eEF2K alleviates doxorubicin-induced cardiotoxicity by inhibiting GSK3β and improving autophagy dysfunction.

Doxorubicin-induced cardiotoxicity (DIC) poses a threat to the health and prognosis of cancer patients. It is important to find a safe and effective method for the prevention and treatment of DIC. eEF2K, which is a highly conserved α-kinase, is thought to be a therapeutic target for several human diseases. Nonetheless, it is still uncertain if eEF2K contributes to the cardiotoxic effects caused by doxorubicin (DOX). Our research revealed that eEF2K expression decreased in the DIC. eEF2K was overexpressed through adeno-associated virus in vivo and adenovirus in vitro, which presented alleviative cardiomyocyte death and cell atrophy induced by DOX. Autophagy dysfunction is one of important mechanisms in DIC. As a result, autophagic function was evaluated using Transmission electron microscopy in vivo, as well as LysoSensor and mRFPGFP-LC3 puncta in vitro. eEF2K overexpression improves DOX-induced autophagy blockade. In addition, eEF2K knockdown aggravated autophagy blockade and cardiomyocyte injury in DIC model. eEF2K also phosphorylated and inhibited GSK3β in DIC model. AR-A014418 (ARi), known for selectively inhibiting GSK3β, countered the effects of eEF2K knockdown, which aggravated autophagy blockade in the DIC. In conclusion, this study proposes that eEF2K alleviates DIC by inhibiting GSK3β and improving autophagy dysfunction. eEF2K is a promising therapeutic target against DIC.