Increase in Surface Expression of ICAM-1, VCAM-1 and E-Selectin in Human Cerebromicrovascular Endothelial Cells Subjected to Ischemia-Like Insults

Summary

Secondary ischemic brain injury has been shown to develop as a consequence of inflammation and vasogenic brain edema. In this study we show that inflammatory cytokines and simulated in vitro ischemia stimulate the surface expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and endothelial-leukocyte adhesion molecule-1 (E-selectin) in human cerebromicrovascular endothelial cells (HCEC) in culture. The levels of all three adhesion molecules were dramatically (3 to 10-fold) up-regulated by 4–24 hour exposure to the inflammatory cytokines, IL-1β (10–200 u/ml) or TNFα (50–200 u/ml), and by a 4 hour exposure to “simulated” in vitro ischemia, as determined by immunocytochemistry and ELISA. Following 24 hours of subsequent reperfusion, the expression of ICAM-1 and VCAM-1 was maintained at ischemia-induced levels, whereas E-selectin was no longer detectable. Both the cytokine- and ischemia-induced up-regulation of adhesion molecules were completely abolished by the transcriptional inhibitor, actinomycin D (10 µg/ml), and inhibited by the cycloxygenase (COX) inhibitor, indomethacin (300 µM). These findings implicate HCEC in the processes of leukocyte adhesion and recruitment in the brain durin stroke in vivo.