Ca2+-dependent generation of mitochondrial reactive oxygen species serves as a signal for poly(ADP-ribose) polymerase-1 activation during glutamate excitotoxicity
Ca2+-dependent generation of mitochondrial reactive oxygen species serves as a signal for poly(ADP-ribose) polymerase-1 activation during glutamate excitotoxicity
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DOI：
10.1113/jphysiol.2007.145409
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发表时间：
2007-12-15
影响因子：
5.5
通讯作者：
Sheu, Shey-Shing
中科院分区：
文献类型：
--
作者：
Duan, Yuntao;Gross, Robert A.;Sheu, Shey-Shing
线粒体 Ca2+ 摄取和聚（ADP-核糖）聚合酶 1 (PARP-1) 激活都是谷氨酸诱导的兴奋性毒性神经元死亡所必需的。由于谷氨酸受体的激活可以诱导活性氧 (ROS) 水平增加，因此我们研究了线粒体 Ca2+ 摄取和 ROS 生成的关系，以及 ROS 增加是否是培养的纹状体神经元中 PARP-1 激活所需信号的可能性。根据 NMDA 诱导的 ROS 生成的空间分布，我们发现只有线粒体在 NMDA 受体激活后 30 分钟内表现出显着的 ROS 增加。这种 ROS 增加受到线粒体复合物抑制剂鱼藤酮和寡霉素的抑制，但不受胞质磷脂酶 A(2) 或黄嘌呤氧化酶抑制剂的抑制。线粒体 ROS 的产生也受到细胞外介质中 Ca2+ 的去除以及线粒体解偶联剂或 Ca2+ 单向转运蛋白抑制剂阻断线粒体 Ca2+ 摄取的抑制。此外，NMDA 处理诱导的 DNA 损伤和 PARP-1 激活均可以通过阻断线粒体 Ca2+ 摄取或抗氧化剂来抑制。我们的结果表明，急性兴奋性毒性早期阶段的 ROS 产生主要来自线粒体，并且是 Ca2+ 依赖性的。更重要的是，线粒体ROS的增加作为PARP-1激活的信号，表明伴随的线粒体Ca2+摄取和PARP-1激活构成了兴奋毒性神经元死亡的统一机制。
Mitochondrial Ca2+ uptake and poly(ADP-ribose) polymerase-1 (PARP-1) activation are both required for glutamate-induced excitotoxic neuronal death. Since activation of the glutamate receptors can induce increased levels of reactive oxygen species (ROS), we investigated the relationship of mitochondrial Ca2+ uptake and ROS generation, and the possibility that ROS increase is a required signal for PARP-1 activation in cultured striatal neurons. Based on the spatial profile of NMDA-induced ROS generation, we found that only mitochondria showed a significant ROS increase within 30 min after NMDA receptor activation. This ROS increase was inhibited by the mitochondrial complex inhibitors rotenone and oligomycin, but not by the cytosolic phospholipase A(2) or xanthine oxidase inhibitors. Mitochondrial ROS generation was also inhibited by both removal of Ca2+ from extracellular medium and blockage of mitochondrial Ca2+ uptake by either a mitochondrial uncoupler or a Ca2+ uniporter inhibitor. Furthermore, both DNA damage and PARP-1 activation induced by NMDA treatment was inhibited by blocking mitochondrial Ca2+ uptake or by antioxidants. Our results demonstrate that ROS production during the early stage of acute excitotoxicity derives primarily from mitochondria and is Ca2+-dependent. More importantly, the increase of mitochondrial ROS serves as a signal for PARP-1 activation, suggesting that concomitant mitochondrial Ca2+ uptake and PARP-1 activation constitute a unified mechanism for excitotoxic neuronal death.