ACTIVATION OF ICAM-1 PROMOTER BY LYSOPHOSPHATIDYLCHOLINE - POSSIBLE INVOLVEMENT OF PROTEIN-TYROSINE KINASES

Lysophosphatidylcholine (lyse-PC) selectively upregulates the mRNA lev el of intercellular adhesion molecule-1 (ICAM-1) but not that of vascu lar cell adhesion molecule-1 (VCAM-1) in cultured human umbilical vein endothelial cells. Transfection studies show that lyse-PC activates t he ICAM-1 promoter but not the VCAM-1 promoter. Gel mobility shift ass ays document an increase in NF-kappa B binding in cells treated with l yse-PC. The increases of ICAM-1 mRNA and NF-kappa B binding were inhib ited by the protein tyrosine kinase inhibitors, genistein and lavendus tin A, but not by inhibitors for cyclic AMP-dependent protein kinases or protein kinase C. Our results suggest that lyse-PC induces ICAM-1 e xpression most likely by activating NF-kappa B, and that the effect ap pears to be protein tyrosine kinase-dependent.