Morandini, Ana Carolina F.Souza, Pedro Paulo Chaves [UNESP]Ramos-Junior, Erivan SchnaiderBrozoski, Daniel ThomasSipert, Carla RenataSouza Costa, Carlos Alberto [UNESP]Santos, Carlos Ferreira2014-05-272014-05-272013-04-01Journal of Periodontology, v. 84, n. 4, p. 535-544, 2013.0022-3492http://hdl.handle.net/11449/75023Background: Fibroblasts are now seen as active components of the immune response because these cells express Toll-like receptors (TLRs), recognize pathogen-associated molecular patterns, and mediate the production of cytokines and chemokines during inflammation. The innate host response to lipopolysaccharide (LPS) from Porphyromonas gingivalis is unusual inasmuch as different studies have reported that it can be an agonist for Toll-like receptor 2 (TLR2) and an antagonist or agonist for Toll-like receptor 4 (TLR4). This study investigates and compares whether signaling through TLR2 or TLR4 could affect the secretion of interleukin (IL)-6, IL-8, and stromal derived factor-1 (SDF-1/CXCL12) in both human gingival fibroblasts (HGF) and human periodontal ligament fibroblasts (HPDLF). Methods: After small interfering RNA-mediated silencing of TLR2 and TLR4, HGF and HPDLF from the same donors were stimulated with P. gingivalis LPS or with two synthetic ligands of TLR2, Pam2CSK4 and Pam3CSK4, for 6 hours. IL-6, IL-8, and CXCL12mRNA expression and protein secretion were evaluated by quantitative polymerase chain reaction and enzymelinked immunosorbent assay, respectively. Results: TLR2 mRNA expression was upregulated in HGF but not in HPDLF by all the stimuli applied. Knockdown of TLR2 decreased IL-6 and IL-8 in response to P. gingivalis LPS, or Pam2CSK4 and Pam3CSK4, in a similar manner in both fibroblasts subpopulations. Conversely, CXCL12 remained unchanged by TLR2 or TLR4 silencing. Conclusion: These results suggest that signaling through TLR2 by gingival and periodontal ligament fibroblasts can control the secretion of IL-6 and IL-8, which contribute to periodontal pathogenesis, but do not interfere with CXCL12 levels, an important chemokine in the repair process.535-544engCytokinesFibroblastsGene silencingPorphyromonas gingivalisToll-like receptor 2Toll-like receptor 4interleukin 6interleukin 8stromal cell derived factor 1toll like receptor 2toll like receptor 4adolescentadultanalysis of variancebiosynthesiscell culturecytologyfemalefibroblastgene silencinggeneticsgingivahumaninflammationmalemetabolismnonparametric testperiodontal ligamentRNA interferencesignal transductionAdolescentAdultAnalysis of VarianceCells, CulturedChemokine CXCL12FemaleGene Knockdown TechniquesGingivaHumansInflammationInterleukin-6Interleukin-8MalePeriodontal LigamentRNA InterferenceSignal TransductionStatistics, NonparametricToll-Like Receptor 2Toll-Like Receptor 4Young AdultArtigo10.1902/jop.2012.120177WOS:000317321100013Acesso restrito2-s2.0-848761497474517484241515548