Construction and identification of RNAi-A2aR lentiviral vector in rats / 中华麻醉学杂志

ABSTRACT

Objective:To construct and identify the lentiviral vector of adenosine RNAi-adenosine A2a receptor (A2aR) in rats.Methods:Three pairs of short hairpin RNA(shRNA)-A2aR sequences (shRNA-A2aR 1, shRNA-A2aR 2, shRNA-A2aR 3) were designed, and three pairs of double-stranded shRNA oligos were respectively inserted into the shRNA virus vector to gain three kinds of shRNA lentiviral recombinant plasmid.The recombinant plasmid, packaging vector, and shuttle vector were co-transfected into 293T cells to obtain virus liquid.The experiment was performed in two parts.Part Ⅰ The rat primary cardiomyocytes were divided into 3 groups ( n= 6 each) by a random number table method: vehicle group (V group), shRNA-A2aR 1 group and shRNA-A2aR 3 group.Each group was transfected with virus solution of MOI 10 for 48 h. The expression of A2aR was detected by Western blot to select the most efficient lentivirus vector.Part Ⅱ The cardiomyocytes were randomly divided into 6 groups ( n=36 each) vehicle group (V group), MOI5 group, MOI10 group, MOI15 group and MOI20 group.Each group was transfected with the corresponding MOI virus liquid (the most effective lentivirus vector). At 24, 48, and 72 h of transfection, the cell viability and cell death were observed with a fluorescent microscope, and the A2aR expression was detected by Western blot to determine the interference efficiency. Results:Part Ⅰ Two types of shRNA-A2aR lentiviral vectors (shRNA-A2aR 1, 3) were successfully constructed, among which shRNA-A2aR 3 virus solution with a titer of 3.5×10 8 TU/ml had the best effect.Compared with group V and group shRNA-A2aR 1, the expression of A2aR in cardiomyocytes was significantly down-regulated ( P<0.01), and the interference efficiency of shRNA-A2aR 3 was 73% in shRNA-A2aR 3 group.Part Ⅱ shRNA-A2aR 3 was selected to screen out the transfection plan.The cell survival rate in each group was more than 85% at 24 h of transfection, the cell survival rate was more than 80% at 48 h of transfection in MOI5 and MOI10 groups; the cell survival rate in each group was less than 70% at 72 h of transfection.Under an inverted fluorescent microscope, a slightly lower fluorescence density was found in MOI5 group, the fluorescent density was higher and the cell condition was better at 48 h of transfection in MOI10 group and at 24 h of transfection in MOI20 group, and the cardiomyocyte viability was significantly decreased, and dead cells were increased at 72 h of transfection in each group.The results of Western blot showed that the interference efficiency at 48 h of transfection in MOI10 group, 48 h in MOI15 group, 24 and 48 h in MOI20 group was all > 70%. Conclusion:MOI of 10, transfection for 48 h or MOI of 20, transfection for 24 h is the optimal transfection protocol.