转染Elafin对百草枯诱导的肺泡上皮凋亡的影响

摘要

Objective:To investigate the effect of recombinant Elafin on A549 apoptosis induced by paraquat and the underlying mechanism.Methods:pEGFP-C1-Elafin was transformed into A549 competent cells by electroporation.Transformed A549 was cultured for additional 24 h before Elafin mRNA was detected by RT-PCR and cocultured with or without various concentration of paraquat( PQ ) for different duration.A549 apoptosis percentage and reactive oxygen species ( ROS ) content were tested by flow cytometry .Nuclear factor erythroid like-2(Nrf2) heme oxygenase-1(HO-1) were examed by Western blot .Results:Elafin expressed successfully in A549 after transformation.PQ caused A549 apoptosis in a concentration dependent manner and leaded to ROS content increasing and Nrf2 and HO-1 decreasing.However,elafin could inhibit ROS production and A549 apoptosis,upregulate Nrf2 and HO-1.Conclusion:Elafin could restrict A549 apoptosis to some extent and the possible mechanism lied in its ability to upregulate Nrf2 ex-pression.%目的：探讨转染Elafin对百草枯（ Paraquat，PQ ）诱导的肺泡上皮凋亡的影响及可能机制。方法：电穿孔法转染pEGFP－C1－Elafin进入A549细胞，培养24 h后，RT－PCR检测Elafin mRNA在A549细胞中的表达情况；并给予生理盐水、不同浓度PQ（5、50、100μmol／L）作用后，Annexin V／PI双染法流式细胞仪检测A549细胞凋亡率、活性氧类物质（ Reactive oxygen species，ROS）含量。 Western blot 检测核因子相关因子2（ Nuclear factor erythroid like－2， Nrf2）、血红素加氧酶－1（ Heme oxygenase－1，HO－1）表达情况。结果：转入A549细胞Elafin成功表达。 PQ呈浓度依赖性导致A549细胞凋亡；PQ可使ROS含量明显增加，Nrf2、HO－1表达下调。 Elafin可抑制PQ诱导的细胞调亡，上调Nrf2、HO－1蛋白表达。结论：Elafin可以一定程度抑制PQ诱导的A549细胞凋亡，其机制可能与其上调抗氧化蛋白Nrf2等有关。