Associate Laboratory i4HB-Institute for Health and Bioeconomy, Laboratory of Toxicology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal.
UCIBIO-Applied Molecular Biosciences Unit, REQUIMTE, Laboratory of Toxicology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal.
Arch Toxicol. 2023 Dec;97(12):3163-3177. doi: 10.1007/s00204-023-03586-1. Epub 2023 Sep 7.
Doxorubicin (DOX) is a potent chemotherapeutic agent used against several cancer types. However, due to its cardiotoxic adverse effects, the use of this drug may be also life-threatening. Although most cancer patients are elderly, they are poorly represented and evaluated in pre-clinical and clinical studies. Considering this, the present work aims to evaluate inflammation and oxidative stress as the main mechanisms of DOX-induced cardiotoxicity, in an innovative approach using an experimental model constituted of elderly animals treated with a clinically relevant human cumulative dose of DOX. Elderly (18-20 months) CD-1 male mice received biweekly DOX administrations, for 3 weeks, to reach a cumulative dose of 9.0 mg/kg. One week (1W) or two months (2 M) after the last DOX administration, the heart was collected to determine both drug's short and longer cardiac adverse effects. The obtained results showed that DOX causes cardiac histological damage and fibrosis at both time points. In the 1W-DOX group, the number of nuclear factor kappa B (NF-κB) p65 immunopositive cells increased and a trend toward increased NF-κB p65 expression was seen. An increase of inducible nitric oxide synthase (iNOS) and interleukin (IL)-33 and a trend toward increased IL-6 and B-cell lymphoma-2-associated X (Bax) expression were seen after DOX. In the same group, a decrease in IL-1β, p62, and microtubule-associated protein 1A/1B-light chain 3 (LC3)-I, p38 mitogen-activated protein kinase (MAPK) expression was observed. Contrariwise, the animals sacrificed 2 M after DOX showed a significant increase in glutathione peroxidase 1 and Bax expression with persistent cardiac damage and fibrosis, while carbonylated proteins, erythroid-2-related factor 2 (Nrf2), NF-κB p65, myeloperoxidase, LC3-I, and LC3-II expression decreased. In conclusion, our study demonstrated that in an elderly mouse population, DOX induces cardiac inflammation, autophagy, and apoptosis in the heart in the short term. When kept for a longer period, oxidative-stress-linked pathways remained altered, as well as autophagy markers and tissue damage after DOX treatment, emphasizing the need for continuous post-treatment cardiac monitoring.
多柔比星（DOX）是一种用于多种癌症类型的有效化疗药物。然而，由于其心脏毒性的不良副作用，这种药物的使用也可能危及生命。尽管大多数癌症患者是老年人，但他们在临床前和临床研究中的代表性和评估都很差。考虑到这一点，本研究旨在评估炎症和氧化应激作为多柔比星诱导的心脏毒性的主要机制，采用一种创新的方法，使用由接受临床相关的人类累积剂量 DOX 治疗的老年动物组成的实验模型。老年（18-20 个月）CD-1 雄性小鼠每周接受两次 DOX 给药，共 3 周，达到 9.0mg/kg 的累积剂量。在最后一次 DOX 给药后 1 周（1W）或 2 个月（2M），收集心脏以确定药物的短期和长期心脏不良影响。结果表明，DOX 在两个时间点均引起心脏组织学损伤和纤维化。在 1W-DOX 组中，核因子 kappa B（NF-κB）p65 免疫阳性细胞的数量增加，并且观察到 NF-κB p65 表达的趋势增加。诱导型一氧化氮合酶（iNOS）和白细胞介素（IL）-33 的增加，以及 IL-6 和 B 细胞淋巴瘤-2 相关 X（Bax）表达的趋势增加在 DOX 后被看到。在同一组中，IL-1β、p62 和微管相关蛋白 1A/1B-轻链 3（LC3）-I、p38 丝裂原激活蛋白激酶（MAPK）的表达减少。相反，在 DOX 后 2M 处死的动物表现出谷胱甘肽过氧化物酶 1 和 Bax 表达的显著增加，同时伴有持续性心脏损伤和纤维化，而羰基蛋白、红细胞衍生 2 相关因子 2（Nrf2）、NF-κB p65、髓过氧化物酶、LC3-I 和 LC3-II 的表达减少。总之，我们的研究表明，在老年小鼠群体中，DOX 在短期内会引起心脏炎症、自噬和凋亡。当保持更长时间时，与氧化应激相关的途径仍然发生改变，并且在 DOX 治疗后自噬标志物和组织损伤仍然存在，这强调了需要对心脏进行持续的治疗后监测。
