Regulation of myelination by myosin II-mediated mechanotransduction

肌球蛋白 II 介导的机械转导对髓鞘形成的调节

• 批准号: 8828793
• 负责人: Carmen V Melendez-Vasquez
• 金额: $ 34.43万
• 依托单位: HUNTER COLLEGE
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-04-01 至 2016-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8828793
• 关键词: Address; Adopted; Affect; Alleles; Axon; Basal lamina; Biological; Brain; Breeding; Cell Differentiation process; Cells; Cellular Morphology; Characteristics; Clinical; Corpus Callosum; Cytoskeleton; Data; Demyelinations; Development; Differentiation Antigens; Disease; Down-Regulation; ESR1 gene; Elasticity; Embryo; Employee Strikes; Environment; Exhibits; Extracellular Matrix; Extracellular Matrix Proteins; Genes; Goals; Guillain-Barré Syndrome; Immunofluorescence Immunologic; Inflammatory; Knockout Mice; Knowledge; Laboratories; Life; Link; Lysophosphatidylcholines; Mechanics; Mediating; Molecular; Monomeric GTP-Binding Proteins; Morphogenesis; Morphology; Multiple Sclerosis; Mus; Myelin; Myelin Proteolipid Protein; Myosin Type II; Nerve; Nervous system structure; Neural Conduction; Neuroglia; Neurons; Neurophysiology - biologic function; Oligodendroglia; Paralysed; Pathway interactions; Pattern; Peripheral; Play; Process; Property; Protein Isoforms; Public Health; Recovery; Recovery of Function; Regulation; Research; Resolution; Role; Schwann Cells; Stem cells; Symptoms; Syndrome; System; Tamoxifen; Testing; Transducers; Transgenic Organisms; Undifferentiated; cell motility; cellular imaging; crosslink; design; extracellular; gain of function; glial cell development; improved; in vivo; inhibitor/antagonist; loss of function; myelination; new therapeutic target; non-muscle myosin; novel; novel therapeutics; polyacrylamide gels; promoter; remyelination; repaired; research study; response; rho; rho GTP-Binding Proteins; sciatic nerve; therapy design; tool

DESCRIPTION (provided by applicant): In diseases such as Multiple Sclerosis in the central (CNS) and Guilain-Barre Syndrome in the peripheral (PNS) nervous system, loss of myelin results in conduction block along affected axons and underlies the clinical deficits characteristic of these disorders. Recovery of neural function is associated with remyelination, which not only restores nerve conduction, but also re-establish the normal molecular organization of the myelinated axon. Although therapies are available that address the inflammatory attack on CNS and PNS myelin, there are currently no treatments designed to directly target the efficiency of myelin repair and the return of nerve function. We identified non-muscle myosin II (NMII) as a novel key regulator of glial cell differentiation and myelin formation in both the PNS and the CNS. NMII is necessary for the ensheathment of axons by Schwann cells, and its inhibition impairs their morphological differentiation and ability to form myelin. By contrast, inhibition of NMII in oligodendrocytes promotes cell branching and enhances myelin formation. The molecular mechanisms behind these remarkably opposite effects are currently unknown, but if understood might provide novel therapeutic targets to promote repair of demyelinated nerves and restore nerve function. In this application we propose to test the hypothesis that the ability of Schwann cells and oligodendrocytes to sense and respond to the unique mechanical properties of their environment plays a major role in the differential response of these cells to NMII inhibition. Of particular relevance for this application are the observations that the extent f cell branching and the lineage commitment of undifferentiated cells can be regulated by changes in the extracellular matrix (ECM) elasticity in a NMII-dependant manner. In Aim#1 we will characterize how differences in ECM elasticity affect glial cell morphology and differentiatio using a culture system that allows the control of substrate elasticity and determine the direct rol of NMII in mediating these effects by performing loss and gain of function experiments. In Aim#2 we will establish the direct mechanistic link between process extension and downregulation of NMII activity downstream of Rho/ROCK, using a combination of live-cell imaging and loss and gain of function experiment. Finally in Aim#3 we will directly examine the relevance of NMII for myelin development and remyelination in vivo using mice in which NMIIB has been conditionally ablated in myelinating CNS and PNS glia. The long-term goal of our research is to understand the cytoskeletal mechanisms regulating Schwann cell and oligodendrocyte differentiation as a way to identify novel therapeutic targets to promote myelin repair and recovery of nerve function.

描述（由申请人提供）：在中枢 (CNS) 多发性硬化症和周围 (PNS) 神经系统吉兰-巴利综合征等疾病中，髓鞘质损失会导致受影响轴突的传导阻滞，并成为临床缺陷特征的基础 这些疾病。神经功能的恢复与髓鞘再生有关，髓鞘再生不仅恢复神经传导，而且重新建立有髓轴突的正常分子组织。尽管有治疗中枢神经系统和三七总皂甙髓磷脂炎症攻击的疗法，但目前还没有专门针对髓磷脂修复效率和神经功能恢复的治疗方法。我们确定非肌肉肌球蛋白 II (NMII) 是 PNS 和 CNS 中胶质细胞分化和髓磷脂形成的新型关键调节因子。 NMII 对于施万细胞形成轴突是必需的，其抑制会损害其形态分化和形成髓磷脂的能力。相比之下，抑制少突胶质细胞中的 NMII 可促进细胞分支并增强髓磷脂形成。这些截然不同的作用背后的分子机制目前尚不清楚，但如果了解的话，可能会提供新的治疗靶点，以促进脱髓鞘神经的修复和恢复神经功能。在本申请中，我们建议测试以下假设：雪旺细胞和少突胶质细胞感知和响应其环境的独特机械特性的能力在这些细胞对 NMII 抑制的差异反应中发挥着重要作用。与该应用特别相关的是观察到细胞分支的程度和未分化细胞的谱系定型可以通过细胞外基质（ECM）弹性的变化以NMII依赖性方式调节。在目标＃1中，我们将使用允许控制基质弹性的培养系统来描述ECM弹性的差异如何影响神经胶质细胞的形态和分化，并通过进行功能丧失和获得实验来确定NMII在介导这些影响中的直接作用。在 Aim#2 中，我们将结合活细胞成像和功能丧失与获得实验，建立 Rho/ROCK 下游 NMII 活性的过程扩展和下调之间的直接机制联系。最后，在 Aim#3 中，我们将使用 NMIIB 在髓鞘化中枢神经系统和三七总皂苷神经胶质细胞中被条件性消除的小鼠，直接检查 NMI​​I 与体内髓鞘发育和髓鞘再生的相关性。我们研究的长期目标是了解调节雪旺细胞和少突胶质细胞分化的细胞骨架机制，以此确定促进髓磷脂修复和神经功能恢复的新治疗靶点。