IRF9-dependent transcriptional regulation of SLC40A1 suppresses ferroptosis in dilated cardiomyopathy

The specific involvement and regulatory mechanisms of programmed cell death (PCD) subtypes in the pathogenesis of dilated cardiomyopathy (DCM) remain poorly characterized. This study aims to systematically investigate PCD network alterations and identify pivotal therapeutic targets in DCM progression. We performed Gene Set Variation Analysis (GSVA) enrichment analysis across two clinical DCM transcriptomic datasets to evaluate the activity of 18 PCD pathways. Following differential and protein-protein interaction (PPI) network analyses, the crucial hub gene was identified. The cardioprotective role of this gene was subsequently validated both in vitro (doxorubicin-induced cardiomyocyte injury) and in vivo (rat DCM model). Functional assessments included EdU incorporation, TUNEL staining, echocardiography, and redox homeostasis evaluations (GPX4, MDA, and GSH levels). Bioinformatic analysis revealed that the enrichment patterns of three PCD pathways were significantly dysregulated in DCM, with the ferroptosis pathway signature demonstrating the most prominent alteration. Integrated analysis identified the iron exporter SLC40A1 as a central hub gene, which was notably upregulated in DCM. Single-cell RNA sequencing further corroborated the pronounced upregulation of SLC40A1 in surviving cardiomyocytes and highlighted its extensive intercellular communication. In vitro and in vivo validation demonstrated that SLC40A1 overexpression significantly promoted cardiomyocyte proliferation, reduced apoptosis, and mitigated pathological cardiac remodeling and systolic dysfunction. Mechanistically, SLC40A1 overexpression exerted its cardioprotective effects by suppressing ferroptosis, evidenced by upregulated GPX4 expression, decreased lipid peroxidation (MDA), and restored intracellular GSH levels. Furthermore, dual-luciferase assays confirmed that the transcription factor IRF9 directly regulates SLC40A1 expression to modulate cellular redox status. Our multi-omics and experimental approach identifies SLC40A1 as a critical endogenous suppressor of ferroptosis in DCM pathogenesis, driven by IRF9-dependent transcriptional regulation. Enhancing the IRF9/SLC40A1 axis provides a novel therapeutic strategy for mitigating ferroptosis-mediated cardiac injury in cardiomyopathy.