调控ERK1/2通路在H_2S保护心肌细胞对抗阿霉素损伤中的作用

Role of Modulating Extracellular Signal-Regulated Kinases 1/2 Pathway in Cardioprotection of Hydrogen Sulfide against Doxorubicin-induced Injury

【目的】探讨胞外信号调节激酶1/2(ERK1/2)在阿霉素心肌毒性中的作用及硫化氢(H2S)是否通过调控ERK1/2通路抑制阿霉素的心肌毒性。【方法】应用阿霉素处理H9c2心肌细胞建立心肌细胞毒性损伤模型;CCK-8比色法测定细胞存活率;蛋白印迹法(Western blot)检测ERK1/2蛋白的表达水平;双氯荧光素(DCFH-DA)染色荧光显微镜照相测定细胞内的活性氧(ROS)水平;罗丹明123(Rh123)染色荧光显微镜照相检测线粒体膜电位(MMP)。【结果】5μmol/L阿霉素呈时间依赖性地上调磷酸化(p)ERK1/2表达水平;硫氢化钠(NaHS,为H2S的供体)预处理心肌细胞30 min明显地抑制阿霉素对p-ERK1/2表达的上调作用;400μmol/L NaHS和10μmol/L PD-98059(ERK1/2抑制剂)预处理30 min,均能对抗阿霉素引起的心肌细胞损伤,分别使H9c2的存活率增加,胞内ROS堆积和MMP丢失均减少。【结论】ERK1/2通路介导阿霉素的心肌毒性作用;通过抑制ERK1/2通路可能是H2S保护心肌细胞对抗阿霉素心肌毒性的作用机制之一。

[ Objective ] To investigate the role of extracellular signal-regulated kinases 1/2 （ERK1/2） in cardiotoxicity induced by doxorubicin （DOX） and whether hydrogen sulfide （H2S） inhibits DOX-induced cardiotoxicity by modulating ERK1/2 pathway in H9c2 cardiac ceils. [Methods] H9c2 cardiac cells were treated with DOX to establish the model of cardiotoxicity injury. The expression level of ERK1/2 was tested by Western blot assay. Intracellular level of reactive oxygen species （ROS） was detected by DCFH-DA staining and photoflurography. Mitochondrial membrane potential （MMP） was measured by rhodamine 123 staining and photoflurography. [Results] DOX at 5 μmol/L time-dependently upregulated expressive level of phosphorylated （p） ERK1/2. Pretreatment of H9c2 cardiac cells with sodium hydrosulfide （NariS, a H2S donor） for 30 min obviously inhibited up-regulation of p- ERK1/2 expression induced by DOX. Pretreatment of cardiac ceils with both NariS （400） μmol/L） or PD-98059 （an inhibitor of ERK1/2,10 μmol/L） for 30 min respectively blocked cardiomyocyte injury induced by DOX, increasing cell viability of H9c2 cardiac cells, reducing accumulation of intracellular ROS and loss of MMP. [Conclusion] ERK1/2 pathway mediates DOX-induced cardiotoxicity. Inhibition of ERK1/2 pathway may be one of the mechanism underlying cardioprotection of H2S against cardiotoxicity induced by DOX.