造影剂对大鼠肾小球内皮细胞凋亡及Bcl-2/Bax mRNA表达的影响

Effects of contrast media on the apoptosis of glomerular endothelial cells with expression change of Bcl-2/Bax mRNA

目的研究非离子型低渗造影剂诱导体外培养大鼠肾小球内皮细胞凋亡的作用,以及对凋亡蛋白Bcl-2和BaxmRNA表达的影响。方法不同浓度和时间的碘佛醇(Ioversol)作用于体外培养的大鼠肾小球内皮细胞,用噻唑蓝(MTT)法检测细胞存活率。用倒置显微镜观察碘佛醇作用24h后细胞形态学变化,用DNA凝胶电泳分析细胞凋亡。采用半定量RT-PCR研究碘佛醇作用前后Bcl-2和BaxmRNA的表达变化。结果非离子型低渗造影剂碘佛醇能显著降低大鼠肾小球内皮细胞存活率,并呈剂量和时间依赖性。肾小球内皮细胞在90mL碘佛醇培养液(每升细胞培养液中含90mL碘佛醇)中培养24h后皱缩、变圆、漂浮,DNA凝胶电泳呈现典型的凋亡梯度。RT-PCR结果提示,Bcl-2mRNA表达降低,BaxmRNA表达升高,BaxmRNA/Bcl-2mRNA比值明显增加。结论非离子型低渗造影剂能够通过Bcl-2/Bax基因表达变化诱导肾小球内皮细胞凋亡,该机制可能与造影剂肾病的发生有关。

Objective To investigate the effects of non-ionic low osmolar contrast media （LOCM） on the apoptosis and mRNA expression of Bcl-2/Bax in rat glomerular endothelial cells cultured in vitro. Methods Rat glomerular endothelial cells were exposed to ioversol with different concentrations for different time. Cell viability was then assessed by MTT method and morphological changes of cells were observed by inverted microscopy. In order to analyze cell apoptosis, DNA electrophoresis was applied. Meanwhile, the expression changes of Bcl-2/Bax at mRNA level were determined by RT-PCR. Results The viability of rat glomerular endothelial cells was inhibited by ioversol in a concentration and time dependent manner. After being exposed to ioversol（90 mL/L）for 24 h, the cells began to become crimple, round, and even floating. A typical DNA ladder determined by agarose gel electrophoresis was observed. Noticeably, the mRNA level of Bcl-2 in ioversol treated cells was downregulated, while Bax was up-regulated, so that the ratio of Bcl-2 mRNA to Bax mRNA increased significantly. Conclusion Non-ionic LOCM can induce glomerular endothelial cells apoptosis, which may be partly due to the disturbance of Bcl-2/Bax balance. This is probably related to the pathogenesis of contrast media nephropathy.