血红素加氧酶-1对急性肝衰竭大鼠肝组织HMGB1及炎症的影响

Effects of HO-1 on the expression of HMGB1 and inflammatory cytokines in rats with acute liver failure

目的:探索血晶素(hemin)诱导血红素加氧酶-1(HO-1)过表达对急性肝衰竭(急性肝衰)大鼠肝脏中高迁移率族蛋白B1(HMGB1)及相关炎症因子的影响。方法:将96只SD大鼠按给药方法不同分成4组,即对照组、急性肝衰、hemin(HO-1诱导剂)组、锌原卟啉(znpp,HO-1抑制剂)组,每组24只。对照组腹腔注射生理盐水;急性肝衰组腹腔注射D-Gal 0.8 g·kg^(-1)及LPS 20μg·kg^(-1)制作肝衰竭模型;hemin、znpp组腹腔分别注射hemin 40μmol·kg^(-1)或znpp 50μmol·kg^(-1),12 h后给予D-Gal和LPS,方法同急性肝衰组。检测各组大鼠诱导后24、72 h肝脏功能变化,比较4组大鼠肝脏组织病理学表现。应用RT-PCR及Western Blot检测肝组织中HO-1、HMGB1水平,ELISA检测TNF-α及IL-1β浓度;检测HO-1活性。结果:采用D-Gal和LPS成功建立了大鼠急性肝衰竭模型,与对照组比较,急性肝衰组谷氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)、IL1β、TNF-α浓度及HMGB1水平均升高(P<0.05),肝脏组织损伤严重。与急性肝衰组比较:hemin组HO-1水平及活性上调,ALT、AST、IL1β、TNF-α浓度(P<0.05)及HMGB1水平显著降低,肝脏组织损伤缓解;而znpp组HO-1水平及活性降低,ALT、AST、IL1β、TNF-α浓度(P<0.05)及HMGB1水平升高,肝脏组织损伤加重。结论:在急性肝衰竭中HMGB1明显增加,HO-1的过表达可以缓解急性肝衰竭肝脏损伤,其机制与抑制HMGB1、IL1β、TNF-α的表达有关。

Objective：To investigate the effects of upregulation of heme oxygenase-1 with hemin on the expression of liver HMGB1 and associated inflammatory cytokines in rats during acute liver failure .Methods： Ninety six SD rats were divided into 4 groups （n=24） according to the processing conditions：control group, acute liver failure＆amp;nbsp;（ALF） group, hemin（HO-1 inducer） group, znpp（HO-1 inhibitor） group.Acute liver failure model was induced by intraperitoneally injection of D-Gal （0.8 g·kg -1）and LPS （20μg·kg -1）, control group was given the same volume of saline.Hemin （40μmol·kg -1 ） or znpp （50μmol·kg -1 ） was given intraperitoneally starting from 12 hours before D-Gal and LPS administration.The level of ALT and AST were detected at 24, 72 h after injection and the liver histopathological sections were compared .RT-PCR and Western blot were used to calculate the mRNA and protein levels of HO-1 or HMGB1 in liver.Serum IL1βand TNF-αconcentration were measured by ELISA . HO-1 activity was detected .ALF model were successfully induced .Results：ALF model were successfully induced by intraperitoneal injection of D-Gal and LPS.Compared with control group , the levels of ALT, AST, IL1β,TNF-αand HMGB1 in ALF group increased significantly （ P〈0.05 ） , the structure of liver was damaged severely . Compared with ALF group , hemin treatment markedly increased the levels of HO-1 and HO-1 activity which inhibited the levels of ALT, AST, IL1β,TNF-αand HMGB1（P〈0.05）;While znpp treatment inhibited the levels of HO-1 and HO-1 activity thus leading to the up regulation of ALT , AST, IL1β、TNF-αand HMGB1（ P〈0.05） which aggravated liver damage .Conclusion：The level of HMGB1 is in accordance with the severity of ALF .HO-1 over-expression could ameliorate the damage of liver .Down-regulated HMGB1, IL1βand TNF-αmight be its potential mechanism .