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：
10640920
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/10640920
关键词：
Acetylation Acute Animals Antioxidants Bioenergetics Cardiac Cardiac Myocytes Cause of Death Cell Culture Techniques Cell Death Cell Death Induction 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 Heterozygote Histologic Homeostasis Hypoxia In Vitro Infarction Inflammatory Infiltrate Intervention Ischemia Ischemic Preconditioning Knock-out Knockout Mice Mediating Mediator Mitochondria Mitochondrial Proteins Modeling Molecular Molecular Biology Mus Muscle Cells Myocardial Myocardial Infarction Myocardial Ischemia Myocardial Reperfusion Injury Outcome Oxidative Stress Oxidative Stress Induction Patients Peptide Hydrolases Physiological Production Proteomics Publishing Quality Control Reactive Oxygen Species Regulation Reperfusion Injury Reperfusion Therapy Reporting Role Signal Transduction Site Superoxides Techniques Terpenes Testing Therapeutic Tissues Transgenic Organisms United States Work biological adaptation to stress cardioprotection effective therapy heart function high throughput screening improved in vivo inhibitor ischemic injury 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.

项目摘要缺血 - 再灌注（IR）损伤是治疗心肌梗塞（MI）的重大挑战，美国死亡原因。电子产生的线粒体活性氧（MTROS） transport chain (ETC) Complex-I are the principal mediators of IR injury.在早期的IR触发了自由基生产的恶性周期，促进心肌细胞死亡。所以，了解再灌注的早期分子事件将为发展新颖的目标提供新的目标限制心脏损伤的干预措施。我们发表的发现表明，LONP1-主要的线粒体压力反应蛋白酶减轻IR早期氧化应激诱导的损伤；因此，LONP1可能是衰减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治疗策略来减轻IR损伤的关键点并发出微弱的心力衰竭。我们已发表的发现表明，诱发心脏中LONP1的表达增加 by ischemic preconditioning (IPC) or transgenic overexpression (LonTg) reduced IR injury and favors 心脏保护。而LONP1下调（LONP1 +/-）废除了IPC介导的心脏保护区。重要的是，Lontg心脏表现出降低的复合体亚基（但不是复杂的II-V亚基）和与NTG对照相比，IR早期（30分钟再灌注）期间的氧化损伤。相反，我们的其他发现表明，心肌细胞中的LONP1下调上调复合物I活性，升高超氧化物水平，并显示早期再灌注诱导的细胞死亡激活。 In addition, we have 确定了LONP1的小分子活化剂，该激活剂显着降低了低氧抗氧（H/R）诱导的在体外以剂量依赖性方式的心肌细胞死亡。还有有关IR诱导的乙酰化的其他数据复合物I矩阵亚基和LONP1依赖性复合物I重塑，我们假设LONP1 通过严格调节复合物I来抑制过量的MTROS来减轻心肌损伤在IR早期。我们将通过以下特定目的检验我们的假设：AIM 1将描述 LONP1调节复合物I水平，活性并降低IR期间的氧化应激的机制。 AIM 2将通过降解IR诱导的翻译后修饰（PTM）复合物I矩阵亚基，从而减少IR早期的MTROS。目标3 将确定LONP1激活剂在体内治疗心肌损伤中的治疗潜力。经过确定LONP1介导的心脏保护的分子机制和 LONP1激活剂，我们将定义LONP1在心脏保护中的作用，并开发新颖的治疗工具和减轻IR损伤的策略。