Comparative study of cigarette smoke, Klebsiella pneumoniae, and their combination on airway epithelial barrier function in mice
Comparative study of cigarette smoke, Klebsiella pneumoniae, and their combination on airway epithelial barrier function in mice
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DOI：
10.1002/tox.23753
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发表时间：
2023-02-09
影响因子：
4.5
通讯作者：
Li，Jiansheng
中科院分区：
文献类型：
--
作者：
Li，Kangchen;Mei，Xiaofeng;Li，Jiansheng
背景气道上皮细胞作为一种物理屏障，保护肺气道免受病原微生物和有毒物质，如香烟烟雾（CS），细菌和病毒的侵害。破坏的结构完整性和功能障碍的气道上皮细胞的发生和进展的慢性阻塞性肺diseases.PurposeThe本研究的目的是比较CS，肺炎克雷伯氏菌（KP），和他们的组合对气道上皮屏障function.MethodsThe小鼠暴露于CS，KP，和他们的组合从1至8周。在第8周停止CS和KP后，我们观察到小鼠上皮屏障功能的恢复持续另外16周。为了比较不同组间随时间推移的上皮屏障功能，在第4、8、16和24周处死小鼠，然后收获肺以检测肺病理学、炎性细胞因子和紧密连接蛋白。为了确定潜在的机制，用表皮生长因子受体（EGFR）抑制剂（AG 1478）处理BEAS-2B细胞。结果本研究的结果表明，CS诱导小鼠在第8周观察到肺功能下降、支气管壁厚度（BWT）增加、炎症因子升高和紧密连接蛋白水平降低，这些变化持续到第16周。在KP组中，仅在第8周观察到BWT增加和炎性因子升高，而在CS + KP组中，在第4周观察到肺功能降低、肺组织损伤、炎性细胞浸润和上皮屏障损伤，并持续至第24周。为了进一步确定CS、细菌及其组合对上皮屏障损伤的机制，我们研究了小鼠肺组织和BEAS-2B细胞中EGFR及其下游蛋白的变化。我们的研究表明，CS、KP或二者联合应用可激活EGFR，而EGFR可磷酸化并激活ERK 1/2，且这种作用在CS + KP组中更为明显。此外，EGFR抑制剂AG 1478抑制ERK 1/2的磷酸化，随后上调ZO-1和occludin的表达。结论CS和KP联合应用对上皮屏障功能的损伤较单独应用CS或KP更早、更严重、持续时间更长，其机制可能与EGFR/ERK 1/2信号通路有关。可能与EGFR/ERK信号通路有关。
BackgroundThe airway epithelium acts as a physical barrier to protect pulmonary airways against pathogenic microorganisms and toxic substances, such as cigarette smoke (CS), bacteria, and viruses. The disruption of the structural integrity and dysfunction of the airway epithelium is related to the occurrence and progression of chronic obstructive pulmonary disease.PurposeThe aim of this study is to compare the effects of CS,Klebsiella pneumoniae(KP), and their combination on airway epithelial barrier function.MethodsThe mice were exposed to CS, KP, and their combination from 1 to 8 weeks. After the cessation of CS and KP at Week 8, we observed the recovery of epithelial barrier function in mice for an additional 16 weeks. To compare the epithelial barrier function among different groups over time, the mice were sacrificed at Weeks 4, 8, 16, and 24 and then the lungs were harvested to detect the pulmonary pathology, inflammatory cytokines, and tight junction proteins. To determine the underlying mechanisms, the BEAS‐2B cells were treated with an epidermal growth factor receptor (EGFR) inhibitor (AG1478).ResultsThe results of this study suggested that the decreased lung function, increased bronchial wall thickness (BWT), elevated inflammatory factors, and reduced tight junction protein levels were observed at Week 8 in CS‐induced mice and these changes persisted until Week 16. In the KP group, increased BWT and elevated inflammatory factors were observed only at Week 8, whereas in the CS + KP group, decreased lung function, lung tissue injury, inflammatory cell infiltration, and epithelial barrier impairment were observed at Week 4 and persisted until Week 24. To further determine the mechanisms of CS, bacteria, and their combination on epithelial barrier injury, we investigated the changes of EGFR and its downstream protein in the lung tissues of mice and BEAS‐2B cells. Our research indicated that CS, KP, or their combination could activate EGFR, which can phosphorylate and activate ERK1/2, and this effect was more pronounced in the CS + KP group. Furthermore, the EGFR inhibitor AG1478 suppressed the phosphorylation of ERK1/2 and subsequently upregulated the expression of ZO‐1 and occludin. In general, these results indicated that the combination of CS and KP caused more severe and enduring damage to epithelial barrier function than CS or KP alone, which might be associated with EGFR/ERK1/2 signaling.ConclusionEpithelial barrier injury occurred earlier, was more severe, and had a longer duration when induced by the combination of CS and KP compared with the exposure to CS or KP alone, which might be associated with EGFR/ERK signaling.