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

基本信息

批准号：
8502743
负责人：
Lufang Zhou
金额：
$ 22.67万
依托单位：
UNIVERSITY OF ALABAMA AT BIRMINGHAM
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-08-20 至 2015-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8502743
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

项目摘要

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.

心脏病是美国人的最大杀手。越来越多的证据表明，有 Ca2+处理异常与心脏病的发生有着密切的关系。所以了解病理条件下 Ca2+ 信号传导的调节至关重要。 Ca2+ 诱导的 Ca2+ 释放 (CICR) 的局部控制取决于 L 型 Ca2+ 的空间组织通道和兰尼碱受体 (RyR) 成对存在。类似地，线粒体对 Ca2+ 的吸收是由于它们靠近 Ca2+ 释放位点，这是刺激氧化所需的过程工作变化期间的磷酸化。然而，人们对 CICR 的线粒体反馈知之甚少。由于线粒体是活性氧 (ROS) 的主要来源，它们可能会影响细胞质氧化还原状态，进而改变 RyR 开放概率。在这项拟议的研究中，双光子激光器显微镜系统将用于直接检查能量状态动态如何急剧变化在各种实验条件下影响 Ca2+ 火花特性。胞质 Ca2+（或 ROS）、A^m、和 NADH 将在分离的豚鼠心肌细胞中同时记录并使用离线分析成像。线粒体之间的时空耦合！去极化和 Ca2+ 火花将使用定量方法进行分析。此外，线粒体和 Ca2+ 的计算模型将开发释放单元来定量研究线粒体能量学之间的相互作用和局部 Ca2+ 处理。最后，心肌细胞整合基质的集成模型将开发代谢、细胞电生理学、pH 调节和 E-C 耦合来研究能量产生、离子通道、Ca2+ 处理和 pH 值变化的潜在机制，以及缺血再灌注期间心脏收缩功能的降低。通过结合实验和计算结果，这些研究将有助于全面了解缺血后损伤和心力衰竭的发展，并显着促进新型心脏的发展疾病疗法。