Alkbh5 promotes Ythdf1 expression through demethylation thereby facilitating Fth1 translation to inhibit ferroptosis of myocardial infarction.

BACKGROUND: Myocardial infarction (MI) is a leading cause of global mortality. Ferroptosis, an iron-dependent form of programmed cell death, has recently emerged as a critical player in cardiovascular diseases. N6-methyladenosine (m6A), the most prevalent RNA methylation modification in eukaryotic cells, has been implicated in various pathological processes; however, its regulatory role in MI through ferroptosis remains poorly understood. This study aimed to elucidate the mechanism by which m6A methylation mediates MI via ferroptosis. METHODS: A hypoxia/reoxygenation (H/R) model was established using H9C2 cells to simulate myocardial injury. RNA methylation levels were quantified via dot blot assay. Ferroptosis was evaluated by measuring lactate dehydrogenase (LDH) release, Fe(2+) levels, glutathione (GSH), lipid reactive oxygen species (ROS), malondialdehyde (MDA), and apoptosis. The underlying molecular mechanisms were investigated using western blotting, quantitative real-time PCR (qPCR), methylated RNA immunoprecipitation (MeRIP), and RIP. Findings were further validated in a myocardial ischemia/reperfusion injury (MIRI) rat model. RESULTS: The results revealed that m6A levels were significantly elevated in the H/R cell model, accompanied by reduced expression of Alkbh5 mRNA. Moreover, Alkbh5 overexpression inhibited ferroptosis increased in the H/R model. Mechanistically, Alkbh5 overexpression decreased m6A levels of Ythdf1 and H9C2 cells while promoting Fth1 translation by enhancing Ythdf1 mRNA expression. Knockdown of Ythdf1 restored ferroptosis in the H/R model, counteracting the effects of Alkbh5 overexpression. Furthermore, Alkbh5 overexpression alleviated myocardial injury in the MIRI rat model, upregulated Ythdf1 mRNA expression, and increased Fth1 protein levels. CONCLUSION: This study demonstrates that Alkbh5 ameliorates MI by inhibiting ferroptosis through m6A demethylation of Fth1. These findings provide novel insights into the molecular mechanisms underlying MI and highlight potential therapeutic targets for MI treatment.