HO-1 and VGEF gene expression in human arteries with advanced atherosclerosis

Objectives: Both heme oxygenase-1 (HO-1) and vascular endothelial growth factor (VEGF) have been shown to be involved in the progression of atherosclerosis. The relationship between HO-1 and VEGF gene expression and their proteins in endothelial cells from human atherosclerotic arterial specimens was investigated. Design and Methods: The study included seventeen human arterial specimens with early and six specimens with advanced atherosclerotic lesions. Ten specimens were obtained from healthy young adults undergoing arterial reconstruction for trauma and were considered as non-atherosclerotic control. HO-1 and VEGF expressions as well as HO activity and VEGF protein content were measured in isolated endothelial cells (ECs). Results: HO-1 expression and activity (5.3±2.1 nmol bilirubin/mg protein/h) were only present in ECs from advanced atherosclerotic lesions. VEGF expression was more strongly expressed in ECs from advanced lesion compared with early lesions and was absent in healthy arteries. VEGF protein (1.35±0.69 ng/mg) was only detected in advanced lesions. A significant positive correlation (r=0.9, p<0.01) exists between HO activity and VEGF protein content in ECs of advanced lesions. Conclusions: This study demonstrated that HO-1 expression and activity in ECs are present only in advanced atherosclerosis whereas, VEGF expression is present in early as well as in advanced atherosclerosis and the degree of its expression increases with severity of atherosclerosis. This study suggests an association between HO activity and VEGF protein in human ECs from advanced atherosclerotic lesions.