Characterizing patient-specific TBR1 mutations: Understanding a master regulator of autism risk.

表征患者特异性 TBR1 突变：了解自闭症风险的主要调节因子。

• 批准号: 10590496
• 负责人: Brian James O'Roak
• 金额: $ 25.08万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-01 至 2023-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10590496
• 关键词: Address; Affect; Binding; Biological; Biology; Brain; Brain region; Child; Computer Analysis; Development; Disease; Etiology; Future; Genes; Genetic; Genetic Variation; Genotype; Glutamates; Human; Individual; Intervention; Knowledge; Link; Modeling; Mutate; Mutation; Neurodevelopmental Disorder; Neurons; Organoids; Patients; Pharmacology; Phenotype; Play; Prosencephalon; Proteins; Recurrence; Research Personnel; Risk; Risk Factors; Role; Route; Symptoms; Testing; Therapeutic; Therapeutic Intervention; autism spectrum disorder; autistic children; de novo mutation; disorder risk; effective therapy; functional genomics; genome editing; individualized medicine; induced pluripotent stem cell; interest; loss of function mutation; migration; mouse genetics; mutant; next generation sequencing; rational design; repetitive behavior; risk variant; social communication impairment; targeted treatment; transcription factor

PROJECT SUMMARY/ABSTRACT Autism spectrum disorder (ASD) is a common neurodevelopmental disorder characterized by impaired social communication and restricted, repetitive behaviors. As of now, there are limited effective therapies to help individuals manage the core symptoms of ASD. The diversity of genetic factors underlying ASD risk highlights the need to shift our focus from one-size fits all therapeutics to more tailored, individualized therapies. Recently, next-generation sequencing (NGS) has enabled researchers to identify de novo (newly appearing in the child) loss of function mutations in many important brain development genes, including genes with in multiple mutations in unrelated children. These findings provide strong evidence for recurrently mutated genes playing a significant role in ASD risk and indicate that heterozygous disruption of a single gene essential for brain development is sufficient to cause autism. TBR1, a transcription factor that serves as a `master regulator' in brain development, is one such gene of particular interest. TBR1 is mutated in ~0.2% of children with ASD, making it one of the most common risk factors. Computational analyses using biologic network approaches suggest that, despite the genetic complexity, converging biology at particular developmental windows and brain regions may be at play in genetic subsets of ASD. Specifically, the co-expression of high confidence risk genes converge at midfetal stages of cortical development, where TBR1 is thought to play a key role in the differentiation, migration, and function of deep layer glutamatergic cortical projection neurons. Moreover, it is now clear that TBR1 also binds to and regulates ~1/3 of other high confidence autism risk genes, making it a potential `master regulator' of at least one emerging common autism etiology. Evaluating the functional consequences of specific mutations represents a critical step in validating and understanding the causal link between genotype and phenotype and designing rational targeted therapies/interventions. We hypothesize that loss of a single copy of TBR1 disrupts human cortical development by altering the TBR1-regulated network required for proper neuronal identity and migration. Moreover, disrupting TBR1 or its target genes during this critical developmental window of ASD risk define a common route to ASD. We previously confirmed that de novo mutations severely impacted the localization and ability of mutant TBR1 proteins to regulate target genes. Here, we will address the current gaps in our knowledge of how patient-specific TBR1 mutations affect developing neurons by utilizing cutting-edge genome editing, functional genomics, and complementary models that leverage patient-derived induced pluripotent stem cells (iPSCs) converted to forebrain-like organoids (Aim 1) and mouse genetics (Aim 2). These studies will provide an unprecedented view into the consequences of TBR1 patient-specific mutations on neurons during cortical development. Moreover, this iPSC/mouse genetics platform can be expanded to other risk genes and be the basis for designing rational targeted therapies/interventions for ASD and related disorders.

项目摘要/摘要 自闭症谱系障碍（ASD）是一种常见的神经发育障碍，其特征是 社会交流和受限制的重复行为。截至目前，有限的有效疗法 帮助个人管理ASD的核心症状。 ASD风险的遗传因素多样性 强调需要将我们的重点从一件尺寸转变为所有疗法变成更量身定制的个性化疗法的必要性。 最近，下一代测序（NGS）使研究人员能够识别从头开始（新出现在 儿童）在许多重要的大脑发育基因中失去功能突变，包括具有IN的基因 无关儿童的多个突变。这些发现为经常突变的基因提供了有力的证据 在ASD风险中发挥重要作用，并表明单个基因的杂合破坏对 大脑发育足以引起自闭症。 TBR1，作为“主调节器”的转录因子 在大脑发育中，是一种特别感兴趣的基因。在约0.2％的ASD儿童中，TBR1被突变， 使其成为最常见的风险因素之一。使用生物网络方法进行计算分析 表明，尽管遗传复杂性，但在特定的发育窗口和 大脑区域可能在ASD的遗传子集中发挥作用。具体而言，高信心风险的共同表达 基因在皮质发育的中部阶段收敛，其中TBR1被认为在 深层谷氨酸能皮质投影神经元的分化，迁移和功能。而且，是 现在清楚的是，TBR1还与其他高信心自闭症风险基因结合并调节〜1/3，使其成为 至少一个新兴的自闭症病因的潜在“主调节器”。 评估特定突变的功能后果是验证和 了解基因型与表型之间的因果关系以及设计有理目标 治疗/干预措施。我们假设单个副本的TBR1丢失破坏了人类皮质 通过改变适当的神经元身份和迁移所需的TBR1调节网络来开发。 此外，在ASD风险的关键发展窗口中破坏TBR1或其靶基因定义A 通往ASD的通用路线。我们以前证实，从头突变严重影响了本地化和 突变TBR1蛋白调节靶基因的能力。在这里，我们将解决我们的当前差距 了解患者特异性TBR1突变如何通过利用尖端基因组影响发展神经元的知识 编辑，功能基因组学和互补模型，以利用患者衍生的诱导多能 干细胞（IPSC）转化为前脑样类动物（AIM 1）和小鼠遗传学（AIM 2）。这些研究 将为TBR1患者特异性突变对神经元的后果提供前所未有的观点 在皮质发育期间。此外，这个IPSC/鼠标遗传学平台可以扩展到其他风险 基因，并且是为ASD和相关疾病设计合理的靶向疗法/干预措施的基础。