Gut microbiota-derived trimethylamine N-oxide contributes to cardiomyocyte pyroptosis and cardiac injury via the tRF-Glu–ANT1–GSDMD axis

AIMS: Recent research has shown that the gut microbiota arrests the progression of myocardial infarction (MI) by modulating immune inflammation, oxidative stress, and metabolism. However, the mechanism by which gut-derived trimethylamine N-oxide (TMAO) promotes cardiomyocyte pyroptosis following MI remains unclear. METHODS AND RESULTS: We found that a high-choline diet exacerbated cardiac injury in mice by disrupting the intestinal barrier. Under high-choline conditions, the expression levels of tRF-1:31-Glu-TTC-2 (tRF-Glu) derived from tRF and tiRNAs (tsRNAs) were elevated, serving as a key target for intervention in cardiomyocyte pyroptosis. Loss of tRF-Glu significantly ameliorated TMAO-induced deterioration of myocardial fibrosis and cardiac function. Mechanistically, tRF-Glu directly binds to the mitochondrial inner membrane protein ANT1 and stabilizes its expression by inhibiting ubiquitination. Cardiomyocyte knockdown of ANT1 significantly blocked the generation of TMAO-induced cardiomyocyte mitochondrial reactive oxygen species, restored cardiomyocyte membrane potential, and reduced mitochondrial DNA (mtDNA) leakage. CONCLUSIONS: Our findings indicate that tRF-Glu inhibits the ubiquitination of ANT1 under the induction of TMAO, which in turn activates gasdermin D (GSDMD) and mtDNA release, accelerating cardiac remodeling. In conclusion, our study provides new insights into the role of the gut microbial metabolite-driven tRF-Glu–ANT1–GSDMD pathway in blocking cardiomyocyte pyroptosis and cardiac injury.