Cyclic strain enhances adhesion of monocytes to endothelial cells by increasing intercellular adhesion molecule-1 expression.
Since endothelial cells are constantly subjected to pressure-induced strain, we examined how cyclic strain affects the expression of intercellular adhesion molecule-1 (ICAM-1). Endothelial cells grown on a flexible membrane base were deformed by different sinusoidal negative pressures (-10, -15, or -20 kPa) to produce an average strain of 9%, 11%, and 12%, respectively, for various times. The release of the soluble form of ICAM-1 from strained endothelial cells increased in a time- and strain-dependent manner. Using flow cytometric analysis, we showed the induction of ICAM-1 expression on the endothelial cell surface to depend on both time and the amount of strain. Northern blot analysis revealed a sustained, approximately 1.8-fold increase in ICAM-1 mRNA levels in 11% strained cells. Strain-induced expression of ICAM-1 correlated with a strain-dependent increase in adhesion of monocytic cells to strained cells. This increase in monocytic cell adhesion could be partially inhibited by pretreatment of strained cells with antibody to ICAM-1. These results indicate that mechanical strain can stimulate the expression of ICAM-1 by endothelial cells and thus contribute to the increased adhesion of monocytes to strained cells. Such strain-induced expression of ICAM-1 may contribute to the trapping of monocytes on local vascular walls where strain is high and to the initiation of atherogenesis, thus providing a possible link between hypertension and atherogenesis.
Cheng
J J
JJ
Cardiovascular Division, Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, ROC.
Wung
B S
BS
Chao
Y J
YJ
Wang
D L
DL
D002448:Cell Adhesion / Q000502:physiology; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology / Q000502:physiology*; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism*; D009000:Monocytes / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D012995:Solubility; D013314:Stress, Mechanical
D012333:RNA, Messenger; D018799:Intercellular Adhesion Molecule-1