白细胞介素-4在脂多糖诱导急性肺损伤模型中的保护作用

  目的  探讨白细胞介素-4（IL-4）在急性肺损伤（acute lung injury，ALI）中的保护作用。  方法  脂多糖（lipopolysaccharide，LPS）诱导A549细胞形成ALI细胞模型。使用不同浓度的IL-4（0.1 μg/mL、1 μg/mL、10 μg/mL）在不同时长下干预该模型，通过流式细胞术检测A549细胞凋亡率，ELISA法测定A549细胞分泌IL-1、IL-6、IL-10、TNF-α、TNF-γ情况。  结果  IL-4可降低ALI模型中A549细胞凋亡率、抑制Caspase3表达（P < 0.05），其效果随IL-4浓度增加及干预时长延长而加强；同时促进Bcl-2表达（P < 0.05），IL-4浓度1 μg/mL干预12 h时效果最佳。上述条件下，IL-4可降低ALI模型中A549细胞的IL-1、IL-6、TNF-α、TNF-γ，并增加IL-10（P < 0.05）。  结论  IL-4可以通过改善ALI体外模型中细胞因子分泌情况，在急性肺损伤中发挥正向调节作用。

Protective Effect of Interleukin-4 in Lipopolysaccharide-induced Acute Lung Injury Models

  Objective  To investigate the protective effect of interleukin-4 （IL-4） on acute lung injury （ALI）.   Methods  ALI cell models were developed using lipopolysaccharide （LPS） to induce A549 cells. The model was treated with different concentrations of IL-4 （0.1 μg/mL, 1 μg/mL, 10 μg/mL） for different durations. Then the apoptosis rate of A549 cells was detected by flow cytometry, and the secretion of IL-1, IL-6, IL-10, TNF-α, TNF-γ of A549 cells was determined by ELISA.   Results  IL-4 reduced the apoptosis rate of A549 cells and inhibited the expression of Caspase3 in ALI model （P < 0.05）. The effect was enhanced with the increase of IL-4 concentration and the extension of intervention time. IL-4 promoted the expression of Bcl-2 （P < 0.05）, and the best effect was achieved when the concentration of IL-4 was 1 μg/mL for 12 h. Under the above conditions, IL-4 decreased IL-1, IL-6, TNF-α, TNF-γ and increased IL-10 in A549 cells in ALI model （P < 0.05）.  Conclusion  IL-4 can positively regulate acute lung injury by improving cytokine secretion in ALI in vitro model.