Title: 2651 - Expression of Wnt Signalling Molecules in Gingival and Periodontal Fibroblasts
Devy Garna, Kings College London
Shir Tan (Presenter)
Kings College London
Emily Ming-Chieh Lu, Kings College London
Francis Hughes, Kings College London
Objectives: Our recent studies suggest that epithelial migration in the dentogingival tissues may be regulated by different fibroblast populaltions via the canonical wnt signalling pathway. The aim of the study here is to investigate the differential expression of candidate wnt signalling ligands and antagonists in gingival and periodontal fibroblasts both constitutively and following stimulation with pro-inflammatory cytokines.
Methods: Primary human periodontal ligament (PDL) and gingival fibroblast (GF) cultures were established. Cells were cultured for up to 7 days to test for constitutive expression of candidate wnt signalling molecules including the ligand wnt10b, and antagonists secreted frizzled related protein (SFRP)-1 and SFRP-4. Cells were also treated for 3 days with tumor necrosis factor alpha and interleukin 1 beta (concentration 10nM and 100nM each). Gene expression was determined using qRT-PCR. One-way ANOVA with Bonferroni post-test was used to analyse the results.
Results: The constitutive expression of SFRP-4 was low in GF cells whereas it was consistently elevated in PDL cells by between 35 – 60 fold ( P <0.01). Stimulation of PDL cells with 100ng /ml IL-1ß or TNFα reduced SFRP-4 expression by approximately 2 fold. There was no difference in constitutive expression of wnt10b between PDL and GF cells, and cytokine stimulation did not significantly alter expression. In contrast, constitutive SFRP-1 expression was significantly enhanced in GF cells when compared to PDL cell expression. Both 100ng /ml IL-1ß or TNFα reduced expression by 3 – 4 fold.
Conclusions: The results show that the wnt antagonist SFRP-4 is differentially expressed by PDL cells but is down regulated by inflammatory cytokines. This is consistent with an inhibition of wnt signalling regulating epithelial differentiation in the dentogingival junction, which may be altered during inflammation leading to apical migration of the junctional epthelium.
The submitter must disclose the names of the organizations with which any author have a relationship, the nature of the relationship, and the clinical or research area involved. The following is submitted: None