Integrative Molecular and Phenotype Analysis of 22q11.2 Deletion Syndrome

描述（由申请人提供）：22q11.2微缺失综合征(心动面部综合征；22q11DS发生在约1/3000活产婴儿中，是已知最常见的精神分裂症复发性遗传原因，占一般人群中精神分裂症病例的1- 2%。本项目的总体目标是研究人类诱导多能干细胞（iPSCs）衍生的神经细胞和神经元，以确定22q11DS患者神经精神表型的细胞和分子机制。在过去的五年中，我们已经开发了高度可重复的方法来研究多能干细胞向神经元的分化，并使用经过验证的遗传和细胞生物学分析来表征这些细胞。使用这种方法，我们发现了22q11DS神经元中钙（CA）信号和发育失调相关的基因表达可重复变化的证据。我们通过实验验证了CA信号异常、多巴胺能D2受体功能障碍以及树突分支缺陷的存在。我们现在已经有了能够显著提高通量的技术，在这项研究中，我们将把我们的研究扩展到更大的22q11DS患者样本中，以便将细胞缺陷与患者特征联系起来。具体来说，我们将：1)通过从40例具有良好特征的22q11DS - 20例诊断为精神病的患者和20例未诊断为精神病的患者以及20例人口统计学上可比较的对照组中获得皮肤成纤维细胞，生成iPSC患者资源。2)利用这些资源，我们将首先验证我们关于多巴胺能信号缺陷的初步发现，然后确定钙信号的哪些方面受到缺失的影响。通过选择性地表达22q11.2区域内缺失的每个基因来挽救表型，我们将确定哪些基因与特定缺陷有因果关系。3)同时，我们将对22q11DS患者的转录组进行综合分析，以确定神经元中出现异常的关键枢纽和通路，并比较22q11DS患者与非精神病患者的共表达模块，探索可能与22q11DS患者精神分裂症发展特异性相关的潜在通路。最后，我们将：4)连接细胞、基因表达和行为表型，通过比较22q11DS患者的细胞表型，并将其与基因表达数据相结合，从而将分子途径与22q11DS患者的形态或生理表型以及实际临床表现联系起来。

DESCRIPTION (provided by applicant): 22q11.2 microdeletion syndrome (Velocardiofacial Syndrome; 22q11DS) occurs in about 1/3000 live births, and is the most frequent known recurrent genetic cause of schizophrenia, accounting for 1-2 % of schizophrenia cases in the general population The overall goal of this project is to study neural progrenitors and neurons derived from human induced pluripotent stem cells (iPSCs), in order to identify the cellular and molecular mechanisms underlying the neuropsychiatric phenotype in patients with 22q11DS. In the last five years we have developed highly reproducible methods for studying the differentiation of iPSCs into neurons, and for characterizing these cells using well-validated genetic and cell biological assays. Using this approach, we found evidence of reproducible changes in gene expression that implicate calcium (CA) signaling and developmental dysregulation in 22q11DS neurons. We experimentally validated the presence of aberrant CA signaling and dopaminergic D2 receptor dysfunction, as well as defects in dendritic branching. We now have the technology in place to significantly increase the throughput, and in this study we will expand our investigations to a much larger sample of patients with 22q11DS, in order to connect the cellular defects with patient characteristics. Specifically, we will: 1) generate an iPSC patient resource by obtaining skin fibroblasts from 40 well-characterized patients with 22q11DS - 20 with a diagnosis of psychotic disorder and 20 without - and 20 demographically comparable controls. 2) Using these resources, we will first validate our preliminary findings of defects in dopaminergic signaling, and then determine which aspects of calcium signaling are impacted by the deletion. By rescuing the phenotype through selectively expressing each of the genes deleted within the 22q11.2 region we will determine which gene(s) are causally implicated in the specific defects. 3) In parallel, we will comprehensively analyze the transcriptome in order to identify key hubs and pathways that are dysregulated in neurons from 22q11DS patients, and compare the co-expression modules in 22q11DS patients with and without psychosis, to explore potential pathways that may be specifically relevant to the development of schizophrenia in 22q11DS. Finally we will: 4) connect cellular, gene expression and behavioral phenotypes, by comparing cellular phenotypes derived from 22q11DS patients with and without psychosis, which will be integrated with gene expression data, in order to connect molecular pathways to morphological or physiological phenotypes, and actual clinical presentations in 22q11DS patients.