Dissecting the role of cellular transport in neurodegeneration using A.nidulans

描述（由申请人提供）：本项目的长期研究目标是阐明微管（MT）转运缺陷促进神经退行性疾病的常见机制。尽管神经退行性疾病通常在症状和病因上存在差异，但沿MT路径的远程转运缺陷和RNA代谢蛋白TDP-43的生物学功能障碍正在成为与肌萎缩性侧索硬化症（ALS）、阿尔茨海默病和帕金森病等广泛疾病相关的共同因素。TDP-43和转运缺陷在驱动发病机制中的作用尚不清楚。本研究的目的是研究TDP-43与远程转运之间的关系，并确定它们是否协同作用以促进疾病。基于TDP-43的简单和遗传可处理的酵母病理学模型是有价值的，但酵母不像人类那样使用mt进行远程细胞运输，因此不太适合解剖它与TDP-43的关系。为了了解这种关系，我们将开发丝状真菌a . nidulans作为模型系统来研究基于TDP- 43的毒性和基于mt的转运。A. nidulans具有与酵母相当的遗传易变性，但与酵母不同的是，它使用mt在与哺乳动物神经元非常相似的细胞区域进行远程运输。其次，该模型将用于检验关于运输和TDP-43之间关系的两个可选假设。第一个假设是TDP-43的致病物种广泛损害基于mt的运输过程。为了验证这一点，将在A. nidulans中基于mt的货物在TDP- 43表达期间进行荧光标记和跟踪，以检测缺陷。第二种假设是，基于mt的转运缺陷促进了TDP-43病理的致病特征，例如增加了向细胞质的定位。这一假设将通过在基于mt的转运机制中产生已知的致病突变并随后研究TDP-43的生物学行为来验证。最后，为了确定与TDP-43生物学或基于mt的转运相关的导致疾病的新因素，将在A. nidulans病理模型中进行公正和系统的突变筛选。这项工作不仅阐明了基于TDP-43的病理原因，而且为阐明和理解神经退行性疾病的普遍转运缺陷提供了一个范例。

DESCRIPTION (provided by applicant): The long-term research goal of this project is to elucidate common mechanisms by which defects in microtubule-(MT)-based transport promote neurodegenerative disease. Though neurodegenerative diseases are often divergent in symptoms and etiologies, defective long-range transport along MT tracks and the biological dysfunction of the RNA metabolism protein TDP-43 are emerging as common factors associated with a broad range of disorders, including Amyotrophic Lateral Sclerosis (ALS), Alzheimer's disease, and Parkinson's disease. The roles of both TDP-43 and transport defects in driving pathogenesis are poorly understood. The goal of the work proposed here is to investigate the relationship between TDP-43 and long- range transport and determine if they act synergistically to promote disease. Simple and genetically tractable yeast models of TDP-43-based pathology have been valuable, but yeast do not use MTs for long-range cellular transport as humans do and thus are less well suited to dissect is relationship with TDP-43. To understand this relationship, the filamentous fungus A. nidulans will be developed as a model system for studying both TDP- 43-based toxicity and MT-based transport. A. nidulans has genetic tractability comparable to that of yeast, but unlike yeast, uses MTs for long-range transport in cellular regions that closely resemble mammalian neurons. Second, this model will be used to test two alternative hypotheses about the relationship between transport and TDP-43. The first hypothesis is that pathogenic species of TDP-43 broadly impair MT-based transport processes. To test this, MT-based cargos in A. nidulans will be fluorescently-tagged and tracked during TDP- 43 expression in order to detect defects. The second hypothesis is that defects in MT-based transport promote pathogenic features of TDP-43 pathology, such as increased localization to the cytoplasm. This hypothesis will be tested by generating known pathogenic mutations in the MT-based transport machinery and subsequently investigating the biological behavior of TDP-43. Finally, to identify novel factors related to either TDP-43 biology or MT-based transport that contribute to disease, an unbiased and systematic mutagenesis screen will be performed in the A. nidulans pathology model. This work will not only illuminate the causes of TDP-43 based pathology, but also provide a paradigm for elucidating and understanding the pervasive transport defects of neurodegenerative diseases.