Mechanistic studies of novel factors regulating axon regeneration in the PNS/CNS

调节 PNS/CNS 轴突再生的新因子的机制研究

• 批准号: 8753538
• 负责人: Yuanquan Song
• 金额: $ 9.48万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2016-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8753538
• 关键词: Address; Adult; Afferent Neurons; American; Animal Model; Axon; Basic Science; Behavior; Biochemistry; Bioinformatics; Biological Assay; Biological Models; Biological Process; Brain; Brain Injuries; Candidate Disease Gene; Cell Culture Techniques; Clinical Research; Collaborations; Cues; Data; Development; Doctor of Philosophy; Drosophila genus; Endocytosis; Environment; Enzymes; Excision; Exhibits; Failure; Foundations; Future; Genes; Genetic; Genetic Screening; Goals; Health; Homologous Gene; Image; Injury; Intrinsic factor; Invertebrates; Knock-out; Knockout Mice; Knowledge; Laboratories; Lead; Link; Locomotion; Maintenance; Mammals; Mentors; Modeling; Molecular; Molecular Target; Multiple Sclerosis; Mus; Mutation; Natural regeneration; Nervous system structure; Neuraxis; Neurodegenerative Disorders; Neurologic Dysfunctions; Neuronal Injury; Neurons; Neurosurgical Procedures; Operative Surgical Procedures; Outcome; PTEN gene; Paper; Paralysed; Pathway interactions; Peripheral; Pharmacology; Phase; Physiological; Positioning Attribute; Publications; Publishing; RNA; RNA Processing; RNA Sequences; Reagent; Recovery of Function; Regulation; Research; Research Personnel; Research Project Grants; Rodent; Role; Societies; Solid; Spinal Injuries; Spinal cord injury; Spinal cord injury patients; Supervision; Testing; Time; Tissues; Transgenic Model; Traumatic Brain Injury; United States National Academy of Sciences; Work; axon regeneration; axonal degeneration; base; career; central nervous system injury; coping; developmental neurobiology; disability; effective therapy; extracellular; fly; improved; inhibitor/antagonist; innovation; inorganic phosphate; insight; loss of function; member; mutant; nerve injury; nervous system disorder; neural circuit; new therapeutic target; novel; novel strategies; overexpression; post-doctoral training; professor; programs; regenerative; research study; residence; screening; spinal cord and brain injury; spinal cord surgery; tool; young adult

DESCRIPTION (provided by applicant): My long-term career goal is to elucidate the cellular and molecular basis governing the maintenance and function of neural circuits under physiological and pathological conditions. To understand how the nervous system copes with injury thus offers a unique opportunity to tap into these questions and defines the objective of this proposal-to identify and delineate novel factors regulating axon regeneration, and develop effective strategies to promote axon regeneration based on these new targets. To lay a solid foundation for achieving this goal, I joined the laboratory of Dr. Yuh Nung Jan, a world-renowned pioneer in studying neural circuits assembly and function. I initiated my postdoctoral research by establishing a Drosophila sensory neuron injury model that resembles the mammalian injury model at the phenotypical and molecular level, to screen for novel regulators of axon regeneration. My studies have already led to the identification of the RNA processing enzyme Rtca as an inhibitory factor for axon regeneration in the central nervous system (CNS). Successful completion of the proposed studies will validate the novel concept of targeting the Rtca pathway in treating neural injury and neurodegenerative diseases, and spur my future independent research to uncover the repertoire of molecules governing regeneration. Damage to the adult CNS, such as spinal cord injury (SCI) often leads to persistent deficits due to the inability of mature axons to regenerate after injury. Under pathological situations such as multiple sclerosis (MS), the second most common neurological disorder leading to disability in young adults, the failure of damaged axons to regenerate contributes to non-reversible neurologic dysfunction. Currently, only a few therapies with limited efficacy are available, highlighting the urgent need to identify novel molecular targets and develop targeted therapies. To this end, I have focused my postdoctoral research on building a platform to take advantages of the power of fly genetics in discovering novel factors together with the mammalian injury model to study their homologs and functional recovery. I propose two directions to go after the regeneration regulators: in specific aim 1, I will determine the interplay between axon degeneration and regeneration, test the hypothesis that perturbing degeneration delays regeneration; in specific aims 2 and 3, I will determine the mechanisms underlying dRtca/Rtca's regulation on axon regeneration using fly and mouse injury models, and test the hypothesis that removal of dRtca/Rtca enhances circuit reassembly and functional recovery. My extensive study has already resulted in a recent first author publication in Genes and Development in 2012 (cover article), with two co-first author papers in revision in Neuron and Nat Neurosci. I have generated many novel reagents (e.g. the Drosophila injury model, transgenic and knockout fly strains, and knockout mice), and assembled an extraordinary advisory team consisting of co-mentors (Dr. Michael S. Beattie, Professor in Residence of Neurological Surgery at UCSF, Director of Research of UCSF Brain and Spinal Injury Center (BASIC); Dr. Jacqueline C. Bresnahan, Professor of Neurological Surgery at UCSF and President of the National Neurotrauma Society), and consultant (Dr. Jonathan S. Weissman, Professor of Cellular Pharmacology and Biochemistry at UCSF, an HHMI investigator and a member of the National Academy of Science). I have also established close collaborations with members of the BASIC at UCSF, which specializes in animal models of brain and spinal cord injury. The culture of BASIC is highly collaborative, and includes both basic and clinical research projects in neurotrauma. I am therefore uniquely poised to undertake the novel studies proposed in this application with great translational potential. Research proposed in my K99 mentored phase (year 1 and 2) is mainly focused on studying the regulation of axon regeneration by degeneration and dRtca in flies, as well as establishing the mice injury model. I will carry out these proposed experiments with the supervision of Dr. Yuh Nung Jan and support from my advisory team. In the R00 independent phase (year 3 to 5), I will focus on characterizing the roles of four new factors, which came out from my degeneration screen, in modulating regeneration in flies, as well as studying the function of Rtca in regulating regeneration in mice, with the continual support from my advisory/collaborative team. At the completion of this project I expect to have (1) established mechanistic links between axon degeneration and regeneration, (2) determined the molecular mechanisms of how removal of dRtca/Rtca promotes CNS axon regeneration in flies and mice, and (3) identified additional new regulators of axon degeneration/regeneration. My proposed research is highly innovative because our knowledge of the underlying mechanisms is still far from complete for axon degeneration/regeneration, and my studies will bring in new approaches to systematically uncover novel regulators, with the potential to provide new therapeutic targets. With a Ph.D. background in developmental neurobiology, and postdoctoral training in bioinformatics, mouse genetics and surgery, I possess a unique skillset and hence am in a highly advantageous position to accomplish the proposed novel studies. Dr. Jan has extended his full support towards my career goals and has encouraged me to take these projects to my independent lab in the future. The proposed studies build logically on my prior and ongoing works as evidenced by my recent publication, and will undoubtedly prepare me to lead a novel and strong independent research program in the near future.

描述（由申请人提供）：我的长期职业目标是阐明在生理和病理条件下神经回路的维持和功能的细胞和分子基础。了解神经系统如何应对损伤，从而提供了一个独特的机会，挖掘这些问题，并确定了这个提议的目标，以确定和描绘新的因素调节轴突再生，并制定有效的策略，以促进轴突再生的基础上，这些新的目标。为了实现这一目标奠定坚实的基础，我加入了Yuh Nung Jan博士的实验室，他是研究神经回路组装和功能的世界知名先驱。我通过建立一个在表型和分子水平上类似于哺乳动物损伤模型的果蝇感觉神经元损伤模型开始了我的博士后研究，以筛选轴突再生的新调节因子。我的研究已经导致RNA加工酶Rtca作为中枢神经系统（CNS）轴突再生的抑制因子的鉴定。拟议研究的成功完成将验证靶向Rtca通路治疗神经损伤和神经退行性疾病的新概念，并刺激我未来的独立研究，以揭示控制再生的分子库。对成年CNS的损伤，例如脊髓损伤（SCI），通常由于损伤后成熟轴突不能再生而导致持续性缺陷。在病理情况下，如多发性硬化症（MS），第二个最常见的神经系统疾病，导致残疾的年轻人，受损的轴突再生的失败有助于不可逆的神经功能障碍。目前，只有少数疗效有限的治疗方法可用，突出了迫切需要确定新的分子靶点和开发靶向治疗。为此，我把博士后研究的重点放在建立一个平台，利用苍蝇遗传学的力量，发现新的因素与哺乳动物损伤模型一起研究它们的同源物和功能恢复。我提出了两个方向的再生调控：在具体目标1中，我将确定轴突变性和再生之间的相互作用，测试扰动变性延迟再生的假设;在具体目标2和3中，我将使用果蝇和小鼠损伤模型确定dRtca/Rtca对轴突再生的调节的潜在机制，并检验去除dRtca/Rtca增强电路重组和功能恢复的假设。我的广泛研究已经导致了最近的第一作者发表在2012年的《基因与发育》（封面文章），还有两篇共同第一作者的论文在《神经元》和《自然神经科学》的修订版中。我已经产生了许多新的试剂（例如果蝇损伤模型，转基因和基因敲除果蝇品系，和基因敲除小鼠），并组建了一个由共同导师组成的非凡顾问团队（Michael S. Beattie，加州大学旧金山分校神经外科住院教授，加州大学旧金山分校脑和脊髓损伤中心（BASIC）研究主任; Bresnahan，加州大学旧金山分校神经外科教授和国家神经创伤学会主席）和顾问（Jonathan S。韦斯曼，加州大学旧金山分校细胞药理学和生物化学教授，HHMI研究员和国家科学院院士）。我还与加州大学旧金山分校的BASIC成员建立了密切的合作关系，该组织专门研究脑和脊髓损伤的动物模型。BASIC的文化是高度合作的，包括神经创伤的基础和临床研究项目。因此，我唯一准备承担这项申请中提出的具有巨大翻译潜力的新研究。我在K99指导阶段（第1年和第2年）提出的研究主要集中在研究果蝇中变性和dRtca对轴突再生的调节，以及建立小鼠损伤模型。我将在Yuh Nung Jan博士的监督和我的顾问团队的支持下进行这些拟议的实验。在R 00独立阶段（第3至5年），我将专注于表征从我的退化筛选中产生的四种新因子在调节果蝇再生中的作用，以及研究Rtca在调节小鼠再生中的功能， 在我的咨询/合作团队的持续支持下。在这个项目完成后，我希望（1）建立轴突变性和再生之间的机制联系，（2）确定去除dRtca/Rtca如何促进果蝇和小鼠CNS轴突再生的分子机制，（3）确定轴突变性/再生的其他新调节因子。我提出的研究是高度创新的，因为我们对轴突变性/再生的潜在机制的了解还远远没有完成，我的研究将带来新的方法来系统地发现新的调节剂，并有可能提供新的治疗靶点。具有博士学位我有发育神经生物学的背景，以及生物信息学、小鼠遗传学和外科学的博士后培训，我拥有独特的技能，因此我处于非常有利的地位来完成所提出的新研究。Jan博士对我的职业目标给予了全力支持，并鼓励我将来将这些项目带到我的独立实验室。拟议的研究逻辑上建立在我以前和正在进行的工作，我最近的出版物证明，无疑将准备我在不久的将来领导一个新颖而强大的独立研究计划。