SELECTIVE NEURONAL VULNERABILITY IN SPORADIC ALS

包括肌萎缩侧索硬化症在内的神经退行性疾病 肌萎缩侧索硬化症是一种破坏性的特发性临床疾病 这会导致选择性神经元损伤和死亡。我们的将军 假说是细胞内钙的增加，由活跃的 钙跨质膜内流或从质膜释放钙 细胞内存储和/或有限的钙缓冲能力是 在神经退行性细胞损伤中至关重要。决定因素 这些疾病的选择性脆弱性可能包括任何 这些过程中，很可能伴随着对改变的选择性敏感性 钙稳态。我们自己对散发性神经退行性变的研究 疾病记录了电压门控抗体的存在 散发性而非家族性肌萎缩侧索硬化症的钙通道。ALS免疫球蛋白 对不同的人产生不同的电生理效应 VGCC型，当加入骨骼肌时抑制钙电流L- VGCCs，同时增强钙电流，增加细胞内 钙，并导致细胞死亡时，神经元VGCC的运动 神经元细胞系。 本实验室建立的运动神经元细胞系(VSC 4.1) 小鼠N18TG2神经母细胞瘤细胞株与分离胚胎大鼠的融合 脊髓腹侧，表达生化和形态运动神经元 标记物和神经元VGCC在存在的情况下分化 夏令营和阿菲多科林。在体外加入ALS免疫球蛋白后，有明显的 分化细胞中钙电流的增强(未见 疾病控制免疫球蛋白)。使用钙成像技术，ALS免疫球蛋白也 导致细胞内钙显著持续增加，这是 24-72小时后VSC 4.1细胞死亡。 这个细胞系统将使我们能够确定ALS免疫球蛋白依赖的机制 允许细胞内钙的持续增加。我们计划 详细定义细胞内增加的 钙和随后的细胞死亡。此外，由于VSC 4.1细胞 显示免疫组织化学识别的Calbindin D28K和 分化过程中的小白蛋白水平(伴随着 对ALS免疫球蛋白的脆弱性)，将对 这些钙结合蛋白在选择性钙结合蛋白中的作用 脆弱性。 这些研究应该有助于理解增加的作用 细胞内钙及选择性神经元钙缓冲的改变 散发性肌萎缩侧索硬化症的脆弱性。

The neurodegenerative diseases including amyotrophic lateral sclerosis (ALS) are devastating idiopathic clinical disorders that result in selective neuronal injury and death. Our general hypothesis is that increased intracellular calcium, produced by active calcium influx across the plasmalemma or release of calcium from intracellular stores, and/or limited calcium buffering capacity, is critically important in neurodegenerative cell injury. Factors dictating selective vulnerability in these diseases may include alterations in any of these processes, likely coupled with selective sensitivity to altered calcium homeostasis. Our own studies of sporadic neurodegenerative disease have documented the presence of antibodies to voltage-gated calcium channels (VGCCs) in sporadic but not familial ALS. ALS IgG produce different electrophysiologically assayed effects on different VGCC types, inhibiting calcium current when added to skeletal muscle L- type VGCCs, while enhancing calcium current, increasing intracellular calcium, and causing cell death when added to neuronal VGCCs in motor neuron cell lines. The motor neuron cell line (VSC 4.1), developed in our laboratory by fusion or murine N18TG2 neuroblastoma line and dissociated embryonic rat ventral spinal cord, expresses biochemical and morphological motor neuron markers as well as neuronal VGCCs when differentiated in the presence of cAMP and aphidocolin. After ALS IgG addition in vitro, there is a marked enhancement of calcium current in differentiated cells (not noted with disease control IgG). Using calcium imaging techniques, ALS IgG also induces a marked, prolonged increase in intracellular calcium, which is followed by VSC 4.1 cell death after twenty-four to seventy-two hours. This cell system will allow us to define ALS IgG-dependent mechanisms permitting prolonged increases in intracellular calcium. We plan to define the relationship in detail between the increased intracellular calcium and the subsequent cell death. Furthermore, since VSC 4.1 cells demonstrate decreased immunohistochemically recognized calbindin D28K and parvalbumin levels during differentiation (concomitant with onset of vulnerability to ALS IgG), a detailed evaluation will be undertaken of the potential role of these calcium binding proteins in selective vulnerability. These studies should aid in understanding the roles played by increased intracellular calcium and altered calcium buffering on selective neuronal vulnerability in sporadic ALS.