Effect of selenium supplementation in asthmatic subjects on the expressionof endothelial cell adhesion molecules in culture

Endothelial cells play a major role in immunologic reactions, in which cell ular adhesion molecules P-selectin, ICAM-1, VCAM-1, and ELAM-1 are importan t mediators in the recruitment of leukocytes in pulmonary inflammation. Sel enium (Se) is known to modulate immunological mechanisms of asthma. The aim of our investigation was to examine whether Se supplementation in cortico- dependent asthmatic patients may modulate adhesion molecule expression in c ultured endothelium. Our findings indicated that P-selectin, VCAM-1, and EL AM-1 expression on human umbilical vein endothelial cells stimulated with p eripheral blood mononuclear cells obtained from asthmatics before supplemen tation with Se was significantly higher than from healthy donors (p < 0.05) . The production of ICAM-1 showed only slight augmentation. The levels of V CAM-1 and ELAM-1 expression were significantly decreased after 3 mo of Se s upplementation (p < 0.05). After 6 mo of intervention period the intensity of P-selectin and ICAM-1 expression was also significantly reduced (p < 0.0 5 and p < 0.01, respectively). The inhibitory effect of Se on the adhesion molecule expression was studied in cultured endothelial cells after interfe ron-gamma stimulation. Our data suggest that Se affects the expression of P -selectin, ICAM-1, VCAM-1, and ELAM-1 in a dose-dependent manner and the ha lf-maximal inhibitory concentrations were 3.4, 0.5, 4, and 3.8 mu g/mL, res pectively. The maximal inhibitions (greater than 80%) were observed in vitr o with 10 mu g/mL Se (p < 0.01). Regulation of adhesion molecule expression may be an important mechanism through which the inflammation may be contro lled.