腺病毒E1A基因对细菌脂多糖所致肺泡上皮细胞MMP-9/TIMP-1失衡的影响

Effect of adenovirus E1A on matrix metalloproteinases-9/tissue inhibitor of metalloproteinase-1 imbalance induced by lipopolysaccharide in alveolar epithelial cells

目的:明确腺病毒E1A基因对细菌脂多糖(lipopolysaccharide,LPS)所致肺泡上皮细胞基质金属蛋白酶9(MMP-9)/基质金属蛋白酶组织抑制剂1(TIMP-1)失衡是否存在影响。方法:将人Ⅱ型肺泡上皮细胞系A549细胞分为正常对照组、转染腺病毒E1A质粒组(E1A+组)和转染不含有腺病毒E1A的空白质粒组(E1A-组),分别以不同浓度的LPS刺激,刺激后12、24 h用反转录聚合酶链反应技术检测各组细胞MMP-9 mRNA和TIMP-1 mRNA的表达,用酶联免疫吸附分析(ELISA)检测MMP-9和TIMP-1蛋白的表达。结果:在LPS刺激12 h后E1A+组的MMP-9/TIMP-1 mRNA比值高于其他2组(P=0.045);在刺激24 h后3组之间的差别更加显著(P=0.032)。MMP-9/TIMP-1蛋白比值在LPS刺激12 h后E1A+组高于其他2组,但无统计学意义(P=0.069),在刺激24 h后3组蛋白比值的差别比较显著(P=0.039)。结论:腺病毒E1A基因可导致Ⅱ型肺泡上皮细胞在LPS刺激下大量释放MMP-9,使MMP-9/TIMP-1的失衡进一步加重。

Objective To study the effect of adenovirus E1A gene on matrix metalloproteinases-9/tissue inhibitor of metalloproteinase-1 0VIMP-9/TIMP-1） imbalance induced by lipopolysaccharide （LPS） in alveolar epithelial cells. Methods Human type Ⅱ alveolar epithelial A549 cells were divided into control group, transfected with adenovirus E1A plasmid （E1A＋ group） and transfected with blank plasmid （E1A group）. All the cells were stimulated with different concentrations of LPS. Investigated the expressions of MMP-9 mRNA and TIMP-1 mRNA by RT-PCR after 12 h, 24 h. And determined the protein expression of MMP-9 and TIMP-1 with ELISA. Results After 12 h of LPS stimulation, MMP-9/TIMP-I mRNA ratio in the E1A＋ group was higher than the other two groups （P=0.045）. The difference between the three groups was more significant after 24 h of LPS stimulation. After 12 h of LPS stimulation, MMP-9/TIMP-1 protein ratio in E1A＋ group was higher than the other two groups, but had not reached statistical significance （P=0.069）, the differences between the three groups was significant after 24 h of LPS stimulation （P=0.039）. Conclusions Adenovirus EIA gene accelerated the release of MMP-9 in type Ⅱ alveolar epithelial cells stimulated by LPS, thereby aggravated the imbalance in MMP-9/FIMP-1.