Hypermethylation and low transcription of TLR2 gene in chronic periodontitis.

Periodontitis is an inflammatory disorder characterized by interactions between periodontal pathogens and host's immune response. Epigenetic may contribute to disease development and outcome by influencing the expression of genes involved in the immune response. It has been shown that Toll-like receptors (TLR) play an important role in the response to periodontopathic bacteria. The aim of study was to evaluate the methylation status and the expression of TLR2 gene in gingival samples from individuals with and without periodontitis. DNA was analyzed using the Methyl Profiler DNA Methylation qPCR assay. DNA methylation and transcript levels were evaluated by real-time polymerase chain reaction. The periodontitis group showed a hypermethylated profile and a low expression of gene. Positive correlation between the TLR2 methylation frequency and probing depth was observed. This study gives the first evidence of methylation frequency in inflamed periodontal tissues and of the possible participation of methylation in the development of periodontitis.

Transcription factor STAT1 gene polymorphism is associated with the development of severe forms of periodontal disease.

INTRODUCTION: Periodontal disease (PD) is one of the most common inflammatory diseases, affecting about 10 % of the world population. The establishment of PD is influenced by polymorphisms in genes involved with the inflammatory response. Signal Transducer and Activator of Transcription (STAT)-1 is a transcription factor that plays a key role in the intracellular signaling triggered by cytokines and, thus, its activation is critical in inflammatory diseases. AIM AND METHODS: We aim to evaluate the occurrence of association between STAT-1 (rs3771300) polymorphism and distinct clinical forms and severity of PD; we genotyped 180 subjects using realtime PCR. RESULTS AND CONCLUSION: We observed that the presence of the G allele for STAT-1 was associated with twice as high of a chance to develop aggressive periodontitis, and the most severe form of the disease.

Methylation pattern of IFNG in periapical granulomas and radicular cysts.

INTRODUCTION: Interferon-γ plays an important role in the pathogenesis of periapical lesions, and the methylation of IFNG has been associated with transcriptional inactivation. The purpose of the present study was to investigate IFNG promoter methylation in association with gene transcription and protein levels in periapical granulomas and radicular cysts. METHODS: Methylation-specific polymerase chain reaction was used to assess the DNA methylation pattern of the IFNG gene in 16 periapical granulomas and 13 radicular cyst samples. The transcription levels of IFNG mRNA were verified by quantitative real-time polymerase chain reaction, and protein expression was evaluated by immunohistochemistry. RESULTS: All the periapical lesion samples exhibited partial or total methylation of the IFNG gene. In addition, an increased methylation profile was found in radicular cysts compared with periapical granulomas. Increased IFNG mRNA expression was observed in the partially methylated periapical lesion samples relative to the samples that were completely methylated. CONCLUSIONS: The present study provides the first evidence of the possible impact of IFNG methylation on IFNG transcription in periapical lesions.

Evaluation of MAGE A1 in oral squamous cell carcinoma.

MAGE A1 is a cancer testis antigen (CTA) described in a variety of human cancers. CTAs exhibit a highly restricted tissue expression and by virtue of their immunogenic potential, these genes are promising target molecules for cancer vaccines. DNA hypomethylation is associated with gene regulation in several types of tumours. The aim of this project was to identify the presence of MAGE A1 in oral squamous cell carcinoma (OSCC) samples and to investigate the hypomethylation profile of CpG islands situated in the promoter region of this gene. The expression of MAGE A1 in OSCC and healthy oral mucosal samples was determined by real-time quantitative and conventional endpoint PCR and also by immunohistochemistry staining. In addition, to investigate the hypomethylation profile of promoter MAGE A1 CpG islands, we performed bisulphite sequencing. Real-time quantitative and endpoint PCR assays demonstrated a lower level of MAGE A1 transcription. Endpoint PCR showed expression of MAGE A1 in 10% (2/20) of OSCCs. Sodium bisulphite sequencing analysis of MAGE A1 CpG islands did not reveal a difference between OSCC and normal oral mucosal samples. We further assessed MAGE A1 protein immunoexpression and found 80% (16/20) of immunopositivity in OSCCs. We did not observe a correlation between the presence of MAGE A1 protein and lower levels of transcripts. Identification of MAGE A1 protein in OSCCs and absence of immunoexpression in normal oral mucosa support the idea that this protein can be used as a biomarker for detection of OSCC; however, it is not associated with hypomethylation or high expression of the MAGE A1 gene.

Oral cGVHD screening tests in the diagnosis of systemic chronic graft-versus-host disease.

To determine the diagnostic properties of oral manifestations and histological features of graft-versus-host disease (GVHD) screening tests in the diagnosis of systemic chronic graft-versus-host disease (cGVHD). Sixty patients having undergone allogeneic haematopoietic stem cell transplantation were selected. The patients were submitted to a clinical oral examination to assess symptoms and clinical changes in the oral mucosa. Histopathologic analysis of the lower lip oral mucosa (LLOM) and salivary glands (SG) was also performed. Systemic cGVHD was used for a comparison to oral cGVHD. The accuracy of oral cGVHD tests was low for all methods (58.4% and 52.6% for white lesions and white/red lesions, respectively, in the clinical analysis; 50.4% for the presence of oral pain; and 66.8% and 55.1% for LLOM and SG histopathologic tests, respectively). However, the presence of oral pain had good diagnostic properties [specificity: 100.0, 95% confidence interval (CI): 88.0-100.0; positive predictive value (PPV): 100.0, 95% CI: 94.4-100.0; and negative predictive value (NPV): 72.0, 95% CI: 57.3-83.3]. Moreover, SG alterations revealed by the histopathological analysis also exhibited good diagnostic properties (sensitivity: 98.6, 95% CI: 81.5-99.8; PPV: 71.1, 95% CI: 62.1-79.7; NPV: 85.9 95% CI: 32.9-99.4). The clinical severity of oral lesions and histophatological changes in the LLOM did not exhibit adequate diagnostic properties, whereas both oral pain and SG histopathological analysis exhibited adequate properties for the diagnosis of systemic cGVHD. Histological changes in lip oral mucosa and salivary glands together with a clinical manifestation of the disease in the oral mucosa can be useful to determining the systemic cGVHD.

Interleukin-1beta and serotonin transporter gene polymorphisms in burning mouth syndrome patients.

UNLABELLED: Burning mouth syndrome (BMS) is a chronic pain syndrome that encompasses all forms of burning sensations in the oral cavity when the oral mucosa is clinically normal. Neural, psychologic, and cytokine factors may be implicated in the pathogenesis of BMS. There are no studies of genetic factors associated with psychologic behavior and cytokine pain sensitivity in BMS patients. The purpose of the present study was to investigate a possible association between functional genetic polymorphisms, +3,954 (C/T) interleukin-1beta, and the polymorphic site on promoter region of the serotonin transporter gene (5-HTTLPR) in a sample of Brazilian patients. Thirty patients affected by BMS and 31 healthy volunteers were genotyped for 5-HTTLPR and IL-1beta gene. The chi-squared test was used for statistical analysis. There was no statistical difference in 5-HTTLPR genotypes between the case and control groups (P = .60), however a significant increase was observed in the IL-1beta high production genotype CT in BMS subjects (P = .005). In conclusion, the present study shows association between BMS and IL-1beta high producer genotype. PERSPECTIVE: This article shows evidence that genetic polymorphisms associated with IL-1beta high production genotype are implicated on the pathogenesis of BMS. The modulation of IL1beta production may be an interesting tool in BMS management.