组织蛋白酶B及其抑制剂Cystatin C在人腹主动脉瘤平滑肌细胞中的表达

目的 观察组织蛋白酶B及其抑制剂Cystatin C在人腹主动脉瘤平滑肌细胞中的表达情况,以探讨其在腹主动脉瘤发生发展中的作用.方法 对21例腹主动脉瘤患者和8例正常腹主动脉尸检者的腹主动脉血管标本行苏木精-伊红染色和免疫组织化学染色,观察组织蛋白酶B及其抑制剂Cystatin C对血管中膜的影响.结果 免疫组织化学染色可见组织蛋白酶B和Cystatin C分别在腹主动脉瘤、正常腹主动脉中免疫反应阳性,阳性定位于平滑肌细胞质;腹主动脉瘤平滑肌细胞中组织蛋白酶B阳性细胞平均光密度值明显增高,Cystatin C明显降低,与正常腹主动脉之间有显著差异(P<0.01).结论 腹主动脉瘤平滑肌细胞中组织蛋白酶B表达增强,Cystatin C表达下降,组织蛋白酶及其抑制剂Cystatin C间的不平衡可能引起动脉瘤壁细胞外基质广泛降解,从而导致腹主动脉瘤的发生和破裂.

Expressions of Cathepsin B and Cystatin C in Smooth Muscle Cells of Abdominal Aortic Aneurysms

Aim To study the expression and significance of cathepsin B and Cystatin C in vascular smooth muscle cells (VSMC) of patients with abdominal aortic aneurysms (AAA) and to investigate underlying roles in pathogenesis of AAA. Methods 21 cases of AAA and 8 cases of normal abdominal aortas were collected in this study. HE staining and immunohistochemical technique were used to evaluate the change of cathepsin B and Cystatin C in the media of AAA. Results Immune reaction of cathepsin B was positive in the AAA,and immune reaction of Cystatin C was positive in the normal abdominal aortas. The positive cells were mainly localized in the smooth muscle cell (SMC). Imagine analysis results showed that the MOD value of cathepsin B in SMC of AAA evidently increased,while Cystatin C evidently decreased. There were significant differences in cathepsin B and Cystatin C between the AAA and normal abdominal aortas. Conclusion The expression of cathepsin B promoted and expression of Cystatin C reduced in the SMC of AAA. An imbalance between cysteine cathepsins and their inhibitor may cause the excessive breakdown of extracellular matrix (ECM) in the arterial walls leading to the progression and rupture of AAA.