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: 10166616
• 负责人: Brian James O'Roak
• 金额: $ 49.92万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2023-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10166616
• 关键词: 3-Dimensional; Address; Affect; Alleles; Binding; Biological; Biological Assay; Biological Models; Biology; Brain; Brain region; Cell Separation; Cells; Child; Complement; Complex; Computer Analysis; Data; Development; Disease; Embryo; Etiology; Event; Female; Fetal Development; Future; Genes; Genetic; Genetic Transcription; Genetic Variation; Genomics; Genotype; Glutamates; Human; Impairment; In Vitro; Individual; Inherited; Intervention; Knock-in; Knowledge; Link; Methods; Modeling; Mus; Mutate; Mutation; Nervous system structure; Neurodevelopmental Disorder; Neurons; Organoids; Pathway interactions; Patients; Pharmacology; Phenotype; Play; Prosencephalon; Proteins; Quantitative Evaluations; Recurrence; Research Personnel; Risk; Risk Factors; Role; Route; Structural defect; Symptoms; System; Techniques; Testing; Therapeutic; Therapeutic Intervention; Time; Variant; autism spectrum disorder; autistic children; brain tissue; cell motility; critical developmental period; de novo mutation; design; disorder risk; effective therapy; functional genomics; genome editing; in vivo; individualized medicine; individuals with autism spectrum disorder; induced pluripotent stem cell; interest; loss of function mutation; male; migration; mouse genetics; mouse model; mutant; next generation sequencing; overexpression; personalized medicine; public health relevance; repetitive behavior; risk variant; social communication impairment; targeted treatment; tool; 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.

项目概要/摘要 自闭症谱系障碍（ASD）是一种常见的神经发育障碍，其特征是发育障碍 社交沟通和受限、重复的行为。截至目前，有效的治疗方法有限 帮助个人应对自闭症谱系障碍的核心症状。 ASD 风险遗传因素的多样性 强调需要将我们的重点从一刀切的治疗方法转向更有针对性、个性化的治疗方法。 最近，新一代测序 (NGS) 使研究人员能够从头识别（新出现在 孩子）许多重要的大脑发育基因的功能丧失突变，包括具有以下特征的基因 无关儿童的多重突变。这些发现为反复突变的基因提供了强有力的证据 在 ASD 风险中发挥着重要作用，并表明单个基因的杂合破坏对于 ASD 风险至关重要 大脑发育足以导致自闭症。 TBR1，一种充当“主调节器”的转录因子 在大脑发育中，基因就是一种特别令人感兴趣的基因。 TBR1 在约 0.2% 的 ASD 儿童中发生突变， 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，生物学在特定的发育窗口和 大脑区域可能在自闭症谱系障碍的遗传亚型中发挥作用。具体来说，高置信度风险的共表达 基因在皮质发育的中期胎儿阶段汇聚，TBR1被认为在皮质发育中发挥关键作用 深层谷氨酸能皮质投射神经元的分化、迁移和功能。而且，它是 现在清楚，TBR1 还结合并调节约 1/3 的其他高置信度自闭症风险基因，使其成为 至少一种新出现的常见自闭症病因的潜在“主调节器”。 评估特定突变的功能后果是验证和验证的关键一步。 了解基因型和表型之间的因果关系并设计合理的目标 治疗/干预。我们假设丢失一个 TBR1 拷贝会破坏人类皮质 通过改变正确神经元身份和迁移所需的 TBR1 调节网络来实现发育。 此外，在 ASD 风险的关键发育窗口期间破坏 TBR1 或其靶基因定义了 ASD 的常见途径。我们之前证实，从头突变严重影响了定位和 突变TBR1蛋白调节靶基因的能力。在这里，我们将解决当前的差距 利用尖端基因组了解患者特异性 TBR1 突变如何影响发育中的神经元 编辑、功能基因组学和利用源自患者的诱导多能性的补充模型 干细胞 (iPSC) 转化为类前脑类器官（目标 1）和小鼠遗传学（目标 2）。这些研究 将为 TBR1 患者特异性突变对神经元的影响提供前所未有的视角 在皮质发育过程中。此外，该 iPSC/小鼠遗传学平台可以扩展到其他风险 基因，并成为设计针对 ASD 和相关疾病的合理靶向治疗/干预措施的基础。