Investigating neuronal RNA localisation and translational deficits as gain of function mechanisms in ALS.

运动神经元是从脊髓向我们的肌肉发送信号的神经。它们是体内最大的神经细胞之一，是高度专业化的，因为它们的细胞体位于脊髓中，其纤维(称为‘轴突’)投射到肌肉之外。肌萎缩侧索硬化症(ALS)是一种无情且无法治愈的疾病，可杀死运动神经元，导致进行性瘫痪，并在确诊后5年内死亡。在英国，肌萎缩侧索硬化症的终生风险为1/250。我们体内的每个细胞都含有DNA、RNA和蛋白质。DNA位于细胞的细胞核中，携带着如何构建蛋白质的信息。蛋白质是我们细胞的基石，它们也可以为细胞的功能执行重要的任务。RNA是中间体，携带着从DNA中制造单个蛋白质的指令，到达细胞内制造这些蛋白质的不同位置，这些蛋白质是特定工作所需的。最近已经清楚的是，轴突是来自单个神经元的长投射，需要蛋白质贯穿其全长，包括距离细胞体最远的末端。我们还不知道这是为什么，但可以肯定的是，需要对远处轴突的局部损伤做出快速反应，这是为什么需要在神经元的局部区域沿着轴突制造蛋白质的一个很好的原因。为了有能力在需要的地方制造蛋白质，神经元必须在细胞内运输RNA，特别是沿着轴突。运动神经元是人体中最大的细胞之一，有非常长的轴突，在人类中，一个轴突可以从脊髓延伸到我们的脚，通常超过1米长。因此，特别是在这些细胞中，RNA的运动和蛋白质的局部生产是极其重要的。不幸的是，目前我们不知道哪些RNA在运动神经元周围移动，也不知道哪些蛋白质可以由此产生。我们缺乏知识在很大程度上是因为分析分开的细胞体和轴突中的RNA和蛋白质的剪切技术困难。但这一知识对于理解肌萎缩侧索硬化症至关重要，因为事实证明，在运动神经元中结合和运输RNA的蛋白质，包括一种名为FUS的蛋白质，可以在肌萎缩侧索硬化症中发生突变。为了理解肌萎缩侧索硬化症，我们需要知道在健康和肌萎缩侧索硬化症运动神经元的不同区域，FUS和它结合的RNA以及它产生的蛋白质发生了什么。在这里，我们解决了观察运动神经元不同区域的RNA和蛋白质的技术问题，包括非常重要的轴突，通过结合新的分子生物学和显微镜技术，以及我们制作的新的小鼠模型，以一种创新的方法来找出运动神经元内不同区域存在什么RNA和蛋白质。我们将随着时间的推移，观察症状前动物和患有ALS的动物，这样我们就可以看到随着老鼠年龄的增长而健康的状态，以及疾病的进展状态。然后，我们可以在从人类ALS患者身上提取的样本中验证我们的结果。我们迫切需要这些信息来了解ALS的机制和病理，并开发有效的运动神经元疾病的治疗方法。

Motor neurons are the nerves that send signals from the spinal cord to our muscles. They are amongst the largest nerve cells in the body and are highly specialized, in that their cell body is located in the spinal cord and its fiber (called 'axon') projects outside to the muscles. Amyotrophic Lateral Sclerosis (ALS) is a relentless and incurable disease that can kill the motor neurons, resulting in progressive paralysis and death within 5 years of diagnosis. ALS has a lifetime risk in UK of 1 in 250 in the UK population.Every cell in our body contains DNA, RNA and proteins. DNA is in the nucleus of cells and carries the information on how to build the proteins. Proteins are the building block of our cells and they can also perform important tasks for the cell's functions. RNA is the intermediate and carries the instructions for making individual proteins from the DNA, to the various locations inside a cell where these proteins are made and needed for specific jobs. Relatively recently it has become clear that axons, the long projections from individual neurons, need proteins to be made throughout their length, including at the very end most distant from the cell body. We do not yet know why this is, but certainly the need to respond quickly to local injury of an axon at a distant site, is one good reason why proteins need to be made in a localized region of a neuron, along the axon. To have the capacity to be able to make proteins where they are needed, neurons have to transport RNA around the cell, especially along the axon. Motor neurons are some of the largest cells in the body and have tremendously long axons, in humans one single axon can extend from the spinal cord out to our feet, often for over 1 meter in length. So in these cells particularly, the movement of RNA, and the local production of proteins is extremely important.Unfortunately, currently, we do not know which RNAs are moved around motor neurons and nor do we know which proteins can be made as a result. Our lack of knowledge has been largely because of the shear technical difficulty of analyzing RNA and protein in the separate cell bodies and axons. But this knowledge is critical to understanding ALS, because it turns out that proteins that bind and transport RNA in motor neurons, including a protein called FUS, can be mutated in ALS. So to understand ALS, we need to know what happens to FUS and the RNA it binds and the proteins that it makes, in health and in ALS, in different regions of motor neurons.Here, we tackle the technical problems of looking at RNA and protein in different regions of motor neurons, including the very important axon, by combining new molecular biology and microscope techniques, with novel mouse model we have made, in an innovative approach to find out what RNA and proteins are present in different regions within motor neurons. We will look over time, at presymptomatic animals, and at animals with ALS, so that we can see the healthy state as mice age, and the progressive disease state. We can then validate our results in samples taken from human ALS patients. We badly need this information to understand the mechanisms and pathology of ALS and to develop effective therapeutics for motor neuron disorders.