Suppression of inducible nitric oxide synthase by 10–23 DNAzymes in murine macrophage

iNOS mRNA of J774 murine macrophage cells was cleaved by 10–23 DNAzymes. DNAzyme target site I or translation initiation site and site II have computer predicted (MFOLD) secondary structures but site III has no secondary structure. All the three DNAzymes cleaved the short transcripts generated from cloned DNA almost with equal efficiency while cleavage efficiency is higher at site III than the other two sites on isolated iNOS mRNA. Interestingly, at intracellular level, DNAzyme targeted at translation initiation codon (site I) having secondary structure cleaved iNOS mRNA, and suppressed its activity and protein expression more efficiently than that targeted at sites II and III.