TY - JOUR
T1 - Single particle characterization of iron-induced pore-forming α-synuclein oligomers
AU - Kostka, Marcus
AU - Högen, Tobias
AU - Danzer, Karin M.
AU - Levin, Johannes
AU - Habeck, Matthias
AU - Wirth, Andreas
AU - Wagner, Richard
AU - Glabe, Charles G.
AU - Finger, Sabine
AU - Heinzelmann, Udo
AU - Garidel, Patrick
AU - Duan, Wenzhen
AU - Ross, Christopher A.
AU - Kretzschmar, Hans
AU - Giese, Armin
PY - 2008/4/18
Y1 - 2008/4/18
N2 - Aggregation of α-synuclein is a key event in several neurodegenerative diseases, including Parkinson disease. Recent findings suggest that oligomers represent the principal toxic aggregate species. Using confocal single-molecule fluorescence techniques, such as scanning for intensely fluorescent targets (SIFT) and atomic force microscopy, we monitored α-synuclein oligomer formation at the single particle level. Organic solvents were used to trigger aggregation, which resulted in small oligomers ("intermediate I"). Under these conditions, Fe3+ at low micromolar concentrations dramatically increased aggregation and induced formation of larger oligomers ("intermediate II"). Both oligomer species were on-pathway to amyloid fibrils and could seed amyloid formation. Notably, only Fe3+-induced oligomers were SDS-resistant and could form ion-permeable pores in a planar lipid bilayer, which were inhibited by the oligomer-specific A11 antibody. Moreover, baicalein and N′-benzylidene- benzohydrazide derivatives inhibited oligomer formation. Baicalein also inhibited α-synuclein-dependent toxicity in neuronal cells. Our results may provide a potential disease mechanism regarding the role of ferric iron and of toxic oligomer species in Parkinson diseases. Moreover, scanning for intensely fluorescent targets allows high throughput screening for aggregation inhibitors and may provide new approaches for drug development and therapy.
AB - Aggregation of α-synuclein is a key event in several neurodegenerative diseases, including Parkinson disease. Recent findings suggest that oligomers represent the principal toxic aggregate species. Using confocal single-molecule fluorescence techniques, such as scanning for intensely fluorescent targets (SIFT) and atomic force microscopy, we monitored α-synuclein oligomer formation at the single particle level. Organic solvents were used to trigger aggregation, which resulted in small oligomers ("intermediate I"). Under these conditions, Fe3+ at low micromolar concentrations dramatically increased aggregation and induced formation of larger oligomers ("intermediate II"). Both oligomer species were on-pathway to amyloid fibrils and could seed amyloid formation. Notably, only Fe3+-induced oligomers were SDS-resistant and could form ion-permeable pores in a planar lipid bilayer, which were inhibited by the oligomer-specific A11 antibody. Moreover, baicalein and N′-benzylidene- benzohydrazide derivatives inhibited oligomer formation. Baicalein also inhibited α-synuclein-dependent toxicity in neuronal cells. Our results may provide a potential disease mechanism regarding the role of ferric iron and of toxic oligomer species in Parkinson diseases. Moreover, scanning for intensely fluorescent targets allows high throughput screening for aggregation inhibitors and may provide new approaches for drug development and therapy.
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U2 - 10.1074/jbc.M709634200
DO - 10.1074/jbc.M709634200
M3 - Article
C2 - 18258594
AN - SCOPUS:44849084558
SN - 0021-9258
VL - 283
SP - 10992
EP - 11003
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 16
ER -