The Study On The Relationship Between The Expression Of The Matrix Metalloproteinases-2 And Matrix Metalloproteinases-9 In Intracranial Aneurysm

Objectives: Through the observation of the cerebral aneurysms wall pathology change, the thesis seeks to detect the expression of matrix metalloproteinases (MMP– 2 and MMP– 9) in the cerebral aneurysm wall and to explore whether there exists any relationship between the expressions and clinical characteristics. This study aims to provide clues for the etiology research of the emergence, growth and rupture mechanism of cerebral aneurysms.Methord: The test group includes 17 surgical specimens of human cerebral aneurysms after the craniotomy surgery of clipping the aneurysm in the craniotomy in the Hospital Two of Hebei Province. The control group comprises the five normal hematoma specimens from hematoma removal and the patients are proven not suffering from a vascular disease by CTA or MRI. All the above specimens are obtained with the guarantee of protecting the patient and operation safety. All the specimens are soaked in 10% formalin solution within 24 hours after the operation for further pathological examination. Under the general macroscopic observation, under the light microscopy with the H&E staining and immunohistochemical MMP– 2 and MMP– 9 staining, this thesis attempts to detect the aneurysms wall and the normal blood vessel walls MMP– 2 and MMP– 9 staining and their expressive place and degree, to combine the pathological feature and clinical characteristics, to do the statistical analysis of the relationship between the expression of the MMP– 2 and MMP– 9 and the age, sex of the patients, the size of the aneurysm and the Hunt– Hess classification.Results:1 under the general macroscopic observationFive cases are all in normal superficial temporoparietal artery with grey pink color and moderate elastic texture. Among 17 cases, most of them appear with dark purple or mauve aneurysm specimens, some of them with the yellow tumor wall. The texture of the specimen is tough and elastic. The inner wall of them is with the attachment of thrombus composition or atherosclerotic plaque adhesion. Aneurysm wall specimens are with thickness asymmetry, a part of them with thin wall, especially on the top. Some walls of the tumors have broken down, some only with a thin layer of transparent tissue.2 under the H&E Staining light microscopyThe control group appears with normal layer structure and without the obvious inflammatory cells infiltrating. Aneurysm tumor wall in the test group have mostly lost the normal three layer structure; the endometrium is becoming thinner or is left only with a layer of endothelial cells, some even disappear completely. The smooth muscle layer of the middle becomes atrophic and turns thinner,the abundant fibroblast fill in it,some of them with visible mucoid degeneration. The tissues of the outer membrane stay loose. The middle and outer membrane is visible with large inflammatory cells infiltrating. The partial aneurysms wall appears with the disorderly distribution of collage. Partial tumor wall is visible with collagen composition desultorily distribution. Most of the tube of intracranial aneurysm attaches with thrombus.3 Immunohistochemical resultsThe positive expression of the MMP-2 and MMP-9 shows that the cytoplasm is tan-yellow or dark brown. The blood vessel walls of the control group have no obvious MMP– 2 and MMP - 9. The inner membrane, media and out membrane in the test group shows the positive expression, the degree of the expression of the outer and middle membrane is higher than that of the inner membrane. The expressive place concentrates on the area of the endothelial cells, macrophages, smooth muscle cells and inflammatory cells. The positive expression rates of the MMP– 2 and MMP - 9 in the test group are respectively 88.24%(15/17)and 6.67%(1/15), and that in the control group respectively 82.35% (14/17) and 13.33%(2/15). The positive expression rate of cerebral aneurysms wall MMP– 2 and MMP– 9 is significantly higher than that of the normal arterial wall. With the SPSS13.0 statistical analysis, the expression differences between the test group and the control group have statistical significance (P < 0.05).Conclusion:1 The main pathological change in the aneurysms wall is the severe damage of the matrix structure, at the same time with different degree of inflammatory reaction. The endodermis of the aneurysms wall is becoming thin; the cells of the smooth muscle of the middle are decreasing, the muscular layer becomes atrophic with mucoid degeneration; the middle and outer membrane are in different degree of inflammatory cells infiltrating, among them macrophages are the main parts. The partial aneurysm walls are accompanied with atherosclerosis and with the disorderly distribution of collage. The tube of intracranial aneurysm attaches with thrombus, which displays that possibly the formation of the intracranial aneurysm is connected with the acquired degenerative disease.2 MMP– 2 and MMP– 9 appear with positive expression in each layer of aneurysm wall, mainly in the middle and outer membrane. The positive expression rate of MMP– 2 and MMP– 9 in the walls of intracranial aneurysm is obviously higher than that of the group with normal cerebral artery, which shows that they may be involved in the formation of intracranial aneurysm and its rupture.3 MMP– 2 and MMP– 9 play an important role in the pathogenesis of intracranial aneurysm, the inhibition of their high expression could be effective in reducing its emergence and development and provide a new direction in the treatment for the intracranial aneurysm.