Trodusquemine enhances Aβ42 aggregation but suppresses its toxicity by displacing oligomers from cell membranes.

DOI: http://doi.org/10.1038/s41467-018-07699-5 Journal: Nat Commun E-pub date: 15 Jan 2019 Authors: R Limbocker, S Chia, FS Ruggeri, M Perni, R Cascella, GT Heller, G Meisl, B Mannini, J Habchi, TCT Michaels, PK Challa, M Ahn, ST Casford, N Fernando, CK Xu, ND Kloss, SIA Cohen, JR Kumita, C Cecchi, M Zasloff, S Linse, TPJ Knowles, F Chiti, M Vendruscolo, CM Dobson

Trodusquemine enhances Aβ42 aggregation but suppresses its toxicity by displacing oligomers from cell membranes.

Abstract:

Transient oligomeric species formed during the aggregation process of the 42-residue form of the amyloid-β peptide (Aβ42) are key pathogenic agents in Alzheimer's disease (AD). To investigate the relationship between Aβ42 aggregation and its cytotoxicity and the influence of a potential drug on both phenomena, we have studied the effects of trodusquemine. This aminosterol enhances the rate of aggregation by promoting monomer-dependent secondary nucleation, but significantly reduces the toxicity of the resulting oligomers to neuroblastoma cells by inhibiting their binding to the cellular membranes. When administered to a C. elegans model of AD, we again observe an increase in aggregate formation alongside the suppression of Aβ42-induced toxicity. In addition to oligomer displacement, the reduced toxicity could also point towards an increased rate of conversion of oligomers to less toxic fibrils. The ability of a small molecule to reduce the toxicity of oligomeric species represents a potential therapeutic strategy against AD.