Multi-level mapping of mitochondrial quality control pathways in Parkinson's dopaminergic neurons

帕金森病（PD）是一种影响运动、认知和行为的神经退行性疾病。这些运动问题的原因之一是黑质中产生多巴胺的神经元的逐渐丧失，黑质是大脑中参与运动控制的区域。帕金森氏症的病因尚不完全清楚，在一些人身上，它是由少数基因的巨大变化引起的，但在大多数帕金森氏症患者身上，它被认为是由遗传和环境因素共同引起的。PD患者失去的细胞的两个关键特征是α -突触核蛋白团块的积累和线粒体功能障碍。线粒体是细胞的动力发电站，它们在能量产生中起着关键作用，并影响细胞工作的许多方面。产生多巴胺的细胞有几个特征，包括它们的大小和活性，使它们更容易受到线粒体损伤。线粒体自噬（“吞噬线粒体”）是细胞降解受损线粒体的过程。这是一个严格控制的过程，对维持线粒体和细胞的健康至关重要。线粒体自噬的减少与多种神经退行性疾病有关，包括帕金森病。特别是，控制有丝分裂的基因改变会导致早发性帕金森病。我们最近发现这些蛋白-突触核蛋白团块可以破坏线粒体并激活线粒体自噬过程。这项研究将首先了解产生多巴胺的细胞通常如何进行线粒体自噬，因为这似乎与其他细胞类型不同。然后，我们将研究α -突触核蛋白团块或控制有丝分裂的基因的罕见变化如何影响细胞如何进行有丝分裂。利用这些信息，我们将研究与PD相关（但不是导致PD的）基因的微小变化如何影响线粒体自噬。为了了解这些基因如何参与改变有丝分裂，我们将使用称为CRISPR激活或CRISPR干扰的新技术，通过增加或减少基因的活性来模拟这些基因变化的影响-就像音量控制器一样。为了进一步了解这些基因如何影响产生多巴胺的细胞，我们将测量这些细胞中许多蛋白质的水平。使用一种新技术，我们还可以测量蛋白质的活性，让我们更全面地了解PD中更常见的小基因变化如何影响细胞。这将是有趣的，因为它可以告诉我们更多关于有丝分裂的变化，但它可以告诉我们细胞中的其他过程（如α -突触核蛋白聚集）发生了变化。我们还将能够看到哪些基因变化彼此相似，哪些不同，这可能意味着我们能够准确地对帕金森病患者进行分组和治疗。这项研究将告诉我们，微小的基因变化是如何累积起来，最终导致某些人患上帕金森病的，以及细胞的哪些部分受到的影响最大。鉴于线粒体是产生多巴胺的细胞的关键，我们将首先关注这一点，并得到一个非常详细的图片，这可能会导致确定哪些人可能从线粒体靶向治疗中获益最多。这项研究将被许多PD研究人员使用，并将帮助我们了解常见的基因变化如何模仿导致PD的罕见的较大基因变化，这种理解将导致更好地了解PD并最终产生新的治疗方法。

Parkinson's disease (PD) is a neurodegenerative disorder that affects movement, cognition, and behaviour. One of the causes of these movement problems is the progressive loss of dopamine-producing neurons in the substantia nigra, a region of the brain that is involved in movement control. The cause of PD is not fully understood, in some people it is caused by large changes in a few genes but in most people with Parkinson's it is thought to be caused by a combination of genetic and environmental factors.Two key features of cells that are lost in PD are the accumulation of clumps of a protein called alpha-synuclein and dysfunction of mitochondria. Mitochondria are the powerhouses of the cell, and they play critical roles in energy production as well as affecting many aspects of how cells work. The dopamine-producing cells have several features including their size and activity that make them more susceptible to mitochondrial damage.Mitophagy ('eating mitochondria') is a process by which damaged mitochondria are degraded by the cell. It is a tightly controlled process that is essential for maintaining the health of mitochondria and cells. Decreases in mitophagy have been linked to a variety of neurodegenerative diseases, including PD. In particular, changes in genes that control mitophagy cause early-onset PD. We have recently discovered that these clumps of the protein alpha-synuclein can damage mitochondria and activate the process of mitophagyThis study will first understand how the dopamine-producing cells usually perform mitophagy as this appears to be different to other cell types. We will then investigate how clumps of alpha-synuclein or rare changes in genes which control mitophagy affect how cells perform mitophagy.Using this information, we will then investigate how small changes in genes that are linked to (but don't cause) PD affect mitophagy. To understand how these genes might be involved in changing mitophagy, we will use new technology, called CRISPR activation or CRISPR interference, to mimic the effect of these gene changes by increasing or decreasing how active the gene is- like a volume controller.To further understand how these genes affect dopamine producing cells, we will measure the levels of lots of proteins in these cells. Using a new technique we can also measure how active the proteins are, giving us a more complete picture of how small gene changes that are more common in PD affect cells. This will be interesting as it may tell us more about changes in mitophagy but it could tell us that other processes in the cell (like alpha-synuclein clumping) are changed. We will also be able to see which gene changes are similar to each other and which are different and may mean we are able to group and treat people with Parkinson's accurately.This research will tell us about how small gene changes might build up to eventually cause PD in some people and which parts of the cell are most affected. Given mitochondria are key to the dopamine-producing cells, we will first focus on this and get a very detailed picture of this that may lead to identifying which people might benefit the most from mitochondria-targeted treatments.This research will be used by many PD researchers and will help us understand how common gene changes might mimic the rarer larger gene changes that cause PD, this understanding will lead to better understanding of PD and eventually new treatments.