Neutrophils' Contribution to Periodontitis and Periodontitis-Associated Cardiovascular Diseases

Association Between `Life's Essential 8' and Periodontitis: A Cross-Sectional Study From the NHANES Database

BACKGROUND

Periodontitis is a chronic inflammatory disease, and the persistent inflammatory state it confers may lead to cardiovascular disease. Studies have shown that `Life's Essential 8 (LE8)`, an indicator of cardiovascular health, was associated with the risk of several inflammatory diseases. This study aimed to assess the association between LE8 and its subsets and the risk of periodontitis.

METHODS

Data of participants who consented to periodontitis examinations were extracted from the National Health and Nutrition Examination Surveys (NHANES) database (2009-2014). LE8 contains 4 health behaviours (diet, physical activity, nicotine exposure, sleep health) and 4 health factors (body mass index, blood lipids, blood glucose, and blood pressure) and was categorised into low (0-49), moderate (50-79), and high (80-100) levels. Covariates included demographic information, laboratory values, disease history, and medication history. Weighted univariate and multivariate logistic regression models were performed to assess the association between LE8 and periodontitis, with odds ratios (ORs) and 95% confidence intervals (CIs). Subgroup analyses based on age, gender, and cardiovascular disease (CVD) history were further assessed the association.

RESULTS

A total of 5106 adults were included, of whom 2606 (51.04%) had periodontitis. After adjustment for age, gender, race, poverty-to-income ratio, education level, marital status, drinking, CVD, nonsteroidal anti-inflammatory agents, waist circumference (WC), vitamin D, and dental floss using, a high LE8 score (odds ratio [OR], 0.48; 95% confidence interval [CI], 0.32-0.73), a higher health behaviours score (OR, 0.56; 95% CI, 0.42-0.73), and a higher health factors score (OR, 0.71; 95% CI, 0.51-0.99) were associated with a lower occurrence of periodontitis, especially in adults who were male, younger than 60 years, and without a history of CVD. Moreover, the occurrence of periodontitis decreased when scores of total LE8, health factors, and health behaviours increased every 10 scores.

CONCLUSIONS

LE8 score and its subscale scores were associated with lower odds of periodontitis. Promoting improved cardiovascular health may be beneficial to reduce the burden of periodontitis.

Role of CD86 on granulocyte in mediating the effect of Genus Roseburia on periodontitis

OBJECTIVES

This study aimed to explore the causal link between the gut microbiota and periodontitis, and to delineate and quantify the intermediary role of immune cells, so as to provide new insights into the pathogenesis, prevention and treatment of periodontitis.

MATERIALS AND METHODS

We employed a two-sample Mendelian randomization (MR) approach to analyze the genetic predictors of gut microbiota composition (covering 412 gut microbiota taxa and functions) and periodontitis (involving 4,784 cases and 272,252 controls) derived from genome-wide association study (GWAS) datasets. A subsequent two-step MR analysis was conducted to evaluate the extent to which immune cell traits (encompassing 731 immune cell characteristics) mediate the influence of gut microbiota on periodontitis risk.

RESULTS

Our analysis implicated nine gut microbiota taxa as causal factors in periodontitis susceptibility (p < 0.05). Notably, the Genus Roseburia was identified as exerting a protective effect against periodontitis, partially mediated through the upregulation of CD86 expression on granulocytes, with an 8.15% mediation effect observed.

CONCLUSIONS

Our findings establish a causal relationship between the gut microbiota and periodontitis, highlighting the protective role of Roseburia against this condition. A notable proportion of this protective effect is mediated via the upregulation of CD86 on granulocytes.

CLINICAL RELEVANCE

It can provide new ideas for the pathogenesis, prevention and treatment for periodontitis through exploring the causal link between the gut microbiota and periodontitis, and describing and quantifying the intermediary role of immune cells.

Local Drug Delivery Systems as Novel Approach for Controlling NETosis in Periodontitis

Periodontitis is a chronic inflammation caused by periodontopathogenic bacteria in the dental biofilm, and also involves the inflammatory-immune response of the host. Polymorphonuclear neutrophils (PMNs) play essential roles in bacterial clearance by multiple mechanisms, including the formation of neutrophil extracellular traps (NETs) that retain and destroy pathogens. During PD progression, the interaction between PMNs, NETs, and bacteria leads to an exaggerated immune response and a prolonged inflammatory state. As a lesion matures, PMNs accumulate in the periodontal tissues and die via NETosis, ultimately resulting in tissue injury. A better understanding of the role of NETs, the associated molecules, and the pathogenic pathways of NET formation in periodontitis, could provide markers of NETosis as reliable diagnostic and prognostic tools. Moreover, an assessment of NET biomarker levels in biofluids, particularly in saliva or gingival crevicular fluid, could be useful for monitoring periodontitis progression and treatment efficacy. Preventing excessive NET accumulation in periodontal tissues, by both controlling NETs' formation and their appropriate removal, could be a key for further development of more efficient therapeutic approaches. In periodontal therapy, local drug delivery (LDD) systems are more targeted, enhancing the bioavailability of active pharmacological agents in the periodontal pocket and surrounding tissues for prolonged time to ensure an optimal therapeutic outcome.

Xenogenous implanted dental follicle stem cells promote periodontal regeneration through inducing the N2 phenotype of neutrophils

BACKGROUND

Periodontal tissue loss is the main reason for tooth mobility and loss caused by periodontal disease. Dental follicle stem cells (DFSCs) have significant therapeutic potential in periodontal regeneration, which maybe mainly depends on their potent immunomodulatory capacity. Consequently, this study aims to elucidate the impact of implanted xenogenous DFSCs on innate immune responses during early and late stages in the periodontal defect repair period.

METHODS

To trace and investigate the immunomodulation mechanisms of DFSCs in vivo, DFSCs were engineered (E-DFSCs) using lentiviral vectors expressing CD63-enhanced green fluorescent protein (CD63-EGFP) and β-Actin-mCherry protein (ACTB-mCherry) to exhibit green and red fluorescence. The biological characteristics and functions of E-DFSCs were verified by proliferation, differentiation, and co-culture experiments in vitro. In vivo, the periodontal regeneration capacity of E-DFSCs was detected by implantation of murine periodontal defect model, and the response of innate immune cells was detected at the 1st, 3rd, and 5th days (early stage) and 4th week (late stage) after implantation.

RESULTS

In vitro assessments showed that E-DFSCs retain similar properties to their non-engineered counterparts but exhibit enhanced macrophage immunomodulation capability. In mice models, four-week micro-CT and histological evaluations indicated that E-DFSCs have equivalent efficiency to DFSCs in periodontal defect regeneration. At the early stage of repair in mice periodontal defect, fluorescence tracking showed that implanted E-DFSCs might primarily activate endogenous cells through direct contact and indirect actions, and most of these cells are myeloperoxidase-positive neutrophils. Additionally, compared with the control group, the neutrophilic infiltration and conversion of N2-type were significantly increased in the E-DFSC group. At the late stage of defect regeneration, more M2-type macrophages, fewer TRAP + osteoclasts, and an upregulated OPG/RANKL ratio were detected in the E-DFSC group compared to the control group, which indicated that immune balance tilts towards healing and bone formation.

CONCLUSION

The xenogenous implanted DFSCs can induce the N2 phenotype of neutrophils in the early stage, which can activate the innate immune mechanism of the host to promote periodontal tissue regeneration.

Therapeutic Strategies and Genetic Implications for Periodontal Disease Management: A Systematic Review

The objective of this review is to identify the microbiological alterations caused by various therapy modalities by critically analyzing the current findings. We limited our search to English-language papers published between 1 January 2004 and 7 May 2024 in PubMed, Scopus, and Web of Science that were relevant to our topic. In the search approach, the Boolean keywords "microbio*" AND "periodontitis" were used. A total of 5152 papers were obtained from the databases Web of Science (2205), PubMed (1793), and Scopus (1154). This resulted in 3266 articles after eliminating duplicates (1886), and 1411 entries were eliminated after their titles and abstracts were examined. The qualitative analysis of the 22 final articles is included in this study. Research on periodontal disease shows that periodontitis alters the oral microbiome and increases antibiotic resistance. Treatments like scaling and root planing (SRP), especially when combined with minocycline, improve clinical outcomes by reducing harmful bacteria. Comprehensive mechanical debridement with antibiotics, probiotics, EMD with bone grafts, and other adjunctive therapies enhances periodontal health. Personalized treatment strategies and advanced microbial analyses are crucial for effective periodontal management and antibiotic resistance control.

The Role of Microbes in Surgical Decision Making for Infective Endocarditis: Mitral Valve Repair or Replacement?

BACKGROUND

The benefits of mitral repair versus replacement for endocarditis are inconclusive. This study compares outcomes of patients with infective endocarditis undergoing mitral valve repair versus replacement and investigates the impact of microbial etiology.

METHODS

All 251 patients undergoing mitral valve surgery for active endocarditis between 2010 and 2023 were enrolled, 180 (71.7%) replacement and 71 (28.3%) repair. To adjust for imbalances, inverse probability of treatment weighting was applied and 187 patients were obtained.

RESULTS

The analysis between groups, following the application of inverse probability of treatment weighting, showed no statistically significant differences across all considered outcomes. Early and late death was observed respectively in 6 (8.5%) and 11 (15.5%) patients in the repair group versus 24 (13.3%) and 45 (25.0%) in the replacement group without statistical significance (p = 0.221 and p = 0.446). Relapse occurred in six patients (8.5%) in the repair group after a median time of 4.0 months and in six (3.3%) in the replacement after 6.9 months (p = 0.071).

CONCLUSIONS

Surgical strategy in mitral endocarditis has no effect on major postoperative complications, mortality, or medium/long-term survival. Staphylococcus aureus and Coagulase-negative Staphylococci represent a risk for early mortality and relapse. However, mitral valve repair for endocarditis can be pursued when it ensures the complete eradication of all infected tissue, particularly in cases caused by Streptococcus infection, in young patients, and after a minimum of 18 days of antibiotic therapy.

Pyroptosis: A major trigger of excessive immune response in the gingiva

OBJECTIVES

The gingival mucosal barrier, an important oral cavity barrier, plays a significant role in preventing pathogenic microorganism invasion and maintaining periodontal tissue health. Pathogenic microorganism invasion of the gingival mucosa produces a large number of cytokines. Among them, pyroptosis is an important player in exacerbating immune-inflammatory responses, leading to tissue destruction. However, the mechanism of pyroptosis and the immune response it triggers have not been fully elucidated. We provide an overview of recent advances in understanding gingival physical barrier pyroptosis and inflammation-induced hyperimmunity.

METHODS

PubMed, Web of Science databases were searched for articles, reviews, and clinical studies published until March 2024.

RESULTS

We summarised the importance of the gingival barrier in terms of the functions of different cells, described the progress in research on gingival epithelial cell and gingival fibroblast pyroptosis and the immune-inflammatory response it induces, and discussed the relationship between pyroptosis and systemic diseases, association of multiple cell death systems. Finally, we propose future directions for pyroptosis research.

CONCLUSIONS

Pyroptosis often triggers a range of inflammatory immune responses that lead to associated diseases. Therefore, further study of the molecular mechanisms of pyroptosis and the immune responses is warranted.

Impact of Non-Surgical Periodontal Treatment on the Concentration and Level of MRP-8/14 (Calprotectin) as an Inflammatory Biomarker in Women with Periodontitis and Rheumatoid Arthritis: A Quasi-Experimental Study

The aim of this study was to evaluate the impact of non-surgical periodontal treatment (NS-PT) on periodontal parameters and inflammatory biomarkers in the concentration and level of calprotectin (CLP) in women with periodontitis and rheumatoid arthritis (RA). In this quasi-experimental study, we evaluated 30 women (mean age: 52.0 ± 5.8 years) with periodontitis and RA who had been diagnosed and treated for RA for more than 3 years and whose activity markers remained at similar values without significant reduction over three consecutive months. Patients underwent NS-PT, which included plaque control, scaling, and root planing. Serum and saliva samples, periodontal indices, RA activity markers, Disease Activity Score-28 (DAS28), the erythrocyte sedimentation rate (ESR), and the C-reactive protein (CRP) and CLP contents were measured at the beginning of the study and 6 and 12 weeks after NS-PT. Parametric and nonparametric tests were used in the analysis. The mean age was 52.0 ± 5.8 years. Compared to the baseline results, all periodontal indices were significantly reduced 6 and 12 weeks after NS-PT (p < 0.001). DAS28 was also significantly reduced after 12 weeks (p < 0.0001). Similarly, the serum CLP concentration decreased 6 and 12 weeks after NS-PT (p < 0.0001). Of the patients, 100% presented lower levels of CRP and ESR (p < 0.0001). Overall, NS-PT reduced inflammation and disease activity, highlighting the importance of oral health in the control and treatment of systemic diseases such as RA and confirming that NS-PT effectively reduces periodontitis activity and plays a key role in modulating RA activity. Therefore, NS-PT should be considered as an adjunct treatment for RA.

Understanding Bartonella-Associated Infective Endocarditis: Examining Heart Valve and Vegetation Appearance and the Role of Neutrophilic Leukocytes

BACKGROUND

The endocardium and cardiac valves undergo severe impact during infective endocarditis (IE), and the formation of vegetation places IE patients at a heightened risk of embolic complications and mortality. The relevant literature indicates that 50% of IE cases exhibit structurally normal cardiac valves, with no preceding history of heart valve disease. Gram-positive cocci emerge as the predominant causative microorganisms in IE, while Gram-negative Bartonella spp., persisting in the endothelium, follow pathogenic pathways distinct from those of typical IE-causing agents. Employing clinical as well as advanced microbiological and molecular assays facilitated the identification of causative pathogens, and various morphological methods were applied to evaluate heart valve damage, shedding light on the role of neutrophilic leukocytes in host defense. In this research, the immunohistochemical analysis of neutrophilic leukocyte activation markers such as myeloperoxidase, neutrophil elastase, calprotectin, and histone H3, was performed. A distinct difference in the expression patterns of these markers was observed when comparing Bartonella spp.-caused and non-Bartonella spp.-caused IE. The markers exhibited significantly higher expression in non-Bartonella spp.-caused IE compared to Bartonella spp.-caused IE, and they were more prevalent in vegetation than in the valvular leaflets. Notably, the expression of these markers in all IE cases significantly differed from that in control samples. Furthermore, we advocated the use of 16S rRNA Next-Generation Sequencing on excised heart valves as an effective diagnostic tool for IE, particularly in cases where blood cultures yielded negative results. The compelling results achieved in this study regarding the enigmatic nature of Bartonella spp. IE's pathophysiology contribute significantly to our understanding of the peculiarities of inflammation and immune responses.