核因子-κB在硫代乙酰胺所致急性肝损伤中的作用及机制研究

目的 探讨核因子-κB(NF-κB)在硫代乙酰胺(TAA)所致急性肝损伤中的作用及机制.方法 雄性Wistar大鼠78只分为正常组18只,TAA造模组30只及脯氨酸二硫代氨基甲酸酯(PDTC)预处理组30只.PDTC预处理组于建立急性肝损伤模型前1 h腹腔内注射PDTC 100 mg/kg.然后,三组大鼠分别于6、24、48 h处死,TAA造模组及PDTC预处理组每时间点各取10只大鼠,正常组每时间点各取6只大鼠.测定大鼠血浆内毒素、肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)水平,RT-PCR方法检测肝脏组织细胞间粘附因子-1(ICAM-1)mRNA表达,取肝脏行病理学及免疫组化检测NF-κB活性.结果 ①TAA造模组造模后6、24和48 h NF-κB细胞阳性率分别为(87.11±8.23)%、(78.55±6.82)%和(74.27±6.26)%,与正常组相比差异均有统计学意义(4.64±1.82)%、(4.55±1.67)%和(4.91±2.12)%,P值均＜0.01].PDTC预处理组各时间点NF-κB细胞阳性率分别为(31.88±4.14)%、(27.58±3.44)%和(26.67±3.88)%,与TAA造模组相比阳性率明显降低(P值均＜0.01).②TAA造模组各时间点血浆内毒素和TNF-α水平含量明显较正常组升高(P值均＜0.01),而PDTC预处理组则较TAA造模组降低(P值均＜0.01),但较正常组有所增高(P值均＜0.01).③TAA造模组各时间点IL-6水平较正常组显著升高(P值均＜0.01).PDTC预处理组各时间点IL-6水平较TAA造模组明显降低(P值分别＜0.05和0.01);24和48 h较正常组增加(P值均＜0.01).④TAA造模组各时间点ICAM-lmRNA表达较正常组显著升高(P值均＜0.01).PDTC预处理组各时间点ICAM-lmRNA表达较TAA造模组明显降低(P值均＜0.01).但较正常组增高(P值均＜0.01).⑤TAA造模组各时间段可见肝组织坏死,PDTC预处理组各时间段肝组织病理改变较TAA造模组同时间点明显减轻.结论 NF-κB在TAA所致急性肝损伤中通过促进TNF-α、IL-6及ICAM-1的表达而发挥作用,加重肝损伤.

The mechanism of nuclear factor-kappa B in thioactamide induced acute hepatic injury

Objective To investigate the mechanism of nuclear factor-kappa B(NF-κB)in thioactamide(TAA)induced acute hepatic injury.Methods Seventy-eight Wistar rats were randomly divided into normal group(n=18),TAA model group(n=30)and pyrrolidine dithiocarbamate (PDTC)pretreated group(n=30).The rats in PDTC group were received 100 rag/kg of PDTC 1 h before induction of the model.Every 10 rats in TAA group and PDTC pretreated group and 6 rats in normal group were sacrificed at 6,24,48 hour after induction of the model tO mesure levels of endotoxin,tumor necrosis factor(TNF)-α and interleukin(IL)-6.The expression of the intercellular adhesion molecular(ICAM)-1 in hepatic tissue was tested using RT-PCR and the NF-κB activity was 48 hour were higher in TAA group(87.11±8.23)%.(78.55±6.82)%and(74.27±6.26)%,respectively]than those in normal group(4.64±1.82)%,(4.55±1.67)%and(4.91±2.12)%,all comparison with normal group(P＜0.01).The serum concentration of endotoxin and TNF-α in PDTC pretreated group were higher than those in normal group(P＜0.0 1).but lower than those in TAA with ticrmal group(P＜0.01).The serum concentration of IL-6 in PDTC pretreated group was higher at 24 and 48 hour than those in normal group(P＜0.01),but lower than thoes in TAA group(P＜group(P＜0.01).The expression of ICAM-1 in PDTC pretreated group was higher than that in immunohistochemical examination showed that liver necrosis was folund in TAA group and PDTC pretreated group.Conclusion The Nuclear factor-κB may aggravate the injury of liver by promoting expressions of TNF-α,IL-6 and ICAM-1.