解整合素-金属蛋白酶17在肺泡上皮细胞间质转化中的作用研究

Role of ADAM17 during epithelial-mesenchymal transition in human lung alveolar epithelial cells

目的探讨解整合素-金属蛋白酶17(a disintegrin and metalloproteinase-17,ADAM 17)过表达和抑制在转化生长因子-β1(transforming growth factor-beta 1,TGF-β1)介导的A549细胞上皮向间质转化(epithelial-to-mesenchymal transition,EMT)过程中的作用,以进一步揭示肺纤维化的机制。方法将A549细胞分为空白对照组、TGF-β1组、PMA(ADAM 17激活剂)组和TNF484(ADAM 17抑制剂)组。各组细胞培养36 h后,应用倒置相差显微镜观察各组细胞形态,Real-time PCR和Western blotting分别检测ADAM 17、上皮及间质细胞标记物在m RNA和蛋白水平上的表达情况。结果镜下观察发现未诱导的A549细胞呈鹅卵石形态,排列比较紧密;经TGF-β1诱导后,细胞形态伸长,出现伪足,排列较松散,细胞与细胞之间的紧密连接消失。Real-time PCR和Western blotting检测结果均显示ADAM 17在PMA组高表达,而在TNF484组低表达,差异有统计学意义;上皮细胞标记物E-cadherin在空白对照组和TNF484组高表达,间质细胞标记物Vimentin在TGF-β1组和PMA组高表达,差异同样有统计学意义。结论 ADAM 17的过表达有助于TGF-β1介导的A549细胞EMT进程,提示ADAM 17可作为肺纤维化的标记物之一。

Objective To investigate the role of ADAM17 in epithelial - mesenchymal transition （EMT） of A549 cells and the mechanism underlying pulmonaryfibrosis.Methods A549 cells were equally divided into four groups： blank control group,TGF-β1-mediated group, PMA （the activator of ADAM 17） group and TNF484 （the inhibitor of ADAM17） group. A549 cells were cultured in vitro, cellular morphology changesafter 36 h were observed by phase contrast microscope. The mRNA and protein expressions of ADAM17 and the markers of epithelial cell and mesenchymal cell were determined by Real-time PCR and Western blotting. Results A549 cells lined up tightly in the blank control group, however, after mediated by TGF-β1, the cells became spindle and loosen. Real-time PCR and Western blotting results showed that the expression of ADAM 17 were higher in PMA group and lower in TNF484 group than that in blank control group, which had significant difference. The high expression of E-cadherin in blank control group and TNF484 group and the high expression of Vimentin in TGF-β1-mediated group and PMA group were also of significant difference.Conclusion High expression of ADAM 17 contributes to the EMT of alveolar epithelial cells, which suggests that ADAM 17 can be one of fundamental mechanisms of pulmonaryfibrosis.