Blockade of the Fas/Fas ligand interaction suppresses hepatocyte apoptosis in ischemia-reperfusion rat liver.

Hepatic ischemia-reperfusion injury remains a significant problem for liver surgery, including transplantation, and apoptosis has been implicated in this type of hepatic injury. Here we found that through the Fas/Fas ligand interaction apoptosis is involved in the late phase of hepatic ischemia-reperfusion injury. The appearance of apoptotic hepatocytes increases significantly after reperfusion, reaching a maximum 12 h after reperfusion. The transcription levels of Fas and Fas ligand are increased after reperfusion. Fas is expressed on hepatocytes, while Fas ligand is expressed on infiltrating immune cells. A close spatial and temporal association of Fas expression and apoptotic cells is demonstrated in the histological observation. These results suggest that infiltrating cells induce apoptosis of hepatocytes through the Fas/Fas ligand interaction, leading to hepatocyte injury. Furthermore, an injection of anti-Fas antibody or neutralizing anti-Fas ligand antibody results in a dramatic decrease in the occurrence of hepatocyte apoptosis and hepatic infiltration of macrophages and natural killer cells as well as liver injury. Our results suggest that blockage of the Fas/Fas ligand interaction is a promising strategy for suppression of hepatic ischemia-reperfusion injury.