Ceramide, a bioactive lipid, plays an essential role in the development of several pulmonary inflammatory diseases. Matrix metallopeptidase 9 (MMP-9) regulates the synthesis and degradation of extracellular matrix, and is associated with airway remodeling and tissue injury. This study was conducted to investigate the effects and underlying mechanisms of ceramide on MMP-9 expression in airway epithelium. BEAS-2B cells, normal human bronchial epithelium cell lines, were pretreated with AG490, a selective janus tyrosine kinase 2 (JAK2) inhibitor, or Stattic, a selective signal transducer and activator of transcription 3 (STAT3) inhibitor. The cells were then stimulated with C6-ceramide. The levels of MMP-9 were determined by ELISA and real-time quantitative PCR (RT-qPCR). JAK2, phosphorylated JAK2 (p-JAK2), STAT3, and phosphorylated STAT3 (p-STAT3) expression was examined by Western blotting. BALB/c mice were pretreated with AG490 or Stattic before intratracheally instillated with C6-ceramide. Pathological changes in lung tissues were examined by Hematoxylin and Eosin staining, Periodic-acid Schiff staining, and Masson’s trichrome staining. MMP-9, JAK2, p-JAK2, STAT3, and p-STAT3 expression in the lung tissues was examined by Western blotting. The expression of MMP-9, p-JAK2 and p-STAT3 in BEAS-2B cells was significantly increased after the treatment of C6-ceramide. Furthermore, the increased expression of MMP-9 induced by C6-ceramide was inhibited by AG490 and Stattic. Similar results were obtained in the lung tissues of C6-ceramide-exposed mice which were treated with AG490 or Stattic. Ceramide could up-regulate MMP-9 expression through the activation of the JAK2/STAT3 pathway in airway epithelium. Targeted modulation of the ceramide signaling pathway may offer a potential therapeutic approach for inhibiting MMP-9 expression. This study points to a potentially novel approach to alleviating airway remodeling in inflammatory airway diseases.

中文翻译：

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神经酰胺通过JAK2 / STAT3途径在气道上皮细胞中诱导MMP-9表达。

神经酰胺，一种生物活性脂质，在几种肺炎性疾病的发展中起着至关重要的作用。基质金属肽酶9（MMP-9）调节细胞外基质的合成和降解，并与气道重塑和组织损伤有关。进行这项研究以调查神经酰胺对气道上皮中MMP-9表达的影响及其潜在机制。BEAS-2B细胞（正常人​​支气管上皮细胞系）用AG490（一种选择性的剑突酪氨酸激酶2（JAK2）抑制剂）或Stattic（一种选择性的信号转导和转录激活因子3（STAT3）抑制剂）进行了预处理。然后用C6-神经酰胺刺激细胞。通过ELISA和实时定量PCR（RT-qPCR）测定MMP-9的水平。JAK2，磷酸化JAK2（p-JAK2），STAT3，蛋白质印迹法检测磷酸化STAT3（p-STAT3）的表达。BALB / c小鼠用AG490或Stattic预处理，然后气管内滴注C6-神经酰胺。通过苏木精和曙红染色，高碘酸席夫氏染色和马森三色染色检查肺组织的病理变化。通过蛋白质印迹检查肺组织中的MMP-9，JAK2，p-JAK2，STAT3和p-STAT3表达。C6-神经酰胺处理后，BEAS-2B细胞中MMP-9，p-JAK2和p-STAT3的表达明显增加。此外，AG490和Stattic抑制了C6-神经酰胺诱导的MMP-9表达的增加。在接受AG490或Stattic治疗的C6神经酰胺暴露的小鼠的肺组织中获得了相似的结果。神经酰胺可以通过激活气道上皮中的JAK2 / STAT3途径来上调MMP-9表达。神经酰胺信号通路的靶向调节可提供抑制MMP-9表达的潜在治疗方法。这项研究指出了减轻炎症性气道疾病中气道重塑的潜在新方法。