Role of the mitochondrial LonP1 in myocardial ischemia and reperfusion injury protection

线粒体LonP1在心肌缺血再灌注损伤保护中的作用

基本信息

批准号：
10446477
负责人：
Venkatesh Sundararajan
金额：
$ 38万
依托单位：
WEST VIRGINIA UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-06-10 至 2027-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10446477
关键词：
Acetylation Acute Animals Antioxidants Attenuated Bioenergetics Cardiac Cardiac Myocytes Cause of Death Cell Culture Techniques Cell Death Cellular biology Cessation of life Chronic Clinical Complex Data Dose Down-Regulation Electron Transport Event Failure Fibrosis Free Radicals Gel Generations Glycyrrhetinic Acid Goals Heart Heart Injuries Heart failure Histologic Homeostasis Hypoxia In Vitro Infarction Infiltration Inflammatory Intervention Ischemia Ischemic Preconditioning Knock-out Knockout Mice Mediating Mediator of activation protein Mitochondria Mitochondrial Proteins Molecular Molecular Biology Mus Muscle Cells Myocardial Myocardial Infarction Myocardial Ischemia Outcome Oxidative Stress Patients Peptide Hydrolases Physiological Production Proteomics Publishing Quality Control Reactive Oxygen Species Regulation Reperfusion Injury Reperfusion Therapy Reporting Role Signal Transduction Site Superoxides Techniques Testing Therapeutic Tissues Transgenic Organisms United States Work base biological adaptation to stress cardioprotection effective therapy heart function high throughput screening improved in vivo inhibitor mouse model mutant myocardial injury novel novel therapeutics overexpression oxidative damage prevent proteostasis small molecule therapeutic evaluation tool

项目摘要

PROJECT SUMMARY Ischemia-reperfusion (IR) injury is a significant challenge in treating myocardial infarction (MI), the leading cause of death in the United States. Mitochondrial reactive oxygen species (mtROS) generated by electron transport chain (ETC) Complex-I are the principal mediators of IR injury. Excess mtROS generated during early IR triggers vicious cycles of free radical production promoting cardiomyocyte death. Therefore, understanding the early molecular events of reperfusion will provide new targets for developing novel interventions for limiting cardiac injury. Our published findings show that LonP1- a major mitochondrial stress response protease mitigates oxidative stress-induced damage during early IR; therefore, LonP1 could be a promising target for attenuating reperfusion injury. Our long-term goal is to leverage the mitochondrial protein quality control mechanisms of LonP1 as a pivotal point to develop therapeutic strategies for mitigating IR injury and post MI- heart failure. Our published findings show that increased LonP1 expression in the heart induced by ischemic preconditioning (IPC) or transgenic overexpression (LonTg) reduced IR injury and favors cardioprotection. Whereas, LonP1 downregulation (LONP1+/-) abrogated IPC-mediated cardioprotection. Importantly, LonTg hearts showed reduced levels of Complex-I subunits (but not Complex II-V subunit) and oxidative damage during early IR (within 30 min reperfusion) compared to NTg controls. Conversely, our additional findings show that LonP1 downregulation in cardiomyocytes upregulated Complex-I activity, increased superoxide levels, and showed early reperfusion-induced cell death activation. In addition, we have identified a small molecule activator of LonP1 that significantly reduced hypoxia-reoxygenation (H/R) induced myocyte death in a dose-dependent manner in vitro. With additional data on IR-induced acetylation of Complex-I matrix subunits and LonP1 dependent Complex-I remodeling during IR, we hypothesize that LonP1 mitigates myocardial injury by suppressing excess mtROS generation through tight regulation of Complex-I during early IR. We will test our hypothesis by the following specific aims: Aim 1 will delineate the mechanism(s) by which LonP1 modulates Complex-I levels, activity and reduces oxidative stress during IR. Aim 2 will test that LonP1 remodels Complex-I and its associated supercomplexes by degrading IR-induced post-translationally modified (PTM) Complex-I matrix subunits, thereby reduce mtROS during early IR. Aim 3 will determine the therapeutic potential of LonP1 activators in treating myocardial IR injury in vivo. By determining the molecular mechanisms of LonP1-mediated cardioprotection and the therapeutic potential of LonP1 activators, we will define the role of LonP1 in cardioprotection and develop novel therapeutic tools and strategies to mitigate IR injury.

项目概要缺血再灌注（IR）损伤是治疗心肌梗死（MI）的一个重大挑战，心肌梗死是主要的疾病美国的死因。电子产生的线粒体活性氧（mtROS）转运链 (ETC) 复合体-I 是 IR 损伤的主要介质。期间产生过量的 mtROS 早期IR会引发自由基产生的恶性循环，从而促进心肌细胞死亡。所以，了解再灌注的早期分子事件将为开发新的药物提供新的目标限制心脏损伤的干预措施。我们发表的研究结果表明，LonP1——一种主要的线粒体应激反应蛋白酶减轻早期 IR 期间氧化应激引起的损伤；因此，LonP1 可能是减轻再灌注损伤的有希望的目标。我们的长期目标是利用线粒体蛋白 LonP1 的质量控制机制是制定减轻 IR 损伤治疗策略的关键点以及 MI 后心力衰竭。我们发表的研究结果表明，心脏中 LonP1 表达增加会诱导通过缺血预适应 (IPC) 或转基因过度表达 (LonTg) 减少 IR 损伤并有利于心脏保护。然而，LonP1 下调 (LONP1+/-) 消除了 IPC 介导的心脏保护作用。重要的是，LonTg 心脏显示复合物 I 亚基水平降低（但复合物 II-V 亚基水平不降低）并且与 NTg 对照相比，早期 IR（再灌注 30 分钟内）期间的氧化损伤。相反，我们的其他研究结果表明，心肌细胞中 LonP1 的下调上调了 Complex-I 的活性，超氧化物水平增加，并显示出早期再灌注诱导的细胞死亡激活。此外，我们还有鉴定出 LonP1 的小分子激活剂，可显着减少缺氧-复氧 (H/R) 诱导的体外心肌细胞死亡呈剂量依赖性。具有有关 IR 诱导的乙酰化的附加数据 IR 期间 Complex-I 矩阵亚基和 LonP1 依赖的 Complex-I 重塑，我们假设 LonP1 通过严格调节 Complex-I 抑制过量 mtROS 生成，从而减轻心肌损伤在早期 IR 期间。我们将通过以下具体目标来检验我们的假设：目标 1 将描述 LonP1 调节 Complex-I 水平、活性并减少 IR 期间氧化应激的机制。目标 2 将测试 LonP1 通过降解 IR 诱导的复合物-I 及其相关超复合物来重塑翻译后修饰 (PTM) Complex-I 基质亚基，从而减少早期 IR 期间的 mtROS。目标 3 将确定 LonP1 激活剂在体内治疗心肌 IR 损伤中的治疗潜力。经过确定 LonP1 介导的心脏保护的分子机制及其治疗潜力 LonP1激活剂，我们将定义LonP1在心脏保护中的作用并开发新型治疗工具和减轻IR损伤的策略。