Use of induced pluripotent stem cells to study mechanims of familial and sporadic

摘要 肌萎缩侧索硬化症是一种进行性神经退行性疾病，其特征是上肢和 较低的运动神经元，最终导致肌肉萎缩和呼吸衰竭死亡 [1-3]。大多数肌萎缩侧索硬化症病例是散发性的，90%的患者表现出疾病。 无肌萎缩侧索硬化家族史的症状。剩下的10%的ALS患者是 诊断为家族性肌萎缩侧索硬化症[1-3]。大约25%的ALS家族性病例是 由编码超氧化物歧化酶的显性遗传基因突变引起 (Sod)[4]。SOD1致病等位基因的鉴定导致了 用于ALS研究的转基因小鼠和大鼠模型[5-8]。生产过剩 致病性人类SOD1蛋白在小鼠和大鼠中导致迟发、进展性 神经退行性疾病[5、6、8]。对SOD1动物模型的研究导致了 肌萎缩侧索硬化症运动神经元内源性致病特性的鉴定与研究 包括蛋白质聚集体的形成、细胞骨架的异常、蛋白酶体 功能障碍和对细胞死亡信号的敏感性增加[1，5]。尽管有很多 在这些家族性疾病的动物模型中已经了解到，对此知之甚少 这种散发性疾病是由于缺乏合适的体内系统造成的。我们建议 利用干细胞研究的最新进展[9-13]来产生和研究人类 培养的运动神经元来源于散发性肌萎缩侧索硬化患者捐献的成纤维细胞。 这些运动神经元将在长期细胞培养中用于检测 散发性疾病的病理生理特征，包括蛋白质分析 聚集体，形态改变的线粒体，电生理特性，基因 表达分析，以及对可供选择的前mRNA剪接模式的检查。如果 这些研究的成功可能会为零星事件提供重要的新机制见解 ALS，并为药物筛选提供基于细胞的分析。

Abstract ALS is a progressive neurodegenerative disease characterized by the loss of upper and lower motor neurons, culminating in muscle wasting and death from respiratory failure [1-3]. The majority of ALS cases are sporadic, with 90% of patients presenting disease symptoms with no family history of ALS. The remaining 10% of ALS patients are diagnosed with familial ALS [1-3]. Approximately 25% of the familial cases of ALS are caused by mutations in the dominantly inherited gene encoding super oxide dismutase (SOD) [4]. Identification of pathogenic alleles of SOD1 has led to the production of transgenic mouse and rat models for the study of ALS [5-8]. Overproduction of pathogenic human SOD1 protein in mice and rats leads to late onset, progressive neurodegenerative disease [5, 6, 8]. Studies of the SOD1 animal models have led to the identification and study of intrinsic pathogenic characteristics of ALS motor neurons including the formation of protein aggregates, cytoskeletal abnormalities, proteasome dysfunction and increased sensitivity to cell death signals [1, 5]. Although much has been learned in these animal models of the familial disease, very little is known about the sporadic disease because of the lack of a suitable in vivo system. We propose to make use of recent advances in stem cell research [9-13] to generate and study human motor neurons in culture derived from fibroblasts donated by sporadic ALS patients. These motor neurons will be used in long term cell cultures to examine pathophysiological hallmarks of the sporadic disease, including analysis of protein aggregates, morphologically altered mitochondria, electrophysiological properties, gene expression analyses, and examination of patterns of alternative pre-mRNA splicing. If successful, these studies may provide important new mechanistic insights into sporadic ALS, and provide cell-based assays for drug screening.