The Mechanism Of LncRNA-AK138945 In Regulating Myocardial Ischemia-reperfusion Injury

Background and PurposeMyocardial ischemia-reperfusion injury（MIRI）is one of the main causes of high mortality in cardiovascular diseases.Therefore,it is important to clarify the pathogenesis of myocardial ischemia-reperfusion injury and explore the treatment strategies to improve myocardial ischemia-reperfusion injury.A large number of studies have found that long non-coding RNA（lncRNA）has an important regulatory role in the occurrence and development of myocardial ischemia-reperfusion.This study aims to explore the regulatory effect and mechanism of lncRNA-AK138945 on myocardial ischemia-reperfusion injury.Methods（1）The animal model of myocardial ischemia-reperfusion injury was established by ligating the left anterior descending coronary artery of the mouse heart for 50minutes and reperfusion for 48 hours;（2）100μmol/L hydrogen peroxide（H₂O₂）treats primary cultured neonatal rat cardiomyocytes to simulate oxidative stress cell damage;（3）Mouse heart ultrasound to detect changes in mouse heart function;（4）q RT-PCR was used to detect the expression of lncRNA-AK138945,circ RNA-CDR1as,lncRNA-ZFAS1,GRP94,miR-1a-3p in cardiomyocytes and heart tissues;（5）Western blot was used to detect the expression of Bad,Bcl 2,Caspase 9,Caspase 3and GRP94 proteins in cardiomyocytes and heart tissues;（6）CCK-8（Cell Counting Kit-8）experiment was used to detect the effect of silencing AK138945 on the viability of cardiomyocytes;（7）LIVE/DEAD Survival and Death Kit was used to detect the effect of silencing AK138945 on the survival and death of cardiomyocytes;（8）TUNEL staining was used to detect the effect of silencing AK138945 on cardiomyocyte apoptosis;（9）The interaction between lncRNA-AK138945 and miR-1a-3p was detected by Luciferase assay technology.Results（1）The expression level of lncRNA-AK138945 and Bcl 2 protein were decreased and the expression of Caspase 9 protein was increased in the heart tissue of MIRI mouse;（2）The expression of lncRNA-AK138945 was decreased in cardiomyocytes treated with H₂O₂,and the apoptosis of cardiomyocytes was increased after silencing AK138945,the expression of Bcl 2 protein decreased,and the protein expression of Bad,Caspase 9,and Caspase 3 increased;（3）Compared with the NC group,the miR-1a-3p group had reduced luciferase activity;（4）The expression of miR-1a-3p was increased while the expression of GRP94 was decreased after silencing AK138945 in cardiomyocytes;（5）Compared with the H₂O₂treatment group,the expression level of Caspase 3,Caspase 9,Bad protein was increased,and the expression of Bcl 2 protein was decreased after administration of GRP94 inhibitor（PU-WS13）;（6）Compared with the NC group,the expression of lncRNA-AK138945and GRP94 was increased,and the expression of miR-1a-3p was decreased after FOXO3 was overexpressed.ConclusionslncRNA-AK138945 inhibits the expression of endoplasmic reticulum stress-related protein GRP94 by regulating miR-1a-3p to cause cardiomyocyte apoptosis.The transcription factor FOXO3 participate in ERS induced cardiomyocyte apoptosis by up-regulating lncRNA-AK138945.