Transcriptional regulation of NF-kappaB by ring type decoy oligodeoxynucleotide in an animal model of nephropathy.

Inflammation of the tubulointerstitial compartment, leading to fibrosis, is a major factor in the progressive loss of renal function in a wide variety of kidney diseases. In order to develop a therapeutic approach for nephropathy, we examined the simultaneous inhibition of transcription factor nuclear factor-kappaB (NF-kappaB), which is responsible for a wide range of cellular processes, especially inflammation, in a mouse model of unilateral ureteral obstruction. In this study, we employed a ring-type NF-kappaB (R-NF-kappaB) decoy oligodeoxynucleotide (ODN), containing consensus promoter sequences of NF-kappaB. This R-NF-kappaB decoy ODN is more highly resistant to degradation by nucleases than is the current phosphothiolated double stranded NF-kappaB decoy ODN. The inhibitory effect of R-NF-kappaB decoy ODN on nephropathy was confirmed by molecular and histological examinations. In addition, treatment with R-NF-kappaB decoy ODN reduced the activities of inflammatory cytokines, such as tumor necrosis factor-alpha and interleukin-1beta. Interestingly, the treatment with R-NF-kappaB decoy ODN also suppressed the gene expression of transforming growth factor-beta1 and fibronectin, resulting in the inhibition of fibrotic changes. These results suggest that the inhibition of NF-kappaB using R-NF-kappaB decoy ODN has potential therapeutic application in the prevention of renal fibrosis.