P62-autophagic pathway degrades SLC7A11 to regulate ferroptosis in doxorubicin-induced cardiotoxicity.

Doxorubicin-induced cardiotoxicity (DIC) poses a significant challenge, impeding its widespread application. Emerging evidence suggests the involvement of ferroptosis in the DIC. While the downregulation of SLC7A11 expression has been linked to the promotion of ferroptosis, the precise regulatory mechanism remains unclear. Recent studies, including our own, have highlighted abnormal levels of autophagy adapter protein P62 and autophagy in DIC development. Thus, our study aimed to further investigate the role of autophagy and ferroptosis in DIC, elucidating underlying molecular mechanisms across molecular, cellular, and whole-organ levels utilizing gene knockdown, immunoprecipitation, and mass spectrometry techniques. The results of our findings unveiled cardiomyocyte damage, heightened autophagy levels, and ferroptosis in DOX-treated mouse hearts. Notably, inhibition of autophagy levels attenuated DOX-induced ferroptosis. Mechanistically, we discovered that the autophagy adaptor protein P62 mediates the entry of SLC7A11 into the autophagic pathway for degradation. Furthermore, the addition of autophagy inhibitors (CQ or BAF) could elevate SLC7A11 and GPX4 protein expression, reduce the accumulation of Fe and ROS in cardiomyocytes, and thus mitigate DOX-induced ferroptosis. In summary, our findings underscore the pivotal role of the P62-autophagy pathway in SLC7A11 degradation, modulating ferroptosis to exacerbate DIC. This finding offers significant insights into the underlying molecular mechanisms of DOX-induced ferroptosis and identifies new targets for reversing DIC.