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The relationship between the termination of cell proliferation and expression of heat‐shock protein‐25 in the rat developing tooth germ
Author(s) -
Nakasone Naohiro,
Yoshie Hiromasa,
Ohshima Hayato
Publication year - 2006
Publication title -
european journal of oral sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.802
H-Index - 93
eISSN - 1600-0722
pISSN - 0909-8836
DOI - 10.1111/j.1600-0722.2006.00362.x
Subject(s) - odontoblast , ameloblast , biology , cell growth , microbiology and biotechnology , heat shock protein , molar , morphogenesis , immunohistochemistry , mesenchymal stem cell , pathology , andrology , enamel paint , immunology , dentin , medicine , dentistry , genetics , paleontology , gene
Odontoblast‐ and ameloblast‐lineage cells acquire heat‐shock protein (HSP)‐25 immunoreactivity after they complete cell division during postnatal odontogenesis in rat molars. However, there are no data available concerning the relationship between the termination of cell proliferation and HSP‐25 immunoreactivity during tooth morphogenesis. We compared the expression of HSP‐25 in tooth germs with their proliferative activity in the rat prenatal to perinatal molar and postnatal incisor to clarify the functional significance of HSP‐25 during tooth morphogenesis by immunohistochemistry using anti‐HSP‐25 and anti‐Ki67/5‐bromo‐2′‐deoxyuridine (BrdU). Numerous proliferating cells in developing molars were distributed throughout the tooth germ and HSP‐25 immunoreactivity was recognizable in the dental epithelial and mesenchymal cells after they completed cell division. However, both cell proliferation and immunoreaction for HSP‐25 are absent in the enamel knots. The distribution pattern of the proliferating cells in the incisors was basically identical to that in the prenatal molars except for the lack of non‐proliferating secondary enamel knots and the sparse distribution of proliferating cells in the apical bud. Thus, HSP‐25 protein is suggested to act as a switch between cell proliferation and terminal cyto‐differentiation during odontogenesis.