Piao Ying, Liu Li-Mei, Chen Xie-Qun, Liang Rong, Huang Gao-Sheng, Qiao Yan, Wang Ai-Qing, Wang Zhe
Department of Hematology, Xijing Hospital, The Fourth Military Medical University, Xi'an 710032, China.
Zhongguo Shi Yan Xue Ye Xue Za Zhi. 2005 Jun;13(3):379-82.
The purpose of study was to explore the possible functions of Bcl-xL in the glucosamine sulfate-induced apoptosis of chronic myeloid leukemia K562 cells. Light microscopy and Wright-Giemsa staining were used to investigate the morphologic evidences for apoptosis of K562 cells induced by glucosamine sulfate (GS); immunofluorescence was used to observe the translocation of cathepsin D and cytochrome C during the apoptosis; Western blot was performed to detect the expression of Bcl-xL, Bid, Bax in K562 cells treated by GS. The results showed that many vacuoles were observed in the cytoplasma of the K562 cells treated by GS; fluorescent signals of cathepsin D and cytochrome were fransformed from granules to disperse form by using immunofluorescence; the expression of Bcl-xL was found down-regulated in K562 cells treated by GS, but not in the cells pre-treated with pepstatin A; the significant changes were not detected in expression of Bax and Bid protein before or after apoptosis. It is concluded that Bcl-xL protein may mediate relationship between cathepsin D and mitochondia pathway, Cathepsin D may play an important role in the GS inducing apoptosis of K562 cells through downregulation of Bcl-xL expression.
本研究的目的是探讨Bcl-xL在硫酸氨基葡萄糖诱导的慢性髓性白血病K562细胞凋亡中的可能作用。采用光学显微镜和瑞氏吉姆萨染色法观察硫酸氨基葡萄糖（GS）诱导K562细胞凋亡的形态学证据；利用免疫荧光法观察细胞凋亡过程中组织蛋白酶D和细胞色素C的转位情况；采用蛋白质免疫印迹法检测GS处理的K562细胞中Bcl-xL、Bid、Bax的表达。结果显示，GS处理的K562细胞胞质中可见许多空泡；通过免疫荧光观察到组织蛋白酶D和细胞色素的荧光信号从颗粒状转变为弥散状；发现GS处理的K562细胞中Bcl-xL的表达下调，但用胃蛋白酶抑制剂A预处理的细胞中未下调；凋亡前后Bax和Bid蛋白的表达未检测到明显变化。结论是，Bcl-xL蛋白可能介导组织蛋白酶D与线粒体途径之间的关系，组织蛋白酶D可能通过下调Bcl-xL的表达在GS诱导K562细胞凋亡中起重要作用。
