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.     

Gene polymorphism of interleukin-1 alpha and beta in keratocystic odontogenic tumors

J Oral Pathol Med (2012) 41: 697-701 Aim and background: Odontogenic keratocysts have a different growth mechanism and biologic behavior in comparison with more common dentigerous and radicular cysts. It was reclassified as keratocystic odontogenic tumor (KCOT). The proliferative activity of the epithelial cells of KCOT has a close relationship with tissue levels of interleukin-1 (IL-1). Moreover, IL-1 increases the expression of several matrix metalloproteinases in the fibroblasts of adjacent stroma and activates the osteoclastogenesis process. So it plays an important role in the activity, spread, and local aggressiveness of this tumor. Therefore, it seems that the gene polymorphism of the cytokines of the IL-1 family is influential in the pathogenesis of KCOT and the patients' susceptibility to disease. Method: A total of 38 blood samples of patients suffering from KCOT and 150 blood samples of healthy patients were assessed using PCR-SSP. The blood samples were assessed for the following polymorphisms: interleukin-1 alpha (-889) and interleukin-1 beta (-511). Following up the patients, we found six recurrent and one syndromic cases. Findings: By comparing the case and control groups, we observed the significant dominance of allele T over C, and genotype TT over CC and CT in IL-1α, although no significant difference was seen in the allele frequency and genotypes regarding IL-1β. Conclusion: The function of IL-1α has a significant relationship with KCOT. Its effective genotype associated with pathogenesis, growth, local invasion, and recurrence is TT.     

Local Minocycline Effect on Inflammation and Clinical Attachment During Periodontal Maintenance: Randomized Clinical Trial

Background: Minocycline microspheres (MMs) are being used to treat residual inflamed periodontal pockets during periodontal maintenance therapy (PMT), but evidence for efficacy from randomized clinical trials is lacking. The purpose of this study is to evaluate the effect of MMs plus scaling and root planing (SRP) on these sites. Methods: Sixty patients with chronic periodontitis on 6‐month PMT intervals to be followed for 1 year were randomized (51 completed the study) into two statistically similar groups, SRP + MM (aged 66.8 years) and SRP alone (aged 67 years), to treat a ≥5 mm posterior interproximal pocket during PMT with a history of bleeding on probing (BOP). Group treatments were applied to the site at baseline and 6 months. Clinical attachment levels (CALs; primary outcome), probing depths (PDs), plaque, and BOP also were recorded at baseline and 6 and 12 months. In addition, gingival crevicular fluid was analyzed for an inflammation index ratio of interleukin (IL)‐1β/IL‐1 receptor antagonist (ra) using enzyme‐linked immunosorbent assays. Results: All clinical parameters improved significantly (P <0.005) from baseline in both groups with no differences between groups at any time point. CAL decreased 17% (0.9 ± 0.8 mm) and 13% (0.7 ± 0.9 mm) in SRP + MM and 11% (0.7 ± 1.1 mm) and 21% (1.2 ± 0.9 mm) in SRP at 6 and 12 months, respectively. The odds of having BOP decreased 90% (down to 38% of patients) and 95% (26%) in SRP + MM and 82% (42%) and 82% (41%) in SRP at 6 and 12 months, respectively. IL‐1β/IL‐1ra decreased a significant 61% (P = 0.009) only in SRP + MM at 6 months. Conclusions: SRP of inflamed moderate pockets during 6‐month PMT, with or without MMs, improves CALs, along with PDs and BOP over a 1‐year period. The use of MMs did not result in an additional benefit over SRP alone.     

LINE‐1 methylation difference between ameloblastoma and keratocystic odontogenic tumor

Oral Diseases (2010) 16 , 286–291 Objective: Global hypomethylation is a common epigenetic event in cancer. Keratocystic odontogenic tumor (KCOT) and ameloblastoma are different tumors but posses the same tissue in origin. Here, we investigated long interspersed nuclear element‐1 (LINE‐1 or L1) methylation status between ameloblastoma and KCOT. Materials and methods: We studied the methylation levels of the long interspersed nucleotide element‐1 (LINE‐1) in ameloblastoma and KCOT. After collecting ameloblastoma cells and epithelium lining cells of KCOT by laser capture microdissection from paraffin embedded tissue, combined bisulfite restriction analysis of LINE‐1 (COBRALINE‐1) was performed to measure LINE‐1 methylation levels. Results: The LINE‐1 methylation level in KCOT (53.16 ± 12.03%) was higher than that in ameloblastoma (36.90 ± 16.52%), with a statistical significance of P = 0.001. The ranges of LINE‐1 methylation of both lesions were not associated with either age or sex. Conclusion: We found LINE‐1 hypomethylation levels between ameloblastoma and KCOT are different. Therefore, global methylations between these tumors are processed differently.     

An update of knowledge on PD‐L1 in head and neck cancers: Physiologic,prognostic and therapeutic perspectives

Programmed cell death‐ligand 1 (PD‐L1) is a transmembrane protein that acts as a co‐inhibitory factor in the immune response. Its receptor, programmed cell death protein 1 (PD‐1), is found on immune cells, where binding to PD‐L1 can reduce the proliferation of PD‐1‐positive cells, inhibit their cytokine secretion and induce apoptosis. PD‐L1 in immune‐privileged tissue plays a crucial role in peripheral tolerance. PD‐L1 can be overexpressed in various malignancies, including oral squamous cell carcinoma, where it can attenuate the host immune response to tumour cells and has been associated with a worse prognosis. Monoclonal antibody therapies targeting the PD‐1:PD‐L1 axis have shown initial promise, but further research is needed to identify which patients will benefit. We provide an update of knowledge on PD‐L1, including its structure, function and regulation. We also review studies on the overexpression of PD‐L1 in cancer, specifically oral squamous cell carcinoma, and explore its potential value as a therapeutic target.     

Herpes viruses in periodontal compromised sites: comparison between HIV-positive and -negative patients

Aim: The objective of this study was to compare the frequency of herpes simplex virus type 1 (HSV‐1), Epstein–Barr virus (EBV) and human cytomegalovirus (HCMV) in subgingival plaque, saliva and peripheral blood of HIV‐positive and‐negative patients with periodontal disease. Material and Methods: Fifty HIV‐positive subjects (23 with gingivitis, 27 with periodontitis) and 50 healthy HIV‐negative patients with chronic periodontitis were included in the study. Parameters of probing depth (PD), clinical attachment level (CAL), gingival index and plaque index were recorded. The samples were processed for viral identification by the nested polymerase chain reaction technique. Results: HCMV was the most prevalent virus in HIV‐positive (82%) and‐negative patients (84%), and the detection in the three samples was similar (p>0.05). HSV‐1 was the least prevalent virus in both groups, being detected in similar frequencies in oral sites and in peripheral blood. EBV‐1 was found more frequently in saliva and subgingival plaque of HIV‐positive patients than in HIV‐negative patients (p0.05). Conclusions: EBV‐1 was more frequently recovered in oral sites of HIV‐positive patients than in HIV‐negative patients.     

Salivary Levels of NLRP3 Inflammasome‐Related Proteins as Potential Biomarkers of Periodontal Clinical Status

Background: Emerging evidence suggests that activation of inflammasomes plays a central mechanism in pathogenesis of periodontitis. This study aims to compare salivary levels of nod‐like receptor family pyrin domain containing protein (NLRP) 3, apoptosis‐associated speck‐like protein containing a caspase recruitment domain (ASC), cysteine aspartase (caspase)‐1, and interleukin (IL)‐1β from individuals with aggressive (AgP) or chronic periodontitis (CP) and healthy controls (HC), as well as elucidate its association with periodontal clinical status. Methods: Saliva samples from individuals with CP (n = 75), AgP (n = 20), and HC (n = 69) were collected. Periodontal status was assessed by measurement of probing depth, clinical attachment level, and extent and severity of disease. Salivary levels of analytes were analyzed by enzyme‐linked immunosorbent assay. Association between biomarkers with CP or AgP was analyzed using multivariate binary logistic regression models. Results: Significantly higher levels of NLRP3, ASC, and IL‐1β were detected in periodontitis groups in comparison to the periodontally HC group. However, no significant differences were observed for caspase‐1 levels between clinical groups, and only NLRP3 salivary concentration was significantly higher in AgP compared with CP patients. Also, positive significant correlations among NLRP3, ASC, and IL‐1β salivary concentrations and clinical parameters were observed. Logistic regression analyses revealed a strong/independent association of NLRP3, ASC, and IL‐1β salivary levels with CP and AgP. Conclusion: Although the concentration of caspase‐1 in saliva samples makes its determination useless for detection of periodontal disease and/or its severity, salivary levels of NLRP3, ASC, and IL‐1β may act as strong/independent indicators of amount and extent of periodontal breakdown in both CP and AgP and could potentially be used for prevention and therapy of this group of diseases.     

Upregulation of immunoreactivity of endothelin-1 and alpha-SMA in PDL microvasculature following acute tooth loading: an immunohistochemical study in the marmoset

Authors – Sims MR, Ashworth JF, Sampson WJ Objectives – To test the hypothesis that a continuous mechanical tooth load would elevate immunoreactivity of endothelin‐1 (ET‐1) and alpha‐smooth muscle actin (α‐SMA) in the periodontal ligament (PDL) microvasculature. Design – A randomized control study employing 1.5 h of loading to first molars. Setting and Sample Population – Orthodontic Research Laboratory, Dental School, Adelaide University. Four young adult, male marmoset monkeys were consecutively anaesthetized and treated. Experimental Variable – An external telescoping frame applied a jaw closing load (120–200 g) transmitted occlusally, via a rubber pad, to randomly assigned mandibular left or right first molars. Contralateral molars were used as controls. Outcome Measure – Undemineralized, midsagittal, mandibular molar slices, ～150 μm thick were immunolabelled with ET‐1 and α‐SMA antibodies and examined in a confocal laser scanning microscope (CLSM) for vascular endothelium and smooth muscle immunolabelling. Results – Three categories of post‐capillary‐sized venule endothelial cell immunolabelling occurred: endothelium labelled solely with ET‐1; endothelium labelled solely with α‐SMA; endothelium labelled with both ET‐1 and α‐SMA. In endothelial cells, the α‐SMA showed a moderate cytoplasmic distribution with dense peripheral concentration. Loading increased arteriole α‐SMA actin labelling. Conclusion – Scattered expression of ET‐1 is the default state in primate PDL endothelial cells. Increased antigenicity of endothelial cells to both ET‐1 and α‐SMA, and of arteriolar smooth muscle to α‐SMA, is a response to shear and compression loads.     

Irsogladine maleate regulates epithelial barrier function in tumor necrosis factor-α-stimulated human gingival epithelial cells

Fujita T, Yumoto H, Shiba H, Ouhara K, Miyagawa T, Nagahara T, Matsuda S, Kawaguchi H, Matsuo T, Murakami S, Kurihara H. Irsogladine maleate regulates epithelial barrier function in tumor necrosis factor‐α‐stimulated human gingival epithelial cells. J Periodont Res 2012; 47: 55–61. © 2011 John Wiley & Sons A/S Background and Objective: As epithelial cells function as a mechanical barrier, the permeability of the gingival epithelial cell layer indicates a defensive capability against invasion by periodontal pathogens. We have reported the expression of claudin‐1 and E‐cadherin, key regulators of permeability, in the gingival junctional epithelium. Irsogladine maleate (IM) is a medication for gastric ulcers and also regulates Aggregatibacter actinomycetemcomitans‐stimuated chemokine secretion and E‐cadherin expression in gingival epithelium. In this study, we have further investigated the effects of IM on the barrier functions of gingival epithelial cells under inflammatory conditions. Material and methods: We examined the permeability, and the expression of claudin‐1 and E‐cadherin, in human gingival epithelial cells (HGECs) stimulated with tumor necrosis factor (TNF)‐α, with or without IM. Results: TNF‐α increased the permeability of HGECs, and IM abolished the increase. TNF‐α reduced the expression of E‐cadherin in HGECs, and IM reversed the reduction. In addition, immunofluorescence staining showed that TNF‐α disrupted claudin‐1 expression in HGECs, and IM reversed this effect. Conclusion: The results suggest that IM reverses the TNF‐α‐induced disruption of the gingival epithelial barrier by regulating E‐cadherin and claudin‐1.