Unravelling the Molecular Mechanism of Progression in Alzheimer's Disease: Implications for therapy

揭示阿尔茨海默病进展的分子机制：对治疗的影响

• 批准号: 2742039
• 金额: --
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2742039
• 关键词: Unravelling; Molecular; Mechanism; Progression; Alzheimer

Alzheimer's disease (AD) is a neurodegenerative disorder that affects 36 million people worldwide. Owing to an increased life expectancy and aging populations, by 2050 more 115 million are predicted to have AD. The pathology of AD results from the progressive accumulation of protein aggregates (called amyloid plaques and neurofibrillary tangles) in the brain and no disease modifying therapies exist. Tangles are made up of Tau protein monomers that misfold, self-assemble and accumulate in disease. In this project, we will develop novel spectroscopic and in silico tools to understand the structure-pathogenicity relationships in Tau protein that determine its disease-related misfolding, subsequent aggregation and spread of disease. In this way we will pave the way for disease-modifying therapies. In previous work, we have demonstrated that we can acquire the vibrational Raman spectra of tau oligomers, and demonstrated time evolution as fibrils form. Separately, we have demonstrated that we can calculate the electric fields, and hence the vibrational frequencies, of molecular probes in proteins. Here we will combine novel spectroscopic and molecular simulation studies, to study peptide aggregation in general, and tau oligomer structure and evolution into larger fibrils, in particular. To confirm that simulation and spectroscopy can be combined and to determine the conformation of Tau seeds, the methodology will be developed and tested on two relevant hexapeptides VQIVYK (PHF6) and VQIINK (PHF6*). Both are essential for fibril formation in Tau and spontaneously aggregate. Spectra will be derived using our previously published Raman approach. Advanced simulation techniques will be used to characterise the kinetic and thermodynamic parameters of peptide aggregate formation. Advanced polarisable force fields will be used to calculate vibrational spectra. Following refinement of computational models using calibration data, Raman spectra of hexapeptides as monomers, oligomers and fibrils will be acquired. Predictions from simulations will be tested against monomer spectra first. This will be followed by optimisation which will allow understanding the Raman spectra of oligomers and fibrils, which are more complex, and can consist of polymorphs. Thus, elucidation of conformational structures in terms of molecular motifs, intra- and inter-molecular bonding will be possible. The insight gained by simulations will help understand interactions and allow the development of in silico models of compound (drug) interactions with tau aggregates. To establish and verify ground truth of the structures, and to further correlate the Raman spectra with simulations, the student will visit the University of Sussex, to the Serpell lab, to prepare X-ray fibre diffraction samples of the fibrils formed by PHF6 and PHF6*. This will help gain further insight into the molecular architecture of the mature fibrils. The Serpell lab have extensively experience of working with tau peptides and other amyloidogenic fragments and investigating the structural organisation of fibrils using X-ray fibre diffraction. Negative stain transmission electron microscopy will be performed at Sussex to verify the morphology of filaments. This project will link experimental and simulation structural ensembles, allowing the mechanism of oligomer formation to be followed with molecular detail, giving vital insights into potential therapeutic interventions.

阿尔茨海默病(AD)是一种神经退行性疾病，影响全球3600万人。由于预期寿命的延长和人口老龄化，到2050年，预计将有1.15亿人患有阿尔茨海默病。阿尔茨海默病的病理结果是蛋白质聚集物(称为淀粉样斑块和神经原纤维缠结)在大脑中逐渐积累，目前还没有改善疾病的治疗方法。Tangles是由Tau蛋白单体组成的，这些单体错误折叠、自我组装并在疾病中积累。在这个项目中，我们将开发新的光谱和电子计算工具来了解Tau蛋白的结构-致病关系，这些关系决定了它与疾病相关的错误折叠、随后的聚集和疾病的传播。通过这种方式，我们将为疾病修正疗法铺平道路。在以前的工作中，我们已经证明了我们可以获得tau低聚物的振动拉曼光谱，并演示了随着纤维的形成而发生的时间演化。另外，我们已经证明，我们可以计算蛋白质中分子探针的电场，从而计算其振动频率。在这里，我们将结合新的光谱和分子模拟研究，以研究一般的多肽聚集，特别是tau低聚物的结构和进化成更大的纤维。为了确认模拟和光谱可以结合起来并确定Tau种子的构象，将开发该方法，并在两个相关的六肽VQIVYK(PHF6)和VQIINK(PHF6*)上进行测试。两者都是Tau和自发聚集体中形成原纤维所必需的。光谱将使用我们之前发表的拉曼方法得到。先进的模拟技术将被用来描述多肽聚集形成的动力学和热力学参数。先进的可极化力场将被用来计算振动光谱。在使用校准数据对计算模型进行改进后，将获得六肽单体、齐聚物和纤维的拉曼光谱。来自模拟的预测将首先针对单体光谱进行测试。这之后将进行优化，这将允许了解齐聚物和纤维的拉曼光谱，这是更复杂的，可以由多晶型组成。因此，根据分子基序、分子内和分子间键来阐明构象结构将是可能的。通过模拟获得的洞察力将有助于理解相互作用，并允许开发化合物(药物)与tau聚集体相互作用的电子计算机模型。为了建立和验证结构的基本事实，并进一步将拉曼光谱与模拟相关联，学生将访问苏塞克斯大学的Serpell实验室，准备由PHF6和PHF6*形成的纤维的X射线纤维衍射样本。这将有助于进一步深入了解成熟纤维的分子结构。Serpell实验室在处理tau多肽和其他淀粉样蛋白片段以及使用X射线纤维衍射研究纤维的结构组织方面拥有丰富的经验。将在苏塞克斯进行负染的透射电子显微镜检查，以验证细丝的形态。该项目将连接实验和模拟结构集合，允许低聚物形成的机制与分子细节保持一致，为潜在的治疗干预提供重要的见解。