Inflammatory and immune pathways in the pathogenesis of periodontal disease

Periodontal disease and sports performance: a systematic review and meta-analysis

This systematic review and meta-analysis aimed to assess the association between athletic performance and periodontal disease (PD). Observational studies published up to April 2022 were searched in online databases (PubMed, Scopus, Web of Science, The Cochrane Library, LILACS, OpenGrey, and Google Scholar). PECO statement focused on studies with professional athletes (Participants) with PD (Exposition) compared to those with healthy periodontium (Comparison) and its effects on sports performance (outcome). Searches were conducted according to the PRISMA guidelines (registration protocol: 10.17605/OSF.IO/7ADH6) and risk of bias evaluation according to the Joanna Briggs Institute checklist. A total of 793 references were retrieved, of which eight were considered eligible. Two studies did not show an association between clinical PD parameters and performance. A meta-analysis with 396 participants suggested a relationship between PD and self-reported reduction in sports performance (odds ratio [OR] = 1.55; 95% confidence interval [CI] 1.04-2.31; p = 0.03; I2 = 0%) with moderate quality of evidence accordingly GRADE analysis. Despite the differences in performance evaluations between studies, PD was associated with reduced self-reported sports performance. Additional studies assessing confounding factors and objective assessment of PD and performance are needed to clarify the real effect of both conditions.

Neural epidermal growth factor-like 1 protein (Nell-1) alleviates periodontal tissue destruction in periodontitis by regulating the ratio of M2/M1 macrophage phenotypes

BACKGROUND

Periodontitis is a common oral disease with high prevalence worldwide. Neural epidermal growth factor-like 1 protein (Nell-1) has recently been reported to have anti-inflammation effects and may be a drug candidate for osteoarthritis. However, its immunotherapeutic effects in periodontitis remain unknown. Therefore, this study aimed to investigate the effects of Nell-1 on periodontitis in terms of macrophage polarization and analyze its possible underlying mechanism.

METHODS

A rat ligation-induced experimental periodontitis model was established and locally injected with Nell-1 (n = 6/group). Periodontal tissue destruction and macrophage polarization in vivo were analyzed using micro-CT, histology analysis, and western blot. Enzyme-linked immunosorbent assay was used to evaluate serum inflammatory cytokines. Then, the RAW 264.7 macrophage cells were treated with lipopolysaccharide (LPS), Nell-1, and the c-Jun N-terminal kinases (JNK) inhibitor (SP600125). RT-PCR, western blot, and flow cytometry were performed to further analyze the effect of Nell-1 on macrophage polarization and the underlying mechanism in vitro.

RESULTS

Local treatment with Nell-1 significantly alleviated the destruction of alveolar bone and fibers in periodontitis, and upregulated the ratio of M2/M1 macrophages in periodontal tissues (P < 0.05). In vitro, Nell-1 at the concentrations of 200 and 500 ng/mL could significantly inhibit the expression of M1-related inflammatory factors in LPS-stimulated macrophages, and increase the expression of M2-related markers, regulating the macrophage phenotype switch into M2 (P < 0.05). The mRNA of JNK and relative protein level of phospho-JNK/JNK were also upregulated by Nell-1 (P < 0.05). Additionally, the JNK inhibitor (SP600125) could reverse the effect of Nell-1 on macrophage polarization (P < 0.05).

CONCLUSIONS

Nell-1 could modulate the ratio of M2/M1 macrophages possibly through the JNK/MAPK signaling pathway, subsequently attenuating the inflammation and destruction of periodontal tissues caused by periodontitis.

Exploration of the shared diagnostic genes and mechanisms between periodontitis and primary Sjögren's syndrome by integrated comprehensive bioinformatics analysis and machine learning

BACKGROUND

Accumulating evidence has showed a bidirectional link between periodontitis (PD) and primary Sjögren's syndrome (pSS), but the mechanisms of their occurrence remain unclear. Hence, this study aimed to investigate the shared diagnostic genes and potential mechanisms between PD and pSS using bioinformatics methods.

METHODS

Gene expression data for PD and pSS were acquired from the Gene Expression Omnibus (GEO) database. Differential expression genes (DEGs) analysis and weighted gene co-expression network analysis (WGCNA) were utilized to search common genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were conducted to explore biological functions. Three machine learning algorithms (least absolute shrinkage and selection operator (LASSO), support vector machine recursive feature elimination (SVM-RFE), and random forest (RF)) were used to further identify shared diagnostic genes, and these genes were assessed via receiver operating characteristic (ROC) curves in discovery and validation datasets. CIBERSORT was employed for immune cell infiltration analysis. Transcription factors (TFs)-genes and miRNAs-genes regulatory networks were conducted by NetworkAnalyst. Finally, relevant drug targets were predicted by DSigDB.

RESULTS

Based on DEGs, 173 overlapping genes were obtained and primarily enriched in immune- and inflammation-related pathways. WGCNA revealed 34 common disease-related genes, which were enriched in similar biological pathways. Intersecting the DEGs with WGCNA results yielded 22 candidate genes. Moreover, three machine learning algorithms identified three shared genes (CSF2RB, CXCR4, and LYN) between PD and pSS, and these genes demonstrated good diagnostic performance (AUC>0.85) in both discovery and validation datasets. The immune cell infiltration analysis showed significant dysregulation in several immune cell populations. Regulatory network analysis highlighted that WRNIP1 and has-mir-155-5p might be pivotal co-regulators of the three shared gene expressions. Finally, the top 10 potential gene-targeted drugs were screened.

CONCLUSION

CSF2RB, CXCR4, and LYN may serve as potential biomarkers for the concurrent diagnosis of PD and pSS. Additionally, we identified common molecular mechanisms, TFs, miRNAs, and candidate drugs between PD and pSS, which may provide novel insights and targets for future research on the pathogenesis, diagnosis, and therapy of both diseases.

Metronidazole may display anti-inflammatory features in periodontitis treatment: A scoping review

AIM

Metronidazole (MTZ) is an antimicrobial agent used to treat anaerobic infections. It has been hypothesized that MTZ may also have anti-inflammatory properties, but the evidence is limited and has not been previously reviewed. Thus, this scoping review aimed to answer the following question: "What is the evidence supporting anti-inflammatory properties of metronidazole that are not mediated by its antimicrobial effects?"

METHODS

A scoping review was conducted according to the PRISMA-ScR statement. Five databases were searched up to January 2023 for studies evaluating the anti-inflammatory properties of MTZ used as monotherapy for treating infectious and inflammatory diseases.

RESULTS

A total of 719 records were identified, and 27 studies (21 in vivo and 6 in vitro) were included. The studies reported experimental evidence of MTZ anti-inflammatory effects on (1) innate immunity (barrier permeability, leukocyte adhesion, immune cell populations), (2) acquired immunity (lymphocyte proliferation, T-cell function, cytokine profile), and (3) wound healing/resolution of inflammation.

CONCLUSION

Taken together, this scoping review supported a potential anti-inflammatory effect of MTZ in periodontitis treatment. We recommend that future clinical studies should be conducted to evaluate specific MTZ anti-inflammatory pathways in the treatment of periodontitis.

Magnesium Ions Promote the Induction of Immunosuppressive Bone Microenvironment and Bone Repair through HIF-1α-TGF-β Axis in Dendritic Cells

The effect of immunoinflammation on bone repair during the recovery process of bone defects needs to be further explored. It is reported that Mg2+ can promote bone repair with immunoregulatory effect, but the underlying mechanism on adaptive immunity is still unclear. Here, by using chitosan and hyaluronic acid-coated Mg2+ (CSHA-Mg) in bone-deficient mice, it is shown that Mg2+ can inhibit the activation of CD4+ T cells and increase regulatory T cell formation by inducing immunosuppressive dendritic cells (imDCs). Mechanistically, Mg2+ initiates the activation of the MAPK signaling pathway through TRPM7 channels on DCs. This process subsequently induces the downstream HIF-1α expression, a transcription factor that amplifies TGF-β production and inhibits the effective T cell function. In vivo, knock-out of HIF-1α in DCs or using a HIF-1α inhibitor PX-478 reverses inhibition of bone inflammation and repair promotion upon Mg2+-treatment. Moreover, roxadustat, which stabilizes HIF-1α protein expression, can significantly promote immunosuppression and bone repair in synergism with CSHA-Mg. Thus, the findings identify a key mechanism for DCs and its HIF-1α-TGF-β axis in the induction of immunosuppressive bone microenvironment, providing potential targets for bone regeneration.

Re-evaluation of dietary interventions in rheumatoid arthritis: can we improve patient conversations around food choices?

Rheumatoid arthritis (RA) is one of over 100 different types of autoimmune conditions. In RA, the cells of the immune system attack the tissue lining the joints, triggering inflammation. A large body of research suggests that the underlying trigger(s) of RA are unique to an individual. For example, increased risk of RA can be driven by smoking tobacco in one individual and mercury exposure in another. Due to the development of next-generation sequencing technology, the critical role of the microbiota in shaping RA risk has been elucidated. Therefore, it is surprising that diet, arguably the most important lever in shaping the gut microbiota, is ineffective in the treatment of RA, even in a sub-set of patients. To attempt to rationalise this apparent paradox, we conducted an umbrella review to address the question as to whether diet can affect outcomes in RA.

Extracellular vesicles-Potential link between periodontal disease and diabetic complications

It has long been suggested that a bidirectional impact exists between periodontitis and diabetes. Periodontitis may affect diabetes glycemic control, insulin resistance, and diabetic complications. Diabetes can worsen periodontitis by delaying wound healing and increasing the chance of infection. Extracellular vesicles (EVs) are heterogeneous particles of membrane-enclosed spherical structure secreted by eukaryotes and prokaryotes and play a key role in a variety of diseases. This review will introduce the biogenesis, release, and biological function of EVs from a microbial and host cell perspective, discuss the functional properties of EVs in the development of periodontitis and diabetes, and explore their role in the pathogenesis and clinical application of these two diseases. Their clinical implication and diagnostic value are also discussed.

Emerging therapeutic strategies targeting bone signaling pathways in periodontitis

Periodontitis is a multifactorial immune-mediated disease exacerbated by dysregulated alveolar bone homeostasis. Timely intervention is crucial for disease management to prevent tooth loss. To successfully manage periodontitis, it is imperative to understand the cellular and molecular mechanisms involved in its pathogenesis to develop novel treatment modalities. Non-surgical periodontal therapy (NSPT) such as subgingival instrumentation/debridement has been the underlying treatment strategy over the past decades. However, new NSPT approaches that target key signaling pathways regulating alveolar bone homeostasis have shown positive clinical outcomes. This narrative review aims to discuss endogenous bone homeostasis mechanisms impaired in periodontitis and highlight the clinical outcomes of preventive periodontal therapy to avoid invasive periodontal therapies. Although the anti-resorptive therapeutic adjuncts have demonstrated beneficial outcomes, adverse events have been reported. Diverse immunomodulatory therapies targeting the osteoblast/osteoclast (OB/OC) axis have shown promising outcomes in vivo. Future controlled randomized clinical trials (RCT) would help clinicians and patients in the selection of novel preventing therapies targeting key molecules to effectively treat or prevent periodontitis.

Early detection of cardiovascular risk markers through non-invasive ultrasound methodologies in periodontitis patients

Objectives

This narrative review aims to update the current evidence and offer insight into the new non-invasive ultrasound techniques used to early identify degenerative vascular changes in subjects with periodontitis and to investigate if these methodologies could be useful to identify subclinical cardiovascular disease (CVD) dysfunction in periodontitis patients and to monitor changes in CVD risk after periodontal treatment.

Methods

Studies examining the assessment of vascular endothelial function through the latest methodologies were analyzed. Systematic reviews, observational studies, and clinical trials in the English language were identified using PubMed, Web of Science, and Google Scholar databases with key search terms such as "periodontitis," "endothelial dysfunction (ED)," "arterial stiffness," and "periodontal therapy."

Results

Several mechanisms are involved in the association between periodontitis and CVD. The key players are periodontal bacteria and their toxins, which can enter the circulation and infiltrate blood vessel walls. The increase in proinflammatory molecules such as interleukins and chemokines, c-reactive protein, fibrinogen, and oxidative stress also plays a decisive role. In addition, an increase in parameters of ED, arterial stiffness, and atherosclerosis, such as carotid intima-media thickness, pulse wave velocity, and flow-mediated dilatation, has been shown in periodontal patients.

Conclusions

The literature today agrees on the association of periodontitis and CVD and the positive role of periodontal therapy on systemic inflammatory indices and cardiovascular outcomes. Hopefully, these non-invasive methodologies could be extended to periodontal patients to provide a comprehensive understanding of the CVD-periodontitis link from the perspective of a personalized medicine approach in periodontology.

Porphyromonas gingivalis virulence factors induce toxic effects in SH-SY5Y neuroblastoma cells: GRK5 modulation as a protective strategy

Periodontitis (PDS) is a chronic inflammatory disease initiated by a dysbiosis of oral pathogenic bacterial species, such as Porphyromonas gingivalis (Pg). These bacteria can penetrate the bloodstream, releasing various endo and exotoxins that fuel the infection, and stimulate toxic inflammation in different compartments, including the brain. However, the specific mechanisms by which PDS/Pg contribute to brain disorders, such as Alzheimer's disease (AD), remain unclear. This study assessed the effects of Pg's virulence factors - lipopolysaccharide (LPS-Pg) and gingipains (gps) K (Kgp) and Rgp - on SH-SY5Y cells. Our results demonstrated that LPS-Pg activated signaling through the Toll-like receptor (TLR)-2/4 induced a significant downregulation of G protein-coupled receptor kinase 5 (GRK5). Additionally, LPS-Pg stimulation resulted in a robust increase in Tau phosphorylation (pTau) and p53 levels, while causing a marked reduction in Bcl2 and increased cell death compared to unstimulated cells (Ns). LPS-Pg also elevated inducible nitric oxide synthase (iNOS) expression, leading to oxidative damage. In cells overexpressing GRK5 via Adenovirus, LPS-Pg failed to increase iNOS and pTau levels compared to GFP control cells. High GRK5 levels also prevented the nuclear accumulation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB). Furthermore, the overexpression of a GRK5 mutant form lacking the nuclear localization signal (ΔNLS) nearly abolished LPS-Pg induced p53 and iNOS upregulation. Finally, we tested whether Kgp and Rgp mediated similar effects and our data showed that both gps caused a marked downregulation of GRK5 leading to increased p53 and pTau levels. In conclusion, this study provides further insight into the toxic effects elicited by Pg in cells and suggests that preventing GRK5 deficiency may be a valid strategy to mitigate Pg-induced toxic effects (i.e. cell death, oxidative damage, and Tau hyperphosphorylation) in SH-SY5Y cells, which are typical molecular hallmarks of neurodegenerative disorders.

Harnessing the power of bee venom for therapeutic and regenerative medical applications: an updated review

Honeybees have been helpful insects since ancient centuries, and this benefit is not limited to being a honey producer only. After the bee stings a person, pain, and swelling occur in this place, due to the effects of bee venom (BV). This is not a poison in the total sense of the word because it has many benefits, and this is due to its composition being rich in proteins, peptides, enzymes, and other types of molecules in low concentrations that show promise in the treatment of numerous diseases and conditions. BV has also demonstrated positive effects against various cancers, antimicrobial activity, and wound healing versus the human immunodeficiency virus (HIV). Even though topical BV therapy is used to varying degrees among countries, localized swelling or itching are common side effects that may occur in some patients. This review provides an in-depth analysis of the complex chemical composition of BV, highlighting the diverse range of bioactive compounds and their therapeutic applications, which extend beyond the well-known anti-inflammatory and pain-relieving effects, showcasing the versatility of BV in modern medicine. A specific search strategy was followed across various databases; Web of sciences, Scopus, Medline, and Google Scholar including in vitro and in vivo clinical studies.to outline an overview of BV composition, methods to use, preparation requirements, and Individual consumption contraindications. Furthermore, this review addresses safety concerns and emerging approaches, such as the use of nanoparticles, to mitigate adverse effects, demonstrating a balanced and holistic perspective. Importantly, the review also incorporates historical context and traditional uses, as well as a unique focus on veterinary applications, setting it apart from previous works and providing a valuable resource for researchers and practitioners in the field.

Feasibility of Nanostructured Lipid Carrier Loaded with Alpha-Mangostin and Clove Oil for Canine Periodontal Therapy

Nanostructured lipid carriers (NLC) represent the second generation of nanoparticles, offering numerous advantages over conventional delivery systems. These include improved stability, enhanced drug-loading capacity, and controlled release profiles, making them highly attractive candidates for a wide range of therapeutic applications. Their suitability for hydrophobic drugs like a traditional medicinal plant of Thailand as clove oil and alpha-mangostin. We investigated into nanostructured lipid carriers loaded with Alpha-Mangostin and clove oil (NLC-AMCO) into the physicochemical and biological characteristics to identify the formulation with the highest efficacy for treatment. The particle size, charge, polydispersity index, and other characterizations were recorded. The realtime ex vivo penetration was explored using canine gingival tissue. Drug sustained release was assessed by HPLC. Moreover, the antibacterial properties were tested by conventional methods. The NLC-AMCO can be stored at up to 40 °C for 60 days without any alterations in particle characteristics. Gingival tissue penetration and sustained drug release were superior compared to unencapsulated counterparts. It exhibited greater effectiveness in inhibiting bacterial growth than the antibiotics tested, particularly against bacteria from the oral cavities of dogs. Therefore, this alternative treatment approach offers cost-effectiveness and ease of administration for pet owners and reduces discomfort for the animals during restraint.

Causal role of immune cells in chronic periodontitis: a bidirectional Mendelian randomization study

BACKGROUND

This study aims to explore the bidirectional causal relationship between immune cell phenotypes and chronic periodontitis using a Mendelian randomization framework.

MATERIALS AND METHODS

Through a two-sample Mendelian randomization analysis, this research examined genetic data related to 731 immune cell traits and chronic periodontitis. Instrumental variables were chosen based on their genetic links to either immune traits or periodontitis. Various statistical techniques, including MR-Egger regression, weighted median, and inverse-variance weighted (IVW) analysis, were employed to determine the causal connections.

RESULTS

Predominantly using the IVW method, 26 distinct immune phenotypes were identified as potentially influencing periodontitis (P < 0.05). Conversely, periodontitis potentially affected 33 different immune phenotypes (P < 0.05). The results for pleiotropy and sensitivity tests were stable. However, these associations lost significance after adjusting for the False Discovery Rate.

CONCLUSION

This study uncovers a complex bidirectional causal relationship between certain immune cell phenotypes and chronic periodontitis, underscoring the intricate interaction between the immune system and the pathogenesis of periodontal disease.

The role of WTAP in regulating macrophage-mediated osteoimmune responses and tissue regeneration in periodontitis

Periodontitis, delineated by the destruction of structures that support teeth, is predominantly propelled by intricate immune responses. Immunomodulatory treatments offer considerable promise for the management of this ailment; however, the modulation of the periodontal immune microenvironment to facilitate tissue regeneration presents a substantial biomedical challenge. Herein, our study investigates the role of Wilms' tumor 1-associating protein (WTAP), a critical m6A methyltransferase, in the immunomodulation of periodontitis and assesses its viability as a therapeutic target. We observed heightened expression of WTAP in macrophages extracted from gingival tissues impacted by periodontitis, with a strong association with M1 polarization. Via loss-of-function experiments, we demonstrated that diminishing WTAP expression precipitates a transition from M1 to M2 macrophage phenotypes amidst inflammatory conditions, thus improving the periodontal immune landscape. Further, RNA sequencing and indirect co-culture assays indicated that suppressing of WTAP expression modulates osteoimmune responses and enhances the osteogenic differentiation of bone marrow stromal cells. The local deployment of adeno-associated virus-shWTAP in murine models of periodontitis robustly validated the therapeutic promise of targeting WTAP in this disease. Collectively, our findings highlight the crucial role of WTAP in orchestrating macrophage-mediated osteoimmune responses and tissue regeneration in periodontitis, proposing novel avenues for immunotherapeutic interventions in its treatment.

Utility of gingival crevicular fluid components for periodontal diagnosis

Periodontal diseases are highly prevalent chronic diseases, and severe periodontitis creates functional and esthetic problems and decreases self-esteem for a large percentage of the older population worldwide. In many cases of periodontitis, there is no distinct tell-tale pain that motivates a patient to seek treatment, rather the signs become clinically detectable late, and typically when the disease has progressed to a problematic level for the life of the dentition. Early periodontal screening and diagnostics tools will provide early recognition of periodontal diseases and facilitate timely management of the disease to reduce tooth loss. To this goal, gingival crevicular fluid is easily sampled, can be repeatedly and non-invasively collected, and can be tested for potential biomarkers. Moreover, the site specificity of periodontal diseases enhances the usefulness of gingival crevicular fluid sampled from specific sites as a biofluid for diagnosis and longitudinal monitoring of periodontal diseases. The present review aimed to provide up-to-date information on potential diagnostic biomarkers with utility that can be assayed from gingival crevicular fluid samples, focusing on what is new and useful and providing only general historic background textually and in a tabulated format.

Gut microbial dysbiosis and inflammation: Impact on periodontal health

Periodontitis is widely acknowledged as the most prevalent type of oral inflammation, arising from the dynamic interplay between oral pathogens and the host's immune responses. It is also recognized as a contributing factor to various systemic diseases. Dysbiosis of the oral microbiota can significantly alter the composition and diversity of the gut microbiota. Researchers have delved into the links between periodontitis and systemic diseases through the "oral-gut" axis. However, whether the associations between periodontitis and the gut microbiota are simply correlative or driven by causative mechanistic interactions remains uncertain. This review investigates how dysbiosis of the gut microbiota impacts periodontitis, drawing on existing preclinical and clinical data. This study highlights potential mechanisms of this interaction, including alterations in subgingival microbiota, oral mucosal barrier function, neutrophil activity, and abnormal T-cell recycling, and offers new perspectives for managing periodontitis, especially in cases linked to systemic diseases.

Periodontal disease and emerging point-of-care technologies for its diagnosis

Periodontal disease (PD), a chronic inflammatory disorder that damages the tooth and its supporting components, is a common global oral health problem. Understanding the intricacies of these disorders, from gingivitis to severe PD, is critical for efficient treatment, diagnosis, and prevention in dental care. Periodontal biosensors and biomarkers are critical in improving oral health diagnostic skills. Clinicians may accomplish early identification, tailored therapy, and efficient tracking of periodontal diseases by using these technologies, ushering in a new age of accurate oral healthcare. Traditional periodontitis diagnostic methods frequently rely on physical probing and visual examinations, necessitating the development of point-of-care (POC) devices. As periodontal disorders necessitate more precise and rapid diagnosis, incorporating novel innovations in biosensors and biomarkers becomes increasingly crucial. These innovations improve our capacity to diagnose, monitor, and adapt periodontal therapies, bringing in the next phase of customized and effective dental healthcare. The review discusses the characteristics and stages of PD, clinical treatment techniques, prominent biomarkers and infection-associated factors that may be employed to determine PD, biomedical sensing, and POC appliances that have been created so far to diagnose stages of PD and its progression profile, as well as predicting future developments in this field.

Association between nonalcoholic fatty liver disease scores and chronic periodontitis: A retrospective cohort study

BACKGROUND

Although several studies have demonstrated a bidirectional relationship between nonalcoholic fatty liver disease (NAFLD) and chronic periodontitis, few studies have reported that NAFLD causes chronic periodontitis, especially in the Asian population.

METHODS

This study was conducted on 129,087 individuals, and the NAFLD score was assessed using the Fatty Liver Index (FLI), Hepatic Steatosis Index (HSI), and Framingham Steatosis Index (FSI). The incidence of chronic periodontitis was defined as a diagnostic code with dental procedures. Multi-variable adjusted Cox proportional hazard regression analysis was performed with hazard ratio (HR) and 95% confidence intervals (CIs).

RESULTS

Nine thousand one hundred and twenty-eight chronic periodontitis cases (7.1%) were identified during a mean 7.4 years follow-up period. Each NAFLD score was related to chronic periodontitis. In the FLI score, HR and 95% CIs for the incidence of chronic periodontitis compared with a low FLI group were as follows: indeterminate FLI: 1.19 (1.12-1.26), high FLI: 1.32 (1.18-1.47). In the HSI and FSI scores, HR and 95% CIs for the incidence of chronic periodontitis were 1.13 (1.05-1.22) and 1.23 (1.05-1.31), respectively.

CONCLUSIONS

All NAFLD scores were associated with chronic periodontitis in the Korean population. As chronic periodontitis can aggravate the liver status, patients with NAFLD may need regular dental visits.

Brazilin cream from Caesalpinia sappan inhibit periodontal disease: in vivo study

Background

Gingivitis is an inflammation of the gums that is the initial cause of the development of periodontal disease by the activity of Nuclear Factor-kappa B (NF-κB), Interleukin-1β (IL-1β), Interleukin-6 (IL-6), p38, and Tumor Necrosis Factor-α (TNF-α). Unaddressed chronic inflammation can lead to persistent disturbances in other parts of the body. Brazilin is a naturally occurring plant chemical that may have antibacterial and anti-inflammatory effects. Treatment based on the natural plant compound, brazilin, is developed in the form of a topical cream for easy application.

Objective

The aim is to develop the natural compound brazilin in the form of a topical cream as an anti-inflammatory agent to reduce NF-κB expression through Imunohistochemistry (IHC) methods, and the expression of pro-inflammatory genes IL-1β, IL-6, p38, and TNF-α.

Methods

Male Sprague-Dawley rats were induced with gingivitis using P. gingivalis bacteria. The observed groups included rats treated with a single application of brazilin cream and rats treated with two applications of brazilin cream. The treatment was administered for 15 days. On days 3, 6, 9, 12, and 15, anatomical wound observations and wound histology using hematoxylin-eosin and Masson's Trichrome staining were performed. NF-κB protein expression was analyzed using the IHC method. Gingival inflammation gene expression of NF-κB, IL-1β, IL-6, p38, and TNF-α was measured using q-RTPCR.

Results

Single and double applications of brazilin cream increased angiogenesis and decreased NF-κB protein expression, in addition to the IL-1β, IL-6, p38, and TNF-α gene expressions.

Conclusion

In a rat gingivitis model, Brazilin cream may function as an anti-inflammatory agent in the gingival tissue.

Macrophage-derived apoptotic bodies impair the osteogenic ability of osteoblasts in periodontitis

OBJECTIVES

Periodontitis is induced by the imbalance between osteoblast and osteoclast activity, which leads to periodontal tissue destruction. Macrophages play a vital role in periodontitis. However, the hypoxic periodontal environment will also induce macrophage apoptosis within a short time. Apoptotic bodies (ABs) are the major products generated from apoptotic cells, but whether macrophage-derived ABs play a regulatory role as their mother cells in periodontitis remains unknown. In the present study, we aimed to investigate the effects of ABs on osteoblasts.

METHOD

ABs derived from hypoxia-induced macrophages were co-cultured with osteoblasts and the impact of ABs on osteoblast differentiation in vitro was assessed. In vivo, periodontitis model was established and macrophages-derived ABs were injected into the gingival sulcus. The effects of ABs on periodontal bone resorption were determined.

RESULTS

The results showed that ABs significantly inhibit osteoblast differentiation and promoted alveolar bone resorption in periodontitis. MicroRNA (miRNAs) array analysis was performed and revealed that miR-483-5p is the key miRNA in ABs. Dual luciferase reporter assays were performed and confirmed that miR-483-5p targeted Col1A1 mRNA and attenuated its expression.

CONCLUSION

Macrophage-derived ABs inhibit osteoblast differentiation via the transfer of miR-483-5p, which downregulates Col1A1 expression and finally suppresses osteogenic activity.

Periodontal and microbiological data in patients with mucous membrane pemphigoid in a French population in 2021-2022: A pilot cross-sectional study

Background and Aims

In the case of mucous membrane pemphigoid with gingival expression (gMMP), the complete healing of the gingiva is generally not achieved despite medical treatment. Therefore, patients' oral comfort is impaired. The dysbiotic periodontal microbiota, generated by a lack of oral hygiene associated with persistent gingival pain, could the immunopathological mechanism to persist. The main objective of this study was to characterize the subgingival microbiota of the gMMP patients, and to highlight a potential link between this microbiological data and the clinical data.

Methods

Subgingival biofilm was collected from 15 gMMP patients, medically treated or not, but not receiving periodontal treatment. The usual clinical periodontal parameters were recorded. The biofilm was analyzed by polymerase chain reaction quantitative. The risk factors of severe erosive gingivitis and severe periodontitis were assessed using Chi-square or Fischer's exact test were used.

Results

Whatever the medical and periodontal conditions of the patients, the results showed the existence of three main communities of periodontopathic, dysbiotic bacteria. The first including Tannnerella forsythia, Peptostreptococcus micros, Fusobacterium nucleatum, and Campylobacter rectus, was found in 100% of the patients, the second enriched with Treponema denticola in 60% and the third enriched with Porphyromonas gingivalis and Prevotella intermedia in 26%. Furthermore, there was a significant positive link between the duration of gMMP and the severity of erosive gingivitis (p = 0.009), and the loss of deep periodontal tissue (p = 0.04).

Conclusion

This pilot study suggests a high periodontal risk in gMMP patients. The pathological processes, autoimmune on the one hand and plaque-induced on the other, may amplify each other. The application of periodontal therapy is therefore necessary in parallel with medical treatment. Nevertheless, further controlled studies are required to validate and complement these preliminary results.

Periodontal inflammatory and microbial profiles in healthy young African Americans and Caucasians

AIM

This study aimed to compare microbial and inflammatory profiles in periodontally/systemically healthy African American (AA) and Caucasian (C) individuals.

MATERIALS AND METHODS

Thirty-seven C and 46 AA aged from 5 to 25 years were evaluated regarding periodontal disease, caries, microbial subgingival profile via 16-s sequencing, as well as salivary and gingival crevicular fluid (GCF) inflammatory profile via multiplex assay.

RESULTS

Greater probing depth percentage was detected in AA (p = .0075), while a higher percentage of caries index (p = .0069) and decayed, missing, filled teeth (DMFT) index (p = .0089) was observed in C, after adjusting for number of teeth, sex and age. Salivary levels of IL-6, IL-8 and TNFα were higher for C, whereas GCF levels of eotaxin, IL-12p40, IL-12p70, IL-2 and MIP-1α were higher in AA (p < .05). Different microbial profiles were observed between the races (p = .02). AA presented higher abundance of periodontopathogens (such as Tanerella forsythia, Treponema denticola, Filifactor alocis, among others), and C presented more caries-associated bacteria (such as Streptococcus mutans and Prevotella species). Bacillaceae and Lactobacillus species were associated with higher DMFT index, whereas Fusobacterium and Tanerella species with periodontal disease parameters.

CONCLUSIONS

A different inflammatory and bacterial profile was observed between healthy AA and C, which may predispose these races to higher susceptibility to specific oral diseases.

The bidirectional effect of neutrophils on periodontitis model in mice: A systematic review

OBJECTIVE

To evaluate the regulatory role of neutrophils as the first line of host immune defense in the periodontal microenvironment of mice.

METHODS

A systematic search was performed using PubMed, Web of Science, and ScienceDirect databases for articles published between 2012 and 2023. In this review, articles investigating the effect of neutrophils on alveolar bone resorption in a mouse model of periodontitis were selected and evaluated according to eligibility criteria. Important variables that may influence outcomes were analyzed.

RESULTS

Eleven articles were included in this systematic review. The results showed that because of their immune defense functions, the functional homeostasis of local neutrophils is critical for periodontal health. Neutrophil deficiency aggravates alveolar bone loss. However, several studies have shown that excessive neutrophil infiltration is positively correlated with alveolar bone resorption caused by periodontitis in mice. Therefore, the homeostasis of neutrophil function needs to be considered in the treatment of periodontitis.

CONCLUSIONS

Pooled analysis suggests that neutrophils play a bidirectional role in periodontal tissue remodeling in mouse periodontitis models. Therefore, targeted regulation of local neutrophil function provides a novel strategy for the treatment of periodontitis.

Immune-mediated inflammatory diseases and periodontal disease: a bidirectional two-sample mendelian randomization study

BACKGROUND

Previous observational studies have shown a bidirectional association between immune-mediated inflammatory disorders (IMID) and periodontal disease. However, evidence regarding the causal role of IMID and periodontal disease is still lacking. Therefore, we conducted a bidirectional two-sample Mendelian randomization (MR) study to uncover the potential genetic causal effects between IMID and periodontal disease.

METHODS

Bidirectional two-sample MR analysis was employed. Data for ten IMIDs were sourced from genome-wide association studies (GWAS) conducted by the FinnGen Consortium (range from 1023 to 36321 cases) and UK Biobank (UKB) (range from 150 to 17574 cases). Furthermore, GWAS data for periodontal disease were obtained from the FinnGen Consortium (87497 cases), UKB (458 cases), and Gene Lifestyle Interactions in Dental Endpoints (GLIDE) consortium (17,353 periodontitis cases). Subsequently, the causal relationships were analyzed by random effects inverse variance weighting, weighted median, and MR-Egger. Sensitivity analyses were performed using the Cochrane Q test, funnel plot, and Mr-Egger intercept test to ensure robustness. Eventually, replication analysis and meta-analysis across different databases were carried out.

RESULTS

Systemic lupus erythematosus (SLE) [IVW: OR = 1.079 (95% CI: 1.032-1.128) and P < 0.001], Sjogren syndrome [IVW: OR = 1.082 (95% CI: 1.012-1.157) and P = 0.022] and hypothyroidism [IVW: OR = 1.52 (95% CI: 1.13-2.04) and P = 0.005] may increase the risk of periodontal disease. In addition, periodontal disease may reduce the risk of SLE [IVW: OR = 0.8079 (95% CI: 0.6764-0.9650) and P = 0.019] and hyperthyroidism [IVW: OR = 5.59*10-9 (95% CI: 1.43*10-15-2.18*10-2) and P = 0.014]. Meta-analysis indicated a causal correlation between SLE and an increased risk of periodontal disease: [OR = 1.08 (95% CI: 1.03-1.13), P = 0.0009]. No significant evidence suggests bilateral causal relationships between other IMIDs and periodontal disease. No significant estimation of heterogeneity or pleiotropy is detected.

CONCLUSIONS

Our study has confirmed a genetic causal relationship between IMIDs and periodontal disease, thereby unveiling novel potential mechanisms underlying IMIDs and periodontal disease. This discovery is promising in fostering interdisciplinary collaboration between clinicians and stomatologists to facilitate appropriate and precise screening, prevention, and early treatment of IMIDs and periodontal disease.

The association between periodontitis and the impact of oral health on the quality of life of individuals with psoriasis and psoriatic arthritis

OBJECTIVE

To evaluate the association between psoriasis (PSO), psoriatic arthritis (PsA) and periodontitis (PE), and the Oral Health-Related Quality of Life (OHRQoL) impacts on individuals with psoriatic disease's daily activities compared to the non-psoriatic ones.

MATERIALS & METHODS

296 individuals with psoriatic disease (PSO n = 210, APS n = 86) (cases) and 359 without these diseases (controls) were included. Complete periodontal examinations and collection of variables of interest were performed. The Brazilian version of the Oral Impacts on Daily Performance (OIDP) instrument was applied.

RESULTS

The prevalence of PE was higher in PsA (57.0%; OR = 2.67 95%CI 1.65-4.32; p<0.001) than in PSO (34.3%; OR = 1.05 95% CI 0.73-1.51; p<0.001) compared to controls (33.1%). Both PsA and PSO groups showed more sites and teeth with 4-6mm probing depth (PD) and had higher OIDP scores than controls (p<0.001), thus indicating worse self-reported quality of life. PE, PSO+PE and consumption of alcohol/anxiolytics significantly influenced OHRQoL (p<0.05). The influence of periodontal parameters on OHRQoL was observed for the presence of PE; PD >6 mm; clinical attachment level >6 mm; higher plaque index, % sites and teeth with bleeding on probing (p<0.05).

CONCLUSION

Negative impacts of PE on the OHRQoL were demonstrated. The ones having PSO and especially PsA and PE presented significantly worse indicators.

Glycemic Control and Oral Health Outcomes in Patients With Diabetes: Insights From a Nationwide Korean Survey

BACKGROUND

Diabetes is recognized as a risk factor for various inflammatory conditions, including periodontitis. There exists a bidirectional relationship between glycemic control and oral health in individuals with diabetes. This study aimed to analyze the link between glycemic control and oral health status among Korean patients with diabetes.

METHODS

Using data from a population-based nationwide survey conducted between 2007 and 2019, we identified 70,554 adults with diabetes-related information. The study population included 9,090 individuals diagnosed with diabetes and 61,164 healthy controls. The association between glycemic control, defined by mean glycated hemoglobin (HbA1c) values, and various oral health measures, such as tooth brushing frequency, periodontitis, denture wearing, Decayed, Missing, and Filled Teeth (DMFT) index, number of remaining teeth, and past-year dental clinic visits, was evaluated using multivariate logistic regression analyses.

RESULTS

Compared to the control group, patients with diabetes exhibited a higher prevalence of periodontitis (88.6% vs. 73.3%), complete dentures (5.0% vs. 1.5%), and elevated DMFT index (33.2% vs. 26.7%) (all P < 0.001). Multivariate analyses revealed significant associations between diabetes and several oral health factors: denture status (No denture: adjusted odds ratio [aOR], 0.784; 95% confidence interval [CI], 0.627-0.979), and having fewer permanent teeth (0-19) (aOR, 1.474; 95% CI, 1.085-2.003). Additionally, a positive correlation was found between higher HbA1c levels and the risk of having fewer remaining teeth (0-19) (HbA1c < 6.5%: aOR, 1.129; 95% CI, 0.766-1.663; 6.5% ≤ HbA1c < 8.0%: aOR, 1.590; 95% CI, 1.117-2.262; HbA1c ≥ 8%: aOR, 1.910; 95% CI, 1.145-3.186) (P for trends = 0.041).

CONCLUSION

We found a positive association between diabetes and poor oral health, as well as a noteworthy relationship between reduced permanent teeth (≤ 19) and glycemic control. These insights emphasize the critical role of oral health management in diabetic care and underscore the importance of maintaining effective glycemic control strategies for overall health and well-being in patients with diabetes.

Expression of IL-1β, IL-6, TNF-α, and a-MMP-8 in sites with healthy conditions and with periodontal and peri-implant diseases: A case-control study

Background

This study evaluated the gingival crevicular fluid (GCF) and Peri- implant crevicular fluid (PICF) concentrations of interleukin-1 beta (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α) and active metalloproteinase-8 (a-MMP-8) in sites with healthy conditions vs. sites affected by periodontitis (PER) and peri-implantitis (PIM).

Methods

Periodontally healthy (PH) sites with PER, sites with peri-implant health (PIH), and sites with PIM were investigated intra-individually, according to the inclusion criteria of each group. Probing pocket depth (PPD), plaque index, gingival index, and the presence or absence of bleeding on probing (BoP) were evaluated. In GCF and PICF samples, IL-1β, IL-6, and TNF-α were quantified by ELISA Duoset® kit in combination with Ultramark® micro-ELISA digital reader; a-MMP8 concentration was analyzed by a chairside test (Perio/ImplantSafe®) in combination with a digital reader (ORALyzer®).

Results

The concentrations of IL-6 and IL-1β, TNF-α, and a-MMP-8 were significantly higher in the PIM and PER sites compared to healthy sites (P<0.05). Significantly higher concentrations of IL-1β and a-MMP-8 were found in PIM vs. PER sites (P<0.05), while the concentrations of IL-6 and TNF-α did not differ between the PIM and PER groups (P>0.05).

Conclusion

aMMP-8, IL-6, IL-1β, and TNF-α presented higher GCF/PICF concentrations in diseased periodontal and peri-implant sites. However, only the concentrations of IL-1β and a-MMP-8 were significantly higher in PIM than in PER sites.

Treatment of periodontitis ameliorates the severity and extent of psoriasis-A randomized clinical trial

AIM

To assess the impact of non-surgical periodontitis treatment over conventional dermatological treatment on the severity and extent of psoriasis in patients affected by comorbid psoriasis and periodontitis.

METHODS

Seventy-four patients affected by both psoriasis and Stages I-IV periodontitis were randomized to receive either Steps 1-2 (non-surgical) of periodontal therapy (test group; n = 37) or no treatment (control group; n = 37). The two groups were balanced in terms of psoriasis medications, with the majority of the included patients undergoing biologics (74.0%) as monotherapy, while minor proportions were under systemic medications (13.7%) or none/topical/phototherapy (12.3%). The psoriasis area severity index (PASI) was regarded as the primary outcome. The Body Surface Area (BSA) and the Dermatology Life Quality Index (DLQI) were additionally considered as dermatological outcomes. Probing pocket depth, recession depth, clinical attachment level, periodontal inflamed surface area, and full-mouth plaque and bleeding scores were also measured. [Correction added on July 5, 2024, after first online publication: The preceding sentence has been revised].

RESULTS

Periodontal therapy in the test group led to statistically significant lower PASI scores at 10 weeks (mean = 3.15; standard deviation [SD] = 3.78) compared to the control group (mean = 7.11; SD = 6.09) (mean difference [MD] = -4.0; 95% confidence interval [CI]: -6.3, -1.6; p = .001). The test group also showed improvements in BSA (MD = -4.3) and periodontal parameters compared to the control group. DLQI only showed a non-statistically significant tendency (MD = -2.0).

CONCLUSION

Steps 1-2 of periodontal therapy showed an additional effect over conventional dermatological treatment in reducing the severity and extent of psoriasis (Clinicaltrials.gov: NCT05311501).

Effects of the DL76 Antagonist/Inverse Agonist of Histamine H3 Receptors on Experimental Periodontitis in Rats: Morphological Studies

BACKGROUND

Periodontitis preceded by gingivitis is the most common form of periodontal disease and occurs due to the interaction of microorganisms present in the complex bacterial aggregates of dental plaque biofilm and their metabolism products with periodontal tissues. Histamine is a heterocyclic biogenic amine acting via four types of receptors. Histamine H3 receptors act as presynaptic auto/heteroreceptors to regulate the release of histamine and other neurotransmitters.

AIM

Since the nervous system is able to regulate the progression of the inflammatory process and bone metabolism, the aim of this study was to investigate the effects of DL76, which acts as an antagonist/inverse agonist of H3 receptors, on the course of experimental periodontitis.

MATERIALS AND METHODS

This study was conducted in 24 mature male Wistar rats weighing 245-360 g, aged 6-8 weeks. A silk ligature was placed on the second maxillary molar of the right maxilla under general anesthesia. From the day of ligating, DL76 and 0.9% NaCl solutions were administered subcutaneously for 28 days in the experimental and control groups, respectively. After the experiment, histopathological, immunohistochemical and radiological examinations were performed.

RESULTS

Ligation led to the development of the inflammatory process with lymphocytic infiltration, increased epithelial RANKL and OPG expression as well as bone resorption. DL76 evoked a reduction in (1) lymphocytic infiltration, (2) RANKL and OPG expression as well as (3) bone resorption since the medians of the mesial and distal interdental spaces in the molars with induced periodontitis were 3.56-fold and 10-fold lower compared to the corresponding values in saline-treated animals with periodontitis.

CONCLUSION

DL76 is able to inhibit the progression of experimental periodontitis in rats, as demonstrated by a reduction in the inflammatory cell infiltration, a decrease in the RANKL/RANK OPG pathway expression and a reduction in the alveolar bone resorption.

In-vitro effects of different hyaluronic acids on periodontal biofilm-immune cell interaction

Introduction

Recent studies have demonstrated a positive role of hyaluronic acid (HA) on periodontal clinical outcomes. This in-vitro study aimed to investigate the impact of four different HAs on interactions between periodontal biofilm and immune cells.

Methods

The four HAs included: high-molecular-weight HA (HHA, non-cross-linked), low-molecular-weight HA (LHA), oligomers HA (OHA), and cross-linked high-molecular-weight HA (CHA). Serial experiments were conducted to verify the influence of HAs on: (i) 12-species periodontal biofilm (formation and pre-existing); (ii) expression of inflammatory cytokines and HA receptors in monocytic (MONO-MAC-6) cells and periodontal ligament fibroblasts (PDLF) with or without exposure to periodontal biofilms; (iii) generation of reactive oxygen species (ROS) in MONO-MAC-6 cells and PDLF with presence of biofilm and HA.

Results

The results indicated that HHA and CHA reduced the bacterial counts in a newly formed (4-h) biofilm and in a pre-existing five-day-old biofilm. Without biofilm challenge, OHA triggered inflammatory reaction by increasing IL-1β and IL-10 levels in MONO-MAC cells and IL-8 in PDLF in a time-dependent manner, whereas CHA suppressed this response by inhibiting the expression of IL-10 in MONO-MAC cells and IL-8 in PDLF. Under biofilm challenge, HA decreased the expression of IL-1β (most decreasing HHA) and increased IL-10 levels in MONO-MAC-6 cells in a molecular weight dependent manner (most increasing CHA). The interaction between HA and both cells may occur via ICAM-1 receptor. Biofilm stimulus increased ROS levels in MONO-MAC-6 cells and PDLF, but only HHA slightly suppressed the high generation of ROS induced by biofilm stimulation in both cells.

Conclusion

Overall, these results indicate that OHA induces inflammation, while HHA and CHA exhibit anti-biofilm, primarily anti-inflammatory, and antioxidant properties in the periodontal environment.

Physical training minimizes immunological dysfunction, oxidative stress and tissue destruction on experimental periodontitis in rats

The objective of this study is to investigate the effects of a moderate intensity physical training protocol, on alveolar bone morphology of rats submitted to ligature-induced periodontitis. Twenty-eight male Wistar rats were divided into four groups, considering the presence/absence of periodontitis and presence/absence of training. The training protocol was performed on a treadmill, 30 min/day, 5 days a week, for 4 weeks. In the experimental periodontal breakdown, with/without training, ligatures were placed on the lower first molars on the 14th day of the experiment, and were followed until the end of the protocol. At the end of the experiment, animals were euthanized and samples of plasma and mandibles were collected for immunoenzymatic evaluation of interleukins (IL)-1β, IL-6, TNF-α and IL-10, evaluation of serum concentrations of C-reactive protein, analysis of lipid peroxidation (LPO) and reduced glutathione, histological and microtomographic analyses were performed. Physical training resulted in a reduced levels of IL-1β, IL-6, TNF-α C-reactive protein and LPO and an increase in the levels of IL-10 in rats with periodontitis (p<0.05); a reduction in the inflammatory infiltrate and decreased fiber degradation was identified in histological analysis. Additionally, it was shown a decrease in vertical bone loss and an increase in the bone volume/trabecular volume ratio was identified in periodontitis+physical training group (p<0.05). Based on the results, the practice of frequent physical exercise, at moderate intensity, can contribute to the reduction of damage related to the disproportionate inflammatory response in periodontitis.

Impaired oral health: a required companion of bacterial aspiration pneumonia

Laryngotracheal aspiration has a widely-held reputation as a primary cause of lower respiratory infections, such as pneumonia, and is a major concern of care providers of the seriously ill orelderly frail patient. Laryngeal mechanical inefficiency resulting in aspiration into the lower respiratory tract, by itself, is not the cause of pneumonia. It is but one of several factors that must be present simultaneously for pneumonia to develop. Aspiration of oral and gastric contentsoccurs often in healthy people of all ages and without significant pulmonary consequences. Inthe seriously ill or elderly frail patient, higher concentrations of pathogens in the contents of theaspirate are the primary catalyst for pulmonary infection development if in an immunocompromised lower respiratory system. The oral cavity is a complex and ever changing eco-environment striving to maintain homogeneity among the numerous microbial communities inhabiting its surfaces. Poor maintenance of these surfaces to prevent infection can result inpathogenic changes to these microbial communities and, with subsequent proliferation, can altermicrobial communities in the tracheal and bronchial passages. Higher bacterial pathogen concentrations mixing with oral secretions, or with foods, when aspirated into an immunecompromised lower respiratory complex, may result in bacterial aspiration pneumonia development, or other respiratory or systemic diseases. A large volume of clinical evidence makes it clear that oral cleaning regimens, when used in caring for ill or frail patients in hospitals and long-term care facilities, drastically reduce the incidence of respiratory infection and death. The purpose of this narrative review is to examine oral health as a required causative companionin bacterial aspiration pneumonia development, and the effectiveness of oral infection control inthe prevention of this disease.

Enhanced immunomodulation and periodontal regeneration efficacy of subgingivally delivered progranulin-loaded hydrogel as an adjunct to non-surgical treatment for Class II furcation involvement in dogs

AIM

To evaluate the effect of subgingival delivery of progranulin (PGRN)/gelatin methacryloyl (GelMA) complex as an adjunct to scaling and root planing (SRP) on an experimental periodontitis dog model with Class II furcation involvement (FI).

MATERIALS AND METHODS

A Class II FI model was established, and the defects were divided into four treatment groups: (a) no treatment (control); (b) SRP; (c) SRP + GelMA; (d) SRP + PGRN/GelMA. Eight weeks after treatment, periodontal parameters were recorded, gingival crevicular fluid and gingival tissue were collected for ELISA and RT-qPCR, respectively, and mandibular tissue blocks were collected for micro computed tomography (micro-CT) scanning and hematoxylin and eosin (H&E) staining.

RESULTS

The SRP + PGRN/GelMA group showed significant improvement in all periodontal parameters compared with those in the other groups. The expression of markers related to M1 macrophage and Th17 cell significantly decreased, and the expression of markers related to M2 macrophage and Treg cell significantly increased in the SRP + PGRN/GelMA group compared with those in the other groups. The volume, quality and area of new bone and the length of new cementum in the root furcation defects of the PGRN/GelMA group were significantly increased compared to those in the other groups.

CONCLUSIONS

Subgingival delivery of the PGRN/GelMA complex could be a promising non-surgical adjunctive therapy for anti-inflammation, immunomodulation and periodontal regeneration.

Diabetes Mellitus and Periodontal Disease: A New Perspective

First recorded in 1928, people living with diabetes mellitus (DM) are at a three to four times higher risk of developing periodontal disease (PD) than non-diabetics; for those who smoke this risk increases up to ten times. However, many doctors are unaware of this.DM and PD are bidirectionally linked, the one affecting the other and vice versa, although the mechanism is not fully understood and may be linked to chronic infection. PD has an adverse effect on glycaemic control. That improves when periodontitis is successfully treated.Doctors should consider PD when their patients have persistently high glycated haemoglobin (HbA1c) levels, and dentists should consider diabetes or pre-diabetes when they have patients with unstable or progressive periodontitis.Doctors, dentists, and their teams need to share results. A traffic light system of red, amber and green for both medical and dental risks is proposed, and a pro forma designed, so that diabetics themselves can share them with their professional advisors until such times as there are reliable methods of interprofessional communication and a paradigm shift in working practices is achieved.Dentists need to find ways to teach their medical colleagues about the basics of PD, update their medical records, and understand more about medical risks. More research is required.

Mycobacterium tuberculosis : a new hitchhiker in the etiopathogenesis of periodontitis

Periodontitis, a chronic inflammatory disease of the gums affects both the ligament and alveolar bone. A severe form of periodontal disease affects a strikingly high number of one billion adults globally. The disease permutes both the soft and hard tissues of the oral cavity leading to localized and systemic diseases. Periodontitis has a deleterious impact on systemic health causing diabetes, cardiovascular diseases (CVD), and other disease. The cause of the enhanced inflammatory process is due to dysbiosis and an unregulated immune response. Innate immune response and T cells trigger uninhibited cytokine release causing an unwarranted inflammatory response. The RANK- RANKL interaction between osteoblasts, immune cells, and progenitor osteoclasts results in the maturation of osteoclasts, which promote bone resorption. It is well established that dysbiosis of the oral cavity has been implicated in periodontitis. But emerging reports suggest that the pulmonary pathogen, Mycobacterium tuberculosis (Mtb), causes extrapulmonary diseases such as periodontitis. Many clinical case reports advocate the involvement of Mtb in periodontitis, which poses a threat with the surge of tuberculosis in HIV and other immunocompromised individuals. Fostering a better understanding of the mechanism, causative agents and control on inflammatory response is imperative in the prevention and treatment of periodontitis.

Copper Chelation Therapy Attenuates Periodontitis Inflammation through the Cuproptosis/Autophagy/Lysosome Axis

Periodontitis development arises from the intricate interplay between bacterial biofilms and the host's immune response, where macrophages serve pivotal roles in defense and tissue homeostasis. Here, we uncover the mitigative effect of copper chelator Tetrathiomolybdate (TTM) on periodontitis through inhibiting cuproptosis, a newly identified form of cell death which is dependent on copper. Our study reveals concurrent cuproptosis and a macrophage marker within murine models. In response to lipopolysaccharide (LPS) stimulation, macrophages exhibit elevated cuproptosis-associated markers, which are mitigated by the administration of TTM. TTM treatment enhances autophagosome expression and mitophagy-related gene expression, countering the LPS-induced inhibition of autophagy flux. TTM also attenuates the LPS-induced fusion of autophagosomes and lysosomes, the degradation of lysosomal acidic environments, lysosomal membrane permeability increase, and cathepsin B secretion. In mice with periodontitis, TTM reduces cuproptosis, enhances autophagy flux, and decreases Ctsb levels. Our findings underscore the crucial role of copper-chelating agent TTM in regulating the cuproptosis/mitophagy/lysosome pathway during periodontitis inflammation, suggesting TTM as a promising approach to alleviate macrophage dysfunction. Modulating cuproptosis through TTM treatment holds potential for periodontitis intervention.

Microbial- and host immune cell-derived extracellular vesicles in the pathogenesis and therapy of periodontitis: A narrative review

Periodontitis is a chronic inflammatory disease caused by dysbiotic biofilms and destructive host immune responses. Extracellular vesicles (EVs) are circulating nanoparticles released by microbes and host cells involved in cell-to-cell communication, found in body biofluids, such as saliva and gingival crevicular fluid (GCF). EVs are mainly involved in cell-to-cell communication, and may hold promise for diagnostic and therapeutic purposes. Periodontal research has examined the potential involvement of bacterial- and host-cell-derived EVs in disease pathogenesis, diagnosis, and therapy, but data remains scarce on immune cell- or microbial-derived EVs. In this narrative review, we first provide an overview of the role of microbial and host-derived EVs on disease pathogenesis. Recent studies reveal that Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans-derived outer membrane vesicles (OMVs) can activate inflammatory cytokine release in host cells, while M1 macrophage EVs may contribute to bone loss. Additionally, we summarised current in vitro and pre-clinical research on the utilisation of immune cell and microbial-derived EVs as potential therapeutic tools in the context of periodontal treatment. Studies indicate that EVs from M2 macrophages and dendritic cells promote bone regeneration in animal models. While bacterial EVs remain underexplored for periodontal therapy, preliminary research suggests that P. gingivalis OMVs hold promise as vaccine candidates. Finally, we acknowledge the current limitations present in the field of translating immune cell derived EVs and microbial derived EVs in periodontology. It is concluded that microbial and host immune cell-derived EVs have a role in periodontitis pathogenesis and hence may be useful for studying disease pathophysiology, and as diagnostic and treatment monitoring biomarkers.

Influence of Hypoxic Condition on Cytotoxicity, Cellular Migration, and Osteogenic Differentiation Potential of Aged Periodontal Ligament Cells

OBJECTIVE

 This study aimed to investigate and compare the influence of hypoxic conditions on cytotoxicity, cellular migration, and osteogenic differentiation of aged periodontal ligament (PDL) cells.

MATERIALS AND METHODS

 Isolated human PDL cells from aged and young subjects were cultured under hypoxic conditions, which were treated with hydrogen peroxide (H2O2) (0, 25, 50, 100, 200, and 500 µM). To assess cytotoxicity, lactate dehydrogenase release was determined by the optical density at 490 nm, and the percentage of cell death was calculated. An in vitro wound healing assay was performed over 24 to 48 hours for cellular migration determination. Osteogenic differentiation was determined by alizarin red staining and osteogenic gene expression, including the expression of runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), and osteopontin (OPN).

RESULTS

 There was a significant difference in the percentage of cell death with high hypoxic condition (200 and 500 µM) compared to low hypoxic conditions on both day 1 and 2. The highest cellular migration was depicted at 50 µM in both young and aged groups of the in vitro wound healing assay. Osteogenic gene expression of RUNX2 in the aged group was increased at 25 and 50 µM hypoxic condition at day 7, but the expression was gradually decreased after 14 days. On the contrary, the expression of ALP and OPN in the aged group was increased at day 14. Only OPN had been found to be statistically significantly different when compared with gene expression at day 7 and 14 (p < 0.05). The results showed no statistically significant differences when compared with the young and aged groups in all genes and all concentrations.

CONCLUSION

 The concentration of low hypoxic condition (25-50 µM) was proposed to promote cell viability, cellular migration, and osteogenic differentiation in aged PDL cells. We suggested that the potential of aged PDL cells for use in cell therapy for periodontal regeneration might possibly be similar to that of young PDL cells.

Association of phthalate metabolites with periodontitis: a population-based study

BACKGROUND

Widespread exposure to phthalates may raise the probability of various diseases. However, the association of phthalate metabolites with periodontitis remains unclear.

METHODS

Totally 3402 participants from the National Health and Nutrition Examination Survey (NHANES) 2009 to 2014 cycles were enrolled in the cross-sectional investigation. We utilized weighted logistic regression to evaluate the association of ten phthalate metabolites with periodontitis. Restricted cubic spline analysis was applied to investigate potential nonlinear relationships.

RESULTS

The weighted prevalence of periodontitis in the study was 42.37%. A one standard deviation (SD) rise in log-transformed levels of mono-2-ethyl-5-carboxypenty phthalate (MECPP), mono-n-butyl phthalate (MnBP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono-isobutyl phthalate (MiBP), mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono-benzyl phthalate (MBzP) was associated with higher odds of periodontitis, with odds ratios (95% confidence intervals) of 1.08 (1.02-1.14), 1.07 (1.02-1.11), 1.10 (1.05-1.15), 1.05 (1.01-1.09), 1.09 (1.04-1.14), and 1.08 (1.03-1.13), respectively. Individuals with the highest quartile concentrations of MECPP, MnBP, MEHHP, MEOHP, and MBzP were associated with 32%, 20%, 30%, 25%, and 26% increased odds of periodontitis, respectively, compared to those with the lowest quartile. Additionally, mono-(3-carboxypropyl) phthalate (MCPP) demonstrated an interesting inverted J-shaped relationship with periodontitis.

CONCLUSIONS

The findings indicate an association of certain phthalate metabolites with periodontitis among US adults.

Patent Mining on the Use of Antioxidant Phytochemicals in the Technological Development for the Prevention and Treatment of Periodontitis

Periodontal disease is an inflammatory condition characterized by an aberrant immune response against a dysbiotic dental biofilm, with oxidative stress performing an essential role in its pathogenesis. This paper presents a patent mining, performed in the Orbit Intelligence patent database, related to antioxidant phytochemicals in the technological developments that are working to prevent and treat periodontal disease. To access the documents, the descriptors "PERIODONTAL" and "ANTIOXIDANT" were typed in the title, abstract, and claim search fields. A total of 322 patents demonstrate the growing interest in researching natural antioxidants for scientific and technological purposes. The top ten countries regarding the number of family patents produced were the United States, the European Office, Japan, South Korea, China, India, Mexico, Denmark, Canada, and Great Britain. The most cited compounds were vitamin C, green tea, quercetin, melatonin, lycopene, resveratrol, and curcumin. These compounds have been used for the technological development of gels, membranes, dentifrices, chewing gum, orally disintegrating film, mouthwash, mouth spray, and mouth massage cream and exhibit the ability to neutralize free radicals and reduce oxidative stress, a critical factor in the development and progression of periodontal diseases. The patent documents have shown that using antioxidant compounds in conjunction with traditional periodontal treatments is a promising area of interest in periodontal therapy.

Macrophage-enriched novel functional long noncoding RNAs LRRC75A-AS1 and GAPLINC regulate polarization and innate immune responses

INTRODUCTION

Macrophages (Mφs) are functionally dynamic immune cells that bridge innate and adaptive immune responses; however, the underlying epigenetic mechanisms that control Mφ plasticity and innate immune functions are not well elucidated.

OBJECTIVE

To identify novel functions of macrophage-enriched lncRNAs in regulating polarization and innate immune responses.

METHODS

Total RNA isolated from differentiating monocyte-derived M1 and M2 Mφs was profiled for lncRNAs expression using RNAseq. Impact of LRRC75A-AS1, GAPLINC and AL139099.5 knockdown was examined on macrophage differentiation, polarization markers, phagocytosis, and antigen processing by flow cytometry and florescence microscopy. Cytokine profiles were examined by multiplex bead array and cytoskeletal signaling pathway genes were quantified by PCR-based array. Gingival biopsies were collected from periodontally healthy and diseased subjects to examine lncRNAs, M1/M2 marker expression.

RESULTS

Transcriptome profiling of M1 and M2 Mφs identified thousands of differentially expressed known and novel lncRNAs. We characterized three Mφ-enriched lncRNAs LRRC75A-AS1, GAPLINC and AL139099.5 in polarization and innate immunity. Knockdown of LRRC75A-AS1 and GAPLINC downregulated the Mφ differentiation markers and skewed Mφ polarization by decreasing M1 markers without a significant impact on M2 markers. LRRC75A-AS1 and GAPLINC knockdown also attenuated bacterial phagocytosis, antigen processing and inflammatory cytokine secretion in Mφs, supporting their functional role in potentiating innate immune functions. Mechanistically, LRRC75A-AS1 and GAPLINC knockdown impaired Mφ migration by downregulating the expression of multiple cytoskeletal signaling pathways suggesting their critical role in regulating Mφ migration. Finally, we showed that LRRC75A-AS1 and GAPLINC were upregulated in periodontitis and their expression correlates with higher M1 markers suggesting their role in macrophage polarization in vivo.

CONCLUSION

Our results show that polarized Mφs acquire a unique lncRNA repertoire and identified many previously unknown lncRNA sequences. LRRC75A-AS1 and GAPLINC, which are induced in periodontitis, regulate Mφ polarization and innate immune functions supporting their critical role in inflammation.

Periodontitis-induced neuroinflammation impacts dendritic spine immaturity and cognitive impairment

OBJECTIVE

This study investigated the spinal changes in ligature-induced periodontitis and the role of periodontitis in cognitive impairment.

METHODS

Twenty mice were randomized into the control and chronic periodontitis (CP) groups, with the latter receiving ligature-induced periodontitis. Cognitive performance was assessed by fear conditioning test. Periodontal inflammation and alveolar bone resorption were evaluated by micro-computed tomography and histopathology. The hippocampal microglial activation was evaluated by immunohistochemistry (IHC). The expressions of hippocampal cytokines (TNF-α, iNOS, IL-1β, IL-4, IL-10, and TREM2) were measured by reverse transcription-polymerase chain reaction. The morphology and density of the dendritic spines were determined by Golgi-Cox staining.

RESULTS

The CP mice reported significant inflammatory cell infiltration and alveolar bone resorption, with marked increases in cytokine levels (TNF-α, iNOS, IL-1β, and TREM2) in the brain. Moreover, the CP mice showed significantly reduced freezing to the conditioned stimulus in the cued and contextual tests, indicating impaired memory. Further analyses revealed, in the hippocampus of the CP mice, enhanced microglial activation, decreased dendritic spine density, and increased proportion of thin dendritic spines.

CONCLUSIONS

Periodontitis-induced neuroinflammation may impair the cognitive function by activating hippocampal microglia and inducing dendritic spine immaturity.

Identifying MS4A6A+ macrophages as potential contributors to the pathogenesis of nonalcoholic fatty liver disease, periodontitis, and type 2 diabetes mellitus

Purpose

Concrete epidemiological evidence has suggested the mutually-contributing effect respectively between nonalcoholic fatty liver disease (NAFLD), type 2 diabetes mellitus (T2DM), and periodontitis (PD); however, their shared crosstalk mechanism remains an open issue.

Method

The NAFLD, PD, and T2DM-related datasets were obtained from the NCBI GEO repository. Their common differentially expressed genes (DEGs) were identified and the functional enrichment analysis performed by the DAVID platform determined relevant biological processes and pathways. Then, the STRING database established a PPI network of such DEGs and topological analysis through Cytoscape 3.7.1 software along with the machine-learning analysis by the least absolute shrinkage and selection operator (LASSO) algorithm screened out hub characteristic genes. Their efficacy was validated by external datasets using the receiver operating characteristic (ROC) curve, and gene expression and location of the most robust one was determined using single-cell sequencing and immunohistochemical staining. Finally, the promising drugs were predicted through the CTD database, and the CB-DOCK 2 and Pymol platform mimicked molecular docking.

Result

Intersection of differentially expressed genes from three datasets identified 25 shared DEGs of the three diseases, which were enriched in MHC II-mediated antigen presenting process. PPI network and LASSO machine-learning analysis determined 4 feature genes, of which the MS4A6A gene mainly expressed by macrophages was the hub gene and key immune cell type. Molecular docking simulation chosen fenretinide as the most promising medicant for MS4A6A+ macrophages.

Conclusion

MS4A6A+ macrophages were suggested to be important immune-related mediators in the progression of NAFLD, PD, and T2DM pathologies.

Advances in periodontal biomarkers

Due to technologic advancements, periodontology has witnessed a boost in biomarker research over the past three decades. Indeed, with the aid of omics, our understanding of the healthy periodontium, pathogenesis of periodontal diseases, and healing after periodontal treatment has improved significantly. Yet, the traditional methods, periodontal probing and radiographies, remain the most common methods to diagnose periodontal disease and monitor treatment. Although these approaches can produce reliable diagnostic outcomes, they generally detect disease only after significant tissue degradation thus making treatment outcome highly uncertain. Accordingly, laboratories worldwide have collaborated with clinicians to design accurate, rapid and cost-effective biomarkers for periodontal disease diagnosis. Despite these efforts, biomarkers that can be widely used in early disease diagnosis and for treatment outcome prediction are far from daily use. The aim of this chapter is to give a general overview on periodontal health and diseases, and review recent advancements in periodontal biomarker research. A second aim will discuss the strengths and limitations of translating periodontal biomarker research to clinical practice. Genetic biomarkers of periodontitis are not discussed as the available confirmatory data is scarce.

Preventive and Therapeutic Potential of Streptococcus cristatus CA119 in Experimental Periodontitis in Rats

Periodontitis is an inflammatory condition of the oral cavity caused by a mixed infection of various bacteria, which not only severely affects the alveolar bone and connective tissues but also displays potential correlations with distal intestinal inflammation. In this study, we aimed to elucidate the therapeutic effects of Streptococcus cristatus CA119 on experimental periodontitis in rats and its impact on intestinal morphology. The results demonstrate that CA119 is capable of colonizing the oral cavity and exerting antagonistic effects on Porphyromonas gingivalis and Fusobacterium nucleatum, thus leading to a significant reduction in the oral pathogen load. Following CA119 intervention, there was a significant alleviation of weight loss in rats induced by periodontitis (P < 0.001). CA119 also regulated the expression of IL-6 (P < 0.05), IL-1β (P < 0.001), IL-18 (P < 0.001), COX-2 (P < 0.001), iNOS (P < 0.001), and MCP-1 (P < 0.01) in the gingival tissue. Additionally, CA119 reduced oxidative stress levels in rats and enhanced their antioxidant capacity. Microcomputed tomography (micro-CT) and histological analysis revealed that CA119 significantly reduced alveolar bone loss and reversed the downregulation of OPG/RANKL (P < 0.001). Furthermore, CA119 exhibited a significant protective effect against intestinal inflammation induced by periodontal disease and improved the colonic morphology in rats. In conclusion, this study demonstrates the role of CA119 as a potential oral probiotic in the prevention and treatment of experimental periodontitis, underscoring the potential of probiotics as a complementary approach to traditional periodontal care.

Effect of initial periodontal therapy on metallothionein levels in smokers and non-smokers with periodontitis

The aim of this study was to determine the effect of non-surgical periodontal therapy (NSPT) on mRNA expression of metallothionein (MT) and its levels in serum, saliva and gingival crevicular fluid (GCF) of smokers (S) and non-smokers (NS) with periodontitis (P).A total of 100 participants were included: 48 periodontally healthy (PH) subjects (24 S [PH + S] and 24 NS [PH + NS]) and 52 patients with P (27 S [P + S] and 25 NS [P + NS]). Clinical parameters were recorded, and biofluids (serum, saliva and GCF) and gingival tissue samples were obtained at baseline in all groups and 3 months after NSPT in P groups. MT levels in biofluids were determined by ELISA. In gingival tissues, MT-mRNA expression was quantified using real-time PCR. mRNA expression of MT and its levels in biofluids were significantly higher in P + S compared to other groups, and the differences between P + NS and PH + S were non-significant. A significant decrease was observed for MT levels in biofluids, and MT-mRNA expression in periodontitis patients after NSPT. In conclusion, smoking and periodontitis are associated with higher MT expression which decreases after NSPT. MT as an oxidative stress biomarker and its therapeutic role in periodontitis should be investigated in future studies.Clinical trial registration: The study was prospectively registered at Clinical Trials Registry-India (ctri.nic.in) as CTRI/2018/08/015427 on August 23, 2018.

Toll-like receptor-2 induced inflammation causes local bone formation and activates canonical Wnt signaling

It is well established that inflammatory processes in the vicinity of bone often induce osteoclast formation and bone resorption. Effects of inflammatory processes on bone formation are less studied. Therefore, we investigated the effect of locally induced inflammation on bone formation. Toll-like receptor (TLR) 2 agonists LPS from Porphyromonas gingivalis and PAM2 were injected once subcutaneously above mouse calvarial bones. After five days, both agonists induced bone formation mainly at endocranial surfaces. The injection resulted in progressively increased calvarial thickness during 21 days. Excessive new bone formation was mainly observed separated from bone resorption cavities. Anti-RANKL did not affect the increase of bone formation. Inflammation caused increased bone formation rate due to increased mineralizing surfaces as assessed by dynamic histomorphometry. In areas close to new bone formation, an abundance of proliferating cells was observed as well as cells robustly stained for Runx2 and alkaline phosphatase. PAM2 increased the mRNA expression of Lrp5, Lrp6 and Wnt7b, and decreased the expression of Sost and Dkk1. In situ hybridization demonstrated decreased Sost mRNA expression in osteocytes present in old bone. An abundance of cells expressed Wnt7b in Runx2-positive osteoblasts and ß-catenin in areas with new bone formation. These data demonstrate that inflammation, not only induces osteoclastogenesis, but also locally activates canonical WNT signaling and stimulates new bone formation independent on bone resorption.

Oxytocin alleviates periodontitis in adult rats

OBJECTIVE

The objective of the study was to evaluate the expression of oxytocin receptors in normal and inflamed gingiva, as well as the effects of systemic administration of oxytocin in bone loss and gum inflammatory mediators in a rat model of experimental periodontitis.

BACKGROUND DATA

Current evidence supports the hypothesis of a disbalance between the oral microbiota and the host's immune response in the pathogenesis of periodontitis. Increased complexity of the microbial biofilm present in the periodontal pocket leads to local production of nitrogen and oxygen-reactive species, cytokines, chemokines, and other proinflammatory mediators which contribute to periodontal tissue destruction and bone loss. Oxytocin has been suggested to participate in the modulation of immune and inflammatory processes. We have previously shown that oxytocin, nitric oxide, and endocannabinoid system interact providing a mechanism of regulation for systemic inflammation. Here, we aimed at investigating not only the presence and levels of expression of oxytocin receptors on healthy and inflamed gingiva, but also the effects of oxytocin treatment on alveolar bone loss, and systemic and gum expression of inflammatory mediators involved in periodontal tissue damage using ligature-induced periodontitis. Therefore, anti-inflammatory strategies oriented at modulating the host's immune response could be valuable adjuvants to the main treatment of periodontal disease.

METHODS

We used an animal model of ligature-induced periodontitis involving the placement of a linen thread (Barbour flax 100% linen suture, No. 50; size 2/0) ligature around the neck of first lower molars of adult male rats. The ligature was left in place during the entire experiment (7 days) until euthanasia. Animals with periodontitis received daily treatment with oxytocin (OXT, 1000 μg/kg, sc.) or vehicle and/or atosiban (3 mg/kg, sc.), an antagonist of oxytocin receptors. The distance between the cement-enamel junction and the alveolar bone crest was measured in stained hemimandibles in the long axis of both buccal and lingual surfaces of both inferior first molars using a caliper. TNF-α levels in plasma were determined using specific rat enzyme-linked immunosorbent assays (ELISA). OXT receptors, IL-6, IL-1β, and TNF-α expression were determined in gingival tissues by semiquantitative or real-time PCR.

RESULTS

We show that oxytocin receptors are expressed in normal and inflamed gingival tissues in male rats. We also show that the systemic administration of oxytocin prevents the experimental periodontitis-induced increased gum expression of oxytocin receptors, TNF-α, IL-6, and IL-1β (p < .05). Furthermore, we observed a reduction in bone loss in rats treated with oxytocin in our model.

CONCLUSIONS

Our results demonstrate that oxytocin is a novel and potent modulator of the gingival inflammatory process together with bone loss preventing effects in an experimental model of ligature-induced periodontitis.

Rhein induces bone regeneration via alleviating inflammation in murine periodontitis model

OBJECTIVE

To evaluate the effect of rhein on eliminating the inflammation and promoting bone regeneration of periodontitis after local administration.

MATERIALS AND METHODS

In vivo, periodontitis model was established in murine mandibular first molar by using ligature for 7 days, followed by ligature removal and local administration of rhein/vehicle for 7 consecutive days. In vitro, periodontal ligament fibroblasts were treated by LPS, along with the applications of rhein/vehicle. Histology and molecular biology approaches were applied for analysis.

RESULTS

In vivo, rhein alleviated periodontitis inflammation through downregulating the inflammatory index and promoted the osteogenic potential of PDL fibroblasts in a dosage-dependent manner. The result of micro-CT validated this phenomenon. In vitro, rhein administration inhibited the phosphorylation and nuclear translocation of P65, along with the arose runx2 level of PDL fibroblasts with the stimulus of LPS in mimicking periodontitis.

CONCLUSION

Rhein played its inhibitory role on inflammation via curbing the activation of P65 but uprising the activities of Runx2 in PDL fibroblasts in periodontitis microenvironment. These data suggested that rhein could be an effective and potential clinical choice for the treatment of periodontitis.

Obesity and Oral Health: The Link Between Adipokines and Periodontitis

Periodontitis is a chronic inflammatory disease of the periodontium, or the supportive tissues around the tooth. This disease has been related to different risk factors, such as the presence of plaque and calculus, tobacco smoking, low socioeconomic status, and the immune state of the host. Importantly, the chronic inflammatory environment generated by periodontitis may lead to tooth loss and diverse systemic complications, such as cardiovascular disease, osteoarthritis and metabolic disease. Recent investigations have supported the role of obesity as a risk factor for periodontitis. Furthermore, studies have found obesity to compromise healing after periodontal therapy; however, the mechanisms underlying this association are not well understood. Proteins called 'adipokines' could be the factor linking obesity to periodontitis. Adipokines are bioactive molecules with hormonal properties and a structure similar to cytokines produced by the adipose tissue. Although adipokines have both pro-and anti-inflammatory effects, the shift towards pro-inflammatory actions occurs when the adipose tissue becomes pathological, as observe in the progression of conditions such as obesity or adiposopathy. This article reviews the role of adipokines in the pathophysiology and progression of periodontitis by focusing on their impact on inflammation and the molecular mechanisms through which adipokines contribute to the onset and development of periodontitis.