Effects Of Interferon Regulatory Factor-1 In Regulating MAPK-JNK Pathway In The Acute Pulmonary Injuries Of Murine Hepatic Ischemic-reperfusion

Objective: Acute lung injury is the most common visceral injury in the process of liver ischemia reperfusion,which can lead to acute respiratory distress syndrome,seriously affecting the prognosis and postoperative survival rate of liver transplantation,partial hepatectomy and other liver surgery patients.The purpose of our study is to investigate the effects of autophagy on acute lung injury during the process of liver ischemia and reperfusion in mice,and to explore the expression of interferon regulatory factor-1(IRF-1)regulating the MAPK-JNK signaling pathway in this process,thus revealing the process of lung injury induced by liver ischemia-reperfusion.The potential mechanism provides experimental evidence and ideas for the prevention and treatment of complications after liver surgery.Methods:Using Random digital table method,50 wild type healthy male C57BL/6 mice were divided into 5 groups,group Sham,2h group,6h group,12 h group and 24 h group,10 rats in each group.The mice liver ischemia reperfusion model was established.Group Sham only underwent abdominal abdominal operation.The other 4 groups were treated with noninvasive vascular clamp to block hepatic portal for 1.5h,and then reperfused for 2h,6h,12 h and 24 h respectively.Mice in each group were killed after reperfusion,serum and lung tissues were collected.The level of TNF-alpha and IL-6 in serum was detected by ELISA,and the pathological alterations of lung tissue and the expression of autophagy related protein LC3 were observed under the light microscope.The number of autophagy in lung tissue of mice was observed by transmission electron microscope,and the levels of IRF-1,SAPK-JNK,beclin-1 and LC3 protein in lung tissue were detected by Western blot method.Gene knockout technology was used to inhibit the expression of IRF-1 in mice(group KO).Through intravenous injection of tail vein,Ad IRF-1 adenovirus was injected into mice to increase the expression of IRF-1(group Ad IRF-1)and unloaded adenovirus(group Ad GFP)were injected in other mice for control group.The model of 70% liver ischemia reperfusion(6h)in mice and the corresponding blank control group were established respectively.The changes of IRF-1,MAPK-JNK,and beclin-1 levels in lung tissues were detected by Western blot,The results were compared with wild type mice.Results: Compared with the Sham group,the serum levels of TNF-A and IL-6 increased significantly in the mice of IR,and the structure of lung tissue was destroyed,vacuoles,edema,and large number of inflammatory cells aggregated,the most serious inflammation were aroud 6h and 12 h.Autophagy activities increased obviously under transmission electron microscope in IR groups.The expression of IRF-1,JNK,beclin-1,and LC3 protein in the lung tissues of all the mice treated with IR increased significantly with time,reaching the highest level around 6h,and still higher than the normal level after 24 h.Compared with the wild type(WT)mice,the level of IRF-1 in the IRF1 gene knockout mice(KO)group was not significantly changed after IR treatment.The level of JNK,Beclin-1 protein and the extent of lung tissue injury were relatively reduced.Compared with the unloaded adenovirus group(Ad GFP),the increase of JNK protein and beclin-1 protein increased significantly after IR treatment in the Ad IRF-1 group with high level of IRF-1 expression,and the pathological damage of lung tissue was aggravated.Conclusion:Liver ischemia-reperfusion injury promotes cytokine release,up regulate the expression of IRF-1 in lung tissue,enhance the activation of autophagy pathway,and aggravate acute lung injury.Inhibition of IRF-1 expression can reduce lung injury.Its mechanism is related to IRF-1 regulating JNK signaling pathway and increasing autophagy level of lung cells.