Evaluation of Serum Interleukin-33 Level in Iraqi Patients with and without Periodontal Disease

Objective

Periodontitis is a multifactorial inflammatory illness characterized by periodic tissue support deterioration. Interleukin-33 has recently been discovered as a new pro-inflammatory cytokine implicated in the pathogenesis of periodontitis. The objective of this case control study is to compare IL-33 levels among periodontitis patients and healthy volunteers using serum samples and investigate the potential association with clinical periodontal parameters.

Materials and Methods

A total of 100 subjects (50 patients with periodontal disease and 50 healthy individuals) were included in this case control study. Clinical plaque index (PLI), gingival index (GI), bleeding on probing (BOP), probing pocket depth (PPD) and clinical attachment loss (CAL) were assessed. Serum was extracted from the venous blood that was collected. Serum IL-33 values were measured using an enzyme-linked immunosorbent assay (ELISA).

Results

Serum levels of interleukin-33 showed considerably elevated level in the patient's group than in the healthy control group (P<0.01). There was a strong correlation between the blood levels of IL-33 and PLI, GI, and BOP (P≤ 0.05). While PPD and CAL demonstrated a non-significant relationship (P˃0.05).

Conclusion

 The results of this study suggested that IL-33 may be used as a potential indicator of the inflammation associated with periodontitis and might have a role in the development of the disease. Further studies with large sample sizes are needed to improve knowledge about the role of IL-33 in periodontal health and disease.

Clinical Significance

Owing to the noticeable role that IL-33 plays in the pathogenicity of periodontitis as a local waring clue for the periodontal tissue breakdown, tissue-specific therapeutic strategies may improve.

Oral Fluid Biomarkers for Peri-Implantitis: A Scoping Review

Peri-implantitis, a prevalent complication in dental implant therapy, poses a significant threat to long-term implant success. The identification of reliable biomarkers for the early detection and monitoring of peri-implantitis is crucial for timely intervention and improved treatment outcomes. Salivary and peri-implant sulcular fluid (PISF) biomarkers have become promising diagnostic tools in the field of implant dentistry. This scoping review aims to explore current studies in the literature on salivary and PISF biomarkers for peri-implantitis. A systematic search was conducted on 2 databases (PubMed and Scopus) to identify relevant studies published up to January 2023. A total of 86 articles were included, which underwent data extraction and analysis. Several biomarkers have been investigated in salivary and PISF samples for association with peri-implantitis. Investigations included a wide range of biomarkers, including inflammatory markers, matrix metalloproteinases and bone loss markers. The findings suggested that certain salivary and PISF biomarkers demonstrated potential in distinguishing healthy peri-implant conditions from peri-implantitis. Elevated levels of proinflammatory cytokines, such as interleukin-1β (IL-1β) and interleukin-6 (IL-6), tumour necrosis factor-alpha (TNF-α), and matrix metalloproteinases, have been consistently associated with peri-implantitis. Additionally, alterations in bone loss markers have shown potential as indicators of disease progression and treatment response. In conclusion, this scoping review provides an overview of current knowledge on salivary and PISF biomarkers for peri-implantitis. The identified biomarkers are promising as noninvasive diagnostic tools for early detection, monitoring, and personalised management of peri-implantitis. Future studies should focus on establishing standardised protocols and conducting well-designed clinical trials to validate the diagnostic accuracy and clinical relevance of these biomarkers.

Preparation and In Vitro Characterization of Lactococcus lactis-Loaded Alginate Particles as a Promising Delivery Tool for Periodontal Probiotic Therapy

Probiotic microorganisms are used in a variety of food supplements and medical formulations to promote human health. In periodontal therapy, probiotics are mainly used in the form of gels, tablets or rinses that often tend to leak from the periodontal pocket, resulting in a strongly reduced therapeutic effect. In this pilot in vitro study, we present biodegradable alginate-based particles as an alternative, highly efficient system for a periodontal delivery of probiotic bacteria to the inflammation site. For this purpose, Lactococcus (L.) lactis was encapsulated using a standardized pump-controlled extrusion-dripping method. Time-dependent bacterial release in artificial saliva was investigated over 9 days. The effect of freeze drying was explored to ensure long-term storage of L. lactis-loaded particles. Additionally, the particles were bound to dentin surface using approved bioadhesives and subjected to shear stress in a hydrodynamic flow chamber that mimics the oral cavity in vitro. Thus, round particles within the range of 0.80-1.75 mm in radius could be produced, whereby the diameter of the dripping tip had the most significant impact on the size. Although both small and large particles demonstrated a similar release trend of L. lactis, the release rate was significantly higher in the former. Following lyophilization, particles could restore their original shape within 4 h in artificial saliva; thereby, the bacterial viability was not affected. The attachment strength to dentin intensified by an adhesive could resist forces between 10 and 25 N/m2. Full degradation of the particles was observed after 20 days in artificial saliva. Therefore, alginate particles display a valuable probiotic carrier for periodontal applications that have several crucial advantages over existing preparations: a highly stable form, prolonged continuous release of therapeutic bacteria, precise manufacturing according to required dimensions at the application site, strong attachment to the tooth with low risk of dislocation, high biocompatibility and biodegradability.

Investigating the diagnostic potential of IL-1β, IL-10, and IL-36γ in gingival crevicular fluid in patients with different periodontal conditions

BACKGROUND

The study aimed to analyze cytokine levels, including interleukin (IL)-1β, IL-10, and IL-36γ, to investigate the link between pro- and anti-inflammatory responses in periodontal conditions and assess their potential as diagnostic biomarkers for distinguishing between different types of periodontal conditions.

METHODS

80 systemically healthy non-smokers (25 periodontally healthy, 25 with gingivitis, 30 with periodontitis) were included. Clinical periodontal parameters were recorded, and gingival crevicular fluid (GCF) samples were obtained. Receiver operating characteristic (ROC) curve analysis was applied to determine the diagnostic value of cytokines.

RESULTS

IL-36γ had the highest sensitivity for diagnosing periodontitis, although its specificity for identifying those without periodontitis was relatively low. The combination of IL-1β and IL-36γ was the most effective in differentiating periodontitis from periodontal health. IL-10 was found to be an acceptable discriminator for distinguishing gingivitis from healthy conditions. However, its sensitivity and specificity for identifying gingivitis were lower. The combination of the three cytokines showed the highest ability to distinguish between periodontitis and gingivitis.

CONCLUSION

The levels of IL-1β, IL-10, and IL-36γ in GCF may provide insights into periodontal health and disease status. Further studies are needed to validate these results and explore the potential of these cytokines in periodontal disease management.

Cystatin C: immunoregulation role in macrophages infected with Porphyromonas gingivalis

Background

Periodontitis is a chronic infectious disease, characterized by an exacerbated inflammatory response and a progressive loss of the supporting tissues of the teeth. Porphyromonas gingivalis is a key etiologic agent in periodontitis. Cystatin C is an antimicrobial salivary peptide that inhibits the growth of P. gingivalis. This study aimed to evaluate the antimicrobial activity of this peptide and its effect on cytokine production, nitric oxide (NO) release, reactive oxygen species (ROS) production, and programmed cell death in human macrophages infected with P. gingivalis.

Methods

Monocyte-derived macrophages generated from peripheral blood were infected with P. gingivalis (MOI 1:10) and stimulated with cystatin C (2.75 µg/ml) for 24 h. The intracellular localization of P. gingivalis and cystatin C was determined by immunofluorescence and transmission electron microscopy (TEM). The intracellular antimicrobial activity of cystatin C in macrophages was assessed by counting Colony Forming Units (CFU). ELISA assay was performed to assess inflammatory (TNFα, IL-1β) and anti-inflammatory (IL-10) cytokines. The production of nitrites and ROS was analyzed by Griess reaction and incubation with 2',7'-dichlorodihydrofluorescein diacetate (H2DCFDA), respectively. Programmed cell death was assessed with the TUNEL assay, Annexin-V, and caspase activity was also determined.

Results

Our results showed that cystatin C inhibits the extracellular growth of P. gingivalis. In addition, this peptide is internalized in the infected macrophage, decreases the intracellular bacterial load, and reduces the production of inflammatory cytokines and NO. Interestingly, peptide treatment increased ROS production and substantially decreased bacterial-induced macrophage apoptosis.

Conclusions

Cystatin C has antimicrobial and immuno-regulatory activity in macrophages infected with P. gingivalis. These findings highlight the importance of understanding the properties of cystatin C for its possible therapeutic use against oral infections such as periodontitis.

The role of acquired host immunity in periodontal diseases

The aim of this narrative review is to relate the contribution of European researchers to the complex topic of the host immune system in periodontal disease, focusing on acquired immunity. Other chapters in this volume will address the genetics and autoantibody responses and other forms of immunity to periodontal disease. While the contribution of European authors is the focus, global literature is included in this descriptive narrative for contextual clarity, albeit many with European co-authors. The topic is relatively intense and is thus broken down into sections outlined below, tackled as descriptive narratives to enhance understanding. Any attempt at a systematic or scoping review was quickly abandoned given the descriptive nature and marked variation of approach in almost all publications. Even the most uniform area of this acquired periodontal immunology literature, antibody responses to putative pathogens in periodontal diseases, falls short of common structures and common primary outcome variables one would need and expect in clinical studies, where randomized controlled clinical trials (RCTs) abound. Addressing 'the host's role' in immunity immediately requires a discussion of host susceptibility, which necessitates consideration of genetic studies (covered elsewhere in the volume and superficially covered here).

Highlighting the Effect of Pro-inflammatory Mediators in the Pathogenesis of Periodontal Diseases and Alzheimer's Disease

Alzheimer's disease (AD) is a neurological condition that is much more common as people get older. It may start out early or late. Increased levels of pro-inflammatory cytokines and microglial activation, both of which contribute to the central nervous system's inflammatory state, are characteristics of AD. As opposed to this, periodontitis is a widespread oral infection brought on by Gram-negative anaerobic bacteria. By releasing pro-inflammatory cytokines into the systemic circulation, periodontitis can be classified as a "low-grade systemic disease." Periodontitis and AD are linked by inflammation, which is recognized to play a crucial part in both the disease processes. The current review sought to highlight the effects of pro-inflammatory cytokines, which are released during periodontal and Alzheimer's diseases in the pathophysiology of both conditions. It also addresses the puzzling relationship between AD and periodontitis, highlighting the etiology and potential ramifications.

Evaluation of Salivary Il-38 Levels in Periodontitis: A Cross-Sectional Study

The goal of the current study was to assess levels of salivary interleukin (IL)-38, IL-1β, and IL-10 in various periodontal clinical conditions. In total, 60 (20 healthy, 20 gingivitis, and 20 stage II-III, grade A-B periodontitis) subjects were included in the study. Demographic and clinical periodontal parameters were recorded. Samples were examined for IL-38, IL-1β, and IL-10 levels by means of enzyme-linked immunosorbent assay. Results demonstrated that the periodontitis group had significantly lower salivary IL-38 levels (P < 0.05) than the healthy group. Salivary IL-10 levels did not differ significantly between the groups (P > 0.05). The salivary IL-1β levels of gingivitis (P < 0.001) and periodontitis groups (P < 0.01) were significantly higher than those of the healthy group. The present study indicated that IL-38 level is decreased in periodontal disease. The results suggested a possible role of IL-38 in the periodontal inflammation process. Clarifying the mechanisms of IL-38 in the inflammatory process may contribute to the development of novel treatment strategies in periodontal diseases.

Bioinformatics reveals the pathophysiological relationship between diabetic nephropathy and periodontitis in the context of aging

Diabetic nephropathy (DN) is one of the most common microvascular complications of diabetes mellitus. Periodontitis (PD) is a microbially-induced chronic inflammatory disease that is thought to have a bidirectional relationship with diabetes mellitus. DN and PD are recognized as models associated with accelerated aging. This study is divided into two parts, the first of which explores the bidirectional causal relationship through Mendelian randomization (MR). The second part aims to investigate the relationship between PD and DN in terms of potential crosstalk genes, aging-related genes, biological pathways, and processes using bioinformatic methods. MR analysis showed no evidence to support a causal relationship between DN and PD (P = 0.34) or PD and DN (P = 0.77). Using the GEO database, we screened 83 crosstalk genes overlapping in two diseases. Twelve paired genes identified by Pearson correlation and the four hub genes in the key cluster were jointly evaluated as key crosstalk-aging genes. Using support vector machine recursive feature elimination (SVM-RFE) and maximal clique centrality (MCC) algorithms, feature selection established five genes as the key crosstalk-aging genes. Based on five key genes, an ANN diagnostic model with reliable diagnosis of two diseases was developed. Gene enrichment analysis indicates that AGE-RAGE pathway signaling, the complement system, and multiple immune inflammatory pathways may be involved in common features of both diseases. Immune infiltration analysis reveals that most immune cells are differentially expressed in PD and DN, with dendritic cells and T cells assuming vital roles in both diseases. Overall, although there is no causal link, CSF1R, CXCL6, VCAM1, JUN and IL1B may be potential crosstalk-aging genes linking PD and DN. The common pathways and markers explored in this study could contribute to a deeper understanding of the common pathogenesis of both diseases in the context of aging and provide a theoretical basis for future research.

Using 8-Hydroxy-2'-Deoxiguanosine (8-OHdG) as a Reliable Biomarker for Assessing Periodontal Disease Associated with Diabetes

In recent years, research has shown that oxidative stress plays a significant role in chronic inflammatory conditions. The alteration of the oxidant/antioxidant balance leads to the appearance of free radicals, important molecules involved in both diabetes mellitus and periodontal disease. Diabetes is considered to be one of the major risk factors of periodontal disease and the inflammation characterizing this condition is associated with oxidative stress, implicitly resulting in oxidative damage to DNA. 8-Hydroxydeoxyguanosine (8-OHdG) is the most common stable product of oxidative DNA damage caused by reactive oxygen species, and its levels have been reported to increase in body fluids and tissues during inflammatory conditions. 8-OHdG emerges as a pivotal biomarker for assessing oxidative DNA damage, demonstrating its relevance across diverse health conditions, including neurodegenerative disorders, cancers, inflammatory conditions, and periodontal disease. Continued research in this field is crucial for developing more precise treatments and understanding the detailed link between oxidative stress and the progression of periodontitis. The use of the 8-OHdG biomarker in assessing and managing chronic periodontitis is an area of increased interest in dental research, with the potential to provide crucial information for diagnosis and treatment.

Effect of three clinical therapies on cytokines modulation in the hip articular cartilage and bone improvement in rat early osteonecrosis of the femoral head

BACKGROUND

Extracorporeal shockwave therapy (ESWT) and adipose-derived mesenchymal stem cells (ADSCs) have been used clinically for the treatment of osteonecrosis of the femoral head (ONFH). The study elucidated that ESWT, ADSCs, and combination therapy modulated pro-inflammatory cytokines in the articular cartilage and subchondral bone of early rat ONFH.

METHODS

ESWT and ADSCs were prepared and isolated for treatment. Micro-CT, pathological analysis, and immunohistochemistry were performed and analysed.

RESULTS

After treatments, subchondral bone of ONFH was improved in trabecular bone volume (BV/TV) (p < 0.001), thickness (Tb.Th) (p < 0.01 and 0.001), and separation (Tb.Sp) (p < 0.001) and bone mineral density (BMD) (p < 0.001) using micro-CT analysis. The articular cartilage was protected and decreased apoptosis markers after all the treatments. The expression of IL33 (p < 0.001), IL5 (p < 0.001), IL6 (p < 0.001), and IL17A (p < 0.01) was significantly decreased in the ESWT, ADSCs, and Combination groups as compared with ONFH group. The IL33 receptor ST2 was significantly increased after treatment (p < 0.001) as compared with ONFH group. The Combination group (p < 0.01) decreased the expression of IL6 better than the ESWT and ADSCs groups.

CONCLUSION

ESWT, ADSCs and combination therapy significantly protected articular cartilage and subchondral bone of early rat ONFH by modulating the expression of pro-inflammatory cytokines including, IL33 and its receptor ST2, IL5, IL6, and IL17A.

Ageing and Inflammation: What Happens in Periodontium?

Periodontitis is a chronic inflammatory disease with a high incidence and severity in the elderly population, making it a significant public health concern. Ageing is a primary risk factor for the development of periodontitis, exacerbating alveolar bone loss and leading to tooth loss in the geriatric population. Despite extensive research, the precise molecular mechanisms underlying the relationship between ageing and periodontitis remain elusive. Understanding the intricate mechanisms that connect ageing and inflammation may help reveal new therapeutic targets and provide valuable options to tackle the challenges encountered by the rapidly expanding global ageing population. In this review, we highlight the latest scientific breakthroughs in the pathways by which inflammaging mediates the decline in periodontal function and triggers the onset of periodontitis. We also provide a comprehensive overview of the latest findings and discuss potential avenues for future research in this critical area of investigation.

Systemic inflammatory markers following adjunctive Nd:YAG (1064 nm) laser irradiation to step 2 of periodontal therapy: a 12-month, randomized, controlled trial

OBJECTIVES

The aim of this study was to investigate whether the use of adjunctive Nd:YAG (1064 nm) laser irradiation to full-mouth scaling and root planing (FM-SRP) may offer additional benefit in the systemic inflammatory status of the patient, as depicted in a variety of systemic biomarkers over FM-SRP alone, up to 12 months after treatment.

MATERIALS AND METHODS

A total of 60 otherwise healthy stage III/IV periodontal patients were equally distributed in 3 groups. The control group received FM-SRP. In laser A group, 1 week after FM-SRP, Nd:YAG laser irradiation was delivered in periodontal pockets with PD ≥ 4 mm using specific settings (3 W, 150 mJ, 20 Hz, 100 μs). In laser B group Nd:YAG laser irradiation was delivered twice, 1 week after FM-SRP and 1 week later with different settings compared to laser A (2 W, 200 mJ, 10 Hz, 100 μs).

RESULTS

A significant reduction (p = 0.038) of IL-1β serum levels at the 6-month time point was observed for laser A group. IL-6 was found statistically significantly increased (p = 0.011) in the control group at the 6-week time point, whereas no difference was reported for the laser-treated groups (laser A, laser B).

CONCLUSIONS

The adjunctive use of Nd:YAG laser irradiation, prevented from IL-6 increase after FM-SRP, 6 weeks after treatment. Similarly, Nd:YAG laser irradiation (3 W, 150 mJ, 20 Hz,100 μs) was associated with significantly lower IL-1β levels, 6 months post-operatively.

CLINICAL RELEVANCE

Additional Nd:YAG laser application to FM-SRP may provide a potential beneficial effect on systemic inflammation.

TRIAL REGISTRATION NUMBER

ISRCTN26692900.

REGISTRATION DATE

09/06/2022.

The effect of antipsychotic medication and the associated hyperprolactinemia as a risk factor for periodontal diseases in schizophrenic patients: a cohort retrospective study

BACKGROUND

Periodontal disease is a major health problem that results in tooth loss and thus affects oral health, which affects quality of life. In particular, schizophrenic patients are at higher risk for periodontal disease due to several factors, including the effect of antipsychotic medications received by those patients. Accordingly, the aim of the present cohort retrospective study is to explore the effect of antipsychotics on periodontal health and the possible effect of antipsychotic-induced hyperprolactinemia as a risk factor for periodontal disease progression in schizophrenic patients.

METHODS AND OUTCOMES

The study population consisted of three groups: Group A (n = 21): schizophrenic patients that have been taking "prolactin-inducing" antipsychotics for at least 1 year; Group B (n = 21): schizophrenic patients who have been taking "prolactin-sparing" antipsychotics for at least 1 year; and Group C (n = 22): newly diagnosed schizophrenic patients and/or patients who did not receive any psychiatric treatment for at least 1 year. The study groups underwent assessment of periodontal conditions in terms of pocket depth (PD), clinical attachment loss (CAL), gingival recession, tooth mobility, and bleeding on probing (BOP). Also, bone mineral density was evaluated using DEXA scans, and the serum prolactin level was measured by automated immunoassay.

RESULTS

Results revealed a statistically significant difference in PD, CAL, and serum prolactin levels (P ≤ 0.001, P = 0.001, and P ≤ 0.001, respectively) among the 3 study groups. For both PD and CAL measurements, group A has shown significantly higher values than both groups B and C, whereas there was no statistically significant difference between the values of groups C and B. Concerning serum prolactin levels, group A had significantly higher values than groups B and C (P ≤ 0.001 and P ≤ 0.001 respectively). There was a statistically significant difference (P ≤ 0.001) between the 3 study groups in terms of bone mineral density. Moreover, there was a statistically significant direct relation between serum prolactin level and other parameters including clinical attachment loss, pocket depth measurements and bone mineral density.

CONCLUSION

According to our results, it could be concluded that all antipsychotics contribute to the progression of periodontal disease, with a higher risk for prolactin-inducing antipsychotics. However, further long term, large sampled, interventional and controlled studies are required to reach definitive guidelines to allow clinicians properly manage this group of patients.

Salivary interleukin-1β as a biomarker to differentiate between periodontal health, gingivitis, and periodontitis

BACKGROUND

Periodontal diagnosis is based on recording clinical parameters including bleeding on probing (BOP), probing pocket depth (PPD), and clinical attachment loss (CAL). These techniques may be prone to errors due to different factors. Available biomarkers in the oral biofluid such as interleukin (IL)-1β could provide solutions for these issues. The study aimed to determine the potential of salivary IL-1β to differentiate periodontal health from disease and between gingivitis and periodontitis.

METHODS

Patients with gingivitis (N.=25), periodontitis (N.=50), and healthy periodontium (N.=25) were recruited for this study. For each patient, whole unstimulated saliva was collected followed by recording periodontal parameters namely; Plaque Index (PI), BOP, PPD, CAL. Level of salivary IL-1β was assayed by using enzyme-linked immunosorbent assays. Sensitivity and specificity of IL-1β, to differentiate any given condition, was determined by Receiver operating characteristic curve and area under the curve (AUC).

RESULTS

Both BOP and PI were significantly higher in association with gingivitis and periodontitis groups as compared to controls. Concentration of salivary IL-1β in periodontal health was significantly lower than gingivitis and periodontitis groups. The biochemical analyses showed that salivary IL-1β differentiated periodontal health from gingivitis (AUC 0.949) and periodontitis (AUC 0.852) but could not discriminate gingivitis from periodontitis (AUC 0.532). The proposed cut-off points to differentiate periodontal health from gingivitis was 103.8 pg/mL, while the value of the biomarker to differentiate periodontal health from periodontitis was 102.0 pg/mL.

CONCLUSIONS

Salivary IL-1β could be a reliable biomarker with a good level of accuracy to differentiate periodontal health from disease but not to discriminate gingivitis from periodontitis.

Modeling periodontal host-microbe interactions using vascularized gingival connective tissue equivalents

Gingival connective tissue and its vasculature play a crucial role in the host's immune response against the periodontal microbiome and serve as a bridge between the oral and systemic environments. However, there is a lack of representative models that mimic the complex features of vascularized gingival connective tissue and its interaction with the periodontal microbiome, hindering our understanding of periodontal health and disease. Towards this pursuit, we present the characterization of vascularized gingival connective tissue equivalents (CTEs) as a model to study the interactions between oral biofilm colonizers and gingival tissues in healthy and diseased states. Whole-mount immunolabeling and label-free confocal reflectance microscopy of human fibrin-based matrix embedded with gingival fibroblasts and microvascular endothelial cells demonstrated the generation of bi-cellular vascularized gingival CTEs. Next, we investigated the response of the vascularized gingival CTEs to early, intermediate, and late oral biofilm colonizers. Despite colonization, the early colonizers did not elicit any significant change in the production of the cytokines and chemokines by the CTEs representative of the commensal and homeostatic state. In contrast, intermediate and late colonizers representing a transition to a diseased state exhibited connective tissue and vascular invasion, and elicited a differential immune response accompanied by increased monocyte migration. The culture supernatants produced by the vascularized gingival CTEs in response to early and intermediate colonizers polarized macrophages towards an immunomodulatory M2-like phenotype which activates and protects the host, while the late colonizers polarized towards a pro-inflammatory M1-like phenotype. Lastly,in silicoanalysis showed a high strength of associations between the proteins and transcripts investigated with periodontitis and vascular diseases. In conclusion, the vascularized gingival CTEs provide a biomimeticin vitroplatform to study host-microbiome interactions and innate immune response in periodontal health and diseased states, which potentially paves the way toward the development and assessment of novel periodontal therapeutics.

Systemic Inflammation, Endothelial Function, and Risk of Periodontitis in Overweight/Obese Adults

The network interaction between systemic inflammatory mediators, endothelial cell adhesion function, and adiponectin as mediators of the association between metabolic diseases and periodontitis has not been evaluated. The objective of this study is to assess whether the interaction of baseline serum levels of TNF-α, hs-CRP, ICAM-1, VCAM-1, and adiponectin leads to periodontitis. Five hundred and ninety-seven overweight/obese (overweight: BMI 25 to <30 kg/m2; obese: >30 kg/m2) adults, aged 40-65 years, with complete 3-year follow-up data were included. Generalized structural equation models with negative binomial regression were used to estimate the regression coefficient (β) for the outcome number of teeth with probing pocket depth (PPD) ≥ 4 mm and bleeding on probing (BOP) at 3-year follow-up for a 1 standard deviation unit increase (Δ = +1SD) in each biomarker. After adjusting for multiple covariates, baseline ICAM-1 and VCAM-1 had significant direct effects on increased log-transformed number of teeth with PPD ≥ 4 mm and BOP (β: 0.16; 95% CI: 0.02-0.30; β: 0.15; 95% CI: 0.02-0.30, respectively). Baseline hs-CRP showed a significant indirect effect via ICAM-1 on the log-transformed number of teeth with PPD ≥ 4 mm and BOP (β: 4.84; 95% CI: 0.27-9.42). Thus, elevated serum ICAM-1 and VCAM-1 have a significant direct effect and increased hs-CRP has a significant indirect effect on the predicted level of periodontitis at the 3-year follow-up among overweight/obese Hispanic adults.

Periodontal Inflamed Surface Area (PISA) associates with composites of salivary cytokines

BACKGROUND

Periodontal disease (PerioD) is a chronic, complex inflammatory condition resulting from the interaction between subgingival dysbiotic bacteria and the host immune response leading to local inflammation. Since periodontal inflammation is characterized by multiple cytokines effects we investigated whether Periodontal Inflamed Surface Area (PISA), a continuous measure of clinical periodontal inflammation is a predictor of composite indexes of salivary cytokines.

METHODS AND FINDINGS

In a cross-sectional study of 67 healthy, well-educated individuals, we evaluated PISA and several cytokines expressed in whole stimulated saliva. Two salivary cytokine indexes were constructed using weighted and unweighted approaches based on a Principal Component Analysis [named Cytokine Component Index (CCI)] or averaging the (standardized) level of all cytokines [named Composite Inflammatory Index (CII)]. In regression analysis we found that PISA scores were significantly associated with both salivary cytokine constructs, (CCI: part R = 0.51, p<0.001; CII: part R = 0.40, p = 0.001) independent of age, gender and BMI showing that single scores summarizing salivary cytokines correlated with severity of clinical periodontal inflammation.

CONCLUSIONS

Clinical periodontal inflammation may be reflected by a single score encompassing several salivary cytokines. These results are consistent with the complexity of interactions characterizing periodontal disease. In addition, Type I error is likely to be avoided.

Salivary macrophage chemokines as potential biomarkers of gingivitis

OBJECTIVE

The present study aimed to analyze the salivary levels of macrophage-activating factor (MAF), macrophage-chemotactic factor (MCF), and macrophage migration inhibitory factor (MIF) in healthy and gingivitis patients, and to correlate between the concentrations of these chemo attractants with the intensity of gingival inflammation clinically.

METHODS

Sixty saliva specimens were collected from periodontally healthy (n = 30), and gingivitis patients (n = 30). Bleeding on probing (BOP), Visible Plaque Index (VPI), and Simplified Modified Gingival Index (SMGI) were recorded through clinical examination. Salivary MAF, MCF, and MIF concentrations were assayed using enzyme-linked immunosorbent assays (ELISA). Statistical analysis was performed using SPSS (version 28). Total mean score for each biomarker was determined, and descriptive bivariate statistics were conducted to characterize the levels of biomarkers among the study groups. The difference in the biomarker levels among the study groups were analyzed by independent sample t test and one-way ANOVA. The diagnostic ability of the biomarkers was further tested by ROC curve analysis.

RESULTS

Salivary levels of MAF was not significantly different between periodontally healthy individuals and gingivitis patients. The difference in MCF and MIF levels between patients with gingivitis and those with healthy periodontium was statistically significant (p 0.05 and p 0.001, respectively). When examined across the various stages of disease progression, MIF showed statistically significant difference among the three biomarkers (p 0.05). ROC curve analysis further revealed that area under the curve (AUC) for MIF has a better diagnostic capacity than MCF (AUC 0.981 vs. 0.673).

CONCLUSIONS

Our results suggest that MIF could be considered as a potential salivary biomarker for gingivitis.

Updates on immunological mechanistic insights and targeting of the oral lichen planus microenvironment

Oral lichen planus (OLP) is a chronic immune inflammatory disease that is an oral potentially malignant disorder (OPMD), occurs in the oral mucosa and affects approximately 0.5% to 4% of the general population. There are usually five types of OLP: reticular/papular, plaque-like, atrophic/erythematous, erosive/ulcerative, and bullous. Furthermore, the chance of causing oral squamous cell carcinoma (OSCC) is 1.4%. Although the etiology of OLP is still unknown, accumulating evidence supports that immune dysregulation may play a vital role in the pathogenesis of OLP, especially the massive production of various inflammatory cells and inflammatory mediators. In this review, we focus on the relationship between OLP and its immune microenvironment. We summarize current developments in the immunology of OLP, summarizing functional cell types and crucial cytokines in the OLP immune microenvironment and the underlying mechanisms of key signaling pathways in the OLP immune microenvironment. We highlight the application potential of targeted immune microenvironment therapy for OLP.

Sema3A Drives Alternative Macrophage Activation in the Resolution of Periodontitis via PI3K/AKT/mTOR Signaling

Macrophages actively participate in immunomodulatory processes throughout periodontal inflammation. Regulation of M1/M2 polarization affects macrophage chemokine and cytokine secretion, resulting in a distinct immunological status that influences prognosis. Semaphorin 3A (Sema3A), a neurite growth factor, exerts anti-inflammatory effects. In this study, we investigated the immunomodulation of Sema3A on macrophage-related immune responses in vivo and in vitro. Topical medications of Sema3A in mice with periodontitis alleviated inflammatory cell infiltration into gingival tissue and reduced areas with positive IL-6 and TNFα expression. We observed that the positive area with the M2 macrophage marker CD206 increased and that of the M1 macrophage marker iNOS decreased in Sema3A-treated mice. It has been postulated that Sema3A alleviates periodontitis by regulating alternative macrophage activation. To understand the mechanism underlying Sema3A modulation of macrophage polarization, an in vitro macrophage research model was established with RAW264.7 cells, and we demonstrated that Sema3A promotes LPS/IFNγ-induced M1 macrophages to polarize into M2 macrophages and activates the PI3K/AKT/mTOR signaling pathways. Inhibition of the PI3K signaling pathway activation might reduce anti-inflammatory activity and boost the expression of the inflammatory cytokines, iNOS, IL-12, TNFα, and IL-6. This study indicated that Sema3A might be a feasible drug to regulate alternative macrophage activation in the inflammatory response and thus alleviate periodontitis.

Validity of a combination of periodontal pathogens and salivary biomarkers as predictors of periodontitis

OBJECTIVE

Chronic periodontitis is caused by multiple risk factors. To predict chronic periodontitis in older people, we evaluated the association between a combination of major periodontal pathogens and salivary biomarkers and the presence of periodontitis.

METHODS

Stimulated saliva samples were collected to analyze the prevalence of Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, and Prevotella intermedia, as well as four biomarkers: interleukin (IL)-1β, IL-6, tumor necrosis factor-α (TNF-α), and prostaglandin E2 (PGE2). A total of 201 Japanese patients were recruited. Oral examinations ware performed to determine chronic periodontitis as measured by Community Periodontal Index. The sociodemographic and behavioral characteristics were also obtained, and the parameters were adjusted as potential confounders to employ statistical models.

RESULTS

The odds ratio (OR) for the presence of P. gingivalis and the third tertile level of IL-1β as compared with the absence of P. gingivalis and the lowest tertile of IL-1β was highest in individuals with periodontitis (OR = 13.98; 95% confidence interval [CI] 3.87-50.52) with the best level (0.79) of area under the curve (AUC) based on the receiver operating characteristic curve. The OR for the presence of P. gingivalis and the third tertile of PGE2 was 7.76 (CI 1.89-31.91) with an AUC of 0.78. The coexistence of more than two periodontal bacteria and the third tertile of PGE2 was also strongly associated with chronic periodontitis (OR = 9.23, 95% CI 2.38-35.79) with an AUC of 0.76.

CONCLUSIONS

The combined information of the presence of P. gingivalis in stimulated saliva, and higher levels of salivary IL-1β may play a vital role in the detection and prediction of chronic periodontitis in older adults.

Biphasic Functions of Sodium Fluoride (NaF) in Soft and in Hard Periodontal Tissues

Sodium fluoride (NaF) is widely used in clinical dentistry. However, the administration of high or low concentrations of NaF has various functions in different tissues. Understanding the mechanisms of the different effects of NaF will help to optimize its use in clinical applications. Studies of NaF and epithelial cells, osteoblasts, osteoclasts, and periodontal cells have suggested the significant roles of fluoride treatment. In this review, we summarize recent studies on the biphasic functions of NaF that are related to both soft and hard periodontal tissues, multiple diseases, and clinical dentistry.

Impact of Liability to Periodontitis on Glycemic Control and Type II Diabetes Risk: A Mendelian Randomization Study

While the association of periodontitis with Type II diabetes (T2DM) is well-established, the causal relationship remains uncertain. We examined the causal association of periodontitis with glycemic traits (HbA1c, fasting glucose, and fasting insulin) and T2DM using Mendelian randomization (MR) taking advantage of large genome-wide association studies of European and East Asian adults, i.e., the UK Biobank (n ≈ 350,000) (HbA1c), trans-ancestral MAGIC (HbA1c, fasting glucose, and insulin), and DIAMANTE (74,124 cases/824,006 controls), and AGEN for T2DM in Europeans and East Asians, respectively. Periodontitis was instrumented using single-nucleotide polymorphisms (SNPs), strongly and independently predicting liability to periodontitis in each ancestry group. SNP-specific Wald estimates were combined using inverse variance weighting. Sensitivity analyses were performed using the weighted median and MR-Egger with meta-analysis of MR estimates for Europeans and East Asians. Genetically instrumented liability to periodontitis was not associated with glycemic traits or T2DM in either ancestry or when ancestry specific estimates were meta-analyzed. Our findings do not support a causal association of liability to periodontitis with glycemic traits or T2DM. However, further research is required confirming these findings among other racial/ethnic groups, especially groups who carry a heavy burden of both periodontitis and T2DM.

Activation of GATA-binding protein 4 regulates monocyte chemoattractant protein-1 and chemotaxis in periodontal ligament cells

BACKGROUND AND OBJECTIVES

Periodontitis is a chronic inflammatory disease of periodontal supporting tissues. The persistent inflammatory reaction depends on the release of chemokines to continuously recruit inflammation cells. GATA-binding protein 4 (GATA4) exerts effects on senescence and inflammation, while its role in periodontitis is far from clear. The present study aims to address the effect of GATA4 on regulating chemokines and the chemotaxis in periodontitis.

MATERIAL AND METHODS

Periodontitis rat models were constructed to detect the expression of GATA4 and the chemokine monocyte chemoattractant protein-1 (MCP-1) by immunohistochemistry. Lipopolysaccharide (LPS)-stimulated human periodontal ligament (PDL) cells and GATA4-knockdown by siRNA transient transfection PDL cells were used to explore the correlation between GATA4 and chemokines. Transwell assay was performed to detect the role of GATA4 for the recruitment effect of chemokines on macrophages. Mitogen-activated protein kinase (MAPK) inhibitors were scheduled to intervene in LPS-stimulated PDL cells to examine the association between MAPK signaling pathways and GATA4. The expression of GATA4, chemokines, or MAPK signaling molecules was determined by quantitative real-time polymerase chain reaction, western blotting, or cell immunofluorescence.

RESULTS

The expression of GATA4 and MCP-1 was significantly increased in periodontitis rat models and in LPS-stimulated PDL cells. Knockdown GATA4 inhibited the expression of GATA4 and MCP-1 as well as suppressed the recruitment of macrophage in LPS-stimulated PDL cells. Inhibitors of p38 and ERK1/2 signaling pathways significantly downregulated the increased expression of GATA4 and MCP-1 induced by LPS in PDL cells.

CONCLUSIONS

GATA-binding protein 4 could act as an upstream regulator of MCP-1 and as a downstream regulator of p38 and ERK1/2 signaling pathways to initiate inflammation response and regulate chemotaxis during the progression of periodontitis.

Pathophysiological association between periodontal disease and Alzheimer's disease: Importance of periodontal health in the elderly

BACKGROUND

As the global aging population is rapidly advancing, recognizing the full potential of periodontal disease (PD) in the onset or progression of Alzheimer's disease (AD) is important for reducing geriatric morbidity. This review explores the possible role of PD in the pathogenesis of AD, as the pathological mechanisms underlying AD are the most well-studied among all types of dementia. The investigation was conducted using the electronic academic databases PubMed and ScienceDirect, employing a combination of keywords "periodontal disease," "periodontitis," "Alzheimer's disease," "dementia," and "Porphyromonas gingivalis." After applying the selection and eligibility criteria and removing overlaps, from an initial search finding of 5933 studies, 11 were finally included for qualitative analysis.

HIGHLIGHT

The inflammatory reaction induced by oral pathogenic bacteria related to PD, through complex pathways, may exacerbate inflammation in the central nervous system, thereby contributing to the progression of AD.

CONCLUSION

Maintenance of adequate oral hygiene in patients diagnosed with AD is significant because they suffer from a gradual loss of manual dexterity as the disease advances. Additionally, the evidence presents the potential of systemic inflammation from PD-induced pathogenic bacteria, illustrating the grave cyclical progression of AD.

Influence of the treatment with the antineoplastic agents 5-fluorouracil and cisplatin on the severity of experimental periodontitis in rats

PURPOSE

The determination on how antineoplastic agents interfere on the progression of periodontitis is critical for improvement and even development of novel therapeutic approaches for periodontal management. This study evaluated the influence of chemotherapy with 5-fluorouracil (5-FU) or cisplatin (CIS) on healthy periodontal tissues and on the progression of experimental periodontitis (EP).

METHODS

One hundred forty-four male rats were divided into six groups (n = 24). Each group was treated with physiological saline solution (PSS) 0.9%, 5-FU, or CIS. Experimental periodontitis (EP) was induced by ligature placement. Animals were euthanized at 7, 15, and 30 days after treatment. Data were statistically analyzed (p ≤ 0.05).

RESULTS

The groups with EP and treated with 5-FU or CIS showed lower percentage of bone volume in the furcation region and higher percentage of alveolar bone loss, higher number of TRAP-positive cells, and lower number of PCNA-positive cells when compared group with EP and treated with PSS (p ≤ 0.05). Groups with EP and treated with 5-FU or CIS showed high immunolabelling pattern of RANKL, TNF-α, and IL-1β, moderate of BAX, and low of HIF-1α. Histological analysis showed severe tissue breakdown in the groups with EP and treated with 5-FU or CIS.

CONCLUSIONS

Chemotherapy with antineoplastic agents 5-FU and CIS increased the intensity and duration of the inflammation and compromised tissue repair by reduction in cellular and vascular turnover. The more severe periodontal breakdown was caused by 5-FU.

Association between hepatic and systemic inflammation and localized stage II/III periodontitis in young males: The CHIEF Oral Health study

AIM

To clarify the role of systemic inflammation in the associations between hepatic inflammation and localized periodontitis, which were conflicting among races.

MATERIALS AND METHODS

The study included 1112 military personnel (males), aged 18-40 years, in Taiwan. Localized periodontitis was classified into healthy/stage I (n = 796) and stage II/III (n = 316) according to the 2017 criteria. Systemic and hepatic inflammation were defined by the greatest tertiles of blood leukocyte counts (7.51 × 10³ /μl) and alanine aminotransferase (30 U/L), respectively. Multiple logistic regression analysis with adjustments for age, metabolic syndrome, betel nut consumption, and smoking were utilized to determine the associations.

RESULTS

There was a significant association between having a high systemic inflammation, whatever the hepatic inflammation severity, and the risk of having a localized stage II/III periodontitis (odds ratio [OR]: 1.62 [1.09-2.42] and 1.47 [1.00-2.15], respectively, for the presence of a high hepatic inflammation or not). However, no significant association was found among participants with low systemic inflammation, whatever the hepatic inflammation severity (OR: 1.31 [0.91-1.91]).

CONCLUSIONS

An association between hepatic inflammation and localized periodontitis in Taiwanese was observed only if systemic inflammation co-existed, possibly accounting for the racial difference in the association significantly reported in Japanese but not in non-Asian populations in prior studies.

The -592C>A Variation of IL-10 Gene and Susceptibility to Chronic Periodontitis: A Genetic Association Study and In-Silico Analysis

OBJECTIVES

Chronic periodontitis (CP) is a common inflammatory disorder with a considerable impact of genetic variations in the interleukin family on predisposition to this disease. This study aimed to investigate the association between the -592C>A polymorphism of the interleukin 10 (IL-10) gene with CP risk in an Iranian population. This experimental study was followed by a meta-analysis and in silico examination.

METHODS

In a case-control study, 270 subjects, including 135 patients with CP and 135 healthy controls, were enrolled. The -592C>A genotyping was performed using the PCR-RFLP method. In the meta-analysis, valid databases were systematically searched to identify relevant studies. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were computed to examine the association between -592C>A and CP. In silico analysis was conducted using bioinformatics tools to evaluate the impact of the -592C>A polymorphism on IL-10 gene function.

RESULTS

Our case-control study revealed a significant association between polymorphism and CP risk. Overall, we found significant associations between -592C>A genetic variation and CP and stratified meta-analysis. In silico analysis revealed that this polymorphism could change the pattern of the transcription binding site upstream of the IL-10 gene. It may also alter the hsa-miR-101-3p miRNA-targeted sequence upstream of IL-10.

CONCLUSIONS

Based on our results, the -592C>A variation in IL-10 may be a genetic risk factor for susceptibility to chronic periodontitis. However, further studies in different ethnicities and results adjusted for clinical and demographic characteristics are needed to obtain more accurate deductions.

Impact of calorie restriction and intermittent fasting on periodontal health

The scientific evidence indicates that calorie restriction and intermittent fasting are among the appropriate strategies targeting factual causative factors of various inflammatory and lifestyle-related disorders. Periodontitis is a common oral inflammatory disease leading to bone loss that is associated with various systemic problems. Previous studies suggest that calorie restriction may dampen inflammation and concomitant tissue damage under inflammatory conditions, such as periodontal diseases in nonhuman primates. However, insufficient research has been carried out to assess the effects of a calorie-restricted diet on the initiation and progression of periodontal disease in humans. This review of the literature aims to describe the general concepts of calorie restriction, its clinical implications, and related therapeutic potential in controlling periodontal inflammation. The review shows that fasting regimen groups have shown lesser bone loss because of an increase in osteoprogenitor cells than non-fasting groups. Calorie restriction dampens the inflammatory response and reduces circulating inflammatory mediators like tumor necrosis factor-alpha, interleukin-6, matrix metalloproteinase-8, matrix metalloproteinase-9, and interleukin-1-beta in gingival crevicular fluid. However, the incorporation of this form of dietary intervention continues to be challenging in our current society, in which obesity is a major public concern. Calorie restriction and intermittent fasting can play a key role in the cost-effective resolution of periodontal inflammation as a primary prevention strategy for the management of chronic inflammatory diseases, including periodontal diseases.

Levels of myeloid-related proteins in saliva for screening and monitoring of periodontal disease

AIM

To evaluate the salivary levels of myeloid-related markers in relation to periodontal disease and their potential screening capability, as well as the effects of periodontal treatment on these markers in periodontitis patients.

MATERIALS AND METHODS

Participants with a healthy periodontium (n = 60) and with gingivitis (n = 63) and periodontitis (n = 72) were recruited. Periodontitis patients received non-surgical treatment and were re-examined after 3 and 6 months. Unstimulated saliva was collected at baseline and at 1, 3, and 6 months after therapy for the periodontitis patients. Levels of colony-stimulating factor-1 (CSF-1), interleukin-34 (IL-34), S100A8/A9, S100A12, hepatocyte growth factor (HGF), IL-1β, and matrix metalloproteinase-8 (MMP-8) were analysed by immunoassays.

RESULTS

CSF-1, S100A8/A9, S100A12, IL-1β, MMP-8, and HGF were significantly elevated in saliva from periodontitis and gingivitis patients in comparison to healthy individuals, whereas IL-34 was significantly lower in periodontitis compared to both healthy individuals and gingivitis patients. IL-34 increased significantly 3 months after treatment, while IL-1β and MMP-8 decreased 1 month after therapy. Additionally, periodontitis patients clustered in high and low levels of S100A8/A9, whereby those with high levels had more bleeding, deeper pockets, and higher S100A12.

CONCLUSIONS

Salivary levels of myeloid-related markers are altered in periodontitis and are partially modulated by periodontal treatment. Measuring S100A8/A9 in saliva may identify distinct groups of periodontitis patients.

Human gingiva-derived mesenchymal stem cells promote osteogenic differentiation through their immunosuppressive function

OBJECTIVES

Human gingiva-derived mesenchymal stem cells (GMSCs) have emerged as a new MSC population exhibiting robust immune regulatory functions, multipotent differentiation potential, and regenerative ability. However, the effects of GMSCs on T cells remain unexplored. Herein, we aimed to evaluate whether GMSCs promote osteogenic differentiation by regulating immune cells.

METHODS

The GMSC phenotype was confirmed using the colony-forming assay, immunophenotyping, Oil red O staining, and Alizarin red staining. mRNA expression levels of proinflammatory molecules (interleukin-1β [IL-1β] and tumor necrosis factor-α [TNF-α]) and anti-inflammatory factors (IL-10) were measured by quantitative reverse-transcription PCR (qRT-PCR). Then, MC3T3-E1 cells were treated with the collected co-culture supernatant, followed by alkaline phosphatase (ALP) and immunofluorescence staining to evaluate osteogenic differentiation of MC3T3-E1 cells. qRT-PCR and western blotting were employed to analyze the expression levels of osteogenic differentiation proteins, including collagen type I (COL-1), ALP, osteopontin (OPN), and runt-related transcription factor 2 (RUNX2).

RESULTS

GMSCs were successfully isolated and identified. We observed that GMSCs suppressed the activated T-cell function by downregulating IL-1β and TNF-α and upregulating IL-10. Simultaneously, the expression levels of osteogenesis-related genes (COL-1, ALP, OPN, and RUNX2) were markedly lower in the co-culture supernatant and Jurkat T cell supernatant groups than those in the normal culture medium group; however, expression levels were significantly increased in the co-culture supernatant group when compared with the Jurkat T cell supernatant group.

CONCLUSION

Our findings indicate that GMSCs could promote the osteogenic differentiation of MC3T3-E1 cells by inhibiting the biological activity of activated T cells.

Central Regulatory Role of Cytokines in Periodontitis and Targeting Options

BACKGROUND

Periodontitis is an immune-inflammatory disease that leads to the progressive destruction of bone and connective tissue in the periodontal area. The cytokine network plays a primary role in tissue homeostasis, the recruitment of immune cells to control the pathogenic impact and the regulation of osteoclastic function, thus modulating the intensity and duration of the immune response. This review provides an update on the main cytokines implicated in the pathogenesis and progression of periodontitis and their targeting potential in order to enrich current treatment options.

METHODS

A structured search of bibliographic databases (PubMed, MEDLINE, Scopus) was performed for peer-reviewed cytokine studies focused on periodontitis the last ten years. A qualitative content analysis was performed in screened papers and a critical discussion of main findings is provided.

RESULTS

An altered cytokine profile has been detected in periodontitis patients and the interplay of pro-inflammatory and/or anti-inflammatory cytokines has been associated with disease pathogenesis. Among the most prominent pro-inflammatory cytokines, TNF-α, IL-1β, IL-17, IL-6 and the chemokines CXCL-6, CXCL-8 are overexpressed in periodontitis patients and correlate with disease progression. On the other hand, the anti-inflammatory IL-4 and IL- 11 levels are reduced while IL-12 and IFN-γ expression play a dual role in periodontal disease. Current periodontitis treatment strategies include selective antibiotics, antimicrobial photodynamic therapy and probiotics, which can modulate the cytokine network and when applied in combination with specific anti-cytokine agents can exert additional beneficial effects.

CONCLUSION

It is evident that cytokines play a central regulatory role in the inflammatory process and immune cell response that underlies bone destruction in periodontitis. Specific cytokine targeting should be considered as a complementary therapeutic scheme to current periodontal management.

Cytokines in gingival crevicular fluid in elderly rheumatoid arthritis patients in a population-based cross-sectional study: RANTES was associated with periodontitis

Objective

We studied cytokines in gingival crevicular fluid (GCF) in a cross‐sectional population‐based cohort of rheumatoid arthritis (RA) patients ≥61 years of age with and without a diagnosis of periodontitis.

Background data

Earlier studies on cytokines in GCF in RA patients have not given clear results.

Methods

In a population‐based cross‐sectional study of patients ≥61 years of age, 233 RA patients were identified. 132 (57%) dentate RA patients participated. All participants received rheumatological and dental examinations, and had a panoramic radiograph taken. GCF was sampled on each patient. Interleukins 1‐β (IL‐1β), IL‐4, IL‐6, IL‐10, IL‐17A, tumor necrosis factor alpha (TNF‐α), interferon gamma (IFN‐γ), and chemokines RANTES/CCL5, eotaxin and monocyte chemoattractant protein (MCP‐1) were analyzed in GCF. These cytokines were stratified for periodontitis, age, gender, body mass index (BMI), smoking, and anti‐cyclic citrullinated protein (anti‐CCP) status. Binary logistic regression analyses with periodontitis as outcome were performed adjusting for the above mentioned confounding factors including anti‐rheumatic medication, disease duration and the cytokine in question.

Results

Periodontitis was diagnosed in 80/132 (61%) of study participants. The 110 RA patients not participating were older, had a higher mean erythrocyte sedimentation rate (ESR), had a higher mean DAS28ESR (Disease Activity Score 28 using ESR) and were less often on biologic treatment. Only RANTES was associated with periodontitis (p = .049, OR 1.001, 95% CI 1.000–1.002) in the binary logistic regression analyses.

Conclusion

In this population‐based elderly RA cohort, neither pro‐inflammatory nor anti‐inflammatory cytokines in GCF were clearly associated with a diagnosis of periodontitis.

Fermented milk with Lactobacillus curvatus SMFM2016-NK alleviates periodontal and gut inflammation, and alters oral and gut microbiota

This study aimed to analyze the effect of milk fermented with Lactobacillus curvatus SMFM2016-NK on periodontal diseases and gut health in a rat model. To improve the effect of Lb. curvatus SMFM2016-NK-fermented milk administration for relieving periodontitis, the periodontitis rat models were treated with the following for 4 wk: 10% skim milk (normal), periodontitis + 10% skim milk (negative control), periodontitis + Lactobacillus rhamnosus GG-fermented milk (positive control), and periodontitis + Lb. curvatus SMFM2016-NK-fermented milk (PD+LCFM). Transcriptional analysis of inflammatory cytokines [tumor necrosis factor α (TNF-α), IL-1β, IL-6, and IL-10] was performed via quantitative reverse-transcription PCR. The changes in the oral and gut microbiomes after administering Lb. curvatus SMFM2016-NK-fermented milk were analyzed with metagenomics sequencing using DNA extracted from the oral gingival tissues and feces from the cecum of the rat models. After treatment with Lb. curvatus SMFM2016-NK-fermented milk, the relative gene expression levels of TNFA and IL1B in the gingiva decreased in the PD+LCFM group compared with those in the negative control group. In the oral microbiome, the proportion of the phylum Proteobacteria in the PD+LCFM group was lower than that in the negative control after treatment with Lb. curvatus SMFM2016-NK-fermented milk. For the effect in the gut, the relative gene expression levels of inflammatory cytokines in the colon between the normal and negative control groups were not different; however, the expression levels of TNFA and IL1B in the PD+LCFM and positive control groups, respectively, were lower than those in the negative control group. The composition and diversity of the gut microbiome differed among normal, periodontitis, and Lb. curvatus SMFM2016-NK-fermented milk treatment groups. These results indicate that Lb. curvatus SMFM2016-NK-fermented milk could alleviate periodontal and gut inflammation and change oral and gut microbiota.

The trefoil factor family 1 (TFF-1) and 3 (TFF-3) are upregulated in the saliva, gingival crevicular fluid and serum of periodontitis patients

OBJECTIVE

This study aimed to investigate the levels of trefoil factor family (TFF)-1, TFF-3 and interleukin (IL)-1β in gingival crevicular fluid (GCF), saliva and serum of patients with gingivitis, stage 3 periodontitis and healthy individuals.

MATERIALS AND METHODS

A total of 100 individuals consisting of 25 periodontally healthy, 25 gingivitis and 50 stage 3 periodontitis, were enrolled in the study. Clinical periodontal examinations were recorded and GCF, saliva and serum samples were obtained. TFF-1, TFF-3 and IL-1β were measured by ELISA.

RESULTS

TFF-1 and TFF-3 levels in both GCF, saliva and serum were higher in periodontitis patients than healthy controls (p < .001) and gingivitis group (p < .01). The levels of these peptides in all biofluids were similar between gingivitis and healthy control groups (p > .05). GCF, saliva and serum IL-1β levels were also higher in periodontitis patients than the controls (p < .01). Periodontitis patients had elevated GCF and saliva IL-β levels than gingivitis group (p < .001).

CONCLUSION

Elevated TFF-1 and TFF-3 levels both locally and systemically in periodontitis in parallel to increased IL-1β levels might suggest that these peptides are involved in host response during the periodontal tissue destruction.

Pro-inflammatory cytokine interleukin-6-induced hepcidin, a key mediator of periodontitis-related anemia of inflammation

OBJECTIVES

To investigate whether anemia of inflammation (AI) occurs in periodontitis patients and to further explore underlying pathogenesis of periodontitis-related AI by an experimental periodontitis model.

BACKGROUND

Previous studies have reported periodontitis patients could show a tendency toward AI. However, the relationship between periodontitis and AI remains unclear, and the related pathological mechanisms have not been identified.

MATERIALS AND METHODS

Periodontal clinical parameters, inflammatory markers, and anemia-related indicators were compared between 98 aggressive periodontitis (AgP) patients and 103 healthy subjects. An experimental periodontitis model was induced by ligature placement in mice. The changes in mice inflammatory markers, anemia indicators, hepcidin mRNA expression, and serum hepcidin concentrations were measured. Human and mouse liver cells were treated with interleukin-6 (IL-6) for analyzing the changes in hepcidin expression based on mRNA and protein levels.

RESULTS

AgP patients exhibited higher white blood cell counts, IL-6, and C-reactive protein. Adjusted linear regression analyses showed correlations between AgP and decreased hemoglobin (HGB) and hematocrit (HCT). The ligature-induced periodontitis caused systemic inflammation and elevated IL-6 levels. Lower red blood cell counts, HGB, and HCT were detected, whereas the levels of hepcidin mRNA expression and serum hepcidin concentrations increased. The treatment of hepatocytes with IL-6 induced both hepcidin mRNA expression and hepcidin secretion.

CONCLUSIONS

Systemic inflammation induced by periodontitis leads to an increased risk for AI. IL-6-induced hepcidin could play a central mediator role and act as a key pathologic mechanism. Our results demonstrate periodontitis may be considered as an additional inflammatory disease contributing to the development of AI.

Resveratrol and Its Analogs as Functional Foods in Periodontal Disease Management

Periodontitis is a common chronic inflammatory disease driven by the interaction between a dysbiotic oral microbiome and the dysregulated host immune-inflammatory response. Naturally derived nutraceuticals, such as resveratrol and its analogs, are potential adjunctive therapies in periodontal treatment due to their antimicrobial and anti-inflammatory properties. Furthermore, different analogs of resveratrol and the choice of solvents used may lead to varying effects on therapeutic properties. This review presents the current findings and gaps in our understanding on the potential utility of resveratrol and its analogs in periodontal treatment.

Specific inhibition of IL-6 receptor attenuates inflammatory bone loss in experimental periodontitis

BACKGROUND

Periodontal pathogenesis takes into consideration that disease results from a complex inflammatory immune response. Among the major cytokines related to periodontal damage, interleukin (IL)-6 enhances a cascade of tissue destruction. Tocilizumab (TCZ) is a humanized monoclonal anti-human IL-6 receptor that inhibits IL-6-mediated proinflammatory activity. This study aimed to elucidate whether TCZ inhibits the deleterious effect of ligature-induced periodontitis.

METHODS

Experimental ligature-induced periodontitis was treated with systemic administration of TCZ intraperitoneally in three different concentration dosages (2 mg/kg, 4 mg/kg, and 8 mg/kg. Euthanasia occurred at 7 and 14 days after the initiation of the study. Local changes in the alveolar bone were measured by bone volume, the ratio of bone volume, and trabecular thickness using microcomputed tomography. Attachment loss and inflammatory infiltrate were evaluated by histology. Immune response was analyzed focusing on the Th17 pattern.

RESULTS

TCZ inhibited alveolar bone resorption and attachment loss in 7 and 14 days for all dosage groups in comparison to controls (P  < 0.05). Besides, TCZ induced lower expression of inflammatory infiltrate (P <0.05) and less production of Th17-related cytokines (P <0.05) and RANKL (P <0.05).

CONCLUSIONS

The inhibition of IL-6-mediated proinflammatory activity by IL-6R blocking reduced alveolar bone resorption and attachment loss supported by the modulation of the Th17 periodontal response. Considering the inflammatory status, modulatory therapy may be a promising approach to periodontal disease.

Periodontitis Deteriorates Cognitive Function and Impairs Neurons and Glia in a Mouse Model of Alzheimer's Disease

BACKGROUND

Although periodontitis is reportedly associated with increased cognitive decline in Alzheimer's disease, the mechanisms underlying this process remain unknown. Porphyromonas gingivalis lipopolysaccharide (P.g-LPS) is an endotoxin associated with periodontal disease.

OBJECTIVE

We investigated the effect of periodontitis on learning capacity and memory of amyloid-β protein precursor (AβPP)/presenilin (PS1) transgenic mice along with the mechanisms underlying these effects.

METHODS

Mice were randomly assigned to three groups, namely AβPP/PS1 (control), P.g-LPS Injection, and P.g-LPS Injection + Ligation. Mice from the P.g-LPS Injection group were injected with P.g-LPS in the periodontal tissue three times per week for 8 weeks, while mice from the P.g-LPS Injection + Ligation group were injected with P.g-LPS and subjected to ligation of the gingival sulcus of the maxillary second molar.

RESULTS

Expression of gingival proinflammatory cytokines as well as alveolar bone resorption in P.g-LPS-injected and ligatured mice was increased compared to that in control mice. Mice in the P.g-LPS Injection + Ligation group exhibited cognitive impairment and a significant reduction in the number of neurons. Glial cell activation in the experimental groups with significantly increased amyloid-β (Aβ) levels was more pronounced relative to the control group. Induction of periodontitis was concurrent with an increase in cyclooxygenase-2, inducible nitric oxide synthase, AβPP, and beta-secretase 1 expression and a decrease in A disintegrin and metalloproteinase domain-containing protein 10 expression.

CONCLUSION

These findings indicated that periodontitis exacerbated learning and memory impairment in AβPP/PS1 mice and augmented Aβ and neuroinflammatory responses. Our study provides a theoretical basis for risk prediction and early intervention of Alzheimer's disease and periodontitis.

Treatment of localized aggressive periodontitis alters local host immunoinflammatory profiles: A long-term evaluation

AIM

To evaluate the local immunoinflammatory profiles in localized aggressive periodontitis patients (LAP) before and after periodontal treatment and maintenance.

METHODS

Sixty-six African-Americans with LAP (7-21 years old) were included. After periodontal examination, all patients received periodontal treatment with mechanical debridement plus systemic amoxicillin/metronidazole for 7 days. Gingival crevicular fluid was collected from diseased and healthy sites at baseline and 3, 6, 12, and 24 months following treatment. Levels of 16 inflammatory/bone resorption markers were determined using Milliplex^® . Univariate and correlation analyses were performed among all parameters/biomarkers. Discriminant analyses (DA) evaluated profile differences between LAP diseased and healthy sites at each time point as compared to the baseline.

RESULTS

Reductions in the clinical parameters (except for visible plaque) were observed at all time points compared to the baseline. Levels of IL-12p70, IL-2, IL-6, MIP-1α, RANKL, and OPG were reduced after treatment, and several cytokines/chemokines were correlated with clinical parameters reductions. DA showed that differences in the immunoinflammatory profiles between LAP diseased and healthy sites decreased after periodontal treatment compared to the baseline.

CONCLUSIONS

Periodontal treatment modified the local immunoinflammatory profile of LAP sites in the long term, as suggested by changes in biomarkers from baseline, along with clinical stability of the disease. (Clinicaltrials.gov number, NCT01330719).

Effect of Subantimicrobial Dose Doxycycline Treatment on Gingival Crevicular Fluid Levels of MMP-9 and MMP-13 in Periodontitis Stage 2, Grade B in Subjects with Type 2 Diabetes Mellitus

The aim of this study was to investigate the effect of using subantimicrobial dose doxycycline as an adjunct in periodontitis stage 2, grade B in subjects with type 2 diabetes mellitus. A total of thirty patients were divided into the following two groups with reference to periodontitis, type 2 diabetes mellitus, and administration of the doxycycline drug: Group I: patients with periodontitis stage 2, grade B and type 2 diabetes mellitus who received SRP only. Group II: patients with periodontitis stage 2, grade B and type 2 diabetes mellitus who received SRP and doxycycline 20 mg. The following clinical measurements were recorded at baseline (prior to scaling and root planning) and after one and three months postoperatively: GI, PI, and PD with a periodontal calibrated probe. The levels of both MMP-9 and MMP-13, from 60 GCF samples, were analyzed by ELISA. Patients treated with SRP and doxycycline 20 mg showed a significant reduction of PD, PI, GI, MMP-9, and MMP-13 than patients who received SRP only. Improvements in parameters clinically and biochemically were observed following the adjunctive use of doxycycline subantimicrobial dose therapy for the management of stage 2, grade B periodontitis patients with type 2 diabetes mellitus.

Oral P. gingivalis impairs gut permeability and mediates immune responses associated with neurodegeneration in LRRK2 R1441G mice

Background

The R1441G mutation in the leucine-rich repeat kinase 2 (LRRK2) gene results in late-onset Parkinson’s disease (PD). Peripheral inflammation and gut microbiota are closely associated with the pathogenesis of PD. Chronic periodontitis is a common type of peripheral inflammation, which is associated with PD. Porphyromonas gingivalis (Pg), the most common bacterium causing chronic periodontitis, can cause alteration of gut microbiota. It is not known whether Pg-induced dysbiosis plays a role in the pathophysiology of PD.

Methods

In this study, live Pg were orally administrated to animals, three times a week for 1 month. Pg-derived lipopolysaccharide (LPS) was used to stimulate mononuclear cells in vitro. The effects of oral Pg administration on the gut and brain were evaluated through behaviors, morphology, and cytokine expression.

Results

Dopaminergic neurons in the substantia nigra were reduced, and activated microglial cells were increased in R1441G mice given oral Pg. In addition, an increase in mRNA expression of tumor necrosis factor (TNF-α) and interleukin-1β (IL-1β) as well as protein level of α-synuclein together with a decrease in zonula occludens-1 (Zo-1) was detected in the colon in Pg-treated R1441G mice. Furthermore, serum interleukin-17A (IL-17A) and brain IL-17 receptor A (IL-17RA) were increased in Pg-treated R1441G mice.

Conclusions

These findings suggest that oral Pg-induced inflammation may play an important role in the pathophysiology of LRRK2-associated PD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-020-02027-5.

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.

Leucine-rich alpha-2 glycoprotein (LRG): A novel acute phase protein expressed in Stage 3 Grade C periodontitis before and after periodontal therapy

BACKGROUND

Leucine-rich alpha-2 glycoprotein (LRG) is a novel acute phase protein involved in inflammation-associated diseases and that considered to be induced by multiple proinflammatory cytokines. This study aimed to investigate gingival crevicular fluid (GCF) and serum levels of LRG, interleukin (IL)-6 and tumor necrosis factor (TNF)-α in patients with Stage 3 periodontitis before and after non-surgical periodontal treatment.

METHODS

Twenty-five Stage 3 periodontitis and twenty-five periodontally healthy individuals were enrolled in the study. Clinical periodontal measurements were recorded; periodontitis patients received non-surgical periodontal treatment, and GCF and serum samples were obtained at baseline and at 6 weeks after treatment. LRG, IL-6 and TNF-α were determined by ELISA.

RESULTS

GCF and serum LRG, IL-6 and TNF-α were significantly higher in periodontitis group than healthy controls (P < .001). A significant decrease in GCF and serum LRG, IL-6 and TNF-α was detected after periodontal treatment compared with baseline values of periodontitis patients (P < .001).

CONCLUSION

Our findings revealed that LRG expression was increased in Stage 3 periodontitis both locally and systemically, and non-surgical periodontal therapy was effective in reducing LRG levels in GCF and serum of these patients.

Management of periodontal disease in patients with diabetes- good clinical practice guidelines: A joint statement by Indian Society of Periodontology and Research Society for the Study of Diabetes in India

There is a huge body of literature suggesting an association and a bidirectional relationship between periodontal disease and diabetes. Diabetes and periodontal diseases are both chronic diseases with a high prevalence. Dentists/periodontists, in their daily clinical practice, very often attend to diabetes patients with diverse oral health conditions and cater to their dental treatment needs. Safe and effective periodontal therapy in this population requires a broad understanding of diabetes, medical management of diabetes, and essential modifications to dental/periodontal therapy that may be required. This paper describes a joint statement put forth by the Indian Society of Periodontology and the Research Society for the Study of Diabetes in India aiming to provide expert consensus and evidence-based guidelines for optimal clinical management of periodontal conditions in diabetes patients or patients at risk for diabetes. Although this paper is not envisioned to be a comprehensive review of this topic, it intends to provide the guidelines for dental professionals and periodontists.

Defining Metaniches in the Oral Cavity According to Their Microbial Composition and Cytokine Profile

The human oral microbiota consists of over 700 widespread taxa colonizing the oral cavity in several anatomically diverse oral niches. Lately, sequencing of the 16S rRNA genes has become an acknowledged, culture-independent method to characterize the oral microbiota. However, only a small amount of data are available concerning microbial differences between oral niches in periodontal health and disease. In the context of periodontitis, the cytokine expression in the gingival crevicular fluid has been studied in detail, whereas little is known about the cytokine profile in hard and soft tissue biofilms. In order to characterize oral niches in periodontal health, the oral microbiota and cytokine pattern were analyzed at seven different sites (plaque (P), gingival crevicular fluid (GCF), saliva (S), tongue (T), hard palate (HP), cheek (C) and sublingual area (U)) of 20 young adults using next-generation sequencing and multiplex immunoassays. Site-specific microbial compositions were detected, which clustered into three distinct metaniches ("P-GCF", "S-T-HP" and "C-U") and were associated with niche-/metaniche-specific cytokine profiles. Our findings allow the definition of distinct metaniches according to their microbial composition, partly reflected by their cytokine profile, and provide new insights into microenvironmental similarities between anatomical diverse oral niches.

Silencing matrix metalloproteinase-13 (Mmp-13) reduces inflammatory bone resorption associated with LPS-induced periodontal disease in vivo

OBJECTIVES

The aim of this study was to evaluate the effect of specific inhibition of MMP-13 on inflammation and inflammatory bone resorption in a murine model of lipopolysaccharide (LPS)-induced periodontitis.

MATERIALS AND METHODS

Periodontitis was induced in mice by micro-injections of LPS into the gingival tissues adjacent to the palatal surfaces of maxillary molars twice a week for 15 days. Matrix metalloproteinase-13 (Mmp-13) shRNA or a specific biochemical inhibitor were also injected into the same sites in alternating days with the LPS injections. Efficacy of shRNA-mediated silencing of Mmp-13 was verified by quantitative real-time polymerase chain reaction (qPCR) and immunoblot. Bone resorption was assessed by microcomputed tomography (uCT). Histological sections stained with hematoxylin/eosin (H/E) were used in the stereometric analysis of the inflammatory infiltrate. Gingival tissues were used to evaluate expression of Mmp-13, Il-6, Tnf-α, Ptgs2, and Rankl (qPCR). Protein levels of TGF-β and IL-10 in the tissues were determined by enzyme-linked immunosorbent assays (ELISA) or by MMP-13 and p38 immunoblot.

RESULTS

Silencing Mmp-13 expression reduced bone resorption significantly. Expression of Mmp-13, Il-6, and Tnf-α, as well as the protein levels of IL-6 and TNF-α, was reduced in the animals treated with adenovirus-delivered shRNA; however, these effects were not associated with modulation of p38 MAPK signaling. Interestingly, inhibition Mmp-13 did not affect the severity of inflammatory infiltrate.

CONCLUSIONS

Site-specific inhibition of MMP-13 reduced bone resorption and production of inflammatory mediators associated with periodontal disease.

CLINICAL RELEVANCE

The results suggest that site-specific inhibition of MMP-13 may be an interesting strategy to modulate inflammation and reduce bone resorption in osteolytic inflammatory diseases.

Adjunctive Antiseptic Irrigation of Periodontal Pockets: Effects on Microbial and Cytokine Profiles

To evaluate the effect of adjunctive antiseptic irrigation of periodontal pockets on microbial and cytokine profiles. Fifty-nine patients with severe periodontitis were allocated to one of three groups for scaling and root planing facilitated with different adjunctive antiseptics: 1% polyhexamethyleneguanidine phosphate (PHMG-P) (n = 19), 0.2% chlorhexidine (CHX) (n = 21) or distilled water (n = 19). Gingival crevicular fluid and subgingival bacterial samples were collected at baseline, and at 2 weeks, and 1 and 4 months. The levels of interleukin (IL)-1β, IL-8, IL-10, and IL-17A, matrix metalloproteinase (MMP)-8, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Fusobacterium nucleatum,Aggregatibacter actinomycetemcomitans, and Prevotella intermedia were determined. There were no intergroup differences in cytokine concentrations and bacterial counts at any follow-up, however, varying patterns were observed. In the PHMG-P and water groups IL-1β expression peaked at 2 weeks and then gradually declined. In all three groups, the dynamics of MMP-8 concentration were non-linear, increasing by 2 weeks and then declining to below baseline (p > 0.05). P. gingivalis and T. forsythia declined within the first month and increased thereafter, not regaining the baseline level. Adjunctive antiseptic treatment was associated with changes in biomarkers and bacterial counts in the course of the study. The effects of adjunctive antiseptic irrigation were limited in the applied protocol.