TFEB activator protects against ethanol toxicity-induced cardiac injury by restoring mitophagy and autophagic flux.

Excessive alcohol consumption is a major cause of alcoholic cardiomyopathy (ACM) and myocardial injury. This study aims to investigate the role of transcription factor EB (TFEB) in ethanol-induced cardiac anomalies using a murine model, AC16 human cardiomyocytes, and human plasma. Wild-type mice treated with a TFEB activator (Compound 1) or vehicle (25 mg/kg/d) were challenged with or without ethanol (3 g/kg/d, i.p.) for three consecutive days. Cardiac geometry and function were evaluated by echocardiography. The expressions of TFEB, molecules related to mitochondria, markers of apoptosis, mitophagy and lysosomes were examined in heart tissues and AC16 cardiomyocytes. Mitochondrial function, lysosome activity, and their localizations were measured in AC16 cardiomyocytes. Levels of TFEB and autophagic markers were also detected in human serum from healthy individuals and patients with ACM. Ethanol administration in mice induced severe cardiac dysfunction accompanied by upregulated P62 and LC3B, downregulated TFEB, lysosomal markers and mitophagy-associated receptors in heart tissues. Ethanol toxicity also led to reduced mitochondrial and lysosomal activity. Interestingly, TFEB activation mitigated the detrimental effects caused by ethanol. Inhibition of autophagy abolished the anti-apoptotic effect of TFEB in AC16 cells. In conclusion, TFEB is beneficial in ethanol-induced cardiac anomalies by reducing apoptosis, recovering lysosomal activity, and restoring proper mitophagy by unblocking mitochondrial autophagic flux.