Department of Biology, University of Padova, 35121 Padova, Italy.
BMC Neurosci. 2010 Mar 25;11:41. doi: 10.1186/1471-2202-11-41.
Oxidative stress has been proposed to be involved in the pathogenesis of Parkinson's disease (PD). A plausible source of oxidative stress in nigral dopaminergic neurons is the redox reactions that specifically involve dopamine and produce various toxic molecules, i.e., free radicals and quinone species. alpha-Synuclein, a protein found in Lewy bodies characteristic of PD, is also thought to be involved in the pathogenesis of PD and point mutations and multiplications in the gene coding for alpha-synuclein have been found in familial forms of PD.
We used dopaminergic human neuroblastoma BE(2)-M17 cell lines stably transfected with WT or A30P mutant alpha-synuclein to characterize the effect of alpha-synuclein on dopamine toxicity. Cellular toxicity was analyzed by lactate dehydrogenase assay and by fluorescence-activated cell sorter analysis. Increased expression of either wild-type or mutant alpha-synuclein enhances the cellular toxicity induced by the accumulation of intracellular dopamine or DOPA.
Our results suggest that an interplay between dopamine and alpha-synuclein can cause cell death in a neuron-like background. The data presented here are compatible with several models of cytotoxicity, including the formation of alpha-synuclein oligomers and impairment of the lysosomal degradation.
氧化应激被认为与帕金森病（PD）的发病机制有关。在黑质多巴胺能神经元中，氧化应激的一个合理来源是涉及多巴胺的氧化还原反应，这些反应会产生各种有毒分子，如自由基和醌类物质。α-突触核蛋白是 PD 路易体中发现的一种蛋白质，也被认为与 PD 的发病机制有关，在 PD 的家族形式中已经发现了编码α-突触核蛋白的基因突变和扩增。
我们使用稳定转染 WT 或 A30P 突变α-突触核蛋白的多巴胺能人神经母细胞瘤 BE(2)-M17 细胞系来描述α-突触核蛋白对多巴胺毒性的影响。通过乳酸脱氢酶测定和荧光激活细胞分选分析来分析细胞毒性。野生型或突变型α-突触核蛋白的表达增加都会增强细胞内多巴胺或 DOPA 积累所诱导的细胞毒性。
我们的结果表明，多巴胺和α-突触核蛋白之间的相互作用可能导致神经元样背景下的细胞死亡。这里呈现的数据与几种细胞毒性模型一致，包括α-突触核蛋白寡聚物的形成和溶酶体降解的损伤。
