Gene silencing efficiency of shRNA expression vectors targeting Cx43 in vitro

Our previous studies showed that there were close relationships between connexin 43 (Cx43) and acupoints and meridians. In order to further investigate the effect of Cx43 in acupuncture treatment, RNA interference technique was used to construct small hairpin RNA (shRNA) expression vectors targeting Cx43 and identify the efficiency of RNA interference in NIH/3T3 cell lines for further use in vivo. Aiming directly at the two targets of Cx43 mRNA sequence of the rat and mouse homology region, we synthesized two pairs of complementary oligonucleotide strands in vitro. Double strands were formed after annealing, and then inserted into Pgenesil-1 plasmid expression vector. After identification by enzyme cutting and sequencing, the recombinant plasmids named P-Cx43-shRNA (1), P-Cx43-shRNA (2) and P-con-shRNA were transfected into the NIH/3T3 cells. Immunofluorescence and Western blot assays were used to detect the protein level of Cx43 after being screened by G418. The results of enzyme cutting and sequencing showed that we successfully constructed two shRNA expression vectors targeting Cx43, and a control expression vector for rat and mouse. Also, the Cx43 protein level was decreased by 73.5% (P < 0.01) and 10.8%, accordingly. The Cx43 protein level was not influenced by the transfection of P-con-shRNA. The outcomes demonstrate that the plasmid P-Cx43-shRNA (1) can specifically silence better the expression of Cx43 in NIH/3T3 cells, which offers an experimental evidence for further in vivo investigation. © Higher Education Press and Springer-Verlag GmbH 2009.