Abstract title: Mutation-dependent seeding and neuronal toxicity of α-synuclein aggregates in an in vitro cortical model
Poster board: SHIFT 01-017
Poster number: 1719
Authors: Lotta Agholme1, Marziyeh Ghaeidamini2, Maitrayee Sardar Sinha1, Albin Skilje1, Fritjof Havemeister2, Johan Pihl1, Elin Esbjörner2
Affiliations: 1Cellectricon AB, Mölndal, Sweden, 2Division of Chemical Biology, Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
Aims: Parkinson’s disease is defined by the formation of Lewy bodies composed of aggregated α-synuclein (α-syn). Point mutations in the SNCA gene result in diverse α-syn variants including A30P, E46K, H50Q, and A53T, each exhibiting unique self-aggregation tendencies, and varying abilities to initiate endogenous α-syn aggregation in neurons. This study investigates how different mutated forms of α-syn pre-formed fibrils (PFFs) induce aggregation in mouse and rat cortical neurons, and how this impacts neuronal function and viability. By exploring the cellular uptake and trafficking of α-syn PFFs, we seek to establish links between their structural features (such as size, shape, and secondary structure) and their biological effects in neuronal cell models.
Methods: All α-synuclein variants were expressed in E. coli and purified. PFFs were prepared following the Michael J. Fox Foundation protocol for reproducibility in PD research, sonicated to ~100 nm for high uptake, and characterized biophysically. Mouse and rat E18 cortical neurons were seeded in 384-well plates, and sonicated PFFs were added at 7DIV, followed by a 7-day incubation. At 14DIV, cells were fixed, stained for α-syn pS129, NeuN, and MPA2, then imaged.
Results: Our study shows that both wild-type and mutated alpha-syn PFFs promote endogenous α-syn aggregation in mouse and rat cortical neurons, with significant variation in aggregate structure between variants. While overall neuronal viability was unaffected, mutations like A53T and H50Q caused marked dendritic disruption, suggesting potential neurotoxicity. These findings highlight how specific α-syn mutations drive distinct aggregation patterns and contribute differently to neurodegenerative processes in Parkinson’s disease.
Conclusions: This study reveals that α-synuclein variants drive distinct aggregation patterns and neurotoxic effects, enhancing our understanding of mutation-specific contributions to Parkinson’s disease pathology.