Enamel with overexpressed ameloblastin

项目摘要/摘要 釉质发育缺陷包括磨牙切牙矿化不足(MIH)。这种情况会影响 牙釉质的质量和数量并严重干扰咬合缺失儿童的口腔功能 敏感度和龋齿易感性增加。患有MIH的儿童对牙科治疗的需求更大 在他们的一生中，经常表现出牙齿行为管理问题。MIH存在于许多 世界各地不同的人群，患病率从2.4%到40.2%不等。釉质风琴 上皮细胞受到未知因素的影响，导致MIH。MIH的病理生理学机制尚不清楚。 治疗选择仅限于使用氟化物的传统疗法，修复通常是 保留力和萃取力差。釉质基质促进牙釉质形成最坚硬的矿物 蛋白质。成釉蛋白(AmBN)是釉质蛋白的一种，占釉质蛋白的5%。在……里面 牙釉质矿化程度低，矿物质含量达不到所需浓度。安本是 在拔除的牙齿的低矿化牙釉质中发现，但尚不清楚它是否在 MIH的发病机制。我们已经建立了一个小鼠模型来研究AMBN过表达对血管内皮细胞生长因子的影响 釉质器官上皮细胞呈MIH样釉质。当AMBN过度表达时，这些小鼠体内的釉质 显示白色的、有分界的“斑块”，很容易从牙本质上断裂。MIH小鼠模型将发挥作用 剖析牙釉质低矿化过程中的细胞和分子事件，以找出治疗釉质低矿化的策略 低矿化牙釉质的诊断与防治。 我们已经培育出牙釉质中有分界的MIH样病变的转基因小鼠。我们的初步结果 结果显示，随着成釉蛋白(AmBN)浓度的增加，病变扩大。通常情况下，釉质基质 被成釉细胞快速加工、降解和内化，但当AmBN过度表达时， 牙釉质基质残留，矿物质积累受阻，表现为矿化不足。 珐琅。我们已经开发了利用MicroCT精确量化矿物质含量和牙釉质体积的工具 方法：研究方法。在转录组分析的釉质器官上皮途径的釉质基质，酶 降解、蛋白质运输和离子处理都是失调的。我们的总体假设是 成釉蛋白过表达影响釉质形成机制导致MIH损伤 珐琅。在SA1中，我们将确定牙釉质分阶段形成中的分界性混浊的开始 小鼠过度表达AMBN。在SA2中，我们将确定釉质内吞的生物途径 成釉蛋白在体内和体外过表达的结果。在SA3中，我们将确定 在AMBN小鼠中过表达的AMBN的内吞作用可以通过增加AMBN的酶活性来促进 釉质基质。对于拟议的研究，一个由临床医生科学家、定量成像专家、 蛋白质组学和生物信息学已经被组合成独特的相互作用和新的方法。

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.