Cellular and genetic analysis of central nervous system myelination in zebrafish

斑马鱼中枢神经系统髓鞘形成的细胞和遗传分析

• 批准号: BB/F023243/1
• 负责人: David Lyons
• 金额: $ 96.07万
• 依托单位: University of Edinburgh
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2009
• 资助国家: 英国
• 起止时间: 2009 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FF023243%2F1
• 关键词: Cellular; genetic; analysis; central; nervous

The myelin sheath is a plasma membrane extension of specialized glial cells that wraps around neuronal processes, called axons: in so doing, myelin permits the rapid conduction of nerve impulses. Damage to myelin causes the symptoms of many human diseases including multiple sclerosis (MS) and Charcot-Marie-Tooth (CMT) neuropathies. Myelin formation (myelination) is a much more efficient mechanism than the alternative way to increase nerve conduction, namely increasing axon diameter. Large diameter axons take up space, which constrains the size and complexity of organism that can evolve using only this strategy. It is fair to say, therefore, that complex nervous systems, such as our own, have evolved in large part due to the properties of the myelin sheath. Understanding the mechanisms that control myelination is thus of both fundamental biological and medical relevance. The zebrafish is a powerful model organism in which to dissect the cellular and genetic basis of myelination. Zebrafish embryos are transparent, and tools exist to watch fluorescently labeled cells behave in real time in the living organism, at a level of detail that is not feasible in other vertebrate laboratory animals. A second major attraction of the zebrafish is the ability to carry out large-scale affordable genetic screens to find genes required for specific biological processes. In a genetic screen carried out in our lab we identified 10 genes required for the development of myelinated axons. Although we have learned a great deal our screen certainly did not have the scope to identify all the genes that regulate myelination. Our current understanding of the genetic and cellular basis of myelin formation in the central nervous system (the brain and spinal cord) remains particularly rudimentary. The overall goal of my proposal, therefore, is to determine the cellular and genetic basis of myelin formation in the zebrafish central nervous system. 1. I will directly observe the precise cellular interactions between axons and glial cells that culminate in myelination, by high-resolution time-lapse microscopy in zebrafish. 2. Previous studies have led to the intriguing hypothesis that the level of neuronal activity can regulate myelin production, which may represent a fundamental mechanism by which localized brain activity could enhance nervous system function. I will test this hypothesis in intact animals for the first time by altering levels of neural activity in zebrafish embryos and looking at the effects of different treatments on myelin production and on neurophysiology. 3. Recently a particular genetic pathway (the neuregulin-erbb pathway) has been implicated as a key regulator of myelin formation in the peripheral nervous system (the part of the nervous system outside of the brain and spinal cord), but its role in the CNS is somewhat controversial. I have exciting preliminary data that I will now fully explore that this fundamental regulatory pathway does indeed regulate myelination in the CNS. 4. We still do not know the identity of many of the genes that are required for myelination in the CNS. I will perform a new genetic screen in zebrafish and focus in particular on genes that are required for myelination in the CNS. By comparing animals with mutations in specific genes with normal animals by high-resolution analyses such as time-lapse microscopy I will be able to define exactly which aspects of myelination those genes are normally required for. I hope to set up my own independent research group at the University of Edinburgh, in laboratories that are part of a new £600m research development at the Little France Biomedical Sciences Centre. This environment will provide a world-class infrastructure, and I will be adjacent to two of the leading researchers in the field of myelin biology, which will provide an ideal environment of intellectual support and potential collaboration, to continue to unravel the mysteries of myelination.

髓鞘是特殊神经胶质细胞的质膜延伸，包裹着称为轴突的神经元突起：在这种情况下，髓鞘允许神经冲动的快速传导。髓鞘的损伤会导致包括多发性硬化症 (MS) 在内的许多人类疾病的症状。髓鞘形成（髓鞘形成）是一种比增加神经传导的替代方法（即增加轴突直径）更有效的机制。大直径轴突占据空间，这限制了仅使用这种策略才能进化的生物体的大小和复杂性，因此，公平地说，像我们这样的复杂神经系统在很大程度上是由于这些特性而进化的。因此，了解控制髓鞘形成的机制具有重要的生物学和医学意义，斑马鱼是一种强大的模型生物，可以清楚地剖析斑马鱼胚胎的细胞和遗传基础，并且存在可以观察的工具。荧光标记的细胞在活生物体中实时表现，其详细程度在其他脊椎动物实验动物中是不可能的。斑马鱼的第二个主要吸引力是能够进行大规模、经济实惠的遗传筛选来寻找所需的基因。在我们实验室进行的基因筛选中，我们鉴定出了有髓鞘轴突发育所需的 10 个基因，尽管我们已经了解了很多，但我们的筛选肯定无法鉴定出所有调节髓鞘形成的基因。我们目前的对中枢神经系统（大脑和脊髓）髓磷脂形成的遗传和细胞基础的了解仍然非常初级，因此，我的提议的总体目标是确定斑马鱼中枢髓磷脂形成的细胞和遗传基础。 1. 我将通过斑马鱼的高分辨率延时显微镜直接观察轴突和神经胶质细胞之间的精确细胞相互作用，最终形成髓鞘。有趣的假设是，神经活动水平可以调节髓磷脂的产生，这可能代表了局部大脑活动可以增强神经系统功能的基本机制，我将通过改变神经活动水平，首次在完整的动物中测试这一假设。在斑马鱼胚胎中观察不同治疗对髓磷脂生成和神经生理学的影响 3. 最近，一种特殊的遗传途径（神经调节蛋白-erbb 途径）被认为是外周髓磷脂形成的关键调节因子。神经系统（大脑和脊髓之外的神经系统的一部分），但它在中枢神经系统中的作用有些争议，我有令人兴奋的初步数据，现在我将充分探索这一基本调节途径确实调节髓鞘形成。 4. 我们仍然不知道中枢神经系统髓鞘形成所需的许多基因的身份，我将在斑马鱼中进行新的遗传筛选，并特别关注中枢神经系统髓鞘形成所需的基因。比较有突变的动物通过高分辨率分析（例如延时显微镜）对正常动物的特定基因进行分析，我将能够准确地确定这些基因通常需要哪些方面的髓鞘形成，我希望在爱丁堡大学建立自己的独立研究小组。 ，在小法国生物医学科学中心耗资 6 亿英镑的新研究开发项目的一部分的实验室中。这个环境将提供世界一流的基础设施，我将与髓磷脂生物学领域的两位领先研究人员相邻。将提供一个理想的智力支持和潜在合作的环境，继续揭开髓鞘形成的奥秘。

项目成果

Kif1b is essential for mRNA localization in oligodendrocytes and development of myelinated axons.

Kif1b 对于少突胶质细胞中的 mRNA 定位和有髓轴突的发育至关重要。

• DOI: http://dx.10.1038/ng.376
• 发表时间: 2009
• 期刊: Nature genetics
• 影响因子: 30.8
• 作者: Lyons DA

Oligodendrocyte Development in the Absence of Their Target Axons In Vivo.

体内缺乏目标轴突的少突胶质细胞发育。

• DOI: http://dx.10.1371/journal.pone.0164432
• 发表时间: 2016
• 期刊: PloS one
• 影响因子: 3.7
• 作者: Almeida R

Adaptive myelination from fish to man

从鱼到人的适应性髓鞘形成

• DOI: 10.1016/j.brainres.2015.10.026
• 发表时间: 2016-06-15
• 期刊: Brain Research
• 影响因子: 2.9
• 作者: Baraban M;Mensch S;Lyons DA
• 通讯作者: Lyons DA

Individual oligodendrocytes have only a few hours in which to generate new myelin sheaths in vivo.

单个少突胶质细胞只有几个小时的时间在体内产生新的髓鞘。

• DOI: http://dx.10.1016/j.devcel.2013.05.013
• 发表时间: 2013
• 期刊: Developmental cell
• 影响因子: 11.8
• 作者: Czopka T

Intersectional Gene Expression in Zebrafish Using the Split KalTA4 System.

使用 Split KalTA4 系统在斑马鱼中进行交叉基因表达。

• DOI: http://dx.10.1089/zeb.2015.1086
• 发表时间: 2015
• 期刊: Zebrafish
• 影响因子: 2
• 作者: Almeida RG