Hartog Matthew, Zhang Qing-Yu, Ding Xinxin
College of Nanoscale Science and Engineering, SUNY Polytechnic Institute, Albany, New York 12203.
Wadsworth Center, New York State Department of Health, Albany, New York 12201.
Toxicol Sci. 2019 Nov 1;172(1):123-131. doi: 10.1093/toxsci/kfz171.
Many constituents of tobacco smoke (TS) require bioactivation to exert toxic effects; however, few studies have examined the role of bioactivation enzymes in the adverse effects of TS exposure. This knowledge gap is a major source of uncertainty for risk assessment and chemoprevention efforts. Our aim is to test the hypothesis that cytochrome P450 (P450) enzyme-mediated bioactivation is essential to the development of TS exposure-induced lung toxicity, by determining the contributions of P450 enzymes in the mouse Cyp2abfgs gene subfamilies to environmental tobacco smoke (ETS)-induced lung inflammation. Adult female wildtype (WT) and Cyp2abfgs-null mice (both on C57BL/6J background) were exposed to filtered air or ETS, intermittently, for 1 or 2 weeks. Lung inflammation was assessed by quantification of inflammatory cells, cytokines, chemokines, and proteins in bronchoalveolar lavage fluid (BALF) and histopathological analysis. Glutathione (GSH) conjugates of 2 ETS constituents, naphthalene (NA), and 3-methylindole (3MI), were measured in mice exposed to ETS for 4 h. Persistent macrophagic and neutrophilic lung inflammation was observed in ETS-exposed WT mice; the extent of which was significantly reduced in ETS-exposed Cyp2abfgs-null mice. Levels of proinflammatory cytokines and chemokines, along with the total protein concentration, were increased in cell-free BALF from ETS-exposed WT mice, but not Cyp2abfgs-null mice. Additionally, GSH conjugates of NA and 3MI were detected in the lungs of WT, but not Cyp2abfgs-null, mice following ETS exposure. These results provide the first in vivo evidence that the mouse Cyp2abfgs gene cluster plays an important role in ETS-induced lung inflammation.
烟草烟雾（TS）的许多成分需要生物活化才能发挥毒性作用；然而，很少有研究探讨生物活化酶在TS暴露的不良反应中的作用。这一知识空白是风险评估和化学预防工作不确定性的主要来源。我们的目的是通过确定小鼠Cyp2abfgs基因亚家族中的细胞色素P450（P450）酶对环境烟草烟雾（ETS）诱导的肺部炎症的贡献，来检验P450酶介导的生物活化对TS暴露诱导的肺部毒性发展至关重要这一假设。成年雌性野生型（WT）和Cyp2abfgs基因敲除小鼠（均为C57BL/6J背景）间歇性暴露于过滤空气或ETS中1或2周。通过对支气管肺泡灌洗液（BALF）中的炎症细胞、细胞因子、趋化因子和蛋白质进行定量以及组织病理学分析来评估肺部炎症。在暴露于ETS 4小时的小鼠中测量了两种ETS成分萘（NA）和3-甲基吲哚（3MI）的谷胱甘肽（GSH）结合物。在暴露于ETS的WT小鼠中观察到持续性巨噬细胞和中性粒细胞肺部炎症；在暴露于ETS的Cyp2abfgs基因敲除小鼠中，炎症程度显著降低。暴露于ETS的WT小鼠的无细胞BALF中促炎细胞因子和趋化因子水平以及总蛋白浓度增加，但Cyp2abfgs基因敲除小鼠未出现这种情况。此外，在暴露于ETS的WT小鼠肺部检测到了NA和3MI的GSH结合物，但Cyp2abfgs基因敲除小鼠未检测到。这些结果提供了首个体内证据，表明小鼠Cyp2abfgs基因簇在ETS诱导的肺部炎症中起重要作用。
