Regulation of spinal cord development and the Wnt signaling pathway by Oto

Oto 调控脊髓发育和 Wnt 信号通路

• 批准号: 7678362
• 负责人: Roeben Munji
• 金额: $ 2.97万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7678362
• 关键词: Address; Affect; Biology; Brain Neoplasms; Cell Culture System; Cell membrane; Cells; Chick Embryo; Collaborations; Complementary DNA; Complex; Congenital Abnormality; Cultured Cells; Defect; Development; Disease; Dorsal; Electroporation; Embryo; Embryonic Development; Endoplasmic Reticulum; Enzymes; Erinaceidae; Event; Exhibits; Fibroblasts; GPI Membrane Anchors; General Population; Genes; Genetic; Genetic Transcription; Glycosylphosphatidylinositols; Golgi Apparatus; Growth; Holoprosencephaly; Human; Laboratories; Lead; Link; Lipids; Mediating; Membrane; Membrane Lipids; Membrane Microdomains; Modification; Molecular; Movement; Mus; Mutant Strains Mice; Mutate; Mutation; Nervous system structure; Neural Tube Defects; Neural tube; Neuraxis; Neurons; Pathway interactions; Pattern; Pharmaceutical Preparations; Phenotype; Phospholipase; Physiological; Positioning Attribute; Proteins; RNA Interference; Regulation; Reporter; Role; Series; Signal Pathway; Signal Transduction; Signaling Molecule; Sorting - Cell Movement; Spinal Cord; Syndrome; Time; Tissues; Transgenic Organisms; Transport Vesicles; Wnt proteins; Wnt1 Protein; Work; base; design; early onset; human disease; insight; link protein; malformation; mutant; nervous system development; novel; overexpression; pleasure; progenitor; protein distribution; research study; response; tumor

DESCRIPTION (provided by applicant): Wnt signaling is one of the key pathways controlling growth and patterning of the vertebrate central nervous system. Mutations in components of the Wnt signaling pathway often lead to birth defects and tumors affecting the nervous system. Thus, understanding the mechanisms of Wnt regulation in the context of nervous system development is vital for our understanding and treatment of disease. The focus of this study is to elucidate the role of Oto, a novel regulator of Wnt proteins, in spinal cord development and the Wnt signaling pathway. The otocephaly mutant has a variety of phenotypes that appear to be due to either excess or early onset of Wnt signaling, including holoprosenchephaly, agnathia and spinal cord overgrowth. The Oto locus encodes an enzyme required for proper glycosylphosphatidylinositol (GPI)-modification of Wnts. This provides potential new insights into the mechanisms of Wnt regulation. Wnts, which are secreted and considered to be long-range signaling molecules, may be GPI-anchored to lipid membranes in some physiological conditions. GPI-linked proteins are targeted to lipid rafts and segregate from the general population of nonGPI-linked proteins in the secretory pathway. The complex biology conferred by GPI modification provides multiple points of regulation for the activity of GPI-linked Wnts. I hypothesize that Oto functions to regulate cellular sorting, secretion and/or tissue mobility of Wnts, thus regulating the availability and/or signaling efficiency of Wnts. To address this hypothesis, I will examine Oto function at multiple levels. I will examine well-described features of spinal cord development known to be under Wnt control, including progenitor proliferation and dorsal-ventral patterning, and correlate potential findings to changes in Wnt signal transduction. I will also examine the function of Oto in the maturation of Wnt proteins through the secretory pathway in cultured cell systems. Furthermore, I will directly analyze the function of Oto in the establishment of chick Wnt1 protein distribution in the chick spinal cord. For the spinal cord experiments, both mouse genetics and in ovo chick embryo electroporation will be utilized. The proposed studies should expand our understanding of spinal cord development and Wnt signaling regulation. A number of human diseases and malformations are associated with developmental defects in the Wnt pathway, including holoprosencephaly, brain tumors and neural tube defects. Many of these syndromes have a genetic basis in mutations affecting the Wnt pathway, but teratogenic effects of drugs augmenting the Wnt pathway are also an important cause of neural tube defects in humans. This proposal will allow new understanding of the molecular and developmental events causing these important syndromes.

描述（由申请人提供）：Wnt信号传导是控制脊椎动物中枢神经系统生长和模式的关键途径之一。 Wnt信号通路成分中的突变通常会导致影响神经系统的先天缺陷和肿瘤。因此，在神经系统发展的背景下，了解WNT调节的机制对于我们对疾病的理解和治疗至关重要。这项研究的重点是阐明OTO（Wnt蛋白的新调节剂）在脊髓发育和Wnt信号通路中的作用。耳畸形突变体具有多种表型，这些表型似乎是由于Wnt信号的过量或早期发作，包括Holoproposenchephaly，Agnathia和脊髓过度生长。 OTO基因座编码适当的糖基磷脂酰肌醇（GPI） - 修饰Wnt所需的酶。这为WNT调节机制提供了潜在的新见解。在某些生理条件下，可以将其分泌并被认为是远程信号分子的WNT被GPI锚定为脂质膜。 GPI连接的蛋白针对脂质筏，并与分泌途径中NONGPI连接蛋白的一般种群分离。 GPI修饰赋予的复杂生物学为GPI连接WNT的活性提供了多个调节点。我假设OTO功能可以调节WNT的细胞分选，分泌和/或组织迁移率，从而调节WNT的可用性和/或信号传导效率。为了解决这一假设，我将在多个级别检查OTO功能。我将检查已知在WNT控制下的脊髓发育的描述良好的特征，包括祖细胞增殖和背腹模式，并将潜在的发现与Wnt信号转导的变化相关联。我还将检查OTO通过培养细胞系统中的分泌途径在Wnt蛋白成熟中的功能。此外，我将直接分析OTO在雏鸡脊髓中鸡Wnt1蛋白分布建立中的功能。对于脊髓实验，将使用小鼠遗传学和在OVO雏鸡胚胎中的电穿孔。拟议的研究应扩大我们对脊髓发育和WNT信号调节的理解。许多人类疾病和畸形与Wnt途径中的发育缺陷有关，包括全脑脑，脑肿瘤和神经管缺陷。这些综合征中的许多在影响WNT途径的突变中具有遗传基础，但是增强WNT途径的药物的致膜作用也是人类神经管缺陷的重要原因。该提案将允许对引起这些重要综合症的分子和发育事件的新理解。