CELL AND GENETICS APPROACHES TO ENAMEL BIOMIMETICS

牙釉质仿生学的细胞和遗传学方法

• 批准号: 8106413
• 负责人: Malcolm L. Snead
• 金额: $ 38.38万
• 依托单位: UNIVERSITY OF SOUTHERN CALIFORNIA
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-08-01 至 2015-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8106413
• 关键词: Ablation; Ameloblasts; Amino Acids; Animal Model; Animals; Architecture; Biological; Biomimetics; C-terminal; Cell Cycle; Cells; Communicable Diseases; Coupled; Data; Dental Enamel; Dental caries; Disease; Ectoderm; Enamel Formation; Engineering; Gene Expression; Genes; Genetic; Genome; Grouping; Habits; Human; Knock-in Mouse; Knock-out; Knockout Mice; Knowledge; Link; Maps; Measures; Minerals; Mus; N Domain; Normal tissue morphology; Outcome; Pattern; Pharmaceutical Preparations; Production; Property; Protein Engineering; Proteins; Proteomics; Research; Role; Site; Structure; Structure-Activity Relationship; Technology; Tertiary Protein Structure; Tissues; Transgenic Mice; Trauma; Two-Hybrid System Techniques; Work; Yeasts; amelogenin; base; biomineralization; design; enamel matrix proteins; extracellular; functional genomics; genetic manipulation; homologous recombination; insight; knockout animal; knockout gene; mouse Ambn protein; mouse genome; nanoscale; novel; protein function; public health relevance; retinal rods; success; tool

DESCRIPTION (provided by applicant): Deciphering structure/function relationships underpins the acquisition of biomedical knowledge while providing the basis to create novel materials and drugs. A powerful tool for deciphering structure/function outcomes has been germline genetic manipulation in mice. In this application, we apply germline manipulation to link structure to function for the enamel matrix protein ameloblastin. Enamel is a composite bioceramic tissue with unique material properties that are owed to its mode of biological fabrication. Ameloblast cells create an extracellular enamel protein matrix that serves to control both crystallite habit and the organization of crystallite bundles, allowing thousands of nanoscale crystallites to be organized and grouped together under the control of a single cell. We hypothesize that the grouping and organization of the nanocrystallites by a single ameloblast cell is the outcome achieved by the function(s) of critical domain(s) within the ameloblastin protein. The ameloblastin protein has been described as being organized into at least two domains, an N'- and a C'- terminal domain [Iwata et al. '07], based on the finding that following cleavage the N'- and C'- ameloblastin domains are no longer found in the same physical site in the enamel rod. The N'-terminus is enriched around the rod boundaries, much as a sheath covers a knife blade, while the C'-terminal domain behaves quite differently. We hypothesize that the N'-terminus of ameloblastin is likely responsible for the cell-to-matrix interactions that maintain the highly patterned rod-to-interrod boundaries observed in enamel. We hypothesize that the C'-terminus is responsible for the protein-to-mineral interactions producing the enamel bioceramic tissue. Outcomes will be measured by changes to stereotypic enamel architecture and by analysis of the material properties of the enamel in the knockin condition compared to wildtype animals. The outcomes from this experimental strategy will contribute to our understanding of functional genomics and proteomics while furthering our understanding of the formation of the only ectoderm-derived biomineralized tissue in the vertebrate body. Preliminary data from our research team suggest that this knockin approach will yield novel insights into the structure/function relationship for the ameloblastin protein, the second most abundant protein contributing to enamel organic matrix assembly and biomineralization. PUBLIC HEALTH RELEVANCE: The function(s) for the second most abundant protein of the forming mammalian enamel matrix is not known. Here, we map the function(s) of ameloblastin protein domains to the production of the enamel matrix required to control enamel biomineralization. In performing this project we will create an animal model useful to study caries, the most prevalent-, infectious-disease of humankind and provide one more design specification for creating an enamel biomimetic, useful for restoring enamel lost to trauma and disease.

描述（由申请人提供）：破译结构/功能关系是获取生物医学知识的基础，同时为创造新材料和药物提供基础。破译结构/功能结果的有力工具是小鼠的生殖系遗传操作。在这个应用中，我们应用种系操作连接结构功能的釉基质蛋白成釉蛋白。牙釉质是一种复合生物陶瓷组织，具有独特的材料特性，这归因于其生物制造模式。成釉细胞产生细胞外釉质蛋白基质，其用于控制微晶习性和微晶束的组织，允许数千个纳米级微晶在单个细胞的控制下组织和分组在一起。我们假设单个成釉细胞的纳米颗粒的分组和组织是成釉蛋白内关键结构域的功能实现的结果。 成釉蛋白被描述为被组织成至少两个结构域，即N ′-和C ′-末端结构域[岩田等人，′ 07]，这是基于以下发现：在切割后，N ′-和C ′-成釉蛋白结构域不再存在于釉棒中的相同物理位点。N '-末端在杆状边界周围富集，就像鞘覆盖刀片一样，而C'-末端结构域的行为完全不同。我们推测成釉蛋白的N '-末端可能负责维持在釉质中观察到的高度模式化的杆-杆间边界的细胞-基质相互作用。我们推测C '-末端负责蛋白质与矿物质的相互作用，产生釉质生物陶瓷组织。结果将通过与野生型动物相比，在敲入条件下对刻板牙釉质结构的变化和牙釉质的材料性质的分析来测量。 该实验策略的结果将有助于我们对功能基因组学和蛋白质组学的理解，同时进一步加深我们对脊椎动物体内唯一外胚层来源的生物矿化组织形成的理解。我们研究小组的初步数据表明，这种敲入方法将产生新的见解成釉蛋白的结构/功能关系，第二丰富的蛋白质有助于釉质有机基质组装和生物矿化。 公共卫生相关性：哺乳动物釉质基质形成中第二丰富的蛋白质的功能尚不清楚。在这里，我们映射成釉蛋白蛋白结构域的功能（S），以控制釉质生物矿化所需的釉质基质的生产。在执行这个项目时，我们将创建一个动物模型，用于研究龋齿，人类最普遍的传染病，并提供一个更多的设计规范，用于创建一个牙釉质仿生，用于恢复牙釉质损失的创伤和疾病。