Lysosomal Exocytosis Releases Pathogenic α-Synuclein Species from Neurons

Abstract

Considerable evidence supports the release of pathogenic aggregates of the neuronal protein -Synuclein (Syn) into the extracellular space. While this release is proposed to instigate the neuron-to-neuron transmission and spread of Syn pathology in synucleinopathies including Parkinsons disease, the molecular-cellular mechanism(s) remain unclear. Here we show that pathogenic species of Syn accumulate within neuronal lysosomes in mouse brains and primary neurons. We then find that neurons release these pathogenic Syn species via SNARE-dependent lysosomal exocytosis; proposing a central mechanism for exocytosis of aggregated and degradation-resistant proteins from neurons.