MicroRNAs, cardiac development and function

MicroRNA、心脏发育和功能

• 批准号: 7617184
• 负责人: Da-Zhi Wang
• 金额: $ 36.31万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-16 至 2009-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7617184
• 关键词: Animals; Biological Models; Cardiac; Code; Congenital Heart Defects; Development; Ectopic Expression; Event; Gene Expression; Genome; Goals; Heart; Heart Hypertrophy; Heart failure; Human; In Vitro; Knockout Mice; Mammals; Mediating; Messenger RNA; MicroRNAs; Molecular; Muscle; Myoblasts; Myocardium; Nucleotides; Organism; Pathway interactions; Play; Process; Proteins; RNA; Regulation; Research; Role; Testing; Tissue-Specific Gene Expression; Tissues; Translations; cardiogenesis; human DICER1 protein; in vivo; insight

DESCRIPTION (provided by applicant): MicroRNAs (miRNAs) are a recently identified class of small regulatory RNA molecules found in most organisms, including human. miRNAs are encoded by the genomes and processed into ~ 22-nucleotide products which are thought to play important regulatory role, mainly through degrading target messenger RNAs (mRNAs) and/or inhibiting translation of protein-coding mRNAs. Interestingly, many miRNAs are expressed in a tissue-specific manner, suggesting their potential roles in regulating tissue-specific gene expression. However, given more than 400 miRNAs identified in mammals, the molecular mechanisms and the in vivo functions of most miRNAs remain unknown. In our preliminary studies, we found that miR-1, miR- 133, miR-206 and miR-208 are muscle-specifically expressed (and therefore referred to as "muscle miRNAs"). Ectopic expression or knockdown of miR-1 and miR-133 in myoblasts modulates their proliferation and differentiation processes, indicating that miRNAs are importance for animal development and function. The long-term goal of our research is to understand the molecular mechanisms that control development and function of cardiac muscle. The discovery of miRNAs opened a completely new field to investigate how miRNAs may participate in "classical" gene expression pathways. Our central hypothesis is that miRNAs are components of the molecular circuitry that controls mammalian cardiac development and function. The overall goal of this proposal is to explore the molecular mechanisms of miRNA function, using cardiac muscle as our model system. In particular, we will study the in vitro and in vivo function of cardiac- specific miR-208 and identify its regulatory targets which are involved in cardiac muscle differentiation and development. In addition, we will assess the global role of miRNAs in heart development, using Dicer conditional knockout mice. The specific aims are: Aim #1. To study the in vitro and in vivo role of miR- 208 in heart development and cardiac gene expression. Aim #2. To define the global role of miRNA- mediated regulation in cardiac muscle using Dicer conditional knock-out mice. Aim #3. To identify and experimentally test the regulatory targets of miRNAs in the heart. Identification of the regulatory mRNA targets of miRNAs in the heart will be the key to the understanding of the molecular mechanisms of miRNA function. We will use a combination of computational prediction and experimental confirmation to study the regulatory targets repressed by miRNAs in the heart. Our studies will provide important insights into the molecular mechanisms behind miRNAs that control mammalian heart development and cardiac gene expression. The molecular strategies revealed in these studies may apply to pathophysiologically- related cardiac muscle events such as human congenital heart defects (CHD), cardiac failure and cardiac hypertrophy.

描述（由申请人提供）：MicroRNA (miRNA) 是最近发现的一类小调节 RNA 分子，存在于包括人类在内的大多数生物体中。 miRNA 由基因组编码并加工成约 22 个核苷酸的产物，这些产物被认为发挥着重要的调节作用，主要是通过降解靶信使 RNA (mRNA) 和/或抑制蛋白质编码 mRNA 的翻译。有趣的是，许多 miRNA 以组织特异性方式表达，表明它们在调节组织特异性基因表达中的潜在作用。然而，鉴于在哺乳动物中发现了 400 多种 miRNA，大多数 miRNA 的分子机制和体内功能仍然未知。在我们的初步研究中，我们发现 miR-1、miR-133、miR-206 和 miR-208 是肌肉特异性表达的（因此称为“肌肉 miRNA”）。成肌细胞中 miR-1 和 miR-133 的异位表达或敲低可调节其增殖和分化过程，表明 miRNA 对于动物发育和功能非常重要。我们研究的长期目标是了解控制心肌发育和功能的分子机制。 miRNA 的发现为研究 miRNA 如何参与“经典”基因表达途径开辟了一个全新的领域。我们的中心假设是 miRNA 是控制哺乳动物心脏发育和功能的分子电路的组成部分。该提案的总体目标是以心肌作为我们的模型系统，探索 miRNA 功能的分子机制。特别是，我们将研究心脏特异性miR-208的体外和体内功能，并确定其参与心肌分化和发育的调节靶点。此外，我们将使用 Dicer 条件敲除小鼠评估 miRNA 在心脏发育中的整体作用。具体目标是： 目标#1。研究 miR-208 在心脏发育和心脏基因表达中的体外和体内作用。目标#2。使用 Dicer 条件敲除小鼠确定 miRNA 介导的调节在心肌中的整体作用。目标#3。识别并通过实验测试心脏中 miRNA 的调控靶点。心脏中miRNA调控mRNA靶点的鉴定将是理解miRNA功能分子机制的关键。我们将结合计算预测和实验确认来研究心脏中 miRNA 抑制的调控靶点。我们的研究将为控制哺乳动物心脏发育和心脏基因表达的 miRNA 背后的分子机制提供重要的见解。这些研究中揭示的分子策略可能适用于病理生理学相关的心肌事件，例如人类先天性心脏缺陷（CHD）、心力衰竭和心脏肥大。