Silencing of Voltage-Dependent Anion Channel 2 Alleviates Myocardial Ischemia-Reperfusion Injury by Reversing Autophagy-Induced Ferroptosis of Cardiomyocytes

Background: Myocardial ischemia-reperfusion injury (IRI) is a critical pathological process impacting clinical outcomes after cardiac events. While the voltage-dependent anion channel 1 (VDAC1) has been implicated in IRI progression, the role of its isoform, VDAC2, remains less defined. Herein, we investigated the specific role and potential mechanism of VDAC2 in myocardial IRI. Methods: H9c2 cardiomyocytes of rats were transfected and underwent hypoxia/reoxygenation (H/R) modeling, after which treatment with Rapamycin was performed. Key molecules, including VDAC2, autophagy-related proteins, and mechanistic target of rapamycin complex 1 (mTORC1) signaling components, were quantified using quantitative real-time PCR and Western Blotting. Cell viability and apoptosis were assessed via Cell Counting Kit-8 assay and flow cytometry. Creatine kinase (CK) and lactate dehydrogenase (LDH) activities, along with Fe2+ content, were measured to evaluate myocardial injury and ferroptosis. Results: VDAC2 expression was promoted in H/R-induced H9c2 cells. VDAC2 silencing promoted viability and suppressed apoptosis of H/R-induced H9c2 cells. VDAC2 silencing reversed H/R-induced down-regulation of mTORC1 signaling (p-mTOR/mTOR and p-p70s6k/p70s6k ratios), and up-regulation of CK and LDH activities, Fe2+ content, and autophagy markers (Beclin-1 and LC3B-II/LC3B-I ratio) in H9c2 cells. However, Rapamycin reversed the protective effect of VDAC2 silencing on H/R-induced H9c2 cells, as evidenced by enhanced autophagy and apoptosis, elevated Fe2+ levels, and decreased viability. Conclusion: VDAC2 silencing alleviates myocardial IRI potentially through modulation of autophagy and ferroptosis-related processes of cardiomyocytes. These findings identify a novel role of VDAC2 in IRI pathogenesis and position it as a promising candidate for therapeutic intervention in cardiac reperfusion injury.