Role of Protein Acetylation in Ncx1 Expression

蛋白质乙酰化在 Ncx1 表达中的作用

• 批准号: 8241023
• 负责人: Donald R. Menick
• 金额: $ 36.51万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-04-20 至 2013-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8241023
• 关键词: Acetylation; Adult; Affect; Arrhythmia; Binding Sites; Blood; Calcium; Cardiac; Cardiac Myocytes; Cardiovascular Diseases; Cause of Death; Complex; Congestive Heart Failure; Data; Deacetylation; Depressed mood; Deterioration; Disease; EP300 gene; Event; Failure; Figs - dietary; Financial compensation; Functional disorder; Gene Expression; Gene Expression Regulation; Gene Proteins; Genes; Genetic Transcription; HDAC1 gene; HDAC2 gene; HDAC5 gene; Health; Heart; Heart Hypertrophy; Heart failure; Histone Deacetylation; Histones; Hypertrophy; Individual; Knockout Mice; Malignant Neoplasms; Mediating; Metabolic; Metabolism; Modeling; Molecular; Mus; Myocardial; Myocardial Contraction; Myosin Heavy Chains; Nerve Degeneration; Nuclear; Nuclear Proteins; Pathogenesis; Physiological; Physiology; Play; Population; Protein Acetylation; Proteins; Pump; Recruitment Activity; Regulation; Regulator Genes; Research; Rheumatoid Arthritis; Role; Signal Transduction; Stimulus; Testing; Therapeutic; Transcription Coactivator; Transcriptional Activation; United States; Up-Regulation; Ventricular Tachycardia; Western World; Work; cell growth regulation; clinically relevant; combinatorial; histone acetyltransferase; improved; in vivo; in vivo Model; inhibitor/antagonist; insight; interest; meetings; novel; outcome forecast; pressure; prevent; programs; promoter; protein function; research study; response; transcription factor

DESCRIPTION (provided by applicant): Congestive heart failure is a complex disorder in which the heart is unable to pump a sufficient quantity of blood to meet the metabolic needs of the individual. It is the leading cause of death in the Western world with approximately 5,000,000 people (2-3% of the population) affected with this disease in the United States. Heart failure is a progressive disorder with a very poor prognosis. The factors that contribute to heart failure and drive its progress are the focus of our research program. At the molecular level, hypertrophic signals mediate change in transcriptional activation causing a change in gene expression. This programmatic change in gene expression negatively impacts calcium handling, contractile function, and metabolism. The Na+-Ca2+ exchanger (Ncx1) is one of the genes whose change in expression directly impacts cardiac function and physiology. Upregulation of Ncx1 directly results in depressed SR Ca2+ stores, impaired systolic function, and a greater potential for delayed after depolarizations (DADs), with subsequent ventricular tachycardia. Inhibition of exchanger activity or suppression of exchanger upregulation is expected to limit arrhythmias and potentially improve contractile function. In recent years, studies have shown that acetylation and deacetylation of cystolic and nuclear proteins play an important regulatory role in mediating the rapid and long-term changes in gene expression in response to pathophysiological stimuli and that acetylation imbalance can play an important role in cardiovascular disease. In this application, we will examine the role that histone deacetylases (HDAC) have in the regulation of Ncx1. Our findings reveal a unique role for HDAC1/2/5 as required for transcriptional activation of Ncx1 in the adult heart and provide a possible molecular explanation for the cardioprotective actions of HDAC inhibitors. The preliminary data support our hypothesis that the HDAC1/2/5 complex deacetylates Nkx2.5 leading to the recruitment of p300 and upregulation of the Ncx1 promoter. Experiments in Aim 1 will identify the acetylated residues and test how acetylation affects Nkx2.5 interaction with p300 and Ncx1 expression. In Aim 2 we will use ChIP and re-ChIP to test our hypothesis by examining the chronological sequence of events that occur during Ncx1 transcriptional upregulation and in Aim 3 investigate the clinical relevance and requirement of HDAC5/9 in vivo. Our long-term objectives are to provide insight into the diverse mechanisms by which HDACs regulate cardiac gene expression and improve our overall understanding regarding how the acetylation state of nuclear factors affect transcription. This work will contribute to our understanding of the role HDACs play in the regulation of cellular events and gene expression in physiology and pathophysiology of the heart. These studies will have the potential of demonstrating the therapeutic potential of HDAC inhibitors in preserving systolic function in cardiac hypertrophy. PUBLIC HEALTH RELEVANCE: Congestive heart failure is the leading cause of death in the United States. Calcium, which is critical for heart contraction is mis-regulated in the failing heart. We have found that one of the proteins regulating cardiac calcium is upregulation in cardiac hypertrophy and failure. We have found that a regulator of gene expression prevents the upregulation of the exchanger in a hypertrophic heart.

描述（由申请人提供）：充血性心力衰竭是一种复杂的疾病，其中心脏无法泵送足够量的血液以满足个体的代谢需求。它是西方世界死亡的主要原因，在美国约有5，000，000人（占人口的2-3%）患有这种疾病。心力衰竭是一种预后极差的进行性疾病。导致心力衰竭并推动其进展的因素是我们研究计划的重点。在分子水平上，肥大信号介导转录激活的变化，引起基因表达的变化。这种基因表达的程序性变化对钙处理、收缩功能和代谢产生负面影响。Na+-Ca 2+交换器（Ncx 1）是其表达变化直接影响心脏功能和生理的基因之一。Ncx 1的上调直接导致SR Ca 2+储存降低，收缩功能受损，延迟后除极（DAD）的可能性更大，随后发生室性心动过速。预期抑制交换活性或抑制交换上调可限制心律失常并可能改善收缩功能。近年来的研究表明，细胞核蛋白和核蛋白的乙酰化和去乙酰化在介导病理生理刺激引起的基因表达的快速和长期变化中起着重要的调节作用，乙酰化失衡在心血管疾病中可能发挥重要作用。在本申请中，我们将研究组蛋白脱乙酰酶（HDAC）在Ncx 1调控中的作用。我们的研究结果揭示了HDAC 1/2/5在成年心脏中Ncx 1转录激活所需的独特作用，并为HDAC抑制剂的心脏保护作用提供了可能的分子解释。初步的数据支持我们的假设，HDAC 1/2/5复合物脱乙酰化Nkx2.5导致募集p300和上调Ncx 1启动子。目的1中的实验将鉴定乙酰化残基并测试乙酰化如何影响Nkx2.5与p300和Ncx 1表达的相互作用。在目标2中，我们将使用ChIP和re-ChIP通过检查Ncx 1转录上调期间发生的事件的时间顺序来测试我们的假设，并在目标3中研究HDAC 5/9在体内的临床相关性和要求。我们的长期目标是深入了解HDAC调节心脏基因表达的不同机制，并提高我们对核因子乙酰化状态如何影响转录的整体理解。这项工作将有助于我们了解HDACs在心脏生理和病理生理中的细胞事件和基因表达调控中的作用。这些研究将有可能证明HDAC抑制剂在保持心脏肥大的收缩功能方面的治疗潜力。公共卫生相关性：充血性心力衰竭是美国的主要死亡原因。钙，这是心脏收缩的关键是在衰竭的心脏失调。我们已经发现，调节心脏钙的蛋白质之一是在心肌肥厚和衰竭中上调。我们已经发现，基因表达的调节器阻止了肥厚心脏中交换器的上调。