The role of Hippo signaling pathway proteins in the pathogenesis of periodontal disease

Objective: The Hippo signaling pathway is involved in many crucial processes, such as cell differentiation and death. This study aims to compare the levels of Hippo signaling pathway proteins (YAP, TAZ, MST1, TEAD, MAP4K4, and LATS1), apoptosis-related BCL-2, and bone metabolism-related ALP in gingival crevicular fluid (GCF) and gingival tissue in individuals with different periodontal conditions. Material and Method: A total of 75 systemically healthy participants were divided into three groups: periodontal healthy (n=25), gingivitis (n=25), and stage 3 grade B periodontitis (n=25). GCF samples were collected from these participants. Another 60 systemically healthy participants were also divided into equal numbers with the same periodontal classifications, and gingival tissue was collected from these patients. The levels of YAP, TAZ, MST1, LATS1, MAP4K4, TEAD, ALP, and BCL-2 in GCF were determined by ELISA, while gene expression levels in gingival tissue were detected by RT-qPCR. Results: The total amount of YAP and TEAD in GCF and the concentrations of YAP, TAZ, MST1, TEAD, LATS1, MAP4K4, ALP, and BCL-2 were lower in the periodontitis group compared to the healthy controls (p<0.05). However, ALP total levels in GCF were higher. Gene expression of YAP and TAZ was downregulated, while TEAD, MST1, LATS1, MAP4K4, ALP, and BCL-2 were upregulated in the periodontitis group (p<0.05). A positive correlation between YAP and TAZ gene expression and ALP was observed. Conclusions: Hippo signaling pathway may play a role in the pathogenesis of periodontal disease by showing different effects in GCF and gingival tissue. Keywords: Hippo signaling pathway, ALP, BCL-2, periodontal inflammation, GCF