Fig. 3

Effect of ligature-induced periodontal disease microbiome on inflammatory cytokines and toll-like receptors (TLRs) expression of microglial cells. A Levels of mRNA expression of pro-inflammatory cytokines TNF-α, IL-1β, and IL-6 in microglial cells stimulated with microbiome associated with experimental periodontal disease. Lig. D1, D10, D20, and D30: microglial cells incubated with heat-inactivated PD-associated microbiome harvested from ligatures for different timepoints corresponding to 1,10, 20, and 30 days, respectively, at MOI = 20 for 24 h. (Two different experiments in triplicates, mean ± SEM, ANOVA, *p < 0.05, ****p < 0.0001, all comparisons were made to unstimulated microglial cells represented by the dashed line). B Levels of mRNA expression of pro-inflammatory cytokines TNF-α, IL-1β, and IL-6 in microglial cells stimulated with different MOIs of 10-day-old ligature-induced PD-associated microbiome for 24 h. (Three different experiments in duplicates, mean ± SEM, ANOVA, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001 all comparisons were made to unstimulated microglial cells represented by the dashed line). C Levels of mRNA expression of toll-like receptors TLR2, TLR4, and TLR9 in microglial cells stimulated with different MOIs of 10-day-old ligature-induced PD-associated microbiome for 24 h. (Three different experiments in duplicate, mean ± SEM, ANOVA, *p < 0.05, **p < 0.01, all comparisons were made to unstimulated microglial cells represented by the dashed line). D Levels of mRNA expression of co-receptor CD14 in microglial cells stimulated with MOI = 20 of 10-day-old ligature-induced PD-associated microbiome for 24 h (three different experiments in triplicate, mean ± SEM, unpaired t test, ***p < 0.001)