Multi-platform quantitation of alpha-synuclein human brain proteoforms suggests disease-specific biochemical profiles of synucleinopathies

• DOI: 10.1186/s40478-022-01382-z
• Publication Date: 2022-06-03T10:03:45Z
• Authors: Tim E. Moors; Daniel Mona; Stefan Luehe; Gonzalo Duran-Pac...; Liz Spycher; Olaf Mundigl; Klaus Kaluza; Sylwia Huber; Melanie N. Hug; Thomas Kremer; Mirko Ritter; Sebastian Dziadek; Gregor Dernick; Wilma D. J. van d...; Markus Britschgi
• Keywords: Synucleinopathies

Based on immunostainings and biochemical analyses, certain post-translationally modified alpha-synuclein (aSyn) variants, including C-terminally truncated (CTT) Serine-129 phosphorylated (pSer129) aSyn, are proposed to be involved in the pathogenesis of synucleinopathies such as Parkinson's disease with (PDD) without dementia (PD), Lewy bodies (DLB), multiple system atrophy (MSA). However, quantitative information about aSyn proteoforms human brain physiological different pathological conditions is still limited. To address this, we generated sequential extracts substantia nigra, putamen hippocampus from 28 donors diagnosed neuropathologically-confirmed (PD/PDD/DLB/MSA), well Alzheimer's disease, progressive supranuclear palsy, aged normal subjects. The tissue were used build a reverse phase array 65 antibodies for detection. In this multiplex approach, observed increased immunoreactivity compared controls detergent-insoluble fractions, mainly against CT pSer129 aSyn. addition, despite restricted sample size, clustering analysis suggested disease-specific signatures patient groups synucleinopathies. We aimed validate quantify these findings using newly developed immunoassays towards total, 119 122 CTT, line previous studies, found that shared an enrichment fractions other analyzed groups. Our measurements allowed separation PDD/DLB patients based higher concentrations hippocampus. MSA stood out due CTT also detergent-soluble fraction SN putamen. Together, our results achieved by multiplexed immunoassay-based approaches limited set point proteoform profiles distinct neurodegenerative disorders.