Gene expression profiling of IPSC derived neurons in Autism Spectrum Disorder

自闭症谱系障碍（ASD）是一种遗传和表型异质性 神经发育障碍数百个基因导致了ASD的风险， 遗传位点占病例的1%以上。这就提出了这样一个问题： 机制集中于最终导致一种表型的较少数量的生物学途径， 即ASD。无法研究活体的神经元和大脑阻碍了 了解ASD和其他神经发育的细胞和分子机制 紊乱 来源于人诱导多能干细胞（hiPSC）的神经元重演了神经细胞分化的多个阶段。 体外神经发育因为它们保留了病人的基因组成， 神经元的研究具有与ASD相关的复杂遗传背景。神经元的来源 hiPSC是劳动密集型的且昂贵的，并且迄今为止研究已经检查了非常少量的患者。 hiPSC研究的范围需要捕捉特发性ASD是不可能的，完全限制了我们的研究。 确定这种形式的障碍的机械基础的能力。我们建议进行一项 通过利用我们的加州研究所， 再生医学（CIRM）资助了现有的300多个hiPSC的收集，以检查100个患有hiPSC的个体。 特发性ASD和100名年龄和性别匹配的对照。我们将使用商业衍生的神经元（iCell 神经元），其是>95%纯的谷氨酸能（兴奋性）和GABA能（抑制性）神经元群体。 为了确定这些神经元中失调的分子通路，我们将对人类转录组进行测序， 在神经元成熟过程中的三个时间点。我们还将进行细胞活力，形态， 使用活细胞成像的神经突生长和通过钙成像的功能。我们的目标是找出 通过鉴定来自ASD个体的这些hiPSC衍生的神经元中的失调分子通路， 在每个时间点与对照差异表达的基因，并进行因子分析以研究 时间点和疾病变量之间的交互作用。这将确定显示分化的基因- 在ASD患者的神经元分化中诱导表达变化。我们将确定关键 使用加权基因共表达网络分析（WGCNA）的生物途径变化的驱动因素。 最后，我们将把基因表达谱与细胞和行为表型联系起来。

Autism Spectrum Disorder (ASD) is a genetically and phenotypically heterogeneous neurodevelopmental disorder. Hundreds of genes contribute to the risk to develop ASD with no individual genetic locus accounting for more than 1% of cases. This raises the issue of whether, and how such diverse mechanisms converge on a smaller number of biological pathways that ultimately result in one phenotype, namely ASD. The inability to study neurons and brains from living subjects has blocked progress toward understanding the cellular and molecular mechanisms underlying ASD and other neurodevelopmental disorders. Neurons derived from human induced pluripotent stem cell (hiPSC) recapitulate multiple stages of in vivo neural development in vitro. Because they retain the genetic makeup of the patient they enable in vitro studies of neurons that harbor the complex genetic background associated with ASD. Deriving neurons from hiPSCs is labor intensive and costly, and to date studies have examined very small numbers of patients. hiPSC studies of the scope required to capture idiopathic ASD have not been possible, entirely limiting our ability to determine the mechanistic underpinnings of this form of the disorder. We propose to conduct an investigation of hiPSC derived neurons on an unprecedented scale by leveraging our California Institute for Regenerative Medicine (CIRM) funded existing collection of over 300 hiPSCs, to examine 100 individuals with idiopathic ASD and 100 age- and sex-matched controls. We will use commercially derived neurons (iCell Neurons) which are a >95% pure population of glutamatergic (excitatory) and GABAergic (inhibitory) neurons. To identify dysregulated molecular pathways in these neurons we will sequence the human transcriptome at three time points during maturation of the neurons. We will also conduct assays of cell viability, morphology, neurite outgrowth using live cell imaging, and function through calcium imaging. We aim to identify dysregulated molecular pathways in these hiPSC-derived neurons from individuals with ASD, by identifying genes that are differentially expressed from controls at each time point and perform a factorial analysis to study interactive effects between time point and disease variable. This will identify genes showing differentiation- induced expression changes across neuronal differentiation in individuals with ASD. We will identify key drivers of biological pathway changes using Weighted Gene Co-expression Network Analysis (WGCNA). Finally, we will relate gene expression profiles to cellular and behavioral phenotypes.