Synaptic and dendritic dysfunction in psychiatric disorders

摘要 大规模基因组研究的最新数据显示，拷贝数变异（CNVs）是基因组中的主要遗传变异。 一类在精神疾病（包括自闭症（ASD）和精神分裂症）病因学中起关键作用的突变 (SZ)风险增加30倍。然而，CNVs中大量的基因，以及各种各样的临床表现， 与它们相关的表型，使人们了解CNV相关疾病及其基因型-表型 相关性尤其具有挑战性。16p11.2染色体区域的重复，发生在ASD、SZ、智力低下、 残疾（ID）、罗兰癫痫和其他疾病，并且是前2位最高渗透率和最常见的CNV 在深圳。尽管在基因组学方面取得了这些进展，但16p11.2 CNV模型中的突触表型尚未得到彻底的研究。 研究了对强大的突触表型的鉴定将导致实验上可接近的治疗靶点。 神经精神障碍的常见方面，如认知功能障碍。神经元能突触的改变， 树突状结构已经被基因组学、神经病理学和功能研究所牵连， 神经发育性精神障碍包括SZ、ASD和ID的发病机制。然而， 导致CNV病症的发病机制仍然在很大程度上难以捉摸。在此更新申请中，我们建议 研究CNV对SZ、ASD和其他神经发育障碍中的突触和树突功能障碍的影响。 通过关注16p11.2重复来治疗疾病。我们假设16p11.2基因座内的单个基因驱动 不同的亚表型，通常表达为细胞区室特异性改变，通过调节 由CNV以外的基因编码的蛋白质。这些表型可以通过靶向网络枢纽来逆转。在这 应用程序，我们将使用一个综合的方法，跨越培养的神经元，小鼠模型，和患者来源的iN，和一个 结合尖端技术，包括SIM和双光子成像，子宫内电穿孔，切片 电生理学、蛋白质组学、多阵列电极记录和高内容成像屏幕，以追求以下目标 目的：1）16p11.2微复制障碍中突触亚表型的潜在机制; 2） 16p11.2微复制障碍中潜在的树突状亚表型。3)16p11.2的药理学逆转 重复表型鉴于16p11.2重复是一个主要的基因组，因此拟议的研究是新颖的和有影响力的。 精神病风险因素及其对突触-树突的影响尚未研究。如果成功的话，这将是 第一个证明了细胞亚区室特异性蛋白质组学和高度渗透性单基因疾病基因 可以利用CNV内的驱动因子来鉴定新的机制，从而CNV内的驱动因子可以调节蛋白质 CNV之外的网络。这种细胞区室特异性蛋白质网络的改变，不是全球预测的。 mRNA谱分析可以作为特定疾病亚表型的基础。这些表型可以通过以下方式在全球范围内逆转： 以网络中心为目标，为精神疾病的治疗开辟了新的策略。

ABSTRACT Recent data emerging from large-scale genomic studies has revealed that copy number variations (CNVs) are a major class of mutations that play a key role in the etiology of psychiatric disorders, including autism (ASD) and schizophrenia (SZ), increasing risk up to 30 fold. However, the large number of genes in CNVs, and the wide variety of clinical phenotypes associated with them, has made understanding CNV-associated disorders and their genotype-phenotype correlations especially challenging. Duplications of 16p11.2 chromosomal region, occur in ASD, SZ, intellectual disability (ID), Rolandic epilepsy, and other disorders, and are among the top 2 most highly penetrant and frequent CNVs in SZ. Despite this progress in genomics, synaptic phenotypes in models of 16p11.2 CNV have not yet been thoroughly studied. The identification of robust synaptic phenotypes would result in experimentally approachable targets for treating common aspects of neuropsychiatric disorders such as cognitive dysfunction. Alterations in glutamatergic synapses and dendritic architecture have been implicated by genomic, neuropathological, and functional studies as key sites of pathogenesis in neurodevelopmental psychiatric disorders including SZ, ASD, and ID. However, the synaptic biology that contributes to the pathogenesis of CNV disorders remains largely elusive. In this renewal application we propose to investigate the impact of CNVs on synaptic and dendritic dysfunction in SZ, ASD and other neurodevelopmental disorders by focusing on the 16p11.2 duplication. We hypothesize that individual genes within the 16p11.2 locus drive distinct sub-phenotypes, often expressed as cellular compartment-specific alterations, by modulating localization of proteins encoded by genes outside the CNV. These phenotypes can be reversed by targeting network hubs. In this application, we will use an integrated approach spanning cultured neurons, mouse models, and patient-derived iNs, and a combination of cutting-edge technologies including SIM and two-photon imaging, in utero electroporations, slice electrophysiology, protemics, multi-array electrode recordings, and high-content imaging screens, to pursue the following Aims: 1) Mechanisms underlying synaptic sub-phenotypes in 16p11.2 microduplication disorder; 2) Mechanisms underlying dendritic sub-phenotypes in 16p11.2 microduplication disorder. 3) Pharmacological reversal of 16p11.2 duplication phenotypes. The proposed studies are novel and impactful, given that the 16p11.2 duplication is a major psychiatric risk factor and its synapto-dendritic impact has not yet been investigated. If successful, this proposal will be the first to demonstrate that cellular subcompartment-specific proteomics and highly penetrant monogenic disease genes within the CNV can be harnessed to identify novel mechanisms whereby a driver within the CNV can regulate a protein network outside of the CNV. Such cellular compartment-specific protein network alterations, not predicted by global mRNA profiling, could underlie specific disease sub-phenotypes. Such phenotypes could be be reversed globally by targeting network hubs, opening novel strategies for the treatment of psychiatric disorders.