Strn3 is a novel Rac1 effector in Schwann cells

Strn3 是雪旺细胞中一种新型 Rac1 效应子

基本信息

批准号：
10066569
负责人：
Michael Weaver
金额：
$ 3.12万
依托单位：
STATE UNIVERSITY OF NEW YORK AT BUFFALO
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-08-01 至 2021-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10066569
关键词：
Ablation Actins Animals Axon Biochemical Biological Assay Cell Differentiation process Cell physiology Cells Clinical Co-Immunoprecipitations Communication Complex Critical Thinking Crush Injury Cytoskeletal Modeling Data Defect Deformity Demyelinating Diseases Development Disease Electron Microscopy Electrophysiology (science)Financial compensation GTP Binding Goals Immunofluorescence Immunologic Impairment In Vitro Individual Injury Integrin alpha6beta1 Interdisciplinary Study Joints Laboratories Laboratory Study Laminin Measures Mediating Membrane Microtomy Morphology Motor Mus Muscle Weakness Muscular Atrophy Myelin Nerve Neural Conduction Neuropathy Neurosciences Nuclear Translocation Outcome Pain Paresthesia Pathway interactions Patients Performance Peripheral Nerves Peripheral Nervous System Peripheral Nervous System Diseases Peripheral nerve injury Phenotype Phosphoproteins Phosphoric Monoester Hydrolases Phosphotransferases Physiological Play Problem Solving Process Protein Phosphatase 2A Regulatory Subunit PR53 Proteins Proteomics Radial Rattus Recovery of Function Regenerative response Regulation Research Institute Research Training Role Schwann Cells Sensory Sorting - Cell Movement Technical Expertise Techniques Testing Tissues Training Transcription Coactivator Western Blotting afferent nerve base burden of illness cell motility defined contribution disabling symptom experience experimental study knock-down member mouse model myelination nervous system development new therapeutic target novel polymerization remyelination repaired response to injury scaffold sciatic nerve

项目摘要

Project Summary / Abstract During peripheral nervous system (PNS) development, Schwann cells (SCs) undergo extensive Rac1- dependent cytoskeletal reorganization as they insert cytoplasmic extensions into axon bundles to radially sort, ensheath, and myelinate individual axons. Similarly, following peripheral nerve injury there is extensive Rac1- dependent actin polymerization around specialized regions known as Schmidt-Lantermann incisures (SLIs) as SCs differentiate into a repair phenotype2. The Feltri laboratory previously demonstrated that Rac1 activation in SCs is driven by engagement of α6β1 integrin with laminins, and that this is essential for peripheral nerve development4. Using a proteomic screen, we then identified Striatin-3 (Strn3) as a novel candidate Rac1 interactor in peripheral nerves. Striatin proteins (Strn1/3/4) function as core scaffolding components of STriatin- Interacting Phosphatase And Kinase (STRIPAK) complexes. STRIPAK complex members include the upstream Hippo pathway kinases Mst1/2 and the phosphatase PP2A-C, which dephosphorylates Mst1/2 to deactivate the Hippo pathway, permitting nuclear translocation of the mechanosensitive transcriptional co- activators Yap/Taz26,27,28. The Feltri laboratory previously demonstrated that Yap/Taz activity in SCs is also critical for myelinated peripheral nerve development25. Initial in vitro data suggest that knockdown of Strn3 in SCs impairs their ability to adhere to various substrates, decreases proliferation, and disrupts their association with axons. I then generated a mouse model with Strn3 specifically deleted in SCs (Strn3SCKO) and demonstrated early radial sorting and hypomyelination defects. Additionally, Strn3 null SCs isolated from these animals display reduced elongation and process extension on a laminin substrate. I thus hypothesize that Strn3 is required in SCs for peripheral nerve development and injury response via interaction with Rac1 and STRIPAK-mediated regulation of the Hippo pathway. To investigate this hypothesis, Strn3SCKO mice will be further characterized by morphological, functional, and electrophysiological measures during development and after injury. Cell and biochemical experiments in tissues and isolated Strn3 null SCs will determine if Strn3 indeed regulates SCs by interacting with Rac1, the STRIPAK complex, and the Hippo pathway. The long-term goal of this project is to understand the functions of Strn3 and the STRIPAK complex during peripheral nerve development and repair to advance the field of basic neuroscience and to identify new therapeutic targets with the potential to alleviate the burden of disease for patients suffering from demyelinating neuropathies and traumatic peripheral nerve injuries. This project will be integrated with a training plan that emphasizes scientific communication, problem solving, critical thinking, technical skills, and clinical experience. Research training will take place at the Hunter James Kelly Research Institute, an interdisciplinary research center devoted to understanding and treating diseases of myelin.

项目概要/摘要在周围神经系统 (PNS) 发育过程中，雪旺细胞 (SC) 经历广泛的 Rac1- 依赖的细胞骨架重组，因为它们将细胞质延伸插入轴突束中以进行径向排序，类似地，周围神经损伤后，存在广泛的 Rac1- 鞘和髓鞘化轴突。围绕称为 Schmidt-Lantermann 切口 (SLI) 的特殊区域的依赖性肌动蛋白聚合 Feltri 实验室先前证明，SCs 分化为修复表型2。 SC 由 α6β1 整合素与层粘连蛋白的结合驱动，这对于周围神经至关重要然后，我们使用蛋白质组学筛选，将 Striatin-3 (Strn3) 确定为新的候选 Rac1。 Striatin 蛋白 (Strn1/3/4) 作为 STriatin- 的核心支架成分发挥作用。相互作用的磷酸酶和激酶 (STRIPAK) 复合物成员包括上游 Hippo 通路激酶 Mst1/2 和磷酸酶 PP2A-C，可将 Mst1/2 去磷酸化失活 Hippo 通路，允许机械敏感转录共核转位激活剂 Yap/Taz26,27,28 Feltri 实验室先前证明 SC 中的 Yap/Taz 活性也是如此。初步体外数据表明，Strn3 的敲低对有髓周围神经发育至关重要。 SC 损害其粘附各种底物的能力，减少增殖并破坏其结合然后我生成了一个小鼠模型，其中在 SC 中专门删除了 Strn3 (Strn3SCKO) 和此外，从这些细胞中分离出 Strn3 null SCs 的早期放射状分选和髓鞘形成不足。动物在层粘连蛋白基质上表现出伸长和过程延伸减少，因此我寻求这一点。 Strn3 在 SC 中是周围神经发育和损伤反应所必需的，通过与 Rac1 和 STRIPAK 介导的 Hippo 通路调节为了研究这一假设，将使用 Strn3SCKO 小鼠。进一步通过发育和发育过程中的形态学、功能和电生理学测量来表征损伤后，组织和分离的 Strn3 缺失 SC 中的细胞和生化实验将确定 Strn3 是否存在。确实通过与 Rac1、STRIPAK 复合体和 Hippo 通路相互作用来调节 SC。该项目的目标是了解 Strn3 和 STRIPAK 复合物在周围神经过程中的功能开发和修复以推进基础神经科学领域并确定新的治疗靶点减轻脱髓鞘性神经病患者疾病负担的潜力，该项目将与强调科学的训练计划相结合。沟通、解决问题、批判性思维、技术技能和临床经验。亨特·詹姆斯·凯利研究所是一个跨学科研究中心，致力于了解和治疗髓磷脂疾病。