Evidence for redox regulation of cytochrome c release during programmed neuronal death: Antioxidant effects of protein synthesis and caspase inhibition
Evidence for redox regulation of cytochrome c release during programmed neuronal death: Antioxidant effects of protein synthesis and caspase inhibition
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DOI：
10.1523/jneurosci.21-06-01949.2001
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发表时间：
2001-03-15
影响因子：
5.3
通讯作者：
Franklin, JL
中科院分区：
文献类型：
--
作者：
Kirkland, RA;Franklin, JL
当交感神经元缺乏神经生长因子（NGF）时，它们会因细胞凋亡而死亡。线粒体释放的细胞色素 c 激活半胱天冬酶是这种死亡的关键。在本报告中，我们提供了细胞氧化还原状态调节这些神经元中细胞色素 c 重新分布的证据。 NGF 撤除后 3 小时内，细胞培养物中大鼠交感神经元中线粒体产生的活性氧 (ROS) 增加。 Caspase 抑制剂阻止了这种 ROS 爆发。剥夺 NGF 后 6 小时，谷胱甘肽 (GSH) 水平增加，中和了升高的过氧化氢水平，并使细胞氧化还原状态恢复到基础水平。剥夺后 12 小时，ROS 水平再次升高，并在细胞凋亡过程的其余过程中保持升高状态。后来的 ROS 爆发似乎同时具有 caspase 依赖性和 caspase 独立成分，并且与细胞色素 c 释放的时期一致。用放线菌酮 (CHX) 抑制蛋白质合成并用抗氧化剂化合物 N-乙酰基-L-半胱氨酸 (L-NAC) 处理，通过增加细胞 GSH 水平来阻止早期和晚期 ROS 爆发（Ratan 等，1994；Tan 等，1998）。这两种化合物以及谷胱甘肽的透膜形式也能抑制细胞色素 c 的释放和死亡。用过氧化氢处理 NGF、CHX-、L-NAC- 和 GSH 保存的细胞会导致细胞色素 c 快速释放。这些数据表明细胞氧化还原状态在 NGF 撤除诱导的细胞凋亡过程中调节细胞色素 c 释放中的作用。
Sympathetic neurons die by apoptosis when they are deprived of nerve growth factor (NGF). Activation of caspases by cytochrome c released from mitochondria is central to this death. In this report we present evidence that cellular redox state regulates cytochrome c redistribution in these neurons. An increase of mitochondrial-produced reactive oxygen species (ROS) occurred in rat sympathetic neurons in cell culture within 3 hr of NGF withdrawal. Caspase inhibitors blocked this ROS burst. By 6 hr after NGF deprivation, glutathione (GSH) levels had increased, neutralizing elevated hydrogen peroxide levels and returning cellular redox state to basal levels. By 12 hr after deprivation, ROS levels had again increased and remained elevated during the rest of the apoptotic process. The later ROS burst appeared to have both caspase-dependent and caspase-independent components and was coincident with the period of cytochrome c release. Inhibition of protein synthesis with cycloheximide (CHX) and treatment with the antioxidant compound, N-acetyl-L-cysteine (L-NAC), blocked both the early and late ROS bursts by increasing cellular GSH levels (Ratan et al., 1994; Tan et al., 1998). Both compounds, and a membrane-permeant form of GSH, also inhibited cytochrome c release and death. Treatment of NGF, CHX-, L-NAC-, and GSH-saved cells with hydrogen peroxide caused rapid cytochrome c release. These data suggest a role for cellular redox state in regulating cytochrome c release during apoptosis induced by NGF withdrawal.