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

Abstract

Aggregation of α-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 α-synuclein, a natively unfolded protein, which may undergo dramatic structural changes resulting in the formation of β-sheet rich assemblies. In vitro studies have shown that recombinant α-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 α-synuclein aggregation in vitro, as well as crucial factors affecting this process. We also describe how PD-linked α-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.

Protein aggregation and neurodegeneration in prototypical neurodegenerative diseases: Examples of amyloidopathies, tauopathies and synucleinopathies

“…Several types of protofibrils have been characterized ranging from spheres to chains and rings (Conway et al, 2000). A number of endogenous and exogenous factors can influence either the aggregation kinetics or the solubility and the stability of a-syn (reviewed in Narkiewicz et al, 2014).…”

Parkinson's disease as a member of Prion-like disorders

“…can profoundly alter the efficiency of the outcome, leading also to structurally different alpha-synuclein fibril conformations Guo et al, 2013). Therefore, the development of a fast, reliable and reproducible assay to study the aggregation of alpha-synuclein and the effect of drugs in the formation of these aggregates was a pressing need (Narkiewicz et al, 2014).…”

Nanomolar oligomerization and selective co-aggregation of α-synuclein pathogenic mutants revealed by single-molecule fluorescence

“…Interestingly, α-synuclein adopts a prion-like behavior when aggregating1415. Auto-catalysis of aggregation has been demonstrated in vitro 1617 and more critically participates in the propagation of the phenotype in cell cultures18192021 and in vivo 2223. Different conformations of aggregates promote their own replication only, reminiscent of the prion strains2324.…”