| Objective This study was conducted (1) to investigate the inhibitoryeffect of TIMP-3 on endothelial cell (EC) proliferation by the vitro cell culture.(2) To build experimental model of orthotopic aortic allografts and isograftstransplantation in rats, dynamic observe the rule of the expressions of MMPSand TIMPS on the transplanted artery, which is for discussing these functionsof transplanted arteriosclerosis. (3) To transfection the exogenous TIMP-3 intotransplanted vessels, observe the contribution of the expression of TIMP-3 intransplanted vessels, and try to probe into the function of exogenous TIMP-3gene in chronic rejection. Methods (1) In the study of vitro cell culture, The inhibition ofdifferent concentration of TIMP-3 in EC proliferation was analyzed bylight microscopy, MTT, [3H]-TdR up-take, flow cytometry andimmunhistochemistry et al. (2) In the 2nd part's animal experiment,orthotopic aortic allografts and isografts transplanta-tion in rats wasperformed. Rats were divided into two groups: allografts group (SD-Wistar) and isografts group (Wistar-Wistar) , Rats were killed at 3d,1,2,4,8w after operation and graft aortic tissues were collected. And thenthe expressions of MMPS and TIMPS in the tissues of transplantedabdominal aortic were mensurated by morphology, immunohistochemicalSP staining method and the expression of MMP-2 was detected byNorthern blot quantitative analysis in abdominal aortic orthotopictransplantation model. (3) In the 3rd part animal experiment,orthotopicaortic transplanted rats were divided into three groups: allografts group(SD-Wistar)(A, B) and isografts group (Wistar-Wistar)(C) , Rats werekilled at 3d,1,2,4,8w after operation and graft aortic tissues werecollected. The expressions of MMP-2 and TIMP-2, 3 and Fas in thetissues of transplanted abdominal aortic were mensurated by morphology,immunohistochemical SP staining method and the expression of MMP-2was detected by Northern blot quantitative analysis etc. Results (1) In the study of vitro cell culture:A concentration-dependent and time-dependent proliferation inhibition and survival weredemonstrated in the HUVEC incubated for 1~7days in the presence ofTIMP-3. The proliferation inhibition was shown as the lessened cellgrowth, decreased counting of mitotic cells. TIMP-3 could also aggravatethe increase of apoptotic cells and cell ratio in G2/M phase. (2) In the 2ndpart's animal experiment:The thickness of tunica intima of the allograftswas much evidently thicker than isografts 2 weeks after transplantation(P<0.05). The expressions of MMPS and TIMPS in the isografts came tothe highest on 14th day and then declined. But the expressions of MMPSand TIMPS in the allografts were observably higher than the former, andthe peak of the expression of TIMP-1 was prolonged to 4th week. TIMP-3kept lowly expressed in every group. (3) In the 3rd part's animalexperiment:The thickness of tunica intima of the transplanted abdominalaortic from strong to feeble was group B, A and C. The expression ofMMP-2, TIMP-2 in the isografts reached the peak at 4th week, while theMMP-2 was much low. The expression of MMP-2 in group C wasmarkedly increased, and the peak came at 2nd week. The expression ofTIMP-3 on 1st and 2nd (1.7±1.1&0.9±0.4) were much higher than groupB and C (p<0.05). Much more Fas staining positive cells(2.7±0.8&1.8±0.9) were detected in tunica intima and tunica media ingroup A 2 weeks after surgery than group B and C (P<0.05),as well as theAI (14.9%±6.8%) in tunica intima (P<0.05). Conclusion (1) TIMP-3 has significant inhibitory influence on ECproliferation, migration and promotion apoptosis. (2) The unbalance ofexpressions of MMPS/TIMPS leading to the turbulence of synthesizationand degradation ECM, is an important reason for the process of chronicrejection. (3) While The exogenous TIMP-3 gene is admitted on earlystage of CR, the balance between MMPS and TIMPS could be intervened,the degradation could be restrained, the transferring of SMC to the tunicaintima could be blocked, and apoptosis of tunica intima could bepro...
|
PDF Full Text Request