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: 7328890
• 负责人: Roeben Munji
• 金额: $ 2.95万
• 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/7328890
• 关键词: Address; Affect; Biology; Brain Neoplasms; Cell Culture System; Cell membrane; Cells; Chick Embryo; Collaborations; Complementary DNA; Complex; Condition; 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; Numbers; Pathway interactions; Pattern; Pharmaceutical Preparations; Phenotype; Phospholipase; Physiological; Positioning Attribute; Protein Overexpression; Proteins; RNA Interference; Range; Regulation; Reporter; Role; Series; Signal Pathway; Signal Transduction; Signaling Molecule; Sorting - Cell Movement; Spinal Cord; Syndrome; Thinking; Time; Tissues; Transgenic Organisms; Transport Vesicles; Wnt proteins; Wnt1 Protein; Work; base; concept; design; early onset; human disease; insight; link protein; malformation; mutant; nervous system development; novel; 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化的关键途径之一。Wnt信号通路组分的突变通常会导致出生缺陷和影响神经系统的肿瘤。因此，了解神经系统发育背景下Wnt调控的机制对于我们理解和治疗疾病至关重要。本研究的重点是阐明一种新的Wnt蛋白调节因子Oto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信号传导过量或早发所致，包括全颅畸形、无颌症和脊髓过度生长。Oto基因座编码Wnt的适当糖基磷脂酰肌醇（GPI）修饰所需的酶。这为Wnt调控机制提供了潜在的新见解。Wnt被认为是一种长距离的信号分子，在某些生理条件下可以被GPI锚定在脂质膜上。GPI连接的蛋白质靶向脂筏，并在分泌途径中与非GPI连接的蛋白质的一般群体分离。GPI修饰赋予的复杂生物学为GPI相关Wnt的活性提供了多个调节点。我推测Oto的功能是调节Wnt的细胞分选、分泌和/或组织移动性，从而调节Wnt的可用性和/或信号传导效率。为了解决这个假设，我将在多个层面上检查Oto功能。我将研究已知在Wnt控制下的脊髓发育的良好描述特征，包括祖细胞增殖和背腹图案，并将潜在的发现与Wnt信号转导的变化相关联。我还将研究Oto在培养细胞系统中通过分泌途径在Wnt蛋白成熟中的功能。此外，我将直接分析Oto在建立鸡Wnt 1蛋白在鸡脊髓中的分布中的功能。对于脊髓实验，将使用小鼠遗传学和卵内鸡胚电穿孔。这些研究将扩大我们对脊髓发育和Wnt信号调控的理解。许多人类疾病和畸形与Wnt通路的发育缺陷有关，包括前脑无裂畸形、脑肿瘤和神经管缺陷。这些综合征中的许多在影响Wnt通路的突变中具有遗传基础，但是增强Wnt通路的药物的致畸作用也是人类神经管缺陷的重要原因。这一建议将使新的分子和发育事件导致这些重要的综合征的理解。