Abstract:

Objective To investigate the expression changes of the lysosomal protein transmembrane 5(LAPTM5) in periodontitis tissues, analyze its correlation with the level of macrophage infiltration, and explore the clinical significance of this correlation in the occurrence and development of periodontitis. Methods GEO datasets(GSE16134, GSE171213) were integrated for differential gene expression analysis, functional enrichment, immune infiltration profiling, and WGCNA to identify core genes, combined with single-cell data for cellular localization. Gingival tissue samples from 53 periodontitis patients and 5 healthy controls were collected, and immunohistochemistry was performed to validate the correlation between the target gene and macrophage infiltration as well as inflammation. Results The leukocyte migration pathway was most significantly enriched in periodontitis group (P=7.27×10^-6), and its activity was positively correlated with pro-inflammatory immune cell infiltration. LAPTM5 was identified as the core gene of this pathway, showing upregulated expression in periodontitis tissues, and positively correlated with disease severity. Single-cell RNA sequencing and immunofluorescence analyses confirmed the localization of LAPTM5 in macrophages. Clinical validation revealed that the proportion of CD68⁺ macrophages was significantly positively correlated with IL-6(P<0.001) and LAPTM5(P<0.001) expression levels, suggesting that LAPTM5 expression level is positively correlated with the severity of periodontitis. Conclusion As a core gene of the leukocyte migration pathway, LAPTM5 may participate in periodontitis progression by regulating macrophage function and represents a potential immunotherapeutic target.

Key words: periodontitis, leukocyte migration pathway, LAPTM5, macrophage infiltration