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Liang J, Wang J, Ye C, Bai Y, Tong Y, Li Y, Ji Y, Zhang Y. Ptip is essential for tooth development via regulating Wnt pathway. Oral Dis 2024; 30:1451-1461. [PMID: 36648392 DOI: 10.1111/odi.14509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 01/03/2023] [Accepted: 01/09/2023] [Indexed: 01/18/2023]
Abstract
OBJECTIVE Epigenetic regulation plays important role in stem cell maintenance. Ptip was identified as epigenetic regulator, but the role in dental progenitor cells remains unclear. SUBJECTS AND METHODS Dental mesenchymal progenitor cells were targeted by Sp7-icre and visualized in mTmG; Sp7-icre mice. The Ptipf/f; Sp7-icre mice were generated and the phenotype of incisors and molars were shown by micro-computerized tomography, scanning electron microscope, hematoxylin & eosin staining, and immunofluorescence. Dental mesenchymal progenitor cells were sorted by fluorescence-activated cell sorting from lower incisors and RNA sequencing was performed. RESULTS The Sp7-icre targets dental mesenchymal progenitor cells in incisors and molars. The Ptipf/f; Sp7-icre mice showed spontaneous fractures in the cusp of upper incisors and lower incisors at 3 weeks (w), compensative overgrowth of lower incisors at 1 month (M), and overgrowth extended to the outside at 2 M. The molars showed shortened roots. The functions of odontoblasts and dental mesenchymal progenitor cells were impaired. Mechanically, loss of Ptip activates the Wnt pathway and upregulates the expression of Wls in dental mesenchymal progenitor cells. Also, the regenerative ability of lower incisors was significantly impaired. CONCLUSION We first demonstrated that Ptip was crucial for tooth development via regulating Wnt signaling.
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Affiliation(s)
- Jianfei Liang
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, China
- Laboratory Center of Stomatology, College of Stomatology, Xi'an Jiaotong University, Xi'an, China
- Department of Implant Dentistry, College of Stomatology, Xi'an Jiaotong University, Xi'an, China
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine, Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Jing Wang
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, China
- Medical Research Institute, School of Medicine, Wuhan University, Wuhan, China
| | - Chen Ye
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, China
| | - Yi Bai
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, China
| | - Yibo Tong
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Biomedicine and Health, Huazhong Agricultural University, Wuhan, China
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Yashu Li
- Medical Research Institute, School of Medicine, Wuhan University, Wuhan, China
| | - Yaoting Ji
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, China
| | - Yufeng Zhang
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, China
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2
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Yang Y, Zhu J, Chiba Y, Fukumoto S, Qin M, Wang X. Enamel defects of Axenfeld-Rieger syndrome and the role of PITX2 in its pathogenesis. Oral Dis 2023; 29:3654-3664. [PMID: 35836351 DOI: 10.1111/odi.14315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 06/09/2022] [Accepted: 07/06/2022] [Indexed: 11/27/2022]
Abstract
OBJECTIVES To investigate the detailed ultrastructural patterns of dental abnormalities affected by Axenfeld-Rieger syndrome (ARS) with a heterozygous microdeletion involving paired-like homeodomain 2 (PITX2) and explored the underlying molecular mechanisms driving enamel defects. SUBJECTS AND METHODS Sanger sequencing, genomic quantitative PCR analysis, and chromosomal microarray analysis (CMA) were used to screen the disease-causing mutation in one ARS proband. An exfoliated tooth from an ARS patient was analyzed with scanning electron microscopy and micro-computerized tomography. A stable Pitx2 knockdown cell line was generated to simulate PITX2 haploinsufficiency. Cell proliferation and ameloblast differentiation were analyzed, and the role of the Wnt/β-catenin pathway in proliferation of ameloblast precursor cells was investigated. RESULTS An approximately 0.216 Mb novel deletion encompassing PITX2 was identified. The affected tooth displayed a thinner and broken layer of enamel and abnormal enamel biomineralization. PITX2 downregulation inhibited the proliferation and differentiation of inner enamel epithelial cells, and LiCl stifmulation partially reversed the proliferation ability after Pitx2 knockdown. CONCLUSIONS Enamel formation is disturbed in some patients with ARS. Pitx2 knockdown can influence the proliferation and ameloblast differentiation of inner enamel epithelial cells, and PITX2 may regulate cell proliferation via Wnt/β-catenin signaling pathway.
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Affiliation(s)
- Yi Yang
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, China
| | - Junxia Zhu
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, China
| | - Yuta Chiba
- Division of Oral Health, Section of Oral Medicine for Children, Growth and Development, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Satoshi Fukumoto
- Division of Oral Health, Section of Oral Medicine for Children, Growth and Development, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
- Division of Pediatric Dentistry, Department of Oral Health and Development Sciences, Tohoku University Graduate School of Dentistry, Sendai, Japan
| | - Man Qin
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, China
| | - Xin Wang
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, China
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3
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Kyrkanides S, Trochesset D, Cordero‐Ricardo M, Brouxhon SM. Conditional ablation of E‐cadherin in the oral epithelium progeny results in tooth anomalies. Clin Exp Dent Res 2022; 8:1185-1191. [PMID: 35703471 PMCID: PMC9562492 DOI: 10.1002/cre2.612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 06/01/2022] [Accepted: 06/04/2022] [Indexed: 11/06/2022] Open
Abstract
Objectives The objective of this study is to confirm the developmental origin of the enamel organ and evaluate the role of E‐cadherin in tooth development by conditional deletion in the oral epithelium and its enamel organ progeny. K5‐Cre;ROSA26 compound mice were included in this study in order to confirm the oral epithelial origin of the enamel organ, as well as of the action of the K5‐Cre transgene in ablating E‐cadherin in the enamel organ. K5‐Cre;Ecadfl/fl knockout mice were included to evaluate the effects of the conditional E‐cadherin ablation onto tooth development. Material and Methods K5‐Cre transgenic mice were crossed into the ROSA26 reporter mouse to trace the cell fate of the oral epithelium and its progeny in vivo. Moreover, K5‐Cre mice were crossed into the Ecadfl/fl mice to produce K5‐Cre;Ecadfl/fl compound mouse, as well as K5‐Cre;Ecadfl/+ and Ecadfl/fl littermate controls. These litters were euthanized at postnatal day P2 to study the effects of conditional E‐cadherin ablation in vivo. Results The K5‐Cre;ROSA26 compound mouse demonstrated that the origin of the enamel organ and the structures thereof are of oral epithelial origin. Furthermore, using the K5‐Cre;Ecadfl/fl compound mouse, we determined that conditional ablation of E‐cadherin in the oral epithelium, and its progeny, results in dental anomalies involving elongation of the molar root, shrinkage of the pulp space, and alterations of the periapical area, including cementum hyperplasia. The K5‐Cre;Ecadfl/fl mice also displayed a smaller overall stature compared with heterozygotes and wild‐type littermates. Conclusions E‐cadherin is important in tooth development, including the formation of enamel, the crown, pulp space, and the roots.
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Affiliation(s)
- Stephanos Kyrkanides
- Department of Oral Health Science, College of Dentistry University of Kentucky Lexington Kentucky USA
- Department of Neuroscience (Adjunct), School of Medicine and Dentistry University of Rochester Rochester New York USA
| | - Denise Trochesset
- Oral and Maxillofacial Pathology, Radiology and Medicine New York University New York New York USA
| | - Maria Cordero‐Ricardo
- Department of Pediatric Dentistry, Maurice H Kornberg School of Dentistry Temple University Philadelphia Pennsylvania USA
| | - Sabine M. Brouxhon
- Department of Physiology and Biophysics Stony Brook University Stony Brook New York USA
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4
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Abstract
The tooth provides an excellent system for deciphering the molecular mechanisms of organogenesis, and has thus been of longstanding interest to developmental and stem cell biologists studying embryonic morphogenesis and adult tissue renewal. In recent years, analyses of molecular signaling networks, together with new insights into cellular heterogeneity, have greatly improved our knowledge of the dynamic epithelial-mesenchymal interactions that take place during tooth development and homeostasis. Here, we review recent progress in the field of mammalian tooth morphogenesis and also discuss the mechanisms regulating stem cell-based dental tissue homeostasis, regeneration and repair. These exciting findings help to lay a foundation that will ultimately enable the application of fundamental research discoveries toward therapies to improve oral health.
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Affiliation(s)
- Tingsheng Yu
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California, San Francisco, CA 94143, USA
| | - Ophir D Klein
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California, San Francisco, CA 94143, USA
- Department of Pediatrics and Institute for Human Genetics, University of California, San Francisco, CA 94143, USA
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5
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Yu M, Jiang Z, Wang Y, Xi Y, Yang G. Molecular mechanisms for short root anomaly. Oral Dis 2020; 27:142-150. [PMID: 31883171 DOI: 10.1111/odi.13266] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 12/11/2019] [Accepted: 12/19/2019] [Indexed: 12/20/2022]
Abstract
Short root anomaly (SRA) is a dental disorder that presents an abnormal root morphology with short and blunt dental roots. In this situation, many dental treatments face a difficult challenge, especially orthodontic and prosthodontic treatments. Therefore, an understanding of how SRA develops is urgently needed. Here we describe that the abnormal expression of nuclear factor I C-type (Nfic), osterix (Osx), hedgehog (Hh), bone morphogenetic proteins (BMPs), transforming growth factor-β (TGF-β), Smad, Wnt, β-catenin, and dickkopf-related protein 1 (DKK1) leads to SRA. These factors interact with each other and constitute complicated signaling network in tooth formation. Specifically, BMP signaling inhibits the activity of Wnt/β-catenin directly or by inducing Osx via Runx2-dependent and Runx2-independent pathways. And Osx is a main inhibitor of Wnt/β-catenin signaling. In return, Wnt/β-catenin signaling has an antagonistic action of BMP pathway and a stimulation of Runx2. We highlight the importance of Wnt/β-catenin signaling in the pathological mechanisms. Either suppression or overactivation of this signaling influences the normal odontogenesis. Finally, we list rescue experiments on animal models, which have been reported to restore the interrupted cell differentiation and impaired tooth formation. We hope to find potential treatments for SRA based on these evidences in the future.
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Affiliation(s)
- Mengjia Yu
- The Affiliated Stomatology Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Oral Biomedical Research of Zhejiang Province, Zhejiang University School of Stomatology, Hangzhou, China
| | - Zhiwei Jiang
- The Affiliated Stomatology Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Oral Biomedical Research of Zhejiang Province, Zhejiang University School of Stomatology, Hangzhou, China
| | - Yang Wang
- The Affiliated Stomatology Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Oral Biomedical Research of Zhejiang Province, Zhejiang University School of Stomatology, Hangzhou, China
| | - Yue Xi
- The Affiliated Stomatology Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Oral Biomedical Research of Zhejiang Province, Zhejiang University School of Stomatology, Hangzhou, China
| | - Guoli Yang
- The Affiliated Stomatology Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Oral Biomedical Research of Zhejiang Province, Zhejiang University School of Stomatology, Hangzhou, China
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6
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Wnt/β-catenin signaling, which is activated in odontomas, reduces Sema3A expression to regulate odontogenic epithelial cell proliferation and tooth germ development. Sci Rep 2019; 9:4257. [PMID: 30862786 PMCID: PMC6414619 DOI: 10.1038/s41598-019-39686-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Accepted: 01/29/2019] [Indexed: 01/03/2023] Open
Abstract
Odontomas, developmental anomalies of tooth germ, frequently occur in familial adenomatous polyposis patients with activated Wnt/β-catenin signaling. However, roles of Wnt/β-catenin signaling in odontomas or odontogenic cells are unclear. Herein, we investigated β-catenin expression in odontomas and functions of Wnt/β-catenin signaling in tooth germ development. β-catenin frequently accumulated in nucleus and/or cellular cytoplasm of odontogenic epithelial cells in human odontoma specimens, immunohistochemically. Wnt/β-catenin signaling inhibited odontogenic epithelial cell proliferation in both cell line and tooth germ development, while inducing immature epithelial bud formation. We identified Semaphorin 3A (Sema3A) as a downstream molecule of Wnt/β-catenin signaling and showed that Wnt/β-catenin signaling-dependent reduction of Sema3A expression resulted in suppressed odontogenic epithelial cell proliferation. Sema3A expression is required in appropriate epithelial budding morphogenesis. These results suggest that Wnt/β-catenin signaling negatively regulates odontogenic epithelial cell proliferation and tooth germ development through decreased-Sema3A expression, and aberrant activation of Wnt/β-catenin signaling may associate with odontoma formation.
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7
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Apps JR, Carreno G, Gonzalez-Meljem JM, Haston S, Guiho R, Cooper JE, Manshaei S, Jani N, Hölsken A, Pettorini B, Beynon RJ, Simpson DM, Fraser HC, Hong Y, Hallang S, Stone TJ, Virasami A, Donson AM, Jones D, Aquilina K, Spoudeas H, Joshi AR, Grundy R, Storer LCD, Korbonits M, Hilton DA, Tossell K, Thavaraj S, Ungless MA, Gil J, Buslei R, Hankinson T, Hargrave D, Goding C, Andoniadou CL, Brogan P, Jacques TS, Williams HJ, Martinez-Barbera JP. Tumour compartment transcriptomics demonstrates the activation of inflammatory and odontogenic programmes in human adamantinomatous craniopharyngioma and identifies the MAPK/ERK pathway as a novel therapeutic target. Acta Neuropathol 2018. [PMID: 29541918 PMCID: PMC5904225 DOI: 10.1007/s00401-018-1830-2] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Adamantinomatous craniopharyngiomas (ACPs) are clinically challenging tumours, the majority of which have activating mutations in CTNNB1. They are histologically complex, showing cystic and solid components, the latter comprised of different morphological cell types (e.g. β-catenin-accumulating cluster cells and palisading epithelium), surrounded by a florid glial reaction with immune cells. Here, we have carried out RNA sequencing on 18 ACP samples and integrated these data with an existing ACP transcriptomic dataset. No studies so far have examined the patterns of gene expression within the different cellular compartments of the tumour. To achieve this goal, we have combined laser capture microdissection with computational analyses to reveal groups of genes that are associated with either epithelial tumour cells (clusters and palisading epithelium), glial tissue or immune infiltrate. We use these human ACP molecular signatures and RNA-Seq data from two ACP mouse models to reveal that cell clusters are molecularly analogous to the enamel knot, a critical signalling centre controlling normal tooth morphogenesis. Supporting this finding, we show that human cluster cells express high levels of several members of the FGF, TGFB and BMP families of secreted factors, which signal to neighbouring cells as evidenced by immunostaining against the phosphorylated proteins pERK1/2, pSMAD3 and pSMAD1/5/9 in both human and mouse ACP. We reveal that inhibiting the MAPK/ERK pathway with trametinib, a clinically approved MEK inhibitor, results in reduced proliferation and increased apoptosis in explant cultures of human and mouse ACP. Finally, we analyse a prominent molecular signature in the glial reactive tissue to characterise the inflammatory microenvironment and uncover the activation of inflammasomes in human ACP. We validate these results by immunostaining against immune cell markers, cytokine ELISA and proteome analysis in both solid tumour and cystic fluid from ACP patients. Our data support a new molecular paradigm for understanding ACP tumorigenesis as an aberrant mimic of natural tooth development and opens new therapeutic opportunities by revealing the activation of the MAPK/ERK and inflammasome pathways in human ACP.
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Affiliation(s)
- John R Apps
- Developmental Biology and Cancer Programme, Birth Defects Research Centre, UCL Great Ormond Street Institute of Child Health, University College London, London, UK.
- Histopathology Department, Great Ormond Street Hospital NHS Trust, London, UK.
| | - Gabriela Carreno
- Developmental Biology and Cancer Programme, Birth Defects Research Centre, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Jose Mario Gonzalez-Meljem
- Developmental Biology and Cancer Programme, Birth Defects Research Centre, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
- Basic Research Department, National Institute of Geriatrics, Mexico City, Mexico
| | - Scott Haston
- Developmental Biology and Cancer Programme, Birth Defects Research Centre, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Romain Guiho
- Developmental Biology and Cancer Programme, Birth Defects Research Centre, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Julie E Cooper
- Developmental Biology and Cancer Programme, Birth Defects Research Centre, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Saba Manshaei
- Developmental Biology and Cancer Programme, Birth Defects Research Centre, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Nital Jani
- Centre for Translational Omics-GOSgene, Genetics and Genomic Medicine Programme, UCL Institute of Child Health, University College London, London, UK
| | - Annett Hölsken
- Department of Neuropathology, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | | | - Robert J Beynon
- Centre for Proteome Research, Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| | - Deborah M Simpson
- Centre for Proteome Research, Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| | - Helen C Fraser
- Developmental Biology and Cancer Programme, Birth Defects Research Centre, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Ying Hong
- Infection, Immunity and Inflammation Programme, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Shirleen Hallang
- Centre for Craniofacial and Regenerative Biology, King's College London, London, UK
| | - Thomas J Stone
- Developmental Biology and Cancer Programme, Birth Defects Research Centre, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
- Histopathology Department, Great Ormond Street Hospital NHS Trust, London, UK
| | - Alex Virasami
- Histopathology Department, Great Ormond Street Hospital NHS Trust, London, UK
| | - Andrew M Donson
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - David Jones
- German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Kristian Aquilina
- Neurosurgery Department, Great Ormond Street Hospital NHS Trust, London, UK
| | - Helen Spoudeas
- Endocrinology Department, Great Ormond Street Hospital NHS Trust, London, UK
| | - Abhijit R Joshi
- Laboratory Medicine, Royal Victoria Infirmary, Newcastle, UK
| | - Richard Grundy
- Children's Brain Tumour Research Centre, University of Nottingham, Nottingham, UK
| | - Lisa C D Storer
- Children's Brain Tumour Research Centre, University of Nottingham, Nottingham, UK
| | - Márta Korbonits
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University, London, UK
| | - David A Hilton
- Pathology Department, Plymouth Hospitals NHS Trust, Plymouth, UK
| | - Kyoko Tossell
- MRC London Institute of Medical Sciences, Imperial College London, London, UK
| | - Selvam Thavaraj
- Head and Neck Pathology, Dental Institute, King's College London, London, UK
| | - Mark A Ungless
- MRC London Institute of Medical Sciences, Imperial College London, London, UK
| | - Jesus Gil
- MRC London Institute of Medical Sciences, Imperial College London, London, UK
| | - Rolf Buslei
- Department of Neuropathology, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany
- Institute of Pathology, Klinikum Sozialstiftung Bamberg, Bamberg, Germany
| | - Todd Hankinson
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Darren Hargrave
- Haematology and Oncology Department, Great Ormond Street Hospital NHS Trust, London, UK
| | - Colin Goding
- Ludwig Institute for Cancer Research, Oxford University, Old Road Campus, Headington, Oxford, UK
| | - Cynthia L Andoniadou
- Centre for Craniofacial and Regenerative Biology, King's College London, Guy's Hospital, Floor 27 Tower Wing, London, UK
- Department of Internal Medicine III, Technische Universität Dresden, Fetscherstaße 74, 01307, Dresden, Germany
| | - Paul Brogan
- Infection, Immunity and Inflammation Programme, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
- Rheumatology Department, Great Ormond Street Hospital NHS Trust, London, UK
| | - Thomas S Jacques
- Developmental Biology and Cancer Programme, Birth Defects Research Centre, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
- Histopathology Department, Great Ormond Street Hospital NHS Trust, London, UK
| | - Hywel J Williams
- Centre for Translational Omics-GOSgene, Genetics and Genomic Medicine Programme, UCL Institute of Child Health, University College London, London, UK
| | - Juan Pedro Martinez-Barbera
- Developmental Biology and Cancer Programme, Birth Defects Research Centre, UCL Great Ormond Street Institute of Child Health, University College London, London, UK.
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8
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Zhang B, Meng B, Viloria E, Naveau A, Ganss B, Jheon AH. The Role of Epithelial Stat3 in Amelogenesis during Mouse Incisor Renewal. Cells Tissues Organs 2018; 205:63-71. [PMID: 29550820 DOI: 10.1159/000486745] [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: 09/24/2017] [Accepted: 01/05/2018] [Indexed: 11/19/2022] Open
Abstract
The aim of this study was to evaluate the role of epithelial signal transducer and activator of transcription 3 (STAT3) in mouse incisor amelogenesis. Since Stat3 is expressed in the epithelial component of developing and adult mouse teeth, we generated and analyzed Krt14Cre/+;Stat3fl/fl mutant mice in which Stat3 was inactivated in epithelia including ameloblast progenitors and ameloblasts, the cells responsible for enamel formation. Histological analysis showed little enamel matrix in mutant incisors compared to controls. Delayed incisor enamel mineralization was demonstrated using micro-computed X-ray tomography analysis and was supported by an increase in the pre-expression distance of enamel-enriched proteins such as amelogenin, ameloblastin, and kallikrein-4. Lastly, scanning electron microscopy analysis showed little enamel mineralization in mutant incisors underneath the mesial root of the 1st molar; however, the micro-architecture of enamel mineralization was similar in the erupted portion of control and mutant incisors. Taken together, our findings demonstrate for the first time that the absence of epithelial Stat3 in mice leads to delayed incisor amelogenesis.
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Affiliation(s)
- Bin Zhang
- Department of Oral and Maxillofacial Surgery, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, China.,Program in Craniofacial Biology and Department of Orofacial Sciences, University of California San Francisco (UCSF), San Francisco, California, USA
| | - Bo Meng
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California San Francisco (UCSF), San Francisco, California, USA
| | - Edward Viloria
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California San Francisco (UCSF), San Francisco, California, USA
| | - Adrien Naveau
- Université Paris Descartes, Sorbonne Paris Cite, UMR S872, Paris, France.,Centre de Recherche des Cordeliers, Université Pierre et Marie Curie, UMR S872, Paris, France.,INSERM U872, Paris, France
| | - Bernhard Ganss
- Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada
| | - Andrew H Jheon
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California San Francisco (UCSF), San Francisco, California, USA.,Department of Orofacial Sciences and Division of Craniofacial Anomalies, UCSF School of Dentistry, San Francisco, California, USA
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9
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Abstract
The Encouraging Novel Amelogenesis Models and Ex vivo cell Lines (ENAMEL) Development workshop was held on 23 June 2017 at the Bethesda headquarters of the National Institute of Dental and Craniofacial Research (NIDCR). Discussion topics included model organisms, stem cells/cell lines, and tissues/3D cell culture/organoids. Scientists from a number of disciplines, representing institutions from across the United States, gathered to discuss advances in our understanding of enamel, as well as future directions for the field.
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10
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Naveau A, Zhang B, Meng B, Sutherland MT, Prochazkova M, Wen T, Marangoni P, Jones KB, Cox TC, Ganss B, Jheon AH, Klein OD. Isl1 Controls Patterning and Mineralization of Enamel in the Continuously Renewing Mouse Incisor. J Bone Miner Res 2017; 32:2219-2231. [PMID: 28650075 PMCID: PMC5685895 DOI: 10.1002/jbmr.3202] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 06/09/2017] [Accepted: 06/21/2017] [Indexed: 01/15/2023]
Abstract
Rodents are characterized by continuously renewing incisors whose growth is fueled by epithelial and mesenchymal stem cells housed in the proximal compartments of the tooth. The epithelial stem cells reside in structures known as the labial (toward the lip) and lingual (toward the tongue) cervical loops (laCL and liCL, respectively). An important feature of the rodent incisor is that enamel, the outer, highly mineralized layer, is asymmetrically distributed, because it is normally generated by the laCL but not the liCL. Here, we show that epithelial-specific deletion of the transcription factor Islet1 (Isl1) is sufficient to drive formation of ectopic enamel by the liCL stem cells, and also that it leads to production of altered enamel on the labial surface. Molecular analyses of developing and adult incisors revealed that epithelial deletion of Isl1 affected multiple, major pathways: Bmp (bone morphogenetic protein), Hh (hedgehog), Fgf (fibroblast growth factor), and Notch signaling were upregulated and associated with liCL-generated ectopic enamel; on the labial side, upregulation of Bmp and Fgf signaling, and downregulation of Shh were associated with premature enamel formation. Transcriptome profiling studies identified a suite of differentially regulated genes in developing Isl1 mutant incisors. Our studies demonstrate that ISL1 plays a central role in proper patterning of stem cell-derived enamel in the incisor and indicate that this factor is an important upstream regulator of signaling pathways during tooth development and renewal. © 2017 American Society for Bone and Mineral Research.
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Affiliation(s)
- Adrien Naveau
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA, USA
- Université Paris Descartes, Sorbonne Paris Cite, UMR S872, France
- Centre de Recherche des Cordeliers, Université Pierre et Marie Curie, UMR S872, Paris, France
- INSERM U872, Paris, France
| | - Bin Zhang
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Bo Meng
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - McGarrett T. Sutherland
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Michaela Prochazkova
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA, USA
- Laboratory of Transgenic Models of Diseases, Institute of Molecular Genetics of the ASCR, v.v.i., Prague 4 14220, Czech Republic
| | - Timothy Wen
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Pauline Marangoni
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Kyle B. Jones
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Timothy C. Cox
- Department of Pediatrics (Craniofacial Medicine), University of Washington & Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, USA
| | - Bernhard Ganss
- Faculty of Dentistry, University of Toronto, Toronto, ON Canada
| | - Andrew H. Jheon
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Ophir D. Klein
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA, USA
- Department of Pediatrics and Institute for Human Genetics, University of California, San Francisco, San Francisco, CA, USA
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11
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Brown S, Pineda CM, Xin T, Boucher J, Suozzi KC, Park S, Matte-Martone C, Gonzalez DG, Rytlewski J, Beronja S, Greco V. Correction of aberrant growth preserves tissue homeostasis. Nature 2017; 548:334-337. [PMID: 28783732 PMCID: PMC5675114 DOI: 10.1038/nature23304] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 06/23/2017] [Indexed: 01/08/2023]
Abstract
Cells in healthy tissues acquire mutations with surprising frequency. Many of these mutations are associated with abnormal cellular behaviours such as differentiation defects and hyperproliferation, yet fail to produce macroscopically detectable phenotypes. It is currently unclear how the tissue remains phenotypically normal, despite the presence of these mutant cells. Here we use intravital imaging to track the fate of mouse skin epithelium burdened with varying numbers of activated Wnt/β-catenin stem cells. We show that all resulting growths that deform the skin tissue architecture regress, irrespective of their size. Wild-type cells are required for the active elimination of mutant cells from the tissue, while utilizing both endogenous and ectopic cellular behaviours to dismantle the aberrant structures. After regression, the remaining structures are either completely eliminated or converted into functional skin appendages in a niche-dependent manner. Furthermore, tissue aberrancies generated from oncogenic Hras, and even mutation-independent deformations to the tissue, can also be corrected, indicating that this tolerance phenomenon reflects a conserved principle in the skin. This study reveals an unanticipated plasticity of the adult skin epithelium when faced with mutational and non-mutational insult, and elucidates the dynamic cellular behaviours used for its return to a homeostatic state.
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Affiliation(s)
- Samara Brown
- Department of Genetics, Yale School of Medicine, New Haven, Connecticut 06510, USA
| | - Cristiana M Pineda
- Department of Genetics, Yale School of Medicine, New Haven, Connecticut 06510, USA
| | - Tianchi Xin
- Department of Genetics, Yale School of Medicine, New Haven, Connecticut 06510, USA
| | - Jonathan Boucher
- Department of Genetics, Yale School of Medicine, New Haven, Connecticut 06510, USA
| | - Kathleen C Suozzi
- Department of Genetics, Yale School of Medicine, New Haven, Connecticut 06510, USA
| | - Sangbum Park
- Department of Genetics, Yale School of Medicine, New Haven, Connecticut 06510, USA
| | | | - David G Gonzalez
- Department of Genetics, Yale School of Medicine, New Haven, Connecticut 06510, USA
| | - Julie Rytlewski
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
| | - Slobodan Beronja
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
| | - Valentina Greco
- Department of Genetics, Yale School of Medicine, New Haven, Connecticut 06510, USA
- Yale Stem Cell Center, Yale School of Medicine, New Haven, Connecticut 06510, USA
- Yale Cancer Center, Yale School of Medicine, New Haven, Connecticut 06510, USA
- Department of Dermatology, Yale School of Medicine, New Haven, Connecticut 06510, USA
- Department of Cell Biology, Yale School of Medicine, New Haven, Connecticut 06510, USA
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12
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WNT10A mutation causes ectodermal dysplasia by impairing progenitor cell proliferation and KLF4-mediated differentiation. Nat Commun 2017; 8:15397. [PMID: 28589954 PMCID: PMC5467248 DOI: 10.1038/ncomms15397] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Accepted: 03/27/2017] [Indexed: 02/06/2023] Open
Abstract
Human WNT10A mutations are associated with developmental tooth abnormalities and adolescent onset of a broad range of ectodermal defects. Here we show that β-catenin pathway activity and adult epithelial progenitor proliferation are reduced in the absence of WNT10A, and identify Wnt-active self-renewing stem cells in affected tissues including hair follicles, sebaceous glands, taste buds, nails and sweat ducts. Human and mouse WNT10A mutant palmoplantar and tongue epithelia also display specific differentiation defects that are mimicked by loss of the transcription factor KLF4. We find that β-catenin interacts directly with region-specific LEF/TCF factors, and with KLF4 in differentiating, but not proliferating, cells to promote expression of specialized keratins required for normal tissue structure and integrity. Our data identify WNT10A as a critical ligand controlling adult epithelial proliferation and region-specific differentiation, and suggest downstream β-catenin pathway activation as a potential approach to ameliorate regenerative defects in WNT10A patients. Human WNT10A mutations are associated with dental defects and adult onset ectodermal dysplasia. Xu et al. show that WNT10A-activated ß-catenin plays dual roles in adult epithelial progenitor proliferation and differentiation by complexing with KLF4 in differentiating, but not proliferating, cells.
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13
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Yang Z, Balic A, Michon F, Juuri E, Thesleff I. Mesenchymal Wnt/β-Catenin Signaling Controls Epithelial Stem Cell Homeostasis in Teeth by Inhibiting the Antiapoptotic Effect of Fgf10. Stem Cells 2016; 33:1670-81. [PMID: 25693510 DOI: 10.1002/stem.1972] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 01/17/2015] [Indexed: 01/05/2023]
Abstract
Continuous growth of rodent incisors relies on epithelial stem cells (SCs) located in the SC niche called labial cervical loop (LaCL). Here, we found a population of apoptotic cells residing in a specific location of the LaCL in mouse incisor. Activated Caspase 3 and Caspase 9, expressed in this location colocalized in part with Lgr5 in putative SCs. The addition of Caspase inhibitors to incisors ex vivo resulted in concentration dependent thickening of LaCL. To examine the role of Wnt signaling in regulation of apoptosis, we exposed the LaCL of postnatal day 2 (P2) mouse incisor ex vivo to BIO, a known activator of Wnt/β-catenin signaling. This resulted in marked thinning of LaCL as well as enhanced apoptosis. We found that Wnt/β-catenin signaling was intensely induced by BIO in the mesenchyme surrounding the LaCL, but, unexpectedly, no β-catenin activity was detected in the LaCL epithelium either before or after BIO treatment. We discovered that the expression of Fgf10, an essential growth factor for incisor epithelial SCs, was dramatically downregulated in the mesenchyme around BIO-treated LaCL, and that exogenous Fgf10 could rescue the thinning of the LaCL caused by BIO. We conclude that the homeostasis of the epithelial SC population in the mouse incisor depends on a proper rate of apoptosis and that this apoptosis is controlled by signals from the mesenchyme surrounding the LaCL. Fgf10 is a key mesenchymal signal limiting apoptosis of incisor epithelial SCs and its expression is negatively regulated by Wnt/β-catenin. Stem Cells 2015;33:1670-1681.
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Affiliation(s)
- Zheqiong Yang
- Developmental Biology Program, Institute of Biotechnology, University of Helsinki, Helsinki, Finland; Department of Pharmacology, Wuhan University School of Basic Medical Science, Wuhan, Hubei, People's Republic of China
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14
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Guan X, Xu M, Millar SE, Bartlett JD. Beta-catenin is essential for ameloblast movement during enamel development. Eur J Oral Sci 2016; 124:221-7. [PMID: 26957367 DOI: 10.1111/eos.12261] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/21/2016] [Indexed: 12/21/2022]
Abstract
Beta-catenin is a multifunctional protein that plays key roles in cadherin-based cell adherens junctions and in the Wnt signaling pathway. The canonical Wnt/β-catenin pathway can regulate transcription factors that control cell movement/invasion. We investigated whether β-catenin regulates ameloblast movement through canonical Wnt signaling. The morphological and physical properties of enamel were assessed in enamel from control and β-catenin conditional knockout (cKO) mice. Ameloblast-lineage cells (ALC) were used to investigate the potential roles of β-catenin in cell migration and in E-cadherin expression. Compared with controls, incisors from β-catenin cKO mice were short, blunt, and where enamel was present, it was soft and malformed. Scanning electron microscopy revealed a dysplastic rod pattern within the enamel of incisors from β-catenin cKO mice, and Vickers microhardness measurements confirmed that mice with β-catenin ablated from their enamel organ had enamel that was significantly softer than normal. Amelogenesis was disrupted in the absence of β-catenin and the ameloblasts did not differentiate properly. We further demonstrated that migration of ALCs was inhibited in vitro and that E-cadherin expression was significantly up-regulated when ALCs were treated with the β-catenin inhibitor, ICG-001. Beta-catenin ablation causes enamel malformation in mice and this phenotype may occur, in part, by a lack of ameloblast differentiation and/or movement necessary to form the decussating enamel rod structure.
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Affiliation(s)
- Xiaomu Guan
- Department of Mineralized Tissue Biology and Harvard School of Dental Medicine, Forsyth Institute, Cambridge, MA, USA
| | - Mingang Xu
- Departments of Dermatology and Cell & Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Sarah E Millar
- Departments of Dermatology and Cell & Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - John D Bartlett
- Division of Biosciences, College of Dentistry, Ohio State University, Columbus, OH, USA
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15
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Verstraeten B, van Hengel J, Huysseune A. Beta-Catenin and Plakoglobin Expression during Zebrafish Tooth Development and Replacement. PLoS One 2016; 11:e0148114. [PMID: 26938059 PMCID: PMC4777446 DOI: 10.1371/journal.pone.0148114] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 02/17/2016] [Indexed: 11/18/2022] Open
Abstract
We analyzed the protein distribution of two cadherin-associated molecules, plakoglobin and β-catenin, during the different stages of tooth development and tooth replacement in zebrafish. Plakoglobin was detected at the plasma membrane already at the onset of tooth development in the epithelial cells of the tooth. This pattern remained unaltered during further tooth development. The mesenchymal cells only showed plakoglobin from cytodifferentiation onwards. Plakoglobin 1a morpholino-injected embryos showed normal tooth development with proper initiation and differentiation. Although plakoglobin is clearly present during normal odontogenesis, the loss of plakoglobin 1a does not influence tooth development. β-catenin was found at the cell borders of all cells of the successional lamina but also in the nuclei of surrounding mesenchymal cells. Only membranous, not nuclear, β-catenin, was found during morphogenesis stage. However, during cytodifferentiation stage, both nuclear and membrane-bound β-catenin was detected in the layers of the enamel organ as well as in the differentiating odontoblasts. Nuclear β-catenin is an indication of an activated Wnt pathway, therefore suggesting a possible role for Wnt signalling during zebrafish tooth development and replacement.
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Affiliation(s)
| | - Jolanda van Hengel
- Molecular Cell Biology Unit, Department for Molecular Biomedical Research, VIB Ghent, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Ann Huysseune
- Evolutionary Developmental Biology, Ghent University, Ghent, Belgium
- * E-mail:
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16
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Abstract
β catenin belongs to the armadillo family of proteins. It plays a crucial role in developmental and homeostatic processes. Wnts are a family of 19 secreted glycoproteins that transduce multiple signaling cascades, including the canonical Wnt/β catenin pathway, Wnt/Ca(2+) pathway and the Wnt/polarity pathway. This is a review on β catenin, Wnt proteins and their secretion, the signaling pathway, the associated factors and the crucial role of β catenin in odontogenesis.
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Affiliation(s)
- Sharada Prakash
- Department of Oral and Maxillofacial Pathology, AECS Maaruti College of Dental Sciences, Bengaluru, Karnataka, India
| | - Uma Swaminathan
- Department of Oral and Maxillofacial Pathology, AECS Maaruti College of Dental Sciences, Bengaluru, Karnataka, India
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17
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Yu T, Volponi AA, Babb R, An Z, Sharpe PT. Stem Cells in Tooth Development, Growth, Repair, and Regeneration. Curr Top Dev Biol 2015; 115:187-212. [PMID: 26589926 DOI: 10.1016/bs.ctdb.2015.07.010] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Human teeth contain stem cells in all their mesenchymal-derived tissues, which include the pulp, periodontal ligament, and developing roots, in addition to the support tissues such as the alveolar bone. The precise roles of these cells remain poorly understood and most likely involve tissue repair mechanisms but their relative ease of harvesting makes teeth a valuable potential source of mesenchymal stem cells (MSCs) for therapeutic use. These dental MSC populations all appear to have the same developmental origins, being derived from cranial neural crest cells, a population of embryonic stem cells with multipotential properties. In rodents, the incisor teeth grow continuously throughout life, a feature that requires populations of continuously active mesenchymal and epithelial stem cells. The discrete locations of these stem cells in the incisor have rendered them amenable for study and much is being learnt about the general properties of these stem cells for the incisor as a model system. The incisor MSCs appear to be a heterogeneous population consisting of cells from different neural crest-derived tissues. The epithelial stem cells can be traced directly back in development to a Sox10(+) population present at the time of tooth initiation. In this review, we describe the basic biology of dental stem cells, their functions, and potential clinical uses.
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Affiliation(s)
- Tian Yu
- Craniofacial Development and Stem Cell Biology, Dental Institute, Kings College London, London, United Kingdom
| | - Ana Angelova Volponi
- Craniofacial Development and Stem Cell Biology, Dental Institute, Kings College London, London, United Kingdom
| | - Rebecca Babb
- Craniofacial Development and Stem Cell Biology, Dental Institute, Kings College London, London, United Kingdom
| | - Zhengwen An
- Craniofacial Development and Stem Cell Biology, Dental Institute, Kings College London, London, United Kingdom
| | - Paul T Sharpe
- Craniofacial Development and Stem Cell Biology, Dental Institute, Kings College London, London, United Kingdom.
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18
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Xavier GM, Patist AL, Healy C, Pagrut A, Carreno G, Sharpe PT, Martinez-Barbera JP, Thavaraj S, Cobourne MT, Andoniadou CL. Activated WNT signaling in postnatal SOX2-positive dental stem cells can drive odontoma formation. Sci Rep 2015; 5:14479. [PMID: 26411543 PMCID: PMC4585991 DOI: 10.1038/srep14479] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 09/01/2015] [Indexed: 01/27/2023] Open
Abstract
In common with most mammals, humans form only two dentitions during their lifetime. Occasionally, supernumerary teeth develop in addition to the normal complement. Odontoma represent a small group of malformations containing calcified dental tissues of both epithelial and mesenchymal origin, with varying levels of organization, including tooth-like structures. The specific cell type responsible for the induction of odontoma, which retains the capacity to re-initiate de novo tooth development in postnatal tissues, is not known. Here we demonstrate that aberrant activation of WNT signaling by expression of a non-degradable form of β-catenin specifically in SOX2-positive postnatal dental epithelial stem cells is sufficient to generate odontoma containing multiple tooth-like structures complete with all dental tissue layers. Genetic lineage-tracing confirms that odontoma form in a similar manner to normal teeth, derived from both the mutation-sustaining epithelial stem cells and adjacent mesenchymal tissues. Activation of the WNT pathway in embryonic SOX2-positive progenitors results in ectopic expression of secreted signals that promote odontogenesis throughout the oral cavity. Significantly, the inductive potential of epithelial dental stem cells is retained in postnatal tissues, and up-regulation of WNT signaling specifically in these cells is sufficient to promote generation and growth of ectopic malformations faithfully resembling human odontoma.
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Affiliation(s)
- Guilherme M Xavier
- Department of Orthodontics, King's College London, UK.,Department of Craniofacial Development and Stem Cell Biology, King's College London, UK
| | - Amanda L Patist
- Department of Craniofacial Development and Stem Cell Biology, King's College London, UK
| | - Chris Healy
- Department of Craniofacial Development and Stem Cell Biology, King's College London, UK
| | - Ankita Pagrut
- Department of Craniofacial Development and Stem Cell Biology, King's College London, UK
| | - Gabriela Carreno
- Developmental Biology and Cancer Programme, Birth Defects Research Centre, Institute of Child Health, University College London, UK
| | - Paul T Sharpe
- Department of Craniofacial Development and Stem Cell Biology, King's College London, UK
| | - Juan Pedro Martinez-Barbera
- Developmental Biology and Cancer Programme, Birth Defects Research Centre, Institute of Child Health, University College London, UK
| | - Selvam Thavaraj
- Department of Mucosal and Salivary Biology, King's College London, UK
| | - Martyn T Cobourne
- Department of Orthodontics, King's College London, UK.,Department of Craniofacial Development and Stem Cell Biology, King's College London, UK
| | - Cynthia L Andoniadou
- Department of Craniofacial Development and Stem Cell Biology, King's College London, UK
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19
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Yang G, Zhou J, Teng Y, Xie J, Lin J, Guo X, Gao Y, He M, Yang X, Wang S. Mesenchymal TGF-β signaling orchestrates dental epithelial stem cell homeostasis through Wnt signaling. Stem Cells 2015; 32:2939-48. [PMID: 24964772 DOI: 10.1002/stem.1772] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 05/21/2014] [Accepted: 06/21/2014] [Indexed: 01/04/2023]
Abstract
In mouse, continuous growth of the postnatal incisor is coordinated by two populations of multipotent progenitor cells, the dental papilla mesenchymal cells and dental epithelial stem cells, residing at the proximal end of the incisor, yet the molecular mechanism underlying the cooperation between mesenchymal and epithelial cells is largely unknown. Here, transforming growth factor-β (TGF-β) type II receptor (Tgfbr2) was specifically deleted within the postnatal dental papilla mesenchyme. The Tgfbr2-deficient mice displayed malformed incisors with wavy mineralized structures at the labial side as a result of increased differentiation of dental epithelial stem cells. We found that mesenchymal Tgfbr2 disruption led to upregulated expression of Wnt5a and downregulated expression of Fgf3/10 in the mesenchyme, both of which synergistically enhanced Lrp5/6-β-catenin signaling in the cervical loop epithelium. In accord with these findings, mesenchyme-specific depletion of the Wnt transporter gene Wls abolished the aberrant mineralized structures caused by Tgfbr2 deletion. Thus, mesenchymal TGF-β signaling provides a unifying mechanism for the homeostasis of dental epithelial stem cells via a Wnt signaling-mediated mesenchymal-epithelial cell interaction.
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Affiliation(s)
- Guan Yang
- Molecular Laboratory for Gene Therapy and Tooth Regeneration, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing, People's Republic of China; State Key Laboratory of Proteomics, Genetic Laboratory of Development and Diseases, Institute of Biotechnology, Beijing, People's Republic of China
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20
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BMP-SHH signaling network controls epithelial stem cell fate via regulation of its niche in the developing tooth. Dev Cell 2015; 33:125-35. [PMID: 25865348 DOI: 10.1016/j.devcel.2015.02.021] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Revised: 12/17/2014] [Accepted: 02/24/2015] [Indexed: 11/22/2022]
Abstract
During embryogenesis, ectodermal stem cells adopt different fates and form diverse ectodermal organs, such as teeth, hair follicles, mammary glands, and salivary glands. Interestingly, these ectodermal organs differ in their tissue homeostasis, which leads to differential abilities for continuous growth postnatally. Mouse molars lose the ability to grow continuously, whereas incisors retain this ability. In this study, we found that a BMP-Smad4-SHH-Gli1 signaling network may provide a niche supporting transient Sox2+ dental epithelial stem cells in mouse molars. This mechanism also plays a role in continuously growing mouse incisors. The differential fate of epithelial stem cells in mouse molars and incisors is controlled by this BMP/SHH signaling network, which partially accounts for the different postnatal growth potential of molars and incisors. Collectively, our study highlights the importance of crosstalk between two signaling pathways, BMP and SHH, in regulating the fate of epithelial stem cells during organogenesis.
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21
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Blackburn J, Kawasaki K, Porntaveetus T, Kawasaki M, Otsuka-Tanaka Y, Miake Y, Ota MS, Watanabe M, Hishinuma M, Nomoto T, Oommen S, Ghafoor S, Harada F, Nozawa-Inoue K, Maeda T, Peterková R, Lesot H, Inoue J, Akiyama T, Schmidt-Ullrich R, Liu B, Hu Y, Page A, Ramírez Á, Sharpe PT, Ohazama A. Excess NF-κB induces ectopic odontogenesis in embryonic incisor epithelium. J Dent Res 2014; 94:121-8. [PMID: 25376721 DOI: 10.1177/0022034514556707] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Nuclear factor kappa B (NF-κB) signaling plays critical roles in many physiological and pathological processes, including regulating organogenesis. Down-regulation of NF-κB signaling during development results in hypohidrotic ectodermal dysplasia. The roles of NF-κB signaling in tooth development, however, are not fully understood. We examined mice overexpressing IKKβ, an essential component of the NF-κB pathway, under keratin 5 promoter (K5-Ikkβ). K5-Ikkβ mice showed supernumerary incisors whose formation was accompanied by up-regulation of canonical Wnt signaling. Apoptosis that is normally observed in wild-type incisor epithelium was reduced in K5-Ikkβ mice. The supernumerary incisors in K5-Ikkβ mice were found to phenocopy extra incisors in mice with mutations of Wnt inhibitor, Wise. Excess NF-κB activity thus induces an ectopic odontogenesis program that is usually suppressed under physiological conditions.
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Affiliation(s)
- J Blackburn
- Craniofacial Development and Stem Cell Biology and Biomedical Research Centre, Kings College London, London, UK
| | - K Kawasaki
- Craniofacial Development and Stem Cell Biology and Biomedical Research Centre, Kings College London, London, UK Department of Pediatric Dentistry, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - T Porntaveetus
- Craniofacial Development and Stem Cell Biology and Biomedical Research Centre, Kings College London, London, UK Department of Physiology, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
| | - M Kawasaki
- Craniofacial Development and Stem Cell Biology and Biomedical Research Centre, Kings College London, London, UK Division of Bio-Prosthodontics, Department of Oral Health Science, Course for Oral Life Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Y Otsuka-Tanaka
- Craniofacial Development and Stem Cell Biology and Biomedical Research Centre, Kings College London, London, UK Department of Special Needs Dentistry, Nihon University School of Dentistry at Matsudo, Matsudo, Japan
| | - Y Miake
- Department of Ultrastructural Science, Tokyo Dental College, Chiyoda-ku, Tokyo, Japan
| | - M S Ota
- Laboratory of Food Biological Science, Department of Food and Nutrition, Japan Women's University, Bunkyō, Japan
| | - M Watanabe
- Division of Oral Anatomy, Department of Oral Biological Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - M Hishinuma
- Department of Special Needs Dentistry, Nihon University School of Dentistry at Matsudo, Matsudo, Japan
| | - T Nomoto
- Department of Special Needs Dentistry, Nihon University School of Dentistry at Matsudo, Matsudo, Japan
| | - S Oommen
- Craniofacial Development and Stem Cell Biology and Biomedical Research Centre, Kings College London, London, UK
| | - S Ghafoor
- Craniofacial Development and Stem Cell Biology and Biomedical Research Centre, Kings College London, London, UK
| | - F Harada
- Craniofacial Development and Stem Cell Biology and Biomedical Research Centre, Kings College London, London, UK
| | - K Nozawa-Inoue
- Craniofacial Development and Stem Cell Biology and Biomedical Research Centre, Kings College London, London, UK
| | - T Maeda
- Division of Oral Anatomy, Department of Oral Biological Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - R Peterková
- Department of Teratology, Institute of Experimental Medicine, Academy of Sciences CR, Prague, Czech Republic
| | - H Lesot
- INSERM UMR_S1109, Team "Osteoarticular and Dental Regenerative NanoMedicine," FMTS, Faculté de Médecine, Faculté de Chirurgie Dentaire, Université de Strasbourg, Strasbourg, France
| | - J Inoue
- Division of Cellular and Molecular Biology, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo, Japan
| | - T Akiyama
- Division of Cellular and Molecular Biology, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo, Japan
| | - R Schmidt-Ullrich
- Department of Signal Transduction in Tumor Cells, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - B Liu
- Department of Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Smithville, TX, USA
| | - Y Hu
- Laboratory of Experimental Immunology, Inflammation and Tumorigenesis Section, National. Cancer Institute-Frederick, Frederick, MD, USA
| | - A Page
- Department of Epithelial Biomedicine, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Madrid, Spain
| | - Á Ramírez
- Department of Epithelial Biomedicine, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Madrid, Spain
| | - P T Sharpe
- Craniofacial Development and Stem Cell Biology and Biomedical Research Centre, Kings College London, London, UK
| | - A Ohazama
- Craniofacial Development and Stem Cell Biology and Biomedical Research Centre, Kings College London, London, UK Division of Oral Anatomy, Department of Oral Biological Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
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22
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Kiso H, Takahashi K, Saito K, Togo Y, Tsukamoto H, Huang B, Sugai M, Shimizu A, Tabata Y, Economides AN, Slavkin HC, Bessho K. Interactions between BMP-7 and USAG-1 (uterine sensitization-associated gene-1) regulate supernumerary organ formations. PLoS One 2014; 9:e96938. [PMID: 24816837 PMCID: PMC4016158 DOI: 10.1371/journal.pone.0096938] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 04/13/2014] [Indexed: 11/26/2022] Open
Abstract
Bone morphogenetic proteins (BMPs) are highly conserved signaling molecules that are part of the transforming growth factor (TGF)-beta superfamily, and function in the patterning and morphogenesis of many organs including development of the dentition. The functions of the BMPs are controlled by certain classes of molecules that are recognized as BMP antagonists that inhibit BMP binding to their cognate receptors. In this study we tested the hypothesis that USAG-1 (uterine sensitization-associated gene-1) suppresses deciduous incisors by inhibition of BMP-7 function. We learned that USAG-1 and BMP-7 were expressed within odontogenic epithelium as well as mesenchyme during the late bud and early cap stages of tooth development. USAG-1 is a BMP antagonist, and also modulates Wnt signaling. USAG-1 abrogation rescued apoptotic elimination of odontogenic mesenchymal cells. BMP signaling in the rudimentary maxillary incisor, assessed by expressions of Msx1 and Dlx2 and the phosphorylation of Smad protein, was significantly enhanced. Using explant culture and subsequent subrenal capsule transplantation of E15 USAG-1 mutant maxillary incisor tooth primordia supplemented with BMP-7 demonstrated in USAG-1+/- as well as USAG-1-/- rescue and supernumerary tooth development. Based upon these results, we conclude that USAG-1 functions as an antagonist of BMP-7 in this model system. These results further suggest that the phenotypes of USAG-1 and BMP-7 mutant mice reported provide opportunities for regenerative medicine and dentistry.
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Affiliation(s)
- Honoka Kiso
- Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Kyoto University, Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, Japan
| | - Katsu Takahashi
- Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Kyoto University, Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, Japan
| | - Kazuyuki Saito
- Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Kyoto University, Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, Japan
| | - Yumiko Togo
- Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Kyoto University, Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, Japan
| | - Hiroko Tsukamoto
- Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Kyoto University, Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, Japan
| | - Boyen Huang
- Department of Paediatric Dentistry, School of Medicine and Dentistry, James Cook University, Cairns, Australia
| | - Manabu Sugai
- Translational Research Center, Kyoto University Hospital, Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, Japan
| | - Akira Shimizu
- Laboratory of Host Defense, World Premier International Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan
| | - Yasuhiko Tabata
- Department of Biomaterials, Institute for Frontier Medical Sciences, Kyoto University, Kyoto, Japan
| | - Aris N. Economides
- Regeneron Pharmaceuticals, Tarrytown, New York, United States of America
| | - Harold C. Slavkin
- Center for Craniofacial Molecular Biology, Division of Biomedical Sciences, Ostrow School of Dentistry, University of Southern California, Los Angeles, California, United States of America
| | - Kazuhisa Bessho
- Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Kyoto University, Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, Japan
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23
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Hu JKH, Mushegyan V, Klein OD. On the cutting edge of organ renewal: Identification, regulation, and evolution of incisor stem cells. Genesis 2014; 52:79-92. [PMID: 24307456 PMCID: PMC4252016 DOI: 10.1002/dvg.22732] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Revised: 11/22/2013] [Accepted: 11/25/2013] [Indexed: 12/14/2022]
Abstract
The rodent incisor is one of a number of organs that grow continuously throughout the life of an animal. Continuous growth of the incisor arose as an evolutionary adaptation to compensate for abrasion at the distal end of the tooth. The sustained turnover of cells that deposit the mineralized dental tissues is made possible by epithelial and mesenchymal stem cells residing at the proximal end of the incisor. A complex network of signaling pathways and transcription factors regulates the formation, maintenance, and differentiation of these stem cells during development and throughout adulthood. Research over the past 15 years has led to significant progress in our understanding of this network, which includes FGF, BMP, Notch, and Hh signaling, as well as cell adhesion molecules and micro-RNAs. This review surveys key historical experiments that laid the foundation of the field and discusses more recent findings that definitively identified the stem cell population, elucidated the regulatory network, and demonstrated possible genetic mechanisms for the evolution of continuously growing teeth.
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Affiliation(s)
- Jimmy Kuang-Hsien Hu
- Department of Orofacial Sciences and Program in Craniofacial and Mesenchymal Biology, University of California San Francisco, San Francisco, CA 94143, USA
| | - Vagan Mushegyan
- Department of Orofacial Sciences and Program in Craniofacial and Mesenchymal Biology, University of California San Francisco, San Francisco, CA 94143, USA
| | - Ophir D. Klein
- Department of Orofacial Sciences and Program in Craniofacial and Mesenchymal Biology, University of California San Francisco, San Francisco, CA 94143, USA
- Department of Pediatrics and Institute for Human Genetics, University of California San Francisco, San Francisco, CA 94143, USA
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24
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Cessation of epithelial Bmp signaling switches the differentiation of crown epithelia to the root lineage in a β-catenin-dependent manner. Mol Cell Biol 2013; 33:4732-44. [PMID: 24081330 DOI: 10.1128/mcb.00456-13] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The differentiation of dental epithelia into enamel-producing ameloblasts or the root epithelial lineage compartmentalizes teeth into crowns and roots. Bmp signaling has been linked to enamel formation, but its role in root epithelial lineage differentiation is unclear. Here we show that cessation of epithelial Bmp signaling by Bmpr1a depletion during the differentiation stage switched differentiation of crown epithelia into the root lineage and led to formation of ectopic cementum-like structures. This phenotype is related to the upregulation of Wnt/β-catenin signaling and epithelial-mesenchymal transition (EMT). Although epithelial β-catenin depletion during the differentiation stage also led to variable enamel defect and precocious/ectopic formation of fragmented root epithelia in some teeth, it did not cause ectopic cementogenesis and inhibited EMT in cultured dental epithelia. Concomitant epithelial β-catenin depletion rescued EMT and ectopic cementogenesis caused by Bmpr1a depletion. These data suggested that Bmp and Wnt/β-catenin pathways interact antagonistically in dental epithelia to regulate the root lineage differentiation and EMT. These findings will aid in the design of new strategies to promote functional differentiation in the regeneration and tissue engineering of teeth and will provide new insights into the dynamic interactions between the Bmp and Wnt/β-catenin pathways during cell fate decisions.
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25
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Chang JYF, Wang C, Liu J, Huang Y, Jin C, Yang C, Hai B, Liu F, D'Souza RN, McKeehan WL, Wang F. Fibroblast growth factor signaling is essential for self-renewal of dental epithelial stem cells. J Biol Chem 2013; 288:28952-61. [PMID: 23979135 DOI: 10.1074/jbc.m113.506873] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
A constant supply of epithelial cells from dental epithelial stem cell (DESC) niches in the cervical loop (CL) enables mouse incisors to grow continuously throughout life. Elucidation of the cellular and molecular mechanisms underlying this unlimited growth potential is of broad interest for tooth regenerative therapies. Fibroblast growth factor (FGF) signaling is essential for the development of mouse incisors and for maintenance of the CL during prenatal development. However, how FGF signaling in DESCs controls the self-renewal and differentiation of the cells is not well understood. Herein, we report that FGF signaling is essential for self-renewal and the prevention of cell differentiation of DESCs in the CL as well as in DESC spheres. Inhibiting the FGF signaling pathway decreased proliferation and increased apoptosis of the cells in DESC spheres. Suppressing FGFR or its downstream signal transduction pathways diminished Lgr5-expressing cells in the CL and promoted cell differentiation both in DESC spheres and the CL. Furthermore, disruption of the FGF pathway abrogated Wnt signaling to promote Lgr5 expression in DESCs both in vitro and in vivo. This study sheds new light on understanding the mechanism by which the homeostasis, expansion, and differentiation of DESCs are regulated.
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Affiliation(s)
- Julia Yu Fong Chang
- From the Center for Cancer and Stem Cell Biology, Institute of Biosciences and Technology, Texas A&M University, Houston, Texas 77030-3303
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26
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Specialized stem cell niche enables repetitive renewal of alligator teeth. Proc Natl Acad Sci U S A 2013; 110:E2009-18. [PMID: 23671090 DOI: 10.1073/pnas.1213202110] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Reptiles and fish have robust regenerative powers for tooth renewal. However, extant mammals can either renew their teeth one time (diphyodont dentition) or not at all (monophyodont dentition). Humans replace their milk teeth with permanent teeth and then lose their ability for tooth renewal. Here, we study tooth renewal in a crocodilian model, the American alligator, which has well-organized teeth similar to mammals but can still undergo life-long renewal. Each alligator tooth is a complex family unit composed of the functional tooth, successional tooth, and dental lamina. Using multiple mitotic labeling, we map putative stem cells to the distal enlarged bulge of the dental lamina that contains quiescent odontogenic progenitors that can be activated during physiological exfoliation or artificial extraction. Tooth cycle initiation correlates with β-catenin activation and soluble frizzled-related protein 1 disappearance in the bulge. The dermal niche adjacent to the dermal lamina dynamically expresses neural cell adhesion molecule, tenascin-C, and other molecules. Furthermore, in development, asymmetric β-catenin localization leads to the formation of a heterochronous and complex tooth family unit configuration. Understanding how these signaling molecules interact in tooth development in this model may help us to learn how to stimulate growth of adult teeth in mammals.
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27
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Wang X, Wang S, Lu Y, Gibson MP, Liu Y, Yuan B, Feng JQ, Qin C. FAM20C plays an essential role in the formation of murine teeth. J Biol Chem 2012; 287:35934-42. [PMID: 22936805 DOI: 10.1074/jbc.m112.386862] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
FAM20C is highly expressed in bone and tooth. Previously, we showed that Fam20C conditional knock-out (KO) mice manifest hypophosphatemic rickets, which highlights the crucial roles of this molecule in promoting bone formation and mediating phosphate homeostasis. In this study, we characterized the dentin, enamel, and cementum of Sox2-Cre-mediated Fam20C KO mice. The KO mice exhibited small malformed teeth, severe enamel defects, very thin dentin, less cementum than normal, and overall hypomineralization in the dental mineralized tissues. In situ hybridization and immunohistochemistry analyses revealed remarkable down-regulation of dentin matrix protein 1 (DMP1) and dentin sialophosphoprotein in odontoblasts, along with a sharply reduced expression of ameloblastin and amelotin in ameloblasts. Collectively, these data indicate that FAM20C is essential to the differentiation and mineralization of dental tissues through the regulation of molecules critical to the differentiation of tooth-formative cells.
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Affiliation(s)
- Xiaofang Wang
- Department of Biomedical Sciences, Texas A&M Health Science Center Baylor College of Dentistry, Dallas, Texas 75246, USA
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28
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Juuri E, Saito K, Ahtiainen L, Seidel K, Tummers M, Hochedlinger K, Klein OD, Thesleff I, Michon F. Sox2+ stem cells contribute to all epithelial lineages of the tooth via Sfrp5+ progenitors. Dev Cell 2012; 23:317-28. [PMID: 22819339 DOI: 10.1016/j.devcel.2012.05.012] [Citation(s) in RCA: 185] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Revised: 02/22/2012] [Accepted: 05/18/2012] [Indexed: 12/21/2022]
Abstract
The continuously growing mouse incisor serves as a valuable model to study stem cell regulation during organ renewal. Epithelial stem cells are localized in the proximal end of the incisor in the labial cervical loop. Here, we show that the transcription factor Sox2 is a specific marker for these stem cells. Sox2+ cells became restricted to the labial cervical loop during tooth morphogenesis, and they contributed to the renewal of enamel-producing ameloblasts as well as all other epithelial cell lineages of the tooth. The early progeny of Sox2-positive stem cells transiently expressed the Wnt inhibitor Sfrp5. Sox2 expression was regulated by the tooth initiation marker FGF8 and specific miRNAs, suggesting a fine-tuning to maintain homeostasis of the dental epithelium. The identification of Sox2 as a marker for the dental epithelial stem cells will facilitate further studies on their lineage segregation and differentiation during tooth renewal.
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Affiliation(s)
- Emma Juuri
- Developmental Biology Program, Institute of Biotechnology, University of Helsinki, 00014 Helsinki, Finland
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29
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Jheon AH, Seidel K, Biehs B, Klein OD. From molecules to mastication: the development and evolution of teeth. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2012; 2:165-82. [PMID: 24009032 DOI: 10.1002/wdev.63] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Teeth are unique to vertebrates and have played a central role in their evolution. The molecular pathways and morphogenetic processes involved in tooth development have been the focus of intense investigation over the past few decades, and the tooth is an important model system for many areas of research. Developmental biologists have exploited the clear distinction between the epithelium and the underlying mesenchyme during tooth development to elucidate reciprocal epithelial/mesenchymal interactions during organogenesis. The preservation of teeth in the fossil record makes these organs invaluable for the work of paleontologists, anthropologists, and evolutionary biologists. In addition, with the recent identification and characterization of dental stem cells, teeth have become of interest to the field of regenerative medicine. Here, we review the major research areas and studies in the development and evolution of teeth, including morphogenesis, genetics and signaling, evolution of tooth development, and dental stem cells.
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Affiliation(s)
- Andrew H Jheon
- Department of Orofacial Sciences and Program in Craniofacial and Mesenchymal Biology, University of California San Francisco, San Francisco, CA, USA
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30
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Du Y, Ling J, Wei X, Ning Y, Xie N, Gu H, Yang F. Wnt/β-catenin signaling participates in cementoblast/osteoblast differentiation of dental follicle cells. Connect Tissue Res 2012; 53:390-7. [PMID: 22360497 DOI: 10.3109/03008207.2012.668980] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Dental follicle cells (DFCs) are reported to contain stem cells. The canonical Wnt signaling pathway plays an important role in stem cell self-renewal and tooth development through β-catenin expression. The objective of this study was to investigate whether Wnt/β-catenin signaling pathway participates in the cementoblast/osteoblast differentiation of rat DFCs. Immunohistochemistry was used to compare the expression of β-catenin in rat mandibular first molars from postnatal days 1-13. The effects of Wnt/β-catenin signaling on DFCs in vitro were examined by lithium chloride (LiCl) treatment by immunofluorescence, cell counting, dual-luciferase reporter assays, western blotting, and alkaline phosphatase activity analysis. β-Catenin expression was absent in the dental follicles on days 1 and 3 in vivo. It then progressively increased from days 5 to 13. In vitro studies of the DFCs showed that LiCl stimulation caused β-catenin, which was mainly located in the cell membrane and cytoplasm of DFCs, to be immediately transferred to the nucleus and led to the inhibition of proliferation at 12 and 24 hr. LiCl treatment also downregulated the levels of phosphorylated-β-catenin, while upregulating the levels of total β-catenin, nuclear β-catenin, osteocalcin, runt-related transcription factor 2, and collagen type I. In addition, LiCl enhanced the β-catenin/T-cell factor luciferase activity and alkaline phosphatase activity. These results suggest that Wnt/β-catenin signaling pathway positively regulates the cementoblast/osteoblast differentiation of the DFCs.
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Affiliation(s)
- Yu Du
- Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, PR China
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31
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Wang XP, Fan J. Molecular genetics of supernumerary tooth formation. Genesis 2011; 49:261-77. [PMID: 21309064 DOI: 10.1002/dvg.20715] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Revised: 01/02/2011] [Accepted: 01/06/2011] [Indexed: 01/07/2023]
Abstract
Despite advances in the knowledge of tooth morphogenesis and differentiation, relatively little is known about the aetiology and molecular mechanisms underlying supernumerary tooth formation. A small number of supernumerary teeth may be a common developmental dental anomaly, while multiple supernumerary teeth usually have a genetic component and they are sometimes thought to represent a partial third dentition in humans. Mice, which are commonly used for studying tooth development, only exhibit one dentition, with very few mouse models exhibiting supernumerary teeth similar to those in humans. Inactivation of Apc or forced activation of Wnt/β(catenin signalling results in multiple supernumerary tooth formation in both humans and in mice, but the key genes in these pathways are not very clear. Analysis of other model systems with continuous tooth replacement or secondary tooth formation, such as fish, snake, lizard, and ferret, is providing insights into the molecular and cellular mechanisms underlying succesional tooth development, and will assist in the studies on supernumerary tooth formation in humans. This information, together with the advances in stem cell biology and tissue engineering, will pave ways for the tooth regeneration and tooth bioengineering.
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Affiliation(s)
- Xiu-Ping Wang
- Department of Developmental Biology, Harvard School of Dental Medicine, Harvard University, Boston, Massachusetts 02115, USA.
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