Enamel with overexpressed ameloblastin

牙釉质过度表达成釉细胞

基本信息

批准号：
10133047
负责人：
Yong-Hee Patricia Chun
金额：
$ 36.18万
依托单位：
UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-04-01 至 2022-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10133047
关键词：
Accounting Address Affect Ameloblasts Amelogenesis Attention Behavioral Bioinformatics Biological Cells Child Clinical Clinical Management Data Defect Dental Dental Care Dental Enamel Dental caries Dentin Development Diagnosis Disease Enamel Formation Enamel Organ Endocytosis Endocytosis Pathway Epithelial Esthetics Event Excision Exhibits Fluorides Fracture Functional disorder High Prevalence Homeostasis Image Immunohistochemistry Impairment In Situ Hybridization In Vitro Incisor Individual Ions Lesion Life MMP-20 Mass Spectrum Analysis Methods Minerals Molecular Morphology Mus Oral Partner in relationship Pathogenesis Pathway interactions Phase Play Population Predisposition Prevalence Prevention therapy Process Proteins Proteomics Risk Role Scientist Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization Texas Therapeutic Tissues Tooth structure Transgenic Mice United States ameloblastin analytical tool base bioinformatics tool conventional therapy deciduous tooth enamel matrix proteins in vivo malformation microCT mineralization mouse model novel strategies overexpression permanent tooth protein transport public health relevance quantitative imaging restoration targeted treatment tool transcriptome uptake

项目摘要

PROJECT SUMMARY/ABSTRACT Developmental defects of enamel include molar-incisor hypomineralization (MIH). This condition affects the quality and quantity of enamel and severely disrupts oral functions in children with loss of occlusion, tooth sensitivity and increased caries susceptibility. Children with MIH have greater needs for dental treatment throughout their life and often exhibit dental behavioral management problems. MIH is found in many different populations worldwide with a prevalence ranging from 2.4% to 40.2%. The enamel organ epithelium is affected by unknown factors resulting in MIH. The pathophysiology of MIH is not understood. Therapeutic options are limited to conventional therapy with fluoride applications, restorations often with poor retention and extractions. Enamel formation into the hardest mineral is promoted by enamel matrix proteins. One of the enamel proteins is ameloblastin (Ambn) accounting for 5% of the enamel proteins. In hypomineralized enamel, the mineral content does not reach the necessary concentration. Ambn was identified in hypomineralized enamel of extracted teeth, but it is not clear if it plays a role in the pathogenesis of MIH. We have developed a mouse model to study the effect of Ambn overexpression in MIH-like enamel in enamel organ epithelium. When Ambn is overexpressed, the enamel in these mice displays white, demarcated ‘patches’ that fracture easily from the dentin. The MIH mouse model will serve to dissect the cellular and molecular events in enamel hypomineralization to identify strategies for the diagnosis, prevention and therapy of hypomineralized enamel. We have developed transgenic mice with demarcated, MIH-like lesions in enamel. Our preliminary results show that the lesions enlarge as the ameloblastin (Ambn) concentration increases. Normally, enamel matrix is rapidly processed, degraded and internalized by ameloblasts, but when Ambn is overexpressed, the enamel matrix lingers on and the accumulation of mineral is hampered, manifesting as hypomineralized enamel. We have developed tools to accurately quantify mineral content and enamel volume with microCT methods. In a transcriptome analysis of enamel organ epithelium pathways for enamel matrix, enzymatic degradation, protein trafficking and ion handling were dysregulated. Our overall hypothesis is that overexpressed ameloblastin influences the mechanisms of enamel formation resulting in MIH lesions in enamel. In SA1 we will determine the onset of demarcated opacities within the phased formation of enamel in mice overexpressing Ambn. In SA2, we will determine the biological pathways of endocytosis of enamel proteins in vivo and in vitro as a consequence of ameloblastin overexpression. In SA3, we will determine if endocytosis of overexpressed Ambn can be promoted in Ambn mice by increasing the enzymatic activity in the enamel matrix. For the proposed studies a team of clinician scientists, experts in quantitative imaging, proteomics and bioinformatics has been assembled for unique interaction and novel approaches.

项目概要/摘要牙釉质发育缺陷包括磨牙-切牙矿化不足（MIH），这种情况会影响牙齿的发育。牙釉质的质量和数量，严重破坏儿童咬合、牙齿缺失的口腔功能 MIH 儿童对牙科治疗的需求更大。 MIH 存在于许多人的一生中，并且经常表现出牙科行为管理问题。全世界不同人群的患病率从 2.4% 到 40.2% 不等。上皮细胞受到导致 MIH 的未知因素的影响 MIH 的病理生理学尚不清楚。治疗选择仅限于使用氟化物的常规疗法，修复体通常采用牙釉质基质促进牙釉质形成最硬的矿物质。釉质蛋白之一是成釉细胞蛋白（Ambn），占釉质蛋白的 5%。牙釉质矿化不足，矿物质含量未达到必要的浓度。在拔牙的牙釉质矿化不足中发现了这种物质，但尚不清楚它是否在我们开发了一种小鼠模型来研究 Ambn 过度表达对 MIH 的影响。釉质器官上皮细胞中的 MIH 样釉质当 Ambn 过度表达时，这些小鼠的釉质会发生变化。 MIH 小鼠模型将显示白色、有界限的“斑块”，很容易从牙本质上断裂。剖析牙釉质矿化不足的细胞和分子事件，以确定治疗策略牙釉质矿化不足的诊断、预防和治疗。我们已经培育出牙釉质中具有明显的 MIH 样病变的转基因小鼠，这是我们的初步结果。结果表明，随着成釉细胞蛋白 (Ambn) 浓度的增加，病变会扩大。被成釉细胞快速加工、降解和内化，但是当 Ambn 过度表达时，牙釉质基质残留，矿物质积累受到阻碍，表现为矿化不足我们开发了利用 microCT 准确量化矿物质含量和牙釉质体积的工具。在牙釉质基质的牙釉质器官上皮途径的转录组分析中，酶促方法。我们的总体假设是，降解、蛋白质运输和离子处理失调。过度表达的成釉细胞蛋白影响牙釉质形成机制，导致 MIH 病变在 SA1 中，我们将确定牙釉质分阶段形成中划界不透明的开始。在 SA2 中过度表达 Ambn 的小鼠，我们将确定牙釉质内吞作用的生物学途径。在 SA3 中，我们将确定是否存在由于成釉细胞过度表达而导致的体内和体外蛋白质。通过增加 Ambn 小鼠中的酶活性，可以促进过度表达的 Ambn 的内吞作用对于所提出的研究，由临床科学家、定量成像专家组成的团队，蛋白质组学和生物信息学已被整合起来以实现独特的相互作用和新颖的方法。