D. Hallahan et al., E-SELECTIN GENE INDUCTION BY IONIZING-RADIATION IS INDEPENDENT OF CYTOKINE INDUCTION, Biochemical and biophysical research communications, 217(3), 1995, pp. 784-795
The mechanism of the x-ray-mediated inflammatory response in normal ti
ssues is unknown. To determine whether leukocyte infiltration into irr
adiated tissue is regulated by adhesion molecule expression, we quanti
fied the synthesis of glycoproteins that participate in inflammation,
We found that E-selectin is synthesized in a time-dependent manner fol
lowing exposure to doses as low as 0.5 Gy, Northern blot analysis demo
nstrated that E-selectin mRNA expression increased at 2 h after x-irra
diation and increased expression required no de novo protein synthesis
, Transcription of the promoter region of E-selectin (-578 to +35) was
transiently induced following x-irradiation, whereas deletion of the
NFkB binding site eliminated x-ray induction, Electrophoretic mobility
gel shift analysis confirmed increased binding of nuclear proteins fr
om irradiated endothelial cells to the NFkB binding sequence from the
E-selectin promoter, Nuclear protein binding to the NFkB binding seque
nce was altered by antibodies to the p50 and p65 components of NFkB, T
hese data demonstrate that E-selectin expression does not require cyto
kine synthesis, but involves NFkB activation. (C) 1995 Academic Press,
Inc.