Objective: To validate the effect of Lewy body extracts from Parkinson’s disease (PD) brains in high-throughput screens of neurotoxicity and the α-synuclein (α-syn) spreading from cell-to-cell.

Background: The anatomo-pathological landmark of PD is the deposit of aggregated proteins of aberrant conformation into Lewy bodies (LB). Misfolded α-syn is a major protein component of LB. Recent data suggest that α-syn can act like a prion-like protein in PD. Recently, through an innovative strategy based on the purification of aggregated α-syn of PD patients, we assessed the prion-like properties of endogenous α-syn assemblies in animal models, ranging from wild-type mice and non-human primates. Besides validating the infectious nature of aggregated α-syn, our approach allowed establishing that authentic α-syn assemblies, e.g. LB, possess “pathological” characteristics absent in α-syn assemblies made in vitro that account for the specific infectivity of assemblies. Nevertheless, the actual type of neurotoxic insult wreaked upon neurons by α-syn assemblies, the mechanism of passage from cell-to-cell as well as the cellular identity of cells amenable to α-syn assemblies transfer remains unknown.

Methods: The toxicity of human LB-derived α-syn assemblies will be assessed by live content imaging, by kinetically monitoring the neurite outgrowth (neuritic length and neurite branching) by phase-contrast time-lapse, over a period of ∼6-7 days. We also studied the passage from neuron-to-neuron, neuron-to-glia, glia-to-neuron and glia-to-glia in microfluidic experiments.

Results: The neurotoxic results exhibited that human LB-derived α-syn assemblies have a modest cytotoxicity but dose-dependently inhibited the growth of neurite length and the number of branching points. The microfluidic experiments showed that human LB-derived α-syn assemblies are uptaken by all cell type by endocytosis grounding the mechanism for spreading both in interconnected regions (neuronal transfer) and within large structures (glial cells might cover large territories within a nucleus).

Conclusions: We validated the unique behaviour of human LB-derived α-syn assemblies and developed in vitro high-throughput screening platforms for identification of potential therapeutics against α-syn assemblies-induced toxicity and spreading.

« Back to 2016 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/lewy-body-extracts-from-parkinsons-disease-brains-as-models-for-high-throughput-screens-of-neurotoxicity-and-synuclein-spreading-from-cell-to-cell/