血管内皮生长因子基因治疗大鼠脑缺血的实验研究

为探讨血管内皮生长因子(VEGF)基因治疗大鼠脑缺血的可行性,构建了pcD2/hVEGF121真核表达质粒,建立持续性大脑中动脉堵塞(MCAO)的局灶性脑梗塞模型,大鼠脑皮质直接注射法转移pcD2/hVEGF121真核表达质粒。应用逆转录聚合酶链反应(RT-PCR)、VEGF免疫组织化学法、脑血管计数及梗塞面积测定等方法检测转移pcD2/hVEGF121真核表达质粒后大鼠脑中VEGF基因表达及生物学效应。结果发现,与转移空载质粒的对照组相比,转移VEGF基因后7d的大鼠脑组织中有VEGFmRNA高表达,VEGF免疫组化染色可见VEGF蛋白表达水平增高,脑血管数增多,梗塞体积缩小。因此,直接注射法转移VEGF基因能够在缺血脑组织中表达,表达产物能够发挥生物学效应,进而起到保护脑组织作用。

Direct Gene Transfer of Naked DNA Encoding Vascular Endothelial Growth Factor into Ischemic Rat Brain

Vascular endothelial growth factor (VEGF) eukaryotic expression plasmid (pcD 2/hVEGF 121 ) was constructed by cloning human VEGF 121 cDNA into the eukaryotic expression vector pcD 2.pcD 2/hVEGF 121 was directly injected into the ischemic rat brain following the permanent middle cerebral artery occlusion(MCAO).RT PCR,immunohistochemistry,vessel count,infarct size analysis were used to investigate VEGF gene expression and biological effect.High levels of VEGF mRNA and protein expression were detected.There was a significant increase in the number of vessels( P <0 05) and a significant reduction in the ratio of infarct volume( P <0 05)when compared with control group.The results indicate that topical VEGF gene application can transfect the ischemic brain tissue and express VEGF protein.The VEGF gene product can enhance angiogenesis,increase vessel number and reduce infarct volume.