NF-κB及其相关炎性因子致大鼠移植肝冷保存损伤的机制

The effect of NF-κB and correlated inflammatory factors in rat donor liver after cold preservation

目的通过大鼠移植肝在不同冷保存时间再灌注后核因子-κB(nuclear transcription factor-κB,NF-κB)及其相关炎性因子的激活情况,判断冷保存时间、NF-κB激活以及移植肝功能损伤三者之间的联系。方法用Wistar大鼠建立原位肝移植模型,假手术组(A组)作为对照组,观察大鼠移植肝在4℃UW液中保存45 min(B组)、120 min(C组)1、80 min(D组)以及再灌注3 h后肝组织、血清中NF-κB、肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)和肝损伤指标丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)和肝细胞凋亡的变化情况。结果随着移植肝冷保存时间的延长NF-κB逐渐激活(P<0.05),并使肝组织内TNF-αI、L-1β水平上调(P<0.05);再灌注后,NF-κB近一步激活(P<0.05),肝组织中TNF-αI、L-1β进一步上调(P<0.05),ALT、AST和肝细胞凋亡指数明显升高(P<0.05),肝功能损害加重。结论NF-κB在供肝的冷保存阶段随时间的延长呈诱导性激活,再灌注后呈爆发式激活,并通过上调其靶基因TNF-α、IL-1β的转录产生肝脏损伤,这可能是肝脏冷保存再灌注损伤发生的重要机制。

Objective To establish a model of rat orthotopic liver transplantation and investigate the relationship among cold preservation time, activation of nuclear transcription factor-κB （NF-κB） and donor preservation injury after liver transplantation. Methods Orthotopic liver transplantation was performed in Wistar rats which were randomly divided into the following groups according to the different duration of liver cold storage in UW solution： group A （sham operation, n = 10）, group B （45 min cold storage group, n = 10）, group C （120 min cold storage group, n = 10）, and group D （180 rain cold storage group, n = 10）. The expression of NF-κB in liver before and after transplantation was measured by electrophoretie mobility shift assays; protein expression of tumor necrosis factor-alpha （TNF-α） and interleukin-1 beta （IL-1β） in the liver was measured by immunohistochemistry; the serum TNF-α and IL-1β, alanine aminotransferase （ALT）, aspartate aminotransferase （AST） and hepatic cell apoptosis were examined. Results With extended cold storage duration, the activity of NF-κB in the donor liver increased （P〈0.05, group D vs. groups A, B and C）. TNF-α and IL-1β levels also increased （P〈0.05, group D vs. groups A, B and C）. Donor liver reperfusion injury was gradually aggravated with the prolonging of graft cold preservation. Both the serum TNF-α and IL-1β levels increased highly （P〈0.05 group A vs. groups B, C and D）,and the expression of NF-κB in the liver significantly increased （P〈0. 05, group A vs. groups D, B and C） with gradual prolonging of graft cold preservation time. The serum ALT and AST level and apoptosis index level elevated greatly （P〈0.05, group A vs. groups D, B and C）. Conclusion NF-κB of donor liver was activated inductively in cold preservation phase and activated explosively in reperfusion phase. The longer cold preservation time was, the higher NF-κB level in donor liver became. NF-κB led to the expression of TNF-α and IL-1β in donor liver. Inflammatory factors are one of the most important mechanisms for the donor liver injury after liver transplantation.