脂氧素A4通过p38 MAPK及Nrf2通路调控气道炎症反应

目的：研究脂氧素A4（LXA4）对脂多糖（LPS）诱导的人正常支气管上皮细胞炎症反应的抑制作用及其机制。方法：将对数生长期的BEAS-2B细胞分为3组。对照组：不做任何处理；LPS组：100 ng/mL LPS刺激24 h；LPS+LXA4组：100 nmol/L LXA4预处理30 min，加入100 ng/mL LPS刺激24 h。qPCR法检测IL-6、IL-1β、血红素加氧酶-1（HO-1）、醌氧化还原酶（NQO-1）mRNA表达水平；流式细胞术测定胞内活性氧（ROS）水平；谷胱甘肽（GSH）试剂盒检测GSH水平。为进一步了解LXA4的作用机制，Western blot法检测各处理组p38的磷酸化水平以及Nrf2的核转位及磷酸化水平。结果：与对照组相比，LPS组IL-6、IL-1β mRNA以及胞内ROS表达水平升高（P＜0.05），HO-1 mRNA水平下降（P＜0.01），p38磷酸化水平上升（P＜0.01），胞核中Nrf2相对表达量下降（P＜0.01），总Nrf2磷酸化水平下降（P＜0.05）。经LXA4干预后，与LPS组相比，除上述改变逆转外（P＜0.05），NQO-1和GSH水平显著上升（P＜0.05）。结论：LXA4可减轻LPS引起的BEAS-2B细胞炎症反应并促进炎症消退，其机制可能一方面与抑制p38 MAPK通路，减少促炎因子的分泌有关；另一方面与增强Nrf2的核转位以及磷酸化，减轻氧化应激损伤有关。

Lipoxin A4 regulation of LPS induced pro-inflammatory responses through inhibiting activation of p38 MAPK and activating Nrf2 pathway

Conclusion: LXA4 may attenuate Objective: To investigate the effect and mechanism of Lipoxin A4 (LXA4) on inflammatory response induced by lipopolysaccharide (LPS) in BEAS-2B cells. Methods: Cultured BEAS-2B cells in logarithmic growth phase were divided into 3 groups: control group (group A, non-treatment), LPS group (group B, incubated with 100 ng/mL LPS for 24 h), LPS+LXA4 treatment group (group C, pretreated with 100 nmol/L LXA4 for 30 min and incubated with 100 ng/mL LPS for 24 h). The mRNA levels of IL-6, IL-1β, heme oxygenase (HO-1) and NAD (P) H: quinone oxidoreductase (NQO-1) were detected by qPCR. The expression of reactive oxygen species (ROS) was detected by flow cytometric analysis. Glutathione (GSH) was measured by a GSH assay kit. Moreover, we investigated the effects of LXA4 on LPS-induced phosphorylation of p38 mitogen-activated protein kinases (MAPK) as well as nuclear translocation and phosphorylation of Nrf2. Results: Compared with group A, the mRNA expressions of IL-6, IL-1β and the level of ROS in group B were significantly increased (P<0.05), while the mRNA level of HO-1 in cells was significantly decreased (P<0.01). Nuclear translocation and phosphorylation of Nrf2 were reduced (P<0.05) and phosphorylation of p38 MAPK was significantly increased (P<0.01) after LPS stimulation. In contrast, in LXA4 treatment group, the above changes were reversed (P<0.05); besides, GSH activity and the mRNA level of NQO-1 were elevated (P<0.05). Conclusion: LXA4 may attenuate Objective: To investigate the effect and mechanism of Lipoxin A4 (LXA4) on inflammatory response induced by lipopolysaccharide (LPS) in BEAS-2B cells. Methods: Cultured BEAS-2B cells in logarithmic growth phase were divided into 3 groups: control group (group A, non-treatment), LPS group (group B, incubated with 100 ng/mL LPS for 24 h), LPS+LXA4 treatment group