Integrative bioinformatics and experimental study of calcium metabolism-related genes in gestational diabetes mellitus

The role of calcium metabolism-related genes (CMRGs) in gestational diabetes mellitus (GDM) is unclear, and potential biomarkers remain unidentified. This study aims to identify CMRGs as potential biomarkers for GDM and explore their functional roles, diagnostic performance, and associations with immune infiltration and signaling pathways in the pathogenesis of GDM. We conducted a retrospective transcriptomic and experimental validation study, integrating bioinformatics analyses from GEO datasets and quantitative real-time polymerase chain reaction (qRT-PCR) validation. Candidate genes were identified by intersecting differentially expressed genes from 2 GDM-related GEO datasets (GSE154414 and GSE9984) with 178 known CMRGs. Biomarker potential was assessed through receiver operating characteristic curve analysis, consistency of gene expression across datasets, and functional enrichment analysis. Expression of selected genes was validated by qRT-PCR. Further mechanistic insights were obtained through immune infiltration analysis, regulatory network construction, drug prediction, and gene-disease association studies. Eight candidate genes were identified from the intersection of 649 differentially expressed genes and CMRGs. Among these, AGTR1 and ADCY4 were consistently downregulated in placental tissues of GDM patients and demonstrated strong diagnostic performance (area under the curve > 0.7). qRT-PCR validation confirmed significantly decreased expression levels of both genes. Functional enrichment analysis indicated involvement in ribosomal, lysosomal, and calcium signaling pathways. Immune infiltration analysis revealed a significant increase in activated B cells in GDM placentas, which were negatively correlated with AGTR1 (r = -0.738) and ADCY4 (r = -0.881) expression. Regulatory network analysis associated these genes with pathways including cAMP metabolism and vascular smooth muscle contraction. A total of 59 potential therapeutic compounds were identified. AGTR1 and ADCY4 are promising biomarkers for GDM, likely contributing to disease progression through dysregulation of calcium signaling and the immune microenvironment. These findings offer a theoretical foundation for further mechanistic studies and targeted therapeutic development for GDM.