Abstract
BACKGROUND/PURPOSE: Sjögren's syndrome (SS) is a chronic systemic autoimmune disease characterized by lymphocytic infiltration and formation of lymphoepithelial lesions (LEL) in exocrine glands, leading to secretory dysfunction. DNA methylation, a dynamically regulated epigenetic mark, has been increasingly recognized as a key regulatory mechanism in the pathogenesis of autoimmune diseases including SS, and holds promise for identifying novel diagnostic and therapeutic strategies. METHODS: Reduced representation bisulfite sequencing (RRBS) was performed on 4 cases of SS and 3 controls to profile genome-wide DNA methylation patterns. Differentially methylated regions (DMRs) and associated differentially methylated genes (DMGs) were detected, followed by functional enrichment analysis. Integration with transcriptomic data (GSE40611) was performed to identify overlapping epigenetic and transcriptional changes. RESULTS: A total of 29,462 DMRs were detected, with 24,116 hypermethylated and 5,346 hypomethylated regions, indicating an overall increase in methylation levels of SS, and DMGs located in gene promoter regions were significantly enriched in pathways related to immune response, transcriptional regulation, and inflammation. Nine hub genes (LCP2, BTK, LAPTM5, ARHGAP9, IKZF1, WDFY4, CSF2RB, ARHGAP25, DOCK8) were identified, which displayed promoter hyper-or hypomethylation, indicating the complex epigenetic regulatory mechanisms. CONCLUSION: This study reveals extensive DNA methylation alterations in SS, providing new insights into the epigenetic mechanisms underlying pathogenesis. Moreover, these findings suggest potential biomarkers or therapeutic targets for further investigation to elucidate detailed molecular mechanisms of SS.