Purpose: Matrix metalloproteinases -2 and -9 (MMP-2 and MMP-9) are representatives of the group of gelatinases that have similar effect, resulting in the degradation of collagen type IV. MMP-2 and MMP-9 have a key role in the pathogenesis of atherosclerosis. The aim of the present study was to determine the extent of the immunohistochemical expression of MMP-2 and MMP-9 in the vascular wall of the abdominal aorta in patients with atherosclerotic changes.
Methods: We investigated by immunohistochemistry (polyclonal antibodies,class IgG, Santa Cruz Biotechnology, USA) the expressional changes of MMP-2 and MMP-9 in abdominal aorta obtained from autopsied cases. We used 5 nonatherosclerotic (control group - G1) and 20 atherosclerotic segments (group - G2) from human abdominal aorta. These arteries were colected at autopsy from 25 cases within 5 hours of death.
Results: In the nonatherosclerotic aorta MMP-2 and MMP-9 were expressed mainly in the endothelium and the smooth muscle cells (VSMC) of the vascular wall. The expression of MMP-2 and MMP-9 was significantly increased (p<0.05) in the atheromatous plaques of atherosclerotic abdominal aorta in comparison with nonatherosclerotic.
Conclusions: The increased expression of MMP-2 and MMP-9 in the atheromatous plaques of the atherosclerotic abdominal aorta (G2) confirms the theory that MMP-2 and MMP-9 are leading factors in the destabilization of the atheromatous plaque through interaction with proinflammatory cytokines.