Dessi F, Ben-Ari Y, Charriaut-Marlangue C
INSERM U29, Paris, France.
Brain Res. 1994 Aug 15;654(1):27-33. doi: 10.1016/0006-8993(94)91567-9.
We have previously shown that glutamate-induced neurotoxicity is mediated by a sodium-chloride component and a calcium component in our cerebellar granule cell culture. In order to further characterize these two different components, the time course of neuronal death induced by glutamate (100 microM) in basal solution and in low sodium-chloride solution was studied by morphological and biochemical criteria. As shown by phase-contrast microscopy, cerebellar granule cells exhibited clear neuronal degeneration within 4 h after exposure to this excitotoxin. These morphological changes correlated [35S]methionine incorporation into proteins which rapidly declined during the first hour of treatment. Qualitative change in [35S]methionine incorporation into proteins was further investigated by two-dimensional gel electrophoresis performed after glutamate exposure in basal solution and in low sodium-chloride solution. Most of the proteins showed a decreased labelling after glutamate exposure as expected, but some polypeptides showed an increased labelling or appeared to be newly synthesized. Furthermore, a different pattern of protein synthesis was observed when glutamate exposure was performed in basal solution or in low sodium-chloride solution. The identification of these polypeptides and their implication in the neuronal death are discussed.
我们之前已经表明，在我们的小脑颗粒细胞培养物中，谷氨酸诱导的神经毒性由氯化钠成分和钙成分介导。为了进一步表征这两种不同的成分，通过形态学和生化标准研究了在基础溶液和低氯化钠溶液中谷氨酸（100微摩尔）诱导神经元死亡的时间进程。相差显微镜显示，小脑颗粒细胞在暴露于这种兴奋性毒素后4小时内出现明显的神经元变性。这些形态学变化与[35S]甲硫氨酸掺入蛋白质相关，在处理的第一小时内蛋白质掺入量迅速下降。通过在基础溶液和低氯化钠溶液中谷氨酸暴露后进行的二维凝胶电泳，进一步研究了[35S]甲硫氨酸掺入蛋白质的定性变化。如预期的那样，大多数蛋白质在谷氨酸暴露后标记减少，但一些多肽显示标记增加或似乎是新合成的。此外，当在基础溶液或低氯化钠溶液中进行谷氨酸暴露时，观察到不同的蛋白质合成模式。讨论了这些多肽的鉴定及其在神经元死亡中的作用。
