In conclusion, these novel findings indicate that baicalin inhibits the TLR2 and TLR4 expression and the downstream signaling and mitigates inflammatory responses and the alveolar bone loss in rat experimental periodontitis.
Therefore, the objective of this study was to examine the association between TLR4Asp299Gly (rs4986790) with alveolar bone height loss (ABHL) and periodontitis, accounting for interactions between this SNP with smoking and P. gingivalis prevalence.
We investigated the effects of a synthetic GAG, GM-0111, on various molecular events associated with periodontitis: growth of Porphyromonas gingivalis (P. gingivalis) and Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) pathogenic bacteria associated with periodontitis; activation of pro-inflammatory signaling through TLR2 and TLR4 in mouse macrophage RAW 264.7 cells and heterologously expressed HEK 293 cells; osteoclast formation and bone matrix resorption in cultured mouse pre-osteoclasts.
We have previously shown that a single nucleotide polymorphism rs11536889 in the 3'-untranslated region (UTR) of TLR4 was associated with periodontitis.
We purified IgG from 16 subjects with elevated or normal levels of aCL and examined their ability to activate TLR2- or TLR4-transfected human embryonic kidney (HEK) cells, and observed that IgG from periodontitis patients with elevated aCL activated HEK-TLR4 cells, but not HEK-TLR2 cells.
The involvement of TLR4 gene in the inflammatory response of periodontitis results in periodontitis, and its mechanism may be that it activates TLR4, so as to affect the expression of T-bet, GATA3 and Foxp3.
Considering the low number of periodontitis patients carrying TLR4 variants (11%), a comparison of the periodontitis severity depending on the genotype has to be interpreted cautiously.
The prevalence of TLR2 Arp677Trp polymorphism seemed to be rather high, while that of TLR4Asp299Gly and Thr399Ile polymorphisms seemed to be rather low in the Chinese population, which did not permit any conclusion regarding its effects on periodontitis.
Functional polymorphisms of the genes TLR4 and TLR9 were found to be associated with alveolar bone loss in a Porphyromonas gingivalis-induced periodontitis model in mice.
Gene expressions of IL-17, TNF-a, OPG, RANKL, TLR-2, and TLR-4 were higher in periodontitis, when compared to periodontally healthy sites (P < 0.05), while no differences between groups were observed for the other genes evaluated (P > 0.05).
Because Toll-like receptor 2 and Toll-like receptor 4 have been shown to play an important role in the recognition of periodontal pathogens, we investigated the relevance of genetic variations in TLR2 and TLR4 to susceptibility to periodontitis.
However, we did not detect any significant relevance between other TLR4 polymorphism and periodontitis susceptibility in overall and subgroup analyses.
No differences were found in the prevalence of the TLR4Asp299Gly genotype in men with CP (18.9%) compared with an age-matched control group with no evidence of periodontitis (17%).
Other published meta-analyzes showed no significant association between single nucleotide polymorphisms of TLR4 and periodontitis nor its clinical types.No publication bias was reported.
Meta-analysis of the TLR4Asp299Gly and Thr399Ile polymorphisms showed no association between periodontitis and the TLR4 299Asp allele in all study subjects (OR=0.984, 95% CI=0.761-1.271, p=0.900; OR=1.030, 95% CI=0.748-1.418, p=0.854).
Three SNPs of TLR4, i.e., rs1927911 (TT/CC+CT), rs2149356 (TT/GG+GT) and rs2737190 (GG/AA+AG), were associated with moderate/severe chronic periodontitis in Chinese population infected with <i>P. gingivalis</i>.<i>P. gingivalis</i>, which interacted with TLR4 gene plays an important role in the pathogenesis of periodontitis.
On the other hand, while the sTLR-2 and the paired epithelial cell associated TLR-2 mRNA exhibited a direct correlation (r2 = 0.62), that of sTLR4 and TLR-4 mRNA exhibited an inverse correlation (r2 = 0.53) in the periodontitis cohort.
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.