Vascular endothelial growth factor expression levels of gingiva in gingivitis and periodontitis patients with/without diabetes mellitus

Gingival Crevicular Fluid Cytokines in Moderate and Deep Sites of Stage III Periodontitis Patients in Different Rates of Clinical Progression

Clinical criteria are inappropriate to measure the degree of susceptibility to progression of periodontal damage. Thus, the aim of this study was to assess whether gingival crevicular fluid (GCF) levels of cytokines could discriminate patients suffering from stage III periodontitis with moderate (Grade B) and rapid rates of progression (Grade C) prior to and 6 months after non-surgical periodontal treatment. GCF samples were obtained from moderate and deep sites of 20 patients diagnosed as Grade B and 20 patients as grade C stage III periodontitis and analyzed for interleukin (IL)-1β, IL-9, tumor necrosis factor (TNF)-α, and vascular endothelial growth factor (VEGF) using a high-sensitivity Bio-Plex Suspension Array System. At baseline, higher IL-1β but lower IL-9 GCF levels were observed in moderate sites of the grade C compared to the grade B group. In spite of comparable clinical improvement, this difference maintained after treatment, suggesting a residual pro-inflammatory state. In deep sites, no differences were observed between periodontitis groups except for VEGF levels that decreased more in Grade B periodontitis at 6 months post-therapy. A mathematical model was constructed to identify Grade C periodontitis patients based on the subjects’ GCF levels of IL-1β and IL-9, which achieved an area under the receiver-operating characteristic (ROC) curve of 0.94. This study can contribute to the early assessment of risk of future breakdown in periodontitis patients.

Does Diabetes Induce the Vascular Endothelial Growth Factor (VEGF) Expression in Periodontal Tissues? A Systematic Review

Aim: Diabetes and periodontal disease are both chronic pathological conditions linked by several underlying biological mechanisms, in which the inflammatory response plays a critical role, and their association has been largely recognized. Recently, attention has been given to diabetes as an important mediator of vascular endothelial growth factor (VEGF) overexpression in periodontal tissues, by virtue of its ability to affect microvasculature. This review aims to summarize the findings from studies that explored VEGF expression in diabetic patients with periodontitis, compared to periodontally healthy subjects. Materials and Methods: A systematic literature review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A PubMed search of select medical subject heading (MeSH) terms was carried out to identify all studies reporting findings about VEGF expression in periodontal tissues of diabetic patients up to May 2018. The inclusion criteria were studies on VEGF expression in periodontally diseased tissues of diabetic patients compared with nondiabetic subjects, with any method of analysis, and published in the English language. Results: Eight articles met the inclusion criteria. Immunohistochemistry was used in six of the studies, reverse transcriptase polymerase chain reaction (real-time RT-PCR) aiming to quantify mRNA VEGF expression was used in one study, and ELISA analysis was used for one study. Compared with nondiabetic patients, a higher VEGF expression in gingival tissue and gingival crevicular fluid (GCF) samples in diabetic patients with periodontitis was reported. Conclusions: Overall, novel evidence for the VEGF expression within the periodontal tissue of diabetic patients paves the way for further studies on the role of this protein in neovascularization physiology and pathophysiology in microvasculature of the periodontium.

Histopathological and biochemical evaluation of paeoniflorin administration in an experimental periodontitis model

The purpose of this study was to evaluate the effects of administered Paeoniflorin (Pae) on periodontal tissues within an experimental periodontitis model. Forty male Wistar rats were used in this study and experimental periodontitis was created in all rats except in the control group (n = 10, first group). In the periodontitis group, experimental periodontitis was created but no other application was performed (n = 10, second group). In the other groups created experimental periodontitis, systemic Pae (n = 10, third group) or saline (n = 10, fourth group) was applied. A biochemical analysis of the gingival vascular endothelial growth factor (VEGF) levels and a histomorphometric analysis (measurements of the area of alveolar bone, alveolar bone resorption, and attachment loss) were performed. In the Pae group, the area of the alveolar bone was increased, while alveolar bone resorption and attachment loss decreased. Gingival VEGF levels increased in all groups that created experimental periodontitis and the greatest increase seen in the Pae group. Histomorphometric and biochemical analyses in this study suggest that Pae has a curative effect on periodontal tissues. However, additional studies are needed to confirm these results.

A disintegrin-like and metalloproteinase with thrombospondin-1 (ADAMTS-1) levels in gingival crevicular fluid correlate with vascular endothelial growth factor-A, hypoxia-inducible factor-1α, and clinical parameters in patients with advanced periodontitis

BACKGROUND

ADAMTS (a disintegrin-like and metalloproteinase with thrombospondin) are a family of proteinases that are structurally similar to the family of matrix metalloproteinases with critical roles in damage and repair of the extracellular matrix. Their functions are closely related to inflammation, hypoxia, and vascularization. Our aim was to determine levels of ADAMTS-1 in gingival crevicular fluid (GCF) in patients with advanced periodontal diseases and identify their association with hypoxia-inducible factor-1alpha (HIF-1α), vascular endothelial growth factor (VEGF-A), and clinical parameters of periodontitis.

METHODS

The study consisted of three groups: healthy individuals (control; n = 20), generalized chronic periodontitis (CP; n = 21), and generalized aggressive periodontitis (GAgP; n = 20). Clinical parameters were measured. Levels of ADAMTS-1, VEGF-A, and HIF-1α in GCF and serum were quantified by enzyme-linked immunosorbent assay (ELISA) and reported as total amounts and concentration.

RESULTS

ADAMTS-1 total amount in GCF were significantly higher in patients with CP and GAgP compared with healthy individuals (P < 0.05). HIF-1α total amount in GCF were also higher in periodontitis groups compared with the control group (P < 0.05). GCF total VEGF-A content was significantly higher in the GAgP group compared with the CP and the controls (respectively; P = 0.023, P = 0.003). There was a significant correlation between ADAMTS-1, VEGF-A, and HIF-1α levels in the GCF and clinical periodontal parameters (probing depth [PD], bleeding on probing [BOP], and clinical attachment loss (CAL); P < 0.05).

CONCLUSION

ADAMTS-1 may play a role in advanced periodontal disease pathogenesis in correlation with tissue hypoxia and vascularization.

Salivary cytokine levels in early gingival inflammation

Salivary protein levels have been studied in periodontitis. However, there is lack of information on salivary cytokine levels in early gingival inflammation. The aim of this study was to determine salivary levels of vascular endothelial growth factor (VEGF), interleukin (IL)-8, monocyte chemoattractant protein (MCP)-1, IL-1β, and IL-1 receptor antagonist (IL-1Ra) in gingival inflammation. Twenty-eight systemically and orally healthy nonsmokers abstained from oral hygiene protocols for 10 days. After that, self-performed cleaning was resumed for 14 days. Plaque and gingival indexes were measured, and saliva samples were collected at days 1, 4, 7, 10, and 24. Salivary cytokines were detected with Luminex®-xMAP™. Salivary IL-1β, IL-1Ra, and VEGF levels decreased after 10 days' development of experimental gingivitis and reached baseline levels at the end of the 2-week resolution period. Salivary IL-8 levels decreased and remained low during development and resolution of experimental gingivitis. Initial inflammation in gingival tissues is associated with a decrease in inflammatory cytokines in saliva. Further studies are needed to evaluate if inflammatory cytokines bind to their functional receptors within the gingival tissue during early gingivitis, which may limits their spillover to the gingival crevice and ultimately saliva.

Expression of Vascular Endothelial Growth Factor Has a Regulatory Role in Gingival Venules in Experimental Diabetes

BACKGROUND

In the present study, the possible localization and role of vascular endothelial growth factor receptor type 2 (VEGFR2) in the regulation of gingival venules in a rat model of experimental diabetes are examined.

METHODS

Six weeks after streptozotocin premedication, Wistar male rats presenting blood sugar levels >20 mmol/L were selected for investigation. The VEGFR2 antagonist ZM323881 [5-((7-benzyloxyquinazolin-4-yl)amino)-4-fluoro-2-methylphenol-hydrochloride] (20 μg/mL) was dripped onto the gingiva between the mandibular incisors. Changes in diameter of the selected gingival venule were measured by vital microscopy combined with digital photography at specified times. Immunohistochemical staining was used to localize VEGFR2. For controls, the same protocol was used on animals with normal blood sugar levels and healthy gingiva.

RESULTS

There was a significant difference between the baseline venule diameter of the diabetic and the control groups (47 ± 1 and 28 ± 2 μm, respectively). After 15, 30, and 60 minutes of local application of ZM323881, significant vasoconstriction was observed in the venules of diabetic rats compared with the baseline (81.4% ± 4.6%, 81.8% ± 4.4%, and 80.6% ± 5.1%, respectively). The control group showed no change in the venule diameter. The immunohistochemical analysis showed significantly increased VEGFR2 expression in the mast cells along the venules in the diabetic group, whereas mast cells were rarely found in the control group.

CONCLUSIONS

The findings suggest that VEGF expression is increased in gingiva in experimentally induced diabetes. After VEGFR2 activation, the mast cell-derived vasodilatory and inflammatory mediators may contribute markedly to the concomitant changes in the microcirculation.

Vascular endothelial growth factor levels in gingival crevicular fluid before and after periodontal therapy

INTRODUCTION

Of the various cytokines and growth factors regulating angiogenesis, the most potent agent acting on vascular endothelium is vascular endothelial growth factor(VEGF). The present study aims to access VEGF concentration in periodontal diseases and the effect of periodontal therapy on its concentration in gingival crevicular fluid (GCF).

MATERIALS AND METHODS

Ninety five subjects (47 females and 48 males) 25- 47 y of age were divided into healthy (group-1), gingivitis (group-2), and periodontitis (group-3). GCF samples were collected using micro-capillary pipettes & were transferred immediately to plastic vials and stored at -70˚C until the time of the assay. The concentration of VEGF was determined using commercially available ELISA kit.

RESULTS

The mean VEGF concentration was highest in periodontitis patients (Group 3) (88.08±8.04pg/ml), with lowest in healthy patients (Group 1). VEGF levels reduced significantly after therapy in Groups 2 and 3.

CONCLUSION

VEGF levels in GCF had a significant correlation with both periodontal disease progression and healing after therapy.

Global metabolomic analysis of human saliva and plasma from healthy and diabetic subjects, with and without periodontal disease

Recent studies suggest that periodontal disease and type 2 diabetes mellitus are bi-directionally associated. Identification of a molecular signature for periodontitis using unbiased metabolic profiling could allow identification of biomarkers to assist in the diagnosis and monitoring of both diabetes and periodontal disease. This cross-sectional study identified plasma and salivary metabolic products associated with periodontitis and/or diabetes in order to discover biomarkers that may differentiate or demonstrate an interaction of these diseases. Saliva and plasma samples were analyzed from 161 diabetic and non-diabetic human subjects with a healthy periodontium, gingivitis and periodontitis. Metabolite profiling was performed using Metabolon's platform technology. A total of 772 metabolites were found in plasma and 475 in saliva. Diabetics had significantly higher levels of glucose and α-hydroxybutyrate, the established markers of diabetes, for all periodontal groups of subjects. Comparison of healthy, gingivitis and periodontitis saliva samples within the non-diabetic group confirmed findings from previous studies that included increased levels of markers of cellular energetic stress, increased purine degradation and glutathione metabolism through increased levels of oxidized glutathione and cysteine-glutathione disulfide, markers of oxidative stress, including increased purine degradation metabolites (e.g. guanosine and inosine), increased amino acid levels suggesting protein degradation, and increased ω-3 (docosapentaenoate) and ω-6 fatty acid (linoleate and arachidonate) signatures. Differences in saliva between diabetic and non-diabetic cohorts showed altered signatures of carbohydrate, lipid and oxidative stress exist in the diabetic samples. Global untargeted metabolic profiling of human saliva in diabetics replicated the metabolite signature of periodontal disease progression in non-diabetic patients and revealed unique metabolic signatures associated with periodontal disease in diabetics. The metabolites identified in this study that discriminated the periodontal groups may be useful for developing diagnostics and therapeutics tailored to the diabetic population.

Vascular endothelial cadherin and vascular endothelial growth factor in periodontitis and smoking

OBJECTIVE

This study investigated the vascularization in periodontal disease process via revealing: (i) vascular endothelial cadherin (VE-cadherin) and vascular endothelial growth factor (VEGF) productions in periodontitis and (ii) the impact of smoking on this phenomenon.

MATERIALS AND METHODS

Fifteen smokers and 15 non-smokers with/without periodontitis were allocated by split-mouth randomization regarding their smoking and periodontal statuses. The teeth with periodontitis in smokers (group 1), without periodontitis in smokers (group 2), with periodontitis in non-smokers (group 3), and without periodontitis in non-smokers (group 4) constituted the study groups. Gingival crevicular fluid (GCF) levels of VE-cadherin and VEGF were determined by ELISA to evaluate their profiles in the groups.

RESULTS

There were increased VE-cadherin levels in groups 1 and 3 compared with groups 2 and 4 (P < 0.05). Group 2 demonstrated higher VE-cadherin level than group 4 (P < 0.05). Increased VEGF was noted in groups 1 and 3 compared with groups 2 and 4 (P < 0.05) with similar levels between groups 1 and 3 and groups 2 and 4 (P > 0.05). There were no correlations between the VE-cadherin and VEGF levels in all groups (P > 0.05).

CONCLUSION

The results suggest that VE-cadherin and VEGF may increase in periodontitis, and smoking may uniquely cause VE-cadherin production in GCF.

Secreted caveolin-1 enhances periodontal inflammation by targeting gingival fibroblasts

Caveolin-1 (Cav-1) is a membrane protein. Recently, it has been reported that secreted Cav-1 induces angiogenesis in inflammatory microenvironment. However, it is unclear that Cav-1 regulates gingival inflammation. Therefore, we investigated the Cav-1 function to periodontal cells. Expression of Cav-1 in human periodontitis tissues was examined pathologically. Secretion of Cav-1 from human gingival fibroblasts (HGFs) or human periodontal ligament cells (HPLFs) treated with IL-1β and TNF-α was examined using Western blotting. Likewise, intracellular signals induced by Cav-1 were examined. Finally, we examined whether the secreted Cav-1 induces production of inflammatory mediators in HGFs using ELISA or qRT-PCR. Pathologically, high expression of Cav-1 was observed in human periodontitis tissues. Cav-1 secretion increased in both cultured HGFs and HPLFs treated with IL-1β and TNF-α. Cav-1 induced phosphorylation of JNK and ERK, but not Stat3 in HGFs. Furthermore, Cav-1 increased proMMP-1 and VEGF secretion in HGFs, and the VEGF secretion was statistically suppressed by JNK inhibitor SP600125, but not ERK inhibitor PD98059. ProMMP-1 secretion was suppressed statistically by both SP600125 and PD98059. In addition, Cav-1 increased significantly MMP-1, -10 and -14 mRNA expressions, whereas no increase of TIMPs mRNA was observed in HGFs treated with Cav-1. These data suggest that secreted Cav-1 derived from periodontal fibroblastic cells enhances inflammation-related several proteases and VEGF secretion in HGFs via MAPKs pathway, resulting in progression of periodontitis through induction of tissue degradation or angiogenesis.

Assessment of vascular endothelial growth factor and matrix metalloproteinase-9 in the periodontium of rats treated with atorvastatin

BACKGROUND

The aim of this study is to examine, for the first time, the role of systemic and local atorvastatin application on periodontium using histomorphometric and immunohistochemical analysis during and after experimental periodontitis induction with or without the presence of microbial dental biofilm.

METHODS

One hundred ten male Wistar rats were used. Silk ligatures were placed around the cervical area of the mandibular first molars; rats in the healthy control group received no ligatures (n = 10). In experimental periodontitis groups (n = 90), systemic and local atorvastatin and saline were administered in three different periods; the control periodontitis group (n = 10) received no treatment. Histomorphometric analysis, which included alveolar bone area, alveolar bone level, and attachment loss, and immunohistochemical analysis, which included immunoreactivity of vascular endothelial growth factor (VEGF) and matrix metalloproteinase (MMP)-9, were performed after the rats were sacrificed at the end of the experimental procedure.

RESULTS

There was a greater increase in alveolar bone area and VEGF immunoreactivity, as well as a greater decrease in alveolar bone and attachment loss and MMP-9 immunoreactivity, with systemic and local atorvastatin application during and after induction of experimental periodontitis. Local atorvastatin application showed better results on periodontium with regard to alveolar bone findings.

CONCLUSIONS

Systemic and local atorvastatin application showed beneficial effects on periodontium during and after induction of experimental periodontitis. Within the limits of this study, it can be concluded that atorvastatin, which is used for hypercholesterolemia treatment, can also be used as a protective and therapeutic agent for periodontal disease.

Biochemical analysis of pentraxin 3 and fibrinogen levels in experimental periodontitis model

Objective. Pentraxin 3 (PTX3), newly discovered inflammation marker, is a member of acute-phase proteins. The hypothesis, synthesis of gingival tissue and serum PTX-3 increases in the experimental periodontitis model (with 10-day and 40-day periods), was tested by detecting gingival tissue and serum PTX-3 levels in rats with experimental periodontitis. Methods. Thirty rats were randomly divided into three groups of ten animals each: ligature-induced experimental periodontitis groups (with 10-day (Group1) and 40-day periods (Group2)) and healthy group (Group3). At the end of experimental period, rats were sacrificed, and radiological and histomorphometric analyses were performed on the mandibles. PTX3 levels were measured in gingival tissue and serum samples using ELISA. Plasma fibrinogen levels were measured according to the nephelometric method. Results. Significant alveolar bone resorption and periodontal inflammation were evident in periodontitis groups. Levels of PTX3 in gingival tissue were statistically higher in Group 1 than those in groups 2 and 3 (P < 0.01). No significant difference was found in serum PTX3 levels between experimental periodontitis and control groups (P > 0.05). Plasma fibrinogen levels were significantly increased in the experimental periodontitis groups (P < 0.001). Conclusion. PTX3 seems to be associated with tissue destruction in earlier periods of inflammatory periodontal disease, contrary to the fibrinogen findings.

Periodontal microcirculation in diabetics: an in vivo non-invasive analysis by means of videocapillaroscopy

Background

Diabetes mellitus is today considered a society-wide disease of a chronic/degenerative nature. Among the secondary effects of diabetes, the one that interests the dental surgeon most is diabetic parodontopathy. The aim of this study was to underline and objectify microcirculatory variations at a periodontal mucous level in type 2 diabetics.

Material/Methods

The study enrolled 80 subjects: 40 subjects with a diagnosis of diabetes mellitus type II (18 males and 22 females, between 44 and 85 years of age); and 40 healthy subjects (17 males and 23 females, between 44 and 78 years of age). All the subjects, both diabetic and healthy, were submitted to a videocapillaroscopic examination of the mucosa of the oral cavity.

Results

The measurements concerning the density (expressed in the number of loops/mm²) of the capillary loops presented differences between the healthy subjects and the diabetic subjects. The average periodontal capillary density (DC-P) was clearly superior in diabetic subjects (35.62±10.40 n°loop/mm²) compared to healthy subjects (17.55±3.88 n°loop/mm²). The statistical analysis was performed by means of the Mann Whitney test. The value of P (p=0.000000986), well below the level of significance, demonstrates the high significance of the results obtained.

Conclusions

The increase in capillary density could suggest the presence of active inflammatory phenomena or, more probably, a tendency to a greater susceptibility to inflammatory phenomena. Ultimately, this study shows that there is some peripheral damage to microcirculation at the masticatory mucous level in diabetic subjects and that such alterations can be instrumentally objectified and quantified through the videocapillaroscopic method.