血管生成素在COS-7细胞中的表达及其生物活性研究

本研究旨在实现血管生成素（ANG）在真核细胞中的表达并探讨其生物学功能。通过RT—PCR获得ang基因，构建真核表达载体pcDNA3．1-ang，在转染COS-7细胞后进行瞬时表达，通过Western blot对表达产物进行鉴定。利用MTT法分析表达上清对ECV304细胞的促增殖作用，同时利用鸡胚分析表达上清的促血管生成作用。结果表明：瞬时转染后细胞培养上清中有重组ANG的表达，并能与抗-ANG单克隆抗体发生特异性反应。与转染空载体的对照相比．转染pcDNA3．1-ang的细胞培养上清具有促进ECV304细胞增殖的作用，并能显著促进鸡胚尿囊膜血管生长。结论：ang可在COS-7细胞中瞬时表达，其表达产物具有显著的促细胞增殖和促进血管生成的作用。

Expression of Angiogenin in COS-7 Cells and Analysis of Its Biological Activity

This study was purposed to investigate the angiogenin (ANG) expression in COS-7 cells and its biological activity. The gene of angiogenin was obtained from mononuclear cells of peripheral blood by using RT-PCR and inserted into eukaryotic expression vector of pcDNA3.1. After being transfected into COS-7 cells, the recombinant ANG was identified by Western blot assay. The function of promoting proliferation of ANG to ECV304 cells was detected by MTT method, and its activity of vascularization was analyzed by chick embryo chorioallantois treated by the culture supernatant after transfection with pcDNA3.1-ang. The result showed that recombinant ANG was expressed in COS-7 cells after transfection for 24 to 36 hours. It could specifically react with monoclonal antibody against ANG. The recombinant ANG could obviously promote the proliferation of ECV304 cells. In contrast with the control group, the culture supernatant of pcDNA3.1-ang transfected group could stimulate the angiogenesis in embryo chorioallantois. It is concluded that the ang transiently expresses in COS-7 cells, and its expression product obviously stimulates the cell proliferation and angiogenesis.