Enamel Structure Sophistication throuth Amelogenin Evolution

釉原蛋白进化带来的复杂牙釉质结构

• 批准号: 7880098
• 负责人: Tom Diekwisch
• 金额: $ 38.86万
• 依托单位: UNIVERSITY OF ILLINOIS AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2012-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7880098
• 关键词: Affect; Amphibia; Apatites; Architecture; Atomic Force Microscopy; Biocompatible Materials; Biological Assay; Biological Models; Biology; Biomimetics; Carbonates; Cell Culture System; Cell physiology; Complex; Cultured Cells; Dental Enamel; Development; Electron Microscopy; Enamel Formation; Evolution; Genes; Glutamine; Growth; Human; Hydroxyapatites; In Vitro; Knock-in Mouse; Knock-out; Knockout Mice; Lead; Mammals; Mechanics; Minerals; Modeling; Mus; Organ Culture Techniques; Pattern; Phenotype; Play; Principal Investigator; Proline; Property; Proteins; Rana; Reptiles; Research; Research Design; Research Project Grants; Role; Running; Solutions; Structure; Tandem Repeat Sequences; Testing; Thick; Thinking; Tooth structure; Transgenic Mice; Transgenic Model; Transgenic Organisms; amelogenin; base; biomineralization; design; in vitro Assay; in vivo; interest; light scattering; mineralization; mouse model; overexpression; programs; public health relevance; repaired; research study; retinal rods; self assembly

DESCRIPTION (provided by applicant): Tooth enamel consists of tightly packed carbonated hydroxyapatite crystals which are organized into rods (prisms) running obliquely to one another in alternating rows. This extraordinary 3D architecture is established during enamel development as a result of the coordinated activity of cellular processes and organic matrix secretion. The present proposal focuses on the role of the unique C-domain of the major enamel matrix gene product, amelogenin, as it pertains to enamel structural organization. In previous studies, we have documented a significant increase in amelogenin C-domain proline and glutamine tandem repeats and prismatic enamel organization during the amphibian/reptile to mammal transition. In the present application, we are using this evolutionary biology approach to decipher the role of the amelogenin C-domain in the evolution of complex enamel structure. As a first step, we have generated frog amelogenin- overexpressing mouse models featuring grossly altered enamel mineral organization and lack of prism formation. Enamel thickness was further decreased and prisms were lacking when amel-overexpressors were crossed with amel null mice. In order to understand how specific domains of the amelogenin gene might affect alterations in enamel biomineralization during vertebrate evolution, we are now submitting a research plan to determine the effect of amelogenin C-domain evolution as it relates to enamel matrix organization, enamel crystal and prism formation. Our studies are designed to test the hypothesis that complex mammalian enamel architecture is a result of enamel matrix structure sophistication facilitated by amelogenin C-domain evolution. PUBLIC HEALTH RELEVANCE: The purpose of this research project is to identify key factors in tooth enamel formation. Tooth enamel in frog teeth is thin, little organized, and soft, while tooth enamel in mammals' features sophisticated organization and is thicker and harder than frog enamel. Here we are comparing the difference between frog and mouse enamel to identify key differences in enamel formation on a protein level. We are interested in the center portion of the major enamel protein, amelogenin. We believe that this center portion plays an important role in enamel formation and we will use a number of models to find out whether our thinking is accurate. Among those model systems will be experiments in which we will mix this protein with crystal growth solutions and experiments in which we manipulate the major gene in mice. We hope that one day our approach will lead to new ways of repairing human teeth.

描述（由申请人提供）：牙釉质由紧密堆积的碳酸羟基磷灰石晶体组成，这些晶体被组织成以交替行彼此倾斜延伸的棒（棱柱）。这种非凡的 3D 结构是在牙釉质发育过程中建立的，是细胞过程和有机基质分泌协调活动的结果。本提案重点关注主要牙釉质基质基因产物釉原蛋白的独特 C 结构域的作用，因为它与牙釉质结构组织有关。在之前的研究中，我们记录了在两栖动物/爬行动物向哺乳动物过渡期间，牙釉蛋白 C 结构域脯氨酸和谷氨酰胺串联重复序列以及棱柱状牙釉质组织的显着增加。在本申请中，我们使用这种进化生物学方法来破译牙釉蛋白 C 结构域在复杂牙釉质结构进化中的作用。作为第一步，我们建立了青蛙釉原蛋白过度表达的小鼠模型，其特征是牙釉质矿物组织发生了严重改变并且缺乏棱柱形成。当 amel 过度表达小鼠与 amel 缺失小鼠杂交时，牙釉质厚度进一步降低，棱晶消失。为了了解釉原蛋白基因的特定结构域如何影响脊椎动物进化过程中牙釉质生物矿化的变化，我们现在提交了一项研究计划，以确定釉原蛋白 C 结构域进化的影响，因为它与牙釉质基质组织、牙釉质晶体和棱柱形成有关。我们的研究旨在验证以下假设：复杂的哺乳动物牙釉质结构是釉原蛋白 C 结构域进化促进的牙釉质基质结构复杂化的结果。 公共健康相关性：该研究项目的目的是确定牙釉质形成的关键因素。青蛙牙齿的牙​​釉质薄、组织较少且柔软，而哺乳动物的牙釉质组织复杂，比青蛙的牙釉质更厚、更硬。在这里，我们比较青蛙和小鼠牙釉质之间的差异，以确定蛋白质水平上牙釉质形成的关键差异。我们对主要牙釉质蛋白釉原蛋白的中心部分感兴趣。我们相信这个中心部分在牙釉质形成中起着重要作用，我们将使用许多模型来检验我们的想法是否准确。在这些模型系统中，我们将这种蛋白质与晶体生长溶液混合的实验以及我们操纵小鼠主要基因的实验。我们希望有一天我们的方法能够带来修复人类牙齿的新方法。