AGING, LIPID PEROXIDATION, AND CARDIAC REPERFUSION

衰老、脂质过氧化和心脏再灌注

• 批准号: 6488849
• 负责人: LUKE I. SZWEDA
• 金额: $ 22.63万
• 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/6488849
• 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， 严重程度随着年龄的增长而增加。对能量状况至关重要 心脏的功能，心脏线粒体表现出再灌注诱导 自由基生产的增加。免费之间的直接联系 自由基和线粒体功能障碍尚未确定。 4- 羟基-2-非纳尔（HNE），脂质过氧化的主要产物很容易 与酶反应并灭活。校长的工作 研究者的实验室已经确定，再灌注会导致 通过HNE修饰特定蛋白质。 HNE修改级别 随着年龄的增长而增加，线粒体呼吸的相似之处下降。 浓度HNE的完整心脏线粒体治疗 再灌注期间的预期导致NADH依赖性的迅速下降 呼吸类似于再灌注过程中观察到的呼吸。校长 因此，研究者提出：再灌注引起的下降 线粒体呼吸的部分原因是修改特定 HNE的线粒体蛋白，这些过程有助于 与年龄相关的心肌再灌注损伤增加。 为了检验这一假设，从不同年龄的大鼠隔离的心脏 将受到缺血和再灌注持续时间的不同持续时间。 然后将分离线粒体以确定： 1。在缺血期间灭活的特定呼吸酶和 再灌注。 2。线粒体蛋白的身份（S）由HNE和 HNE修改水平。 3。线粒体对HNE损伤和超氧化物的敏感性的变化 阴离子一代。 化学，免疫化学和质谱技术将是 用于检测和净化HNE修饰的蛋白质。关系 在通过HNE修饰的线粒体蛋白的水平和身份之间 （AIM 2）和表现出再灌注引起的活动下降的人 （AIM 1）将定义负责线粒体损失的机制 再灌注过程中的功能。 HNE介导的损害的决定因素 线粒体将通过评估线粒体的变化来建立 衰老和缺血期间发生的特性（AIM 1），并导致 HNE形成率升高和/或增加的敏感性 特定的呼吸酶进行修饰（AIM 3）。识别 心肌再灌注损伤和条件的特定机制 如果要实现干预，则必须在其中发生。