Inhibition of Ced-3/ICE-related proteases does not prevent cell death induced by oncogenes, DNA damage, or the Bcl-2 homologue Bak.
Inhibition of Ced-3/ICE-related proteases does not prevent cell death induced by oncogenes, DNA damage, or the Bcl-2 homologue Bak.
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DOI：
10.1083/jcb.136.1.215
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发表时间：
1997-01-13
期刊：
影响因子：
--
通讯作者：
Evan GI
中科院分区：
文献类型：
--
作者：
McCarthy NJ;Whyte MK;Gilbert CS;Evan GI
越来越多的证据表明，半胱氨酸蛋白酶的白细胞介素-1 β-转化酶（ICE）家族在哺乳动物细胞凋亡中发挥着重要作用，该家族是线虫“死亡”基因ced-3产物的同源物。Ced-3被认为是线虫程序性细胞死亡的执行者而不是调节者。然而，目前尚不清楚哺乳动物ICE相关蛋白酶（IRP）是否参与哺乳动物细胞凋亡的执行或调节。此外，哺乳动物细胞凋亡对一种或多种IRP的绝对需求尚未建立。我们已经使用了两种IRP的细胞渗透性抑制剂，Z-Val-Ala-Asp.fluoromethylketone（ZVAD. fetamine）和t-丁氧基羰基-Asp.fluoromethylketone（BD. fetamine），以证明IRP在由几种不同机制（癌基因表达失调、Bcl-2相对巴克的异位表达和DNA损伤诱导的细胞死亡）诱导的哺乳动物细胞凋亡中的关键作用。在所有情况下，ZVAD. factory和BD. factory处理抑制与细胞凋亡相关的特征性生化和形态学事件，包括核纤层蛋白和聚（ADP-核糖）聚合酶的裂解、染色质凝聚和核小体梯状化以及磷脂酰丝氨酸的外部展示。然而，无论是ZVAD. fastener还是BD. fastener都不能抑制细胞凋亡的发生，其特征在于表面起泡的发生;相反，一旦启动，两者都能延迟程序的完成。与此完全相反，IGF-I和Bcl-2延迟了凋亡的发生，但一旦启动，对程序的动力学没有影响。我们的数据表明，IRP构成的执行机制的一部分，哺乳动物细胞凋亡诱导的癌基因失调，DNA损伤，或巴克，但他们的作用点后，细胞成为致力于凋亡或可以拯救的生存因素。此外，所有这些被阻断的细胞都失去了增殖潜力，并且最终都通过涉及细胞质起泡的过程死亡。
There is increasing evidence for a central role in mammalian apoptosis of the interleukin-1β– converting enzyme (ICE) family of cysteine proteases, homologues of the product of the nematode “death” gene, ced-3. Ced-3 is thought to act as an executor rather than a regulator of programmed cell death in the nematode. However, it is not known whether mammalian ICE-related proteases (IRPs) are involved in the execution or the regulation of mammalian apoptosis. Moreover, an absolute requirement for one or more IRPs for mammalian apoptosis has yet to be established. We have used two cell-permeable inhibitors of IRPs, Z-Val-Ala-Asp.fluoromethylketone (ZVAD.fmk) and t-butoxy carbonyl-Asp.fluoromethylketone (BD.fmk), to demonstrate a critical role for IRPs in mammalian apoptosis induced by several disparate mechanisms (deregulated oncogene expression, ectopic expression of the Bcl-2 relative Bak, and DNA damage–induced cell death). In all instances, ZVAD.fmk and BD.fmk treatment inhibits characteristic biochemical and morphological events associated with apoptosis, including cleavage of nuclear lamins and poly-(ADP-ribose) polymerase, chromatin condensation and nucleosome laddering, and external display of phosphatidylserine. However, neither ZVAD.fmk nor BD.fmk inhibits the onset of apoptosis, as characterized by the onset of surface blebbing; rather, both act to delay completion of the program once initiated. In complete contrast, IGF-I and Bcl-2 delay the onset of apoptosis but have no effect on the kinetics of the program once initiated. Our data indicate that IRPs constitute part of the execution machinery of mammalian apoptosis induced by deregulated oncogenes, DNA damage, or Bak but that they act after the point at which cells become committed to apoptosis or can be rescued by survival factors. Moreover, all such blocked cells have lost proliferative potential and all eventually die by a process involving cytoplasmic blebbing.