Study Of Venous Bridge Restenosis Mechanism Of Cathepsin S Gene Knockout In Mice After CABG

Objective Coronary artery bypass grafting(CABG) is an effective method for treatment of coronary heart disease.But the high incidence of venous bridge restenosis after CABG.Inflammatory reaction and neointimal hyperplasia as the main factors in restenosis.One study found that cathepsin S(Cathepsin S, Cat S) play an important role in the vascular restenosis. If Cathepsin S gene knockout can inhibit venous bridge restenosis after CABG, still need further study.The purpose of this study is confirm the inhibitory effect after Cathepsin S knockout to the venous bridge restenosis,and the inhibition by means of MMP- 9content reducing effect, reduce venous bridge vascular restenosis.Methods The experimental group as the mice of after Cathepsin S gene knockout as the research object, the C57 BL / 6 mice, as control group. Using the Cuff casing technology establish inferior vena cava- carotid artery transplantation model in mice. By identifying gene knockout, a microscope neointimal hyperplasia to confirm the inhibitory effect to the venous bridge restenosis after Cathepsin S knockout. At the same time by the enzyme-linked immunosorbent method(enzyme- linked immunosorbent assay, ELISA) to determine the content of MMP- 9 enzymes to explore the mechanism of restenosis inhibition of CABG after Cathepsin S knockout,and provide a new theory for the prevention and treatment of venous bridge restenosis.Results At the different time points after venous transplantation(8h, 1d, 3d, 7d and 14 d and 28d), by means of transplanted vein based and microscopically observed after treatment:early postoperative, endometrial hyperplasia showed no statistically significant difference between the two groups, With the passage of time, postoperative hyperplasia of endometrium gradually, the control and change is more apparent, and Cat S knockout group although have endometrial hyperplasia, but the degree of hyperplasia was significantly reduce than control group. With the extension of time after venous transplantation, the Cat S(- /-) contents of MMP- 9 express decreased significantly with the C57 BL / 6 group contrast. Especially in 2weeks postoperatively, the experimental group(Cat S(- /-) group) and control group(groupC57BL / 6) expression of MMP- 9 content respectively(6.12 ± 0.11)ng/ml and(9.23 ±0.12)ng/ml, comparing the two groups P < 0.05, the difference was statistically significant.Conclusion The study was established on the basis of complete the Cuff casing technology inferior vena cava- carotid artery transplantation in mice model, through microscope observe the neointimal hyperplasia confirmed the inhibitory effect of venous bridge restenosis after Cat S gene knockout. By means of MMP- 9 content reducing effect,confirmed that it can inhibit the endothelial cells and vascular smooth muscle cell proliferation, extracellular matrix deposition, relieve venous bridge vascular restenosis.