Dynamics of Cardiac Nuclei in Heart Disease

描述（由申请人提供）：心力衰竭是一种进行性综合征，需要新的机制见解。心脏肥大是已知的涉及激活胎儿基因程序，改变心肌细胞的功能。最近来自非心脏领域的研究使得核小体定位和染色质结构的全基因组分析在技术上是可行的。我们推断，精心安排的染色质重塑事件必须存在以促进心脏基因表达，并提出心力衰竭等疾病涉及基因组尺度上的染色质结构紊乱。这项工作的短期目标是了解细胞核中蛋白质的总数，这些蛋白质在心脏肥厚期间的变化以及疾病发生时核小体定位的改变。这些问题将在临床相关的压力负荷引起的心脏肥厚和衰竭小鼠模型中进行探讨。该项目的长期目标是整合这些概念，以了解细胞核蛋白质组成的变化如何影响核小体，改变核小体的组成和翻译后修饰，从而改变整个基因组的染色质结构。我们的统一假设是，肥厚性刺激调动了一个蛋白质网络，改变了正常发育过程中发生的心脏特异性染色质包装，使心肌细胞恢复到更像胎儿的状态，从而导致心力衰竭。该应用程序利用最先进的蛋白质组学和下一代DNA测序技术，从概念上推进我们对心力衰竭的理解。这项应用的主要优势在于创新——我们提供了一个新的假设，由强有力的初步数据支持，解释了心力衰竭期间心脏表型是如何重新编程的。我们的方法将揭示离散的分子机制，而且，它有可能为心脏蛋白质组如何影响基因组以调节染色质结构从而调节心脏表型提供范式改变的见解。从这项工作中获得的见解与心力衰竭的公共卫生问题直接相关。这些研究将绘制核蛋白质组，并辨别核小体定位在心脏表型中的作用。这些知识将为基因组如何与疾病重新编程提供机制基础，并有助于建立新的治疗范例。

DESCRIPTION (provided by applicant): Heart failure is a progressive syndrome for which novel mechanistic insights are needed. Cardiac hypertrophy is known to involve activation of a fetal gene program that alters myocyte function. Recent studies from the non-cardiac field have made genome-wide analysis of nucleosome positioning and chromatin structure technically feasible. We reason that well-orchestrated chromatin remodeling events must exist to facilitate cardiac gene expression and propose that diseases like heart failure involve deranged chromatin structure at the genomic scale. The short term goal of this work is to understand the totality of proteins in the nucleus, the changes in these proteins during cardiac hypertrophy and the alterations in nucleosome positioning that occur with disease. These questions will be pursued in a clinically-relevant mouse model of pressure overload-induced cardiac hypertrophy and failure. The long term goal of this project is to integrate these concepts to understand how the changing protein makeup of the nucleus impinges on nucleosomes to alter their composition and post-translational modification leading to modified chromatin structure across the genome. Our unifying hypothesis is that hypertrophic stimuli mobilize a protein network that alters the cardiac- specific chromatin packaging that occurs during normal development, reverting the myocyte to a more fetal- like state and causing heart failure. This application leverages state-of-the-art proteomic and next generation DNA sequencing technology to conceptually advance our understanding of heart failure. The major strength of this application is innovation-we provide a novel hypothesis, supported by strong preliminary data, explaining how cardiac phenotype is reprogrammed during heart failure. Our approach will reveal discrete molecular mechanisms, but moreover, it has the potential to provide paradigm changing insights into how the cardiac proteome impinges on the genome to regulate chromatin structure and thereby cardiac phenotype. The insights gained from this work have direct relevance to the public health problem of heart failure. These studies will map the nuclear proteome and discern the role of nucleosome positioning in cardiac phenotype. This knowledge will provide a mechanistic basis for how the genome is reprogrammed with disease and help establish new paradigms for therapy. PUBLIC HEALTH RELEVANCE: Heart failure is a deadly syndrome for which novel mechanistic insights are desperately needed. We hypothesize that changes in proteins interacting with DNA during disease fundamentally alter the higher order structure of DNA by affecting positioning and modifications of chromatin structural proteins. These studies will provide the first insights into dynamics of chromatin structure in the heart and have the potential to establish a new paradigm for how the genome affects the behavior of the heart during disease.