Gene Regulation of Rat Dentin Sialoprotein

大鼠牙本质唾液酸蛋白的基因调控

• 批准号: 6897588
• 负责人: HELENA H Ritchie
• 金额: $ 24.29万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-09-30 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6897588
• 关键词: calcium; chemical binding; dentin; dentinogenesis; developmental genetics; gene induction /repression; genetic promoter element; hydroxyapatites; in situ hybridization; laboratory rat; odontoblasts; polymerase chain reaction; protein structure function; tissue /cell culture; transcription factor

DESCRIPTION (provided by applicant): During tooth development, odontoblasts modulate dentin formation by producing a predentin matrix into which additional NCPs are subsequently secreted to initiate the mineralization process so necessary for healthy tooth formation. Abnormalities in dentin mineralization due to genetic diseases such as dentinogenesis imperfecta II (DGI-II; affecting 1 in 7,000 newborns) leave these children few choices other than placement of crowns on the teeth or a complete denture. A nonsense mutation, located in the coding sequence for dentin sialoprotein (DSP) is likely responsible for blocking both DSP and phosphophoryn (PP) expression in these individuals because these two NCPs are located on a single DSP-PP transcript. Importantly, some DGI patients also experience tinnitus as well as balancing problems making it necessary to consider problems in DSP-PP transcript and protein expression as an important public health concern. This application proposes a series of studies to better define DSP-PP transcript expression and DSP/PP protein function in dentin mineralization. The specific aims of this proposal are 1) to test the hypothesis that odontoblast-specific factors acting on the DSP-PP gene promoter, regulate DSP-PP expression, 2) to test the hypothesis that multiple DSP-PP transcripts generate functionally distinct PP isoforms with distinct calcium binding capacity and hydroxyapatite forming ability which are required for orderly dentin mineralization, 3) to correlate DSP-PP transcript and DSP-only transcript expression patterns with dentin mineralization, and 4) to validate Aims 2 and 3 by examining mineral formation as a function of DSP and PP isoform expression in cell culture. These ongoing studies, which combine gene regulation and protein function approaches, will reveal underlying mechanisms of dentin mineralization and will later be applicable to reparative dentistry.

描述（由申请人提供）：在牙齿发育过程中，成牙细胞通过产生预牙本质基质来调节牙本质的形成，随后分泌额外的ncp来启动矿化过程，这是健康牙齿形成所必需的。由于遗传疾病，如牙本质发育不全II型（DGI-II，每7000名新生儿中就有1名受影响）导致的牙本质矿化异常，使这些儿童除了在牙齿上放置牙冠或全口义齿之外别无选择。牙本质唾液蛋白（DSP）编码序列中的无义突变可能会导致这些个体中DSP和磷酸化蛋白（PP）的表达被阻断，因为这两种ncp位于单个DSP-PP转录物上。重要的是，一些DGI患者还会出现耳鸣和平衡问题，因此有必要将DSP-PP转录和蛋白表达问题视为一个重要的公共卫生问题。为了更好地确定牙本质矿化过程中DSP-PP转录物的表达和DSP/PP蛋白的功能，本研究提出了一系列的研究。本研究的具体目的是：1)验证成牙细胞特异性因子作用于DSP-PP基因启动子调控DSP-PP表达的假设；2)验证多个DSP-PP转录物产生具有不同钙结合能力和羟基磷灰石形成能力的功能不同的PP异构体的假设，这是有序牙本质矿化所必需的；3)将DSP-PP转录物和仅DSP-PP转录物的表达模式与牙本质矿化相关联。4)通过检测细胞培养中DSP和PP异构体表达对矿物质形成的影响来验证目标2和目标3。这些正在进行的研究结合了基因调控和蛋白质功能的方法，将揭示牙本质矿化的潜在机制，并将在以后的修复性牙科中应用。