DBT Modulates Copper-Dependent Cuproptosis-Related Injury in Experimental Alcoholic Cardiomyopathy

Alcoholic cardiomyopathy (ACM) is a severe cardiovascular complication of chronic alcohol consumption, but its underlying mechanisms remain incompletely understood. Cuproptosis is a recently identified copper-dependent form of regulated cell death; however, its role in ACM remains unclear. In this study, male C57BL/6 mice were fed an ethanol-containing Lieber-DeCarli liquid diet to establish an ACM model, and RNA sequencing combined with bioinformatics analysis was performed to identify cuproptosis-related genes. Among the candidate genes, dihydrolipoamide branched-chain transacylase E2 (DBT) showed a consistent trend of downregulation across both independent RNA-seq cohorts, and was further validated by qRT-PCR and Western blotting. ACM mice exhibited increased serum and cardiomyocyte copper content, altered cuproptosis-related markers and impaired cardiac function. In AC16 cells, DBT knockdown induced copper overload, cuproptosis-related molecular alterations and mitochondrial dysfunction, which were markedly alleviated by the copper chelator tetrathiomolybdate. Conversely, DBT overexpression attenuated EtOH-induced copper overload, cuproptosis-related molecular alterations and mitochondrial dysfunction, with effects similar to those of tetrathiomolybdate. These findings suggest that DBT regulates ACM-related cardiomyocyte injury through cuproptosis-associated processes at the cellular level and may represent a potential therapeutic target for alcohol-induced myocardial injury.