Integrated Analysis of Macrophage‐Associated Necroptosis in Alopecia Areata

ABSTRACT

Necroptosis, a form of programmed cell death, promotes inflammation in immune‐mediated diseases, but its role in alopecia areata (AA) remains unclear. In this study, we investigated necroptosis‐related signatures in AA using integrated transcriptomic and histological analyses. Four bulk RNA‐seq datasets from the GEO database, comprising 191 scalp samples from AA patients and healthy controls, were analysed by ssGSEA and GSEA to assess necroptosis‐related signatures. To address the cellular heterogeneity inherent in bulk RNA data, we further performed single‐cell RNA‐sequencing (scRNA‐seq) to investigate cell‐specific mechanisms, and immunofluorescence staining of scalp biopsies was conducted to validate the expression and cellular localisation of key necroptosis‐related markers. Necroptosis‐related scores were significantly higher in AA than in controls, correlated with disease severity and decreased after JAK/TYK2 inhibitor therapy. At single‐cell resolution, a macrophage subset (IL4I1 ⁺ macrophages_1) showed the strongest necroptosis‐related signal and was associated with enhanced macrophage–fibroblast communication involving TGFβ, ITGB2 and GAS6 signalling, suggesting perifollicular microenvironmental remodelling. Immunofluorescence further supported increased necroptosis‐associated signalling and macrophage enrichment in AA lesions. Together, these findings suggest that macrophage‐associated necroptosis‐related programmes may represent a disease‐associated inflammatory component in AA and support further mechanistic investigation of necroptosis‐associated pathways in this disease.