ATF3 promotes ferroptosis by transcriptional repression of SLC7A11 in ischemic stroke

Activating transcription factor 3 (ATF3) and solute carrier family 7 member 11 (SLC7A11) have been implicated in ferroptosis following ischemic stroke. However, the precise regulatory mechanisms between ATF3 and SLC7A11 remain incompletely understood. This study aims to investigate the regulatory mechanism of ATF3 and SLC7A11 in ferroptosis during ischemic stroke. The stroke-related microarray dataset GSE58294 was downloaded from the GEO database. Differential gene expression analysis was performed to identify ferroptosis-related differentially expressed genes (FRDEGs). Bioinformatics analyses, including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment, and protein-protein interaction (PPI) network construction, were conducted. Key hub genes were validated in both a rat model of middle cerebral artery occlusion/reperfusion (MCAO/R) and a cellular model of oxygen-glucose deprivation/reoxygenation (OGD/R) using BV2 microglia. Cell viability was assessed by CCK-8 assay. Ferroptosis-related proteins were analyzed by Western blot, and apoptosis was detected by flow cytometry. Levels of reactive oxygen species (ROS) and Fe²⁺ were measured using immunofluorescence and ELISA, respectively. Bioinformatic analysis identified SLC7A11 as a significantly altered gene in stroke. The PPI network predicted ATF3 as a key transcription factor regulating SLC7A11. In vitro, transfection with si-ATF3 downregulated GPX4 and FTH1 levels while upregulating IREB2 and ALOX15. Furthermore, si-ATF3 transfection reduced ROS levels and iron concentration in microglia, effects that were reversed by the ferroptosis inducer erastin. Notably, SLC7A11 expression was significantly increased following ATF3 knockdown. Our findings demonstrate that ATF3 preliminarily promotes ferroptosis by binding to the SLC7A11 promoter and inhibiting its expression, providing a novel mechanistic insight into ischemic stroke pathology.