CRP诱导人肺泡上皮细胞凋亡及对Bcl-2和Bax表达的影响

Effect of CRP induced apoptosis and expression of Bcl-2 and Bax in human alveolar epithelial cells

目的观察C-反应蛋白(CRP)对人肺泡II型上皮细胞(A549)凋亡及对Bcl-2和Bax表达的影响。方法体外培养人肺泡II型上皮细胞株A549,给予终浓度为50μg/L的CRP刺激后,分别在0h、6h、12h、24h和48h,采用流式细胞术检测细胞凋亡,RT-PCR检测Bcl-2和Bax mRNA的表达,Westernblot和免疫组化检测Bcl-2和Bax蛋白的表达。结果随着CRP刺激时间的延长,细胞凋亡率逐渐升高(P<0.05),Bcl-2mRNA和蛋白表达与CRP0h组相比均有明显降低(P<0.05),BaxmRNA和蛋白表达与CRP0h组相比则均有明显升高(P<0.05)。结论CRP可以诱导人肺泡II型上皮细胞凋亡,其机制可能与Bcl-2下调和Bax上调有关。

Objective To investigate the influence of CRP induced apoptosis and the expression of Bcl-2 and Bax in human alveolar type II epithelial cells(A549). Methods A549 were cultured in vitro and exposed to CRP at the final concentration of 50μg/L. The rate of apoptosis was mesured by flow cytometry,the expression of Bcl-2 and Bax mRNA were mesured by RT-PCR,the expression of Bcl-2 and Bax protein were mesured by Westernblot at the time of 0h,6h,12h,24h and 48h. Results The rate of apoptosis was gradually increased in a time-dependent manner,there were significant differences(P<0.05),The expression of Bcl-2 mRNA were significantly decreased (P<0.05) and the expression of Bax mRNA and protein were significantly increased (P<0.05) compared with CRP 0h group. Conclusion CRP can induce apoptosis in human alveolar epithelial cells,it is related to the down-regulation of Bcl-2 and the up-regulation of Bax.