Department of Human Biology & Toxicology, Faculty of Medicine and Pharmacy, University of Mons, Place du Parc 20, 7000 Mons, Belgium.
Cells. 2020 Sep 27;9(10):2177. doi: 10.3390/cells9102177.
Doxorubicin (DOX) is an anticancer drug widely used in oncology, especially for breast cancer. The main limitation of DOX treatment is its cardiotoxicity due to the cumulative dose. Clinically, DOX-induced cardiomyopathy develops as a progressive heart failure caused by a progressive cardiomyocyte's death. For long, the oxidative stress induced by DOX was considered as the main toxic mechanism responsible for heart damage, but it is now controverted, and other processes are investigated to develop cardioprotective strategies. Previously, we studied DOX-induced cardiotoxicity and dexrazoxane (DEX), the only cardioprotective compound authorized by the FDA, by H-NMR metabonomics in H9C2 cells. We observed an increased succinate secretion in the extracellular fluid of DEX-exposed cardiomyocytes, a finding that led us to the hypothesis of a possible protective role of this agonist of the GPR91 receptor. The objective of the present work was to study the effect of succinate (SUC) and epoxysuccinate (-ES), two agonists of the GPR91 receptor, on DOX-induced cardiotoxicity to H9C2 cells. To this purpose, several toxicity parameters, including cell viability, oxidative stress and apoptosis, as well as the GPR91 expression, were measured to assess the effects of DEX, SUC and -ES either alone or in combination with DOX in H9C2 cells. A H-NMR-based metabonomic study was carried out on cellular fluids collected after 24 h to highlight the metabolic changes induced by those protective compounds. Moreover, the effects of each agonist given either alone or in combination with DOX were evaluated on MCF-7 breast cancer cells. GPR91 expression was confirmed in H9C2 cells, while no expression was found in MCF-7 cells. Under such experimental conditions, both SUC and -ES decreased partially the cellular mortality, the oxidative stress and the apoptosis induced by DOX. The SUC protective effect was similar to the DEX effect, but the protective effect of -ES was higher on oxidative stress and apoptosis. In addition, the metabonomics findings pointed out several metabolic pathways involved in the cardioprotective effects of both GPR91 agonists: the stimulation of aerobic metabolism with glucose as the main fuel, redox balance and phospholipids synthesis. Finally, none of the GPR91 agonists jeopardized the pharmacological effects of DOX on MCF-7 breast cancer cells.
多柔比星（DOX）是一种广泛应用于肿瘤学的抗癌药物，尤其适用于乳腺癌。DOX 治疗的主要限制是其累积剂量引起的心脏毒性。临床上，多柔比星诱导的心肌病是一种进行性心力衰竭，由进行性心肌细胞死亡引起。长期以来，DOX 诱导的氧化应激被认为是导致心脏损伤的主要毒性机制，但现在这一观点受到了质疑，人们正在研究其他过程以开发心脏保护策略。之前，我们通过 H9C2 细胞的 H-NMR 代谢组学研究了 DOX 诱导的心脏毒性和唯一获得 FDA 批准的心脏保护化合物右雷佐生（DEX）。我们观察到 DEX 暴露的心肌细胞细胞外液中琥珀酸盐分泌增加，这一发现使我们假设这种 GPR91 受体激动剂可能具有保护作用。本工作的目的是研究琥珀酸盐（SUC）和环氧琥珀酸盐（-ES）这两种 GPR91 受体激动剂对 H9C2 细胞 DOX 诱导的心脏毒性的影响。为此，我们测量了几种毒性参数，包括细胞活力、氧化应激和细胞凋亡以及 GPR91 表达，以评估 DEX、SUC 和-ES 单独或与 DOX 联合应用于 H9C2 细胞的作用。对 24 小时后收集的细胞液进行了基于 H-NMR 的代谢组学研究，以突出这些保护化合物诱导的代谢变化。此外，还评估了每种激动剂单独或与 DOX 联合应用于 MCF-7 乳腺癌细胞的效果。在 H9C2 细胞中证实了 GPR91 的表达，而在 MCF-7 细胞中未发现表达。在这种实验条件下，SUC 和-ES 均可部分降低 DOX 诱导的细胞死亡率、氧化应激和细胞凋亡。SUC 的保护作用与 DEX 相似，但-ES 对氧化应激和细胞凋亡的保护作用更高。此外，代谢组学研究结果指出了两种 GPR91 激动剂的心脏保护作用涉及的几种代谢途径：以葡萄糖为主要燃料的有氧代谢刺激、氧化还原平衡和磷脂合成。最后，两种 GPR91 激动剂都没有影响 DOX 对 MCF-7 乳腺癌细胞的药理作用。
