FRET-based assay for intracellular evaluation of α-synuclein aggregation inhibitors

J Neurochem. 2021 Dec;159(5):901-912. doi: 10.1111/jnc.15528. Epub 2021 Nov 8.

Abstract

Aggregation of small neuronal protein α-synuclein (αSyn) in amyloid fibrils is considered to be one of the main causes of Parkinson's disease. Inhibition of this aggregation is a promising approach for disease treatment. Dozens of compounds able to inhibit αSyn fibrillization in solution were developed during the last decade. However, the applicability of most of them in the cellular environment was not established because of the absence of a suitable cell-based assay. In this work, we developed an assay for testing αSyn aggregation inhibitors in cells that is based on fluorescence resonance energy transfer (FRET) between labeled αSyn molecules in fibrils. The assay directly reports the amount of fibrillized αSyn and is more reliable than the assays based on cell viability. Moreover, we showed that cell viability decline does not always correlate with the amount of misfolded αSyn. The developed FRET-based assay does not interfere with the aggregation process and is suitable for high-throughput testing of αSyn aggregation inhibitors. Its application can sort out non-specific inhibitors and thus significantly facilitate the development of drugs for Parkinson`s disease.

Keywords: FRET; Parkinson's Disease; amyloid; assay; intracellular; α-synuclein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Benzodioxoles / pharmacology
  • Cell Survival / drug effects
  • Cell Survival / physiology
  • Dose-Response Relationship, Drug
  • Electroporation / methods
  • Fluorescence Resonance Energy Transfer / methods*
  • HeLa Cells
  • Humans
  • Intracellular Fluid / chemistry
  • Intracellular Fluid / drug effects*
  • Intracellular Fluid / metabolism*
  • Protein Aggregates / drug effects*
  • Protein Aggregates / physiology
  • Pyrazoles / pharmacology
  • alpha-Synuclein / analysis
  • alpha-Synuclein / antagonists & inhibitors*
  • alpha-Synuclein / metabolism*

Substances

  • 3-(1,3-benzodioxol-5-yl)-5-(3-bromophenyl)-1H-pyrazole
  • Benzodioxoles
  • Protein Aggregates
  • Pyrazoles
  • alpha-Synuclein