远端缺血后处理对对乙酰氨基酚源性急性肝损伤小鼠的保护作用

Protective effect of remote ischemic postconditioning against acetaminophen-induced acute liver injury in mice

目的探讨肢体远端缺血后处理(RIPoC)对对乙酰氨基酚(APAP)源性急性肝损伤小鼠的保护机制。方法40只BALB/c雄性小鼠按随机数字表法分为空白对照组、假手术组、肝损伤组、肝损伤+远端缺血后处理组。假手术组小鼠腹腔注射1 ml生理盐水,5 min后实施远端缺血后处理;肝损伤组腹腔注射1 ml APAP溶液;肝损伤+远端缺血后处理组小鼠腹腔注射1 ml APAP溶液,5 min后实施远端缺血后处理。采用腹腔注射APAP溶液诱导小鼠急性肝损伤模型。处理16 h后取血标本及肝脏组织,检测各组血清谷丙转氨酶(ALT)活性、谷草转氨酶(AST)活性,血清肿瘤坏死因子-α(TNF-α)水平、白介素-6(IL-6)水平;观察肝脏病理形态学改变;检测肝组织丙二醛(MDA)含量、谷胱甘肽酶(GSH)活性;检测核因子-κB(NF-κB)、血红素加氧酶-1(HO-1)表达的变化。组间比较采用单因素方差分析。结果与对照组和假手术组相比,肝损伤组病理学显示大量的炎性细胞浸润,肝小叶结构破坏明显,血清ALT、AST和炎症相关因子TNF-α、IL-6明显升高(P<0.05),肝匀浆MDA含量显著增多(P<0.05),GSH活性显著下降(P<0.05)。与肝损伤组相比,肝损伤+远端缺血后处理组血清ALT、AST活性显著降低(P<0.05);病理学显示肝小叶结构破坏减少,肝细胞坏死及炎性细胞浸润程度降低;肝指数明显降低(P<0.05);血清炎症因子TNF-α、IL-6水平显著降低(P<0.05);肝匀浆MDA含量显著减少(P<0.05),肝匀浆GSH活性显著增强(P<0.05);肝组织内NF-κB蛋白表达显著降低(P<0.05),HO-1蛋白表达显著上调(P<0.05)。结论远端缺血后处理具有对抗对乙酰氨基酚诱导急性肝损伤的作用,其机制可能与调节肝组织NF-κB、HO-1的表达水平有关。

Objective To investigate the protective effect of remote ischemic postconditioning(RIPoC)against acetaminophen(APAP)-induced acute liver injury in mice and its possible mechanism.Methods Mouse models of liver injury were obtained by intraperitoneal injection with APAP.Forty male C57BL/6 mice were randomly divided into four groups:blank control group,sham operation group,model group,APAP+remote ischemic postconditioning(RIPoC)group.Mice were intraperitoneally injected with 1 ml saline,and 5 min later performed remote ischemic postconditioning in sham operation group.Mice were intraperitoneally injected with 1 ml APAP to induce acute liver injury in model group.Mice were intraperitoneally injected with 1 ml APAP,and 5 min later performed remote ischemic postconditioning in APAP+RIPoC group.Blood samples and liver tissues were collected at 16 h after APAP modeling to determine serum levels of aspartate transaminase(AST),alanine transaminase(ALT),liver index,malondialdehyde(MDA),glutathione(GSH),tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6).Pathological changes were observed.The expression of nuclear factor kappa-B(NF-κB),heme oxygnease-1(HO-1)in liver tissue was detected by Western blot.One-way ANOVA were used to analyze the data between groups.Results Compared with blank control group and sham operation group,the destruction of liver structure and the infiltration of inflammatory cells were more obvious in APAP group.And the levels of ALT,AST,TNF-α,IL-6 and MDA were increased in APAP group(P<0.05),while GSH level was decreased in APAP group(P<0.05).Compared with model group,ALT,AST,liver index,TNF-α,IL-6 and MDA levels were decreased in APAP+RIPoC group(P<0.05),while GSH level was increased(P<0.05);the pathological changes were attenuated in APAP+RIPoC group;the expression of NF-κB protein was significantly down-regulated and the expression of HO-1 protein was up-regulated in APAP+RIPoC group(all P<0.05).Conclusion RIPoC has therapeutic effect against APAP-induced hepatotoxicity by regulating NF-κB,HO-1 protein levels in liver tissues.