基质金属蛋白酶9在胸主动脉瘤和胸主动脉夹层中的表达

Expression of matrix metalloproteinase-9 in thoracic aortic dissection and aneurysm

目的观察基质金属蛋白酶（MMP）-9在DebakeyⅠ型胸主动脉夹层（TAD）和胸主动脉瘤（TAA）中的表达，探讨其在TAD和TAA中的作用。方法苏木素-伊红（HE）染色、铁苏木素染色、TUNEL染色、免疫组织化学染色分别观察11例TAD和10例TAA的病理特征、弹力纤维断裂、管壁细胞凋亡、MMP-9在动脉管壁中的表达和定位，并分析MMP-9表达与各项临床参数的关系。结果MMP-9在TAD和TAA中高表达（P〈0．05），主要位于中外膜平滑肌细胞和炎性细胞，MMP-9表达与主动脉直径显著相关（P〈0．05）。结论MMP-9在TAD和TAA中高表达，中外膜平滑肌细胞和炎性细胞是其主要表达细胞；MMP-9可能通过弹力板层的破坏来影响管壁重构过程。

Objective To investigate the MMP-9 expression and localization in Debakey type I thoracic aortic dissection （TAD） and thoracic aortic aneurysm （TAA） and their possible roles in TAD and TAA. Methods Histological examination and immunohistochemistry were performed to detect the expression and localization of MMP-9 in dissected and dilated thoracic aortas and normal controls. Hematoxylin staining was used to investigate the fragmentation of elastic fibers. TUNEL staining was used to detect the apoptosis of smooth muscle cells （SMCs） and inflammatory cells in thoracic aortas. The correlation between the MMP-9 expression and some clinical parameters such as age, hypertension, smoking, course of disease,diameter of artery was analyzed. Results Immunohistochemistry showed that MMP-9 was expressed in TAD and TAA （P 〈 0.05 ） , but scarcely expressed in normal controls. MMP-9 mainly localized in the SMCs and inflammatory cells of the media and adventitia. There was a significant correlation between the MMP-9 expression and diameter of artery （ P 〈 0.05 ）. Conclusion Increased MMP-9 expression appeared in TAD and TAA. SMCs and inflammatory cells were the main cellular resource. MMP-9 may play an important role in TAD and TAA through some mechanisms such as fragmentation of elastic fibers.