黄酒多酚对阿霉素所致心脏毒性的干预机制研究

Finding effective strategies for doxorubicin-induced cardiotoxicity remains a challenge in clinic. Studies demonstrated that doxorubicin treatment may up-regulate the level of the metabolic product of gut microbiota named Trimethylamine N-Oxide (TMAO), to affect the mitochondrial metabolism of myocardial cells and to induce cardiotoxicity. Our preliminary study found that yellow wine polyphenols (YWPs) significantly attenuated doxorubicin-induced oxidative stress and inhibit mitochondrial-dependent cell apoptosis, suggesting it could effectively protect against doxorubicin-induced cardiotoxicity. However, the exact mechanisms underlying this action are exclusive. Here, we hypothesize that YWPs could attenuate doxorubicin-induced cardiotoxicity by decreasing TMAO-mediated mitochondria injury via gut microbiota remodeling. In this study, confocal microscopy, scanning electron microscope, transmission electron microscope, fluorescence immunohistochemistry, 16S rRNA sequencing etc. are used to identified whether doxorubicin induces cardiotoxicity through gut microbiota-TMAO-mitochondria pathway, to explore the role and the mechanisms of YWPs on doxorubicin-induced cardiotoxicity via gut microbiota remodeling and to reveal the relationship between cardiotoxicity and gut microbiota. The aims of this study are to provide experimental evidence for the intervention of YWPs to doxorubicin-induced cardiotoxicity through regulation of gut microbiota and to provide a noninvasive approach for clinical prediction of doxorubicin-induced cardiotoxicity based on gut microbiota.

寻找针对阿霉素所致心脏毒性的有效干预方法是亟待解决的临床问题。研究表明阿霉素可能调节肠道菌群代谢产物氧化三甲胺（TMAO）水平影响心肌细胞线粒体代谢而引起心脏毒性。前期研究发现黄酒多酚可抑制阿霉素诱导的氧化应激，减轻线粒体途径的细胞凋亡，提示黄酒多酚对阿霉素所致的心脏毒性具有保护作用。但其确切机制不明。我们假设：黄酒多酚可通过调节肠道菌群TMAO水平来减轻心肌细胞线粒体损伤，从而拮抗阿霉素诱导的心脏毒性。本研究采用激光共聚焦、扫描及透射电镜、荧光免疫组织化学、16S rRNA测序等技术探讨阿霉素通过肠道菌群-TMAO-线粒体通路诱导心脏毒性的新途径，研究黄酒多酚经由肠道菌群途径保护阿霉素所致心脏毒性的作用及机制，揭示肠道菌群与阿霉素所致心脏毒性的关联性。研究旨在明确肠道菌群在黄酒多酚保护阿霉素所致心脏毒性中的重要作用，为临床基于肠道菌群预测阿霉素所致心脏毒性提供一种非侵入性的评估方法。

阿霉素是对于乳腺癌、恶性淋巴瘤及白血病等都有着优越疗效的蒽环类化疗药物，但是其较大的心脏毒性却限制了他的使用，且目前尚无特效药物对抗其心肌毒性。本课题首先通过建立阿霉素心肌病大鼠模型，发现阿霉素的心肌毒性一部分是由TINCR基因介导的焦亡相关机制导致的。而通过超声心动图、HE染色和马松染色等技术，发现黄酒中分离提纯得到的活性物质黄酒多酚，可以抑制心肌细胞的凋亡和纤维化，改善氧化应激水平，进而显著缓解阿霉素造成的心力衰竭。同时，通过16S RNA测序，发现注射阿霉素会严重破坏正常肠道菌群的物种多样性及分布比例，但摄入黄酒多酚则促使菌群恢复原先的稳态。进一步采用非靶向血清代谢物测序技术检测了阿霉素及黄酒多酚干预后大鼠血清各类代谢物的丰度，揭示了黄酒多酚对肠道菌群的调节可以通过血清代谢物来与心脏产生联系，进而发挥心脏保护作用。最后，利用超声心动图、病理染色及心肌损伤标志物检测等手段，评价了芒柄花苷、岩藻多糖和二氢杨梅素这三个中药单体的心脏保护作用，发现这三个中药单体也可以通过抗氧化、抗凋亡、抗纤维化等机制，缓解阿霉素的心脏毒性。本研究从心脏功能视角和肠道微生态视角，分别阐明了以黄酒多酚为代表的中药活性成分抗阿霉素心脏毒性的功效及具体分子机制，为祖国中医药在蒽环类化疗药物所致心脏毒副作用防治方面奠定扎实的理论基础。