c-jun氨基末端激酶抑制剂对小鼠急性肝功能衰竭的保护作用

摘要

Objective To investigate the protective effect of c-jun N-terminal kinase (JNK)inhibitor SP600125 against acute liver failure in mice.Methods Fifty-five male C57/BL6 mice were divided into control group (n =30) and SP600125 group (n =25).The animals were given an intraperitoneal injection of D-galactosamine (D-GalN,400 mg/kg body weight)/lipopolysaccharide (LPS,30 μg/kg body weight).The control group and SP600125 group were given 10％ dimethyl sulfoxide (15 mL/kg body weight) or SP600125 (75 mg/kg body weight) subcutaneously 12 h and 1 h before D-GalN/LPS administration,respectively.D GalN/LPS induced mouse JNK activation was detected by immunohistochemistry for phospho JNK (p-JNK).D-GalN/LPS induced mouse liver cell apoptosis was detected by immunohistochemistry for Caspase-3 and TdT-mediated-dUTP nick endlabeling (TUNEL).Serum alanine transaminase (ALT) level was tested to assess liver injury.Survival rate of mice within 24 h after D-GalN/LPS administration was observed.The comparison between groups was done by t test and survival rate was analyzed by Kaplan-Meier method.Results JNK activity in liver tissues,as indicated by observation of p-JNK positive cells by immunohistochemistry,was diminished 4 h after D-GalN/LPS administration in SP600125 group.Reduced Caspase-3 activity was observed 6 h after D-GalN/LPS administration in SP600125 group (as indicated in immunohistochemistry by Caspase-3 positive cells).Mice in SP600125 group showed significantly lower TUNEL-positive cell count than control group (43.0±24.5 vs 194.7±73.8; t=9.743,P=0.000).Serum ALT level 6 h after D-GalN/LPS administration was (24.0±54.7) U/L in SP600125 group,which was significantly lower than that in control group [(1234.4±478.4) U/L; t=4.734,P=0.0015].SP600125 also significantly improved the survival rate within 24 h after D-GalN/LPS administration (4/5 vs 1/10； x2=5.225,P=0.0223).Conclusions JNK inhibitor SP600125 exerts protective effects against D-GalN/LPS induced acute liver failure in mice by suppressing JNK activation and hepatocyte apoptosis.%目的 观察c-jun氨基末端激酶(JNK)抑制剂SP600125对小鼠急性肝功能衰竭的保护作用.方法 55只雄性C57/BL6小鼠采用随机数字表法分为实验组25只和对照组30只.实验组在腹腔注射D-半乳糖胺(D-GalN)/脂多糖(LPS)行肝功能衰竭造模前12h、1h皮下注射溶解于10％二甲基亚砜(DMSD)的JNK抑制剂SP600125,对照组在相同时间点皮下注射10％ DMSO.两组分别干造模后0、2、4、6h各处死小鼠5只.免疫组织化学检测小鼠肝组织磷酸化JNK(p-JNK)、Caspase3的表达情况.原位末端标记(TUNEL)染色观察肝组织中细胞凋亡情况.比较两组小鼠ALT水平、肝组织损伤程度及24 h存活情况.组间比较采用t检验,生存率分析采用Kaplan-Meiey法.结果 D GalN/LPS造模后4h,实验组小鼠肝组织偶见p-JNK阳性细胞,对照组小鼠肝组织出现大量肝实质细胞表达p-JNK.D-GalN/LPS造模后6h,实验组小鼠肝组织Caspase-3阳性细胞少见,对照组见满视野阳性细胞,实验组肝组织凋亡细胞计数为43.0±24.5,显著低于对照组的194.7±73.8(t=9.743,P=0.000).实验组小鼠造模后6h,血清ALT水平为(214.0±54.7) U/L,显著低于对照组的(1234.4±478.4) U/L(t=4.734,P=0.0015),肝组织损伤程度较轻,且24h5只小鼠存活4只,显著高于对照组的10只小鼠存活1只(x2 =5.225,P=0.0223).结论 JNK抑制剂SP600125通过抑制JNK的激活,减少肝组织细胞凋亡,从而实现对D-GalN/LPS诱导的小鼠急性肝功能衰竭的保护作用.