In vitro aggregation assays for the characterization of α-synuclein prion-like properties

Aggregation of ?-synuclein plays a crucial role in the pathogenesis of synucleinopathies, a group of neurodegenerative diseases including Parkinson disease (PD), dementia with Lewy bodies (DLB), diffuse Lewy body disease (DLBD) and multiple system atrophy (MSA). The common feature of these diseases is a pathological deposition of protein aggregates, known as Lewy bodies (LBs) in the central nervous system. The major component of these aggregates is ?-synuclein, a natively unfolded protein, which may undergo dramatic structural changes resulting in the formation of ?-sheet rich assemblies. In vitro studies have shown that recombinant ?-synuclein protein may polymerize into amyloidogenic fibrils resembling those found in LBs. These aggregates may be uptaken and propagated between cells in a prion-like manner. Here we present the mechanisms and kinetics of ?-synuclein aggregation in vitro, as well as crucial factors affecting this process. We also describe how D-linked ?-synuclein mutations and some exogenous factors modulate in vitro aggregation. Furthermore, we present a current knowledge on the mechanisms by which extracellular aggregates may be internalized and propagated between cells, as well as the mechanisms of their toxicity. © 2014 Landes Bioscience. Do not distribute.