Figure 9.

Isolated secreted α-synuclein oligomeric and monomeric species decrease the viability of differentiated SH-SY5Y cells. A, α-Synuclein-expressing and uninduced CTL cells were cultured in 2% FBS for 48 h. After removal of cell debris, the CM was fractionated by SEC. Extracellular HMW and LMW α-synuclein-containing species were collected, lyophilized, and applied to differentiated SH-SY5Y cells for 48 h. Representative phase micrographs are shown. Scale bar, 50 μm. B, Quantification graph presenting the increase in cell death after application of extracellular HMW or LMW α-synuclein species for 48 h (n = 3; mean ± SD, one-way ANOVA test followed by Tukey's test, *p < 0.001, **p = 0.001).