Amelioration of Mitochondrial Dysfunction by Thioredoxin in Hyperoxia

高氧状态下硫氧还蛋白改善线粒体功能障碍

基本信息

批准号：
9113702
负责人：
KUMUDA C DAS
金额：
$ 25.14万
依托单位：
TEXAS TECH UNIVERSITY HEALTH SCIS CENTER
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-04-01 至 2016-09-14
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9113702
关键词：
Adverse effects Affect Anesthesia procedures Antioxidants Biochemical Biological Assay Bronchopulmonary Dysplasia Cell Nucleus Cell model Cells Clinical Critical Care Cytosol Data Dynamin Electron Spin Resonance Spectroscopy Ensure Environment Enzymes Event Fluorescence Microscopy Functional disorder Generations Human Hyperoxia In Vitro Injury Intervention Knockout Mice Lung Lung diseases MAP Kinase Gene MAPK14 gene Mediating Medical Mitochondria Mitochondrial Proteins Molecular Movement Mus NADH dehydrogenase (ubiquinone)Natural regeneration Nuclear Translocation Oxidation-Reduction Oxidative Stress Oxygen Oxygen Therapy Care Patients Phosphorylation Phosphotransferases Physiological Play Production Proteins Publishing Reactive Oxygen Species Reporting Research Resistance Respiratory Insufficiency Role Signal Transduction Structure of parenchyma of lung Superoxides TXN gene Techniques Testing Toxic effect Transgenic Mice UCP2 protein Up-Regulation antioxidant enzyme base improved in vivo injured lung injury mitochondrial dysfunction mortality mouse model mutant novel overexpression oxidation oxygen toxicity prevent programs protein degradation protein transport public health relevance respiratory distress syndrome response

项目摘要

DESCRIPTION (provided by applicant): Oxygen therapy is a common clinical necessity, but it comes with significant negative side effects. Specifically, the hyperoxic condition it produces generates a number of reactive oxygen species, including superoxide anions that cause mitochondrial dysfunction. Although this toxicity is a key factor in the application of oxygen therapy, little is known about how hyperoxia impacts mitochondrial energy production, or the protein regeneration mechanisms that can offer protection from its effects. Our research program focuses on thioredoxin (Trx), a cytoplasmic redox protein that can reduce oxidative stress and regenerate enzymes that oxidation has inactivated. Recently we published that increased expression of Thioredoxin protects the lung injury and increased survival of Trx-Tg mice in hyperoxia, but mice with lower expression of Trx were more sensitive to hyperoxia and suffered significant mortality. However, the mechanism by which high levels of Thioredoxin protects against lung injury remains unknown. Our preliminary data establish that cytoplasmic Trx1 translocates to mitochondria during hyperoxia, but this movement does not occur in dnTrx-Tg mice. These findings propel us to hypothesize that Trx protects mitochondria from hyperoxia by reducing oxidative stress through UCP-2-dependent uncoupling, and furthermore by protecting mitochondrial dysfunction in hyperoxia as superoxide anion generation in the mitochondria is a key mechanism of pulmonary oxygen toxicity. Accordingly, in Aim 1 we will determine whether and how translocated cytoplasmic Trx1 protects against mitochondrial dysfunction in hyperoxia. In Aim 2 we will find if high levels of Trx prevents dynamin-related protein (Drp1) activation and thereby protects against mitochondrial fragmentation and dysfunction. In Aim 3 we will determine if increased translocation of PGC-1α to the nucleus in Trx-Tg mice can protect against the mitochondrial dysfunction caused by hyperoxia. Using state-of-the-art techniques that include mitochondrial flux analysis, EPR spectroscopy, biochemical enzymatic assay, and cutting-edge molecular approaches, we will dissect the role Trx1 plays in protecting the dysfunctional mitochondria in hyperoxia. We will also create a novel conditional Trx knockout mouse, a PGC1a-knockout mouse with increased or decreased expression of Trx to understand in vivo role of high levels of Trx on mitochondrial dysfunction in hyperoxia. The project is expected to provide a clear understanding of the way cytosolic Trx1 affects mitochondrial function during normoxia and hyperoxia. Using the transgenic mice (and cells derived from them) for in vivo and in vitro mechanistic studies, we expect to uncover mitochondrial mechanisms that are modulated by Trx1 during hyperoxia. We believe results produced by the project will incite novel intervention strategies to protect patients against pulmonary toxicity resulting from oxygen therapy.

描述（由应用提供）：氧疗法是常见的临床必需品，但具有显着的负面影响。具体而言，它会产生多种活性氧，包括引起线粒体功能障碍的超氧化物阴离子。尽管这种毒性是氧疗法应用的关键因素，但对于高氧如何影响线粒体能量产生或蛋白质再生机制，可以保护其影响的蛋白质再生机制，鲜为人知。我们的研究计划着重于硫氧还蛋白（TRX），硫氧还蛋白是一种可减少氧化应激和再生酶灭活的酶的细胞质氧化还原蛋白。最近，我们发表了硫氧还蛋白的表达增加可保护肺损伤并增加TRX-TG小鼠在高氧中，但TRX表达较低的小鼠对高氧更敏感并具有显着的死亡率。但是，高水平的硫氧还蛋白预防肺损伤的机制尚不清楚。我们的初步数据建立，即在高氧期间细胞质TRX1易位到线粒体，但是在DNTRX-TG小鼠中不会发生这种运动。这些发现推动我们假设TRX通过通过UCP-2依赖性解偶偶联来减少氧化应激来保护线粒体免受高氧，然后通过保护高氧中的线粒体功能障碍作为超氧化物的线粒体产生的线粒体产生的线粒体产生的线粒体氧化物的钥匙是肺氧化物的钥匙机制。根据AIM 1，我们将确定易位的细胞质TRX1是否以及如何预防高氧中线粒体功能障碍。在AIM 2中，我们将发现高水平的TRX是否可以防止动力学相关蛋白（DRP1）激活，从而防止线粒体碎片化和功能障碍。在AIM 3中，我们将确定在TRX-TG小鼠中PGC-1α向细胞核的易位是否可以预防由高氧引起的线粒体功能障碍。使用包括线粒体通量分析，EPR光谱，生化酶测定和尖端分子方法的最先进技术，我们将剖析TRX1在保护高氧中功能障碍线粒体方面的作用。我们还将创建一种新型的有条件TRX敲除小鼠，一种PGC1A-敲除小鼠，其TRX表达增加或降低，以了解高水平TRX对高氧中线粒体功能障碍的体内作用。预计该项目将清楚地了解胞质TRX1在常氧和高氧期间影响线粒体功能的方式。使用转基因小鼠（以及从中得出的细胞）进行体内和体外机械研究，我们希望在高氧过程中揭示由TRX1调节的线粒体机制。我们认为，该项目产生的结果将促进新的干预策略，以保护患者免受氧气治疗引起的肺毒性。