Cellular Anatomy of Tau Seeding

项目摘要/摘要： Tau病理沿突触连接的大脑回路传播被认为是一种 阿尔茨海默病(AD)认知功能下降的主要原因。然而，潜在的机制 蛋白致病的tau种子在人类神经元内的进入和放大仍不清楚。鉴于推定的 脑回路在tau传播中的作用，tau种子可能涉及轴突/轴突终末或树突 领悟。然而，这在神经元模型和典型的研究方法中从未被确定。 这些事件，如光学显微镜和免疫荧光本身，都有关键的分辨率限制。 因此，我们还不能假设tau种子在神经元的什么地方接触细胞质和 复制。为了回答这些问题，我们将应用高分辨率的关联光和电子 显微成像(3D-Clem)，结合先进的细胞荧光生物传感器和新型 诱导性多能性来源的人神经元中具有活细胞成像的构象抗体 干细胞(IPSCs)在我们的中心可用。我们的策略应该能够确定tau种子在哪里 摄取发生，以及涉及的局部化和亚细胞成分和/或分子机制 在tau种子扩增中，同时绕过了引入蛋白质聚集体提取技术 实验文物。通过使用内部高分辨率相关成像来探索这些机制 关于人类神经元，我们将讨论蛋白病态种子是如何进入细胞质并复制的，这 可能对其他相关的神经退行性疾病有更广泛的影响。

Project Summary/Abstract: The propagation of tau pathology along synaptically connected brain circuits is considered a major driver of cognitive decline in Alzheimer’s Disease (AD). However, the mechanisms underlying proteopathic tau seed entry and amplification within human neurons remain unclear. Given the putative role of brain circuits in tau propagation, axons/axon terminals or dendrites may be involved in tau seed uptake. However, this has never been determined in neuronal models, and typical methods to study these events, such as light microscopy and immunofluorescence alone, have critical resolution limits. Thus, we cannot yet hypothesize where in a neuron that the tau seeds access the cytoplasm and replicate. To answer these questions, we will apply high-resolution correlative light and electron microscopic imaging (3D-CLEM), combined with advanced cell-based fluorescent biosensors and novel conformational antibodies with live cell imaging in human neurons derived from inducible pluripotent stem cells (iPSCs) available here in our center. Our strategy should enable determining where tau seed uptake occurs, and the localization and sub-cellular components and/or molecular machinery involved in tau seed amplification, while bypassing protein aggregate extraction techniques that introduce experimental artifact. By exploring these mechanisms using high-resolution correlative imaging within human neurons, we will address how proteopathic seeds access the cytoplasm and replicate, which may have broader implications for other related neurodegenerative diseases.