The genomic interface of microRNA regulation and heart failure

项目概要/摘要 心力衰竭是世界范围内发病率和死亡率的主要原因。心脏病的发病和临床过程 失败是由环境和遗传因素的复杂相互作用决定的。人口研究表明， 确定了许多与心脏病的遗传联系，然而，许多变异本质上是非编码的， 而我们理解这些联系的能力也受到了我们对宇宙中 控制循环系统基因表达的基因组调节系统。最近，microRNAs（miRs） 作为心脏生物学和疾病的关键基因调节因子出现。这些小的非编码RNA被加载到 Argonaute（Ago）蛋白通过与靶转录物的碱基配对来指导转录后基因抑制， 值得注意的是，破坏这种调节的遗传变异与疾病有关。了解miR的功能 以及它们与遗传学和心脏病的相互作用，确定它们的靶点是至关重要的。不幸的是， 在人类心脏组织中缺乏经验性的miR靶向数据，减缓了miR的翻译影响。 对疾病相关miR的许多研究。为了支持这些努力，我们的首要目标是定义miR 靶向事件及其在人类心脏中的生物学相关性，并了解 改变心脏miR功能的遗传变异。在这项资助中，我们将解决识别miR结合的局限性， 通过采用高通量技术，对心脏病的发病机制和遗传基础重要的位点 以全面分析人类心脏组织中miR-靶标的相互作用。核心假设有两个方面：1） miR-靶标相互作用在衰竭的人类心脏中显着重新连接，2）遗传变异（例如SNP） 干扰这些相互作用将影响心脏病的临床进程。在目标1中，我们将填补重要的 关于心脏miR机制靶点的知识缺口，通过生成 "正常"非衰竭和衰竭人类心脏组织中的miR结合位点。由此产生的数据将指向 可能调节心肌病和心肌炎相关miR-靶标相互作用的功能相关SNP （在目标2中测试），具有揭示有助于疾病异质性的新遗传修饰剂的潜力。 最后，在目标3中，我们将确定这种性质的SNP是否与临床结果（例如生存和死亡）相关。 在多个心力衰竭患者队列中，发现了可能影响 病人管理此外，我们将超越基本的基因型-表型联系，深入了解 通过定义全局心肌基因表达特征的基因型特异性变化来研究潜在机制。 总体而言，这项工作将1）广泛推进我们对心脏miR功能的了解，2）促进miR的翻译， 心脏病的遗传学研究朝着新的致病机制和个性化治疗的改进 3）支持未来努力将miR靶向的"身体图谱"扩展到血管组织， 与其他具有复杂遗传基础的流行多因素心脏代谢疾病相关。

PROJECT SUMMARY / ABSTRACT Heart failure is a primary cause of morbidity and mortality worldwide. The onset and clinical course of heart failure is dictated by a complex interplay of environmental and hereditary factors. Population studies have identified a number of genetic links to heart disease, however, many of the variants are non-coding in nature, and our ability to make sense of these associations has been hampered by our limited knowledge of the vast genomic regulatory system that controls circulatory system gene expression. Recently, microRNAs (miRs) have emerged as key gene regulators in cardiac biology and disease. These small non-coding RNAs are loaded into Argonaute (Ago) proteins to direct post-transcriptional gene suppression by base-pairing with target transcripts, and notably, genetic variants disrupting this regulation have been linked to disease. To understand miR functions and their interface with genetics and heart disease, identifying their targets sites is paramount. Unfortunately, there is a paucity of empirical miR targeting data in human cardiac tissues, slowing the translational impact of the many investigations of disease-relevant miRs. To bolster these efforts, our overarching goal is to define miR targeting events and their biological-relevance in human hearts and to understand the clinical significance of genetic variants that alter cardiac miR functions. In this grant, we will address limitations in identifying miR binding sites important to the pathogenesis and genetic basis of heart disease by employing high-throughput techniques to globally profile miR-target interactions in human cardiac tissues. The central hypothesis is two-fold: 1) that miR-target interactions are significantly rewired in failing human hearts, and 2) that genetic variations (e.g. SNPs) perturbing these interactions will impact the clinical course of heart disease. In Aim 1, we will fill significant knowledge gaps regarding the mechanistic targets of cardiac miRs by generating transcriptome-wide maps of miR binding sites in “normal” non-failing and failing human heart tissues. The resulting data will point to translationally-relevant SNPs that may modulate cardiomyopathy- and arrhythmia-related miR-target interactions (tested in Aim 2), having the potential to reveal new genetic modifiers that contribute to disease heterogeneity. Finally, in Aim 3, we will determine if SNPs of this nature are linked to clinical outcomes (e.g. survival and fatal arrhythmias) in multiple heart failure patient cohorts, discovering novel inherited risk factors that could impact patient management. In addition, we will push beyond basic genotype-phenotype links to gain insight into the underlying mechanisms by defining genotype-specific changes in global myocardial gene expression signatures. Overall, this work will 1) broadly advance our knowledge of cardiac miR functions, 2) facilitate the translation of genetic studies of heart disease towards novel pathogenic mechanisms and improvements in personalized medicine, and 3) support future efforts to extend the “body map” of miR targeting to vascular tissues that are related to other prevalent multifactorial cardio-metabolic diseases with complex genetic underpinnings.