Neurofibromin, Ras & NFAT in Cardiovascular Development

神经纤维蛋白、Ras

• 批准号: 7008158
• 负责人: FRAZ Ahmed ISMAT
• 金额: $ 13.39万
• 依托单位: CHILDREN'S HOSP OF PHILADELPHIA
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-01-15 至 2009-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7008158
• 关键词: cardiovascular system; cell differentiation; cell growth regulation; cell nucleus; cell proliferation; developmental genetics; embryo /fetus; embryogenesis; gene interaction; genetic regulation; genetically modified animals; guanine nucleotide binding protein; histogenesis; intermolecular interaction; laboratory mouse; molecular pathology; neurofibromatosis; neurofibromatosis type 1 protein /gene; protein localization; protein structure function; transcription factor; vascular smooth muscle

DESCRIPTION (provided by applicant): I am proposing a training program with didactic coursework and experiments that are logical extensions of our previous work in understanding how Nf1 functions in cardiovascular development. Neuro-fibromatosis type 1 (Von Recklinghausen's Disease) is an autosomal dominant condition affecting 1 in 3000-4000 individuals. It is characterized by pathology of neural crest-derived tissues, but also causes cardiovascular abnormalities. The gene NF1 encodes neurofibromin, a large molecule that in part acts as a ras GTPase activating protein (GAP). Mice homozygous for a null allele of the murine homologue (Nf1) have a set of embryonic lethal cardiovascular defects reminiscent of common forms of congenital heart disease. Endothelial specific disruption of Nf1 reproduces much of this cardiovascular phenotype. Further, we believe that it occurs through the ras-GAP function of neurofibromin and its effect on nuclear localization of the transcription factor NFATc1 (nuclear factor of activated T-cells). Specific Aim 1 will test the hypothesis that ras-GAP function is the critical aspect of neurofibromin responsible for proper cardiovascular development. The ras GAP related domain of neurofibromin has been knocked into the Rosa26 locus by me and will be expressed in a tissue-specific manner in mice through the activity of cre recombinase. Specific Aim 2 will test the hypothesis that the loss of Nf1 in vascular smooth muscle will recapitulate the vascular disease of neurofibromatosis. I will test this by crossing floxed Nf1 mice with a tamoxifen-inducible, smooth muscle specific cre line. Specific Aim 3 will test the hypothesis that NF1 and NFATc1 are in the same genetic pathway in cardiovascular development. Through genetic analysis of mice and mouse embryos deficient in both NF1 and NFATc1, I will determine the role of NFATc1 in the development of the cardiovascular phenotype of Nf1 null embryos. Finally, Specific Aim 4 will extend our previous work on the observation that NFATc1 undergoes nuclear localization in endothelial cells in the setting of elevated ras activity. I will continue testing specific signaling pathways downstream of ras to determine those that are critical for this phenotype. This experimental work will be supported by a foundation of didactic training in molecular and developmental biology. Together this training program will prepare me for independent investigation, lead to a better understanding of cardiovascular abnormalities in neurofibromatosis, and address fundamental issues of cardiovascular development.

描述（由申请人提供）： 我提出了一个包含教学课程和实验的培训计划，这些课程和实验是我们之前了解 Nf1 在心血管发育中如何发挥作用的工作的逻辑延伸。 1 型神经纤维瘤病（冯·雷克林豪森病）是一种常染色体显性遗传疾病，每 3000-4000 人中就有 1 人受影响。 其特征是神经嵴衍生组织的病理学，但也会导致心血管异常。 NF1 基因编码神经纤维蛋白，这是一种大分子，部分充当 ras GTP 酶激活蛋白 (GAP)。 小鼠同源基因（Nf1）无效等位基因纯合的小鼠具有一系列胚胎致命性心血管缺陷，让人想起常见的先天性心脏病。 Nf1 的内皮特异性破坏再现了大部分心血管表型。 此外，我们认为它是通过神经纤维蛋白的 ras-GAP 功能及其对转录因子 NFATc1（活化 T 细胞核因子）核定位的影响而发生的。 具体目标 1 将检验以下假设：ras-GAP 功能是神经纤维蛋白负责心血管正常发育的关键方面。 神经纤维蛋白的ras GAP相关结构域已被我敲入Rosa26位点，并将通过cre重组酶的活性在小鼠中以组织特异性方式表达。 具体目标 2 将检验以下假设：血管平滑肌中 Nf1 的缺失将重现神经纤维瘤病的血管疾病。 我将通过将 floxed Nf1 小鼠与他莫昔芬诱导的平滑肌特异性 cre 系杂交来测试这一点。 具体目标 3 将检验 NF1 和 NFATc1 在心血管发育中处于同一遗传途径的假设。 通过对同时缺乏 NF1 和 NFATc1 的小鼠和小鼠胚胎进行遗传分析，我将确定 NFATc1 在 Nf1 缺失胚胎心血管表型发育中的作用。 最后，具体目标 4 将扩展我们之前的观察工作，即 NFATc1 在 ras 活性升高的情况下在内皮细胞中进行核定位。 我将继续测试 ras 下游的特定信号传导途径，以确定对该表型至关重要的那些信号传导途径。 这项实验工作将得到分子和发育生物学教学培训基础的支持。 总之，这个培训计划将使我为独立调查做好准备，更好地了解神经纤维瘤病的心血管异常，并解决心血管发育的基本问题。