DISSECTING MOLECULAR AND GENETIC MECHANISMS THAT PROMOTE MYELINATION

剖析促进髓鞘形成的分子和遗传机制

基本信息

批准号：
8718487
负责人：
Sarah Petersen
金额：
$ 5.33万
依托单位：
WASHINGTON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-03-01 至 2017-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8718487
关键词：
Action Potentials Adhesions Alleles Axon Binding Biological Models C-terminal Caliber Cell Communication Cell Differentiation process Cell membrane Cells Cellular biology Charcot-Marie-Tooth Disease Cleaved cell Data Defect Demyelinating Diseases Demyelinations Development Disease Enhancers Extracellular Domain Family Foundations G Protein-Coupled Receptor Genes G-Protein-Coupled Receptors Gene Mutation Genes Genetic Genetic Screening Genomics Human In Situ Hybridization Inherited Ligands Membrane Modeling Molecular Genetics Multiple Sclerosis Mus Mutant Strains Mice Mutation Myelin Myelin Sheath N-terminal Nerve Nervous system structure Neuraxis Neuroglia Neurons Neuropathy Numbness Orphan Pain Peripheral Peripheral Nerves Peripheral Nervous System Pharmacologic Substance Phenotype Process Radial Reporter Resources Role Schwann Cells Signal Transduction Sorting - Cell Movement Staging Structure Syndrome Technology Testing Transgenic Organisms Transmission Electron Microscopy Universities Washington Work Zebrafish base design in vivo innovation molecular domain mutant myelination myelinopathy nervous system disorder novel prevent programs public health relevance receptor therapeutic target therapy development

项目摘要

DESCRIPTION (provided by applicant): Myelin is a multilayered membrane that ensheathes axons in vertebrate nervous systems. In the peripheral nervous system, specialized glia called Schwann cells wrap themselves around axonal segments to form the myelin sheath. Myelin is essential for trophic support of neurons and provides insulation to efficiently conduct nerve impulses. Disruption of the peripheral myelin sheath can result in devastating neuropathies such as Charcot-Marie-Tooth (CMT) disease. There are currently no treatments to prevent de-myelination or stimulate re-myelination, and development of these therapies is hindered by an incomplete understanding of the genetic and molecular factors that drive Schwann cells to form the myelin sheath. Schwann cell myelination requires Gpr126, an orphaned adhesion family G protein-coupled receptor (aGPCR). Loss of Gpr126 function in vertebrate models results in arrested development of Schwann cells at the promyelinating state and reduced or absent peripheral myelin. Although Gpr126 is essential for peripheral myelination, very little is known about the mechanism by which it functions. This study will utilize the zebrafish model system to define the role of Gpr126 in myelination. In the first aim, I will use structure-function analysis o define the molecular domains of Gpr126 that regulate key steps in peripheral myelination. I predict that the large N-terminal domain of Gpr126 has a distinct function in sorting each Schwann cell around a single large-caliber axon. In contrast, I hypothesize the transmembrane C-terminus of Gpr126 is sufficient to direct the Schwann cell to wrap the axon following sorting. I will generate specific zebrafish mutants and perform in vivo analyses to test these hypotheses. In my second aim, I will perform an innovative forward genetic screen for mutations that enhance or suppress myelin defects in gpr126 hypomorphic mutants. This enhancer/suppressor screen will identify regulators of the Gpr126 myelination program as well as novel factors that function in parallel to Gpr126 for myelination. By defining the molecular and genetic factors that promote myelination, these studies will provide the basis for identifying causative mutations for genetic neuropathies like CMT. This work also will also deepen our understanding of Schwann cell biology and can lay the foundation for developing therapies to treat demyelination and promote re-myelination of peripheral nerves.

描述（由申请人提供）：髓磷脂是一种多层膜，可在脊椎动物神经系统中包含轴突。在周围神经系统中，称为Schwann细胞的专门神经胶质包裹在轴突段周围形成髓鞘鞘。髓磷脂对于神经元的营养支持至关重要，并提供了有效进行神经冲动的绝缘材料。外周髓磷脂鞘的破坏会导致造成毁灭性的神经病，例如charcot-marie-tooth（CMT）疾病。目前尚无治疗方法可以防止脱髓性或刺激再髓鞘形成，并且对这些疗法的发展受到了对驱动schwann细胞形成髓鞘鞘的遗传和分子因子的不完全理解。 Schwann细胞髓鞘形成需要GPR126，这是一种孤立的粘附家族G蛋白偶联受体（AGPCR）。脊椎动物模型中GPR126功能的丧失导致在寄生虫状态下的雪旺细胞发育，并减少或不存在外周髓髓磷脂。尽管GPR126对于周围髓鞘化至关重要，但对其功能的机制知之甚少。这项研究将利用斑马鱼模型系统来定义GPR126在髓鞘中的作用。在第一个目标中，我将使用结构功能分析o定义调节外围髓鞘中关键步骤的GPR126的分子结构域。我预测，GPR126的大N末端结构域在对单个大型轴突周围的每个Schwann细胞进行分类方面具有明显的功能。相比之下，我假设GPR126的跨膜C端足以指导Schwann细胞在排序后包裹轴突。我将产生特定的斑马鱼突变体并进行体内分析以检验这些假设。在我的第二个目标中，我将对突变进行创新的前向遗传筛选，以增强或抑制GPR126肌明和肌肌髓磷脂缺陷。该增强子/抑制器屏幕将识别GPR126髓鞘化程序的调节因子以及与GPR126并行作用的新因素。通过定义促进髓鞘化的分子和遗传因素，这些研究将为鉴定CMT等遗传神经病的病因突变提供基础。这项工作还将加深我们对Schwann细胞生物学的理解，并为开发治疗脱髓鞘和促进外周神经的髓鞘形成奠定基础。