Investigation of the role of signal-transducing adaptor proteins in periodontal disease

Aim: Signal-transducing adaptor protein (STAP) family members STAP-1 and STAP-2 play important roles in key biological processes such as cancer, cell growth, and immune responses. The aim of the present study was to evaluate STAP-1 and STAP-2, along with their regulatory proteins STAT3 and STAT5A, as well as NLRP3 and CASP3—molecules associated with inflammation and apoptosis—in gingival tissue, gingival crevicular fluid (GCF), and saliva samples from individuals with different periodontal conditions. Materials and Methods: Seventy-five systemically healthy participants were divided into three groups: periodontally healthy (n = 25), gingivitis (n = 25), and periodontitis (n = 25). STAP-1, STAP-2, STAT3, STAT5A, NLRP3 and CASP3 levels in GCF and saliva were measured using ELISA. Additionally, gingival tissue samples were collected from 60 systemically healthy participants equally distributed across the same periodontal groups, and gene expression levels were analyzed using RT-qPCR. Results: In patients with periodontitis, total GCF levels of STAT3 and CASP3 were significantly increased, while STAT5A was decreased (p < 0.05). In saliva, STAT3, CASP3, and NLRP3 were significantly elevated, whereas STAP-1 and STAT5A were reduced (p < 0.05). In gingival tissues, STAP-1, STAT3, CASP3 and NLRP3 gene expression levels were upregulated in the presence of periodontitis, whereas STAP-2 and STAT5A were downregulated. STAT3 expression in gingiva, GCF, and saliva showed positive correlations with CASP3 and NLRP3. CASP3 and NLRP3 gene expression levels demonstrated positive correlations with STAP-1 and negative correlations with STAP-2 and STAT5A (p < 0.05). Conclusion: STAP-1, STAP-2, STAT3 and STAT5A may play roles in the pathogenesis of periodontal disease. The observed increase in STAT3 levels in saliva, gingiva and GCF in periodontitis may be associated with inflammation and apoptosis. Keywords: GCF, Periodontal inflammation, STAP, STAT