Translational Control of Oxidative Stress in Myocardial Infarction

心肌梗死中氧化应激的转化控制

• 批准号: 7658039
• 负责人: QIN M CHEN
• 金额: $ 45.33万
• 依托单位: UNIVERSITY OF ARIZONA
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7658039
• 关键词: 5' Untranslated Regions; Address; Animals; Anterior Descending Coronary Artery; Antioxidants; Apoptosis; Automobile Driving; BIRC4 gene; Binding; Binding Proteins; Cardiac; Cardiac Myocytes; Characteristics; Code; Computer Simulation; Coupled; Cytoprotection; DNA; Data; Databases; Disease; Dose; Drug Metabolic Detoxication; Firefly Luciferases; GC Rich Sequence; Gene Expression; Genes; Genetic Transcription; Genomics; Grant; Heart failure; Human; In Vitro; Initiator Codon; Injury; Internal Ribosome Entry Site; Investigation; Ischemia; Knockout Mice; Knowledge; Left; Link; Measurement; Measures; Mediating; Messenger RNA; Mus; Mutate; Myocardial; Myocardial Infarction; Myocardial Ischemia; Myocardial tissue; Myocardium; NF-E2-related factor 2; Nucleotides; Organ; Oxidants; Oxidative Stress; Phase; Play; Polyribosomes; Promoter Regions; Proteins; Proteomics; RNA; RNA Probes; Rattus; Reactive Oxygen Species; Recruitment Activity; Regulation; Renilla Luciferases; Reperfusion Therapy; Reporter; Research; Response Elements; Ribonucleases; Ribosomes; Role; Set protein; Site; Staging; Stress; Stress-Induced Protein; Stretching; Structure; Structure-Activity Relationship; Technology; Testing; Tissues; Trans-Activators; Transfection; Translating; Translations; Work; artery occlusion; base; cell type; genome-wide; infancy; preconditioning; programs; protective effect; public health relevance; response; stem; transcription factor; translation assay

DESCRIPTION (provided by applicant): Ischemic reperfusion (I/R) is known to trigger an increase of reactive oxygen species in the myocardium. Although high levels of oxidants can cause damages, low doses of oxidant elicit a protective effect, such as during preconditioning induced by cycles of brief I/R. Our recent data suggest that induction of antioxidant and detoxification genes dominates the gene expression network of oxidants in cardiomyocytes. A master switch controlling the expression of these genes is the transcription factor Nrf2. We found that 2 to 4 cycles of 5 min ischemia and 5 min reperfusion cause elevation of Nrf2 protein in the myocardium. With isolated cardiomyocytes, oxidants cause rapid onset of Nrf2 protein translation. Stress generally causes global reduction of protein translation. Recent studies suggest that several genes containing an Internal Ribosomal Entry Site (IRES) in the 5' Untranslated Region (5'UTR) of mRNA can escape the general translational control and undergo stress induced protein translation. A group of IRES Trans-Acting Factors (ITAFs) appears to be critical in recruiting the ribosomes to initiate the translation of these genes. Little is known about which proteins and how they are translated when the myocardium or cardiomyocytes encounter oxidative stress. We plan to take advantage of genomic and proteomic technologies to test the hypothesis that "cycles of brief I/R cause selective increase of Nrf-2 protein in the myocardium through IRES mediated translation". The Specific Aims include 1) Test that Nrf2 protein translation occurs in the myocardium by cycles of brief I/R and mediates preconditioning induced cardiac protection; 2) Test that lack of well defined Kozak sequence and formation of stable "stems and loops" secondary structure in 5'UTR enable a battery of genes to undergo I/R induced protein translation; 3) Test that Nrf2 mRNA contains an IRES that allows rapid protein translation in cardiomyocytes following cycles of brief I/R or low dose of oxidants; 4) Test that cardiomyocytes express a unique set of ITAFs to regulate Nrf2 protein translation in response to I/R. The field of stress induced protein translation is in its stage of infancy. Although Nrf2 plays a critical role in cytoprotection among various cell types, the function and regulation of Nrf2 have not been well studied in cardiomyocytes. Studying the mechanism of protein translation under oxidative stress becomes a necessary task in understanding the transition to heart failure from adaptive response. PUBLIC HEALTH RELEVANCE: This grant proposes to study the mechanism of Nrf2 protein translation in cardiomyocytes and in the myocardium following oxidative stress.

描述（由申请人提供）：已知缺血性再灌注（I/R）会引发心肌中活性氧的增加。尽管高水平的氧化剂会导致损害，但低剂量的氧化剂会引起保护作用，例如在短暂I/R周期引起的预处理过程中。我们最近的数据表明，抗氧化剂和解毒基因的诱导主要主导心肌细胞中氧化剂的基因表达网络。控制这些基因表达的主开关是转录因子NRF2。我们发现5分钟缺血和5分钟再灌注的2至4个周期会导致心肌中NRF2蛋白的升高。在分离的心肌细胞中，氧化剂引起NRF2蛋白翻译的快速发作。应力通常会导致蛋白质翻译的全球减少。最近的研究表明，在5'未翻译区域（5'UTR）中包含内部核糖体入口位点（IRE）的几个基因可以逃脱一般的翻译控制并接受应力诱导的蛋白质翻译。一组IRES跨作用因子（ITAF）对于募集核糖体以启动这些基因的翻译至关重要。关于心肌或心肌细胞会遇到氧化应激时，几乎了解哪种蛋白质以及如何翻译它们。我们计划利用基因组和蛋白质组学技术来检验以下假设：“短暂I/R的循环通过IRES介导的翻译导致心肌中NRF-2蛋白的选择性增加”。具体目的包括1）测试NRF2蛋白的翻译发生在心肌中通过简短I/R的循环发生，并介导预处理诱导的心脏保护； 2）测试缺乏定义明确的Kozak序列和5'UTR中稳定的“茎和环”二级结构的形成，使一系列基因可以进行I/R诱导的蛋白质翻译； 3）测试NRF2 mRNA包含一个IRES，该IRE允许在短暂I/R或低剂量的氧化剂周期后进行心肌细胞快速蛋白质翻译； 4）测试心肌细胞表达了一组独特的ITAF，以响应I/R调节NRF2蛋白翻译。应激诱导的蛋白质翻译领域处于其婴儿期。尽管NRF2在各种细胞类型的细胞保护中起着至关重要的作用，但在心肌细胞中尚未对NRF2的功能和调节进行研究。研究氧化应激下蛋白质翻译的机制成为理解自适应反应过渡到心力衰竭的必要任务。公共卫生相关性：该赠款提议研究心肌细胞中NRF2蛋白翻译的机制以及在氧化应激后心肌中的机制。