COPD患者肺组织中活化转录因子对γ-谷氨酰半胱氨酸合酶的影响

Effect of Activated Transcription Factor on Gamma-Glutamyl Cysteine Synthase in Lung Tissue of COPD Patients

目的探讨慢性阻塞性肺疾病(COPD)患者肺组织中活化转录因子(Klf2)对γ-谷氨酰半胱氨酸合酶(γ-GCS)的影响及作用机制.方法收集行肺癌根治术30例患者的无癌细胞浸润外周肺组织标本,根据是否伴COPD分为COPD组和对照组,采用原位杂交和免疫组化检测两组肺组织标本中Klf2,γ-GCS mRNA和蛋白表达情况,并分析其与吸烟指数和肺功能的相关性.使用终浓度为10%的烟草烟雾提取物体外诱导人支气管上皮细胞氧化应激模型,Elisa法检测其中谷胱甘肽含量;使用Klf2特异性抑制剂anti-92a转染支气管上皮细胞,RTPCR和Western blot检测各组细胞中Klf2,γ-GCS mRNA和蛋白表达变化.结果 COPD组患者肺组织中Klf2,γ-GCS mRNA和蛋白的相对表达量均明显高于对照组,差异具有统计学意义(P<0.05).相关性分析显示:Klf2mRNA和蛋白表达与γ-GCS呈正相关;Klf2,γ-GCS mRNA和蛋白表达水平均与吸烟指数、FEV1%、FEV1/FVC呈正相关.模型组支气管上皮细胞中谷胱甘肽含量明显高于空白对照组,差异具有显著统计学意义(P<0.01);支气管上皮细胞中Klf2,γ-GCS mRNA和蛋白相对表达量模型组明显高于空白对照组;NC+模型组明显高于NC组;Klf2抑制剂组明显低于空白对照组、NC组;Klf2抑制剂+模型组明显低于Klf2抑制剂组、NC组、模型组,上述各组间差异均具有统计学意义(P<0.05).结论 Klf2通过调控COPD支气管上皮细胞中γ-GCS的表达而发挥抗氧化作用.

Objective To investigate the effect of activated transcription factor 2( Klf2) on gamma-glutamyl cysteine synthase( gamma-GCS) in lung tissue of patients with chronic obstructive pulmonary disease( COPD)and its mechanism. Method 30 cases of lung cancer were collected and divided into COPD group and control group according to whether they had COPD or not. In situ hybridization and immunohistochemistry were used to detect the expression of Klf2 and gamma-GCS m RNA in lung tissue specimens of the two groups. The correlation between smoking index and pulmonary function was analyzed. The oxidative stress model of human bronchial epithelial cells was induced by 10% tobacco smoke extract in vitro. The content of glutathione was detected by Elisa method. The bronchial epithelial cells were transfected with Klf2 specific inhibitor anti-92 a. The expression of Klf2,gamma-GCS m RNA and protein was detected by RT-PCR and Western blot. Results The relative expressions of Klf2,gamma-GCS m RNA and protein in lung tissue of COPD group were significantly higher than those of control group( P<0. 05). The correlation analysis showed that there was a positive correlation between the expression of Klf2 and gamma-GCS,and the expression levels of Klf2 and gamma-GCS m RNA and protein were positively correlated with smoking index,FEV1%,FEV1/FVC. The content of glutathione in bronchial epithelial cells of model group was significantly higher than that of blank control group( P <0. 01). The relative expressions of Klf2,gamma-GCS m RNA and protein in bronchial epithelial cells in model group were significantly higher than that in blank control group;NC + model group was significantly higher than those in NC group;Klf2 inhibitor group was significantly lower than that in blank control group and NC group;Klf2 inhibitor + model group was significantly lower than that in Klf2 inhibitor group,NC group and model group,and the differences among the above groups were statistically significant( P<0. 05). Conclusion Klf2 plays an antioxidant role by regulating the expression of gamma-GCS in COPD bronchial epithelial cells.