| Co-Investigator(Kenkyū-buntansha) |
ISHIWARI Yuzo Okayama University, Dental School, Assistant, 歯学部, 助手 (10304312)
INOUE Masahisa Okayama University, Dental School, Assistant, 歯学部, 助手 (20223274)
NAGATSUKA Hitoshi Okayama University, Dental School, Associate Professor, 歯学部, 助教授 (70237535)
|
|---|
| Research Abstract |
Tooth morphogenesis and cytodifferentiations are regulated by epithelium-mesenchymal interactions, and the basement membrane plays a role in mediating these interactions Type IV collagen, the major component of the dental basement membrane, is composed of three αchains. Using indirect immunofluorescence on cryosections, we characterized the changes in protein localization of α1 to α6 chains of type IV collagen during mouse molar development. We propose that the inner enamel epithlium in the cap stage is composed of type IV collagen consist of α1, α2 and α4 chains, probably in molecular forms of α1(IV) α2(IV) α4(IV), [α4(IV)]ィイD23ィエD2 and [α1(IV)]ィイD22ィエD2 α2(IV). These forms containing α4 chain have not been detected in other organs yet. Therefore, it is thought that these forms is related to morphogenesis and cytodifferentiation characteristic of tooth development that regulated y epithelial-mesenchymal interactions.
Recently, it has gradually been ascertained that some growth factors secreted by epithelial or mesenchymal tissue bind to type IV collagen with greater affinity, condens there and contribute to organ morphogenesis in cooperation with basement membrane. We observed the expression patterns of several growth factors (TGF-β, BMPs and FGFs) in the basement menbrane of mouse first molar during tooth germ development and explored the relation between these growth factors and the tooth germ-specific molecular forms of type IV collage. No examined growth factor was detected in the basement membrane in and after cap stage. On the other hand, in the dental lamina and bud stages FGF-2 and TGF-β1 were detected in the dental basement membrane. FGF-2 and TGF-β1 may play an important role in early tooth morphogenesis and cytodifferentiation in cooperation with the molecular form, α3(IV)α4(IV)α5(IV), which exsists in the early stage of tooth development.
|
