本研究探讨5-氨基乙酰丙酸介导的光动力疗法（ALA-PDT）作用于白血病细胞株HL-60后线粒体膜电位改变及凋亡相关基因Bcl-2表达的变化。以白血病细胞株HL-60为实验模型,实验分为4组：对照组、单纯ALA组、单纯光照组及ALA＋PDT组。采用阳离子脂质荧光探针JC-1检测线粒体跨膜电位,RT-PCR及实时定量PCR方法检测PDT前后Bcl-2基因表达变化。结果表明,ALA-PDT后线粒体膜电位出现快速下降,0 h时线粒体跨膜电位崩塌的细胞比例升高至（58.28±0.92）%,与对照组相比有显著差异（P〈0.05）。随着时间延长,这种细胞比例逐步增多,而单纯ALA组和单纯光照组则无明显变化;ALA-PDT后2 h Bcl-2基因表达显著下降,4 h进一步下降达到谷底,24 h时仍呈低表达,并通过实时定量PCR进一步得到了证实。结论：ALA-PDT诱导的HL-60细胞凋亡过程与其影响线粒体跨膜电位有关,即通过影响线粒体功能促进细胞凋亡;ALA介导的光动力作用部分是通过在基因转录水平下调抗凋亡基因Bcl-2而促进凋亡的。
This study was purposed to investigate the changes of mitochondrial membrane potential （MMP） and apoptosis-related gene Bcl-2 expression of HL-60 cells treated with 5-aminolevulinic acid-based photodynamic therapy （ALA-PDT）. HL-60 cell line was used as a model and divided into 4 groups： ALA group, PDT group, ALA ＋ PDT group and control group. The change of MMP was detected by flow cytometry with JC-1 （lipophilic cation 5,5＇ ,6,6＇- tetrachloro-1,1＇,3,3 ＇-tetraethyl-benzimidazol-carbocyanine iodide） ; the mRNA expression of Bcl-2 was determined by semi-quantitative RT-PCR and real-time PCR. The results demonstrated that MMP significantly decreased after treatment with ALA-PDT and the ratio of cells with disrupted MMP obviously increased in ALA ＋ PDT group in time-dependence manner, as compared with control, ALA and PDT groups （ P 〈 0.05 ）, while no difference between ALA and PDT groups was found. The semi-quantitative RT-PCR and real-time PCR showed that the expression level of Bcl-2 was obviously down regulated at 2 h after ALA-PCT, further down-regulated at 4 h, and lasted in low level at 24 h. It is concluded that ALA-PDT-induced apoptosis of HL-60 ceils is associated with its effect on MMP, that is ALA-PDT promotes cell apoptosis through effect on mitochondrial function.
Journal of Experimental Hematology