Overexpression of human alpha-synuclein causes dopamine neuron death in primary human mesencephalic culture.
Mutations in the alpha-synuclein gene have been linked to rare cases of familial Parkinson's disease (PD). Alpha-synuclein is a major component of Lewy bodies (LB), a pathological hallmark of PD. Transgenic mice and Drosophila expressing either wild-type or mutant human alpha-synuclein develop motor deficits, LB-like inclusions in some neurons, and neuronal degeneration. However, the relationship between abnormal aggregates of alpha-synuclein and human dopamine (DA) neuron degeneration remains unclear. In this report, we have investigated the influence of alpha-synuclein expression on DA neurons in primary culture of embryonic human mesencephalon. Two days after culture, human DA cells were transduced with wild-type or mutant human (Ala(53)Thr) alpha-synuclein adenoviruses and maintained for 5 days. Overexpression of mutant and wild-type human alpha-synuclein resulted in 49% (P<0.01) and 27% (P<0.05) loss of DA neurons, respectively, while not affecting viability of other cells in the culture. Overexpression of rat alpha-synuclein or GFP (green fluorescent protein) had no effect on DA neuron survival. Cytoplasmic inclusions of alpha-synuclein were detected immunohistochemically in DA cells transduced with mutant human alpha-synuclein, but not wild-type alpha-synuclein. These results show that overexpression of human alpha-synuclein, particularly the mutant form, can cause human DA neuron death, suggesting that alpha-synuclein may have a primary role in the pathogenesis of PD.
Zhou
Wenbo
W
Division of Clinical Pharmacology, Department of Medicine, and the Neuroscience Program, University of Colorado Health Sciences Center, 4200 East Ninth Avenue, Denver, CO 80262, USA.
Schaack
Jerome
J
Zawada
W Michael
WM
Freed
Curt R
CR
D000256:Adenoviridae / Q000235:genetics; D017209:Apoptosis / Q000502:physiology*; D002478:Cells, Cultured; D004298:Dopamine / Q000502:physiology*; D005333:Fetus / Q000166:cytology; D015967:Gene Expression Regulation, Viral; D049452:Green Fluorescent Proteins; D006801:Humans; D002479:Inclusion Bodies / Q000737:chemistry; D007202:Indicators and Reagents / Q000378:metabolism; D008164:Luminescent Proteins / Q000235:genetics; D008636:Mesencephalon / Q000166:cytology; D009419:Nerve Tissue Proteins / Q000032:analysis / Q000235:genetics*; D009474:Neurons / Q000166:cytology* / Q000502:physiology; D010300:Parkinson Disease / Q000235:genetics / Q000473:pathology; D013378:Substantia Nigra / Q000473:pathology; D051843:Synucleins; D051844:alpha-Synuclein
D007202:Indicators and Reagents; D008164:Luminescent Proteins; D009419:Nerve Tissue Proteins; C497604:SNCA protein, human; D051843:Synucleins; D051844:alpha-Synuclein; D049452:Green Fluorescent Proteins; D004298:Dopamine