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，抑制神经突生长。针对Nogo-NgR通路的疗法在脊髓损伤和其他中枢神经系统疾病的治疗中显示出希望。然而，关于Nogo在未损伤细胞中的功能，仍有许多未知之处。Nogo是Reticulon家族的一员，Reticulon家族是一组功能不明确的内质网（ER）相关的保守蛋白。Nogo的大部分表达是在细胞内而不是表面相关的。此外，Nogo在神经元和少突胶质细胞中显著表达。这些事实证明，除了抑制轴突生长外，Nogo还具有其他作用。我们已经获得的数据表明Nogo亚型调节细胞内交通。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gtpase介导其对交通的影响。此外，Nogo可能会影响其自身受体的贩运，从而形成一种以前未被探索过的NgR调节形式。最后，在运动神经元疾病的情况下，Nogo可能会提高神经元的存活率。更好地了解这些作用是至关重要的，因为正在开发阻断Nogo通路治疗中枢神经系统损伤的疗法。本提案的目的是利用各种细胞成像和生化技术进一步探索Nogo参与细胞内贩运的机制。Nogo对轴突运输和突触囊泡循环的特殊神经元运输通路的影响将通过野生型和Nogo敲除小鼠神经元的活细胞成像研究来探索。这些研究将在Stephen M. Strittmatter博士的指导下进行，他是神经再生和轴突信号转导领域的领导者。他和他的资金极其充足的实验室为成功的神经科学研究所需的技术发展提供了最佳的环境。此外，耶鲁大学神经学系致力于促进申请人的发展，限制临床责任，允许至少85%的精力用于研究，并在申请人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通路因其在阻断脑和脊髓损伤神经再生中的作用而受到广泛研究。然而，这一提议表明，Nogo也起着重要的作用，可能有助于未受伤的神经功能。对这些作用的深入了解将有助于阐明Nogo在肌萎缩性侧索硬化症等疾病中的作用，并将有助于指导开发更安全的疗法，在脊髓损伤和其他破坏性中枢神经系统疾病的背景下抑制Nogo通路。

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.