The induction of periodontal tissues by dentin-derived matrix

已知脱矿牙本质基质具有在种植部位诱导异位成骨的高潜能，暗示牙本质基质中存在某些生物活性分子，促进局部细胞分化为软骨和/或成骨细胞。目前的研究目的是验证一种假说，即在牙齿发育过程中，形成根部牙本质的基质成分实际上可能有助于牙周组织的诱导，主要是促进牙周间充质细胞向成牙骨质细胞的分化。研究的最终目的是鉴定生物活性分子(S)，并将数据应用于牙周组织的再生。HEBP是一种已知的双膦酸类化合物，对生物矿化具有很高的抑制作用，对骨和牙齿细胞的基质形成功能没有明显干扰。我们已经注意到，在HEBP感染的动物中，厚细胞性CEM…如果形成的根部牙本质的矿化受到抑制，从而使未矿化的牙本质表面暴露于未来的牙周膜，则更多的牙本质沉积在牙根表面，在那里只有在生理条件下已知的无细胞的宫颈形成。免疫组织化学数据显示，牙本质唾液蛋白是牙本质基质的主要非胶原性成分之一，如果牙本质矿化受到抑制，它会穿透牙本质的非矿化层并扩散到未来的牙周膜，提示蛋白质分子通过牙本质层进行动态移位。在这些区域，尽管牙本质基质中含有低分子釉原蛋白，而且至少通过聚合酶链式反应分析成牙本质细胞可以瞬时表达釉原蛋白，但免疫组织化学并不能定位釉原蛋白。在正常牙齿发育中，牙釉质和牙本质形成细胞层之间的上皮-间充质界面是串扰的地方，各种信号分子在那里交错。我们的数据表明，非矿化的外套质层允许各种分子在两个细胞层之间几乎自由地通过，这些分子分别产生非胶原性牙本质基质蛋白和某些釉原蛋白mRNA剪接产物，这可能有助于成牙骨质细胞的诱导，进而促进牙周组织的形成。在未来的研究中引入高灵敏的分析方法可能会使在牙本质表面从头形成处诱导成牙骨质细胞的候选分子的不同定位可视化。较少

The demineralized dentin matrix has been known to have a high potential to induce ectopic bone formation at the site of implantation, implicating presence of certain bioactive molecules in the dentin matrix that facilitate differentiation of local cells into the chondrogenic and/or osteogenic cells. The aim of current investigation was to test a hypothesis that matrix components of the forming root dentin may in fact contribute to the induction of periodontal tissues, primarily on the differentiation of periodontal mesenchymal cells to cementoblasts, in the process of tooth development. The final goal of the study was to identify the bioactive molecule(s) and apply the data for the regeneration of periodontal tissues.HEBP is a type of bisphosphonate known to have high inhibitory effects on biological mineralization without causing notable interferences on the matrix forming functions of the cells of bones and teeth. We have noticed that, in the HEBP-affected animals, thick cellular cem … More entum is deposited on the root surface, where only acellular cernentum is known to form under physiological conditions, if mineralization of the forming root dentin is inhibited and hence the non-mineralized dentin surface is exposed to the future periodontal ligament. Immunohistochemical date revealed that dentin sialaprotein, one of major non-collagenous components of dentin matrix, penetrates through the non-mineralized layers of dentin and diffuses into the future periodontal ligament, implicating dynamic translocation of the proteinaceous molecules through dentin layers, if mineralization of dentin is inhibited. In such areas, amelogenin proteins could not be localized by immunohistochemistry, despite the fact that dentin matrix contains low molecular amelogenins and that odontoblasts are reported to transiently express amelogenin messages at least by PCR analyses.In normal tooth development, the epithelial-mesenchymal interface between the enamel and dentin forming cell layers is the site of crosstalk, where various signaling molecules are crisscrossing. Our data indicate that non-mineralized mantle dentin layers allow almost free passage of various molecules between the two cell layers that respectively generate non-collagenous dentin matrix proteins and certain amelogenin mRNA splice products, which might contribute to the induction of cementoblasts and further the formation of periodontal tissues. Introduction of highly sensitive analytical methods in future studies may allow visualization of distinct localization of candidate molecules for the induction of cementoblasts at the site of de novo formation of root dentin surface. Less