过氧化氢抑制三氧化二砷诱导的伯基特氏淋巴瘤细胞凋亡

目的 探讨过氧化氢(H₂O₂)对三氧化二砷(As₂O₃)诱导人类伯基特氏淋巴瘤细胞凋亡的影响及双染法荧光显微技术在检测细胞凋亡中的作用。方法 应用As₂O₃诱导人类伯基特氏淋巴瘤细胞株BJAB细胞凋亡,采用Hoechst 33342和碘化丙啶(PI)核染料双染法荧光显微镜和透射电镜对细胞死亡进行观察及定量分析。结果 BJAB细胞经As₂O₃处理后,荧光显微镜下可见大多数细胞出现细胞染色质凝集、核边集、核碎裂等凋亡的特征性改变;在低剂量(200 μmol/L)H₂O₂的影响下,抑制了As₂O₃诱导的细胞凋亡,降低细胞的死亡率;细胞的死亡方式由凋亡转变为核固缩性坏死,表现为既无凋亡的特征性改变,又非典型的细胞坏死,死亡细胞的细胞核呈固缩状态而非肿胀。结论 低浓度(200 μmol/L)H₂O₂可抑制临床治疗浓度的As₂O₃诱导的人类伯基特氏淋巴瘤BJAB细胞凋亡;双染法荧光显微镜技术不但可明确区分细胞凋亡及坏死,还可判断早期凋亡细胞和晚期凋亡细胞,并可进行定量分析,是一种良好的细胞凋亡检测方法。

Hydrogen peroxide inhibits arsenic trioxide-induced apoptosis of Burkitt lymphoma cells

Objective To examine the effects of hydrogen peroxide (H₂O₂) on arsenic trioxide (As₂O₃)-induced apoptosis of human Burkitt lymphoma cells and evaluate the value of fluorescence microscope in analyzing cellular apoptosis. Methods As₂O₃ was used to induce apoptosis in human Burkitt lymphoma cells BJAB, and the cellular changes were analyzed quanti- tatively using transmission electron microscope and fluorescence microscope after staining with Hoechst 33342/propidium iodide (PI). Results Under fluorescence microscope and electron microscope, BJAB cells displayed chromatin aggregation, nuclear margination and fragmentation in response to As₂O₃ treatment. In the presence of relatively low levels of H₂O₂ (200 μmol/L), the cell death resulting from apoptosis was inhibited with pyknosis and necrosis becoming the major pathway, while As₂O₃ failed to induce cell apoptosis. The cells showed none of the typical markers of apoptosis nor any characteristic necrotic changes, and the nuclei exhibited condensation instead of swelling. In addition, the rate of cell death induced by As₂O₃ was decreased in the presence of H₂O₂. Conclusions Low levels of H₂O₂ (200 μmol/L) inhibits As₂O₃-induced (at clinically achievable concentrations) apoptosis of the human malignant lymphoma cells. Fluorescence microscopy makes possible quantitative analysis of apoptosis, capable of distinguishing not only cell apoptosis from necrosis, but also membrane-intact from membrane-permeable apoptotic cells.