Dopamine facilitates alpha-synuclein oligomerization in human neuroblastoma SH-SY5Y cells.
Parkinson's disease is characterized by selective loss of dopaminergic neurons in the substantia nigra and by the appearance of Lewy bodies. Fibrillar alpha-synuclein is the main component of Lewy bodies. Previous studies have suggested that dopamine promotes alpha-synuclein oligomerization and that partially aggregated or oligomeric alpha-synuclein could be cytotoxic. To confirm this hypothesis using cell cultures, we performed size exclusion chromatography as a pretreatment method prior to Western blotting to more clearly detect a small amount of alpha-synuclein oligomers in wild-type alpha-synuclein-overexpressing SH-SY5Y cells. Using this method, we confirmed that stable overexpression of alpha-synuclein in SH-SY5Y cells indeed increased the amounts of alpha-synuclein oligomers in these cells and exposure of the cells to dopamine for 6h facilitated alpha-synuclein oligomerization. These dopamine-induced alpha-synuclein oligomers continued to exist for the following 24h. However, the dopamine-treated cells did not undergo cell death or apoptosis in spite of the presence of increased oligomeric alpha-synuclein. Our data may contribute to the understanding of the mechanisms underlying alpha-synuclein oligomer formation and its suspected cytotoxicity toward dopaminergic neurons.
Yamakawa
Kentaro
K
Clinical Research Center, Utano National Hospital, National Hospital Organization, Kyoto 616-8255, Japan.
Izumi
Yasuhiko
Y
Takeuchi
Hiroki
H
Yamamoto
Noriyuki
N
Kume
Toshiaki
T
Akaike
Akinori
A
Takahashi
Ryosuke
R
Shimohama
Shun
S
Sawada
Hideyuki
H
D017209:Apoptosis; D015153:Blotting, Western; D045744:Cell Line, Tumor; D002850:Chromatography, Gel; D004298:Dopamine / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D016631:Lewy Bodies / Q000737:chemistry / Q000378:metabolism; D009474:Neurons / Q000737:chemistry / Q000378:metabolism*; D010300:Parkinson Disease / Q000378:metabolism*; D013378:Substantia Nigra / Q000378:metabolism; D051844:alpha-Synuclein / Q000737:chemistry / Q000378:metabolism*
D051844:alpha-Synuclein; D004298:Dopamine