1
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Benard EL, Küçükaylak I, Hatzold J, Berendes KU, Carney TJ, Beleggia F, Hammerschmidt M. wnt10a is required for zebrafish median fin fold maintenance and adult unpaired fin metamorphosis. Dev Dyn 2024; 253:566-592. [PMID: 37870737 PMCID: PMC11035493 DOI: 10.1002/dvdy.672] [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: 08/24/2023] [Revised: 10/03/2023] [Accepted: 10/08/2023] [Indexed: 10/24/2023] Open
Abstract
BACKGROUND Mutations of human WNT10A are associated with odonto-ectodermal dysplasia syndromes. Here, we present analyses of wnt10a loss-of-function mutants in the zebrafish. RESULTS wnt10a mutant zebrafish embryos display impaired tooth development and a collapsing median fin fold (MFF). Rescue experiments show that wnt10a is essential for MFF maintenance both during embryogenesis and later metamorphosis. The MFF collapse could not be attributed to increased cell death or altered proliferation rates of MFF cell types. Rather, wnt10a mutants show reduced expression levels of dlx2a in distal-most MFF cells, followed by compromised expression of col1a1a and other extracellular matrix proteins encoding genes. Transmission electron microscopy analysis shows that although dermal MFF compartments of wnt10a mutants initially are of normal morphology, with regular collagenous actinotrichia, positioning of actinotrichia within the cleft of distal MFF cells becomes compromised, coinciding with actinotrichia shrinkage and MFF collapse. CONCLUSIONS MFF collapse of wnt10a mutant zebrafish is likely caused by the loss of distal properties in the developing MFF, strikingly similar to the proposed molecular pathomechanisms underlying the teeth defects caused by the loss of Wnt10 in fish and mammals. In addition, it points to thus fur unknown mechanisms controlling the linear growth and stability of actinotrichia and their collagen fibrils.
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Affiliation(s)
- Erica L. Benard
- Institute of Zoology, Developmental Biology Unit,
University of Cologne, Cologne, Germany
| | - Ismail Küçükaylak
- Institute of Zoology, Developmental Biology Unit,
University of Cologne, Cologne, Germany
| | - Julia Hatzold
- Institute of Zoology, Developmental Biology Unit,
University of Cologne, Cologne, Germany
| | - Kilian U.W. Berendes
- Institute of Zoology, Developmental Biology Unit,
University of Cologne, Cologne, Germany
| | - Thomas J. Carney
- Discovery Research Division, Institute of Molecular and
Cell Biology (IMCB), A*STAR (Agency for Science, Technology and Research),
Singapore, Republic of Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological
University, Singapore, Republic of Singapore
| | - Filippo Beleggia
- Department I of Internal Medicine, Faculty of Medicine and
University Hospital Cologne, University of Cologne, Germany
- Department of Translational Genomics, Faculty of Medicine
and University Hospital Cologne, University of Cologne, Cologne, Germany
- Mildred Scheel School of Oncology Aachen Bonn Cologne
Düsseldorf (MSSO ABCD), Faculty of Medicine and University Hospital Cologne,
University of Cologne, Cologne, Germany
| | - Matthias Hammerschmidt
- Institute of Zoology, Developmental Biology Unit,
University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne, University of
Cologne, Cologne, Germany
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2
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Michel ZD, Aitken SF, Glover OD, Alejandro LO, Randazzo D, Dambkowski C, Martin D, Collins MT, Somerman MJ, Chu EY. Infigratinib, a selective FGFR1-3 tyrosine kinase inhibitor, alters dentoalveolar development at high doses. Dev Dyn 2023; 252:1428-1448. [PMID: 37435833 PMCID: PMC10784415 DOI: 10.1002/dvdy.642] [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: 08/31/2022] [Revised: 06/14/2023] [Accepted: 06/22/2023] [Indexed: 07/13/2023] Open
Abstract
BACKGROUND Fibroblast growth factor receptor-3 (FGFR3) gain-of-function mutations are linked to achondroplasia. Infigratinib, a FGFR1-3 tyrosine kinase inhibitor, improves skeletal growth in an achondroplasia mouse model. FGFs and their receptors have critical roles in developing teeth, yet effects of infigratinib on tooth development have not been assessed. Dentoalveolar and craniofacial phenotype of Wistar rats dosed with low (0.1 mg/kg) and high (1.0 mg/kg) dose infigratinib were evaluated using micro-computed tomography, histology, and immunohistochemistry. RESULTS Mandibular third molars were reduced in size and exhibited aberrant crown and root morphology in 100% of female rats and 80% of male rats at high doses. FGFR3 and FGF18 immunolocalization and extracellular matrix protein expression were unaffected, but cathepsin K (CTSK) was altered by infigratinib. Cranial vault bones exhibited alterations in dimension, volume, and density that were more pronounced in females. In both sexes, interfrontal sutures were significantly more patent with high dose vs vehicle. CONCLUSIONS High dose infigratinib administered to rats during early stages affects dental and craniofacial development. Changes in CTSK from infigratinib in female rats suggest FGFR roles in bone homeostasis. While dental and craniofacial disruptions are not expected at therapeutic doses, our findings confirm the importance of dental monitoring in clinical studies.
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Affiliation(s)
- Zachary D Michel
- Skeletal Disorders and Mineral Homeostasis Section, National Institute of Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Sarah F Aitken
- Laboratory of Oral Connective Tissue Biology, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health, Bethesda, Maryland, USA
| | - Omar D Glover
- Laboratory of Oral Connective Tissue Biology, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health, Bethesda, Maryland, USA
| | - Lucy O Alejandro
- Laboratory of Oral Connective Tissue Biology, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health, Bethesda, Maryland, USA
| | - Davide Randazzo
- Light Imaging Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health (NIH), Bethesda, Maryland, USA
| | | | - David Martin
- QED Therapeutics, San Francisco, California, USA
| | - Michael T Collins
- Skeletal Disorders and Mineral Homeostasis Section, National Institute of Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Martha J Somerman
- Laboratory of Oral Connective Tissue Biology, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health, Bethesda, Maryland, USA
| | - Emily Y Chu
- Laboratory of Oral Connective Tissue Biology, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health, Bethesda, Maryland, USA
- Department of Comprehensive Dentistry, Division of Cariology and Operative Dentistry, University of Maryland School of Dentistry, Baltimore, Maryland, USA
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3
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Chen X, Li Y, Paiboonrungruang C, Li Y, Peters H, Kist R, Xiong Z. PAX9 in Cancer Development. Int J Mol Sci 2022; 23:5589. [PMID: 35628401 PMCID: PMC9147292 DOI: 10.3390/ijms23105589] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 05/12/2022] [Accepted: 05/14/2022] [Indexed: 02/05/2023] Open
Abstract
Paired box 9 (PAX9) is a transcription factor of the PAX family functioning as both a transcriptional activator and repressor. Its functional roles in the embryonic development of various tissues and organs have been well studied. However, its roles and molecular mechanisms in cancer development are largely unknown. Here, we review the current understanding of PAX9 expression, upstream regulation of PAX9, and PAX9 downstream events in cancer development. Promoter hypermethylation, promoter SNP, microRNA, and inhibition of upstream pathways (e.g., NOTCH) result in PAX9 silencing or downregulation, whereas gene amplification and an epigenetic axis upregulate PAX9 expression. PAX9 may contribute to carcinogenesis through dysregulation of its transcriptional targets and related molecular pathways. In summary, extensive studies on PAX9 in its cellular and tissue contexts are warranted in various cancers, in particular, HNSCC, ESCC, lung cancer, and cervical SCC.
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Affiliation(s)
- Xiaoxin Chen
- Cancer Research Program, Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University, 700 George Street, Durham, NC 27707, USA; (X.C.); (Y.L.); (C.P.); (Y.L.)
| | - Yahui Li
- Cancer Research Program, Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University, 700 George Street, Durham, NC 27707, USA; (X.C.); (Y.L.); (C.P.); (Y.L.)
| | - Chorlada Paiboonrungruang
- Cancer Research Program, Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University, 700 George Street, Durham, NC 27707, USA; (X.C.); (Y.L.); (C.P.); (Y.L.)
| | - Yong Li
- Cancer Research Program, Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University, 700 George Street, Durham, NC 27707, USA; (X.C.); (Y.L.); (C.P.); (Y.L.)
- Department of Thoracic Surgery, National Cancer Center, Cancer Hospital of Chinese Academy of Medical Sciences, 17 Panjiayuan Nanli Road, Beijing 100021, China
| | - Heiko Peters
- Newcastle University Biosciences Institute, Newcastle upon Tyne NE2 4BW, UK;
| | - Ralf Kist
- Newcastle University Biosciences Institute, Newcastle upon Tyne NE2 4BW, UK;
- School of Dental Sciences, Newcastle University Centre for Cancer, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4BW, UK
| | - Zhaohui Xiong
- Cancer Research Program, Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University, 700 George Street, Durham, NC 27707, USA; (X.C.); (Y.L.); (C.P.); (Y.L.)
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4
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Paudel S, Gjorcheska S, Bump P, Barske L. Patterning of cartilaginous condensations in the developing facial skeleton. Dev Biol 2022; 486:44-55. [DOI: 10.1016/j.ydbio.2022.03.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 03/14/2022] [Accepted: 03/23/2022] [Indexed: 11/30/2022]
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5
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Zhou C, Yang G, Chen M, He L, Xiang L, Ricupero C, Mao JJ, Ling J. Lhx6 and Lhx8: cell fate regulators and beyond. FASEB J 2015; 29:4083-91. [PMID: 26148970 PMCID: PMC4566936 DOI: 10.1096/fj.14-267500] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Accepted: 06/22/2015] [Indexed: 12/11/2022]
Abstract
As transcription factors of the lines (LIN)-11/Islet (Isl)-1/mitosis entry checkpoint (MEC)-3 (LIM)-homeobox subfamily, LIM homeobox (Lhx)6 and -8 are remarkably conserved and involved in the morphogenesis of multiple organ systems. Lhx6 and -8 play overlapping and distinctive roles, but in general act as cell fate mediators and in turn are regulated by several transcriptional factors, such as sonic hedgehog, fibroblast growth factors, and wingless-int (Wnt)/β-catenin. In this review, we first summarize Lhx6 and -8 distributions in development and then explore how Lhx6 and -8 act as transcription factors and coregulators of cell lineage specification. Known Lhx6 and -8 functions and targets are outlined in neurogenesis, craniofacial development, and germ cell differentiation. The underlying mechanisms of Lhx6 and -8 in regulating cell fate remain elusive. Whether Lhx6 and -8 affect functions in tissues and organs other than neural, craniofacial, oocytes, and germ cells is largely unexplored. Taken together, Lhx6 and -8 are important regulators of cell lineage specification and may act as one of the pivotal mediators of stem cell fate. Undoubtedly, future investigations of Lhx6 and -8 biology will continue to yield fascinating insights into tissue development and homeostasis, in addition to their putative roles in tissue regeneration and ageing.
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Affiliation(s)
- Chen Zhou
- *Center for Craniofacial Regeneration, Columbia University Medical Center, New York, New York, USA; Guanghua School of Stomatology, Hospital of Stomatology, and Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, China
| | - Guodong Yang
- *Center for Craniofacial Regeneration, Columbia University Medical Center, New York, New York, USA; Guanghua School of Stomatology, Hospital of Stomatology, and Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, China
| | - Mo Chen
- *Center for Craniofacial Regeneration, Columbia University Medical Center, New York, New York, USA; Guanghua School of Stomatology, Hospital of Stomatology, and Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, China
| | - Ling He
- *Center for Craniofacial Regeneration, Columbia University Medical Center, New York, New York, USA; Guanghua School of Stomatology, Hospital of Stomatology, and Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, China
| | - Lusai Xiang
- *Center for Craniofacial Regeneration, Columbia University Medical Center, New York, New York, USA; Guanghua School of Stomatology, Hospital of Stomatology, and Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, China
| | - Christopher Ricupero
- *Center for Craniofacial Regeneration, Columbia University Medical Center, New York, New York, USA; Guanghua School of Stomatology, Hospital of Stomatology, and Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, China
| | - Jeremy J Mao
- *Center for Craniofacial Regeneration, Columbia University Medical Center, New York, New York, USA; Guanghua School of Stomatology, Hospital of Stomatology, and Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, China
| | - Junqi Ling
- *Center for Craniofacial Regeneration, Columbia University Medical Center, New York, New York, USA; Guanghua School of Stomatology, Hospital of Stomatology, and Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, China
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6
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Tapaltsyan V, Charles C, Hu J, Mindell D, Ahituv N, Wilson GM, Black BL, Viriot L, Klein OD. Identification of novel Fgf enhancers and their role in dental evolution. Evol Dev 2015; 18:31-40. [PMID: 26086993 DOI: 10.1111/ede.12132] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Mammalian dental morphology is under strong evolutionary pressure because of its importance for mastication and diet. While the mechanisms underlying tooth development have been widely studied in model organisms, the role of genetic regulatory elements in patterning the different elements of the occlusal surface and crown height across species is not well understood. Previous studies showed that Fibroblast Growth Factor (FGF) genes are important regulators of tooth development that influence morphological variation. We hypothesized that inter-specific variation in rodent dental morphology could be governed by nucleotide variation in genetic regulatory elements that modulate the spatial and temporal expression of the genes encoding FGF signaling molecules. In this study, we compared the variation in dental morphology across nine taxa of rodents to the variation in sequences of non-coding evolutionary conserved regions (ECRs) of Fgf3, 4, 8, 9, and 10. We correlated the variation in molar tooth cusp shape and the evolution of high molar crowns (hypsodonty) to the patterns of sequence variation in two ECRs, Fgf10ECR3, and Fgf9ECR1, respectively. By conducting luciferase and electrophoretic mobility shift assays, we determined that these ECRs could function as enhancers. These data suggest that emergence of hypsodonty and occlusal cusp patterning may have happened through the evolutionary changes in enhancers, such as Fgf9ECR1 and Fgf10ECR3, which affected the expression of major signaling molecules involved in tooth development.
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Affiliation(s)
- Vagan Tapaltsyan
- Department of Orofacial Sciences and Program in Craniofacial Biology, University of California San Francisco, San Francisco, CA 94143, USA
| | - Cyril Charles
- Department of Orofacial Sciences and Program in Craniofacial Biology, University of California San Francisco, San Francisco, CA 94143, USA.,Team Evo-Devo of Vertebrate Dentition, Institut de Génomique Fonctionnelle de Lyon, ENS de Lyon, Université de Lyon, Université Lyon 1, CNRS, Ecole Normale Supérieure de Lyon, Lyon, France
| | - Jianxin Hu
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA 94158, USA
| | - David Mindell
- Division of Environmental Biology, National Science Foundation, Arlington, VA 22230, USA
| | - Nadav Ahituv
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA 94158, USA.,Institute for Human Genetics, University of California San Francisco, San Francisco, CA 94143, USA
| | - Gregory M Wilson
- Department of Biology, University of Central Oklahoma, Edmond, OK 73034, USA
| | - Brian L Black
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA 94158, USA
| | - Laurent Viriot
- Team Evo-Devo of Vertebrate Dentition, Institut de Génomique Fonctionnelle de Lyon, ENS de Lyon, Université de Lyon, Université Lyon 1, CNRS, Ecole Normale Supérieure de Lyon, Lyon, France
| | - Ophir D Klein
- Department of Orofacial Sciences and Program in Craniofacial Biology, University of California San Francisco, San Francisco, CA 94143, USA.,Institute for Human Genetics, University of California San Francisco, San Francisco, CA 94143, USA.,Department of Pediatrics, University of California San Francisco, San Francisco, CA 94143, USA
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7
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Kwon HJE, Park EK, Jia S, Liu H, Lan Y, Jiang R. Deletion of Osr2 Partially Rescues Tooth Development in Runx2 Mutant Mice. J Dent Res 2015; 94:1113-9. [PMID: 25916343 DOI: 10.1177/0022034515583673] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Tooth organogenesis depends on genetically programmed sequential and reciprocal inductive interactions between the dental epithelium and neural crest-derived mesenchyme. Previous studies showed that the Msx1 and Runx2 transcription factors are required for activation of odontogenic signals, including Bmp4 and Fgf3, in the early tooth mesenchyme to drive tooth morphogenesis through the bud-to-cap transition and that Runx2 acts downstream of Msx1 to activate Fgf3 expression. Recent studies identified Osr2 as a repressor of tooth development and showed that inactivation of Osr2 rescued molar tooth morphogenesis in the Msx1(-/-) mutant mice as well as in mice with neural crest-specific inactivation of Bmp4. Here we show that Runx2 expression is expanded in the tooth bud mesenchyme in Osr2(-/-) mutant mouse embryos and is partially restored in the tooth mesenchyme in Msx1(-/-)Osr2(-/-) mutants in comparison with Msx1(-/-) and wild-type embryos. Whereas mandibular molar development arrested at the bud stage and maxillary molar development arrested at the bud-to-cap transition in Runx2(-/-) mutant mice, both mandibular and maxillary molar tooth germs progressed to the early bell stage, with rescued expression of Msx1 and Bmp4 in the dental papilla as well as expression of Bmp4, p21, and Shh in the primary enamel knot in the Osr2(-/-)Runx2(-/-) compound mutants. In contrast to the Msx1(-/-)Osr2(-/-) compound mutants, which exhibit nearly normal first molar morphogenesis, the Osr2(-/-)Runx2(-/-) compound mutant embryos failed to activate the expression of Fgf3 and Fgf10 in the dental papilla and exhibited significant deficit in cell proliferation in both the dental epithelium and mesenchyme in comparison with the control embryos. These data indicate that Runx2 synergizes with Msx1 to drive tooth morphogenesis through the bud-to-cap transition and that Runx2 controls continued tooth growth and morphogenesis beyond the cap stage through activation of Fgf3 and Fgf10 expression in the dental papilla.
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Affiliation(s)
- H J E Kwon
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - E K Park
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA Department of Oral Pathology, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea
| | - S Jia
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA School of Dentistry, University of Utah, Salt Lake City, UT, USA
| | - H Liu
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Y Lan
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA Division of Plastic Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - R Jiang
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA Division of Plastic Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
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8
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Yamanaka A, Iwai H, Uemura M, Goto T. Patterning of mammalian heterodont dentition within the upper and lower jaws. Evol Dev 2015; 17:127-38. [PMID: 25801220 DOI: 10.1111/ede.12116] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mammalian heterodont dentition is differentiated into incisors, canines, premolars, and molars in the mesial-distal direction, in both the upper and lower jaws. Although all the lower teeth are rooted in the mandible, the upper incisors are rooted in the premaxilla and the upper canine and the teeth behind it are in the maxilla. The present study uncovers ontogenetic backgrounds to these shared and differing mesiodistal patterns of the upper and lower dentition. To this end, we examined the dentition development of the house shrew, Suncus murinus, instead of the rodent model animals because the dentition of this primitive eutherian species includes all the tooth classes, and no toothless diastema region. In the shrew, the upper incisor-forming region extended over the medial nasal prominence and the mesial part of the maxillary prominence. Consequently, the maxillary and mandibular prominences were in a mirror-image relationship in terms of the mesiodistally differentiated tooth-forming regions and of the complementary gene expression pattern, with Bmp4 in the mesial and Fgf8 in the distal regions. This suggests shared molecular mechanisms regulating tooth class differentiation between the upper and lower jaws. However, the premaxillary bone appeared within the mesenchyme of the medial nasal prominence, but grew distally beyond the former epithelial boundary with the maxillary prominence to form, finally, the incisive (premaxillary-maxillary) suture just mesial to the canine. Therefore, the developmental locations of the upper incisors are not inconsistent with the classical osteological criterion of the upper canine by comparative odontologists.
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Affiliation(s)
- Atsushi Yamanaka
- Department of Oral Anatomy and Cell Biology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8544, Japan
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9
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Suryadeva S, Khan MB. Role of homeobox genes in tooth morphogenesis: a review. J Clin Diagn Res 2015; 9:ZE09-12. [PMID: 25859538 PMCID: PMC4378821 DOI: 10.7860/jcdr/2015/11067.5606] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 12/03/2014] [Indexed: 11/24/2022]
Abstract
In oral cavity, disturbances due to genetic alterations may range from lack of tooth development to morphological defects. Due to technical advances in genetic engineering and molecular biology, valuable information regarding dentofacial growth could be studied in detailed manner. This helped us to explain the aetiology and pathogenesis of many dentofacial disorders. The success in treatment lies first in determining the aetiology of tooth anomalies and finally differentiating the effect of genes and environment on the orofacial diseases of that particular individual. Several genes belonging to class II homeobox families are expressed during odontogenesis however homeobox genes are not directly imvolved in tooth formation as they are not directly expressed in the first branchial arch derivatives.
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Affiliation(s)
- Sreevalli Suryadeva
- Associate Professor, Department of Orthodontics, Drs. Sudha and Nageswara Rao Pinnamineni Siddhartha Institute of Dental Sciences, Gunnavaram, Vijayawada, Andhara Pradesh, India
| | - Mohammadi Begum Khan
- Assistant Professor, Department of Orthodontics, Drs. Sudha and Nageswara Rao Pinnamineni Siddhartha Institute of Dental Sciences, Gunnavaram, Vijayawada, Andhara Pradesh, India
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10
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11
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Jackman WR, Davies SH, Lyons DB, Stauder CK, Denton-Schneider BR, Jowdry A, Aigler SR, Vogel SA, Stock DW. Manipulation of Fgf and Bmp signaling in teleost fishes suggests potential pathways for the evolutionary origin of multicuspid teeth. Evol Dev 2014; 15:107-18. [PMID: 25098636 DOI: 10.1111/ede.12021] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Teeth with two or more cusps have arisen independently from an ancestral unicuspid condition in a variety of vertebrate lineages, including sharks, teleost fishes, amphibians, lizards, and mammals. One potential explanation for the repeated origins of multicuspid teeth is the existence of multiple adaptive pathways leading to them, as suggested by their different uses in these lineages. Another is that the addition of cusps required only minor changes in genetic pathways regulating tooth development. Here we provide support for the latter hypothesis by demonstrating that manipulation of the levels of Fibroblast growth factor (Fgf) or Bone morphogenetic protein (Bmp) signaling produces bicuspid teeth in the zebrafish (Danio rerio), a species lacking multicuspid teeth in its ancestry. The generality of these results for teleosts is suggested by the conversion of unicuspid pharyngeal teeth into bicuspid teeth by similar manipulations of the Mexican Tetra (Astyanax mexicanus). That these manipulations also produced supernumerary teeth in both species supports previous suggestions of similarities in the molecular control of tooth and cusp number. We conclude that despite their apparent complexity, the evolutionary origin of multicuspid teeth is positively constrained, likely requiring only slight modifications of a pre-existing mechanism for patterning the number and spacing of individual teeth.
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12
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Landin Malt A, Cesario JM, Tang Z, Brown S, Jeong J. Identification of a face enhancer reveals direct regulation of LIM homeobox 8 (Lhx8) by wingless-int (WNT)/β-catenin signaling. J Biol Chem 2014; 289:30289-30301. [PMID: 25190800 DOI: 10.1074/jbc.m114.592014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Development of the mammalian face requires a large number of genes that are expressed with spatio-temporal specificity, and transcriptional regulation mediated by enhancers plays a key role in the precise control of gene expression. Using chromatin immunoprecipitation for a histone marker of active enhancers, we generated a genome-wide map of candidate enhancers from the maxillary arch (primordium for the upper jaw) of mouse embryos. Furthermore, we confirmed multiple novel craniofacial enhancers near the genes implicated in human palate defects through functional assays. We characterized in detail one of the enhancers (Lhx8_enh1) located upstream of Lhx8, a key regulatory gene for craniofacial development. Lhx8_enh1 contained an evolutionarily conserved binding site for lymphoid enhancer factor/T-cell factor family proteins, which mediate the transcriptional regulation by the WNT/β-catenin signaling pathway. We demonstrated in vitro that WNT/β-catenin signaling was indeed essential for the expression of Lhx8 in the maxillary arch cells and that Lhx8_enh1 was a direct target of the WNT/β-catenin pathway. Together, we uncovered a molecular mechanism for the regulation of Lhx8, and we provided valuable resources for further investigation into the gene regulatory network of craniofacial development.
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Affiliation(s)
- André Landin Malt
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, New York 10010 and
| | - Jeffry M Cesario
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, New York 10010 and
| | - Zuojian Tang
- Center for Health Informatics and Bioinformatics, New York University School of Medicine, New York, New York 10016
| | - Stuart Brown
- Center for Health Informatics and Bioinformatics, New York University School of Medicine, New York, New York 10016
| | - Juhee Jeong
- Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, New York 10010 and.
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13
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Moustakas-Verho JE, Zimm R, Cebra-Thomas J, Lempiäinen NK, Kallonen A, Mitchell KL, Hämäläinen K, Salazar-Ciudad I, Jernvall J, Gilbert SF. The origin and loss of periodic patterning in the turtle shell. Development 2014; 141:3033-9. [DOI: 10.1242/dev.109041] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The origin of the turtle shell over 200 million years ago greatly modified the amniote body plan, and the morphological plasticity of the shell has promoted the adaptive radiation of turtles. The shell, comprising a dorsal carapace and a ventral plastron, is a layered structure formed by basal endochondral axial skeletal elements (ribs, vertebrae) and plates of bone, which are overlain by keratinous ectodermal scutes. Studies of turtle development have mostly focused on the bones of the shell; however, the genetic regulation of the epidermal scutes has not been investigated. Here, we show that scutes develop from an array of patterned placodes and that these placodes are absent from a soft-shelled turtle in which scutes were lost secondarily. Experimentally inhibiting Shh, Bmp or Fgf signaling results in the disruption of the placodal pattern. Finally, a computational model is used to show how two coupled reaction-diffusion systems reproduce both natural and abnormal variation in turtle scutes. Taken together, these placodal signaling centers are likely to represent developmental modules that are responsible for the evolution of scutes in turtles, and the regulation of these centers has allowed for the diversification of the turtle shell.
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Affiliation(s)
- Jacqueline E. Moustakas-Verho
- Developmental Biology Program, Institute of Biotechnology, University of Helsinki, P.O. Box 56, Helsinki FIN-00014, Finland
| | - Roland Zimm
- Developmental Biology Program, Institute of Biotechnology, University of Helsinki, P.O. Box 56, Helsinki FIN-00014, Finland
| | - Judith Cebra-Thomas
- Biology Department, Millersville University, P.O. Box 1002, Millersville, PA 17551, USA
| | - Netta K. Lempiäinen
- Developmental Biology Program, Institute of Biotechnology, University of Helsinki, P.O. Box 56, Helsinki FIN-00014, Finland
| | - Aki Kallonen
- Division of Materials Physics, Department of Physics, University of Helsinki, P.O. Box 64, Helsinki FIN-00014, Finland
| | - Katherine L. Mitchell
- Biology Department, Swarthmore College, 500 College Avenue, Swarthmore, PA 19081, USA
| | - Keijo Hämäläinen
- Division of Materials Physics, Department of Physics, University of Helsinki, P.O. Box 64, Helsinki FIN-00014, Finland
| | - Isaac Salazar-Ciudad
- Developmental Biology Program, Institute of Biotechnology, University of Helsinki, P.O. Box 56, Helsinki FIN-00014, Finland
- Departament de Genètica i Microbiologia, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Barcelona, Spain
| | - Jukka Jernvall
- Developmental Biology Program, Institute of Biotechnology, University of Helsinki, P.O. Box 56, Helsinki FIN-00014, Finland
| | - Scott F. Gilbert
- Developmental Biology Program, Institute of Biotechnology, University of Helsinki, P.O. Box 56, Helsinki FIN-00014, Finland
- Biology Department, Swarthmore College, 500 College Avenue, Swarthmore, PA 19081, USA
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14
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Jandzik D, Hawkins MB, Cattell MV, Cerny R, Square TA, Medeiros DM. Roles for FGF in lamprey pharyngeal pouch formation and skeletogenesis highlight ancestral functions in the vertebrate head. Development 2014; 141:629-38. [PMID: 24449839 DOI: 10.1242/dev.097261] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A defining feature of vertebrates (craniates) is a pronounced head supported and protected by a cellularized endoskeleton. In jawed vertebrates (gnathostomes), the head skeleton is made of rigid three-dimensional elements connected by joints. By contrast, the head skeleton of modern jawless vertebrates (agnathans) consists of thin rods of flexible cellular cartilage, a condition thought to reflect the ancestral vertebrate state. To better understand the origin and evolution of the gnathostome head skeleton, we have been analyzing head skeleton development in the agnathan, lamprey. The fibroblast growth factors FGF3 and FGF8 have various roles during head development in jawed vertebrates, including pharyngeal pouch morphogenesis, patterning of the oral skeleton and chondrogenesis. We isolated lamprey homologs of FGF3, FGF8 and FGF receptors and asked whether these functions are ancestral features of vertebrate development or gnathostome novelties. Using gene expression and pharmacological agents, we found that proper formation of the lamprey head skeleton requires two phases of FGF signaling: an early phase during which FGFs drive pharyngeal pouch formation, and a later phase when they directly regulate skeletal differentiation and patterning. In the context of gene expression and functional studies in gnathostomes, our results suggest that these roles for FGFs arose in the first vertebrates and that the evolution of the jaw and gnathostome cellular cartilage was driven by changes developmentally downstream from pharyngeal FGF signaling.
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Affiliation(s)
- David Jandzik
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Boulder, CO 80309, USA
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15
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Biggs LC, Mikkola ML. Early inductive events in ectodermal appendage morphogenesis. Semin Cell Dev Biol 2014; 25-26:11-21. [DOI: 10.1016/j.semcdb.2014.01.007] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 01/23/2014] [Accepted: 01/24/2014] [Indexed: 01/18/2023]
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16
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Molecular patterning of the mammalian dentition. Semin Cell Dev Biol 2013; 25-26:61-70. [PMID: 24355560 DOI: 10.1016/j.semcdb.2013.12.003] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 11/20/2013] [Accepted: 12/09/2013] [Indexed: 01/15/2023]
Abstract
Four conserved signaling pathways, including the bone morphogenetic proteins (Bmp), fibroblast growth factors (Fgf), sonic hedgehog (Shh), and wingless-related (Wnt) pathways, are each repeatedly used throughout tooth development. Inactivation of any of these resulted in early tooth developmental arrest in mice. The mutations identified thus far in human patients with tooth agenesis also affect these pathways. Recent studies show that these signaling pathways interact through positive and negative feedback loops to regulate not only morphogenesis of individual teeth but also tooth number, shape, and spatial pattern. Increased activity of each of the Fgf, Shh, and canonical Wnt signaling pathways revitalizes development of the physiologically arrested mouse diastemal tooth germs whereas constitutive activation of canonical Wnt signaling in the dental epithelium is able to induce supernumerary tooth formation even in the absence of Msx1 and Pax9, two transcription factors required for normal tooth development beyond the early bud stage. Bmp4 and Msx1 act in a positive feedback loop to drive sequential tooth formation whereas the Osr2 transcription factor restricts Msx1-mediated expansion of the mesenchymal odontogenic field along both the buccolingual and anteroposterior axes to pattern mouse molar teeth in a single row. Moreover, the ectodermal-specific ectodysplasin (EDA) signaling pathway controls tooth number and tooth shape through regulation of Fgf20 expression in the dental epithelium, whereas Shh suppresses Wnt signaling through a negative feedback loop to regulate spatial patterning of teeth. In this article, we attempt to integrate these exciting findings in the understanding of the molecular networks regulating tooth development and patterning.
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17
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Liu C, Gu S, Sun C, Ye W, Song Z, Zhang Y, Chen Y. FGF signaling sustains the odontogenic fate of dental mesenchyme by suppressing β-catenin signaling. Development 2013; 140:4375-85. [PMID: 24067353 DOI: 10.1242/dev.097733] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Odontoblasts and osteoblasts develop from multipotent craniofacial neural crest cells during tooth and jawbone development, but the mechanisms that specify and sustain their respective fates remain largely unknown. In this study we used early mouse molar and incisor tooth germs that possess distinct tooth-forming capability after dissociation and reaggregation in vitro to investigate the mechanism that sustains odontogenic fate of dental mesenchyme during tooth development. We found that after dissociation and reaggregation, incisor, but not molar, mesenchyme exhibits a strong osteogenic potency associated with robustly elevated β-catenin signaling activity in a cell-autonomous manner, leading to failed tooth formation in the reaggregates. Application of FGF3 to incisor reaggregates inhibits β-catenin signaling activity and rescues tooth formation. The lack of FGF retention on the cell surface of incisor mesenchyme appears to account for the differential osteogenic potency between incisor and molar, which can be further attributed to the differential expression of syndecan 1 and NDST genes. We further demonstrate that FGF signaling inhibits intracellular β-catenin signaling by activating the PI3K/Akt pathway to regulate the subcellular localization of active GSK3β in dental mesenchymal cells. Our results reveal a novel function for FGF signaling in ensuring the proper fate of dental mesenchyme by regulating β-catenin signaling activity during tooth development.
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Affiliation(s)
- Chao Liu
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA 70118, USA
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18
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Leone A, Volponi AA, Renton T, Sharpe PT. In-vitro regulation of odontogenic gene expression in human embryonic tooth cells and SHED cells. Cell Tissue Res 2012; 348:465-73. [PMID: 22427065 DOI: 10.1007/s00441-012-1379-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Accepted: 02/13/2012] [Indexed: 01/09/2023]
Abstract
The bud-to-cap stage transition during early tooth development is a time when the tooth-inducing potential becomes restricted to the mesenchyme. Several key genes, expressed in the mesenchyme at this stage, are an absolute requirement for the progression of tooth development. These include the transcription factors Msx1 and Pax9. The inductive potential of tooth mesenchyme cells is a key requisite for whole-tooth bioengineering and thus identification of cells that can retain this property following expansion in culture is an important as yet unresolved, goal. We show here that in-vitro culture of embryonic human tooth mesenchyme cells and SHED cells express low levels of PAX9 and MSX1 and that these levels can be significantly upregulated by activation of different signalling pathways. Such in-vitro manipulation may thus offer a simple way of maintaining/restoring/inducing the odontogenic-inducing capacity in mesenchymal cells.
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Affiliation(s)
- Angelo Leone
- BioNec, Section of Histology and Embryology, Faculty of Medicine, University of Palermo, Palermo, Italy
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19
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Michon F. Tooth evolution and dental defects: From genetic regulation network to micro-RNA fine-tuning. ACTA ACUST UNITED AC 2011; 91:763-9. [DOI: 10.1002/bdra.20787] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Revised: 12/09/2010] [Accepted: 01/10/2011] [Indexed: 11/06/2022]
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20
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Osr2 acts downstream of Pax9 and interacts with both Msx1 and Pax9 to pattern the tooth developmental field. Dev Biol 2011; 353:344-53. [PMID: 21420399 DOI: 10.1016/j.ydbio.2011.03.012] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Revised: 03/07/2011] [Accepted: 03/10/2011] [Indexed: 11/23/2022]
Abstract
Mammalian tooth development depends on activation of odontogenic potential in the presumptive dental mesenchyme by the Msx1 and Pax9 transcription factors. We recently reported that the zinc finger transcription factor Osr2 was expressed in a lingual-to-buccal gradient pattern surrounding the developing mouse molar tooth germs and mice lacking Osr2 developed supernumerary teeth lingual to their molars. We report here generation of a gene-targeted mouse strain that allows conditional inactivation of Pax9 and subsequent activation of expression of Osr2 in the developing tooth mesenchyme from the Pax9 locus. Expression of Osr2 from one copy of the Pax9 gene did not disrupt normal tooth development but was sufficient to suppress supernumerary tooth formation in the Osr2(-/-) mutant mice. We found that endogenous Osr2 mRNA expression was significantly downregulated in the developing tooth mesenchyme in Pax9(del/del) mice. Mice lacking both Osr2 and Pax9 exhibited early tooth developmental arrest with significantly reduced Bmp4 and Msx1 mRNA expression in the developing tooth mesenchyme, similar to that in Pax9(del/del) mutants but in contrast to the rescue of tooth morphogenesis in Msx1(-/-)Osr2(-/-) double mutant mice. Furthermore, we found that Osr2 formed stable protein complexes with the Msx1 protein and interacted weakly with the Pax9 protein in co-transfected cells. These data indicate that Osr2 acts downstream of Pax9 and patterns the mesenchymal odontogenic field through protein-protein interactions with Msx1 and Pax9 during early tooth development.
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21
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Ohazama A, Porntaveetus T, Ota MS, Herz J, Sharpe PT. Lrp4: A novel modulator of extracellular signaling in craniofacial organogenesis. Am J Med Genet A 2011; 152A:2974-83. [PMID: 21108386 DOI: 10.1002/ajmg.a.33372] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The low-density lipoprotein (LDL) receptor family is a large evolutionarily conserved group of transmembrane proteins. It has been shown that LDL receptor family members can also function as direct signal transducers or modulators for a broad range of cellular signaling pathways. We have identified a novel mode of signaling pathway integration/coordination that occurs outside cells during development that involves an LDL receptor family member. Physical interaction between an extracellular protein (Wise) that binds BMP ligands and an Lrp receptor (Lrp4) that modulates Wnt signaling, acts to link these two pathways. Mutations in either Wise or Lrp4 in mice produce multiple, but identical abnormalities in tooth development that are linked to alterations in BMP and Wnt signaling. Teeth, in common with many other organs, develop by a series of epithelial-mesenchymal interactions, orchestrated by multiple cell signaling pathways. In tooth development, Lrp4 is expressed exclusively in epithelial cells and Wise mainly in mesenchymal cells. Our hypothesis, based on the mutant phenotypes, cell signaling activity changes and biochemical interactions between Wise and Lrp4 proteins, is that Wise and Lrp4 together act as an extracellular mechanism of coordinating BMP and Wnt signaling activities in epithelial-mesenchymal cell communication during development.
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Affiliation(s)
- Atsushi Ohazama
- Department of Craniofacial Development, Dental Institute, King's College London, Guy's Hospital, London Bridge, London, UK
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22
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Fuchs A, Inthal A, Herrmann D, Cheng S, Nakatomi M, Peters H, Neubüser A. Regulation of Tbx22 during facial and palatal development. Dev Dyn 2011; 239:2860-74. [PMID: 20845426 DOI: 10.1002/dvdy.22421] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Mutations in the gene encoding the T-box transcription factor TBX22 cause X-linked cleft palate and ankyloglossia in humans. Here we show that Tbx22 expression during facial and palatal development is regulated by FGF and BMP signaling. Our results demonstrate that FGF8 induces Tbx22 in the early face while BMP4 represses and thus restricts its expression. This regulation is conserved between chicken and mouse, although the Tbx22-expression patterns differ considerably between these two species. We suggest that these species-specific differences may result at least in part from differences in the spatiotemporal patterns of BMP activity, but we exclude a direct repression of Tbx22 by the BMP-inducible transcriptional repressor MSX1. Together these findings help to integrate Tbx22 into the molecular network of factors regulating facial development.
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Affiliation(s)
- Alisa Fuchs
- Developmental Biology, Institute of Biology 1, Faculty of Biology, University of Freiburg, Freiburg, Germany
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23
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Jin YR, Turcotte TJ, Crocker AL, Han XH, Yoon JK. The canonical Wnt signaling activator, R-spondin2, regulates craniofacial patterning and morphogenesis within the branchial arch through ectodermal-mesenchymal interaction. Dev Biol 2011; 352:1-13. [PMID: 21237142 DOI: 10.1016/j.ydbio.2011.01.004] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2010] [Revised: 01/05/2011] [Accepted: 01/05/2011] [Indexed: 12/21/2022]
Abstract
R-spondins are a recently characterized family of secreted proteins that activate Wnt/β-catenin signaling. Herein, we determine R-spondin2 (Rspo2) function in craniofacial development in mice. Mice lacking a functional Rspo2 gene exhibit craniofacial abnormalities such as mandibular hypoplasia, maxillary and mandibular skeletal deformation, and cleft palate. We found that loss of the mouse Rspo2 gene significantly disrupted Wnt/β-catenin signaling and gene expression within the first branchial arch (BA1). Rspo2, which is normally expressed in BA1 mesenchymal cells, regulates gene expression through a unique ectoderm-mesenchyme interaction loop. The Rspo2 protein, potentially in combination with ectoderm-derived Wnt ligands, up-regulates Msx1 and Msx2 expression within mesenchymal cells. In contrast, Rspo2 regulates expression of the Dlx5, Dlx6, and Hand2 genes in mesenchymal cells via inducing expression of their upstream activator, Endothelin1 (Edn1), within ectodermal cells. Loss of Rspo2 also causes increased cell apoptosis, especially within the aboral (or caudal) domain of the BA1, resulting in hypoplasia of the BA1. Severely reduced expression of Fgf8, a survival factor for mesenchymal cells, in the ectoderm of Rspo2(-/-) embryos is likely responsible for increased cell apoptosis. Additionally, we found that the cleft palate in Rspo2(-/-) mice is not associated with defects intrinsic to the palatal shelves. A possible cause of cleft palate is a delay of proper palatal shelf elevation that may result from the small mandible and a failure of lowering the tongue. Thus, our study identifies Rspo2 as a mesenchyme-derived factor that plays critical roles in regulating BA1 patterning and morphogenesis through ectodermal-mesenchymal interaction and a novel genetic factor for cleft palate.
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Affiliation(s)
- Yong-Ri Jin
- Center for Molecular Medicine, Maine Medical Center Research Institute, Maine Medical Center, 81 Research Drive, Scarborough, ME 04074, USA
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24
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Gibert Y, Bernard L, Debiais-Thibaud M, Bourrat F, Joly JS, Pottin K, Meyer A, Retaux S, Stock DW, Jackman WR, Seritrakul P, Begemann G, Laudet V. Formation of oral and pharyngeal dentition in teleosts depends on differential recruitment of retinoic acid signaling. FASEB J 2010; 24:3298-309. [PMID: 20445074 DOI: 10.1096/fj.09-147488] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
One of the goals of evolutionary developmental biology is to link specific adaptations to changes in developmental pathways. The dentition of cypriniform fishes, which in contrast to many other teleost fish species possess pharyngeal teeth but lack oral teeth, provides a suitable model to study the development of feeding adaptations. Here, we have examined the involvement of retinoic acid (RA) in tooth development and show that RA is specifically required to induce the pharyngeal tooth developmental program in zebrafish. Perturbation of RA signaling at this stage abolished tooth induction without affecting the development of tooth-associated ceratobranchial bones. We show that this inductive event is dependent on RA synthesis from aldh1a2 in the ventral posterior pharynx. Fibroblast growth factor (FGF) signaling has been shown to be critical for tooth induction in zebrafish, and its loss has been associated with oral tooth loss in cypriniform fishes. Pharmacological treatments targeting the RA and FGF pathways revealed that both pathways act independently during tooth induction. In contrast, we find that in Mexican tetra and medaka, species that also possess oral teeth, both oral and pharyngeal teeth are induced independently of RA. Our analyses suggest an evolutionary scenario in which the gene network controlling tooth development obtained RA dependency in the lineage leading to the cypriniforms. The loss of pharyngeal teeth in this group was cancelled out through a shift in aldh1a2 expression, while oral teeth might have been lost ultimately due to deficient RA signaling in the oral cavity.
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Affiliation(s)
- Yann Gibert
- Molecular Zoology Group, Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, CNRS, INRA, UCB Lyon 1, Ecole Normale Supérieure de Lyon, 69364 Lyon Cedex 07, France
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25
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Yamanaka A, Uemura M. The House Shrew, Suncus murinus, as a Model Organism to Investigate Mammalian Basal Condition of Tooth Development. J Oral Biosci 2010. [DOI: 10.1016/s1349-0079(10)80024-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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26
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Chen J, Lan Y, Baek JA, Gao Y, Jiang R. Wnt/beta-catenin signaling plays an essential role in activation of odontogenic mesenchyme during early tooth development. Dev Biol 2009; 334:174-85. [PMID: 19631205 DOI: 10.1016/j.ydbio.2009.07.015] [Citation(s) in RCA: 176] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2009] [Revised: 07/12/2009] [Accepted: 07/14/2009] [Indexed: 01/01/2023]
Abstract
Classical tissue recombination studies demonstrated that initiation of tooth development depends on activation of odontogenic potential in the mesenchyme by signals from the presumptive dental epithelium. Although several members of the Wnt family of signaling molecules are expressed in the presumptive dental epithelium at the beginning of tooth initiation, whether Wnt signaling is directly involved in the activation of the odontogenic mesenchyme has not been characterized. In this report, we show that tissue-specific inactivation of beta-catenin, a central component of the canonical Wnt signaling pathway, in the developing tooth mesenchyme caused tooth developmental arrest at the bud stage in mice. We show that mesenchymal beta-catenin function is required for expression of Lef1 and Fgf3 in the developing tooth mesenchyme and for induction of primary enamel knot in the developing tooth epithelium. Expression of Msx1 and Pax9, two essential tooth mesenchyme transcription factors downstream of Bmp and Fgf signaling, respectively, were not altered in the absence of beta-catenin in the tooth mesenchyme. Moreover, we found that constitutive stabilization of beta-catenin in the developing palatal mesenchyme induced aberrant palatal epithelial invaginations that resembled early tooth buds both morphologically and in epithelial molecular marker expression, but without activating expression of Msx1 and Pax9 in the mesenchyme. Together, these results indicate that activation of the mesenchymal odontogenic program during early tooth development requires concerted actions of Bmp, Fgf and Wnt signaling from the presumptive dental epithelium to the mesenchyme.
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Affiliation(s)
- Jianquan Chen
- Department of Biology, University of Rochester, Rochester, New York 14642, USA
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27
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Denaxa M, Sharpe PT, Pachnis V. The LIM homeodomain transcription factors Lhx6 and Lhx7 are key regulators of mammalian dentition. Dev Biol 2009; 333:324-36. [PMID: 19591819 PMCID: PMC2738952 DOI: 10.1016/j.ydbio.2009.07.001] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2009] [Revised: 07/01/2009] [Accepted: 07/01/2009] [Indexed: 12/30/2022]
Abstract
Genes encoding LIM homeodomain transcription factors are implicated in cell type specification and differentiation during embryogenesis. Two closely related members of this family, Lhx6 and Lhx7, are expressed in the ectomesenchyme of the maxillary and mandibular processes and have been suggested to control patterning of the first branchial arch (BA1) and odontogenesis. However, mice homozygous for single mutations either have no cranial defects (Lhx6) or show only cleft palate (Lhx7). To reveal the potential redundant activities of Lhx6 and Lhx7 in cranial morphogenesis, we generated mice with all combinations of wild-type and mutant alleles. Double homozygous mice have characteristic defects of the cranial skeleton and die shortly after birth, most likely because of cleft palate. In addition, Lhx6/7 deficient embryos lack molar teeth. The absence of molars in double mutants is not due to patterning defects of BA1 but results from failure of specification of the molar mesenchyme. Despite molar agenesis, Lhx6/7-deficient animals have normal incisors which, in the maxilla, are flanked by a supernumerary pair of incisor-like teeth. Our experiments demonstrate that the redundant activities of the LIM homeodomain proteins Lhx6 and Lhx7 are critical for craniofacial development and patterning of mammalian dentition.
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Affiliation(s)
- Myrto Denaxa
- Division of Molecular Neurobiology, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK.
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28
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Elluru RG, Thompson F, Reece A. Fibroblast growth factor 18 gives growth and directional cues to airway cartilage. Laryngoscope 2009; 119:1153-65. [PMID: 19358209 DOI: 10.1002/lary.20157] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
OBJECTIVES/HYPOTHESIS The majority of congenital airway anomalies arise from deficits in the respiratory tract cartilage, emphasizing the importance of this cartilage to the form and function of the upper airway. The primary objective of this study was to characterize molecular mechanisms that regulate rate and direction of chondrocyte growth in the larynx and trachea. Our hypothesis for this study was that fibroblast growth factor 18 (FGF18) provides proliferative and directional cues to the developing laryngeal and tracheal cartilage in the mouse by up-regulating the cartilage-specifying gene, Sox9. STUDY DESIGN Molecular genetic and histological analyses of gene expression and cartilage growth in a mouse model. METHODS Controlled mating of wild-type FVB/N (Friend Virus B-type/NIH mouse) mice and FGF18 overexpressing mice were carried out, and embryos ranging from embryonic (E) day 10.5 to E18.5 were obtained. The respiratory tract, including the larynx, trachea, and lung, was removed through meticulous dissection, and subjected to whole-mount in situ hybridization with RNA probes, or was sectioned and subjected to immunohistochemistry. Respiratory tracts from FVB/N mice were grown in culture in the presence of exogenous FGF18 or known inhibitors of the FGF pathway, and then subjected to quantitative reverse transcriptase polymerase chain reaction to measure the expression of cartilage-specific genes. RESULTS The upper respiratory tract begins as a simple out-pouching from the ventral foregut endoderm at E10.5. The chondrocytes that form the cartilaginous structures of the upper respiratory tract are located at the junction of the respiratory tract out-pouching and the ventral foregut endoderm. This population of chondrocytes then undergoes directional proliferation to eventually assume the mature three-dimensional configuration of the upper respiratory tract cartilaginous framework. Immunohistochemical localization of extracellular signal-regulated kinases, a known modulator of FGF signaling, demonstrated the presence of this enzyme at the periphery of growing cartilage. Explants of larynx-trachea-lung grown in culture with exogenous FGF18 demonstrated hyperplastic growth and directed growth towards the FGF18 source. Finally, both FGF18 overexpressing tracheas and tracheas cultured with exogenous FGF18 demonstrated increased expression of the cartilage-specifying gene, Sox9. CONCLUSIONS FGF18 provided both directional and proliferative cues to chondrocytes in the developing upper respiratory tract. FGF18 exerted this effect on developing chondrocytes by up-regulating Sox9 expression. Laryngoscope, 2009.
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Affiliation(s)
- Ravindhra G Elluru
- Cincinnati Children's Hospital Medical Center, Division of Pediatric Otolaryngology-Head and Neck Surgery, Cincinnati, Ohio, USA.
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29
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Doufexi AE, Mina M. Signaling pathways regulating the expression of Prx1 and Prx2 in the chick mandibular mesenchyme. Dev Dyn 2009; 237:3115-27. [PMID: 18942149 DOI: 10.1002/dvdy.21762] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Prx1 and Prx2 are members of the aristaless-related homeobox genes shown to play redundant but essential roles in morphogenesis of the mandibular processes. To gain insight into the signaling pathways that regulate expression of Prx genes in the mandibular mesenchyme, we used the chick as a model system. We examined the patterns of gene expression in the face and the roles of signals derived from the epithelium on the expression of Prx genes in the mandibular mesenchyme. Our results demonstrated stage-dependent roles of mandibular epithelium on the expression of Prx in the mandibular mesenchyme and provide evidence for positive roles of members of the fibroblast and hedgehog families derived from mandibular epithelium on the expression of Prx genes in the mandibular mesenchyme. Our studies suggest that endothelin-1 signaling derived from the mesenchyme is involved in restricting the expression of Prx2 to the medial mandibular mesenchyme.
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Affiliation(s)
- Aikaterini-El Doufexi
- Division of Pediatric Dentistry, Department of Craniofacial Sciences, School of Dental Medicine, University of Connecticut Health Center, Farmington, Connecticut 06030, USA
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Tosios KI, Gopalakrishnan R, Koutlas IG. So-called hybrid central odontogenic fibroma/central giant cell lesion of the jaws. A report on seven additional cases, including an example in a patient with cherubism, and hypotheses on the pathogenesis. Head Neck Pathol 2008; 2:333-8. [PMID: 20614305 PMCID: PMC2807578 DOI: 10.1007/s12105-008-0076-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2007] [Accepted: 02/05/2008] [Indexed: 11/24/2022]
Abstract
BACKGROUND Central odontogenic fibroma (COF) is characterized by poor to cellular fibroblastic proliferation and a variable odontogenic epithelial (OE) component. Central giant cell lesions (CGCL) are osteolytic fibroblastic proliferations characterized by osteoclast-like multinucleated giant cells (MGC). Rare examples of hybrid COF/CGCL have been described. Two pathogenetic theories prevail based on clinicopathologic characteristics. One regards the CGCL component as reactive to the COF, while the other regards the CGCL as inductive of a COF-like proliferation. The possibility of colliding tumors seems unlikely. METHODS AND MATERIALS Seven patients with hCOF/CGCL, among them one with cherubism, were studied. Immunohistochemistry for cytokeratin 19 was applied to better appreciate the epithelial component. RESULTS Six patients were males and one female and their age ranged from 15 to 73 years old. All lesions occurred in the premolars and molars of the mandible and presented as radiolucencies with primarily well-delineated borders. All patients underwent surgical excision and recurrences have not been reported to this date in 6 out of 7 patients (mean follow-up 60.6+/-36.25 months). The COF component predominated in 3 cases and the CGCL component in 3. Zones of collagen fibers featuring a whorling pattern and containing multiple nests of OE were present. In four cases there were hyalinized deposits in OE, while some foci of MGC contained few OE. CONCLUSIONS Gender predilection in our series is in contrast with previously published reports. However, when all previously reported cases are reviewed there is still female predilection. The predominant site, as previously reported, is the tooth-bearing areas of the posterior mandible. This is the first report of hCOF/CGCL in cherubism. The pathogenesis of hCOF/CGCG remains obscure and molecular interactions would be of interest to be investigated.
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Affiliation(s)
- Konstantinos I. Tosios
- Division of Oral and Maxillofacial Pathology, Faculty of Dentistry, National and Kapodestrian University of Athens, Athens, Greece
| | - Rajaram Gopalakrishnan
- Division of Oral and Maxillofacial Pathology, School of Dentistry, University of Minnesota, 515 Delaware Street SE, 16-108A, Minneapolis, MN 55455 USA
| | - Ioannis G. Koutlas
- Division of Oral and Maxillofacial Pathology, School of Dentistry, University of Minnesota, 515 Delaware Street SE, 16-108A, Minneapolis, MN 55455 USA
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Ikeda E, Tsuji T. Growing bioengineered teeth from single cells: potential for dental regenerative medicine. Expert Opin Biol Ther 2008; 8:735-44. [PMID: 18476785 DOI: 10.1517/14712598.8.6.735] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND The ultimate goal of regenerative therapy is to develop fully functioning bioengineered organs that can replace organs lost or damaged due to disease, injury or aging. Dental regenerative medicine has made the most progress and is the most useful model for the consideration of strategies in future organ replacement therapies. OBJECTIVE This review describes strategies that have been pursued to date and experiments currently being conducted to bioengineer teeth in anticipation of the production of fully functional organs. METHODS To realize the practical application of 'bioengineered tooth' transplantation therapy, four major hurdles must be overcome. The present status of the hurdles to this therapy are described and discussed in this review. RESULTS/CONCLUSION The bioengineering techniques developed for tooth regeneration will in the future make substantial contributions to the ability to grow primordial organs in vitro and also to grow fully functioning organs, such as the liver, kidney and heart.
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Affiliation(s)
- Etsuko Ikeda
- Faculty of Industrial Science and Technology Tokyo University of Science, Department of Biological Science and Technology, Noda, Chiba 278-8510, Japan
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32
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Duverger O, Morasso MI. Role of homeobox genes in the patterning, specification, and differentiation of ectodermal appendages in mammals. J Cell Physiol 2008; 216:337-46. [PMID: 18459147 DOI: 10.1002/jcp.21491] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Homeobox genes are an evolutionarily conserved class of transcription factors that are key regulators during developmental processes such as regional specification, patterning, and differentiation. In this review, we summarize the expression pattern, loss- and/or gain-of-function mouse models, and naturally occurring mouse and human mutations of known homeobox genes required for the development of ectodermal appendages.
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Affiliation(s)
- Olivier Duverger
- Developmental Skin Biology Unit, National Institute of Arthritis Musculoskeletal and Skin Diseases, NIH, Bethesda, Maryland, USA
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33
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Stock DW. Zebrafish dentition in comparative context. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2007; 308:523-49. [PMID: 17607704 DOI: 10.1002/jez.b.21187] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Studies of the zebrafish (Danio rerio) promise to contribute much to an understanding of the developmental genetic mechanisms underlying diversification of the vertebrate dentition. Tooth development, structure, and replacement in the zebrafish largely reflect the primitive condition of jawed vertebrates, providing a basis for comparison with features of the more extensively studied mammalian dentition. A distinctive derived feature of the zebrafish dentition is restriction of teeth to a single pair of pharyngeal bones. Such reduction of the dentition, characteristic of the order Cypriniformes, has never been reversed, despite subsequent and extensive diversification of the group in numbers of species and variety of feeding modes. Studies of the developmental genetic mechanism of dentition reduction in the zebrafish suggest a potential explanation for irreversibility in that tooth loss seems to be associated with loss of developmental activators rather than gain of repressors. The zebrafish and other members of the family Cyprinidae exhibit species-specific numbers and arrangements of pharyngeal teeth, and extensive variation in tooth shape also occurs within the family. Mutant screens and experimental alteration of gene expression in the zebrafish are likely to yield variant tooth number and shape phenotypes that can be compared with those occurring naturally within the Cyprinidae. Such studies may reveal the relative contribution to trends in dental evolution of biases in the generation of variation and sorting of this variation by selection or drift.
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Affiliation(s)
- David W Stock
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado 80309-0334, USA.
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Yamanaka A, Yasui K, Sonomura T, Uemura M. Development of heterodont dentition in house shrew (Suncus murinus). Eur J Oral Sci 2007; 115:433-40. [DOI: 10.1111/j.1600-0722.2007.00499.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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35
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D'Souza RN, Klein OD. Unraveling the molecular mechanisms that lead to supernumerary teeth in mice and men: current concepts and novel approaches. Cells Tissues Organs 2007; 186:60-9. [PMID: 17627119 DOI: 10.1159/000102681] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Supernumerary teeth are defined as those that are present in excess of the normal complement of human dentition and represent a unique developmental anomaly of patterning and morphogenesis. Despite the wealth of information generated from studies on normal tooth development, the genetic etiology and molecular mechanisms that lead to congenital deviations in tooth number are poorly understood. For developmental biologists, the phenomenon of supernumerary teeth raises interesting questions about the development and fate of the dental lamina. For cell and molecular biologists, the anomaly of supernumerary teeth inspires several questions about the actions and interactions of transcription factors and growth factors that coordinate morphogenesis, cell survival and programmed cell death. For human geneticists, the condition as it presents itself in either syndromic or non-syndromic forms offers an opportunity to discover mutations in known or novel genes. For clinicians faced with treating the dental complications that arise from the presence of supernumerary teeth, knowledge about the basic mechanisms involved is essential. The purpose of this manuscript is to review current knowledge about how supernumerary teeth form, the molecular insights gained through studies on mice that are deficient in certain tooth signaling molecules and the questions that require further research in the field.
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Affiliation(s)
- Rena N D'Souza
- Department of Biomedical Sciences, Baylor College of Dentistry, Texas A&M University Health Science Center, Dallas, TX 75246, USA.
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36
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Mikkola ML. Genetic basis of skin appendage development. Semin Cell Dev Biol 2007; 18:225-36. [PMID: 17317239 DOI: 10.1016/j.semcdb.2007.01.007] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2006] [Revised: 01/18/2007] [Accepted: 01/22/2007] [Indexed: 12/23/2022]
Abstract
Morphogenesis of hair follicles, teeth, and mammary glands depends on inductive epithelial-mesenchymal interactions mediated by a conserved set of signalling molecules. The early development of different skin appendages is remarkably similar. Initiation of organogenesis is marked by the appearance of a local epithelial thickening, a placode, which subsequently invaginates to produce a bud. These early developmental stages require many of the same genes and signalling circuits and consequently alterations in them often cause similar phenotypes in several skin appendages. After the bud stage, these organs adopt diverse patterns of epithelial growth, reflected in the usage of more divergent genes in each.
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Affiliation(s)
- Marja L Mikkola
- Developmental Biology Program, Institute of Biotechnology, P.O. Box 56 (Viikinkaari 9), University of Helsinki, 00014 Helsinki, Finland.
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Abe G, Ide H, Tamura K. Function of FGF signaling in the developmental process of the median fin fold in zebrafish. Dev Biol 2006; 304:355-66. [PMID: 17258191 DOI: 10.1016/j.ydbio.2006.12.040] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2006] [Revised: 12/18/2006] [Accepted: 12/19/2006] [Indexed: 12/12/2022]
Abstract
Median fins, unpaired appendages in fish, are fundamental locomotory organs that are believed to have evolved before paired lateral appendages in vertebrates. However, the early process of median fin development remains largely unknown. We investigated the early development of the median fin fold, a rudiment of median fins, and report here the process in zebrafish embryos and the function of FGF signaling in the process. Using expressions of three genes, dlx5a, sp9 and fgf24, as markers of different phases of fold development, our findings suggest that the early process of median fin fold development can be divided into two steps, specification of the median fin fold territory and construction of the fold structure. Both loss-of-function and gain-of-function assays revealed that FGF signaling plays roles in each step, suggesting a common mechanism for the development of median appendages and paired lateral appendages.
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Affiliation(s)
- Gembu Abe
- Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai 980-8578, Japan
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38
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Mikkola ML, Millar SE. The mammary bud as a skin appendage: unique and shared aspects of development. J Mammary Gland Biol Neoplasia 2006; 11:187-203. [PMID: 17111222 DOI: 10.1007/s10911-006-9029-x] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Like other skin appendages, the embryonic mammary gland develops via extensive epithelial-mesenchymal interactions. Early stages in embryonic mammary development strikingly resemble analogous steps in the development of hair follicles and teeth. In each case the first morphological sign of development is a localized thickening in the surface epithelium that subsequently invaginates to form a mammary, hair follicle or tooth bud. Similar sets of intersecting signaling pathways are involved in patterning the mammary, hair follicle and dental epithelium, directing placode formation, and controlling bud invagination. Despite these similarities, subsequent events in the formation of these appendages are diverse. The mammary bud extends to form a sprout that begins to branch upon contact with the mammary fat pad. Hair follicles also extend into the underlying mesenchyme, but instead of branching, hair follicle epithelium folds around a condensation of dermal cells. In contrast, teeth undergo a more complex folding morphogenesis. Here, we review what is known of the molecular and cellular mechanisms controlling early steps in the development of these organs, attempt to unravel both common themes and unique aspects that can begin to explain the diversity of appendage formation, and discuss human genetic diseases that affect appendage morphogenesis.
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Affiliation(s)
- Marja L Mikkola
- Developmental Biology Program, Institute of Biotechnology, University of Helsinki, PO Box 56, Viikinkaari 9, Helsinki, 00014, Finland
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Matalová E, Setková J, Blackburn J, Mísek I, Sharpe PT. CD 95 mediated apoptosis in embryogenesis: implication in tooth development. Orthod Craniofac Res 2006; 9:123-8. [PMID: 16918676 DOI: 10.1111/j.1601-6343.2006.00365.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
INTRODUCTION Understanding of apoptotic mechanisms involved in tissue shaping is of particular interest because of possible targeted modulation of the development of organ structures such as teeth. Research of CD 95 mediated apoptosis has been focused particularly on cell death in the immune system and related disorders. However, CD 95 mediated apoptosis is also involved in embryogenesis of many organs as the kidney, the lung, the intestine and tissue networks such as the nervous system. DESIGN Narrative review. RESULTS This review briefly summarizes the current knowledge of CD 95 mediated apoptosis in embryogenesis with possible implication in tooth development. CD 95 receptor and CD 95 ligand are found at early stages of tooth development. The data suggest some positive correlations with dental apoptosis distribution, particularly in the primary enamel knot where apoptosis occurs during elimination of this structure. CD 95 deficient (lpr) adult mouse tooth phenotype, however, did not show any alterations in final tooth pattern and morphology. CONCLUSION To date studies of apoptotic machinery during tooth development show spatial localization of many of the components together with precise and localized timing of cell death. There is still much to be learned about the regulation and importance of apoptosis in tooth development. Nevertheless, the involvement of apoptotic regulatory mechanisms interplaying with other molecules participates to the cellular cross-talk in developing tissues, which opens possible targeted modulations as suggested, e.g. for future molecular dentistry.
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Affiliation(s)
- E Matalová
- Laboratory of Animal Embryology, Institute of Animal Physiology and Genetics, Brno, Czech Republic.
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40
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Stock DW, Jackman WR, Trapani J. Developmental genetic mechanisms of evolutionary tooth loss in cypriniform fishes. Development 2006; 133:3127-37. [PMID: 16831836 DOI: 10.1242/dev.02459] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The fossil record indicates that cypriniform fishes, a group including the zebrafish, lost oral teeth over 50 million years ago. Despite subsequent diversification of feeding modes, no cypriniform has regained oral teeth, suggesting the zebrafish as a model for studying the developmental genetic basis of evolutionary constraint. To investigate the mechanism of cypriniform tooth loss, we compared the oral expression of seven genes whose mammalian orthologs are involved in tooth initiation in the zebrafish and the Mexican tetra, Astyanax mexicanus, a related species retaining oral teeth. The most significant difference we found was an absence in zebrafish oral epithelium of expression of dlx2a and dlx2b, transcription factors that are expressed in early Astyanax odontogenic epithelium. Analysis of orthologous genes in the Japanese medaka (Oryzias latipes) and a catfish (Synodontis multipunctatus) suggests that expression was lost in cypriniforms, rather than gained in Astyanax. Treatment of Astyanax with an inhibitor of Fibroblast growth factor (Fgf) signaling produced a partial phenocopy of the zebrafish oral region, in that oral teeth, and expression of dlx2a and dlx2b, were lost, whereas shh and pitx2, genes whose expression is present in zebrafish oral epithelium, were unaffected. We hypothesize that a loss of Fgf signaling to oral epithelium was associated with cypriniform tooth loss.
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Affiliation(s)
- David W Stock
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO 80309-0334, USA.
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41
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Yen AHH, Sharpe PT. Regeneration of teeth using stem cell-based tissue engineering. Expert Opin Biol Ther 2006; 6:9-16. [PMID: 16370910 DOI: 10.1517/14712598.6.1.9] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Tooth autotransplantation, allotransplantation and dental implants have existed for many years, but have never been totally satisfactory. Thus, the development of new methods of tooth replacement has become desirable, and with the increasing knowledge of stem cell biology becomes a realistic possibility. Stem cell-based tissue engineering involving the recapitulation of the embryonic environment demonstrates that dental, non-dental, embryonic and adult stem cells can contribute to teeth formation in the appropriate setting. Evidence that stem cell populations may be present in human teeth provides the opportunity to consider biological tooth replacement 'new for old'.
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Affiliation(s)
- Amanda H-H Yen
- Dental Institute, Department of Craniofacial Development, Odontis Ltd, Kings College London, Guy's Hospital, London Bridge, SE1 9RT, UK
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42
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Torres CBB, Goes VS, Goes AM, Pacífico LGG, Silva GAB, Junior NL, Alves JB. Fibroblast growth factor 9: Cloning and immunolocalisation during tooth development in Didelphis albiventris. Arch Oral Biol 2006; 51:263-72. [PMID: 16188224 DOI: 10.1016/j.archoralbio.2005.08.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2005] [Revised: 08/16/2005] [Accepted: 08/17/2005] [Indexed: 11/19/2022]
Abstract
There are no reports in literature about functional roles of fibroblast growth factor 9 (FGF-9) in tooth development in animals with complete tooth pattern. The classical model for studying tooth development is the mouse, which has small number of teeth and distinctive incisor and molar patterns. The opossum Didelphis albiventris with five upper and four lower incisors, one canine, three premolars, and four molars, on each side of the jaw, seems to be a convenient model to test results obtained in the mouse. Molecular expression studies indicate that FGF-9 participates in murine tooth initiation and regulation of morphogenesis. Searching for similarities and differences in FGF-9 expression between the opossum and the mouse, amino acid sequence and expression pattern of FGF-9 in the developing first molars of D. albiventris were characterised. FGF-9 cDNA sequence was obtained using RT-PCR and expressed in bacterial system for recombinant protein production and analysis of immunoreactivity. FGF-9 expression during tooth development was investigated by immunoperoxidase method. FGF-9 protein consists in a 209-residue polypeptide with a predicted molecular mass of 23.5 kDa. FGF-9 amino acid sequence has 98% of sequence identity to human and 97% to rodents. During tooth development, epithelial FGF-9 expression was seen at the dental lamina stage. Mesenchymal expression was seen at the bud stage and at the cap stage. No significant expression was found in the enamel knot. While in rodents FGF-9 is involved in initiation and regulation of tooth shape, it is suggested that it is only involved in tooth initiation in D. albiventris.
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Affiliation(s)
- Cristiane B B Torres
- Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, UFMG, Presidente Antônio Carlos Avenue 6627, 31270-901 Belo Horizonte, Minas Gerais, Brazil.
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Abstract
Tooth development, a process which occurs in the developing embryo, involves the reciprocal and sequential signalling between epithelial and mesenchymal tissue of the developing first branchial arch. The oral epithelium produces the first inductive signals for odontogenesis at around E10.0, which trigger off a cascade of events that result in the formation of a tooth. We have engineered a tooth in vitro by harnessing the basic principles of odontogenesis and the inductive capability of the oral epithelium of the developing embryo. We replaced the mesenchymal portion of the developing mandibular primordium with aggregates of stem cells from embryos as well as stem cells taken from adult mice. The cell aggregates were covered with embryonic epithelium from E10.0 mouse embryos to form recombinant explants. In vitro culture of these recombinant explants resulted in the induction of early tooth marker genes in the cell aggregates, indicating that the cells were able to respond to the odontogenic signals produced by the oral epithelium. In vivo culture of explants resulted in the induction of Dspp within the cell aggregates indicating that tooth tissue was present. Three recombinant explants, where the cell aggregates consisted of adult bone marrow cells, produced teeth. To determine whether the oral cavity would be able to sustain the growth of an implanted tooth germ, E14.5 molar rudiments were implanted into the diastema region of the maxilla of adult mice. The resulting teeth appeared to be normal in size and were connected to the underlying bone. These experiments are an indication that it is possible to induce odontogenesis and engineer a tooth using adult cells of non-dental origin. They also indicate that developing tooth germs could be successfully implanted into the gingiva of patients.
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Affiliation(s)
- Sonie A C Modino
- Department of Craniofacial Development and Odontis Ltd., Dental Institute, Kings College London, Floor 28 Guy's Tower, Guy's Hospital, London Bridge, London, SE1 9RT, UK
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44
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Miletich I, Sharpe PT. Neural crest contribution to mammalian tooth formation. ACTA ACUST UNITED AC 2005; 72:200-12. [PMID: 15269893 DOI: 10.1002/bdrc.20012] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The cranial neural crest cells, which are specialized cells of neural origin, are central to the process of mammalian tooth development. They are the only source of mesenchyme able to sustain tooth development, and give rise not only to most of the dental tissues, but also to the periodontium, the surrounding tissues that hold teeth in position. Tooth organogenesis is regulated by a series of interactions between cranial neural crest cells and the oral epithelium. In the development of a tooth, the epithelium covering the inside of the developing oral cavity provides the first instructive signals. Signaling molecules secreted by the oral epithelium 1) establish large cellular fields competent to form a specific tooth shape (mono- or multicuspid) along a proximodistal axis; 2) define an oral (capable of forming teeth) and non-oral mesenchyme along a rostrocaudal axis; and 3) position the sites of future tooth development. The critical information to model tooth shape resides later in the neural crest-derived mesenchyme. Cranial neural crest cells ultimately differentiate into highly specialized cell types to produce mature dental organs. Some cranial neural crest cells located in the dental pulp, however, maintain plasticity in their developmental potential up to postnatal life, offering new prospects for regeneration of dental tissues.
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Affiliation(s)
- Isabelle Miletich
- Department of Craniofacial Development, Dental Institute, King's College London, United Kingdom.
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45
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Echevarria D, Martinez S, Marques S, Lucas-Teixeira V, Belo JA. Mkp3 is a negative feedback modulator of Fgf8 signaling in the mammalian isthmic organizer. Dev Biol 2005; 277:114-28. [PMID: 15572144 DOI: 10.1016/j.ydbio.2004.09.011] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2004] [Revised: 08/04/2004] [Accepted: 09/08/2004] [Indexed: 10/26/2022]
Abstract
The pivotal mechanisms that govern the correct patterning and regionalization of the distinct areas of the mammalian CNS are driven by key molecules that emanate from the so-called secondary organizers at neural plate and tube stages. FGF8 is the candidate morphogenetic molecule to pattern the mesencephalon and rhombencephalon in the isthmic organizer (IsO). Recognizable relevance has been given to the intracellular pathways by which Fgf8 is regulated and modulated. In chick limb bud development, a dual mitogen-activated protein kinase phosphatase-3 (Mkp3) plays a role as a negative feedback modulator of Fgf8 signaling. We have investigated the role of Mkp3 and its functional relationship with the Fgf8 signaling pathway in the mouse IsO using gene transfer microelectroporation assays and protein-soaked bead experiments. Here, we demonstrate that MKP3 has a negative feedback action on the MAPK/ERK-mediated FGF8 pathway in the mouse neuroepithelium.
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Affiliation(s)
- Diego Echevarria
- Instituto de Neurociencias, University of Miguel Hernández (UMH-CSIC), Carretera de Valencia (N-332), Campus de San Juan, 03550 Alicante, Spain.
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Cebra-Thomas J, Tan F, Sistla S, Estes E, Bender G, Kim C, Riccio P, Gilbert SF. How the turtle forms its shell: a paracrine hypothesis of carapace formation. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2005; 304:558-69. [PMID: 15968684 DOI: 10.1002/jez.b.21059] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We propose a two-step model for the evolutionary origin of the turtle shell. We show here that the carapacial ridge (CR) is critical for the entry of the ribs into the dorsal dermis. Moreover, we demonstrate that the maintenance of the CR and its ability to attract the migrating rib precursor cells depend upon fibroblast growth factor (FGF) signaling. Inhibitors of FGF allow the CR to degenerate, with the consequent migration of ribs along the ventral body wall. Beads containing FGF10 can rearrange rib migration in the chick, suggesting that the CR FGF10 plays an important role in attracting the rib rudiments. The co-ordinated growth of the carapacial plate and the ribs may be a positive feedback loop (similar to that of the limbs) caused by the induction of Fgf8 in the distal tips of the ribs by the FGF10-secreting mesenchyme of the CR. Once in the dermis, the ribs undergo endochrondral ossification. We provide evidence that the ribs act as signaling centers for the dermal ossification and that this ossification is due to bone morphogenetic proteins secreted by the rib. Thus, once the ribs are within the dermis, the ossification of the dermis is not difficult to achieve. This relatively rapid means of carapace formation would allow for the appearance of turtles in the fossil record without obvious intermediates.
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Affiliation(s)
- Judith Cebra-Thomas
- Department of Biology, Swarthmore College, Swarthmore, Pennsylvania 19081, USA
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Nakao K, Itoh M, Tomita Y, Tomooka Y, Tsuji T. FGF-2 potently induces both proliferation and DSP expression in collagen type I gel cultures of adult incisor immature pulp cells. Biochem Biophys Res Commun 2004; 325:1052-9. [PMID: 15541395 DOI: 10.1016/j.bbrc.2004.10.136] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2004] [Indexed: 01/09/2023]
Abstract
We investigated the effects of both cytokines and extracellular matrices on the proliferation and differentiation of immature adult rat incisor dental pulp cells. These immature cells, which have a high-proliferative potency in vitro and do not express mRNAs for dentin non-collagenous proteins such as dentin sialoprotein (DSP), bone sialoprotein (BSP), and osteocalcin, exist in the root regions of adult rat incisors. Fibroblast growth factor-2 (FGF-2) stimulated the proliferation of these immature cells and the subsequent production of mineralized calcium was induced by beta-glycerophosphate treatment. Additionally, FGF-2 dramatically induced the expression of DSP and BSP mRNAs, but only in collagen type I gel cultures, whereas neither plate-coated collagen type I nor fibronectin, laminin or collagen type IV cultures could produce this effect and generate sufficient physiological levels of these transcripts. Although bone morphogenetic protein-4 could not induce the proliferation of immature dental pulp cells nor upregulate DSP mRNA expression, it had a synergistic effect upon DSP transcript levels in conjunction with FGF-2. These results suggest that both the presence of FGF-2 and the three-dimensional formation of immature dental pulp cells in collagen type I gel cultures are essential for both DSP expression and odontoblast differentiation. These observations provide valuable information concerning the study of the commitment and differentiation of odontoblast lineages, and also provide a basis for the rational design of cytokine and extracellular matrix based compounds for regenerative therapies in new dental treatments.
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Affiliation(s)
- Kazuhisa Nakao
- Department of Biological Science and Technology, Faculty of Industrial Science and Technology, Tokyo University of Science, Yamazaki 2641, Noda, Chiba 278-8510, Japan
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Jackman WR, Draper BW, Stock DW. Fgf signaling is required for zebrafish tooth development. Dev Biol 2004; 274:139-57. [PMID: 15355794 DOI: 10.1016/j.ydbio.2004.07.003] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2004] [Revised: 06/29/2004] [Accepted: 07/01/2004] [Indexed: 11/24/2022]
Abstract
We have investigated fibroblast growth factor (FGF) signaling during the development of the zebrafish pharyngeal dentition with the goal of uncovering novel roles for FGFs in tooth development as well as phylogenetic and topographic diversity in the tooth developmental pathway. We found that the tooth-related expression of several zebrafish genes is similar to that of their mouse orthologs, including both epithelial and mesenchymal markers. Additionally, significant differences in gene expression between zebrafish and mouse teeth are indicated by the apparent lack of fgf8 and pax9 expression in zebrafish tooth germs. FGF receptor inhibition with SU5402 at 32 h blocked dental epithelial morphogenesis and tooth mineralization. While the pharyngeal epithelium remained intact as judged by normal pitx2 expression, not only was the mesenchymal expression of lhx6 and lhx7 eliminated as expected from mouse studies, but the epithelial expression of dlx2a, dlx2b, fgf3, and fgf4 was as well. This latter result provides novel evidence that the dental epithelium is a target of FGF signaling. However, the failure of SU5402 to block localized expression of pitx2 suggests that the earliest steps of tooth initiation are FGF-independent. Investigations of specific FGF ligands with morpholino antisense oligonucleotides revealed only a mild tooth shape phenotype following fgf4 knockdown, while fgf8 inhibition revealed only a subtle down-regulation of dental dlx2b expression with no apparent effect on tooth morphology. Our results suggest redundant FGF signals target the dental epithelium and together are required for dental morphogenesis. Further work will be required to elucidate the nature of these signals, particularly with respect to their origins and whether they act through the mesenchyme.
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Affiliation(s)
- William R Jackman
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO 80309-0334, USA.
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Mustonen T, Ilmonen M, Pummila M, Kangas AT, Laurikkala J, Jaatinen R, Pispa J, Gaide O, Schneider P, Thesleff I, Mikkola ML. Ectodysplasin A1 promotes placodal cell fate during early morphogenesis of ectodermal appendages. Development 2004; 131:4907-19. [PMID: 15371307 DOI: 10.1242/dev.01377] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Organs developing as appendages of the ectoderm are initiated from epithelial thickenings called placodes. Their formation is regulated by interactions between the ectoderm and underlying mesenchyme, and several signalling molecules have been implicated as activators or inhibitors of placode formation. Ectodysplasin (Eda) is a unique signalling molecule in the tumour necrosis factor family that, together with its receptor Edar, is necessary for normal development of ectodermal organs both in humans and mice. We have shown previously that overexpression of the Eda-A1 isoform in transgenic mice stimulates the formation of several ectodermal organs. In the present study, we have analysed the formation and morphology of placodes using in vivo and in vitro models in which both the timing and amount of Eda-A1 applied could be varied. The hair and tooth placodes of K14-Eda-A1transgenic embryos were enlarged, and extra placodes developed from the dental lamina and mammary line. Exposure of embryonic skin to Eda-A1 recombinant protein in vitro stimulated the growth and fusion of placodes. However, it did not accelerate the initiation of the first wave of hair follicles giving rise to the guard hairs. Hence, the function of Eda-A1 appears to be downstream of the primary inductive signal required for placode initiation during skin patterning. Analysis of BrdU incorporation indicated that the formation of the epithelial thickening in early placodes does not involve increased cell proliferation and also that the positive effect of Eda-A1 on placode expansion is not a result of increased cell proliferation. Taken together, our results suggest that Eda-A1 signalling promotes placodal cell fate during early development of ectodermal organs.
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Affiliation(s)
- Tuija Mustonen
- Developmental Biology Program, Institute of Biotechnology, PO Box 56 (Viikinkaari 9), University of Helsinki, Finland
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Wilson J, Tucker AS. Fgf and Bmp signals repress the expression of Bapx1 in the mandibular mesenchyme and control the position of the developing jaw joint. Dev Biol 2004; 266:138-50. [PMID: 14729484 DOI: 10.1016/j.ydbio.2003.10.012] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The development of the jaw joint between the palatoquadrate and proximal part Meckel's cartilage (articular) has recently been shown to involve the gene Bapx1. Bapx1 is expressed in the developing mandibular arch in two distinct caudal, proximal patches, one on either side of the head. These domains coincide later with the position of the developing jaw joint. The mechanisms that result in the restricted expression of Bapx1 in the mandibular arch were investigated, and two signaling factors that act as repressors were identified. Fibroblast growth factors (Fgfs) expressed in the oral epithelium restrict expression of Bapx1 to the caudal half of the mandibular arch, while bone morphogenetic proteins (Bmps) expressed in the distal mandibular arch restrict expression of Bapx1 to the proximal part of the mandible. Application of Fgf8 and Bmp4 beads to the proximal mesenchyme led to loss of Bapx1 expression and later fusion of the quadrate and articular as the jaw joint failed to form. In addition to fusion of the jaw joint, loss of Bapx1 lead to loss of the retroarticular process (RAP), phenocopying the defects seen after Bapx1 function was reduced in the zebrafish. By manipulating these signals, we were able to alter the expression domain of Bapx1, resulting in a new position of the jaw joint.
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Affiliation(s)
- Joanne Wilson
- Craniofacial Development and Orthodontics, King's College London, London SE1 9RT, UK
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