ショウガオールはヒト歯肉線維芽細胞において酸化ストレス反応の調節を介してAGEs誘導性のIL-6およびICAM-1産生を抑制する

Advanced glycation end-products (AGEs) cause diabetes mellitus (DM) complications and accumulate more highly in periodontal tissues of patients with periodontitis and DM. AGEs aggravate periodontitis with DM by increasing the expression of inflammation-related factors in periodontal tissues. 6-Shogaol, a major compound in ginger, has anti-inflammatory and anti-oxidative activities. However, the influence of shogaol on DM-associated periodontitis is not well known. In this study, the effects of 6-shogaol on AGEs-induced oxidative and anti-oxidative responses, and IL-6 and ICAM-1 expression in human gingival fibroblasts (HGFs) were investigated. When HGFs were cultured with 6-shogaol and AGEs, the activities of reactive oxygen species (ROS) and antioxidant enzymes (heme oxygenase-1 [HO-1] and NAD(P)H quinone dehydrogenase 1 [NQO1]), and IL-6 and ICAM-1 expressions were investigated. RAGE expression and phosphorylation of MAPKs and NF-κB were examined by western blotting. 6-Shogaol significantly inhibited AGEs-induced ROS activity, and increased HO-1 and NQO1 levels compared with the AGEs-treated cells. The AGEs-stimulated expression levels of receptor of AGE (RAGE), IL-6 and ICAM-1 and the phosphorylation of p38, ERK and p65 were attenuated by 6-shogaol. These results suggested that 6-shogaol inhibits AGEs-induced inflammatory responses by regulating oxidative and anti-oxidative activities and may have protective effects on periodontitis with DM

S100A9は、骨細胞様細胞においてMAPKsおよびSTAT3シグナル伝達経路を介してIL-6およびRANKLの発現を増加させる

Objective: Calprotectin is hetero-complex of S100A8 and S100A9 and mainly secreted from neutrophils, monocytes and chondrocytes in inflammatory condition. Calprotectin binds to RAGE and TLR4, and induces the expression of pro-inflammatory chemokines and cytokines in various cells. Periodontitis is chronic inflammatory disease to lead gingival inflammation and alveolar bone resorption. Calprotectin levels in gingival crevicular fluid of periodontitis patients are higher than healthy patients. In the present study, the effects of S100A8 and S100A9 on the expressions of pro-inflammatory cytokines and bone metabolism related factor in mouse osteocyte like cells (MLO-Y4-A2) were investigated. Design: MLO-Y4-A2 cells were treated with S100A8 and S100A9, and the expressions of RAGE, TLR4, RANKL and several inflammatory cytokines were analyzed by PCR and Western blotting or ELISA methods. To investigate the intracellular signaling pathways, phosphorylation of MAPK and STAT3 was determined by Western blotting, and chemical specific inhibitors and siRNAs were used. Results: Expressions of IL-6 and RANKL were increased by treatment with S100A9 but not S100A8. However, both S100A8 and S100A9 did not changed expression of IL-1β, IL-8 and TNF-α. Although RAGE and TLR4 expressions were not up-regulated by S100A9 treatment, transfection of siRNA for RAGE and TLR4 significantly decreased IL-6 and RANKL expressions. In addition, S100A9 activated p38, ERK and STAT3 signaling pathways, and inhibitors for these factors significantly decreased S100A9 induced IL-6 and RANKL expressions. Conclusions: These results indicated that S100A9 induces IL-6 and RANKL production via engagement with RAGE and TLR4 signalings in osteocytes and suggested that S100A9 may play important roles in the periodontal alveolar bone destruction

AGEs increase lipocalin 2 expression

Background and Objectives: Diabetes mellitus (DM), a risk factor of periodontal diseases, exacerbates the pathological condition of periodontitis. A major factor for DM complications is advanced glycation end-products (AGEs) that accumulate in periodontal tissues and cause inflammatory events. Lipocalin 2 (LCN2) is an antimicrobial peptide and inflammation-related factor, and LCN2 levels increase in DM. In the present study, the effects of AGEs and lipopolysaccharide of Porphyromonas gingivalis (P.g-LPS) on LCN2 expression in human oral epithelial cells (TR146 cells) and the role of secreted LCN2 in periodontitis with DM were investigated. Material and Methods: TR146 cells were cultured with AGEs (AGE2) and control BSA and cell viability was estimated, or with P.g-LPS. Conditioned medium and cell lysates were prepared from cultures of epithelial cells and used for western blotting and ELISA to analyze LCN2, RAGE, IL-6, MAPK and NF-κB. RNA was isolated from AGE-treated TR146 cells and differentiated HL-60 (D-HL-60) cells and used for quantitative real-time PCR to examine the expression of LCN2 and interleukin-6 (IL-6) mRNAs. RAGE- and LCN2-siRNAs (siRAGE, siLCN2) were transfected into epithelial cells, and AGE-induced LCN2 expression was investigated. D-HL-60 cells were co-cultured with TR146 cells that were transfected with siLCN2 and treated with AGEs, IL-6 mRNA expression in D-HL-60 cells and cell migration were investigated. Results: AGEs increased the expression levels of LCN2 and IL-6 in oral epithelial cells. siRAGE and a neutralizing antibody for RAGE inhibited AGE-induced LCN2 expression. AGEs stimulated the phosphorylation of ERK, p38 and NF-kB in epithelial cells, and their inhibitors suppressed AGE-induced LCN2 expression. In contrast, P.g-LPS did not show a significant increase on LCN2 level in TR146 cells that expressed toll-like receptor 2. In co-culture experiments, AGE-induced LCN2 inhibited IL-6 mRNA expression in D-HL-60 cells, and LCN2 knockdown in epithelial cells suppressed HL-60 cell migration. Conclusion: These results suggested that AGEs increase LCN2 expression via RAGE, MAPK, and NF-κB signaling pathways in oral epithelial cells, and secreted LCN2 may influence the pathological condition of periodontitis with DM

Glycated Albumin in Gingival Crevicular Fluid from Patients With Diabetes

Background: Diabetes mellitus (DM) patients have a high prevalence of periodontitis. DM-associated periodontitis (DM-P) is characterized by severe inflammation and tissue destruction. To diagnose DM-P is important for cures of periodontitis and DM. The purpose of this study was to investigate the levels of glycated albumin (GA), a DM marker, and calprotectin, an inflammatory marker, in gingival crevicular fluid (GCF) from patients with periodontitis and DM. Methods: Seventy-eight subjects participated in this study were the patients with DM, chronic periodontitis (CP), DM-P and healthy individuals (H). GCF and blood were collected from four groups. GA and calprotectin in GCF were analyzed using western blotting and ELISA, and their levels were compared among H, DM, CP, and DM-P groups. GA and glycated hemoglobin (HbA1c) in blood were determined, and the correlation between GCF GA level and blood HbA1c or GA level was investigated. ROC analysis for GCF GA level to predict DM was performed. Results: GA was identified in GCF, and its amount and concentration in GCF samples from DM and DM-P were significantly higher than those of non-DM groups (H and CP). Calprotectin amount in GCF from CP and DM-P was significantly higher than that in H and DM groups. GCF GA level was positively correlated to blood HbA1c and GA level. ROC analysis of GCF GA level showed an optimal cut-off value to predict DM. Conclusions: GA showed a high level in GCF from DM patients. GA and calprotectin in GCF may be useful markers to diagnose DM-associated periodontitis

Gan-Lu-Yin (Kanroin), Traditional Chinese Herbal Extracts, Reduces Osteoclast Differentiation In Vitro and Prevents Alveolar Bone Resorption in Rat Experimental Periodontitis

Gan-Lu-Yin (GLY), a traditional Chinese herbal medicine, shows therapeutic effects on periodontitis, but that mechanism is not well known. This study aims to clarify the precise mechanism by investigating the inhibitory effects of GLY extracts on osteoclastogenesis in vitro and on bone resorption in periodontitis in vivo. RAW264.7 cells are cultured with soluble receptor activator of nuclear factor-kappa B (sRANKL) and GLY extracts (0.01–1.0 mg/mL), and stained for tartrate-resistant acid phosphatase (TRAP) to evaluate osteoclast differentiation. Experimental periodontitis is induced by placing a nylon ligature around the second maxillary molar in rats, and rats are administered GLY extracts (60 mg/kg) daily for 20 days. Their maxillae are collected on day 4 and 20, and the levels of alveolar bone resorption and osteoclast differentiation are estimated using micro-computed tomography (CT) and histological analysis, respectively. In RAW264.7 cells, GLY extracts significantly inhibit sRANKL-induced osteoclast differentiation at a concentration of more than 0.05 mg/mL. In experimental periodontitis, administering GLY extracts significantly decreases the number of TRAP-positive osteoclasts in the alveolar bone on day 4, and significantly inhibits the ligature-induced bone resorption on day 20. These results show that GLY extracts suppress bone resorption by inhibiting osteoclast differentiation in experimental periodontitis, suggesting that GLY extracts are potentially useful for oral care in periodontitis

Association between periodontal condition and kidney dysfunction in Japanese adults : A cross‐sectional study

Recent studies have demonstrated that chronic kidney disease (CKD) may be associated with the progression of periodontal disease. Diabetes mellitus (DM) is a major risk factor for CKD. The objective of this study was to clarify the relationship between periodontal condition and kidney dysfunction in patients who had kidney failure with or without DM. One hundred sixty‐four patients with kidney dysfunction were enrolled (male: N = 105; female: N = 59), and the relationship between periodontal condition and kidney dysfunction was analyzed in a cross‐sectional study. The subjects were divided into three groups: (a) patients with DM, (b) dialysis patients with nephropathy due to various kidney diseases, and (c) dialysis patient with nephropathy due to DM (diabetic nephropathy). Then, the effect of DM on the periodontal condition was analyzed. The patients were also stratified by CKD stage (into G1–G5) using the estimated glomerular filtration rate (eGFR), and the G5 group was divided in patients with or without DM. Correlations between eGFR and parameters of periodontal condition were calculated in patients from G1 to G4. The number of missing teeth was significantly higher in dialysis patients with diabetic nephropathy than in patients with DM, whereas alveolar bone loss did not show a significant difference among the three groups. In addition, the G5 patients with DM had a significantly higher number of missing teeth than the other CKD groups, whereas alveolar bone loss did not show a significant difference. In G5 patients with DM, Community Periodontal Index and Oral Hygiene Index scores were significantly higher than in G1‐4 patients with DM. There was a significant negative correlation between eGFR and the number of missing teeth. Patients with diabetic nephropathy have a higher rate of periodontal problems such as missing teeth in Japanese adults

ω-Carboxyl variants of 7-ketocholesteryl esters are ligands for β2-glycoprotein I and mediate antibody-dependent uptake of oxidized LDL by macrophages

beta(2)-Glycoprotein I (beta(2)-GPI) is a major antigen for anticardiolipin antibodies (aCL, Abs) present in patients with antiphospholipid syndrome. We recently reported that beta(2)-GPI specifically binds to oxidized LDL (oxLDL) and that the beta(2)-GPI's major ligand, oxLig-1 is 7-ketocholesteryl-9-carboxynonanoate (Kobayashi, K, E. Matsuura, Q. P. Liu, J. Furukawa, K. Kaihara, J. Inagaki, T. Atsumi, N. Sakairi, T. Yasuda, D. R. Welker, and T. Koike. 2001. A specific ligand for beta(2)-glycoprotein I mediates autoantibody-dependent uptake of oxidized low density lipoprotein by macrophages. J Lipid Res. 42: 697-709). In the present study, we demonstrate that omega-carboxylated 7-ketocholesteryl esters are critical for beta(2)-GPI binding. A positive ion mass spectrum of a novel ligand, designated oxLig-2, showed fragmented ions at m/z 383 and 441 in the presence of acetone, which share features of oxLig-1 and 7-ketocholesterol. In the negative ion mode, ions at m/z 627, 625, and 243 were observed. oxLig-2 was most likely 7-ketocholesteryl-12-carboxy (keto) dodecanoate. These ligands were recognized by beta(2)-GPI. Liposome binding to macrophages was significantly increased depending on the ligand's concentration, in the presence of beta(2)-GPI and an anti-beta(2)-GPI Ab. Synthesized variant, 7-ketocholesteryl-13-carboxytxidecanoate (13-COOH-7KC), also showed a significant interaction with beta(2)-GPI and a similar binding profile with macrophages. Methylation of the carboxyl function diminished all of the specific ligand interactions with beta(2)-GPI. Thus, omega-carboxyl variants of 7-ketocholesteryl esters can mediate anti-beta(2)-GPI Ab-dependent uptake of oxLDL by macrophages, and autoimmune atherogenesis linked to beta(2)-GPI interaction with oxLDL

β-defensin-1 SNPs in Japanese periodontitis

Background and Objective: Periodontitis is a multifactorial disease associated with genetic and environmental factors. Recent reports have shown that single-nucleotide polymorphisms (SNPs) are associated with susceptibility to common diseases such as not only diabetes and hypertension but also periodontitis. Although the oral cavity is continuously exposed to various pathogenic organisms, the oral conditions are well controlled by innate and acquired immune systems. Antimicrobial peptides (AMPs) play an important role in the innate immune system; however, the association of AMP-SNPs with periodontitis has not been fully elucidated. The aim of the present study was to investigate the relationship between AMP-SNPs and periodontitis in Japanese. Methods: One hundred and five Japanese subjects were recruited, which included 21 patients with aggressive, 28 with severe, 13 with moderate and 22 with mild periodontitis, as well as 21 age-matched healthy controls. Genomic DNA was isolated from peripheral blood in each subject. Genotypes of four reported SNPs of β-defensin-1 and lactoferrin genes (DEFB1: rs1799946, rs1800972 and rs11362; and LTF: rs1126478) were investigated using the PCR-Invader assay. Protein levels of AMP in gingival crevicular fluid (GCF) were quantified by ELISA. Results: Case-control studies revealed that the -44 CC genotype of DEFB1 (rs1800972) was associated with severe chronic periodontitis (odds ratio 4.15) and with combined severe and moderate chronic periodontitis (odds ratio 4.04). No statistical differences were found in other genotypes. The β-defensin-1 concentrations in GCF were significantly lower in the subjects with the -44 CC genotype of DEFB1 than in those without this genotype. No significant differences between GCF concentrations of AMPs and other genotypes were detected. Conclusion: The -44 CC genotype of the β-defensin-1 gene (DEFB1 rs1800972) may be associated with susceptibility to chronic periodontitis in Japanese

AGEs increase IL-6 and ICAM-1 expression

Background and Objectives: Diabetes mellitus (DM) is a risk factor for periodontal diseases and may exacerbate the progression of the pathogenesis of periodontitis. Advanced glycation end-products (AGEs) cause DM complications relative to levels of glycemic control and larger amounts accumulate in the periodontal tissues of patients with periodontitis and DM. In the present study, we investigated the effects of AGEs on the expression of inflammation-related factors in human gingival fibroblasts (HGFs) in order to elucidate the impact of AGEs on DM-associated periodontitis. Materials and Methods: HGFs were cultured with or without AGEs. Cell viability was examined, and RNA and protein fractions were isolated from AGE-treated cells. The expression of IL-6, ICAM-1, and the receptor for AGE (RAGE) was investigated using RT-PCR, quantitative real-time PCR, and ELISA, and reactive oxygen species (ROS) activity was measured using a kit with 2’,7’-dichlorofluorescin diacetate. Human monocytic cells (THP-1) labelled with a fluorescent reagent were co-cultured with HGFs treated with AGEs and IL-6 siRNA, and the adhesive activity of THP-1 cells to HGFs was assessed. The expression of IL-6 and ICAM-1 was examined when HGFs were pretreated with recombinant human IL-6 (rhIL-6), the siRNAs of RAGE and IL-6, and inhibitors of MAPK and NF-κB, and then cultured with and without AGEs. The phosphorylation of MAPK and NF-κB was assessed using Western blotting. Results: AGEs increased the mRNA and protein expressions of RAGE, IL-6, ICAM-1 and ROS activity in HGFs, and promoted the adhesion of THP-1 cells to HGFs, but had no effect on cell viability until 72 h. rhIL-6 increased ICAM-1 expression in HGFs, while the siRNAs of RAGE and IL-6 inhibited AGE-induced IL6 and ICAM1 mRNA expression, and IL-6 siRNA depressed AGE-induced THP-1 cell adhesion. AGEs increased the phosphorylation of p38 and ERK MAPKs, p65 NF-κB, and IκBα, while inhibitors of p38, ERK MAPKs, and NF-κB significantly decreased AGE-induced IL-6 and ICAM-1 expression. Conclusions: AGEs increase IL-6 and ICAM-1 expression via the RAGE, MAPK and NF-κB pathways in HGFs and may exacerbate the progression of the pathogenesis of periodontal diseases