BCL-XL AND THE HEART; THE METABOLIC BASIS TO CARDIOPROTECTION AND DISEASE

BCL-XL 与心脏；

• 批准号: 7953852
• 负责人: PETER JS SMITH
• 金额: $ 3.36万
• 依托单位: MARINE BIOLOGICAL LABORATORY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-12-01 至 2009-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7953852
• 关键词: Address; Adenoviruses; Apoptotic; Attenuated; Bioenergetics; Biological Assay; Cardiac; Cardiac Myocytes; Cell Death; Cell Survival; Cells; Computer Retrieval of Information on Scientific Projects Database; Confocal Microscopy; Consumption; Disease; Dyes; Energy Metabolism; Esters; Free Radicals; Funding; Grant; Growth; Heart; Heart Diseases; Heart failure; Homeostasis; Inner mitochondrial membrane; Institution; Intervention; Ischemia; Kinetics; Luciferases; Measures; Membrane Potentials; Metabolic; Metabolism; Mitochondria; Mitochondrial Membrane Protein; Mitochondrial Proteins; Muscle Cells; Organ; Oxidative Phosphorylation; Oxygen; Production; Protein Overexpression; Proteins; Reaction; Regulation; Reperfusion Therapy; Research; Research Personnel; Resources; Signal Transduction; Societies; Source; Technology; United States National Institutes of Health; Up-Regulation; base; genetic regulatory protein; luciferin; member; mitochondrial membrane; mortality; prevent; receptor; therapeutic target; uptake

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Heart disease and consequent heart failure contibutes to high mortality in Western society. A greater understanding of the regulatory proteins associated with this disease is required. In heart, the anti-apoptotic factor, Bcl-xL attenuates cell death during ischemia-reperfusion. This is observed at the single cell and whole organ level. Though the pro-survival mechanism of Bcl-xl in unclear, Bcl-xl is thought to inhibit pro-apoptotic factors such as Bax and Bak while also regulating ATP-ADP exchange across the inner mitochondrial membranes. For example, anti-apoptotic Bcl-2 proteins (of which Bcl-xL is a member) inhibits the glycolytic consumption of ATP thereby maintaining the ATP pool during ischemia and preventing metabolic breakdown. Overexpression of these proteins in cardiac myocytes also maintains mitochondrial membrane potential and prevents the release of mitochondrial proteins during ischemic interventions. Prior studies on Bcl-xL in the heart have focused on mitochondrial transport kinetics, free radical production and cell death/growth assays. There is a lack of information concerning the metabolic changes associated with Bcl-xL, unexpected since Bcl-xL interacts directly with mitochondrial membrane proteins associated with the regulation of oxidative phosphorylation. In addition, there is limited information on Ca2+ homeostasis during cardioprotective and/or ischemic interventions. Bcl-xL-dependent modulation of IP3-receptors and mitochondrial Na+-Ca2+ exchange by Bcl-xL has been proposed and may contribute to the proposed cardioprotective qualities of Bcl-xL. The BRC aims to characterize the effect of Bcl-xl overepxression on both cellular energy metabolism and contractile function in cardiac myocytes. Metabolism will be assessed using self-referencing oxygen microsensors that will assess the oxygen uptake of control and Bcl-xL+ myocytes. In addition, myocytes will be co-infected with adenovirus containing constructs for cytosolic and mitochondrial luciferase in order to assess intracellular ATP concentration via the luciferin/luciferase reaction. Ca2+ homeostasis will be measured using AM ester Ca2+ dyes and confocal microscopy. It is the aim of the BRC to address whether there is a metabolic basis to the cardioprotective action of Bcl-2 proteins. In addition, it is our objective to assess Ca2+ transport and Ca2+-dependent signal transduction during Bcl-xL upregulation and to address whether this contributes to the observed changes in cardiac bioenergetics and cell survival. It is anticipated that integrated technologies available at the BRC will generate invaluable information regarding cardiac bioenergetics and identify potential therapeutic targets for the implementation of cardioprotection.

该副本是利用众多研究子项目之一 由NIH/NCRR资助的中心赠款提供的资源。子弹和 调查员（PI）可能已经从其他NIH来源获得了主要资金， 因此可以在其他清晰的条目中代表。列出的机构是 对于中心，这不一定是调查员的机构。 心脏病和随之而来的心力衰竭在西方社会中与高死亡率相关。需要对与该疾病相关的调节蛋白有更深入的了解。在心脏中，抗凋亡因子，BCl-XL减弱了缺血 - 再灌注期间的细胞死亡。这是在单细胞和整个器官水平上观察到的。 尽管BCl-XL在不清楚的促生物生存机制中被认为可以抑制促凋亡因子，例如Bax和Bak，同时还调节跨线粒体内部膜的ATP-ADP交换。例如，抗凋亡BCL-2蛋白（其中BCL-XL是成员）抑制ATP的糖酵解消耗，从而在缺血期间保持ATP池并防止代谢分解。这些蛋白质在心肌细胞中的过表达也保持线粒体膜电位，并防止缺血性干预期间线粒体蛋白的释放。 先前对心脏中BCL-XL的研究集中在线粒体转运动力学，自由基生产和细胞死亡/生长测定方面。缺乏有关与BCL-XL相关的代谢变化的信息，因为BCL-XL与与氧化磷酸化的调节有关的线粒体膜蛋白直接相互作用。此外，在心脏保护和/或缺血性干预期间，有关CA2+稳态的信息有限。已经提出了BCl-XL的IP3受体和线粒体Na+ -ca2+交换的BCl-XL依赖性调制，并可能有助于BCl-XL的拟议心脏保护质量。 BRC的目的是表征BCL-XL过度抑制对心肌细胞中细胞能量代谢和收缩功能的影响。 将使用自我引用的氧显微传感器评估代谢，这些微传感器将评估对照和BCL-XL+肌细胞的氧气摄取。此外，肌细胞将与含有胞质和线粒体荧光素酶的腺病毒共同感染，以通过荧光素/荧光素酶反应评估细胞内ATP浓度。 CA2+稳态将使用AM酯Ca2+染料和共聚焦显微镜测量。 BRC的目的是解决Bcl-2蛋白的心脏保护作用是否存在代谢基础。此外，我们的目标是评估BCL-XL上调期间CA2+转运和Ca2+依赖性信号转导，并解决这是否有助于观察到的心脏生物能和细胞存活的变化。可以预计，BRC可用的集成技术将生成有关心脏生物能学的宝贵信息，并确定实施心脏保护的潜在治疗靶标。