Tumor necrosis factor-induced apoptosis stimulates p53 accumulation and p21WAF1 proteolysis in ME-180 cells
Tumor necrosis factor-induced apoptosis stimulates p53 accumulation and p21WAF1 proteolysis in ME-180 cells
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DOI：
10.1074/jbc.273.9.5067
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发表时间：
1998-02-27
影响因子：
4.8
通讯作者：
Perez, M
中科院分区：
文献类型：
--
作者：
Donato, NJ;Perez, M
肿瘤坏死因子（TNF）介导的凋亡信号传导的特征在于激活调节凋亡开始的特异性蛋白酶或蛋白激酶级联，TNF还显示在某些细胞类型中诱导氧化或遗传毒性应激，并且凋亡潜力可以通过细胞对这种应激的反应来确定。为了确定遗传毒性应激在TNF介导的凋亡中的作用，我们检测了在TNF处理的ME-180细胞中p53的细胞积累，所述细胞被选择用于对TNF的凋亡敏感性（ME-180 S）或抗性（ME-180 R）。尽管TNF能够在任一细胞系中激活受体介导的信号传导，但p53积累仅在对TNF敏感的ME-180 S细胞中是可测量的。TNF诱导的p53水平的变化在治疗后1小时检测到，并且在TNF暴露后4-8小时可测量峰值水平。TNF不能在任一细胞系中诱导p21 WAF 1，但影响了该蛋白在抗肿瘤应答的ME-180 S细胞中的稳定性。通过监测16-kDa免疫印迹p21 WAF 1片段的出现来检测p21 WAF 1蛋白水解的证据，该片段在加入TNF后4小时变得可检测，并且在DNA片段化开始之前（16-24小时）含量增加，p21 WAF 1蛋白水解的动力学密切的聚（ADP-核糖）聚合酶，表明切割的p21 WAF 1。通过激活凋亡蛋白酶，用凋亡蛋白酶抑制剂YVAD预处理ME-180 S细胞阻断TNF诱导的凋亡，并阻止聚（ADP-核糖）聚合酶和p21 WAF 1降解，但不影响p53诱导。这些结果提供了证据，早期发病的基因毒性应激细胞致力于TNF-介导的凋亡和发散传播的信号在无反应的细胞。此外，肿瘤坏死因子诱导的p21 WAF 1蛋白水解可能是由一种凋亡蛋白酶介导的，并可能通过破坏p53信号传导，改变细胞周期抑制，并限制细胞从遗传毒性应激中恢复来促进凋亡过程。
Tumor necrosis factor (TNF)-mediated apoptotic signaling has been characterized by activation of specific protease or protein kinase cascades that regulate the onset of apoptosis, TNF has also been shown to induce oxidative or genotoxic stress in some cell types, and apoptotic potential may be determined by the cellular response to this stress, To determine the role of genotoxic stress in TNF-mediated apoptosis, we examined cellular accumulation of p53 in TNF-treated ME-180 cells selected for apoptotic sensitivity (ME-180S) or resistance (ME-180R) to TNF, Although TNF was able to activate receptor-mediated signaling in either cell line, p53 accumulation was measurable only in apoptotically sensitive ME-180S cells. TNF-induced changes in p53 levels were detected Ih after treatment, and peak levels were measurable 4-8 h after TNF exposure. TNF was unable to induce p21WAF1 in either cell line but affected the stability of this protein in apoptotically responsive ME-180S cells, Evidence of p21WAF1 proteolysis was detected by monitoring the appearance of a 16-kDa immunoblottable p21WAF1 fragment, which became detectable 4 h after TNF addition and increased in content before the onset of DNA fragmentation (16-24 h), The kinetics of p21WAF1 proteolysis closely paralleled those of poly(ADP-ribose) polymerase, suggesting cleavage of p21WAF1. by activation of an apoptotic protease, Pretreatment of ME-180S cells with the apoptotic protease inhibitor YVAD blocked TNF-induced apoptosis and prevented both poly(ADP-ribose) polymerase and p21WAF1 degradation but did not affect p53 induction. These results provide evidence for the early onset of genotoxic stress in cells committed to TNF-mediated apoptosis and for divergence in propagation of this signal in non-responsive cells. In addition, TNF-induced p21WAF1 proteolysis may be mediated by an apoptotic protease and may contribute to the apoptotic process by disrupting p53 signaling, altering cell cycle inhibition, and limiting cellular recovery from genotoxic stress.