Hypothermic Oxygenated Machine Perfusion Alleviates Donation after Cardiac Death Liver Injury Through Regulating P-Selectin-Dependent and -Independent Pathways in Mice

Hypothermic oxygenated machine perfusion (HOPE) has been demonstrated to improve the quality of donation after cardiac death (DCD) livers compared with cold storage (CS). However, the mechanism underlying HOPE is unclear. Herein, a mouse liver HOPE system was established to verify the role of P-selectin in the protective effect of HOPE on DCD livers. A warm ischemia 30 min model of the liver and isolated perfused liver system were established to verify a suitable flow for HOPE. Wild-type and P-selectin knockout mice were employed to explore the protective mechanism of HOPE. Perfusate and tissue samples were tested, focusing on liver function, apoptosis and necrosis, DNA injury and oxidative stress, leukocyte and endothelial cell activation, and inflammatory reactions. A mouse liver HOPE system was successfully established. In the DCD liver, a protective effect was observed for HOPE at flow rates between 0.1 and 0.5 ml/min * g (i.e., AST, P < 0.05). We discovered that P-selectin knockout in the CS group improved the quality of the DCD liver. In the wild-type HOPE group, protection of DCD livers was observed by the similar reduction of the P-selectin expression. Subsequently, there was a reduction in the degree of oxidative stress and DNA injury in the P-selectin knockout HOPE group compared with the P-selectin knockout CS group (i.e., HMGB-1, P < 0.05). We established a mouse HOPE system and validated its suitable flow. We also proved that P-selectin deficiency alleviated DCD liver injury. HOPE protected the DCD liver through regulating P-selectin-dependent and -independent pathways. Funding: This study was supported by the National Natural Science Foundation of China-Xinjiang joint fund (no. U1403222) and National Natural Science Foundation of China (no. 81570079). Declaration of Interest: None. Ethical Approval: All animals were treated based on the Animal Experimental Ethics Committee's requirements for experiments.