Expression of endothelin-1 in gingival epithelial cells

Diagnostic potential of endothelin-1 in peri-implant diseases: a cross-sectional study

PURPOSE

This study aimed to evaluate the potential of Endothelin-1 (ET-1), a peptide derived from vascular endothelial cells, as a biomarker for diagnosing peri-implant diseases.

METHODS

A cohort of 29 patients with a total of 76 implants was included in this study and subsequently divided into three groups based on peri-implant clinical parameters and radiographic examination: healthy (peri-implant health) (n = 29), mucositis (n = 22), and peri-implantitis (n = 25) groups. The levels of ET-1 (ρg/site) and interleukin (IL)-1β (ρg/site) in peri-implant sulcus fluid (PISF) samples were determined using enzyme immunoassay. Statistical analyses were conducted using Kruskal-Wallis and Steel-Dwass tests. Logistic regression and receiver operating characteristic (ROC) curve analyses were performed to evaluate the diagnostic performance of the biomarkers.

RESULTS

ET-1 levels were significantly elevated in the peri-implantitis group compared to those in the healthy group, and were highest in the peri-implant mucositis group. Additionally, IL-1β levels were significantly higher in the peri-implantitis group than those in the healthy group. ROC curve analysis indicated that ET-1 exhibited superior area under the curve values, sensitivity, and specificity compared to those of IL-1β.

CONCLUSIONS

Our findings suggest that the presence of ET-1 in PISF plays a role in peri-implant diseases. Its significantly increased expression in peri-implant mucositis indicates its potential for enabling earlier and more accurate assessments of peri-implant inflammation when combined with conventional examination methods.

Biocompatibility of Subperiosteal Dental Implants: Effects of Differently Treated Titanium Surfaces on the Expression of ECM-Related Genes in Gingival Fibroblasts

INTRODUCTION

Titanium alloys currently are the most used material for the manufacture of dental endosseous implants. However, in partially or totally edentulous patients, varying degrees of maxillary bone resorption usually occur, making the application of these devices difficult or even impossible. In these cases, a suitable alternative is offered by subperiosteal implants, whose use is undergoing a revival of interest following the introduction of novel, computer-assisted manufacturing techniques. Several procedures have been developed for the modification of titanium surfaces so to improve their biocompatibility and integration with bone. Information is, however, still incomplete as far as the most convenient surface modifications to apply with subperiosteal implants, in which an integration with soft mucosal tissues is just as important.

OBJECTIVES

The present study aimed at evaluating whether different treatments of titanium surfaces can produce different effects on the viability, attachment, and differentiation of gingival fibroblasts, i.e., the cell type mainly involved in osteointegration as well as the healing of soft tissues injured by surgical procedures, in order to verify whether any of the treatments are preferable under these respects.

METHODOLOGY

The human immortalized gingival fibroblast (CRL-4061 line) were cultured in the presence of titanium specimens previously treated with five different procedures for surface modification: (i) raw machined (Ti-1); (ii) electropolished (Ti-2); (iii) sand-blasted acid-etched (Ti-3); (iv) Al Ti Color™ proprietary procedure (Ti-4); and (v) anodized (Ti-5). At different times of incubation, viability and proliferation of cells, was determined along with the changes in the expression patterns of ECM-related genes involved in fibroblast attachment and differentiation: vinculin, fibronectin, collagen type I-alpha 1 chain, focal adhesion kinase, integrin β-1, and N-cadherin. Three different experiments were carried out for each experimental point. The release from fibroblasts of endothelin-1 was also analyzed as a marker of inflammatory response. The proliferation and migration of fibroblasts were evaluated by scratch tests.

RESULTS

None of the five types of titanium surface tested significantly affected the fibroblasts' viability and proliferation. The release of endothelin-1 was also not significantly affected by any of the specimens. On the other hand, all titanium specimens significantly stimulated the expression of ECM-related genes at varying degrees. The proliferation and migration abilities of fibroblasts were also significantly stimulated by all types of titanium surface, with a higher-to-lower efficiency in the order: Ti-3 > Ti-4 > Ti-5 > Ti-2 > Ti-1, thus identifying sandblasting acid-etching as the most convenient treatment.

CONCLUSIONS

Our observations suggest that the titanium alloys used for manufacturing subperiosteal dental implants do not produce cytotoxic or proinflammatory effects on gingival fibroblasts, and that sandblasting acid-etching may be the surface treatment of choice as to stimulate the differentiation of gingival fibroblasts in the direction of attachment and migration, i.e., the features allegedly associated with a more efficient implant osteointegration, wound healing, and connective tissue seal formation.

Differential gene expression profiles of periodontal soft tissue from rat teeth after immediate and delayed replantation: a pilot study

Purpose

In dental avulsion, delayed replantation usually has an uncertain prognosis. After tooth replantation, complex inflammatory responses promote a return to periodontal tissue homeostasis. Various types of cytokines are produced in the inflammatory microenvironment, and these cytokines determine the periodontal tissue response. This study aimed to identify the gene expression profiles of replanted teeth and evaluate the functional differences between immediate and delayed replantation.

Methods

Maxillary molars from Sprague-Dawley rats were extracted, exposed to a dry environment, and then replanted. The animals were divided into 2 groups according to the extra-oral time: immediate replantation (dry for 5 minutes) and delayed replantation (dry for 60 minutes). Either 3 or 7 days after replantation, the animals were sacrificed. Periodontal soft tissues were harvested for mRNA sequencing. Hallmark gene set enrichment analysis was performed to predict the function of gene-gene interactions. The normalized enrichment score (NES) was calculated to determine functional differences.

Results

The hallmark gene sets enriched in delayed replantation at 3 days were oxidative phosphorylation (NES=2.82, Q<0.001) and tumor necrosis factor-alpha (TNF-α) signaling via the nuclear factor kappa light chain enhancer of activated B cells (NF-κB) pathway (NES=1.52, Q=0.034). At 7 days after delayed replantation, TNF-α signaling via the NF-κB pathway (NES=–1.82, Q=0.002), angiogenesis (NES=–1.66, Q=0.01), and the transforming growth factor-beta signaling pathway (NES=–1.46, Q=0.051) were negatively highlighted.

Conclusions

Differentially expressed gene profiles were significantly different between immediate and delayed replantation. TNF-α signaling via the NF-κB pathway was marked during the healing process. However, the enrichment score of this pathway changed in a time-dependent manner between immediate and delayed replantation.

Analysis of Endothelin-1 Concentrations in Individuals with Periodontitis

Endothelin 1 (ET-1) has been shown to have a key role in homeostasis and function of endothelium and maybe fundamental in the relationship between coronary heart disease (CHD) and periodontitis. In this trial, we assessed the influence on serum and salivary ET-1 levels of gingival health, CHD, periodontitis, or a combination of periodontitis-CHD. Clinical and periodontal parameters, were collected from periodontitis patients (n = 34), CHD patients (n = 34), periodontitis + CHD patients (n = 34), and from healthy patients (n = 34) together with saliva and serum samples. The median concentrations of salivary and serum ET-1 were significantly higher in the CHD patients [serum: 1.4(1.1-1.6) pg/ml; saliva 1.2 (0.9-1.6) µmol/g, p < 0.01] and in the periodontitis + CHD patients [serum: 1.7 (1.2-21.8) pg/ml; salivary 1.4(1-1.6) µmol/g, p < 0.001] respect to periodontitis and control patients. Through a univariate regression analysis, c-reactive protein (CRP) and CHD (both p < 0.001) and periodontitis (p = 0.029) were statistically correlated with ET-1 in serum. The multivariate regression analysis demonstrated that only CRP was the statistically predictor of ET-1 in serum(p < 0.001). The multivariate regression analysis in saliva demonstrated that, regarding ET-1 levels the only predictor were CRP (p < 0.001) and total cholesterol (p = 0.042). The present study evidenced that subjects with CHD and periodontitis plus CHD had higher serum and salivary levels of ET-1 compared to subjects with periodontitis and healthy controls. Moreover, only CRP remained a major predictor of increased ET-1 concentrations in both serum and saliva.

Assessment of salivary endothelin-1 in patients with leukoplakia, submucous fibrosis, oral cancer and healthy individuals - a comparative study

BACKGROUND

Oral cancer is one of the highly prevalent cancers worldwide being. According to data of GLOBOCAN 2018, the estimated incidence, mortality and 5-year survival rates due to lip, oral cavity and salivary gland cancer in world is (2.0%), (0.5%) and (0.3%) respectively. (Bray, Ferlay and Soerjomataram, 2018). Endothelin-1 (ET-1) is a 21-amino acid peptide; its receptors have been implicated in the growth and progression of both primary and metastatic neoplasms throughout the human body. Studies have shown that ET-1 is expressed in tissue, serum and other body fluids.

AIM

To estimate the levels of salivary endothelin-1 in Oral potentially malignant disorders (oral leukoplakia and submucous fibrosis) and oral squamous cell carcinoma.

MATERIALS AND METHODS

The study population included 60 subjects and were divided into 4 groups. All patients included in the study are clinically and histopathological diagnosed cases of oral leukoplakia, submucous fibrosis and oral cancer and assessed for salivary ET-1 levels using human ELISA kit. Significant differences between the groups were determined using one-way analysis of variance, LSD and Post HOC, unpaired t test, biserial and spearson's correlation.

RESULTS

The mean levels of salivary Endothelin-1 level in study groups were: 82.78 ± 5.9 pg/mL (OSCC), 65.02 ± 1.8 pg/mL (SMF), 57.76 ± 4.1 pg/mL (LEUKOPLAKIA), 29.72 ± 14.1 pg/mL (CONTROLS). The mean Salivary ET-1 levels among these four groups was compared and the difference was statistically significant (P < 0.001). We also found a significant difference in the means of ET-1 levels among the clinical and histopathological staging of the study groups.

CONCLUSION

Our results demonstrate potential utility of salivary analysis for ET-1 levels to monitor patients at risk for OSCC. Although provides the basis for a larger prospective study to determine the critical levels of salivary ET-1 necessary to diagnose and monitor OPMD's and its potential to undergo malignant transformation.

The impact of implant abutment surface treatment with TiO2 on peri-implant levels of angiogenesis and bone-related markers: a randomized clinical trial

The goal of this randomized, blinded, split-mouth controlled clinical trial was to assess the influence of abutment surface treatment on tissue healing. Fifteen patients received two implants distributed randomly to two groups: test (TiO₂ abutment surface), control (standard abutment surface). Levels of epidermal growth factor (EGF), bone morphogenetic protein 9 (BMP-9), endothelin 1 (ET-1), fibroblast growth factor (FGF), placental growth factor (PlGF), and vascular endothelial growth factor (VEGF) were quantified in the peri-implant fluid after 3, 14, 30, and 60 days. Inter-group comparisons indicated higher levels of EGF, BMP-9, ET-1, FGF, and PlGF in the test group after 30days (P<0.05). PlGF levels were also higher in the test group after 60 days. In the test group, intra-group analysis revealed different levels of ET-1 and FGF between days 3 and 30, and days 3 and 60 (P<0.05); furthermore, VEGF levels were significantly higher on day 60 than on day 3 (P <0.05). In the control group, intra-group analysis demonstrated significantly different levels of ET-1, FGF, and PlGF between days 3 and 60 and of PlGF between days 14 and 60 (P<0.05). In conclusion, abutment surfaces treated with TiO₂ influenced the levels of angiogenesis and bone-related markers.

Identification of novel genes involved in gingival epithelial cells responding to Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis infections

OBJECTIVE

This study aimed to identify the differentially expressed genes (DEGs) in gingiva epithelial cells responding to Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis infections using bioinformatics method.

STUDY DESIGN

GSE9723 dataset was downloaded from Gene Expression Omnibus, and DEGs between the infected cells and controls were identified using unpaired t-test. Overlapping DEGs in responding to Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis infections were extracted. Protein-protein interaction networks were constructed and functional modules were isolated using Molecular Complex Detection algorithm. Key genes in protein-protein interaction network and Molecular Complex Detection modules were subjected to functional enrichment analyses. In addition, the transcriptional factors were predicted.

RESULTS

A total of 533 co-up-regulated and 202 co-down-regulated genes were identified. The up-regulated genes, including IL6, CCL19, EDN1, ADCY9, and BCL2 and the down-regulated genes, including CCNB1, PLK1, and CCNA2 were the key genes in the protein-protein interaction network and modules. They were intensively enriched in chemokine signaling pathway, calcium signaling pathway and cell cycle. Finally, two transcriptional factors, E12 and NRSF, targeting to the up-regulated genes and one transcriptional factor, NRP1, targeting the down-regulated genes, were predicted.

CONCLUSIONS

CCNB1, PLK1, and CCNA2 might play important roles in the response of host epithelial cells to Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis.

Endothelin-1 Elicits TRP-Mediated Pain in an Acid-Induced Oral Ulcer Model

Oral ulcer is the most common oral disease and leads to pain during meals and speaking, reducing the quality of life of patients. Recent evidence using animal models suggests that oral ulcers induce cyclooxygenase-dependent spontaneous pain and cyclooxygenase-independent mechanical allodynia. Endothelin-1 is upregulated in oral mucosal inflammation, although it has not been shown to induce pain in oral ulcers. In the present study, we investigated the involvement of endothelin-1 signaling with oral ulcer-induced pain using our proprietary assay system in conscious rats. Endothelin-1 was significantly upregulated in oral ulcers experimentally induced by topical acetic acid treatment, while endothelin-1 production was suppressed by antibacterial pretreatment. Spontaneous nociceptive behavior in oral ulcer model rats was inhibited by swab applications of BQ-788 (ET_B receptor antagonist), ONO-8711 (prostanoid receptor EP₁ antagonist), and HC-030031 (TRPA1 antagonist). Prostaglandin E₂ production in the ulcers was suppressed by BQ-788. Mechanical allodynia in the model was inhibited not only by BQ-788 and HC-030031 but also by BQ-123 (ET_A receptor antagonist), SB-366791 (TRPV1 antagonist), and RN-1734 (TRPV4 antagonist). In naive rats, submucosal injection of endothelin-1 caused mechanical allodynia that was sensitive to HC-030031 and SB-366791 but not to RN-1734. These results suggest that endothelin-1 production following oral bacterial invasion via ulcerative regions elicits TRPA1-mediated spontaneous pain. This pain likely occurs through an indirect route that involves ET_B receptor-accelerated prostanoid production. Endothelin-1 elicits directly TRPA1- and TRPV1-mediated mechanical allodynia via both ET_A and ET_B receptors on nociceptive fibers. The TRPV4-mediated allodynia component seems to be independent of endothelin signaling. These findings highlight the potential of endothelin signaling blockers as effective analgesic approaches for oral ulcer patients.

Comparison of Serum Levels of Endothelin-1 in Chronic Periodontitis Patients Before and After Treatment

INTRODUCTION

Endothelin-1 (ET-1) is a potent vasoconstrictive peptide with multi functional activity in various systemic diseases. Previous studies indicate the detection of ET-1 in gingival tissues and gingival crevicular fluid.

AIM

The aim of this study was to estimate the serum ET-1 levels in clinically healthy subjects and subjects with chronic periodontitis, before and after treatment, and correlate it with the clinical parameters.

MATERIALS AND METHODS

A total of 44 patients were included in the study. Group I comprised of 20 subjects with clinically healthy periodontium. Group II comprised of 24 subjects with chronic periodontitis. Group III comprised of same Group II subjects following periodontal management. Serum samples were collected from the subjects and an Enzyme Linked Immunosorbent Assay (ELISA) was done to estimate the ET-1 levels. The ET-1 levels were then correlated among the three groups with the clinical parameters namely, Plaque Index (PI), Sulcus Bleeding Index (SBI), probing pocket depth, clinical attachment loss and Periodontally Inflamed Surface Area (PISA). The independent t-test and paired t-test were used for comparison of clinical parameters and Pearson's correlation coefficient test was used for correlating the ET-1 levels.

RESULTS

ET-1 levels in chronic periodontitis subjects were significantly higher compared to healthy subjects (p<0.001). However, the clinical parameters did not statistically correlate with the ET-1 levels. There was a significant decrease in ET-1 levels following treatment (p<0.001).

CONCLUSION

Serum ET-1 is increased in chronic periodontitis and reduces after periodontal therapy. Further studies are required to establish ET-1 as a biomarker for periodontal disease.

Endothelin Regulates Porphyromonas gingivalis-Induced Production of Inflammatory Cytokines

Periodontitis is a very common oral inflammatory disease that results in the destruction of supporting connective and osseous tissues of the teeth. Although the exact etiology is still unclear, Gram-negative bacteria, especially Porphyromonas gingivalis in subgingival pockets are thought to be one of the major etiologic agents of periodontitis. Endothelin (ET) is a family of three 21-amino acid peptides, ET-1, -2, and -3, that activate G protein-coupled receptors, ET_A and ET_B. Endothelin is involved in the occurrence and progression of various inflammatory diseases. Previous reports have shown that ET-1 and its receptors, ET_A and ET_B are expressed in the periodontal tissues and, that ET-1 levels in gingival crevicular fluid are increased in periodontitis patients. Moreover, P. gingivalis infection has been shown to induce the production of ET-1 along with other inflammatory cytokines. Despite these studies, however, the functional significance of endothelin in periodontitis is still largely unknown. In this study, we explored the cellular and molecular mechanisms of ET-1 action in periodontitis using human gingival epithelial cells (HGECs). ET-1 and ET_A, but not ET_B, were abundantly expressed in HGECs. Stimulation of HGECs with P. gingivalis or P. gingivalis lipopolysaccharide increased the expression of ET-1 and ET_A suggesting the activation of the endothelin signaling pathway. Production of inflammatory cytokines, IL-1β, TNFα, and IL-6, was significantly enhanced by exogenous ET-1 treatment, and this effect depended on the mitogen-activated protein kinases via intracellular Ca²⁺ increase, which resulted from the activation of the phospholipase C/inositol 1,4,5-trisphosphate pathway. The inhibition of the endothelin receptor-mediated signaling pathway with the dual receptor inhibitor, bosentan, partially ameliorated alveolar bone loss and immune cell infiltration. These results suggest that endothelin plays an important role in P. gingivalis-mediated periodontitis. Thus, endothelin antagonism may be a potential therapeutic approach for periodontitis treatment.

Serum big endothelin-1 as a biomarker in oral squamous cell carcinoma patients: an analytical study

Detection of abnormally elevated levels of molecules in patients with oral cancer may be useful in early diagnosis. These markers can be included in current Histopathology grading and in TNM staging systems of Oral Squamous Cell Carcinoma (OSCC) to make it more efficient. Several pro-angiogenic molecules have been assessed for the same reason. Endothelin-1 (ET-1) is a vasoactive peptide associated with the development and spread of many solid tumors, including Squamous Cell Carcinoma (SCC), but its utility in OSCC has not been confirmed.

ET-1 Promotes Differentiation of Periodontal Ligament Stem Cells into Osteoblasts through ETR, MAPK, and Wnt/β-Catenin Signaling Pathways under Inflammatory Microenvironment

Periodontitis is a kind of chronic inflammatory disease that affects the tooth-supporting tissues. ET-1 is related to periodontitis and involved in the regulation of cytokines, but the mechanisms remain unclear. The aim of this study is to investigate how ET-1 affects proinflammatory cytokine expression and differentiation in human periodontal ligament stem cells (PDLSCs). PDLSCs were isolated from the periodontal ligament tissues of periodontitis patients and then treated with ET-1 (1, 10, or 100 nM) for 12 h, 24 h, or 72 h. The osteogenic potential of PDLSCs was tested using ALP staining. TNF-α, IL-1β, and IL-6 levels were evaluated by ELISA and western blot. Runx2, OCN, and COL1 mRNA and western levels were detected by RT-PCR and western blot, respectively. To examine the signaling pathways and molecular mechanisms involved in ET-1-mediated cytokine expression and osteogenic differentiation, ETR pathway, MAPKs pathway, Wnt/β-catenin pathway, and Wnt/Ca²⁺ pathway were detected by RT-PCR and western blot, respectively. ET-1 promoted differentiation of PDLSCs into osteoblasts by increasing secretion of TNF-α, IL-1β, and IL-6 in a dose- and time-dependent manner. ET-1 also increased expression of Runx2, OCN, and COL1. ET-1 promotes differentiation of PDLSCs into osteoblasts through ETR, MAPK, and Wnt/β-catenin signaling pathways under inflammatory microenvironment.

Endothelin-1 stimulates proinflammatory cytokine expression in human periodontal ligament cells via mitogen-activated protein kinase pathway

BACKGROUND

Endothelin-1 (ET-1) is a 21-amino acid peptide with multifunctional regulation. Initial research indicated that ET-1 is related to the inflammatory pathogenesis of periodontitis and involved in the regulation of cytokines, but the mechanisms involved remain unclear. The primary aim of this study is to investigate how ET-1 affects proinflammatory cytokine expression in human periodontal ligament (hPDL) cells.

METHODS

hPDL cells were obtained from both healthy (H)- and periodontitis (P)-affected periodontal tissues. H-hPDL and P-hPDL cells were treated with ET-1 (1, 10, and 100 nM) for 12, 24, and 48 hours. The untreated cells served as a control. To confirm the specificity of the ET-1 effects, 100 nM of the specific endothelin A (ETA) receptor antagonist BQ123 and 100 nM of the specific ETB receptor antagonist BQ788, as negative control, were used. To examine the signaling pathways and molecular mechanisms involved in ET-1-mediated cytokine expression, H-hPDL and P-hPDL cells were pretreated with specific inhibitors for extracellular signal-regulated kinase (ERK1/2) (PD98059), c-Jun N-terminal kinase (SP600125), and p38 kinase (SB203580) for 1 hour before 100 nM ET-1 stimulation. Tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 messenger RNA (mRNA) and protein levels were evaluated by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay, respectively.

RESULTS

ET-1 dose- and time-dependently induced the production of proinflammatory cytokines TNF-α, IL-1β, and IL-6 by H-hPDL and P-hPDL cells at both mRNA and protein levels. However, ETA and ETB receptor antagonists inhibited the stimulatory effects of ET-1 on inflammatory cytokine expression in H-hPDL and P-hPDL cells. Furthermore, inhibitors of the mitogen-activated protein kinases (MAPKs) significantly reduced ET-1-stimulated TNF-α, IL-1β, and IL-6 expression in H-hPDL and P-hPDL cells.

CONCLUSION

ET-1 may be involved in the inflammatory process of periodontitis, at least in part, by stimulating proinflammatory cytokine production via the MAPK pathway in hPDL cells.

Endothelin receptor-mediated responses in trigeminal ganglion neurons

Recent evidence implicates endothelin in nociception, but it is unclear how endothelin activates trigeminal ganglion (TRG) neurons. In the present study, we investigated the expression of the endothelin receptors ETA and ETB and endothelin-induced responses in rat TRG neurons. Double-immunofluorescence studies demonstrated that ETA and ETB were expressed in TRG neurons and that 26% of ETA- or ETB-expressing neurons expressed both receptors. During whole-cell patch-clamp recording, endothelin-1 enhanced an induced current in response to capsaicin, a TRPV1 agonist, in approximately 20% of dissociated neurons. The enhancement was blocked by the PKC inhibitor chelerythrine and by the ETA antagonist BQ-123, but not by the ETB antagonist BQ-788. Ca(2+)-imaging showed that endothelin-1 increased the intracellular Ca(2+) concentration in more than 20% of the dissociated neurons. Importantly, unlike the effect of endothelin-1 on capsaicin-induced current, the Ca(2+) response was largely suppressed by BQ-788 but not by BQ-123. These results suggest that ETA-mediated TRPV1 hyperactivation via PKC activation and ETB-mediated Ca(2+) mobilization occurs in different subsets of TRG neurons. These endothelin-induced responses may contribute to the induction of orofacial pain. The ETB-mediated function in TRG neurons is a special feature in the trigeminal system because of no ETB expression in dorsal root ganglion neurons.

Periodontal disease and gene-expression levels of metalloendopeptidases in human buccal mucosal epithelium

BACKGROUND AND OBJECTIVE

Endopeptidases, such as neutral endopeptidase (NEP), endothelin-converting enzyme-1 (ECE-1) and a disintegrin and metalloprotease 17 (ADAM17), are believed to have various important roles in oral mucosal and epidermal tissue for the regulation of defensive biological responses in the oral cavity, and their expression and activity are influenced by various factors, including oral diseases. However, knowledge concerning these endopeptidases in the oral cavity has been minimal until now. This study focused on three metalloendopeptidases - NEP, ECE-1 and ADAM17 - in the oral buccal mucosal epithelium of patients with periodontal diseases and investigated the relationship between their gene-expression levels and periodontal disease.

MATERIAL AND METHODS

The levels of expression of NEP, ECE-1 and ADAM17 mRNAs in tissue samples collected from the oral buccal mucosal epithelium of 61 patients were investigated by relative quantification using real-time RT-PCR analysis. information on oral and systemic health was obtained from the clinical record of each patient.

RESULTS

Among the three groups, classified based on the diagnosis of periodontal diseases (healthy/gingivitis, early periodontitis and moderate/advanced periodontitis), the relative expression level of NEP mRNA was significantly increased in the early periodontitis group and in the moderate/advanced periodontitis group compared with that in the healthy/gingivitis group. Moreover, the relative expression levels of ECE1 and ADAM17 mRNAs were significantly increased in the moderate/advanced periodontitis group compared with those in the healthy/gingivitis group. The correlation coefficients between the mean relative expression levels of NEP and ECE1 mRNAs, NEP and ADAM17 mRNAs, and ECE1 and ADAM17 mRNAs were r = 0.758, r = 0.707 and r = 0.934, respectively (p < 0.001). Furthermore, among the oral-related factors, there was a significant correlation between the number of sites with probing pocket depths of more than 4 mm and of more than 6 mm and the relative expression levels of NEP, ECE1 and ADAM17 mRNAs. In stepwise logistic regression models, high relative expression levels of ECE1 and ADAM17 mRNAs were significantly associated with moderate/advanced periodontitis.

CONCLUSION

The present study suggests that the severity of periodontal disease may be associated with the expression of metalloendopeptidase genes, including NEP, ECE1 and ADAM17, in the buccal mucosal epithelium.

Influence of mast cells in drug-induced gingival overgrowth

Mast cells (MCs) are multifunctional effector cells that were originally thought to be involved in allergic disorders. Now it is known that they contain an array of mediators with a multitude of effects on many other cells. MCs have become a recent concern in drug-induced gingival overgrowth (DIGO), an unwanted outcome of systemic medication. Most of the studies have confirmed the significant presence of inflammation as a prerequisite for the overgrowth to occur. The inflammatory changes within the gingival tissue appear to influence the interaction between the inducing drug and the fibroblast activity. The development of antibodies to MC-specific enzymes, tryptase and chymase, has facilitated the study of mast cells in DIGO. Many immunohistochemical studies involving MCs have been conducted; as a result, DIGO tissues are found to have increased the number of MCs in the gingiva, especially in the area of fibrosis. At the cellular level, gingival fibrogenesis is initiated by several mediators which induce the recruitment of a large number of inflammatory cells, including MCs. The purpose of this paper is to access the roles played by MCs in gingival overgrowth to hypothesize a relationship between these highly specialized cells in the pathogenesis of DIGO.

Salivary endothelin-1 potential for detecting oral cancer in patients with oral lichen planus or oral cancer in remission

Endothelin-1 (ET-1) is a potent vasoconstrictor involved not only in vascular biology but also in carcinogenesis. Results of a study in 2007 suggested salivary ET-1 as a potential biomarker for oral squamous cell carcinoma (OSCC), but a later study showed conflicting results. The purpose of our pilot study was to investigate feasibility of using salivary ET-1 as a biomarker for OSCC in two groups: oral lichen planus (OLP) patients and patients with OSCC in remission. Saliva samples were collected from five groups of subjects: patients with newly diagnosed, active OSCC (Group A); patients with OSCC in remission (Group B); patients with active OLP lesions (Group C); patients with OLP in remission (Group D); and normal controls (Group E). Salivary ET-1 levels were determined by enzyme-linked immunosorbent assay, and the results were analyzed by the Mann-Whitney U test. The mean salivary ET-1 level in Group A was significantly higher than that found in Group C (p=0.001), Group D (p=0.015) or Group E (p=0.004). There were no significant differences (p>0.05) in the mean salivary ET-1 levels between Groups A and B; Groups B and C; Groups B and D; Groups B and E; Groups C and D; Groups C and E; or Groups D and E. Salivary ET-1 could be a good biomarker for OSCC development in OLP patients regardless of the degree of OLP disease activity. However, it appeared not to be a good biomarker for detecting recurrence of OSCC in patients in remission.

Endothelins and their receptors as biological markers for oral cancer

Oral squamous cell carcinoma (OSCC) is one of the most common malignancies recognized nowadays, and represents a public health problem. Its early detection is the better alternative to provide a good quality of life for the patients. During the last years, several studies have identified potential biomarkers of OSCC progression and prognosis. Endothelins and their receptors are involved in several pathophysiological conditions and in various cancer types. The present review article discusses whether the endothelin system would represent a biomarker for OSCC.

Spontaneous pigmentation of non-pigmented palatal tissue after periodontal surgery

BACKGROUND

A 22-year-old African American female was referred for augmentation of keratinized gingiva around implants at the right and left maxillary second premolar sites. Presurgical evaluation revealed generalized melanosis of the buccal gingiva and a lack of keratinized tissue around implants at sites #4 and #13. No pigmentation was noted on the palatal tissues.

METHODS

Thick free gingival grafts were harvested bilaterally from the non-pigmented palate and secured to the recipient sites with bioabsorbable sutures. Hemostasis was achieved at the palatal donor sites with moistened gauze, and an acrylic stent was delivered for patient comfort.

RESULTS

Both palatal donor sites healed with spontaneous pigmentation. The pigmentation intensified with time but resulted in no adverse outcome.

CONCLUSIONS

Post-surgical healing in patients with gingival pigmentation is not entirely predictable, as multiple studies have demonstrated widely inconsistent results in regards to gingival pigmentation upon healing. When performing periodontal plastic surgery in patients with pigmented oral tissues, it is important to discuss all possible outcomes, including spontaneous pigmentation.

Gene expression in periodontal tissues following treatment

BACKGROUND

In periodontitis, treatment aimed at controlling the periodontal biofilm infection results in a resolution of the clinical and histological signs of inflammation. Although the cell types found in periodontal tissues following treatment have been well described, information on gene expression is limited to few candidate genes. Therefore, the aim of the study was to determine the expression profiles of immune and inflammatory genes in periodontal tissues from sites with severe chronic periodontitis following periodontal therapy in order to identify genes involved in tissue homeostasis.Gingival biopsies from 12 patients with severe chronic periodontitis were taken six to eight weeks following non-surgical periodontal therapy, and from 11 healthy controls. As internal standard, RNA of an immortalized human keratinocyte line (HaCaT) was used. Total RNA was subjected to gene expression profiling using a commercially available microarray system focusing on inflammation-related genes. Post-hoc confirmation of selected genes was done by Realtime-PCR.

RESULTS

Out of the 136 genes analyzed, the 5% most strongly expressed genes compared to healthy controls were Interleukin-12A (IL-12A), Versican (CSPG-2), Matrixmetalloproteinase-1 (MMP-1), Down syndrome critical region protein-1 (DSCR-1), Macrophage inflammatory protein-2beta (Cxcl-3), Inhibitor of apoptosis protein-1 (BIRC-1), Cluster of differentiation antigen 38 (CD38), Regulator of G-protein signalling-1 (RGS-1), and Finkel-Biskis-Jinkins murine osteosarcoma virus oncogene (C-FOS); the 5% least strongly expressed genes were Receptor-interacting Serine/Threonine Kinase-2 (RIP-2), Complement component 3 (C3), Prostaglandin-endoperoxide synthase-2 (COX-2), Interleukin-8 (IL-8), Endothelin-1 (EDN-1), Plasminogen activator inhibitor type-2 (PAI-2), Matrix-metalloproteinase-14 (MMP-14), and Interferon regulating factor-7 (IRF-7).

CONCLUSION

Gene expression profiles found in periodontal tissues following therapy indicate activation of pathways that regulate tissue damage and repair.

Crevicular fluid endothelin-1 levels in periodontal health and disease

BACKGROUND AND OBJECTIVE

Endothelin-1 is a 21-amino-acid peptide with multifunctional regulation. Initial research indicated that endothelin-1 levels in the gingival crevicular fluid from patients with chronic periodontitis were higher than those in the gingival crevicular fluid from healthy subjects. The aim of the present study was to assess the relationship between the clinical parameters and the concentrations of endothelin-1 within the gingival crevicular fluid from inflamed gingiva and periodontitis sites and, subsequently, after the treatment of periodontitis sites.

MATERIAL AND METHODS

A total of 60 subjects were divided into three groups - healthy (group I), gingivitis (group II) and chronic periodontitis (group III) - based on gingival index, pocket probing depth and clinical attachment loss. A fourth group consisted of 20 subjects from group III, 6-8 wk after treatment (i.e. scaling and root planing). Gingival crevicular fluid samples collected from each patient were quantified for endothelin-1 using an enzymatic immunometric assay.

RESULTS

Endothelin-1 was not detected in any sample from any of the study groups.

CONCLUSION

The results showed that all the gingival crevicular fluid samples were negative for the endothelin-1 molecule. Therefore, endothelin-1 cannot be considered as a potential biomarker of periodontal disease progression.

Endothelin-1 and its receptors ET(A) and ET(B) in drug-induced gingival overgrowth

BACKGROUND

The purpose of this study was to study the expression of endothelin-1 (ET-1) and its receptors ETA and ETB in normal human gingiva and cyclosporin-induced gingival fibroblasts.

METHODS

Gingival samples were collected from eight normal healthy individuals, eight patients with periodontitis, and eight patients with cyclosporin A (CsA)-induced gingival overgrowth. Total RNA was extracted from tissue samples, and reverse transcriptase-polymerase chain reaction was performed for ET-1, ETA, and ETB. ET-1 protein was estimated from the tissues by enzyme-linked immunosorbent assay. The expression of ET-1 and its receptors was also examined in gingival fibroblast cells treated with CsA.

RESULTS

ET-1 mRNA expression was significantly higher in patients with CsA-induced gingival overgrowth (P <0.001) than in patients with periodontitis and the controls. ETA mRNA was expressed more than the ETB in all examined samples. In human gingival fibroblasts, ET-1 expression was increased with CsA incorporation compared to controls (P <0.001).

CONCLUSION

These results suggest that CsA can modulate the expression of ET-1 in gingival fibroblasts and CsA-induced gingival overgrowth.