m6A-modified ATF4 regulates glucose/lipid metabolism via the Sestrin2/GSK3β axis to alleviate myocardial ischemia-reperfusion injury

Myocardial ischemia-reperfusion injury (MIRI) is a critical complication in the treatment of cardiovascular diseases, and its pathogenesis is closely associated with mitochondrial dysfunction and the imbalance of glucose/lipid metabolism. This study aims to investigate the molecular mechanisms underlying glucose/lipid metabolism in MIRI and identify potential therapeutic targets. Key genes and prognostic biomarkers related to MIRI were identified through bioinformatics analysis, and a hypoxia/reoxygenation (H/R) model using HL-1 cardiomyocytes was employed to simulate the pathological process of MIRI. RNA interference was used to knock down ATF4, and bioinformatics analysis identified key molecules involved in m6A methylation. The regulatory mechanism of ATF4 mRNA stability mediated by RBM15 was further explored. Flow cytometry, mitochondrial membrane potential, and ATP assays were conducted to evaluate cell apoptosis, glucose uptake, fatty acid oxidation, and mitochondrial function. Bioinformatics analysis and the H/R model experiments in HL-1 cardiomyocytes revealed that ATF4 was highly expressed in MIRI. Knockdown of ATF4 exacerbated H/R-induced cell apoptosis and metabolic disturbances. m6A methyltransferase RBM15 modulated the stability and expression of ATF4 mRNA through methylation. Further investigation showed that ATF4 upregulates Sestrin2 to inhibit GSK3β activity, thereby maintaining mitochondrial membrane potential and ATP production, promoting glucose uptake, and enhancing fatty acid oxidation. This study is the first to reveal the molecular mechanism by which the m6A modified ATF4-Sestrin2/GSK3β signaling axis alleviates MIRI through dual regulation of glucose/lipid metabolism homeostasis and mitochondrial energy supply. It elucidates the bridging role of RBM15-mediated m6A epigenetic modification in this process. These findings provide a new strategy for targeting metabolic reprogramming in MIRI therapy and suggest that ATF4 may serve as an intervention target. 1 ATF4 promotes glucose/lipid metabolism to ameliorate the progression of myocardial ischemia-reperfusion injury; 2 The m6A methylation modification of ATF4 ameliorates myocardial ischemia-reperfusion injury through Sestrin2; 3 In myocardial ischemia-reperfusion injury, Sestrin2 promotes glucose/lipid metabolism by negatively regulating GSK3β.