DNA damage and DNA damage-inducible protein Gadd45 following ischemia in the P7 neonatal rat
DNA damage and DNA damage-inducible protein Gadd45 following ischemia in the P7 neonatal rat
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DOI：
10.1016/s0165-3806(99)00084-x
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发表时间：
1999-09-06
期刊：
影响因子：
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通讯作者：
Ben-Ari, Y
中科院分区：
文献类型：
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作者：
Charriaut-Marlangue, C;Richard, E;Ben-Ari, Y
成年啮齿类动物的脑缺血导致基因组DNA中产生几种类型的损伤，随后激活损伤反应指示剂Gadd 45。我们的目的是研究新生儿脑缺血损伤后染色质DNA的结构变化和修复过程。新生儿缺血诱导的永久性左MCA闭塞与1小时闭塞的左颈总动脉在7天大的Wistar幼鼠。以延迟的方式观察到被认为是特征性DNA梯状条带的寡核小体片段。双链断裂导致50和300 kbp的高分子量片段，如脉冲场凝胶电泳所示，并在24小时的恢复通过TUNEL测定可视化。与此相反，DNA单链断裂，所示的使用DNA聚合酶I介导的生物素-dATP缺口翻译是不那么丰富。Gadd 45免疫反应性依次增加，在脆弱的神经元在梗死（4至24小时）和亚致死损伤的神经元在半影区（24-48小时）。总之，这些发现表明Gadd 45对新生儿缺血后的DNA损伤有反应。此外，修复过程似乎在半影区更活跃，因此Gadd 45也可能在脑缺血中具有保护作用。(C)1999 Elsevier Science B. V.保留所有权利。
Cerebral ischemia in adult rodents leads to the production of several types of lesions in the genomic DNA, followed by the activation of the damage-response indicator Gadd45. Our purpose was to investigate the structural changes that occur in chromatin DNA and repair processes after ischemic injury in neonatal brain. Neonatal ischemia was induced by the permanent left MCA occlusion in association with 1 h occlusion of the left common carotid artery in 7-day-old Wistar pups. Oligonucleosome fragments that are recognized as the characteristic DNA ladder was observed in a delayed fashion. Double-strand breaks result in high molecular weight fragments of 50- and 300-kbp as demonstrated by pulsed-field gel electrophoresis, and visualized by the TUNEL assay at 24 h of recovery. In contrast, DNA single-strand breaks, shown by the use of DNA polymerase I-mediated biotin-dATP nick translation were not so abundant. Gadd45 immunoreactivity was sequentially increased in vulnerable neurons in the infarct (4 to 24 h) and in sublethally injured neurons in the penumbra (24-48 h). Taken together, these findings suggest that Gadd45 responds to DNA damage following neonatal ischemia. Furthermore, repairing processes seem to be more active in the penumbra and therefore Gadd45 could have also a protective role in cerebral ischemia. (C) 1999 Elsevier Science B.V. All rights reserved.