Vascular endothelial growth factor and matrix metalloproteinase 9 expression in human carotid atherosclerotic plaques: relationship with plaque destabilization via neovascularization

BACKGROUND: The aim of this study was to evaluate the potential impact of vascular endothelial growth factor (VEGF) on carotid plaque destabilization in association with matrix metalloproteinase 9 (MMP-9) production. METHODS: Expression of VEGF and MMP-9 were determined immunohistochemically in 53 human endarterectomized atherosclerotic carotid plaques. The relationship to carotid plaque characteristics, clinical data and histological morphology was investigated. RESULTS: VEGF and MMP-9 had parallel overexpression in the inflammatory cells, especially in the neovascularized plaque lesions and around the cholesterol crystals. Strong expression of VEGF was evident in symptomatic patients (p < 0.057), in high-degree stenosis (p = 0.005), and in patients with ischemic infarct in brain scan (p = 0.021). No relation was proved between molecule expression and plaque ultrasonic characteristics. CONCLUSIONS: An intense expression of VEGF and MMP-9 in carotid plaques is related to plaque instability, high degree of stenosis and presence of symptomatic carotid occlusive disease.