大鼠肺缺血再灌注损伤后前炎症细胞因子IL-1β mRNA的表达分析

The Expression of proinflammatory cytokine IL-1β mRNA after lung ischemia-reperfusion injury in rat transplant model

目的通过对大鼠移植肺灌洗后、冷缺血保存和再灌注期间前炎症细胞因子IL-1β mRNA的表达进行分析,探讨IL-1β在此过程中介导的移植肺炎性损伤机制。方法本研究大鼠分6组,包括:正常肺(未灌洗)对照组、仅肺灌洗处理组、肺灌洗后冷缺血保存6h、12h、24h各1组、冷缺血保存24h后左肺移植再灌注3h组。在相应各时间点采取肺组织,用荧光定量实时PCR法检测IL-1β mRNA的表达并进行髓过氧化物酶(MPO)活性测定。结果除冷缺血12h组和冷缺血24h组之间IL-1β mRNA表达相对量差别不显著外(P=0.167),其余各组之间IL-1β表达相对量差别均有显著统计学意义(P<0.05)。仅灌洗组、冷缺血组和24h冷缺血移植再灌注3h组的IL-1β mRNA表达相对量均高于正常对照组,且随处理时间的延长而表达增加。仅灌洗组、冷缺血组和24h冷缺血移植再灌注3h组的MPO活性均高于正常对照组,且随处理时间的延长而表达增加,P<0.05。各组肺组织中MPO活性和IL-1β mRNA相对表达量呈较强的正相关关系,相关系数r=0.869,P<0.01。结论前炎症因子IL-1β在肺缺血再灌注损伤机制中发挥着重要炎性损伤作用,可以作为移植肺功能评价及预后的重要指标之一;IL-1β基因的表达在保存液灌洗后的冷缺血保存早期就开始出现,而不是在再灌注之后的事件。

Objective To study the role of IL-1β in ischemia-reperfusion inflammatory injury of the graft lung in rat model. Methods There were 6 rat groups included. Lung tissures were taken before flushing （normal）, flushing, 6 h,12 h and 24 h cold ischemic storage after flushing, 3 h reperfusion after transplantation（after 24 h cold ischemic storage）, respectively. Quantitative real-time RT-PCR was used to analyze the expression of IL-1β mRNA in lung tissures at all time points. Myeloperoxidase （MPO） activity （the change in absorbance at 460 nm over 1 minute） was recorded in each group. Results IL-1β mRNA expression was obviously increased in groups of 6 h,12 h and 24 h cold ischemic storage after flushing, 3 h reperfusion after transplantation （after 24 h cold ischemic storage）, and much higher than that in the normal lung tissuere group （P〈0. 05）. IL-1β mRNA expression increased with the cold storage time. MPO activity was increased obviously in groups of 6 h, 12 h and 24 h cold ischemic storage after flushing, 3 h reperfusion after transplantation（P〈0. 05）. IL-1β mRNA expression had a strong correlation with MPO activity （r = 0. 869, P〈0.01 ）. Conclusions Proinflammatory cytokine IL-1β plays an important role in ischemia-reperfusion iniury of the lung. Not initiated after reperfusion, IL-1β is increased as early as the lung graft is flushed, then sets the stage for pro-inflammatory responses in the grafts during cold storage.