Synergistic inflammatory responses to metals associated with fuel oil ash

我们的初步研究目标是阐明与残油飞灰(ROFA)相关的金属如何启动和加剧肺部的炎症反应。我们的总体假设是：易感个体的肺巨噬细胞和上皮细胞在遗传水平上对ROFA中的金属做出不成比例的反应。肺细胞被预先存在的炎症状态“启动”，导致调节基因表达的信号转导通路内的协同放大。其具体目标是：1)确定ROFA的金属成分，以介导其毒性和炎症潜能；2)表征ROFA相关金属的毒性及其单独和联合诱导促炎细胞因子的能力；3)建立导致细胞因子表达增加的分子机制；4)确定氧化应激在金属诱导的细胞因子表达中的作用；以及5)表征巨噬细胞和上皮细胞对金属的整体遗传反应。为了确定ROFA相关金属的炎症潜能，我们将通过气管内滴注的方式将大鼠暴露于可溶金属中，并通过巨噬细胞、上皮细胞系和原代细胞培养来评估肺炎症和促炎介质，以响应体外挑战。细胞要么是巨噬细胞，要么是上皮细胞系，要么是原代培养的细胞，以应对体外挑战。细胞将要么是正常的，要么是用细菌脂多糖或肿瘤坏死因子(肿瘤坏死因子)-α预先处理(“预置”)的。调控细胞因子基因表达的信号转导途径将在分子水平上阐明。我们将比较金属刺激和非刺激的巨噬细胞和上皮细胞的差异基因表达，并确定差异表达基因。氧化应激在控制这些基因调控的信号转导途径中的作用将被研究。我们预测，能够引发细胞呼吸爆发的金属将导致产量增加。促炎症细胞因子在肺上皮和巨噬细胞中的表达。这种对周围环境或低水平金属的不适当反应将是理解所观察到的与空气中颗粒物浓度升高相关的发病率/死亡率增加的重要第一步。

Our preliminary research objectives is to elucidate how metals associated with residual oil fly ash (ROFA) initiates and exacerbates the inflammatory response in the lung. Our overall hypothesis is: Lung macrophages and epithelial cells in susceptible individuals respond disproportionately at a genetic level to metals in ROFA. "Priming" of lung cells by a pre-existing inflammatory condition results in synergistic amplification within the signal transduction pathways regulating gene expression. Specific aims are: 1) To determine the metal constituents of ROFA that mediate toxicity and its inflammatory potential; 2) To characterize the toxicity of ROFA-associated metals and their ability to induce pro-inflammatory cytokines, individually and in combination; 3) To establish molecular mechanisms responsible for increased cytokine expressions; 4) To establish a role for oxidative stress in metal-induced cytokine expression; and 5) To characterize the overall genetic response of macrophages and epithelial cells to metals. To determine the inflammatory potential of ROFA-associated metals, we will expose rats to soluble metals by intratracheal instillation and assess pulmonary inflammation and pro-inflammatory mediators by macrophages and epithelial cell lines and primary cell cultures in response to an in vitro challenge. Cells will be either macrophages and epithelial cell lines and primary cell cultures in response to an vitro challenge. Cells will be either normal or pre-treated ("primed") with bacterial lipopolysaccharide or tumor necrosis factor (TNF)-alpha, respectively. Signal transduction pathways regulating cytokine gene expression will be elucidated at a molecular level. Differential gene expression in primed and unprimed- macrophages and epithelial cells in response to metals will be compared and differentially-expressed genes identified. A role for an oxidant stress in the signal transduction pathway controlling regulation of these genes will be examined. We predict that metals capable of inducing a cellular respiratory burst will elicit enhanced production. of pro-inflammatory cytokines in primed lung epithelium and macrophages. This inappropriate response to ambient or low levels of metals would be an important first step in understanding the observed increase in morbidity/mortality associated with elevated airborne particle concentrations.