Effect Of LncRNA CAF On Doxorubicin-induced Cardiotoxicity And Its Possible Mechanisms

ObjectiveDoxorubicin?DOX?as a chemotherapeutic drug is widely used to treat a variety of human tumors.However,a major factor limiting its clinical use is its cardiotoxicity.Themolecularcomponentsanddetailedmechanismsregulating DOX-induced cardiotoxicity remain largely unidentified.MethodLncRNAs expression profles in 2?mol/L doxorubicin-induced cell samples compared with control group samples were studied by high-throughput microarray.The Significantly differentially expressed lncRNAs were verifed by real-time quantitative PCR and weatern blot.Six healthy male 8 week old mice,produced the model of cardiotoxicity in mice by Dox?model group?;Six healthy C57BL/6J mice were fed with basal diet as control group;neonatal mouse cardiomyocytes were divided in negative control?NC?,pcDNA3.1?-?-LncRNA group and si-Ln RNA group by their different transfection.cardiotoxicity model and control mice were used to determine the Mief1 expression using fluorescence quantitative polymerase chain reaction?PCR?and weatern blot method.Result?1?According to the microarray analysis,Results of RT-qPCR revealed that one Lnc-RNA we named cardiac apoptosis-related lncRNA?CAF?was up-regulated significantly in the DOX group?n=4;t=7.79;P<0.01?;?2?Doxorubicin-induced mouse cardiotoxicity model building success.The fluorescence quantitative PCR results showed that compared with the control group,the expression of MIEF1 mRNA in model group was decreased signifcantly?n=3;t=14.978;P<0.01?.The higher the concentration of doxorubicin,The expression of MIEF1 mRNA was signifcantly decreased(n=4;t_2?mol/L=33.423,P<0.01;t_4?mol/L=36.120,P<0.01;t_6?mol/L=40.205,P<0.01).MIEF1 was up-regulated in the CAF-siRNA group?n=4;t=12.909,P<0.01?and down-regulated in the CAF group?n=4;t=33.634,P<0.01?.?3?Western Blot results showed a significant down regulation of expression of MIEF1?n=4;t=6.47;P<0.01?in CAF group and a significant upregulation of expression of MIEF1?n=4;t=4.892,P<0.01?in CAF-siRNA group compared to control group.Conclusion This study used C57 mice to establish doxorubicin-induced cardiotoxicity models.According to the results of the microarray analysis by the biotechnology company,we screened differentially expressed lncRNA NONMMUT071802 by qPCR,and we named it the cardiac apoptosis-related lncRNA?CAF?.The RT-qPCR technique was used to investigate the changes in the expression of cardiac CAF compared with normal mice.The function of lncRNA CAF was explored using primary mouse cardiomyocytes and the following conclusions were drawn:1.The expression of lncRNA CAF in myocardial tissue was higher than that in normal mice induced by doxorubicin.lncRNA CAF is downregulated in the cardiomyocyte and mouse heart in response to DOX treatment.The expression level of MIEF1 was significantly decreased after treatment with doxorubicin.2.lncRNA CAF may regulates mitochondrial dynamics protein of 51 kDa?MIEF1?and suppresses its expression at ranscriptional level.3.Our study identifies a novel pathway composed of lncRNA CAF and MIEF1 that mediates DOX cardiotoxicity.This discovery provides a promising therapeutic strategy for the treatment of cardioprotection.