Oxidative lipidomics of pulmonary endothelial apoptosis in hyperoxia

高氧条件下肺内皮细胞凋亡的氧化脂质组学

• 批准号: 7515555
• 负责人: Valerian E Kagan
• 金额: $ 37.88万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-01 至 2012-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7515555
• 关键词: APAF1 gene; Accounting; Acute; Acute Lung Injury; Affect; Antibodies; Antioxidants; Apoptosis; Apoptotic; Binding; Biochemical; Biological Assay; Blood capillaries; Cardiolipins; Caspase; Catalysis; Cell Death; Cell membrane; Cells; Cessation of life; Complex; Cytosol; Data; Disease; Dose; Electron Spin Resonance Spectroscopy; Electrons; Endothelial Cells; Endothelium; Event; Experimental Models; Exposure to; Fluorescence Microscopy; Free Radicals; Functional disorder; Funding; GNAS gene; Gastrointestinal tract structure; Genetic; Hydrogen Peroxide; Hydroxylamine; Hyperoxia; In Situ; Injury; Ions; Lecithin; Link; Lipids; Lung; Maintenance; Membrane; Microscopic; Mitochondria; Modeling; Modification; Molecular; Mus; Newborn Infant; Nitric Oxide Donors; Nitrogen; Organ; Outer Mitochondrial Membrane; Oxidative Stress; Oxygen; Pathogenesis; Pathway interactions; Peroxidase; Peroxidases; Personal Satisfaction; Phagocytosis; Phosphatidylethanolamine; Phosphatidylserines; Phospholipids; Play; Process; Production; Public Health; Pulmonary Edema; Respiratory physiology; Role; Signal Transduction; Signal Transduction Pathway; Small Interfering RNA; Spectrometry, Mass, Electrospray Ionization; Structure; Surface; Syndrome; Testing; Therapeutic; Therapeutic Intervention; Time; Vesicle; Work; antibody conjugate; apoptotic protease-activating factor 1; base; capillary; cardiolipin synthase; caspase-9; cell type; cytochrome c; design; drug discovery; in vivo; inhibitor/antagonist; lung injury; macrophage; mitochondrial dysfunction; mitochondrial membrane; mortality; novel; oxidation; perilla alcohol; peroxidation; phosphatidylethanolamine; prevent; programs; research study; response

DESCRIPTION (provided by applicant): Acute lung injury (ALI), including hyperoxic lung injury, is a syndrome of great public health importance. Although the pathogenesis of ALI remains unclear, an imbalance between production and elimination of reactive oxygen and nitrogen species is well accepted as a contributing factor. Pulmonary endothelium is the locus of early structural and functional changes in hyperoxic lung injury and apoptosis of pulmonary endothelium is a contributing factor to genesis and maintenance of the injury. Nonetheless, the early molecular pathways that account for hyperoxic induced pulmonary endothelial cell apoptosis are unknown and therapies for ALI remain entirely palliative. We have recently shown that upon interaction with anionic phospholipids, particularly mitochondria-specific cardiolipin (CL), cytochrome c (cyt c) loses its tertiary structure and its peroxidase activity dramatically increases. CL-induced peroxidase activity of cyt c has been found to be important for selective CL oxidation in cells undergoing programmed death. During apoptosis, the peroxidase activity and the fraction of CL-bound cyt c markedly increase, suggesting that CL acts as a switch to regulate cyt c's mitochondrial functions. In preliminary data, using ion trap electrospray ionization mass spectrometry based lipidomics for the first time in lung, we show that selective oxidation of CL is an early event in hyperoxic lung and also occurs in simple models (e.g. LPS) of apoptosis in cultured pulmonary endothelial cells. Furthermore we have designed an antioxidant/electron scavenger (XJB-5-131; an hemigramicidin-4-amino-2,2,6,6- tetramethylpiperidine-N-oxyl) and a peroxidase-activatable nitric oxide donor (HVTP, 2- hydroxylamino-vinyl-triphenyl-phosphonium) that are specifically targeted to mitochondria and show that they can effectively inhibit apoptosis in a variety of cell types and ameliorate acute organ dysfunction in vivo. Accordingly, the SPECIFIC AIMS of this proposal are to determine: 1) the molecular role of CL-induced peroxidase activity of cytochrome c in pulmonary endothelial cell apoptosis in hyperoxic mouse lung; 2) the molecular role of oxidized anionic phospholipids in the signal transduction pathway of pulmonary endothelial cell apoptosis including scavenging of apoptotic pulmonary endothelium by macrophages; 3) the therapeutic potential of XJB-5-131 and HVTP, two mitochondria-targeted antioxidants/inhibitors of cyt c/CL peroxidase, in preventing pulmonary endothelial cell CL oxidation, apoptosis and favorably affecting the course of hyperoxic lung injury. PUBLIC HEALTH RELEVANCE: While antioxidants have been long viewed as potentially effective for therapeutic interventions, elucidation of specific mechanisms through which cyt c and CL oxidation products link free radical production with early apoptotic events in mitochondria will contribute to a roadmap to new effective drug discovery targets.

描述(申请人提供)：急性肺损伤(ALI)，包括高氧性肺损伤，是一种对公共卫生具有重要意义的综合征。虽然ALI的发病机制尚不清楚，但人们普遍认为，活性氧和氮物种的产生和消除之间的失衡是一个促成因素。肺内皮细胞是高氧性肺损伤早期结构和功能改变的部位，肺内皮细胞凋亡是高氧性肺损伤发生和维持的重要因素。然而，高氧诱导肺内皮细胞凋亡的早期分子途径尚不清楚，治疗ALI的方法仍然完全是姑息性的。我们最近发现，当细胞色素c(Cytc)与阴离子磷脂，特别是线粒体特异性心磷脂(CL)相互作用时，细胞色素c失去了它的三级结构，其过氧化物酶活性急剧增加。CL诱导的细胞色素c过氧化物酶活性在细胞程序性死亡的选择性CL氧化中起重要作用。在细胞凋亡过程中，过氧化物酶活性和CL结合的Cytc的比例显著增加，提示CL是调节Cytc线粒体功能的开关。在初步数据中，我们首次在肺内应用基于离子陷阱电喷雾电离质谱仪的脂质组学，表明CL的选择性氧化是高氧肺的早期事件，也发生在培养的肺内皮细胞凋亡的简单模型中(如内毒素)。此外，我们还设计了针对线粒体的抗氧化剂/电子清除剂(XJB-5-131；半杀菌素-4-氨基-2，2，6，6-四甲基哌啶-N-氧基)和过氧化物酶激活的一氧化氮供体(HVTP，2-羟氨基-乙烯基三苯基膦)，并表明它们可以有效地抑制多种细胞类型的凋亡，改善体内急性器官功能障碍。因此，本建议的具体目的是确定：1)CL诱导的细胞色素c过氧化物酶活性在高氧小鼠肺内皮细胞凋亡中的分子作用；2)氧化阴离子磷脂在肺内皮细胞凋亡信号转导通路中的分子作用，包括巨噬细胞清除凋亡的肺内皮细胞；3)两种线粒体靶向的细胞色素c/CL过氧化物酶的抗氧化剂/抑制剂XJB-5-131和HVTP在防止肺内皮细胞CL氧化、凋亡中的作用，并有利于影响高氧性肺损伤的过程。 与公共健康相关：虽然抗氧化剂长期以来一直被视为潜在的有效治疗干预措施，但阐明细胞色素C和CL氧化产物将自由基产生与线粒体早期凋亡事件联系起来的具体机制将有助于制定新的有效药物发现靶点的路线图。