Dual Mechanisms of sHA 14-1 in Inducing Cell Death through Endoplasmic Reticulum and Mitochondria
Dual Mechanisms of sHA 14-1 in Inducing Cell Death through Endoplasmic Reticulum and Mitochondria
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DOI：
10.1124/mol.109.055830
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发表时间：
2009-09-01
影响因子：
3.6
通讯作者：
Xing, Chengguo
中科院分区：
文献类型：
--
作者：
Hermanson, David;Addo, Sadiya N.;Xing, Chengguo
HA 14-1是一种促进恶性细胞凋亡的小分子Bcl-2拮抗剂，但其作用机制尚不明确。我们最近报道了HA 14-1在体外的半衰期仅为15分钟，这使我们开发了HA 14-1的稳定类似物（sHA 14-1）。目前的研究描述了它的作用方式。由于Bcl-2家族蛋白对内质网（ER）和线粒体具有抗凋亡功能，因此我们评估了sHA 14-1对这两种细胞器的影响。sHA 14-1在1 min内诱导人白血病细胞内质网钙释放，随后诱导内质网应激诱导转录因子ATF4。肌内质网Ca2+- atp酶（SERCA）抑制剂thapsigargin诱导的ER钙释放动力学相似，强度更强，ATF4诱导的动力学和强度也相似。sHA 14-1直接抑制SERCA酶活性，但对肌醇三磷酸受体无影响。对线粒体通路的评估表明，sHA 14-1引发了线粒体跨膜电位（Delta psi m）的丧失和caspase-9的弱激活，而thapsigargin则没有影响。(R)-4-（3-二甲氨基-1-苯基磺胺基甲基-丙基氨基）- n-{4-[4-（4'-氯联苯-2-甲基）-哌嗪-1-基]-苯甲酰}-3-硝基苯磺酰胺（ABT-737）是一种成熟的小分子Bcl-2拮抗剂，可快速诱导δ psi m的丧失和caspase-9的激活，但对ER没有影响。pan-caspase抑制剂n-苄基氧羰基val - ala - asp -氟甲基酮对sHA - 14-1诱导的细胞死亡有一定的保护作用。这些结果表明，sHA 14-1在肿瘤细胞抗凋亡机制中具有独特的双重靶向机制，包括抗凋亡Bcl-2家族蛋白和SERCA蛋白。
HA 14-1 is a small-molecule Bcl-2 antagonist that promotes apoptosis in malignant cells, but its mechanism of action is not well defined. We recently reported that HA 14-1 has a half-life of only 15 min in vitro, which led us to develop a stable analog of HA 14-1 (sHA 14-1). The current study characterizes its mode of action. Because of the antiapoptotic function of Bcl-2 family proteins on the endoplasmic reticulum (ER) and mitochondria, the effect of sHA 14-1 on both organelles was evaluated. sHA 14-1 induced ER calcium release in human leukemic cells within 1 min, followed by induction of the ER stress-inducible transcription factor ATF4. Similar kinetics and stronger intensity of ER calcium release were induced by the sarcoendoplasmic reticulum Ca2+-ATPase (SERCA) inhibitor thapsigargin, accompanied by similar kinetics and intensity of ATF4 induction. sHA 14-1 directly inhibited SERCA enzymatic activity but had no effect on the inositol triphosphate receptor. Evaluation of the mitochondrial pathway showed that sHA 14-1 triggered a loss of mitochondrial transmembrane potential (Delta psi m) and weak caspase-9 activation, whereas thapsigargin had no effect. (R)-4-(3-Dimethylamino-1-phenylsulfanylmethyl-propylamino)-N-{4-[4-(4'-chloro-biphenyl-2-ylmethyl)-piperazin-1-yl]-benzoyl}-3-nitrobenzenesulfonamide (ABT-737), a well established small-molecule Bcl-2 antagonist, rapidly induced loss of Delta psi m and caspase-9 activation but had no effect on the ER. The pan-caspase inhibitor N-benzyloxycarbonylVal-Ala-Asp-fluoromethyl ketone had some protective effect on sHA 14-1-induced cell death. These collective results suggest a unique dual targeting mechanism of sHA 14-1 on the apoptotic resistance machinery of tumor cells that includes antiapoptotic Bcl-2 family proteins and SERCA proteins.