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-kappaB mediated expression of these genes involved in the inflammatory response of endothelial cells to tumor necrosis factor-alpha, 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-kappaB to its specific cis element effectively. In addition, we transfected the reporter gene chloramphenicol acetyltransferase driven by three repeated nuclear factor-kappaB 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-kappaB decoy oligodeoxynucleotides, but not by transfection of scrambled oligodeoxynucleotides. Also nuclear factor-kappaB decoy oligodeoxynucleotides but not scrambled oligodeoxynucleotides inhibited tumor necrosis factor-induced 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-kappaB decoy oligodeoxynucleotides transfected by cationic liposome method inhibited tumor necrosis factor--induced expression of interleukin-6 and intracellular adhesion molecule-1 in endothelial cells.