NF-κB-dependent fractalkine induction in rat aortic endothelial cells stimulated by IL-1β, TNF-α, and LPS

Fractalkine is an endothelial cell-derived CX3C chemokine that is chemotactic mainly to mononuclear cells. Fractalkine was induced in rat aortic endothelial cells (RAEC) by interleukin-1 beta (IL-1 beta), tumor necrosis factor alpha (TNF-alpha), and lipopolysaccharide (LPS) transcriptionally and translationally, This induction correlated with increased NF-kappa B DNA binding activity as determined by gel mobility shift assay. Supershift assays revealed 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 induction 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 stimuli, suggesting a role for NF-kappa B activation in fractalkine induction. The inhibition of fractalkine expression by two potent NF-kappa B inhibitors, sulfasalazine and sanguinarine, further supported the central role of NF-kappa B in fractalkine transcription regulation and suggested a novel therapeutic target aimed at modulating leukocyte endothelial cell interaction.