Mitochondria-mediated mechanisms of ferroptosis in response to cardiac ischemia-reperfusion injury

线粒体介导的铁死亡响应心脏缺血再灌注损伤的机制

• 批准号: 10681495
• 负责人: Sabzali Javadov
• 金额: $ 15万
• 依托单位: UNIVERSITY OF PUERTO RICO MED SCIENCES
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10681495
• 关键词: Accounting; Apoptosis; Autophagocytosis; Biology; Cardiac; Cardiac Myocytes; Cell Death; Cells; Cessation of life; Citric Acid Cycle; Complex; Coronary heart disease; Cysteine; Cystine; Data; Dependence; Development; Endoplasmic Reticulum; Exposure to; Gases; Generations; Glutamates; Heart; Image; Imaging Techniques; Ions; Iron; Ischemia; Lipoxygenase; Maps; Mediating; Mitochondria; Modeling; Molecular; Morbidity - disease rate; Myocardial Infarction; Myocardial Ischemia; Myocardial Reperfusion Injury; Myocardial dysfunction; Myocardium; Necrosis; Oxidation-Reduction; Oxidative Stress; Oxidoreductase; Pathogenesis; Phosphatidylethanolamine; Phospholipids; Play; Polyunsaturated Fatty Acids; Prevention; Process; Production; Reduced Glutathione; Reducing Agents; Reperfusion Injury; Reperfusion Therapy; Resolution; Role; Severities; Severity of illness; Signal Transduction; Spectrometry, Mass, Secondary Ion; System; Techniques; Therapeutic; Therapeutic Intervention; antiporter; cardioprotection; comparative; coronary perfusion; dihydrolipoic acid; effectiveness evaluation; glutathione peroxidase; heart damage; in vivo; inhibitor; innovation; ischemic injury; mass spectrometric imaging; mortality; novel; novel therapeutic intervention; oxidation; prevent; response; restoration; selenoprotein; specific biomarkers; therapeutically effective; treatment strategy

ABSTRACT Coronary heart disease is the leading cause of mortality and morbidity worldwide that occurs due to the detrimental effects of myocardial infarction (MI)/ischemia-reperfusion injury (IRI). Mechanisms of MI/IRI are not completely clear, and hence, there are no effective therapeutic strategies; current therapeutic approaches to mitigate heart damage mostly focus on restoring coronary perfusion but not limiting reperfusion injury. Multiple forms of cell death occur at different stages of post-MI/IRI depending on the severity of the disease. This project will elucidate the regulatory mechanisms of a recently discovered iron- dependent programmed cell death, ferroptosis, in cardiac IRI. Ferroptosis arises via excessive oxygenation of phospholipids (PLs) accompanied by the insufficient capacity of a selenoprotein glutathione peroxidase 4 (GPX4) to eliminate oxidized PLs, particularly, phosphatidylethanolamine (PEox) at the expense of reduced glutathione (GSH). We have recently identified and quantified pro-ferroptotic PEox species in response to RSL3 (GPX4 inhibitor, ferroptosis inducer) in cardiomyocytes by a state-of-art technique. In addition, our preliminary studies revealed accumulation of ferroptotic PEox species in mitochondria isolated from hearts exposed to global IRI as well as from cardiomyocytes challenged with RSL3. We propose that mitochondria participate in MI/IRI-induced ferroptotic signaling through two major GSH- dependent mechanisms: i) IR-induced mitochondrial ROS generation by ETC and TCA cycle deplete GSH, and hence, inactivate the GSH/GPX4 system, and ii) glutamate deficiency due to inhibition of glutaminolysis in mitochondria inhibits GSH synthesis as a result of low glutamate and cysteine levels. Thus, this project will explore a novel paradigm by investigating the role of mitochondria in cardiac IRI ferroptosis. Our central hypothesis is that mitochondria are engaged in ferroptosis induced by cardiac IRI through diminishing GPX4 activity and inability to control the accumulation of pro-ferroptotic PEox species. Also, we propose that major cell death mechanisms have different impacts during post-MI/IRI depending on the severity and duration of post-MI/IRI. Hence, we will evaluate specific biomarkers to distinguish the contributions of apoptosis, ferroptosis, necroptosis, and pyroptosis to post-MI/IRI. Two approaches will be employed to mitigate cardiac IRI via i) specific suppression of mtROS production/GSH depletion, and ii) replenishment of the GSH pool by a potent reductant lipoic/dihydrolipoic acid (LA/DHLA). Specific Aims of the project will (i) determine comparative contributions of ferroptosis to cardiac dysfunction during IRI, (ii) explore molecular mechanisms of mitochondria-mediated ferroptotic signaling in cardiac cells, and (iii) examine the effectiveness of novel inhibitors of ferroptosis against cardiac IRI. The project will establish the contribution of ferroptosis, in comparison with other major cell death mechanisms, to MI/IRI-induced cardiac dysfunction, and discover new mitochondria-mediated mechanisms of ferroptotic signaling that will lead to innovative therapeutic strategies for the treatment of cardiac IRI.

摘要 冠状动脉心脏病是世界范围内死亡率和发病率的主要原因， 心肌梗死（MI）/缺血-再灌注损伤（IRI）的有害作用。MI/IRI的机制 还不完全清楚，因此，没有有效的治疗策略;目前的治疗方法 减轻心脏损伤的方法主要集中在恢复冠状动脉灌注， 再灌注损伤多种形式的细胞死亡发生在MI/IRI后的不同阶段，这取决于 疾病的严重程度。该项目将阐明最近发现的铁的调节机制- 心脏IRI中的依赖性程序性细胞死亡，铁凋亡。过度氧合引起的铁凋亡 磷脂（PLs）伴随硒蛋白谷胱甘肽过氧化物酶能力不足 4（GPX 4）以消除氧化的PL，特别是磷脂酰乙醇胺（PEox）， 还原型谷胱甘肽（GSH）。我们最近已经确定和量化的pro-ferroptotic PEox物种， 通过最先进的技术在心肌细胞中对RSL 3（GPX 4抑制剂，铁凋亡诱导剂）的反应。在 此外，我们的初步研究表明，铁中毒PEox物种在线粒体中的积累 分离自暴露于整体IRI的心脏以及用RSL 3攻击的心肌细胞。我们 提出线粒体通过两个主要的GSH- 依赖性机制：i）通过ETC和TCA循环消耗GSH的IR诱导的线粒体ROS产生， 因此，抑制GSH/GPX 4系统，和ii）由于抑制 由于谷氨酸和半胱氨酸水平较低，线粒体中的谷氨酸胺解抑制GSH合成。 因此，本项目将通过研究线粒体在心脏IRI中的作用来探索一种新的范式 铁性下垂我们的中心假设是线粒体参与心脏IRI诱导的铁凋亡 通过降低GPX 4活性和不能控制促铁蛋白酶PEox物质的积累。 此外，我们提出，在MI/IRI后，主要的细胞死亡机制有不同的影响， MI/IRI后的严重程度和持续时间。因此，我们将评估特定的生物标志物，以区分 凋亡、铁凋亡、坏死凋亡和焦凋亡对MI/IRI后的作用。两种方法将是 用于通过i）特异性抑制mtROS产生/GSH消耗来减轻心脏IRI，和ii） 通过有效的还原剂硫辛酸/二氢硫辛酸（LA/DHLA）补充GSH库。具体目标 该项目将（i）确定IRI期间铁缺乏症对心功能障碍的比较贡献，（ii） 探索心脏细胞中的神经氨酸介导的铁凋亡信号传导的分子机制，以及（iii） 检查新型铁凋亡抑制剂对心脏IRI的有效性。该项目将建立 与其他主要的细胞死亡机制相比，铁凋亡对MI/IR诱导的细胞凋亡的贡献， 心功能不全，并发现新的神经元介导的铁凋亡信号机制， 导致心脏IRI治疗的创新治疗策略。