Integrating Single-Cell Sequencing, Machine Learning, and Molecular Docking to Elucidate the Molecular Network...

Di-(2-ethylhexyl) phthalate (DEHP), a pervasive environmental plasticizer, is detected in humans through dietary intake, inhalation, and dermal contact. Epidemiological evidence links urinary DEHP metabolites (e.g., MEHHP and MEOHP) to cardiovascular dysfunction, including reduced heart rate variability and endothelial impairment, which are key risk factors for myocardial infarction (MI). However, the cell-type-specific molecular mechanisms underlying DEHP-aggravated MI pathogenesis in specific cell types remain poorly characterized. This study aims to identify and validate DEHP-specific molecular mechanisms in immune cells that link exposure to MI pathogenesis through integrated machine learning (ML), single-cell RNA sequencing (scRNA-seq), and molecular docking (MD) approaches. Transcriptomic data sets (GSE66360, GSE60993, GSE61144, GSE48060, and GSE141512) were integrated to screen for MI-related genes via weighted gene co-expression network analysis (WGCNA) and a combined differential expression analysis. Simultaneously, DEHP targets were predicted using ChEMBL, PharmMapper, and SwissTargetPrediction. Shared DEHP-MI targets were then identified via intersection analysis and prioritized via an ensemble of 11 ML algorithms. Subsequently, immune cell infiltration was profiled via CIBERSORT, and scRNA-seq data (GSE269269) spatially validated cell-type-specific expression patterns of core genes. Finally, DEHP-target binding stability was evaluated by MD simulations. Intersection analysis identified 56 DEHP-MI targets that are shared and implicated in innate immune activation and chemotaxis. Six core genes (SLC2A3, MMP9, AKR1C3, DAPK2, MAP3K8, and TRIB1) were prioritized as diagnostic biomarkers (AUC = 0.981), with SHAP indicating SLC2A3 and MMP9 as primary drivers of MI prediction. These genes correlated with pro-inflammatory neutrophil/M0 macrophage infiltration (*r* = 0.585-0.772), while suppressing adaptive immune cells. scRNA-seq revealed cell-type-specific pathogenic mechanisms: MMP9 and SLC2A3 were localized to inflammation-primed CD14⁺ monocytes, and AKR1C3 was enriched in cytotoxic NK cells. MD confirmed high-affinity DEHP binding to all core targets (ΔG < -5.0 kcal/mol), structurally supporting their role as disruptors. DEHP exacerbates MI by directly binding to SLC2A3 and MMP9. This activates a pro-inflammatory immune dysregulation potential through cell-type-specific pathogenic mechanisms. Monocyte-enriched SLC2A3/MMP9 drives neutrophil recruitment and M0 macrophage polarization (*r* = 0.585-0.772), while NK cell-localized AKR1C3 disrupts cytotoxic regulation. This study deciphers DEHP cardiotoxicity via spatially resolved inflammatory-immune networks and provides novel therapeutic targets for environmental cardiovascular intervention.