Real-Time Characterization of Cell Membrane Disruption by α-Synuclein Oligomers in Live SH-SY5Y Neuroblastoma Cells

Aggregation of the natively unfolded protein α-synuclein (α-Syn) has been widely correlated to the neuronal death associated with Parkinson's disease. Mutations and protein overaccumulation can promote the aggregation of α-Syn into oligomers and fibrils. Recent work has suggested that α-Syn oligomers can permeabilize the neuronal membrane, promoting calcium influx and cell death. However, the mechanism of this permeabilization is still uncertain and has yet to be characterized in live cells. This work uses scanning ion conductance microscopy (SICM) to image, in real time and without using chemical probes, the topographies of live SH-SY5Y neuroblastoma cells after exposure to α-Syn oligomers. Substantial morphological changes were observed, with micrometer-scale hills and troughs observed at lower α-Syn concentrations (1.00 μM) and large, transient pores observed at higher α-Syn concentrations (6.0 μM). These findings suggest that α-Syn oligomers may permeabilize the neuronal membrane by destabilizing the lipid bilayer and opening transient pores.