Caspase-3 is actively involved in okadaic acid-induced lens epithelial cell apoptosis
Caspase-3 is actively involved in okadaic acid-induced lens epithelial cell apoptosis
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DOI：
10.1006/excr.2001.5223
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发表时间：
2001-06-10
影响因子：
3.7
通讯作者：
Xu, C
中科院分区：
文献类型：
--
作者：
Li, DWC;Xiang, H;Xu, C
磷酸化和去磷酸化是调节信号转导、基因表达、细胞周期进程和细胞凋亡等主要代谢活动的重要细胞事件。据充分证明，冈田酸是蛋白磷酸酶-1 (PP-1) 和-2A (PP-2A) 的有效抑制剂，可以诱导多种细胞系凋亡。我们最近的研究表明，在永生兔晶状体上皮细胞系中，N/N1003A 抑制 PP-1（而非 PP-2A）会导致晶状体上皮细胞快速凋亡。这种细胞死亡的诱导与一组基因的表达上调有关，包括肿瘤抑制基因 p53 和促凋亡基因 box。在本研究中，我们证明在大鼠晶状体上皮细胞的原代培养物中，冈田酸抑制 PP-1 也会导致细胞凋亡。此外，我们发现半胱氨酸蛋白酶 caspase-3 在冈田酸诱导的细胞凋亡的执行中很重要。用 100 nM 冈田酸处理大鼠晶状体上皮细胞的原代培养物可上调 caspase-3 在 mRNA、蛋白质和酶活性水平上的表达。用化学合成抑制剂抑制 caspase 3 活性可防止冈田酸诱导的大鼠晶状体上皮细胞凋亡。在永生细胞系 N/N1003A 中也观察到类似的结果。此外，编码晶状体αB晶状体蛋白的小鼠基因的稳定表达可抑制大田酸诱导的细胞凋亡，并且这种抑制与抑制大田酸诱导的caspase-3活性上调有关。总之，这些结果表明 caspase-3 积极参与冈田酸诱导的晶状体上皮细胞凋亡。 (C) 2001 年学术出版社。
Phosphorylation and dephosphorylation are important cellular events regulating major metabolic activities such as signal transduction, gene expression, cell cycle progression, and apoptosis. It is well documented that okadaic acid, a potent inhibitor of protein phosphatase-1 (PP-1) and -2A (PP-2A), can induce apoptosis in a variety of cell lines. Our recent studies have revealed that in the immortal rabbit lens epithelial cell Line, N/N1003A, inhibition of PP-1, but not PP-2A, leads to rapid apoptosis of the lens epithelial cells. This induction of cell death is associated with up-regulated expression of a set of genes, including the tumor-suppressor gene, p53, and the proapoptotic gene, box. In the present study, we demonstrate that inhibition of PP-1 by okadaic acid in the primary cultures of rat lens epithelial cells also leads to apoptotic death. Moreover,we show that the cysteine protease, caspase-3, is important in the execution of okadaic acid-induced apoptosis. Treatment of the primary cultures of rat lens epithelial cells with 100 nM okadaic acid up-regulates expression of caspase-3 at the mRNA, protein, and enzyme activity levels. Inhibition of the caspase 3 activity with a chemically synthesized inhibitor prevents okadaic acid-induced apoptosis in rat lens epithelial cells. Similar results are also observed in the immortal cell line N/N1003A. Furthermore, stable expression of the mouse gene encoding lens alphaB crystallin inhibits okadaic acid-induced apoptosis, and this inhibition is associated with repression of the okadaic acid-induced up-regulation of caspase-3 activity. Taken together, these results demonstrate that caspase-3 is actively involved in okadaic acid-induced lens epithelial cell apoptosis. (C) 2001 Academic Press.