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

臭氧（O3）暴露与成人哮喘恶化和肺功能改变有关， 儿童和死亡率。超过50%的美国人口生活在O3浓度接近 或超过百万分之0.12的国家环境空气质量标准。我们之前发现 天然免疫基因Toll样受体4（Tlr 4）作为O3诱导肺损伤的候选易感基因 高渗透性和炎症。C3 H/HeOuJ小鼠（Tlr 4充足）对Tlr 4显著更敏感。 OS诱导的高渗透性和炎症与同基因C3 H/HeJ小鼠（Tlr 4显性）相比 负突变）。然而，TLR 4介导的应答的下游效应机制仍然是未知的。 不清楚本提案的总体目标是确定TLR 4介导OS-1的机制。 诱导肺部炎症和高通透性。拟议的研究将使用多学科 在体内动物模型中使用分子生物学、遗传学和药理学技术， 解决以下具体目标：1）检查菌株背景对TLR 4在以下中的作用的影响： OS诱导的肺高通透性和炎症，使用TLR 4显性阴性的小鼠， TLR 4转基因小鼠; 2）确定TLR 4下游的即时信号传导事件是否在TLR 4转基因小鼠中改变; 在Tlr 4缺陷或Tlr 4过表达小鼠中对O3暴露的反应，并评估下游 这些菌株的细胞因子谱，以确定菌株背景是否可以调节细胞因子的类型 3）研究TLR 4依赖性途径调节OS的下游机制。 通过验证从Affyssin全局基因中鉴定的候选基因的重要性来诱导应答 使用分子方法和利用遗传（敲除小鼠）和药理学 研究先前通过微阵列方法鉴定的特定候选基因的方法。这 该提案将通过以下方式增强我们对OS诱导的肺部炎症和损伤机制的理解： 确定新的调节OS易感性的途径。这些新的途径可以提供 对O3易感人群的预防策略。

Ozone (O3) exposure associates with exacerbation of asthma and altered lung function in adults and children, and mortality. Over 50% of the U.S. population live in regions where O3 concentrations approach or exceed the National Ambient Air Quality Standard of 0.12parts per million (ppm). We 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 OS-induced hyperpermeability and inflammation compared to coisogenic 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 OS- 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 OS-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 OS- 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 our understanding of the mechanisms of OS-induced lung inflammation and injury by the identification of novel pathways regulating OSsusceptibility. These novel pathways may provide preventive strategies for those individuals susceptible to O3.