Liraglutide attenuates doxorubicin-induced cardiomyocyte ferroptosis via DHHC7-mediated STAT3 palmitoylation

Abstract

Aims: This study aimed to investigate liraglutide's protective effects against doxorubicin (DOX)-induced cardiotoxicity and ferroptosis, and to elucidate the underlying mechanisms involving signal transducer and activator of transcription 3 (STAT3) signaling and its post-translational palmitoylation.

Materials and methods: In vivo models of chronic DOX-induced cardiotoxicity were established in male C57BL/6 J mice. Cardiac function was assessed via echocardiography. Ferroptosis markers such as malondialdehyde (MDA), glutathione (GSH), iron (Fe²⁺), reactive oxygen species (ROS), mitochondrial ultrastructure) were evaluated in myocardial tissue and H9c2 cardiomyocytes. Bioinformatics analysis of the GSE193861 dataset identified ferroptosis-related differentially expressed genes. STAT3 and DHHC7 were modulated using short hairpin RNA (shRNA) knockdown and cardiomyocyte-specific adeno-associated virus 9 (AAV9)-mediated overexpression. Molecular interactions were assessed via co-immunoprecipitation, acyl-biotin exchange assays, and western blotting.

Key findings: Liraglutide administration significantly attenuated DOX-induced cardiac dysfunction and cardiomyocyte ferroptosis. Bioinformatics identified STAT3 as a central regulator, with liraglutide restoring DOX-impaired STAT3 phosphorylation and nuclear translocation, thereby enhancing transcription of the anti-ferroptotic enzyme glutathione peroxidase 4 (GPX4). STAT3 knockdown abolished liraglutide's protection. Mechanistically, liraglutide upregulated the palmitoyltransferase DHHC7, rescuing DOX-suppressed STAT3 palmitoylation. DHHC7 knockdown and palmitoylation inhibition abrogated liraglutide-mediated STAT3 phosphorylation and anti-ferroptotic effects. Crucially, cardiomyocyte-specific DHHC7 overexpression replicated liraglutide's cardioprotection, mitigating DOX-induced ferroptosis and dysfunction.

Significance: We demonstrate a novel cardioprotective axis wherein liraglutide enhances DHHC7-dependent STAT3 palmitoylation, facilitating its phosphorylation, nuclear translocation, and transcriptional activation of GPX4 to suppress ferroptosis. This study provides the first evidence that DHHC7-mediated STAT3 palmitoylation is essential for liraglutide's efficacy, identifying a promising therapeutic target for DOX cardiotoxicity.

Keywords: DHHC7; Doxorubicin induced cardiotoxicity; Ferroptosis; Liraglutide; Palmitoylation; STAT3.