Peripheral benzodiazepine receptor ligands: mitochondrial transmembrane potential depolarization and apoptosis induction in rat C6 glioma cells
Peripheral benzodiazepine receptor ligands: mitochondrial transmembrane potential depolarization and apoptosis induction in rat C6 glioma cells
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DOI：
10.1016/j.bcp.2004.03.008
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发表时间：
2004-07-01
影响因子：
5.8
通讯作者：
Martini, C
中科院分区：
文献类型：
--
作者：
Chelli, B;Lena, A;Martini, C
外周苯二氮卓类受体(PBR)是线粒体内外膜接触处的多蛋白复合体，构成线粒体通透性转换孔(MPT孔)。MPT孔的开放导致跨膜线粒体电位(DeltaPsi(M))的消失，是细胞凋亡机制中的一个关键事件。在目前的工作中，我们研究了特定的PBR配体，PK 11195或Ro5-4864，影响线粒体电位并诱导大鼠C6胶质瘤细胞凋亡的能力。MTS转化率分析表明，两种特异性配体均以剂量和时间依赖的方式抑制细胞存活，而非位点选择性配体地西潘或低亲和力的苯二氮卓类药物氯硝西潘则无明显作用。细胞暴露于PK-11195或Ro5-4864后，我们分别通过流式细胞仪和透射电子显微镜分析发现了典型的细胞死亡改变，如DNA片段化和染色质凝集。“效应器”caspase-3的激活证实了特定的PBR配体诱导细胞凋亡的能力。此外，JC-1流式细胞仪分析表明，PK 11195和Ro5-486 4可诱导DeltaPsi(M)降低。我们的数据证实了特定的PBR配体对大鼠C6胶质瘤细胞的促凋亡作用。(C)2004 Elsevier Inc.保留所有权利。
The peripheral benzodiazepine receptor (PBR) is a component of a multiprotein complex, located at the contact site between the inner and outer mitochondrial membranes, which constitutes the mitochondrial permeability transition (MPT)-pore. The opening of the MPT-pore, leading to the transmembrane mitochondrial potential (DeltaPsi(m)) dissipation, is a critical event in the mechanism of apoptosis. In the present work, we investigated the ability of the specific PBR ligands, PK 11195 or Ro5-4864, to affect mitochondrial potential and to induce apoptotic cell death in rat C6 glioma cells. Both specific ligands inhibited cell survival in a dose- and time-dependent manner, as assessed by MTS conversion assay, whereas the non-site selective ligand Diazepam or the low-affinity benzodiazepine Clonazepam showed no significant effects. After cell exposure to PK 11195 or Ro5-4864 we evidenced typical alterations of apoptotic cell death such as DNA fragmentation and chromatin condensation assessed by flow cytometric and transmission electron microscopy (TEM) analysis, respectively. Activation of the "effector" caspase-3 confirmed the ability of specific PBR ligands to induce apoptosis. Moreover, PK 11195 and Ro5-4864 induced a decrease of DeltaPsi(m), as evidenced by JC-1 flow cytometry analysis. Our data demonstrate the pro-apoptotic effects of specific PBR ligands on rat C6 glioma cells. (C) 2004 Elsevier Inc. All rights reserved.