Local administration of transcription factor decoy oligonucleotides to nuclear factor-kB prevents carrageenin-induced inflammation in rat hind paw.

The transcription factor nuclear factor-kB (NF-kB) plays a key role in the expression of several genes involved in the inflammatory process. In the present study we investigated in an acute model of inflammation, the carrageenin-induced hind paw edema, the anti-inflammatory effect of double stranded oligodeoxynucleotides (ODN) with consensus nuclear factor-kB (NF-kB) sequence as transcription factor decoys (TFD) to inhibit NF-kB binding to native DNA sites. Local administration of wild-type, but not mutant-ODN decoy, dose-dependently inhibited edema formation induced by carrageenin in rat paw. Molecular analysis performed on soft tissue obtained from inflamed paw demonstrated: (1) aninhibition of NF-kB DNA binding activity; (2) a decreased nuclear level of p50 and p65 NF-kB subunits; (3) an inhibition of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) protein expression, two inflammatory enzymes transcriptionally controlled by NF-kB. Furthermore, SN-50, a cell-permeable peptide capable of inhibiting the nuclear translocation of NF-kB complexes, exhibited a similar profile of activity of ODN decoy. Our results indicate for the first time that ODN decoy, acting as an in vivo competitor for the transcription factor’s ability to bind to cognate recognition sequence, may represent a novel strategy to modulate acute inflammation.