糖代谢异常对大鼠肝脏组织中巨噬细胞移动抑制因子及C-Jun氨基端激酶表达水平的影响

目的 观察巨噬细胞移动抑制因子（MIF）和C-Jun氨基端激酶（JNK）在糖代谢异常大鼠肝脏组织中表达水平的变化，探讨糖代谢异常合并非酒精性脂肪肝（NAFLD）的病理机制。方法 将60只大鼠随机分为糖耐量受损（IGT）模型组（n=20）、2型糖尿病（T2DM）模型组（n=20）、IGT对照组（n=10）及T2DM对照组（n=10），高脂饲料喂养复制IGT大鼠模型，高脂饲料喂养加腹腔注射小剂量链脲佐菌素（STZ）制备T2DM大鼠模型，采用TUNEL法检测各组大鼠肝脏细胞凋亡；实时荧光PCR 技术检测肝脏组织中MIF mRNA的表达； Western Blot方法检测肝脏组织中MIF 、Caspase-3、JNK蛋白表达及磷酸化JNK （p-JNK）的表达。结果 IGT大鼠及T2DM大鼠肝组织凋亡细胞明显增多；IGT组和T2DM组肝组织MIF基因表达较各自对照组明升高（P<0.01），MIF 、Caspase-3、JNK蛋白表达及JNK磷酸化水平也明显升高（P<0.05或P<0.01）；与IGT组相比，T2DM组Caspase-3、MIF、JNK蛋白表达水平明显降低（P<0.01），而JNK磷酸化水平是明显升高（P<0.01）。结论 糖代谢异常大鼠肝组织的损伤以及非酒精性脂肪肝的发生可能与肝组织MIF 、Caspase-3、JNK表达水平的升高及JNK磷酸化水平的增强有关。

Effect of abnormal glucose metabolism on the expression of macrophage migration inhibitory factor and JNK in the rat liver

Objective To investigate the expression changes of macrophage migration inhibitory factor(MIF)and C-Jun N-terminal kinase (JNK) in the liver of rat with abnormal glucose metabolism and explore the pathological mechanism of abnormal glucose metabolism with non-alcoholic fatty liver disease (NAFLD). Methods Sixty SD rats were randomly divided into impaired glucose tolerance (IGT) model group (n=20), type 2 diabetes mellitus (T2DM) model group (n=20), IGT control group (n=10) and T2DM control group (n=10). IGT models were produced by feeding high-fat diet, T2DM models were produced by feeding high-fat diet for 4 weeks and intraperitoneally injected streptozotocin. Liver cell apoptosis was detected by TUNEL staining. The expression of MIF mRNA in liver tissue was determined by real-time PCR. The expressions of MIF, caspase-3, JNK proteins and phosphorylated JNK(p-JNK)in the liver tissue were determined by Western blotting. Results Apoptotic cells were obviously increased in the IGT and T2DM groups. Expression of MIF mRNA in the IGT and T2DM groups was markedly higher than that in the control group, respectively (P<0.01). The expressions of MIF, caspase-3, JNK proteins and phosphorylated JNK were markedly higher than that of the control group, respectively (P<0.05 or P<0.01). The expressions of MIF, caspase-3, JNK proteins in the T2DM group were significantly decreased compared with those of the IGT group, while the expression of phosphorylated JNK was significantly higher (P<0.01). Conclusions Abnormal glucose metabolism accompanied with NAFLD is probably related to the increase of MIF, Caspase-3, JNK and phosphorylated JNK expression.