Considering melatonin possesses significant anti-inflammatory property, this study aimed to determine whether prophylactic treatment with melatonin would effectively normalize RANKL/OPG signaling, depress toll-like receptor 4/myeloid differentiation factor 88 (TLR4/MyD88)-mediated pro-inflammatory cytokine activation, and successfully suppress the pathogenesis of PD.
These patterns of gene expression and cytokine production indicate that Gram-negative periodontal bacteria or their LPS might play a role in triggering TLR2 and/or TLR4, and be of importance for the immune responses in periodontitis.
We hypothesize (I) PD-driven endotoxemia may increase the host responsiveness to autoantigens via TLR4 activation and (II) this participates in development and propagation of RA (III) circulating PD-derived bacterial DNA is taken up by phagocytes, activates TLR9, and thus increases the responsiveness to autoantigens.
Ninety-four subjects with periodontitis were genotyped for polymorphisms in IL-1A (-889), IL-1B (-511, +3954), TNF-A (-308), IL-6 (-174) and TLR4 (-299, -399) genes.
Carriage of the TLR4-rs7873784 was associated with higher odds for periodontitis (GG versus CC and GC, P = 0.05, OR 2.30, 95% CI 1.00-5.63; GG versus GC, P = 0.05, OR 2.46, 95% CI 1.01-5.99).
In addition, miR-22-3p also upregulated the expression levels of the inflammatory cytokines tumor necrosis factor-α, interleukin-1β (IL-1β), and IL-8 in PDLSC through SIRT1 pathway and downregulated the expression of TLR-2 and TLR-4. miR-22-3p is a new target either for the treatment of periodontitis or the improvement of inflammation caused by orthodontics.
CONCLUSIONS Taken together, our results revealed that SAC effectively attenuates LPS-induced inflammation and apoptosis via the TLR4/NF-kappaB pathway and that SAC is effective in treating periodontitis.
TLR4 immunoreactivity was found in healthy gingival epithelium and periodontitis tissue, and appeared to be lower in junctional epithelium ( p ≤ 0.01).