Higher-molecular-weight a-synuclein oligomers are increased in the brain cytosol of patients with dementia with Lewy bodies

The demonstration of MJFR14-6-4-2 proximity ligation assay positive aggregates in brains affected by Parkinson’s disease and LRRK2 mutations, motivated the analysis of α-synuclein oligomers in brain cytosol from dementia with Lewy bodies (DLB) and control cases by combining size-exclusion chromatography, aggregate-specific MJFR14-6-4-2 ELISA and SDS-denaturing immunoblotting. We demonstrate a DLB-specific accumulation of large SDS-soluble oligomers, and the presence of medium-sized oligomers consisting of SDS-resistant α-synuclein dimers and trimers in both DLB and controls.