Investigate the effect of mitochondrial energy state on Ca2+ sparks and handling

研究线粒体能量状态对 Ca2 火花和处理的影响

• 批准号: 8321454
• 负责人: Lufang Zhou
• 金额: $ 24.43万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-20 至 2014-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8321454
• 关键词: Acute; American; Calcium; Cardiac; Cardiac Myocytes; Cavia; Cells; Communication; Computer Simulation; Coupling; Development; Diagnostic; Disease; Electrophysiology (science); Energy Metabolism; Event; Feedback; Frequencies; Functional disorder; Glutathione; Heart Diseases; Heart failure; Image; Individual; Injury; Ion Channel; Ischemia; Knowledge; Lasers; Link; Membrane Potentials; Metabolic; Metabolism; Microscope; Mitochondria; Modeling; Molecular; NADH; Oxidation-Reduction; Oxidative Phosphorylation; Oxidative Stress; Pattern; Probability; Process; Production; Property; Pyrimidine Nucleotides; Reactive Oxygen Species; Regulation; Reperfusion Therapy; Rest; Ryanodine Receptor Calcium Release Channel; Ryanodine Receptors; Sarcomeres; Signal Transduction; Simulate; Site; Source; System; Therapeutic; Translating; Work; base; design; experimental analysis; follow-up; models and simulation; mortality; novel; spatiotemporal; sudden cardiac death; two-photon; uptake

Heart disease is the single largest killer of the American. A growing body of evidence has shown that there is a close relationship between Ca2+ handling abnormalities and development of heart disease. Therefore it is fundamentally important to understand the regulation of Ca2+ signaling under pathological conditions. Local control of Ca2+-induced Ca2+ release (CICR) depends on the spatial organization of L-type Ca2+ channels and ryanodine receptors (RyR) in the dyad. Analogously, Ca2+ uptake by mitochondria is facilitated by their close proximity to the Ca2+ release sites, a process required for stimulating oxidative phosphorylation during changes in work. Mitochondrial feedback on CICR, however, is less well understood. Since mitochondria are a primary source of reactive oxygen species (ROS), they could potentially influence the cytosolic redox state, in turn altering RyR open probability. In this proposed study, a two photon laser microscope system will be used to directly examine how acute changes in energy state dynamically influence Ca2+ spark properties under various experimental conditions. Cytosolic Ca2+ (or ROS), A^m, and NADH will be recorded simultaneously in isolated guinea pig cardiomyocytes and analyzed offline using imaged. The spatiotemporal coupling between mitochondria! depolarization and Ca2+ sparks will be analyzed using a quantitative approach. Furthermore, a computational model of mitochondria and Ca2+ release unit will be developed to quantitatively investigate the interaction between mitochondrial energetics and local Ca2+ handling. Finally, an integrated model of the cardiomyocyte incorporating substrate metabolism, cellular electrophysiology, pH regulation and E-C coupling will be developed to investigate the mechanisms underlying alterations in energy production, ion channels, Ca2+ handling and pH, as well as the resulting reduction of cardiac contractile function during ischemia-reperfusion. By combining the experimental and computational results, these studies will allow for a complete understanding the origin of post-ischemic injury and development of heart failure, and significantly spur the development of novel heart disease therapies.

心脏病是美国人最大的杀手。越来越多的证据表明那里 是CA2+处理异常和心脏病发展之间的密切关系。所以 从根本上了解病理条件下的CA2+信号传导的调节非常重要。 Ca2+诱导的Ca2+释放（CICR）的局部控制取决于L型Ca2+的空间组织 二元组中的通道和ryanodine受体（RYR）。类似地，线粒体的Ca2+摄取是 由于它们与Ca2+释放位点的近距离靠近，这是刺激氧化所需的过程 工作变化期间的磷酸化。然而，线粒体反馈对CICR的反馈知之甚少。 由于线粒体是活性氧（ROS）的主要来源，因此它们可能会影响 胞质氧化还原状态，反过来改变了RYR OPEN概率。在这项拟议的研究中，两个光子激光器 显微镜系统将用于直接检查能量状态的急性变化 在各种实验条件下影响Ca2+火花特性。胞质Ca2+（或ROS），A^M， NADH将同时记录在孤立的豚鼠心肌细胞中，并使用 成像。线粒体之间的时空耦合！去极化和Ca2+火花将是 使用定量方法分析。此外，线粒体和Ca2+的计算模型 将开发释放单元以定量研究线粒体能量之间的相互作用 和本地CA2+处理。最后，掺入底物的心肌细胞的集成模型 将开发代谢，细胞电生理学，pH调节和E-C耦合以研究 能源生产，离子通道，CA2+处理和pH的机制以及 在缺血 - 重新灌注期间，导致的心脏收缩功能降低。通过结合 实验和计算结果，这些研究将允许完全了解 缺血后损伤和心力衰竭的发展，并显着刺激了新心脏的发展 疾病疗法。