Coordinate actions between methyl-CpG binding proteins in neuronal development

甲基-CpG 结合蛋白在神经元发育中的协调作用

• 批准号: 9137740
• 负责人: Xinyu Zhao
• 金额: $ 19.13万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-15 至 2018-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9137740
• 关键词: Adult; Autistic Disorder; Behavioral; Binding; Binding Proteins; Binding Sites; Biological Assay; Biological Process; Brain; Cells; ChIP-seq; DNA Methylation; Development; Disease; Exhibits; Financial compensation; Gene Expression; Gene Expression Regulation; Gene Targeting; Genes; Genomic DNA; Genomics; Health; Heterochromatin; Impairment; Intellectual functioning disability; Knock-in Mouse; Knock-out; Knockout Mice; Knowledge; Learning; Literature; Methods; Methyl-CpG-Binding Protein 2; MicroRNAs; Mus; Mutant Strains Mice; Mutation; Neurodevelopmental Disorder; Neuronal Differentiation; Neuronal Plasticity; Neurons; Pathway interactions; Patients; Phenotype; Play; Prefrontal Cortex; Process; Proteins; Publishing; RNA; Regulation; Research Personnel; Rett Syndrome; Role; Site; Specificity; Stem cells; Testing; Tissues; Translating; autism spectrum disorder; cell type; deep sequencing; design; developmental disease; epigenetic regulation; genome-wide; insight; mouse model; nervous system disorder; neurodevelopment; neurogenesis; neuron development; next generation sequencing; novel; postnatal; preference; protein profiling; synaptogenesis

 DESCRIPTION (provided by applicant): Methyl-CpG binding proteins (MBPs) are central players of epigenetic regulation by translating DNA methylation into phenotypic changes. Mutations in MeCP2 result in Rett Syndrome and certain autism- spectrum disorders. Alterations in MBD1 are found in a subset of autistic patients and intellectual disabilities. We have demonstrated that MBD1 null mice display learning impairment and autism-like behavioral deficits. Thus, both MeCP2 and MBD1 are autism-associated genes (SFARI). We have shown that both MeCP2 and MBD1 are expressed in immature stem cells and new neurons in the postnatal brains and regulate neurogenesis and neuronal maturation. We found that such regulations are at least in part through controlling the expression of noncoding microRNAs. Although many studies have focused on MeCP2 target identification, MeCP2 targets in specific neural cell types remain largely unknown. In addition, little has been done to identify the targets of MBD1 in the brain. Literatures have suggested that MBD1 and MeCP2 may have different sets of targets, however both protein exhibit similar heterochromatin binding and share at least several noncoding gene targets. Functional relationship between these two proteins during neuronal development has not been explored. We observed that mice lacking both MBD1 and MeCP2 die much earlier than single mutant mice, at postnatal day 21, which coincides with the postnatal synaptogenesis and neuronal maturation period as well as the dynamic changes in DNA methylation in neurons. Therefore a lack of both MBD1 and MeCP2 during this period is extremely detrimental but the reason is unknown. In addition, despite the apparent functional compensations between these two proteins, questions remained why MBD1 cannot fully compensate for MeCP2 deficiency and which genomic binding targets might be responsible for this lack of compensation. A direct comparison of genome-wide MBD1 and MeCP2 targets will yield valuable information for understanding MBD regulation of neurodevelopment and disorders. The PI and collaborators are uniquely suited to fill these knowledge gaps. In this exploratory R21 proposal, we aim to take advantage of a MeCP2-FLAG line created by collaborator Dr Chang and our newly created MBD1-FLAG mouse line to directly compare the targets between MBD1 and MeCP2 in developing brain. We aim to test the hypothesis that MBD1 and MeCP2 have both common and unique targets which underlie their specific functions during postnatal development. We will first identify genomic binding profiles of these proteins. We will then determine whether the genomic binding specificities have impact on gene expression and neuronal maturation. The proposed study is built upon the complimentary expertise of the PI and collaborators. The results of this study will provide much needed understanding in biological functions of MBP and its significance in gene regulation. Since both MBPs are important for autism and neurodevelopmental disorders, the study will unveil the novel genes and pathways involved in developmental disorders.

 描述（由申请人提供）：甲基-CpG 结合蛋白（MBP）通过将 DNA 甲基化转化为表型变化，是表观遗传调控的核心参与者。 MeCP2 突变会导致雷特综合症和某些自闭症谱系障碍。在一部分自闭症患者和智力障碍患者中发现了 MBD1 的改变。我们已经证明 MBD1 缺失小鼠表现出学习障碍和自闭症样行为缺陷。因此，MeCP2 和 MBD1 都是自闭症相关基因 (SFARI)。我们已经证明，MeCP2 和 MBD1 在出生后大脑的未成熟干细胞和新神经元中表达，并调节神经发生和神经元成熟。我们发现这种调控至少部分是通过控制非编码 microRNA 的表达来实现的。尽管许多研究都集中在 MeCP2 靶点识别上，但特定神经细胞类型中的 MeCP2 靶点仍然很大程度上未知。此外，在确定目标方面几乎没有采取任何行动 大脑中的MBD1。文献表明 MBD1 和 MeCP2 可能具有不同的靶标集，但是两种蛋白质都表现出相似的异染色质结合，并且共享至少几个非编码基因靶标。神经元发育过程中这两种蛋白质之间的功能关系尚未被探索。我们观察到同时缺乏MBD1和MeCP2的小鼠比单一突变小鼠更早死亡，即出生后第21天，这与出生后突触发生和神经元成熟期以及神经元DNA甲基化的动态变化相一致。因此，在此期间同时缺乏 MBD1 和 MeCP2 是极其有害的，但原因尚不清楚。此外，尽管这两种蛋白之间存在明显的功能补偿，但为什么 MBD1 不能完全补偿 MeCP2 缺陷以及哪些基因组结合靶点可能导致这种补偿的缺乏，仍然存在疑问。全基因组 MBD1 和 MeCP2 靶标的直接比较将为了解神经发育和疾病的 MBD 调节提供有价值的信息。 PI 和合作者非常适合填补这些知识空白。在这个探索性的 R21 提案中，我们的目标是利用合作者 Chang 博士创建的 MeCP2-FLAG 系和我们新创建的 MBD1-FLAG 小鼠系来直接比较 MBD1 和 MeCP2 在发育中大脑中的靶标。我们的目的是检验以下假设：MBD1 和 MeCP2 具有共同和独特的靶点，这些靶点是它们在出生后发育过程中特定功能的基础。我们将首先确定这些蛋白质的基因组结合谱。然后我们将确定基因组结合特异性是否对基因表达和神经元成熟有影响。拟议的研究建立在 PI 和合作者的互补专业知识的基础上。这项研究的结果将为人们了解 MBP 的生物学功能及其在基因调控中的意义提供急需的理解。由于这两种 MBP 对自闭症和神经发育障碍都很重要，因此该研究将揭示与发育障碍有关的新基因和途径。