A novel role of NF-kB in viral-induced airway oxidative stress

描述（由申请人提供）：呼吸道合胞病毒（RSV）是儿童流行性呼吸道疾病的最常见原因，仅在美国每年就有10万例住院病例，目前尚无疫苗或有效治疗方法。在过去的几年中，我们已经表明，RSV感染导致转录因子核因子（NF）-kB的激活，以及活性氧（ROS）的快速产生，这两者都参与了趋化因子的表达，促炎介质调节白细胞迁移和激活感染部位。此外，由于ROS产生和抗氧化细胞防御之间的不平衡，RSV诱导的ROS产生与体外和体内的氧化应激和肺损伤相关。初步实验揭示了NF-κ B通过抑制NF-E2相关因子2（Nrf 2）的活化（Nrf 2调节AOE基因的基础和诱导型表达），在RSV感染后调节AOE基因表达中的新的基本作用。在这个项目中，我们将探讨NF-B在RSV诱导的肺部疾病中起关键作用的假设，因为它拮抗Nrf 2依赖性基因表达，导致气道抗氧化防御和随后的氧化性肺损伤的抑制。我们将通过追求以下具体目标来检验我们的假设：目标1。确定NF-kB激活导致Nrf 2激活抑制的机制。我们将研究NF-κ B是否通过影响其乙酰化，通过组蛋白脱乙酰酶的招募和转录辅激活因子的竞争，以及通过促进Nrf 2泛素化和降解来影响Nrf 2的激活。目标二。研究RSV诱导的NF-kB活化在体内的调节是否导致肺氧化应激和疾病的降低。我们将在RSV感染的小鼠模型中抑制NF-κ B活化，并评估氧化损伤、AOE表达和临床疾病的标志物。我们的研究结果将有助于阐明呼吸道病毒诱导肺部疾病的一个重要的新分子途径，这对开发新的治疗策略具有重要意义，不仅针对病毒诱导的下呼吸道感染（LRTI）， 还有炎症和氧化应激起重要致病作用的其它急性和慢性肺病，例如哮喘和慢性阻塞性肺病。

DESCRIPTION (provided by applicant): Respiratory syncytial virus (RSV) is the most common cause of epidemic respiratory disease in children, responsible for 100,000 hospital admissions annually in the US alone, for which no vaccine or effective treatment is currently available. In the past years, we have shown that RSV infection leads to activation of the transcription factor Nuclear Factor (NF)-kB, as well as to the rapid generation of reactive oxygen species (ROS), both of which are involved in the expression of chemokines, proinflammatory mediators that regulate the migration and activation of leukocytes to the site of infection. In addition, RSV-induced ROS generation is associated with oxidative stress and lung damage both in vitro and in vivo, due to an imbalance between ROS production and antioxidant cellular defenses. Preliminary experiments revealed a new and fundamental role of NF-kB in modulating AOE gene expression in response to RSV infection, by inhibiting activation of NF-E2- related factor 2 (Nrf2), which regulates basal and inducible expression of AOE genes. In this project we will pursue the hypothesis that NF-¿B plays a key role in RSV-induced lung disease as it antagonizes Nrf2- dependent gene expression, leading to inhibition of airway antioxidant defenses and subsequent oxidative lung damage. We will test our hypothesis by pursuing the following Specific Aims: Aim 1. To determine the mechanism(s) by which NF-kB activation leads to inhibition of Nrf2 activation. We will investigate whether NF- kB affects Nrf2 activation by affecting its acetylation, through the recruitment of histone deacetylases and competition of transcriptional coactivators, and by promoting Nrf2 ubiquitination and degradation. Aim 2. To investigate whether modulation of RSV-induced NF-kB activation in vivo leads to decreased lung oxidative stress and disease. We will pharmacologically inhibit NF-kB activation in a mouse model of RSV infection and assess markers of oxidative injury, AOE expression and clinical disease. Our results will help elucidate an important and novel molecular pathway by which respiratory viruses induce lung disease, with strong implications for developing novel therapeutic strategies not only against viral-induced lower respiratory tract infections (LRTI) but also other acute and chronic lung diseases where inflammation and oxidative stress play an important pathogenic role, such as asthma and chronic obstructive pulmonary disease.