Couldα-Synuclein Amyloid-Like Aggregates Trigger a Prionic Neuronal Invasion?

Abstract

Parkinson’s disease (PD), a progressive neurodegenerative disease primarily affecting voluntary and controlled movement, is characterized by abnormal accumulations ofα-synuclein (α-syn) in intraneuronal Lewy bodies. In the last years, the increased number of evidences from both thein vitroandin vivostudies has shown the ability ofα-syn to misfold in amyloid conformations and to spread via neuron-to-neuron transmission, suggesting a prion-like behaviour. However, in contrast to prion protein (PrP),α-syn transmission is far from neuronal invasion. The high neuronal toxicity of both mature fibres and oligomeric species, as well as the intracellular localization of the protein and the difficulty to be secreted, could be key factors impeding the prion ability ofα-syn aggregates.