Effect of heat shock preconditioning on NF-κB/I-κB pathway during I/R injury of the rat liver
Hepatic ischemia-reperfusion (I/R) injury continues to be a fatal complication after liver surgery. Heat shock (HS) preconditioning is an effective strategy for protecting the liver from I/R injury, but its exact mechanism is still unclear. Because the activation of nuclear factor-κB (NF-κB) is an important event in the hepatic I/R-induced inflammatory response, the effect of HS preconditioning on the pathway for NF-κB activation was investigated. In the control group, NF-κB was activated 60 min after reperfusion, but this activation was suppressed in the HS group. Messenger RNA expressions of proinflammatory mediators during reperfusion were also reduced with HS preconditioning. Concomitant with NF-κB activation, NF-κB inhibitor I-κB proteins were degraded in the control group, but this degradation was suppressed in the HS group. This study shows that HS preconditioning protected the liver from I/R injury by suppressing the activation of NF-κB and the subsequent expression of proinflammatory mediators through the stabilization of I-κB proteins.