The role of toll-like receptor 4 in O3-induced lung inflammation and injury.

描述(由申请人提供) 臭氧暴露与成人和儿童的哮喘加重和肺功能改变以及死亡有关。超过50%的美国人口生活在臭氧浓度接近或超过国家环境空气质量标准(百万分之0.12)的地区。候选人先前发现先天免疫基因Toll样受体4(TLR4)是03诱导的肺高通透性和炎症的候选易感基因。C3H/HeOuJ小鼠(TLR4充足)与同基因C3H/HeJ小鼠(TLR4显性负突变)相比，更容易受到臭氧诱导的高通透性和炎症反应。然而，TLR4介导的反应的下游效应机制仍然不清楚。这项建议的总体目标是确定TLR4介导臭氧诱导的肺部炎症和高通透性的机制。建议的研究将在活体动物模型中使用分子生物学、遗传学和药理学技术的多学科方法来解决以下具体目标：1)利用TLR4显性阴性和TLR4转基因小鼠，研究菌株背景对TLR4在臭氧诱导的肺高通透性和炎症中的作用的影响；2)确定TLR4下游的即时信号事件是否因臭氧暴露而改变，并评估这些菌株的下游细胞因子谱，以确定菌株背景是否可以调节产生的细胞因子的类型；3)通过使用分子方法验证从Affymetrix全球基因阵列中识别的候选基因在活体中的重要性，并利用遗传学(基因敲除小鼠)和药理学方法来研究先前通过微阵列方法识别的特定候选基因，来研究TLR4依赖的通路调节臭氧诱导的反应的下游机制。这一建议将通过识别调节臭氧敏感性的新途径来加强对臭氧诱导的肺炎症和损伤机制的理解。这些新的途径可能会为那些易受臭氧影响的人提供预防策略。

DESCRIPTION (provided by applicant) Ozone (O3) exposure associates with exacerbation of asthma and altered lung function in adults and children, and mortality. Over 50% of the United States population live in regions where O3 concentrations approach or exceed the National Ambient Air Quality Standard of 0.12 parts per million (ppm). The candidate previously identified the innate immunity gene toll-like receptor 4 (Tlr4) as a candidate susceptibility gene for 03-induced lung hyperpermeability and inflammation. C3H/HeOuJ mice (Tlr4 sufficient) are significantly more susceptible to O3-induced hyperpermeability and inflammation compared to co-isogenic C3H/HeJ mice (Tlr4 dominant negative mutation). However, the downstream effector mechanisms for TLR4-mediated responses are still unclear. The overall objective of this proposal is to determine the mechanisms by which TLR4 mediates O3 induced lung inflammation and hyperpermeability. The proposed studies will use a multidisciplinary approach using molecular biology, genetics, and pharmacological techniques in an in vivo animal model to address the following specific aims: 1) examine the influence of strain background on the role of Tlr4 in O3-induced lung hyperpermeability and inflammation using mice that are Tlr4 dominant negative and Tlr4 transgenic mice; 2) determine if immediate signaling events downstream of Tlr4 are altered in response to O3 exposure in Tlr4 deficient or Tlr4 over-expressed mice and to evaluate the downstream cytokine profiles for these strains to determine if strain background can modulate the types of cytokines produced; 3) investigate the downstream mechanisms by which Tlr4-dependent pathways regulate O3-induced responses by verifying the importance of candidate genes identified from Affymetrix global gene arrays in vivo using molecular approaches and utilizing genetic (knockout mice) and pharmacologic methods to investigate specific candidate genes previously identified by the microarray approach. This proposal will enhance the understanding of the mechanisms of O3-induced lung inflammation and injury by the identification of novel pathways regulating O3 susceptibility. These novel pathways may provide preventive strategies for those individuals susceptible to O3.