【Abstract】 Objective To construct a recombinant adeno-associated virus (AAV) shuttle vector expressing nervegrowth factor β (NGF-β) gene. Methods By PCR amplification, the structural element of pAAV-multi ple cloning site(MCS) and the functional element of pGenesil-1.1 were obtained and cloned into T-easy vector, respectively; the recombinant T-easy vectors were digested by restriction enzyme, then the target fragments were reclaimed and connected by DNA l igase, so the recombinant AAV shuttle vector pAAV-U6/CMV-enhanced green fluorescent protein (EGFP) containing U6 promoter and CMV promoter was obtained. The vector was transfected into 293 cells. The human Miapaca-2 cell l ine was cultured, and total RNA was extracted, then human NGF-β gene was obtained by RT-PCR. T-easy-NGF-β vector was constructed by cloning human NGF-β gene into T-easy vector and identified by RT-PCR, digestion, and DNA sequencing. As NGF-β gene was cloned into pAAV-U6/CMV-EGFP vector, the recombinant AAV shuttle vector expressing NGF-β gene was obtained and identified by RT-PCR, digestion, and DNA sequencing. Results The bands of 800 bp and 4 250 bp were detected when pAAV-U6/CMVEGFP was digested. The GFP was detected when pAAV-U6/CMV-EGFP was transfected into 293 cells. The bands of 736 bp and 3 015 bp were detected when T-easy-NGF-β was digested; DNA sequencing result of T-easy-NGF-β was fully consistent. The bands of 736 bp and 4 250 bp were detected when pAAV-U6/CMV-NGF-β was digested. DNA sequencing result of pAAV-U6/ CMV-NGF-β showed that sequences were completely correct. Conclusion The AAV shuttle vector pAAV-U6 /CMV-NGF-β is successfully constructed, providing experimental basis for investigation of the repair of spinal cord injury.
Objective To construct and screen neurite outgrowth inhibitory 66-samll interfering RNA (nogo66-siRNA) eukaryotic expression vectors of effective interference, so as to lay a foundation for further reconstruction of related viral vector. Methods The nogo66-siRNA fragments were designed and cloned into pGenesil-1.1, 4 plasmids of pGenesil-nogo66-siRNA-1, pGenesil-nogo66-siRNA-2, pGenesil-nogo66-siRNA-hk, and pGenesil-nogo66-siRNA-kb were obtained, sequenced and identified, then were transfected into C6 cell l ine. The transfection efficiency was measured by fluorescence microscope. RT-PCR and Western blot were used to detect the expression of nogo gene and select the plasmid of effective interference. Results DNA sequencing results showed interference sequences were correct. The bands of 800 bp and 4.3 kb were detected when pGenesil-nogo66-siRNAs were digested by Kpn I /Xho I. The expression of green fluorescent protein could be detected under fluorescence microscope, and the transfection efficiency was about 73%. RT-PCR and Western blot results showed that compared to non-transfected cells, the transfection of pGenesil-nogo66-siRNA-1 made the expression of nogo gene decl ine 22% and the expression of nogo protein decl ine 73%; the transfection of pGenesil-nogo66-siRNA-2 made the expression of nogo gene decl ine 28% and the expression of nogo protein decl ine 78%; the differences were significant (P lt; 0.05); and the transfection of pGenesil-nogo66-siRNA-hk and pGenesil-nogo66- siRNA-kb did not make the expressions of nogo gene and nogo protein decrease significantly (P gt; 0.05). Conclusion Nogo66-siRNA eukaryotic expression vector is successfully constructed, it lays an experimental foundation for repair of spinal cord injury.