In vivo transfection of nuclear factor κB decoy protects pulmonary function against acute lung contusion in rabbits

Regulation of activity of transcription factor NF-κB by synthetic oligonucleotides

Eukaryotic dimeric nuclear factor-κB (NF-κB) is one of the main transcription factors that activate expression of genes, products of which play the key role in development of cardiovascular pathologies, carcinogenesis, and inflammatory and viral diseases. In this review, the main attention is given to modulation of the transcription factor NF-κB activity by antisense oligonucleotides and oligonucleotide decoys. Also, current concepts about interactions between NF-κB dimers and DNA and general problems that arise in experimental use of synthetic oligonucleotides in vivo are discussed.

Knockdown of myeloid differentiation protein-2 reduces acute lung injury following orthotopic autologous liver transplantation in a rat model

BACKGROUND

Acute lung injury (ALI) is a serious complication that commonly occurs during orthotopic liver transplantation (OLT). Toll-like receptor 2/4 (TLR2/4) are the main membrane receptors that respond to inflammatory stimuli and mediate NF-kappa B (NF-κB) signal pathway. We previously showed that TLR2/4 expression on monocytes and serum cytokine levels were increased in patients with ALI induced by OLT. Myeloid differentiation protein-2 (MD-2) expresses the functional domains that combines TLRs and play a key regulatory role in TLRs activation. Therefore, we hypothesized that blocking MD-2 would inhibit the TLR2/4-mediated inflammatory response and lessen ALI induced by liver transplantation.

METHOD

Thirty-two Sprague Dawley (SD) rats were randomly divided into four groups. One group received a sham operation (Group S), and the other three groups underwent orthotopic autologous liver transplantation (OALT) 48 h after intratracheal administration of saline (Model group; Group M), non-targeting siRNA (negative siRNA control group; Group NC) or siRNA against MD-2 (intervention group; Group RNAi). Lung pathology, lung water content, PaO2, and expression levels of MD-2, TLR2/4, NF-κB, TNF-α, IL-1β and IL-6 were assessed 8 h after OALT.

RESULTS

In Groups M and NC, OALT produced marked lung pathology with decreased PaO2 levels and increased MD-2, TLR2/4 gene and protein expression levels. Furthermore, the nuclear translocation of the NF-κB P65 subunit, was increased, as were lung concentrations of TNF-α, IL-1β and IL-6. The pathology of ALI and the severity of the above biochemical changes induced by OALT were significantly reduced in the group treated with MD-2 siRNA.

CONCLUSION

MD-2 gene knock-down attenuated the increase in TLR2/4 activation and reduced ALI after OALT.