Mechanisms of Cardioprotection in Ischemia and Failure

描述(由申请人提供)： 这项研究计划涉及三个相互关联和相互作用的项目，这些项目将使用新的方法来阐明与人类心脏病相关的急性心肌缺血、损伤、修复和心力衰竭的调节机制。整个提案将广泛使用转基因和基因靶向缺失模型。方法将包括分离的亚线粒体颗粒和完整线粒体的生化和分子方法；细胞培养的生化和分子研究；分离的细胞和心肌条的生物物理研究；离体心的血流动力学研究；以及活体动物的系列血流动力学和超声心动图研究。所有必要的技术目前都在负责调查人员的实验室中使用。以前在心脏中没有研究过的细胞和分子过程将成为靶点。第一个总体目标是了解溶血磷脂介体神经鞘氨醇I-磷酸和溶血磷脂酸以及肌动蛋白调节蛋白凝胶如何调节心肌对急性氧化应激、损伤和重塑的反应。第二个目的是研究基质金属蛋白酶-2(明胶酶A)在心脏成纤维细胞增殖、细胞外基质形成和心脏重塑中的分子调控。第三个目的是了解在急性心肌缺血和可逆性充血性心力衰竭模型中钙反应是如何调节的。这些项目将依赖于三个核心单元：血液动力学核心、细胞培养核心和转基因小鼠核心。每个项目都将与其他项目和核心单位进行广泛的互动。这项建议汇集了一组不同的研究人员的技能，他们对了解心脏对氧化应激的反应机制感兴趣而团结在一起。建议的研究是新颖和可行的，旨在为预防急性和慢性氧化应激期间的心肌损伤提供新的方法。

DESCRIPTION (provided by applicant): This research program involves three interrelated and interacting projects that will use novel approaches to elucidate regulatory mechanisms in acute myocardial ischemia, injury, repair, and heart failure that have relevance to human cardiac disease. The overall proposal will make extensive use of transgenic and gene targeted deletion models in mice. Methods will include biochemical and molecular approaches in isolated submitochondrial particles and intact mitochondria; biochemical and molecular studies in cell culture; biophysical studies in isolated cells and myocardial strips; hemodynamic investigations in isolated hearts; and serial hemodynamic and echocardiographic studies in living animals. All of the required techniques are currently in use in the laboratories of the responsible investigators. Cellular and molecular processes not previously investigated in the heart will be targeted. The first overall goal is to learn about how the lysophospholipid mediators sphingosine I -phosphate and lysophosphatidic acid and the actin regulatory protein gelsolin regulate myocardial responses to acute oxidative stress, injury, and remodeling. The second aim is to study the molecular regulation of matrix metalloproteinase-2 (gelatinase A) in cardiac fibroblast proliferation, extracellular matrix formation, and cardiac remodeling. The third aim is to learn how calcium responsiveness is regulated in models of acute myocardial ischernia and reversible congestive heart failure. These projects will rely on three Core Units: a hemodynamics core, a cell culture core, and a transgenic mouse core. Each of the projects will have extensive interactions with the other projects and with the core units. This proposal brings together the skills of a diverse group of investigators united by an interest in understanding mechanisms underlying the heart's response to oxidative stress. The proposed studies are novel and feasible, and are designed to lead to new approaches for the prevention of myocardial damage during acute and chronic oxidative stress.