Mechanistic Characterization of Calcium and ROS Induced Mitochondrial Dysfunction

描述（由申请人提供）：在美国，有超过800万人在其一生中至少遭受过一次急性心肌梗死。致死性缺血/再灌注（I/R）损伤是心肌梗死的主要损伤之一。这种类型的损伤表现为线粒体通透性转变（MPT）现象，这是线粒体功能障碍的一种有害形式。MPT导致心肌凋亡或坏死，并与线粒体Ca2+处理和氧化应激功能障碍有关。直到最近，MPT才被认为是心肌I/R损伤的一种生理反应，但目前的临床治疗方法仍然需要改进。本研究旨在量化与线粒体功能障碍相关的生物物理现象和化学动力学，阐明在离体豚鼠心脏线粒体生理和病理生理条件下，特别是I/R损伤下，线粒体Ca2+和ROS稳态与MPT诱导之间的关系。这种协同计算/实验方法将包括计算建模和实验观察，以帮助制定和定量测试与线粒体功能障碍相关的假设。在此过程中，本研究将促进一种合理和机制的方法来确定新的治疗靶点，并开发新的疗法来纠正或预防病理条件下的线粒体功能障碍，特别是I/R损伤。该项目的主要目的是帮助首席研究员建立独立性并获得终身教职，以便建立一个研究项目，阐明与线粒体Ca2+失调和氧化应激相关的线粒体功能障碍的起源。在指导阶段，申请人将发展必要的实验敏锐度，以补充他们的建模技能，并在线粒体生理学和计算生物学领域保持独立的研究生涯。培训将包括操作最先进的设备来表征线粒体Ca2+封存系统，并开发心脏线粒体ROS稳态模型。在独立阶段，申请人将运用他最近的实验训练来确定线粒体Ca2+和ROS稳态丢失的机制，并表征这些信号成分的失调如何导致MPT导致灾难性的细胞和器官系统衰竭。本项目的工作将使我们更接近了解MPT的病理生理学，并且开发的模型将成为开发新疗法的宝贵工具，以帮助预防或减轻未减轻MPT诱导的有害后果。

DESCRIPTION (provided by applicant): In the United States, there are more than 8 million people who have suffered from at least one acute myocardial infarction in their lifetime. One of the major injuries associated with myocardial infarction is lethal ischemia/reperfusion (I/R) injur. This type of injury manifests from a phenomenon known as mitochondrial permeability transition (MPT), a detrimental form of mitochondrial dysfunction. MPT results in myocardial apoptosis or necrosis and is linked to dysfunction in mitochondrial Ca2+ handling and oxidative stress. Only recently has MPT been accepted as being a physiological response to myocardial I/R injury, but there still remains a significant need to improve current clinical treatments. This proposal aims to quantify the biophysical phenomena and chemical kinetics associated with mitochondrial dysfunction and to elucidate the relationship between mitochondrial Ca2+ and ROS homeostasis with MPT induction under physiological and pathophysiological conditions, particularly I/R injury, in isolated guinea pig cardiac mitochondria. This synergistic computational/experimental approach will encompass computational modeling and experimental observation to help formulate and quantitatively test hypotheses related to mitochondrial dysfunction. In doing so, this study will facilitate a rational and mechanistic approach to identify new therapeutic targets and develop novel therapies to correct or prevent mitochondrial dysfunction under pathological conditions, particularly I/R injury. The main purpose of this project is to provide the Principal Investigator with assistance to establish his independence and obtain a tenure-track faculty position in order to setup a research program to elucidate the origin of mitochondrial dysfunction associated with mitochondrial Ca2+ dysregulation and oxidative stress. During the mentored phase, the applicant will develop the necessary experimental acumen to complement their modeling skill set and sustain an independent research career in the field of mitochondrial physiology and computational biology. The training will include operating state-of-the-art equipment to characterize the mitochondrial Ca2+ sequestration system and develop a model of ROS homeostasis for cardiac mitochondria. During the independent phase, the applicant will apply his recent experimental training to determine the mechanism(s) responsible for the loss in mitochondrial Ca2+ and ROS homeostasis and characterize how dysregulation in these signaling constituents lead to MPT resulting in catastrophic cellular and organ system failure. The work laid out in this project will move us one step closer to understanding the pathophysiology of MPT, and the model developed will be an invaluable tool for the development of novel therapeutics to help prevent or assuage the detrimental consequences of unmitigated MPT induction.