The relationship between Sjögren's syndrome and recurrent pregnancy loss: a bioinformatics analysis.

Research Question: As Sjögren's syndrome is an autoimmune disease and an essential factor in recurrent pregnancy loss (RPL), are there gene-related relationships between the pathogenesis of Sjögren's syndrome and RPL?

Design: The gene datasets for Sjögren's syndrome and RPL were obtained from the Gene Expression Omnibus database, and the co-expression modules and shared differentially expressed genes were identified through weighted gene co-expression network analysis (WGCNA) and limma analysis based on sample size. Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes analyses were applied to reveal the hidden biological pathways. Additionally, shared hub gene identification, gene set enrichment analysis, association of the hub gene with ferroptosis and immunity, drug sensitivity analysis, single-cell RNA sequencing analysis, and construction of the competing endogenous RNA (ceRNA) network were conducted.

Results: By intersecting the genes from WGCNA and limma analysis, one shared hub gene (KCNN3) was derived, exhibiting up-regulation in Sjögren's syndrome and RPL. There was a positive relationship between KCNN3 and the immune-related gene TLR2. The ceRNA network revealed that XIST was the most shared long non-coding RNA, which may bind competitively with eight microRNA to regulate the expression of KCNN3. Forty-eight drugs were found to be strongly associated with KCNN3 expression, including estramustine and cyclosporine. Moreover, KCNN3 exhibited high expression in RPL endothelial cells of villous tissue.

Conclusions: This is one of the first studies to reveal that Sjögren's syndrome shares common biological pathways with RPL. KCNN3 was identified as the hub gene associated with Sjögren's syndrome and RPL, and may be a new target for mechanistic studies on Sjögren's syndrome and RPL.