香烟提取物和脂多糖对小鼠肺上皮细胞株MLE-12活性及水通道蛋白5 mRNA表达的影响

Cigarette Smoke Extract and Lipopolysaccharide Reduce the Expression of Aquaporin 5 in Mouse Lung Epithelial Cells

目的:探讨香烟提取物(CSE)和脂多糖(LPS)对小鼠肺上皮细胞株MLE-12水通道蛋白5(AQP5)表达的影响及其在慢性阻塞性肺疾病(COPD)中的作用。方法:MTT法检测CSE和LPS对MLE-12的毒性,并选择合适的CSE和LPS浓度单独或共同刺激MLE-12细胞后,实时定量PCR检测其AQP5的表达。结果:与正常不含CSE的DMEM培养液相比较,MLE-12细胞在CSE小于10%时的DMEM/F12培养液中活性无明显降低(P>0.05),当CSE浓度达15%时各组细胞活性显著降低(P<0.01)。而不同浓度LPS对MLE-12活性无明显影响。CSE(10%)、LPS(20μg/ml)分别刺激MLE-12后,其AQP5的表达水平降低,CSE(10%)和LPS(20μg/ml)共刺激后,其水平进一步降低。CSE组和LPS组之间差异无显著性统计学意义。结论:CSE协同LPS可降低MLE-12细胞AQP5的表达,AQP5的下调可能参与了COPD的发生和发展。

Objective:To investigate the influence of cigarette smoke extract(CSE)and lipopolysaccharide(LPS)on the expression of aquaporin(AQP5)in MLE-12 cells and the role of AQP5 in chronic obstructive pulmonary diseases(COPD).Method:MTT method was used to assess the toxicity of CSE and LPS on MLE-12.Proper concentration of CSE and LPS were chosen to stimulate MLE-12 alone or together.After stimulation,cells were collected to detect the expression of AQP5 by real-time quantitative RT-PCR.Results:The viability of MLE-12 cells was not changed at low concentrations of CSE(≤10%)and different concentration of LPS,and remarkably decreased at higher concentrations of CSE(≥15%).Twenty-four hours of stimulation with CSE(10%)and LPS(20μg/ml)individually moderately reduced AQP5 production.CSE augmented the reduction of AQP5 production by LPS.There was no significant difference between the CSE and LPS group.Conclusion:Cigarette smoke extract and lipopolysaccharide reduce the expression of aquaporin5 in MLE-12 cells.The reduction of aquaporin5 may play a role in the pathogenesis of COPD.