Role of NF-κB on liver cold ischemia-reperfusion injury

The role of NF-κB, the rapid-response transcription factor for multiple genes, in cold ischemia-reperfusion (I/R) injury was examined after syngeneic transplantation of liver grafts. Lewis rat recipients were killed 1-48 h after reperfusion of three different liver grafts: 1) uninfected control, 2) infected ex vivo with control adenoviral vector (AdEGFP), and 3) infected ex vivo with AdIκB. In uninfected control livers, NF-κB was activated biphasically at 1-3 and 12 h after reperfusion with aspartate transaminase (AST) levels of 4,244 ± 691 IU/l. The first peak of NF-κB activation associated with an increase of mRNA for TNF-α, IL-1β, and IL-10. AdEGFP transfection resulted in similar outcomes. Interestingly, AdIκB-transfected liver grafts suffered more severe I/R injury (AST <9,000 IU/l). Transfected IκB was detected in transplanted livers as early as 6 h, and this correlated with the abrogation of the second, but not the first, peak of NF-κB activation at 12-48 h and increased apoptosis. Thus inhibition of the second wave of NF-κB activation in IκB-transfected livers resulted in an increase of liver injury, suggesting that NF-κB may have a dual role during liver I/R injury.