基质金属蛋白酶-2及其组织抑制因子在急性升主动脉夹层中的表达和意义

The Expression of Matrix Metalloproteinase-2 and Tissue Inhibitor of Metalloproteinase-2 in the Acute Ascending Aortic Dissection

目的:研究基质金属蛋白酶-2(MMP-2)和金属蛋白酶组织抑制因子-2(TIMP-2)在急性升主动脉夹层(AAD)中的表达与意义。方法:以35例急性AAD患者为病变组,以同期21例心脏移植供心升主动脉为对照组,应用免疫组化等方法,分析比较MMP-2和TIMP-2在病变组和对照组主动脉壁中的表达。结果:病变组主动脉内层撕裂,少量炎性细胞浸润于夹层边缘;主动脉中层病变显著,平滑肌细胞密度下降,弹性纤维碎裂、崩解,中层粘液样变,新生血管形成。对照组主动脉壁弹性板层结构致密有序,无中层退行性变。免疫组化染色见正常主动脉壁MMP-2和TIMP-2低水平表达,病变组与对照组MMP-2表达未见显著性差异(P>0.05);病变组TIMP-2表达明显高于对照组(P<0.05)。结论:病变组MMP-2低水平表达、TIMP-2表达增加参与急性AAD发生及其血管壁组织重构过程。

Objective：To evaluate the contribution of the expressions of matrix metalloproteinase（MMP）-2 and tissue inhibitor of metalloproteinase（TIMP）-2 to the acute ascending aortic dissection （AAD）.Methods：Acute AAD samples （n=35） were taken during aortic replacement operation within 72 hours from onset of dissection and the control aortic samples （n=21） were taken from the donar hearts were investigated by hematoxylin-eosin（H-E） and Mallory staining. The immunohistochemical staining of MMP-2 and TIMP-2 was carried out for all aortic samples and semiquantified by staining intensity analysis. Results： The medial layer of the dissected aortic wall demonstrated degenarative pathologies. The elastic lamella were often exhibited fragmentation and disruption in dissected group and the number of vascular smooth muscle cells decreased significantly compared with the control group. The expression of MMP-2 and TIMP-2 was mainly in the cytoplasm of vascular smooth muscle cells. The expression of TIMP-2 increased significantly （P〈0.05） in the dissected group compared with the control group. There was no difference in the expression of MMP-2 between the two groups（P〉0.05）. Conclusion：The increased expression of TIMP-2 and unchanged expression of MMP-2 might account for the occurrence of acute AAD and indicate the tissue remodelling occurred in the dissected aortic wall.