Toxicology Program, Department of Biological Sciences, North Carolina State University, Raleigh, NC, USA.
Department of Population Health and Pathobiology, North Carolina State University, Raleigh, NC, USA.
Inhal Toxicol. 2022;34(9-10):244-259. doi: 10.1080/08958378.2022.2086651. Epub 2022 Jun 15.
Per- and polyfluoroalkyl substances (PFAS) have been associated with respiratory diseases in humans, yet the mechanisms through which PFAS cause susceptibility to inhaled agents is unknown. Herein, we investigated the effects of ammonium perfluoro(2-methyl-3-oxahexanoate) (GenX), an emerging PFAS, on the pulmonary immune response of mice to carbon black nanoparticles (CBNP). We hypothesized that pulmonary exposure to GenX would increase susceptibility to CBNP through suppression of innate immunity.
Male C57BL/6 mice were exposed to vehicle, 4 mg/kg CBNP, 10 mg/kg GenX, or CBNP and GenX by oropharyngeal aspiration. Bronchoalveolar lavage fluid (BALF) was collected at 1 and 14 days postexposure for cytokines and total protein. Lung tissue was harvested for histopathology, immunohistochemistry (Ki67 and phosphorylated (p)-STAT3), western blotting (p-STAT3 and p-NF-κB), and qRT-PCR for cytokine mRNAs.
CBNP increased CXCL-1 and neutrophils in BALF at both time points evaluated. However, GenX/CBNP co-exposure reduced CBNP-induced CXCL-1 and neutrophils in BALF. Moreover, CXCL-1, CXCL-2 and IL-1β mRNAs were increased by CBNP in lung tissue but reduced by GenX. Western blotting showed that CBNP induced p-NF-κB in lung tissue, while the GenX/CBNP co-exposed group displayed decreased p-NF-κB. Furthermore, mice exposed to GenX or GenX/CBNP displayed increased numbers of BALF macrophages undergoing mitosis and increased Ki67 immunostaining. This was correlated with increased p-STAT3 by western blotting and immunohistochemistry in lung tissue from mice co-exposed to GenX/CBNP.
Pulmonary exposure to GenX suppressed CBNP-induced innate immune response in the lungs of mice yet promoted the proliferation of macrophages and lung epithelial cells.
全氟和多氟烷基物质 (PFAS) 已被证明与人类的呼吸系统疾病有关，但 PFAS 导致对吸入物易感性的机制尚不清楚。在此，我们研究了新兴 PFAS 之一过氧全氟(2-甲基-3-恶己酸)铵 (GenX) 对小鼠肺部对碳黑纳米颗粒 (CBNP) 免疫反应的影响。我们假设，肺部接触 GenX 会通过抑制先天免疫来增加对 CBNP 的易感性。
雄性 C57BL/6 小鼠通过口咽吸入暴露于载体、4mg/kg CBNP、10mg/kg GenX 或 CBNP 和 GenX。在暴露后 1 天和 14 天收集支气管肺泡灌洗液 (BALF) 用于细胞因子和总蛋白检测。采集肺组织进行组织病理学、免疫组织化学（Ki67 和磷酸化 (p)-STAT3）、western blot（p-STAT3 和 p-NF-κB）和 qRT-PCR 用于细胞因子 mRNA 检测。
CBNP 在两个评估时间点均增加了 BALF 中的 CXCL-1 和中性粒细胞。然而，GenX/CBNP 共暴露减少了 CBNP 诱导的 BALF 中的 CXCL-1 和中性粒细胞。此外，CBNP 在肺组织中增加了 CXCL-1、CXCL-2 和 IL-1β mRNA，而 GenX 减少了这些 mRNA。Western blot 显示 CBNP 诱导了肺组织中的 p-NF-κB，而 GenX/CBNP 共暴露组显示出 p-NF-κB 的减少。此外，暴露于 GenX 或 GenX/CBNP 的小鼠的 BALF 巨噬细胞增殖增多，Ki67 免疫染色增多。这与 GenX/CBNP 共暴露小鼠肺组织中 p-STAT3 的 western blot 和免疫组织化学结果一致。
肺部接触 GenX 抑制了 CBNP 诱导的小鼠肺部先天免疫反应，但促进了巨噬细胞和肺上皮细胞的增殖。
