血管内皮生长因子和血小板反应蛋白-1在大鼠胸主动脉瘤中的表达

Expression of vascular endothelial growth factor and thrombospondin-1 in rat thoracic aortic aneurysm

目的探讨血管内皮生长因子(VEGF)及血小板反应蛋白-1(TSP-1)在实验性大鼠胸主动脉瘤中的表达及其意义。方法 30只成年雄性Wistar大鼠随机分为对照组和手术组,每组15只。采用氯化钙(CaCl2)诱导法制备胸主动脉瘤模型,于术后4周取外敷CaCl2段胸主动脉。HE染色及地衣红染色观察胸主动脉组织学改变;免疫组织化学和免疫印迹法检测动脉瘤壁VEGF和TSP-1的表达。结果免疫组织化学显示,VEGF主要表达于动脉瘤中膜和外膜,而对照组表达很弱;TSP-1表达于正常动脉全层,而动脉瘤表达很弱。免疫印迹法显示,动脉瘤组织中VEGF表达均强于对照组,而TSP-1弱于对照组。结论 VEGF和TSP-1均参与胸主动脉瘤的形成,其可能是胸主动脉瘤新生血管生成的关键决定因素。

Objective To investigate the expression and significance of vascular endothelial growth factor（VEGF） and thrombospondin-1 （TSP-1）in the experimental rat thoracic aortic aneurysm. Methods Thirty adult male Wistar rats were randomly divided into two groups： sham group and operated group. The thoracic aortic aneurysm model was induced by CaC12. The thoracic aortic segments were collected at 4 weeks after surgery. HE staining and Orcein staining were used to observe histological changes in the thoracic aorta. Immunohistochemistry and Western blotting were performed to detect the expressions of VEGF and TSP-1 in the wall of aneurysm. Results Immunohistochemistry staining results showed that VEGF was mainly located in the tunica media and tunica adventitia in the aortic aneurysm and there was few positive staining in the control group. TSP-1 was located in the normal aorta but the positive staining in the aneurysm was weak. Western blotting results indicated that the expression level of VEGF in the aortic aneurysm was stronger than the control, while the expression level of TSP-1 was weaker than the control. Conclusion Both TSP-1 and VEGF participate in the pathogenesis of thoracic aortic aneurysm. They may be the key factors in the new vessel formation of aortic aneurysm.