Xanthosine alleviates myocardial ischemia-reperfusion injury through attenuation of cardiomyocyte ferroptosis.

Background: Ischemic heart disease remains a leading cause of morbidity and mortality worldwide, with myocardial ischemia-reperfusion (I/R) injury significantly contributing to cardiomyocyte death and poor outcomes post-acute myocardial infarction (AMI). Emerging evidence highlights metabolic changes during myocardial injury, particularly in purine metabolism. This study investigates the protective role of xanthosine (XTS), a purine metabolism intermediate, in alleviating I/R injury.

Methods: Neonatal and adult mouse myocardial tissues post-myocardial infarction (MI) were analyzed using untargeted and targeted metabolomics to explore metabolic profiles. The effects of XTS on I/R injury were evaluated in vivo using a murine I/R model and in vitro with hypoxia/reoxygenation-treated neonatal rat cardiomyocytes (NRCMs). Cardiac function, fibrosis, apoptosis, oxidative stress markers, and ferroptosis-related pathways were assessed via echocardiography, biochemical assays, western blotting, and electron microscopy. Integrated drug affinity responsive target stability (DARTS)-based drug target screening and RNA-seq transcriptomic profiling elucidate XTS-mediated mechanisms against I/R injury.

Results: Metabolomics revealed distinct differences in purine metabolism between neonatal and adult mice post-MI, with significant XTS accumulation observed in neonatal hearts. In vivo, XTS treatment in adult mice enhanced left ventricular function, reduced fibrosis, and alleviated lipid peroxidation and mitochondrial damage post-I/R injury. In vitro, XTS significantly improved cardiomyocyte viability, reduced oxidative stress, and mitigated ferroptosis by restoring glutathione peroxidase 4 (GPX4) levels and reducing acyl-coenzyme A synthetase long-chain family member 4 (ACSL4) expression. Mechanistically, XTS stabilized metabolic enzymes, upregulated L-arginine and glutathione (GSH) to mitigate reactive oxygen species(ROS), and inhibited ferroptosis.

Conclusions: XTS, a key purine metabolism intermediate, improves cardiac remodeling and function following I/R injury by suppressing ferroptosis and reducing mitochondrial ROS production. These findings provide novel insights into the therapeutic potential of XTS as an adjunctive treatment for patients with AMI undergoing revascularization.