Exosome-Mediated Propagation

Using imaging and biochemical assays, I demonstrated that a subset of fibrils are packaged into exosomes and transferred to neighboring naïve cells. This work provided direct evidence that α-synuclein pathology spreads through extracellular vesicles, contributing to the prion-like propagation observed in Parkinson’s disease.

Gold-Labeled Fibril-Decorated Exosomes

Here, I used gold-labeled PFFs to directly visualize their association with exosomes during transfer to naïve cells. Electron microscopy revealed exosomes decorated with fibrils making contact with recipient cell membranes, often near ruffling regions and forming macropinosomes. This provided ultrastructural evidence that α-synuclein fibrils “hitchhike” on the outer surface of exosomes to spread between cells.

Exosome-Mediated Transfer of α-syn to Naïve Cells

In this assay, I showed that exosomes released from donor cells containing fluorescently labeled α-synuclein fibrils (PFFs) can transfer both CD63 and fibril signal to naïve recipient cells. Confocal imaging revealed extracellular vesicles positive for CD63-GFP and PFF-Alexa within previously untreated cells, demonstrating that exosomes act as carriers of fibrils between cells. Importantly, this transfer was blocked by macropinocytosis inhibition, confirming that exosome uptake requires this pathway