N-myc下游调节基因-2在大鼠肠缺血再灌注肺损伤中的表达及其与NF-κBp65的相关研究

N-myc down stream regulated gene 2 expression in lung tissue of rat with acute lung injury induced by intestinal ischemia-reperfusion injury and relationship with nuclear transcription factor-kappaBp65

目的通过建立大鼠肠缺血再灌注肺损伤(IIRI)模型,观察大鼠肠缺血再灌注肺损伤,肺组织中N-myc下游调节基因-2(NDRG2)表达水平的变化。方法 50只健康成年雄性SD大鼠随机分成对照组(control)、缺血再灌注组(I/R)(其中根据缺血再灌注时间又分4个亚组),每组10只。缺血再灌注4个亚组选择缺血60min后分别再灌注30、60、120和180min,获取样本肺组织。术后样本行病理(HE)、湿干重比例(W/D)检测,免疫组化、Western-blot对NDRG2、核转录因子-κBp65(NF-κBp65)检测,RT-PCR方法对NDRG2在mRNA水平含量进行检测,TUNEL法对凋亡细胞进行检测。结果缺血再灌注组与对照组比较,缺血再灌注组肺泡壁增宽,肺泡腔内可见出血等炎症表现,W/D比值显著性升高(P<0.05),免疫组化显示NF-κBp65发生核转位现象,NF-κBp65蛋白水平表达明显升高(P<0.05),肺组织NDRG2在mRNA水平和蛋白水平的表达明显降低(P<0.05)。结论缺血再灌注损伤可下调肺组织中NDRG2的表达,NDRG2可能通过对NF-κB通路进行调控,是导致缺血再灌注后肺损伤的靶向调控位点,对肠缺血再灌注肺损伤的大鼠起保护作用。

Objective To investigate alterations induced by intestinal ischemia-reperfusion in lurig gene expression of N-myc down stream regulated gene 2 （ NDRG2 ） and relationship with nuclear transcription factor-kappa- Bp65 （ NF-KBp65 ）. Methods Totally 50 healthy male Sprague Dawley （SD） rats were randomizely separated into 5 groups, 10 rats in every group. Rats which were anesthetized with pentobarbital sodium（40mg/kg） and didn＇t have superior mesenteric artery clamped as control group, and rats which had superior mesenteric artery clamped for 60 minutes and then unclamped for 30 minutes ,60 minutes,120 minutes, 180 minutes were taken as ischemia-reperfusion group （ I/R1, I/R2, I/R3, I/R4 ） in order. After operation, the pathological changes by hematoxylin and eosin （HE） dyeing, were observed microscopically ,wet/dry（ W/D } ratio of lung tissues were examined for every group. The expression of NDRG2 in the lung tissue of every group was detected by immunohistochemistry, RT-PCR, Westernblot. The expression of NF-KBp65 in the lung tissue of every group was detected by immunohistochemistry and Westernblot examination. DNA ends situ labeling assay （TUNEL） was used to detect the apoptosis of cells. Resuits Compared with the control group, some hemorrhage and inflammation changes of lung tissues was observed, W/D was obviously increased （ P 〈 0.05）. The nuclear translocation of NF-KBp65 increased significantly （ P 〈 0.05 ）, while the expression of NDRG2 protein and NDRG2 mRNA significantly decreased （ P 〈 0.05 ） after ischemiareperfusion. The percentage of apoptotic cells increased significantly after ischemiareperfusion （ P 〈 0. 05 ）. Conclusion Ischemiareperfusion injury can down-regulate NDRG2 gene expressions in lung tissue. NDRG2 could regulate NF-KB expression to protect rats with intestinal ischemiareperfusion lung injury.