胸腺细胞和细胞器水平的线粒体膜电势研究

以地塞米松(DEX)诱导小鼠胸腺细胞凋亡；利用PI和AnneXin V/PI流式细胞术分别检测细胞晚期和早期凋亡；利用JC-1和DiOC_6(3)/PI在细胞水平检测凋亡中线粒体膜电势(△ψm)变化：抽提线粒体,利用JC-1直接染色技术检测现存线粒体△ψm情况。实验结果显示,DEX显著诱导胸腺细胞早期和晚期凋亡,凋亡细胞主要来自G_0/G_1期；细胞水平可见DEX介导与△ψm相关的J-aggregate和DiOC_6(3)可染性降低,同时介导线粒体数量显著降低,6h细胞膜完整性无显著变化：单纯线粒体检测结果显示,多数线粒体维持正常△ψm。提示,DEX介导胸腺细胞凋亡中线粒体数量降低,现存线粒体多保持着正常△ψm以维持凋亡过程细胞能量供给。

STUDY ON THE MITOCHONDRIAL INNER MEMBRANE POTENTIAL OF APOPTOTIC THYMOCYTES AT CELL AND ORGANELLE LEVEL

In this study, dexamethasone was used to induce mouse thymocyte apoptosis. The PI and Annexin V/PI staining flowcytometry methods were adopted to detect late and early phases apoptosis. Inner mitochondrial membrane potential (deltapsim) was examined by JC-1 and DiOC6(3)/PI staining flowcytometry. Direct JC-1 staining technology was applied to test the of deltapsim abstracted pure mitochondria. Results showed: DEX could significantly induce late and early phase mouse thymocyte apoptosis; at cell level, DEX was observed to reduce staining ability of deltapsim dependant fluorescence, J-aggregate and DiOC6(3), to drop down mitochondria number, but to cause no significant change of cell membrane integrity. Results of pure mitochondria detection showed most of them maintained normal deltapsim. According to above results, we concluded DEX could reduce mitochondria number when inducing mouse thymocyte apoptosis; and the remaining ones maintain normal function to meet the energy need for apoptotic process.