RBM15-mediated m6A methylation of Entpd1/CD39 regulates extracellular ATP hydrolysis and alleviates myocardial ischemia-reperfusion injury.

Myocardial ischemia-reperfusion (I/R) injury is a major cause of heart damage, linked to disrupted ATP metabolism and oxidative stress. While m6A RNA methylation regulates various cellular processes, its role in modulating I/R injury and ATP hydrolysis remains unclear. In this study, we demonstrate that both in vivo (rat I/R model) and in vitro (H/R-treated cardiomyocytes) models exhibit increased m6A modification levels during I/R injury. Among key m6A regulators, RBM15 is significantly upregulated in ischemic heart tissue. Functional assays reveal that RBM15 directly modulates the m6A methylation of Entpd1 (CD39), enhancing its expression and activity. Overexpression of RBM15 promotes ATP hydrolysis, resulting in increased adenosine production. These molecular changes collectively mitigated oxidative stress, reduced inflammation, and decreased apoptosis, resulting in improved cardiac function, smaller infarct sizes, and less cell death in the I/R model. These protective effects are reversed by CD39 inhibitor (sodium polyoxotungstate, POM-1), confirming the pivotal role of CD39 in this pathways. Mechanistically, RBM15 also activates the AMPK and AKT/ERK/GSK3β signaling pathway by increasing phosphorylation levels, further contributing to cardioprotection. In summary, RBM15-mediated m6A methylation enhances CD39 expression, facilitating extracellular ATP hydrolysis and exerting protective effects against myocardial I/R injury, highlighting its potential as a therapeutic target.