Roles for uniquely human enhancers in brain development and WNT signaling

人类独特的增强子在大脑发育和 WNT 信号传导中的作用

• 批准号: 10577092
• 负责人: Debra Silver
• 金额: $ 62.41万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-03-09 至 2027-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10577092
• 关键词: Acceleration; Address; Agonist; Apical; Behavior; Biological Assay; Biological Process; Brain; Cell Communication; Cell Cycle; Cells; Cerebral cortex; Code; Cognition; Complex; Data Set; Development; Embryo; Enhancers; Evolution; Exhibits; Gene Expression; Generations; Genes; Genetic; Genome; Genomic approach; Genomics; Goals; Human; Image; Immunofluorescence Immunologic; In Vitro; Individual; Intellectual functioning disability; Luciferases; Macaca; Modeling; Modification; Molecular; Mus; Mutation; Neocortex; Neuroanatomy; Neuroglia; Neurons; Nucleotides; Organoids; Pan Genus; Phenotype; Positioning Attribute; Primates; Proliferating; Regulation; Regulator Genes; Regulatory Element; Reporter; Research; Role; Schizophrenia; Signaling Molecule; Structure; Testing; Untranslated RNA; Variant; WNT Signaling Pathway; autism spectrum disorder; brain size; cell cortex; cell immortalization; cognitive capacity; epigenome editing; experimental study; fascinate; imaging approach; induced pluripotent stem cell; innovation; insight; mouse model; neocortical; nerve stem cell; nervous system disorder; neurogenesis; neuropsychiatric disorder; neuroregulation; nonhuman primate; progenitor; receptor; self-renewal; single-cell RNA sequencing; tool

ABSTRACT Humans diverge from other primates in numerous ways including their neuroanatomy and cognitive capacities. Human-specific features are particularly prominent in the cerebral cortex, which has undergone an expansion in size and acquired unique cellular composition and circuitry. Many of these features arose through modifications to cortical development, explained by human-specific gene expression. However, how human-specific gene expression explains divergent brain development is poorly understood. This proposal aims to fill that gap by investigating how non-coding regulatory loci impact human-specific brain development. Specifically, we focus on human accelerated regions (HARs), which are ultra-conserved sequences which have rapidly acquired mutations in the human lineage. HARs frequently physically associate with neurodevelopmental genes, and at least 50% of HARs have enhancer activity in human neural cells. Further, HARs are broadly associated with neurological disorders. Yet, biological functions for HARs in brain development remain largely unknown. Our group discovered HARE5, which shows divergent human-chimpanzee (Hs-Pt) enhancer activity in the developing mouse brain, due to just 4 mutations over 600 conserved nucleotides. HARE5 activates expression of Fzd8, a receptor in the WNT signaling pathway which is implicated in brain size and neurological disease. We have generated humanized HARE5 mouse models which exhibit expanded progenitor and neuron number and enlarged brains. We have additionally discovered new HARs, which like HARE5, are predicted to impact WNT signaling. This proposal will test the central hypothesis that evolutionary modifications of HAR enhancer activity modulate WNT signaling to control neural progenitor dynamics in the developing brain. Our proposal leverages our expertise and unique genetic tools, including mouse models, and human and non-human primate iPSCs and organoids. We will investigate mechanisms of HARE5 function in mouse models (Aim 1) and in cortical organoids generated from human and non-human primate iPSCs (Aim 2). We will then test roles for 12 WNT-associated HARs in neurogenesis (aim 3). Upon completion of this study, we will gain valuable insights into the developmental underpinnings of human cognitive capacities which can inform the basis for neuropsychiatric diseases.

摘要 人类在许多方面与其他灵长类动物不同，包括神经解剖学和认知能力。 人类特有的特征在大脑皮层中尤为突出，大脑皮层在2000年经历了扩张。 大小和获得独特的细胞组成和电路。其中许多功能是通过修改而产生的 大脑皮层的发育，这可以用人类特有的基因表达来解释。然而，人类特有的基因 表情解释了不同的大脑发育，但人们对此知之甚少。这项建议旨在填补这一空白， 研究非编码调节基因座如何影响人类特定的大脑发育。具体来说，我们专注于 人类加速区（HAR），是一种超保守序列， 人类血统的突变HAR经常与神经发育基因发生物理联系， 至少50%的HAR在人神经细胞中具有增强子活性。此外，HAR与以下因素广泛相关： 神经系统疾病然而，HARs在大脑发育中的生物学功能在很大程度上仍然未知。 我们的研究小组发现了HARE 5，它在人类-黑猩猩（Hs-Pt）中表现出不同的增强子活性。 在小鼠大脑的发育过程中，600个保守的核苷酸发生了4次突变。HARE 5激活表达 Fzd 8是WNT信号通路中的一种受体，与大脑大小和神经系统疾病有关。我们 已经产生了人源化的HARE 5小鼠模型，其表现出祖细胞和神经元数量的扩增， 扩大的大脑。我们还发现了新的HARs，如HARE 5，预计会影响WNT 信号这项提议将检验HAR增强子的进化修饰 活动调节WNT信号传导以控制发育中大脑的神经祖细胞动态。我们 该提案利用了我们的专业知识和独特的遗传工具，包括小鼠模型，以及人类和非人类 灵长类iPSC和类器官。我们将在小鼠模型中研究HARE 5功能的机制（目的1）， 在由人和非人灵长类iPSC产生的皮质类器官中（目的2）。然后，我们将测试角色， 12例神经发生中的WNT相关HAR（目的3）。在完成这项研究后，我们将获得宝贵的见解 人类认知能力的发展基础，这可以为人类认知能力的发展提供基础。 神经精神疾病