IBIS-iPSC: Organoid modeling of cortical surface area hyperexpansion in autism spectrum disorder

项目摘要/摘要 许多单基因和特发性形式的自闭症谱系障碍(Asd)患者表现为大脑。 在生命早期就变大。然而，导致早期大脑的潜在细胞和分子机制 ASD的过度生长是未知的。为了确定导致大脑过度生长的机制，我们将使用 合适的模型系统，IPSC衍生的有机化合物，来自动力良好、表型深刻的队列 多个对照组，进行婴儿脑成像研究(IBIS)。IBIS是最大的纵向神经影像研究 有较大的兄弟姐妹/先证者患有自闭症的婴儿(&gt；250名参与者)有较高的家庭自闭症风险。 重要的是，IBIS参与者之前曾在多个时间点接受过纵向神经成像 婴儿期(6-24个月)和学龄期，在这些时间点进行广泛的行为评估， 以及罕见和常见的变异基因分型。在这个队列中产生的大量表型数据使它 一个理想的群体，从中产生IPSC衍生的有机模型并将体外表型与In 活体脑生长和行为轨迹。我们的研究也代表着一个独特的机会来评估如何 有机化合物表型模拟了个体的活体脑生长轨迹。 派生的。在这项提案中，我们将从血液中提取并验证来自高危家庭的参与者的IPSCs 患房间隔缺陷症(HR+)的高危参与者(HR-)和没有患房间隔缺陷症(HR-)的低风险个体 ASD(LR-)，共99名参与者。我们将把IPSC系区分为皮质类器官，以模拟细胞间 大脑发育的个体差异。我们将使用单细胞(Sc)rna-seq来鉴定细胞类型、细胞周期 状态，以及每个参与者派生的有机体在两个时间点上的分化轨迹 皮质神经发育期，共2.38M个测序细胞。我们将验证单元类型计数和状态 使用组织透明，然后用光片显微镜观察皮质有机体。我们将确定细胞类型、命运 决策和细胞周期状态与皮质表面积的横截面和纵向相关 随着时间的推移，发育和自闭症症状以及认知能力。利用这一独特的、具有深刻特征的临床 队列，我们将确定皮质类有机化合物的体内相关性以及细胞和分子 自闭症患者脑过度生长的机制。

Project Summary/Abstract Many individuals with monogenic and idiopathic forms of autism spectrum disorder (ASD) exhibit brain enlargement early in life. However, the underlying cellular and molecular mechanisms leading to early brain overgrowth in ASD are unknown. To identify the mechanisms leading to brain overgrowth, we will use an appropriate model system, iPSC-derived organoids, from a well-powered, deeply phenotyped cohort with multiple control groups, the Infant Brain Imaging Study (IBIS). IBIS is the largest longitudinal neuroimaging study of infants (>250 participants) at high familial risk for autism by virtue of having an older sibling/proband with ASD. Importantly, IBIS participants have previously undergone longitudinal neuroimaging at multiple time points in infancy (between 6-24 months of age) and school age, extensive behavioral assessments at these time points, as well as rare and common variant genotyping. The extensive phenotypic data generated in this cohort make it an ideal population from which to generate iPSC-derived organoid models and relate in vitro phenotypes to in vivo brain growth and behavioral trajectories. Our study also represents a unique opportunity to evaluate how well organoid phenotypes model the in vivo brain growth trajectories of the individual from whom they were derived. In this proposal, we will derive and validate iPSCs from blood for participants from high risk families who developed ASD (HR+), high risk participants who did not develop ASD (HR-), and low risk individuals without ASD (LR-) totaling 99 participants. We will differentiate the iPSC lines to cortical organoids to model inter- individual differences in brain development. We will use single cell (sc)RNA-seq to identify cell types, cell cycle states, and differentiation trajectories in each participant-derived organoid across two time points modeling the period of cortical neurogenesis, totaling 2.38M sequenced cells. We will validate cell type counts and states using tissue clearing followed by lightsheet microscopy of the cortical organoids. We will identify cell types, fate decisions, and cell cycle states that correlate with both cross-sectional and longitudinal cortical surface area growth and ASD symptoms and cognitive ability over time. Leveraging this unique, deeply characterized clinical cohort, we will determine both the in vivo relevance of cortical organoids and the cellular and molecular mechanisms underlying brain overgrowth in ASD.