SPP IN AUDITORY ONTOGENY

听觉个体发育中的 SPP

• 批准号: 3218006
• 负责人: DAVID T DENHARDT
• 金额: $ 23.4万
• 依托单位: RUTGERS, THE STATE UNIV OF N.J.
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-09-30 至 1994-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3218006
• 关键词: audiometry; auditory pathways; balance; cell type; developmental genetics; diphtheria toxin; electrodes; electrophysiology; embryonic stem cell; gene expression; gene mutation; genetic disorder; genetic enhancer element; genetic manipulation; genetic promoter element; genetically modified animals; hearing disorders; histogenesis; histology; laboratory mouse; labyrinth; morphology; nucleic acid sequence; protein structure function; site directed mutagenesis; vestibuloocular reflex

Spp (secreted phosphoprotein, osteopontin) is a gene that is expressed transiently in both neural and non-neural tissues during embryogenesis. In the nervous system, spp is observed almost exclusively in the auditory and vestibular ganglionic neurons, as well as in specific cell types of the inner ear. This pattern of expression and its regulation by growth factors suggest that spp may play an important role in development of the inner ear. At present, the function of the encoded protein is unknown, although much is known about its structure and distribution. It was originally thought to be involved exclusively in bone development, but since the protein has now been localized to tissues in other organs, such as the inner ear, ovary and the kidney, this belief is no longer tenable. By establishing transgenic mouse strains in which spp expression has been specifically altered we can investigate how expression of this gene affects the inner ear. In this way, we hope to learn more about the function of this protein and the molecular signals that control and direct inner ear ontogenesis. The murine gene has been extensively characterized and elements in the enhancer/promoter tat regulate expression have been identified. Vectors will be constructed in which these enhancer/promoter elements will be used to drive expression in transgenic mice of (1) RNA complementary to the normal mRNA (antisense RNA) or (2) a protein (diphtheria toxin) lethal to the cell. Mice carrying specific mutations in the spp gene will be produced by first engineering the mutation in embryonic stem cells, which are then incorporated into blastocysts, some of which give rise to mice with the mutation in the germ line. The consequences of alterations in spp expression in the inner ear will be examined both morphologically and physiologically. In parallel studies the properties of various inner ear cell types in cell culture will be studied with particular reference to the effects of SPP. Wild-type and mutant forms of SPP will be produced in an appropriate host and incorporated into extracellular matrices to assess their effect on various cell types. We believe that SPP conveys signals to cells and endows them with particular properties that are important developmentally. This approach will afford us the unique opportunity to manipulate the peripheral auditory and vestibular systems on a molecular level and to relate these data to known hereditary disorders that affect hearing and balance.

SPP（分泌的磷蛋白，骨桥蛋白）是一种表达的基因 在胚胎发生过程中，在神经组织和非神经组织中暂时瞬时。 在神经系统中，在听觉中几乎只观察到SPP 和前庭神经节神经元以及特定细胞类型 内耳。 这种表达方式及其按增长的调节 因素表明，SPP可能在开发中起重要作用 内耳。 目前，编码蛋白的功能尚不清楚， 尽管对其结构和分布知之甚少。 是 最初被认为仅参与骨骼发育，但 由于该蛋白现在已定位在其他器官中的组织中，因此 作为内耳，卵巢和肾脏，这种信念不再是可行的。 通过建立转基因小鼠菌株，其中spp表达已成为 特别改变了我们可以研究该基因的表达方式 影响内耳。 这样，我们希望能进一步了解 该蛋白质的功能以及控制和控制的分子信号 直接内耳发生。 鼠基因已被广泛表征，并在 增强子/启动子TAT调节表达。 向量 将构建这些增强子/启动子元素的构造 用于在（1）RNA互补的转基因小鼠中驱动表达 正常mRNA（反义RNA）或（2）蛋白质（白喉毒素） 对细胞致命。 在SPP基因中携带特定突变的小鼠 将首先在胚胎茎中进行突变产生 然后将其掺入胚泡中，其中一些给出 在细菌系中突变升至小鼠。 后果 将检查内耳中SPP表达的改变 从形态和生理上。 在平行研究中 将研究细胞培养中各种内耳细胞类型 特别提到了spp的影响。 野生型和突变形式 SPP的属于适当的主机并将其纳入 细胞外矩阵评估其对各种细胞类型的影响。 我们 相信SPP传达信号并赋予它们特定的信号 在发展上很重要的属性。 这种方法将负担得起 我们有独特的机会来操纵外围听觉和 分子水平上的前庭系统，并将这些数据与 已知影响听力和平衡的遗传疾病。