α-Synuclein pre-formed fibrils induce prion-like protein aggregation and neurotoxicity in C. elegans models of Parkinson’s disease

Parkinson’s disease (PD) is a debilitating neurodegenerative disorder characterized by progressive motor decline and the aggregation of α-synuclein protein. Growing evidence suggests that α-synuclein aggregates may spread from neurons of the digestive tract to the brain in a prion-like manner. While rodent models have recapitulated gut-to-brain α-synuclein transmission, animal models that are amenable to high-throughput investigations are needed to facilitate the discovery of disease mechanisms. Here we describe the first C. elegans models in which feeding with α-synuclein pre-formed fibrils (PFFs) induced prion-like dopamine neuron degeneration and seeding of aggregation of human α-synuclein expressed in the host. PFF acceleration of α-synuclein aggregation in C. elegans muscle cells was associated with a progressive motor deficit, whereas feeding with α-synuclein monomer produced much milder effects. RNAi-mediated knockdown of the C. elegans syndecan sdn-1 , and enzymes involved in heparan sulfate proteoglycan biosynthesis, afforded protection from PFF-induced seeding of aggregation and toxicity, as well as dopaminergic neurodegeneration. This work offers new models by which to investigate gut-derived α-synuclein spreading and propagation of disease.