Nogo's role in intracellular trafficking

描述(由申请人提供)：NOGO通过神经元表面受体NGR作用于髓鞘表面，从而抑制轴突生长。针对Nogo-NGR通路的治疗方法在治疗脊髓损伤和其他中枢神经系统疾病方面显示出良好的前景。然而，关于Nogo在未受损伤的细胞中的功能仍有许多未知之处。Nogo是网状蛋白家族的一员，该家族是一组与内质网(ER)相关的保守蛋白质，功能不明。Nogo的大部分表达是细胞内的，而不是表面相关的。此外，Nogo在神经元和少突胶质细胞中也有显著表达。这些事实证明，Nogo除了抑制轴突生长外，还发挥了其他作用。我们已经获得的数据表明，Nogo亚型调节细胞内的交通。此外，NOGO水平影响轴突运输的特殊神经元运输途径。Nogo可能通过Rab家族的小GTP酶来调节其对交通的影响。此外，Nogo可能会影响其自身受体的贩运，从而产生一种以前从未探索过的NGR调控形式。最后，在运动神经元病的背景下，Nogo可能会提高神经元的存活率。更好地理解这些作用是至关重要的，因为正在开发治疗中枢神经系统损伤的阻断Nogo途径的疗法。这项提议的目的是利用各种细胞成像和生化技术进一步探索NOGO参与细胞内转运的机制。通过野生型和Nogo基因敲除小鼠神经元的活细胞成像研究，将探索Nogo对轴突运输和突触小泡回收的专门神经元运输途径的影响。这些研究将在神经再生和轴突信号转导领域的领导者斯蒂芬·M·斯特里特马特博士的指导下进行。他和他的资金极其充足的实验室为开发成功的神经科学研究所需技术方面的专业知识提供了最佳环境。此外，耶鲁大学神经病学系致力于促进申请者的发展，限制临床责任，允许至少85%的精力用于研究，并在申请者在本提案期间过渡到运营独立实验室时保持开放的实验室空间。Nogo通路因其在阻止大脑和脊髓中受损神经再生方面的作用而被广泛研究。然而，这一建议表明，NOGO也发挥着重要作用，可能有助于未受损伤的神经功能。深入了解这些作用将有助于阐明Nogo参与肌萎缩侧索硬化症等疾病，并将有助于指导开发更安全的治疗方法，在脊髓损伤和其他毁灭性的中枢神经系统疾病的背景下抑制Nogo途径。

DESCRIPTION (provided by applicant): Nogo inhibits neurite outgrowth by acting at the myelin surface through a neuronal surface receptor, NgR. Therapies targeting the Nogo-NgR pathway show promise in the treatment of spinal cord injury and other central nervous system diseases. However, much remains unknown regarding Nogo's function in uninjured cells. Nogo is a member of the Reticulon family, a conserved set of endoplasmic reticulum (ER)-associated proteins with unclear functions. The bulk of Nogo expression is intracellular rather than surface-associated. Additionally, Nogo is prominently expressed in neurons as well as in oligodendrocytes. These facts argue for other roles played by Nogo besides inhibiting axon growth. We have obtained data suggesting that Nogo isoforms regulate intracellular traffic. Furthermore, Nogo levels affect the specialized neuronal trafficking pathway of axon transport. Nogo may mediate its effects on traffic through small GTPases of the Rab family. Additionally, Nogo may affect trafficking of its own receptor, thereby creating a form of NgR regulation that has not previously been explored. Finally, Nogo may enhance neuronal survival in the context of motor neuron disease. Better understanding of these roles is crucial as therapies are being developed to block the Nogo pathway in the treatment of central nervous system injury. The Aims of this proposal are to further explore the mechanisms of Nogo's involvement in intracellular trafficking using a variety of cell imaging and biochemical techniques. Nogo's effects on the specialized neuronal trafficking pathways of axon transport and synaptic vesicle recycling will be explored with live cell imaging studies in neurons from wild type and Nogo-knockout mice. These studies will be performed under the mentorship of Dr. Stephen M. Strittmatter, a leader in the field of neuroregeneration and axonal signal transduction. He and his extremely well-funded laboratory provide the optimal setting for developing expertise in the techniques required for successful neuroscientific research. Furthermore, Yale's Department of Neurology has committed to fostering the applicant's development by limiting clinical responsibilities to allow at least 85% effort devoted to research, and by keeping open laboratory space available as the applicant transitions to running an independent laboratory during the period of this proposal. The Nogo pathway is intensely studied for its role in blocking injured nerves in the brain and spinal cord from regenerating. However, this proposal shows that Nogo also plays important roles that may help uninjured nerves function. Insight into these roles will shed light on Nogo's involvement in diseases like amyotrophic lateral sclerosis, and will help guide the development of safer therapies to inhibit the Nogo pathway in the context of spinal cord injury and other devastating central nervous system diseases.