胰腺弹力蛋白酶在大鼠肝纤维化组织中的表达

目的:观察胰腺丝氨酸弹力蛋白酶的基因、蛋白及活性在大鼠肝纤维化中的表达,探讨弹力蛋白酶在肝纤维化形成中的作用.方法:采用二甲基亚硝胺(DMN)4周12次腹腔注射制备Wistar雄性大鼠肝纤维化模型,以正常组作对照.观察肝功能,肝脏病理组织学,肝组织羟脯氨酸含量以及肝组织弹力蛋白酶mRNA、蛋白及其活性的表达.结果:弹力蛋白酶mRNA、蛋白及其活性在正常大鼠肝组织均有一定程度的表达,在肝纤维化模型组,假小叶内肝细胞弹力蛋白酶mRNA表达有所减少,弹力蛋白酶活性在正常组和模型组分别为(11.43±2.35)U/g、(8.02±1.62)U/g,模型组显著降低(P＜0.05).结论:某种程度的弹力蛋白酶表达是维持正常细胞外基质合成与降解动态平衡的需要;在肝纤维化形成过程中,大鼠胰腺丝氨酸弹力蛋白酶的表达下降是促进肝纤维化形成的因素之一.

Expression of Pancreatic Elastase in Dimethylnitrosamin-Induced Liver Fibrosis in Rats

Objective:To investigate mRNA and protein expression and activity of pancreatic serine elastase at fibrotic liver induced by dimethylnitrosamine(DMN) in rats and to explore the role of serine elastase in hepatic fibrosis.Methods:31 Wistar male rats were randomly divided into normal group(10) and model group(21).The liver fibrotic models were induced by intraperitoneally injection with DMN 3 times a week for 4 weeks.Normal control rats were injected with same volume of saline as model group did.The following parameters were examined:liver function,histological examination,liver tissue hydroxyproline content,mRNA and protein expression and activity of liver tissue elastase.Results:There is some extent of mRNA and protein expression of elastase in normal rats.Compared to the normal rats,mRNA expression in pseudolobule in model rats decreases moderately while the elastase activity decreases markedly.Conclusion:Some extent of serine elastase expression is necessary for keeping the balance of degradation and synthesis of extracellular matrix;Decreased activity of serine elastase is one of the factors that contributes to formation of liver fibrosis.