AGING, LIPID PEROXIDATION, AND CARDIAC REPERFUSION

衰老、脂质过氧化和心脏再灌注

• 批准号: 2743533
• 负责人: LUKE I. SZWEDA
• 金额: $ 20.71万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-01-01 至 2003-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2743533
• 关键词: age difference; cell senescence; cellular pathology; cellular respiration; endopeptidases; enzyme activity; enzyme inhibitors; free radicals; histology; immunochemistry; laboratory rat; lipid peroxides; lipids; mass spectrometry; mitochondria; myocardial ischemia /hypoxia; oxidative stress; peroxidation; posttranslational modifications; protein localization; protein purification; protein structure function; reperfusion; respiratory enzyme; superoxides

DESCRIPTION (Adapted from the Applicant's Abstract): Reperfusion of cardiac tissue results in declines in mitochondrial respiration, the severity of which increases with age. Critical to the energy status and function of the heart, cardiac mitochondria exhibit reperfusion-induced increases in free radical production. A direct link between free radicals and mitochondrial dysfunction has yet to be established. 4- Hydroxy-2-nonenal (HNE), a major product of lipid peroxidation readily reacts with and inactivates enzymes. Work from the Principal Investigator's laboratory had established that reperfusion results in modification of specific proteins by HNE. The level of HNE modification increases with age and parallels declines in mitochondrial respiration. Treatment of intact cardiac mitochondria with concentrations of HNE expected during reperfusion causes rapid declines in NADH-dependent respiration similar to that observed during reperfusion. The Principal Investigator thus proposes that: Reperfusion-induced declines in mitochondrial respiration are due, in part, to modification of specific mitochondrial proteins(s) by HNE and that these processes contribute to age-related increases in myocardial reperfusion injury. To test this hypothesis, hearts isolated from rats of different ages will be subjected to varying durations of ischemia and reperfusion. Mitochondria will then be isolated to determine: 1. Specific respiratory enzymes inactivated during ischemia and reperfusion. 2. The identities of mitochondrial protein(s) modified by HNE and the level of HNE modification. 3. Changes in mitochondrial susceptibility to HNE damage and superoxide anion generation. Chemical, immunochemical, and mass spectroscopic techniques will be utilized to detect and purify HNE-modified protein. Relationships between the level and identity of mitochondrial proteins modified by HNE (Aim 2) and those exhibiting reperfusion-induced declines in activity (Aim 1) will define mechanisms responsible for loss in mitochondrial function during reperfusion. Determinants of HNE-mediated damage to mitochondria will be established by evaluating changes in mitochondrial properties which occur during aging and ischemia (Aim 1) and result in elevated rates of HNE formation and/or increased susceptibility of specific respiratory enzymes to modification (Aim 3). Identification of specific mechanisms of myocardial reperfusion injury and conditions under which they occur is necessary if intervention is to be achieved.

描述（改编自申请人的摘要）： 心脏组织导致线粒体呼吸下降， 其严重性随着年龄的增长而增加。对能源状况至关重要， 心脏的功能，心肌线粒体表现出再灌注诱导 增加自由基的产生。自由之间的直接联系 自由基和线粒体功能障碍尚未建立。4- 羟基-2-壬烯醛（HNE）是脂质过氧化的主要产物， 与酶反应并使酶失活。来自校长的工作 研究人员的实验室已经确定，再灌注导致 通过HNE修饰特定蛋白质。HNE改性水平 随着年龄的增长而增加，并与线粒体呼吸的下降平行。 用一定浓度的HNE处理完整的心肌线粒体 预期在再灌注过程中， 呼吸类似于再灌注期间观察到的。校长 因此，研究者提出：再灌注诱导的 线粒体呼吸的部分原因是由于特定的 线粒体蛋白（S）的HNE和这些过程有助于 年龄相关的心肌再灌注损伤增加。 为了验证这一假设，从不同年龄的大鼠中分离出心脏， 将经受不同持续时间的缺血和再灌注。 然后分离线粒体以确定： 1.在缺血期间失活的特异性呼吸酶， 再灌注 2.经HNE修饰的线粒体蛋白质的身份和经HNE修饰的线粒体蛋白质的身份。 HNE改性水平。 3.线粒体对HNE损伤和超氧化物敏感性的变化 负离子生成 化学、免疫化学和质谱技术将被广泛应用。 用于检测和纯化HNE修饰的蛋白。关系 HNE修饰的线粒体蛋白质的水平和特性之间 (Aim 2）和那些表现出再灌注诱导的活性下降的 (Aim 1）将定义负责线粒体损失的机制 再灌注期间的功能。HNE介导的损伤的决定因素 线粒体将通过评估线粒体的变化来建立。 在老化和局部缺血期间发生的性质（目的1），并导致 HNE形成率升高和/或HNE敏感性增加 特异性呼吸酶的修饰（目的3）。鉴定 心肌再灌注损伤的特殊机制和条件 如果要进行干预，就必须确定它们发生的条件。