二甲双胍对D-氨基半乳糖联合Pam3CSK4诱导的SD大鼠的急性肝损伤及炎症反应的作用及机制

摘要

目的 研究二甲双胍在D-氨基半乳糖联合Pam3CSK4(以下简称DP)诱导的SD大鼠急性肝损伤动物模型中的抗损伤及抗炎作用.方法 选取18只雄性SD大鼠腹腔注射D-氨基半乳糖(350 mg/kg)和Pam3CSK4(50μg/kg)混合液构建急性肝损伤大鼠模型,干预组大鼠分别给予PBS与二甲双胍.分别称量大鼠肝重、体质量并评估肝/体质量比变化;通过HE染色观察大鼠肝脏病理改变;收集大鼠空腹血清用于检测血清转氨酶(ALT、AST)水平;同时通过ELISA与RT-qPCR检测肝组织中促炎因子(IL-6与TNF-α)的表达水平;最后通过Western blotting检测大鼠肝脏中MAPK信号通路的活化情况.结果 与对照组相比,两干预组的肝重比、血清转氨酶以及促炎因子IL-6与TNF-α的表达水平均显著升高;同时肝细胞水样变性与肝间质渗出表明DP成功构建了SD大鼠急性肝损伤模型.与PBS干预组相比,二甲双胍干预组肝重比降低,肝细胞损伤明显减轻;血清转氨酶与促炎因子的表达水平均显著下降;同时肝组织中p-ERK1/2、p-SAPK/JNK、p-P38 MAPK的蛋白表达降低,提示二甲双胍可能通过抑制MAPK信号通路发挥抗炎作用.结论 二甲双胍在DP成功诱导的SD大鼠急性肝损伤动物模型中减轻了炎症反应.%Objective To investigate the anti-injury and anti-inflammation protective effects of metformin in acute-liver-injury SD rat model induced by D-galactosamine and Pam3CSK4 .Methods Eighteen male Sprague-Dawley rats were treated with the mixture of D-galactosamine (350 mg/kg ) and Pam3CSK4 (50 μg/kg ) by intraperitoneal injection (i .p .) to construct acute liver injury model .The rats in intervention group were given PBS and metformin ,respectively .The liver and body weight were measured and the ratio of liver weight to body weight was calculated .HE staining was used to observe the pathological changes of the liver .Fasting serum was collected for detection of serological parameters .ELISA and RT-qPCR were used to determine the expression levels of IL-6 and TNF-α.Finally , activation of MAPK signal pathway in rat liver was detected by Western blot .Results Compared with those in control group , the ratio of body weight to liver weight , serum transaminase and proinflammatory cytokines IL-6 and TNF-a were all significantly increased in the two intervention groups .Meanwhile , hepatic degeneration and hepatic interstitial exudation indicated that D -galactosamine combined with Pam3CSK4 successfully constructed acute liver injury model in the SD rats.Compared with PBS group, the ratio of body weight to liver weight , hepatic damage , serum transaminase levels.and the expressions of proinflammatory cytokines IL-6 and TNF-a were significantly decreased in metformin-treated group.Meanwhile,the expressions of p-ERKl/2,p-SAPK/JNK and p-P38 MAPK decreased in liver tissues by metformin pretreatment,suggesting that metformin may play an anti-inflammatory effect by suppressing MAPK signaling pathway.Conclusion Metformin attenuated inflammatory reactions in SD rats with acute liver injury induced by D -galactosamine and Pam3CSK4.