姜黄素预处理通过上调miR-21缓解多柔比星心肌毒性

Curcumin Pretreatment Relieves Doxorubicin-induced Cardiotoxicity through up-regulating miR-21

目的:探究miR-21是否介导姜黄素(Cur)预处理抗多柔比星(DOX)心肌毒性作用。方法:体外分离培养大鼠原代心肌细胞,用DOX处理24 h建立心肌毒性离体模型。姜黄素于DOX处理前12 h加入心肌细胞培养液中。实验分组如下:Control组;Cur组;DOX组;Cur+DOX组;miR-21i(miR-21抑制剂)+Cur+DOX组;miR-21i+DOX组。DOX处理24 h后检测miR-21表达情况、细胞活力、凋亡和氧化应激相关指标。结果:与DOX组相比,姜黄素预处理可呈剂量依赖性地提高DOX处理后心肌细胞活力,且浓度为5μM时效果最佳。此外,姜黄素预处理可以明显提高Bcl-2和miR-21表达,降低心肌Bax和cleaved Caspase-3表达、凋亡率以及心肌细胞活性氧(ROS)产量和丙二醛(MDA)含量。而用miR-21i下调miR-21表达可明显削弱姜黄素预处理对DOX心肌损伤的上述保护作用(均P<0.05)。结论:姜黄素预处理可通过上调miR-21表达,缓解心肌凋亡和氧化应激损伤,进而缓解DOX心肌毒性。

Objective: To investigate whether miR-21 mediates the cardioprotective effects of curcumin(Cur) pretreatment against doxorubicin(DOX)-induced cardiotoxicity. Methods: Neonatal rat cardiac myocytes(NRCMs) were isolated and cultured in vitro, and then treated with DOX for 24 h to establish the cardiotoxicity model in vitro. Curcumin was added to the culture medium 12 h before DOX treatment. The experiments were grouped as follows: Control group;Cur group;DOX group;Cur+DOX group;miR-21 i(miR-21 inhibitor)+Cur+DOX group;and miR-21 i+DOX group. The expression of miR-21, cell viability and indicators of apoptosis and oxidative stress were detected 24 h after DOX treatment. Results: Compared with the DOX group, curcumin pretreatment increased the cell viability of DOX-treated NRCMs in a dose-dependent manner, and the optimal concentration was 5 μM. In addition, curcumin pretreatment significantly increased the expression of Bcl-2 and miR-21, and decreased the expression of Bax and cleaved Caspase-3,apoptotic ratio, and the production of reactive oxygen species(ROS) and malondialdehyde(MDA) in NRCMs. Down-regulation of miR-21 expression by miR-21 i significantly attenuated the protective effects of curcumin pretreatment on DOX-induced cardiotoxicity mentioned above(all P <0.05). Conclusions: Curcumin pretreatment can up-regulate the expression of miR-21, thereby alleviating myocardial apoptosis and oxidative stress, and mitigating the cardiotoxicity of DOX.