Targets of microRNA-132 in adult neurogenesis

microRNA-132 在成人神经发生中的靶标

基本信息

批准号：
8201725
负责人：
Xiaolu Ang Cambronne
金额：
$ 4.84万
依托单位：
OREGON HEALTH & SCIENCE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-07-01 至 2013-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8201725
关键词：
3&apos Untranslated Regions Ablation Accounting Acute Address Adult Affect Aging Antidepressive Agents Area Biological Assay Brain Brain region C-terminal CREB1 gene Cells Complex Conflict (Psychology)Cultured Cells Data Dendrites Development Disease Dominant-Negative Mutation Down-Regulation EGF gene Epithelial Excision Exonuclease Family Fibrinogen Functional RNA Gene Expression Genes Growth Factor Heparin Binding Hippocampus (Brain)Human In Vitro Indium Injury Knock-out Learning Life Luciferases Mediating Memory Messenger RNA MicroRNAs Modeling Molecular Mutate Neurons Newborn Infant Nucleotides Paper Parahippocampal Gyrus Pathway interactions Phenocopy Phenotype Positioning Attribute Process Publishing RNA Interference RNA-Induced Silencing Complex Regulation Repression Role Screening for Neuroblastoma Signal Pathway Signal Transduction Synapses Testing Time Transcript Translating Whole Organism adult neurogenesis cellular targeting cohort dentate gyrus granule cell in vivo insight interest mRNA Expression member mouse model nerve stem cell neuroblastoma cell neurogenesis newborn neuron novel novel strategies overexpression research study response synaptogenesis transcription factor

项目摘要

DESCRIPTION (provided by applicant): One distinguishing attribute of the mammalian hippocampus is its ability to continuously produce newborn neurons throughout adult life. These newborn neurons are first exposed to GABAergic signals as they emerge from the subgranule layer of the dentate gyrus. This activity drives a CREB-dependent signaling pathway that alters the gene expression within that newborn neuron, and as such, is required for its maturation and survival. Nevertheless, the exact mechanism is still poorly understood as to how CREB-signaling translates into the maturation, survival, and functional integration of that particular cell into the hippocampal circuitry. We do know that one of the important CREB targets for the maturation of adult newborn neurons in vivo is non-coding transcript microRNA-132 (miR-132). When we excised the miR-132 locus in adult newborn neurons it resulted in an immature dendritic arbor that phenocopied disruption of CREB signaling. Nevertheless as a microRNA, miR-132 has the ability to downregulate a number of diverse transcripts. The important issue that this proposal addresses is the identification and characterization of specific miR-132 targets that contribute to this establishment of the dendritic arbor. Without understanding the identity of specific cellular targets, we cannot fully appreciate the regulation conferred by miR-132, and only know that its activity is required for this process. Through preliminary screens and the availability of a mouse model, I am in a unique position to characterize how the regulation of candidate target Heparin-binding Epithelial Growth Factor (Hb-EGF) by miR- 132 contributes to the dendritic arbor of newborn neurons. Preliminary data demonstrate that levels of Hb-EGF are dramatically downregulated specifically in response to miR-132 activity. Aim 1 takes advantage of being able to target excision of the miR-132 locus in the adult newborn neurons of the floxed mouse model to examine how Hb-EGF is regulated by miR-132 in these cells. Changes in Hb-EGF levels will be evaluated for how they affect dendritic arborization, and then we will determine whether depletion of Hb-EGF can rescue the immature dendritic phenotype that occurs with miR-132 activity is ablated in adult newborn neurons. It is likely that other miR-132 direct targets are also important for maturation of the adult newborn neuron. To identify direct miR-132 targets that may function with Hb-EGF, I have developed a molecular miR- 132 target trap that I will develop into a screen in Aim 2. This approach takes advantage of a dominant- negative RNAi-Induced Silencing Complex (RISC)- a central component in the microRNA pathway that bridges the recognition of microRNAs and their targets-to stabilize and capture associated mRNA target transcripts that would otherwise decay via deadenylation and exonuclease activity. PUBLIC HEALTH RELEVANCE: In order to address how adult neurogenesis relates to human aging, disease, and injury, it is absolutely vital to have a clear and detailed understanding of the molecular mechanisms underlying this process. Over the years various cellular factors have been implicated in the establishment and maturation of adult newborn neurons, however, the revelation that activity- dependent microRNA-132 is important in this process provides a unique opportunity to flesh out significant and specific molecular pathways in greater depth. This proposal brings together detailed preliminary data from in vitro molecular studies-which reveal mechanistic insight down to the specific nucleotides that are targeted my miR-132-with important in vivo analysis of how the identified regulation affects the development of these newborn neurons within the context of a whole organism.

描述（由申请人提供）：哺乳动物海马的一个区别属性是它在整个成人生活中不断产生新生神经元的能力。这些新生神经元首先暴露于GABA能信号中，因为它们从齿状回的亚颗粒层出现。该活性驱动CREB依赖性信号通路，以改变该新生神经元内的基因表达，因此，其成熟和存活是必需的。然而，关于CREB信号如何转化为该特定细胞进入海马电路的成熟，存活和功能整合的确切机制仍然很熟悉。我们确实知道，体内成年新生神经元成熟的重要CREB靶标之一是非编码转录本microRNA-132（miR-132）。当我们在成年新生儿神经元中切除miR-132基因座时，导致了未成熟的树突状乔木，该植物会破坏CREB信号传导。然而，作为microRNA，miR-132具有下调许多不同转录本的能力。该提议解决的重要问题是对有助于树突状植物园建立的特定miR-132目标的识别和表征。在不了解特定细胞靶标的身份的情况下，我们无法完全理解miR-132所提供的调节，并且只知道其活性是此过程所必需的。通过初步筛选和小鼠模型的可用性，我处于一个独特的位置，可以表征候选靶向肝素结合上皮生长因子（HB-EGF）如何通过miR-132来促进新生儿神经元的树突状凉亭。初步数据表明，HB-EGF的水平显着下调，以响应miR-132活性。 AIM 1利用能够靶向Floxed小鼠模型的成年新生神经元中miR-132基因座的切除，以检查这些细胞中miR-132如何调节HB-EGF。 HB-EGF水平的变化将评估它们如何影响树突状树皮化，然后我们将确定HB-EGF的耗尽是否可以挽救成人新生儿神经元中miR-132活性发生的未成熟树突状表型。其他miR-132直接靶标也可能对成年新生神经元的成熟也很重要。要识别可能与HB-EGF一起起作用的直接miR-132目标，我已经开发了一个分子miR-132目标陷阱，我将在目标2中发展为屏幕2。这种方法利用了占主导地位的RNAI诱导的沉默复合物（RISC）（RISC）（RISC）（RISC） - 通过MicroRNA路径中的稳定性和稳定量相关的MrimORNA型号的核心组成部分，以至于稳定了MrimORNAS和MRIGNA的识别。外切酶活性。公共卫生相关性：为了解决成年神经发生与人类衰老，疾病和损伤的关系，对这一过程的分子机制有清晰而详细的了解绝对至关重要。多年来，各种细胞因素与成人新生神经元的建立和成熟有关，但是，在这一过程中，依赖于活动的microRNA-132很重要的启示为更大深度提供充实的重要和特定的分子途径提供了独特的机会。该提案将来自体外分子研究的详细初步数据汇总到详细的初步数据，这些数据揭示了机械洞察到针对我的miR-132的特定核苷酸，这是对鉴定的调节如何影响这些新生神经元在整个生物体的上下文中的发展的重要分析。