Diphosphorylation and involvement of extracellular signal-regulated kinases (ERK1/2) in glutamate-induced apoptotic-like death in cultured rat cortical neurons
Diphosphorylation and involvement of extracellular signal-regulated kinases (ERK1/2) in glutamate-induced apoptotic-like death in cultured rat cortical neurons
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DOI：
10.1016/s0006-8993(99)02364-1
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发表时间：
2000-02-28
期刊：
影响因子：
2.9
通讯作者：
Jing, GZ
中科院分区：
文献类型：
--
作者：
Jiang, Q;Gu, ZL;Jing, GZ
谷氨酸诱导的兴奋性毒性，具有一定的细胞凋亡特征，与多种神经元退行性疾病有关。在某些生理情况下，细胞外信号调节激酶（ERK 1/2）通过刺激谷氨酸受体而被激活。在本研究中，激活（二磷酸化）和ERK 1/2在谷氨酸诱导的神经元凋亡样死亡的作用进行了研究。蛋白质水平和活化（二磷酸化）水平的ERK 1/2的蛋白质免疫印迹，分别探测与抗ERK 1/2和抗活性（二磷酸化）ERK 1/2抗体。通过DAPI染色确定凋亡样死亡。在暴露于50 μ M谷氨酸15 min后9-18 h观察到显著增加的促凋亡样细胞死亡之前，ERK 1/2的二磷酸化水平迅速增加，在暴露的5-15 min达到峰值，并在暴露后3 h恢复到假对照水平，而ERK 1/2的蛋白水平不受影响。有效诱导凋亡样细胞死亡的谷氨酸浓度与诱导ERK 1/2二磷酸化的谷氨酸浓度相关。ERK 1/2的二磷酸化和细胞凋亡样的细胞死亡在很大程度上被MK-801，一个特定的NMDA受体（谷氨酸受体亚型）拮抗剂，或消除细胞外Ca 2+与EGTA。ERK 1/2激酶特异性抑制剂PD 98059可完全抑制ERK 1/2的二磷酸化，部分抑制细胞凋亡样死亡。这些结果表明，主要通过NMDA受体介导的细胞外Ca ~（2+）内流，ERK 1/2被迅速和短暂激活，并参与谷氨酸诱导的大鼠皮层神经元凋亡样死亡。(C)2000 Elsevier Science B. V.保留所有权利。
Glutamate-induced excitotoxicity, with certain characteristics of apoptosis, has been implicated in a variety of neuronal degenerative disorders. In some physiological cases, extracellular signal-regulated kinases (ERK1/2) are activated by stimulation of glutamate receptors. In the present study, the activation (diphosphorylation) and role of ERK1/2 in glutamate-induced apoptotic-like death in cultured cortical neurons were investigated. Protein levels and activation (diphosphorylation) levels of ERK1/2 were examined by Western immunoblot, probed with anti-ERK1/2 and anti-active (diphosphorylated) ERK1/2 antibodies, respectively. Apoptotic-like death was determined by DAPI staining. Before a remarkable increase of apoptotic-like cell death was observed at 9-18 h after 15 min exposure to 50 mu M glutamate, diphosphorylation levels of ERK1/2 were rapidly increased, peaked at 5-15 min of the exposure, and reverted to sham control level 3 h after the exposure, while the protein levels of ERK1/2 were unaffected. The glutamate concentration effective for inducing apoptotic-like cell death was correlated with that for inducing ERK1/2 diphosphorylation. Both ERK1/2 diphosphorylation and the apoptotic-like cell death were largely prevented by MK-801, a specific NMDA receptor (a subtype receptor of glutamate) antagonist, or the elimination of extracellular Ca2+ with EGTA. PD98059, a specific inhibitor of ERK1/2 kinase, completely inhibited ERK1/2 diphosphorylation and partially inhibited the apoptotic-like cell death. These results suggest that largely via NMDA receptor-mediated influx of extracellular Ca2+, ERK1/2 were rapidly and transiently activated and were involved in glutamate-induced apoptotic-like death in cultured rat cortical neurons. (C) 2000 Elsevier Science B.V. All rights reserved.