体内转染血管内皮生长因子基因对慢性低氧诱导小鼠肺动脉高压的影响

Effect of transfecting the vascular endothelial growth factor genein vivo on the mice with pulmonary hypertension induced by chronic hypoxia

目的探讨血管内皮生长因子(Vegf)体内转基因对慢性低氧诱导小鼠肺动脉高压(PAH)的治疗作用。方法将昆明雄性小鼠36只随机分为3组:低氧Vegf治疗组(P-V组),模型组(PAH组),对照组(C组),每组12只。采用间断性常压缺氧法复制小鼠PAH模型。观察4周后,P-V组经尾静脉注射聚乙烯亚胺(PEI)包被的pBudCE4.1-Vegf-EGFP载体,其他组注射等量生理盐水,继续低氧处理。转基因治疗后30 d,观察小鼠的一般情况、平均肺动脉压(mPAP)、动脉血气、右心肥大指数[右心室/(左心室+室间隔)]及肺小动脉形态学改变,RT-PCR方法检测增强绿色荧光蛋白(EGFP)表达情况;Real-time PCR方法检测各实验组肺组织Vegf mRNA量; ELISA方法及硝酸还原酶法分别检测各实验组肺组织VEGF和NO含量。结果 PAH组小鼠出现代谢性酸中毒,平均肺动脉压升高,右心室肥厚,肺小动脉管壁厚度(WT)增加,与C组相比,差异有统计学意义(P<0.05)。与PAH组相比,P-V组小鼠平均肺动脉压升高、右心室肥厚及肺小动脉管壁增厚减轻,差异有统计学意义(P<0.05)。与PAH组小鼠相比,P-V组小鼠外源基因Vegf的mRNA及蛋白水表达增加,差异有统计学意义(P<0.05)。结论 Vegf转基因治疗能上调慢性低氧诱导小鼠的肺组织中Vegf mRNA和VEGF的表达,从而拮抗肺动脉压升高,减轻右心肥厚及肺动脉血管增厚。

Objective To explore the therapeutic effect of transfecting the vascular endothelial growth factor （Vegf） gent in vivo on the mice with pulmonary hypertension induced by chronic hypoxia. Methods Thirty six male mice were randomly divided into 3 groups： P-V group, PAH group and control group, 12 mice per group. The mouse model was prepared using normal pressure intermittent hypoxia method. After four weeks, the mice in P-V group were transfected with pBudCE4.1-Vegf-EGFP by PEI-mediated in vivo, and the mice in other groups were treated with saline. Hypoxia was continued while transfection. The mean pulmonary artery pressure （mPAP）, arterial gas analysis, right ventrieular hypertrophy index[ RV/（ LV ＋ S） ] as well as pulmonary microvascular changes were observed after 30 days. The RT-PCR, Real-time PCR, ELISA, and nitrate reductase method were used in order to detect expression of EGFP, amount of Vegf mRNA, the level of VEGF and NO for pulmonary tissues, respectively. Results Compared with the control group, mPAP, right ventricular hypertrophy and wall thiuckness （WT） increased in the PAH group （P 〈 0. 05）. The extent of mPAP increasing,right ventricular hypertrophy and pulmonary artery WT had reduced in P-V group compared with the PAH group （P 〈 0. 05）. Vegf mRNA,VEGF and NO protein expressions increased in lung tissue of the P-V group compared with the PAH group（P 〈 0.05）. Conclusion After transfecting the exogenous Vegf gene into mice, Vegf mRNA and protein expressions increased in the lung tissue of the mice, reduced the thickening of the small arteries and decreased the right ventricular hypertrophy index, and mPAP in mice of pulmonary hypertension induced by chronic hypoxia.