Molecular biological study of the function of matrix proteins in the early stage of tooth development, with special reference to cytodifferentiation and initial calcification

牙齿发育早期基质蛋白功能的分子生物学研究，特别是细胞分化和初始钙化

基本信息

批准号：
18592002
负责人：
UCHIDA Takashi
金额：
$ 2.57万
依托单位：
Hiroshima University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

项目摘要

Sheath protein (ameloblastin), one of the main constituent of the enamel matrix protein, is expressed not only in the secretory ameloblast but also in other cell types such as immature odontoblasts and epithelial cell rest of Malassez. In order to understand the role of Sheath protein in the epithelial-mesenchymal interaction, we have attempted to demonstrate the expression of sheathe protein and the relation of cement blast differentiation of the earliest stage of the cementgenesis in the rat moral tooth germs and incisors. The results are summarized as follows.1. A part of cells in the Hertwig's epithelial root sheath and the epithelial cell rest of Malassez expressed sheath protein whose molecular form is identical to that expressed in the secretory ameloblast. Electron microscopic immunocytochemitry revealed that sheath protein is contained in the Golgi apparatus located periodontal side of the epithelial cell rest of Malassez. Cement matrix itself did not contain sheath protein.2. Mesenchymal cells located near the surface of the root dentin expressed osteopontin, one of the marker of initial cementum, and have processes extending to the surface of the root dentin. Thses cells are usually attached to the epithelial cell rest of Malassez.3. After the administration of Monesin, one of the inhibitor of the cell secretory activity, osteopontin are clearly localized in the cytoplasmic processes extending from these mesenchynal cells.4. Expression of sheath protein was always prior to that of osteopontin.These results suggested that sheath protein secreted from the cells of Hertwig's epithelial root sheath and the epithelial cell rest of Malassez induced differentiation of mesenchymal cells to odontoblasts which extend cytoplasmmic processes to the surface of calcified dentin and form initial cement layer.

鞘蛋白（蛋白质细胞蛋白）是牙釉质基质蛋白的主要成分之一，不仅在分泌的ameleblast中表达，而且在其他细胞类型中，例如未成熟的odontotoblasts和Malassez的上皮细胞。为了理解鞘蛋白在上皮间质相互作用中的作用，我们试图证明鞘蛋白的表达以及在大鼠道德牙齿细菌和牙齿中胶结性最早阶段的水泥爆炸的关系。结果总结如下1。 Hertwig上皮根鞘中的细胞的一部分和Malassez的上皮细胞静物表达了鞘蛋白，其分子形式与在分泌的成棉布中表达的分子形式相同。电子显微镜免疫细胞化学化学表明，鞘蛋白包含位于马拉西斯上皮细胞静止的高尔基体中。水泥基质本身不含鞘蛋白。2。位于根牙本质表面附近的间充质细胞表达骨桥蛋白，这是初始胶质的标记之一，并具有延伸至根牙本质表面的过程。 THSES细胞通常附着在Malassez的上皮细胞中。3。在给予Monesin（细胞分泌活性的一种抑制剂）后，骨桥蛋白显然位于从这些介质细胞延伸的细胞质过程中。4。鞘蛋白的表达始终是在骨桥蛋白之前的。这些结果表明，鞘蛋白是从赫特维格的上皮根鞘细胞中分泌的，而马萨斯兹的上皮细胞中的上皮细胞诱导了间质细胞的分化向odonthasts的分化，从牙本质并形成初始水泥层。