Understanding the neurodevelopmental role and mechanism of histone demethylase JMJD3

了解组蛋白去甲基化酶 JMJD3 的神经发育作用和机制

• 批准号: 10212470
• 负责人: DANIEL A LIM
• 金额: $ 37.95万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-15 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10212470
• 关键词: Address; Adult; Architecture; Area; Behavior; Behavioral; Biological Models; Brain; CRISPR/Cas technology; Childhood Brain Neoplasm; Chromatin; Cognitive deficits; Complex; Cytoplasmic Granules; Data; Development; Disease; Engineering; Enhancers; Epigenetic Process; Gene Dosage; Gene Expression; Genes; Genetic; Genome; Genomic Segment; Genomics; Goals; Higher Order Chromatin Structure; Hippocampus (Brain); Histones; Human; Human Genome; Impaired cognition; Impairment; Intellectual functioning disability; Knowledge; Learning; Life; Lysine; Malignant Neoplasms; Memory; Methods; Molecular; Molecular Mechanisms of Action; Mus; Mutant Strains Mice; Mutation; Neurodevelopmental Disorder; Neurons; Nuclear; Outcome; Pharmacotherapy; Phenotype; Population; Process; Production; Proteins; Regulator Genes; Research; Role; Structure; Testing; Tissues; Transcriptional Activation; autism spectrum disorder; base; cancer therapy; chromatin modification; dentate gyrus; drug development; emotional behavior; experimental study; gene repression; histone demethylase; human disease; in vivo; inhibitor/antagonist; innovation; insight; mouse development; mouse model; nerve stem cell; nervous system disorder; neurodevelopment; neurogenesis; novel; postnatal; promoter; recruit; single-cell RNA sequencing; stem cell population

JMJD3 (KDM6B) is a chromatin regulator with roles central to normal development as well as a wide range of human diseases including cancer and human neurological disorders. For instance, mutations in JMJD3 are autosomal recessive for familial intellectual disability, and de novo JMJD3 mutations are associated with autism spectrum disorder (ASD). An important next step to understanding genetic causes of complex diseases is to study disease-associated genes in mouse models. While it is known that JMJD3 is important to certain aspects of neural cell development, whether JMJD3 deficiency can actually cause cognitive dysfunction has not been known. Preliminary Studies indicate that JMJD3 is critical for the development of the mouse hippocampal dentate gyrus (DG). In the DG, granule neurons are generated throughout life from a population of neural stem cells (NSCs). Defective DG neurogenesis impairs many hippocampal-dependent behaviors and has been associated with cognitive deficits including that of intellectual disability and ASD. Without Jmjd3, NSCs failed to become established in the adult DG, and granule neuron production was severely decreased and abnormal. In these mice, hippocampal-dependent learning was defective. Heterozygous deletion of Jmjd3 also resulted in abnormal postnatal DG development, indicating that this process is sensitive to gene dosage. Aim 1 is to determine the role of Jmjd3 in DG neurogenesis. In vivo experiments will test the hypothesis that Jmjd3 regulates the postnatal expansion and establishment of the DG NSC population, and that even reduced Jmjd3 gene dosage causes cognitive dysfunction. Single cell RNA sequencing analysis will provide molecular insights into the observed phenotype and help guide mechanistic studies of Aim 2. Aim 2 is to determine the mechanisms by which JMJD3 regulates gene expression. JMJD3 has demethylase activity for histone 3 lysine 27 trimethylation (H3K27me3), which is a chromatin modification associated with transcriptional repression. To investigate demethylase-dependent and potential demethylase-independent activities of JMJD3, we have developed innovative CRISPR-based technologies to recruit JMJD3 proteins to the genome. By developing a novel, easy-to-use method for mapping lamina-associated domains (LADs) – a repressive nuclear compartment – we have also found that JMJD3 in NSCs is enriched at the genomic LAD “borders,” which are genomic regions enriched for transcriptional regulatory elements. Thus, we propose investigating the role of JMJD3 in regulating this aspect of higher-order chromatin structure. The proposed neurodevelopmental and behavioral analyses combined with mechanistic studies is expected to provide a scientific framework in which to begin understanding how human JMJD3 mutations can cause disease. The studies of JMJD3 mechanism is also expected to be important to the broader field of chromatin-based epigenetics as well as nuclear compartment-associated genome organization – an emerging area of research.

JMJD3 (KDM6B) 是一种染色质调节因子，对于正常发育以及多种 人类疾病，包括癌症和人类神经系统疾病。例如，JMJD3 的突变是 常染色体隐性遗传导致家族性智力障碍，而新的 JMJD3 突变与 自闭症谱系障碍（ASD）。了解复杂疾病遗传原因的重要下一步 是在小鼠模型中研究疾病相关基因。虽然众所周知 JMJD3 对某些人来说很重要 在神经细胞发育方面，JMJD3 缺陷是否真的会导致认知功能障碍 不为人所知。初步研究表明JMJD3对于小鼠的发育至关重要 海马齿状回（DG）。在 DG 中，颗粒神经元在整个生命周期中从群体中产生 神经干细胞（NSC）。 DG 神经发生缺陷会损害许多海马依赖性行为 与认知缺陷有关，包括智力障碍和自闭症谱系障碍。没有Jmjd3， NSC 未能在成年 DG 中建立，颗粒神经元的产生严重减少 和异常。在这些小鼠中，海马依赖性学习存在缺陷。杂合缺失 Jmjd3还导致出生后DG发育异常，表明该过程对基因敏感 剂量。目标 1 是确定 Jmjd3 在 DG 神经发生中的作用。体内实验将测试 假设 Jmjd3 调节 DG NSC 群体的出生后扩张和建立，以及 即使减少 Jmjd3 基因剂量也会导致认知功能障碍。单细胞RNA测序分析将 提供对观察到的表型的分子见解，并帮助指导目标 2 的机制研究。目标 2 是 以确定 JMJD3 调节基因表达的机制。 JMJD3 具有去甲基化酶活性 组蛋白 3 赖氨酸 27 三甲基化 (H3K27me3)，这是一种与 转录抑制。研究去甲基化酶依赖性和潜在的去甲基化酶独立性 JMJD3 的活性，我们开发了基于 CRISPR 的创新技术来招募 JMJD3 蛋白 基因组。通过开发一种新颖、易于使用的方法来绘制层相关域 (LAD) – 抑制性核区室 – 我们还发现 NSC 中的 JMJD3 在基因组 LAD 处富集 “边界”，是富含转录调控元件的基因组区域。因此，我们建议 研究 JMJD3 在调节高级染色质结构方面的作用。拟议的 神经发育和行为分析与机制研究相结合有望提供 开始了解人类 JMJD3 突变如何导致疾病的科学框架。这 JMJD3机制的研究预计对更广泛的基于染色质的领域也很重要 表观遗传学以及核区室相关的基因组组织——一个新兴的研究领域。