SELECTIVE VULNERABILITY OF SPORADIC NEURODEGENERATIVE DISEASE

神经退行性疾病-肌萎缩侧索硬化症（ALS）， 帕金森氏症和阿尔茨海默氏症-是毁灭性的临床 导致选择性神经元损伤和死亡的疾病。 我们的一般 一种假说认为，细胞内钙增加， 缓冲能力，可能是至关重要的神经退行性细胞 损伤 我们在ALS中的具体研究已经证明了 电压门控钙通道（VGCC）抗体，导致 增加细胞内钙和体外细胞毒性;我们的研究 在阿尔茨海默氏病中已经证明β淀粉样肽也 增加细胞内钙，尽管是通过不同的机制， 体外细胞毒性。 肌萎缩侧索硬化症IgG增强不同细胞的钙电流 神经元VGCC（例如浦肯野细胞和脂质双层中的P型通道; 表达大鼠脑VGCC的非洲爪蟾卵母细胞中的N型通道; 运动神经元细胞系中的Q型通道[VSC 4.1]）。 在VSC 4.1中， ALS IgG介导的钙电流增加导致 细胞内钙和细胞死亡。 这种细胞系统以及 注射了VGCC和大鼠脑mRNA的非洲爪蟾卵母细胞将允许我们使用 钙成像和电生理技术来表征 ALS IgG对不同VGCC和钙稳态的影响， 检查第二信使系统对细胞毒性的贡献， 包括G蛋白、蛋白激酶和磷酸酶， 结合蛋白钙结合蛋白D28 K和小清蛋白。 散发性阿尔茨海默病中介导选择性易感性的因素 并没有很好的定义。 我们最近的研究表明β淀粉样蛋白导致 黑质的细胞内钙离子增加和细胞死亡 细胞系 细胞外钙的去除减弱了细胞毒性，但 VGCC拮抗剂无此作用。 金精三羧酸， 凋亡，完全阻断细胞死亡。 这个细胞系统可以让我们 采用相同的钙成像，电生理和 药理学技术来确定β淀粉样蛋白如何导致增加 细胞内钙，并确定增加的细胞内钙的作用， 钙离子介导β淀粉样蛋白诱导的细胞毒性及 钙结合蛋白、钙结合蛋白D28 K和/或小清蛋白对细胞损伤的影响。 这些研究应该提供洞察力，以发挥作用，增加 选择性神经元细胞内钙和钙缓冲改变 散发性神经退行性疾病的脆弱性。

The neurodegenerative diseases - Amyotrophic Lateral Sclerosis (ALS), Parkinson's disease, and Alzheimer's disease - are devastating clinical disorders that result in selective neuronal injury and death. Our general hypothesis is that increased intracellular calcium, and limited calcium buffering capacity, may be critically important in neurodegenerative cell injury. Our specific studies in ALS have documented the presence of antibodies to voltage-gated calcium channels (VGCC), which lead to increased intracellular calcium and cytotoxicity in vitro; and our studies in Alzheimer's disease have documented that beta amyloid peptide also increases intracellular calcium, albeit by a different mechanism, leading to cytoxicity in vitro. ALS IgG enhance calcium current of different neuronal VGCC (e.g. P-type channels in Purkinje cells and lipid bilayers; N-type channels in Xenopus oocytes expressing rat brain VGCC; and P-type or Q-type channels in a motor neuron cell line [VSC 4.1]). In VSC 4.1, the ALS IgG-mediated increase in calcium current leads to increased intracellular calcium and to cell death. This cell system as well as Xenopus oocytes injected with VGCC and rat brain mRNA will allow us to use calcium imaging and electrophysiological techniques to characterize the effects of ALS IgG on different VGCC and on calcium homeostasis and to examine the contribution to cytotoxicity of second messenger systems, including G proteins, protein kinases and phosphatases, and the calcium binding proteins calbindin D28K and parvalbumin. Factors mediating selective vulnerability in sporadic Alzheimer's disease are not well defined. Our recent studies document that beta amyloid leads to increased intracellular calcium and cell death of a substantia nigra cell line. Removal of extracellular calcium attenuates cytotoxicity, but VGCC antagonists have not effect. Aurintricarboxylic acid, an inhibitor of apoptosis, completely blocks cell death. This cell system will permit us to employ the same calcium imaging, electrophysiological and pharmacological techniques to define how beta amyloid leads to increased intracellular calcium, and to determine the role of increased intracellular calcium in mediating beta amyloid-induced cytoxicity and the influence of calcium binding proteins, calbindin D28K and/or parvalbumin on cell injury. Such studies should provide insight into the roles played by increasing intracellular calcium and altered calcium buffering on selective neuronal vulnerability in sporadic neurodegenerative disorders.