Antioxidants regulators in VALI

本SCCOR应用程序的总体目标是了解与呼吸机相关肺损伤（VALI）相关的复杂事件。在项目6中，我们将确定氧化应激在VALI中的作用。氧化应激通常通过产生活性氧（ROS）参与急性肺损伤。为了解毒ROS，肺细胞表达由经典解毒酶和II相解毒酶组成的集成抗氧化酶（AOE）网络。然而，如果氧化应激是压倒性的，ROS可能会抑制或破坏AOE系统，导致细胞损伤。我们最近通过基因和 NF-E2相关因子2（Nrf 2）在高氧肺损伤中起重要作用。该转录因子参与肺上皮细胞修复和伸展，并调节II相AOE的诱导。我们还表明，Nrf 2基因敲除小鼠更容易受到高氧诱导的肺损伤。与SCCOR的各种核心合作，基因组分析揭示了Nrf 2和AP-1家族成员的上调，如Fos相关蛋白-1（Fra-1），以及暴露于机械通气（MV）的小鼠和犬肺中的特定AOE。因此，我们假设转录因子如Nrf 2和Fra-1及其下游效应子的激活在VALI的调节中起关键作用。为了验证这一假设，我们提出了以下具体目标：1）确定肺对VALI发展中MV和高氧的分子反应。我们将比较小鼠肺损伤的基因和蛋白质表达谱以及标记物， 暴露于MV和高氧的狗; 2）检查Nrf 2的作用并鉴定其在VALI中的下游效应物;和3）检查Fra-1的作用并鉴定其在VALI中的下游效应物。对于这些研究，我们将使用相应的基因敲除和/或转基因小鼠与特定的肺过表达的突变体或野生型蛋白的Nrf 2和Fra-1，以及基因组学和蛋白质组学技术与各种核心合作。这些结果在人体中的跨物种比较和验证将分别通过与其他基础和临床研究项目的合作进行。这些研究的结果将提供进一步了解氧化应激的作用以及VALI的分子和遗传基础。识别 分子靶点的研究将有助于开发新的策略，旨在最大限度地减少MV和高氧的潜在危险作用。

The overall aim of this SCCOR application is to understand the complex events related to ventilator-associated lung injury (VALI). In Project 6, we will determine the role of oxidative stress in VALI. Oxidative stress has been generally implicated in acute lung injury through production of reactive oxygen species (ROS). To detoxify ROS, lung cells express a network of integrated antioxidant enzymes (AOE) consisting of both classical and phase II detoxifying enzymes. However, if the oxidant stress is overwhelming, ROS may suppress or inactivate the AOE system resulting in cellular damage. We have recently shown by genetic and functional analysis that NF-E2 related factor 2 (Nrf2) plays a critical role in hyperoxia-induced lung injury. This transcription factor is involved in lung epithelial cell repair and stretch and regulates the induction of phase II AOEs. We have also shown that Nrf2-knockout mice are more susceptible to hyperoxia-induced lung injury. In collaboration with the various Cores of the SCCOR, genomic analysis revealed an upregulation of Nrf2 and AP-1 family members, such as fos-related protein-1 (Fra-1), as well as specific AOEs in the lungs of mice and dogs exposed to mechanical ventilation (MV). Thus, we hypothesize that activation of transcription factors such as Nrf2 and Fra-1 and their downstream effectors plays a critical role in the modulation of VALI. To test this hypothesis, we propose the following Specific Aims: 1) Determine the molecular responses of the lung in response to MV and hyperoxia in the development of VALI. We will compare gene and protein expression profiles and markers of injury in the lungs of mice and dogs exposed to MV and hyperoxia; 2) Examine the role of Nrf2 and identify its downstream effectors in VALI; and 3) Examine the role of Fra-1 and identify its downstream effectors in VALI. For these studies, we will use respective knockout and/or transgenic mice with specific lung overexpression of mutant or wildtype proteins of Nrf2 and Fra-1, as well as genomics and proteomics techniques in collaboration with the various Cores. Cross species comparison and validation of these results in human will be done through collaboration with other Basic and Clinical Research Projects, respectively. Results of these studies will provide further insight into the role of oxidative stress as well as the molecular and genetic basis of VALI. The identification of molecular targets will aid in the development of new strategies aimed at minimizing the potential I hazardous effects of MV and hyperoxia.