Inflammatory responses in a new mouse model of prolonged hepatic cold ischemia followed by arterialized orthotopic liver transplantation

The current models of liver ischemia/reperfusion injury (IRI) in mice are largely limited to a warm ischemic component. To investigate the mechanism of hepatic “cold” IRI, we developed and validated a new mouse model of prolonged cold preservation followed by syngeneic orthotopic liver transplantation (OLT). Two hundred and forty‐three OLTs with or without rearterialization and preservation in University of Wisconsin solution at 4°C were performed in Balb/c mice. The 14‐day survivals in the nonarterialized OLT groups were 92% (11/12), 82% (9/11), and 8% (1/12) after 1‐hour, 6‐hour and 24‐hour preservation, respectively. In contrast, hepatic artery reconstruction after 1‐hour, 6‐hour, and 24‐hour preservation improved the outcome as evidenced by 2‐week survival of 100% (12/12), 100% (10/10), and 33% (4/12), respectively, and diminished hepatocellular damage (serum alanine aminotransferase /histology). Moreover, 24‐hour (but not 1‐h) cold preservation of rearterialized OLTs increased hepatic CD4 + T‐cell infiltration and proinflammatory cytokine (tumor necrosis factor‐α, interleukin 2, interferon‐γ) production, as well as enhanced local apoptosis, and Toll‐like receptor 4/caspase 3 expression. These cardinal features of hepatic IRI validate the model. In conclusion, we have developed and validated a new mouse model of IRI in which hepatic artery reconstruction was mandatory for long‐term animal survival after prolonged (24‐h) OLT preservation. With the availability of genetically manipulated mouse strains, this model should provide important insights into the mechanism of antigen‐independent hepatic IRI and help design much needed refined therapeutic means to combat hepatic IRI in the clinics. (Liver Transpl 2005;11:1273–1281.)