医学免费论文:NFκB及其相关炎性因子致大鼠移植肝冷保存损伤的机制
【摘要】 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 factorκB, NFκB)及其相关炎性因子的激活情况,判断冷保存时间、NFκB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45min(B组)、120min(C组)、180min(D组)以及再灌注3h后肝组织、血清中NFκB、肿瘤坏死因子α(TNFα)、白细胞介素1β(IL1β)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NFκB逐渐激活(P<0.05),并使肝组织内TNFα、IL1β水平上调(P<0.05);再灌注后,NFκB近一步激活(P<0.05),肝组织中TNFα、IL1β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 NFκB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TNFα、IL1β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。
【关键词】 肝移植;器官保存;冷保存再灌注损伤;核因子κB
The effect of NFκB and correlated inflammatory factors
in rat donor liver after cold preservation
JIANG An, LIU Feng, LIU Chang, SONG Yulong, MENG Kewei, L Yi
1. Department of Hepatobiliary Surgery, the First Affiliated Hospital, Medical School of Xian Jiaotong University, Xian 710061; 2. Department of General Surgery,
the Second Affiliated Hospital, Medical School of Xian Jiaotong University, Xian 710004;3. Department of Hepatobiliary Surgery, Qianfoshan Hospital, Jinan 250014;
4. Department of Anesthesiology, Shaanxi Provincial Peoples Hospital, Xian 710068;5. Department of Hepatobiliary Surgery, Yuhuangding Hospital, Yantai 264000, China
ABSTRACT: Objective To establish a model of rat orthotopic liver transplantation and investigate the relationship among cold preservation time, activation of nuclear transcription factorκB (NFκB) 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 (45min cold storage group, n=10), group C (120min cold storage group, n=10), and group D (180min cold storage group, n=10). The expression of NFκB in liver before and after transplantation was measured by electrophoretic mobility shift assays; protein expression of tumor necrosis factoralpha (TNFα) and interleukin1 beta (IL1β) in the liver was measured by immunohistochemistry; the serum TNFα and IL1β, alanine aminotransferase (ALT), aspartate aminotransferase (AST) and hepatic cell apoptosis were examined. Results With extended cold storage duration, the activity of NFκB in the donor liver increased (P<0.05, group D vs. groups A, B and C). TNFα and IL1β 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 TNFα and IL1β levels increased highly (P<0.05 group A vs. groups B, C and D),and the expression of NFκB 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 NFκB of donor liver was activated inductively in cold preservation phase and activated explosively in reperfusion phase. The longer cold preservation time was, the higher NFκB level in donor liver became. NFκB led to the expression of TNFα and IL1β in donor liver. Inflammatory factors are one of the most important mechanisms for the donor liver injury after liver transplantation医.学.全.在.线www.lindalemus.com.
KEY WORDS: liver transplantation; organ preservation; cold preservationwarm reperfusion injury; nuclear transcription factorκB
移植肝冷保存再灌注损伤(cold preservationwarm reperfusion injury, P/RI)是移植肝功能不良(poor graft function, PGF)和原发性无功能(primary nonfunction, PNF)的直接原因[1]。PGF及其严重形式PNF的发生率分别占移植总数的5%~10%[2]和1.4%~8.5%[3]。PNF占术后1周内再次肝移植病因的81%和再次肝移植总病因的21.7%[1],危害严重。冷保存时间超过20h,PNF发生率是保存4h以内的4倍[4],所以冷保存时间是PNF的独立预测因子[5]。而且,P/RI还可导致多器官功能不全和胆管非吻合口狭窄等并发症[6],严重影响患者预后。因此,如何最大限度地减轻供肝冷保存损伤、提高移植物成活率是当今肝移植领域面临的重要课题。本实验通过研究移植肝P/RI过程中核转录因子κB(nuclear transcription factorκB, NFκB)及其相关炎性因子的表达变化,探讨NFκB在移植肝冷保存中的作用机制。
1 材料与方法
1.1 动物模型的制作
清洁级健康成年封闭群雄性Wistar大鼠70只(第四军医大学实验动物中心提供),体重(272±31)g。术前禁食12h,不禁饮,清洁手术。氯胺酮100mg/kg体重腹腔注射麻醉。采用改良两袖套法建立大鼠全血供原位肝移植模型[7]。
1.2 实验动物分组
依据供肝冷保存时间的不同,将Wistar大鼠随机分为4组,每组10只:A组,假手术组;B组,冷保存45min再灌注3h组;C组,冷保存120min再灌注3h组;D组,冷保存180min再灌注3h组。供肝以4℃ UW液保存,冷保存结束前,留取乳头叶腹侧叶片。移植肝植入3h后,留取乳头叶背侧叶片,并取血留作标本。
1.3 观察指标及检测方法
1.3.1 肝组织NFκB水平的测定