血管生长素-1基因慢病毒载体的构建及其在间质干细胞的表达

目的： 构建带有血管生长素-1（Ang-1）基因的慢病毒载体并实现该基因在大鼠骨髓间质干细胞（rMSCs）中的表达。方法： RT-PCR获得大鼠Ang-1基因，限制性内切酶酶切和基因重组构建慢病毒载体质粒PNL-Ang-1-IRES₂-EGFP，在脂质体介导下与包装质粒HELPER,包膜质粒VSVG共转染293T细胞包装生产慢病毒颗粒并感染rMSCs。 PCR检测Ang-1基因的插入，细胞RT-PCR检测Ang-1 mRNA表达，免疫细胞化学和Western blotting检测Ang-1蛋白的表达。结果： 所获Ang-1基因经测序证实与GenBank报道的序列一致。慢病毒载体质粒PNL-Ang-1-IRES₂-EGFP经SalⅠ和BamHⅠ双酶切后电泳显示 1 512 bp Ang-1目的基因片段和10.5 kb PNL-IRES2-EGFP载体片段。病毒基因组PCR证实Ang-1基因插入。荧光显微镜观察到EGFP表达。细胞RT-PCR检测到Ang-1 mRNA表达。免疫细胞化学和Western blotting检测到Ang-1蛋白表达。结论： 成功构建带有Ang-1基因的慢病毒载体并实现在rMSCs中的表达，为Ang-1基因修饰干细胞的应用研究奠定了基础。

Construction of lentiviral vector carrying the Ang-1 gene and its expression in the rMSCs

AIM: To construct lentiviral vector carrying the angiopoietin-1(Ang-1) gene,and make it express Ang-1 in the rat mesenchymal stem cells(rMSCs).METHODS: The cDNA encoding the CDS of Ang-1 gene was obtained from the placenta of the adult Fisher 344 rats with RT-PCR.After digestion with restrication endonuclease,the Ang-1 gene was recombined to construct the transfer plasmid PNL-Ang1-IRES2-EGFP.The three-plasmid system of lentiviral vector was consisted of PNL-Ang1-IRES2-EGFP,the packaging plasmid HELPER,and the envelope plasmid VSVG,which were co-transfected to 293T cells mediated by lipofectamin2000 to produce lentiviral particles.The rMSCs were infected by obtained lentiviral particles.The insertion of Ang-1 gene was detected by PCR,the mRNA expression of Ang-1 in rMSCs was detected with RT-PCR,the protein expression of Ang-1 was observed with immunocytochemistry and Western blotting methods.RESULTS: The result of sequencing showed that the cloned Ang-1 gene was consistent with the sequence reported in GenBank.After digestion with restrication endonuclease,the 1 512 bp fragment of Ang-1 gene and the 10.5 kb vector fragment of PNL-IRES2-EGFP were observed with gel electrophoresis.The insertion of Ang-1 gene in viral genome was confirmed.The EGFP expression was observed with the fluorescent microscope.In infected rMSCs,the mRNA and protein expressions of Ang-1 were confirmed.CONCLUSION: Lentiviral vector carrying Ang-1 gene has been successfully constructed.The infected rMSCs are able to express the Ang-1 mRNA and Ang-1 abundantly.This will facilitate the following exploratory development of Ang-1 gene-modified rMSCs.