Induction of neuronal apoptosis by thiol oxidation: Putative role of intracellular zinc release
Induction of neuronal apoptosis by thiol oxidation: Putative role of intracellular zinc release
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DOI：
10.1046/j.1471-4159.2000.0751878.x
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发表时间：
2000-11-01
影响因子：
4.7
通讯作者：
Reynolds, IJ
中科院分区：
文献类型：
--
作者：
Aizenman, E;Stout, AK;Reynolds, IJ
在无细胞体系中，膜渗透性氧化剂2，2 '-二硫代二吡啶（DTDP）可诱导金属蛋白释放Zn ~（2+）。在这里，我们报告说，短暂暴露于DTDP触发培养的神经元细胞凋亡，检测到的DNA梯状和不对称染色质形成的存在。神经元死亡被细胞外钾水平增加，四乙基铵，和广谱半胱氨酸蛋白酶抑制剂丁氧基羰基天冬氨酸-氟甲基酮阻断。N，N，N '，N'-四（2-吡啶甲基）乙二胺（TPEN）和其他细胞渗透性金属螯合剂也有效地阻断DTDP诱导的神经元毒性。然而，细胞死亡，并没有被废除的NMDA受体阻滞剂MK 801，细胞内钙释放拮抗剂丹曲林，或高浓度的ryanodine。DTDP在装有锌选择性染料纽波特绿色的培养神经元中产生荧光信号增加。DTDP处理后，fura-2和magfura-2负载神经元的荧光信号也增加。这些反应被TPEN完全逆转，与DTDP介导的细胞内游离Zn 2+浓度增加一致。我们的研究表明，在氧化应激的条件下，从细胞内储存的Zn 2+释放可能有助于启动神经元凋亡。
The membrane-permeant oxidizing agent 2,2'-dithiodipyridine (DTDP) can induce Zn2+ release from metalloproteins in cell-free systems. Here, we report that brief exposure to DTDP triggers apoptotic cell death in cultured neurons, detected by the presence of both DNA laddering and asymmetric chromatin formation. Neuronal death was blocked by increased extracellular potassium levels, by tetraethylammonium, and by the broad-spectrum cysteine protease inhibitor butoxy-carbonylaspartate-fluoromethylketone. N,N,N',N'-Tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) and other cell-permeant metal chelators also effectively blocked DTDP-induced toxicity in neurons. Cell death, however, was not abolished by the NMDA receptor blocker MK801, by the intracellular calcium release antagonist dantrolene, or by high concentrations of ryanodine. DTDP generated increases in fluorescence signals in cultured neurons loaded with the zinc-selective dye Newport Green. The fluorescence signals following DTDP treatment also increased in fura-2- and magfura-2-loaded neurons. These responses were completely reversed by TPEN, consistent with a DTDP-mediated increase in intracellular free Zn2+ concentrations. Our studies suggest that under conditions of oxidative stress, Zn2+ released from intracellular stores may contribute to the initiation of neuronal apoptosis.