Department of Structural and Functional Biology, University of Insubria, Busto Arsizio, Italy.
FEBS J. 2010 Dec;277(23):4909-19. doi: 10.1111/j.1742-4658.2010.07896.x. Epub 2010 Oct 26.
Altered dopamine homeostasis is an accepted mechanism in the pathogenesis of Parkinson's disease. α-Synuclein overexpression and impaired disposal contribute to this mechanism. However, biochemical alterations associated with the interplay of cytosolic dopamine and increased α-synuclein are still unclear. Catecholaminergic SH-SY5Y human neuroblastoma cells are a suitable model for investigating dopamine toxicity. In the present study, we report the proteomic pattern of SH-SY5Y cells overexpressing α-synuclein (1.6-fold induction) after dopamine exposure. Dopamine itself is able to upregulate α-synuclein expression. However, the effect is not observed in cells that already overexpress α-synuclein as a consequence of transfection. The proteomic analysis highlights significant changes in 23 proteins linked to specific cellular processes, such as cytoskeleton structure and regulation, mitochondrial function, energetic metabolism, protein synthesis, and neuronal plasticity. A bioinformatic network enrichment procedure generates a significant model encompassing all proteins and allows us to enrich functional categories associated with the combination of factors analyzed in the present study (i.e. dopamine together with α-synuclein). In particular, the model suggests a potential involvement of the nuclear factor kappa B pathway that is experimentally confirmed. Indeed, α-synuclein significantly reduces nuclear factor kappa B activation, which is completely quenched by dopamine treatment.
多巴胺稳态的改变是帕金森病发病机制中的一个公认机制。α-突触核蛋白的过度表达和处置受损促成了这一机制。然而，与细胞溶质多巴胺和增加的α-突触核蛋白相互作用相关的生化改变仍不清楚。儿茶酚胺能 SH-SY5Y 人神经母细胞瘤细胞是研究多巴胺毒性的合适模型。在本研究中，我们报告了多巴胺暴露后过表达α-突触核蛋白（诱导 1.6 倍）的 SH-SY5Y 细胞的蛋白质组学模式。多巴胺本身能够上调α-突触核蛋白的表达。然而，在由于转染而过表达α-突触核蛋白的细胞中，没有观察到这种效应。蛋白质组学分析强调了与特定细胞过程相关的 23 种蛋白质的显著变化，如细胞骨架结构和调节、线粒体功能、能量代谢、蛋白质合成和神经元可塑性。生物信息学网络富集程序生成了一个包含所有蛋白质的显著模型，并允许我们富集与本研究中分析的因素组合相关的功能类别（即多巴胺与α-突触核蛋白）。特别是，该模型表明核因子 kappa B 途径可能参与其中，这一点通过实验得到了证实。事实上，α-突触核蛋白显著降低了核因子 kappa B 的激活，而多巴胺处理则完全抑制了这种激活。
