DENTIN SIALOPHOSPHOPROTEIN (DSPP) DURING ODONTOGENESIS

描述：(改编自调查人员的摘要)目前很少 已知牙齿细胞外的组织特异性基因调控 牙齿发育过程中的基质蛋白。这项建议的目的是研究 牙本质形成过程的调控机制 唾液磷蛋白(DSPP)基因在牙齿形成过程中的表达，而 获取有关其生物学功能的信息。DSPP是一个大型处理器 被特异性切割的蛋白质，产生两种牙本质蛋白 牙本质唾液蛋白(DSP)和牙本质磷蛋白也称为 磷酸果糖(DPP)。原位杂交研究显示了限制性模式 DSPP。应用计划阐明控制的分子机制 DSPP在成牙本质细胞(增强子)中的表达及下调 在成釉细胞中表达(沉默)。假设是组织和 DSPP的发育调节是通过离散的向上和向下调节的 转录因子与其同源顺式元件的相互作用 启动子的特定区域，该蛋白在 牙齿矿化。为了验证这一假设，我们提出了四个具体目标： 1)测定沙门氏菌5‘端启动子区DNA序列 先前已鉴定的小鼠和人类基因组克隆；2)确定区域 DSPP启动子的启动子允许潜在的组织特异性表达 使用新型永生化牙科细胞系和体内使用 转基因方法；3)建立转基因敲入DSPP LacZ小鼠模型 研究天然DSPP在体内的内源性表达模式 启动子，同时允许在纯合缺失中探索其功能作用 DSPP动物；以及4)确定DSPP过表达的影响 转基因小鼠模型。这些实验将提供所需的初步数据 以及未来DSPP启动子在人类基因中的潜在应用背景 多种牙本质和牙釉质遗传病的治疗策略。 此外，一旦完全特征化，DSPP启动子可以用于其他 在治疗应用中获得牙齿特异的有益表达 与盖髓方式相关的靶基因。

DESCRIPTION: (Adapted from the investigator's abstract) Currently very little is known regarding the tissue-specific gene regulation of tooth extracellular matrix proteins during odontogenesis. The purpose of this proposal is to study the regulatory mechanisms that control the process of dentine Sialophosphoprotein (DSPP) gene expression during tooth formation, while gaining information to its biological function. DSPP is a large processor protein that is specifically cleaved giving rise to two dentine proteins dentine sialoprotein (DSP) and dentine phosphoprotein also known as phosphophoryn (DPP). In situ hybridization studies show the restricted pattern of DSPP. The application plan to elucidate the molecular mechanism that control the expression of DSPP in the odontoblasts (enhancers) and down-regulate expression (silencers) in ameloblasts. The hypothesis is that tissue and developmental regulation of DSPP is regulated both up and down through discrete interactions of transcription factors with their cognate cis-elements in specific region of the promoter and that this protein has an important role in tooth mineralization. To test this hypothesis, four specific aims are proposed: 1) to determine the DNA sequences of the 5' upstream promoter region of previous identified mouse and human genomic clones; 2) to determine the region of the DSPP promoter that confers the potential tissue specific expression of DSPP gene using novel immortalized dental cell lines and in vivo using a transgenic approach; 3) to generate transgenic Knock-in DSPP LacZ mouse model to investigate the in vivo endogenous patterns of expression of native DSPP promoter, while allowing the functional role to be explored in homozygous null DSPP animals; and 4) to determine the effects of DSPP over-expression using trasgenic mouse model. These experiments will provide needed preliminary data and background for the future potential use of the DSPP promoter in human gene therapy strategy for the numerous dentine and enamel genetic diseases. Furthermore, once fully characterized, the DSPP promoter could be used in other therapeutic applications to derive tooth specific expression of beneficial target genes related to pulp capping modalities.