Decoding monocyte signatures in ischemic stroke: A multi-scale transcriptomic approach

Monocytes play a crucial role in post-stroke immune infiltration, yet the intricate immune regulatory networks they orchestrate in ischemic stroke remain poorly understood. This knowledge gap has hindered the development of targeted monocyte-based therapies for stroke. Here, we used a multi-omics approach combining single-cell and bulk transcriptomics. CellChat analysis revealed intercellular communication networks, while key genes were identified and predictive models built through Lasso regression. Immune cell infiltration dynamics were quantified using single-sample gene set enrichment analysis. Gene set enrichment analysis and gene set variation analysis identified disease-regulated pathways of core genes. MicroRNA networks and transcription factors were investigated using mircode and RcisTarget. Experimental validation was performed using oxygen–glucose deprivation and transient middle cerebral artery occlusion models, focusing on the influence of abhydrolase domain-containing protein 2 on monocyte function. We observed significantly elevated monocyte content in stroke brain tissue samples, and identified key monocyte genes associated with immune inflammation, chemokine signaling, and cell receptor function. A robust seven-gene predictive model for ischemic stroke was developed. CD274 strongly correlated with these seven genes, suggesting a potential immunomodulatory axis. In vivo transient middle cerebral artery occlusion experiments validated the predictive value of key genes. In vitro studies demonstrated that abhydrolase domain-containing protein 2 overexpression enhanced monocyte proliferation and phagocytic activity post-oxygen–glucose deprivation while reducing reactive oxygen species generation. In conclusion, this study maps post-stroke monocyte communication networks, identifies key signaling pathways, identifies regulatory mechanisms, and validates the functional importance of key genes, particularly abhydrolase domain-containing protein 2. These findings provide a foundation for developing targeted immunomodulatory therapies and precision diagnostics in ischemic stroke management.