Transcription factor decoy for nuclear factor-κB inhibits tumor necrosis factor-α-induced expression of interleukin-6 and intracellular adhesion molecule-1 in endothelial cells

Abstract

Background Several cytokines and adhesion molecules released from endothelium play an important role in inflammation, immune responses, and probably atherogenesis. Objective To determine whether the transcription factor nuclear factor-κB mediated expression of these genes involved in the inflammatory response of endothelial cells to tumor necrosis factor-α, by using transcription factor decoy oligodeoxynucleotides. Design and methods We first transfected fluorescein isothiocyanate (FITC)-labeled double-stranded oligodeoxynucleotides into endothelial cells by a cationic liposome-mediated method of gene transfer. We then confirmed that the decoy oligodeoxynucleotides could block binding of nuclear factor-κB to its specific cis element effectively. In addition, we transfected the reporter gene chloramphenicol acetyltransferase driven by three repeated nuclear factor-κB binding sequences in the promoter and enhancer region. Results FITC-labeled oligodeoxynucleotides were detected in the nuclei of approximately 70% of the total cells. Tumor necrosis factor—stimulated expression of chloramphenicol acetyltransferase was partially inhibited by transfection of nuclear factor-κB decoy oligodeoxynucleotides, but not by transfection of scrambled oligodeoxynucleotides. Also nuclear factor-κB decoy oligodeoxynucleotides but not scrambled oligodeoxynucleotides inhibited tumor necrosis factorinduced expression of interleukin-6 and intracellular adhesion molecule-1 both at the messenger RNA and at protein level (assessed by reverse transcription—polymerase chain reaction and enzyme-linked immunosorbent assay). Conclusion Our results demonstrate that nuclear factor-κB decoy oligodeoxynucleotides transfected by cationic liposome method inhibited tumor necrosis factor —induced expression of interleukin-6 and intracellular adhesion molecule-1 in endothelial cells.