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

描述(申请人提供)：呼吸道合胞病毒(RSV)是导致儿童呼吸道传染病的最常见原因，仅在美国每年就有10万人入院，目前还没有疫苗或有效的治疗方法。在过去的几年里，我们已经证明RSV感染导致转录因子核因子(NF)-kB的激活和活性氧物种(ROS)的快速产生，这两者都参与了趋化因子的表达，趋化因子是调节白细胞迁移和激活到感染部位的促炎介质。此外，RSV诱导的ROS的产生在体外和体内都与氧化应激和肺损伤有关，这是由于ROS的产生和抗氧化细胞防御之间的失衡。初步实验揭示了核因子-kB通过抑制核因子-E2相关因子2(Nrf2)的激活来调节呼吸道合胞病毒感染后AOE基因的表达，Nrf2调节AOE基因的基础和诱导表达。在这个项目中，我们将继续假设，核因子-B在RSV诱导的肺部疾病中发挥关键作用，因为它拮抗依赖于Nrf2的基因表达，导致抑制呼吸道抗氧化防御和随后的氧化性肺损伤。我们将通过追求以下特定目标来验证我们的假设：目的1.确定NF-kB激活导致抑制NRF2激活的机制(S)。我们将研究NF-kB是否通过影响Nrf2的乙酰化，通过组蛋白脱乙酰酶的募集和转录辅助激活物的竞争，以及通过促进Nrf2的泛素化和降解来影响Nrf2的激活。目的2.探讨呼吸道合胞病毒(RSV)体内诱导的核因子-kB(NF-kB)活化的调节是否导致肺组织氧化应激和疾病的减少。我们将在RSV感染的小鼠模型中从药物上抑制NF-kB的激活，并评估氧化损伤、AOE表达和临床疾病的标记物。我们的结果将有助于阐明呼吸道病毒引起肺部疾病的一个重要和新的分子途径，这对开发新的治疗策略具有重要意义，不仅针对病毒引起的下呼吸道感染(LRTI)，而且 还有炎症和氧化应激起重要致病作用的其他急性和慢性肺部疾病，如哮喘和慢性阻塞性肺疾病。

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.