Neurobiology of Autism With Macrocephaly

自闭症大头畸形的神经生物学

• 批准号: 9479337
• 负责人: FLORA M VACCARINO
• 金额: $ 14.69万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-17 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9479337
• 关键词: Affect; Autistic Disorder; Binding Sites; Biological; Biological Assay; Biological Process; Brain; Cell Adhesion; Cell Line; Cell Proliferation; Cell division; Cells; ChIP-seq; Child; Chromatin; Code; Collection; DNA Sequence Alteration; Data; Data Set; Development; Electrophysiology (science); Epigenetic Process; Etiology; FOXG1B gene; Family; First Pregnancy Trimester; Forebrain Development; Future; Gene Expression; Genes; Genetic; Genetic Heterogeneity; Genetic Transcription; Genome; Genomic Segment; Genotype; Glutamates; Goals; Growth; Heterogeneity; Histones; Human; In Vitro; Individual; Inherited; Macrocephaly; Maps; Measures; Neurobiology; Neuronal Differentiation; Neurons; Nucleic Acid Regulatory Sequences; Organoids; Pathogenesis; Pathway Analysis; Pathway interactions; Patients; Phenotype; Proteins; RNA Interference; Regulator Genes; Role; Source; Structure; Subgroup; Synapses; Technology; Testing; Therapeutic; Untranslated RNA; Validation; Variant; autism spectrum disorder; brain size; brain volume; differential expression; experimental study; gamma-Aminobutyric Acid; genetic variant; genome sequencing; genome-wide; genomic variation; induced pluripotent stem cell; inhibitory neuron; insight; knock-down; molecular marker; nerve stem cell; neurodevelopment; outcome forecast; overexpression; patient subsets; proband; progenitor; programs; public health relevance; rare variant; structural genomics; synaptogenesis; trait; transcription factor; transcriptome; transcriptome sequencing; whole genome

 DESCRIPTION (provided by applicant): Autism spectrum disorders (ASDs) affect 1%-2.5% of children worldwide. We suggest that etiological and genetic heterogeneity might converge in a few neurobiological downstream pathways. We have been investigating the pathobiology of ASD with large brain volume (macrocephaly), a phenotype which confers poorer prognosis. Ongoing studies have shown that telencephalic organoids differentiated in vitro from induced pluripotent stem cells (iPSC) derived from patients with ASD and macrocephaly have increased cell proliferation, increased synaptic growth and overproduction of GABAergic inhibitory neurons, indicating an early imbalance in glutamate/GABA neuron ratio. RNA interference experiments suggested that the overproduction of GABAergic cells is attributable, at least in part, to an increase in expression of FOXG1, a master regulatory transcription factor crucial for telencephalic development. Major goals of this application are (1) to expand our analysis of the developmental pathways that are dysregulated in ASD to a larger number of families and (2) to understand to what extent developmental alterations we identified in ASD with macrocephaly also apply to ASD in general. To this end, we will obtain data on neurobiological measures, transcriptome and chromatin active regions in organoids derived from ASD patients with enlarged brain size and ASD patients with normal brain size. The altered gene regulatory network will be inferred and the two networks will be compared to understand similarities and differences in the two subgroups of ASD. To begin to understand the upstream causes of these developmental alterations, we will then investigate whether patients with ASD carry an increased burden of rare genomic variations in regions of the genome that participate in this regulatory network. Finally we will perform overexpression and RNAi knockdown experiments to examine the specific role of our current best candidate transcription factor, FOXG1, in the constellation of neurobiological and transcriptome alterations found in ASD-derived progenitors. We will assess the impact of perturbing FOXG1 gene expression on neurobiological functions (cell proliferation, glutamate/GABA neuron fate, synaptic growth), transcriptome and activity of transcription regulatory regions by RNA-seq and ChIP-seq, respectively, to gain insights into the role of a FOXG1-driven transcriptional program in the aberrant neuronal differentiation of ASD-derived neural progenitors. In summary, in this application we delineate strategies for (1) identifying gene networks and biological pathways that characterize altered development in two subgroups of ASD; (2) testing the causal role of one crucial node in such networks, the transcription factor FOXG1, which is over- active in ASD with macrocephaly; and (3) identifying regulatory factors, both genetic and epigenetic, upstream from neurobiological and gene expression abnormalities. The impact of these experiments will be the definition of a number of biological functions and molecular markers that are implicated in the neurobiology of ASD.

 描述（由申请人提供）：自闭症谱系障碍（ASD）影响全球 1%-2.5% 的儿童。我们认为病因学和遗传异质性可能集中在一些神经生物学下游途径中。我们一直在研究大脑 ASD 的病理学。体积（大头畸形），一种预后较差的表型，正在进行的研究表明，端脑类器官在体外与诱导多能分化。来自自闭症谱系障碍（ASD）和大头畸形患者的干细胞（iPSC）细胞增殖增加，突触生长增加，GABA能抑制性神经元过量产生，这表明谷氨酸/GABA神经元比例的早期失衡表明GABA能细胞过量产生。至少部分地增加了 FOXG1 的表达，FOXG1 是一种对端脑发育至关重要的主调控转录因子。该应用的主要目标是 (1) 扩大我们对端脑发育的分析。 (2) 了解我们在患有大头畸形的 ASD 中发现的发育改变在多大程度上也适用于一般 ASD。为此，我们将获得有关神经生物学测量、转录组的数据。将推断来自脑部增大的 ASD 患者和脑部正常的 ASD 患者的类器官中的染色质活性区域，并比较这两个网络，以了解两者的异同。为了开始了解这些发育改变的上游原因，我们将研究 ASD 患者参与该调控网络的基因组区域是否携带增加的罕见基因组变异负担。 RNAi 敲低实验旨在检查我们当前最佳候选转录因子 FOXG1 在 ASD 衍生祖细胞中发现的神经生物学和转录组改变中的具体作用，我们将评估扰动的影响。分别通过 RNA-seq 和 ChIP-seq 分析 FOXG1 基因表达对神经生物学功能（细胞增殖、谷氨酸/GABA 神经元命运、突触生长）、转录组和转录调控区活性的影响，以深入了解 FOXG1 驱动的转录的作用总之，在本申请中，我们描述了以下策略：（1）识别表征两个发育改变的基因网络和生物途径。 ASD 的亚组；(2) 测试此类网络中一个关键节点的因果作用，即转录因子 FOXG1，该因子在患有巨头畸形的 ASD 中过度活跃；(3) 识别神经生物学上游的遗传和表观遗传调节因素；这些实验的影响将是与 ASD 神经生物学有关的许多生物功能和分子标记的定义。