Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, USA.
Department of Environmental and Occupational Health and Justice, School of Public Health, Rutgers University, Piscataway, NJ 08854, USA.
Toxicol Appl Pharmacol. 2023 Feb 15;461:116388. doi: 10.1016/j.taap.2023.116388. Epub 2023 Jan 20.
Chlorine (Cl) gas is a highly toxic and oxidizing irritant that causes life-threatening lung injuries. Herein, we investigated the impact of Cl-induced injury and oxidative stress on lung macrophage phenotype and function. Spontaneously breathing male C57BL/6J mice were exposed to air or Cl (300 ppm, 25 min) in a whole-body exposure chamber. Bronchoalveolar lavage (BAL) fluid and cells, and lung tissue were collected 24 h later and analyzed for markers of injury, oxidative stress and macrophage activation. Exposure of mice to Cl resulted in increases in numbers of BAL cells and levels of IgM, total protein, and fibrinogen, indicating alveolar epithelial barrier dysfunction and inflammation. BAL levels of inflammatory proteins including surfactant protein (SP)-D, soluble receptor for glycation end product (sRAGE) and matrix metalloproteinase (MMP)-9 were also increased. Cl inhalation resulted in upregulation of phospho-histone H2A.X, a marker of double-strand DNA breaks in the bronchiolar epithelium and alveolar cells; oxidative stress proteins, heme oxygenase (HO)-1 and catalase were also upregulated. Flow cytometric analysis of BAL cells revealed increases in proinflammatory macrophages following Cl exposure, whereas numbers of resident and antiinflammatory macrophages were not altered. This was associated with increases in numbers of macrophages expressing cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS), markers of proinflammatory activation, with no effect on mannose receptor (MR) or Ym-1 expression, markers of antiinflammatory activation. Metabolic analysis of lung cells showed increases in glycolytic activity following Cl exposure in line with proinflammatory macrophage activation. Mechanistic understanding of Cl-induced injury will be useful in the identification of efficacious countermeasures for mitigating morbidity and mortality of this highly toxic gas.
氯气（Cl）气体是一种高毒性和强氧化性的刺激性气体，可导致危及生命的肺部损伤。在此，我们研究了 Cl 诱导的损伤和氧化应激对肺巨噬细胞表型和功能的影响。将雄性 C57BL/6J 小鼠置于全身暴露箱中，分别暴露于空气或 Cl（300ppm，25 分钟）中。24 小时后收集支气管肺泡灌洗液（BAL）和细胞以及肺组织，并分析损伤、氧化应激和巨噬细胞激活的标志物。暴露于 Cl 的小鼠的 BAL 细胞数量和 IgM、总蛋白和纤维蛋白原水平增加，表明肺泡上皮屏障功能障碍和炎症。BAL 水平的炎症蛋白，包括表面活性蛋白（SP）-D、糖基化终产物可溶性受体（sRAGE）和基质金属蛋白酶（MMP）-9 也增加。Cl 吸入导致支气管上皮和肺泡细胞中二链 DNA 断裂的磷酸组蛋白 H2A.X 标志物上调；氧化应激蛋白血红素加氧酶（HO）-1 和过氧化氢酶也上调。BAL 细胞的流式细胞术分析显示，Cl 暴露后促炎型巨噬细胞数量增加，而常驻和抗炎型巨噬细胞数量没有改变。这与表达环氧化酶（COX）-2 和诱导型一氧化氮合酶（iNOS）的巨噬细胞数量增加有关，这是促炎激活的标志物，而甘露糖受体（MR）或 Ym-1 的表达没有改变，这是抗炎激活的标志物。肺细胞的代谢分析显示，Cl 暴露后糖酵解活性增加，与促炎型巨噬细胞激活一致。对 Cl 诱导损伤的机制理解将有助于确定减轻这种高毒性气体发病率和死亡率的有效对策。
