An iPS Disease-in-a-Dish Model of Familial Alzheimers

描述（由申请人提供）：阿尔茨海默病（AD）是最常见的痴呆症，其特征是淀粉样肽沉积为“老年性”淀粉样斑块，由异常磷酸化的tau蛋白组成的神经原纤维缠结，以及神经元功能障碍和丧失。目前可用的阿尔茨海默病治疗在数量上对疾病的影响很小，对改善患有这种使人衰弱的疾病的患者的生活质量或持续时间几乎没有作用，这种疾病的临床特征是肺功能和高级皮质功能的丧失。开发一种既有效又安全的阿尔茨海默病治疗方法的关键是忠实地概括人类综合征的模型系统。在这方面，在一个或多个引起早发性家族性AD （fAD）的基因中携带突变的转基因小鼠在询问潜在的治疗靶点和了解疾病的病理机制方面都有很大的帮助。然而，由于它们的物种，这些模型必然是有限的，并且小鼠是否能够像人类一样忠实地模拟阿尔茨海默病的神经病理学仍然是一个悬而未决的问题。我们的R21资助申请的中心主题是使用一项具有巨大前景的新兴技术来模拟人类疾病：人类诱导多能干细胞（hiPS）。基本步骤包括培养皮肤成纤维细胞，这些细胞来自携带导致fAD基因突变的个体或来自年龄匹配的无疾病对照亲属，并将其重新编程为hiPS细胞，这些细胞随后分化为前脑谷氨酸能神经元。一旦分化，这些前脑神经元将被功能询问，以特异性评估人类AD的病理特征。我们建议分两部分来开展这项工作。特异性目的1的重点是从4个fAD突变株和4个相关的对照成纤维细胞系中建立iPS细胞系。我们将绘制成纤维细胞

DESCRIPTION (provided by applicant): Alzheimer's disease (AD) is the most common dementia, and is hallmarked by deposition of amyloid-¿ peptides as 'senile' ¿-amyloid plaques, neurofibrillary tangles comprised of abnormally phosphorylated tau protein, and neuronal dysfunction and loss. Currently available AD treatments have a quantitatively minor impact on the disease, doing little to improve the quality or duration of life of patients suffering from thi debilitating illness, which is clinically characterized by loss of pneumonic and higher cortical functions. A critical lynchpin for the development of an AD treatment that is both effective and safe is model systems that faithfully recapitulate the human syndrome. In this regard, transgenic mice harboring mutations in one or more genes that cause early-onset familial AD (fAD) have been enormously helpful, both in terms of interrogating potential therapeutic targets and also for understanding pathological mechanisms of disease. Yet, these models are necessarily limited due to their species, and it remains an open question as to whether the mouse will ever be able to faithfully model AD neuropathology as it occurs in the human. The central theme of our R21 grant application is to use an emerging technology with great promise for modeling human diseases: human induced pluripotent stem (hiPS) cells. The basic steps involve culturing skin fibroblasts from individuals bearing mutations in genes that cause fAD or from age-matched control relatives lacking disease, and reprogramming them into hiPS cells that are later differentiated into forebrain glutamatergic neurons. Once differentiated, these forebrain neurons will be functionally interrogated to specifically assess pathologic hallmarks of human AD. We propose to carry out this work in two parts. The focus of Specific Aim 1 is to establish iPS cell lines from four fAD mutant and four related control fibroblast cell lines. We will draw fibroblasts from ~175 lines derived from individuals bearing fAD mutations and age-matched control relatives, maintained through the NIH/NIA Aging Cell Culture Repository at the Coriell Institute for Medical Research. The main goal of Specific Aim 2 is to interrogate Alzheimer phenotypes in fAD mutant vs. control forebrain neurons differentiated from reprogrammed iPS cells. In Sub-Aim 2a, we hypothesize that Alzheimer disease phenotypes will occur and be exacerbated by experimental induction of excitotoxicity in fAD mutant vs. non-mutant hiPS-derived forebrain neurons. Sub-Aim 2b will test proof-of-concept for whether the current standard of care AD drug, memantine, will at least partially rescue Alzheimer phenotype(s) in differentiated fAD mutant forebrain neurons. Completion of this exploratory work is expected to lead to a 'disease-in-a-dish' model of human fAD. Such a model could pave the way toward understanding both basic pathologic mechanisms of the disease as well as potential therapeutic approaches. PUBLIC HEALTH RELEVANCE: There are now over 3 million Americans afflicted with Alzheimer's disease, a figure that is projected to increase to 9 million by 2050, underscoring a rapidly developing public health crisis. We propose to utilize cutting-edge human induced pluripotent stem (hiPS) cell technology to model this devastating disease in cultured neurons. If successful, this exciting disease-in-a-dish model could allow pre-clinical testing of therapeutic approaches.