阿糖胞苷诱导HL-60细胞凋亡时线粒体膜电位变化

为研究阿糖胞苷(Ara-C)诱导HL-60细胞凋亡时线粒体膜电位(△Ψm)的变化及相互关系,采用Rhodamine123染色及流式细胞术检测HL-60细胞线粒体膜电位变化;流式细胞仪、AO/EB染色检测HL-60细胞凋亡.结果显示Ara-C作用于HL-60细胞6小时时出现细胞线粒体膜电位下降,当Ara-C浓度为0.05 mg/ml作用6、12、24小时时HL-60细胞线粒体中Rhodamine123荧光强度分别为117.9±7.6,100.9±7.7,87.6±10.7,不同时间荧光强度差异有显著性(p＜0.05);当Ara-C浓度为0.1 mg/ml作用6、12、24小时时HL-60细胞线粒体中Rhodamine123荧光强度分别为111.9±10.1,86.6±9.2,68.4±12.2,不同时间差异有显著性(p＜0.05);不同浓度组在12、24小时时比较有显著性差异(p＜0.05).当Ara-C浓度为0.05 mg/ml作用6、12、24小时时HL-60细胞凋亡率分别为(41.2±3.0)%,(53.7±5.1)%,(65.8±2.6)%,不同时间差异有显著性(p＜0.01);当Ara-C浓度为0.1 mg/ml作用6、12、24小时时HL-60细胞凋亡率分别为(45.7±4.1)%,(58.2±4.3)%,(70.1±2.3)%,不同时间差异有显著性(p＜0.01);不同浓度Ara-C在相同时间凋亡率无差别.HL-60细胞线粒体膜电位变化与其凋亡率呈高度负相关,当Ara-C浓度为0.05 mg/ml时,r=-0.89,p＜0.01;当Ara-C浓度为0.1 mg/ml时,r=-0.76,p＜0.01.结论阿糖胞苷在诱导HL-60细胞凋亡时伴有线粒体膜电位下降,两者呈显著负相关.线粒体膜电位下降可能是阿糖胞苷诱导HL-60细胞凋亡的重要机制之一.

Mitochondrial Membrane Potential at HL-60 Cell Apoptosis Induced by Cytarabine

This study was aimed to investigate the changes of mitochondrial membrane potential (DeltaPsim) of HL-60 cells induced by cytarabine and the correlation between mitochondrial membrane potential and apoptosis of HL-60 cells. HL-60 cells were stained with Rhodamine 123; change of mitochondrial membrane potential of HL-60 cells was detected by flow cytometry. AO/EB staining and flow cytometry were used to examine the apoptosis of HL-60 cells. The results showed that the levels of HL-60 cell DeltaPsim in experimental groups decreased after cultured for 6 hours. In Ara-C 0.05 mg/ml group, rhodamine 123 fluorescence intensity in mitochondria of HL-60 cells at 6, 12, 24 hours were 117.9+/-7.6, 100.9+/-7.7, 87.6+/-10.7, respectively, there was significant difference between the different culture groups (p<0.05). In Ara-C 0.1 mg/ml group, rhodamine 123 fluorescence intensity in mitochondria of HL-60 cells at 6, 12, 24 hours were 111.9+/-10.1, 86.6+/-9.2, 68.4+/-12.2, respectively, there was significant difference between the different culture groups (p<0.05); rhodamine 123 fluorescence intensity was significantly different between the two groups at 12, 24 hours (p<0.05). In Ara-C 0.05 mg/ml group, the apoptosis rate of HL-60 cells at 6, 12, 24 hours were (41.2+/-3.0)%, (53.7+/-5.1)%, (65.8+/-2.6)% respectively, there was significant difference between the different culture groups (p<0.01); In Ara-C 0.1 mg/ml group, the apoptosis rate of HL-60 cells at 6, 12, 24 hours were (45.7+/-4.1)%, (58.2+/-4.3)%, (70.1+/-2.3)% respectively, there was significant difference between the different culture groups (p<0.01); the apoptosis rates showed no significantly difference between the two groups at same time. The changes of mitochondrial membrane potential and apoptosis rate of HL-60 cells were significantly negatively correlated. In Ara-C 0.05 mg/ml group, r was -0.89, p<0.01, while in Ara-C 0.1 mg/ml group, r was -0.76, p<0.01. It is concluded that the mitochondrial membrane potential on HL-60 cells decrease at HL-60 cells apoptosis induced by Ara-C, therefore the reduction of mitochondrial membrane potential may be one of the important mechanisms at the induced apoptosis.