Lnc-ANRIL Protects Against Myocardial Ischemia-Reperfusion Injury by Suppressing Ferroptosis via the miR-7238-3p/GPX4 Axis.

BACKGROUND/AIMS: Myocardial infarction remains a leading cause of cardiovascular morbidity and mortality. Although reperfusion therapy restores myocardial blood flow, it can induce myocardial ischemia-reperfusion injury (MI/RI). Ferroptosis, an iron-dependent form of regulated cell death driven by excessive lipid reactive oxygen species, contributes to MI/RI and is characterized by downregulation of GPX4 and upregulation of ACSL4. LncRNA ANRIL is aberrantly expressed in acute myocardial infarction and may provide myocardial protection, but its role in MI/RI-induced ferroptosis is unclear.

METHODS

A mouse MI/R model was established by ligating the left anterior descending coronary artery in C57BL/6 mice. HL-1 and H9C2 cardiomyocytes underwent hypoxia-reoxygenation to simulate MI/RI in vitro. Lnc-ANRIL was overexpressed using pEGFP-lnc-ANRIL or silenced using siANRIL. Ferroptosis indicators (ROS, malondialdehyde, Fe2+, GPX4, ACSL4) were assessed. Candidate miRNAs targeting lnc-ANRIL and GPX4 were predicted (miRDB) and validated by dual-luciferase assays.

RESULTS

Ferroptosis was activated in MI/R tissues and hypoxia-reoxygenation-treated cardiomyocytes, with decreased GPX4, increased ACSL4, and elevated ROS, malondialdehyde, and Fe2+. Lnc-ANRIL expression was reduced. Overexpression of lnc-ANRIL attenuated ferroptosis markers and increased GPX4, whereas lnc-ANRIL silencing exacerbated ferroptosis. Mechanistically, lnc-ANRIL acted as a sponge for miR-7238-3p, which targets the 3'-UTR of GPX4 to suppress expression. Overexpression of miR-7238-3p enhanced ferroptosis and cardiomyocyte damage.

CONCLUSION

MI/RI downregulates lnc-ANRIL, relieving inhibition of miR-7238-3p and suppressing GPX4, thereby triggering ferroptosis in cardiomyocytes. Lnc-ANRIL protects against MI/RI-induced ferroptosis via the miR-7238-3p/GPX4 axis, suggesting a potential therapeutic target.