CELLULAR AND MOLECULAR CONTROLS OF BIOMINERALIZATION

该计划项目的总体目标是提供新的和基本的信息，自然如何控制矿化在发展中的矿化组织，如釉质，使用成釉作为模型。我们的总体工作假设是，高度组织化的釉质组织的形成是遗传控制过程的结果，涉及：细胞运动性，矿物质离子通量;基质蛋白的分泌，自组装和加工，以及随后的成核和晶体生长的控制，由专门的蛋白质加上细胞控制的内在驱动力的建立，以支持矿化。具体而言，我们建议通过以下方面的综合研究来阐明控制釉质形成的基本机制：1）。基质蛋白-矿物质相互作用在晶体成核和晶体生长的控制; 2）细胞（成釉细胞）对矿物质离子转运、细胞外矿物质离子组成、pH和矿物质沉积的驱动力的控制; 3）特异性蛋白质-蛋白质相互作用在矿化控制中的作用; 4）通过组织特异性蛋白酶加工釉质基质蛋白来控制蛋白质功能和矿化;和5）细胞（成釉细胞）-细胞相互作用和细胞-基质相互作用，导致细胞运动性和釉质图案化的控制。这些研究将通过由蛋白质核心促进的五个独立项目的整合进行，该项目将在细菌和真核细胞表达系统中产生重组釉质蛋白。这些研究领域将采用最先进的技术（例如酵母双杂交系统;基于PCR的同源克隆，原子力显微镜，共聚焦显微镜和直接3-D荧光显微镜; SEM和TEM;免疫组织化学）和生理化学因素以多学科的方式解决，以解决釉质形成的整体机制。从长远来看，这些信息将是有用的：1）设计新的方法，用于制备具有特定理想特性的生物材料; 2）通过遗传手段诊断和预防疾病矿化组织;和3）设计程序，用于再生受损和疾病矿化组织。

The overall objective of this Program Project is to provide new and fundamental information on how nature controls mineralization in developing mineralized tissues, like enamel, using amelogenesis as a model. Our overall working hypothesis is that the formation of the highly organized enamel tissue results from genetically-controlled processes involving: cell motility, mineral ion fluxes; the secretion, self assembly and processing of matrix proteins, and the subsequent control of nucleation and crystal growth by specialized proteins coupled with the cell-controlled establishment of inherent driving forces to support mineralization. Specifically, we propose to elucidate fundamental mechanisms which control enamel formation through integrated studies on: 1). matrix protein-mineral interactions in the control of crystal nucleation and crystal growth; 2) the cellular (ameloblast) control of mineral ion transport, extracellular mineral ion composition, pH. and the driving force for mineral deposition; 3) the role of specific protein-protein interactions in the control of mineralization; 4) the control of protein function and mineralization via the processing of enamel-matrix proteins by tissue-specific proteinases; and 5) cell (ameloblast)-cell interactions and cell-matrix interactions, leading to the control of cell motility and enamel patterning. These studies will be carried out through the integration of five independent projects facilitated by a Protein Core, which will generate recombinant enamel proteins in both bacteria and eukaryotic cell expression systems. These areas of research will be addressed in a multi-disciplinary fashion using state-of-the-art techniques (e.g. the yeast two-hybrid system; PCR-based homology cloning, atomic force microscopy, confocal microscopy and direct 3-D fluorescence microscopy; SEM and TEM; immunohistochemistry) and physiochemical considerations to address the overall mechanisms of enamel formation. Long term, this information will be useful in: 1) the design of new methodologies for the preparation of biomaterials with specific desirable properties; 2) the diagnosis and prevention of diseases mineralized tissues through genetic means; and 3) the design of procedures for the regeneration of damaged and diseases mineralized tissues.