An interdisciplinary approach to unravel mechanistic understanding of Frontotemporal lobar degeneration

痴呆症造成巨大的个人困难，每年花费英国约230亿英镑。第二种最常见的形式是额颞叶变性（FTLD）。约40%的FTLD病例具有遗传原因，其中>8%涉及C9 orf 72基因中的异常内含子GGGGCC六核苷酸重复扩增，其可另外引起运动神经元疾病（OMIM #105550）。这些病理性扩增产物被转录并通过双向重复相关的非ATG（RAN）翻译产生5种不同的聚集体形成性GA、GR、PR、GP和AP二肽重复蛋白（DPRs）。我们将重点放在毒性是由DRP结构引起的假设上，与阿尔茨海默病中的淀粉样斑块相当。该项目将利用三位主管的互补专业知识，以及一组现成的、独特的4个GFP标记的结构，这些结构具有高的病理相关重复数。具体的目标和结果是：产生纯化的DRPs，并进行生化和生物物理分析，以了解其毒性的原因，并确定有用的治疗策略，这将有利于患者和他们的家庭。我们将使用强大的果蝇遗传学和成熟的细胞生物学方法来鉴定神经元死亡途径和DRP诱导的病理机制上游。有大量的原则证明果蝇的使用和翻译潜力。我们将在SH-SY 5 Y细胞和可诱导的神经元细胞系中使用成熟的DRP模型进行补充实验。该项目是高度跨学科的，通过分析从体外溶剂到人类和苍蝇细胞系的二肽重复序列蛋白质。学生将在多肽结构和聚集，细胞培养，苍蝇和人类遗传学以及细胞生物学的表征方面接受广泛的培训，所有这些都在遗传疾病和神经退行性疾病的背景下进行。

Dementia causes enormous personal hardship and costs the UK ~£23 billion every year. The second most common form is Frontotemporal lobar degeneration (FTLD). About 40% of FTLD cases have genetic causes, with >8% involving abnormal intronic GGGGCC hexanucleotide repeat expansions in the C9orf72 gene which can additionally cause motor neuron disease (OMIM #105550). These pathological expansions are actively transcribed and, via bidirectional repeat-associated non-ATG (RAN) translation, generate 5 different aggregate-forming GA, GR, PR, GP and AP dipeptide repeat proteins (DPRs).This project will gain new understanding of this type of FTLD by unravelling neurodegenerative pathomechanisms of DRPs through using interdisciplinary approaches. We will focus on the hypothesis that toxicity is caused by DRP structure, comparable to amyloid plaques in Alzheimer's disease. The project will capitalise on the complementary expertises of the three supervisors, and a readily available, unique set of 4 GFP-tagged constructs with high, pathologically relevant repeat numbers. The detailed aims and outcomes are:To generate purified DRPs and perform biochemical and biophysical analyses, in order to understand the reasons for their toxicity and identify useful therapeutic strategies which will benefit patients and their families.To generate transgenic Drosophila fly stocks to obtain primary neurons expressing the four DRPs. We will use powerful fly genetics and well established cell biological approaches to identify the neuronal death pathway and of the DRP-induced pathomechanisms upstream.There is substantial proof-of-principle for the use and translational potential of Drosophila To validate identified DRP pathomechanisms in mammalian contexts, we will carry out complementary experiments using well established DRP models in SH-SY5Y cells and inducible neuronal cell lines.This project is highly interdisciplinary, with the analysis of the dipeptide repeat proteins spanning systems from in vitro solvents to human and fly cell lines. The student will receive a broad training in characterisation of polypeptide structure and aggregation, cell culture, fly and human genetics, and cell biology, all in the context of genetic disease and neurodegeneration.