IGFBPrP1与硫代乙酰胺对小鼠肝组织的影响及其机制

目的:通过对胰岛素样生长因子结合蛋白相关蛋白1(IGFBPrP1)与硫代乙酰胺(TAA)对小鼠肝组织影响的研究,明确IGFBPrP1在肝纤维化中的作用及其机制。方法:清洁级C57BL/6野生型小鼠32只,随机分为4组:正常对照组、重组小鼠IGFBPrP1(rmIGFBPrP1)4周组、TAA2周组及TAA4周组,每组8只。取肝组织行HE、苦味酸-天狼星红及免疫组织化学染色和Westernblotting检测。结果:rmIGFBPrP14周组肝细胞广泛脂肪变性,TAA2周组出现纤维组织增生,TAA4周组病理改变较TAA2周组严重。与正常对照组相比,rmIGFBPrP14周组、TAA2周组和TAA4周组IGFBPrP1、转化生长因子β1(TGF-β1)、Smad3、p-Smad2/3、Ⅲ型胶原(ColⅢ)、I型胶原(ColⅠ)、纤维连接蛋白(FN)的表达增高(P0.05)。rmIGFBPrP14周组IGFBPrP1、ColⅠ和FN的表达与TAA2周组无显著差异。结论:IGFBPrP1在TAA诱导的肝纤维化形成过程中发挥重要作用,并可作为独立致病因子引起小鼠肝组织中细胞外基质生成增多,且该作用是通过TGF-β1/Smad3信号通路来实现的。

Effects of IGFBPrP1 and thioacetamide on liver tissues in mice

AIM: To investigate the effects of insulin-like growth factor binding protein related protein 1(IGFBPrP1) and thioacetamide (TAA) on the liver tissues, and to identify the role of IGFBPrP1 in liver fibrosis. METHODS: Thirty-two male C57BL/6 wild-type mice were randomly divided into 4 groups (n=8 in each group): control group, recombinant murine IGFBPrP1(rmIGFBPrP1) 4 weeks group, TAA 2 weeks group and TAA 4 weeks group. The methods of hematoxylin-eosin (HE) staining, picric acid-Sirius red staining, immunohistochemistry and Western blotting were performed. RESULTS: The extensive fatty degeneration of liver cells in rmIGFBPrP1 4 weeks group was observed. The collagen deposition was found in TAA 2 weeks group. In TAA 4 weeks group, the degree of hepatic fibrosis was more serious than that in TAA 2 weeks group. The expression levels of IGFBPrP1, transforming growth factor beta 1(TGF-β₁), Smad3, p-Smad2/3, collagen Ⅲ, collagenⅠand fibronectin (FN) in liver tissues were higher in rmIGFBPrP1 4 weeks group, TAA 2 weeks group and TAA 4 weeks group than those in control group. No significant difference of the expression levels of IGFBPrP1, collagen I and FN between rmIGFBPrP1 4 weeks group and TAA 2 weeks group was observed. CONCLUSION: IGFBPrP1 plays an important role in the process of thioacetamide-induced liver fibrosis. Meanwhile, IGFBPrP1 induces excessive deposition of extracellular matrix through TGF-β₁/Smad3 pathway.