Study On The Mechanism Of β-catenin And Mst1 In Myocardial Ischemia-reperfusion Injury In Mice

Ischemia-reperfusion injury is an evitable phenomenon in the process of organ transplantation,and it is one of the important causes of organ failure and damage to the transplanted organ.In recent years,the happen of myocardial diseases has increased,and myocardial ischemia-reperfusion injury has received more and more attention.However,the process of myocardial ischemia-reperfusion injury is complicated,and there is no clear explanation for its occurrence.Many studies have shown that oxidative damage,cell apoptosis,calcium ion overload,etc.are important causes of cell death due to ischemia-reperfusion injury.Theβ-catenin signaling pathway is mainly involved in life activities such as various tumors and cell growth and development.β-catenin pathway has been studied in the ischemia-reperfusion injury of many organs.However,the mechanism of action in the myocardial ischemia-reperfusion injury has not been clearly reported except for this study.Therefore,this study uses mouse neck Heterotopic heart transplantation as a basic model reveals the effect ofβ-catenin pathway on myocardial ischemia-reperfusion injury.Other documents indicate that the process of ischemia-reperfusion injury also involves cell oxidative damage,and Mst1 is activated in the process of oxidative damage.Therefore,another direction of this research is to construct Mst1 knockdown models to explore Mst1 paly another effect in ischemia-reperfusion.There are two experimental methods used in this study.One is to construct a mouse cervical heterotopic heart transplantation model when exploring theβ-catenin pathway.The transplanted heart ischemia and reperfusion for different times.Then the transplanted heart was taken to detect the changes in m RNA and protein levels ofβ-catenin,Pten and other related genes.In order to further explore the role ofβ-catenin in ischemia-reperfusion injury,a hypoxia-reoxygenation model was constructed in mouse cardiomyocytes（HL-1）with CoCl₂ to exploreβ-catenin and related genes whenβ-catenin was overexpressed Changes in transcription and translation levels.Second,Rock when exploring the Mst1 signaling pathway,Mst1 knockdown mice were prepared by tail vein injection of Mst1 knockdown lentivirus,and then this mouse was used as a donor mouse to prepare mouse cervical heterotopic heart transplantation.model.By placing the transplanted heart in cardiac arrest solution（HTK）for 8 hours to cause cold ischemia injury,the role of Mst1 in cold ischemia was detected.In in vitro experiments,CoCl₂ was used to treat macrophages to construct a hypoxia-reoxygenation model,and to detect the expression of Mst1 and other related genes at the transcription and translation levels.Through the above experiment,we get the following results.In the study of theβ-catenin pathway,when the ischemia time is 10 minutes and the reperfusion time is 1day,the expression ofβ-catenin at the transcription and translation level is significantly reduced,the expression of Pten is significantly increased,and myocardial damage is also the most serious.CoCl₂ was used to construct a hypoxia-reoxygenation model in HL-1 cells.The optimal concentration of CoCl₂ was 600μmol/L,and the treatment time was 24h.Afterβ-catenin was overexpressed and treated with CoCl₂,the expression ofβ-catenin increased,and the expression of Pten decreased.β-catenin can reversely regulate Pten and reduce the damage of cardiomyocytes.In the study of the Mst1pathway,cold ischemia of cardiomyocytes will lead to an increase in the transcription level of Mst1.In the in vitro cellular hypoxia-reoxygenation model,the optimal concentration of CoCl₂ is 900μmol/L,and the treatment time is 32h.After knocking down Mst1 and then treating with CoCl₂,the expression of Mst1 increased at both transcription and translation levels compared to the knockdown group of Mst1,while the expression of Keap was down-regulated,and the expression of Nrf2 and HO-1 was up-regulated.From this we can conclude that in the mouse myocardial ischemia-reperfusion injury model,β-catenin can inhibit the expression of Pten/Rock to improve the growth of myocardial cells,thereby alleviating the injury caused by ischemia-reperfusion.Myocardial ischemia-reperfusion injury leads to the production of ROS,which activates Mst1 kinase.The activation of Mst1 prevents Keap1 from polymerizing,blocking the degradation of Nrf2,and increasing the activity of antioxidant enzymes,thereby reducing cell oxidative damage.