Selective Inhibitors of Pro-Ferroptotic Lipoxygenases - Next Generation Radiomitigators

促铁死亡脂氧合酶的选择性抑制剂 - 下一代放射减缓剂

• 批准号: 10408142
• 负责人: Valerian E Kagan
• 金额: $ 40.88万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-01 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10408142
• 关键词: Aggressive behavior; Anti-Inflammatory Agents; Apoptosis; Apoptotic; Arachidonate 15-Lipoxygenase; Automobile Driving; Bacteria; Biological Markers; Cardiolipins; Cell Death; Cell Respiration; Cells; Cessation of life; Complex; Data; Disease; Drug Combinations; Epithelial; Epithelial Cells; Exposure to; Face; Failure; Fatty Acids; Functional disorder; Grant; Hematopoietic; Hemeproteins; Imidazole; Immune; Immunosuppression; In Vitro; Inflammation; Inflammatory; Injury; Ionizing radiation; Knockout Mice; Lipids; Lipoxygenase; Mitochondria; Molecular; Mus; Necrosis; Nuclear Accidents; Occupational Exposure; Organ; Oxidation-Reduction; Pathway interactions; Peroxidases; Pharmacotherapy; Phosphatidylethanolamine; Phosphatidylethanolamine Binding Protein; Phospholipids; Plasma; Production; Pseudomonas aeruginosa; Radiation; Radiation Injuries; Radiation Tolerance; Radiation therapy; Reaction; Resistance; Role; Scaffolding Protein; Signal Transduction; Sterility; System; Terrorism; Testing; Theft; Time; Tissues; Whole-Body Irradiation; base; catalyst; cytochrome c; cytokine; design; gastrointestinal; gastrointestinal epithelium; immunogenic; in vivo; inflammatory milieu; inhibitor; intestinal epithelium; lipid mediator; lipidomics; macrophage; microbiome components; mortality; neutrophil; new therapeutic target; next generation; novel; oxidation; pathogenic bacteria; programs; protein biomarkers; radiation mitigation; radiation mitigator; response; therapeutic target

In spite of the serious threats of intentional or accidental exposures to radiation, molecular mechanisms of injury after total body irradiation (TBI) are not completely clear, hence radiomitigative approaches remain insufficient. Our discoveries of oxygenated cardiolipins (CLs) as required stages of TBI apoptosis have already resulted in mitochondria-targeted GS-nitroxides and imidazole-substituted fatty acids as anti-apoptotic radiomitigators. Similarly, deciphering the TBI ferroptotic signaling by hydroperoxy-phosphatidylethanolamines (HOO-PEs) produced by 15- lipoxygenases (15LOX) complexes with phosphatidylethanolamine-binding protein 1 (15-LOX/PEBP1) guides us to new inhibitors as novel radiomitigators. Our demonstration of “theft- ferroptosis” by a bacterial pathogen, Pseudomonas aeruginosa, utilizing its 15-LOX (pLoxA) (12) to trigger ferroptosis of the host (epithelial) cells indicates that TBI induced non-sterile inflammation may be also therapeutically targeted. Our central hypothesis is that radiation triggered responses engage several types of programmed necrotic death, particularly ferroptosis, in GI epithelial cells and the major innate immune cells, neutrophils and macrophages, evolving over time and driving necro-inflammatory vs pro-resolving apoptotic responses during sterile and non-sterile inflammation and culminating in multiple organ dysfunction and mortality. This sets the stage for a principally new understanding of the TBI mechanisms and leads to a new harmonized radiomitigation strategy of time- and mechanism-specific targeting of the leading cell death pathways. Our hypothesis will be tested as follows: Aim 1: By employing Redox Lipidomics identify specific oxygenated phospholipid signatures of the major death programs in epithelial cells, neutrophils and macrophages of the GI of irradiated mice at different stages of sterile and non-sterile necro-inflammation. These newly discovered TBI lipid biomarkers will be related to: i) specific protein markers of cell death, ii) major pro- and anti-inflammatory lipid mediators, iii) cytokines, and iv) breach of the epithelial barrier and immunosuppression. Aim 2: Explore molecular mechanisms of sensitivity/resistance to ferroptosis of macrophages and neutrophils polarized to M1 (N1) and M2 (N2) states in response to pro-/anti-inflammatory conditions and expression of 15LOX and iNOS/NO• system in vitro and TBI induced ferroptosis in vivo. We will employ 15LOX and iNOS KO mice and also quantitatively assess the role of P. aeruginosa and its pLoxA in gut ferroptosis and radiosensitivity of mice to TBI. Aim 3: Design new selective inhibitors of pro-ferroptotic catalytic activity of mammalian 15LOX as well as prokaryotic pLoxA of P. aeruginosa and test them as anti-ferroptotic radiomitigators during sterile and non-sterile stages of TBI radiation disease. Overall, this project is based on an entirely new concept that abandons the search for a single “silver-bullet” radiomitigator and includes a harmonized combination of several mitigators controlling TBI triggered aberrant reactions in time- and mechanism-dependent manner.

尽管有意或无意暴露于辐射具有严重威胁，但术后损伤的分子机制 全身照射（TBI）尚不完全清楚，因此我们的放射缓解方法仍然不足。 含氧心磷脂（CL）作为 TBI 细胞凋亡所需阶段的发现已经导致 线粒体靶向的 GS-硝基氧和咪唑取代的脂肪酸作为抗凋亡放射缓解剂。 破译 15- 产生的氢过氧磷脂酰乙醇胺 (HOO-PE) 的 TBI 铁死亡信号传导 脂氧合酶 (15LOX) 与磷脂酰乙醇胺结合蛋白 1 (15-LOX/PEBP1) 的复合物引导我们 新的抑制剂作为新型放射缓解剂，我们展示了细菌病原体的“盗窃铁死亡”， 铜绿假单胞菌利用其 15-LOX (pLoxA) (12) 触发宿主（上皮）细胞的铁死亡表明 TBI 引起的非无菌性炎症也可能成为治疗目标。我们的中心假设是辐射。 触发的反应涉及胃肠道上皮细胞中几种类型的程序性坏死性死亡，特别是铁死亡 以及主要的先天免疫细胞、中性粒细胞和巨噬细胞，随着时间的推移而进化并驱动坏死性炎症 与无菌和非无菌炎症期间促凋亡反应的对比，并在多个器官中达到顶峰 这为对 TBI 机制的新认识奠定了基础，并导致 一种新的协调放射缓解策略，针对主要细胞死亡进行时间和机制特异性靶向 我们的假设将进行如下检验： 目标 1：通过采用氧化还原脂质组学来识别特定的途径。 上皮细胞、中性粒细胞和巨噬细胞主要死亡程序的氧化磷脂特征 受辐射小鼠的胃肠道在无菌和非无菌坏死性炎症的不同阶段。 脂质生物标志物将与：i) 细胞死亡的特定蛋白质标志物，ii) 主要促炎和抗炎脂质相关 介体，iii) 细胞因子，以及 iv) 破坏上皮屏障和免疫抑制 目标 2：探索分子机制。 极化为 M1 (N1) 和 M2 (N2) 的巨噬细胞和中性粒细胞对铁死亡的敏感性/抵抗机制 体外对促炎/抗炎条件以及 15LOX 和 iNOS/NO• 系统表达的反应状态 我们将采用 15LOX 和 iNOS KO 小鼠，并定量评估 TBI 诱导的铁死亡的作用。 铜绿假单胞菌及其 pLoxA 在小鼠肠道铁死亡和 TBI 放射敏感性中的作用 目标 3：设计新的选择性目标。 哺乳动物 15LOX 以及铜绿假单胞菌原核 pLoxA 的促铁死亡催化活性抑制剂 在 TBI 辐射疾病的无菌和非无菌阶段测试它们作为抗铁焦亡放射缓解剂。 该项目基于一个全新的概念，放弃寻找单一的“银弹”放射缓解剂， 包括多种缓解剂的协调组合，控制 TBI 及时触发的异常反应 机制依赖的方式。