Ca2+ and ROS Crosstalk Signaling in Cardiac Mitochondria

心脏线粒体中的 Ca2 和 ROS 串扰信号传导

基本信息

批准号：
8011076
负责人：
Shey-Shing Sheu
金额：
$ 38.72万
依托单位：
THOMAS JEFFERSON UNIVERSITY
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：
2011-02-01 至 2013-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8011076
关键词：
ATP Synthesis Pathway Adenine Nucleotide Translocase Adult Aging Apoptotic Attention Biochemistry Cardiac Cardiac Myocytes Cardiomyopathies Cell Death Cells Cellular biology Cessation of life Chronic Citric Acid Cycle Confocal Microscopy Coupling Diabetes Mellitus Disease Dynamin Electron Transport Electrons Environment Enzymes Equilibrium Feedback Gene Transfer Generations Guanosine Triphosphate Phosphohydrolases Heart Heart Mitochondria Heart failure Homeostasis Human Knockout Mice Laboratories Lead Libraries Life Link Literature Mediating Metabolism Mitochondria Molecular Biology Mus Myocardial Ischemia Neurodegenerative Disorders Obesity Outer Mitochondrial Membrane Oxidation-Reduction Oxidative Stress Pathology Pathway interactions Permeability Physiological Physiology Play Probability Process Proteins Rattus Reaction Reactive Oxygen Species Reporting Research Reverse Transcriptase Polymerase Chain Reaction Role Ryanodine Receptor Calcium Release Channel Signal Pathway Signal Transduction Symbiosis Techniques Therapeutic Transgenic Mice Translating Ventricular Western Blotting Work cell growth regulation cyclophilin D cytochrome c human disease interdisciplinary approach mouse model public health relevance theories trafficking uptake

项目摘要

DESCRIPTION (provided by applicant): The long-term objective of this proposal is to establish a unified theory to describe the mechanisms of crosstalk signaling between Ca2+ and reactive oxygen species (ROS) in cardiac muscle cells, and to translate these signaling mechanisms to the physiology and pathology of cardiac function. The pivotal role of mitochondrial Ca2+ and ROS in mediating the life and death of cardiac muscle cells is well recognized. The separation between mitochondria-mediated life versus death resides in the finest balance between concentrations of Ca2+ and ROS. The majority of existing research in the field focuses individually either on Ca2+ or ROS homeostasis. The interaction between these two signaling pathways, however, has just begun to gain attention by a small number of laboratories. Intriguingly, there is a growing library of literature suggesting that mitochondrial dynamics (fission, fusion, and trafficking) play an essential role in the physiological regulation of cellular ATP, Ca2+, and ROS homeostasis. In this proposal, we will study how these three important components (Ca2+, ROS, and mitochondrial fission machinery) communicate to regulate cardiac Ca2+ and ROS crosstalk signaling. We will use a multidisciplinary approach encompassing techniques of cell biology (e.g. confocal microscopy), molecular biology (e.g. gene transfer), biochemistry (e.g. western blots), and transgenic mouse models (e.g. cyclophilin D (CypD) knockout mice and mt-cpYFP transgenic mice) to elucidate the mechanisms of ROS and Ca2+ symbiosis with an unique emphasis on mitochondrial fission protein DLP1 and mitochondrial permeability transition (MPT). Our central hypothesis is: an increased mitochondrial Ca2+ concentration ([Ca2+]m) favors the balance of mitochondrial dynamics towards fission that in turn increases ROS generation. The resulting oxidized environment leads to additional mitochondrial Ca2+ influx. Both the increases in [Ca2+]m and ROS enhance the opening probability of MPT that further augments ROS generation. Eventually, this positive feedback loop is counter balanced by Ca2+ and ROS activated mitochondrial Ca2+ efflux mechanisms including Na/Ca exchange and MPT. The three specific aims are: 1) To determine whether an increased [Ca2+]m promotes mitochondrial fission processes, which then lead to increase ROS generation. 2) To assess the contribution of a CypD containing MPT pathway in [Ca2+]m-mediated ROS generation. 3) To determine the role of MPT as a rapid Ca2+ efflux mechanism of mitochondria. PUBLIC HEALTH RELEVANCE: Oxidative stress can cause numerous human diseases including cardiomyopathy in chronic heart failure, ischemic heart disease, neurodegenerative diseases, diabetes, obesity, and aging. The proposed research focuses on the elucidation of cellular mechanisms of reactive oxygen species generation. It is our objective, not only to make a scientific contribution to oxidative stress-mediated disease mechanisms, but also to develop possible therapeutic means for treating these debilitating disorders.

描述（由申请人提供）：该提案的长期目标是建立一个统一的理论来描述心肌细胞中Ca2+和活性氧（ROS）之间的串扰信号传导机制，并将这些信号传导机制转化为心脏功能的生理学和病理学。线粒体 Ca2+ 和 ROS 在介导心肌细胞的生与死中的关键作用已得到广泛认可。线粒体介导的生命与死亡之间的区别在于 Ca2+ 和 ROS 浓度之间的最佳平衡。该领域的大多数现有研究分别关注 Ca2+ 或 ROS 稳态。然而，这两种信号通路之间的相互作用才刚刚开始引起少数实验室的关注。有趣的是，越来越多的文献表明线粒体动力学（裂变、融合和运输）在细胞 ATP、Ca2+ 和 ROS 稳态的生理调节中发挥着重要作用。在本提案中，我们将研究这三个重要组成部分（Ca2+、ROS 和线粒体裂变机制）如何进行通信以调节心脏 Ca2+ 和 ROS 串扰信号传导。我们将使用多学科方法，包括细胞生物学（例如共聚焦显微镜）、分子生物学（例如基因转移）、生物化学（例如蛋白质印迹）和转基因小鼠模型（例如亲环蛋白 D (CypD) 敲除小鼠和 mt-cpYFP 转基因小鼠）小鼠）阐明 ROS 和 Ca2+ 共生机制，特别强调线粒体裂变蛋白 DLP1 和线粒体渗透率转变（MPT）。我们的中心假设是：线粒体 Ca2+ 浓度 ([Ca2+]m) 的增加有利于线粒体动力学向裂变的平衡，从而增加 ROS 的产生。由此产生的氧化环境导致额外的线粒体 Ca2+ 流入。 [Ca2+]m 和 ROS 的增加都增强了 MPT 的开放概率，从而进一步增加了 ROS 的生成。最终，这种正反馈循环通过 Ca2+ 和 ROS 激活的线粒体 Ca2+ 流出机制（包括 Na/Ca 交换和 MPT）来平衡。三个具体目标是： 1) 确定 [Ca2+]m 增加是否会促进线粒体裂变过程，从而导致 ROS 生成增加。 2) 评估含有 MPT 途径的 CypD 在 [Ca2+]m 介导的 ROS 生成中的贡献。 3) 确定MPT作为线粒体快速Ca2+流出机制的作用。公共卫生相关性：氧化应激可导致多种人类疾病，包括慢性心力衰竭引起的心肌病、缺血性心脏病、神经退行性疾病、糖尿病、肥胖和衰老。拟议的研究重点是阐明活性氧生成的细胞机制。我们的目标不仅是对氧化应激介导的疾病机制做出科学贡献，而且还开发可能的治疗方法来治疗这些使人衰弱的疾病。