Nrf2 Protein Translation for Protection Against Tissue Injury

项目概要/摘要： 心肌梗死（MI）是一种需要立即医疗干预的紧急状态。冠状动脉 旁路移植（CABG）手术或血管成形术已经成为标准但有效的治疗。 在几乎所有CABG患者或约30%的CABG患者中， 血管成形术患者。即使患者表现为心肌细胞坏死， 从MI中恢复。细胞死亡的程度可以预测发生心力衰竭和其他疾病的风险。 并发症识别细胞保护基因并揭示其作用机制为以下研究铺平了道路： 开发新的疗法来减少心脏损伤。氧化应激，由于缺血或再灌注 和/或大手术，通常会导致蛋白质合成的抑制。我们发现，Nrf 2 mRNA可以逃逸， 这种普遍的抑制，并被选择性地翻译。发现Nrf 2 mRNA的5 'UTR募集La自身抗原 用于核糖体结合和从头Nrf 2蛋白翻译。Nrf 2最为人所知的是作为转录因子， 调节抗氧化和解毒基因的表达。我们发现Nrf 2可以保护 线粒体的氧化损伤的物理协会。我们建议使用高分辨率LC-MS/MS 基于蛋白质组学，新型Nrf 2诱导剂与转基因动物的组合，以及体外和体内 实验模型，以测试假设，升高的Nrf 2蛋白在保存中起着重要作用， 线粒体和保护心肌损伤。目的1探索Nrf 2诱导表达的新途径 通过从头Nrf 2蛋白质翻译。La和核糖体蛋白质复合物中的成分将被揭示出来 以了解心肌细胞在氧化或缺血应激下的翻译机制。 目的2：通过检测Nrf 2在细胞凋亡中的作用，揭示Nrf 2介导的细胞保护作用的新机制。 维持线粒体的完整性和代谢。Nrf 2蛋白的结构域与 将鉴定线粒体或线粒体外膜蛋白，用于测试在 线粒体完整性、代谢和线粒体自噬。目标3将为Nrf 2作为先导药物提供临床前证据 保护心脏Nrf 2蛋白的从头翻译对心脏保护的重要性将被 使用针对La自身抗原的siRNA证实。将建立收缩心肌细胞， 选择具有合适治疗指数的Nrf 2诱导剂。线粒体保存与心脏保护 这些化合物的效果将使用Nrf 2过表达转基因作为阳性对照进行测试。我们有 积累了大量的数据来支持项目的成功。完成拟议的 这项工作不仅将为基础科学问题提供所需的答案，而且还将提出一种新的 心脏保护类药物。

Project Summary/Abstract: Myocardial infarction (MI) is an emergency state that requires immediate medical intervention. Coronary artery bypass graft (CABG) surgery or angioplasty procedures have becoming standard but effective treatment. Biomarkers of myocardial cell death are detected postoperatively in nearly all CABG patients or about 30% of angioplasty patients. Cell death remains detectable in the myocardium even when patients appear to have recovered from MI. The degree of cell death predicts the risk of developing heart failure and other complications. Identifying cytoprotective genes and uncovering their mechanisms of action pave the way for developing new therapies to reduce cardiac injury. Oxidative stress, as a result of ischemic or reperfusion and/or major surgery, usually causes an inhibition of protein synthesis. We found that Nrf2 mRNA can escape such general inhibition and be translated selectively. 5'UTR of Nrf2 mRNA was found to recruit La autoantigen for ribosomal association and de novo Nrf2 protein translation. Nrf2 is best known as a transcription factor for regulating the expression of antioxidant and detoxification genes. We have found that Nrf2 protects mitochondria from oxidative injury by physical association. We propose to utilize high resolution LC-MS/MS based proteomics, novel Nrf2 inducers in combination with transgenic animals, and in vitro and in vivo experimental models to test the hypothesis that elevated Nrf2 protein plays an important role in preservation of mitochondria and protection against myocardial injury. Aim 1 will investigate a novel pathway of Nrf2 induction by de novo Nrf2 protein translation. Components in the La and ribosomal protein complexes will be uncovered in an effort to understand the translational machinery under oxidative or ischemic stress in cardiomyocytes. Aim 2 will reveal a novel mechanism of Nrf2 mediated cytoprotection by testing Nrf2 participation in maintenance of mitochondrial integrity and metabolism. The domain of Nrf2 protein for physical interaction with mitochondria or mitochondrial outer membrane proteins will be identified for testing the significance in mitochondrial integrity, metabolism and mitophagy. Aim 3 will provide preclinical evidence for Nrf2 as the lead for cardiac protection. The importance of de novo Nrf2 protein translation for cardiac protection will be demonstrated using siRNA against La autoantigen. Contracting cardiomyocytes will be established for selection of Nrf2 inducers with suitable therapeutic indices. Mitochondrial preservation and cardiac protective effect of these compounds will be tested using Nrf2 overexpressing transgenics as a positive control. We have accumulated a large volume of data to support the success of the project. Accomplishment of the proposed work will not only provide needed answers to basic science questions, but also present the feasibility of a new category of drugs for cardiac protection.