Biological substrates of risk and resilience using patient-derived stem cells

自闭症谱系障碍(ASD)是一种产前大脑发育障碍。而ASD的症状形式 已经得到了相当大的关注，这些异质性疾病的研究结果在多大程度上也适用于 更广泛的或特发性的ASD形式，没有确定的单一遗传风险，目前尚不清楚。在这个项目中，我们将 研究特发性脑发育正常的胎儿期神经生物发育轨迹是如何被破坏的 ASD.在产前确定与ASD风险或保护相关的神经生物学因素 在发展方面，我们将从特征良好的儿童年幼兄弟姐妹队列中招募参与者 ASD，他们被纵向跟踪。兄弟姐妹对于ASD的诊断将是一致的(ASD：ASD； N=12对)或将不协调(ASD：type；n=12对)。我们将使用诱导多能干细胞(IPSC) 派生的皮质器官，3D细胞结构，在体外模拟人类胎儿的发育 大脑皮层。有机化合物将通过高分辨率成像方法、分子工具和 转录学。在目标1中，我们将获得一组生物学测量(兴奋性/抑制性神经元命运、密度 突触和神经元树枝)，比较和对比ASD：ASD一致性的表型 SIBS ASD：类型不协调的同胞。这种比较将提高我们隔离风险/保护因素的能力，这些因素将 专心致志地穿着不和谐的鞋子工作。在目标2中，我们将通过以下方式进行全球基因表达分析 Rna-seq和网络分析，旨在发现基因表达和网络组织的差异。 在ASD：ASD协调网络和ASD：TYP不协调网络之间。我们将执行关联 分析神经生物学指标和基因表达将在哪里相互关联以及与 临床严重度评分。神经生物学和基因表达指标之间的相关性 症状的严重性可能有助于区分风险和保护。在AIM 3中，与项目2合作， 我们将在Concordant(ASD：ASD)上获得基于BOLD的结构MRI和功能连接数据 参与目标1和目标2研究的不一致(ASD：TYP)同胞对。然后我们将进行关联 成像与神经生物学和基因表达测量之间的关系。我们假设增加了 ASD中抑制性神经元的命运可能与皮质网络连接效率较低有关，并且 突触生成和神经元树枝形成的增加可能与较高的灰质比率有关，而且 改变连通性。该项目将把数据提供给统计核心，在那里成像和神经生物学 测量方法可用于预测临床严重程度，从而对ASD的风险因素进行更有力的分析。在……里面 总结，我们的体外ASD风险人类细胞模型原则上将允许开发未来的生物标记物 早期诊断和基于潜在生物学的新治疗方案的探索。

Autism spectrum disorder (ASD) is a disorder of prenatal brain development. While syndromic forms of ASD have received considerable attention, to what extent findings in these heterogeneous disorders apply also to the broader or idiopathic form of ASD with no identified single genetic risk is unclear. In this project, we will study how the normal trajectory of prenatal neurobiological development of the brain is disrupted in idiopathic ASD. To identify neurobiological factors that are associated with risk or protection from ASD during prenatal development, we will recruit participants from a well-characterized cohort of younger siblings of children with ASD, who were followed longitudinally. The siblings will be either concordant for ASD diagnosis (ASD:ASD; n=12 pairs) or will be discordant (ASD:TYP; n=12 pairs). We will use induced pluripotent stem cells (iPSC) derived cortical organoids, 3D cellular structures which model in vitro the fetal development of the human cerebral cortex. Organoids will be analyzed by high resolution imaging approaches, molecular tools and transcriptomics. In Aim 1 we will obtain sets of biological measures (excitatory/inhibitory neuron fate, density of synapse, and neuronal arborization), comparing and contrasting phenotypes between ASD:ASD concordant sibs ASD:TYP discordant sibs. This comparison will refine our ability to isolate risk/protective factors that will be exclusively at work in the discordant pairs. In Aim 2 we will perform global gene expression analysis by RNA-seq and network analyses, aiming at finding differences in gene expression and network organization between the ASD:ASD concordant network and the ASD:TYP discordant network. We will perform correlation analyses where neurobiological measures and gene expression will be correlated with each other and with clinical severity scores. The correlations between neurobiological and gene expression measures with symptoms severity may help discriminate between risk and protection. In Aim 3, in collaboration with Project 2, we will obtain structural MRI and BOLD-based functional connectivity data on the concordant (ASD:ASD) and discordant (ASD:TYP) sib pairs that participate in Aim 1 and Aim 2 studies. We will then make correlations between imaging and neurobiological and gene expression measures. We hypothesize that increased inhibitory neuron fate in ASD may be correlated with less efficient cortical network connectivity and that increased synaptogenesis and neuronal arborization may be correlated with higher gray matter ratio, and also to altered connectivity. This project will feed data to the statistical core, where imaging and neurobiological measures can be used to predict clinical severity, allowing a more powerful analysis of risk factors for ASD. In summary, our in vitro ASD risk human cellular model will allow, in principle, to develop future biomarkers for early diagnosis and the exploration of new treatment options based on the underlying biology.