METTL14 Promotes Cuproptosis-Associated Changes in Rats With Myocardial Ischemia-Reperfusion Injury

To investigate the role and mechanism of METTL14-mediated regulation of cuproptosis in myocardial ischemia-reperfusion injury (MI/RI). An MI/RI rat model was established. H9C2 cells were cultured and subjected to hypoxia/reoxygenation (H/R) modeling. Cells were transfected with siRNAs targeting METTL14 and ATP7A. Cell viability was detected by CCK-8 assay. Intracellular Cu²⁺ levels were measured using a biochemical kit. The interaction between METTL14 and ATP7A mRNA was verified by RNA immunoprecipitation (RIP) assay. Adenovirus containing si-METTL14 was constructed and injected into rats, followed by the induction of the MI/RI model. Cardiac function was evaluated by measuring ejection fraction (EF) and fractional shortening (FS) using echocardiography. Rat myocardial tissues were collected for Hematoxylin and Eosin (HE) staining. The mRNA expression of m6A regulatory enzymes was detected by quantitative PCR (qPCR). Cu²⁺ levels in myocardial tissue were measured using a biochemical assay kit. The expression of cuproptosis-related proteins was assessed by Western blot. MI/RI rats showed significantly decreased FS and EF values, with necrosis and hemorrhage, increased Cu²⁺ content, elevated mRNA levels of FTO, METTL3, ALKBH5, and METTL14, decreased ATP7A protein expression, and increased protein expression of FDX1, LIAS, and DLAT in the myocardial tissue. Intramyocardial injection of adenovirus containing si-METTL14 reversed the MI/RI-induced changes. In vitro, decreased cell viability, increased Cu²⁺ content, decreased ATP7A protein expression, and increased FDX1, LIAS, and DLAT protein expression were observed in H/R stimulated H9C2 cells, which were remarkably rescued by si-METTL14. Moreover, co-transfection with both si-METTL14 and si-ATP7A reversed effects induced by si-METTL14 alone. METTL14 promotes cuproptosis-associated changes and exacerbates MI/RI.