Cellular Anatomy of Tau Seeding

项目总结/文摘:

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.