Aloin Inhibits Interleukin (IL)‐1β−Stimulated IL‐8 Production in KB Cells

Background: Interleukin (IL)‐1β, which is elevated in oral diseases including gingivitis, stimulates epithelial cells to produce IL‐8 and perpetuate inflammatory responses. This study investigates stimulatory effects of salivary IL‐1β in IL‐8 production and determines if aloin inhibits IL‐1β?stimulated IL‐8 production in epithelial cells. Methods: Saliva was collected from volunteers to determine IL‐1β and IL‐8 levels. Samples from volunteers were divided into two groups: those with low and those with high IL‐1β levels. KB cells were stimulated with IL‐1β or saliva with or without IL‐1 receptor agonist or specific mitogen‐activated protein kinase (MAPK) inhibitors. IL‐8 production was measured by enzyme‐linked immunosorbent assay (ELISA). MAPK protein expression involved in IL‐1β?induced IL‐8 secretion was detected by Western blot. KB cells were pretreated with aloin, and its effect on IL‐1β?induced IL‐8 production was examined by ELISA and Western blot analysis. Results: Saliva with high IL‐1β strongly stimulated IL‐8 production in KB cells, and IL‐1 receptor agonist significantly inhibited IL‐8 production. Low IL‐1β–containing saliva did not increase IL‐8 production. IL‐1β treatment of KB cells induced activation of MAPK signaling molecules as well as nuclear factor‐kappa B. IL‐1β?induced IL‐8 production was decreased by p38 and extracellular signal‐regulated kinase (ERK) inhibitor treatment. Aloin pretreatment inhibited IL‐1β?induced IL‐8 production in a dose‐dependent manner and inhibited activation of the p38 and ERK signaling pathway. Finally, aloin pretreatment also inhibited saliva‐induced IL‐8 production. Conclusions: Results indicated that IL‐1β in saliva stimulates epithelial cells to produce IL‐8 and that aloin effectively inhibits salivary IL‐1β–induced IL‐8 production by mitigating the p38 and ERK pathway. Therefore, aloin may be a good candidate for modulating oral inflammatory diseases.     

IL‐1β and PGE2 levels are increased in the saliva of children with Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is a rare disorder mainly of children, whose pathogenesis is still unknown. Some studies have demonstrated that LCH lesions produce different cytokines abnormally that may be relevant to the pathogenesis of the disease. The purpose of this study was to investigate interleukin‐1β (IL‐1β) and prostaglandin E2 (PGE₂) levels in saliva from children with different clinical subtypes of LCH. We studied 29 children with LCH: seven unifocal (Group I), seven multifocal (Group II), 15 multisystemic (Group III) and 12 healthy volunteers (Group IV). Salivary IL‐1β and PGE₂ levels were significantly higher in LCH than in normal children. A multi‐comparison test showed significantly (P < 0.001) higher levels of both IL‐1β and PGE₂ in saliva from Group III compared with Groups II and I. A significant correlation (r = 0.05) between IL‐1β and PGE₂ concentrations in saliva from each group was determined. Our findings demonstrated an association between high concentrations of salivary IL‐1β and PGE₂ and advanced stages of the disease. This allows us to suggest that the abnormal amount of these factors in saliva may serve as a risk marker for disease progression.     

Orthodontic Force Increases Interleukin‐1β and Tumor Necrosis Factor‐α Expression and Alveolar Bone Loss in Periodontitis

Background: The present study aims to evaluate the effects of orthodontic movement (OM) on the periodontal tissues of rats with ligature‐induced periodontal disease. Methods: Eighty‐eight rats were divided into four groups: 1) negative control (sham operated); 2) periodontal disease; 3) OM; and 4) periodontal disease followed by OM (OMP). Rats were sacrificed 3 hours or 1, 3, or 7 days after OM commencement. Bone volume fraction (BVF) and bone mineral density (BMD) were assessed in hemimaxillae by microcomputed tomography analysis. Expression of the proinflammatory cytokines interleukin (IL)‐1β and tumor necrosis factor (TNF)‐α were evaluated in gingival samples by quantitative polymerase chain reaction and enzyme‐linked immunosorbent assay, and in the furcation region by immunohistochemistry analysis (IHC). Results: The OMP group had lower BVF and BMD levels compared to the other groups at day 7 (P <0.05). Maximum messenger ribonucleic acid expression of both cytokines was observed in the OMP group at day 1 (P <0.05). In the same period, all proteins were expressed in high levels for all test groups compared to the control group. The number of cells positive for IL‐1β and TNF‐α by IHC was highest in the OMP group at day 1, with progressive reduction thereafter. Conclusion: The results suggest that OM acts synergistically with periodontal disease in periodontal breakdown through upregulation of proinflammatory cytokines.     

Effects of interleukin‐1β and tumor necrosis factor‐α on macrophage inflammatory protein‐3α production in synovial fibroblast‐like cells from human temporomandibular joints

Background

Interleukin‐1β (IL‐1β) and tumor necrosis factor‐α (TNF‐α) are key mediators of the intracapsular pathological conditions of the temporomandibular joint (TMJ). Therefore, the gene expression profiles in synovial fibroblast‐like cells (SFCs) from patients with internal derangement of the TMJ were examined after they were stimulated with IL‐1β or TNF‐α to determine which genes were altered.

Methods

Ribonucleic acid was isolated from SFCs after IL‐1β or TNF‐α treatment. Gene expression profiling was performed using oligonucleotide microarray analysis. On the basis of the results of this assay, we investigated the kinetics of macrophage inflammatory protein‐3α (MIP‐3α) gene expression using PCR, and protein production in TMJ SFCs stimulated by IL‐1β or TNF‐α using an ELISA. Inhibition experiments were performed with MAPK and NFκB inhibitors. SFCs were stimulated with IL‐1β or TNF‐α after treatment with inhibitors. The MIP‐3α levels were measured using an ELISA.

Results

Macrophage inflammatory protein‐3α was the gene most upregulated by IL‐1β‐ or TNF‐α stimulation. The mRNA and protein levels of MIP‐3α increased in response to IL‐1β in a time‐dependent manner. In contrast, during TNF‐α stimulation, the MIP‐3α mRNA levels peaked at 4 h, and the protein levels peaked at 8 h. In addition, the IL‐1β‐ and TNF‐α‐stimulated MIP‐3α production was potently reduced by the MAPK and NFκB signaling pathway inhibitors.

Conclusion

Interleukin‐1β and TNF‐α increased the MIP‐3α production in SFCs via the MAPK and NFκB pathways. These results suggest that the production of MIP‐3α from stimulation with IL‐1β or TNF‐α is one factor associated with the inflammatory progression of the internal derangement of the TMJ.     

Flutamide inhibits nifedipine‐ and interleukin‐1β‐induced collagen overproduction in gingival fibroblasts

Lu H‐K, Tseng C‐C, Lee Y‐H, Li C‐L, Wang L‐F. Flutamide inhibits nifedipine‐ and interleukin‐1β‐induced collagen overproduction in gingival fibroblasts. J Periodont Res 2010; 45: 451–457. © 2010 John Wiley & Sons A/S Background and Objective: To understand the role of the androgen receptor in gingival overgrowth, the effects of flutamide on interleukin‐1β‐ and nifedipine‐induced gene expression of connective tissue growth factor (CTGF/CCN2) and collagen production in gingival fibroblasts were examined. Material and Methods: Gingival fibroblasts from healthy subjects and patients with dihydropyridine‐induced gingival overgrowth (DIGO) were used. Confluent cells were treated with nifedipine, interleukin‐1β or both. The mRNA expression was examined using real‐time polymerase chain reaction, and the concentration of total soluble collagen in conditioned media was analysed by Sircol Collagen Assay. In addition, the protein expressions of androgen receptor, CTGF/CCN2 and type I collagen in gingival tissue were determined by western blot. Results: Interleukin‐1β was more potent than nifedipine in stimulating CTGF/CCN2 and procollagen α1(I) mRNA expression, and there was an additive effect of the two drugs. Healthy cells exhibited an equal or stronger response of procollagen α1(I) than those with DIGO, but DIGO cells displayed a stronger response in the secretion of soluble collagen in the same conditions. Flutamide, an androgen receptor antagonist, inhibited stimulation by nifedipine or interleukin‐1β. Additionally, the protein expressions of androgen receptor and type I collagen were higher in DIGO gingival tissue than those in healthy gingival tissue. Conclusion: The data suggest that both nifedipine and interleukin‐1β play an important role in DIGO via androgen receptor upregulation and that gingival overgrowth is mainly due to collagen accumulation. Flutamide decreases the gene expression and protein production of collagen from dihydropyridine‐induced overgrowth cells.     

Increased Expression of Interleukin (IL)‐35 and IL‐17, But Not IL‐27, in Gingival Tissues With Chronic Periodontitis

Background: Interleukin (IL)‐35 plays an important role in immune regulation through the suppression of effector T‐cell populations, including T‐helper 17 (Th17) cells. Although Th17 cells and IL‐17 are involved in the pathogenesis of periodontitis, the level of IL‐35 in inflamed periodontal tissues is unclear. Here, IL‐35, IL‐17, and IL‐27 production/expression in gingival crevicular fluid (GCF) and human gingival tissue were investigated. Methods: GCF samples were collected from buccal (mesial, center, and distal) sites of teeth from patients with chronic periodontitis (CP) and healthy controls and were analyzed by enzyme‐linked immunosorbent assay for IL‐35 (periodontitis, n = 36; healthy, n = 30) and IL‐17 (periodontitis, n = 16; healthy, n = 13). Gingival tissue, including sulcus/pocket epithelium and underlying connective tissue, was collected from an additional 10 healthy participants and 10 patients with CP and were analyzed by quantitative polymerase chain reaction (qPCR) for Epstein Barr virus‐induced gene 3 (EBI3), IL12A, and IL17A. IL27p28 was also tested by qPCR. Results: IL‐35 and IL‐17 were significantly higher in GCF from patients with periodontitis than healthy participants (P <0.01, P <0.05, respectively). In both healthy participants and those with periodontitis, positive correlations were found among IL‐35 and probing depth and clinical attachment level (CAL) as well as between IL‐17 and CAL. EBI3, IL12A (components of IL‐35), and IL17A messenger RNA expression levels were significantly higher in inflamed gingival tissue than in healthy control tissues (P <0.05). IL27p28 was not detected in any sample, suggesting that IL‐27 is not produced in large quantities in periodontal tissue. Conclusion: IL‐35 and IL‐17, but not IL‐27, may play important roles in the pathogenesis of periodontitis.     

Understanding the pathophysiology behind chairside diagnostics and genetic testing for IL‐1 and IL‐6

In order for chairside diagnostic testing to make an impact on dental therapy, practitioners require a better understanding of genetic mutations contributing to the pathophysiology of periodontal disease. Commensal and pathogenic bacterial colonization in oral cavity tissues produces a cascade of proinflammatory signaling pathways ultimately detrimental to host tissues. Resolving inflammation is a multifactorial process involving the downregulation of proinflammatory cytokines while allowing commensal bacterial levels to return to normal. Because of the complicated nature of commensal bacteria and oral health homeostasis, the emphasis of dental therapy should place renewed focus on limiting destructive inflammation rather than solely eliminating bacteria. Salivary diagnostics are an easy, non‐invasive way to assess inflammatory markers. Inflammatory cytokine levels can help determine the subclinical health of a patient, showing the transition from health to gingivitis, or periodontitis, prior to clinical presentation. Single nucleotide polymorphism mutations can aid in determining increased risk of developing periodontitis. Taken together, and alongside regular clinical evaluations, chairside diagnostics help individualize treatment plans to slow, or halt, the progression of disease—before tissue destruction can take place. While more studies are needed analyzing specific mutations across periodontal categories, chairside diagnostics present an exciting adjunct to improve patient care.     

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.     

Immunohistochemical analysis of interleukin‐1α, its type I receptor and antagonist in keratocystic odontogenic tumors

Background: Interleukin‐1α (IL‐1α) is thought to play a crucial role in the growth of keratocystic odontogenic tumors (KCOTs) in the jaw. The function of IL‐1α is regulated by the local levels of IL‐1α, its receptor and receptor antagonist (IL‐1Ra) in tissues. In this study, the expression of these proteins was investigated both before and after marsupialization in KCOTs. Methods: The expression of IL‐1α, IL‐1 receptor type I (IL‐1RI) and IL‐1Ra was detected immunohistochemically in 10 specimens of KCOTs. Results: IL‐1α was intensively expressed throughout the epithelium in all cases, while mild expression of IL‐1α was detected in the subepithelial layer endothelial cells and fibroblasts. Mild or intensive immunoreactivity for IL‐1RI was also observed in the epithelial cells in all cases, and in the endothelial cells and fibroblasts in five cases respectively. The expression of IL‐1Ra was detected in the epithelial cells in five cases, and in the endothelial cells and fibroblasts in three cases. After marsupialization, the immunoreactivity for IL‐1α and IL‐1RI in the epithelial cells decreased, while the immunoreactivity for IL‐1Ra in the epithelial cells increased. However, the immunoreactivity for IL‐1RI and IL‐1Ra in endothelial cells and fibroblasts did not change significantly. Conclusion: The effects of IL‐1α on the epithelial cells might be downregulated after marsupialization by changing the expression levels of IL‐1α, IL‐1RI and IL‐1Ra in the epithelium of KCOTs.