Figure 6.

Effect of 1,25(OH)₂D₃ on IL-1β or TNF-α or IFN-γ induced prostaglandin-endoperoxide synthase (PTGS)-2/prostaglandin E₂ (PGE₂) production in hPDLSCs. Primary hPDLSCs were stimulated with either 10 ng/mL TNF-α or 5 ng/mL IL-1β or 100 ng/mL IFN-γ in the absence or presence of 1,25(OH)₂D₃ (0.01–100 nM). PTGS-2 gene expression (a) was analyzed by determining n-fold expression levels compared to unstimulated hPDLSCs (n-fold expression = 1) using qPCR. GAPDH functioned as an endogenous reference. (b) shows PGE₂ levels in conditioned media determined by ELISA. Notably, the levels of PGE₂ were below the lower detection limit after IFN-γ stimulation and therefore are not shown. (c) shows the extent of the 1,25(OH)₂D₃ effect on differently-induced PTGS-2 gene expression and on differently-induced PGE₂ production in hPDLSCs (expressed in % of corresponding cytokine treatment). All data are presented as mean ± S.E.M. and were received from five independent experiments using hPDLSCs from five different patients. (a): * significantly higher (p < 0.05) compared to unstimulated hPDLSCs. # significantly lower (p < 0.05) compared to appropriate cytokine treated hPDLSCs in the absence of 1,25(OH)₂D₃. (b): * significantly different (p < 0.05) compared between groups as indicated. (c): * significantly different (p < 0.05) compared between groups as indicated.