@article{oai:niigata-u.repo.nii.ac.jp:00001549,
 author = {Nakasone, Naohiro and Yoshie, Hiromasa and Ohshima, Hayato},
 issue = {5},
 journal = {Archives of Oral Biology, Archives of Oral Biology},
 month = {May},
 note = {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 one, BrdU-immunoreactive cells were densely located in the inner enamel epithelium in the cervical loop and inter-cusped 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.},
 pages = {378--386},
 title = {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},
 volume = {51},
 year = {2006}
}