奥曲肽对脂多糖诱导人肺腺癌上皮细胞A549炎症反应及其信号通路的影响

Effect of octreotide on LPS-induced inflammatory response and signaling pathway in A549 human lung adenocarcinoma epithelial cells

目的检测奥曲肽(OQT)对人肺腺癌上皮细胞A549受脂多糖(LPS)诱导后的抗炎保护及其信号通路发生的变化。方法体外培养人肺腺癌上皮细胞A549,根据给予不同药物处理,将实验分为空白对照组(不加任何药物),LPS组(加上脂多糖200μg/L)、OQT组(加上奥曲肽1 500μg/L),LPS+OQT组(加上脂多糖200μg/L与奥曲肽1 500μg/L),电子显微镜观察细胞的形态,RT-PCR方法和western杂交检测IL-1β、IL-6、PI3K、ERK、p-ERK等细胞炎症反应及相关信号通路,并分析奥曲肽对A549细胞炎症反应相关通路的影响及分子机制。结果 IL-6表达量中,LPS组高于对照组(P<0.05),OQT组低于LPS组(P<0.05),LPS+OQT组低于对照组、LPS组(P<0.05);IL-1β表达量中,LPS组、OQT组与LPS+OQT组均高于对照组(均P<0.05),且以LPS组增高最为显著(P<0.01),LPS+OQT组均低于单独用药的LPS组、OQT组(P<0.05);PI3K表达量中,LPS组高于对照组(P<0.05),OQT组、LPS+OQT组均低于对照组、LPS组(均P<0.05);在p-ERK表达量中,LPS组与OQT组均高于对照组(均P<0.05),而LPS+OQT组较LPS组、OQT组减少(均P<0.05)。结论 LPS能促进A549细胞炎症因子IL-1β和IL-6的显著升高;OQT对LPS诱导的A549细胞炎症反应均具有强烈的抑制作用,能逆转LPS对细胞炎症损伤的影响;奥曲肽可能通过磷酸化ERK的方式介导PI3K/AKT和MAPK/ERK信号通路实现对细胞抗炎保护的调控作用。

Objective To study the effect of octreotide on LPS-induced inflammatory response and signaling pathway in A549 human lung adenocarcinoma epithelial cells. Methods Alveolar adanocarcinoma cell A549 was cultured in vivo and divided into 4 groups： Control Group （no addition of any drug）; Group LPS （addition of 200μg/L LPS）; Group OQT （addition of 1 500 μg/L OQT）; Group LPS＋OQT （addition of 200μg/L LPS ＋ 1 500 μg/L OQT）. Electron microscope was used to observe the cell morphology. The inflammatory factors such as Interleukin-1β （IL-1β） and IL-6 in cells were detected by real- time PCR （RT-PCR）. The expression level of the genes and proteins from the signaling pathway associated with inflammation such as PI3K, ERK, p-ERK were detected by RT-PCR and Western blot, respectively. Results In terms of IL-1β and IL-6 expression, Group LPS was significantly increased compared with Control Group （P〈0.05）, and Group LPS＋OQT was significantly decreased compared with Group LPS （P〈0.05）. In terms of IL-Iβ express, Group LPS, Group OQT and Group LPS＋OQT were all higher than Control Group （P〈0.05 for all）, and the increase in Group LPS was the most significant （P〈0.01）, and Group LPS＋OQT was lower than Group LPS and Group OQT（P〈0.05）; In terms of PI3K expression, Group LPS was higher than Control Group （P〈0.05）, and Group OQT and Group LPS＋OQT were all lower than Control Group and Group LPS （P〈0.05 for all）; In terms of p-ERK expression, Group LPS and Group OQT were all higher than Control Group （P〈0.05 for all）, while Group LPS＋OQT was decreased compared with Group LPS and Group OQT （P〈0.05 for all）. Conclusion Octreodide can promote anti-inflammatory protection of A549 cells induced by LPS, and reversed the inflammation trend affected by LPS. Octreodide may influence A549 cells viability and inflammation via the phosphorylation of ERK in MAPK/ERK pathway and increased expression level of PI3K in PI3K/AKT signaling pathway.