School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, China.
Department of Pathophysiology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100005, China.
Phytomedicine. 2024 May;127:155473. doi: 10.1016/j.phymed.2024.155473. Epub 2024 Feb 21.
Doxorubicin (DOX) is widely used for the treatment of a variety of cancers. However, its clinical application is limited by dose-dependent cardiotoxicity. Recent findings demonstrated that autophagy inhibition and apoptosis of cardiomyocytes induced by oxidative stress dominate the pathophysiology of DOX-induced cardiotoxicity (DIC), however, there are no potential molecules targeting on these.
This study aimed to explore whether aucubin (AU) acting on inimitable crosstalk between NRF2 and HIPK2 mediated the autophagy, oxidative stress, and apoptosis in DIC, and provide a new and alternative strategy for the treatment of DIC.
We first demonstrated the protection of AU on cardiac structure and function in DIC mice manifested by increased EF and FS values, decreased serum CK-MB and LDH contents and well-aligned cardiac tissue in HE staining. Furthermore, AU alleviated DOX-induced myocardial oxidative stress, mitochondrial damage, apoptosis, and autophagy flux dysregulation in mice, as measured by decreased ROS, 8-OHdG, and TUNEL-positive cells in myocardial tissue, increased SOD and decreased MDA in serum, aligned mitochondria with reduced vacuoles, and increased autophagosomes. In vitro, AU alleviated DOX-induced oxidative stress, autophagy inhibition, and apoptosis by promoting NRF2 and HIPK2 expression. We also identified crosstalk between NRF2 and HIPK2 in DIC as documented by overexpression of NRF2 or HIPK2 reversed cellular oxidative stress, autophagy blocking, and apoptosis aggravated by HIPK2 or NRF2 siRNA, respectively. Simultaneously, AU promoted the expression and nuclear localization of NRF2 protein, which was reversed by HIPK2 siRNA, and AU raised the expression of HIPK2 protein as well, which was reversed by NRF2 siRNA. Crucially, AU did not affect the antitumor activity of DOX against MCF-7 and HepG2 cells, which made up for the shortcomings of previous anti-DIC drugs.
These collective results innovatively documented that AU regulated the unique crosstalk between NRF2 and HIPK2 to coordinate oxidative stress, autophagy, and apoptosis against DIC without compromising the anti-tumor effect of DOX in vitro.
多柔比星（DOX）广泛用于治疗多种癌症。然而，其临床应用受到剂量依赖性心脏毒性的限制。最近的研究结果表明，氧化应激诱导的心肌细胞自噬和细胞凋亡主导了多柔比星诱导的心脏毒性（DIC）的病理生理学，但目前还没有针对这些的潜在分子。
本研究旨在探讨熊果苷（AU）是否通过不可复制的 NRF2 和 HIPK2 之间的串扰作用，调节 DIC 中的自噬、氧化应激和细胞凋亡，并为 DIC 的治疗提供新的替代策略。
我们首先证明了 AU 在 DIC 小鼠心脏结构和功能中的保护作用，表现为 EF 和 FS 值增加，血清 CK-MB 和 LDH 含量降低，HE 染色中心脏组织排列整齐。此外，AU 减轻了 DOX 诱导的小鼠心肌氧化应激、线粒体损伤、凋亡和自噬流失调，表现在心肌组织中 ROS、8-OHdG 和 TUNEL 阳性细胞减少，血清中 SOD 增加，MDA 减少，线粒体排列整齐，空泡减少，自噬体增加。在体外，AU 通过促进 NRF2 和 HIPK2 的表达，减轻了 DOX 诱导的氧化应激、自噬抑制和凋亡。我们还发现，DIC 中 NRF2 和 HIPK2 之间存在串扰，通过过表达 NRF2 或 HIPK2，分别逆转了由 HIPK2 或 NRF2 siRNA 加重的细胞氧化应激、自噬阻断和凋亡。同时，AU 促进了 NRF2 蛋白的表达和核定位，这一作用被 HIPK2 siRNA 逆转，AU 还提高了 HIPK2 蛋白的表达，这一作用被 NRF2 siRNA 逆转。重要的是，AU 不影响 DOX 对 MCF-7 和 HepG2 细胞的抗肿瘤活性，弥补了以前抗 DIC 药物的不足。
这些研究结果创新性地表明，AU 通过调节 NRF2 和 HIPK2 之间的独特串扰，在不影响 DOX 抗肿瘤作用的情况下，协调氧化应激、自噬和凋亡，对抗 DIC。
