Figure 5.

Effect of 1,25(OH)₂D₃ on IL-1β or TNF-α or IFN-γ induced tumor necrosis factor inducible gene (TSG)-6 expression 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). TSG-6 gene expression (a) was analyzed by determining n-fold expression levels compared to unstimulated hPDLSCs (n-fold expression = 1) using qPCR. GAPDH served as endogenous control. (b) shows TSG-6 protein levels in conditioned media determined by enzyme-linked immunosorbent assay (ELISA). Notably, the levels of TSG-6 were below the 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 TSG-6 expression 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,b): * 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. & significantly higher (p < 0.05) compared to appropriate cytokine treated hPDLSCs in the absence of 1,25(OH)₂D₃. (c): * significantly different (p < 0.05) compared between groups as indicated.