Multi-omics analysis of early reperfused ischemic heart reveals ERRβ/γ activation protects against acute myocardial infarction injury

• Multi-Omics Analysis: We provide novel insights into the transcriptional and metabolic reprogramming triggered by ETR as compared with LTR, highlighting the roles of cardiomyocyte energenesis and dedifferentiation. • Cardiomyocyte Diversity: Single-nucleus RNA sequencing revealed distinct cardiomyocyte subpopulations preserved by ETR relative to LTR, offering new insights into heart repair mechanisms. • ERRβ/γ Activation: We demonstrate the therapeutic potential of ERRβ/γ activation in enhancing ETR protection, suggesting a promising strategy for AMI treatment. Acute myocardial infarction (AMI) is a leading cause of morbidity and mortality globally, with timely percutaneous coronary intervention (PCI) as the standard treatment. Early time reperfusion (ETR) shown to reduce arrhythmias and improved survival rates compared to late time reperfusion (LTR). However, cellular and molecular mechanisms underlying the protective effects of ETR effects relative to LTR on AMI remain poorly understood. This study aims to elucidate these mechanisms through an integrated multi-omics approach, focusing on cardiomyocyte energenesis and dedifferentiation, while also exploring the therapeutic potential of ERRβ/γ activation. AMI was induced in rats by ligating the left anterior descending coronary artery (LAD) for one hour (ETR) or six hours (LTR), followed by reperfusion. Sham-operated rats served as controls. Comprehensive analyses of the ischemic hearts were performed using bulk tissue transcriptomic sequencing, metabolomic profiling, and single-nucleus RNA sequencing. Additionally, the role of ERRβ and ERRγ was investigated in neonatal rat ventricular myocytes (NRVMs) subjected to hypoxia/reoxygenation (H/R). The ERRβ/γ agonist GSK4716 was administered in vivo before ETR to assess its potential to enhance the therapeutic effects of ETR on AMI injury, and its protective mechanism was compared to fenofibrate. Transcriptomic and metabolomic profiling revealed that the protective effect of ETR on AMI relative to LTR is primarily mediated by cardiomyocyte energenesis and dedifferentiation. Single-nucleus RNA sequencing identified four distinct cardiomyocyte subpopulations (CM1-CM4), with ETR preserving a larger proportion of sub-injured CM2 and immature-like CM4. Additionally, ERRβ/γ was found to regulate the expression of cardiomyocyte energenesis and dedifferentiation signature genes both in vivo and in vitro. Treatment with the ERRβ/γ agonist GSK4716 significantly enhanced ETR’s protective effects on AMI relative to LTR by activating energenesis and dedifferentiation-associated genes. These findings indicate that ETR protects against AMI relative to LTR by preserving cardiomyocyte energenesis and dedifferentiation. The activation of ERRβ/γ significantly enhanced these protective effects, highlighting its therapeutic potential in mitigating AMI outcomes