Investigating structural heterogeneities in amyloid aggregates with multiscale infrared spectroscopic imaging

项目摘要 特定蛋白质的错误折叠和聚集成纤维状淀粉样沉积是 一大类疾病和神经退行性疾病，这是一个主要的公共卫生问题 全世界。虽然人们认识到淀粉样蛋白聚集体在糖尿病的分子病理学中起着积极的作用。 疾病、导致细胞毒性的确切聚集状态以及发病机制与 淀粉样蛋白聚集体中二级结构的分布还没有很好的确定。这个项目的目的是 体外和体外淀粉样蛋白聚集体中蛋白质二级结构的异质性研究 并确定它们与疾病进展的关系。我们的方法依赖于使用最先进的 利用纳米红外光谱和共聚焦红外光谱成像绘制蛋白质二级结构图 在淀粉样蛋白沉积中。我们将重点研究阿尔茨海默病患者的淀粉样蛋白聚集体及其异质性。 开发和优化我们的方法，并随后旨在将这些策略扩展到 研究其他疾病中的淀粉样蛋白聚集物，如帕金森氏病和乳腺癌。这个 支持这一努力的假设是，淀粉样蛋白沉积的结构异质性，而不仅仅是特定的纤维 结构，与疾病的进展相关。我们将利用光热AFM-IR，这是一种 用原子力显微镜增强红外光谱，以获得纳米级聚集体特有的光谱。 阿尔茨海默病患者组织提取物的种子生长将有助于探测聚集途径的差异 与不同疾病阶段相关的结构多态。组织中的淀粉样聚集体将是 通过共聚焦红外显微镜进行了研究。将对组织光谱数据进行分析以对淀粉样蛋白进行分类 基于次级构造分布的矿床以及不同类型矿床之间的相互关系 并将探索疾病的各个阶段。我们的进一步目标是将AFM-IR和IR显微镜相结合，并开发一种 一种空间和光谱自适应红外成像方法，可实现光谱数据的多尺度测量 在纸巾里。这种方法的独特之处在于，它在空间分辨IR中使用了尖端技术 光谱学和成像来研究一个问题，这是一个中心的分子病理学的广泛 疾病和治疗策略的发展。

Project Summary The misfolding and aggregation of specific proteins into fibrillar amyloid deposits is the pathological hallmark of a wide class of diseases and neurodegenerative disorders, which represent a major public health concern worldwide. While it is recognized that amyloid aggregates play an active part in the molecular pathology of the disease, the exact aggregation states that causes cytotoxicity and relationship between pathogenesis and the distribution of secondary structures in amyloid aggregates is not well established. The aim of this project is to investigate the heterogeneities in protein secondary structure in amyloid aggregates both in-vitro and ex-vivo and identify their relationship with disease progression. Our approach relies on utilizing state-of-the-art nanoscale infrared (IR) spectroscopy and confocal IR spectroscopic imaging to map protein secondary structures in amyloid deposits. We will focus on studying amyloid aggregates and their heterogeneities in Alzheimer’s disease (AD) to develop and optimize our methods, and subsequently aim to extend these strategies to investigate amyloid aggregates in other diseases such as Parkinson’s disease and Breast Cancer. The hypothesis underlying this effort is that structural heterogeneities of amyloid deposits, and not just specific fibrillar structures, are correlated with disease progression. We will utilize photothermal AFM-IR, a technique that augments IR spectroscopy with Atomic Force Microscopy, to obtain nanoscale aggregate-specific spectra. Seeded growth from tissue extracts from AD patients will enable probing the differences in aggregation pathways and structural polymorphisms associated with different disease stages. Amyloid aggregates in tissues will be investigated through confocal IR microscopy. The tissue spectral data will be analyzed to classify amyloid deposits based on their secondary structure distributions, and the correlation between distinct classes of deposits and disease stages will be explored. We further aim to integrate AFM-IR and IR microscopy and develop a spatially and spectrally adaptive IR imaging approach that will enable multiscale measurement of spectral data in tissues. The unique aspect of this approach is that it uses cutting edge technologies in spatially resolved IR spectroscopy and imaging to investigate a problem that is central to the molecular pathology of a wide range of diseases and development of therapeutic strategies.