Autophagy and Neurodegeneration

在过去的几年里，巨噬被认为与一系列神经退行性疾病有关，从聚集易感性疾病、亨廷顿病到溶酶体贮积症、内曼-匹克c型疾病。尽管巨噬很普遍，但人们对它的了解仍然很少，很难确定它在发病机制中的作用。也许不足为奇的是，在不同的疾病中，巨噬被认为是疾病进展中潜在的致病因素和潜在的改善因素。如果我们要针对这种复杂的降解途径进行治疗，我们需要更好地定义自噬过程，以便将其应用于大脑。在本次授权申请中，我们建议通过关注相关的关键细胞器：自噬液泡（AV）来获得关于巨噬的新见解。它被定义为一种洋葱样的多层囊泡，对标记物MAP1LC3 （ATG8的哺乳动物同源物）呈阳性，这种结构的形成和成熟是自噬过程的核心，也是迄今为止最不为人所知的。使用我们开发的一种新方法，可以分离特定的AV群体进行蛋白质组学和基于脂质的分析，我们将：1)表征来自神经元细胞和大脑的AV；2)比较MAP1LC3标记的AVs与其他四种ATG8哺乳动物同源物标记的囊泡；3)使用基于功能细胞的检测进一步定义各种ATG8-蛋白质组如何影响巨噬。公共卫生相关性：巨噬是一个知之甚少的过程，它对于允许细胞（如神经元）摆脱不再起作用的蛋白质很重要。有趣的是，这一过程被认为是许多神经退行性疾病的核心，如亨廷顿氏病、帕金森病、阿尔茨海默病、许多溶酶体贮积病等。在这里，我们建议研究巨噬，因为它与大脑有关，这样我们就可以利用这些信息来设计有效的治疗这些疾病。

DESCRIPTION (provided by applicant): Project Summary Over the last several years, macroautophagy has been implicated in a wide array of neurodegenerative disorders from the aggregation prone disorder, Huntington's disease to the lysosomal storage disorders, Neiman-Pick Type C. Despite its prevalence however, macroautophagy is still poorly understood, making it difficult to define how it contributes towards pathogenesis. Perhaps unsurprisingly, in different disorders, macroautophagy has been considered both as a potentially causative and potentially ameliorative element in disease progression. If we are to target this complex degradative pathway for therapeutics, we need to better define the autophagic process in a means we can apply it towards the brain. In this grant submission, we propose to gain new insights into macroautophagy by focusing on the key organelle involved: the autophagic vacuole (AV). Defined as an onion-like multilamellar vesicle that is positive for the marker MAP1LC3 (a mammalian homologue of ATG8), the formation and maturation of this structure is at the heart of the autophagic process and is by far the least understood. Using a novel approach which we have developed that can isolate specific populations of AV for proteomic and lipid-based analyses, we will: 1) characterize AVs from neuronal cells and brain; 2) compare and contrast MAP1LC3- labeled AVs from vesicles labeled with the other four ATG8 mammalian homologues; and 3) use functional cell based assays to further define how the various ATG8- proteomes impact macroautophagy. PUBLIC HEALTH RELEVANCE: Macroautophagy is a poorly understood process that is important for allowing cells, such as neurons to get rid of proteins that no longer function. Interestingly, this process has been implicated to be at the heart of many neurodegenerative diseases such as Huntington's disease, Parkinson's disease, Alzheimer's disease, many lysosomal storage diseases and others. Here we propose to study macroautophagy as it pertains to the brain so that we can use this information to design effective treatment for these many diseases.