Differential cytotoxicity of human wild type and mutant alpha-synuclein in human neuroblastoma SH-SY5Y cells in the presence of dopamine.

Abstract:

:Parkinson's disease (PD) involves loss of dopaminergic neurons in the substantia nigra and is characterized by intracellular inclusions, Lewy bodies, consisting primarily of aggregated alpha-synuclein. Two substitution mutations (A53T and A30P) in alpha-synuclein gene have been identified in familial early-onset PD. To understand the biological changes that incur upon alpha-synuclein-induced cytotoxicity in the presence of dopamine, the current studies were undertaken. Human SH-SY5Y neuroblastoma cells coexpressing the human dopamine transporter [hDAT], and either wild type (wt) or mutant alpha-synucleins, were treated with 50 microM dopamine (DA). In cells expressing wt or A30P alpha-synuclein, DA accelerated production of reactive oxygen species and cell death as compared to cells expressing A53T or hDAT alone. The increased sensitivity of such cells to DA was investigated by measuring changes in cellular ionic gradient, by atomic absorption spectrometry, and cell metabolism, by high-resolution nuclear magnetic resonance spectroscopy. Both wt and A30P alpha-synuclein caused rapid decrease in levels of intracellular potassium, followed by mitochondrial damage and cytochrome c leakage, with decreased cellular metabolism as compared to cells expressing A53T or hDAT alone. Collapse of ionic gradient was significantly faster in A30P (t(1/2) = 3.5 h) than in wt (t(1/2) = 6.5 h) cells, and these changes in ionic gradient preceded cytochrome c leakage and depletion of metabolic energy. Neither wt nor mutant alpha-synuclein resulted in significant changes in ionic gradient or cellular metabolism in the absence of intracellular DA. These findings suggest a specific sequence of events triggered by dopamine and differentially exacerbated by alpha-synuclein and the A30P mutant.

journal_name

Biochemistry

journal_title

Biochemistry

authors

Moussa CE,Wersinger C,Tomita Y,Sidhu A

doi

10.1021/bi036114f

subject

Has Abstract

pub_date

2004-05-11 00:00:00

pages

5539-50

issue

18

eissn

0006-2960

issn

1520-4995

journal_volume

43

pub_type

杂志文章