ABSTRACT
In type 1 diabetes (T1D), a Toll-like receptor (TLR)-hyper-inflammatory monocytic phenotype has been implicated as a mechanism of exacerbated tissue destruction. Other cells of the periodontium, including oral epithelial cells (OECs), express innate immune receptors, including TLRs. To delineate the TLR responses of OECs derived from T1D participants and to determine effects of the anti-inflammatory agent triclosan on the TLR-hyper-inflammatory phenotype, primary human OECs from individuals with T1D and diabetes-free individuals were stimulated with TLR ligands in the presence and/or absence of triclosan. The expression of pro-inflammatory cytokines and micro-RNAs (miRNAs) was evaluated. While the repertoire of TLRs expressed by OECs is similar to that expressed by macrophages (M), the relative amounts and ratios are significantly different. OECs demonstrate a TLR-response profile similar to that of M, yet attenuated. OECs have a unique response to P. gingivalis LPS, where miR146a and miR155 play a regulatory role in responsiveness. OECs from T1D participants are TLR-hyper-responsive, due to dysregulated induction of miR146a and miR155, which is abrogated by pre-treatment with triclosan. The aberrant TLR-activation of OECs in T1D has the potential to contribute to excessive soft- and hard-tissue destruction. Importantly, triclosan's anti-inflammatory property is effective in abrogating TLR-induced OEC hyperactivity.
Subject(s)
Diabetes Mellitus, Type 1/immunology , Mouth Mucosa/immunology , Toll-Like Receptors/immunology , Adolescent , Adult , Aged , Anti-Inflammatory Agents/pharmacology , Cell Culture Techniques , Cells, Cultured , Epithelial Cells/immunology , Humans , Immunity, Innate/immunology , Inflammation Mediators/analysis , Interleukin-8/analysis , Ligands , Lipopolysaccharides/immunology , Macrophages/immunology , MicroRNAs/analysis , Middle Aged , Mouth Mucosa/cytology , Phenotype , Porphyromonas gingivalis/immunology , Toll-Like Receptor 1/analysis , Toll-Like Receptor 2/analysis , Toll-Like Receptor 4/analysis , Toll-Like Receptor 6/analysis , Transforming Growth Factor beta1/analysis , Triclosan/pharmacology , Young AdultABSTRACT
UNLABELLED: Periodontal diseases are a class of pathologies wherein oral microbes induce harmful immune responses in a susceptible host. Therefore, an agent that can both reduce microbial burden and lessen pathogenesis of localized inflammation would have beneficial effects in periodontal disease; 2,4,4-trichloro-2-hydroxydiphenyl-ether [triclosan] is currently used in oral care products owing to broad spectrum antimicrobial and anti-inflammatory properties. OBJECTIVE: To determine effects of triclosan on the response of oral epithelial cells to stimulation with the inflammatory microbial product lipopolysaccharide (LPS), a ligand for toll-like receptor 4 [TLR4]. MATERIALS/METHODS: Primary human oral epithelial cells were stimulated with LPS in the presence and/or absence of triclosan after which expression of pro-inflammatory cytokines, ß-defensins, micro-RNAs [miRNAs], or TLR-signaling pathway proteins were evaluated. RESULTS: Here, we demonstrate that triclosan is a potent inhibitor of oral epithelial cell LPS-induced pro-inflammatory responses by inducing miRNA regulation of the TLR-signaling pathway. Triclosan was not a pan-suppresser of oral epithelial cell responses as ß-defensin 2 [ßD2] and ßD3 were upregulated by triclosan following LPS-stimulation. CONCLUSIONS: These data demonstrate both a novel antimicrobial mechanism by which triclosan improves plaque control and an additional anti-inflammatory property, which could have beneficial effects in periodontal disease resolution.
