Airborne Particulates, Corneal Oxidative Stress and Infection

总结 直径<10 µ m的空气颗粒物（PM10）是全球主要的空气污染物，具有刺激性 对粘膜的影响，造成严重的健康（心血管和呼吸）和经济 结果。与我们的研究相关，临床证据表明，接触PM10与增加 角膜炎、干眼和结膜炎的急诊室就诊加剧了问题。可惜没有 研究从机械上研究了PM10对眼睛的影响以及导致以下情况的联系/机制 增加微生物感染。因此，本研究的长期目标是检验假设， 角膜，PM10触发活性氧（ROS），破坏核因子红细胞2相关因子2（Nrf2） 信号传导，导致炎症，这反过来又增强了对细菌感染的疾病反应。一 由此推论，SKQ 1（一种新型线粒体靶向抗氧化剂）对ROS的抑制将逆转这些变化。 变化初步的体内数据显示，小鼠在空气中暴露于PM10与环境空气相比， Nrf2通路的中断、还原型谷胱甘肽（GSH）水平降低和考克斯-1 mRNA水平升高。 2、iNOS、IL-6和TNF-α，降低Nrf2蛋白水平，升高MDA水平， 后者指示脂质过氧化。我们还表明，PM10暴露加剧了假单胞菌 铜绿假单胞菌（P.aeruginosa）感染的小鼠角膜早期穿孔和角膜变薄 与暴露于环境空气的小鼠相比。在体外，人类角膜上皮细胞培养支持这些发现 并表明PM10对细胞活力有不利影响，SKQ1拯救了它。提出了三个目标： 具体目标1：检验PM10暴露触发ROS，破坏Nrf2信号通路， 减少细胞保护基因，导致角膜炎症; SKQ 1，一种抗氧化剂和抑制剂， ROS逆转了这些效应。 具体目标2：检验以下假设：PM10暴露可加重细菌性角膜炎，SKQ 1单独 或作为莫西沙星的辅助治疗改善疾病结果。 具体目标3：检验人角膜上皮细胞暴露于PM10与小鼠暴露于PM10相似的假设 数据表明，它诱导ROS，Nrf2信号传导，减少细胞保护基因，SKQ1逆转这些 方面的影响.

Summary Airborne particulate matter with a diameter of <10µm (PM10) is a major global airborne pollutant, with an irritant effect on mucous membranes, causing serious health (cardiovascular and respiratory) and economic outcomes. Pertinent to our studies, clinical evidence has shown that exposure to PM10 is linked to increased emergency room visits for keratitis and dry eye and conjunctivitis exacerbate the problem. Unfortunately, no studies have mechanistically investigated the effect of PM10 on the eye and the link/mechanisms leading to increased microbial infection. Therefore, the long-term goal of this study is to test the hypothesis that in the cornea, PM10 triggers reactive oxygen species (ROS), disrupts nuclear factor erythroid 2-related factor 2 (Nrf2) signaling, leading to inflammation and that this in turn enhances the disease response to bacterial infection. A corollary to this is that inhibition of ROS by SKQ1, a novel mitochondrial targeted antioxidant, will reverse these changes. Preliminary in vivo data showed that airborne exposure of mice to PM10 vs ambient air results in disruption of the Nrf2 pathway, lower levels of reduced glutathione (GSH), and elevated mRNA levels of COX- 2, iNOS, IL-6 and TNF-α, decreased protein levels of Nrf2, and increased levels of malondialdehyde (MDA), the latter indicative of lipid peroxidation. We also showed that PM10 exposure exacerbates Pseudomonas aeruginosa (P. aeruginosa) infection in the mouse cornea with earlier perforation and corneal thinning compared with ambient air exposed mice. In vitro, human corneal epithelial cell cultures support these findings and show that PM10 adversely affects cell viability and that SKQ1 rescues it. Three aims are proposed: Specific Aim 1: Tests the hypothesis that PM10 exposure triggers ROS, disrupts the Nrf2 signaling pathway, decreases cytoprotective genes and leads to corneal inflammation; and that SKQ1, an antioxidant and inhibitor of ROS, reverses these effects. Specific Aim 2: Tests the hypothesis that PM10 exposure exacerbates bacterial keratitis and that SKQ1 alone or as an adjunct treatment to Moxifloxacin improves disease outcome. Specific Aim 3: Tests the hypothesis that PM10 exposure of human corneal epithelial cells parallels the mouse data in that it induces ROS, Nrf2 signaling, decreases cytoprotective genes and that SKQ1 reverses these effects.