Nrf2 Protein Translation for Protection Against Tissue Injury

项目摘要/摘要： 心肌梗死(MI)是一种紧急状态，需要立即进行医疗干预。冠状动脉 搭桥手术(CABG)或血管成形术已经成为标准但有效的治疗方法。 几乎所有CABG患者术后都检测到心肌细胞死亡的生物标志物，约30% 血管成形术患者。细胞死亡在心肌中仍然可检测到，即使患者似乎有 从心肌梗塞中恢复过来。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 开发新的治疗方法以减少心脏损伤。缺血或再灌流引起的氧化应激 和/或大手术，通常会导致蛋白质合成受抑。我们发现Nrf2基因可以逃逸 这种普遍的抑制和选择性地翻译。发现Nrf2基因的5‘非翻译区可以募集La自身抗原 用于核糖体结合和从头开始的Nrf2蛋白翻译。NRF2最为人所知的是作为一种转录因子 调节抗氧化和解毒基因的表达。我们发现Nrf2可以保护 线粒体通过物理结合防止氧化损伤。我们建议利用高分辨率的LC-MS/MS 基于蛋白质组学的新型Nrf2诱导剂与转基因动物的结合，以及体外和体内 用实验模型检验Nrf2蛋白升高在心肌细胞保存中的重要作用 线粒体与心肌损伤的保护。目的1研究一种新的Nrf2诱导途径 通过从头翻译Nrf2蛋白。La和核糖体蛋白复合体中的成分将被发现 为了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Nrf2在细胞中的参与，揭示Nrf2介导的细胞保护的新机制。 维持线粒体的完整性和新陈代谢。Nrf2蛋白的结构域与物理相互作用 将确定线粒体或线粒体外膜蛋白，以测试其在 线粒体的完整性、新陈代谢和有丝分裂。AIM 3将为NRF2作为先导提供临床前证据 用来保护心脏。新的Nrf2蛋白翻译对于心脏保护的重要性将是 演示了使用针对La自身抗原的siRNA。收缩心肌细胞将被确立为 治疗指数合适的Nrf2诱导剂的筛选。线粒体保存与心脏保护 这些化合物的效果将以过量表达转基因基因的Nrf2作为阳性对照进行测试。我们有 为项目的成功积累了大量的数据。完成拟议的 这项工作不仅将为基础科学问题提供必要的答案，而且还将展示一种新的 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.