α-Synuclein modulation of Ca2+signaling in human neuroblastoma (SH-SY5Y) cells
α-Synuclein modulation of Ca2+signaling in human neuroblastoma (SH-SY5Y) cells
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DOI：
10.1111/j.1471-4159.2009.06411.x
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发表时间：
2009-12-01
影响因子：
4.7
通讯作者：
Peers, Chris
中科院分区：
文献类型：
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作者：
Hettiarachchi, Nishani T.;Parker, Andrew;Peers, Chris
帕金森病（PD）的部分特征是存在富含α -突触核蛋白（α -syn）的细胞内包涵体（路易体）。α -突触核蛋白基因（SNCA）的突变和增殖与家族性帕金森病有关。由于Ca2+失衡可能在PD的发病机制中发挥重要作用，我们在fura-2负载的SH-SY5Y细胞中使用荧光法来监测稳定转染野生型α -syn、A53T突变型、S129D拟磷突变型或空载体（作为对照）的细胞中的Ca2+稳态。在表达所有三种形式的α -syn的细胞中，暴露于50 mM K+引起的电压门控Ca2+内流增强，这种效应是由于通过l型Ca2+通道增加Ca2+进入。肌碱对Ca2+的动员并没有被任何α -syn形式显著地改变，但它们都减少了肌碱或thapsigargin引起的储存耗尽后的Ca2+进入。在所有测试的细胞中（除了S129D突变体），用环吡唑酸排空储存库引起类似的[Ca2+](i)升高，线粒体Ca2+含量不受任何形式的α -突触核蛋白的影响。然而，只有转染了WT α -syn的细胞表现出明显的活力受损。我们的研究结果表明，α -syn调节Ca2+进入途径，因此，异常α -syn水平可能通过Ca2+稳态失调促进神经元损伤。
Parkinson's disease (PD) is characterized in part by the presence of alpha-synuclein (alpha-syn) rich intracellular inclusions (Lewy bodies). Mutations and multiplication of the alpha-synuclein gene (SNCA) are associated with familial PD. Since Ca2+ dyshomeostasis may play an important role in the pathogenesis of PD, we used fluorimetry in fura-2 loaded SH-SY5Y cells to monitor Ca2+ homeostasis in cells stably transfected with either wild-type alpha-syn, the A53T mutant form, the S129D phosphomimetic mutant or with empty vector (which served as control). Voltage-gated Ca2+ influx evoked by exposure of cells to 50 mM K+ was enhanced in cells expressing all three forms of alpha-syn, an effect which was due specifically to increased Ca2+ entry via L-type Ca2+ channels. Mobilization of Ca2+ by muscarine was not strikingly modified by any of the alpha-syn forms, but they all reduced capacitative Ca2+ entry following store depletion caused either by muscarine or thapsigargin. Emptying of stores with cyclopiazonic acid caused similar rises of [Ca2+](i) in all cells tested (with the exception of the S129D mutant), and mitochondrial Ca2+ content was unaffected by any form of alpha-synuclein. However, only WT alpha-syn transfected cells displayed significantly impaired viability. Our findings suggest that alpha-syn regulates Ca2+ entry pathways and, consequently, that abnormal alpha-syn levels may promote neuronal damage through dysregulation of Ca2+ homeostasis.