A new strategy for brain protection during circulatory arrest

目的：近年来研究发现，针对核因子-κ B（NF-κB）的顺式诱骗寡核苷酸（decoy oligodeoxynucleotides，ODNs）可阻断介导缺血性损伤的基因的激活。为了提高心脏手术停循环时的脑保护作用，我们评价NF-κB decoy ODNs对全脑缺血后神经元损伤的保护作用。方法：将日本血凝病毒（Hemagglutinating virus of Japan，HVJ）-脂质体复合物与FITC标记的NF-κB decoy ODNs经颈动脉注入大鼠全脑缺血20 min，观察其对全脑缺血后神经元损伤的保护作用。再灌注后1小时，采用实时聚合酶链反应（PCR）方法检测海马缺血再灌注损伤相关因子的mRNA水平。结果：经颈动脉将NF-κB诱骗寡核苷酸导入大鼠全脑缺血后海马CA-1区神经元，可明显减轻脑缺血后海马CA-1区神经元的损伤。PCR检测结果显示，转染NF-κB decoy ODNs可有效抑制全脑缺血后1 h肿瘤坏死因子-α（TNF-α）、白细胞介素-1 β（IL-1 β）和细胞内粘附分子-1（ICAM-1）mRNA的表达。结论：NF-κ B decoy ODNs可减轻脑缺血后神经元的损伤，提示NF-κB decoy ODNs可作为脑缺血保护的一种策略。

Objectives : Recent studies have reported that cis element decoy oligodeoxynucleotides (ODNs) against nuclear factor-kappa B (NF-κB) block the activation of genes that mediate ischemic injury. To improve brain protection during circulatory arrest in cardiac surgery, we evaluated the efficacy of NF-κB decoy ODNs in preventing neuronal damage after global brain ischemia.Methods : Hemagglutinating virus of Japan (HVJ)-liposome complex with FITC-labeled NF-κB decoy ODNs was injected via the carotid artery during 20 minutes of global brain ischemia in rats, to evaluate the efficacy of transfecting the decoy ODNs. The mRNA levels of several factors related to ischemic-reperfusion injury in the hippocampus were estimated using a real-time polymerase chain reaction (PCR) method 1-hour after reperfusion. Neuronal damage was evaluated by TUNEL staining and by immunohistochemical study of microtubule-associated protein 2 (MAP2) in the hippocampus CA-1 region seven days after ischemia.Results : Introduction of the NF-κB decoy ODNs into rat brain neurons via the carotid artery during global brain ischemia was markedly successful. The PCR study showed that the transfected NF-κB decoy ODNs effectively inhibited the expression of tumor necrosis factor-α (TNF-α), interleukin-1 β (IL-1 β), and intracellular adhesion molecule-1 (ICAM-1) mRNA 1 hour after global brain ischemia. TUNEL staining and MAP2 immunohistochemistry showed that the transfected NF-κB decoy ODNs significantly attenuated the neuronal damage seven days after global brain ischemia.Conclusions : Therapeutic transfection of NF-κB decoy ODNs during brain ischemia may be useful for attenuating neuronal damage, suggesting a strategy for cerebral protection against global ischemia.