Inhibition of vesicular monoamine transporter-2 activity in alpha-synuclein stably transfected SH-SY5Y cells.
alpha-Synuclein plays a key role in the pathological neurodegeneration in Parkinson's disease. Although its contribution to normal physiology remains elusive, the selective degeneration of alpha-synuclein-containing dopaminergic neurons in Parkinson's disease may be linked to abnormal alpha-synuclein induced toxicity. In the present study, a complex of alpha-synuclein and vesicular monoamine transporter-2 was identified by GST-Pull Down experiment. In wild-type alpha-synuclein stably transfected SH-SY5Y cell lines, the activity of vesicular monoamine transporter-2 decreased by 31% as determined by [(3)H] dopamine uptake, and its expression also decreased in both protein and mRNA levels using western and northern blot analysis. Overexpression of wild-type alpha-synuclein did not induce cell death or apoptosis, but significantly enhanced the intracellular reactive oxygen species level as assayed by flow cytometry. These data suggest that Up-regulated alpha-synuclein expression inhibits the activity of vesicular monoamine transporter-2, thereby interrupting dopamine homeostasis and resulting in dopaminergic neuron injury in Parkinson's disease.
Guo
Jun Tang
JT
Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, 5 Panjiayuannanli, Beijing, 100021, China.
Chen
An Qi
AQ
Kong
Qi
Q
Zhu
Hua
H
Ma
Chun Mei
CM
Qin
Chuan
C
D006690:Bisbenzimidazole / Q000378:metabolism; D001921:Brain / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival; D004298:Dopamine / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D014162:Transfection; D050493:Vesicular Monoamine Transport Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D051844:alpha-Synuclein / Q000378:metabolism*
D012333:RNA, Messenger; D017382:Reactive Oxygen Species; C493452:SLC18A2 protein, human; D050493:Vesicular Monoamine Transport Proteins; D051844:alpha-Synuclein; D006690:Bisbenzimidazole; D004298:Dopamine