PLTP在香烟诱导A549细胞合成白介素8中的作用

Effect of PLTP on CSE-induced IL-8 production in A549 cells

目的:研究磷脂转运蛋白(Phospholipid transfer protein,PLTP)对香烟诱导人肺泡上皮A549细胞合成白介素8(Interleukin-8,IL-8)的影响。方法:体外培养人肺泡上皮A549细胞株24 h,加入不同浓度的烟草提取物(Cigarette smoking extracts,CSE)共培养24 h;1.0%CSE与A549细胞株共培养6、12、24、48 h;PLTP siRNA预处理后,加入CSE共培养24 h。3-(4,5-二甲基噻唑-2)-2,5-二苯基四氮唑溴盐(MTT)法检测A549细胞增殖情况;实时定量PCR(RT-PCR)检测PLTP和IL-8 mRNA的表达量;蛋白质印迹法(Western blot)检测PLTP的表达量;酶联免疫吸附法(Enzyme-Linked Immunosorbent Assay,ELISA)检测IL-8相对含量。结果:0.125%烟草提取物促进A549细胞增殖,0.25%、0.5%、1.0%CSE浓度对A549细胞生长无明显影响,而2.0%、4.0%CSE浓度抑制A549细胞增殖;不同浓度的(0.25%、0.5%、1.0%)CSE作用24 h后,PLTP和IL-8 mRNA及蛋白表达量增加,并且IL-8蛋白分泌呈现一定时间依赖性;PLTP siRNA处理后,IL-8表达量明显升高(P<0.001)。结论:PLTP基因缺失促进香烟诱导A549细胞合成IL-8。

Objective： To investigate the effect of PLTP gene on CSE-induced IL-8 production in human alveolar Type Ⅱ cells（ Adenocarcinomic human alveolar epithelial cells,A549）. Methods： The different concentrations of CSE co-cultured with human alveolar epithelial cell line（ A549） for 24 hours. MTT assay was performed to study the effect of CSE on human alveolar epithelial cell line（ A549） growth. Expression levels of PLTP mRNA and IL-8 mRNA were examined by RT-PCR,protein of PLTP were examined by Western blot,and protein of IL-8 was examined by ELISA. Results： MTT assay showed that the proliferation of A549 cell line were stimulated by the 0. 125% CSE,while the proliferation of A549 cell tends to decrease at high concentrations of CSE（ 2. 0% CSE and4. 0% CSE）,and in this middle concentrations of CSE（ 0. 25% CSE,0. 5% CSE and 1. 0% CSE）,the proliferation of A549 cell was not significantly affected. Our studys suggested that PLTP and IL-8 release were induced by CSE in a concentration-dependent and timedependent manner,and expression levels of IL-8 obviously increased after silence PLTP gene. Conclusion： PLTP siRNA can increased CSE-induced IL-8 production in human alveolar epithelial cells（ A549）.