This article aims to use high-throughput sequencing to identify miRNAs associated with ferroptosis in myocardial ischemia-reperfusion injury, select a target miRNA, and investigate its role in H9C2 cells hypoxia-reoxygenation injury.

In summary, miRNA-541-5p may be a biomarker of myocardial I/R damage diseases and can regulate oxidative stress and iron death by inhibiting the expression of miRNA-541-5p, thereby reducing mechanisms of I/R injury.

SD rats and H9C2 cells were used as subjects. ELISA kits quantified MDA, SOD, GSH, LDH, and ferritin levels. TTC staining evaluated infarction size. HE staining observed histopathological changes. DCFH-DA fluorescent probe detected ROS. CCK-8 kit measured cell viability. HiSeq 2000 sequencing performed differential expression analysis of miRNAs. qRT-PCR and Western blots assessed the expression levels of GPX-4, ACSL-4, HO-1, TFR-1 and TFR-2. SPSS 21.0 software conducted statistical analysis.

Myocardial ischemia-reperfusion injury resulted in decreased levels of SOD and GSH, increased levels of LDH and MDA, up-regulation of ferritin, ACSL-4, HO-1, and TFR-2, down-regulation of GPX-4, increased tissue damage, and accumulation of ROS. However, DFO treatment reversed these changes. Subsequently, the target gene miRNA-541-5p was obtained by miRNA sequencing screening, and further validation revealed that miRNA-541-5p expression was increased in the myocardial tissues of rats in the I/R injury model group compared with those of rats in the NC group, P < 0.05. Subsequently, by constructing H9C2 cell lines with miRNA-541-5p overexpression and miRNA-541-5p expression inhibition, miRNA-541-5p expression was inversely correlated with the survival of H9C2 cells after hypoxia-reoxygenation injury. miRNA-541-5p up-regulation led to a decrease in SOD and GSH, an increase in ferritin and MDA, and an accumulation of ROS. wb and qRT-PCT demonstrated that high miRNA-541-5p expression up-regulated the expression of protein/mRNA expression of ACSL-4, HO-1, ferritin, and TFR-1, but down-regulated protein/mRNA expression of GPX-4. In addition, ADAM 7, FNIP 2, HOXD 10, HCCS and STK 3 were preliminarily identified as potential candidate target genes for miRNA-541-5p by bioinformatics analysis. Among them, ADAM7 emerges as the most suitable potential target gene based on the selection criteria.