Local matrix metalloproteinase 2 gene knockdown in balloon-injured rabbit carotid arteries using nonviral-small interfering RNA transfection

摘要

Background Small interfering RNA (siRNA) delivery is a promising approach for the treatment of cardiovascular diseases. Matrix metalloproteinase (MMP) 2 over-expression in the arterial wall has been implicated in restenosis after percutaneous coronary intervention, as well as in spontaneous atherosclerotic plaque rupture. We hypothesized that in vivo local delivery of siRNA targeted at MMP2 (MMP2-siRNA) in the balloon-injured carotid artery of hypercholesterolemic rabbits may lead to inhibition of MMP2 expression. Methods Two weeks after balloon injury, 5 mol/l of Tamra-tagged MMP2- siRNA, scramble siRNA or saline was locally injected in the carotid artery and incubated for 1 h. Results Fluorescent microscopy studies showed the circumferential uptake of siRNA in the superficial layers of neointimal cells. MMP2 mRNA levels, measured by the real-time reverse transcriptase-polymerase chain reaction, was decreased by 79 25% in MMP2-siRNA- versus scramble siRNA-transfected arteries (p < 0.05). MMP2 activity, measured by gelatin zymography performed on the conditioned media of MMP2-siRNA versus scramble siRNA transfected arteries, decreased by 53 29%, 50 24% and 46 14% at 24, 48 and 72 h, respectively (p < 0.005 for all). No effect was observed on MMP9, pro-MMP9 and TIMP-2 levels. Conclusions The results obtained in the present study suggest that significant inhibition of gene expression can be achieved with local delivery of siRNA in the arterial wall in vivo.