Papadimitriou J C, Phelps P C, Shin M L, Smith M W, Trump B F
Department of Pathology, University of Maryland School of Medicine, Baltimore.
Cell Calcium. 1994 Mar;15(3):217-27. doi: 10.1016/0143-4160(94)90061-2.
We have previously shown [Papadimitriou JC. Ramm LE. Drachenberg CB. Trump BF. Shin ML. (1991) J. Immunol., 147, 212-217] that formation of lytic C5b-9 channels on Ehrlich ascites tumor cells induced rapid depletion of adenine nucleotides associated with prelytic leakage preceding cell death. Extracellular Ca2+ concentration ([Ca2+]e) reduction by chelation markedly delayed the onset of cell death, although the adenine nucleotide leakage was enhanced. In the present study, we examined the temporal relationships between ionized cytosolic Ca2+ ([Ca2+]i), mitochondrial membrane potential (delta psi m) and cell death in individual cells by digital imaging fluorescence microscopy (DIFM), during the earliest phase of C5b-9 attack. The results showed an immediate, > 20-fold rise in [Ca2+]i, rapidly followed by dissipation of delta psi m and subsequent acute cell death. These events were markedly delayed by chelation of Ca2+e, but not by nominally Ca2+ free medium. Differing from previous reports indicating propidium iodide labeling of viable cells bearing C5b-9 channels, with DIFM we observed nuclear fluorescence with that marker only in association with cell death. These findings indicate that Ca2+ influx through lytic C5b-9 channels is responsible for the massive increase in [Ca2+]i, as well as for the rapid loss of delta psi m, followed by acute cell death. When this [Ca2+]i increase is prevented, the cell death is probably related to metabolic depletion.
我们先前已经表明[帕帕迪米特里乌JC、拉姆LE、德拉申伯格CB、特朗普BF、申ML。(1991年)《免疫学杂志》，147，212 - 217]，艾氏腹水癌细胞上溶解性C5b - 9通道的形成会导致腺嘌呤核苷酸迅速耗竭，这与细胞死亡前的溶解性渗漏有关。通过螯合降低细胞外Ca2 +浓度([Ca2 +]e)显著延迟了细胞死亡的发生，尽管腺嘌呤核苷酸渗漏增加。在本研究中，我们通过数字成像荧光显微镜(DIFM)在C5b - 9攻击的最早阶段检查了单个细胞中离子化胞质Ca2 + ([Ca2 +]i)、线粒体膜电位(δψm)与细胞死亡之间的时间关系。结果显示[Ca2 +]i立即升高> 20倍，随后迅速出现δψm的消散以及随后的急性细胞死亡。这些事件通过螯合Ca2 +e显著延迟，但在名义上无Ca2 +的培养基中则不然。与先前报道表明携带C5b - 9通道的活细胞有碘化丙啶标记不同，通过DIFM我们仅在细胞死亡时观察到该标记物的核荧光。这些发现表明，通过溶解性C5b - 9通道的Ca2 +内流是[Ca2 +]i大量增加以及δψm迅速丧失并随后导致急性细胞死亡的原因。当这种[Ca2 +]i增加被阻止时，细胞死亡可能与代谢耗竭有关。
