Selective inhibition of E-selectin, ICAM-1, and VCAM in endothelial cells.

Abstract

Endothelial cells, as they normally exist in the vasculature as quiescent cells, perform several functions. In an inflammatory response, endothelial cells are activated to up-regulate a number of genes, including E-selectin (ELAM-1), VCAM-1, ICAM-1, interleukin (IL)-1, IL-8 and plasminogen activator inhibitor-1 (PAI-1). Very little is known about factors that regulate the activation process. We describe here that a heat-stable protein, normally present in the alpha-globulin fraction of serum, inhibits induced expression of E-selectin, ICAM-1, and VCAM-1 in vitro and also impedes the accumulation of mRNA for these molecules. Inhibition of E-selectin, the only gene tested in this respect, is at the level of transcription. At the same time, the alpha-globulins do not, under the same conditions, repress mRNA accumulation for IL-1, IL-8, or PAI-1. The effect of the inhibitor does not relate to constraints on function of nuclear-factor kappa B, the induced activity of which is not interfered with at the early time points at which the suppression of these three genes is seen.