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.

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 在西方社会，心脏病和随之而来的心力衰竭导致了高死亡率。需要对与这种疾病相关的调节蛋白有更多的了解。在心脏方面，抗凋亡因子Bc l-xl可减轻缺血再灌注期间的细胞死亡。这是在单个细胞和整个器官水平上观察到的。尽管目前尚不清楚BclxL的促生存机制，但BclxL被认为可以抑制促凋亡因子Bax和Bak，同时还可以调节线粒体内膜上的ATP-ADP交换。例如，抗凋亡的Bcl2蛋白(Bclxl是其中的一员)可以抑制ATP的糖酵解消耗，从而在缺血期间维持ATP池，防止代谢崩溃。这些蛋白在心肌细胞中的过度表达也维持了线粒体膜电位，并阻止了缺血干预期间线粒体蛋白的释放。 以往对心脏中的Bclxl的研究主要集中在线粒体转运动力学、自由基的产生和细胞死亡/生长的检测上。关于与Bclxl相关的代谢变化的信息很少，这是意想不到的，因为Bclxl直接与与氧化磷酸化调节相关的线粒体膜蛋白相互作用。此外，有关心肌保护和/或缺血干预过程中的钙稳态的信息有限。已有研究表明，Bc l-xl对IP3受体和线粒体Na+-Ca~(2+)交换的调节依赖于Bc l-xl，这可能与Bc l-xl的心肌保护作用有关。BRC旨在研究bclxl过度表达对细胞能量代谢和心肌细胞收缩功能的影响。 新陈代谢将使用自参照氧微型传感器进行评估，该传感器将评估对照组和Bclxl+心肌细胞的摄氧量。此外，心肌细胞将与含有胞浆和线粒体荧光素酶构建体的腺病毒共同感染，以通过荧光素/荧光素酶反应评估细胞内的ATP浓度。钙离子稳态将使用AM酯钙染料和共聚焦显微镜来测量。 这是BRC的目标是解决是否有代谢基础的心脏保护作用的Bcl-2蛋白。此外，我们的目标是评估在Bcl-xL上调过程中的钙离子转运和钙依赖的信号转导，并探讨这是否有助于观察到的心脏生物能量学和细胞存活的变化。预计BRC提供的综合技术将产生关于心脏生物能量学的宝贵信息，并确定实施心脏保护的潜在治疗目标。