进展性大鼠肝纤维化组织中整合素αVβ3受体和血小板内皮细胞黏附分子的表达

目的 探讨整合素αVβ3和血小板内皮细胞黏附分子(CD31)表达与肝纤维化进展和间质重建的关系.方法 硫代乙酰胺(TAA)腹腔注射和胆总管结扎(BDL)建立两种大鼠肝纤维化模型,TAA组和BDL组每组8只,分别在第3、9周末和第2、4周末取材.肝组织切片天狼猩红染色和计算机图像分析,整合素αVβ3、CD31免疫化学和荧光染色.整合素αVβ3与α-平滑肌肌动蛋白(SMA)荧光染色双重染色及激光共聚焦观察.实时定量PCR和Western印迹分析肝组织中整合素αVβ3、CD31的相对定量表达.结果 肝纤维化中αVβ3表达范围扩大并与α-SMA表达部位一致,CD31在肝血窦、扩大的汇管区和纤维隔表达明显增加,伴有血管新生.模型组和对照组比较肝组织中αVβ3、CD31表达水平差异均有统计学意义(TAA组F=28.66、P＜0.01,F=19.62、P＜0.01和BDL组F=32.60、P＜0.01,F=42.36、P＜0.01).TAA 3周和9周整合素αVβ3和CD31 mRNA的△Ct值分别为5.70±0.25、5.50±0.18和4.40±0.25、4.00±0.18.BDL组1周和4周分别为5.60±0.24、5.30±0.14和4.20±30.16、3.80±0.23,表达增加和纤维化进展一致.结论 肝纤维化进展中整合素αVβ3表达水平增加与星状细胞活化和血管新生有关,并与间质重建程度平行.

Expression of αVβ3 integrin and platelet-endothelial cell adhesion molecule-1 in progressive liver fibrosis: experiment with rats

Objective To investigate the expression of αVβ3 integrin and platelet endothelial cell adhesion molecule-1 (CD31) in progressive liver fibrosis of rats. Methods Sixty-four SD rats were randomly divided into 4 equal groups: TAA group, undergoing peritoneal injection of 10% thioacetamine (TAA) 175 mg/kg twice a week to induce liver fibrosis, TAA control group undergoing peritoneal injection of normal saline (NS), BDL group undergoing ligation and resection of common bile duct to induce liver fibrosis, and BDL control group undergoing sham operation. Three and 9 weeks later 2 rats from the 2 TAA groups and 1 and 4 weeks later 2 rats from the 2 BDL groups were killed with their liver taken out to undergo sirius red staining and computer image analysis to observe the area of fibrosis. Immuuohistochemistry was used to detect the expression of αVβ3 integrin and CD31. The co-location of αVβ3 integrin and α-smooth muscle antibody (SMA) in the liver tissues was observed by immunohistochemical and double immunofluorescence staining. Real-time PCR and Western blotting were used to examine the mRNA and protein expression of αVβ3 integrin and CD31. Results The sirius red stained areas 3 and 9 weeks later of the TAA group were 5.8%±1.2% and 16.5%±3.6% respectively, and the sirius red stained areas 1 and 4 weeks later of the BDL group were 6.6% ±1.6% and 18.5% ±4.5% respectively. Immunohistochemical and double immunofluorescence staining showed that there was an overlapping of αVβ3 and α-SMA expression. Expression of CD31 was extended in the endothelial ceils and portal area of both models, and new blood vessels were seen in the fibrotic septum and among the hyperplastic bile ducts. The levels of αVβ3 and CD31 mRNA expression of the TAA and BDL groups were both upregulated (F = 28.66, P＜0.01,F=19.62, P＜0.01 and F=32.60, P＜0.01, F=42.36, P＜0.01 respectively) and were increased along with the degree of fibrosis. The levels of protein expression of αVβ3 and CD31 showed the similar trend of their mRNA expression. Conclusion The levels of αVβ3 integrin and CD31 expression are upregulated in liver fibrotic tissue. Such overexpression is involved in the activation of hepatic stellate cells and angiogenesis that correspond with fibrotic remodeling.