NF-kappa B-dependent fractalkine induction in rat aortic endothelial cellsstimulated by IL-1 beta, TNF-alpha, and LPS

Fractalkine is an endothelial cell-derived CX3C chemokine that is chemotact ic mainly to mononuclear cells. Fractalkine was induced in rat aortic endot helial cells (RAEC) by interleukin-1 beta (IL-1 beta), tumor necrosis facto r alpha (TNF-alpha), and lipopolysaccharide (LPS) transcriptionally and tra nslationally, This induction correlated with increased NF-kappa B DNA bindi ng activity as determined by gel mobility shift assay. Supershift assays re vealed that the NF-kappa B subunits p50 and p65 were responsible for kappa B binding. Accordingly, we examined the role of NF-kappa B in fractalkine i nduction in RAEC through the use of an adenovirus-mediated mutant I kappa B as a specific inhibitor. Delivery of a dominant-negative form of I kappa B alpha in RAEC dramatically reduced the induction of fractalkine by these s timuli, suggesting a role for NF-kappa B activation in fractalkine inductio n. The inhibition of fractalkine expression by two potent NF-kappa B inhibi tors, sulfasalazine and sanguinarine, further supported the central role of NF-kappa B in fractalkine transcription regulation and suggested a novel t herapeutic target aimed at modulating leukocyte endothelial cell interactio n.