Wilforine attenuates inflammatory osteolysis by suppressing osteoclast fusion through JAK-STAT-stomatin immunoregulatory signaling.

BACKGROUND: Excessive osteoclast fusion and activation are central drivers of bone erosion in inflammatory osteopathies, which are closely linked to immune dysregulation. Wilforine, a natural compound, exhibits immunomodulatory and therapeutic potential, yet its precise mechanism of action-particularly its influence on the osteoclast membrane microenvironment and associated immune signaling-remains incompletely understood. METHODS: We employed a multi-level strategy combining in vivo and in vitro functional validation with systematic multi-omics analysis. The in vivo efficacy of Wilforine was assessed in a Pstpip2(cmo) mouse model via Micro-CT and histopathology. In vitro studies utilized osteoclast culture, TRAP staining, scanning electron microscopy, and immunofluorescence to evaluate cell fusion and protein localization. Preliminary target prediction was conducted using network pharmacology. The core mechanism was elucidated through integrated proteomics and transcriptomics, followed by targeted functional validation including β-cyclodextrin-mediated lipid raft disruption and immune-related pathway analysis. RESULTS: Wilforine significantly alleviated bone erosion, marrow edema, and inflammatory infiltration in vivo, and potently inhibited osteoclast multinucleation in vitro. Multi-omics profiling revealed that Wilforine broadly reversed disease-associated dysregulation, specifically upregulating cholesterol metabolism and glycosphingolipid biosynthesis pathways while modulating key immune-inflammatory networks such as NF-κB. This systemic remodeling of the lipid metabolic landscape was functionally linked to the disruption of membrane lipid raft integrity-critical platforms for immune receptor signaling. Consequently, the raft-dependent localization and function of key fusion proteins (CD9, DC-STAMP) were impaired. Mechanistically, Wilforine exerted these effects by suppressing the JAK-STAT signaling pathway, a central regulator of immune and inflammatory responses, leading to the downregulation of the essential lipid raft scaffold protein Stomatin. CONCLUSION: This study defines a novel immunometabolic mechanism wherein Wilforine inhibits osteoclast fusion and bone resorption by reprogramming cellular lipid metabolism and disrupting the "JAK-STAT - Stomatin - Lipid Raft" functional axis. It highlights lipid rafts as a viable immunomodulatory microenvironment in bone disorders and provides a strong multi-omics-supported rationale for developing Wilforine as a bone-targeted immunotherapeutic agent.