Curcurnin activated both receptor-mediated and mitochondria-mediated proteolytic pathways for apoptosis in human glioblastoma T98G cells
Curcurnin activated both receptor-mediated and mitochondria-mediated proteolytic pathways for apoptosis in human glioblastoma T98G cells
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DOI：
10.1016/j.neulet.2006.08.013
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发表时间：
2006-10-16
影响因子：
2.5
通讯作者：
Ray, Swapan K.
中科院分区：
文献类型：
--
作者：
Karmakar, Surajit;Banik, Naren L.;Ray, Swapan K.
姜黄素是一种从姜黄根茎中提取的多酚类化合物，其治疗胶质母细胞瘤的效果尚未得到证实。我们利用人胶质母细胞瘤T98G细胞，探讨CCM诱导细胞凋亡的效果，并确定其参与的蛋白水解机制。台盼蓝染色排除试验显示，细胞活力随CCM剂量的增加而降低。Wright染色和ApopTag分别显示了25 μ M和50 μ M CCM作用24 h后T98G细胞凋亡的形态学和生化特征。Western blotting显示CCM激活受体介导的凋亡途径激活caspase-8，并使Bid裂解为tBid。此外，CCM引起Bax:Bcl-2比值升高，线粒体释放细胞色素c、低pI的caspases第二线粒体激活因子/直接IAP结合蛋白（Smac/Diablo）和凋亡诱导因子（AIF），表明参与了线粒体介导的途径。CCM治疗后，T98G细胞中核因子κ B （NF κ B）下调，核因子κ B α抑制剂（I κ B α）表达升高，凋亡抑制蛋白（IAPs）如c-IAP1和c-IAP2表达降低，提示生存信号受到抑制。caspase-9和caspase-3分别在35kd和20kd活性片段中被激活。Calpain和caspase-3活性在特定位点裂解270 kD的α -spectrin，分别产生145 kD和120 kD的SBDP。我们的研究结果强烈表明，CCM诱导受体介导和线粒体介导的蛋白水解机制诱导T98G细胞凋亡。2006爱思唯尔爱尔兰有限公司版权所有。
The therapeutic effect of curcumin (CCM), a polyphenolic compound from the rhizome of Curcuma longa, has not yet been examined in glioblastoma. We used human glioblastoma T98G cells to explore the efficacy of CCM for inducing apoptosis and identifying proteolytic mechanisms involved in this process. Trypan blue dye exclusion test showed decrease in cell viability with increasing dose of CCM. Wright staining and ApopTag assay showed, respectively, morphological and biochemical features of apoptosis in T98G cells exposed to 25 mu M and 50 mu M of CCM for 24 h. Treatment with CCM activated receptor-mediated pathway of apoptosis as Western blotting showed activation of caspase-8 and cleavage of Bid to tBid. Besides, CCM caused an increase in Bax:Bcl-2 ratio, and mitochondrial release of cytochrome c, Second mitochondrial activator of caspases/Direct IAP binding protein with low pI (Smac/Diablo), and apoptosis-inducing-factor (AIF) indicating involvement of mitochondria-mediated pathway as well. Down regulation of the nuclear factor kappa B (NF kappa B), increased expression of inhibitor of nuclear factor kappa B alpha (I kappa B alpha), and decreased expression of inhibitor-of-apoptosis proteins (IAPs) such as c-IAP1 and c-IAP2 in T98G cells following CCM treatment suggested suppression of survival signal. Activation of caspase-9 and caspase-3 was detected in generation of 35 kD and 20 kD active fragments, respectively. Calpain and caspase-3 activities cleaved 270 kD alpha-spectrin at specific sites to generate 145 kD spectrin break down product (SBDP) and 120 kD SBDP, respectively. Our results strongly suggest that CCM induced both receptor-mediated and mitochondria-mediated proteolytic mechanisms for induction of apoptosis in T98G cells. (c) 2006 Elsevier Ireland Ltd. All rights reserved.