MECHANISMS OF EPIGENETIC REGULATION IN NERVOUS SYSTEM DEVELOPMENT

神经系统发育中的表观遗传调控机制

• 批准号: 9893903
• 负责人: Harrison W Gabel
• 金额: $ 39.32万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-03-14 至 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9893903
• 关键词: Affect; Automobile Driving; Binding; Brain; Candidate Disease Gene; Cell Culture System; Cell physiology; Centers for Disease Control and Prevention (U.S.); Cerebral cortex; Chromatin; Chromatin Structure; CpG dinucleotide; Cytosine; DNA; DNA Methylation; DNA Modification Methylases; DNA Sequence Alteration; Deposition; Dinucleoside Phosphates; Disease; Enhancers; Enzymes; Epigenetic Process; Functional disorder; Future; Gene Expression; Gene Expression Regulation; Genes; Genetic; Genetic Transcription; Genetic study; Genome; Genomics; Goals; Histone Acetylation; Human Genetics; In Vitro; Individual; Intellectual functioning disability; Interneurons; Lead; Mediating; Methyl-CpG-Binding Protein 2; Methylation; Missense Mutation; Molecular; Mus; Mutant Strains Mice; Mutation; Nature; Nervous System Physiology; Nervous system structure; Neurodevelopmental Disorder; Neurons; Nuclear; Parvalbumins; Pathway interactions; Phenotype; Population; Proteins; Regulator Genes; Regulatory Pathway; Role; Severities; Site; Syndrome; System; Testing; Transcriptional Regulation; Transgenic Mice; United States; Work; autism spectrum disorder; base; cell type; disease-causing mutation; epigenetic regulation; excitatory neuron; gene function; genome-wide analysis; in vivo; inhibitory neuron; insight; mammalian genome; molecular pathology; molecular site; mutant; nervous system development; neurodevelopment; novel; postnatal development; protein expression; public health relevance; therapeutic development; transcriptome sequencing

Abstract Advances in human genetics have led to the identification of a large number of genes associated with autism spectrum disorder (ASD), intellectual disability (ID), and related neurodevelopmental diseases. A critical new challenge is to understand the molecular pathways these genes contribute to in neurons and to dissect how their disruption alters nervous system function. Methylation of cytosines in DNA classically occurs only at CG dinucleotides, but recent studies have also uncovered functions for unique non-CpG DNA methylation in neurons (which occur largely at CA dinucleotides, mCA). We have discovered that the methyl-DNA-binding protein MeCP2, which is critical for proper nervous system function, binds to mCA within the transcribed regions of genes in neurons to downregulate their expression. New studies have identified mutations in DNMT3A, the DNA methyltransferase required for the deposition of mCA in the brain, in individuals with ID and ASD. These findings support the hypothesis that disruption of gene regulation mediated by mCA contributes to disorders caused by mutation of DNMT3A. Our proposed studies will test this hypothesis by pursuing three specific aims: Aim 1 will use in vitro cell culture systems to determine how disease-associated mutations in DNMT3A affect enzyme function and alter deposition of mCA in neurons. Aim 2 will employ newly-generated transgenic mice carrying heterozygous mutations in DNMT3A to determine the effects of this disruption on neuronal DNA methylation, chromatin structure, transcription and cellular functions. Aim 3 will interrogate the mechanisms by which mCA and MeCP2 directly regulate transcription in neurons, testing the hypothesis that these components interact with novel gene-regulatory sites to control transcription. Together these studies will determine the molecular mechanisms by which mCA regulates gene expression in neurons, and define a site of molecular pathology in ASD and ID.

摘要人类遗传学的进步使人们发现了大量与癌症相关的基因。 自闭症谱系障碍(ASD)、智力残疾(ID)和相关的神经发育疾病。一个批判性的新 挑战在于了解这些基因在神经元中的分子通路，并剖析它们是如何 干扰会改变神经系统的功能。DNA中胞嘧啶的甲基化通常只在CG发生 二核苷酸，但最近的研究也发现了神经元中独特的非CpG DNA甲基化的功能 (主要发生在CA二核苷酸，MCA)。我们发现甲基DNA结合蛋白MeCP2， 这对神经系统的正常功能至关重要，它与MCA结合在基因的转录区域 来下调它们的表达。新的研究发现了DNA的DNMT3A突变 在患有ID和ASD的患者中，MCA在大脑中沉积所需的甲基转移酶。这些发现 支持这样的假设，即MCA介导的基因调控中断导致了 DNMT3A基因突变。我们提议的研究将通过追求三个具体目标来检验这一假设：目标1将使用 体外细胞培养系统，以确定疾病相关的DNMT3A突变如何影响酶功能和 改变MCA在神经元中的沉积。目标2将使用新产生的携带杂合子的转基因小鼠 DNMT3A的突变来确定这种干扰对神经元DNA甲基化，染色质结构， 转录和细胞功能。目标3将询问MCA和MeCP2直接通过的机制 调节神经元的转录，测试这些成分与新的基因调节相互作用的假设 控制转录的位置。这些研究将共同确定MCA的分子机制 调节神经元中的基因表达，并确定ASD和ID的分子病理部位。