Inhibition of ferroptosis after intracerebral hemorrhage

抑制脑出血后铁死亡

基本信息

批准号：
9534292
负责人：
Jian Wang
金额：
$ 20.47万
依托单位：
JOHNS HOPKINS UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-07-01 至 2020-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9534292
关键词：
Affect Aging Anabolism Animals Antioxidants Apoptosis Attention Autophagocytosis Biliverdine Binding Proteins Bipyridyl Blood Brain Brain Injuries Brain hemorrhage Carbon Monoxide Cations Cell Death Cells Cerebral hemisphere hemorrhage Clinical Trials Coenzyme A Ligases Deferoxamine Dose Edema Electrons Exhibits Extracellular Space Family member Future Glutamates Glutathione Goals Heme Hemoglobin Hippocampus (Brain)Histologic Homologous Gene Human In Vitro Injections Injury Iron Iron Chelating Agents Ischemic Stroke Lesion Lip structure Lipid Peroxidation Lipids Magnetic Resonance Imaging Measures Membrane Lipids Metabolism Mitochondria Modeling Molecular Morbidity - disease rate Morphology Mus NADPH Oxidase Necrosis Nervous System Physiology Neurologic Deficit Neurologic Dysfunctions Neurological outcome Neurons Oligodendroglia Outcome Oxygenases PTGS2 gene Parkinson Disease Pathway interactions Patients Permeability Pilot Projects Production Reactive Oxygen Species Recovery Reporting Research Response Elements Secondary to Site Slice Stroke TFRC gene Testing Therapeutic Toxic effect Transgenic Mice Transmission Electron Microscopy Validation Work aged brain cell cancer cell cerebral atrophy clinically relevant collagenase cyclooxygenase 2 experimental study functional outcomes glutathione peroxidase improved inhibitor/antagonist insight lipid peroxidation inhibitor lipophilicity molecular marker mortality mouse model neuron loss neuronal survival novel novel therapeutics overexpression preclinical study preclinical trial prevent sex small molecule therapy development white matter injury

项目摘要

Inhibition of ferroptosis after intracerebral hemorrhage Spontaneous intracerebral hemorrhage (ICH) is the stroke subtype with the highest mortality and morbidity. Because large amounts of blood are released into the extracellular space during ICH, the metabolism of hemoglobin/free heme is very important for brain recovery. Heme is degraded by heme oxygenase into iron, biliverdin, and carbon monoxide. Importantly, iron accumulation within the brain contributes to secondary brain injury after ICH. Indeed, iron toxicity contributes to collagenase-induced hemorrhagic brain injury in mice, and reducing iron accumulation with iron chelators can improve neuronal survival. Recently, ferroptosis, an iron- dependent form of non-apoptotic cell death, was identified in cancer cells and in organotypic hippocampal slice cultures after glutamate exposure. It is triggered by small molecules or by conditions that inhibit glutathione biosynthesis or glutathione peroxidase 4 (GPX4) activity. This regulated cell death is characterized by extensive iron-dependent lipid peroxidation, which can be suppressed by lipophilic antioxidant ferrostatin-1 or liproxstatin- 1. Ferroptotic cell death also has been shown to occur in brain cells. To date, it has been reported in mouse models of Parkinson disease and ICH. Whether inhibition of ferroptosis by ferrostain-1 or liproxstain-1 reduces ICH injury and improves functional outcomes in aged animals remains unknown. Therefore, this research is intended to characterize ferroptotic cell death in the context of ICH in aged animals. Our long-term goal is to limit ICH injury and improve functional outcomes. The scientific objective of this proposal is to test the hypothesis that inhibition of ferroptosis by ferrostain-1 or liproxstain-1 protects ICH brain and improves functional outcomes. We will further determine whether augmentation of GPX4 activity inhibits ferroptosis and provides cerebroprotection after ICH. In pilot studies, ferroptotoic cell death, characterized by shrunken mitochondria, was detected by transmission electron microscopy in the mouse ICH brain. Additionally, mice treated with ferrostatin-1 after ICH had better neurologic outcomes than mice treated with vehicle. A second, independent, ferroptosis inhibitor, liproxstatin-1, also exhibited marked protection against ICH injury. Together, these novel observations strongly support the premise that inhibition of ferroptosis might reduce ICH injury in aged animals. The first specific aim will determine whether suppression of iron-dependent lipid peroxidation improves histologic and functional outcomes after ICH in aged mice of both sexes. The second specific aim will determine whether overexpression of GPX4 is cerebroprotective after ICH. This study will provide novel evidence that ferroptotic cell death, in addition to other regulated cell death pathways, is prominent in the brains of aged animals with ICH. It will also provide insight into the molecular mechanism by which increased GPX4 activity prevents post-ICH ferroptosis. Work on the proposed project could render new drugs/treatments for patients with ICH. Successful validation of lipid peroxidation inhibitors in the ICH models of aged animals will provide the rationale and proof-of-concept for future preclinical and clinical trials.

抑制脑出血后铁死亡自发性脑出血（ICH）是死亡率和发病率最高的卒中亚型。由于 ICH 期间大量血液被释放到细胞外间隙，血红蛋白/游离血红素对于大脑恢复非常重要。血红素被血红素加氧酶降解为铁，胆绿素和一氧化碳。重要的是，铁在大脑内的积累有助于辅助大脑 ICH 后受伤。事实上，铁毒性会导致胶原酶诱导的小鼠出血性脑损伤，并且用铁螯合剂减少铁积累可以提高神经元的存活率。最近，铁死亡（ferroptosis）是一种铁在癌细胞和器官型海马切片中发现了非凋亡细胞死亡的依赖性形式谷氨酸暴露后的培养物。它是由小分子或抑制谷胱甘肽的条件触发的生物合成或谷胱甘肽过氧化物酶 4 (GPX4) 活性。这种受调节的细胞死亡的特点是广泛铁依赖性脂质过氧化，可被亲脂性抗氧化剂ferrostatin-1 或 liproxstatin- 抑制 1. 铁死亡也已被证明发生在脑细胞中。迄今为止，已有小鼠报道帕金森病和脑出血模型。 Ferrostain-1 或 liproxstain-1 对铁死亡的抑制是否会减少 ICH 损伤和改善老年动物的功能结果仍然未知。因此，本研究是旨在表征老年动物 ICH 背景下的铁死亡细胞死亡。我们的长期目标是限制 ICH 损伤并改善功能结果。该提案的科学目标是检验以下假设： Ferrostain-1 或 liproxstain-1 抑制铁死亡可保护 ICH 大脑并改善功能结果。我们将进一步确定 GPX4 活性的增强是否会抑制铁死亡并提供脑保护作用 ICH 后。在初步研究中，以线粒体收缩为特征的铁死亡细胞死亡是通过以下方法检测到的：小鼠 ICH 大脑的透射电子显微镜。此外，ICH后用ferrostatin-1治疗的小鼠与用媒介物治疗的小鼠相比，具有更好的神经学结果。第二种独立的铁死亡抑制剂， liproxstatin-1 也表现出对 ICH 损伤的显着保护作用。这些新颖的观察结果共同强烈地支持抑制铁死亡可能减少老年动物脑出血损伤的前提。第一个具体目标将确定抑制铁依赖性脂质过氧化是否改善组织学和功能不同性别老年小鼠 ICH 后的结果。第二个具体目标将确定是否过度表达 GPX4 在 ICH 后具有脑保护作用。这项研究将为铁死亡细胞死亡提供新的证据除了其他受调节的细胞死亡途径外，在患有脑出血的老年动物的大脑中也很突出。它还将深入了解增加的 GPX4 活性可预防 ICH 后铁死亡的分子机制。拟议项目的工作可以为脑出血患者提供新的药物/治疗方法。成功验证老年动物 ICH 模型中的脂质过氧化抑制剂将为以下研究提供基本原理和概念验证：未来的临床前和临床试验。