Pyruvate and oxaloacetate limit zinc-induced oxidative HT-22 neuronal cell injury
Pyruvate and oxaloacetate limit zinc-induced oxidative HT-22 neuronal cell injury
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DOI：
10.1016/j.neuro.2006.05.011
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发表时间：
2006-12-01
期刊：
影响因子：
3.4
通讯作者：
Toms, Nick J.
中科院分区：
文献类型：
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作者：
Berry, Elizabeth V.;Toms, Nick J.
在中枢神经系统缺血期间，越来越多的证据表明，细胞内 Zn2+ 水平升高可能在诱导神经元细胞死亡中发挥重要作用。已经提出了几种介导 Zn2+ 诱导细胞死亡的机制，但精确的分子机制仍不确定。利用 HT-22 小鼠海马神经元细胞系，我们评估了细胞毒性细胞外 Zn2+ 损伤的可能机制。发现细胞外 Zn2+ 水平增加会诱导浓度依赖性细胞毒性。当在 200 mu M 下进行测试时，Zn2+ 会增加细胞内 Zn2+ 水平（通过 FluoZin-3 荧光测定）并迅速诱导细胞死亡。然而，L 型（尼莫地平）和 T 型（米贝拉地尔）电压激活 Ca2+ 通道抑制剂均不能限制 Zn2+ 诱导的细胞毒性。此外，与十字孢菌素相反，Zn2+细胞毒性损伤未能诱导显着的 caspase-3 激活，并且对多聚 caspase 抑制剂 zVAD-fmk 不敏感。与 6 It Zn2+ 损伤相比，联合应用抗氧化剂（Trolox 和 N,N'-二苯基-1,4-苯二胺 (DPPD)）具有神经保护作用。此外，尽管 Zn2+ 诱导显着的线粒体膜电位损失，但未能诱导可检测到的超氧化物产生增加。然而，丙酮酸和草酰乙酸都被发现对 Zn2+ 细胞毒性损伤具有显着的神经保护作用，且不会显着影响细胞内 Zn2+ 的积累。我们得出的结论是，培养的 HT-22 神经元容易通过非 caspase-3 介导的机制（涉及糖酵解抑制）受到 Zn2+ 细胞毒性损伤。 (c) 2006 Elsevier Inc. 保留所有权利。
During CNS ischaemia, accumulating evidence suggests that raised intracellular Zn2+ levels may play a significant role in inducing neuronal cell death. Several mechanisms mediating Zn2+ induced cell death have been suggested, however the precise molecular mechanisms remain uncertain. Employing the HT-22 murine hippocampal neuronal cell line, we have evaluated possible mechanisms of cytotoxic extracellular Zn2+ insults. Increased extracellular Zn2+ levels was found to induce concentration-dependent cytotoxicity. When tested at 200 mu M, Zn2+ increased intracellular Zn2+ levels (determined via FluoZin-3 fluorescence) and rapidly induced cell death. However, neither L-type (nimodipine) nor T-type (mibefradil) voltage-activated Ca2+ channel inhibitors limited Zn2+ induced cytotoxicity. Furthermore, and in contrast with staurosporine, Zn2+ cytotoxic insults failed to induce significant caspase-3 activation and were insensitive to the poly-caspase inhibitor, zVAD-fmk. Antioxidant coapplication (Trolox and N,N'-diphenyl-1,4-phenylenediamine (DPPD)) was neuroprotective versus 6 It Zn2+ insults. Additionally, despite inducing significant mitochondrial membrane potential loss, Zn2+ failed to induce detectable increased superoxide production. However, both pyruvate and oxaloacetate were found to afford significant neuroprotection versus Zn2+ cytotoxic insults, without significantly influencing intracellular Zn2+ accumulation. We conclude that cultured HT-22 neurones are vulnerable to Zn2+ cytotoxic insults via a non-caspase-3 mediated mechanism, which involves glycolytic inhibition. (c) 2006 Elsevier Inc. All rights reserved.