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BMP Signaling Pathway in Dentin Development and Diseases. Cells 2022; 11:cells11142216. [PMID: 35883659 PMCID: PMC9317121 DOI: 10.3390/cells11142216] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 07/08/2022] [Accepted: 07/12/2022] [Indexed: 12/27/2022] Open
Abstract
BMP signaling plays an important role in dentin development. BMPs and antagonists regulate odontoblast differentiation and downstream gene expression via canonical Smad and non-canonical Smad signaling pathways. The interaction of BMPs with their receptors leads to the formation of complexes and the transduction of signals to the canonical Smad signaling pathway (for example, BMP ligands, receptors, and Smads) and the non-canonical Smad signaling pathway (for example, MAPKs, p38, Erk, JNK, and PI3K/Akt) to regulate dental mesenchymal stem cell/progenitor proliferation and differentiation during dentin development and homeostasis. Both the canonical Smad and non-canonical Smad signaling pathways converge at transcription factors, such as Dlx3, Osx, Runx2, and others, to promote the differentiation of dental pulp mesenchymal cells into odontoblasts and downregulated gene expressions, such as those of DSPP and DMP1. Dysregulated BMP signaling causes a number of tooth disorders in humans. Mutation or knockout of BMP signaling-associated genes in mice results in dentin defects which enable a better understanding of the BMP signaling networks underlying odontoblast differentiation and dentin formation. This review summarizes the recent advances in our understanding of BMP signaling in odontoblast differentiation and dentin formation. It includes discussion of the expression of BMPs, their receptors, and the implicated downstream genes during dentinogenesis. In addition, the structures of BMPs, BMP receptors, antagonists, and dysregulation of BMP signaling pathways associated with dentin defects are described.
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Wang F, Tao R, Zhao L, Hao XH, Zou Y, Lin Q, Liu MM, Goldman G, Luo D, Chen S. Differential lncRNA/mRNA Expression Profiling and Functional Network Analyses in Bmp2 Deletion of Mouse Dental Papilla Cells. Front Genet 2022; 12:702540. [PMID: 35003201 PMCID: PMC8727545 DOI: 10.3389/fgene.2021.702540] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 11/29/2021] [Indexed: 12/19/2022] Open
Abstract
Bmp2 is essential for dentin development and formation. Bmp2 conditional knock-out (KO) mice display a similar tooth phenotype of dentinogenesis imperfecta (DGI). To elucidate a foundation for subsequent functional studies of cross talk between mRNAs and lncRNAs in Bmp2-mediated dentinogenesis, we investigated the profiling of lncRNAs and mRNAs using immortalized mouse dental Bmp2 flox/flox (iBmp2fx/fx) and Bmp2 knock-out (iBmp2ko/ko) papilla cells. RNA sequencing was implemented to study the expression of the lncRNAs and mRNAs. Quantitative real-time PCR (RT-qPCR) was used to validate expressions of lncRNAs and mRNAs. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases were used to predict functions of differentially expressed genes (DEGs). Protein-protein interaction (PPI) and lncRNA-mRNA co-expression network were analyzed by using bioinformatics methods. As a result, a total of 22 differentially expressed lncRNAs (16 downregulated vs 6 upregulated) and 227 differentially expressed mRNAs (133 downregulated vs. 94 upregulated) were identified in the iBmp2ko/ko cells compared with those of the iBmp2fx/fx cells. RT-qPCR results showed significantly differential expressions of several lncRNAs and mRNAs which were consistent with the RNA-seq data. GO and KEGG analyses showed differentially expressed genes were closely related to cell differentiation, transcriptional regulation, and developmentally relevant signaling pathways. Moreover, network-based bioinformatics analysis depicted the co-expression network between lncRNAs and mRNAs regulated by Bmp2 in mouse dental papilla cells and symmetrically analyzed the effect of Bmp2 during dentinogenesis via coding and non-coding RNA signaling.
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Affiliation(s)
- Feng Wang
- Laboratory of Clinical Applied Anatomy, Department of Human Anatomy, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China.,Department of Developmental Dentistry, School of Dentistry, The University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Ran Tao
- Laboratory of Clinical Applied Anatomy, Department of Human Anatomy, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
| | - Li Zhao
- Laboratory of Clinical Applied Anatomy, Department of Human Anatomy, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
| | - Xin-Hui Hao
- Laboratory of Clinical Applied Anatomy, Department of Human Anatomy, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
| | - Yi Zou
- Greehey Children's Cancer Research Institute, The University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Qing Lin
- Laboratory of Clinical Applied Anatomy, Department of Human Anatomy, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
| | - Meng Meng Liu
- Department of Developmental Dentistry, School of Dentistry, The University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Graham Goldman
- Department of Developmental Dentistry, School of Dentistry, The University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Daoshu Luo
- Laboratory of Clinical Applied Anatomy, Department of Human Anatomy, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
| | - Shuo Chen
- Department of Developmental Dentistry, School of Dentistry, The University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
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Gao Y, Kobayashi H, Ganss B. The Human KROX-26/ZNF22 Gene is Expressed at Sites of Tooth Formation and Maps to the Locus for Permanent Tooth Agenesis (He-Zhao Deficiency). J Dent Res 2016; 82:1002-7. [PMID: 14630903 DOI: 10.1177/154405910308201213] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Tooth development is mediated by sequential and reciprocal interactions between dental epithelium and mesenchyme under the molecular control of secreted growth factors and responsive transcription factors. We have previously identified the transcription factor Krox-26 as a potential regulator of tooth formation in mice. The purpose of this study was to investigate a potentially similar role for the human KROX-26 orthologue. We cloned the KROX-26 gene and found its single mRNA transcript (2.4 kb) to be expressed in multiple adult tissues. During fetal development, KROX-26 is expressed in the epithelial component of the developing tooth organ during early bud and cap stages as well as in osteoblasts of craniofacial bone and the developing tongue. The KROX-26 gene was mapped to chromosome 10q11.21, a locus that has been associated with permanent tooth agenesis (He-Zhao deficiency). These results indicate a potential function for KROX-26 in the molecular regulation of tooth formation in humans.
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Affiliation(s)
- Y Gao
- Canadian Institutes for Health Research Group in Matrix Dynamics, University of Toronto, Faculty of Dentistry, Fitzgerald Building, Room 239, 150 College Street, Toronto, ON M5S 3E2, Canada
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Gronthos S, Arthur A, Bartold PM, Shi S. A method to isolate and culture expand human dental pulp stem cells. Methods Mol Biol 2011; 698:107-121. [PMID: 21431514 DOI: 10.1007/978-1-60761-999-4_9] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Dentinal repair in teeth occurs through the activity of specialized cells known as odontoblasts that are thought to be maintained by a precursor population associated with the perivascular cells within dental pulp tissue. We have previously isolated candidate dental pulp stem cells (DPSC) from adult human third molars, with the ability to generate clonogenic cell clusters (CFU-F: colony-forming units-fibroblastic), a high proliferation rate, and multi-potential differentiation in vitro. When cultured DPSC are transplanted into immunocompromised mice, they generated a dentin-like structure lined with human odontoblast-like cells that surrounded a pulp-like interstitial tissue, composed of collagen and a vascular network. The present protocol describes a methodology to generate highly purified preparations of human DPSC. This process involves the enzymatic digestion of fresh samples of human dental pulp tissue followed by the isolation of DPSC using magnetic bead cell separation, based on their expression of mesenchymal stem cell associated markers.
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Affiliation(s)
- Stan Gronthos
- Mesenchymal Stem Cell Group, Division of Haematology, Institute of Medical and Veterinary Science/Hanson Institute/CSCR, University of Adelaide, Adelaide, SA, Australia.
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5
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Yu V, Damek-Poprawa M, Nicoll SB, Akintoye SO. Dynamic hydrostatic pressure promotes differentiation of human dental pulp stem cells. Biochem Biophys Res Commun 2009; 386:661-5. [PMID: 19555657 DOI: 10.1016/j.bbrc.2009.06.106] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2009] [Accepted: 06/19/2009] [Indexed: 01/09/2023]
Abstract
The masticatory apparatus absorbs high occlusal forces, but uncontrolled parafunctional or orthodontic forces damage periodontal ligament (PDL), cause pulpal calcification, pulp necrosis and tooth loss. Morphology and functional differentiation of connective tissue cells can be controlled by mechanical stimuli but effects of uncontrolled forces on intra-pulpal homeostasis and ability of dental pulp stem cells (DPSCs) to withstand direct external forces are unclear. Using dynamic hydrostatic pressure (HSP), we tested the hypothesis that direct HSP disrupts DPSC survival and odontogenic differentiation. DPSCs from four teenage patients were subjected to HSP followed by assessment of cell adhesion, survival and recovery capacity based on odontogenic differentiation, mineralization and responsiveness to bone morphogenetic protein-2 (BMP-2). HSP down-regulated DPSC adhesion and survival but promoted differentiation by increasing mineralization, in vivo hard tissue regeneration and BMP-2 responsiveness despite reduced cell numbers. HSP-treated DPSCs displayed enhanced odontogenic differentiation, an indication of favorable recovery from HSP-induced cellular stress.
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Affiliation(s)
- V Yu
- Department of Orthodontics, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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Menicanin D, Bartold PM, Zannettino ACW, Gronthos S. Genomic profiling of mesenchymal stem cells. Stem Cell Rev Rep 2009; 5:36-50. [PMID: 19224407 DOI: 10.1007/s12015-009-9056-2] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2008] [Accepted: 02/02/2009] [Indexed: 01/04/2023]
Abstract
Mesenchymal stem/stromal cells (MSC) are an accessible source of precursor cells that can be expanded in vitro and used for tissue regeneration for different clinical applications. The advent of microarray technology has enabled the monitoring of individual and global gene expression patterns across multiple cell populations. Thus, genomic profiling has fundamentally changed our capacity to characterize MSCs, identify potential biomarkers and determined key molecules regulating biological processes involved in stem cell survival, growth and development. Numerous studies have now examined the genomic profiles of MSCs derived from different tissues that exhibit varying levels of differentiation and proliferation potentials. The knowledge gained from these studies will help improve our understanding of the cellular signalling pathways involved in MSC growth, survival and differentiation, and may aid in the development of strategies to improve the tissue regeneration potential of MSCs for different clinical indications. The present review summarizes studies characterizing the gene expression profile of MSCs.
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Affiliation(s)
- Danijela Menicanin
- Mesenchymal Stem Cell Group, Bone and Cancer Laboratories, Division of Haematology, Institute of Medical and Veterinary Science/ Hanson Institute and CSCR, University of Adelaide, SA, Australia
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Abstract
One of the aims of developmental biology is to understand how a single egg cell gives rise to the complex spatial distributions of cell types and extracellular components of the adult phenotype. This review discusses the main genetic and epigenetic interactions known to play a role in tooth development and how they can be integrated into coherent models. Along the same lines, several hypotheses about aspects of tooth development that are currently not well understood are evaluated. This is done from their morphological consequences from the model and how these fit known morphological variation and change during tooth development. Thus the aim of this review is two-fold. On one hand the model and its comparison with experimental evidence will be used to outline our current understanding about tooth morphogenesis. On the other hand these same comparisons will be used to introduce a computational model that makes accurate predictions on three-dimensional morphology and patterns of gene expression by implementing cell signaling, proliferation and mechanical interactions between cells. In comparison with many other models of development this model includes reaction-diffusion-like dynamics confined to a diffusion chamber (the developing tooth) that changes in shape in three-dimensions over time. These changes are due to mechanical interactions between cells triggered by the proliferation enhancing effect of the reactants (growth factors). In general, tooth morphogenesis can be understood from the indirect cross-regulation between extracellular signals, the local regulation of proliferation and differentiation rates by these signals and the effect of intermediate developing morphology on the diffusion, dilution, and spatial distribution of these signals. Overall, this review should be interesting to either readers interested in the mechanistic bases of tooth morphogenesis, without necessarily being interested in modeling per se, and readers interested in development modeling in general.
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Affiliation(s)
- Isaac Salazar-Ciudad
- Developmental Biology Program, Institute of Biotechnology, P.O. Box 56, FIN-00014, University of Helsinki, Helsinki, Finland
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Jegat N, Septier D, Veis A, Poliard A, Goldberg M. Short-term effects of amelogenin gene splice products A+4 and A-4 implanted in the exposed rat molar pulp. Head Face Med 2007; 3:40. [PMID: 18154672 PMCID: PMC2245914 DOI: 10.1186/1746-160x-3-40] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2007] [Accepted: 12/21/2007] [Indexed: 01/09/2023] Open
Abstract
In order to study the short-time effects of two bioactive low-molecular amelogenins A+4 and A-4, half-moon cavities were prepared in the mesial aspect of the first maxillary molars, and after pulp exposure, agarose beads alone (controls) or beads soaked in A+4 or A-4 (experimental) were implanted into the pulp. After 1, 3 or 7 days, the rats were killed and the teeth studied by immunohistochemistry. Cell proliferation was studied by PCNA labeling, positive at 3 days, but decreasing at day 7 for A+4, whilst constantly high between 3 and 7 days for A-4. The differentiation toward the osteo/odontoblast lineage shown by RP59 labeling was more apparent for A-4 compared with A+4. Osteopontin-positive cells were alike at days 3 and 7 for A-4. In contrast, for A+4, the weak labeling detected at day 3 became stronger at day 7. Dentin sialoprotein (DSP), an in vivo odontoblast marker, was not detectable until day 7 where a few cells became DSP positive after A-4 stimulation, but not for A+4. These results suggest that A +/- 4 promote the proliferation of some pulp cells. Some of them further differentiate into osteoblast-like progenitors, the effects being more precocious for A-4 (day 3) compared with A+4 (day 7). The present data suggest that A +/- 4 promote early recruitment of osteogenic progenitors, and evidence functional differences between A+4 and A-4.
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Affiliation(s)
- Nadège Jegat
- Oral Biology, EA 2496, Faculté de Chirurgie Dentaire, Université Paris Descartes, Montrouge, France.
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Yamada Y, Fujimoto A, Ito A, Yoshimi R, Ueda M. Cluster analysis and gene expression profiles: a cDNA microarray system-based comparison between human dental pulp stem cells (hDPSCs) and human mesenchymal stem cells (hMSCs) for tissue engineering cell therapy. Biomaterials 2006; 27:3766-81. [PMID: 16563496 DOI: 10.1016/j.biomaterials.2006.02.009] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2005] [Accepted: 02/09/2006] [Indexed: 12/11/2022]
Abstract
We investigated gene expression patterns and functional classifications regarding the clusters of human dental pulp stem cells (hDPSCs) and human mesenchymal stem cells (hMSCs)--which possess a multipotent ability--because little is known about the precise moleculobiological clues by which these cells activate their differentiating ability or functionality to eventually form dentin and bone, respectively. We first verified the expressions of the alkaline phosphatase (ALP) gene, dentin matrix protein 1 (DMP-1), and dentinsialophosphoprotein (DSPP) by real-time reverse-transcriptase polymerase chain reaction (RT-PCR) and consequently discovered the high expressions of these genes. Total RNA was also followed by hybridization with a human microarray system consisting of 12,814 genes. Analyses of gene expression patterns indicated several genes which encode extracellular matrix components, cell adhesion molecules, growth factors, and transcription regulators. Functional and clustering analyses of differences in gene expression levels revealed cell signaling, cell communication, or cell metabolism. In the future, information on the gene expression patterns of hDPSCs and hMSCs might be useful in determining the detailed functional roles of the relevant genes and applicable to stem cell therapies, and these cells could also be used as multipotent cell sources for gene technology and tissue engineering technology.
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Affiliation(s)
- Yoichi Yamada
- Center for Genetic and Regenerative Medicine, Nagoya University School of Medicine, Nagoya, Aichi 466-8550, Japan.
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Nadiri A, Kuchler-Bopp S, Perrin-Schmitt F, Lesot H. Expression patterns of BMPRs in the developing mouse molar. Cell Tissue Res 2006; 324:33-40. [PMID: 16432712 DOI: 10.1007/s00441-005-0120-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2005] [Accepted: 11/04/2005] [Indexed: 11/30/2022]
Abstract
During development, Bone Morphogenetic Proteins (BMPs) can induce apoptosis, cell growth or differentiation. These different effects are mediated by dimers of two types of BMP-receptors (BMPRs). To identify the responding cells during tooth development and search for possible tissue-or stage-specificities in the receptors involved, the distribution patterns of BMPR-IA, -IB and -II were investigated in the mouse molar, from bud to bell stage. At the bud stage, BMP-2 was suggested to be involved in the formation of an epithelial signaling center, the primary enamel knot (PEK), while BMP-4 would mediate the condensation of the mesenchyme. Immunostaining showed the presence of BMPR-IA and -II in the epithelium instead of BMPR-IB and -II in the mesenchyme. At the cap stage, BMPR-IB was detected in the epithelium but not BMPR-II, suggesting the existence of another type II receptor to form a functional dimer. At the late cap stage in the epithelium, BMP-4, BMPR-IA and -II were restricted to the internal part of the PEK and the stalk: two apoptotic areas. The three proteins were detected in the mesenchyme, showing a strong staining where cusps were about to form. At the late bell stage, BMP-2 or -4 may induce cell differentiation. BMPR-IB and -II were detected in odontoblasts instead of BMPR-IA and -II in ameloblasts. These results provide the first evidence of multiple type I and type II BMP-receptors, expressed in the dental epithelium and mesenchyme at different stages of development, to signal different cellular activities in a time- and tissue-specific way.
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Affiliation(s)
- A Nadiri
- INSERM UMR S595, Faculté de Chirurgie Dentaire, Université Louis Pasteur, 67085, Strasbourg, France.
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Heikinheimo K, Mori K, Nagatsuka H, Happonen RP. Transforming Growth Factor Beta (TGF-β) Gene Family Members in Developing and Neoplastic Odontogenic Tissues. J HARD TISSUE BIOL 2006. [DOI: 10.2485/jhtb.15.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Kristiina Heikinheimo
- Department of Oral and Maxillofacial Surgery, Institute of Dentistry, University of Turku
- Department of Oral Diseases, Turku University Central Hospital
| | - Kazuhisa Mori
- 2nd Department of Oral and Maxillofacial Surgery, The Nippon Dental University School of Dentistry at Niigata
| | - Hitoshi Nagatsuka
- Department of Oral Pathology and Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University
| | - Risto-Pekka Happonen
- Department of Oral and Maxillofacial Surgery, Institute of Dentistry, University of Turku
- Department of Oral Diseases, Turku University Central Hospital
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Ohazama A, Tucker A, Sharpe PT. Organized tooth-specific cellular differentiation stimulated by BMP4. J Dent Res 2005; 84:603-6. [PMID: 15972586 DOI: 10.1177/154405910508400704] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Mammalian teeth develop on the oral surface of the first pharyngeal arch by a series of reciprocal interactions between epithelial and mesenchymal cells. The embryonic first pharyngeal arch oral epithelium is able to induce tooth formation when combined with mesenchymal cells from the second pharyngeal arch, a region devoid of tooth development. Second pharyngeal arch mesenchyme is thus competent to form teeth if provided with the correct signals. First-arch oral epithelium expresses several signaling molecules that could be potential inducers of tooth development, including BMP4. The addition of BMP4 to intact second-arch explants resulted in the development of organized structures containing layers of cells that express marker genes of tooth-specific cells, odontoblasts and ameloblasts. Thus, although overt tooth development did not occur, BMP4 has the ability to stimulate organized differentiation of epithelial- and mesenchymal-derived dental-specific cells from non-dental primordia.
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Affiliation(s)
- A Ohazama
- Department of Craniofacial Development, Dental Institute, Kings College London, Floor 28 Guy's Hospital, London Bridge, London SE1 9RT, UK
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Hosoya A, Yoshiba K, Yoshiba N, Hoshi K, Iwaku M, Ozawa H. An immunohistochemical study on hard tissue formation in a subcutaneously transplanted rat molar. Histochem Cell Biol 2003; 119:27-35. [PMID: 12548403 DOI: 10.1007/s00418-002-0478-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/05/2002] [Indexed: 10/25/2022]
Abstract
While dental pulp undergoes calcification following tooth replantation or transplantation, we actually know little about these mechanisms. We therefore conducted histological and immunohistochemical evaluations of mineralized tissue that formed in the pulp of rat maxillary molar transplanted into abdominal subcutaneous tissue. One, 2, 3, and 4 weeks post-transplantation, the teeth were investigated immunohistochemically using antibodies to osteocalcin (OCN), osteopontin (OPN), bone sialoprotein (BSP), dentin sialoprotein (DSP), and tissue non-specific alkaline phosphatase (TNAP). In the 1st week after transplantation, cell-rich hard tissue was formed at the root apex. At 2 weeks, formations of hard tissue, with few cells in the root canals and bone-like tissue in the coronal pulp chamber, were noted. After 3 and 4 weeks, the amounts of these hard tissues were increased. The immunolocalization of OCN, OPN, and BSP was seen strongly in coronal and apical hard tissues, but weakly in the root hard tissue. Conversely, DSP localized in the root hard tissue, but not in other newly formed hard tissues. At 1 week, TNAP localized along the periphery of the apical hard tissue and the lower surfaces of root predentin. These results demonstrate that the newly formed hard tissues in the pulp cavity of subcutaneously transplanted molars could be classified into three types, suggesting that these might be formed by type-specific cells.
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Affiliation(s)
- Akihiro Hosoya
- Division of Cariology, Department of Oral Health Science, Course for Oral Life Science, Niigata University Graduate School of Medical and Dental Sciences, 2-5274 Gakkocho, 951-8514 Niigata, Japan
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14
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Bonucci E. Physiopathology of cancer metastases in bone and of the changes they induce in bone remodeling. ACTA ACUST UNITED AC 2002. [DOI: 10.1007/bf02904492] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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15
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Abstract
We compared the gene expression profiles of human dental pulp stem cells (DPSCs) and bone marrow stromal stem cells (BMSSCs) as representative populations of odontoprogenitor and osteoprogenitor cells, respectively. Total RNA from primary cultures was reverse-transcribed to generate cDNA probes and then hybridized with the Research Genetics human gene microarray filter GF211. The microarrays were analyzed using the PATHWAYS software package. Human DPSCs and BMSSCs were found to have a similar level of gene expression for more than 4000 known human genes. A few differentially expressed genes, including collagen type XVIII alpha1, insulin-like growth factor-2 (IGF-2), discordin domain tyrosine kinase 2, NAD(P)H menadione oxidoreductase, homolog 2 of Drosophila large disk, and cyclin-dependent kinase 6 were highly expressed in DPSCs, whereas insulin-like growth factor binding protein-7 (IGFBP-7), and collagen type I alpha2 were more highly expressed in BMSSCs. Furthermore, we confirmed the differential expression of these genes by semiquantitative polymerase chain reaction (PCR) and northern blot hybridization. The protein expression patterns for both IGF-2 and IGFBP-7 correlated with the differential mRNA levels seen between DPSCs and BMSSCs. This report describes the gene expression patterns of two distinct precursor populations associated with mineralized tissue, and provides a basis for further characterization of the functional roles for many of these genes in the development of dentin and bone.
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Affiliation(s)
- S Shi
- Craniofacial and Skeletal Diseases Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA
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16
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Payne TL, Skobe Z, Yelick PC. Regulation of tooth development by the novel type I TGFbeta family member receptor Alk8. J Dent Res 2001; 80:1968-73. [PMID: 11759004 DOI: 10.1177/00220345010800110401] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
We have recently identified, in zebrafish, a novel type I receptor of the TGFbeta family, alk8, that participates in Bmp signaling pathways to mediate early dorsoventral patterning of neurectodermal and mesendodermal tissues. Since Bmps play significant roles in tooth specification, initiation, and differentiation, we hypothesized that alk8 may play a role in directing the Bmp-mediated epithelial mesenchymal cell interactions regulating tooth development. Immunohistochemical analysis demonstrates that Alk8 is expressed in developing zebrafish and mouse teeth. Examination of tooth development in zebrafish with disrupted alk8 signaling revealed specific defects in tooth development. Ectopic expression of constitutively active Alk8 results in the formation of elongated tooth structures, while expression of dominant-negative Alk8 results in arrested tooth development at the bud stage. These results are consistent with the established requirements for Bmp signaling in tooth development and demonstrate that Alk8 is a key regulator of tooth development.
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Affiliation(s)
- T L Payne
- The Forsyth Institute, Department of Cytokine Biology, Boston, MA 02115, USA
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Abstract
Histological and cytological organization confer specificity to the odontoblasts. These postmitotic, neural crest derived, polarized cells are aligned in a single layer at the periphery of the dental pulp and secrete the organic components of predentin-dentin. The developmental history of these cells demands a cascade of epigenetic signalling events comprising the acquisition of odontogenic potential by neural crest cells, their patterning in the developing jaws, the initiation of odontogenesis through interaction with the oral epithelium, commitment, and tooth-specific spatial distribution of competent preodontoblasts able to overtly differentiate. Recent experimental investigations are critically summarized, many open questions are stressed, and current hypotheses concerning the control of terminal odontoblast differentiation are outlined.Key words: odontoblast, neural crest, oral ectoderm, differentiation.
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