Role of Vascular Endothelial Growth Factor in Atherosclerotic Carotid Plaques

Mechanism of atherosclerotic carotid stenosis has not been fully elucidated. Intraplaque hemorrhage is supposed to play an important role in the progression of carotid stenosis and ischemic event. Expression of Vascular Endothelial Growth Factor (VEGF) is related to atherosclerosis. The purpose of this study is to elucidate the role of VEGF in atherosclerotic carotid plaques. We analyzed the expression of VEGF in atherosclerotic carotid plaques obtained at carotid endarterectomy for symptomatic carotid stenosis. Both Immunohistochemical and immunoblotting methods using anti-VEGF antibody were employed. In addition, the correlation between VEGF expression and plaque pathology was examined. Our study showed a high level of VEGF immunoreactivity in carotid plaques with distinct expression of VEGF in foam cells infiltrating carotid plaques. The statistical analyses revealed that the numbers of VEGF expressive cells per unit area in the intimal deep portions of carotid plaques were significantly larger than those in the intimal superficial portions (P<0.01). In addition, it was suggested that the VEGF expression was related to intraplaque hemorrhage. In conclusions, VEGF expression is induced in the deep portion of the atherosclerotic carotid plaques. It may play an important role in induction of intraplaque hemorrhage causing ischemic stroke