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

臭氧暴露与成人哮喘加重和肺功能改变有关 儿童和死亡率。超过50%的美国人口生活在臭氧浓度接近 或超过国家环境空气质量标准的百万分之0.12(Ppm)。我们之前确定了 天然免疫基因Toll样受体4(TLR4)作为03致肺的候选易感基因 高渗透性和炎症。C3H/HeOuJ小鼠(TLR4充足)明显更容易患上 OS诱导的高通透性和炎症反应与同基因C3H/HeJ小鼠(TLR4占优势)的比较 负突变)。然而，TLR4介导的反应的下游效应机制仍然是 不清楚。这项提案的总体目标是确定TLR4调节OS- 诱导肺部炎症和高通透性。拟议的研究将使用多学科的 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方法 解决以下具体目标：1)研究菌株背景对TLR4在 使用TLR4显性阴性和阴性的小鼠，用OS诱导肺高通透性和炎症 TLR4转基因小鼠；2)确定TLR4下游的即时信号事件是否在 TLR4缺乏或过度表达小鼠对臭氧暴露的反应及其下游评估 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TLR4依赖的通路调节OS的下游机制 通过验证从Affymetrix全局基因识别的候选基因的重要性来诱导反应 使用分子方法并利用遗传(基因敲除小鼠)和药理学的活体阵列 方法研究以前通过微阵列方法确定的特定候选基因。这 建议将加强我们对OS引起的肺部炎症和损伤的机制的理解 识别调节OS易感性的新途径。这些新的途径可能会提供 为那些易受臭氧影响的人制定预防策略。

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.