Fas antigen-mediated DNA fragmentation and apoptotic morphologic changes are regulated by elevated cytosolic Ca2+ level.
Fas antigen-mediated DNA fragmentation and apoptotic morphologic changes are regulated by elevated cytosolic Ca2+ level.
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Fas 抗原介导的 DNA 片段化和细胞凋亡形态变化受胞质 Ca2 水平升高的调节。
DOI：
10.4049/jimmunol.154.2.599
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发表时间：
1995
影响因子：
4.4
通讯作者：
S. Miyazaki
中科院分区：
文献类型：
--
作者：
Y. Oshimi;S. Miyazaki
在表达Fas Ag的人B细胞系FMO中，超过80%的细胞在加入抗Fas mAb后2小时内发生凋亡。细胞质内Ca2+浓度（[Ca2+]i）的升高及其影响是通过连续成像单个细胞并将Ca2+螯合剂引入细胞外部和/或细胞内部来研究的。典型的Ca2+反应包括1)早期[Ca2+]i上升（基础[Ca2+]i， 85至110 nM；峰值，140至200 nM；持续时间，15至20 min）， 2) [Ca2+]i在140至150 nM处持续升高，3)第二次Ca2+上升（200至500 nM， 15至30 min）在1.5至2 h之间，4)添加单抗后2至4 h之间[Ca2+]i大幅上升（1.2至2.0微米）。反应1、3和4主要由Ca2+进入引起，反应2涉及细胞内Ca2+从储存中释放。单抗在Ca（2+）缺失的体外培养基中也能诱导细胞凋亡。螯合胞质Ca2+表明[Ca2+]i的升高是DNA和染色质断裂的先决条件，也是细胞断裂的必要条件。临界[Ca2+]i为140 ~ 150 nM，持续升高[Ca2+]i更为有效。A [Ca2+]i升高本身（无单抗）无效。约20%的单克隆抗体处理的细胞在细胞核外围显示染色质凝结（可能是核变化的早期阶段），即使[Ca2+]i保持在100 nM以下，细胞形状仍呈泡状。因此，Ca2+在Fas刺激后立即被动员，并作为引起晚期凋亡变化的关键因素发挥作用。反应4与继发性坏死有关。
More than 80% of cells of the human B cell line FMO, which expresses the Fas Ag, underwent apoptosis within 2 h after addition of an anti-Fas mAb. Rises in cytosolic Ca2+ concentration ([Ca2+]i) and their effects were investigated by imaging individual cells continuously and introducing Ca2+ chelators to the outside and/or inside of the cell. The typical Ca2+ response consisted of 1) an early [Ca2+]i rise (basal [Ca2+]i, 85 to 110 nM; peak, 140 to 200 nM; duration, 15 to 20 min), 2) sustained elevation of [Ca2+]i at 140 to 150 nM, 3) a second Ca2+ rise (200 to 500 nM, 15 to 30 min) between 1.5 and 2 h, and 4) a large [Ca2+]i rise (1.2 to 2.0 microM) between 2 and 4 h after addition of mAb. Responses 1, 3, and 4 were mainly caused by Ca2+ entry, and response 2 involved intracellular Ca2+ release from stores. Apoptosis could be induced by mAb even in Ca(2+)-deprived external medium. Chelating cytosolic Ca2+ revealed that the [Ca2+]i rise is a prerequisite for fragmentation of DNA and chromatin, and is also necessary for fragmentation of cells. The critical [Ca2+]i was 140 to 150 nM and a sustained [Ca2+]i rise was more effective. A [Ca2+]i rise itself (without mAb) was ineffective. About 20% of mAb-treated cells showed chromatin condensation at the periphery of the nucleus (possibly an earlier stage of nuclear change) and a bubble-like cell shape even when [Ca2+]i was held below 100 nM. Thus, Ca2+ is mobilized immediately after Fas stimulation and functions as a key factor causing advanced apoptotic changes. Response 4 was related to secondary necrosis.