RT-QuIC-based detection of alpha-synuclein seeding activity in brains of dementia with Lewy Body patients and of a transgenic mouse model of synucleinopathy

RT-QuIC is a shaking-based cyclic amplification technique originally developed in the prion field to detect minute amounts of scrapie prion protein (PrP(Sc)). In this study, we applied the RT-QuIC assay to investigate a-synuclein (a-syn) seeding activity in brains of Dementia with Lewy Body (DLB) patients and in brains of G2-3 transgenic mice expressing human a-syn with A53T mutation. The results show that a-syn seeding activity varies between patients with detectable dilutions ranging from 10(−3) to 10(−8) dilutions of brain tissue and is stable under exposures to the cycles of freezing, thawing and sonication. A53T a-syn aggregates from G2-3 transgenic mice greatly favoured A53T recombinant human a-syn as substrates in comparison to wild-type a-syn, suggesting that conformations for wild-type a-syn to be able to adopt are not compatible with that of A53T aggregates from G2-3.