POLY(ADP-RIBOSE) POLYMERASE - EARLY INVOLVEMENT IN GLUTAMATE-INDUCED NEUROTOXICITY IN CULTURED CEREBELLAR GRANULE CELLS
POLY(ADP-RIBOSE) POLYMERASE - EARLY INVOLVEMENT IN GLUTAMATE-INDUCED NEUROTOXICITY IN CULTURED CEREBELLAR GRANULE CELLS
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DOI：
10.1002/jnr.490390106
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发表时间：
1994-09-01
影响因子：
4.2
通讯作者：
SKAPER, SD
中科院分区：
文献类型：
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作者：
COSI, C;SUZUKI, H;SKAPER, SD
谷氨酸神经毒性与胞质游离Ca 2+的增加相关。在某些细胞系统中，Ca 2+依赖性核酸内切酶的激活或自由基的形成可损伤DNA并激活染色质结合酶聚（ADP-核糖）聚合酶（pADPRP）。我们研究了pADPRP是否可能参与体外谷氨酸神经毒性。小脑颗粒细胞在培养12天时，用毒性剂量的谷氨酸（100 μ M）处理显示聚ADP-核糖免疫反应性的快速和短暂的增加。细胞免疫染色是异质性的，谷氨酸洗脱后恢复到对照水平。在相同的细胞制剂谷氨酸引起酶蛋白免疫反应性的显着增加，持续在以后的时间。无毒剂量的谷氨酸盐不影响免疫染色。在另一组实验中，pADPRP mRNA在谷氨酸后30分钟增加。为了研究pADPRP在谷氨酸介导的神经毒性中的作用，在该模型中测试了pADPRP的结构不同的抑制剂（3-氨基苯甲酰胺、苯甲酰胺、3-氨基邻苯二甲酰肼）及其无活性类似物（苯甲酸和邻苯二甲酰亚胺）。在谷氨酸盐处理之前60分钟和30分钟期间向培养物中添加抑制剂可防止60- 100%的神经元死亡，24小时后评估。谷氨酸诱导的Ca 2+内流不受影响。非活性类似物未能提供神经保护。这些数据表明，不仅是pADPRP激活的早期，可能的钙离子介导的机制启动谷氨酸，但它也可能积极地促进随后的神经元死亡。(C)1994 Wiley-Liss，Inc.
Glutamate neurotoxicity is correlated with an increase of cytosolic free Ca2+. In some cell systems, activation of Ca2+ dependent endonucleases or formation of free radicals can damage DNA and activate the chromatin bound enzyme poly(ADP-ribose) polymerase (pADPRP). We have investigated whether pADPRP may be involved in glutamate neurotoxicity in vitro. Cerebellar granule cells at 12 days in culture when treated with a toxic dose of glutamate (100 mu M) showed a rapid and transient increase of polyADP-ribose immunoreactivity. Cellular immunostaining was heterogeneous and returned to control levels after washout of glutamate. In the same cell preparations glutamate elicited a marked increase in enzyme protein immunoreactivity which persisted at later times. Non-toxic doses of glutamate did not affect immunostaining. In another set of experiments, pADPRP mRNA was increased 30 min after glutamate. In order to investigate the role of pADPRP in glutamate-mediated neurotoxicity, structurally different inhibitors of pADPRP (3-aminobenzamide, benzamide,3-aminophthalhydrazide) and their inactive analogues (benzoic acid and phthalimide) were tested in this model. Addition of the inhibitors to cultures 60 min before and during the 30 min of glutamate treatment prevented neuronal death by 60-100%, assessed 24 hr later. Glutamate-induced Ca2+ influx was not affected. Inactive analogues failed to afford neuroprotection. These data indicate that not only is pADPRP activated by the early, possibly Ca2+-mediated mechanisms initiated by glutamate, but that it might also actively contribute to the subsequent neuronal death. (C) 1994 Wiley-Liss, Inc.