Regulation of axonal transport by neurotrophic factors in health and disease

健康和疾病中神经营养因子对轴突运输的调节

基本信息

批准号：
MR/S006990/1
负责人：
James Sleigh
金额：
$ 158.08万
依托单位：
University College London
依托单位国家：
英国
项目类别：
Fellowship
财政年份：
2019
资助国家：
英国
起止时间：
2019 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=MR%2FS006990%2F1
关键词：
Regulation axonal transport neurotrophic factors

项目摘要

Charcot-Marie-Tooth disease (CMT) is a debilitating, inherited neuromuscular condition that is characterised by muscle weakness and sensation deficiencies mainly in the hands and feet. The mechanisms linking gene alterations (mutations) to this neurodegeneration remain unresolved, and there are currently no effective treatments for the disease. To better understand CMT and develop therapies, I study the 2D subtype (CMT2D) caused by mutations in the gene GARS, which produces glycyl-tRNA synthetase (GlyRS) protein. GlyRS is found in almost all cells of the body, yet it is the nerves responsible for movement (motor neurons) and sensation (sensory neurons) that are affected by the disease. By understanding exactly why these peripheral nerves deteriorate, we will be better able to engineer targeted, molecular therapies.It has previously been shown that CMT2D-linked mutations in GARS affect the structure of the resulting GlyRS protein. I recently discovered that this conformational change causes mutant GlyRS to aberrantly interact with specific proteins called tropomyosin receptor kinase (Trk) receptors found on the surface of nerve cells. Trk receptors are crucial to life because they bind to survival molecules called neurotrophins, hence they are also known as neurotrophin receptors. I have shown that mutant GlyRS binding to Trk proteins disturbs the usual nerve response to neurotrophins, impairing sensory nervous system development in CMT2D mice. In addition, this non-physiological interaction leads to defects in a process called axonal transport, which is also essential for nerve cell function and survival. I have successfully treated these defects in CMT2D mice by injecting purified neurotrophic factors to overcome the detrimental impact of mutant GlyRS binding. This work has not only identified a possible way to treat CMT2D, but it has uncovered a previously unappreciated role for neurotrophic factors in regulating the dynamics of axonal transport.I now propose to unravel the molecular mechanism responsible for the modulation performed by neurotrophic factors on axonal transport in healthy nerves and, in the process, determine exactly how mutant GlyRS binding to Trk receptors reduces nerve survival in CMT2D.I will begin by testing the effects of a variety of neurotrophic factors on axonal transport in healthy and CMT2D mice in order to identify the signalling nodes most relevant to this essential cellular process. Complementing this, I will assess where the neurotrophic factor receptors are found in the muscle, and determine whether receptor localisation and levels are linked with the susceptibility of different muscles to weakness and degeneration in CMT2D mice. I will then grow nerve cells in tissue culture and use them to determine exactly how impairments in neurotrophic factor-regulated pathways disrupt axonal transport. Finally, I will design gene therapies, which will be delivered by harmless viruses, to boost levels of specific neurotrophic factors in CMT2D mice muscles and test this strategy as a potential therapy for the disease.This proposal will not only enhance our understanding of how neurotrophic factors regulate axonal transport in healthy nerves, but it has the very real potential of generating innovative gene therapies for CMT.

腓骨肌萎缩症 (CMT) 是一种使人衰弱的遗传性神经肌肉疾病，其特征是主要出现在手脚的肌肉无力和感觉缺失。将基因改变（突变）与这种神经变性联系起来的机制仍未解决，目前还没有针对这种疾病的有效治疗方法。为了更好地了解 CMT 并开发治疗方法，我研究了由 GARS 基因突变引起的 2D 亚型 (CMT2D)，该基因产生甘氨酰-tRNA 合成酶 (GlyRS) 蛋白。 GlyRS 存在于身体的几乎所有细胞中，但负责运动（运动神经元）和感觉（感觉神经元）的神经受到该疾病的影响。通过准确了解这些周围神经恶化的原因，我们将能够更好地设计有针对性的分子疗法。此前已表明，GARS 中与 CMT2D 相关的突变会影响所得 GlyRS 蛋白的结构。我最近发现，这种构象变化会导致突变型 GlyRS 与神经细胞表面发现的称为原肌球蛋白受体激酶 (Trk) 受体的特定蛋白质发生异常相互作用。 Trk 受体对生命至关重要，因为它们与称为神经营养蛋白的生存分子结合，因此也称为神经营养蛋白受体。我已经证明，与 Trk 蛋白结合的突变 GlyRS 会扰乱对神经营养素的正常神经反应，从而损害 CMT2D 小鼠的感觉神经系统发育。此外，这种非生理相互作用会导致轴突运输过程中的缺陷，而轴突运输对于神经细胞的功能和生存也至关重要。我通过注射纯化的神经营养因子来克服突变 GlyRS 结合的有害影响，成功治疗了 CMT2D 小鼠的这些缺陷。这项工作不仅确定了治疗 CMT2D 的可能方法，而且还揭示了神经营养因子在调节轴突运输动力学方面以前未被认识到的作用。我现在建议揭开神经营养因子对轴突运输进行调节的分子机制。健康神经中的转运，并在此过程中准确确定与 Trk 受体结合的突变 GlyRS 如何降低 CMT2D 中的神经存活。我将首先测试各种神经营养物质的影响影响健康和 CMT2D 小鼠轴突运输的因素，以确定与这一重要细胞过程最相关的信号传导节点。作为补充，我将评估神经营养因子受体在肌肉中的位置，并确定受体的定位和水平是否与 CMT2D 小鼠不同肌肉无力和退化的易感性相关。然后，我将在组织培养物中培养神经细胞，并用它们来确定神经营养因子调节途径的损伤如何破坏轴突运输。最后，我将设计基因疗法，通过无害的病毒传递，以提高 CMT2D 小鼠肌肉中特定神经营养因子的水平，并测试该策略作为该疾病的潜在疗法。这一提议不仅将增强我们对神经营养因子如何发挥作用的理解。因子调节健康神经中的轴突运输，但它具有为 CMT 产生创新基因疗法的真正潜力。

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Post-synaptic morphology of mouse neuromuscular junctions is linked to muscle fibre type

DOI：
10.1101/2020.04.04.025106
发表时间：
2020-04
期刊：
bioRxiv
影响因子：
0
作者：
Aleksandra M. Mech;Anna L. Brown;G. Schiavo;J. Sleigh
通讯作者：
Aleksandra M. Mech;Anna L. Brown;G. Schiavo;J. Sleigh

NMJ-Analyser: high-throughput morphological screening of neuromuscular junctions identifies subtle changes in mouse neuromuscular disease models

NMJ-Analyser：神经肌肉接头的高通量形态学筛选可识别小鼠神经肌肉疾病模型中的细微变化

DOI：
10.1101/2020.09.24.293886
发表时间：
2020
期刊：
影响因子：
0
作者：
Maza A
通讯作者：
Maza A

Additional file 1 of Loss of BICD2 in muscle drives motor neuron loss in a developmental form of spinal muscular atrophy

肌肉中 BICD2 缺失导致脊髓性肌萎缩症发育过程中运动神经元缺失的附加文件 1

DOI：
10.6084/m9.figshare.11998476
发表时间：
2020
期刊：
影响因子：
0
作者：
Rossor A
通讯作者：
Rossor A

Loss of BICD2 in muscle drives motor neuron loss in a developmental form of spinal muscular atrophy

肌肉中 BICD2 的缺失会导致脊髓性肌萎缩症发育过程中运动神经元的缺失

DOI：
10.1101/854711
发表时间：
2019
期刊：
影响因子：
0
作者：
Rossor A
通讯作者：
Rossor A

NMJ-Analyser identifies subtle early changes in mouse models of neuromuscular disease.

DOI：
10.1038/s41598-021-91094-6
发表时间：
2021-06-10
期刊：
Scientific reports
影响因子：
4.6
作者：
Mejia Maza A;Jarvis S;Lee WC;Cunningham TJ;Schiavo G;Secrier M;Fratta P;Sleigh JN;Fisher EMC;Sudre CH
通讯作者：
Sudre CH