MtDNA repair: An isolated pharmacologic target in acute lung injury

MtDNA 修复：急性肺损伤的一个孤立的药理学靶点

基本信息

批准号：
9020265
负责人：
MARK N GILLESPIE
金额：
$ 37.13万
依托单位：
UNIVERSITY OF SOUTH ALABAMA
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：
2012-04-16 至 2018-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9020265
关键词：
Acute Lung Injury Address Adult Respiratory Distress Syndrome Animal Disease Models Animal Model Antioxidants Apoptosis Apoptotic Attenuated Base Excision Repairs Binding Biological Markers Cell Culture Techniques Cell Death Cell Differentiation process Cell Proliferation Cell Survival Cells Chemical Structure Chimeric Proteins Clinical Trials Cultured Cells Cytoprotection DNA DNA Damage DNA Repair DNA Repair Enzymes DNA Repair Pathway DNA glycosylase Data Disease Endothelial Cells Excision Failure Functional disorder Generations Genetic Genetic Transcription Genome Goals Injury Intervention Laboratories Light Link Logic Lung Mammalian Cell Mediating Mitochondria Mitochondrial DNA Modeling Molecular Nitrogen Nuclear Organ Outcome Oxidants Pathogenesis Pathway interactions Pattern Pharmaceutical Preparations Pharmacotherapy Play Population Prevention Production Proteins Pseudomonas aeruginosa Rattus Reactive Oxygen Species Recovery Reporting Research Rodent Role Second Messenger Systems Sentinel Sepsis Signal Transduction Speed Stress Testing Therapeutic Agents Therapeutic Intervention Translating Validation Vascular Endothelial Cell Ventilator base cellular targeting cytotoxic cytotoxicity drug development extracellular insight lung injury macromolecule mitochondrial genome mitochondrial messenger RNA molecular pathology mutant novel oxidant stress practical application prevent programs repaired research study response second messenger

项目摘要

DESCRIPTION (provided by applicant): Numerous studies have explored anti-oxidants as therapeutic agents in acute lung injury (ALI), but their outcome in clinical trials has been disappointing. One explanation for this failure is that oxidants generated in ALI are not only cytotoxic, but they also function as second messengers in pathways required for lung cell proliferation and differentiation. Thus, non-selective antioxidants may disrupt signaling required for cell survival and recovery. A related possibility is that key molecule(s) integrating ROS actions on the pulmonary vasculature have yet to be identified; antioxidants may fail to protect against damage to these putative sentinel molecule(s) governing activation of cell death programs. Based on multiple lines of compelling evidence obtained from cell culture studies, herein we propose to test the concept that mitochondrial (mt) DNA is a sentinel molecule dictating lung cell fate in response to oxidant stress and that the mtDNA repair pathway is a target for intervention in ALI. Specific Aim 1 will begin translating findings from cell culture ino practical application by testing the hypothesis that increasing mtDNA glycosylase activity using novel fusion protein constructs protects against, and reverses, ALI in rodents with either Pseudomonas aeruginosa- or ventilator- induced ALI. These experiments comprise an important step towards our longer term goal of developing mtDNA repair fusion proteins as platform drug molecules for treating ALI. Even though enhancement of mtDNA repair suppresses ROS-mediated cell death, the mechanism of this salutary effect has remained elusive. Traditional concepts hold that accelerated mtDNA repair prevents accumulation of oxidative mtDNA damage, thereby attenuating mitochondrial generation of pro-apoptotic ROS and attendant activation of mitochondrially-driven cell death, but not all currently available data support this model and some studies suggest that mtDNA repair, per se, is unimportant. Accordingly, Specific Aim 2 will use wild type and mutant Ogg1 proteins differing in their capacities to repair - but not to bind - mtDNA to determine whether repair of RS-induced mtDNA damage is required for prevention of RS-induced EC cytotoxicity, barrier dysfunction, and formation an extracellular release of injury-propagating mtDNA fragments.

描述（由申请人提供）：许多研究探索了抗氧化剂作为急性肺损伤（ALI）的治疗剂，但在临床试验中的结果令人失望。对此失败的一种解释是，在ALI中产生的氧化剂不仅是细胞毒性的，而且它们在肺部细胞增殖和分化所需的途径中也充当第二使者。因此，非选择性抗氧化剂可能会破坏细胞存活和恢复所需的信号传导。相关的可能性是，尚未确定在肺脉管系统上整合ROS作用的关键分子尚待鉴定。抗氧化剂可能无法防止对这些推定的前哨分子的损害，该分子是细胞死亡程序的激活。基于从细胞培养研究中获得的多种引人注目的证据，我们建议测试线粒体（MT）DNA是一种前哨分子，该分子决定了响应氧化剂应激的肺细胞命运，并且mtDNA修复途径是ALI干预的目标。特定的目标1将通过测试以下假说，即使用新型融合蛋白构建体可预防和逆向铜绿假单胞菌或静脉诱导的ALI的啮齿动物中的ALI来提高MTDNA糖基化酶活性的假设，从而开始转化细胞培养物INO实际应用的发现。这些实验构成了我们朝着我们的长期目标迈出的重要步骤，即开发mtDNA修复融合蛋白作为用于治疗ALI的平台药物分子。尽管MTDNA修复的增强抑制了ROS介导的细胞死亡，但这种有益作用的机制仍然难以捉摸。传统概念认为，加速的mtDNA维修可防止氧化mtDNA损伤的积累，从而减弱线粒体的促凋亡ROS的生成和线粒体驱动的细胞死亡的伴随激活，但并非所有当前可用的数据支持该模型和一些研究表明，MTDNA修复本身并不重要。因此，特定目标2将使用野生型和突变体OGG1蛋白的修复能力不同 - 但不结合-MtDNA，以确定RS诱导的mtDNA损害是否需要预防RS诱导的EC诱导的障碍物，屏障功能障碍，形成伤害性mmtdna的细胞外释放。