Nox2-Calcium Signaling in Skeletal Muscle

骨骼肌中的 Nox2-钙信号传导

• 批准号: 8505381
• 负责人: George G Rodney
• 金额: $ 33.2万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-01 至 2017-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8505381
• 关键词: Address; Animal Model; Biological; Calcium; Calcium Signaling; Cells; Coupling; Cytosol; Data; Development; Disease; Dominant-Negative Mutation; Electric Stimulation; Exercise; Fatigue; Foundations; Functional disorder; Generations; Goals; Green Fluorescent Proteins; HIV; Heart failure; Homeostasis; Isometric Exercise; Knockout Mice; Life; Link; Malignant Neoplasms; Measurement; Measures; Mechanical Stress; Membrane; Mitochondria; Multienzyme Complexes; Mus; Muscle; Muscle Contraction; Muscle Fatigue; Muscle Fibers; Muscle Weakness; Muscle function; Muscular Dystrophies; Myopathy; Myosin ATPase; NADPH Oxidase; Oxidation-Reduction; Oxidative Stress; Pathway interactions; Patients; Performance; Phosphorylation; Physiological; Play; Process; Production; Pulmonary Emphysema; Reactive Oxygen Species; Regulation; Research; Research Project Grants; Role; Scientist; Signal Pathway; Signal Transduction; Signal Transduction Pathway; Signaling Molecule; Site; Skeletal Muscle; Specific qualifier value; Staging; Stretching; Testing; Triad Acrylic Resin; Work; antioxidant therapy; base; combat; feeding; flexor digitorum brevis; inhibitor/antagonist; novel; oxidation; prevent; public health relevance; research study; response; sensor; spatiotemporal; src-Family Kinases; tool

DESCRIPTION (provided by applicant): Generation of reactive oxygen species (ROS) under physiological conditions is required for normal force production in skeletal muscle. However, high levels of ROS are observed during intense physical exercise and promote contractile dysfunction, resulting in muscle weakness and fatigue. There is growing evidence that sub-cellular site-specific ROS production governs the beneficial vs. damaging effects of ROS. NADPH oxidase (Nox2) is an enzyme complex that generates ROS. Ongoing work by PI has found that increased ROS generation from Nox2 during intense contractile activity contributes to fatigue. We have strong evidence that Src tyrosine kinase acts as a redox switch to activate Nox2. The central hypothesis of this proposal is that Nox2 and Src act through a feed-forward pathway leading to excessive ROS production and contractile dysfunction. We will use genetically modified mice lacking Nox2, genetically encoded site-specific redox sensors and a novel tool to measure force and Ca2+ transients simultaneously in living skeletal muscle fibers to address the following specific aims: 1. Define the mechanisms by which contractile activity increases Nox2 dependent ROS production in skeletal muscle, 2. Determine whether Src serves as a redox switch to modulate activity dependent ROS production, and 3. Assess the role of Nox2 and Src on cytosolic [Ca2+ ]i transients and force generation. The proposed research will identify the sub-cellular sites of ROS production and elucidate the signaling pathways that control ROS regulation of microdomain Ca2+ signaling in skeletal muscle. Furthermore, it will lay the foundation for the development of targeted antioxidant therapy to combat the deleterious effects of overproduction of ROS seen in muscle fatigue and disease.

描述（由申请人提供）：生理条件下活性氧（ROS）的产生是骨骼肌产生正常力所必需的。然而，在剧烈的体育运动中观察到高水平的ROS，并促进收缩功能障碍，导致肌肉无力和疲劳。越来越多的证据表明，亚细胞位点特异性ROS产生控制着ROS的有益作用与破坏作用。NADPH氧化酶（Nox 2）是一种产生活性氧的酶复合物。PI正在进行的工作发现，在强烈的收缩活动期间，Nox 2产生的ROS增加会导致疲劳。我们有强有力的证据表明，Src酪氨酸激酶作为一个氧化还原开关激活Nox2。该提议的中心假设是Nox 2和Src通过前馈途径起作用，导致过量的ROS产生和收缩功能障碍。我们将使用缺乏Nox 2的转基因小鼠，遗传编码的位点特异性氧化还原传感器和一种新的工具来同时测量活骨骼肌纤维中的力和Ca2+瞬变，以解决以下具体目标：1.定义收缩活动增加骨骼肌中Nox2依赖性ROS产生的机制，2。确定Src是否作为氧化还原开关来调节活性依赖性ROS产生，以及3.评估Nox2和Src对胞质[Ca2+ ]i瞬变和力产生的作用。该研究将确定ROS产生的亚细胞位点，并阐明控制骨骼肌中ROS调节微域Ca 2+信号的信号通路。此外，它将为靶向抗氧化治疗的发展奠定基础，以对抗在肌肉疲劳和疾病中看到的ROS过度产生的有害影响。