Changes in cuproptosis-related gene expression in periodontitis: An integrated bioinformatic analysis

Periodontitis causes inflammatory destruction of tooth-supporting tissues; however, the complex mechanism underlying its etiology remains unclear. Cuproptosis is a type of cell death caused by an imbalance in intracellular copper homeostasis that leads to excess copper. However, changes in the expression and biological function of cuproptosis-related genes (CRGs) in periodontitis are not yet fully understood. This study investigated the comprehensive effects of differentially expressed CRGs (DE-CRGs) on periodontitis via bioinformatic analysis. Nine DE-CRGs were discovered using normal and periodontitis gingival samples, and single-cell RNA sequencing data were analyzed to identify them changes in diverse cell clusters. We then detected the correlation between DE-CRGs and immune infiltration, immune factors, mitochondrial dysfunction, diagnostic efficacy, and predicted drugs. Moreover, changes of DE-CRG in whole periodontitis tissue and a human gingival fibroblast cell line (HGF-1) were confirmed and copper content changes in HGF-1 cells were investigated. Most DE-CRG expression trends were reversed between the periodontal tissues and cell clusters, which may be related to the proportion of cell clusters changes caused periodontitis. Furthermore, most DE-CRG trends in periodontitis cell clusters were inconsistent with the effects of cuproptosis. In HGF-1 cells treated with Porphyromonas gingivalis lipopolysaccharide (Pg-LPS), the intracellular copper content increased by more than threefold, indicating that although some periodontitis cells had excess copper, the amount may not have been sufficient to trigger cuproptosis. Additionally, DE-CRGs were closely associated with multiple biological functions, antibiotic drugs, and natural herbal medicines. Our findings may provide an overview of DE-CRGs in the pathogenesis and treatment of periodontitis.