EXPRESSION OF INTERCELLULAR-ADHESION-MOLECULES-1 (ICAM-1) VIA AN OSMOTIC EFFECT IN HUMAN UMBILICAL VEIN ENDOTHELIAL-CELLS EXPOSED TO HIGH GLUCOSE MEDIUM

To clarify the etiology of accelerated atherosclerosis in patients wit h diabetes mellitus, we measured expression of intercellular adhesion molecule 1 (ICAM-1), vascular cellular adhesion molecule 1 (VCAM-1), a nd E-selectin on the cell surface by enzyme-linked immunosorbent assay and ICAM-1 mRNA content in human umbilical vein endothelial cells exp osed to 5.5 mM glucose (NG), 33 mM glucose (HG), or 27.5 mM mannitol p lus 5.5 mM glucose (HM). 1) Cell-surface ICAM-1 expression in HG and H M cells was maximally increased by 37% and 32% (P < 0.01), respectivel y. This effect was dependent on glucose concentration in the medium an d was found as early as 24 h and maintained until 6 days after exposin g cells to HG. How ever, neither VCAM-1 nor E-selectin expression were affected by HG conditions. 2) Both HG and HM induced increased mRNA c ontent between 6 and 12 h after the stimulation. 3) Adhesion of THP-1 cells to endothelial cells exposed to HG and HM as increased, when com pared to NG conditions. These results indicate that osmotic effects ca n induce increased mRNA and cell-surface expression of ICAM-1 via an a s yet unknown mechanism.