IGFBPrP1对小鼠肝组织胶原含量的影响及其机制的研究

The effect of exogenous IGFBPrP1 on collagen content of liver tissue in mice

目的 明确外源性胰岛素样生长因子结合蛋白相关蛋白1（IGFBPrP1）对肝组织胶原含量的影响及可能的机制。方法24只雄性C57BL／6野生型小鼠随机分为3组：正常对照组、rmIGFBPrP12周组和rmIGFBPrP14周组，每组8只。取肝组织行HE、苦味酸一天狼猩红、免疫组织化学染色及Westernblot检测。结果HE和苦味酸天狼猩红染色显示外源性rmIGFBPrP1可使肝组织发生病理改变，并导致肝组织中胶原含量显著增多（P〈O．05）。Westernblot检测显示rmIGFB—PrP12周组及4周组肝组织中IGFBPrP1、纤维连接蛋白（FN）、I型胶原（Collagen Ⅰ）的表达明显增强，且4周组表达量较2周组高（P〈O．01）。免疫组织化学染色显示Ⅲ型胶原（Collagen Ⅲ）在rmIG—FBPrPl2周组及4周组表达量明显增高，且4周组高于2周组（P〈0．01）。Westernblot及免疫组织化学染色共同显示转化生长因子p1（TGF—p1）、Smad3、PSmad2／3在rmIGrFBPrP12周组及4周组表达显著增强，且4周组强于2周组（P〈0．01）。结论外源性IGFBPrP1可通过TGF-β1／Smad3信号通路导致肝组织中胶原含量明显增加、ECM过度沉积。

Objective To investigate the effect and mechanism of exogenous IGFBPrP1 on eolla gen content in liver tissue. Methods Twenty four male C57BL/6 wild-type mice were randomly divid- ed into three groups： Control group （n= 8）, rmlGFBPrP1 2 weeks group （n=8） and rmlGFBPrP1 4 weeks group （n=8）. Both hematoxylin-eosin （HE） staining and picric acid-Sirius red staining were performed. The protein expression of IGFBPrP1, Collagen Ⅰ , Collagen Ⅲ, FN, TGF-β1, Smad3 and p-Smad2/3 was evaluated by immunohistochemistry or Western blot. Results Exogenous IGFBPrP1 can cause pathological changes in liver tissue. Collagen content was significantly increased by hematox- ylin eosin （HE） staining and picric acid-Sirius red staining （P〈0.05）. The protein expression of IG- FBPrP1, FN and Collagen Ⅰ was gradually increased after rmIGFBPrP1 injection for 2 weeks and 4 weeks by Western blot （P〈0.01）. The protein expression of Collagen Ⅲ was obviously increased in the rmIGFBPrP1 2 weeks group and rmIGFBPrPl 4 weeks group by immunohistochemistry, and the level in the 4 weeks group was higher than that in the 2 weeks group （P〈0.01）. The protein expression of TGF-β1, Smad3 and p Smad2/3 in liver tissue was significantly increased after rmIGFBPrP1 injection in a time-dependent manner by both immunohistochemistry and Western blot （P〈0.01）. Conclusion Exogenous IGFBPrP1 can cause a marked increase in collagen content and the excessive deposition of ECM through the TGF -β/Smad3 pathway in liver tissue.