Caspase-3 controls both cytoplasmic and nuclear events associated with Fas-mediated apoptosis in vivo
Caspase-3 controls both cytoplasmic and nuclear events associated with Fas-mediated apoptosis in vivo
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DOI：
10.1073/pnas.95.23.13618
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发表时间：
1998-11-10
影响因子：
11.1
通讯作者：
Flavell, RA
中科院分区：
文献类型：
--
作者：
Zheng, TS;Schlosser, SF;Flavell, RA
Fas介导的细胞凋亡需要caspase-1和caspase-3样活性。然而，caspase-1和caspase-3在介导Fas诱导的细胞死亡中的作用尚不清楚。我们评估了这些半胱天冬酶在体外肝细胞死亡中对Fas信号传导的贡献。尽管野生型、caspase-1（-/-）和caspase-3（-/-）肝细胞在与表达Fast的NIH 3 T3细胞共培养时以相似的速率被杀死，但caspase-3（-/-）肝细胞显示出显著不同的形态学变化以及显著延迟的DNA片段化。对于野生型和半胱天冬酶-1（-/-）凋亡肝细胞，在6小时内观察到典型的凋亡特征，如细胞质起泡和核碎裂，但半胱天冬酶-3（-/-）肝细胞未观察到这两种事件。我们将这些研究扩展到胸腺细胞，发现凋亡的半胱氨酸天冬氨酸蛋白酶-3（-/-）胸腺细胞表现出类似的“异常”形态学变化和在肝细胞中观察到的延迟的DNA断裂。此外，涉及介导凋亡事件的各种半胱天冬酶底物，包括凝溶胶蛋白、胞衬蛋白、层粘连蛋白B和DFF 45/ICAD的裂解被延迟或不存在。这些关键底物的切割改变可能是导致在caspase-3缺陷的肝细胞和胸腺细胞中观察到的异常凋亡的原因。
Both caspase-1- and caspase3-like activities are required for Fas-mediated apoptosis. However, the role of caspase-1 and caspase-3 in mediating Fas-induced cell death is not clear. We assessed the contributions of these caspases to Fas signaling in hepatocyte cell death in vitro. Although wild-type, caspase-1(-/-), and caspase-3(-/-) hepatocytes were killed at a similar rate when cocultured with Fast expressing NIH 3T3 cells, caspase-3(-/-) hepatocytes displayed drastically different morphological changes as well as significantly delayed DNA fragmentation. For both wild-type and caspase-1(-/-) apoptotic hepatocytes, typical apoptotic features such as cytoplasmic blebbing and nuclear fragmentation were seen within 6 hr, but neither event was observed for caspase-3(-/-) hepatocytes. we extended these studies to thymocytes and found that apoptotic caspase-3(-/-) thymocytes exhibited similar "abnormal" morphological changes and delayed DNA fragmentation observed in hepatocytes. Furthermore, the cleavage of various caspase substrates implicated in mediating apoptotic events, including gelsolin, fodrin, laminB, and DFF45/ICAD, was delayed or absent. The altered cleavage of these key substrates is likely responsible for the aberrant apoptosis observed in both hepatocytes and thymocytes deficient in caspase-3.