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.

抽象的 冠心病是全世界死亡和发病的主要原因 心肌梗塞（MI）/缺血再灌注损伤（IRI）的有害影响。 MI/IRI 的机制 尚不完全清楚，因此没有有效的治疗策略；目前治疗 减轻心脏损伤的方法主要集中于恢复冠状动脉灌注，但不限于 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，具体取决于 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、铁死亡。铁死亡是由于过度氧合引起的 磷脂（PL）的减少伴随着硒蛋白谷胱甘肽过氧化物酶的能力不足 4 (GPX4) 消除氧化的 PL，特别是磷脂酰乙醇胺 (PEox)，但代价是 还原型谷胱甘肽（GSH）。我们最近鉴定并量化了促铁死亡的 PEox 物种 通过最先进的技术对心肌细胞中的 RSL3（GPX4 抑制剂，铁死亡诱导剂）做出反应。在 此外，我们的初步研究揭示了线粒体中铁死亡 PEox 物质的积累 从暴露于整体 IRI 的心脏以及受到 RSL3 攻击的心肌细胞中分离出来。我们 提出线粒体通过两个主要的 GSH-参与 MI/IRI 诱导的铁死亡信号传导 依赖机制：i) ETC 和 TCA 循环通过 IR 诱导线粒体 ROS 生成，消耗 GSH， 因此，使 GSH/GPX4 系统失活，并且 ii) 由于抑制 由于谷氨酸和半胱氨酸水平较低，线粒体中的谷氨酰胺分解会抑制谷胱甘肽的合成。 因此，该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例 铁死亡。我们的中心假设是线粒体参与心脏 IRI 诱导的铁死亡 通过降低 GPX4 活性和无法控制促铁死亡 PEox 物质的积累。 此外，我们认为主要的细胞死亡机制在 MI/IRI 后具有不同的影响，具体取决于 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来区分 细胞凋亡、铁死亡、坏死性凋亡和细胞焦亡对 MI/IRI 后的影响。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，以及 ii) 通过强效还原剂硫辛酸/二氢硫辛酸 (LA/DHLA) 补充 GSH 池。具体目标 该项目将 (i) 确定 IRI 期间铁死亡对心功能障碍的相对影响，(ii) 探索心肌细胞中线粒体介导的铁死亡信号传导的分子机制，以及（iii） 检查新型铁死亡抑制剂对心脏 IRI 的有效性。该项目将建立 与其他主要细胞死亡机制相比，铁死亡对 MI/IRI 诱导的贡献 心脏功能障碍，并发现新的线粒体介导的铁死亡信号传导机制，这将 导致治疗心脏 IRI 的创新治疗策略。