MicroRNA-124 Alleviated Doxorubicin-induced Oxidative Stress Injury On Cardiomyocyte Via P66Shc

Aim p66Shc is involved in producting of ROS in mitochondrion pathway.Down regulation of p66shc was identified to increase cell survive under oxidative stress.However,no ligand could be used to regulate p66Shc specifically.Here we explore the therapeutic potentially miRNAs to suppress p66Shc expression by Bioinformatics and molecular biology.Then the miRNA is used to treat doxorubicin-induced oxidative stress injury in cardiomyocyte.Methods Firstly,we screening the miRNAs database TargetScanMouse and microma.org to discover the potential miRNA which aimed at p66Shc by Bioinformatics methods.Then qRT-PCR and dual-luciferase reporter gene system were used to find the aim miRNA.Then miRNAmimic was used to over-expression the miRNA in primary culture of neonatal mouse ventricular myocytes(NMVMs).Doxorubicin was used to induce oxidative stress and cell injury in NMVMs,which could be suppressed by miRNA treatment.Result1、miR-124 were selected as the aim miRNA in current investigationmiR-9,miR-124 and miR-204 were chosen as potential miRNA aimed at p66Shc by Bioinformatics methods,the mirSVR score,PhastCons score,Pct were-0.5235/-0.7940/-0.6301,0.5809/0.5444/0.5637,0,98/0.92/0.46 respectively.In mouse modle of oxidative stress injury treated by doxorubicin intraperitoneal injection only miR-124 expression was observed to be decreased stably.Dual-luciferase reporter gene system was identified the interaction between p66Shc and miR-124(P<0.05).2、miR-124 reduced the expression of p66ShcDoxorubicin was observed to increase the amount of p66Shc and oxidative stress in NMVMs in a time and dose dependent manners.There was significantly difference of p66shc expression in NMVMs under doxorubicin with the concentration of 5umol/L and exposure time of 24 hours(P<0.05).The total amount of ROS,MDA and apotosis were increased and SOD activity were decreased(P<0.05)with exposed to doxorubicin in NMVMs.miR-124 overexpression could significantly decreased doxorubicin depended NMVMs apoptosis and the level of oxidative stress.Furthermore,the content of p66Shc and ROS were decreased with miR-124 in NMVMs treated with doxorubicin(P<0.05).Conclusion miR-124 played a protective role in doxorubicin-induced oxidative stress injury on cardiomyocyte vis downregulation of p66Shc.