Function And Mechanisms Of Monocyte Chemoattractant Protein-induced Protein 1 In Hepatic Ischemia/Reperfusin Injury

Objective: Hepatic ischemia-reperfusion injury involves two interrelated and interacting stages,one is the local ischemic injury,the other is the inflammation-mediated reperfusion injury.During ischemia,the lack of oxygen and nutrients in the liver leads to cellular metabolism breakdown.After blood flow restoration(reperfusion),the spread of inflammation and cell apoptosis cause more severe damage.The overall mechanisms of hepatic ischemia-reperfusion injury are very complex,involving the interaction of multiple cell types and molecular pathways,which explains the difficulty of formulating therapeutic strategies and translating into clinical application.The aim of this study is to elucidate the effect and molecular mechanism of Monocyte Chemoattractant Protein-Induced Protein 1(MCPIP1)on hepatic ischemia-reperfusion injury disease,so as to provide potential therapeutic targets and drugs for prognosis of hepatic ischemia-reperfusion surgery.Methods: 1.The changes of MCPIP1 protein expression in the livers of liver transplantation patients and mice subjected to hepatic ischemia-reperfusion operation model,and the cells subjected to hypoxia-reoxygenation treatment in vitro were detected by Western blot;2.To explore the function of MCPIP1 on hepatic ischemia-reperfusion injury through constructing hepatocyte-specific MCPIP1 gene knockout mice,histopathological analysis of hepatic ischemia-reperfusion operation model in mice;3.The effects of MCPIP1 on inflammation during hepatic ischemia-reperfusion were evaluated by real-time quantitative PCR and Western blot;4.The effects of MCPIP1 on hepatocyte apoptosis and hepatocyte proliferation and regeneration during hepatic ischemia-reperfusion were evaluated by real-time quantitative PCR and Western blot;5.Screening the target of MCPIP1 by immunoprecipitation,designing rescue experiment to verify the target,and exploring the detailed mechanism of MCPIP1 regulating hepatic ischemia-reperfusion injury through further molecular biology experiments.Results: 1.MCPIP1 protein expression was significantly down-regulated in the livers of liver transplantation patients and mice subjected to hepatic ischemia-reperfusion injury,and primary hepatocytes subjected to hypoxia-reoxygenation treatment.2.Histopathological H&E staining showed that hepatocyte-specific MCPIP1 knockout promoted liver injury during ischemia-reperfusion.3.Hepatocyte-specific MCPIP1 knockout promoted inflammatory response induced by hepatic ischemia-reperfusion.4.Hepatocyte-specific MCPIP1 knockout promoted hepatocyte apoptosis and inhibited hepatocyte proliferation and regeneration induced by ischemiareperfusion.5.MCPIP1 can directly interact with HIF-1α,deubiquitinate HIF-1α,and regulate the protein stability of HIF-1α and its downstream signaling pathways.6.Stabilize HIF-1α can reverse the promotion effects on hepatic ischemia-reperfusion injury of MCPIP1 deficiency.Conclusion: In liver transplantation patients,hepatic ischemia-reperfusion mice model and hypoxia-reoxygenation cell model,the down-regulation of MCPIP1 protein expression was closely related to hepatic ischemia-reperfusion injury.The hepatic ischemiareperfusion injury experiments in hepatocyte-specific MCPIP1 gene knockout mice(HKO)showed that MCPIP1 could improve liver injury,reduce inflammation,prevent hepatocyte death and promote hepatocyte regeneration.Further studies showed that MCPIP1 interacted with HIF-1α and stabilized the expression of HIF-1α through deubiquitination.HIF-1α activator compensated the adverse effects of MCPIP1 deficiency on hepatic ischemia-reperfusion.Therefore,we confirm that MCPIP1-HIF-1α is an important regulatory pathway in the process of hepatic ischemia-reperfusion,and MCPIP1-HIF-1α may be a potential therapeutic target for hepatic ischemiareperfusion injury intervention.