Gene Regulation of Rat Dentin Sialoprotein

大鼠牙本质唾液酸蛋白的基因调控

• 批准号: 6744045
• 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/6744045
• 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）：在牙齿发育期间，成牙本质细胞通过产生前牙本质基质来调节牙本质形成，随后向前牙本质基质中分泌额外的NCP以启动健康牙齿形成所必需的矿化过程。由于遗传性疾病，如牙本质生成障碍II（DGI-II;影响1/7，000的新生儿），牙本质矿化减少，这些儿童除了在牙齿上放置牙冠或全口义齿外，几乎没有选择。位于牙本质涎蛋白（DSP）编码序列中的无义突变可能负责阻断这些个体中DSP和磷酸蛋白（PP）的表达，因为这两个NCP位于单个DSP-PP转录物上。重要的是，一些DGI患者还经历耳鸣以及平衡问题，使得有必要将DSP-PP转录和蛋白质表达中的问题视为重要的公共健康问题。本申请提出了一系列研究，以更好地确定DSP/PP转录本表达和DSP/PP蛋白在牙本质矿化中的功能。该提议的具体目的是1）检验作用于DSP-PP基因启动子的成牙本质细胞特异性因子调节DSP-PP表达的假设，2）检验多种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同种型的假设，所述不同的钙结合能力和羟基磷灰石形成能力是有序牙本质矿化所需的，3）将DSP-PP转录物和仅DSP转录物表达模式与牙本质矿化相关联，以及4）通过检查作为细胞培养物中DSP和PP同种型表达的函数的矿物质形成来验证目标2和3。这些正在进行的研究，结合联合收割机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，并将适用于修复牙科。