三氧化二砷对淋巴细胞的毒性作用及机制研究

Study on cytotoxicity of arsenic trioxide to lymphocytes and its mechanisms

目的研究As2O3对人外周血淋巴细胞的毒性作用,探讨As2O3损伤淋巴细胞的机制。方法从正常人外周血中分离淋巴细胞,台盼蓝染色检测细胞活性;FITG-Annexin-V／PI染色检测细胞凋亡;电镜观察形态学改变;流式细胞术观察细胞bcl-2表达水平。结果 1-50 μmol／L As2O3对正常人外周血淋巴细胞的生长有明显的抑制作用,其抑制效应随着As2O3浓度的增高和作用时间的延长而增强,24、48、72 h的半数抑制浓度分别为7．74、4．81和3．19μmol／L。经10μmol／L As2O3处理的淋巴细胞出现细胞体积缩小、胞质浓缩、染色质聚集、固缩、沿核膜内侧分布呈新月形等典型的凋亡细胞特征性形态改变;2．0—10．0μmol／L As2O3可显著降低淋巴细胞bcl-2蛋白的表达水平。结论 As2O3对人外周血淋巴细胞有明显的毒性效应,主要作用机制为通过抑制bcl-2表达而诱发细胞凋亡。

Objective To study the cytotoxicity of As2O3 to human lymphocytes and its mechanisms. Methods Lymphocytes were separated from normal human peripheral blood. The cell survival was examined by trypan blue dye exclusion assay, apoptosis of lymphocytes was detected by electron microscopy and double staining of FITC-Annexin V/PI, and bcl-2 expression was analyzed by flow cytometry. Results 1-50 mol/L As2O3 inhibited the growth of lymphocytes in concentration- and time-dependant manner（P 〈 0.01）, and the 50% inhibiting concentration（IC50） for 24, 48 and 72 hours was 7.74, 4.81 and 3.19 mol/L, respectively. The typical apoptotic morphological changes of lymphocytes were observed, and the apoptotic rate of the cells by Annexin V/PI staining was greatly increased. During As2Oa-induced apoptosis of lymphocytes the expression of bcl-2 protein was decreased markedly. Conclusion As203 exerts a significant cytotoxicity on human lymphocytes by apoptosis induction via down-regulation of bcl-2 expression.