Role of m⁶A-Modified GAS6 in Rheumatoid Arthritis: Insights from Multi-Omics Analysis

Backgroud: Rheumatoid arthritis (RA) remains a debilitating autoimmune disease, and the involvement of RNA N6-methyladenosine (m⁶A) modification is unclear. This study integrated differential gene expression analysis, m⁶A methylome profiling and a series of functional assays to elucidate how the m⁶A-modified GAS6 contribute to RA. Methods: Synovial tissue samples were collected from RA and HC were used for m⁶A seq and RNA seq analysis. Peripheral blood mononuclear cells (PBMCs) were isolated from RA and HC. The mRNA expression of GAS6 and MERTK was quantified by qRT-PCR, and inflammatory cytokine (IL-1β, IL-6, IL-10, and TGF-β1) were detected by ELISA. GAS6, MERTK were knocked down in RA-FLS using siRNA interference. CCK-8 were used to assess cell viability, Flow cytometry to assess apoptosis , and Cell scratch assay to evaluate cell migration rate. Immunofluorescence and Western blott was used to determine protein localization and expression. Results: Integrated multi-omics analysis of synovial tissue and peripheral blood mononuclear cells from RA patients revealed concordant transcriptomic and epitranscriptomic dysregulation, highlighting 323 genes with both differential expression and m⁶A modification that were enriched in efferocytosis, Th17 differentiation, and cellular senescence.​Among these, GAS6 exhibited the most significant m⁶A hypermethylation and upregulated expression, and was validated as a key effector interacting with MERTK/AXL receptors. In RA patients, GAS6 and MERTK expression were elevated in blood and strongly correlated with clinical disease activity metrics. Functionally, GAS6 and MERTK cooperatively drove the malignant phenotype of fibroblast-like synoviocytes by enhancing proliferation, migration, inflammatory cytokine release, and apoptosis resistance. Conclusion: m⁶A modification, as a key epigenetic switch regulating the pathological process of RA, promotes the proliferation and inflammatory response of synovial cells by mediating abnormal activation of the GAS6/MERTK signaling axis, thereby driving disease progression. Targeting this pathway demonstrates the potential for treating RA.