Abstract / Summary
Objective To identify key histamine-related genes associated with SS-related KCS and to explore their potential underlying mechanisms. Methods The GSE84844 and GSE176510 datasets were analyzed to identify differentially expressed genes (DEGs) associated with SS and KCS, respectively. KCS-specific genes were identified by subtracting SS-related DEGs from the KCS-related DEG sets and were subsequently intersected with a compendium of histamine-related genes to obtain candidate genes. Machine learning algorithms and receiver operating characteristic (ROC) curve analyses were then used to identify key genes with potential diagnostic value. Functional enrichment, immune infiltration, upstream transcription factor (TF) network, and compound prediction analyses were performed to further characterize these genes. In vitro , small interfering RNAs were used to knock down the candidate genes in immortalized human corneal epithelial cells (iHCECs). Cell viability and inflammatory responses under different treatment conditions were evaluated using Cell Counting Kit-8 assays and RT-qPCR analysis of IL-6 and TNF-α expression. Results IFITM1 and CTSS were consistently selected by the machine learning approaches and demonstrated strong diagnostic performance. Both genes were associated with immune-related pathways and showed positive correlations with activated dendritic cells and T helper cells enriched in KCS samples. Upstream TF analysis predicted STAT1/STAT2 as potential regulators of IFITM1 and SPI1 as a potential regulator of CTSS . Molecular docking analysis indicated potential interactions between CTSS and Petesicatib and between IFITM1 and Tetrachlorodibenzodioxin. In vitro , knockdown of either IFITM1 or CTSS attenuated hyperosmotic stress-induced inflammatory injury in iHCECs. Conclusions : IFITM1 and CTSS may represent histamine-related biomarkers with potential diagnostic value and may contribute to the progression from SS to KCS through histamine-associated signaling, immune dysregulation, and ocular surface inflammation.