组织蛋白酶S基因敲除在小鼠CABG后静脉桥再狭窄作用机制的研究

STUDY OF VENOUS BRIDGE RESTENOSIS MECHANISM OF CATHEPSIN S GENE KNOCKOUT IN MICE AFTER CABG

目的:冠状动脉旁路移植术(Coronary artery bypass grafting,CABG)后静脉桥再狭窄发生率高,组织蛋白酶S(Cathepsin S,CatS)在血管再狭窄中起着重要作用,本研究即验证CatS基因敲除后对静脉桥再狭窄有抑制作用。方法:选取CatS基因敲除后的小鼠作为实验组(36只),以C57BL/6小鼠为对照组(36只)。利用Cuff套管技术建立小鼠下腔静脉-颈动脉移植模型,显微镜观察血管内膜增生来证实CatS基因敲除后对静脉桥的再狭窄有抑制作用,通过酶联免疫吸附法(enzyme-linked immuno sorbent assay,ELISA)测定MMP-9酶的含量,进一步探讨CatS基因敲除后抑制CABG静脉桥再狭窄的作用机制。结果:在静脉移植术后早期两组内膜增生无显著差别,随着术后时间的推移,对照组小鼠内膜程度较实验组变化较为明显,且CatS(-/-)组MMP-9含量表达较C57BL/6组明显减少,尤其是在术后2wk,实验组(CatS(-/-)组)和对照组(C57 BL/6组)MMP-9含量表达分别为6.12±0.11ng/m L和9.23±0.12ng/m L,两组比较P<0.05,差异有统计学意义。结论:CatS基因敲除后在一定程度上能对静脉桥再狭窄有抑制作用,并且通过巨噬细胞MMP-9含量减少作用的途径,证实其可以抑制内皮细胞及血管平滑肌细胞增殖反应,细胞外基质沉积,减轻静脉桥血管的再狭窄。

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.One study found that cathepsin S(CathepsinS,CatS)play an important role in the vascular restenosis.The purpose of this study is confirm the inhibitory effect after Cathepsin S knockout to the venous bridge restenosis.Methods:The experimental group as the mice of after Cathepsin S gene knockout as the research object(36),the C57 BL/6 mice,as control group(36).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.Results:At the different time points after venous transplantation(8h,1 d,3 d,7 d and 14 d and 28 d),in early postoperative,endometrial hyperplasia showed no statistically significant difference between the two groups.With the extension of time after venous transplantation,the CatS(-/-)contents of MMP-9 express decreased significantly with the C57 BL/6 group contrast.Especially in 2 weeks postoperatively,the experimental group(CatS(-/-)group)and control group(group C57 BL/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:Through microscope observe the neointimal hyperplasia confirmed the inhibitory effect of venous bridge restenosis after CatS gene knockout.By means of macrophages 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.