【摘要】 【目的】基于细胞水平观察小檗碱对阿霉素诱导心肌细胞沉默信息调节因子2同源蛋白1(SIRT1)/p66Shc通路的影响，探讨小檗碱抗阿霉素所致心肌毒性作用的机制。【方法】应用阿霉素（1μmol/L）处理人心肌细胞系AC16建立阿霉素心肌毒性模型。四甲基偶氮唑盐（MTT）比色法测定细胞存活率，二氯荧光黄双乙酸盐（DCFH-DA）染色荧光显微镜照像测定细胞活性氧簇（ROS）水平，罗丹明123(Rh123)染色荧光显微镜照像测定线粒体膜电位（MMP），荧光染料Rhod2-AM（分子探针）测定线粒体Ca2+浓度（[Ca2+]m），蛋白免疫印迹（Western Blot）法测定细胞SIRT1、p66Shc及凋亡蛋白Bax的表达水平。【结果】用1μmol/L小檗碱预处理可明显抑制1μmol/L阿霉素引起的AC16心肌细胞毒性作用，使细胞存活率升高，表现为抑制阿霉素引起的细胞内ROS生成增多、抑制阿霉素致细胞凋亡（使凋亡蛋白Bax表达下调）和减轻线粒体损伤。阿霉素处理的AC16心肌细胞中p66Shc表达增强且SIRT1蛋白表达下降；预先加用小檗碱组中，阿霉素上调p66Shc及下调SIRT1表达的效应显著减弱；而1μmol/L EX527(SIRT1抑制剂)预处理则加重阿霉素引起的AC16细胞损伤，这种细胞损伤未能被小檗碱预处理所改善。【结论】小檗碱可通过SIRT1介导的p66Shc抑制保护AC16心肌细胞对抗阿霉素诱导的心肌毒性。更多还原

【Abstract】 Objective To observe the effects of berberine(Ber) against silencing information regulator 2homologous protein 1(SIRT1)/p66Shc pathway in doxorubicin(DOX)-induced cardiomyocytes,and to explore the mechanism of Ber in resisting DOX-induced cardiotoxicity. Methods DOX(1 μmol/L)was applied to treat human cardiomyocyte line AC16 to establish a DOX cardiotoxicity model. Cell viability was detected by colorimetric assay with tetramethylazole salt(MTT),cellular reactive oxygen species(ROS)level was detected by fluorescence microscopy with diclofluorescein(DCFH-DA)staining,mitochondrial membrane potential(MMP)was detected by fluorescence microscopy with rhodamine 123(Rh123)staining, mitochondrial Ca2 +([Ca2 +]m)concentration was detected by fluorescent dye Rhod2-AM(molecular probe), the expression levels of SIRT1,p66Shc and apoptotic protein Bax were detected by Western Blot method. Results Pretreatment with 1 μmol/L of Ber significantly inhibited the toxic effect of 1 μmol/L of DOX on AC16 cardiomyocytes and increased cell survival,as evidenced by the inhibition of DOX-induced increase in intracellular ROS production,inhibition of DOX apoptosis(down-regulation of apoptotic protein Bax expression),and alleviation of mitochondrial damage.The p66Shc expression was increased and SIRT1 protein expression was decreased in AC16 cardiomyocytes treated with DOX;the up-regulation of p66Shc and down-regulation of SIRT1 expression by DOX was significantly reduced in the pre-treatment with Ber;while 1 μmol/L of EX527(SIRT1 inhibitor)pre-treatment aggravated the DOX-induced damage in AC16 cells, which was not improved by pre-treatment with Ber. Conclusion Ber protects AC16 cardiomyocytes against DOX-induced cardiotoxicity through SIRT1-mediated inhibition of p66Shc.更多还原