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，随后向其中分泌额外的NCP以启动健康牙齿形成所必需的矿化过程。由于牙本质发育不全 II（DGI-II；影响七千分之一的新生儿）等遗传性疾病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外别无选择。位于牙本质唾液蛋白 (DSP) 编码序列中的无义突变可能导致这些个体中 DSP 和磷酸蛋白 (PP) 表达的阻断，因为这两个 NCP 位于单个 DSP-PP 转录本上。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 转录和蛋白质表达问题视为重要的公共卫生问题。本申请提出了一系列研究，以更好地定义 DSP-PP 转录本表达和 DSP/PP 蛋白在牙本质矿化中的功能。该提案的具体目的是 1) 检验成牙本质细胞特异性因子作用于 DSP-PP 基因启动子、调节 DSP-PP 表达的假设，2) 检验多个 DSP-PP 转录本生成功能不同的 PP 亚型，具有不同的钙结合能力和羟基磷灰石形成能力，这是有序牙本质矿化所需的，3) 关联 DSP-PP 转录本和仅 DSP 转录本表达模式与牙本质矿化的关系，以及 4) 通过检查矿物质形成作为细胞培养物中 DSP 和 PP 同工型表达的函数来验证目标 2 和 3。这些正在进行的研究结合了基因调控和蛋白质功能方法，将揭示牙本质矿化的潜在机制，并将随后应用于修复牙科。