Multi‐omics and machine learning identify neutrophil annexin A3 as a therapeutic target of ginsenoside Rb1 for comorbidity of ischaemic stroke and ulcerative colitis

Abstract Background and Purpose Epidemiological evidence suggests a bidirectional relationship between ischaemic stroke (IS) and ulcerative colitis (UC), yet the underlying molecular mechanisms remain poorly understood. Experimental Approach Four IS and three UC datasets from the gene expression omnibus (GEO) database were analysed to identify key comorbidity genes. Two‐sample Mendelian randomisation (MR) was conducted to infer causal relationships. Clinical validations utilised peripheral blood neutrophils from UC–IS patients, assessed via western blotting and quantitative real‐time polymerase chain reaction (qRT‐PCR). The direct binding of ginsenoside Rb1 to annexin A3 (ANXA3) was verified through molecular docking, molecular dynamics simulations and cellular thermal shift assay (CETSA). Key Results MR analysis indicated a causal association between ANXA3 expression and increased risk of IS and UC. Immune infiltration analysis demonstrated a strong positive correlation between ANXA3 expression and neutrophil infiltration in both IS and UC. ScRNA‐seq confirmed that ANXA3 was expressed in neutrophils within diseased tissues. Circulating neutrophils from UC–IS comorbidity patients showed significantly elevated ANXA3 mRNA and protein levels. Molecular dynamics simulations revealed a stable ginsenoside Rb1‐ANXA3 complex with favourable binding free energy. CETSA confirmed the direct binding of ginsenoside Rb1 to ANXA3 in primary human neutrophils. UC–IS serum induced neutrophil hyperactivation, including excessive migration, NETosis, myeloperoxidase (MPO) release and reactive oxygen species (ROS) production, which was significantly attenuated by ginsenoside Rb1 in vitro. Conclusions and Implications ANXA3 is a predominant neutrophil‐derived biomarker linking UC–IS comorbidity. Ginsenoside Rb1 mitigates comorbidity‐induced neutrophil hyperactivation by directly binding ANXA3, representing a promising therapeutic strategy.