An immunohistochemical study of the expression of heat-shock protein-25 and cell proliferation in the dental pulp and enamel organ during odontogenesis in rat molars.
Arch Oral Biol
; 51(5): 378-86, 2006 May.
Article
em En
| MEDLINE
| ID: mdl-16259940
ABSTRACT
OBJECTIVES:
The aim of this study is to clarify the functional significance of heat-shock protein (HSP)-25 during tooth development.DESIGN:
We compared the expression of HSP-25 in the dental epithelial and mesenchymal cells with their proliferative activity during odontogenesis in rat molars on postnatal days 1-100 by immunohistochemistry using anti-HSP-25 and anti-5-bromo-2'-deoxyuridine (BrdU) for cell proliferation assay.RESULTS:
On day 1, BrdU-immunoreactive cells were densely located in the inner enamel epithelium in the cervical loop and intercusped areas and the dental pulp adjacent to them, whereas HSP-25-immunoractivity (IR) was restricted to the cusped area where odontoblasts and ameloblasts had already differentiated. Subsequently, BrdU-IR shifted in the apical direction to be localized around Hertwig's epithelial root sheath during days 5-30, never overlapping with concomitantly apically-shifted HSP-25-IR. On days 60-100, BrdU-immunoreactive cells were hardly recognizable in the dental pulp, where HSP-25-IR was exclusively localized in the odontoblast layer. Furthermore, the odontoblast- and ameloblast-lineage cells exhibited two steps in the expression of HSP-25 throughout the postnatal stages first, dental epithelial and pulpal mesenchymal cells showed a weak IR for HSP-25 after the cessation of their proliferative activity, and subsequently odontoblasts and ameloblasts consistently expressed an intense HSP-25-IR.CONCLUSION:
Odontoblast- and ameloblast-lineage cells acquire HSP-25-IR after they complete their cell division, suggesting that this protein acts as a switch between cell proliferation and differentiation during tooth development. The consistent expression of HSP-25-IR in the formative cells may be involved in the maintenance of their functional integrity.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Polpa Dentária
/
Órgão do Esmalte
/
Proteínas de Choque Térmico
/
Dente Molar
/
Proteínas de Neoplasias
/
Odontogênese
Limite:
Animals
Idioma:
En
Revista:
Arch Oral Biol
Ano de publicação:
2006
Tipo de documento:
Article
País de afiliação:
Japão