NEDD4L-Mediated Ubiquitination of GPX4 Exacerbates Doxorubicin-Induced Cardiotoxicity.

Doxorubicin (DOX) is an anthracycline chemotherapeutic agent that is clinically limited by doxorubicin-induced cardiotoxicity (DIC), with ferroptosis and apoptosis identified as key mechanisms. As an antioxidant enzyme, GPX4 undergoes ubiquitin-mediated degradation during myocardial ischemia-reperfusion injury; however, the role of its ubiquitination in DIC remains unclear. This study revealed that GPX4 undergoes ubiquitinated degradation during DIC, exacerbating ferroptosis and apoptosis in cardiomyocytes. NEDD4L was found to interact with GPX4, and its expression was upregulated in DOX-treated mouse myocardial tissues and cardiomyocytes. NEDD4L knockdown alleviated DIC, as well as ferroptosis and apoptosis in cardiomyocytes. Mechanistically, NEDD4L recognizes GPX4 through its WW domain and mediates K48-linked ubiquitination and degradation of GPX4 under DOX stimulation via its HECT domain. Knockdown of NEDD4L reduced DOX-induced GPX4 ubiquitination levels and subsequent degradation. Notably, while NEDD4L knockdown mitigated DOX-induced cell death, concurrent GPX4 knockdown attenuated this protective effect, indicating that GPX4 is a key downstream target of NEDD4L in regulating cardiomyocyte death. These findings identify NEDD4L as a potential therapeutic target for preventing and treating DIC.