Effect of inhaled corticosteroid on TNF-α production and alveolar bone loss in Wistar rats

ObjectiveTo evaluate the effect of different concentrations of inhaled budesonide on secretion of tumoral necrosis factor-alpha (TNF-α) and on ligature-induced alveolar bone loss in Wistar rats.Materials and methodsForty-two animals were randomly divided in four groups. Control group (G1) did not receive any procedure. For the other 3 groups, alveolar bone loss was induced by placement of ligatures around the upper second molar. The contralateral molar was considered intra-group control. Group 2 (G2) was nebulized with saline solution (NaCl 0.9%). Groups 3 and 4 (G3 and G4) were nebulized with 30 μg and 100 μg budesonide, respectively. Administration of drugs was performed daily for 14 days. Blood samples were collected from all animals for analysis of TNF-α. The maxillae from G2, G3 and G4 were removed and defleshed with 9% sodium hypochlorite. Morphometric analysis of bone loss was performed in digital standard photographs. Statistical analysis was performed with one-way ANOVA, followed by Tukey HSD or Scheffé multiple comparison's test (significance level P ≤ 0.05).ResultsMean alveolar bone loss values for teeth with ligature were 0.72, 0.70 and 0.77 mm for Groups 2, 3 and 4, respectively. No statistically significant differences were found amongst groups with or without ligature. The production of TNF-α was 60% higher in the presence of ligature (G1 vs. G2/G3/G4). No effect was observed in TNF-α secretion after inhalation of budesonide.ConclusionInhaled budesonide in different concentrations did not alter alveolar bone loss and TNF-α secretion in male Wistar rats.     

Periodontal ligament and gingival fibroblasts participate in the production of TGF-β, interleukin (IL)-8 and IL-10

The aim of this study was to quantify and compare the production of transforming growth factor beta (TGF-β), interleukin (IL)-8 and IL-10 by human cultured periodontal ligament and gingival fibroblasts both obtained from the same donors challenged with lipopolysaccharide (LPS) from Porphyromonas gingivalis. Fibroblasts were exposed to 0.1-10 μg/mL of LPS from P. gingivalis and after 24 h the supernatants were collected and analyzed by enzyme-linked immunosorbent assay (ELISA). TGF-β protein production was upregulated in a concentration-dependent manner, mainly in gingival fibroblasts, which was statistically significant when challenged by 10 μg/mL LPS. Additionally, at this concentration, gingival fibroblasts had almost a two-fold increase in the amount of TGF-β when compared to periodontal ligament fibroblasts. Both periodontal ligament and gingival fibroblasts showed an increase in IL-8 production when challenged with 1 μg/mL and 10 μg/mL LPS. IL-10 production remained unaffected when challenged by any of the LPS concentrations tested in either periodontal ligament or gingival fibroblasts. Our results demonstrate that periodontal ligament and gingival fibroblasts when challenged by LPS from P. gingivalis with 24 h may play a critical role in producing TGF-β and IL-8 but not IL-10.     

Sodium butyrate induces the production of cyclooxygenases and prostaglandin E₂ in ROS 17/2.8 osteoblastic cells

ObjectiveSodium butyrate (butyric acid; BA) is a major metabolic by-product of the anaerobic periodontopathic bacteria present in subgingival plaque. We examined the effects of BA and/or indomethacin on cell proliferation, the expression of cyclooxygenases (COXs), prostaglandin (PG) receptors (EP1-4), extracellular matrix proteins, such as type I collagen and osteopontin, and PGE₂ production, using ROS17/2.8 cells as osteoblasts.MethodsThe rat clonal cell line ROS 17/2.8 was cultured with 0, 10^?5, 10^?4, and 10^?3 M BA in the presence or absence of 0.5 μM indomethacin, for up to 7 days. The expression of COX-1, COX-2, EP1, EP2, EP3, EP4, type I collagen, and osteopontin was examined at the mRNA and protein levels using real-time PCR and Western blotting, respectively. The amount of PGE₂ in the culture medium was measured by ELISA.ResultsProliferation of ROS 17/2.8 cells was not affected by the addition of BA. However, PGE₂ production and the expression of COX-1 and COX-2 increased with the addition of BA. In contrast, indomethacin, an inhibitor of COX, blocked the stimulatory effect of BA. Furthermore, EP2 expression increased with BA treatment, whereas EP1 expression was not affected and the expression of EP3 and EP4 was not detected. The addition of BA also increased the expression of type I collagen and osteopontin. Indomethacin blocked about 50% of the stimulatory effect of BA on type I collagen, whereas it did not block the effect on osteopontin.ConclusionsThese results suggest that BA induces PGE₂ production by increasing the expression of COX-1 and COX-2 in osteoblasts, and that an autocrine action of the produced PGE₂, via EP1 or BA-induced EP2, is related to an increase in type I collagen expression by BA.     

Nicotine and lipopolysaccharide stimulate the production of MMPs and prostaglandin E(2) by hypoxia-inducible factor-1α up-regulation in human periodontal ligament cells

Kim Y‐S, Shin S‐I, Kang K‐L, Herr Y, Bae W‐J, Kim E‐C. Nicotine and lipopolysaccharide stimulate the production of MMPs and prostaglandin E₂ by hypoxia‐inducible factor‐1α up‐regulation in human periodontal ligament cells. J Periodont Res 2012; 47: 719–728. © 2012 John Wiley & Sons A/S Background and Objective: Although hypoxia‐inducible factor 1α (HIF‐1α) is up‐regulated in the periodontal pockets of periodontitis patients, the expression and precise molecular mechanisms of HIF‐1α remain unknown in human periodontal ligament cells (PDLCs). The aim of this study was to explore the effects, as well as the signaling pathway, of nicotine and lipopolysaccharide (LPS) on the expression of HIF‐1α and on the production of its target genes, including cyclooxygenase‐2 (COX‐2)‐derived prostaglandin E₂ (PGE₂), MMP‐2 and MMP‐9 in PDLCs. Material and Methods: The expression of COX‐2 and HIF‐1α proteins was evaluated using western blotting. The production of PGE₂ and MMPs was evaluated using enzyme immunoassays and zymography, respectively. Results: LPS and nicotine synergistically induced the production of PGE₂, MMP‐2 and MMP‐9, and increased the expression of MMP‐2, MMP‐9, COX‐2 and HIF‐1α proteins. Inhibition of HIF‐1α activity by chetomin or knockdown of HIF1α gene expression by small interfering RNA markedly attenuated the production of LPS‐ and nicotine‐stimulated PGE₂ and MMPs, as well as the expression of COX‐2 and HIF‐1α. Furthermore, pretreatment with inhibitors of COX‐2, p38, extracellular signal‐regulated kinase, Jun N‐terminal kinase, protein kinase C, phosphatidylinositol 3‐kinase and nuclear factor‐kappaB decreased the expression of nicotine‐ and LPS‐induced HIF‐1α and COX‐2, as well as the activity of PGE₂ and MMPs. Conclusion: These data demonstrate novel mechanisms by which nicotine and LPS promote periodontal tissue destruction, and provide further evidence that HIF‐1α is a potential target in periodontal disease associated with smoking and dental plaque.     

Influence and countermeasures of the color effect of restorations Ⅱ.Expression and delivery of color message

进行个别前牙或前牙列部分修复时,医师不仅要注意颜色设计的问题,最终还需要将邻近修复体的天然牙颜色精确复制于修复体上.色彩的复制包括色彩的定位、色彩的表达、色彩的再现3个步骤.     

Influence and countermeasures of the color effect of restorations Ⅱ.Expression and delivery of color message

进行个别前牙或前牙列部分修复时,医师不仅要注意颜色设计的问题,最终还需要将邻近修复体的天然牙颜色精确复制于修复体上.色彩的复制包括色彩的定位、色彩的表达、色彩的再现3个步骤.     

Statins regulate interleukin-1β-induced RANKL and osteoprotegerin production by human gingival fibroblasts

Stein SH, Dean IN, Rawal SY, Tipton DA. Statins regulate interleukin‐1β ‐ induced RANKL and osteoprotegerin production by human gingival fibroblasts. J Periodont Res 2011; 46: 483–490. © 2011 John Wiley & Sons A/S Background and Objective: Three‐hydroxy‐3‐methyl‐glutaryl‐CoA (HMG‐CoA) reductase competitive inhibitors, or ‘statins’, are widely used for lowering cholesterol and thereby reducing the risk of a heart attack. Recent data suggest that statins influence metabolic bone activity by their actions on three molecules: RANKL; RANK; and osteoprotegerin (OPG), the soluble decoy receptor for RANKL. The purpose of this study was to evaluate OPG and RANKL production in resting and interleukin‐1β (IL‐1β)‐activated human gingival fibroblasts (HGFs), and to determine the effect of statins on their production. Material and Methods: Fibroblasts were pre‐incubated with atorvastatin or simvastatin for 24 h in serum‐free medium, and then incubated with IL‐1β for 6 d. The concentration of OPG or RANKL in culture supernatants was measured by specific ELISA. Data were analyzed using analysis of variance and Scheffe’s F procedure for post hoc comparison. Results: IL‐1β (1 × 10^?8 m ) stimulated a significant increase in the production of OPG on days 1, 3 and 6. There was a trend towards an increase in RANKL production as a result of stimulation with IL‐1β. Both statins, at multiple concentrations, significantly increased the constitutive RANKL/OPG ratio. Only atorvastatin at the highest concentration (5 × 10^?6 m ) significantly increased the IL‐1β‐stimulated RANKL/OPG ratio. Conclusion: IL‐1β significantly increased OPG production by HGFs. The statins differed minimally in their effects on OPG and RANKL production by resting and IL‐1β‐activated HGFs. Both statins increased constitutive RANKL/OPG ratios, but generally not IL‐1β‐stimulated ratios. Thus, statins may influence the production of RANKL and OPG by HGFs to favor bone catabolism, under noninflammatory conditions.     

Influence and countermeasures of the color effect of restorations Ⅱ.Expression and delivery of color message

进行个别前牙或前牙列部分修复时,医师不仅要注意颜色设计的问题,最终还需要将邻近修复体的天然牙颜色精确复制于修复体上.色彩的复制包括色彩的定位、色彩的表达、色彩的再现3个步骤.     

Influence and countermeasures of the color effect of restorations Ⅱ.Expression and delivery of color message

进行个别前牙或前牙列部分修复时,医师不仅要注意颜色设计的问题,最终还需要将邻近修复体的天然牙颜色精确复制于修复体上.色彩的复制包括色彩的定位、色彩的表达、色彩的再现3个步骤.     

Influence and countermeasures of the color effect of restorations Ⅱ.Expression and delivery of color message

进行个别前牙或前牙列部分修复时,医师不仅要注意颜色设计的问题,最终还需要将邻近修复体的天然牙颜色精确复制于修复体上.色彩的复制包括色彩的定位、色彩的表达、色彩的再现3个步骤.     

Influence and countermeasures of the color effect of restorations Ⅱ.Expression and delivery of color message

进行个别前牙或前牙列部分修复时,医师不仅要注意颜色设计的问题,最终还需要将邻近修复体的天然牙颜色精确复制于修复体上.色彩的复制包括色彩的定位、色彩的表达、色彩的再现3个步骤.     

Alkali production in the mouth and its relationship with certain patient’s characteristics

Objectives

To assess the relationships among alkali production, diet, oral health behaviors, and oral hygiene.

Methods

Data from 52 subjects including demographics, diet, and oral hygiene scores were analyzed against the level of arginine and urea enzymes in plaque and saliva samples. An oral habit survey was completed that included: use of tobacco (TB), alcohol (AH), sugary drinks (SD), and diet. Alkali production through arginine deiminase (ADS) and urease activities were measured in smooth-surface supragingival dental plaque and un stimulated saliva samples from all subjects. ADS and urease activities were measured by quantification of the ammonia generated from the incubation of plaque or saliva samples. Spearman correlations were used to compute all associations.

Results

Participants in the lowest SES (Socio-economic status) group had the habit of consuming sugary drinks the most and had the highest rate of tobacco use. Males consumed significantly more alcohol than females. No significant relationship was found between age or gender and alkali production. Higher rates of sugary drink consumption and tobacco use were significantly related to lower alkali production.

Conclusion

The study showed a relationship between alkali production and oral hygiene, diet, and certain oral health behaviors. Poor oral hygiene was significantly associated with age, lower SES, tobacco use, and alcohol, and sugary drinks consumption.

Clinical relevance

Certain oral health behaviors have an impact on oral hygiene and on alkali production; it is important to address these factors with patients as a strategy for caries control.     

Influence and countermeasures of the color effect of restorations Ⅱ.Expression and delivery of color message

进行个别前牙或前牙列部分修复时,医师不仅要注意颜色设计的问题,最终还需要将邻近修复体的天然牙颜色精确复制于修复体上.色彩的复制包括色彩的定位、色彩的表达、色彩的再现3个步骤.     

Influence and countermeasures of the color effect of restorations Ⅱ.Expression and delivery of color message

进行个别前牙或前牙列部分修复时,医师不仅要注意颜色设计的问题,最终还需要将邻近修复体的天然牙颜色精确复制于修复体上.色彩的复制包括色彩的定位、色彩的表达、色彩的再现3个步骤.     

Influence and countermeasures of the color effect of restorations Ⅱ.Expression and delivery of color message

进行个别前牙或前牙列部分修复时,医师不仅要注意颜色设计的问题,最终还需要将邻近修复体的天然牙颜色精确复制于修复体上.色彩的复制包括色彩的定位、色彩的表达、色彩的再现3个步骤.     

Influence and countermeasures of the color effect of restorations Ⅱ.Expression and delivery of color message

进行个别前牙或前牙列部分修复时,医师不仅要注意颜色设计的问题,最终还需要将邻近修复体的天然牙颜色精确复制于修复体上.色彩的复制包括色彩的定位、色彩的表达、色彩的再现3个步骤.     

MAPKs, activator protein-1 and nuclear factor-κB mediate production of interleukin-1β-stimulated cytokines, prostaglandin E₂ and MMP-1 in human periodontal ligament cells

Murayama R, Kobayashi M, Takeshita A, Yasui T, Yamamoto M. MAPKs, activator protein‐1 and nuclear factor‐κB mediate production of interleukin‐1β‐stimulated cytokines, prostaglandin E ₂ and MMP‐1 in human periodontal ligament cells. J Periodont Res 2011; 46: 568–575. © 2011 John Wiley & Sons A/S Background and Objective: Determination of the interleukin‐1 (IL‐1) signaling cascades that lead to the production of various inflammatory mediators and catabolic factors may clarify attractive targets for therapeutic intervention for periodontitis. We comprehensively assessed the involvement of MAPKs, activator protein‐1 (AP‐1) and nuclear factor‐κB (NF‐κB) in IL‐1β‐induced production of interleukin‐6 (IL‐6), interleukin‐8 (IL‐8), prostaglandin E₂ (PGE₂) and MMP‐1 in human periodontal ligament cells. Material and Methods: Human periodontal ligament cells were pretreated with an inhibitor for each of the MAPKs or NF‐κB and subsequently treated with IL‐1β. Following treatment, phosphorylation of three types of MAPK (ERK, p38 MAPK and c‐Jun N‐terminal kinase), IκB kinase (IKK) α/β/γ and IκB‐α, as well as the DNA binding activity of AP‐1 and NF‐κB and the production of IL‐6, IL‐8, PGE₂ and MMP‐1, were determined by western blotting, a gel mobility shift assay and ELISA, respectively. Results: The three MAPKs, simultaneously activated by IL‐1β, mediated the subsequent DNA binding of AP‐1 at various magnitudes, while IKKα/β/γ, IκB‐α and NF‐κB were also involved in the IL‐1 signaling cascade. Furthermore, IL‐1β stimulated the production of IL‐6, IL‐8, PGE₂ and MMP‐1 via activation of the three MAPKs and NF‐κB, because inhibitors of these significantly suppressed the IL‐1β‐stimulated production of these factors. Conclusion: Our results strongly suggest that MAPK, AP‐1 and NF‐κB mediate the IL‐1β‐stimulated synthesis of IL‐6, IL‐8, PGE₂ and MMP‐1 in human periodontal ligament cells. Therefore, inhibition of activation of MAPK, AP‐1 and/or NF‐κB may lead to therapeutic effects on progression of periodontitis.     

Targeting TNF-α suppresses the production of MMP-9 in human salivary gland cells

Objective

Tumour necrosis factor-α (TNF-α) is a pleiotropic cytokine that plays an essential role in inflammation and apoptosis. Our previous study suggested that TNF-α-induced activation of matrix metalloproteinase-9 (MMP-9) resulted in the destruction of acinar tissue in the salivary glands of patients with Sjögren's syndrome (SS) via disruption of the acinar cell-basement membrane. Recently, a wide array of biological agents has been designed to inhibit TNF, including etanercept and adalimumab.In this study, we demonstrate the suppressive effect of anti-TNF agents on TNF-α-induced MMP-9 production in NS-AV-AC, an immortalized human salivary gland acinar cell line.

Materials and methods

NS-AV-AC cells were treated with etanercept or adalimumab after TNF-α treatment. MMP-9 production and enzymatic activity were, respectively, visualized by real-time PCR and ELISA assay, and evaluated by gelatin zymography, and apoptosis was evaluated by DNA fragmentation assay.

Results

TNF-α induced the production of MMP-9 in NS-SV-AC cells. However, this production was greatly inhibited by treatment with etanercept or adalimumab. In addition, TNF-α-induced DNA fragmentation was prevented by treatment with etanercept or adalimumab.

Conclusions

These results may indicate that anti-TNF agents would have therapeutic efficacy for preventing destruction of the acinar structure in the salivary glands of patients with SS.     

Age-related production of osteoclasts and the changes of serum levels of vascular endothelial growth factor (VEGF) and receptor activator for nuclear factor (NF)-κB ligand (RANKL) in osteopetrotic (op/op) mice

ObjectiveExpression of osteoclasts in osteopetrotic (op/op) mice is substantially reduced by the absence of functional macrophage colony-stimulating factor (M-CSF). However, it has been reported that osteoclasts do gradually appear in the bones of op/op mice and spontaneously correct the osteopetrosis.DesignAge-related production of osteoclasts and the changes of serum levels of vascular endothelial growth factor (VEGF) and receptor activator for nuclear factor (NF)-κB ligand (RANKL) in op/op mice were examined.ResultsThe number of femoral osteoclasts, and the serum levels of VEGF, both gradually increased in op/op mice after birth and reached a peak in 120- and 60-day-old mice, respectively. However, the serum levels of RANKL showed an inverse relationship to osteoclast number.ConclusionsThese findings suggest that the appearance of osteoclasts may be influenced by the serum levels of VEGF and that the serum levels of RANKL may be influenced by the appearance of osteoclasts.