Sphingomonas paucimobilis ‐Driven Epithelial–Endothelial Transition in Adenomyosis Pathogenesis

ABSTRACT Adenomyosis is a common gynecological disorder with incompletely understood pathogenesis. Through single‐cell RNA sequencing of adenomyosis tissues, we identified epithelial–endothelial transition (EET) as a key pathological mechanism and discovered transitional cells co‐expressing epithelial (EPCAM) and endothelial (PECAM1) markers. Using CSI‐Microbes pipeline and 2bRAD‐M validation, we found significant enrichment of Sphingomonas paucimobilis in adenomyosis lesions with spatial co‐localization to EET cells. Mouse experiments confirmed that vaginal inoculation with live S. paucimobilis recapitulated adenomyosis development, indicating that viable bacteria are required. Systematic inhibitor experiments validated a TNFα → NF‐κB → MMP signaling cascade: TNFα neutralization and NF‐κB inhibition blocked pathway activation and EET, while MMP inhibition attenuated downstream phenotypic changes. Protein‐level validation by Western blot and immunofluorescence across human tissue, mouse models, and cell culture confirm EET marker changes. This study elucidates a novel microbial‐driven cellular transformation mechanism and identifies actionable therapeutic targets for adenomyosis.