Targeting α-synuclein oligomers by protein-fragment complementation for drug discovery in synucleinopathies

Objective: Reducing the burden of alpha-synuclein oligomeric species represents a promising approach for disease-modifying therapies against synucleinopathies such as Parkinson's disease and dementia with Lewy bodies. However, the lack of efficient drug discovery strategies that specifically target alpha-synuclein oligomers has been a limitation to drug discovery programs. Research design and methods: Here we describe an innovative strategy that harnesses the power of bimolecular protein-fragment complementation to monitor synuclein-synuclein interactions. We have developed two robust models to monitor alpha-synuclein oligomerization by generating novel stable cell lines expressing alpha-synuclein fusion proteins for either fluorescent or bioluminescent protein-fragment complementation under the tetracycline-controlled transcriptional activation system. Main outcome measures: A pilot screen was performed resulting in the identification of two potential hits, a p38 MAPK inhibitor and a casein kinase 2 inhibitor, thereby demonstrating the suitability of our protein-fragment complementation assay for the measurement of alpha-synuclein oligomerization in living cells at high throughput. Conclusions: The application of the strategy described herein to monitor alpha-synuclein oligomer formation in living cells with high throughput will facilitate drug discovery efforts for disease-modifying therapies against synucleinopathies and other proteinopathies.