Release of cytokines by stimulated peripheral blood mononuclear cells in chronic periodontitis

Gingival fibroblasts produce paracrine signals that affect osteoclastogenesis in vitro

In periodontitis, gingival fibroblasts (GF) appear to produce a multitude of paracrine factors. However, the influence of GF-derived soluble factors on osteoclastogenesis remains unclear. In this case study, production of paracrine factors by GF was assessed under inflammatory and non-inflammatory conditions, as well as their effect on osteoclastogenesis. Human primary GF were cultured in a transwell system and primed with a cocktail of IL-1β, IL-6 and TNF-α to mimic inflammation. GF were co-cultured directly and indirectly with human peripheral blood mononuclear cells (PBMC). Cytokines and chemokines in supernatants (flow cytometry based multiplex assay), osteoclastogenesis (TRAcP staining) and gene expression (qPCR) were quantified on days 7 and 21. Results from this case study showed that GF communicated via soluble factors with PBMC resulting in a two-fold induction of osteoclasts. Reversely, PBMC induced gene expression of IL-6, OPG and MCP-1 by GF. Remarkably, after priming of GF with cytokines, this communication was impaired and resulted in fewer osteoclasts. This could be partly explained by an increase in IL-10 expression and a decrease in MCP-1 expression. Intriguingly, the short priming of GF resulted in significantly higher expression of inflammatory cytokines that was sustained at both 7 and 21 days. GF appear to produce paracrine factors capable of stimulating osteoclastogenesis in the absence of physical cell-cell interactions. GF cultured in the presence of PBMC or osteoclasts had a remarkably inflammatory phenotype. Given profound expression of both pro- and anti-inflammatory cytokines after the inflammatory stimulus, it is probably the effector hierarchy that leads to fewer osteoclasts.

The Association between High-density Lipoproteins and Periodontitis

Periodontitis is one of the most typical chronic dental diseases. This inflammatory disease can change various functions of immune cells and impair lipid metabolism through proinflammatory cytokines. High-Density Lipoprotein (HDL) is considered protective of the cardiovascular system. It has anti-thrombotic and anti-inflammatory effects. In this article, we have reviewed the association between periodontitis and HDL. Various studies have demonstrated a reverse relationship between inflammatory cytokines and HDL. HDL contains antioxidative enzymes and proteins, whereas periopathogens impair HDL's antioxidant function. The presence of periodontal bacteria is associated with a low HDL level in patients with periodontitis. Genetic variants in the interleukin- 6 (IL)-6 gene and cytochrome (CYP)1A1 rs1048943 gene polymorphism are associated with HDL levels and periodontal status. Studies showed that HDL levels improve after treatment for periodontitis. On the one hand, periodontal pathogenic bacteria and their metabolites and pro-inflammatory cytokines from periodontal infection can result in various disorders of lipid metabolism and lipid peroxidation. On the other hand, hyperlipidemia and lipid peroxidation stimulate proinflammatory cytokines, resulting in oxidative stress and delayed wound healing, making individuals susceptible to periodontitis.

Bifidobacterium animalis subspecies lactis HN019 can reduce the sequelae of experimental periodontitis in rats modulating intestinal parameters, expression of lipogenic genes, and levels of hepatic steatosis

OBJECTIVE

To determine whether Bifidobacterium animalis subspecies lactis HN019 (B. lactis HN019) can reduce the sequelae of experimental periodontitis (EP) in rats modulating systemic parameters.

BACKGROUND

This study evaluated the effects of probiotic therapy (PROB) in the prevention of local and systemic damage resulting from EP.

METHODS

Forty-eight rats were allocated into four groups: C (control), PROB, EP, and EP-PROB. PROB (1 × 1010  CFU/mL) administration lasted 8 weeks and PE was induced on the 7th week by placing ligature on the animals' lower first molars. All animals were euthanized in the 9th week of the experiment. Biomolecular analyses, RT-PCR, and histomorphometric analyses were performed. The data obtained were analyzed statistically (ANOVA, Tukey, p < .05).

RESULTS

The EP group had higher dyslipidemia when compared to the C group, as well as higher levels of insulin resistance, proteinuria levels, percentages of systolic blood pressure, percentage of fatty hepatocytes in the liver, and expression of adipokines was up-regulated (LEPR, NAMPT, and FABP4). All these parameters (except insulin resistance, systolic blood pressure, LEPR and FABP4 gene expression) were reduced in the EP-PROB group when compared to the EP group. The EP group had lower villus height and crypt depth, as well as a greater reduction in Bacteroidetes and a greater increase in Firmicutes when compared to the EP-PROB group. Greater alveolar bone loss was observed in the EP group when compared to the EP-PROB group.

CONCLUSION

Bifidobacterium lactis HN019 can reduce the sequelae of EP in rats modulating intestinal parameters, attenuating expression of lipogenic genes and hepatic steatosis.

Insight Into the Laboratory Diagnosis of Periimplantitis Using Reactive Oxygen Metabolite Levels - A Biochemical Study

Aim The study aims to substantiate the quantitative role of the predominant periodontopathogen (Porphyromonas gingivalis) associated with peri-implantitis and evaluate the reactive oxygen metabolite levels in peri-implantitis patients. Methodology A total of 40 participants were taken from the department of periodontology, Thai Moogambigai Dental College and Hospital, Chennai, and divided into groups I (control) and II (test). Group I included 20 participants with healthy peri-implant tissue, and group II included 20 participants with infected peri-implant tissues. The predominant periodontopathogen was detected by using a quantitative real-time polymerase chain reaction. Samples (gingival crevicular fluid (GCF), saliva, and plasma) were collected, and a biochemical assay was conducted for reactive oxygen metabolites (ROM) analysis in healthy implants (control group) and peri-implantitis conditions (test group). ROM levels of the patients were statistically analyzed. Results The qualitative and quantitative profiles of Porphyromonas gingivalis (P. gingivalis) associated with Peri-implantitis were analyzed, and the levels of ROM in periimplantitis patients were assessed. The study results substantiate the quantitative picture of Porphyromonas gingivalis in the detection of periimplantitis. The saliva and GCF samples showed significant differences in ROM levels between the test and control groups. Conclusion This is one of the few studies to detect the predominant bacterial pathogen associated with peri-implantitis and assess the ROM levels in periimplantitis patients. The study gives a correlation between the periopathogens and ROM levels, thereby facilitating the attainment of the best possible treatment options.

Synoviolin alleviates GSDMD-mediated periodontitis by suppressing its stability

INTRODUCTION

Inflammasome and pyroptosis play important roles in periodontitis. Gasdermin D (GSDMD), a key factor in pyroptosis, is cleaved by caspase-1 and regulated by ubiquitination. Synoviolin is a ubiquitin E3 ligase that interacts with GSDMD. In this study, the effects of Synoviolin on inflammasome activation and periodontitis were explored.

METHODS

The expression of IL-1β, GSDMD, and Synoviolin in peripheral blood mononuclear cells from patients with periodontitis was determined. The interaction between GSDMD and Synoviolin was studied. The cytokine level in gingival tissues and the distance from the cementoenamel junction to the alveolar bone crest were measured in mice with Synoviolin deficiency in myeloid cells.

RESULTS

We reported that elevated mRNA and protein levels of IL-1β and GSDMD, decreased levels of Synoviolin mRNA and protein, and decreased ubiquitination of GSDMD were associated with periodontitis. Synoviolin interacted with GSDMD. Synoviolin-deficient bone marrow-derived macrophages had increased IL-1β and IL-18 secretion after ATP stimulation. Mice with Synoviolin deficiency in myeloid cells had more severe periodontitis and upregulated IL-1β and IL-18.

CONCLUSIONS

Therefore, we conclude that Synoviolin suppresses inflammasome activation and periodontitis by regulating GSDMD stability.

STUDY OF IMMUNE-INFLAMMATORY RESPONSE CHANGES IN ORAL FLUID IN PATIENTS WITH DISEASES OF PERIODONTAL TISSUES IN COMBINATION WITH GENERAL SOMATIC PATHOLOGY

OBJECTIVE

The aim: To determine the concentration of markers of the immune-inflammatory response (IL-1β, IL-10, IL-1β / IL-10, hsCRP) in oral fluid in patients with diseases of periodontal tissues in combination with general somatic pathology.

PATIENTS AND METHODS

Materials and methods: The study was conducted at Danylo Halytsky Lviv National Medical University, Department of therapeutic dentistry FPGE, Lviv, Ukraine. The patients were divided into two groups: the main group - 144 patients (with periodontal tissue diseases on the background of general somatic pathology) and the control group - 30 somatically and dentally healthy persons, in whose oral fluid was determined the concentration of IL-1β, IL-10, hsCRP by the enzyme immunoassay method.

RESULTS

Results: As a result of our research, it was found that in people with periodontal tissue diseases, against the background of general somatic pathology, there is an activation of the immune-inflammatory response, which aggravates the course of general somatic and dental diseases in this contingent of patients.

CONCLUSION

Conclusions: Therefore, in patients with periodontal tissue diseases on the background of somatic diseases, a significant increase in the level of the pro-in-flammatory cytokine IL-1β and hsCRP was determined against the background of a decrease in the anti-inflammatory cytokine IL-10 in the oral fluid compared to the values in the control group.

Unveiling the m6A Methylation Regulator Links between Prostate Cancer and Periodontitis by Transcriptomic Analysis

Objective

To identify the N6-methyladenosine (m6A) methylation regulator genes linking prostate adenocarcinoma (PRAD) and periodontitis (PD).

Materials and Methods

PD and TCGA-PRAD GEO datasets were downloaded and analyzed through differential expression analysis to determine the differentially expressed genes (DEGs) deregulated in both conditions. Twenty-three m6A RNA methylation-related genes were downloaded in total. The m6A-related genes that overlapped between PRAD and PD were identified as crosstalk genes. Survival analysis was performed on these genes to determine their prognostic values in the overall survival outcomes of prostate cancer. The KEGG pathways were the most significantly enriched by m6A-related crosstalk genes. We also performed lasso regression analysis and univariate survival analysis to identify the most important m6A-related crosstalk genes, and a protein-protein interaction (PPI) network was built from these genes.

Results

Twenty-three m6A methylation-related regulator genes were differentially expressed and deregulated in PRAD and PD. Among these, seven (i.e., ALKBH5, FMR1, IGFBP3, RBM15B, YTHDF1, YTHDF2, and ZC3H13) were identified as m6A-related cross-talk genes. Survival analysis showed that only the FMR1 gene was a prognostic indicator for PRAD. All other genes had no significant influence on the overall survival of patients with PRAD. Lasso regression analysis and univariate survival analysis identified four m6A-related cross-talk genes (i.e., ALKBH5, IGFBP3, RBM15B, and FMR1) that influenced risk levels. A PPI network was constructed from these genes, and 183 genes from this network were significantly enriched in pathogenic Escherichia coli infection, p53 signaling pathway, nucleocytoplasmic transport, and ubiquitin-mediated proteolysis.

Conclusion

Seven m6A methylation-related genes (ALKBH5, FMR1, IGFBP3, RBM15B, YTHDF1, YTHDF2, and ZC3H13) were identified as cross-talk genes between prostate cancer and PD.

Presence of periodontitis may synergistically contribute to cancer progression via Treg and IL-6

A close causal relationship has been suggested to exist between cancer and periodontitis. We hypothesized that the immune surveillance system is impaired in patients with periodontitis, which contributes to cancer development and growth. Therefore, the present study investigated the relationship between immune surveillance mechanisms and periodontitis in cancer patients. The presence or absence of periodontitis was assessed and the peripheral blood (PB) concentrations of IL-6, immunosuppressive cytokines (VEGF, TGF-β1, and CCL22) and proportion of T regulatory cells (Treg, CD3 + CD4 + CD25 + Foxp3 +) were measured. Subjects were classified into the following four groups: non-cancer patients without periodontitis (C − P −), non-cancer patients with periodontitis (C − P +), cancer patients without periodontitis (C + P −), and cancer patients with periodontitis (C + P +). The results of a multivariate analysis showed that the PB concentration of IL-6 was significantly higher in C + than in C- and higher in C + P + than in C + P −. The PB proportion of Treg was significantly higher in C + P + than in C + P −, C − P + , and C − P −. The results of this study suggested that the presence of periodontitis and cancer synergistically increased Treg in PB, which may be one of the underlying causes of immunosuppression and immune evasion in cancer. It was also suggested that the presence of periodontal disease and/or cancer also increases IL-6 in PB, which would be associated with cancer progression. These results suggest the possibility that the presence of periodontitis might synergistically contribute to cancer progression.

Circulating inflammatory cell profiling and periodontitis: A systematic review and meta-analysis

Inflammation is a key driver of common noncommunicable diseases. Among common triggers of inflammation, chronic gingival inflammation (periodontitis) triggers a consistent humoral host inflammatory response, but little is known on its impact on circulating inflammatory cell profiles. We aimed to systematically appraise all the evidence linking periodontitis and its treatment to circulating inflammatory cell profiles. From 6 databases, 157 studies were eligible for qualitative synthesis and 29 studies for meta-analysis. Our meta-analysis showed that participants with periodontitis exhibited a significant mean increase in circulating CD4⁺ , CD4⁺ CD45RO⁺ , IFNγ-expressing CD4⁺ and CD8⁺ T cells, CD19⁺ CD27⁺ and CD5⁺ B cells, CD14⁺ CD16⁺ monocytes, and CD16⁺ neutrophils but decrease in CD8⁺ T and CD14⁺⁺ CD16^- monocytes. Our qualitative synthesis revealed that peripheral blood neutrophils of patients with periodontitis consistently showed elevated production of reactive oxygen species (ROS) when compared with those of healthy controls. Some evidence suggested that the treatment of periodontitis reversed the exaggerated ROS production, but limited and inconclusive data were found on several circulating inflammatory cell profiling. We conclude that periodontitis and its treatment are associated with minor but consistent alterations in circulating inflammatory cell profiles. These changes could represent key mechanisms explaining the association of periodontitis with other comorbidities such as cardiovascular disease, diabetes, and rheumatoid arthritis.

Down-regulated IL36RN expression based on peripheral blood mononuclear cells and plasma of periodontitis patients and its clinical significance

BACKGROUND

The role of IL-36 receptor antagonist (IL36RN), a mutated gene expression of IL-36 in periodontitis patients with peripheral blood mononuclear cells (PBMC) and plasma remains to be undetermined.

MATERIALS AND METHODS

Our study discovered the IL36RN expression through GEO public databases and further validated by PBMC and plasma of periodontitis patients and healthy participants. A total of 194 participants of public datasets, consisting of 97 cases of periodontitis and 97 cases of healthy control were retrospectively evaluated and explored the gene enrichment pathways and clinical significance of IL36RN expression accompanied by three different cytokines. Furthermore, the clinical significance of IL36RN was evaluated in mild-to-severe patients of periodontitis by the receiver operating curve (ROC) using the area under the curve (AUC).

RESULTS

IL36RN expressions were notably down-regulated in PBMC and plasma of periodontitis patients. Further, a positive correlation of IL36RN expression was significantly observed between PBMC and plasma of periodontitis patients while IL36RN expression was negatively correlated to serum-based three different cytokines of periodontitis patients. Meanwhile, the ROC-AUCs achieved a significantly higher range from 0.80 to 0.87 with PBMC of mild-to-severe and moderate-to-severe periodontitis patients whereas similar patients with plasma obtained a significant AUC range from 0.73 to 0.83.

CONCLUSION

IL36RN can distinctively be detectable in periodontitis patients with PBMC and plasma, which can act as a down-regulated mutated gene that might play an effective role in causing periodontitis. IL36RN may involve by other inflammatory cytokines in the pathogenesis of periodontitis.

Peripheral T helper cell profiles during management of periodontitis

AIM

Periodontitis has been associated with other systemic diseases with underlying inflammation responsible for the shared link. This study evaluated longitudinal variation in peripheral T helper cells in periodontitis patients undergoing management over 1 year.

MATERIALS AND METHODS

Periodontal parameters and peripheral blood mononuclear cells (PBMCs) were collected from 54 periodontitis patients at baseline, and 3-, 6- and 12-months post-treatment and 40 healthy controls. IFN-γ⁺ , IL-4⁺ , IL-17⁺ and Foxp3⁺ and their double-positive expression were identified in CD4⁺ and TCRαβ⁺ cells using flow cytometry. PBMCs were incubated with P. gingivalis, and IFN-γ, IL-4, IL-17 and IL-10 in cell supernatant were measured by ELISA. Cells and cytokines were also assessed based on clinical response to treatment where good (<10% of sites), moderate (10-20%) and poor (>20%) treatment outcome (TxO) groups had probing depths of ≥5 mm at study conclusion.

RESULTS

IFN-γ⁺ cells were lower at baseline, and 3- and 6-months compared to health, whereas Foxp3⁺ cells were increased at 12-months compared to all preceding timepoints and health. The good TxO group showed treatment-related variation in IFN-γ⁺ and Foxp3⁺ cells, whereas the poor TxO group did not. IFN-γ and IL-17 cytokine expression in cell supernatants was significantly lower at baseline compared to health, and IFN-γ and IL-10 showed treatment-related decrease.

CONCLUSION

This study suggests that IFN-γ⁺ and Foxp3⁺ cells may have a role in the systemic compartment in periodontitis. Periodontal management has local and systemic effects, and thus, assessment and management of periodontitis should form an integral part of overall systemic health.

Systemic expression of genes related to inflammation and lipid metabolism in patients with dyslipidemia, type 2 diabetes mellitus and chronic periodontitis

Inflammatory diseases, as periodontal disease (PD), has been associated with disturbance of lipid and glycemic metabolisms, as demonstrated by the increasing of PD patients with type 2 diabetes mellitus (T2D) and/or dyslipidemia comorbidities. We aimed to investigate the expression of inflammation and lipid metabolism genes, and correlations among clinical and biochemical characteristics in normoglycemic or T2D patients with dyslipidemia and PD, in comparison with healthy individuals. Five groups of 30 individuals each (150 patients) were formed based upon T2D, dyslipidemic and periodontal status. Blood analyses of lipid and glycemic profiles were carried out, and the gene expression was assessed by RT-qPCR. The systemic expression of IL6, TNFA and LEP genes were significantly higher in T2D, dyslipidemia and PD patients, while the PECAM1 gene showed the opposite. Higher RETN levels were found in patients with T2D independently of their glycemic control status. There were positive correlations between: TNFA, LEP and RETN with worse periodontal parameters; IL6, TNFA, ADIPOR1, LEP and RETN with waist-to-hip ratio; glycemic parameters with RETN; total cholesterol and triglycerides with LEP expression. We conclude that pro-inflammatory cytokines were related with worse lipid, glycemic and periodontal parameters, reinforcing that a hyper-inflammatory status connects systemic and oral inflammatory diseases.

Periodontal Therapy with 0.25%Lemongrass Oil Mouthwash in Reducing Risk of Cardiovascular Diseases: A 3-Arm Prospective Parallel Experimental Study

BACKGROUND

Periodontal disease is associated with cardiovascular diseases because of its role in host immune-inflammatory response. Serum lipids are the commonest risk factors between periodontal disease and cardiovascular diseases.

MATERIALS AND METHOD

A double blinded randomised clinical trial was carried out among 45 subjects with generalised severe periodontitis. They were divided into 3-groups of 15 subjects each. Group A: 0.25% lemongrass oil mouthwash, Group B: 0.12% chlorhexidine mouthwash and Group C: Oral prophylaxis only Group. Oral examinations like assessment of Probing Pocket Depth and Clinical Attachment Loss and Bio-chemical tests like assessment of C-Reactive Protein, Total Cholesterol, High Density Lipid, Low Density Lipid and triglycerides were conducted at baseline followed by oral prophylaxis at the same visit. Reassessment of the above mentioned parameters were done after 3 months of intervention. Data so collected were subjected for statistical analysis using SPSS ver. 20.0.

RESULTS

A statistically significant reduction in C-Reactive Protein, Probing Pocket Depth, Clinical Attachment Loss, Total Cholesterol and Low Density Lipid level in 0.25% lemongrass oil mouthwash group was found. On comparing a statistically significant difference was observed for the post intervention scores of Probing Pocket Depth and Clinical Attachment Loss only; for Group A v/s C and Group B v/s C.

CONCLUSION

0.25% Lemongrass oil mouthwash was found to be a good herbal alternative; both in the treatment of chronic periodontitis and reduction in the level of serum markers of Cardio Vascular Diseasess.

Decrease of Pericytes is Associated With Liver Disease Caused by Ligature-Induced Periodontitis in Rats

BACKGROUND

Damage caused by periodontitis not only affects periodontal tissues, but also increases the severity of various illnesses such as rheumatoid arthritis, diabetes, and liver diseases. The aim of this study is to investigate the association between induced periodontitis and damage caused through its systemic effects on the liver.

METHODS

Twenty rats were divided into two groups: control and periodontitis. The following parameters were evaluated: gingival bleeding index (GBI), probing depth (PD), myeloperoxidase (MPO) activity, alveolar bone loss (ABL) for periodontal tissues; histopathologic examination of gingival and liver tissues; immunohistochemistry to cells positive for neural/glial antigen 2 (NG2) expressed in hepatic pericytes, glutathione (GSH), and malondialdehyde (MDA) concentrations in liver; and serum levels of alanine aminotransferase and aspartate aminotransferase.

RESULTS

GBI, PD, MPO, ABL, and histopathologic examinations demonstrated the development of periodontitis. There was a significant increase in microvesicular steatosis accompanied by a marked reduction in NG2+ pericytes in the periodontitis group compared with the control group. The periodontitis group had significantly lower GSH and higher MDA concentration in the liver compared with the control group.

CONCLUSIONS

The present study results link the systemic effects of induced periodontitis with changes in hepatic tissues such as microvesicular steatosis, likely caused by an increase in oxidative stress and lipid peroxidation. The findings from the present study implicate an association between a decrease of pericytes and liver disease caused by ligature-induced periodontitis in rats.

General immune status and oral microbiology in patients with different forms of periodontitis and healthy control subjects

Objective

Immunological processes in the etiopathogenesis of periodontitis, especially the aggressive form, are not well understood. This study examined clinical as well as systemic immunological and local microbiological features in healthy controls and patients with different forms of periodontitis.

Materials and Methods

14 healthy subjects, 15 patients diagnosed with aggressive periodontitis, and 11 patients with chronic periodontitis were recruited. Periodontal examination was performed and peripheral blood was collected from each patient. Lymphocyte populations as well as the release of cytokines by T-helper cells were determined by flow cytometry and enzyme linked immunosorbent spot assay. Subgingival plaque samples were taken from each individual and immediately cultivated for microbiological examination.

Results

When stimulating peripheral blood mononuclear cells (PBMCs) with lipopolysaccharide, a higher IL-1β release was found in patients with moderate chronic periodontitis compared to the other groups (p<0.01). Numbers of B-cells, naïve and transitional B-cells, memory B-cells, and switched memory B-cells were within the reference range for all groups, but patients with chronic periodontitis showed the highest percentage of memory B-cells without class switch (p = 0.01). The subgingival plaque differed quantitatively as well as qualitatively with a higher number of Gram-negative anaerobic species in periodontitis patients. Prevotella denticola was found more often in patients with aggressive periodontitis (p<0.001) but did not show an association to any of the systemic immunological findings. Porphyromonas gingivalis, which was only found in patients with moderate chronic periodontitis, seems to be associated with an activation of the systemic immune response.

Conclusion

Differences between aggressive periodontitis and moderate chronic periodontitis are evident, which raises the question of an inadequate balance between systemic immune response and bacterial infection in aggressive periodontitis.

Peripheral blood mononuclear phagocytes from patients with chronic periodontitis are primed for osteoclast formation

BACKGROUND

During inflammatory periodontal disease, peripheral blood mononuclear cells (PBMCs) are attracted to bone and differentiate into active bone-resorbing osteoclasts (OCs), thus providing evidence that the impact of chronic periodontitis (CP) on the activity of circulating mononuclear cells is of central importance. The authors test the hypothesis that peripheral blood mononuclear phagocytes (PBMPs) from patients with CP are activated and more susceptible to differentiation into OCs, which in turn would lead to more intense bone resorption.

METHODS

In vitro cytokine production by both unstimulated and lipopolysaccharide-stimulated PBMCs from individuals with (n = 10) or without (n = 12) periodontitis was determined by cytokine array. OC differentiation from CD14(+) PBMCs was induced by receptor activator of nuclear factor-kappa B ligand (RANKL), either alone or in the presence of macrophage colony-stimulating factor (M-CSF). PBMC differentiation to OCs was confirmed by tartrate-resistant acid phosphatase staining; bone resorbing activity was assessed by using an osteologic plate assay (bone resorption pit formation).

RESULTS

PBMCs from patients with CP produced tumor necrosis factor-α and higher amounts of interferon-γ, interleukin (IL)-1α, IL-1β, IL-1rα, CXC motif chemokine 10, macrophage migration inhibitory factor, macrophage inflammatory protein (MIP)-1α, and MIP-1β than the control cells. OC differentiation was induced by RANKL alone in PBMCs from patients with CP, but not in PBMCs from the healthy controls, which required the addition of M-CSF. In addition, PBMC-derived OCs from patients with CP showed significantly higher resorption activity than that observed in the healthy controls. Also, the circulating concentrations of M-CSF were significantly higher in patients with CP than in the control participants.

CONCLUSIONS

These data indicate that in patients with CP, circulating PBMCs are primed for increased proinflammatory activity and that M-CSF plays a central role in this process by increasing OC formation and the consequent bone resorption activity.

Isolation of Treponema and Tannerella spp. from equine odontoclastic tooth resorption and hypercementosis related periodontal disease

REASONS FOR PERFORMING STUDY

Red complex bacteria, i.e. Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia, are involved in the onset and progression of periodontal disease in man, yet seldom inhabit the oral cavity of healthy individuals. Periodontal disease is also encountered in horses, with equine odontoclastic tooth resorption and hypercementosis (EOTRH) constituting a particular form of disease. However, only little is known about the oral microbiome of healthy and periodontitis-affected equids.

OBJECTIVE

We aimed to test the hypothesis that red complex bacteria are also associated with EOTRH-related periodontal disease.

STUDY DESIGN

Controlled cross-sectional study.

METHODS

We screened DNA purified from crevicular fluid derived from 23 EOTRH-affected and 21 disease-free horses for the presence of Treponema spp., Tannerella spp. and Porphyromonas gingivalis DNA by polymerase chain reaction. Subsequently, amplified DNA was bidirectionally sequenced and identified via BLAST analysis.

RESULTS

Treponema and/or Tannerella DNA was detected in 100% of periodontitis-related samples and in 52.2% of DNA derived from healthy horses. Twenty-six amplicon sequences were 98-100% homologous to published bacterial sequences, which mostly corresponded to Treponema pectinovorum, oral Treponema clones JU025 and OMZ 840, and Tannerella forsythia. P. gingivalis DNA was only found in 3 EOTRH-related samples. Forty-three amplicon sequences revealed weaker homologies ranging between 80% and 97% to known Treponema or Tannerella strains, partly because of their heterogeneity, partly because they obviously represented so far unknown types.

CONCLUSIONS

This is the first report in which known and novel Treponema and Tannerella spp. were isolated in association with EOTRH-related periodontal disease.