| After more than half a century of development,the indications for liver transplantation have gradually expanded.And liver transplantation has become the best choice for patients with end-stage liver disease.Accompanied by this is the relative shortage of donor liver,which has become a bottleneck restricting the operation and development of liver transplantation.Therefore,in the past few decades,how to expand the source of donor liver has become a hot spot in the field of transplantation.Donation after cardiac death(DCD)liver became the option to expand the donor liver pool.However,due to the long-term warm ischemia of this type of donor liver,postoperative complications are likely to occur after transplantation.Traditional cold storage(CS)has been unable to meet the clinical needs of this type of donor liver.Hypothermic machine perfusion(HMP)has a good preservation effect on DCD donor liver,and has the potential to replace CS as a new liver preservation method.HMP is divided into active oxygenation HMP and passive oxygenation HMP.Active oxygenation HMP is also called hypothermic oxygenated perfusion(HOPE).However,the underlying mechanisms of HMP to protect the DCD liver remain unclear.Objective(1)To establish the rat DCD liver,CS,HMP and isolated perfused rat livers(IPRL)model and then explore the protective effect of HMP on rat DCD liver and the specific molecular mechanism;(2)To establish the rat DCD liver model,HOPE model and a rat autologous blood IPRL model on the basis of the previous study and explore the protective effect of HOPE on rat DCD donor liver and the specific molecular mechanism.Methods(1)A total of 18 adult male rats were randomly divided into three groups:Control,HMP and CS(n=6 per group).Rat livers in the CS and HMP groups were subjected to 30 min warm ischemia following cardiac arrest and were then preserved by CS or HMP for 3 h.Subsequently,after 1 h of isolated reperfusion,the extent of IRI and cellular functions were assessed by malondialdehyde(MDA)production,superoxide dismutase(SOD)activity,ATP levels,as well as for histological analysis,immunohistochemistry and a terminal deoxynucleotidyl transferase dUTP nick end labeling assay.Finally,the expression levels of the components associated with the Nrf2-ARE signaling pathway were analyzed via western blotting and reverse transcription-quantitative polymerase chain reaction.(2)A total of 18 adult male rats were randomly divided into three groups: control,CS,and HOPE(n=6 per group).Rat livers in the CS and HOPE groups were subjected to 30 min warm ischemia and were then preserved by CS for 4 h or HOPE for 1 h after CS.Then,the hepatic function and the IRI were assessed after reperfusion.During reperfusion,the bile and perfusate were collected to measure enzyme quantities and other indicators of hepatic function.After reperfusion,the liver sample was used for histological and TEM analysis.After determination of the antioxidant stress level,inflammatory cytokines and apoptosis were also measured.The expression levels of the Notch1 signaling pathway and other signaling pathways associated with Notch1 were analyzed via Western blotting,immunoprecipitation,and immunohistochemistry.Results(1)The results of the present study revealed that,compared with in the CS group,the HMP group exhibited higher levels of ATP and SOD activity,and improved histological results;however,lower levels of apoptosis and MDA were detected.Additionally,the findings of the present study also suggested that the Nrf2-ARE signaling pathway may be activated by the steady laminar flow of HMP.(2)The results of the present study revealed that compared with the CS group,the HOPE group exhibited increased hepatic function.Minor ischemia reperfusion injury was reflected in the level of enzymes(AST,ALT,and LDH),liver function(bile flow,ATP,and O2 consumption),antioxidant stress(ROS,MPO,and SOD),and inflammatory cytokines(TNF-α,IL-1β,IL-6,and IL-10).Histology,rate of apoptosis,and TEM analysis in the HOPE group also revealed more favorable results compared with the CS group.The Western blotting,immunoprecipitation,and immunohistochemistry analysis also suggested that the Notch1 signaling pathway may be activated by the steady laminar flow that was provided by the HOPE treatment.Conclusions(1)HMP may attenuate ischemia-reperfusion injury to rat DCD liversvia activation of the Nrf2-ARE signaling pathway.(2)HOPE may attenuate ischemia-reperfusion injury to rat DCD livers via activation of the Notch1 signaling pathway. |
