缺氧诱导因子-1α表达与移植静脉再内皮化关系的实验研究

The relationship between hypoxia inducible factor-1 α expression and novoendotheliasis after autogenous vein grafting

目的 探讨缺氧诱导因子 1α(HIF 1α)表达水平与移植静脉再内皮化的关系。方法 将6 0只Wistar大鼠随机分为实验组与对照组 ,前者行颈内静脉 颈总动脉移植术。于术后 7d与 14d切取移植静脉。分别采用反转录多聚酶链反应 (RT PCR)、Western印迹法、免疫组织化学及电镜等检测 ,观察HIF 1α和血管内皮生长因子 (VEGF)表达水平及再内皮化过程。结果 术后 7d与 14d相比较 ,移植静脉再内皮化显著 ;HIF 1αmRNA及其蛋白和VEGF蛋白表达增强 (P均 <0 0 1) ;增生内膜中HIF 1α阳性表达细胞增多。HIF 1α与VEGF表达呈正相关 (r=0 90 2 6 ,P <0 0 1)。结论HIF 1α与移植静脉内皮细胞增殖密切相关 ,其早期表达不足是引起内膜过度增生 (IH)的重要基因之一。

Objective To elucidate the relationship between the level of hypoxia inducible factor-1α(HIF-1α)expression and novoendotheliasis after autogenous vein grafting. Methods 40 Wistar rats underwent right internal jugular vein to common jugular artery interposition grafting. Twenty rats were killed 7 and 14 days after the grafting respectively and the grafted veins were harvested respectively. Twenty rats not undergoing grafting were used as controls. The expressions of HIF-1α mRNA and protein and vascular endothelial growth factor (VEGF) mRNA and protein were examined by using reverse transcription polymerase chain reaction, Western blotting, and immunohistochemistry . Electron microscope was used to observe the process of vascular novoendotheliasis. Results The percentage of HIF-1α positive cells 7 days after grafting was 20.5±6.2%, significantly higher than that 14 days after (12.3±3.7, P<0.01) and that of the controls (0.5±0.1%, P<0.01). The percentage of HIF-1α positive cells 14 days after grafting was significantly higher than that of the controls too (P<0.01). The expression of HIF-1αmRNA 7 days after grafting was 53.2±9.3, significantly higher than that 14 days after grafting (43.2±6.3, P<0.01) and that in the control (29.4±5.6, P<0.01). The expression of HIF-1α7 mRNA 14 days after grafting was significantly higher than that of the controls too (P<0.01). The expression of HIF-1α protein 7 days after grafting was 5.6±0.4, significantly higher than that 14 days after grafting (3.5±0.2, P<0.01) and that in the control (0.8±0.1, P<0.01). The expression of VEGF protein 7 days after grafting was 2.2±0.1, significantly higher than that of the control (0.5±0.1, P<0.01). Novoendotheliasis was seen 7 days after grafting and decreased 14 days after. The expression of HIF-1α was positively correlated with the expression of VEGF (r=0.903, P<0.01).Conclusion HIF-1 α is closely related to novoendotheliasis. The deficiency of HIF-1 α expression plays an important role in intima hyperplasia.