微小RNA-124对阿霉素诱导的心肌毒性的影响

Effect of microRNA-124 on doxorubicin-induced cardiotoxicity

目的研究微小RNA-124(miR-124)对阿霉素诱导的心肌毒性的影响以及潜在机制。方法建立阿霉素诱导的C57BL/6小鼠和乳小鼠心肌细胞氧化应激损伤模型,采用Western blot检测Src同源2结构域转化蛋白1(p66Shc)蛋白表达水平。转染miR-124 mimic、inhibitor后观察阿霉素处理心肌细胞活性氧(ROS)水平,比色法检测总超氧化物歧化酶(SOD)活性和丙二醛(MDA)的含量,Western blot检测Caspase-3和p66Shc的蛋白表达,使用荧光素酶报告基因方法验证miR-124与p66Shc蛋白之间的结合作用。结果阿霉素引起心肌p66Shc蛋白表达升高(P<0.05)。过表达miR-124可减轻阿霉素引起的心肌细胞氧化应激损伤,表现为ROS和MDA含量减少、SOD活性升高、Caspase-3和p66Shc的蛋白表达降低(P<0.05)。miR-124与p66Shc存在直接的结合作用。结论miR-124通过抑制p66Shc蛋白表达而对阿霉素诱导的心肌氧化应激损伤起保护作用。

Objective To investigate the effect of microRNA-124(miR-124)on doxorubicin-induced cardiotoxicity and its underlying mechanism.Methods The models with doxorubicin-induced cardiac injury were established in C57 BL/6 mice and neonatal murine cardiomyocytes.The expression of SHC-transforming protein 1(p66 Shc)was detected by Western blot.After transfected with miR-124 mimic and inhibitor,reactive oxygen species(ROS)level was observed while malondialdehyde(MDA)content and superoxide dismutase(SOD)activity were determined by colorimetric methods.The protein expressions of Caspase-3 and p66 Shc were examined by Western blot.Luciferase assay was used to determine if there was a direct combination between miR-124 and p66 Shc protein.Results P66 Shc was significantly increased in doxorubicin-induced hearts and cardiomyocytes(P<0.05).Overexpression of miR-124 significantly reduced oxidative stress injury characterized by lower ROS,MDA content and protein expressions of Caspase-3 and p66 Shc and higher SOD activity(P<0.05).Luciferase results confirmed the direct combination of miR-124 with p66 Shc.Conclusion miR-124 has a protective effect on doxorubicin-induced myocardial oxidative stress injury by inhibiting p66 Shc expression.