Construction and identification of pIRES2-GDNF-VEGF165 bicistronic eukaryotic expression vector / 中国组织工程研究

ABSTRACT

BACKGROUND:Human glial cellline-derived neurotrophic factor (GDNF) and vascular endothelial growth factor 165 (VEGF 165 ) are essential genes for celldifferentiation. OBJECTIVE:To construct and identify pIRES 2-GDNF-VEGF 165 bicistronic eukaryotic expression vector. METHODS:Human GDNF genes were obtained from the genomic DNA of human peripheral blood mononuclear cells by PCR. Then the GDNF cDNA fragment was inserted into the multiple cloning sites of pIRES 2-EGFP, to generate the bicistronic eukaryotic expression plasmid pIRES 2-GDNF-EGFP. The VEGF 165 gene was obtained from pIRES 2-VEGF 165-EGFP plasmid by twin PCR. Then VEGF 165 cDNA fragment was cloned into the pIRES 2-GDNF-EGFP, instead of EGFP, to create a double gene co-expressing vector plasmid pIRES 2-GDNF-VEGF 165 containing internal ribosome entry sites. Then pIRES 2-GDNF-VEGF 165 was used to transfect HEK293 cells. RT-PCR and western blot analysis were performed to test the co-expression of double genes. RESULTS AND CONCLUSION:DNA sequencing analysis demonstrated that the GDNF and VEGF 165 were exactly consistent with the sequence recorded in the GenBank. The size of GDNF gene was 636 bp and the size of VEGF165 gene was 576 bp. Enzyme digestion analysis indicated that, pIRES2-GDNF-VEGF165 bicistronic eukaryotic expression vector inserted GDNF band by Bgl II/Bam HI, inserted IRES-VEGF 165 fragment by Bam HI/Not I, and inserted GDNF-IRES-VEGF165 fragment by Bgl II/Not I. RT-PCR and western blot analysis showed that, after HEK293 cells were transfected with pIRES 2-GDNF-VEGF 165 , double genes were expressed at the mRNA and protein levels. The pIRES 2-GDNF-VEGF 165 bicistronic eukaryotic expression vector is successful y constructed.