ALOX15 Modulates Ferroptosis via the Reactive Oxygen Species-Mediated MAPK Pathway in Doxorubicin-Induced Cardiotoxicity

<b><i>Aims:</i></b> Doxorubicin (Dox) is a potent chemotherapy agent, yet its clinical use is hampered by cardiotoxicity. Although extensive research has focused on Dox-induced cardiotoxicity (DIC), its mechanism remains elusive. Recent evidence implicates ferroptosis as a key contributor to DIC. The 15-lipoxygenase-1 (ALOX15), involved in lipid peroxidation, is known to play an essential role in ischemia-induced myocardial damage and heart failure; however, its function in DIC is undefined. This study seeks to elucidate the role of ALOX15 in DIC and unravel its underlying mechanism. <b><i>Results:</i></b> Both ALOX15 mRNA and protein levels were elevated in DIC models <i>in vivo</i> and <i>in vitro</i>. Inhibition or silencing of ALOX15 ameliorated lipid peroxidation, ferroptosis, and cardiac dysfunction in Dox-treated mice. Consistently, ALOX15 loss of function protected H9C2 cells against Dox and RSL3-induced toxicity. In addition, we found that linoleic acid increased the susceptibility of H9C2 cells toward Dox-induced damage, which was abolished by ALOX15 inhibition. Furthermore, <i>Alox15</i> overexpression aggravated Dox-induced cell damage by aggravating reactive oxygen species (ROS)-mediated ferroptosis. Mechanistically, we discovered that the amelioration of Dox-induced ferroptosis by ALOX15 loss of function occurred through inhibiting the ROS-mediated mitogen-activated protein kinase (MAPK) signaling pathway activation. <b><i>Innovation and Conclusion:</i></b> These results reveal that ALOX15 regulates ferroptosis through ROS-mediated MAPK signaling pathway in DIC, suggesting a potential therapeutic target for DIC intervention. <i>Antioxid. Redox Signal.</i> 43, 363-380.