EBBP‐Mediated Integrated Stress Response Attenuates Anthracycline‐Induced Cardiotoxicity by Inhibiting the Ferroptosis of Cardiomyocytes
Zilong Chen, Can Chen, Yichen Wu, Yinxue Xia, Ruijie Luo, Jiangcheng Shu, Long Chen, Zhaohui Wang, Cheng Wang, Kai Huang
Abstract
Anthracyclines are potent chemotherapeutics, but their clinical application is constrained by dose-dependent cardiotoxicity, in which ferroptosis plays a critical role. Here, EBBP (Estrogen-responsive B Box Protein) is identified as a key cardioprotective regulator in anthracycline-induced cardiotoxicity. Transcriptomic profiling of doxorubicin (DOX)-treated hearts reveals significant EBBP upregulation. Cardiac-specific overexpression of EBBP protects against myocardial injury and dysfunction by reducing DOX-induced ferroptosis. Conversely, EBBP silencing exacerbates DOX-induced cardiac damage, an effect reversed by ferroptosis inhibitor ferrostatin-1 (Fer-1). The molecular targets of EBBP are subsequently identified through bulk RNA sequencing, molecular docking analysis, co-immunoprecipitation experiments, and ubiquitination assays. Mechanistically, EBBP interacts with GRP78 to promote its K63-linked ubiquitination, disrupting the inhibitory GRP78-PERK interaction and activating PERK-mediated integrated stress response (ISR). This signaling cascade ultimately leads to the activation of downstream effectors ATF4 and Nrf2, which coordinately upregulates the SLC7A11/GSH/GPX4 axis and restores iron homeostasis. Importantly, pharmacological inhibition of PERK abolishes the protective effects of EBBP against myocardial injury and ferroptosis. Overall, our findings identify EBBP as a novel suppressor of ferroptosis in anthracycline-induced cardiotoxicity via the PERK-mediated ISR, thereby underscoring its therapeutic potential for preventing anthracycline-induced cardiomyopathy.