A Rapid, Semi-Quantitative Assay to Screen for Modulators of Alpha-Synuclein Oligomerization Ex vivo

Alpha synuclein (alpha syn) aggregates are associated with the pathogenesis of Parkinson's disease and others related disorders. Although modulation of alpha syn aggregation is an attractive therapeutic target, new powerful methodologies are desperately needed to facilitate in vivo screening of novel therapeutics. Here, we describe an in vivo rodent model with the unique ability to rapidly track alpha syn-alpha syn interactions and thus oligomerization using a bioluminescent protein complementation strategy that monitors spatial and temporal alpha syn oligomerization ex vivo. We find that alpha syn forms oligomers in vivo as early as 1 week after stereotactic AAV injection into rat substantia nigra. Strikingly, although abundant alpha syn expression is also detected in striatum at 1 week, no alpha syn oligomers are detected at this time point. By 4 weeks, oligomerization of alpha syn is detected in both striatum and substantia nigra homogenates. Moreover, in a proof-of-principle experiment, the effect of a previously described Hsp90 inhibitor known to prevent alpha syn oligomer formation, demonstrates the utility of this rapid and sensitive animal model to monitor alpha syn oligomerization status in the rat brain.