Cell Biology and Neuroscience, School of Medicine, Juntendo University, Tokyo, Japan
| | - I Takahashi
- 1 Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth, and Development, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| |
Collapse
|
26
|
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.
Collapse
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.
| |
Collapse
|
27
|
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.
Collapse
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
| |
Collapse
|
28
|
Yin K, Guo J, Lin W, Robertson SYT, Soleimani M, Paine ML. Deletion of Slc26a1 and Slc26a7 Delays Enamel Mineralization in Mice. Front Physiol 2017; 8:307. [PMID: 28559854 PMCID: PMC5432648 DOI: 10.3389/fphys.2017.00307] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 04/28/2017] [Indexed: 12/12/2022] Open
Abstract
Amelogenesis features two major developmental stages—secretory and maturation. During maturation stage, hydroxyapatite deposition and matrix turnover require delicate pH regulatory mechanisms mediated by multiple ion transporters. Several members of the Slc26 gene family (Slc26a1, Slc26a3, Slc26a4, Slc26a6, and Slc26a7), which exhibit bicarbonate transport activities, have been suggested by previous studies to be involved in maturation-stage amelogenesis, especially the key process of pH regulation. However, details regarding the functional role of these genes in enamel formation are yet to be clarified, as none of the separate mutant animal lines demonstrates any discernible enamel defects. Continuing with our previous investigation of Slc26a1−/− and Slc26a7−/− animal models, we generated a double-mutant animal line with the absence of both Slc26a1 and Slc26a7. We showed in the present study that the double-mutant enamel density was significantly lower in the regions that represent late maturation-, maturation- and secretory-stage enamel development in wild-type mandibular incisors. However, the “maturation” and “secretory” enamel microstructures in double-mutant animals resembled those observed in wild-type secretory and/or pre-secretory stages. Elemental composition analysis revealed a lack of mineral deposition and an accumulation of carbon and chloride in double-mutant enamel. Deletion of Slc26a1 and Slc26a7 did not affect the stage-specific morphology of the enamel organ. Finally, compensatory expression of pH regulator genes and ion transporters was detected in maturation-stage enamel organs of double-mutant animals when compared to wild-type. Combined with the findings from our previous study, these data indicate the involvement of SLC26A1and SLC26A7 as key ion transporters in the pH regulatory network during enamel maturation.
Collapse
Affiliation(s)
- Kaifeng Yin
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry of University of Southern CaliforniaLos Angeles, CA, USA.,Department of Orthodontics, Herman Ostrow School of Dentistry of University of Southern CaliforniaLos Angeles, CA, USA
| | - Jing Guo
- Department of Endodontics, Herman Ostrow School of Dentistry of University of Southern CaliforniaLos Angeles, CA, USA
| | - Wenting Lin
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry of University of Southern CaliforniaLos Angeles, CA, USA
| | - Sarah Y T Robertson
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry of University of Southern CaliforniaLos Angeles, CA, USA
| | - Manoocher Soleimani
- Department of Medicine, University of Cincinnati, Research Services, Veterans Affairs Medical CenterCincinnati, OH, USA
| | - Michael L Paine
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry of University of Southern CaliforniaLos Angeles, CA, USA
| |
Collapse
|
29
|
Johnson L, Ganss B, Wang A, Zirngibl RA, Johnson DE, Owen C, Bradley G, Voronov I. V-ATPases Containing a3 Subunit Play a Direct Role in Enamel Development in Mice. J Cell Biochem 2017; 118:3328-3340. [PMID: 28295540 DOI: 10.1002/jcb.25986] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 03/09/2017] [Indexed: 12/17/2022]
Abstract
Vacuolar H+ -ATPases (V-ATPases) are ubiquitous multisubunit proton pumps responsible for organellar pH maintenance. Mutations in the a3 subunit of V-ATPases cause autosomal recessive osteopetrosis, a rare disease due to impaired bone resorption. Patients with osteopetrosis also display dental anomalies, such as enamel defects; however, it is not clear whether these enamel abnormalities are a direct consequence of the a3 mutations. We investigated enamel mineralization, spatiotemporal expression of enamel matrix proteins and the a3 protein during tooth development using an osteopetrotic mouse model with a R740S point mutation in the V-ATPase a3 subunit. Histology revealed aberrations in both crown and root development, whereas SEM analysis demonstrated delayed enamel mineralization in homozygous animals. Enamel thickness and mineralization were significantly decreased in homozygous mice as determined by μCT analysis. The expression patterns of the enamel matrix proteins amelogenin, amelotin, and odontogenic ameloblast-associated protein (ODAM) suggested a delay in transition to the maturation stage in homozygous animals. Protein expression of the a3 subunit was detected in ameloblasts in all three genotypes, suggesting that a3-containing V-ATPases play a direct role in amelogenesis, and mutations in a3 delay transition from the secretory to the maturation stage, resulting in hypomineralized and hypoplastic enamel. J. Cell. Biochem. 118: 3328-3340, 2017. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Lisa Johnson
- Faculty of Dentistry, Department of Oral Pathology, University of Toronto, Toronto, Ontario, Canada.,Faculty of Dentistry, Dental Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Bernhard Ganss
- Faculty of Dentistry, Dental Research Institute, University of Toronto, Toronto, Ontario, Canada.,Matrix Dynamics Group, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada
| | - Andrew Wang
- Faculty of Dentistry, Dental Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Ralph A Zirngibl
- Faculty of Dentistry, Dental Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Danielle E Johnson
- Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Celeste Owen
- Centre for Modeling Human Disease, Lunenfeld-Tanenbaum Research Institute, Mt. Sinai Hospital, Toronto, Ontario, Canada
| | - Grace Bradley
- Faculty of Dentistry, Department of Oral Pathology, University of Toronto, Toronto, Ontario, Canada
| | - Irina Voronov
- Faculty of Dentistry, Dental Research Institute, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
30
|
Misgar RA, Hassan Z, Wani AI, Bashir MI. Amelogenesis Imperfecta with Distal Renal Tubular Acidosis: A Novel Syndrome? Indian J Nephrol 2017; 27:225-227. [PMID: 28553046 PMCID: PMC5434692 DOI: 10.4103/0971-4065.202826] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Amelogenesis imperfecta (AI) is a heterogeneous group of inherited dental enamel defects. It has rarely been reported in association with multiorgan syndromes and metabolic disorders. The metabolic disorders that have been reported in association with AI include hypocalciuria, impaired urinary concentrating ability, and Bartter-like syndrome. In literature, only three cases of AI and distal renal tubular acidosis (dRTA) have been described: two cases in adults and a solitary case in the pediatric age group. Here, we report a child with AI presenting with dRTA; to the best of our knowledge, our reported case is the only second such case in pediatric age group. Our case highlights the importance of recognizing the possibility of renal abnormalities in patients with AI as it will affect the long-term prognosis.
Collapse
Affiliation(s)
- R A Misgar
- Department of Endocrinology, Sher-i-Kashmir Institute of Medical Sciences, Srinagar, Jammu and Kashmir, India
| | - Z Hassan
- Department of Endocrinology, Sher-i-Kashmir Institute of Medical Sciences, Srinagar, Jammu and Kashmir, India
| | - A I Wani
- Department of Endocrinology, Sher-i-Kashmir Institute of Medical Sciences, Srinagar, Jammu and Kashmir, India
| | - M I Bashir
- Department of Endocrinology, Sher-i-Kashmir Institute of Medical Sciences, Srinagar, Jammu and Kashmir, India
| |
Collapse
|
31
|
Parry DA, Smith CE, El-Sayed W, Poulter JA, Shore RC, Logan CV, Mogi C, Sato K, Okajima F, Harada A, Zhang H, Koruyucu M, Seymen F, Hu JCC, Simmer JP, Ahmed M, Jafri H, Johnson CA, Inglehearn CF, Mighell AJ. Mutations in the pH-Sensing G-protein-Coupled Receptor GPR68 Cause Amelogenesis Imperfecta. Am J Hum Genet 2016; 99:984-990. [PMID: 27693231 PMCID: PMC5065684 DOI: 10.1016/j.ajhg.2016.08.020] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 08/17/2016] [Indexed: 01/11/2023] Open
Abstract
Amelogenesis is the process of dental enamel formation, leading to the deposition of the hardest tissue in the human body. This process requires the intricate regulation of ion transport and controlled changes to the pH of the developing enamel matrix. The means by which the enamel organ regulates pH during amelogenesis is largely unknown. We identified rare homozygous variants in GPR68 in three families with amelogenesis imperfecta, a genetically and phenotypically heterogeneous group of inherited conditions associated with abnormal enamel formation. Each of these homozygous variants (a large in-frame deletion, a frameshift deletion, and a missense variant) were predicted to result in loss of function. GPR68 encodes a proton-sensing G-protein-coupled receptor with sensitivity in the pH range that occurs in the developing enamel matrix during amelogenesis. Immunohistochemistry of rat mandibles confirmed localization of GPR68 in the enamel organ at all stages of amelogenesis. Our data identify a role for GPR68 as a proton sensor that is required for proper enamel formation.
Collapse
|
32
|
Yamaguti PM, Neves FDAR, Hotton D, Bardet C, de La Dure-Molla M, Castro LC, Scher MDC, Barbosa ME, Ditsch C, Fricain JC, de La Faille R, Figueres ML, Vargas-Poussou R, Houillier P, Chaussain C, Babajko S, Berdal A, Acevedo AC. Amelogenesis imperfecta in familial hypomagnesaemia and hypercalciuria with nephrocalcinosis caused by CLDN19 gene mutations. J Med Genet 2016; 54:26-37. [PMID: 27530400 DOI: 10.1136/jmedgenet-2016-103956] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 07/15/2016] [Accepted: 07/27/2016] [Indexed: 12/30/2022]
Abstract
BACKGROUND Amelogenesis imperfecta (AI) is a group of genetic diseases characterised by tooth enamel defects. AI was recently described in patients with familial hypercalciuria and hypomagnesaemia with nephrocalcinosis (FHHNC) caused by CLDN16 mutations. In the kidney, claudin-16 interacts with claudin-19 to control the paracellular passage of calcium and magnesium. FHHNC can be linked to mutations in both genes. Claudin-16 was shown to be expressed during amelogenesis; however, no data are available on claudin-19. Moreover, the enamel phenotype of patients with CLDN19 mutations has never been described. In this study, we describe the clinical and genetic features of nine patients with FHHNC carrying CLDN19 mutations and the claudin-19 expression profile in rat ameloblasts. METHODS Six FHHNC Brazilian patients were subjected to mutational analysis. Three additional French patients were recruited for orodental characterisation. The expression profile of claudin-19 was evaluated by RT-qPCR and immunofluorescence using enamel epithelium from rat incisors. RESULTS All patients presented AI at different degrees of severity. Two new likely pathogenic variations in CLDN19 were found: p.Arg200Gln and p.Leu90Arg. RT-qPCR revealed low Cldn19 expression in ameloblasts. Confocal analysis indicated that claudin-19 was immunolocalised at the distal poles of secretory and maturing ameloblasts. CONCLUSIONS For the first time, it was demonstrated that AI is associated with FHHNC in patients carrying CLDN19 mutations. The data suggest claudin-19 as an additional determinant in enamel formation. Indeed, the coexistence of hypoplastic and hypomineralised AI in the patients was consistent with claudin-19 expression in both secretory and maturation stages. Additional indirect systemic effects cannot be excluded.
Collapse
Affiliation(s)
- Paulo Marcio Yamaguti
- Faculty of Health Sciences, Division of Dentistry, Oral Care Center for Inherited Diseases, University Hospital of Brasilia, University of Brasilia, Brasilia, Brazil.,Faculty of Health Sciences, Laboratory of Oral Histopathology, University of Brasilia, Brasilia, Brazil
| | | | - Dominique Hotton
- Centre de Recherche des Cordeliers, University Paris-Diderot, INSERM UMR_S1138, Equipe Physiopathologie Orale Moléculaire, Paris, France
| | - Claire Bardet
- EA 2496, Laboratory Orofacial Pathologies, Imaging and Biotherapies, Dental School, University Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Muriel de La Dure-Molla
- INSERM UMR_S1163, Bases moléculaires et physiopathologiques des ostéochondrodysplasies, Institut Imagine, Necker, Paris, France.,AP-HP, Referral Center for Rare Buccal and Facial Dysmorphologies CRMR MAFACE, Hôpital Rothschild, Paris, France
| | - Luiz Claudio Castro
- Unit of Pediatric Endocrinology, University Hospital of Brasilia, Brasilia, Brazil
| | | | | | | | - Jean-Christophe Fricain
- CHU Bordeaux, Dental school, U1026 Tissue Bioengineering, University of Bordeaux/Inserm, Bordeaux, France
| | - Renaud de La Faille
- Department of Nephrology, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
| | - Marie-Lucile Figueres
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, Université Paris Descartes, Sorbonne Paris Cité, UMR_S 1138, Centre de Recherche des Cordeliers, CNRS ERL_8228, Paris, France
| | - Rosa Vargas-Poussou
- AP-HP, Department of Genetics, Reference Center of Children and Adult Renal Hereditary Diseases (MARHEA), Hôpital European Georges Pompidou, Paris, France
| | - Pascal Houillier
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, Université Paris Descartes, Sorbonne Paris Cité, UMR_S 1138, Centre de Recherche des Cordeliers, CNRS ERL_8228, Paris, France.,AP-HP, Department of Genetics, Reference Center of Children and Adult Renal Hereditary Diseases (MARHEA), Hôpital European Georges Pompidou, Paris, France
| | - Catherine Chaussain
- EA 2496, Laboratory Orofacial Pathologies, Imaging and Biotherapies, Dental School, University Paris Descartes, Sorbonne Paris Cité, Paris, France.,AP-HP, Department of Genetics, Reference Center of Children and Adult Renal Hereditary Diseases (MARHEA), Hôpital European Georges Pompidou, Paris, France
| | - Sylvie Babajko
- Centre de Recherche des Cordeliers, University Paris-Diderot, INSERM UMR_S1138, Equipe Physiopathologie Orale Moléculaire, Paris, France
| | - Ariane Berdal
- Centre de Recherche des Cordeliers, University Paris-Diderot, INSERM UMR_S1138, Equipe Physiopathologie Orale Moléculaire, Paris, France.,AP-HP, Referral Center for Rare Buccal and Facial Dysmorphologies CRMR MAFACE, Hôpital Rothschild, Paris, France
| | - Ana Carolina Acevedo
- Faculty of Health Sciences, Division of Dentistry, Oral Care Center for Inherited Diseases, University Hospital of Brasilia, University of Brasilia, Brasilia, Brazil.,Faculty of Health Sciences, Laboratory of Oral Histopathology, University of Brasilia, Brasilia, Brazil
| |
Collapse
|
33
|
Bronckers ALJJ, Lyaruu DM, Jalali R, DenBesten PK. Buffering of protons released by mineral formation during amelogenesis in mice. Eur J Oral Sci 2016; 124:415-425. [PMID: 27422589 DOI: 10.1111/eos.12287] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/01/2016] [Indexed: 12/17/2022]
Abstract
Regulation of pH by ameloblasts during amelogenesis is critical for enamel mineralization. We examined the effects of reduced bicarbonate secretion and the presence or absence of amelogenins on ameloblast modulation and enamel mineralization. To that end, the composition of fluorotic and non-fluorotic enamel of several different mouse mutants, including enamel of cystic fibrosis transmembrane conductance regulator-deficient (Cftr null), anion exchanger-2-deficient (Ae2a,b null), and amelogenin-deficient (Amelx null) mice, was determined by quantitative X-ray microanalysis. Correlation analysis was carried out to compare the effects of changes in the levels of sulfated-matrix (S) and chlorine (Cl; for bicarbonate secretion) on mineralization and modulation. The chloride (Cl- ) levels in forming enamel determined the ability of ameloblasts to modulate, remove matrix, and mineralize enamel. In general, the lower the Cl- content, the stronger the negative effects. In Amelx-null mice, modulation was essentially normal and the calcium content was reduced least. Retention of amelogenins in enamel of kallikrein-4-deficient (Klk4-null) mice resulted in decreased mineralization and reduced the length of the first acid modulation band without changing the total length of all acidic bands. These data suggest that buffering by bicarbonates is critical for modulation, matrix removal and enamel mineralization. Amelogenins also act as a buffer but are not critical for modulation.
Collapse
Affiliation(s)
- Antonius L J J Bronckers
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam, Amsterdam, the Netherlands. .,VU University Amsterdam, MOVE Research Institute, Amsterdam, the Netherlands.
| | - Don M Lyaruu
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam, Amsterdam, the Netherlands
| | - Rozita Jalali
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam, Amsterdam, the Netherlands
| | - Pamela K DenBesten
- Department of Oral Sciences, University of California in San Francisco, CA, USA
| |
Collapse
|
34
|
de Souza JF, Gramasco M, Jeremias F, Santos-Pinto L, Giovanini AF, Cerri PS, Cordeiro RDCL. Amoxicillin diminishes the thickness of the enamel matrix that is deposited during the secretory stage in rats. Int J Paediatr Dent 2016; 26:199-210. [PMID: 26148818 DOI: 10.1111/ipd.12184] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND The use of amoxicillin during early childhood has been associated with molar incisor hypomineralization. AIM The objective of this study was to determine whether the use of amoxicillin interferes with enamel development, during secretion and early mineralization stages. DESIGN Fifteen pregnant rats were randomly assigned to three groups that received physiological solution (sham group), 100 mg/kg/day amoxicillin (A100G), and 500 mg/kg/day amoxicillin (A500G). After birth, the pups in each group received the same treatment until post-natal day 7 or 12. The upper first molars were analyzed histomorphometrical and immunostaining with amelogenin on day 7, and MMP-20 on day 12 was performed using a semiquantitative method (H-score). RESULTS At 7 days, several vacuolar structures were observed in the ameloblasts in the A100G and A500G groups. A significant reduction of the enamel thickness (P < 0.001) was found in amoxicillin-treated rats compared with the sham group. Significant differences were not observed in enamel thickness (P > 0.05) between the groups of 12-day-old rats. Moreover, significant differences were not observed in the number of amelogenin- and MMP-20-immunolabeled ameloblasts (P > 0.05) between groups. CONCLUSION The present results suggest that amoxicillin interferes with the initial stages of amelogenesis by causing structural changes in the ameloblasts and a reduction of the enamel matrix.
Collapse
Affiliation(s)
| | - Marina Gramasco
- Department of Pediatric Dentistry, Dental School, UNESP - University Estadual Paulista, Araraquara, Brazil
| | - Fabiano Jeremias
- Department of Pediatric Dentistry, Dental School, UNESP - University Estadual Paulista, Araraquara, Brazil
| | - Lourdes Santos-Pinto
- Department of Pediatric Dentistry, Dental School, UNESP - University Estadual Paulista, Araraquara, Brazil
| | | | - Paulo Sérgio Cerri
- Laboratory of Histology and Embryology, Department of Morphology, Dental School, UNESP - University Estadual Paulista, Araraquara, Brazil
| | | |
Collapse
|
35
|
Bardet C, Courson F, Wu Y, Khaddam M, Salmon B, Ribes S, Thumfart J, Yamaguti PM, Rochefort GY, Figueres ML, Breiderhoff T, Garcia-Castaño A, Vallée B, Le Denmat D, Baroukh B, Guilbert T, Schmitt A, Massé JM, Bazin D, Lorenz G, Morawietz M, Hou J, Carvalho-Lobato P, Manzanares MC, Fricain JC, Talmud D, Demontis R, Neves F, Zenaty D, Berdal A, Kiesow A, Petzold M, Menashi S, Linglart A, Acevedo AC, Vargas-Poussou R, Müller D, Houillier P, Chaussain C. Claudin-16 Deficiency Impairs Tight Junction Function in Ameloblasts, Leading to Abnormal Enamel Formation. J Bone Miner Res 2016; 31:498-513. [PMID: 26426912 DOI: 10.1002/jbmr.2726] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 09/28/2015] [Accepted: 09/29/2015] [Indexed: 12/26/2022]
Abstract
Claudin-16 protein (CLDN16) is a component of tight junctions (TJ) with a restrictive distribution so far demonstrated mainly in the kidney. Here, we demonstrate the expression of CLDN16 also in the tooth germ and show that claudin-16 gene (CLDN16) mutations result in amelogenesis imperfecta (AI) in the 5 studied patients with familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC). To investigate the role of CLDN16 in tooth formation, we studied a murine model of FHHNC and showed that CLDN16 deficiency led to altered secretory ameloblast TJ structure, lowering of extracellular pH in the forming enamel matrix, and abnormal enamel matrix protein processing, resulting in an enamel phenotype closely resembling human AI. This study unravels an association of FHHNC owing to CLDN16 mutations with AI, which is directly related to the loss of function of CLDN16 during amelogenesis. Overall, this study indicates for the first time the importance of a TJ protein in tooth formation and underlines the need to establish a specific dental follow-up for these patients.
Collapse
Affiliation(s)
- Claire Bardet
- EA 2496, Laboratory Orofacial Pathologies, Imaging and Biotherapies, Dental School Paris Descartes University, Sorbonne Paris Cité, France
| | - Frédéric Courson
- Department of Odontology, AP-HP, and Reference Center for Rare Diseases of the Metabolism of Calcium and Phosphorus, Nord Val de Seine Hospital, Bretonneau, France
| | - Yong Wu
- EA 2496, Laboratory Orofacial Pathologies, Imaging and Biotherapies, Dental School Paris Descartes University, Sorbonne Paris Cité, France.,Department of Oral and Cranio-maxillofacial Science, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai, China
| | - Mayssam Khaddam
- EA 2496, Laboratory Orofacial Pathologies, Imaging and Biotherapies, Dental School Paris Descartes University, Sorbonne Paris Cité, France
| | - Benjamin Salmon
- EA 2496, Laboratory Orofacial Pathologies, Imaging and Biotherapies, Dental School Paris Descartes University, Sorbonne Paris Cité, France.,Department of Odontology, AP-HP, and Reference Center for Rare Diseases of the Metabolism of Calcium and Phosphorus, Nord Val de Seine Hospital, Bretonneau, France
| | - Sandy Ribes
- EA 2496, Laboratory Orofacial Pathologies, Imaging and Biotherapies, Dental School Paris Descartes University, Sorbonne Paris Cité, France
| | - Julia Thumfart
- Department of Pediatric Nephrology, Charité University School of Medicine, Berlin, Germany
| | - Paulo M Yamaguti
- Division of Dentistry, Oral Care Center for Inherited Diseases, University Hospital of Brasilia, Faculty of Health Sciences, University of Brasilia (UnB), Brasilia, Brazil
| | - Gael Y Rochefort
- EA 2496, Laboratory Orofacial Pathologies, Imaging and Biotherapies, Dental School Paris Descartes University, Sorbonne Paris Cité, France
| | - Marie-Lucile Figueres
- INSERM UMRS 1138, Cordeliers Research Center, Paris-Diderot, Pierre et Marie Curie and Paris Descartes Universities, CNRS ERL 8228, Paris, France
| | - Tilman Breiderhoff
- Department of Pediatric Nephrology, Charité University School of Medicine, Berlin, Germany
| | - Alejandro Garcia-Castaño
- Department of Genetics, AP-HP, and Reference Center of Children and Adult Renal Hereditary Diseases (MARHEA), European Hospital Georges Pompidou, Paris, France
| | - Benoit Vallée
- Laboratory CRRET, Paris-Est University, CNRS, Créteil, France
| | - Dominique Le Denmat
- EA 2496, Laboratory Orofacial Pathologies, Imaging and Biotherapies, Dental School Paris Descartes University, Sorbonne Paris Cité, France
| | - Brigitte Baroukh
- EA 2496, Laboratory Orofacial Pathologies, Imaging and Biotherapies, Dental School Paris Descartes University, Sorbonne Paris Cité, France
| | - Thomas Guilbert
- Cochin Institute, Plate-Forme d'Imagerie Photonique, INSERM U1016, CNRS UMR8104, Paris Descartes University Sorbonne Paris Cité, Paris, France
| | - Alain Schmitt
- Cochin Institute, Transmission Electron Microscopy Platform, INSERM U1016, CNRS UMR8104, Paris Descartes University Sorbonne Paris Cité, Paris, France
| | - Jean-Marc Massé
- Cochin Institute, Transmission Electron Microscopy Platform, INSERM U1016, CNRS UMR8104, Paris Descartes University Sorbonne Paris Cité, Paris, France
| | - Dominique Bazin
- Laboratoire de Physique des Solides, CNRS, Paris Sud University, Orsay, and LCMCP-UPMC, Collège de France, Paris, France
| | - Georg Lorenz
- Fraunhofer Institute for Mechanics of Materials IWM, Halle, Germany
| | - Maria Morawietz
- Fraunhofer Institute for Mechanics of Materials IWM, Halle, Germany
| | - Jianghui Hou
- Division of Renal Diseases, Washington University School of Medicine, St. Louis, MO, USA
| | - Patricia Carvalho-Lobato
- Human Anatomy and Embryology, Health University of Barcelona Campus-Bellvitge, University of Barcelona, Barcelona, Spain
| | - Maria Cristina Manzanares
- Human Anatomy and Embryology, Health University of Barcelona Campus-Bellvitge, University of Barcelona, Barcelona, Spain
| | - Jean-Christophe Fricain
- CHU Bordeaux, Dental School, U1026 Tissue Bioengineering, University of Bordeaux/Inserm, Bordeaux, France
| | - Deborah Talmud
- Department of Pediatrics, Centre Hospitalier Régional (CHR) d'Orléans, Orleans, France
| | | | - Francisco Neves
- Laboratory of Molecular Pharmacology, Faculty of Health Sciences, University of Brasilia (UNB), Brasilia, Brazil
| | - Delphine Zenaty
- Department of Pediatric Endocrinology, AP-HP, Paris Diderot University, Robert Debré Hospital, Paris, France
| | - Ariane Berdal
- INSERM UMRS 1138, Cordeliers Research Center, Paris-Diderot, Pierre et Marie Curie and Paris Descartes Universities, CNRS ERL 8228, Paris, France
| | - Andreas Kiesow
- Fraunhofer Institute for Mechanics of Materials IWM, Halle, Germany
| | - Matthias Petzold
- Fraunhofer Institute for Mechanics of Materials IWM, Halle, Germany
| | - Suzanne Menashi
- Laboratory CRRET, Paris-Est University, CNRS, Créteil, France
| | - Agnes Linglart
- Department of Pediatric Endocrinology, AP-HP, Paris Sud University, School of Medicine, and Reference Center for Rare Diseases of the Metabolism of Calcium and Phosphorus, Paris, France
| | - Ana Carolina Acevedo
- Division of Dentistry, Oral Care Center for Inherited Diseases, University Hospital of Brasilia, Faculty of Health Sciences, University of Brasilia (UnB), Brasilia, Brazil
| | - Rosa Vargas-Poussou
- Department of Genetics, AP-HP, and Reference Center of Children and Adult Renal Hereditary Diseases (MARHEA), European Hospital Georges Pompidou, Paris, France
| | - Dominik Müller
- Department of Pediatric Nephrology, Charité University School of Medicine, Berlin, Germany
| | - Pascal Houillier
- INSERM UMRS 1138, Cordeliers Research Center, Paris-Diderot, Pierre et Marie Curie and Paris Descartes Universities, CNRS ERL 8228, Paris, France.,Department of Physiology, AP-HP, and Reference Center of Children and Adult Renal Hereditary Diseases (MARHEA), Georges Pompidou European Hospital, Paris, France
| | - Catherine Chaussain
- EA 2496, Laboratory Orofacial Pathologies, Imaging and Biotherapies, Dental School Paris Descartes University, Sorbonne Paris Cité, France.,Department of Odontology, AP-HP, and Reference Center for Rare Diseases of the Metabolism of Calcium and Phosphorus, Nord Val de Seine Hospital, Bretonneau, France
| |
Collapse
|
36
|
Ida-Yonemochi H, Otsu K, Ohshima H, Harada H. The glycogen metabolism via Akt signaling is important for the secretion of enamel matrix in tooth development. Mech Dev 2016; 139:18-30. [PMID: 26809144 DOI: 10.1016/j.mod.2016.01.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 12/11/2015] [Accepted: 01/20/2016] [Indexed: 01/07/2023]
Abstract
Cells alter their energy metabolism depending on the stage of differentiation or various environments. In the ameloblast differentiation of continuous growing mouse incisors, we found temporary glycogen storage in preameloblasts before the start of enamel matrix secretion and investigated the relationship between enamel matrix secretion and glycogen metabolism. Immunohistochemistry showed that in the transitional stage from preameloblasts to secretory ameloblasts, the glycogen synthase changed from the inactive form to the active form, the expression of glycogen phosphorylase increased, and further, the levels of IGF-1, IGF-1 receptor and activated Akt increased. These results suggested that the activation of Akt signaling via IGF is linked to the onset of both glycogen metabolism and enamel matrix deposition. In the experiments using organ culture and ameloblast cell line, the activation of Akt signaling by IGF-1 stimulated glycogen metabolism through the up-regulation of Glut-1,-4 and Gsk-3β and the dephosphorylation of glycogen synthase. Subsequently, they resulted in increased enamel matrix secretion. In contrast, some inhibitors of Akt signals and glycogen synthesis/degradation down-regulated enamel matrix secretion. Taking these findings together, glycogen metabolism via Akt signaling is an essential system for the secretion of enamel matrix in ameloblast differentiation.
Collapse
Affiliation(s)
- Hiroko Ida-Yonemochi
- 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.
| | - Keishi Otsu
- Division of Developmental Biology and Regenerative Medicine, Department of Anatomy, Iwate Medical University, 2-1-1, Nishitokuda, Yahaba, Shiwa-gun, Iwate 028-3694, 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.
| | - Hidemitsu Harada
- Division of Developmental Biology and Regenerative Medicine, Department of Anatomy, Iwate Medical University, 2-1-1, Nishitokuda, Yahaba, Shiwa-gun, Iwate 028-3694, Japan.
| |
Collapse
|
37
|
Bori E, Guo J, Rácz R, Burghardt B, Földes A, Kerémi B, Harada H, Steward MC, Den Besten P, Bronckers ALJJ, Varga G. Evidence for Bicarbonate Secretion by Ameloblasts in a Novel Cellular Model. J Dent Res 2016; 95:588-96. [PMID: 26792171 DOI: 10.1177/0022034515625939] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Formation and growth of hydroxyapatite crystals during amelogenesis generate a large number of protons that must be neutralized, presumably by HCO3 (-)ions transported from ameloblasts into the developing enamel matrix. Ameloblasts express a number of transporters and channels known to be involved in HCO3 (-)transport in other epithelia. However, to date, there is no functional evidence for HCO3 (-)transport in these cells. To address questions related to HCO3 (-)export from ameloblasts, we have developed a polarized 2-dimensional culture system for HAT-7 cells, a rat cell line of ameloblast origin. HAT-7 cells were seeded onto Transwell permeable filters. Transepithelial resistance was measured as a function of time, and the expression of transporters and tight junction proteins was investigated by conventional and quantitative reverse transcription polymerase chain reaction. Intracellular pH regulation and HCO3 (-)transport were assessed by microfluorometry. HAT-7 cells formed epithelial layers with measureable transepithelial resistance on Transwell permeable supports and expressed claudin-1, claudin-4, and claudin-8-key proteins for tight junction formation. Transport proteins previously described in maturation ameloblasts were also present in HAT-7 cells. Microfluorometry showed that the HAT-7 cells were polarized with a high apical membrane CO2 permeability and vigorous basolateral HCO3 (-)uptake, which was sensitive to Na(+)withdrawal, to the carbonic anhydrase inhibitor acetazolamide and to H2DIDS inhibition. Measurements of transepithelial HCO3 (-)transport showed a marked increase in response to Ca(2+)- and cAMP-mobilizing stimuli. Collectively, 2-dimensional HAT-7 cell cultures on permeable supports 1) form tight junctions, 2) express typical tight junction proteins and electrolyte transporters, 3) are functionally polarized, and 4) can accumulate HCO3 (-)ions from the basolateral side and secrete them at the apical membrane. These studies provide evidence for a regulated, vectorial, basolateral-to-apical bicarbonate transport in polarized HAT-7 cells. We therefore propose that the HAT-7 cell line is a useful functional model for studying electrolyte transport by ameloblasts.
Collapse
Affiliation(s)
- E Bori
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | - J Guo
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam, University of Amsterdam and VU University Amsterdam, MOVE Research Institute, Amsterdam, Netherlands
| | - R Rácz
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | - B Burghardt
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | - A Földes
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | - B Kerémi
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | - H Harada
- Department of Anatomy, Division of Developmental Biology and Regenerative Medicine, Iwate Medical University, Iwate, Japan
| | - M C Steward
- Faculty of Life Sciences, The University of Manchester, Manchester, UK
| | - P Den Besten
- Department of Orofacial Sciences, University of California, San Francisco, CA, USA
| | - A L J J Bronckers
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam, University of Amsterdam and VU University Amsterdam, MOVE Research Institute, Amsterdam, Netherlands
| | - G Varga
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| |
Collapse
|
38
|
Mahdee A, Alhelal A, Eastham J, Whitworth J, Gillespie J. Complex cellular responses to tooth wear in rodent molar. Arch Oral Biol 2016; 61:106-14. [DOI: 10.1016/j.archoralbio.2015.10.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 09/03/2015] [Accepted: 10/05/2015] [Indexed: 11/30/2022]
|
39
|
Yin K, Lei Y, Wen X, Lacruz RS, Soleimani M, Kurtz I, Snead ML, White SN, Paine ML. SLC26A Gene Family Participate in pH Regulation during Enamel Maturation. PLoS One 2015; 10:e0144703. [PMID: 26671068 PMCID: PMC4679777 DOI: 10.1371/journal.pone.0144703] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 11/23/2015] [Indexed: 12/15/2022] Open
Abstract
The bicarbonate transport activities of Slc26a1, Slc26a6 and Slc26a7 are essential to physiological processes in multiple organs. Although mutations of Slc26a1, Slc26a6 and Slc26a7 have not been linked to any human diseases, disruption of Slc26a1, Slc26a6 or Slc26a7 expression in animals causes severe dysregulation of acid-base balance and disorder of anion homeostasis. Amelogenesis, especially the enamel formation during maturation stage, requires complex pH regulation mechanisms based on ion transport. The disruption of stage-specific ion transporters frequently results in enamel pathosis in animals. Here we present evidence that Slc26a1, Slc26a6 and Slc26a7 are highly expressed in rodent incisor ameloblasts during maturation-stage tooth development. In maturation-stage ameloblasts, Slc26a1, Slc26a6 and Slc26a7 show a similar cellular distribution as the cystic fibrosis transmembrane conductance regulator (Cftr) to the apical region of cytoplasmic membrane, and the distribution of Slc26a7 is also seen in the cytoplasmic/subapical region, presumably on the lysosomal membrane. We have also examined Slc26a1 and Slc26a7 null mice, and although no overt abnormal enamel phenotypes were observed in Slc26a1-/- or Slc26a7-/- animals, absence of Slc26a1 or Slc26a7 results in up-regulation of Cftr, Ca2, Slc4a4, Slc4a9 and Slc26a9, all of which are involved in pH homeostasis, indicating that this might be a compensatory mechanism used by ameloblasts cells in the absence of Slc26 genes. Together, our data show that Slc26a1, Slc26a6 and Slc26a7 are novel participants in the extracellular transport of bicarbonate during enamel maturation, and that their functional roles may be achieved by forming interaction units with Cftr.
Collapse
Affiliation(s)
- Kaifeng Yin
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry of University of Southern California, Los Angeles, California, United States of America
| | - Yuejuan Lei
- Department of Operative and Endodontics, The Affiliated Stomatological Hospital, Guangxi Medical University, Nanning, Guangxi, China
| | - Xin Wen
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry of University of Southern California, Los Angeles, California, United States of America
| | - Rodrigo S. Lacruz
- Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, New York, United States of America
| | - Manoocher Soleimani
- Department of Medicine, University of Cincinnati, Research Services, Veterans Affairs Medical Center, Cincinnati, Ohio, United States of America
| | - Ira Kurtz
- Division of Nephrology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, United States of America
| | - Malcolm L. Snead
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry of University of Southern California, Los Angeles, California, United States of America
| | - Shane N. White
- School of Dentistry, University of California Los Angeles, Los Angeles, California, United States of America
| | - Michael L. Paine
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry of University of Southern California, Los Angeles, California, United States of America
- * E-mail:
| |
Collapse
|
40
|
V-type ATPase proton pump expression during enamel formation. Matrix Biol 2015; 52-54:234-245. [PMID: 26586472 DOI: 10.1016/j.matbio.2015.11.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 10/29/2015] [Accepted: 11/09/2015] [Indexed: 01/12/2023]
Abstract
Several diseases such as proximal and distal renal tubular acidosis and osteoporosis are related to intracellular pH dysregulation resulting from mutations in genes coding for ion channels, including proteins comprising the proton-pumping V-type ATPase. V-type ATPase is a multi-subunit protein complex expressed in enamel forming cells. V-type ATPase plays a key role in enamel development, specifically lysosomal acidification, yet our understanding of the relationship between the endocytotic activities and dental health and disease is limited. The objective of this study is to better understand the ameloblast-associated pH regulatory networks essential for amelogenesis. Quantitative RT-PCR was performed on tissues from secretory-stage and maturation-stage enamel organs to determine which of the V-type ATPase subunits are most highly upregulated during maturation-stage amelogenesis: a time when ameloblast endocytotic activity is highest. Western blot analyses, using specific antibodies to four of the V-type ATPase subunits (Atp6v0d2, Atp6v1b2, Atp6v1c1 and Atp6v1e1), were then applied to validate much of the qPCR data. Immunohistochemistry using these same four antibodies was also performed to identify the spatiotemporal expression profiles of individual V-type ATPase subunits. Our data show that cytoplasmic V-type ATPase is significantly upregulated in enamel organ cells during maturation-stage when compared to secretory-stage. These data likely relate to the higher endocytotic activities, and the greater need for lysosomal acidification, during maturation-stage amelogenesis. It is also apparent from our immunolocalization data, using antibodies against two of the V-type ATPase subunits (Atp6v1c1 and Atp6v1e1), that significant expression is seen at the apical membrane of maturation-stage ameloblasts. Others have also identified this V-type ATPase expression profile at the apical membrane of maturation ameloblasts. Collectively, these data better define the expression and role of the V-type ATPase proton pump in the enamel organ during amelogenesis.
Collapse
|
41
|
Paulsen IMS, Dimke H, Frische S. A single simple procedure for dewaxing, hydration and heat-induced epitope retrieval (HIER) for immunohistochemistry in formalin fixed paraffin-embedded tissue. Eur J Histochem 2015; 59:2532. [PMID: 26708177 PMCID: PMC4698609 DOI: 10.4081/ejh.2015.2532] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 10/12/2015] [Accepted: 10/14/2015] [Indexed: 11/22/2022] Open
Abstract
Heat-induced epitope retrieval (HIER) is widely used for immunohistochemistry on formalin fixed paraffin-embedded tissue and includes temperatures well above the melting point of paraffin. We therefore tested whether traditional xylene-based removal of paraffin is required on sections from paraffin-embedded tissue, when HIER is performed by vigorous boiling in 10 mM Tris/0.5 mM EGTA-buffer (pH=9). Immunohistochemical results using HIER with or without prior dewaxing in xylene were evaluated using 7 primary antibodies targeting proteins located in the cytosol, intracellular vesicles and plasma membrane. No effect of omitting prior dewaxing was observed on staining pattern. Semiquantitative analysis did not show HIER to influence the intensity of labelling consistently. Consequently, quantification of immune labelling intensity using fluorescent secondary antibodies was performed at 5 dilutions of primary antibody with and without prior dewaxing in xylene. No effect of omitting prior dewaxing on signal intensity was detectable indicating similar immunoreactivity in dewaxed and non-dewaxed sections. The intensity of staining the nucleus with the DNA-stain ToPro3 was similarly unaffected by omission of dewaxing in xylene. In conclusion, the HIER procedure described and tested can be used as a single procedure enabling dewaxing, hydration and epitope retrieval for immunohistochemistry in formalin fixed paraffin-embedded tissue.
Collapse
|
42
|
Bronckers ALJJ, Lyaruu D, Jalali R, Medina JF, Zandieh-Doulabi B, DenBesten PK. Ameloblast Modulation and Transport of Cl⁻, Na⁺, and K⁺ during Amelogenesis. J Dent Res 2015; 94:1740-7. [PMID: 26403673 DOI: 10.1177/0022034515606900] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Ameloblasts express transmembrane proteins for transport of mineral ions and regulation of pH in the enamel space. Two major transporters recently identified in ameloblasts are the Na(+)K(+)-dependent calcium transporter NCKX4 and the Na(+)-dependent HPO4 (2-) (Pi) cotransporter NaPi-2b. To regulate pH, ameloblasts express anion exchanger 2 (Ae2a,b), chloride channel Cftr, and amelogenins that can bind protons. Exposure to fluoride or null mutation of Cftr, Ae2a,b, or Amelx each results in formation of hypomineralized enamel. We hypothesized that enamel hypomineralization associated with disturbed pH regulation results from reduced ion transport by NCKX4 and NaPi-2b. This was tested by correlation analyses among the levels of Ca, Pi, Cl, Na, and K in forming enamel of mice with null mutation of Cftr, Ae2a,b, and Amelx, according to quantitative x-ray electron probe microanalysis. Immunohistochemistry, polymerase chain reaction analysis, and Western blotting confirmed the presence of apical NaPi-2b and Nckx4 in maturation-stage ameloblasts. In wild-type mice, K levels in enamel were negatively correlated with Ca and Cl but less negatively or even positively in fluorotic enamel. Na did not correlate with P or Ca in enamel of wild-type mice but showed strong positive correlation in fluorotic and nonfluorotic Ae2a,b- and Cftr-null enamel. In hypomineralizing enamel of all models tested, 1) Cl(-) was strongly reduced; 2) K(+) and Na(+) accumulated (Na(+) not in Amelx-null enamel); and 3) modulation was delayed or blocked. These results suggest that a Na(+)K(+)-dependent calcium transporter (likely NCKX4) and a Na(+)-dependent Pi transporter (potentially NaPi-2b) located in ruffle-ended ameloblasts operate in a coordinated way with the pH-regulating machinery to transport Ca(2+), Pi, and bicarbonate into maturation-stage enamel. Acidification and/or associated physicochemical/electrochemical changes in ion levels in enamel fluid near the apical ameloblast membrane may reduce the transport activity of mineral transporters, which results in hypomineralization.
Collapse
Affiliation(s)
- A L J J Bronckers
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam, University of Amsterdam, and MOVE Research Institute, VU University Amsterdam, Amsterdam, Netherlands
| | - D Lyaruu
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam, University of Amsterdam, and MOVE Research Institute, VU University Amsterdam, Amsterdam, Netherlands
| | - R Jalali
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam, University of Amsterdam, and MOVE Research Institute, VU University Amsterdam, Amsterdam, Netherlands
| | - J F Medina
- Division of Gene Therapy and Hepatology, School of Medicine/CIMA, University of Navarra, and CIBERehd, Pamplona, Spain
| | - B Zandieh-Doulabi
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam, University of Amsterdam, and MOVE Research Institute, VU University Amsterdam, Amsterdam, Netherlands
| | - P K DenBesten
- Department of Oral Sciences, University of California, San Francisco, CA, USA
| |
Collapse
|
43
|
Jalali R, Zandieh-Doulabi B, DenBesten PK, Seidler U, Riederer B, Wedenoja S, Micha D, Bronckers ALJJ. Slc26a3/Dra and Slc26a6 in Murine Ameloblasts. J Dent Res 2015; 94:1732-9. [PMID: 26394631 DOI: 10.1177/0022034515606873] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Formation of apatite crystals during enamel development generates protons. To sustain mineral accretion, maturation ameloblasts need to buffer these protons. The presence of cytosolic carbonic anhydrases, the basolateral Na(+) bicarbonate cotransporter Nbce1, and the basolateral anion exchanger Ae2a,b in maturation ameloblasts suggests that these cells secrete bicarbonates into the forming enamel, but it is unknown by which mechanism. Solute carrier (Slc) family 26A encodes different anion exchangers that exchange Cl(-)/HCO3 (-), including Slc26a3/Dra, Slc26a6/Pat-1, and Slc26a4/pendrin. Previously, we showed that pendrin is expressed in ameloblasts but is not critical for enamel formation. In this study, we tested the hypothesis that maturation ameloblasts express Dra and Slc26a6 to secrete bicarbonate into the enamel space in exchange for Cl(-). Real-time polymerase chain reaction detected mRNA transcripts for Dra and Slc26a6 in mouse incisor enamel organs, and Western blotting confirmed their translation into protein. Both isoforms were immunolocalized in ameloblasts, principally at maturation stage. Mice with null mutation of either Dra or Slc26a6 had a normal dental or skeletal phenotype without changes in mineral density, as measured by micro-computed tomography. In enamel organs of Slc26a6-null mice, Dra and pendrin protein levels were both elevated by 52% and 55%, respectively. The amount of Slc26a6 protein was unchanged in enamel organs of Ae2a,b- and Cftr-null mice but reduced in Dra-null mice by 36%. Our data show that ameloblasts express Dra, pendrin, or Slc26a6 but each of these separately is not critical for formation of dental enamel. The data suggest that in ameloblasts, Slc26a isoforms can functionally compensate for one another.
Collapse
Affiliation(s)
- R Jalali
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam, University of Amsterdam, and MOVE Research Institute, VU University Amsterdam, Amsterdam, Netherlands
| | - B Zandieh-Doulabi
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam, University of Amsterdam, and MOVE Research Institute, VU University Amsterdam, Amsterdam, Netherlands
| | - P K DenBesten
- Department of Oral Sciences, University of California, San Francisco, CA, USA
| | - U Seidler
- Abteilung Gastroenterologie, Hepatologie und Endokrinologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - B Riederer
- Abteilung Gastroenterologie, Hepatologie und Endokrinologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - S Wedenoja
- Department of Medical Genetics, Biomedicum Helsinki, University of Helsinki, Finland
| | - D Micha
- Department of Clinical Genetics, Vrije Universiteit Medical Center, Amsterdam, Netherlands
| | - A L J J Bronckers
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam, University of Amsterdam, and MOVE Research Institute, VU University Amsterdam, Amsterdam, Netherlands
| |
Collapse
|
44
|
Athanassiou-Papaefthymiou M, Papagerakis P, Papagerakis S. Isolation and Characterization of Human Adult Epithelial Stem Cells from the Periodontal Ligament. J Dent Res 2015; 94:1591-600. [PMID: 26392003 DOI: 10.1177/0022034515606401] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
We report a novel method for the isolation of adult human epithelial stem cells (hEpiSCs) from the epithelial component of the periodontal ligament-the human epithelial cell rests of Malassez (hERM). hEpiSC-rich integrin-α6(+ve) hERM cells derived by fluorometry can be clonally expanded, can grow organoids, and express the markers of pluripotency (OCT4, NANOG, SOX2), polycomb protein RING1B, and the hEpiSC supermarker LGR5. They maintain the growth profile of their originating hERM in vitro. Subcutaneous cotransplantation with mesenchymal stem cells from the dental pulp on poly-l-lactic acid scaffolds in nude mice gave rise to perfect heterotopic ossicles in vivo with ultrastructure of dentin, enamel, cementum, and bone. These remarkable fully mineralized ossicles underscore the importance of epithelial-mesenchymal crosstalk in tissue regeneration using human progenitor stem cells, which may have already committed to lineage despite maintaining hallmarks of pluripotency. In addition, we report the clonal expansion and isolation of human LGR5(+ve) cells from the hERM in xeno-free culture conditions. The genetic profile of LGR5(+ve) cells includes both markers of pluripotency and genes important for secretory epithelial and dental epithelial cell differentiation, giving us a first insight into periodontal ligament-derived hEpiSCs.
Collapse
Affiliation(s)
- M Athanassiou-Papaefthymiou
- Laboratory of Tooth Organogenesis and Regeneration, Department of Orthodontics and Pediatric Medicine, School of Dentistry; Center for Organogenesis, School of Medicine; Center for Computational Medicine and Bioinformatics; University of Michigan, Ann Arbor, MI, USA Laboratory for Oral, Head, and Neck Cancer Metastasis, Kresge Hearing Research Institute, Department of Otolaryngology and Comprehensive Cancer Center, Medical School, University of Michigan, Ann Arbor, MI, USA The Cancer Cure, Ann Arbor, MI, USA
| | - P Papagerakis
- Laboratory of Tooth Organogenesis and Regeneration, Department of Orthodontics and Pediatric Medicine, School of Dentistry; Center for Organogenesis, School of Medicine; Center for Computational Medicine and Bioinformatics; University of Michigan, Ann Arbor, MI, USA
| | - S Papagerakis
- Laboratory for Oral, Head, and Neck Cancer Metastasis, Kresge Hearing Research Institute, Department of Otolaryngology and Comprehensive Cancer Center, Medical School, University of Michigan, Ann Arbor, MI, USA Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| |
Collapse
|
45
|
Guo J, Bervoets TJM, Henriksen K, Everts V, Bronckers ALJJ. Null mutation of chloride channel 7 (Clcn7) impairs dental root formation but does not affect enamel mineralization. Cell Tissue Res 2015; 363:361-70. [PMID: 26346547 PMCID: PMC4735262 DOI: 10.1007/s00441-015-2263-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 07/29/2015] [Indexed: 12/23/2022]
Abstract
ClC-7, located in late endosomes and lysosomes, is critical for the function of osteoclasts. Secretion of Cl(-) by the ruffled border of osteoclasts enables H(+) secretion by v-H(+)-ATPases to dissolve bone mineral. Mice lacking ClC-7 show altered lysosomal function that leads to severe lysosomal storage. Maturation ameloblasts are epithelial cells with a ruffled border that secrete Cl(-) as well as endocytose and digest large quantities of enamel matrix proteins during formation of dental enamel. We tested the hypothesis that ClC-7 in maturation ameloblasts is required for intracellular digestion of matrix fragments to complete enamel mineralization. Craniofacial bones and developing teeth in Clcn7(-/-) mice were examined by micro-CT, immunohistochemistry, quantified histomorphometry and electron microscopy. Osteoclasts and ameloblasts in wild-type mice stained intensely with anti-ClC-7 antibody but not in Clcn7(-/-) mice. Craniofacial bones in Clcn7(-/-) mice were severely osteopetrotic and contained 1.4- to 1.6-fold more bone volume, which was less mineralized than the wild-type littermates. In Clcn7(-/-) mice maturation ameloblasts and osteoclasts highly expressed Ae2 as in wild-type mice. However, teeth failed to erupt, incisors were much shorter and roots were disfigured. Molars formed a normal dental crown. In compacted teeth, dentin was slightly less mineralized, enamel did not retain a matrix and mineralized fairly normal. We concluded that ClC-7 is essential for osteoclasts to resorb craniofacial bones to enable tooth eruption and root development. Disruption of Clcn7 reduces bone and dentin mineral density but does not affect enamel mineralization.
Collapse
Affiliation(s)
- Jing Guo
- Department Oral Cell Biology, Academic Center of Dentistry Amsterdam (ACTA), University of Amsterdam and VU-University of Amsterdam, MOVE Research Institute, Gustav Mahlerlaan 3004, 1081 LA, Amsterdam, The Netherlands. .,School of Stomatology/Dental Clinic, Zhejiang Chinese Medical University, Mailbox 97, Binwen Road 548, Binjiang District, 310053, Hangzhou, China.
| | - Theodore J M Bervoets
- Department Oral Cell Biology, Academic Center of Dentistry Amsterdam (ACTA), University of Amsterdam and VU-University of Amsterdam, MOVE Research Institute, Gustav Mahlerlaan 3004, 1081 LA, Amsterdam, The Netherlands
| | - Kim Henriksen
- Nordic Bioscience Biomarkers and Research A/S, Hovedgade 207, 2730, Herlev, Denmark
| | - Vincent Everts
- Department Oral Cell Biology, Academic Center of Dentistry Amsterdam (ACTA), University of Amsterdam and VU-University of Amsterdam, MOVE Research Institute, Gustav Mahlerlaan 3004, 1081 LA, Amsterdam, The Netherlands
| | - Antonius L J J Bronckers
- Department Oral Cell Biology, Academic Center of Dentistry Amsterdam (ACTA), University of Amsterdam and VU-University of Amsterdam, MOVE Research Institute, Gustav Mahlerlaan 3004, 1081 LA, Amsterdam, The Netherlands
| |
Collapse
|
46
|
Varga G, Kerémi B, Bori E, Földes A. Function and repair of dental enamel - Potential role of epithelial transport processes of ameloblasts. Pancreatology 2015; 15:S55-60. [PMID: 25747281 DOI: 10.1016/j.pan.2015.01.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 01/28/2015] [Indexed: 12/11/2022]
Abstract
The hardest mammalian tissue, dental enamel is produced by ameloblasts, which are electrolyte-transporting epithelial cells. Although the end product is very different, they show many similarities to transporting epithelia of the pancreas, salivary glands and kidney. Enamel is produced in a multi-step epithelial secretory process that features biomineralization which is an interplay of secreted ameloblast specific proteins and the time-specific transport of minerals, protons and bicarbonate. First, "secretory" ameloblasts form the entire thickness of the enamel layer, but with low mineral content. Then they differentiate into "maturation" ameloblasts, which remove organic matrix from the enamel and in turn further build up hydroxyapatite crystals. The protons generated by hydroxyapatite formation need to be buffered, otherwise enamel will not attain full mineralization. Buffering requires a tight pH regulation and secretion of bicarbonate by ameloblasts. The whole process has been the focus of many immunohistochemical and gene knock-out studies, but, perhaps surprisingly, no functional data existed for mineral ion transport by ameloblasts. However, recent studies including ours provided a better insight for molecular mechanism of mineral formation. The secretory regulation is not completely known as yet, but its significance is crucial. Impairing regulation retards or prevents completion of enamel mineralization and results in the development of hypomineralized enamel that easily erodes after dental eruption. Factors that impair this function are fluoride and disruption of pH regulators. Revealing these factors may eventually lead to the treatment of enamel hypomineralization related to genetic or environmentally induced malformation.
Collapse
Affiliation(s)
- Gábor Varga
- Department of Oral Biology, Semmelweis University, Budapest, Hungary.
| | - Beáta Kerémi
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | - Erzsébet Bori
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | - Anna Földes
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| |
Collapse
|
47
|
MicroRNA 224 Regulates Ion Transporter Expression in Ameloblasts To Coordinate Enamel Mineralization. Mol Cell Biol 2015; 35:2875-90. [PMID: 26055330 DOI: 10.1128/mcb.01266-14] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 06/04/2015] [Indexed: 02/05/2023] Open
Abstract
Enamel mineralization is accompanied by the release of protons into the extracellular matrix, which is buffered to regulate the pH value in the local microenvironment. The present study aimed to investigate the role of microRNA 224 (miR-224) as a regulator of SLC4A4 and CFTR, encoding the key buffering ion transporters, in modulating enamel mineralization. miR-224 was significantly downregulated as ameloblasts differentiated, in parallel with upregulation of SLC4A4 and CFTR. Overexpression of miR-224 downregulated SLC4A4 and CFTR expression in cultured human epithelial cells. A microRNA luciferase assay confirmed the specific binding of miR-224 to the 3' untranslated regions (UTRs) of SLC4A4 and CFTR mRNAs, thereby inhibiting protein translation. miR-224 agomir injection in mouse neonatal incisors resulted in normal enamel length and thickness, but with disturbed organization of the prism structure and deficient crystal growth. Moreover, the enamel Ca/P ratio and microhardness were markedly reduced after miR-224 agomir administration. These results demonstrate that miR-224 plays a pivotal role in fine tuning enamel mineralization by modulating SLC4A4 and CFTR to maintain pH homeostasis and support enamel mineralization.
Collapse
|
48
|
Nishikawa S, Kawamoto T. Localization of Core Planar Cell Polarity Proteins, PRICKLEs, in Ameloblasts of Rat Incisors: Possible Regulation of Enamel Rod Decussation. Acta Histochem Cytochem 2015; 48:37-45. [PMID: 26175546 PMCID: PMC4427563 DOI: 10.1267/ahc.14046] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 03/06/2015] [Indexed: 01/22/2023] Open
Abstract
To confirm the possible involvement of planar cell polarity proteins in odontogenesis, one group of core proteins, PRICKLE1, PRICKLE2, PRICKLE3, and PRICKLE4, was examined in enamel epithelial cells and ameloblasts by immunofluorescence microscopy. PRICKLE1 and PRICKLE2 showed similar localization in the proliferation and secretory zones of the incisor. Immunoreactive dots and short rods in ameloblasts and stratum intermedium cells were evident in the proliferation to differentiation zone, but in the secretion zone, cytoplasmic dots decreased and the distal terminal web was positive for PRICKLE1 and PRICKLE2. PRICKLE3 and PRICKLE4 showed cytoplasmic labeling in ameloblasts and other enamel epithelial cells. Double labeling of PRICKLE2 with VANGL1, which is another planar cell polarity protein, showed partial co-localization. To examine the transport route of PRICKLE proteins, PRICKLE1 localization was examined after injection of a microtubule-disrupting reagent, colchicine, and was compared with CX43, which is a membrane protein transported as vesicles via microtubules. The results confirmed the retention of immunoreactive dots for PRICKLE1 in the cytoplasm of secretory ameloblasts of colchicine-injected animals, but fewer dots were observed in control animals. These results suggest that PRICKLE1 and PRICKLE2 are transported as vesicles to the junctional area, and are involved in pattern formation of distal junctional complexes and terminal webs of ameloblasts, further implying a role in the formed enamel rod arrangement.
Collapse
Affiliation(s)
- Sumio Nishikawa
- Department of Biology, Tsurumi University School of Dental Medicine
| | - Tadafumi Kawamoto
- Radioisotope Research Institute, Tsurumi University School of Dental Medicine
| |
Collapse
|
49
|
Melin L, Lundgren J, Malmberg P, Norén JG, Taube F, Cornell DH. XRMA and ToF-SIMS Analysis of Normal and Hypomineralized Enamel. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2015; 21:407-421. [PMID: 25674916 DOI: 10.1017/s1431927615000033] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Molar incisor hypomineralization (MIH) is a developmental disturbance of the enamel. This study presents analyses of hypomineralized and normal enamel in first molar teeth diagnosed with MIH, utilizing time-of-flight secondary ion mass spectrometry area analyses and X-ray microanalysis of area and spot profiles in uncoated samples between gold lines which provide electrical conductivity. Statistical analysis of mean values allows discrimination of normal from MIH enamel, which has higher Mg and lower Na and P. Inductive analysis using complete data sets for profiles from the enamel surface to the enamel-dentin junction found that Mg, Cl and position in the profile provide useful discrimination criteria. Element profiles provide a visual complement to the inductive analysis and several elements also provide insight into the development of both normal and MIH enamel. The higher Mg content and different Cl profiles of hypomineralized enamel compared with normal enamel are probably related to a relatively short period during the development of ameloblasts between birth and the 1st year of life.
Collapse
Affiliation(s)
- Lisa Melin
- 1Department of Pediatric Dentistry,Institute of Odontology at the Sahlgrenska Academy,University of Gothenburg,P.O. Box 450,SE 405 30 Gothenburg,Sweden
| | - Jesper Lundgren
- 2Department of Psychology,University of Gothenburg,P.O. Box 500,SE 405 30 Gothenburg,Sweden
| | - Per Malmberg
- 3Department of Chemical and Biological Engineering,Chalmers University of Technology,Kemivägen 10,412 96 Gothenburg,Sweden
| | - Jörgen G Norén
- 1Department of Pediatric Dentistry,Institute of Odontology at the Sahlgrenska Academy,University of Gothenburg,P.O. Box 450,SE 405 30 Gothenburg,Sweden
| | - Fabian Taube
- 4Department of Occupational and Environmental Medicine,Sahlgrenska University Hospital,P.O. Box 414,SE 405 30 Gothenburg,Sweden
| | - David H Cornell
- 5Department of Earth Sciences,University of Gothenburg,P.O. Box 460,SE 405 30 Gothenburg,Sweden
| |
Collapse
|
50
|
Wen X, Lacruz RS, Paine ML. Dental and Cranial Pathologies in Mice Lacking the Cl(-) /H(+) -Exchanger ClC-7. Anat Rec (Hoboken) 2015; 298:1502-8. [PMID: 25663454 DOI: 10.1002/ar.23118] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2014] [Revised: 12/01/2014] [Accepted: 12/05/2014] [Indexed: 11/10/2022]
Abstract
ClC-7 is a 2Cl(-) /1H(+) -exchanger expressed at late endosomes and lysosomes, as well as the ruffled border of osteoclasts. ClC-7 deficiencies in mice and humans lead to impaired osteoclast function and therefore osteopetrosis. Failure of tooth eruption is also apparent in ClC-7 mutant animals, and this has been attributed to the osteoclast dysfunction and the subsequent defect in alveolar bone resorptive activity surrounding tooth roots. Ameloblasts also express ClC-7, and this study aims to determine the significance of ClC-7 in enamel formation by examining the dentitions of ClC-7 mutant mice. Micro-CT analysis revealed that the molar teeth of 3-week old ClC-7 mutant mice had no roots, and the incisors were smaller than their age-matched controls. Despite these notable developmental differences, the enamel and dentin densities of the mutant mice were comparable to those of the wild-type littermates. Scanning electron microscopy showed normal enamel crystallite and prismatic organization in the ClC-7 mutant mice, although the enamel was thinner (hypoplastic) than in controls. These results suggested that ClC-7 was not critical to enamel and dentin formation, and the observed tooth defects may be related more to a resulting alveolar bone phenotype. Micro-CT analysis also revealed abnormal features in the calvarial bones of the mutant mice. The cranial sutures in ClC-7 mutant mice remained open compared to the closed sutures seen in the control mice at 3 weeks. These data demonstrate that ClC-7 deficiency impacts the development of the dentition and calvaria, but does not significantly disrupt amelogenesis.
Collapse
Affiliation(s)
- Xin Wen
- Herman Ostrow School of Dentistry of USC, Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, USA
| | - Rodrigo S Lacruz
- Department of Basic Science and Craniofacial Biology, College of Dentistry, New York University, New York, New York, USA
| | - Michael L Paine
- Herman Ostrow School of Dentistry of USC, Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, USA
| |
Collapse
|