A new strategy for brain protection during circulatory arrest

目的：最近的研究报道了抗核因子κB （NF-κB）的顺式元件诱饵寡脱氧核苷酸（ODNs）可阻断介导缺血性损伤的基因的激活。为了改善心脏手术中循环骤停时的脑保护，我们评估了NF-κB诱骗odn对全脑缺血后神经元损伤的预防作用。方法：在大鼠全脑缺血20 min时，经颈动脉注射日本血凝病毒(HVJ)-脂质体复合物及fitc标记的NF-κB诱饵odn，观察其转染效果。再灌注后1小时，采用实时聚合酶链反应（PCR）法检测海马缺血再灌注损伤相关因子mRNA水平。缺血7天后，通过TUNEL染色和海马CA-1区微管相关蛋白2 （MAP2）的免疫组化研究评估神经元损伤。结果：NF-κB诱骗odn在大鼠全脑缺血时经颈动脉导入脑神经元明显成功。PCR研究表明，转染NF-κB诱饵ODNs可有效抑制全脑缺血1小时后肿瘤坏死因子-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。TUNEL染色和MAP2免疫组化结果显示，转染NF-κB诱饵ODNs可显著减轻全脑缺血后7天的神经元损伤。结论：在脑缺血期间治疗性转染NF-κB诱饵odn可能有助于减轻神经元损伤，提示一种脑缺血保护策略。

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.