NF-κB-mediated induction of autophagy in cardiac ischemia/reperfusion injury.

Ischemia/reperfusion (I/R) injury severely attenuates the benefit of revascularization after acute myocardial infarction, in which transcription factor NF-κB plays an important role. Recently, there is increasing evidence to suggest that autophagy is involved in this process. We sought to define the role of NF-κB in the induction of autophagy during cardiac I/R injury. The left circumflex coronary arteries of New Zealand white rabbits were ligated for 1.5h, followed by reperfusion for 1h to induce I/R injury. Production of reactive oxygen species (ROS) was detected in myocardial injury area following I/R injury. Furthermore, the results indicated that the cardiac area at risk (AAR) for ischemia has the most abundant expression of Beclin 1 in parallel to p65 expression after cardiac I/R injury. Inhibition of NF-κB significantly attenuated Beclin 1 expression and autophagy in the AAR, which was associated with a marked reduction in the extent of the AAR. Our data thus suggests that I/R injury promotes NF-κB activity, in response to ROS, to aggravate myocardial injury through the activation of Beclin 1-mediated autophagy.