Synergistic depletion of astrocytic glutathione by glucose deprivation and peroxynitrite: Correlation with mitochondrial dysfunction and subsequent cell death
Synergistic depletion of astrocytic glutathione by glucose deprivation and peroxynitrite: Correlation with mitochondrial dysfunction and subsequent cell death
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DOI：
10.1046/j.1471-4159.2000.0741989.x
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发表时间：
2000-05-01
影响因子：
4.7
通讯作者：
Kim, WK
中科院分区：
文献类型：
--
作者：
Ju, C;Yoon, KN;Kim, WK
以前我们报道过免疫刺激的星形胶质细胞对葡萄糖剥夺非常脆弱。增强的死亡由过氧亚硝酸根（ONOO-）产生试剂3-吗啉基丙酮亚胺（SIN-1）模拟。在这里，我们表明，葡萄糖剥夺和ONOO-协同消耗细胞内还原型谷胱甘肽（GSH），并通过形成环孢菌素A敏感的线粒体通透性转换（MPT）孔增加星形胶质细胞的死亡。星形胶质细胞GSH水平仅轻微降低葡萄糖剥夺或SIN-1（200 μ M）单独。相反，在葡萄糖剥夺/SIN-1处理的星形胶质细胞中观察到GSH的快速和大量消耗。GSH的消耗发生在乳酸脱氢酶（细胞死亡的标志物）的显著释放之前。超氧化物歧化酶和ONOO-清除剂完全阻断了增强的死亡，表明一氧化氮与超氧化物反应形成ONOO-是有牵连的。此外，硝基酪氨酸免疫反应性（ONOO-的标志物）显着增强葡萄糖剥夺/SIN-1处理的星形胶质细胞。在葡萄糖剥夺/SIN-1处理的星形胶质细胞中，线粒体跨膜电位（MTP）协同降低。谷胱甘肽合成酶抑制剂L-丁硫氨酸-（S，R）-亚砜亚胺显着降低MTP和增加乳酸脱氢酶（LDH）的释放SIN-1处理的星形胶质细胞。环孢菌素A，MPT孔阻滞剂，完全阻止MTP去极化，以及在葡萄糖剥夺/SIN-1处理的星形胶质细胞的LDH释放增强。
Previously we reported that immunostimulated astrocytes were highly vulnerable to glucose deprivation. The augmented death was mimicked by the peroxynitrite (ONOO-)-producing reagent 3-morpholinosydnonimine (SIN-1). Here we show that glucose deprivation and ONOO- synergistically deplete intracellular reduced glutathione (GSH) and augment the death of astrocytes via formation of cyclosporin A-sensitive mitochondrial permeability transition (MPT) pore. Astrocytic GSH levels were only slightly decreased by glucose deprivation or SIN-1 (200 mu M) alone. In contrast, a rapid and large depletion of GSH was observed in glucose-deprived/SIN-1-treated astrocytes. The depletion of GSH occurred before a significant release of lactate dehydrogenase (a marker of cell death). Superoxide dismutase and ONOO- scavengers completely blocked the augmented death, indicating that the reaction of nitric oxide with superoxide to form ONOO- was implicated. Furthermore, nitrotyrosine immunoreactivity (a marker of ONOO-) was markedly enhanced in glucose-deprived/SIN-1-treated astrocytes. Mitochondrial transmembrane potential (MTP) was synergistically decreased in glucose-deprived/SIN-1 treated astrocytes. The glutathione synthase inhibitor L-buthionine-(S,R)-sulfoximine markedly decreased the MTP and increased lactate dehydrogenase (LDH) releases in SIN-1-treated astrocytes. Cyclosporin A, an MPT pore blocker, completely prevented the MTP depolarization as well as the enhanced LDH releases in glucose-deprived/SIN-1-treated astrocytes.