Neural Development of Human Induced Pluripotent Stem Cells from Schizophrenia Pat

描述(申请人提供)：严重的精神疾病，如精神分裂症和双相情感障碍，是需要有效治疗的慢性和一般致残的脑部疾病。它们影响到世界上很大一部分人口，并对患者及其家庭和整个社会造成毁灭性的后果。虽然其病因在很大程度上尚不清楚，但越来越多的证据支持这样的观点，即精神分裂症是一种神经元发育疾病。最近从人类遗传关联研究中发现了一些易感基因。在一个苏格兰大家庭中，在平衡(1；11)(q42；q14)易位的断点处发现了一种名为精神分裂症1中断的基因，该易位与精神分裂症和其他主要情感障碍共分离。最近，我们提供了证据支持DISC1在啮齿动物成年神经发生的多个方面发挥关键作用，包括神经元的形态发生、迁移、轴突和树突的发育，以及成年脑中新生神经元的突触形成。然而，DISC1基因在人和啮齿动物之间并不是很保守，目前还不清楚DISC1在人类胚胎神经发生和神经发育中的作用。最近成功地将人类皮肤成纤维细胞重新编程为多能性(诱导多能干细胞或IPSCs)，为研究人类发育和在更相关的使用人类细胞的实验系统中发现人类疾病的分子基础铺平了道路。将精神分裂症患者的IPSCs分化为神经元和神经胶质细胞可能会彻底改变我们研究精神分裂症潜在的分子和细胞机制的能力，包括遗传和零星起源。我们已经从遗传性疾病的患者身上产生了人类IPSCs。我们还开发了一系列方法来检测干细胞来源的神经元在体外和体内的分化、功能成熟和整合，包括免疫细胞化学、共聚焦和电子显微镜、电生理学和移植。在目前的项目中，我们的目标是建立一个平台，使用患者来源的IPSCs及其神经后代来识别与精神分裂症相关的神经发育缺陷，并了解精神分裂症易感基因在人类神经元发育中的功能。在R21阶段，我们将从遗传性(带有DISC1突变)和散发性精神分裂症患者和对照受试者中衍生和鉴定IPSCs。在R33阶段，我们将使用已建立的体外和体内分析来检测患者来源的IPSCs的神经元发育缺陷。我们提出的研究可能会对这些易感基因影响人类神经发育的潜在机制提供新的见解，并更好地理解精神分裂症和其他相关重大精神疾病的病因和发病机制。我们的研究可能导致产生新的人类精神疾病的实验模型，并用潜在的治疗分子进行测试。 公共卫生相关性：人类干细胞生物学的最新进展为研究疾病基因的功能和使用相关的人类细胞类型来模拟人类疾病提供了令人兴奋的可能性。我们将建立一个使用患者来源的IPSCs的平台，以了解精神分裂症易感基因在正常和疾病状态下调节人类神经发生的功能，这是传统动物模型系统无法达到的主题。我们的研究将为精神障碍易感基因在人类神经发育中的功能提供基础信息，并可能揭示这些疾病的病因和发病机制。

DESCRIPTION (provided by applicant): Severe psychiatric illnesses, such as schizophrenia and bipolar affective disorder, are chronic and generally disabling brain diseases in need of effective treatments. They affect a large portion of the world's population and have devastating consequence for the sufferers, their families and for the society as a whole. While their etiology is largely unknown, accumulative evidence support the view that schizophrenia is a disease of neuronal development. A number of susceptibility genes have recently been identified from human genetic association studies. One gene named disrupted-in-schizophrenia 1 (DISC1), was identified at the breakpoint of a balanced (1;11)(q42;q14) translocation that co-segregates with schizophrenia and other major affective disorders in a large Scottish family. Recently we have provided evidence to support a critic role of DISC1 in multiple aspects of adult neurogenesis in rodents, including neuronal morphogenesis, migration, axon and dendritic development, and synapse formation of newborn neurons in the adult brain. However, DISC1 gene is not well conserved between humans and rodents and the function of DISC1 in human embryonic neurogenesis and neural development is currently unknown. Recent success in reprogramming human skin fibroblasts into pluripotency (induced-pluripotent stem cells or iPSCs) paves the way to study human development and to discover the molecular basis of human diseases in more relevant experimental systems using human cells. Differentiation of iPSCs derived from schizophrenia patients into neurons and glia may revolutionize our ability to investigate molecular and cellular mechanisms underlying schizophrenia, including both genetic and sporadic origins. We have generated human iPSCs from patients with genetic disorders. We have also developed a battery of methodologies to examine the differentiation, functional maturation and integration of neurons derived from stem cell both in vitro and in vivo, including immunocytochemistry, confocal and electron microscopy, electrophysiology, and transplantation. In the current project, we aim to establish a platform using patient-derived iPSCs and their neural progeny to identify neurodevelopmental defects associated with schizophrenia and to understand functions of schizophrenia susceptibility genes in human neuronal development. During the R21 phase, we will derive and characterize iPSCs from both genetic (with DISC1 mutations) and sporadic schizophrenia patients and control subjects. During the R33 phase, we will examine the neuronal developmental defects of patient-derived iPSCs using established in vitro and in vivo analysis. Our proposed study may provide novel insight into mechanisms underlying these susceptibility genes in affecting human neurodevelopment and a better understanding of the etiology and pathogenesis of schizophrenia and other related major mental illnesses. Our study may lead to generation of new experimental models of human psychiatric diseases to be tested with potential therapeutic molecules. PUBLIC HEALTH RELEVANCE: Recent advances in human stem cell biology offer exciting possibility to investigate functions of disease genes and to model human diseases using relevant human cell types. We will establish a platform using patient-derived iPSCs to understand functions of schizophrenia susceptibility genes in regulating human neurogenesis under normal and disease state, a topic not accessible with traditional animal model systems. Our study will provide fundamental information on functions of susceptibility genes of mental disorders in human neurodevelopment and may reveal the etiology and pathogenesis of these disorders.