Hypothermia in Cardiac Arrest: Akt Preservation of Mitochondrial Integrity

心脏骤停中的低温：Akt 保护线粒体完整性

• 批准号: 8646978
• 负责人: Willard William Sharp
• 金额: $ 12.66万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-06-10 至 2016-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8646978
• 关键词: Address; Affect; African American; Apoptosis; Biological Preservation; Cardiac; Cardiac Myocytes; Cardiogenic Shock; Cardiopulmonary Resuscitation; Cardiovascular Physiology; Cause of Death; Cell Survival; Cellular biology; Development; Development Plans; Emergency Medicine; Ensure; Erythropoietin; Faculty; Foundations; Functional disorder; Funding; Generations; Genetic; Heart Arrest; Hexokinase 2; Hospitals; Image; In Vitro; Individual; Inhibition of Apoptosis; Injury; Ischemia; K-Series Research Career Programs; Lead; Measures; Mechanics; Mediating; Mentorship; Metabolism; Mitochondria; Modeling; Mus; Myocardial; Myocardium; Nuclear; Outcome; Outer Mitochondrial Membrane; Oxidants; Oxidative Stress; Oxygen; Pathway interactions; Phosphorylation; Phosphotransferases; Physicians; Public Health; Publishing; Reactive Oxygen Species; Reperfusion Injury; Reperfusion Therapy; Resuscitation; Scientist; Signal Transduction; Sirolimus; Solid; Stream; Subcellular Fractions; Techniques; Therapeutic; Training; Training Technics; Transfection; United States; Work; abstracting; career development; heart metabolism; improved; in vitro Model; in vivo; interest; mitochondrial dysfunction; mitochondrial permeability transition pore; mouse model; natural hypothermia; overexpression; oxidant stress; programs; protective effect; tool; young woman

DESCRIPTION (provided by applicant): Project Summary/Abstract Studies and physician-scientist training are proposed to model in vitro and in vivo mechanisms of lethal cardiac reperfusion injury following cardiac arrest resuscitation and therapeutic hypothermia (TH) cardiac protection against this injury. Recent work by the applicant involving mouse cardiac arrest and mouse cardiomyocyte models of ischemia/reperfusion (IR) injury suggests that rapid, early cooling within minutes of resuscitation protects against mitochondrial oxidant injury and preserves contractile function. TH cardioprotection in both these complementary models is associated with Akt1 activation. Finally, cardiomyocytes appear to adapt to oxidant stress within minutes by localization of Akt to the mitochondrial subcellular fraction. The central hypothesis of this proposal is that TH cardioprotection following cardiac arrest is the result of Akt activation and localization to the mitochondria with subsequent inhibition of GSK-32 and activation of hexokinase II. The proposed aims and candidate career development plan will help determine whether: Aim #1) Akt1 activation during cardimyocyte I/R is necessary for TH protection of mitochondrial integrity and is associated with Akt subcellular localization, GSK-32 inhibition and hexokinase II activation; that Aim #2) Overexpression of nuclear versus mitochondrial targeted Akt1 will enhance or replicate TH cardioprotection; and Aim #3) Akt1 phosphorylation and subcellular signaling changes seen in Aims #1 and #2 will also be required for TH cardioprotection in a mouse model of cardiac arrest. The proposed work is a natural progression of Dr Sharp's prior background in cardiac cell biology and training in emergency medicine, and will equip him with several new tools for mitochondrial functional and oxidant stress measures, confocal imaging, targeted transfection strategies, and in vivo as well as in vitro approaches to studies of myocardial I/R injury. The plan will ensure a successful transition from junior faculty to tenure track with independent funding. This proposal addresses a major public health problem that constitutes a leading cause of death in the United States, affecting an estimated 335,000 individuals every year. Rates of cardiac arrest are disproportionately high among African Americans and are rising among young women. Although promising, the effective and rapid implementation of TH during cardiopulmonary resuscitation (CPR) particularly in the out of hospital setting is technically challenging. Understanding the Akt-mediated pathways that improve cardiovascular function and survival with TH could lead to the development of pharmacologic adjuncts that replicate or enhance the protective effects of TH.

描述（由申请人提供）：项目摘要/摘要研究和医师科学家培训旨在模拟心脏骤停复苏后致命性心脏再灌注损伤的体外和体内机制，并针对这种损伤进行治疗性低温（TH）心脏保护。申请人最近涉及小鼠心脏骤停和缺血/再灌注（IR）损伤的小鼠心肌细胞模型的工作表明，在复苏后几分钟内快速、早期冷却可防止线粒体氧化损伤并保留收缩功能。这两种互补模型中的 TH 心脏保护作用均与 Akt1 激活相关。最后，心肌细胞似乎通过将 Akt 定位到线粒体亚细胞部分而在几分钟内适应氧化应激。 该提议的中心假设是心脏骤停后 TH 心脏保护作用是 Akt 激活并定位到线粒体以及随后抑制 GSK-32 和激活己糖激酶 II 的结果。拟议的目标和候选人职业发展计划将有助于确定是否： 目标 #1) 心肌细胞 I/R 期间的 Akt1 激活对于 TH 保护线粒体完整性是必要的，并且与 Akt 亚细胞定位、GSK-32 抑制和己糖激酶 II 激活相关；目标 #2) 细胞核相对于线粒体靶向 Akt1 的过度表达将增强或复制 TH 心脏保护作用；和目标 #3) 在心脏骤停小鼠模型中，TH 心脏保护也需要目标 #1 和目标 #2 中看到的 Akt1 磷酸化和亚细胞信号传导变化。拟议的工作是夏普博士先前在心脏细胞生物学和急诊医学培训方面的背景的自然发展，并将为他配备几种用于线粒体功能和氧化应激测量、共焦成像、靶向转染策略以及体内的新工具作为心肌 I/R 损伤研究的体外方法。该计划将确保从初级教师到独立资助的终身教授的成功过渡。 该提案解决了构成美国主要原因的重大公共卫生问题，每年影响约 335,000 人。非裔美国人的心脏骤停率异常高，年轻女性的心脏骤停率也在上升。尽管前景广阔，但在心肺复苏 (CPR) 期间（尤其是在院外环境中）有效、快速实施 TH 在技术上具有挑战性。了解 Akt 介导的 TH 改善心血管功能和生存的途径可能会导致开发复制或增强 TH 保护作用的药理学辅助剂。