Single-cell sequencing data identifies differentially expressed genes and immune cell subtypes in periodontitis patients

Qiu Xuedi; Guo Chao; He Jiayue; Zhou Zheng

doi:10.12307/2026.224

Abstract：BACKGROUND:Periodontitis is a highly prevalent chronic inflammatory disease.Previous research has predominantly focused on specific immune cells or cytokines.Consequently,systematically elucidating its immune mechanisms and discovering novel therapeutic targets hold significant implications. OBJECTIVE:To analyze the expression profiles of periodontitis-associated immune cell subpopulations and identify key differentially expressed genes with a causal relationship to the disease,thereby exploring potential molecular mechanisms and key genes involved in periodontitis and immune cell dynamics. METHODS:Single-cell RNA sequencing data from the GEO database were used to analyze immune cell subset heterogeneity and identify differentially expressed genes.Mendelian randomization analysis was performed using expression quantitative trait loci data to infer causal relationships between immune cell gene expression and periodontitis risk.Pathway enrichment and immune infiltration analyses were performed on the identified causal genes to reveal the associations between differentially expressed genes and immune cells with the development and progression of periodontitis.CellChat trajectory analysis was used to explore intercellular communication.To validate key findings,gingival tissue samples were collected from 20 patients with periodontitis diagnosed by the Department of Stomatology at The First Affiliated Hospital of Shihezi University(periodontitis group)and 20 healthy gingival tissue samples from patients undergoing orthodontic or impacted tooth extraction(control group).RT-qPCR and immunohistochemistry were used to examine the expression of key genes. RESULTS AND CONCLUSION:Comprehensive analysis identified 23 immune cell clusters in periodontitis and three key genes(annexin A1,solute carrier family 11 member 1,and vimentin)that were significantly causally associated with periodontitis risk.Pathway enrichment analysis revealed their involvement in key immune regulatory mechanisms.Further analysis and characterization of immune subtype receptor ligands and key cell subtype trajectories revealed distinct roles for annexin A1,solute carrier family 11 member 1,and vimentin in disease progression.Annexin A1,solute carrier family 11 member 1,and vimentin mRNA expression levels were upregulated in periodontitis tissues compared with healthy controls(P<0.05).This study reveals the key role of immune cell subsets in periodontitis and validates key genes(annexin A1,solute carrier family 11 member 1,and vimentin)with a causal relationship with periodontitis.