甲基强的松龙对香烟烟雾提取物诱导A549细胞I-κBα的影响

The Alteration of I-κBα induced by cigarette smoke extract and effect of Methylprednisolone in the human pulmonary cell type Ⅱ

目的：观察香烟烟雾提取（CSE）诱导人类怖泡Ⅱ型上皮细胞A549后Ⅰ-κBα的变化及甲基强的松龙（Mp）对其的影响。方法：体外培养A549细胞系，根据条件不同将其分为3组：（1）对照组：无血清DMEM处理。（2）CSE组：10％浓度CSE处理。（3）CSE＋Mp组：CSE刺激后加入0．015％甲基强的松龙处理。于不同时间段收集各组细胞裂解物后，应用免疫印迹法（Western blot）、酶联免疫法（ELISA）观察Ⅰ-κBα的变化。结果：对照组无变化，CSE组Ⅰ-κBα从处理后15min开始后减少，30min后消失，CSE＋Mp组Ⅰ-κBα在15～30min内始终有本底表达，3组间Ⅰ-κBα蛋白的表达水平差异有统计学意义（P〈0．01）。结论：甲基强的松龙能使CSE刺激后A549细胞Ⅰ-κBα蛋白表达增加。

Objective： To observe the alteration of Inhibitor-κBα （Ⅰ-κBα）, induced by cigarette smoke extract and effect of methylprednisolone in the human pulmonary cell type Ⅱ. Methods： A549 cells were cultured in vitro ,and then divided into three groups： serum free DMEM, CSE stimulated group and CSE plus methylprednisolone group, measured by inverted microscope, Western-blot analysis and EIASA, respectively. Results： CSE could change the cells＇ morphology and activity, Western-blot analysis of total protein showed a rapid loss of Ⅰ-κBα protein followed by its reappearance usually 60-90 rain post CSE stimulation.Loss of Ⅰ-κBα was preceded by a mobility shift, observed 5 min continued turnover of Ⅰ-κBα, methylpred-nisolone had an effect on the ability of CSE to cause Ⅰ-κBα degradation, there was some obvious change in the time course of Ⅰ-κBα protein resynthesis（P〈0.01）. Conclusion： Methylprednisolone may increase the resynthesis of Ⅰ-κBα, while weaken the cytotoxicity of CSE and may play a role in the anti-inflammatory treatment of respiratory diseases.