目的：探讨表没食子儿茶素没食子酸酯(EGCG)对人视网膜色素上皮细胞(ARPE-19)凋亡的影响及其机制。

方法：体外培养ARPE-19，分别采用0、40、80、160μg/mL EGCG处理。处理预定时间后分别用hoechst 33258染色法检测细胞凋亡形态学变化； 流式细胞仪检测细胞凋亡率； 实时荧光定量RT-PCR和Western blotting检测细胞凋亡相关因子B淋巴细胞瘤-2基因(bcl-2)、BCL2-Associated X的蛋白质(Bax)、胱天蛋白酶-3(caspase-3)和p53的表达。

结果：hoechst 33258染色结果发现ARPE-19随着EGCG药物浓度的增加，凋亡细胞数量逐渐增多，可见明显的凋亡小体； 流式细胞仪结果显示随着EGCG药物浓度的升高，凋亡率逐渐增高，40、80、160μg/mL凋亡率分别为4.95%±0.071%、11.75%±0.075%和21.25%±0.919%与对照组(2.8%±1.556%)相比有差异(P<0.01)，呈现出药物浓度依赖性； 实时荧光定量PCR和Western blot结果表明EGCG能明显上调凋亡促进因子Bax、caspase-3和p53的mRNA和蛋白表达，同时下调凋亡抑制因子bcl-2的表达，均呈现浓度依赖性。

结论：EGCG能明显诱导ARPE-19发生凋亡，其机制与抑制bcl-2的表达，增强Bax、caspase-3和p53的表达有关。

METHODS:The ARPE-19 cells were cultured in vitro and treated with 0,40,80 and 160 μg/mL EGCG, respectively. At the proposed time of treatment the morphological changes were detected by hoechst 33258 staining. The apoptosis rate was detected by flow cytometry. The expression of apoptosis-related factors B lymphocytoma-2 gene(bcl-2), BCL2-Associated X protein(Bax),caspase-3 and p53 were detected by quantitative RT-PCR and Western blotting.

RESULTS: Hoechst 33258 staining showed that the ARPE-19 cells with the increase of EGCG drug concentration, the number of apoptotic cells gradually increased and the apoptotic bodies were observed. Flow cytometry showed that the apoptosis rate increased gradually with the increase of EGCG drug concentration. The apoptosis rates at 40, 80 and 160 μg/mL were 4.95%±0.071%, 11.75%±0.075% and 21.25%±0.919% respectively, which was significantly different compared with the control group(2.8%±1.556%)(P<0.01), presented with a drug concentration-dependent. The results of quantitative PCR and Western blotting showed that EGCG could significantly up-regulate the expression of apoptosis-promoting factors Bax, caspase-3 and the mRNA and protein expression of p53, and down-regulate the apoptosis-inhibiting factor bcl-2, all of these showed concentration-dependent effects.

CONCLUSION:EGCG can obviously induce the apoptosis of ARPE-19 cells. The mechanism is related with the inhibition of bcl-2 and increase the expression of Bax, caspase-3 and p53.