Spatial multi-omics profiling uncovers metabolic heterogeneity in Sjögren's syndrome and identifies PS(36:1) as a potential therapeutic target.

BACKGROUND: Sjögren syndrome (SS) is a common autoimmune disease characterized by lymphocytic infiltration. Describing the transcriptional and metabolic features of the disease from a spatial perspective can enhance our understanding of the disease pathogenesis and treatment; METHODS: We collected eight human labial samples, including four labial gland samples from patients with SS and from four healthy controls. We integrated single-cell RNA sequencing, spatial transcriptomics, and spatial metabolomics techniques to generate SS-associated spatial gene expression maps and spatial metabolite profiles at a single-cell resolution. We also analyzed the characteristic metabolic and genetic changes of SS samples and infiltrated CD4+ T cells. Immunohistochemistry was used to detect the infiltration of CD4+ T cells in the salivary glands. In vivo experiments were conducted using NOD/ShiLtj mice to validate the therapeutic effects of targeting PS(36:1) on SS-like symptoms, as assessed by HE staining, salivary flow rate assays, and immunofluorescence experiments. RESULTS: Comprehensive data from spatial multi-omics identified the cell types and distributions within the immune microenvironment of salivary glands in SS. CCL19 was significantly increased in lymphocyte infiltration, while IGHG4 was elevated in glandular area. Linoleic acid metabolism undergoes reprogramming in SS, with alterations in lecithin, linoleic acid, 13(S)-hydroxyoctadecadienoic acid and dihomo-γ-linolenate. Furthermore, PS (36:1) was found to be abnormally enriched in lymphocyte focus, which may be related to the abnormal expression of CD74 and HLA-DRA. Also, CXCL13 corresponded to areas resembling high levels of PS(36:1) in infiltrated CD4+T cells. We further investigated the effect of CD4+ T cells on the reprogramming of glycerophospholipid metabolism in SS, including key regulatory genes and key metabolites. Among them, LYPLA2 and PS(36:1) exhibited the most representative results. In vivo, the PS(36:1) synthesis inhibitor alleviated dry mouth symptoms and reduced lymphocyte infiltration in the salivary gland tissues of NOD/ShiLtj mice, while also suppressing CD4+ T cell accumulation in the infiltrating foci. CONCLUSIONS: The multi-omics analysis conducted in this study enhances our understanding of the key regulatory mechanisms driving the pathogenesis of SS and offers novel insights for its precision therapy. Furthermore, PS(36:1) emerged as a potential therapeutic target for future SS research and treatment.