1
|
The Versatile Roles of Nerve Growth Factor in Neuronal Attraction, Odontoblast Differentiation, and Mineral Deposition in Human Teeth. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021. [PMID: 34453293 DOI: 10.1007/978-3-030-74046-7_6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/27/2023]
Abstract
Nerve growth factor (NGF) is an important molecule for the development and differentiation of neuronal and non-neuronal cells. Here we analyze by immunohistochemistry the distribution of NGF in the dental pulp mesenchyme of embryonic and functional human teeth. In the dental pulp of both embryonic and healthy functional teeth, NGF is mainly expressed in the odontoblasts that are responsible for dentine formation, while in functional teeth NGF is also expressed in nerve fibers innervating the dental pulp. In injured teeth, NGF is expressed in the newly formed odontoblastic-like cells, which replace the dying odontoblasts. In these teeth, NGF expression is also upregulated in the intact odontoblasts, suggesting a role for this molecule in dental tissue repair. Similarly, in cultures of human dental pulp cells, NGF expression is strongly upregulated during their differentiation into odontoblasts as well as during the mineralization process. In microfluidic devices, release of NGF from cultured human dental pulp cells induced neuronal growth from trigeminal ganglia toward the NGF secreting cells. These results show that NGF is closely linked to the various functions of odontoblasts, including secretory and neuronal attraction processes.
Collapse
|
2
|
Abstract
Innervation plays a key role in the development, homeostasis, and regeneration of organs and tissues. However, the mechanisms underlying these phenomena are not well understood yet. In particular, the role of innervation in tooth development and regeneration is neglected. Cocultures constitute a valuable method to investigate and manipulate the interactions between nerve fibers and teeth in a controlled and isolated environment. Microfluidic systems for allow cocultures of neurons and different cell types in their appropriate culture media, while permitting the passage of axons from one compartment to the other. Here we describe how to isolate and coculture developing trigeminal ganglia and tooth germs in a microfluidic coculture system. This protocol describes a simple and flexible way to coculture ganglia/nerves and their target tissues and to study the roles of specific molecules on such interactions in a controlled and isolated environment.
Collapse
|
3
|
Mahdee A, Eastham J, Whitworth JM, Gillespie JI. Evidence for changing nerve growth factor signalling mechanisms during development, maturation and ageing in the rat molar pulp. Int Endod J 2018; 52:211-222. [DOI: 10.1111/iej.12997] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 08/06/2018] [Indexed: 11/27/2022]
Affiliation(s)
- A. Mahdee
- Centre for Oral Health Research; Newcastle University; Newcastle upon Tyne UK
- Institute of Cellular Medicine; Newcastle University; Newcastle upon Tyne UK
- School of Dental Sciences; Newcastle University; Newcastle upon Tyne UK
- University of Baghdad College of Dentistry; Baghdad Iraq
| | - J. Eastham
- Institute of Cellular Medicine; Newcastle University; Newcastle upon Tyne UK
| | - J. M. Whitworth
- Centre for Oral Health Research; Newcastle University; Newcastle upon Tyne UK
- School of Dental Sciences; Newcastle University; Newcastle upon Tyne UK
| | - J. I. Gillespie
- School of Dental Sciences; Newcastle University; Newcastle upon Tyne UK
- Urology and Urological Rehabilitation; Antwerp University; Antwerp Belgium
| |
Collapse
|
4
|
Mitsiadis TA, Magloire H, Pagella P. Nerve growth factor signalling in pathology and regeneration of human teeth. Sci Rep 2017; 7:1327. [PMID: 28465581 PMCID: PMC5431060 DOI: 10.1038/s41598-017-01455-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 03/30/2017] [Indexed: 12/25/2022] Open
Abstract
Nerve growth factor (NGF) is a key regulator of the development and differentiation of neuronal and non-neuronal cells. In the present study we examined the distribution of NGF and its low and high-affinity receptors, p75NTR and TrkA respectively, in permanent human teeth under normal and pathological conditions. In intact functional teeth, NGF, p75NTR and TrkA are weakly expressed in dental pulp fibroblasts and odontoblasts that are responsible for dentine formation, while the NGF and p75NTR molecules are strongly expressed in nerve fibres innervating the dental pulp. In carious and injured teeth NGF and TrkA expression is upregulated in a selective manner in odontoblasts surrounding the injury sites, indicating a link between NGF signalling and dental tissue repair events. Accordingly, NGF and TrkA expression is strongly upregulated in cultured primary human dental mesenchymal cells during their differentiation into odontoblasts. Targeted release of NGF in cultured human tooth slices induced extensive axonal growth and migration of Schwann cells towards the NGF administration site. These results show that NGF signalling is strongly linked to pathological and regenerative processes in human teeth and suggest a potential role for this neurotrophic molecule in pulp regeneration.
Collapse
Affiliation(s)
- Thimios A Mitsiadis
- Orofacial Development and Regeneration, Institute of Oral Biology, Centre for Dental Medicine, Medical Faculty, University of Zurich, Zurich, Switzerland.
| | - Henry Magloire
- Institut de Génomique Fonctionnelle de Lyon, Ecole Normale Supérieure (ENS), Lyon, France
| | - Pierfrancesco Pagella
- Orofacial Development and Regeneration, Institute of Oral Biology, Centre for Dental Medicine, Medical Faculty, University of Zurich, Zurich, Switzerland
| |
Collapse
|
5
|
Kawano S, Saito M, Handa K, Morotomi T, Toyono T, Seta Y, Nakamura N, Uchida T, Toyoshima K, Ohishi M, Harada H. Characterization of Dental Epithelial Progenitor Cells Derived from Cervical-loop Epithelium in a Rat Lower Incisor. J Dent Res 2016; 83:129-33. [PMID: 14742650 DOI: 10.1177/154405910408300209] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Dental epithelial progenitor cells differentiate into various cell types during development of tooth germs. To study this mechanism, we produced immortalized dental epithelial progenitor cells derived from the cervical-loop epithelium of a rat lower incisor. The expression patterns of cytokeratin 14, nerve growth factor receptor p75, amelogenin, Notch2, and alkaline phosphatase were examined by immnohistochemistry in both lower and higher cell densities. The patterns of each were compared in the dental epithelium of rat lower incisors. The results demonstrated that these cells could produce ameloblast lineage cells, stratum intermedium cells, stellate reticulum, and outer enamel epithelium. Furthermore, fibroblast growth factor 10 stimulated proliferation of dental progenitor cells and subsequently increased the number of cells expressing alkaline phosphatase. These results suggest that fibroblast growth factor 10 plays a role in coupling mitogenesis of the cervical-loop cells and the production of stratum intermedium cells in rat incisors.
Collapse
Affiliation(s)
- S Kawano
- Department of Oral Anatomy and Cell Biology, Kyushu Dental College, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu 803-8580, Japan
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Mitsiadis TA, Pagella P. Expression of Nerve Growth Factor (NGF), TrkA, and p75(NTR) in Developing Human Fetal Teeth. Front Physiol 2016; 7:338. [PMID: 27536251 PMCID: PMC4972002 DOI: 10.3389/fphys.2016.00338] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 07/21/2016] [Indexed: 11/25/2022] Open
Abstract
Nerve growth factor (NGF) is important for the development and the differentiation of neuronal and non-neuronal cells. NGF binds to specific low- and high-affinity cell surface receptors, respectively, p75NTR and TrkA. In the present study, we examined by immunohistochemistry the expression patterns of the NGF, p75NTR, and TrkA proteins during human fetal tooth development, in order to better understand the mode of NGF signaling action in dental tissues. The results obtained show that these molecules are expressed in a wide range of dental cells of both epithelial and mesenchymal origin during early stages of odontogenesis, as well as in nerve fibers that surround the developing tooth germs. At more advanced developmental stages, NGF and TrkA are localized in differentiated cells with secretory capacities such as preameloblasts/ameloblasts secreting enamel matrix and odontoblasts secreting dentine matrix. In contrast, p75NTR expression is absent from these secretory cells and restricted in proliferating cells of the dental epithelium. The temporospatial distribution of NGF and p75NTR in fetal human teeth is similar, but not identical, with that observed previously in the developing rodent teeth, thus indicating that the genetic information is well-conserved during evolution. The expression patterns of NGF, p75NTR, and TrkA during odontogenesis suggest regulatory roles for NGF signaling in proliferation and differentiation of epithelial and mesenchymal cells, as well as in attraction and sprouting of nerve fibers within dental tissues.
Collapse
Affiliation(s)
- Thimios A Mitsiadis
- Orofacial Development and Regeneration, Institute of Oral Biology, Center for Dentistry (ZZM), University of Zurich Zurich, Switzerland
| | - Pierfrancesco Pagella
- Orofacial Development and Regeneration, Institute of Oral Biology, Center for Dentistry (ZZM), University of Zurich Zurich, Switzerland
| |
Collapse
|
7
|
Pagella P, Miran S, Mitsiadis T. Analysis of Developing Tooth Germ Innervation Using Microfluidic Co-culture Devices. J Vis Exp 2015:e53114. [PMID: 26327218 DOI: 10.3791/53114] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Innervation plays a key role in the development, homeostasis and regeneration of organs and tissues. However, the mechanisms underlying these phenomena are not well understood yet. In particular, the role of innervation in tooth development and regeneration is neglected. Several in vivo studies have provided important information about the patterns of innervation of dental tissues during development and repair processes of various animal models. However, most of these approaches are not optimal to highlight the molecular basis of the interactions between nerve fibres and target organs and tissues. Co-cultures constitute a valuable method to investigate and manipulate the interactions between nerve fibres and teeth in a controlled and isolated environment. In the last decades, conventional co-cultures using the same culture medium have been performed for very short periods (e.g., two days) to investigate the attractive or repulsive effects of developing oral and dental tissues on sensory nerve fibres. However, extension of the culture period is required to investigate the effects of innervation on tooth morphogenesis and cytodifferentiation. Microfluidics systems allow co-cultures of neurons and different cell types in their appropriate culture media. We have recently demonstrated that trigeminal ganglia (TG) and teeth are able to survive for a long period of time when co-cultured in microfluidic devices, and that they maintain in these conditions the same innervation pattern that they show in vivo. On this basis, we describe how to isolate and co-culture developing trigeminal ganglia and tooth germs in a microfluidic co-culture system.This protocol describes a simple and flexible way to co-culture ganglia/nerves and target tissues and to study the roles of specific molecules on such interactions in a controlled and isolated environment.
Collapse
Affiliation(s)
- Pierfrancesco Pagella
- Institute of Oral Biology, Unit of Orofacial Development and Regeneration, University of Zurich
| | - Shayee Miran
- Institute of Oral Biology, Unit of Orofacial Development and Regeneration, University of Zurich
| | - Tim Mitsiadis
- Institute of Oral Biology, Unit of Orofacial Development and Regeneration, University of Zurich;
| |
Collapse
|
8
|
Pagella P, Neto E, Jiménez-Rojo L, Lamghari M, Mitsiadis TA. Microfluidics co-culture systems for studying tooth innervation. Front Physiol 2014; 5:326. [PMID: 25202282 PMCID: PMC4142415 DOI: 10.3389/fphys.2014.00326] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 08/06/2014] [Indexed: 01/01/2023] Open
Abstract
Innervation plays a key role in the development and homeostasis of organs and tissues of the orofacial complex. Among these structures, teeth are peculiar organs as they are not innervated until later stages of development. Furthermore, the implication of neurons in tooth initiation, morphogenesis and differentiation is still controversial. Co-cultures constitute a valuable method to investigate and manipulate the interactions of nerve fibers with their target organs in a controlled and isolated environment. Conventional co-cultures between neurons and their target tissues have already been performed, but these cultures do not offer optimal conditions that are closely mimicking the in vivo situation. Indeed, specific cell populations require different culture media in order to preserve their physiological properties. In this study we evaluate the usefulness of a microfluidics system for co-culturing mouse trigeminal ganglia and developing teeth. This device allows the application of specific media for the appropriate development of both neuronal and dental tissues. The results show that mouse trigeminal ganglia and teeth survive for long culture periods in this microfluidics system, and that teeth maintain the attractive or repulsive effect on trigeminal neurites that has been observed in vivo. Neurites are repealed when co-cultured with embryonic tooth germs, while postnatal teeth exert an attractive effect to trigeminal ganglia-derived neurons. In conclusion, microfluidics system devices provide a valuable tool for studying the behavior of neurons during the development of orofacial tissues and organs, faithfully imitating the in vivo situation.
Collapse
Affiliation(s)
- Pierfrancesco Pagella
- Department of Orofacial Development and Regeneration, Faculty of Medicine, Centre for Dental Medicine, Institute of Oral Biology, University of Zurich Zurich, Switzerland
| | - Estrela Neto
- NEW Therapies Group, INEB - Instituto de Engenharia Biomédica, Universidade do Porto Porto, Portugal ; Faculdade de Medicina da Universidade do Porto Porto, Portugal
| | - Lucia Jiménez-Rojo
- Department of Orofacial Development and Regeneration, Faculty of Medicine, Centre for Dental Medicine, Institute of Oral Biology, University of Zurich Zurich, Switzerland
| | - Meriem Lamghari
- NEW Therapies Group, INEB - Instituto de Engenharia Biomédica, Universidade do Porto Porto, Portugal ; Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto Porto, Portugal
| | - Thimios A Mitsiadis
- Department of Orofacial Development and Regeneration, Faculty of Medicine, Centre for Dental Medicine, Institute of Oral Biology, University of Zurich Zurich, Switzerland
| |
Collapse
|
9
|
Sema3A chemorepellant regulates the timing and patterning of dental nerves during development of incisor tooth germ. Cell Tissue Res 2014; 357:15-29. [DOI: 10.1007/s00441-014-1839-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 01/31/2014] [Indexed: 12/22/2022]
|
10
|
Furfaro F, Ang ESM, Lareu RR, Murray K, Goonewardene M. A histological and micro-CT investigation in to the effect of NGF and EGF on the periodontal, alveolar bone, root and pulpal healing of replanted molars in a rat model - a pilot study. Prog Orthod 2014; 15:2. [PMID: 24393534 PMCID: PMC3896721 DOI: 10.1186/2196-1042-15-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 11/22/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND This study aims to investigate, utilising micro-computed tomography (micro-CT) and histology, whether the topical application of nerve growth factor (NGF) and/or epidermal growth factor (EGF) can enhance periodontal, alveolar bone, root and pulpal tissue regeneration while minimising the risk of pulpal necrosis, root resorption and ankylosis of replanted molars in a rat model. METHODS Twelve four-week-old male Sprague-Dawley rats were divided into four groups: sham, collagen, EGF and NGF. The maxillary right first molar was elevated and replanted with or without a collagen membrane impregnated with either the growth factors EGF or NGF, or a saline solution. Four weeks after replantation, the animals were sacrificed and the posterior maxilla was assessed using histological and micro-CT analysis. The maxillary left first molar served as the control for the corresponding right first molar. RESULTS Micro-CT analysis revealed a tendency for all replanted molars to have reduced root length, root volume, alveolar bone height and inter-radicular alveolar bone volume. It appears that the use of the collagen membrane had a negative effect while no positive effect was noted with the incorporation of EGF or NGF. Histologically, the incorporation of the collagen membrane was found to negatively affect pulpal, root, periodontal and alveolar bone healing with pulpal inflammation and hard tissue formation, extensive root resorption and alveolar bone fragmentation. The incorporation of EGF and NGF did not improve root, periodontal or alveolar bone healing. However, EGF was found to improve pulp vascularisation while NGF-improved pulpal architecture and cell organisation, although not to the level of the control group. CONCLUSIONS Results indicate a possible benefit on pulpal vascularisation and pulpal cell organisation following the incorporation of EGF and NGF, respectively, into the alveolar socket of replanted molars in the rat model. No potential benefit of EGF and NGF was detected in periodontal or root healing, while the use of a collagen membrane carrier was found to have a negative effect on the healing response.
Collapse
Affiliation(s)
- Francesco Furfaro
- Department of Orthodontics, The University of Western Australia, Crawley, Western Australia 6009, Australia.
| | | | | | | | | |
Collapse
|
11
|
Semaphorin 3A controls timing and patterning of the dental pulp innervation. Differentiation 2012; 84:371-9. [DOI: 10.1016/j.diff.2012.09.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Revised: 09/12/2012] [Accepted: 09/17/2012] [Indexed: 01/07/2023]
|
12
|
Nicotinic receptor Alpha7 expression during tooth morphogenesis reveals functional pleiotropy. PLoS One 2012; 7:e36467. [PMID: 22666322 PMCID: PMC3364260 DOI: 10.1371/journal.pone.0036467] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Accepted: 04/06/2012] [Indexed: 01/16/2023] Open
Abstract
The expression of nicotinic acetylcholine receptor (nAChR) subtype, alpha7, was investigated in the developing teeth of mice that were modified through homologous recombination to express a bi-cistronic IRES-driven tau-enhanced green fluorescent protein (GFP); alpha7GFP) or IRES-Cre (alpha7Cre). The expression of alpha7GFP was detected first in cells of the condensing mesenchyme at embryonic (E) day E13.5 where it intensifies through E14.5. This expression ends abruptly at E15.5, but was again observed in ameloblasts of incisors at E16.5 or molar ameloblasts by E17.5–E18.5. This expression remains detectable until molar enamel deposition is completed or throughout life as in the constantly erupting mouse incisors. The expression of alpha7GFP also identifies all stages of innervation of the tooth organ. Ablation of the alpha7-cell lineage using a conditional alpha7Cre×ROSA26-LoxP(diphtheria toxin A) strategy substantially reduced the mesenchyme and this corresponded with excessive epithelium overgrowth consistent with an instructive role by these cells during ectoderm patterning. However, alpha7knock-out (KO) mice exhibited normal tooth size and shape indicating that under normal conditions alpha7 expression is dispensable to this process. The function of ameloblasts in alpha7KO mice is altered relative to controls. High resolution micro-computed tomography analysis of adult mandibular incisors revealed enamel volume of the alpha7KO was significantly reduced and the organization of enamel rods was altered relative to controls. These results demonstrate distinct and varied spatiotemporal expression of alpha7 during tooth development, and they suggest that dysfunction of this receptor would have diverse impacts upon the adult organ.
Collapse
|
13
|
Xiao L, Tsutsui T. Three-dimensional epithelial and mesenchymal cell co-cultures form early tooth epithelium invagination-like structures: Expression patterns of relevant molecules. J Cell Biochem 2012; 113:1875-85. [DOI: 10.1002/jcb.24056] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
14
|
Abstract
Ameloblastomas are uncommon benign neoplasms of the jaws. They originate from dental epithelial cells, but they are not capable of mineralizing or forming enamel. The study of these tumors is limited to live tissue collected from patients during scheduled surgery. Ameloblastomas grow slowly in vivo and this property is translated to their behavior in vitro. Here, we describe the methods to culture ameloblastomas in organotypic cultures, as well as to isolate stem/progenitor cells from these tumors.
Collapse
|
15
|
|
16
|
O’Hara AH, Sampson WJ, Dreyer CW, Pierce AM, Ferguson IA. Immunohistochemical detection of nerve growth factor and its receptors in the rat periodontal ligament during tooth movement. Arch Oral Biol 2009; 54:871-8. [DOI: 10.1016/j.archoralbio.2009.06.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2009] [Revised: 04/17/2009] [Accepted: 06/02/2009] [Indexed: 11/16/2022]
|
17
|
Mitsiadis TA, Caton J, De Bari C, Bluteau G. The large functional spectrum of the heparin-binding cytokines MK and HB-GAM in continuously growing organs: the rodent incisor as a model. Dev Biol 2008; 320:256-66. [PMID: 18582856 DOI: 10.1016/j.ydbio.2008.05.530] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2008] [Revised: 04/10/2008] [Accepted: 05/08/2008] [Indexed: 11/30/2022]
Abstract
The heparin binding molecules MK and HB-GAM are involved in the regulation of growth and differentiation of many tissues and organs. Here we analyzed the expression of MK and HB-GAM in the developing mouse incisors, which are continuously growing organs with a stem cell compartment. Overlapping but distinct expression patterns for MK and HB-GAM were observed during all stages of incisor development (initiation, morphogenesis, cytodifferentiation). Both proteins were detected in the enamel knot, a transient epithelial signaling structure that is important for tooth morphogenesis, and the cervical loop where the stem cell niche is located. The functions of MK and HB-GAM were studied in dental explants and organotypic cultures in vitro. In mesenchymal explants, MK stimulated HB-GAM expression and, vice-versa, HB-GAM upregulated MK expression, thus indicating a regulatory loop between these proteins. BMP and FGF molecules also activated expression of both cytokines in mesenchyme. The proliferative effects of MK and HB-GAM varied according to the mesenchymal or epithelial origin of the tissue. Growth, cytodifferentiation and mineralization were inhibited in incisor germs cultured in the presence of MK neutralizing antibodies. These results demonstrate that MK and HB-GAM are involved in stem cells maintenance, cytodifferentiation and mineralization processes during mouse incisor development.
Collapse
Affiliation(s)
- Thimios A Mitsiadis
- Department of Orofacial Development and Structure, Institute of Oral Biology, ZZMK, Faculty of Medicine, University of Zurich, Plattenstrasse 11, CH 8032 Zurich, Switzerland.
| | | | | | | |
Collapse
|
18
|
Secondary induction and the development of tooth nerve supply. Ann Anat 2008; 190:178-87. [DOI: 10.1016/j.aanat.2007.10.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2007] [Revised: 10/21/2007] [Accepted: 10/21/2007] [Indexed: 12/25/2022]
|
19
|
Mitsiadis TA, De Bari C, About I. Apoptosis in developmental and repair-related human tooth remodeling: a view from the inside. Exp Cell Res 2007; 314:869-77. [PMID: 18054913 DOI: 10.1016/j.yexcr.2007.11.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2007] [Revised: 11/02/2007] [Accepted: 11/03/2007] [Indexed: 10/22/2022]
Abstract
Apoptosis is a key phenomenon in the regulation of the life span of odontoblasts, which are responsible for dentin matrix production of the teeth. The mechanism controlling odontoblasts loss in developing, normal, and injured human teeth is largely unknown. A possible correlation between apoptosis and dental pulp volume reduction was examined. Histomorphometric analysis was performed on intact 10 to 14 year-old premolars to follow dentin deposition and evaluate the total number of odontoblasts. Apoptosis in growing healthy teeth as well as in mature irritated human teeth was determined using a modified TUNEL technique and an anti-caspase-3 antibody. In intact growing teeth, the sequential rearrangement of odontoblasts into a multi-layer structure during tooth crown formation was correlated with an apoptotic wave that leads to the massive elimination of odontoblasts. These data suggest that apoptosis, coincident with dentin deposition changes, plays a role in tooth maturation and homeostasis. Massive apoptotic events were observed after dentin irritation. In carious and injured teeth, apoptosis was detected in cells surrounding the lesion sites, as well as in mono-nucleated cells nearby the injury. These results indicate that apoptosis is a part of the mechanism that regulate human dental pulp chamber remodeling during tooth development and pathology.
Collapse
Affiliation(s)
- Thimios A Mitsiadis
- Institute of Oral Biology, Department of Orofacial Development and Structure, Faculty of Medicine, University of Zurich, Plattenstrasse 11, 8032 Zurich, Switzerland.
| | | | | |
Collapse
|
20
|
FRISTAD INGE, BLETSA ATHANASIA, BYERS MARGARET. Inflammatory nerve responses in the dental pulp. ACTA ACUST UNITED AC 2007. [DOI: 10.1111/j.1601-1546.2010.00247.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
21
|
Abe K, Miyoshi K, Muto T, Ruspita I, Horiguchi T, Nagata T, Noma T. Establishment and characterization of rat dental epithelial derived ameloblast-lineage clones. J Biosci Bioeng 2007; 103:479-85. [PMID: 17609165 DOI: 10.1263/jbb.103.479] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2007] [Accepted: 02/20/2007] [Indexed: 01/21/2023]
Abstract
Teeth are the hardest tissues covered with enamel produced by ameloblasts. The ameloblast differentiation is controlled by sequential epithelial-mesenchymal interactions during tooth morphogenesis. However, the molecular mechanism of ameloblast differentiation remains unclear. To address this question, we developed an in vitro assay system to evaluate the molecular mechanism of amelogenesis. First, we established dental epithelium-derived clones from 6-day-old rat incisors and established that cells of the clone SRE-G5 were the largest producers of amelogenin mRNA. Next, we analyzed the effects of several chemicals on the amelogenin expression in SRE-G5 cells. Only mitogen-activated protein kinase (MAPK) activators enhanced amelogenin mRNA expression. This finding corresponded to the immunohistochemical data showing the presence of phosphorylated forms of p38, c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK) during ameloblast differentiation. To examine the roles of MAPK signals, we compared the effects of anisomycin and sodium salicylate on the expression of tooth-related differentiation markers. Both anisomycin and sodium salicylate induced amelogenin, Abcg2, and Bmp4 mRNA and down-regulated p75NGFR mRNA. On the other hand, ALP, ectodin, Bmp2 and Fgf8 mRNA were up-regulated only by anisomycin. These results indicate that MAPK signaling functions, at least in part, as the inducer of ameloblast differentiation.
Collapse
Affiliation(s)
- Kaori Abe
- Department of Molecular Biology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan
| | | | | | | | | | | | | |
Collapse
|
22
|
Yongchaitrakul T, Pavasant P. Transforming growth factor-?1 up-regulates the expression of nerve growth factor through mitogen-activated protein kinase signaling pathways in dental pulp cells. Eur J Oral Sci 2007; 115:57-63. [PMID: 17305717 DOI: 10.1111/j.1600-0722.2007.00420.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Transforming growth factor-beta1 (TGF-beta1) and nerve growth factor (NGF) have been detected in pulp tissues after injury and are implicated in the differentiation of odontoblast-like cells and in pulp tissue repair. We examined TGF-beta1-mediated regulation of NGF and investigated its signaling pathways in human dental pulp cells. Analyses by reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) revealed that TGF-beta1 (1 ng ml(-1)) induced NGF mRNA and protein expression through the phosphorylation of p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK). Blockade of the p38 MAPK and JNK pathways with the respective upstream inhibitors (SB203580 and SP600125) abolished the TGF-beta1-mediated induction of NGF. In addition, SB225002, a G-protein-coupled receptor antagonist, and staurosporine, a serine-threonine kinase inhibitor, partially inhibited TGF-beta1-mediated induction of NGF. Phospho-p38 MAPK was suppressed by SB225002, whereas phospho-JNK was inhibited by staurosporine. We conclude that TGF-beta1 up-regulates NGF in human dental pulp cells. This suggests that TGF-beta1 plays a role in NGF regulation during pulp tissue repair. The signal of TGF-beta1 involves the activation of MAPK, especially p38 and JNK. We suggest that crosstalk between TGF-beta1 and G-protein-coupled receptor signaling also participates in the inductive mechanism.
Collapse
|
23
|
Veerayutthwilai O, Luis NA, Crumpton RM, MacDonald GH, Byers MR. Peripherin- and CGRP-immunoreactive nerve fibers in rat molars have different locations and developmental timing. Arch Oral Biol 2006; 51:748-60. [PMID: 16720017 DOI: 10.1016/j.archoralbio.2006.03.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2005] [Revised: 03/10/2006] [Accepted: 03/16/2006] [Indexed: 10/24/2022]
Abstract
UNLABELLED Developing rat molars gain mature sensitivity to electric stimulation at 4-5 weeks after eruption, but the related mechanisms are incompletely understood. Preliminary studies showed weak co-localization of calcitonin gene-related peptide (CGRP) immunoreactivity (IR) with peripherin (PER) or neurofilament protein (NF) in rat molar nerve fibers, while the latter two co-localized extensively. OBJECTIVE Our goal was to compare timing and location of PER-IR and CGRP-IR innervation in rat first molars during tooth maturation. METHODS We used single and double immunocytochemistry to study molars of rats aged 10 days to 1 year. Neural patterns were compared with odontoblast maturation stages, dentinogenesis, formation of cell-free and cell-rich zones, and root closure. RESULTS Spatial and temporal patterns showed that most CGRP-IR and PER-IR have different terminal domains in teeth. PER-IR fibers were well established among immature odontoblasts prior to tooth eruption, but CGRP-IR fibers were absent. Two weeks after eruption of first molars, many CGRP-IR beaded fibers entered dentin, the larger PER-IR fibers began shifting away from odontoblasts towards the pulp, and the symmetrical PER-IR pulpal pattern was being established. The CGRP-IR fibers continued to increase their asymmetric dentinal innervation until root growth was completed, during which time odontoblasts matured, the cell-free and cell-rich zones appeared, and roots closed. CONCLUSIONS Sensory maturation of rat molars coincides with closed root apices, extensive innervation of dentin by CGRP-IR nerve fibers, and the appearance of the mature avascular odontoblast layer next to cell-free and cell-rich zones in the pulp horns.
Collapse
|
24
|
Perrard MH, Vigier M, Damestoy A, Chapat C, Silandre D, Rudkin BB, Durand P. β-nerve growth factor participates in an auto/paracrine pathway of regulation of the meiotic differentiation of rat spermatocytes. J Cell Physiol 2006; 210:51-62. [PMID: 17013810 DOI: 10.1002/jcp.20805] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
NGF appears to be involved in spermatogenesis. However, mice lacking NGF or TrkA genes do not survive more than a few days whereas p75(NTR) knockout mice are viable and fertile. Therefore, we addressed the effect of betaNGF on spermatogenesis by using the systems of rat germ cell culture we established previously. betaNGF did not modify the number of Sertoli cells, pachytene spermatocytes, secondary spermatocytes nor the half-life of round spermatids, but increased the number of secondary meiotic metaphases and decreased the number of round spermatids formed in vitro. These effects of betaNGF were reversible and maximal at about 4 x 10(-11) M. Conversely, K252a, a Trk-specific kinase inhibitor, enhanced the number of round spermatids above that of control cultures. The presence of betaNGF and its receptors TrkA and p75(NTR) was investigated in testis sections, in Sertoli cell and germ cell fractions, and in germ cell and Sertoli cell co-cultures. betaNGF was detected only in germ cells from pachytene spermatocytes of stages VII up to spermatids of stages IX-X. TrkA and p75(NTR) were detected in Sertoli cells and in these germ cells. Taken together, these results indicate that betaNGF should participate in an auto/paracrine pathway of regulation of the second meiotic division of rat spermatocytes in vivo.
Collapse
|
25
|
Morotomi T, Kawano S, Toyono T, Kitamura C, Terashita M, Uchida T, Toyoshima K, Harada H. In vitro differentiation of dental epithelial progenitor cells through epithelial-mesenchymal interactions. Arch Oral Biol 2005; 50:695-705. [PMID: 15958201 DOI: 10.1016/j.archoralbio.2004.12.006] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2004] [Accepted: 12/05/2004] [Indexed: 11/16/2022]
Abstract
In developing teeth, dental epithelial progenitor cells differentiate through sequential and reciprocal interactions with neural-crest-derived mesenchyme. However, the molecular mechanisms involved in cell differentiation are not well understood. Continuously growing teeth are useful in the study of differentiation of dental progenitor cells. In rat lower incisors, ameloblasts originate from the dental epithelial adult stem cell compartment referred to as the 'apical bud'. To elucidate the mechanism of ameloblast differentiation, we designed a primary culture system and confirmed the differentiation of dental epithelial cells through interaction with mesenchymal cells. Cytokeratin was used as a marker for epithelial cells, nerve growth factor receptor p75 for inner enamel epithelial (IEE) cells, and ameloblastin for ameloblasts. The apical bud cells could only differentiate into IEE cells and, within 10 days, into ameloblasts expressing ameloblastin in the presence of dental papilla cells. Interestingly, the IEE cells could proliferate transiently and differentiate into ameloblasts in the presence or absence of dental papilla cells. These results suggest that apical bud cells can enter the ameloblast cell lineage through interaction with mesenchymal cells. IEE cells, on the other hand, are already committed to differentiate into ameloblasts. This culture system is useful in future studies of ameloblast differentiation.
Collapse
Affiliation(s)
- Takahiko Morotomi
- Department of Operative Dentistry and Endodontics, Kyushu Dental College, Kokurakita-ku, Kitakyushu, Japan
| | | | | | | | | | | | | | | |
Collapse
|
26
|
Kettunen P, Løes S, Furmanek T, Fjeld K, Kvinnsland IH, Behar O, Yagi T, Fujisawa H, Vainio S, Taniguchi M, Luukko K. Coordination of trigeminal axon navigation and patterning with tooth organ formation: epithelial-mesenchymal interactions, and epithelial Wnt4 and Tgfbeta1 regulate semaphorin 3a expression in the dental mesenchyme. Development 2004; 132:323-34. [PMID: 15604101 DOI: 10.1242/dev.01541] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
During development, trigeminal nerve fibers navigate and establish their axonal projections to the developing tooth in a highly spatiotemporally controlled manner. By analyzing Sema3a and its receptor Npn1 knockout mouse embryos, we found that Sema3a regulates dental trigeminal axon navigation and patterning, as well as the timing of the first mandibular molar innervation, and that the effects of Sema3a appear to be mediated by Npn1 present in the axons. By performing tissue recombinant experiments and analyzing the effects of signaling molecules, we found that early oral and dental epithelia, which instruct tooth formation, and epithelial Wnt4 induce Sema3a expression in the presumptive dental mesenchyme before the arrival of the first dental nerve fibers. Later, at the bud stage, epithelial Wnt4 and Tgfbeta1 regulate Sema3a expression in the dental mesenchyme. In addition, Wnt4 stimulates mesenchymal expression of Msx1 transcription factor, which is essential for tooth formation, and Tgfbeta1 proliferation of the dental mesenchymal cells. Thus, epithelial-mesenchymal interactions control Sema3a expression and may coordinate axon navigation and patterning with tooth formation. Moreover, our results suggest that the odontogenic epithelium possesses the instructive information to control the formation of tooth nerve supply.
Collapse
Affiliation(s)
- Päivi Kettunen
- Division of Anatomy and Cell Biology, Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Luukko K, Løes S, Kvinnsland IH, Kettunen P. Expression of ephrin-A ligands and EphA receptors in the developing mouse tooth and its supporting tissues. Cell Tissue Res 2004; 319:143-52. [PMID: 15517401 DOI: 10.1007/s00441-004-0951-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2003] [Accepted: 06/22/2004] [Indexed: 10/26/2022]
Abstract
Ephrins are cell-membrane-bound ligands for Eph receptor tyrosine kinases and regulate a variety of developmental processes. In order to investigate the potential roles of the ephrin-Eph system in tooth formation, we studied the cellular mRNA expression of Ephrin-A1-A5 and EphA2, EphA3, EphA4, EphA7, and EphA8 receptors during embryonic histomorphogenesis of the mouse first molar (embryonic days 11.5-18.5). Ephrin-A1, ephrin-A5, EphA2, EphA3, EphA4, and EphA7 were expressed in the tooth germ at the epithelial thickening stage, and later, ephrin-A1, ephrin-A5, EphA2, EphA4, and EphA7 showed distinct expression patterns in the enamel organ undergoing epithelial folding morphogenesis. Prior to birth, ephrin-A1, ephrin-A5, EphA2, and EphA4 transcripts were present in the cuspal area of the dental papilla including the preodontoblasts. In addition, ephrin-A1 and ephrin-A5 were seen in the forming blood vessels and alveolar bone, respectively. In contrast, ephrin-A2, ephrin-A3, and ephrin-A4 showed ubiquitous expression during odontogenesis, whereas EphA8 transcripts were not observed. During dental trigeminal axon pathfinding (embryonic days 12.5-13.5), ephrin-A2, ephrin-A4, and ephrin-A5 were evenly distributed in the trigeminal ganglion, whereas EphA7 was expressed in a subset of ganglion cells. These results suggest regulatory roles for ephrin-A/EphA signaling in the formation of the tooth organ proper and its supporting tissues.
Collapse
Affiliation(s)
- Keijo Luukko
- Section of Anatomy and Cell Biology, Department of Biomedicine, University of Bergen, Jonas Lies Vei 91, 5009 Bergen, Norway
| | | | | | | |
Collapse
|
28
|
Kvinnsland IH, Luukko K, Fristad I, Kettunen P, Jackson DL, Fjeld K, von Bartheld CS, Byers MR. Glial cell line-derived neurotrophic factor (GDNF) from adult rat tooth serves a distinct population of large-sized trigeminal neurons. Eur J Neurosci 2004; 19:2089-98. [PMID: 15090036 DOI: 10.1111/j.0953-816x.2004.03291.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Glial cell line-derived neurotrophic factor (GDNF) mediates trophic effects for specific classes of sensory neurons. The adult tooth pulp is a well-defined target of sensory trigeminal innervation. Here we investigated potential roles of GDNF in the regulation of adult trigeminal neurons and the dental pulp nerve supply of the rat maxillary first molar. Western blot analysis and radioactive 35S-UTP in situ hybridization revealed that GDNF in the dental pulp and its mRNAs were localized with Ngf in the coronal pulp periphery, in particular in the highly innervated subodontoblast layer. Retrograde neuronal transport of iodinated GDNF and Fluorogold (FG) from the dental pulp indicated that GDNF was transported in about one third of all the trigeminal dental neurons. Of the GDNF-labelled neurons, nearly all (97%) were large-sized (> or =35 microm in diameter). Analysis of FG-labelled neurons revealed that, of the trigeminal neurons supporting the adult dental pulp, approximately 20% were small-sized, lacked isolectin B4 binding and did not transport GDNF. Of the large-sized dental trigeminal neurons approximately 40% transported GDNF. About 90% of the GDNF-accumulating neurons were negative for the high-temperature nociceptive marker VRL-1. Our results show that a subclass of large adult trigeminal neurons are potentially dependent on dental pulp-derived GDNF while small dental trigeminal neurons seems not to require GDNF. This suggests that GDNF may function as a neurotrophic factor for subsets of nerves in the tooth, which apparently mediate mechanosensitive stimuli. As in dorsal root ganglia both small- and large-sized neurons are known to be GDNF-dependent; these data provide molecular evidence that the sensory supply in the adult tooth differs, in some aspects, from the cutaneous sensory system.
Collapse
Affiliation(s)
- Inger Hals Kvinnsland
- Department of Anatomy and Cell Biology, University of Bergen, Jonas Liesvei 91, N-5009 Bergen, Norway.
| | | | | | | | | | | | | | | |
Collapse
|
29
|
Mitsiadis TA, Angeli I, James C, Lendahl U, Sharpe PT. Role of Islet1 in the patterning of murine dentition. Development 2003; 130:4451-60. [PMID: 12900460 DOI: 10.1242/dev.00631] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
It is believed that mouse dentition is determined by a prepatterning of the oral epithelium into molar (proximal) and incisor (distal) regions. The LIM homeodomain protein Islet1 (ISL1) is involved in the regulation of differentiation of many cell types and organs. During odontogenesis, we find Islet1 to be exclusively expressed in epithelial cells of the developing incisors but not during molar development. Early expression of Islet1 in presumptive incisor epithelium is coincident with expression of Bmp4, which acts to induce Msx1 expression in the underlying mesenchyme. To define the role of ISL1 in the acquisition of incisor shape, we have analysed regulation of Islet1 expression in mandibular explants. Local application of bone morphogenetic protein 4 (BMP4) in the epithelium of molar territories either by bead implantation or by electroporation stimulated Islet1 expression. Inhibition of BMP signalling with Noggin resulted in a loss of Islet1 expression. Inhibition of Islet1 in distal epithelium resulted in a loss of Bmp4 expression and a corresponding loss of Msx1 expression, indicating that a positive regulatory loop exists between ISL1 and BMP4 in distal epithelium. Ectopic expression of Islet1 in proximal epithelium produces a loss of Barx1 expression in the mesenchyme and resulted in inhibition of molar tooth development. Using epithelial/mesenchymal recombinations we show that at E10.5 Islet1 expression is independent of the underlying mesenchyme whereas at E12.5 when tooth shape specification has passed to the mesenchyme, Islet1 expression requires distal (presumptive incisor) mesenchyme. Islet1 thus plays an important role in regulating distal gene expression during jaw and tooth development.
Collapse
Affiliation(s)
- Thimios A Mitsiadis
- GKT Dental Institute, Kings College London, Guy's Hospital, London SE1 9RT, UK
| | | | | | | | | |
Collapse
|
30
|
Løes S, Luukko K, Hals Kvinnsland I, Salminen M, Kettunen P. Developmentally regulated expression of Netrin-1 and -3 in the embryonic mouse molar tooth germ. Dev Dyn 2003; 227:573-7. [PMID: 12889066 DOI: 10.1002/dvdy.10317] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The Netrins form a small, conserved family of laminin-related signaling proteins regulating axon guidance in the developing nervous system. Here, we analyzed the roles of Netrin-1 and -3 in trigeminal axon guidance to the first lower molar of the embryonic mouse. Netrin-1 showed a restricted epithelial expression domain buccal to the tooth germ, toward which the pioneer tooth axons initially appear to navigate. Later, before birth, transcripts were colocalized with nerve fibers around the bell stage tooth germ. Analysis of Netrin-1-deficient mice, however, did not reveal any obvious disturbances in the axon growth or pattern of tooth innervation. In contrast, Netrin-3 showed a prominent, distinct expression in the axon pathway and target field mesenchyme around the tooth. Hence, it is possible that Netrin-3 may regulate pioneer axon growth toward and within the embryonic tooth target field.
Collapse
Affiliation(s)
- Sigbjørn Løes
- Department of Anatomy and Cell Biology, University of Bergen, Norway
| | | | | | | | | |
Collapse
|
31
|
Ono T, Fischer-Hansen B, Nolting D, KjÆr I. Nerve Growth Factor Receptor Immunolocalization During Human Palate and Tongue Development. Cleft Palate Craniofac J 2003. [DOI: 10.1597/1545-1569(2003)040<0116:ngfrid>2.0.co;2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
|
32
|
Ono T, Fischer-Hansen B, Nolting D, Kjaer I. Nerve growth factor receptor immunolocalization during human palate and tongue development. Cleft Palate Craniofac J 2003; 40:116-25. [PMID: 12605516 DOI: 10.1597/1545-1569_2003_040_0116_ngfrid_2.0.co_2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE To investigate the temporospatial pattern of nerve growth factor receptor (NGFR) immunolocalization during human palatal closure. MATERIALS Human palate and tongue tissues from 33 embryos/fetuses, 9 to 22 weeks of fertilization age. METHODS Tissues were divided according to developmental stage and palatal development (before, during, and after closure) and then subjected to decalcification, paraffin embedding, serial sectioning, survey staining, and p75NGFR immunohistochemical staining. RESULTS Specific temporospatial patterns of p75NGFR reactivity were observed; reactivity was intense in the soft tissue palatal shelves before and during palatal closure and was weaker in the palate after palatal closure. In the tongue, intense reactivity was seen throughout 9 to 22 weeks. CONCLUSION The observed patterns suggest that p75NGFR may enable the visualization of physiological events in palatal closure during normal human development.
Collapse
Affiliation(s)
- Takashi Ono
- Maxillofacial Orthognathics, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan
| | | | | | | |
Collapse
|
33
|
Heymann R, About I, Lendahl U, Franquin JC, Obrink B, Mitsiadis TA. E- and N-cadherin distribution in developing and functional human teeth under normal and pathological conditions. THE AMERICAN JOURNAL OF PATHOLOGY 2002; 160:2123-33. [PMID: 12057916 PMCID: PMC1850842 DOI: 10.1016/s0002-9440(10)61161-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Cadherins are calcium-dependent cell adhesion molecules involved in the regulation of various biological processes such as cell recognition, intercellular communication, cell fate, cell polarity, boundary formation, and morphogenesis. Although previous studies have shown E-cadherin expression during rodent or human odontogenesis, there is no equivalent study available on N-cadherin expression in dental tissues. Here we examined and compared the expression patterns of E- and N-cadherins in both embryonic and adult (healthy, injured, carious) human teeth. Both proteins were expressed in the developing teeth during the cap and bell stages. E-cadherin expression in dental epithelium followed an apical-coronal gradient that was opposite to that observed for N-cadherin. E-cadherin was distributed in proliferating cells of the inner and outer enamel epithelia but not in differentiated cells such as ameloblasts, whereas N-cadherin expression was up-regulated in differentiated epithelial cells. By contrast to E-cadherin, N-cadherin was also expressed in mesenchymal cells that differentiate into odontoblasts and produce the hard tissue matrix of dentin. Although N-cadherin was not detected in permanent intact teeth, it was re-expressed during dentin repair processes in odontoblasts surrounding carious or traumatic sites. Similarly, N-cadherin re-expression was seen in vitro, in cultured primary pulp cells that differentiate into odontoblast-like cells. Taken together these results suggest that E- and N-cadherins may play a role during human tooth development and, moreover, indicate that N-cadherin is important for odontoblast function in normal development and under pathological conditions.
Collapse
Affiliation(s)
- Robert Heymann
- Faculté d'Odontologie de Marseille, Université de la Méditerranée, Marseille, France
| | | | | | | | | | | |
Collapse
|
34
|
Magloire H, Romeas A, Melin M, Couble ML, Bleicher F, Farges JC. Molecular regulation of odontoblast activity under dentin injury. Adv Dent Res 2001; 15:46-50. [PMID: 12640739 DOI: 10.1177/08959374010150011201] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Pulp tissue responds to dentin damage by laying down a tertiary dentin matrix (reactionary or reparative) beneath the site of injury. Reactionary dentin is secreted by surviving odontoblasts in response to environmental stimuli, leading to an increase in metabolic activities of the cells. The inductive molecules that determine the success of the pulp healing may be released from the damaged dentin as well as from the pulp tissue subjacent to the injury. This paper will schematically consider two major growth factors probably implicated in the control of odontoblast activity: TGF beta-1 released from demineralized dentin and NGF from pulp. To analyze their role with an in vitro system that mimics the in vivo situation, we have used thick-sliced teeth cultured as described previously. The supply of factors was accomplished by means of a small tube glued onto the dentin. The tube was filled with TGF beta-1 (20 ng/mL) or NGF (50 ng/mL), and slices were cultured for 4 or 7 days. Results showed that TGF beta-1 binding sites are strongly detected on odontoblasts in the factor-rich zone. A strong expression of alpha 1(I) collagen transcripts was also detected. In the NGF-rich environment, p75NTR was re-expressed on odontoblasts and the transcription factor NF-kappa B activated. Modifications in the odontoblast morphology were observed with an atypical extension of the cell processes filled with actin filaments. These results suggest that odontoblasts respond to influences from both dentin and pulp tissue during pulp repair.
Collapse
Affiliation(s)
- H Magloire
- Laboratoire du Développement des Tissus Dentaires (EA 1892), Faculté d'Odontologie, Rue G, Paradin, 69372 Lyon, France.
| | | | | | | | | | | |
Collapse
|
35
|
Lesot H, Lisi S, Peterkova R, Peterka M, Mitolo V, Ruch JV. Epigenetic signals during odontoblast differentiation. Adv Dent Res 2001; 15:8-13. [PMID: 12640731 DOI: 10.1177/08959374010150012001] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Odontoblast terminal differentiation occurs according to a tooth-specific pattern and implies both temporospatially regulated epigenetic signaling and the expression of specific competence. Differentiation of odontoblasts (withdrawal from the cell cycle, cytological polarization, and secretion of predentin/dentin) is controlled by the inner dental epithelium, and the basement membrane (BM) plays a major role both as a substrate and as a reservoir of paracrine molecules. Cytological differentiation implies changes in the organization of the cytoskeleton and is controlled by cytoskeleton-plasma membrane-extracellular matrix interactions. Fibronectin is re-distributed during odontoblast polarization and interacts with cell-surface molecules. A non-integrin 165-kDa fibronectin-binding protein, transiently expressed by odontoblasts, is involved in microfilament reorganization. Growth factors (TGF beta 1, 2, 3/BMP2, 4, and 6), expressed in tooth germs, signal differentiation. Systemically derived molecules (IGF1) may also intervene. IGF1 stimulates cytological but not functional differentiation of odontoblasts: The two events can thus be separated. Immobilized TGF beta 1 (combined with heparin) induced odontoblast differentiation. Only immobilized TGF beta 1 and 3 or a combination of FGF1 and TGF beta 1 stimulated the differentiation of functional odontoblasts over extended areas and allowed for maintenance of gradients of differentiation. Presentation of active molecules in vitro appeared to be of major importance; the BM should fulfill this role in vivo by immobilizing and spatially presenting TGF beta s. Attempts are being made to investigate the mechanisms which spatially control the initiation of odontoblast differentiation and those which regulate its propagation. Analysis of molar development suggested that odontoblast differentiation and crown morphogenesis are interdependent, although the possibility of co-regulation requires further investigation.
Collapse
Affiliation(s)
- H Lesot
- INSERM U424, Institut de Biologie Médicale, Faculté de Médecine, II, rue Humann, 67085 Strasbourg, France.
| | | | | | | | | | | |
Collapse
|
36
|
Fried K, Nosrat C, Lillesaar C, Hildebrand C. Molecular signaling and pulpal nerve development. CRITICAL REVIEWS IN ORAL BIOLOGY AND MEDICINE : AN OFFICIAL PUBLICATION OF THE AMERICAN ASSOCIATION OF ORAL BIOLOGISTS 2001; 11:318-32. [PMID: 11021633 DOI: 10.1177/10454411000110030301] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The purpose of this review is to discuss molecular factors influencing nerve growth to teeth. The establishment of a sensory pulpal innervation occurs concurrently with tooth development. Epithelial/mesenchymal interactions initiate the tooth primordium and change it into a complex organ. The initial events seem to be controlled by the epithelium, and subsequently, the mesenchyme acquires odontogenic properties. As yet, no single initiating epithelial or mesenchymal factor has been identified. Axons reach the jaws before tooth formation and form terminals near odontogenic sites. In some species, local axons have an initiating function in odontogenesis, but it is not known if this is also the case with mammals. In diphyodont mammals, the primary dentition is replaced by a permanent dentition, which involves a profound remodeling of terminal pulpal axons. The molecular signals underlying this remodeling remain unknown. Due to the senescent deterioration of the dentition, the target area of tooth nerves shrinks with age, and these nerves show marked pathological-like changes. Nerve growth factor and possibly also brain-derived neurotrophic factor seem to be important in the formation of a sensory pulpal innervation. Neurotrophin-3 and -4/5 are probably not involved. In addition, glial cell line-derived neurotrophic factor, but not neurturin, seems to be involved in the control of pulpal axon growth. A variety of other growth factors may also influence developing tooth nerves. Many major extracellular matrix molecules, which can influence growing axons, are present in developing teeth. It is likely that these molecules influence the growing pulpal axons.
Collapse
Affiliation(s)
- K Fried
- Department of Neuroscience, Karolinska Institute, Stockholm, Sweden.
| | | | | | | |
Collapse
|
37
|
About I, Laurent-Maquin D, Lendahl U, Mitsiadis TA. Nestin expression in embryonic and adult human teeth under normal and pathological conditions. THE AMERICAN JOURNAL OF PATHOLOGY 2000; 157:287-95. [PMID: 10880398 PMCID: PMC1850197 DOI: 10.1016/s0002-9440(10)64539-7] [Citation(s) in RCA: 155] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Nestin is an intermediate filament most related to neurofilaments and expressed predominantly in the developing nervous system and muscles. In the present study we examined the in vivo distribution of nestin in human teeth during embryonic development and in permanent teeth under normal and pathological conditions. The results show that nestin is first expressed at the bell stage and that its distribution is restricted in pulpal cells located at the cusp area of the fetal teeth. In young permanent teeth, nestin is found only in functional odontoblasts, which produce the hard tissue matrix of dentin. Expression is progressively down-regulated and nestin is absent from older permanent teeth. In carious and injured teeth, nestin expression is up-regulated in a selective manner in odontoblasts surrounding the injury site, showing a link between tissue repair competence and nestin up-regulation under pathological conditions. In an in vitro assay system of human dental pulp explants, nestin is up-regulated after local application of bone morphogenic protein-4. A similar effect is seen in cultures of primary pulp cells during their differentiation into odontoblasts. Taken together, these results suggest that nestin plays a potential role in odontoblast differentiation during normal and pathological conditions and that bone morphogenic protein-4 is involved in nestin up-regulation.
Collapse
Affiliation(s)
- I About
- Laboratoire Interface Matrice Extracellulaire Biomatériaux, Equipe d'Acceuil 2198, Université de la Méditerranée, Marseille, France
| | | | | | | |
Collapse
|
38
|
Byers MR, Närhi MV. Dental injury models: experimental tools for understanding neuroinflammatory interactions and polymodal nociceptor functions. CRITICAL REVIEWS IN ORAL BIOLOGY AND MEDICINE : AN OFFICIAL PUBLICATION OF THE AMERICAN ASSOCIATION OF ORAL BIOLOGISTS 2000; 10:4-39. [PMID: 10759425 DOI: 10.1177/10454411990100010101] [Citation(s) in RCA: 199] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Recent research has shown that peripheral mechanisms of pain are much more complex than previously thought, and they differ for acutely injured normal tissues compared with chronic inflammation or neuropathic (nerve injury) pain. The purpose of the present review is to describe uses of dental injury models as experimental tools for understanding the normal functions of polymodal nociceptive nerves in healthy tissues, their neuroinflammatory interactions, and their roles in healing. A brief review of normal dental innervation and its interactions with healthy pulp tissue will be presented first, as a framework for understanding the changes that occur after injury. Then, the different types of dental injury that allow gradation of the extent of tissue damage will be described, along with the degree and duration of inflammation, the types of reactions in the trigeminal ganglion and brainstem, and the type of healing. The dental injury models have some unique features compared with neuroinflammation paradigms that affect other peripheral tissues such as skin, viscera, and joints. Peripheral inflammation models can all be contrasted to nerve injury studies that produce a different kind of neuroplasticity and neuropathic pain. Each of these models provides different insights about the normal and pathologic functions of peripheral nerve fibers and their effects on tissue homeostasis, inflammation, and wound healing. The physical confinement of dental pulp and its innervation within the tooth, the high incidence of polymodal A-delta and C-fibers in pulp and dentin, and the somatotopic organization of the trigeminal ganglion provide some special advantages for experimental design when dental injury models are used for the study of neuroinflammatory interactions.
Collapse
Affiliation(s)
- M R Byers
- Department of Anesthesiology, University of Washington, Seattle 98195-6540, USA
| | | |
Collapse
|
39
|
Shiomi H, Ohsaki Y, Akamine A, Iijima T. The Re-Expression of Nerve Growth Factor Protein after Cavity Preparation in Rat Molars. Acta Histochem Cytochem 2000. [DOI: 10.1267/ahc.33.393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Hisashi Shiomi
- Department of Oral Anatomy and Cell Biology, Faculty of Dental Science, Kyushu University
- Department of Endodontology and Operative Dentistry, Faculty of Dental Science, Kyushu University
| | - Yasuyoshi Ohsaki
- Department of Oral Anatomy and Cell Biology, Faculty of Dental Science, Kyushu University
| | - Akifumi Akamine
- Department of Endodontology and Operative Dentistry, Faculty of Dental Science, Kyushu University
| | - Tadahiko Iijima
- Department of Oral Anatomy and Cell Biology, Faculty of Dental Science, Kyushu University
| |
Collapse
|
40
|
Amano O, Bringas P, Takahashi I, Takahashi K, Yamane A, Chai Y, Nuckolls GH, Shum L, Slavkin HC. Nerve growth factor (NGF) supports tooth morphogenesis in mouse first branchial arch explants. Dev Dyn 1999; 216:299-310. [PMID: 10590481 DOI: 10.1002/(sici)1097-0177(199911)216:3<299::aid-dvdy8>3.0.co;2-b] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Posterior midbrain and anterior hindbrain neuroectoderm trans-differentiate into cranial neural crest cells (CNCC), emigrate from the neural folds, and become crest-derived ectomesenchyme within the mandibular and maxillary processes. To investigate the growth factor requirement specific for the initiation of tooth morphogenesis, we designed studies to test whether nerve growth factor (NGF) can support odontogenesis in a first branchial arch (FBA) explant culture system. FBA explants containing neural-fold tissues before CNCC emigration and the anlagen of the FBA were microdissected from embryonic day 8 (E8) mouse embryos, and cultured for 8 days in medium supplemented with 10% fetal calf serum only, or serum-containing medium further supplemented with either NGF or epidermal growth factor (EGF) at three different concentrations: 50, 100, or 200 ng/ml. Morphological, morphometric, and total protein analyses indicated that growth and development in all groups were comparable. Meckel's cartilage and tongue formation were also observed in all groups. However, odontogenesis was only detected in explants cultured in the presence of exogenous NGF. NGF-supplemented cultures were permissive for bud stage (50 ng/ml) as well as cap stage of tooth morphogenesis (100 and 200 ng/ml). Morphometric analyses of the volume of tooth organs showed a significant dose-dependent increase in tooth volume as the concentration of NGF increased. Whole-mount in situ hybridization and semiquantitative reverse transcription-polymerase chain reaction for Pax9, a molecular marker of dental mesenchyme, further supported and confirmed the morphological data of the specificity and dose dependency of NGF on odontogenesis. We conclude that (1) E8 FBA explants contain premigratory CNCC that are capable of emigration, proliferation, and differentiation in vitro; (2) serum-supplemented medium is permissive for CNCC differentiation into tongue myoblasts and chondrocytes in FBA explants; and (3) NGF controls CNCC cell fate specification and differentiation into tooth organs.
Collapse
Affiliation(s)
- O Amano
- Center for Craniofacial Molecular Biology, School of Dentistry, University of Southern California, Los Angeles, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Luukko K, Saarma M, Thesleff I. Neurturin mRNA expression suggests roles in trigeminal innervation of the first branchial arch and in tooth formation. Dev Dyn 1998; 213:207-19. [PMID: 9786421 DOI: 10.1002/(sici)1097-0177(199810)213:2<207::aid-aja6>3.0.co;2-k] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Neurturin (NTN) is a recently characterized member of the glial cell line-derived neurotrophic factor (GDNF)-family which, like GDNF, can promote the survival of certain populations of neuronal cells in peripheral and central nervous systems. To elucidate the roles of NTN and a novel glycosyl-phosphatidylinositol (GPI)-linked receptor protein GFRalpha-3, a member of GDNF-family receptor alpha, in the regulation of peripheral trigeminal innervation and tooth formation, their expression patterns during mouse embryonic (E) and early postnatal (P) development (E10-P5) of the first branchial arch were analyzed by in situ hybridization. NTN mRNAs were observed in oral and cutaneous epithelia of the mandibular process at all studied stages and expression became gradually restricted to the suprabasal epithelial cells. In addition, transcripts were also detected in the epithelium of whisker follicles. In the developing first molar tooth germ, NTN showed a developmentally regulated, spatiotemporally changing expression pattern, which partially correlated with the development of innervation. During the initiation of tooth formation NTN mRNAs were expressed in dental epithelium and during later embryonic development transcripts appeared in the dental papilla mesenchyme. In addition, some transcripts were seen in the dental follicle. During postnatal development, NTN expression was restricted to the dental follicle of the incisor tooth germs. GFRalpha-3 mRNAs were not detected in teeth, but an intense expression was seen in non-neuronal cells surrounding trigeminal nerve fibers and in the trigeminal ganglia during E11-E15. Ganglion explant cultures showed that trigeminal neurons start to respond to exogenous NTN at E12, which correlates to the earlier reported appearance of the Ret-tyrosine kinase receptor in the trigeminal ganglion. Local application of NTN with beads on isolated dental mesenchyme did not stimulate cell proliferation or prevent apoptotic cell death. In addition, exogenous NTN had no effects on tooth morphogenesis in in vitro cultures. Taken together, because trigeminal neurons respond to NTN after first axons have reached their primary epithelial target fields, NTN is apparently not involved in the guidance of pioneer trigeminal nerves to their peripheral targets. However, our results show that NTN is a potent neuritogenic factor and, therefore, may act as a target-field-derived neurotrophic factor for trigeminal nerves during innervation of the cutaneous and oral epithelia as well as dental follicle surrounding the developing tooth. In addition, although NTN appears not to be directly involved in the regulation of tooth morphogenesis, it may have non-neuronal, organogenetic functions during tooth formation.
Collapse
Affiliation(s)
- K Luukko
- Program of Developmental Biology, Institute of Biotechnology, University of Helsinki, Finland.
| | | | | |
Collapse
|
42
|
Luukko K, Suvanto P, Saarma M, Thesleff I. Expression of GDNF and its receptors in developing tooth is developmentally regulated and suggests multiple roles in innervation and organogenesis. Dev Dyn 1997; 210:463-71. [PMID: 9415430 DOI: 10.1002/(sici)1097-0177(199712)210:4<463::aid-aja9>3.0.co;2-e] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Glial cell line-derived neurotrophic factor (GDNF) is a recently identified survival factor for several populations of neurons in the central and peripheral nervous system that also regulates kidney development. To study the roles of GDNF in the regulation of tooth innervation and formation, we analyzed by in situ hybridization the expression patterns of GDNF and its receptors Ret, GDNF family receptor alpha-1 (GFRalpha-1), and GFRalpha-2 from the initiation of first molar formation to the completion of crown morphogenesis. At the time of trigeminal axon ingrowth, GDNF mRNAs were expressed in the mesenchyme around the tooth germ (i.e., target field of the dental innervation), suggesting that it is involved in the regulation of the embryonic tooth innervation. This hypothesis was supported by the ability of GDNF to induce neurite outgrowth from embryonic day 12 (E12) to E15 trigeminal ganglia. This timing correlated with the appearance of Ret in the subset of cells in the trigeminal ganglion at E12, whereas GFRalpha-1 and GFRalpha-2 receptors were constantly expressed in trigeminal ganglion during E11-E15. After birth, GDNF expression showed apparent correlation with the ingrowth and presence of trigeminal nerve fibers in the tooth, suggesting that GDNF is involved in the regulation of innervation of the dental papilla and dentin postnatally. Ret, GFRalpha-1, and GFRalpha-2 mRNAs were expressed in the dental epithelial and mesenchymal cells at stages when epithelial-mesenchymal signalling regulates critical steps of tooth morphogenesis. Ret and GFRalpha-2 were colocalized in the dental mesenchyme during bud and cap stages. Expression of GFRalpha-1 associated with the formation of the epithelial enamel knot, which is a putative embryonic signalling center regulating tooth shape. During postnatal development, GDNF and its receptors were expressed in dental papilla mesenchyme. In addition, GDNF and GFRalpha-1 transcripts were seen in the preodontoblasts and odontoblasts, suggesting that they may be involved in differentiation and maintenance of functional properties of the odontoblasts. Taken together, these results suggest that GDNF acts as a target-derived neurotrophic factor during tooth innervation. In addition, GDNF and its receptors may have nonneuronal organogenetic functions during tooth morphogenesis.
Collapse
Affiliation(s)
- K Luukko
- Program of Developmental Biology, Institute of Biotechnology, University of Helsinki, Finland.
| | | | | | | |
Collapse
|
43
|
Luukko K, Arumäe U, Karavanov A, Moshnyakov M, Sainio K, Sariola H, Saarma M, Thesleff I. Neurotrophin mRNA expression in the developing tooth suggests multiple roles in innervation and organogenesis. Dev Dyn 1997; 210:117-29. [PMID: 9337133 DOI: 10.1002/(sici)1097-0177(199710)210:2<117::aid-aja5>3.0.co;2-j] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
To analyze the roles of neurotrophins during early development of rat teeth, we studied the expression of neurotrophin mRNAs from the initiation of first molar formation to the completion of crown morphogenesis. With RNAase protection assay all neurotrophin mRNAs were detected in embryonic teeth. In situ hybridization analysis revealed developmentally changing, distinct expression patterns for nerve growth factor (NGF) and neurotrophin-3 (NT-3), which were shown not to be regulated by or dependent on peripheral innervation. NGF mRNAs appeared in the mesenchymal target field of the tooth at the time of the trigeminal axon ingrowth (embryonic days 14-15: E14-E15), and they were also present along the pathway taken by growing trigeminal axons. NT-4/5 mRNAs were uniformly expressed in all epithelial cells, but brain-derived neurotrophic factor (BDNF) transcripts were not detected. All neurotrophins induced neurite outgrowth from E13-E16 trigeminal ganglion explants. These results suggest that NGF is involved in the guidance of trigeminal axons to embryonic teeth. In postnatal teeth, expression of NGF mRNAs, but not other neurotrophins, correlated with trigeminal axon ingrowth, proposing that NGF is involved in local sprouting and establishment of the final innervation pattern of the dental papilla and dentin. These results suggest that NGF is required for tooth innervation and that other neurotrophins may also have regulatory roles. In addition, the expression patterns of NGF, NT-3, and NT-4/5 as well as of neurotrophin receptors suggest that the neurotrophin system may also serve non-neuronal functions during tooth development.
Collapse
Affiliation(s)
- K Luukko
- Program of Developmental Biology, Institute of Biotechnology, University of Helsinki, Finland.
| | | | | | | | | | | | | | | |
Collapse
|
44
|
Abstract
Oral tissues including the periodontal ligament, gingiva, and tooth pulp have a relatively dense sensory innervation and a rich vascular supply. Teeth and supporting tissues are susceptible to tissue injury and inflammation, partly due to lack of collateral blood and nerve supply and to their low compliance. This review focuses on dental nerve functions and adaptive changes in the trigeminal ganglion and tooth pulp after peripheral injuries. An overview of the peptidergic innervation of oral tissues is presented, followed by a discussion of plasticity in neuropeptide expression in trigeminal peripheral neurons after local insults to teeth and peripheral nerve injuries. The functional implications of these adaptive changes are considered, with special reference to nerve regeneration, inflammation, and hemodynamic regulation.
Collapse
Affiliation(s)
- I Fristad
- Department of Odontology-Endodontics, School of Dentistry, University of Bergen, Norway
| |
Collapse
|
45
|
Maas R, Bei M. The genetic control of early tooth development. CRITICAL REVIEWS IN ORAL BIOLOGY AND MEDICINE : AN OFFICIAL PUBLICATION OF THE AMERICAN ASSOCIATION OF ORAL BIOLOGISTS 1997; 8:4-39. [PMID: 9063623 DOI: 10.1177/10454411970080010101] [Citation(s) in RCA: 177] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Most vertebrate organs begin their initial formation by a common, developmentally conserved pattern of inductive tissue interactions between two tissues. The developing tooth germ is a prototype for such inductive tissue interactions and provides a powerful experimental system for elucidation of the genetic pathways involved in organogenesis. Members of the Msx homeobox gene family are expressed at sites of epithelial-mesenchymal interaction during embryogenesis, including the tooth. The important role that Msx genes play in tooth development is exemplified by mice lacking Msx gene function. Msxl-deficient mice exhibit an arrest in tooth development at the bud stage, while Msx2-deficient mice exhibit late defects in tooth development. The co-expression of Msx, Bmp, Lefl, and Activin beta A genes and the coincidence of tooth phenotypes in the various knockout mice suggest that these genes reside within a common genetic pathway. Results summarized here indicate that Msxl is required for the transmission of Bmp4 expression from dental epithelium to mesenchyme and also for Lefl expression. In addition, we consider the role of other signaling molecules in the epithelial-mesenchymal interactions leading to tooth formation, the role that transcription factors such as Msx play in the propagation of inductive signals, and the role of extracellular matrix. Last, as a unifying mechanism to explain the disparate tooth phenotypes in Msxl- and Msx2-deficient mice, we propose that later steps in tooth morphogenesis molecularly resemble those in early tooth development.
Collapse
Affiliation(s)
- R Maas
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | | |
Collapse
|
46
|
Luukko K, Moshnyakov M, Sainio K, Saarma M, Sariola H, Thesleff I. Expression of neurotrophin receptors during rat tooth development is developmentally regulated, independent of innervation, and suggests functions in the regulation of morphogenesis and innervation. Dev Dyn 1996; 206:87-99. [PMID: 9019249 DOI: 10.1002/(sici)1097-0177(199605)206:1<87::aid-aja8>3.0.co;2-x] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Low-affinity neurotrophin receptor (LANR) and trk receptor tyrosine kinases (trks) serve as low- and high-affinity receptors for neurotrophins. Besides promoting the development and maintenance of the mammalian nervous system, it has been suggested that neurotrophins may have broader functions in the development of non-neuronal tissues. To evaluate the possible roles of neurotrophic factors in tooth development, we performed a detailed examination of the expression patterns of neurotrophin receptors during development of the rat tooth from initiation to completion of crown morphogenesis. mRNA expression was studied by in situ hybridisation and LANR protein was localised by immunohistochemistry. Furthermore, dissected tooth germs were cultured in vitro to examined the role of trigeminal innervation in the expression of neurotrophin receptors. mRNAs for LANR, trkB, and trkC, but not trkA, were detected in developing teeth. LANR and the truncated form of trkB, which lacks the intracellular tyrosine kinase domain, were expressed throughout tooth morphogenesis and their expression patterns were largely non-overlapping and changed spatio-temporally. trkC was expressed after birth, and it was restricted to dental papilla mesenchyme. The expression of all receptors correlated with the development of innervation, but, in addition, the expression of LANR and trkB appeared to be associated with cell differentiation and epithelial-mesenchymal interactions. The patterns of LANR, trkB, and trkC in teeth which underwent morphogenesis in organ culture were similar to those in vivo, which indicates that the expression of these neurotrophin receptors is not regulated by and does not depend on trigeminal innervation. The data suggest that neurotrophin receptors have roles in the development of tooth innervation, but that they also have non-neuronal, organogenetic functions.
Collapse
MESH Headings
- Aging/metabolism
- Animals
- Animals, Newborn/growth & development
- Animals, Newborn/metabolism
- Embryo, Mammalian/metabolism
- Embryonic and Fetal Development
- Nervous System/embryology
- Nervous System/growth & development
- Nervous System Physiological Phenomena
- Organ Culture Techniques
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptor Protein-Tyrosine Kinases/genetics
- Receptor, Ciliary Neurotrophic Factor
- Receptor, trkA/genetics
- Receptor, trkC
- Receptors, Nerve Growth Factor/genetics
- Receptors, Nerve Growth Factor/metabolism
- Tissue Distribution
- Tooth/embryology
- Tooth/innervation
- Tooth/metabolism
- Tooth Germ/metabolism
Collapse
Affiliation(s)
- K Luukko
- Department of Pedodontics and Orthodontics, Institute of Dentistry, University of Helsinki, Finland
| | | | | | | | | | | |
Collapse
|
47
|
Tabata MJ, Kim K, Liu JG, Yamashita K, Matsumura T, Kato J, Iwamoto M, Wakisaka S, Matsumoto K, Nakamura T, Kumegawa M, Kurisu K. Hepatocyte growth factor is involved in the morphogenesis of tooth germ in murine molars. Development 1996; 122:1243-51. [PMID: 8620851 DOI: 10.1242/dev.122.4.1243] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The patterns of gene expression for hepatocyte growth factor (HGF) and its receptor, c-Met, were revealed in the tooth germ of rat mandibular molars using RT-PCR. In situ hybridization demonstrated that the HGF gene was expressed only in the cells of the dental papilla of the tooth germ in vivo. The characteristic temporospatial distribution of HGF and c-Met during germ development was revealed using immunohistochemical studies in vivo. In order to demonstrate the functional role played by HGF in tooth development, HGF translation arrest by antisense phosphorothioate oligodeoxynucleotide (ODN) was carried out in vitro. In the control experiment, explants of tooth germs from embryonic 14 day mice were cultured in a modification of Trowell's system under serum-free and chemically defined conditions for two weeks. Other explants were cultured with 15mer antisense or sense ODN targeted to the HGF mRNA. Both the control and the sense-treated explants showed normal histological structure, as observed in vivo. On the other hand, antisense-treated explants exhibited an abnormal structure in which the enamel organs were surrounded by a thin layer of dentin and dental papilla, appearing ‘inside-out’ compared to the control and sense-treated explants, although the cytodifferentiation of ameloblasts and odontoblasts was not inhibited. The explants treated with recombinant human HGF combined with antisense ODN showed normal development, indicating that exogenous HGF rescued the explants from the abnormal structure caused by antisense ODN. The findings of a BrdU incorporation experiment suggested that the imbalance between the proliferation activity of the inner enamel epithelium and that of the dental papilla caused by HGF translation arrest results in the abnormal structure of the tooth germ. These results indicate that HGF is involved in the morphogenesis of the murine molar.
Collapse
Affiliation(s)
- M J Tabata
- Department of Oral Anatomy and Developmental Biology, Osaka University Faculty of Dentistry, Suita, Japan
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Weil M, Itin A, Keshet E. A role for mesenchyme-derived tachykinins in tooth and mammary gland morphogenesis. Development 1995; 121:2419-28. [PMID: 7545574 DOI: 10.1242/dev.121.8.2419] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Tachykinin peptides such as substance P (SP) function as neurotransmitters and neuromodulators in the mammalian central and peripheral nervous systems. Here, we provide evidence that they may also play an important role in the morphogenesis of some nonneural organs where epithelial-mesenchymal interactions are involved. We show the following. (1) mRNA encoding tachykinin precursor proteins is expressed transiently in condensing mesenchyme during the development of mouse tooth germ, mammary gland, limb bud, external auditory meatus and genital tubercle. (2) In developing tooth germ and mammary gland; mRNA encoding the neutral endopeptidase (NEP) that degrades secreted tachykinins is spatially and temporally co-expressed with tachykinin precursor mRNA. (3) SP and the mRNA encoding SP receptors are also expressed in the developing tooth germ. (4) Tooth development in explant cultures is blocked both by tachykinin-precursor-specific antisense oligonucleotide and by an SP receptor antagonist: in both cases the block is relieved by exogenous SP. Together, these findings suggest a surprising new role for tachykinins in tooth and mammary gland morphogenesis, and possibly also in limb, ear and external genitalia morphogenesis.
Collapse
Affiliation(s)
- M Weil
- Department of Molecular Biology, Hebrew University, Hadassah Medical School, Jerusalem, Israel
| | | | | |
Collapse
|
49
|
Mitsiadis TA, Lardelli M, Lendahl U, Thesleff I. Expression of Notch 1, 2 and 3 is regulated by epithelial-mesenchymal interactions and retinoic acid in the developing mouse tooth and associated with determination of ameloblast cell fate. J Biophys Biochem Cytol 1995; 130:407-18. [PMID: 7615640 PMCID: PMC2199945 DOI: 10.1083/jcb.130.2.407] [Citation(s) in RCA: 148] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Notch 1, Notch 2, and Notch 3 are three highly conserved mammalian homologues of the Drosophila Notch gene, which encodes a transmembrane protein important for various cell fate decisions during development. Little is yet known about regulation of mammalian Notch gene expression, and this issue has been addressed in the developing rodent tooth during normal morphogenesis and after experimental manipulation. Notch 1, 2, and 3 genes show distinct cell-type specific expression patterns. Most notably, Notch expression is absent in epithelial cells in close contact with mesenchyme, which may be important for acquisition of the ameloblast fate. This reveals a previously unknown prepatterning of dental epithelium at early stages, and suggests that mesenchyme negatively regulates Notch expression in epithelium. This hypothesis has been tested in homo- and heterotypic explant experiments in vitro. The data show that Notch expression is downregulated in dental epithelial cells juxtaposed to mesenchyme, indicating that dental epithelium needs a mesenchyme-derived signal in order to maintain the downregulation of Notch. Finally, Notch expression in dental mesenchyme is upregulated in a region surrounding beads soaked in retinoic acid (50-100 micrograms/ml) but not in fibroblast growth factor-2 (100-250 micrograms/ml). The response to retinoic acid was seen in explants of 11-12-d old mouse embryos but not in older embryos. These data suggest that Notch genes may be involved in mediating some of the biological effects of retinoic acid during normal development and after teratogenic exposure.
Collapse
Affiliation(s)
- T A Mitsiadis
- Department of Pedodontics and Orthodontics, University of Helsinki, Finland
| | | | | | | |
Collapse
|
50
|
Mitsiadis TA, Muramatsu T, Muramatsu H, Thesleff I. Midkine (MK), a heparin-binding growth/differentiation factor, is regulated by retinoic acid and epithelial-mesenchymal interactions in the developing mouse tooth, and affects cell proliferation and morphogenesis. J Biophys Biochem Cytol 1995; 129:267-81. [PMID: 7698992 PMCID: PMC2120373 DOI: 10.1083/jcb.129.1.267] [Citation(s) in RCA: 110] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Midkine (MK) is the first cloned gene in a new family of heparin-binding growth/differentiation factors involved in the regulation of growth and differentiation. We have analyzed the expression of MK mRNA and protein during tooth development in mouse embryos and studied the regulation of MK expression and the biological effects of MK protein in organ cultures. MK expression was restricted and preferential in the tooth area as compared to the rest of the developing maxillary and mandibular processes suggesting specific functions for MK during tooth morphogenesis. MK mRNA and protein were expressed during all stages of tooth formation (initiation, morphogenesis, and cell differentiation), and shifts of expression were observed between the epithelial and mesenchymal tissue components. However, the expression of mRNA and protein showed marked differences at some stages suggesting paracrine functions for MK. Tissue recombination experiments showed that MK gene and protein expression are regulated by epithelial-mesenchymal interactions, and, moreover, that dental tissue induces the ectopic expression of MK protein in non-dental tissue. The expression of MK gene and protein in the mandibular arch mesenchyme from the tooth region were stimulated by local application of retinoic acid in beads. Cell proliferation was inhibited in dental mesenchyme around the beads releasing MK, but this effect was modulated by simultaneous application of FGF-2. Morphogenesis and cell differentiation were inhibited in tooth germs cultured in the presence of neutralizing antibodies for MK, whereas the development of other organs (e.g., salivary gland, kidney) was unaffected. These results suggest important roles for MK in the molecular cascade that regulates tooth development.
Collapse
Affiliation(s)
- T A Mitsiadis
- Department of Pedodontics and Orthodontics, University of Helsinki, Finland
| | | | | | | |
Collapse
|