Potent α-Synuclein Aggregation Inhibitors, Identified by High-Throughput Screening, Mainly Target the Monomeric State

Area of Science:

• Neuroscience
• Biochemistry
• Pharmacology

Background:

• Alpha-synuclein (αSN) aggregation is a central pathological hallmark of Parkinson's disease (PD).
• Detecting early-stage αSN oligomers (αSOs) and inhibiting stochastic aggregation are significant challenges in drug discovery for PD.

Purpose of the Study:

• To develop a high-throughput screening (HTS) assay for identifying inhibitors of αSN aggregation.
• To screen a large compound library and characterize effective αSN aggregation inhibitors and their mechanisms.

Main Methods:

• Developed an HTS assay combining SDS-stimulated αSN aggregation with Förster Resonance Energy Transfer (FRET) to detect early aggregation stages.
• Screened 746,000 compounds to identify inhibitors of αSN aggregation and αSO membrane permeabilization.
• Investigated the interaction of inhibitors with monomeric αSN and their effect on αSO-membrane interactions and cellular toxicity.

Main Results:

• Identified 58 hit compounds that inhibit αSN aggregation and reduce αSO membrane permeabilization.
• Discovered that (4-hydroxynaphthalen-1-yl)sulfonamide derivatives were potent inhibitors, interacting with the αSN N-terminus and reducing αSO-membrane interactions.
• Observed that several compounds reduced αSO toxicity in neuronal cell lines and identified phenyl-benzoxazol compounds that promoted aggregation.

Conclusions:

• The developed FRET-based HTS assay reliably detects early αSN aggregation, facilitating the discovery of novel inhibitors.
• Identified potent αSN aggregation inhibitors with potential therapeutic applications for Parkinson's disease.
• Discovered pro-aggregating compounds that could serve as valuable tools for studying αSN aggregation dynamics in cellular models.