Role of The Mitok ATP Channel in Digitalis Signaling in the Heart

Mitok ATP 通道在心脏洋地黄信号传导中的作用

• 批准号: 8250442
• 负责人: Keith D Garlid
• 金额: $ 29.07万
• 依托单位: UNIVERSITY OF TOLEDO HEALTH SCI CAMPUS
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-04-01 至 2014-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8250442
• 关键词: Agonist; Biochemical; Biochemical Pathway; Cardiac; Cause of Death; Cells; Complex; Digitalis preparation; Dose; Electron Microscopy; Funding; Goals; Heart; Heart failure; Human; Infarction; Injury; Ischemic Preconditioning; Label; Lead; Membrane; Mitochondria; Mitogen-Activated Protein Kinases; Modeling; Mus; Myocardial Infarction; Na(+)-K(+)-Exchanging ATPase; Oryctolagus cuniculus; Ouabain; Outer Mitochondrial Membrane; Pathway interactions; Permeability; Pharmaceutical Preparations; Pharmacology; Phosphotransferases; Physiological; Play; Potassium Channel; Production; Proteins; Rattus; Reaction; Reactive Oxygen Species; Recycling; Reperfusion Injury; Reporting; Research; Role; Sarcolemma; Signal Transduction; Signaling Protein; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Stress; Testing; Therapeutic Intervention; Time; Work; caveolin 1; design; migration; mitochondrial K(ATP) channel; receptor; response; src-Family Kinases; transmission process

Cardiac infarction followed by ischemic injury is a major cause of death worldwide. Digitalis, the oldest and best characterized heart failure drug, protects against ischemia-reperfusion injury, and it does so through activation of the mitochondrial ATP-sensitive K+ channel (mitoKATp). The central hypothesis of this project is that ouabain-activated signals are relayed to mitochondria, resulting in mitoKATp opening, increased production of reactive oxygen species (ROS) and activation of survival kinases that protect the heart. Our long-term goal is to uncover the mechanisms that regulate digitalis-induced cardioprotection through activation of the Na,K-ATPase / mitoKATp pathway. During this period, we will focus on the mechanism of signal transmission from the sarcolemmal Na,K-ATPase to mitochondria. Aim 1 will test the hypothesis that digitalis causes formation of functionally active caveolar microdomains (signalosomes) that interact with the mitochondrial outer membrane, leading to mitoKATp opening and inhibition of the mitochondrial permeability transition. Aim 2 will investigate signalosome recycling and the persistence of signalosome function. Aim 3 will investigate signalosome assembly and transport using electron microscopy and immunogold labeling. Aim 4 will investigate key aspects of digitalis protection and signaling in the rabbit heart model, whose cardiac function and digitalis pharmacology are closer to those in human heart. A variety of experimental approaches will be used. Signalosomes will be purified from perfused hearts and tested for functional activity on mitochondria isolated from untreated hearts. Results of these physiological studies will be supported by parallel studies of infarct size on perfused hearts. Purified signalosomes will also be subjected to biochemical and structural analyses to characterize their composition and origin.

心肌梗死继发缺血性损伤是世界范围内死亡的主要原因。洋地黄，最古老的， 最具特征的心力衰竭药物，保护缺血再灌注损伤，它通过 线粒体ATP敏感性K+通道（mitoKATp）的激活。这个项目的核心假设是 哇巴因激活的信号被传递到线粒体，导致mitoKATp开放， 产生活性氧（ROS）和激活保护心脏的存活激酶。我们 长期目标是揭示洋地黄诱导的心脏保护的调节机制， Na，K-ATP酶/ mitoKATp途径的激活。在此期间，我们将重点关注 从肌膜Na，K-ATP酶到线粒体的信号传递。目标1将检验以下假设： 洋地黄引起功能活性小窝微区（信号体）的形成， 线粒体外膜，导致mitoKATp开放和线粒体通透性的抑制 过渡目的2将研究信号体循环和信号体功能的持续性。目标3 将研究信号体组装和运输使用电子显微镜和免疫金标记。 目的4将在兔心脏模型中研究洋地黄保护和信号传导的关键方面， 心功能和洋地黄药理学更接近人类心脏。各种实验 将使用的方法。将从灌注的心脏中纯化信号体，并测试其功能。 对从未经处理的心脏中分离的线粒体的活性。这些生理学研究的结果将 这得到了灌注心脏上梗死面积的平行研究的支持。纯化的信号体也将进行 生物化学和结构分析，以确定其组成和来源。