tsRNA-3025a Impairs Mitochondrial Function and Autophagy to Inhibit Myocardial Regeneration and Repair Following Ischemia-Reperfusion Injury.

Myocardial ischemia-reperfusion (I/R) injury is a frequent complication of acute myocardial infarction (AMI), yet clinical biomarkers and targets remain limited. Although tRNA-derived small RNAs (tsRNAs) are emerging cardiovascular regulators, their roles in I/R injury are not fully elucidated. We identified tsRNA-3025a via sequencing in mouse I/R models and validated its clinical significance. Circulating tsRNA-3025a was significantly upregulated in AMI and unstable angina patients, independently predicting adverse events within 30 days. Functionally, tsRNA-3025a exacerbated apoptosis and mitochondrial dysfunction in vitro, while its in vivo silencing reduced infarct size, improved cardiac function and increased the proportion of Ki67- and pH3-positive cardiomyocytes. Mechanistically, tsRNA-3025a aggravated injury by targeting PIK3C2A, thereby suppressing autophagosome formation and impairing protective autophagic flux during reperfusion. In conclusion, circulating tsRNA-3025a serves as a prognostic biomarker for post-PCI patients. Targeting tsRNA-3025a attenuates myocardial I/R injury and restores myocardial regeneration and repair by regulating PIK3C2A-mediated protective autophagy flux.