Interleukin‐1 and interleukin‐8 in nicotine‐ and lipopolysaccharide‐exposed gingival keratinocyte cultures

Johnson GK, Guthmiller JM, Joly S, Organ CC, Dawson DV. Interleukin‐1 and interleukin‐8 in nicotine‐ and lipopolysaccharide‐exposed gingival keratinocyte cultures. J Periodont Res 2010; 45: 583–588. © 2010 John Wiley & Sons A/S Background and Objective: Tobacco use is associated with increased periodontal destruction in both cigarette smokers and smokeless tobacco users. Gingival keratinocytes are the first cells in contact with microbial and tobacco components and play a key role in the innate immune response to these agents. The objective of this study was to evaluate the effect of nicotine and bacterial lipopolysaccharide (LPS) alone and in combination on gingival keratinocyte production of interleukin‐1α (IL‐1α) and interleukin‐8 (IL‐8). Material and Methods: Gingival keratinocyte cultures were established from 10 healthy, non‐tobacco‐using subjects. The cells were stimulated for 24 h with 1 μm or 1 mm nicotine and/or 10 μg/mL Escherichia coli or Porphyromonas gingivalis LPS. Interleukin‐1α and IL‐8 proteins were quantified using ELISAs. Results: Compared with untreated cultures, 1 mm nicotine stimulated production of IL‐1α (p < 0.001); E. coli and P. gingivalis LPS increased IL‐8 production (p = 0.0014 and p = 0.0232, respectively). A combination of nicotine and LPS produced the highest cytokine quantities. Amounts of IL‐1α and IL‐8 following 1 mm nicotine and LPS exposure were significantly greater than in untreated cultures (p < 0.001). Interleukin‐8 was also responsive to 0.1 μm nicotine combined with E. coli or P. gingivalis LPS compared with control cultures (p < 0.0001 and p = 0.0029, respectively). Both cytokines tended to be elevated following the combined treatment relative to nicotine or LPS treatment alone. Conclusion: These results demonstrate that nicotine and LPS differentially regulate IL‐1 and IL‐8 production by gingival keratinocytes. Combined treatment tended to elevate cytokine production further, which may have implications for the progression of periodontitis in tobacco users.     

Attenuation of radiation‐ and chemoradiation‐induced mucositis using gamma‐d‐glutamyl‐l‐tryptophan (SCV‐07)

Oral Diseases (2010) 16 , 655–660 Objective: To evaluate the efficacy of a novel immunomodulating peptide (SCV‐07) in attenuating the course of radiation‐induced mucositis in an established animal model of oral mucositis (OM). Material and Methods: In three separate experiments, golden Syrian hamsters received either an acute radiation challenge to the buccal mucosa of eight fractionated doses of 7.5 Gy of radiation over a 2‐week‐period, or a combination of acute radiation and cisplatin. In each experiment, animals were treated with varying doses or schedules of SCV‐07 or placebo. OM was scored in a blinded fashion using digital images obtained during the experimental period. Results: We found that SCV‐07 reduced the severity and duration of both acute and fractionated radiation‐induced OM. Similarly, when radiation and chemotherapy were used to induce OM, treatment with SCV‐07 significantly reduced the duration of ulcerative OM. The therapeutic benefit was dependent on both dose and schedule of administration. Conclusion: Taken together, we found SCV‐07 was able to modify the duration and severity of oral mucositis and was dependent on schedule and dose.     

Dental status and self‐assessed chewing ability in 70‐ and 80‐year‐old subjects in Sweden

The objective was to compare two cohorts of elderly people, 70 and 80 years old, with respect to dental status and self‐assessed chewing ability. The hypotheses were as follows: (i) dental status is associated with self‐assessed chewing ability; (ii) chewing ability is poorer among the 80‐ than the 70‐year‐old subjects. Identical questionnaires were in 2012 sent to all subjects born in 1942 and 1932, living in two Swedish counties. The response rate was 70·1% resulting in samples of 5697 70‐ and 2922 80‐year‐old subjects. Answers to questions on self‐assessed chewing ability, dental status and some other factors have been analysed. Dental status varied but was in general good; 72% of the 70‐ and 60% of the 80‐year‐old subjects reported that they had all or only few missing teeth. Rate of edentulism was 3% and 7%, respectively. Removable partial dentures were reported by 6% and 10%, respectively, implant treatment by 13% in both cohorts. Self‐assessed chewing ability was mostly good and correlated with the number of teeth (Spearman rho = 0·46). A majority of the edentulous subjects assessed their chewing ability as very or fairly good. Logistic regression showed that self‐assessed chewing ability was significantly associated with a number of dental variables but also with general health. In conclusion, dental status was relatively good at both ages but somewhat poorer in the older cohort. Dental status, some other dental variables and being healthy were in both age groups significantly associated with self‐assessed chewing ability.     

Insulin‐like growth factor‐binding protein‐2 and ‐3 in gingival crevicular fluid

Takenouchi Y, Ohshima M, Yamaguchi Y, Nishida T, Senda N, Idesawa M, Otsuka K, Ito K. Insulin‐like growth factor‐binding protein‐2 and ‐3 in gingival crevicular fluid. J Periodont Res 2010; 45: 803–808. © 2010 John Wiley & Sons A/S Background and Objective: Insulin‐like growth factor‐binding proteins (IGFBPs) are crucial regulators of insulin‐like growth factor (IGF). They enhance or inhibit IGF functions, but also exhibit IGF‐independent effects. In a previous study, we detected, qualitatively, IGFBP‐2 and ‐3 in gingival crevicular fluid using a cytokine antibody array. Here we extended these results using an ELISA to determine the concentrations of IGFBP‐2 and ‐3 in gingival crevicular fluid. In addition, we explored whether the expression of IGFBP‐2 and IGFBP‐3 correlates with periodontal disease severity. Material and Methods: Gingival crevicular fluid samples from 92 sites of 12 patients affected with periodontal disease and from 100 sites of 19 healthy volunteers, were collected, divided into two groups and analyzed by ELISA for IGFBP‐2 and ‐3 expression. The potential correlation among probing depth, gingival index and the concentrations of IGFBP‐2 and ‐3 was analyzed. Results: Positive correlations were observed between the concentration of IGFBP‐2 and probing depth and gingival index, but not for IGFBP‐3. The IGFBP‐2 concentrations at bleeding on probing‐positive sites and at sites with a probing depth of ≥ 4 mm were higher than at bleeding on probing‐negative sites and at sites with a probing depth of ≤ 3 mm. Conclusion: These results indicate that IGFBP‐2 is a potential novel marker for periodontal disease progression. As IGFBP‐2 modulates bone metabolism and cell migration, IGFBP‐2 in the gingival crevicular fluid may reflect periodontal disease activity.     

T‐ and B‐cell subsets in periodontitis

A large amount of information is available, in the medical literature, on the molecular and immunological mechanisms in which T‐ and B‐cells are involved in the pathogenesis of inflammatory diseases. This review attempts to describe the most important features of the T‐cell subsets and their cytokine networks in periodontitis, including the interaction of pathogens with different cell subsets and their gene‐expression profiles. Additionally, the known interactions of T‐ and B‐cell subsets in periodontitis are described. The purpose of this article was to provide an overview of the cell interactions and cytokine networks specifically involved in the pathogenesis of periodontitis, and models and paradigms from recent research in this area are presented. However, the review of the literature also revealed that relatively little is known about the genetic or structural factors that confer cross‐reactivity of natural and/or autoreactive antibodies in the immunopathogenesis of periodontitis. Pathogens, in turn, are continuously evolving and creating mechanisms to evade immunological reactions controlled and modulated by T‐ and B‐cells.     

Analysis of YKL‐40 Acute‐Phase Protein and Interleukin‐6 Levels in Periodontal Disease

Background: YKL‐40, a new acute‐phase protein, is shown to be elevated in inflammatory diseases, such as rheumatoid arthritis, type 2 diabetes mellitus, and coronary artery diseases. However, there is no data indicating a relationship between YKL‐40 and periodontal disease. Interleukin‐6 (IL‐6) is the major regulator of acute‐phase protein synthesis and one of the most studied inflammatory markers in periodontal disease. The purpose of the present study is to evaluate YKL‐40 and IL‐6 levels in gingival crevicular fluid (GCF) and serum of patients with periodontal disease and healthy individuals. Methods: Periodontally healthy individuals (n = 15), patients with gingivitis (n = 15), and patients with severe chronic periodontitis (CP) (n = 15) without any systemic disease were included in the study. Clinical measurements were recorded; GCF and blood samples were obtained from each participant. GCF and serum YKL‐40 and IL‐6 levels were analyzed by enzyme‐linked immunosorbent assay. Statistical analysis was performed by parametric and non‐parametric tests. Results: Total amounts of YKL‐40 and IL‐6 in GCF as well as serum YKL‐40 and IL‐6 levels were significantly higher in patients with gingivitis and CP compared with healthy controls (P <0.01). YKL‐40 levels in GCF and serum as well as serum IL‐6 levels were significantly higher in patients with CP compared with patients with gingivitis (P <0.01). Conclusions: YKL‐40 levels in GCF as well as serum YKL‐40 and IL‐6 levels increased from gingivitis to periodontitis. Within the limits of the present study, the YKL‐40 molecule might be a potential novel inflammatory marker of periodontal disease.     

Production of IL‐10 and IL‐12 by antigen‐presenting cells in periapical lesions

J Oral Pathol Med (2010) 39 : 690–696 Background: Interferon‐γ (IFN‐γ) plays an important role in the pathogenesis of periapical lesions. Its expression is up‐regulated by interleukin (IL)‐12) and down‐regulated by IL‐10. The aim of this work was to study the cellular source of these cytokines and their mutual interactions in human periapical lesions. Methods: Mononuclear cells, macrophages and dendritic cells were isolated from periapical lesions using plastic adherence and osmotic gradients. Cytokines were measured in culture supernatants by a microbeads fluorescence assay. Phenotypic characteristics of cells were studied by immunocytochemistry, whereas allostimulatory activity of antigen‐presenting cells was tested using a mixed leukocyte reaction. Results: We observed the positive correlations between the levels of IL‐12 and IFN‐γ as well as IL‐12 and IL‐10 in cultures of mononuclear cells. As IL‐10 and IL‐12 are produced by dendritic cells and activated macrophages, we examined their contribution to the production of these cytokines. Macrophages, CD14⁺ adherent cells, produced high levels of IL‐10 and very low levels of IL‐12. In contrast, non‐adherent, strongly HLA‐DR⁺ dendritic cells, potent stimulators of the alloreactive T‐cell response, produced low levels of IL‐10 and moderate levels of IL‐12. Dendritic cells stimulated the production of IFN‐γ by allogeneic CD4⁺ T cells. In contrast, the level of IFN‐γ was significantly decreased and the production of IL‐10 was enhanced by addition of macrophages to the culture system. Conclusion: Our results suggest that a fine balance between the production of IL‐10 and IL‐12 by different antigen‐presenting cells, through IFN‐γ, may control the course of chronic inflammation in periapical lesions.