Role of the mitochondrial ATP-binding cassette protein-1 in cellular protection

线粒体 ATP 结合盒蛋白 1 在细胞保护中的作用

• 批准号: 7837567
• 负责人: Hossein Ardehali
• 金额: $ 37.75万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-06-05 至 2012-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7837567
• 关键词: Animals; Binding; Cardiac Myocytes; Cardiovascular Diseases; Cardiovascular Physiology; Cause of Death; Cell Death; Cell Survival; Cells; Country; Development; Disease; Down-Regulation; Epidemic; Generations; Goals; Heart; Heme Iron; Homeostasis; Homologous Gene; Injury; Investigation; Iron; Ischemia; Knowledge; Lead; Maintenance; Measurement; Measures; Mediator of activation protein; Mitochondria; Mitochondrial Proteins; Molecular; Molecular Biology Techniques; Myocardial; Myocardial Ischemia; Neonatal; Oxidants; Oxidative Stress; Play; Process; Protein Family; Protein Isoforms; Proteins; RNA Interference; Rattus; Reactive Oxygen Species; Reperfusion Therapy; Research; Resistance; Role; Source; Techniques; Testing; Transgenic Mice; Yeasts; base; cell injury; design; expectation; follow-up; innovation; mitochondrial permeability transition pore; novel; novel therapeutics; numb protein; overexpression; oxidant stress; oxidative damage; protective effect; protein function; research study; response; treatment strategy

DESCRIPTION (provided by applicant): Ischemic heart disease (IHD) is a major epidemic throughout the developed world, yet the molecular mechanisms that lead to myocardial cell death in this disorder are not completely understood. Evidence indicates that the mitochondria play an important role in regulating ischemic-induced cellular injury. We previously demonstrated that overexpression of a mitochondrial protein, the mitochondrial ATP-binding cassette protein-1 (mABC1) protects against oxidant induced cell death, while its downregulation causes an increase in cell death at baseline. The primary function of mABC1 is unknown, thus it is unclear how this protein exerts protection against oxidant stress. The yeast homolog of mABC1, Mdl1p, has also been shown to exert protection against oxidant-induced cellular injury and plays a role in mitochondrial iron homeostasis. Intracellular iron accumulation can be a source of oxidative stress, which is thought to be the underlying mechanism for the protective effects of Mdl1p. In this proposal, we will follow up on our key observation that mABC1 is protective against oxidant injury and propose to elucidate the underlying mechanism for this process. Furthermore, we will attempt to extend our studies to intact animals and determine whether mABC1 can also protect against ischemic injury in the heart. Our main hypothesis is that mABC1 plays a role in the maintenance of the mitochondrial iron homeostasis and that it protects against ischemic damage in the heart. In order to test this hypothesis, we propose three interrelated specific aims. In Aim 1, we will determine whether mABC1 plays a role in the maintenance of mitochondrial iron homeostasis and generation of intracellular reactive oxygen species. The levels of mABC1 will be modulated in neonatal rat cardiomyocytes (NRCM) using various molecular biology techniques, followed by measurement of the mitochondria iron and intracellular ROS levels. In Aim 2, we will determine whether the protective effects of mABC1 are through inhibition of the mitochondrial permeability transition pore (mPTP). This channel is believed to be a pivotal player in oxidant-induced cell death. By altering the levels of mABC1 in NRCM, we will study the effect of mABC1 on cell viability and mPTP opening. In Aim 3, we will make transgenic mice that overexpress mABC1, followed by induction of ischemia/reperfusion (I/R). The effects of mABC1 overexpression on l/R-induced cell death will then be examined by various techniques. These lines of investigation promise to advance our knowledge of the molecular mechanisms of myocardial cell death in ischemic heart disease. Furthermore, successful completion of our studies will have potential impact on our understanding of the role of mitochondria in cardiovascular disease, and may open new avenues for the treatment of IHD.

描述（由申请人提供）：缺血性心脏病（IHD）是整个发达国家的主要流行病，但导致这种疾病心肌细胞死亡的分子机制尚未完全了解。有证据表明线粒体在调节缺血引起的细胞损伤中发挥着重要作用。我们之前证明，线粒体蛋白线粒体 ATP 结合盒蛋白-1 (mABC1) 的过度表达可以防止氧化剂诱导的细胞死亡，而其下调会导致基线细胞死亡增加。 mABC1 的主要功能尚不清楚，因此尚不清楚该蛋白如何发挥抗氧化应激的保护作用。 mABC1 的酵母同源物 Mdl1p 也被证明可以发挥保护作用，防止氧化剂诱导的细胞损伤，并在线粒体铁稳态中发挥作用。细胞内铁积累可能是氧化应激的一个来源，这被认为是 Mdl1p 保护作用的潜在机制。在本提案中，我们将跟进我们的关键观察结果，即 mABC1 具有针对氧化损伤的保护作用，并提出阐明该过程的潜在机制。此外，我们将尝试将我们的研究扩展到完整的动物，并确定 mABC1 是否也可以预防心脏缺血性损伤。我们的主要假设是 mABC1 在维持线粒体铁稳态中发挥作用，并防止心脏缺血性损伤。为了检验这一假设，我们提出了三个相互关联的具体目标。在目标 1 中，我们将确定 mABC1 是否在维持线粒体铁稳态和细胞内活性氧的生成中发挥作用。将使用各种分子生物学技术调节新生大鼠心肌细胞 (NRCM) 中的 mABC1 水平，然后测量线粒体铁和细胞内 ROS 水平。在目标 2 中，我们将确定 mABC1 的保护作用是否是通过抑制线粒体通透性转换孔 (mPTP) 来实现的。该通道被认为是氧化剂诱导的细胞死亡的关键参与者。通过改变 NRCM 中 mABC1 的水平，我们将研究 mABC1 对细胞活力和 mPTP 开放的影响。在目标 3 中，我们将制作过度表达 mABC1 的转基因小鼠，然后诱导缺血/再灌注 (I/R)。然后将通过各种技术检查 mABC1 过表达对 l/R 诱导的细胞死亡的影响。这些研究方向有望增进我们对缺血性心脏病心肌细胞死亡分子机制的了解。此外，我们研究的成功完成将对我们对线粒体在心血管疾病中的作用的理解产生潜在影响，并可能为 IHD 的治疗开辟新途径。