Oxidative Stress and the Development of Osteoarthritis

氧化应激与骨关节炎的发展

基本信息

批准号：
8550762
负责人：
RICHARD F LOESER
金额：
$ 36.14万
依托单位：
WAKE FOREST UNIVERSITY HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-09-30 至 2014-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8550762
关键词：
1-Phosphatidylinositol 3-Kinase Affect Age Aging Antioxidants Cartilage Cell Death Cell Survival Cells Chemicals Chondrocytes Chronic Collagen Cysteine Degenerative polyarthritis Development Disease Disease Progression Elderly Enzymes Exhibits Generations Genes Human Joints Label Link MAPK8 gene MEKs Measures Mechanics Medial meniscus structure Meniscus structure of joint Mitochondria Mitogen-Activated Protein Kinases Modification Mus Normal Cell Oxidation-Reduction Oxidative Stress Pathogenesis Pathway interactions Phosphorylation Play Predisposition Process Protein Biosynthesis Proteins Proteoglycan Proteomics Reactive Oxygen Species Regulation Relative (related person)Respiratory Chain Role Second Messenger Systems Serine Severities Signal Pathway Signal Transduction Signaling Protein Source Stress Tests Synovial Cell Testing Tissues Transfection Transgenic Mice Work aged articular cartilage base catalase cytokine disability in vivo inhibitor/antagonist mitochondrial dysfunction novel strategies overexpression oxidation p66(ShcA) protein response second messenger tert-Butylhydroperoxide

项目摘要

DESCRIPTION (provided by applicant): The long-term objective of this project is to determine the mechanisms by which oxidative stress contributes to the pathogenesis of osteoarthritis (OA) by focusing on mechanisms by which reactive oxygen species (ROS) alter cell signaling in the articular cartilage and meniscus. Oxidative stress results when levels of ROS exceed the anti-oxidant capacity of cells. Studies to date suggest that oxidative stress can contribute to fundamental processes found in OA, including excessive catabolic relative to anabolic activity and cell death, but the mechanisms responsible have not been defined. Mitochondria are an important source of intracellular ROS and our preliminary studies demonstrate that overexpression of the anti-oxidant enzyme catalase, targeted to the mitochondria in transgenic mice, reduces the severity of age-associated OA. We propose that in OA, pathological levels of ROS are generated by the mitochondria which, when combined with a deficient anti-oxidant capacity, results in excessive protein oxidation that shifts cell signaling to favor catabolic over anabolic signaling and to promote cell death. Our studies will focus on mechanisms by which excessive levels of ROS disrupt the IRS-1-PI-3 kinase-Akt signaling pathway. Akt plays a central role in integrating anabolic and catabolic signaling as well as in promoting cell survival. We have found that in OA chondrocytes and in normal cells induced to exhibit oxidative stress, Akt activation is inhibited and this is associated with reduced matrix synthesis and increased susceptibility to cell death. We will pursue the following specific aims: 1) Determine the mechanism for inhibition of IRS-1-PI-3kinase-Akt signaling in chondrocytes during oxidative stress and test the hypothesis that excessive levels of ROS oxidize specific proteins that activate the MAP kinase pathway which inhibits Akt1 activation through inhibition of IRS-1-PI-3 kinase signaling and 2) Determine the effects of overexpression of catalase targeted to the mitochondria on the development of osteoarthritis in mice and test the hypothesis that overexpression of catalase will reduce OA severity. Effects on the signaling proteins discovered to be important in inhibiting Akt will be studied. The discoveries made by this work will be used to develop new therapies that would replace the untargeted general anti-oxidant approach with more a more targeted approach aimed at the specific pathways affected by oxidative stress and contributing to OA.

描述（由申请人提供）：该项目的长期目标是通过关注活性氧（ROS）改变骨关节炎（OA）中细胞信号传导的机制来确定氧化应激导致骨关节炎（OA）发病机制。关节软骨和半月板。当 ROS 水平超过细胞的抗氧化能力时，就会产生氧化应激。迄今为止的研究表明，氧化应激可能导致骨关节炎的基本过程，包括相对于合成代谢活动的过度分解代谢和细胞死亡，但其机制尚未明确。线粒体是细胞内 ROS 的重要来源，我们的初步研究表明，针对转基因小鼠线粒体的抗氧化酶过氧化氢酶的过度表达，可以减轻与年龄相关的 OA 的严重程度。我们认为，在 OA 中，病理水平的 ROS 是由线粒体产生的，当与抗氧化能力不足相结合时，会导致蛋白质过度氧化，从而使细胞信号转而有利于分解代谢。合成代谢信号并促进细胞死亡。我们的研究将重点关注过量 ROS 破坏 IRS-1-PI-3 激酶-Akt 信号通路的机制。 Akt 在整合合成代谢和分解代谢信号以及促进细胞存活方面发挥着核心作用。我们发现，在 OA 软骨细胞和被诱导表现出氧化应激的正常细胞中，Akt 激活受到抑制，这与基质合成减少和细胞死亡敏感性增加有关。我们将追求以下具体目标：1）确定氧化应激期间软骨细胞中IRS-1-PI-3激酶-Akt信号传导的抑制机制，并测试过量水平的ROS氧化激活MAP激酶途径的特定蛋白质的假设，通过抑制 IRS-1-PI-3 激酶信号传导来抑制 Akt1 激活，2) 确定靶向线粒体的过氧化氢酶过度表达对小鼠骨关节炎发展的影响，并检验以下假设：过氧化氢酶的过度表达将降低 OA 的严重程度。将研究对抑制 Akt 重要的信号蛋白的影响。这项工作的发现将用于开发新疗法，以针对受氧化应激影响并导致 OA 的特定途径的更有针对性的方法来取代无针对性的一般抗氧化方法。