Expression of endothelial cell adhesion molecules in neovascularized tissue

Objective: Recent studies indicate that endothelial cells of newly formed b lood vessels are activated and exhibit a distinct phenotype that may influe nce the responses of these microvessels to an inflammatory stimulus. The ob jective of this study was to compare that basal and cytokine-stimulated exp ression of endothelial cell adhesion molecules in neovascularized tissue to normal (nonproliferating) vascular beds. Methods: The expression of P- and E-selectin. VCAM-1, ICAM-1, ICAM-2 nad PE CAM-1 was measured, using the dual radiolabeled mAb technique, in subcutane ously implanted (for 10-15 days) polyurethane sponges, skin, heart, lung, a nd intestine of male G57BL/6 mice (background). Results: Basal values of PECAM-1 and ICAM-2 revealed a low vascular density in the implanted sponge are (PECAM-1 or ICAM-1 expression), the basal leve l of E- and P-selectin expression was highest in neovascularized sponge and skin. TNF-alpha elicited an increased expression of all endothelial CAMs, except PECAM-1 and ICAM-2, but the responses were blunted in sponge and ski n, relative to other vascular beds. Conclusions: These findings indicate that endothelial cells in newly formed blood vessels exhibit a pattern of basal and cytokine-induced expression o f certain adhesion glycoproteins that is similar to nonproliferating cutane ous vessels.