暂时性脑缺血诱导c-fos原癌基因和鸟氨酸脱羧酶基因表达

应用大鼠椎动脉与颈内动脉结扎造成暂时性脑缺血再灌注以及RNA点杂交方法观察c-fos基因与鸟氨酸脱羧酶(ODC)基因表达的动力学过程。结果表明:大鼠大脑皮质c-fos基因在再灌后0.5至3小时表达,ODC基因在6小时至14小时表达;海马的c-fos基因则自36至72小时呈现高水平表达,ODC基因表达与之相对同步或稍延后。但是暂时性脑缺血却不能诱导c-Myc基因表达。上述结果提示c-fos及ODC可能在缺血型脑损伤后具有特殊作用。文中对缺蛋再灌引起cfos-及ODC基因表达的机制进行了分析与讨论,并提出“神经元应激状态”这一概念以描述神经元对伤害性刺激的反应历程。

INDUCTION OF EXPRESSION OF PROTO-ONCOGENE C FOS AND ORNITHINE DECARBOXYLASE GENES BY TRANSIENT CEREBRAL ISCHEMIA

The levels of mRNAs for proto-oncogene c-fos and ornithine decarboxylase (ODC)genes were measured in rat cerebral cortex and hippocampus at various recirculation intervals after 20 minutes of ischemia. Striking increases in c-fos and ODC genes expression were observed in rat cerebral cortex 0.5-3h and 6-14h respectively after recirculation. In the meantime, delayed expression of of c-fos and ODC genes were noticed in rat hippocampus 36~72h after recirculation. In contrast to c-fos and ODC genes, c-myc gene expression can not be induced by ischemia. These results imply some specific role of c-fos and ODC after ischemic brain injury. In this article, we analysed the mechanism that recirculation after ischemia induces c-fos and ODC genes expression, and proposed the concept - neuronal stress state to describe neuronal response to destructive stimulation.