The case for periodontitis in the pathogenesis of rheumatoid arthritis

Hepcidin-regulated iron metabolism disorders in patients with stage III/IV periodontitis

Background

/purposeThe disorders of iron metabolism in periodontal diseases have been reported, however, there is still lack of comprehensive and thorough analyses about the association between periodontitis and iron metabolism disorders. This study aimed to examine the association between periodontitis and iron metabolism disorders, and to analyze the characteristic changes of iron metabolism in periodontitis patients.

Materials and methods

79 Stage III/IV periodontitis patients and 79 healthy controls were enrolled in this study. Periodontal clinical parameters, system inflammation markers, iron metabolism parameters and hematological parameters were collected and compared at baseline and 3 months after non-surgical periodontal therapy.

Results

Stage III/IV periodontitis patients exhibited higher levels of systemic inflammatory markers including white blood cell (WBC) counts and high-sensitivity C-reactive protein (hs- CRP). Serum hepcidin and ferritin were significantly increased in the periodontitis group, meanwhile serum iron and transferrin were significantly decreased. Periodontal therapy attenuated the higher levels of hepcidin and ferritin, and the lower levels of Fe and transferrin in periodontitis patients at 3 months after therapy. Probing depth (PD), bleeding index (BI) and clinical attachment loss (CAL) were positively correlated with hepcidin and ferritin, and negatively correlated with Fe and transferrin respectively. Hepcidin was significantly negatively correlated with Fe and positively correlated with ferritin in periodontitis patients.

Conclusion

Our findings suggest the association between periodontitis and iron metabolism disorders and indicate that periodontitis-activated host responses may increase the risk of iron metabolism disorders, while meaningfully provide new insights into the systemic effects of periodontitis.

Association between antibiotic use and the risk of rheumatoid arthritis: a retrospective cohort study in South Korea

OBJECTIVES

Certain studies propose that antibiotic use may influence RA incidence, but the clear association between antibiotics and RA remains unclear. Therefore, this study aimed to examine the relationship between antibiotics and RA risk to provide additional epidemiological evidence.

METHODS

This population-based retrospective cohort study was conducted with adults aged 40 years or older using the Korean National Health Insurance Service database. Antibiotic exposure was measured from 2003 to 2007. Study participants were followed up from 1 January 2008 to 31 December 2019. Multivariable Cox hazard regression was utilized to evaluate adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for the risk of RA according to accumulative days of antibiotic use and the number of antibiotic classes used, respectively.

RESULTS

During 3 395 590 person-years of follow-up, 29 274 cases of RA were identified. Participants who used antibiotics for 91 or more days had a higher risk of RA (aHR, 1.79; 95% CI, 1.67-1.92) than antibiotic non-users. Additionally, individuals who used four or more kinds of antibiotic classes had a higher risk of RA (aHR, 1.61; 95% CI, 1.51-1.71) than those who did not prescribe antibiotics. The risk of RA was positively associated with both higher cumulative days of antibiotic exposure and a larger number of drug classes. These trends were maintained in sensitivity analyses, including variations in antibiotic exposure periods.

CONCLUSION

Our findings suggest a possible association between the long-term use of antibiotics and RA incidence. Further studies are necessary for a clearer understanding of this association.

Impact of increased Porphyromonas gingivalis peptidylarginine deiminase (PPAD) T2 variant allele on oral microbiota composition and severity of chronic periodontitis

Background

Porphyromonas gingivalis (Pg) is a keystone pathogen in periodontitis, encoding a unique peptidyl arginine deiminase (PPAD) linked to protein citrullination, a process associated with rheumatoid arthritis (RA). Recently, we identified a super-active PPAD variant (T2) in Pg isolates. Here, we evaluated if the presence of the super-active T2 variant of PPAD affects the salivary microbiome, the severity of chronic periodontitis (CP), and subsequently CP's causative association with RA onset/progression.

Patients/Materials and Methods

We examined 56 CP patients and 36 healthy volunteers. Pg and Tannerella forsythia counts were measured via RT-PCR, and PPAD variant was typed via PCR. 16S rRNA from salivary DNA sequencing characterized microbiota composition, while CP severity was assessed through bleeding on probing (BoP), clinical attachment loss (CAL), and pocket depth (PD) parameters.

Results

CP patients exhibited higher Pg and T. forsythia counts, with 30.7% harbouring the PPAD-T2 variant, compared to only one healthy volunteer. Clinical CP parameters were unaffected by the PPAD variant. However, PPAD-T2 influenced oral microbiota composition, enriching certain genera.

Conclusion

While the PPAD variant did not affect CP severity, it influenced oral microbiota composition. Further research is needed to understand citrullination's role in oral microbiota and chronic inflammatory disease development.

Comparative Analysis of Salivary and Serum Inflammatory Mediator Profiles in Patients With Rheumatoid Arthritis and Periodontitis

Background: Periodontitis (PD) and rheumatoid arthritis (RA) are chronic inflammatory conditions, characterized by dysregulated immune response and excessive production of inflammatory mediators. The oral disease PD is triggered by periodontal pathogens, leading to the destruction of tissues surrounding the teeth, whereas RA is a systemic autoimmune disease primarily affecting the joints. The objective of this study was to investigate the prevalence of PD and map the profile of salivary and serum inflammatory mediators of patients with RA, with respect to periodontal severity (PD stage II and PD stage III/IV). Methods: For this cross-sectional cohort study, 62 patients diagnosed with RA were recruited. All participants underwent a full-mouth dental examination. Levels of various inflammatory mediators, including tumor necrosis factor (TNF) superfamily proteins, interferon (IFN) family proteins, regulatory T cell (Treg) cytokines, and matrix metalloproteinases were determined in saliva and serum samples from each participant using a human inflammation multiplex immunoassay panel. Results: In the current RA cohort, all participants were diagnosed with PD, of which 35.5% were classified as PD stage II and 64.5% as PD stages III/IV. Inflammatory mediator levels were significantly higher in both saliva and serum samples from patients with RA and PD stages III/IV, compared to those with RA and stage II within the same cohort. These included higher serum levels of sCD30, IL-10, IL-19, osteopontin and elevated salivary levels of BAFF/TNFSF13B and IFN-α2. Additionally, APRIL/TNFSF13 levels were increased in both saliva and serum. Conclusions: Among the studied patients with RA, the majority exhibited severe PD (stage III/IV), underscoring the importance of periodontal prophylaxis and treatment for this group of patients. Higher levels of inflammatory mediators were observed in both saliva and serum in those with PD stages III/IV, suggesting a potential link between the severity of PD and systemic inflammation in RA. Further research is needed to explore the clinical implications of these findings.

Correlation of periodontitis with hepatic and intestinal inflammation and glycemic control, and effects of bioconverted Artemisia herba-alba by Lactiplantibacillus plantarum SMFM2016-RK

Periodontitis has been linked to systemic inflammation, however research on its role in causing systemic diseases remains limited. Recent studies explore probiotics for microbiome modulation and enhancing natural compound bioavailability. This study investigated periodontitis-related systemic disease mechanisms, and evaluated the mitigation effects of bioconversion product using Lactiplantibacillus plantarum SMFM2016-RK and Artemisia herba-alba extracts. Four types of bioconverted milk [BM1 (L. plantarum SMFM2016-RK), BM2 (BM1 + A. herba-alba ethanol extract), BM3 (BM1 + A. herba-alba hot-water extract), and BM4 (BM1+ both A. herba-alba extracts)] were studied in a periodontitis-induced rat model. Rats were divided into six groups: normal control, skim milk with ligature, and four BM groups with ligature.   Periodontitis induction elevated trabecular resorption (0.325 ± 0.057 mm³) and histopathological symptoms. Serum ALT (55.6 ± 6.6 U/L), glucose (261.7 ± 64.3 mg/dL), insulin (1.90 ± 0.87 ng/mL), inflammation in the liver and colon, and gluconeogenesis-related enzyme expression increased. Periodontitis-induced rats showed gut dysbiosis, with decreased Lactobacillaceae level and increased Oscillospiraceae level. BM3 administration significantly reduced the serum glucose (190.9 ± 27.8 mg/dL), ALT (40.5 ± 5.0 U/L), inflammation, and gluconeogenesis-related enzymes, while increasing tight junction proteins expression and phylum Actinobacteria levels in the gut microbiome. The findings highlight the systemic impact of periodontitis on inflammation, glycemic control, and gut microbiome balance. BM3 effectively alleviated these effects suggesting therapeutic potential.

Development of an injectable salicylic acid-choline eutectic hydrogel for enhanced treatment of periodontitis

Periodontitis, a chronic inflammatory disease triggered by dental plaque, often presents challenges in management, particularly in severe cases where mechanical debridement alone may be insufficient. As a result, adjunctive therapies, particularly localized drug delivery systems with both antimicrobial and anti-inflammatory properties, are essential to enhance the efficacy of periodontitis management. In this study, we developed a multifunctional hydrogel by incorporating a salicylic acid-choline deep eutectic solvent (DES) into a chitosan/β-glycerol phosphate sodium (CS/GP) hydrogel matrix for the treatment of periodontitis. The DES-CS/GP hydrogel demonstrated favorable physicochemical properties, including gelation and injectability, making it highly suitable for application in the oral cavity. The hydrogel effectively inhibited the growth of key periodontal pathogens, Porphyromonas gingivalis and Fusobacterium nucleatum, and significantly downregulated the expression of pro-inflammatory cytokines TNF-α and IL-1β in vitro. Cytocompatibility assessments showed over 80% cell viability in human gingival fibroblasts, human gingival epithelial cells, and human oral keratinocytes over 5 days treated with DES-CS/GP, with fluorescence microscopy confirming robust cytoskeletal integrity. Furthermore, the hydrogel enhanced permeability through gingival tissues in vitro. In a rat model of periodontitis, the hydrogel significantly mitigated bone loss, reduced bacterial loads of P. g, and suppressed TNF-α and IL-1β expression in gingival tissues. These findings underscore the hydrogel's potential as a safe and effective adjunctive therapy for periodontitis, offering a combination of antimicrobial, anti-inflammatory, and tissue-permeating properties with high biosafety and ease of application.

Unraveling the Complex Nexus of Macrophage Metabolism, Periodontitis, and Associated Comorbidities

BACKGROUND

Periodontitis is recognized as one of the most prevalent oral dysbiotic inflammatory diseases, ultimately leading to the irreversible destruction of periodontal tissues. Macrophages play a pivotal role in the development and progression of periodontitis, and the feasibility of targeting them therapeutically has been established. Since metabolic switching significantly contributes to macrophage regulation, conducting an in-depth review of macrophage metabolism in periodontitis may serve as the foundation for developing innovative treatments.

SUMMARY

This paper has been carefully reviewed to provide a comprehensive overview of the roles played by macrophages in periodontitis and associated comorbidities. Initially, detailed presentations on the metabolic reprogramming of macrophages, including glucose, lipid, and amino acid metabolism, were provided. Subsequently, dominating macrophage phenotype and metabolism under lipopolysaccharide (LPS) stimulation or during periodontitis were presented with emphasize on critical molecules involved. Furthermore, in recognition of the close association between periodontitis and several comorbidities, the interaction among macrophage metabolism, periodontitis, and related metabolic diseases, was thoroughly discussed.

KEY MESSAGES

Through the examination of current research on macrophage metabolic reprogramming induced by periodontitis, this review provides potential immunometabolic therapeutic targets for the future and raises many important, yet unstudied, subjects for follow-up.

BACKGROUND

Periodontitis is recognized as one of the most prevalent oral dysbiotic inflammatory diseases, ultimately leading to the irreversible destruction of periodontal tissues. Macrophages play a pivotal role in the development and progression of periodontitis, and the feasibility of targeting them therapeutically has been established. Since metabolic switching significantly contributes to macrophage regulation, conducting an in-depth review of macrophage metabolism in periodontitis may serve as the foundation for developing innovative treatments.

SUMMARY

This paper has been carefully reviewed to provide a comprehensive overview of the roles played by macrophages in periodontitis and associated comorbidities. Initially, detailed presentations on the metabolic reprogramming of macrophages, including glucose, lipid, and amino acid metabolism, were provided. Subsequently, dominating macrophage phenotype and metabolism under lipopolysaccharide (LPS) stimulation or during periodontitis were presented with emphasize on critical molecules involved. Furthermore, in recognition of the close association between periodontitis and several comorbidities, the interaction among macrophage metabolism, periodontitis, and related metabolic diseases, was thoroughly discussed.

KEY MESSAGES

Through the examination of current research on macrophage metabolic reprogramming induced by periodontitis, this review provides potential immunometabolic therapeutic targets for the future and raises many important, yet unstudied, subjects for follow-up.

New thoughts on the gut-immune axis of arthritis

Arthritis is associated with varying degrees of intestinal inflammation and microbiota dysbiosis, leading to the 'gut-joint axis hypothesis' in which intestinal and joint inflammation are suggested to be interconnected through immune-microbiota interactions. While clinical observations support this, causality remains uncertain. Rodent models have provided insights into potential mechanisms by uncovering microbial influences and immune pathways that either connect or uncouple gut and joint inflammation. Based on recent findings, we propose the 'immune hypersensitivity hypothesis' whereby central immune hyper-reactivity can independently drive joint inflammation via local sterile triggers, and gut inflammation via microbial triggers. We argue that this suggests a more nuanced role of the microbiota in arthritis pathogenesis that varies according to the predominant immune mechanisms in disease subtypes. We explore gut-immune interactions in arthritis, highlight ongoing challenges, and propose future research directions.

Nanocapsuled Neutrophil Extracellular Trap Scavenger Combating Chronic Infectious Bone Destruction Diseases

Chronic infectious bone destruction diseases, such as periodontitis, pose a significant global health challenge. Repairing the bone loss caused by these chronic infections remains challenging. In addition to pathogen removal, regulating host immunity is imperative. The retention of neutrophil extracellular traps (NETs) in chronic infectious niches is found to be a barrier to inflammation resolution. However, whether ruining the existing NETs within the local infectious bone lesions can contribute to inflammation resolve and bone repair remains understudied. Herein, a nanocapsuled delivery system that scavenges NETs dual-responsively to near-infrared light as a switch and to NETs themselves as a microenvironment sensor is designed. Besides, the photothermal and photodynamic effects endow the nanocapsules with antibacterial properties. Together with the ability to clear NETs, these features facilitate the restoration of the normal host response. The immunocorrective properties and inherent pro-osteogenic effects finally promote local bone repair. Together, the NET scavenging nanocapsules address the challenge of impaired bone repair in chronic infections due to biased host response caused by excessive NETs. This study provides new concepts and strategies for repairing bone destruction attributable to chronic infections via correcting biased host responses in chronic infectious diseases.

Metabolism-epigenetic interaction-based bone and dental regeneration: From impacts and mechanisms to treatment potential

Metabolic pathways exhibit fluctuating activities during bone and dental loss and defects, suggesting a regulated metabolic plasticity. Skeletal remodeling is an energy-demanding process related to altered metabolic activities. These metabolic changes are frequently associated with epigenetic modifications, including variations in the expression or activity of enzymes modified through epigenetic mechanisms, which directly or indirectly impact cellular metabolism. Metabolic reprogramming driven by bone and dental conditions alters the epigenetic landscape by modulating the activities of DNA and histone modification enzymes at the metabolite level. Epigenetic mechanisms modulate the expression of metabolic genes, consequently influencing the metabolome. The interplay between epigenetics and metabolomics is crucial in maintaining bone and dental homeostasis by preserving cell proliferation and pluripotency. This review, therefore, aims to examine the effects of metabolic reprogramming in bone and dental-related cells on the regulation of epigenetic modifications, particularly acetylation, methylation, and lactylation. We also discuss the effects of chromatin-modifying enzymes on metabolism and the potential therapeutic benefits of dietary compounds as epigenetic modulators. In this review, we highlight the inconsistencies in current research findings and suggest potential approaches to translate fundamental insights into clinical treatments for bone and tooth diseases.

Periodontitis associated with brain function impairment in middle-aged and elderly individuals with normal cognition

BACKGROUND

The present study aimed to investigate changes in intranetwork functional connectivity (FC) and internetwork FC in middle-aged and elderly individuals with normal cognition (NC) and varying degrees of periodontitis to determine the effects of periodontitis on brain function.

METHODS

Periodontal findings and resting-state functional magnetic resonance imaging data were acquired from 51 subjects with NC. Independent component analysis and correlation analysis were used for the statistical analysis of the data.

RESULTS

Differences in intranetwork FC were observed among groups in the anterior default-mode network (aDMN), dorsal attention network and dorsal sensorimotor network (dSMN). Compared with the nonperiodontitis (NP) group or the mild-periodontitis group, the analysis of internetwork FC showed increased FC between the auditory network and the ventral attention network (VAN), between the aDMN and the salience network (SN), and between the SN and the VAN and decreased FC between the posterior default-mode network and the right frontoparietal network in the moderate-to-severe periodontitis group. Additionally, internetwork FC between the dSMN and the VAN was also increased in the moderate-to-severe periodontitis group compared to the NP group. The altered intra- and internetwork FC were significantly correlated with the periodontal clinical index.

CONCLUSION

Our results confirmed that periodontitis was associated with both intra- and internetwork FC changes even in NC. The present study indicates that periodontitis might be a potential risk factor for brain damage and provides a theoretical clue and a new treatment target for the early prevention of Alzheimer disease.

PLAIN LANGUAGE SUMMARY

Recent research has proposed that periodontitis is a potential risk factor for Alzheimer disease (AD). However, the relationship between periodontitis and the brain function of middle-aged and elderly individuals with normal cognition (NC) remains unclear. Analyzing the effect of periodontitis on brain function in the NC stage can provide clues to AD development and help achieve early prevention of dementia. The present study aimed to investigate changes in brain functional connectivity (FC) in NC with different severity of periodontitis to determine the effects of periodontitis on brain function. Both changed intranetwork FC and internetwork FC were found in the moderate-to-severe periodontitis group, and periodontitis was associated with brain network function impairment in NC. The present study indicates that periodontitis might be a potential risk factor for brain damage even in NC stage, and provides a theoretical clue and a new treatment target for the early prevention of AD.

Plant and animal-derived fusion nanovesicles rescue inflammation-compromised osteogenic potential of periodontal ligament stem cells

Periodontitis is a chronic inflammatory disease affecting the supporting tissues of the teeth and has emerged as a global public health issue. Current therapies primarily address pathogenic factors and alleviate symptoms, with limited options available for complete restoration and reconstruction of already absorbed periodontal bone tissue. In this study, we developed a nanotherapeutic strategy utilizing fusion nanovesicles (FVs) to modulate the inflammatory microenvironment and create a regenerative niche for periodontal ligament stem cells (PDLSCs), which play a crucial role in periodontal tissue repair. The FVs are composed of Scutellaria baicalensis nanovesicles (SBNVs) with anti-Porphyromonas gingivalis (P. gingivalis) and anti-inflammatory properties, combined with PDLSC membrane-derived nanovesicles genetically engineered to express TNFR1. These FVs preserved the biological activity of SBNVs and the immunomodulatory function of PDLSCs. Additionally, FVs effectively captured and cleared TNF-α from the microenvironment through TNFR1. Moreover, FVs alleviated the inflammatory response of PDLSCs induced by P. gingivalis-LPS (Pg-LPS) and TNF-α, restoring their proliferation, migration, and osteogenic differentiation capabilities. Hence, this nanotherapeutic strategy holds great potential for treating periodontitis.

Revolutionizing oral care: Reactive oxygen species (ROS)-Regulating biomaterials for combating infection and inflammation

The human oral cavity is home to a delicate symbiosis between its indigenous microbiota and the host, the balance of which is easily perturbed by local or systemic factors, leading to a spectrum of oral diseases such as dental caries, periodontitis, and pulp infections. Reactive oxygen species (ROS) play crucial roles in the host's innate immune defenses. However, in chronic inflammatory oral conditions, dysregulated immune responses can result in excessive ROS production, which in turn exacerbates inflammation and causes tissue damage. Conversely, the potent antimicrobial properties of ROS have inspired the development of various anti-infective therapies. Therefore, the strategic modulation of ROS by innovative biomaterials is emerging as a promising therapeutic approach for oral infection and inflammation. This review begins by highlighting the state-of-the-art of ROS-regulating biomaterials, which are designed to generate, scavenge, or modulate ROS in a bidirectional manner. We then delve into the latest innovations in these biomaterials and their applications in treating a range of oral diseases, including dental caries, endodontic and periapical conditions, periodontitis, peri-implantitis, and oral candidiasis. The review concludes with an overview of the current challenges and future potential of these biomaterials in clinical settings. This review provides novel insights for the ongoing development of ROS-based therapeutic strategies for oral diseases.

Exploring the Genetic and Functional Diversity of Porphyromonas gingivalis Survival Factor RagAB

Porphyromonas gingivalis is a key pathogen in periodontitis. Its outer membrane contains the RagAB transport complex, which has been implicated in protein uptake, essential for a proteolytic species. RagA is a 22-stranded β-barrel, and RagB is the corresponding 4-TPR lid, together forming a TonB-dependent system acting as a "pedal bin". Four different alleles were observed, of which ragAB-1 is more virulent than the others. Our aim was to map ragAB in 129 strains of P. gingivalis and related species available in our collection, supported by a newly introduced universal PCR for amplification/sequencing of all four ragA variants and to find reasons for the differences in virulence and/or fitness. Regarding the PCR method, by pairing established Long-PCR primers with our newly designed sequencing primers (ragA-F0, -F1, -R2, -R2a, -R4), it was possible to amplify and sequence all four ragA variants. The same was not possible for ragB due to high heterogeneity. The mapping allowed us to type all strains into ragAB-1-4. For each type, some strains (of mainly animal origin such as Porphyromonas gulae) with slightly different amino acid sequences were identified (designated ragAB-1a to -4a). In terms of function, the transfer of recently discovered SusCD information to the similar RagAB complex provided new insights. Substrate specificity as well as length of pedal could be the route to differential virulence (survival rate, fitness) as Rag-1 (closer related to Rag-3/4) and Rag-2 were found to be massively different here. In general, substrate-ligand-binding sites seem to be quite variable with the exception of Rag-1, probably indicating nutritional preferences. In addition, an insertion (8 aa long) found in loop L7 throughout RagA-2 could not only affect the dynamics of lid opening/closing but might also alter the associated substrate throughput rate.

The association between periodontal disease and adverse pregnancy outcomes: a bibliometric analysis from 2000 to 2023

Background

Periodontal disease (PD) refers to a chronic inflammatory disorder affecting the supporting tissues of the teeth triggered by bacterial infection and is recognized to promote systemic inflammation, leading to dysfunction in specific organs. Adverse pregnancy outcomes (APOs), including preterm birth, small for gestational age infants, gestational diabetes and preeclampsia, are linked to pregnancy complications. Recently, the correlation between periodontal disease and adverse pregnancy outcomes has garnered global attention. However, bibliometric studies in this area remain limited. This study aimed to visualize knowledge framework and research trends concerning the relationship between periodontal disease and adverse pregnancy outcomes from 2000 to 2023 through bibliometric approaches.

Methods

On September 22, 2024, articles and reviews on the connection between periodontal disease and adverse pregnancy outcomes were retrieved from the Web of Science Core Collection (WOSCC). CiteSpace [6.3.R1 (64-bit) Advanced] was used to perform knowledge mapping and bibliometric studies.

Results

Over the past 23 years, 932 articles from 73 countries were collected, with the U.S. contributing over one-third (355), followed by Brazil (85) and India (59). The literature in this field has experienced multiple growth phases since 2000, with particularly rapid growth observed after 2019. The University of North Carolina (n = 34, 3.65%) is the leading institution in terms of publication output, primarily representing the U.S. Notably, the Journal of Periodontology and the American Journal of Obstetrics and Gynecology are the most frequently cited journals in the fields of periodontology and obstetrics, respectively. These publications are authored by 94 researchers, with Steven Offenbacher being both the most productive and most highly cited author, making significant contributions to the field. A visual analysis of keywords identifies "oral microbiota," "oral health," "adverse pregnancy outcomes," and "global burden" as emerging research hotspots in exploring the correlation between periodontal disease and adverse pregnancy outcomes.

Conclusions

This first bibliometric and visual analysis of periodontal disease and adverse pregnancy outcomes offers a concise overview of the field and suggests future research should focus on risk factors, high-risk populations, oral microbiota, mechanisms, interventions, and international collaboration.

A human oral commensal-mediated protection against Sjögren's syndrome with maintenance of T cell immune homeostasis and improved oral microbiota

Sjögren's syndrome (SS) is a prevalent systemic autoimmune disease with substantial impacts on women's health worldwide. Although oral Haemophilus parainfluenzae is reduced in SS, its significance remains unclear. This study aimed to elucidate the pathophysiological role of H. parainfluenzae in SS. Reduced salivary H. parainfluenzae levels in SS patients were confirmed through quantitative PCR. Oral H. parainfluenzae inoculation in NOD mice alleviated focal sialadenitis, improved salivary function, and reduced IFN-γ+CD3+ and IFN-γ+CD8+ T cells in salivary gland-draining lymph nodes, maintaining immune homeostasis against a biased type 1 response. Inoculation also enhanced salivary microbiota diversity, balanced the Firmicutes-to-Proteobacteria ratio, and reduced the overwhelming presence of Pseudomonas mendocina. In vitro, H. parainfluenzae-preconditioned A253 cells limited CD8 T cell expansion with reduced IFN-γ production. These findings suggest that H. parainfluenzae improves oral microbial diversity, promotes homeostatic T-cell immunity, and protects against SS, supporting its potential as a next-generation probiotic.

The PerioGene North study reveals that periodontal inflammation and advanced jawbone loss in periodontitis associate with serum gingipain antibodies but not with systemic autoimmunity

Introduction

Periodontitis is associated with rheumatoid arthritis (RA). One hypothesis posits that this connection arises from the formation of autoantibodies against citrullinated proteins (ACPA) in inflamed gums, possibly triggered by Porphyromonas gingivalis. We previously demonstrated an increased antibody response to P. gingivalis arginine gingipains (anti-Rgp IgG), not only in individuals with severe periodontitis compared to controls, but in RA versus controls, with an association to ACPA. In the present study, we set out to further explore the relationship between anti-Rgp IgG, ACPA and periodontitis, including clinical periodontal parameters, in the large and well-characterized PerioGene North case-control study.

Methods

We measured serum levels of anti-Rgp and ACPA IgG by enzyme-linked immunosorbent assay (ELISA), in 478 patients with periodontitis and 509 periodontally healthy controls within PerioGene North. Subsequently, anti-Rgp IgG levels and ACPA status were analysed in relation to periodontitis and clinical periodontal parameters.

Results

Serum anti-Rgp IgG levels were elevated in cases versus controls (p< 0.001). However, receiver operating characteristic (ROC) curve analysis revealed that anti-Rgp IgG could not efficiently discriminate cases from controls (AUC= 0.63; 95% CI: 0.60 - 0.66). Among cases, increased anti-Rgp IgG levels associated with high periodontal inflammation and advanced alveolar bone loss (p<0.001 for both). An ACPA response was detected in 15 (3.1%) cases and 6 (1.2%) controls (p=0.033), but no association to periodontitis was evident after adjustment for age and smoking and anti-Rgp IgG levels did not differ between ACPA-positive and ACPA-negative individuals.

Conclusion

We show that anti-Rgp IgG identifies a subgroup of periodontitis patients with high degree of periodontal inflammation and advanced alveolar bone loss, but we do not find support for a link between periodontitis or anti-Rgp IgG and ACPA status in PerioGene North. Given the association between anti-Rgp and alveolar bone loss, the mechanistic role of gingipains in bone resorption should be experimentally explored.

Synthetic Vesicle-Based Drug Delivery Systems for Oral Disease Therapy: Current Applications and Future Directions

Oral diseases such as dental caries, periodontitis, and oral cancer are prevalent and present significant challenges to global public health. Although these diseases are typically treated through procedures like dental preparation and resin filling, scaling and root planning, or surgical excision, these interventions are often not entirely effective, and postoperative drug therapy is usually required. Traditional drug treatments, however, are limited by factors such as poor drug penetration, significant side effects, and the development of drug resistance. As a result, there is a growing need for novel drug delivery systems that can enhance therapeutic efficacy, reduce side effects, and improve treatment outcomes. In recent years, drug-loaded vesicles, such as liposomes, polymersomes, and extracellular vesicles (EVs), have emerged as promising drug delivery platforms due to their high drug encapsulation efficiency, controlled release properties, and excellent biocompatibility. This review provides an in-depth examination of the characteristics, advantages, and limitations of liposomes, polymersomes, and extracellular vesicles in the context of oral disease treatment. It further explores the reasons for their advantages and limitations and discusses the specific applications, development prospects, and strategies for optimizing these vesicle-based systems for improved clinical outcomes.

Periodontal Treatment to Improve General Health and Manage Systemic Diseases

Periodontitis is increasingly recognized for its role in overall health and its associations with systemic conditions. Shared etiological factors, including microbiological, immunological, genetic, and environmental influences, have prompted interest in the potential impact of periodontal therapy on broader health outcomes. The oral microbiome plays a key role in the pathogenesis of periodontitis, with microbial imbalances (dysbiosis) contributing to inflammation and systemic disease progression. Additionally, immune responses to periodontal infection, such as chronic inflammation and dysregulated immune activity, are central to linking periodontitis with conditions like diabetes, cardiovascular disease, and autoimmune disorders. This chapter explores the connections between periodontal treatment and systemic diseases, such as diabetes, rheumatoid arthritis, cardiovascular disease, chronic kidney disease, Alzheimer's disease, digestive disorders, and respiratory disease. It also reviews the current research on the mechanisms, including microbial and immune factors, that underlie these associations. By emphasizing the role of periodontal health, the oral microbiome, and immune regulation in disease prevention and management, this chapter underscores the importance of integrated healthcare approaches to improve patient outcomes.

A Review of Connecting Bioinformatic Techniques to Rheumatoid Arthritis and its Associated Comorbidities

Rheumatoid Arthritis (RA) is a progressive autoimmune condition inflicting serious threats to people's life and health by causing severe pain and joint destruction. It affects not only bones and joints but also causes comorbid conditions and shortens the lifetime. The interactions and synergistic effects of comorbid disease with RA are not yet well studied. Hence, understanding how these conditions will collectively affect the progression and outcome of RA is the current area of research. Identification of RA and comorbidities associated with target genes may uncover diagnosis and treatment methodologies. This review is to provide an overview of the interlinking approach of Rheumatoid Arthritis with its comorbid conditions and its systemic complications using bioinformatic techniques which would be useful to identify the genes and pathways that are in common for both RA and comorbid diseases. It would also emphasize the significance of bioinformatics in comparing the pathological features of RA and comorbid diseases. With the help of bioinformatics, valuable insights into the mechanism underlying Rheumatoid arthritis and comorbid diseases would be better understood.

Oral Microbiome Dysbiosis and Citrullination in Rheumatoid Arthritis

Rheumatoid arthritis and periodontal diseases, both characterized by chronic inflammation, share many common risk factors, sparking interest in understanding their established association. Emerging research has shed light on the link between these two diseases potentially occurring through the intricate interactions within the oral microbiome. The enrichment of pathogenic strains and species in this microbial community disrupts the delicate balance of both ecological and immunological homeostasis with the host. Particular attention has been paid to the role of key pathogens, such as Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans, known for their immunomodulatory abilities. The generation of an autoimmune response against proteins modified by citrullination is known to be a key step in the pathogenesis of RA. Importantly, the bidirectional citrullination mediated by both host innate immune cells and oral bacteria generates citrullinated peptide neoepitopes, which may serve as potential triggers for the loss of tolerance and subsequent autoimmunity in susceptible individuals. This review highlights the importance of understanding the mechanisms through which oral microbiome dysbiosis and citrullination contribute to the onset and progression of RA. Insights into these mechanisms not only advance pathobiological understanding but also offer potential therapeutic targets. Furthermore, we discuss the potential impact of nonsurgical periodontal treatment in modifying disease progression or mitigating RA, underscoring the critical role of periodontal health in managing systemic inflammatory conditions.

Relationship Between Rheumatoid Arthritis and Periodontal Disease-Systematic Review and Meta-Analysis

Background/Objectives: The aim of this systematic review and meta-analysis was to determine the association between rheumatoid arthritis and periodontal disease. Methods: This systematic review and meta-analysis of the scientific literature was carried out based on the recommendations of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). We analyzed all studies that evaluated the relationship between the chronic inflammatory diseases through the response to non-surgical periodontal treatment, comparing the values of CAL (Clinical Attachment Level) for PD (periodontal disease) and DAS28 for RA. A total of three databases were searched in the literature search: Pubmed, Scopus, and Web of Science. After eliminating duplicate articles and applying certain inclusion criteria, of the 29 articles found, a total of 6 were included in the present study. Results: A statistically significant difference in mean reduction of -0.56 mm was obtained for CAL, with a 95% confidence interval of the difference between -0.82 and -0.31 (z-test = -4.33; p-value = 0.001) in favor of the periodontal treatment group. The heterogeneity of the meta-analysis was slight (I2 = 39% and Q = 8.19; p-value = 0.146). For DAS28, treatment showed a mean reduction of -0.39 DAS points, with a 95% CI between -0.46 and -0.31 (z-test = -10.3; p-value < 0.001) among patients with PD and RA. Conclusions: The present study shows how the control of periodontal disease through non-surgical periodontal treatment can reduce the severity of RA. This finding consistently supports the idea that there is a pathogenic association between these two chronic inflammatory diseases.

Porphyromonas gingivalis-Lipopolysaccharide Induced Gingival Fibroblasts Trained Immunity Sustains Inflammation in Periodontitis

AIM

To investigate whether trained immunity occurs in gingival fibroblasts (GFs) and its relationship to the persistence of inflammation in periodontitis.

METHODS

Periodontally healthy and inflammatory gingival fibroblasts (HGFs and IGFs) were cultured through continuous adherence subculture of tissue blocks. Trained immunity in HGFs was evaluated via a classic in vitro model, with relevant markers assessed via enzyme-linked immunosorbent assay, lactate content assay, glycolytic rate assay, and chromatin immunoprecipitation. A histone methyltransferase blocker and a PI3K inhibitor were added to investigate the mechanisms underlying trained immunity. The relationship between trained immunity and periodontitis was further examined via immunofluorescence staining and chromatin immunoprecipitation on IGFs.

RESULTS

Compared with untrained cells, GFs trained with Porphyromonas gingivalis-lipopolysaccharide (P. gingivalis-LPS) exhibited a significant increase in IL-6 and TNF-α secretion, enhanced glycolytic metabolism, and enriched mono-methylation of lysine 4 on histone H3 (H3K4me1) at the enhancer regions of TNF-α and IL-6. The addition of a histone methyltransferase blocker and a PI3K inhibitor greatly reduced trained immunity. Additionally, the response of IGFs to P. gingivalis-LPS stimulation and their epigenetic modifications were similar to those observed in trained HGFs.

CONCLUSION

This study novelly discovered that both P. gingivalis-LPS-stimulated HGFs and IGFs in periodontitis acquired trained immunity. Following P. gingivalis-LPS stimulation, HGFs underwent metabolic and epigenetic changes via the PI3K/AKT pathway, with these epigenetic changes also observed in IGFs. This finding suggests that trained immunity in GFs may be a key mechanism underlying the recurrence and persistence of periodontitis.

A cleaved adhesin DNA vaccine targeting dendritic cell against Porphyromonas gingivalis-induced periodontal disease

BACKGROUND

Arg-gingipain A (RgpA) is the primary virulence factor of Porphyromonas gingivalis and contains hemagglutinin adhesin (HA), which helps bacteria adhere to cells and proteins. Hemagglutinin's functional domains include cleaved adhesin (CA), which acts as a hemagglutination and hemoglobin-binding actor. Here, we confirmed that the HA and CA genes are immunogenic, and using adjuvant chemokine to target dendritic cells (DCs) enhanced protective autoimmunity against P. gingivalis-induced periodontal disease.

METHODS

C57 mice were immunized prophylactically with pVAX1-CA, pVAX1-HA, pVAX1, and phosphate-buffered saline (PBS) through intramuscular injection every 2 weeks for a total of three administrations before P. gingivalis-induced periodontitis. The DCs were analyzed using flow cytometry and ribonucleic acid sequencing (RNA-seq) transcriptomic assays following transfection with CA lentivirus. The efficacy of the co-delivered molecular adjuvant CA DNA vaccine was evaluated in vivo using flow cytometry, immunofluorescence techniques, and micro-computed tomography.

RESULTS

After the immunization, both the pVAX1-CA and pVAX1-HA groups exhibited significantly elevated P. gingivalis-specific IgG and IgG1, as well as a reduction in bone loss around periodontitis-affected teeth, compared to the pVAX1 and PBS groups (p < 0.05). The expression of CA promoted the secretion of HLA, CD86, CD83, and DC-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) in DCs. Furthermore, the RNA-seq analysis revealed a significant increase in the chemokine (C-C motif) ligand 19 (p < 0.05). A notable elevation in the quantities of DCs co-labeled with CD11c and major histocompatibility complex class II, along with an increase in interferon-gamma (IFN-γ) cells, was observed in the inguinal lymph nodes of mice subjected to CCL19-CA immunization. This outcome effectively illustrated the preservation of peri-implant bone mass in rats afflicted with P. gingivalis-induced peri-implantitis (p < 0.05).

CONCLUSIONS

The co-administration of a CCL19-conjugated CA DNA vaccine holds promise as an innovative and targeted immunization strategy against P. gingivalis-induced periodontitis and peri-implantitis.

Oral health and rheumatoid arthritis: a case control study

OBJECTIVES

Patients suffering from rheumatoid arthritis (RA) are repeatedly affected by oral diseases or problems, including dental caries and periodontal diseases (PDs). Periodontitis and rheumatoid arthritis are chronic inflammatory destructive diseases that share many similarities. The objective of this study was to assess oral health status including examination of hard dental tissues and periodontium in patients with rheumatoid arthritis and compare the results with healthy controls. We hypothesize some interlink between oral diseases and RA.

METHODS

The epidemiological case-control study involved a total of 64 subjects divided into an experimental group (14 rheumatoid arthritis cases) and a control group (50 healthy individuals). Disease activity in the subjects with RA was assessed by the Disease Activity Score (DAS28). The number of Decayed, Missing and Filled Teeth (DMFT) and Community Periodontal Index of Treatment Need (CPITN) as a basic epidemiological oral health indexes were recorded. Finally, the data were analysed statistically.

RESULTS

The RA patients (19.21, SD = 6.95) showed a higher caries index level measured by DMFT than the control group (17.72, SD = 6.19); the difference was not statistically significant (U = 387.5, p = 0.547). In terms of a mean number of teeth decayed (p = 0.078), teeth filled due to caries (p = 0.397), and missing teeth (p = 0.126), the two groups were not significantly different. In terms of periodontal health, a significant difference was observed between the two groups concerning the CPI maximum score (p = 0.003). The RA patients showed higher prevalence of periodontitis than the controls.

CONCLUSIONS

A complete basic oral examination, along with an oral health instruction including adequate oral and dental hygiene, is crucial to prevent dental caries and periodontal diseases and associated complications in RA patients, since they appear to be more vulnerable than the non-RA population.

Outer Membrane Vesicles Derived From Fusobacterium nucleatum Trigger Periodontitis Through Host Overimmunity

The virulent bacteria-induced host immune response dominates the occurrence and progression of periodontal diseases because of the roles of individual virulence factors from these pathogens in the initiation and spread of inflammation. Outer membrane vesicles (OMVs) as a pathogenic entity have recently attracted great attention as messenger bridges between bacteria and host tissues. Herein, the novel role of OMVs derived from Fusobacterium nucleatum in the occurrence of periodontitis is dissected. In a rat periodontitis model, it is found that OMVs derived from F. nucleatum caused deterioration of periodontitis by enhancing inflammation of the periodontium and absorption of alveolar bone, which is almost equivalent to the effect of F. nucleatum itself. Furthermore, that OMVs can independently induce periodontitis is shown. The pathogenicity of OMVs is attributed to multiple pathogenic components identified by omics. After entering human periodontal ligament stem cells (hPDLSCs) by endocytosis, OMVs activated NLRP3 inflammasomes and impaired the mineralization of hPDLSCs through NF-κB (p65) signaling, leading to the final injury of the periodontium and damage of alveolar bone in periodontitis. These results provide a new understanding of OMVs derived from pathogens and cues for the prevention of periodontitis.

Does non-surgical periodontal treatment contribute to rheumatoid arthritis amelioration? Evidence based on an overview and meta-analysis

The aim of the present study was to provide an overview evaluating the effects of non-surgical periodontal treatment in rheumatoid arthritis, focusing on 28-joint Disease Activity Score (DAS28), C-reactive protein, and erythrocyte sedimentation rate. Systematic reviews, with and without meta-analyses, comparing individuals who had undergone non-surgical periodontal treatment with those who had not, and assessing parameters before and after treatment, were included. Electronic searches were conducted in August 2023 and updated in August 2024 across four databases (PubMed, Scopus, Embase, and Web of Science) and gray literature, with no restriction on language or publication date. The study followed the 2020 PRISMA statement, and a protocol was registered in PROSPERO (CRD42023414714). A total of 10 systematic reviews were included: six with meta-analyses and four without meta-analyses. The number of articles included ranged from three to 31 studies. Non-surgical periodontal treatment resulted in a significant decrease in C-reactive protein, erythrocyte sedimentation rate, and DAS28. The follow-up period after treatment ranged from six to 24 weeks. A meta-analysis was conducted, incorporating data from 18 primary studies identified in the systematic reviews and comparing the difference in DAS28 at baseline (n = 454) and up to three months (n = 449) after the non-surgical periodontal treatment. A significant reduction in DAS28 was observed (MD = - 0.76; 95% CI = - 1.07 to - 0.44). Despite the heterogeneity of data related to rheumatoid arthritis and periodontitis status, non-surgical periodontal treatment can result in a decrease in the concentration of circulating inflammatory mediators and, consequently, in a reduction in DAS28 in rheumatoid arthritis.

Effect of scaling and root planing with and without minocycline hydrochloride microspheres on serum biomarkers and acute phase reactants: A randomized clinical trial and 9- and 12-month follow-up

Background

This study tests the effects of scaling and root planing (SRP) vs SRP with minocycline hydrochloride microspheres (MMs) (SRP with MM) on serum biomarkers interleukin (IL)-1β, IL-6, tumor necrosis factor-α, and matrix metalloproteinase-8 and acute phase reactants hemoglobin A1c (HbA1c), high-sensitivity C-reactive proteins and haptoglobin (Hp) in patients with stage II-IV grade B periodontitis.

Methods

Seventy participants were randomized to receive SRP (n = 35) or SRP+MM (n = 35). Serum was collected at baseline (before SRP), 1-month reevaluation visit, and 3- and 6-month periodontal maintenance visits. MMs were delivered to pockets 5 mm or larger immediately after SRP and immediately after the 3-month periodontal maintenance visit. Serum for acute phase reactants only was collected at the 9- and 12-month posttreatment follow-up. All outcomes were summarized using estimated marginal means back-transformed to the original response scale with 95% CIs.

Results

At 6 months, no statistical significance was yielded in either group for IL-6 (P = .91), tumor necrosis factor-α (P = .34), or matrix metalloproteinase-8 (P = .34). IL-1β (P = .06) was slightly higher in the SRP-alone group, suggesting a clinical impact with the addition of MM. Acute phase reactants were not statistically significant for high-sensitivity C-reactive proteins (P = .59), HbA1c (P = .46), or haptoglobin (P = .22) for either group. These outcomes continued at the 9- and 12-month posttreatment follow-up.

Conclusions

SRP alone and SRP+MM minimally reduced levels of cytokine biomarkers and acute phase reactants in self-reported systemically healthy patients with advanced stages of periodontitis. Thresholds for resolution of local clinical inflammation may not have been achieved in this study to result in a reduction of systemic inflammation.

TFEB alleviates periodontitis by activating autophagy and inhibiting inflammation

Periodontitis is a chronic inflammatory oral disease that impaired the tooth-supporting apparatus, including gingival tissue destruction and alveolar bone resorption. The initiation of periodontitis is linked to the presence of oral bacteria, particularly P. gingivalis within pathogenic biofilms. Here, we demonstrated the central role of the autophagy regulator Transcription Factor EB (TFEB) in orchestrating autophagy activation and modulating the host immune response against P. gingivalis in periodontitis. Upregulation of TFEB expression at the protein level and heightened nuclear localization occurred during the progressive stages of periodontitis. Functionally, TFEB overexpression emerges as a potent alleviator of periodontitis-associated phenotypes, operating through the activation of autophagy and the inhibition of the NF-κB pathway in both in vivo and in vitro models. In addition, TFEB knockdown exacerbates the inflammatory response by upregulating pro-inflammatory cytokines. The dual regulatory role of TFEB in governing both autophagy and inflammatory responses unveils novel insights into periodontitis pathogenesis, positioning TFEB as a promising therapeutic target for periodontitis intervention.

Systemic Factors Affecting Prognosis and Outcomes in Periodontal Disease

This review delves into the effects of autoimmune conditions like rheumatoid arthritis, inflammatory disorders such as irritable bowel syndrome, cardiovascular disease, diabetes, infectious ailments like human immunodeficiency virus, and their medications on periodontal therapy outcomes. It also explores the influence of hormones. Understanding these systemic factors is crucial for optimizing periodontal health and treatment efficacy. The review underscores the necessity of considering these variables in periodontal care. Other vital systemic factors are addressed elsewhere in this special edition.

Changes in Periodontal Parameters and Microbiome Composition of Periodontal Pocket in Patients with Chronic Inflammatory Diseases Receiving Targeted Anti-Cytokine Therapy

Periodontitis is associated with systemic chronic inflammatory diseases. There is limited evidence on the influence of anti-cytokine therapies on the periodontal condition and microbiome in the tooth pocket of such patients, so the aim of this study was to elucidate this issue. In this observational trial, the periodontal status and the gingival crevicular fluid of 13 patients with different chronic inflammatory diseases were obtained before the initiation of anti-cytokine treatment and 14 weeks after. Gingival crevicular fluid was collected for 16S rRNA gene sequencing from a clinically healthy tooth and the deepest measured pocket. The Shannon Diversity Index significantly increased in the deepest pockets of patients (p = 0.039). The data showed alterations in the diversity of the subgingival microbiome over the course of the study, implying a shift towards a healthier condition after starting anti-cytokine therapy. Additional investigations are needed to analyze whether the administration of selective biologicals can improve periodontal conditions in patients with or without chronic inflammatory diseases.

Association between Periodontal Diseases and the Risk of Site-Specific Gastrointestinal Cancers: A Systematic Review and Meta-Analysis

The association between periodontal diseases and the risk of gastrointestinal cancers, especially site-specific gastrointestinal cancers, remains unclear. Here, we comprehensively searched PubMed, EMBASE, Web of Science, and Google Scholar from inception to April 2024 to identify relevant studies. The pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated with a random-effects model. Subgroup analyses and sensitivity analyses were conducted to confirm the robustness of the main findings in different populations. This study was reported according to PRISMA 2020 guidelines. In total, we identified 19 studies, including 16.6 million participants. Individuals with periodontal diseases had an increased risk of overall gastrointestinal cancers compared with those without periodontal diseases (HR 1.31, 95% CI 1.16-1.49). Periodontal diseases significantly increased the risk of esophageal cancer by 39% (HR 1.39, 95% CI 1.15-1.68), gastric cancer by 13% (HR 1.13, 95% CI 1.01-1.26), colorectal cancer by 21% (HR 1.21, 95% CI 1.05-1.39), pancreatic cancer by 35% (HR 1.35, 95% CI 1.00-1.82), and liver cancer by 9% (HR 1.09, 95% CI 1.04-1.13). The risk of gastrointestinal cancers was significantly increased by periodontitis (HR 1.45, 95% CI 1.14-1.85), gingivitis (HR 1.03, 95% CI 1.01-1.04), and periodontitis/gingivitis (HR 1.27, 95% CI 1.07-1.51). Furthermore, severe periodontal diseases showed a significantly increased risk of gastrointestinal cancer (HR 1.79, 95% CI 1.07-2.99). Results of sensitivity analyses for site-specific gastrointestinal cancers were robust with the main findings. In summary, periodontal diseases, especially severe periodontitis, increase the risk of overall and site-specific gastrointestinal cancers. Interventions to prevent and manage periodontal diseases may reduce the risk of developing gastrointestinal cancers.

Identification of cross-talk pathways and PANoptosis-related genes in periodontitis and Alzheimer's disease by bioinformatics analysis and machine learning

Background and objectives

Periodontitis (PD), a chronic inflammatory disease, is a serious threat to oral health and is one of the risk factors for Alzheimer's disease (AD). A growing body of evidence suggests that the two diseases are closely related. However, current studies have not provided a comprehensive understanding of the common genes and common mechanisms between PD and AD. This study aimed to screen the crosstalk genes of PD and AD and the potential relationship between cross-talk and PANoptosis-related genes. The relationship between core genes and immune cells will be analyzed to provide new targets for clinical treatment.

Materials and methods

The PD and AD datasets were downloaded from the GEO database and differential expression analysis was performed to obtain DEGs. Overlapping DEGs had cross-talk genes linking PD and OP, and PANoptosis-related genes were obtained from a literature review. Pearson coefficients were used to compute cross-talk and PANoptosis-related gene correlations in the PD and AD datasets. Cross-talk genes were obtained from the intersection of PD and AD-related genes, protein-protein interaction(PPI) networks were constructed and cross-talk genes were identified using the STRING database. The intersection of cross-talk and PANoptosis-related genes was defined as cross-talk-PANoptosis genes. Core genes were screened using ROC analysis and XGBoost. PPI subnetwork, gene-biological process, and gene-pathway networks were constructed based on the core genes. In addition, immune infiltration on the PD and AD datasets was analyzed using the CIBERSORT algorithm.

Results

366 cross-talk genes were overlapping between PD DEGs and AD DEGs. The intersection of cross-talk genes with 109 PANoptosis-related genes was defined as cross-talk-PANoptosis genes. ROC and XGBoost showed that MLKL, DCN, IL1B, and IL18 were more accurate than the other cross-talk-PANoptosis genes in predicting the disease, as well as better in overall characterization. GO and KEGG analyses showed that the four core genes were involved in immunity and inflammation in the organism. Immune infiltration analysis showed that B cells naive, Plasma cells, and T cells gamma delta were significantly differentially expressed in patients with PD and AD compared with the normal group. Finally, 10 drugs associated with core genes were retrieved from the DGIDB database.

Conclusion

This study reveals the joint mechanism between PD and AD associated with PANoptosis. Analyzing the four core genes and immune cells may provide new therapeutic directions for the pathogenesis of PD combined with AD.

Investigation of the mechanism of baicalein in the treatment of periodontitis based on network pharmacology, molecular docking and experimental validation

PURPOSE

To verify the effect and mechanism of baicalein in the treatment of periodontitis through network pharmacology, molecular docking and in vitro experiments.

METHODS

Firstly, multiple databases were used to predict targets of baicalein and periodontitis. And the screened key target genes of baicalein for treating periodontitis were subjected to GO and KEGG analysis; then these targets were analyzed by molecular docking techniques. In vitro experiments including CCK-8, RT-qPCR, ELISA and Immunofluorescence were conducted to validate the efficacy of baicalein in treating periodontitis.

RESULTS

Seventeen key targets were screened from the databases, GO and KEGG analysis of these targets revealed that baicalein may exert therapeutic effects through regulating TNF, PI3K-Akt, HIF-1 and other signaling pathways. Molecular docking analysis showed that baicalein has good binding potential to several targets. In vitro cellular assays showed that baicalein inhibited the expression of TNF-α, MMP-9, IL-6 and MCP1 in P.g-LPS-induced macrophages at both the mRNA and protein level. And the immunofluorescence intensity of iNOS, a marker of M1 type macrophages, which mainly secretes inflammatory factors, was significantly reduced.

CONCLUSION

Baicalein has the characteristics and advantages of "multicomponent, multitarget, and multipathway" in the treatment of periodontitis. In vitro cellular assays further confirmed the inhibitory effect of baicalein on the secretion of inflammatory factors of macrophages in periodontitis models, providing a theoretical basis for further study of the material basis and molecular mechanism of baicalein in the treatment of periodontal diseases.

Caspase-11 mediated inflammasome activation in macrophages by systemic infection of A. actinomycetemcomitans exacerbates arthritis

Clinical studies have shown that Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) is associated with aggressive periodontitis and can potentially trigger or exacerbate rheumatoid arthritis (RA). However, the mechanism is poorly understood. Here, we show that systemic infection with A. actinomycetemcomitans triggers the progression of arthritis in mice anti-collagen antibody-induced arthritis (CAIA) model following IL-1β secretion and cell infiltration in paws in a manner that is dependent on caspase-11-mediated inflammasome activation in macrophages. The administration of polymyxin B (PMB), chloroquine, and anti-CD11b antibody suppressed inflammasome activation in macrophages and arthritis in mice, suggesting that the recognition of lipopolysaccharide (LPS) in the cytosol after bacterial degradation by lysosomes and invasion via CD11b are needed to trigger arthritis following inflammasome activation in macrophages. These data reveal that the inhibition of caspase-11-mediated inflammasome activation potentiates aggravation of RA induced by infection with A. actinomycetemcomitans. This work highlights how RA can be progressed by inflammasome activation as a result of periodontitis-associated bacterial infection and discusses the mechanism of inflammasome activation in response to infection with A. actinomycetemcomitans.

Surface Pre-Reacted Glass-Ionomer Eluate Suppresses Osteoclastogenesis through Downregulation of the MAPK Signaling Pathway

Surface pre-reacted glass-ionomer (S-PRG) is a new bioactive filler utilized for the restoration of decayed teeth by its ability to release six bioactive ions that prevent the adhesion of dental plaque to the tooth surface. Since ionic liquids are reported to facilitate transepithelial penetration, we reasoned that S-PRG applied to root caries could impact the osteoclasts (OCs) in the proximal alveolar bone. Therefore, this study aimed to investigate the effect of S-PRG eluate solution on RANKL-induced OC-genesis and mineral dissolution in vitro. Using RAW264.7 cells as OC precursor cells (OPCs), TRAP staining and pit formation assays were conducted to monitor OC-genesis and mineral dissolution, respectively, while OC-genesis-associated gene expression was measured using quantitative real-time PCR (qPCR). Expression of NFATc1, a master regulator of OC differentiation, and the phosphorylation of MAPK signaling molecules were measured using Western blotting. S-PRG eluate dilutions at 1/200 and 1/400 showed no cytotoxicity to RAW264.7 cells but did significantly suppress both OC-genesis and mineral dissolution. The same concentrations of S-PRG eluate downregulated the RANKL-mediated induction of OCSTAMP and CATK mRNAs, as well as the expression of NFATc1 protein and the phosphorylation of ERK, JNK, and p38. These results demonstrate that S-PRG eluate can downregulate RANKL-induced OC-genesis and mineral dissolution, suggesting that its application to root caries might prevent alveolar bone resorption.

Exploring the relationship between infectious agents and autoimmune diseases: a review

The relationship between infectious agents and autoimmune diseases is a complex issue. In recent years, increasing clinical cases have indicated that infectious agents play an important role in the development of autoimmune diseases. Molecular mimicry is currently widely regarded as the primary pathogenic mechanism of various autoimmune diseases in humans. Components of infectious agents can undergo molecular mimicry with components in patients' bodies, leading to the development of various autoimmune diseases. In this article, we provide a brief overview of current research of the current research status on the relationship between infectious agents and autoimmune diseases, and describe our current understanding of their mechanisms of action in order to better understand the pathogenesis, diagnosis, and treatment of autoimmune diseases.

Clonal hematopoiesis driven by mutated DNMT3A promotes inflammatory bone loss

Clonal hematopoiesis of indeterminate potential (CHIP) arises from aging-associated acquired mutations in hematopoietic progenitors, which display clonal expansion and produce phenotypically altered leukocytes. We associated CHIP-DNMT3A mutations with a higher prevalence of periodontitis and gingival inflammation among 4,946 community-dwelling adults. To model DNMT3A-driven CHIP, we used mice with the heterozygous loss-of-function mutation R878H, equivalent to the human hotspot mutation R882H. Partial transplantation with Dnmt3aR878H/+ bone marrow (BM) cells resulted in clonal expansion of mutant cells into both myeloid and lymphoid lineages and an elevated abundance of osteoclast precursors in the BM and osteoclastogenic macrophages in the periphery. DNMT3A-driven clonal hematopoiesis in recipient mice promoted naturally occurring periodontitis and aggravated experimentally induced periodontitis and arthritis, associated with enhanced osteoclastogenesis, IL-17-dependent inflammation and neutrophil responses, and impaired regulatory T cell immunosuppressive activity. DNMT3A-driven clonal hematopoiesis and, subsequently, periodontitis were suppressed by rapamycin treatment. DNMT3A-driven CHIP represents a treatable state of maladaptive hematopoiesis promoting inflammatory bone loss.

Identification of biomarkers related to prognosis and diagnosis of periodontitis by bioinformatics based on public database

OBJECTIVES

Periodontitis is a multifactorial disease that has a negative impact on people's life. However, studies on potential key genes with excellent diagnostic value for periodontitis disease have not been systematically explored.

METHODS

GSE10334 data set was downloaded from the Gene Expression Omnibus database. Following the gene expression profiles were normalized by the Robust multi-array average (RMA) algorithm, the differentially expressed genes were screened and incorporated into Weight gene correlation network analysis to obtain hub genes. Receiver-operating characteristic curve analysis was used to verify the validity and agility of the hub genes-based least absolute shrinkage and selection operator model. Furthermore, we validated the expression of these hub genes by real-time polymerase chain reaction and western blotting.

RESULTS

Eight hub genes were identified and had good diagnostic values. Besides, the upregulations of eight hub genes were verified both in protein and mRNA levels in clinical periodontitis gum tissue.

CONCLUSION

We discovered potential biomarkers in periodontitis based on the public database and these biomarkers focused on several immune responses and inflammatory pathways. Thus, this study may provide potential therapeutic targets for early diagnosis and treatment of periodontitis.

Interaction of periodontal clinical indicators in metabolic syndrome and nonalcoholic fatty liver disease: Implications for preventive interventions

Introduction

The behavior of periodontal clinical indicators in metabolic syndrome (MetS) and fatty liver disease (NAFLD) are not clearly defined. It's even considered that high-risk cases for NAFLD are currently underreported or not identified in a timely manner. The aim of the study is to elucidate the interaction of periodontal clinical indicators in MetS and NAFLD. Materials and methods: 336 patients were eligible because they met the diagnostic criteria for metabolic syn-drome and nonalcoholic fatty liver disease. Those selected were randomly selected for a cross-sectional study. Metabolic status and non-alcoholic fatty liver disease were measured using the MetS Metabolic Syndrome Diagnostic Criteria (NCEP/ATP-III) and laboratory tests, respectively. In addition, periodontal clinical indicators were evaluated: probing depth, clinical attachment, plaque index and gingival bleeding.

Results

The association for NAFLD and probing depth was p = 0.736. The association for MetS and probing depth was p = 0.598. For NAFLD and clinical attachment loss, the association was p = 0.751. For MetS and clinical attachment loss, the association was p = 0.435. The plaque index for MetS was p = 0.238. The plaque index for NAFLD was p = 0.269. The gingival bleeding association for NAFLD was p = 0.673 and for MetS was p = 0.522.

Conclusions

Periodontal clinical indicators of metabolic syndrome were as-sociated with elevated serum levels of low-density lipoproteins (LDL), HDL-cholesterol, and triglycerides. However, when comparing the values in NAFLD and MetS, a greater significance is evident in the first study group.

Aberrant immunity in the oral cavity-a link with rheumatoid arthritis?

There are well established epidemiological links between rheumatoid arthritis and periodontitis. Recent data have started to shed light on the mechanisms that might underlie the relationship between these two complex diseases. Unravelling the roles of distinct pathways involved in these mechanisms has the potential to yield novel preventative and therapeutic strategies for both diseases. Perhaps most intriguingly, this represents an area where understanding the biology in the oral cavity might reveal fundamental advances in understanding immune regulation and the relationships between the host and microbiome. Here we seek to discuss aspects of the adaptive immune response that might link periodontitis and rheumatoid arthritis.

A prospective study on maternal periodontal diseases and neonatal adverse outcomes

OBJECTIVE

It is evident that periodontitis is linked to various adverse pregnancy outcomes. This prospective study explored the potential link of maternal periodontal diseases to neonatal adverse outcomes.

MATERIALS AND METHODS

A total of 193 generally healthy females in their third trimester (34-36 weeks) of pregnancy were enrolled. All subjects received full-mouth periodontal assessment, and the periodontal inflamed surface area (PISA) was calculated. Demographic data, lifestyles and anthropometric measurements of the neonates (e.g., body length and head circumference) were recorded. Herein, small-for-gestational age (SGA) referred to gender- and age-adjusted birth weight below the 10th percentile in line with the standard reference. Multivariable logistic regression analysis and restricted cubic spline were performed for examining the association of periodontal parameters with SGA.  Results: There were 8.3% (16/193) of neonates with SGA. Significantly positive correlation existed between the percentage of tooth sites with increased probing depth and an elevated risk of SGA (OR: 1.052; P < 0.05). Yet, the PISA was positively associated with the risk of SGA (OR: 1.002; P < 0.05) as well. No significant link occurred between maternal periodontal status and other neonatal outcome measures.

CONCLUSION

Within the limitations of this study, the findings suggest that there could be a link between maternal periodontal diseases and neonatal adverse outcomes like SGA. Further investigation is required to clarify the current findings and potential implications for promoting maternal oral/periodontal health and newborn health.

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.

Membrane-anchoring selenophene viologens for antibacterial photodynamic therapy against periodontitis via restoring subgingival flora and alleviating inflammation

Antibacterial photodynamic therapy (aPDT) has emerged as a promising strategy for treating periodontitis. However, the weak binding of most photosensitizers to bacteria and the hypoxic environment of periodontal pockets severely hamper the therapeutic efficacy. Herein, two novel oxygen-independent photosensitizers are developed by introducing selenophene into viologens and modifying with hexane chains (HASeV) or quaternary ammonium chains (QASeV), which improve the adsorption to bacteria through anchoring to the negatively charged cell membrane. Notably, QASeV binds only to the bacterial surface of Porphyromonas gingivalis and Fusobacterium nucleatum due to electrostatic binding, but HASeV can insert into their membrane by strong hydrophobic interactions. Therefore, HASeV exhibits superior antimicrobial activity and more pronounced plaque biofilm disruption than QASeV when combined with light irradiation (MVL-210 photoreactor, 350-600 nm, 50 mW/cm2), and a better effect on reducing the diversity and restoring the structure of subgingival flora in periodontitis rat model was found through 16S rRNA gene sequencing analysis. The histological and Micro-CT analyses reveal that HASeV-based aPDT has a better therapeutic effect in reducing periodontal tissue inflammation and alveolar bone resorption. This work provides a new strategy for the development of viologen-based photosensitizers, which may be a favorable candidate for the aPDT against periodontitis.

Presence and Immunoreactivity of Aggregatibacter actinomycetemcomitans in Rheumatoid Arthritis

The presence of periodontal pathogens is associated with an increased prevalence of rheumatoid arthritis (RA). The systemic antibody response to epitopes of these bacteria is often used as a proxy to study correlations between bacteria and RA. The primary aim of the present study is to examine the correlation between the presence of Aggregatibacter actinomycetemcomitans (Aa) in the oral cavity and serum antibodies against the leukotoxin (LtxA) produced by this bacterium. The salivary presence of Aa was analyzed with quantitative PCR and serum LtxA ab in a cell culture-based neutralization assay. The analyses were performed on samples from a well-characterized RA cohort (n = 189) and a reference population of blood donors (n = 101). Salivary Aa was present in 15% of the RA patients and 6% of the blood donors. LtxA ab were detected in 19% of RA-sera and in 16% of sera from blood donors. The correlation between salivary Aa and serum LtxA ab was surprisingly low (rho = 0.55 [95% CI: 0.40, 0.68]). The presence of salivary Aa showed no significant association with any of the RA-associated parameters documented in the cohort. A limitation of the present study is the relatively low number of individuals with detectable concentrations of Aa in saliva. Moreover, in the comparison of detectable Aa prevalence between RA patients and blood donors, we assumed that the two groups were equivalent in other Aa prognostic factors. These limitations must be taken into consideration when the result from the study is interpreted. We conclude that a systemic immune response to Aa LtxA does not fully reflect the prevalence of Aa in saliva. In addition, the association between RA-associated parameters and the presence of Aa was negligible in the present RA cohort.

ABCD of IA: A multi-scale agent-based model of T cell activation in inflammatory arthritis

Biomaterial-based agents have been demonstrated to regulate the function of immune cells in models of autoimmunity. However, the complexity of the kinetics of immune cell activation can present a challenge in optimizing the dose and frequency of administration. Here, we report a model of autoreactive T cell activation, which are key drivers in autoimmune inflammatory joint disease. The model is termed a multi-scale Agent-Based, Cell-Driven model of Inflammatory Arthritis (ABCD of IA). Using kinetic rate equations and statistical theory, ABCD of IA simulated the activation and presentation of autoantigens by dendritic cells, interactions with cognate T cells and subsequent T cell proliferation in the lymph node and IA-affected joints. The results, validated with in vivo data from the T cell driven SKG mouse model, showed that T cell proliferation strongly correlated with the T cell receptor (TCR) affinity distribution (TCR-ad), with a clear transition state from homeostasis to an inflammatory state. T cell proliferation was strongly dependent on the amount of antigen in antigenic stimulus event (ASE) at low concentrations. On the other hand, inflammation driven by Th17-inducing cytokine mediated T cell phenotype commitment was influenced by the initial level of Th17-inducing cytokines independent of the amount of arthritogenic antigen. The introduction of inhibitory artificial antigen presenting cells (iaAPCs), which locally suppress T cell activation, reduced T cell proliferation in a dose-dependent manner. The findings in this work set up a framework based on theory and modeling to simulate personalized therapeutic strategies in IA.

Neutrophil extracellular traps in rheumatoid arthritis and periodontitis: Contribution of PADI4 gene polymorphisms

AIM

We sought to investigate the release of neutrophil extracellular traps (NETs) in neutrophils from individuals with rheumatoid arthritis (RA) and controls and compare the presence of NETs in gingival tissues according to periodontal status. Also, the association between single nucleotide polymorphisms (SNPs) of the peptidyl arginine deaminase type 4 (PADI4) gene and the GTG haplotype with RA, periodontitis and NETs was evaluated in vitro.

MATERIALS AND METHODS

Peripheral neutrophils were isolated by density gradient, and NET concentration was determined by the PicoGreen method. Immunofluorescence was studied to identify NETs by co-localization of myeloperoxidase (MPO)-citrullinated histone H3 (H3Cit). Genotyping for SNPs (PADI4_89; PADI4_90; PADI4_92; and PADI4_104) was performed in 87 individuals with RA and 111 controls.

RESULTS

The release of NETs in vitro was significantly higher in individuals with RA and periodontitis and when stimulated with Porphyromonas gingivalis. Gingival tissues from subjects with RA and periodontitis revealed increased numbers of MPO-H3Cit-positive cells. Individuals with the GTG haplotype showed a higher release of NETs in vitro and worse periodontal parameters.

CONCLUSIONS

The release of NETs by circulating neutrophils is associated with RA and periodontitis and is influenced by the presence of the GTG haplotype.