It is well known the high prevalence of periodontal disease in Down syndrome (DS) .Tumor necrosis factor alpha (TNF-α) augments invasion of Porphyromonas gingivalis (P. gingivalis) in human gingival epithelial cells. We examined the effect of TNF-α on invasion of P. gingivalis to gingival fibroblasts derived from individuals with DS (DGF) and the influence of the cellular response in DGF pretreated with TNF-α prior to inoculation of P. gingivalis. The invasion assay was performed using gingival fibroblasts derived from individuals with non -DS (NGF) and DGF treated with TNF-α prior to inoculation of P. gingivalis. The mRNA expression of interleukin 6 (IL -6) and intercellular adhesion molecule 1 (ICAM -1) were quantified using real time PCR. Furthermore, the protein expressions of TNF-α receptor (TNFR) I and II, and phosphorylation of p65 nuclear factor-κB (NF-κB) and phosphorylation of extracellular signalregulated kinase (ERK) 1/2 were also performed in NGF and DGF pretreated with TNF-α prior to inoculation of P. gingivalis by Western blotting. The number of invasive P. gingivalis in TNF-α pretreated DGF was more than that in NGF. IL -6 and ICAM -1 mRNA expressions in DGF pretreated with TNF-α prior to inoculation of P. gingivalis were significantly higher than those in NGF. The relative signal intensity of TNFR I, phospho p -65 NF-κB, and phospho ERK1/2 were significantly higher than those in NGF. It was considered that TNFR I, phospho p65 NF-κB, and phospho ERK1/2 in DGF pretreated with TNF-α may contribute to enhancement of ICMA -1 mRNA expression and the infection of P. gingivalis. The collaboration of these protein and P. gingivalis may be a key factor for development of severe periodontal disease in DS.

Lipopolysaccharides (LPS) induce reactive oxygen species (ROS) accumulation and oxidative stress in gingival fibroblasts. Glutathione (GSH) plays critical roles in protecting cells from oxidative stress and toxic xenobiotics. Gammaglutamyl transpeptidase (GGT) is the only cell membranebound enzyme of GSH homeostasis that breaks down extracellular GSH. The GGT inhibitor GGsTop ® suppresses ROS and induces the production of collagen and elastin in skin fibroblasts. Effects of GGsTop ® were studied to human gingival fibroblasts (normal gingival fibroblasts; NGFs) stimulated by Porphyromonas gingivalis LPS. Interleukin (IL)-6 and IL-8 productions were measured using Enzymelinked Immunosorbent Assay (ELISA). The gene expressions of IL-6 and IL-8 were analyzed by realtime PCR. In addition, the activity of nuclear factorkappa B (NF-κB) was measured by ELISA. The GGsTopG ® reduced their gene and protein expressions of IL-6 and IL-8, although NF-κB activity was not affected. It is considered that GGsTopG ® may be useful for antiinflammatory in periodontitis.

Individuals with Down syndrome (DS) are prone to periodontitis. No studies have focused on mRNA expression of a proinflammatory cytokine, IL -1β and an antiinflammatory cytokine, IL -37 in gingival fibroblasts (GFs) derived from individuals with DS (DGFs) . We cultured GFs derived from non -DS individuals (NGFs) and DGFs with outer membrane vesicles from Porphyromonas gingivalis (P -OMVs) . IL -1β and IL -37 mRNA expression was quantified using realtime PCR. Extracellular signalregulated kinase (ERK) 1/2 phosphorylation was performed by western blotting. We also analyzed the effect of an ERK1/2 inhibitor on IL -1β and IL -37 mRNA expression in GFs. Furthermore, we examined the influence of recombinant IL -37 (rIL -37) on the cellular response of GFs. We quantified mRNA expression of IL -8 using realtime PCR and measured IL -8 productions in culture medium by an enzymelinked immunosorbent assay.IL -1β mRNA expression and phosphorylated -ERK1/2 expression were significantly higher in P -OMVsstimulated DGFs than in NGFs. In contrast, IL -37 mRNA expression was significantly lower in P -OMVstimulated DGFs than in NGFs. P -OMVsinduced IL -1β and IL -37 mRNA expression in NGFs was reduced by an ERK1/2 inhibitor, while P -OMVsinduced IL -37 mRNA expression was not reduced by an ERK1/2 inhibitor in DGFs. P -OMVsinduced IL -8 mRNA expression and protein production were decreased by rIL -37 in both NGF and DGFs. It is considered that the imbalance of proand antiinflammatory responses via ERK1/2 in DGFs may cause severe periodontal inflammation in DS. In addition, IL -37 may be a key mediator of the antiinflammatory response in DGFs. These results provide insights into the therapeutic potential of targeting antiinflammatory factors for severe periodontal inflammation in DS.

The presence of yeasts in periodontal pockets is well known and Candida albicans (C. albicans) is the species most commonly isolated from the oral cavity. The immune response and anti-candidal activity of oral epithelium cells play a key role in the host defense against C. albicans infection. Rat gingival tissue was infected with C. albicans ATCC90029. Total RNA was extracted from the epithelium and mRNA levels were monitored using DNA microarray. By ingenuity pathway analysis demonstrated that TNF and IL-1 stimulated gene expression of CC type chemokine CCL2, also known as monocyte chemoattractant protein-1 (MCP-1), through NF-κB pathway. Altered mRNA level of CCL2 by rat gingival tissue was infected with C. albicans was confirmed by reverse transcription polymerase chain reaction. The immunohistochemical examination for CCL2 production was carried out. As a result, stronger immunoreactivity against CCL2 was observed in the rat gingival epithelium infected with C. albicans.