RUI: Examining Molecular Players Integrating Autophagy and Neuronal Development and Maintenance

RUI：检查整合自噬和神经元发育和维护的分子参与者

• 批准号: 1656839
• 负责人: Andrea Holgado
• 金额: $ 60万
• 依托单位: Southwestern Oklahoma State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-05-01 至 2017-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1656839&HistoricalAwards=false
• 关键词: RUI; Examining; Molecular; Players; Integrating

During embryonic development, nervous system cells grow and branch off to make specialized connections with other nerve cells (synapses). Synapses are essential for the cell-to-cell communication that nervous systems need to function properly, and are created after threadlike cellular projections, known as axons, reach another target cell. One step in synapse formation involves removing extra material from axons by a process called autophagy. The present research project examines the precise role of one key protein (UNC-33/CRMP-2) that is known from previous work to affect axon growth and maintenance. Experiments use the roundworm C. elegans because of the advantages it offers for genetic manipulation and live cell imaging. Genetic lesions will be introduced in the gene coding for UNC-33/CRMP2, and the hypothesis that this molecule simultaneously regulates autophagy and synapse development will be tested using sophisticated cellular imaging and analysis techniques. This study has the potential to contribute to a deeper understanding of the molecular mechanisms underlying the development of neuronal circuits, as well as to a better understanding of defects in the growth and maintenance of synapses that are characteristic of a range of neurological diseases including autism, schizophrenia, and anxiety disorders. Moreover, this research will be carried out with the assistance of, and support the training of, undergraduate students at Southwestern Oklahoma State University. This project includes a variety of outreach programs for local elementary and high schools, and educational engagement with the general public on topics related to brain development and function.Despite the wealth of information surrounding neurodevelopment and neuronal survival, it is still unclear why neuronal components shown to work at the level of axonal outgrowth and cytoskeleton stability bind to components of the autophagy machinery. Moreover, it is undetermined why autophagy gene products, first characterized in yeast as Atg1, 6, 8, 9, 13, 18, are enriched in the nervous system. To shed light on the link of autophagy and neuronal development and survival, the investigators propose to characterize the role of UNC-33 in neuronal autophagy. The nematode unc-33 gene encodes for conserved members of the CRMP/TOAD/Ulip/DRP family of proteins. In C. elegans, UNC-33 isoforms mediate axonal guidance and axonogenesis in neurons. Moreover, preliminary investigations show that unc-33 mutants have a defect in dauer larva formation, an arrested developmental stage that survives in harsh environments due to enhanced cellular autophagy. In this study, the investigators will test the hypothesis that autophagy and UNC-33 serve to protect against defects in neuronal development and/or neuronal stability. In aim 1, they will define the role of UNC-33 in autophagy in neurons. In aim 2, they will characterize the role of basal autophagy in the maintenance of long-lived cells such as neurons. In aim 3, they propose to uncover the mechanism underlying the synthetic lethality of unc-33; daf-2 double mutants. Together, these studies will advance understanding of both autophagy and neuronal development and maintenance; will significantly enhance undergraduate education and the integration of research in the classroom; and will promote outreach to local communities.

在胚胎发育过程中，神经系统细胞生长并形成分支，与其他神经细胞（突触）建立专门的连接。突触对于神经系统正常运作所需的细胞与细胞之间的通信至关重要，并且是在被称为轴突的线状细胞投射到达另一个靶细胞后产生的。突触形成的一个步骤是通过一种叫做自噬的过程从轴突上去除多余的物质。目前的研究项目检查了一个关键蛋白质（CRMP-33/CRMP-2）的确切作用，该蛋白质从以前的工作中已知会影响轴突的生长和维持。实验用蛔虫C.因为它提供了遗传操作和活细胞成像的优势。遗传损伤将被引入到编码CRMP-33/CRMP 2的基因中，并且该分子同时调节自噬和突触发育的假设将使用复杂的细胞成像和分析技术进行测试。这项研究有可能有助于更深入地了解神经元回路发育的分子机制，以及更好地了解突触生长和维持缺陷，这些缺陷是一系列神经系统疾病的特征，包括自闭症，精神分裂症和焦虑症。此外，这项研究将在西南俄克拉荷马州州立大学的协助下进行，并支持对本科生的培训。 该项目包括为当地小学和高中开展的各种外展计划，以及与公众就与大脑发育和功能相关的主题进行的教育参与。尽管围绕神经发育和神经元存活的信息丰富，但仍不清楚为什么在轴突生长和细胞骨架稳定性水平上起作用的神经元成分与自噬机制的成分结合。 此外，尚不确定为什么自噬基因产物，首先在酵母中表征为Atg 1，6，8，9，13，18，在神经系统中富集。为了阐明自噬与神经元发育和存活的联系，研究人员建议描述β-33在神经元自噬中的作用。线虫unc-33基因编码CRMP/TOAD/Ulip/DRP蛋白家族的保守成员。In C. elegans，β-33同种型介导神经元中的轴突导向和轴突发生。此外，初步研究表明unc-33突变体在dauer幼虫形成方面有缺陷，dauer幼虫形成是一个发育停滞阶段，由于细胞自噬增强而在恶劣环境中存活。 在这项研究中，研究人员将测试自噬和β-33有助于防止神经元发育和/或神经元稳定性缺陷的假设。在目标1中，他们将定义β-33在神经元自噬中的作用。在目标2中，他们将描述基础自噬在维持长寿细胞（如神经元）中的作用。在目标3中，他们提出要揭示unc-33; daf-2双突变体的合成致死性的潜在机制。总之，这些研究将促进对自噬和神经元发育和维持的理解;将显著提高本科教育和课堂研究的整合;并将促进与当地社区的联系。