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Dynamin-Related Protein Drp1 Regulates Cardiac Excitation-Contraction-Bioenergetics Coupling

动力相关蛋白 Drp1 调节心脏兴奋-收缩-生物能耦合

基本信息

批准号：
10063889
负责人：
Shey-Shing Sheu
金额：
$ 62.87万
依托单位：
THOMAS JEFFERSON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-01-01 至 2023-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10063889
关键词：
Actins Adrenergic Receptor Adult Architecture Binding Biochemistry Bioenergetics Biological Assay Biological Markers Brain Cardiac Cardiac Myocytes Cardiomyopathies Cell Death Cell Nucleus Cell Volumes Cell division Cells Cellular biology Cessation of life Chronic Coupling Cytoskeleton Data Diabetes Mellitus Disease Dynamin Echocardiography Electron Microscopy Electrons Endoplasmic Reticulum Energy Metabolism Exhibits F-Actin Face Fibroblasts Fluorescence Resonance Energy Transfer Frequencies Functional disorder Gap Junctions Generations Genes Guanosine Triphosphate Heart Heart Hypertrophy Heart failure Hot Spot Image In Situ In Vitro Infusion procedures Injury Isoproterenol Knock-in Knock-out Knowledge Lead Left Link Location Malignant Neoplasms Mammalian Cell Mediating Membrane Membrane Potentials Messenger RNA Microfilaments Microscopy Mitochondria Molecular Molecular Biology Movement Muscle Cells Myocardial dysfunction Myocardium Myofibrils NMR Spectroscopy Neurodegenerative Disorders Northern Blotting Optic Atrophy Organelles Oxidation-Reduction Phosphorylation Physiological Physiology Process Production Proteins Quality Control RNA Interference Rattus Reactive Oxygen Species Regulation Reporting Research Personnel Resolution Respiration Role Sarcolemma Sarcoplasmic Reticulum Signal Pathway Signal Transduction Site Skeletal Muscle Stress Techniques Testing Therapeutic Agents Tissues Ventricular Work Workload base calmodulin-dependent protein kinase II cell injury cell type density human disease insight mitochondrial membrane mitochondrial permeability transition pore mouse model oocyte maturation overexpression recruit respiratory targeted treatment

项目摘要

Project Summary/Abstract Mitochondrial dynamics, including fission, fusion, and movement, is a fundamental mechanism in regulating mitochondrial function. Dynamin-related protein 1 (Drp1) is the major GTP hydrolyzing protein that is responsible for fission. Studies have shown that Drp1 is abundantly expressed in adult cardiac myocytes. Paradoxically, compared to numerous cell types, adult cardiac myocytes exhibit very low frequency in mitochondrial fission. This dichotomy between the abundance of Drp1 and scarcity of mitochondrial fission has prompted us to investigate the non-canonical roles of Drp1 in cardiac muscle cells. We hypothesize that Drp1 is strategically accumulated in the mitochondria associated sarcoplasmic reticulum (SR) membrane (MAM). During excitation- contraction coupling, the localized high Ca2+ in the SR-mitochondria junctions further increases the translocation of nearby cytosolic Drp1 to mitochondria. Then, Drp1 is anchored firmly in the MAM by actin. The activation of Drp1 leads to enhanced mitochondrial respiration for ATP generation as such the heart can work most effectively and sustainably. However, excessive Drp1 activation leads to persistent mitochondrial transition pore opening and excessive reactive oxygen species (ROS) generation that causes cell injury and death. The following three specific aims are proposed to test this hypothesis. Aim 1: To determine whether and how Drp1 is preferentially localized in the SR-mitochondria junctions. Aim 2: To determine the molecular mechanisms by which Drp1 regulates excitation-contraction-bioenergetics coupling. Aim 3: To determine how chronic over activation of Drp1 leads to dysfunction in the stressed heart. We will employ multiple techniques, including biochemistry (from in vitro to in situ assays), molecular biology (gene knock in or knock out, overexpression, RNA interference), cell biology (confocal, fluorescence resonance energy transfer, super-resolution microscopy, electron microscopy), cardiac physiology (echocardiogram, NMR spectroscopy), and isoproterenol infusion mouse model of cardiac hypertrophy and failure, to obtain experimental results that will lead to mechanistic insights. Successful completion of the proposed aims will allow us to introduce a new paradigm that describes the regulation of excitation-contraction-bioenergetics-ROS nexus by Drp1 through localized Ca2+ activation and actin anchoring. This fundamental signaling mechanism will describe not only how a healthy heart can perform perpetually in face of enormous workload but also why the over activation of this unique process can lead to heart failure. Finally, this new knowledge will provide new insights in developing and discovering therapeutic agents targeting Drp1-mediated signaling pathways for treating heart failure.

项目摘要/摘要线粒体动力学，包括分裂、融合和运动，是调节线粒体功能。动力蛋白相关蛋白1(Drp1)是GTP的主要水解物负责裂变的蛋白质。研究表明，Drp1在成年心肌细胞。矛盾的是，与众多细胞类型相比，成人心肌细胞线粒体分裂的频率很低。在丰富的自然资源和自然资源之间 Drp1和线粒体分裂的稀缺性促使我们研究非典范作用。 DRP1在心肌细胞中的表达。我们假设Drp1在战略上积累在线粒体相关肌浆网(SR)膜(MAM)。在激励过程中- 收缩偶联，肌浆网线粒体连接局部高钙进一步增加邻近胞质的Drp1向线粒体的移位。然后，Drp1被牢固地锚定在肌动蛋白的作用。DRp1的激活导致线粒体对ATP的呼吸增强这样一代人的心才能最有效和可持续地工作。然而，过度 Drp1激活导致线粒体持续过渡孔洞开放和过度反应氧物种(ROS)的产生，导致细胞损伤和死亡。下面是三个具体的为了检验这一假说，我们提出了目标。目标1：确定Drp1是否以及如何优先定位于SR-线粒体连接处。目的2：确定分子 DRp1调节兴奋-收缩-生物能耦合的机制。目标3：实现确定长期过度激活的Drp1是如何导致应激心脏功能障碍的。我们会使用多种技术，包括生物化学(从体外到原位分析)、分子生物学(基因敲入或敲除、过表达、RNA干扰)、细胞生物学(共聚焦、荧光共振能量转移，超分辨显微镜，电子显微镜)，心脏生理学(超声心动图、核磁共振波谱)和异丙肾上腺素注射小鼠心肌肥厚和衰竭的模型，获得的实验结果将导致机械的洞察力。成功完成拟议的目标将使我们能够推出一个新的描述兴奋-收缩-生物能量学-ROS联系调节的范式 Drp1通过局部的钙激活和肌动蛋白锚定。这一基本信号机制不仅描述了健康的心脏如何在面对巨大的工作量，但也是为什么这一独特过程的过度激活会导致心脏失败了。最后，这一新知识将为开发和发现靶向Drp1介导的信号通路的治疗药物用于治疗心力衰竭。