Expression And Clinical Significance Of MMP-2/MMP-9and Timp-1in Intracranial Saccular Aneurysms

ObjectiveTo explore the pathogenesis and clinical significance of intracranial saccular aneurysms through the comparison of intracranial saccular aneurysmal wall expression of MMP-2, MMP-9and TIMP-1and that of normal arterial wall.Methods35intracranial saccular aneurismal specimens were resected after microsurgical clipping of aneurysm neck. Meanwhile, we collect31samples of ipsilateral transectioned meningeal or superficial temporal artery branch vessel as control. Then we observe the pathological changes by hemotoxylin and eosin (HE) staining technique under light microscope. We detect the expression of MMP-2/MMP-9and TIMP-1in samples by immunohistochemistry technique, Statistical analysis of MMP-2, MMP-9and TIMP-1expression in the experimental group and control group, according to the size of aneurysms.ResultsThe vessel wall in the control group shows pink, good elasticity and its structure is clear and tight. Meanwhile some acquired regressive characteristic changes such as endothelial cells arranged in loose and damage、elastic fiber atrophy and fracture、atherosclerosis、infiltration of inflammatory cells etc pathological changes were detected in the intracranial saccular aneurysms walls. The positive expression rate of MMP-2, MMP-9and TIMP-1in the experimental group were85.71%,82.86%and80.00%, with significantly higher than that of the31cases of normal control group positive expression rate were6.45%,9.68%and12.90%. We compare the positive expression rate between the two groups statistical significance (P<0.05). The strong positive expression rate of MMP-2and MMP-9in the large intracranial aneurysms were77.78%and88.89%, with significantly higher than that of the normal control group strong positive expression rate were30.77%and38.46%. The strong positive expression rate between the two groups is statistically significant (P<0.05). The strong positive expression rate of TIMP-1in the large aneurysms wall and the ordinary aneurysms were66.67%and38.46%. The strong positive expression rate of TIMP-1between the two groups is not statistically significant (P=0.245). Still can not confirm that the positive expression rate of TIMP-1between in the large aneurysms group and the ordinary aneurysms group (P>0.05).Conclusion1.The pathological features of intracranial aneurysms are structural damages of the blood vessel wall, and infiltration of inflammatory cells. 2.The higher expression of MMP-2,MMP-9and TIMP-1in the intracranial aneurysm walls indicated that MMP-2, MMP-9and TIMP-1may involve aneurysm formation.3.The strong positive expression rate of MMP-2and MMP-9in the group of large aneurysms is greater than the ordinary aneurysm group, indicating MMP-2and MMP-9may play an important role in the growth of the aneurysm and its rupture.4.The strong positive expression rate of TIMP-1between in the group of large aneurysms and the ordinary aneurysm group have no difference, indicating that the imbalance of MMP-2,MMP-9and TIMP-1is likely to play an important role in aneurysm formation, development and even rupture.5.In this study, to take the aneurysm in patients with ipsilateral superficial temporal or middle meningeal artery branch vessels as normal blood vessels in the control group get above findings, indicated that aneurysm development may not be systemic but local vascular wall expression of MMP-2, MMP-9and TIMP-1in the disorders.