Impact Of CathepsinS On Aortic Ring-derived Micro Vascular Cavity Formation In Experimental Mice

Objective:This study compared the dynamic changes of ischemic and non-ischemic lower limb blood flow in CatS+/+and CatS-/-mice,formation of aortic ring microcavity in two groups of mice,observation of microcatheter formation in mouse aortic rings by using cathepsin S inhibitor and MMP inhibitor and immunofluorescence identification of mouse aortic rings to investigate the impact of CatS on aortic ring-derived micro vascular cavity formation in experimental mice.Methods:Hindlimb ischemia model was established in CatS+/+and CatS-/-mice,n=8 in each group.The blood flow in hindlimb was measured before ischemic surgery;immediately and 1,4,7,14,21 days after surgery.CatS+/+mice were further divided into 4 subgroups:Normal control subgroup,Selective CatS inhibitor(LHVS)subgroup,Non-selective CatS inhibitor(E64d)subgroup and MMP inhibitor(GM6001)subgroup;n=2 in each subgroup.The mice aortic ring-derived micro vascular cavity formation was observed by FITC-CD31 immunofluorescence method.Results:1.CatS-/-mice had inhibited blood flow recovery after ischemic surgery.Laser Doppler blood flow(LDBF)examination indicated that compared with CatS+/+group,CatS-/-group had slower hindlimb blood flow recovery(P<0.05).2.CatS-/-group had the less aortic ring-derived micro vascular cavities(P><0.001).3.Compared with Normal control subgroup,LHVS subgroup,E64d subgroup and GM6001 subgroup had suppressed micro vascular cavity formation(P<0.05).4.Aortic ring-derived micro vascular cavity was composed by endothelial cells.Conclusion:CatS plays a beneficial role in ischemic vascular regeneration in experimental mice;it is not only increasing aortic ring-derived micro vascular cavity formation,but also promoting blood flow recovery in ischemic hindlimb.Our finding provides a theoretical basis for new therapeutic target in ischemic vascular regeneration can be a key member involved in ischemic angiogenesis and has a good application prospect in ischemic diseases.It is worthy of further exploration in clinical applications.