Periodontal pathogens in atheromatous plaque

Periodontal disease measures and risk of incident peripheral artery disease: The Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

The association of periodontal disease with atherosclerotic cardiovascular diseases is well known, but not specifically with incident peripheral artery disease (PAD). Therefore, we studied the associations of periodontal disease with incident PAD in a population-based setting.

METHODS

Among 9,793 participants (aged 53-75 years) without prevalent PAD, self-reported history of periodontal disease was ascertained. Of these, 5,872 participants underwent full-mouth examinations from which periodontal status was defined using the US Centers for Disease Control and Prevention-American Academy of Periodontology (CDC-AAP) definition. We quantified the association of periodontal disease with incident PAD (defined by hospital admission diagnosis or procedures) using multivariable Cox regression models.

RESULTS

During a median follow-up of 20.1 years, 360 participants (3.6%) developed PAD. In models accounting for potential confounders including diabetes and smoking pack-years, there was higher hazard of PAD in participants with self-reported tooth loss because of periodontal disease (hazard ratio:1.54 [95% CI:1.20-1.98]), history of periodontal disease treatment (1.37 [1.05-1.80]), and periodontal disease diagnosis (1.38 [1.09-1.74]), compared to their respective counterparts. The clinical measure of periodontal disease (n = 5,872) was not significantly associated with incident PAD in the fully adjusted model (e.g., 1.53 [0.94-2.50] in CDC-AAP-defined severe periodontal disease versus no disease).

CONCLUSION

We observed a modest association of self-reported periodontal disease, especially when resulting in tooth loss, with incident PAD in the general population. Nonetheless, a larger study with the clinical measure of periodontal disease is warranted.

Unexpected Relationships: Periodontal Diseases: Atherosclerosis-Plaque Destabilization? From the Teeth to a Coronary Event

Atherosclerotic cardiovascular disease (ASCVD) and periodontal disease (PD) are global health problems. High frequency of ASCVD is associated with the spread of many risk factors, including poor diet, sedentary lifestyle, diabetes, hyperlipidemia, obesity, smoking, hypertension, chronic kidney disease, hypertension, hyperhomocysteinemia, hyperuricemia, excessive stress, virus infection, genetic predisposition, etc. The pathogenesis of ASCVD is complex, while inflammation plays an important role. PD is a chronic, multifactorial inflammatory disease caused by dysbiosis of the oral microbiota, causing the progressive destruction of the bone and periodontal tissues surrounding the teeth. The main etiological factor of PD is the bacteria, which are capable of activating the immune response of the host inducing an inflammatory response. PD is associated with a mixed microbiota, with the evident predominance of anaerobic bacteria and microaerophilic. The "red complex" is an aggregate of three oral bacteria: Tannerella forsythia Treponema denticola and Porphyromonas gingivalis responsible for severe clinical manifestation of PD. ASCVD and PD share a number of risk factors, and it is difficult to establish a causal relationship between these diseases. The influence of PD on ASCVD should be treated as a factor increasing the risk of atherosclerotic plaque destabilization and cardiovascular events. The results of observational studies indicate that PD significantly increases the risk of ASCVD. In interventional studies, PD treatment was found to have a beneficial effect in the prevention and control of ASCVD. This comprehensive review summarizes the current knowledge of the relationship between PD and ASCVD.

Porphyromonas gingivalis infection promotes mitochondrial dysfunction through Drp1-dependent mitochondrial fission in endothelial cells

Porphyromonas gingivalis (P. gingivalis), a key pathogen in periodontitis, has been shown to accelerate the progression of atherosclerosis (AS). However, the definite mechanisms remain elusive. Emerging evidence supports an association between mitochondrial dysfunction and AS. In our study, the impact of P. gingivalis on mitochondrial dysfunction and the potential mechanism were investigated. The mitochondrial morphology of EA.hy926 cells infected with P. gingivalis was assessed by transmission electron microscopy, mitochondrial staining, and quantitative analysis of the mitochondrial network. Fluorescence staining and flow cytometry analysis were performed to determine mitochondrial reactive oxygen species (mtROS) and mitochondrial membrane potential (MMP) levels. Cellular ATP production was examined by a luminescence assay kit. The expression of key fusion and fission proteins was evaluated by western blot and immunofluorescence. Mdivi-1, a specific Drp1 inhibitor, was used to elucidate the role of Drp1 in mitochondrial dysfunction. Our findings showed that P. gingivalis infection induced mitochondrial fragmentation, increased the mtROS levels, and decreased the MMP and ATP concentration in vascular endothelial cells. We observed upregulation of Drp1 (Ser616) phosphorylation and translocation of Drp1 to mitochondria. Mdivi-1 blocked the mitochondrial fragmentation and dysfunction induced by P. gingivalis. Collectively, these results revealed that P. gingivalis infection promoted mitochondrial fragmentation and dysfunction, which was dependent on Drp1. Mitochondrial dysfunction may represent the mechanism by which P. gingivalis exacerbates atherosclerotic lesions.

Association of Edentulism with Various Chronic Diseases in Mexican Elders 60+ Years: Results of a Population-Based Survey

Objective: To determine the association of edentulism with different chronic diseases and mental disorders in Mexicans aged 60 years and over. Material and Methods: A cross-sectional study was carried out using data from the World Health Survey for Mexico, in a probabilistic, multi-stage cluster sampling framework. Data for self-report of chronic diseases (diabetes, arthritis, angina pectoris and asthma), mental disorders (depression and schizophrenia) and edentulism were analyzed. Edentulism data were available for 20 of the 32 States of Mexico. Statistical analysis was performed in Stata 14.0 using the svy module for complex sampling (Complex nature under which individuals are sampled). Results: In total 4213 subjects were included, representing a population of 7,576,057 individuals. Mean age was 70.13 ± 7.82 years (range 60 to 98); 56.2% were women. Chronic diseases’ prevalence and mental disorders prevalence were as follows: diabetes 15.0% (N = 1,132,693); arthritis 13.2% (N = 1,001,667); depression 5.5% (N = 414,912); angina pectoris 4.5% (344,315); asthma 3.6% (N = 269,287); and schizophrenia 2.2% (N = 16,988). The prevalence of edentulism was 26.3%, which pertained to 1,993,463 people aged 60 years and over. Angina in women aged 60 to 69 years (p < 0.05) and depression in men aged 70 years and over (p < 0.0001) were associated with higher prevalence of edentulism. Conclusions: There was generally sparse association between edentulism on chronic diseases and mental disorders included in the study, except for women aged 60 to 69 years for angina, and in men aged 70 and over, for depression. Although our findings are misaligned with previous reports, longitudinal studies are required to test causal and temporal relationships between edentulism with chronic diseases and mental disorders.

Role of Periodontal Infection, Inflammation and Immunity in Atherosclerosis

BACKGROUND

Inflammation plays a major role in the development and progression of cardiovascular disease (CVD) morbidity and mortality. The well-established relationship between periodontal disease (PD) and CVD may be causal. Left untreated, PD can lead to high systemic inflammation, thus contributing to inflammatory CVD, such as atherosclerosis. Multiple mechanisms have been proposed to elucidate the causal relationship between PD and its contribution to CVD.

OBJECTIVE

This review article highlights the current evidence supporting the role of PD in the development and progression of atherosclerosis.

METHODS

After creating a list of relevant medical subject heading (MeSH) terms, a systematic search within PubMed in English for each MeSH term between 2000 and 2019 was used to generate evidence for this review article.

CONCLUSION

There is overwhelming evidence in the current literature that supports an association between PD and CVD that is independent of known CVD risk factors. However, the supporting evidence that PD directly causes CVD in humans continues to remain elusive. Multiple biologically plausible mechanisms have been proposed and investigated, yet most studies are limited to mouse models and in vitro cell cultures. Additional studies testing the various proposed mechanisms in longitudinal human studies are required to provide deeper insight into the mechanistic link between these 2 related diseases.

[Research progress of correlation between periodontal pathogens and systemic diseases]

Periodontal pathogens are the main pathogenic factor of periodontitis. Periodontal pathogens have a large variety of virulence factors such as lipopolysaccharide, fimbriae and proteases, which enables the pathogens to infect periodontal tissues and stimulate the secretion of inflammatory cytokines, causing chronic systemic inflammation. Periodontal pathogens may invade multiple systems such as the circulatory system, immune system, respiratory system and digestive system to cause systematic diseases. Recent studies have shown that periodontal pathogens may have close relations with systemic diseases such as cardiovascular disease, diabetes, rheumatoid arthritis, and cancer. Among the periodontal pathogens, Porphyromonas gingivalis can be found in atherosclerotic plaques to impairing the function of the vascular endothelium; Porphyromonas gingivalis may also increase the level of inflammatory factors such as TNF-α to promote insulin resistance and diabetes. Many of the periodontal pathogens such as Porphyromonas gingivalis, Tannerella forsythia and Prevotella intermedia can be detected in the synovial fluid of rheumatoid arthritis patients, suggesting their involvement in the pathogenesis of rheumatoid arthritis. Fusobacterium nucleatum may cause alterations in the intestinal microbiome in mice and promote the occurrence of intestinal tumors. Herein we review the recent progresses in the relationship between periodontal pathogens and systemic diseases.

Innovative application of nested PCR for detection of Porphyromonas gingivalis in human highly calcified atherothrombotic plaques

Atherothrombosis, leading to stroke and myocardial infarction, is responsible for most of the deaths in the world. An increased risk of atherothrombotic vascular events has been reported in patients with periodontitis. Periodontitis is a chronic multifactorial inflammatory disease, which involves a dysbiotic microbiota, and leads to a progressive destruction of the tooth-supporting apparatus. Transcient periodontal pathogen blood translocation, mainly bacteremia, has been associated with the severity of gingival inflammation. The identification of periodontal bacteria within atherothrombotic plaques is challenging and unpredictable. This review aims to summarize existing molecular technics for identifying periodontal microbiota in human atherothrombotic samples. A secondary objective is to describe a protocol for the identification of Porphyromonas gingivalis from highly calcified, atherothrombotic human samples that is based on our experience in translational cardiovascular research. Compared to direct real-time PCR, our protocol based on nested PCR has increased the detection of Porphyromonas gingivalis by 22.2% with good specificity.

Porphyromonas gingivalis-Induced MIF Regulates Intercellular Adhesion Molecule-1 Expression in EA.hy926 Cells and Monocyte-Endothelial Cell Adhesion Through the Receptors CD74 and CXCR4

Porphyromonas gingivalis (P. gingivalis) is an important pathogen that contributes to periodontal disease and causes infections that promote the progression of atherosclerosis. Our previous studies showed that macrophage migration inhibitory factor (MIF) facilitates monocyte adhesion to endothelial cells by regulating the expression of intercellular adhesion molecule-1 (ICAM-1) in P. gingivalis-infected endothelial cells. However, the detailed pathological role of MIF has yet to be elucidated in this context. To explore the functional receptor(s) of MIF that underlie its participation in the pathogenesis of atherosclerosis, we investigated the expression of the chemokine receptors CD74 and CXCR4 in endothelial cells, both of which were shown to be involved in the adhesion of monocytes to endothelial cells pretreated with P. gingivalis. Furthermore, the formation of a MIF, CD74, and CXCR4 ligand-receptor complex was revealed by our immunofluorescence staining and coimmunoprecipitation results. By interacting with the CD74/CXCR4 receptor complex, MIF may act as a crucial regulator of monocyte-endothelial cell adhesion and promote the atherosclerotic plaque formation induced by P. gingivalis.

The Role of the Microbiota in the Diabetic Peripheral Artery Disease

Vascular complications of diabetes mellitus represent a major public health problem. Although many steps forward have been made to define the causes and to find the best possible therapies, the problem remains crucial. In recent years, more and more evidences have defined a link between microbiota and the initiation, promotion, and evolution of atherosclerotic disease, even in the diabetic scenario. There is an urgency to develop the knowledge of modern medicine about the link between gut microbiota and its host's metabolic pathways, and it would be useful to understand and justify the interindividual diversity of clinical disease presentation of diabetic vascular complication even if an optimization of pharmacological treatment has been made or in the case of young patients where hypertension, dyslipidemia, and diabetes are not able to justify a very quick progress of atherosclerotic process. The aim of the present review is to gather all the best available evidence in this regard and to define a new role of the microbiota in this field, from biomarker to possible therapeutic target.

The association of periodontal disease and cardiovascular disease risk: Results from the Hispanic Community Health Study/Study of Latinos

BACKGROUND

Current evidence suggests that periodontal disease (PD) is associated with a significant increased risk of atherosclerotic cardiovascular disease (CVD) independent of known confounders. PD is a chronic oral disease with significant variation in prevalence demonstrated among Hispanic/Latino subgroups. The purpose of this study was to investigate the associations between PD and CVD risk and variations with sex, age, and Hispanic/Latino background.

METHODS

The sample included 7379 participants aged 30 to 74 years, from the Hispanic Community Health Study/Study of Latinos (2008 to 2011). We assessed CVD risk by the Framingham 10-year general CVD risk score (FGRS). PD severity classification was based on calibrated measurements of gingival recession and probing depth. Multivariable sequential linear models for complex sample design assessed FGRS by PD severity, Hispanic/Latino background, and covariates.

RESULTS

The prevalence of moderate and severe PD combined was 46%. For women and men with severe PD, the combined prevalence of moderate and high CVD risk was 44% and 85%, respectively. The FGRS observed for women (5.1% [95% CI: 4.1%, 6.0%], p < 0.001) and men 10.8% (95% CI [9.2%, 12.3%], p < 0.001) with severe PD were 56% and 134% greater than those without PD, respectively. Dominican women and men with moderate or severe PD, aged 60 to 69 years, exhibited the greatest CVD risks (FGRS = 15.1%, 95% CI [7.8%, 22.5%]) and (FGRS = 40.2%, 95% CI [30.2%, 50.3%]), respectively.

CONCLUSIONS

Moderate and severe PD were associated with significant CVD risk with marked sex disparity and heterogeneity by Hispanic/Latino background.

Linkages between oral commensal bacteria and atherosclerotic plaques in coronary artery disease patients

Coronary artery disease is an inflammatory disorder characterized by narrowing of coronary arteries due to atherosclerotic plaque formation. To date, the accumulated epidemiological evidence supports an association between oral bacterial diseases and coronary artery disease, but has failed to prove a causal link between the two. Due to the recent surge in microbial identification and analyses techniques, a number of bacteria have been independently found in atherosclerotic plaque samples from coronary artery disease patients. In this study, we present meta-analysis from published studies that have independently investigated the presence of bacteria within atherosclerotic plaque samples in coronary artery disease patients. Data were collated from 63 studies covering 1791 patients spread over a decade. Our analysis confirms the presence of 23 oral commensal bacteria, either individually or in co-existence, within atherosclerotic plaques in patients undergoing carotid endarterectomy, catheter-based atherectomy, or similar procedures. Of these 23 bacteria, 5 (Campylobacter rectus, Porphyromonas gingivalis, Porphyromonas endodontalis, Prevotella intermedia, Prevotella nigrescens) are unique to coronary plaques, while the other 18 are additionally present in non-cardiac organs, and associate with over 30 non-cardiac disorders. We have cataloged the wide spectrum of proteins secreted by above atherosclerotic plaque-associated bacteria, and discuss their possible roles during microbial migration via the bloodstream. We also highlight the prevalence of specific poly-microbial communities within atherosclerotic plaques. This work provides a resource whose immediate implication is the necessity to systematically catalog landscapes of atherosclerotic plaque-associated oral commensal bacteria in human patient populations.

A review of bacterial populations in the mouth and in diseased arteries will help research into the role of bacteria in heart disease. Amit Sharma and colleagues at the International Centre for Genetic Engineering and Biotechnology, with co-workers at the All India Institute of Medical Sciences, both in New Delhi, India, analyzed 63 studies covering 1791 patients spread over a decade. They summarize evidence of 23 types of oral bacteria that are also found in atherosclerotic plaques in artery walls. The review also cataloged the proteins secreted by the bacteria and discussed possible involvement of these proteins in the migration of bacteria through the bloodstream. Full genetic details are available for 19 of the 23 bacterial species, which should greatly assist further investigations into the significance of bacteria in the onset of heart disease.

The Association of Gum Bleeding with Respiratory Health in a Population Based Study from Northern Europe

BACKGROUND

There is little knowledge about how oral and respiratory health is interrelated even though the mucosa of the oral cavity and airways constitutes a continuum and the exposures to these are partly similar.

AIMS

To investigate whether gum bleeding is related to asthma, respiratory symptoms and self-reported COPD.

METHODS

A postal questionnaire including questions about respiratory and oral health was sent to general population samples in seven Northern European centres. In 13,409 responders, gum bleeding when brushing teeth was reported always/often by 4% and sometimes by 20%. Logistic regressions accounted for age, smoking, educational level, centre and gender. Effects of BMI, cardio-metabolic diseases, early life factors, gastro-oesophageal reflux, dental hygiene, nasal congestion, and asthma medication were addressed.

RESULTS

Gum bleeding always/often was significantly associated with ≥ 3 asthma symptoms (OR 2.58, 95% CI 2.10-3.18), asthma (1.62 [1.23-2.14]) and self-reported COPD (2.02 [1.28-3.18]). There was a dose-response relationship between respiratory outcomes and gum bleeding frequency (≥ 3 symptoms: gum bleeding sometimes 1.42 [1.25-1.60], often/always 2.58 [2.10-3.18]), and there was no heterogeneity between centres (p(heterogeneity) = 0.49). None of the investigated risk factors explained the associations. The observed associations were significantly stronger among current smokers (p(interaction) = 0.004).

CONCLUSIONS

A consistent link between gum bleeding and obstructive airways disease was observed, not explained by common risk factors or metabolic factors. We speculate that oral pathogens might have unfavourable impact on the airways, and that the direct continuity of the mucosa of the oral cavity and the airways reflects a pathway that might provide novel opportunities for interventions.

Association between Bacterial Infection and Peripheral Vascular Disease: A Review

There are an increasing number of data showing a clinically important association between bacterial infection and peripheral artery disease (PAD). Bacteria suspected of being involved in PAD pathogenesis are: periodontal bacteria, gut microbiota, Helicobacter pylori, and Chlamydia pneumoniae. Infectious agents may be involved in the pathogenesis of atherosclerosis via activation of a systemic or local host immunological response to contamination of extravascular tissues or the vascular wall, respectively. A systemic immunological reaction may damage vascular walls in the course of autoimmunological cross-reactions between anti-pathogen antibodies and host vascular antigens (immunological mimicry), pathogen burden mechanisms (nonspecific activation of inflammatory processes in the vascular wall), and neuroendocrine-immune cross-talk. Besides activating the inflammatory pathway, bacterial infection may trigger PAD progression or exacerbation by enhancement of platelet reactivity, by a stimulatory effect on von Willebrand factor binding, factor VIII, fibrinogen, P-selectin activation, disturbances in plasma lipids, increase in oxidative stress, and resistance to insulin. Local inflammatory host reaction and induction of atherosclerotic plaque progression and/or instability result mainly from atherosclerotic plaque colonization by microorganisms. Despite these premises, the role of bacterial infection in PAD pathogenesis should still be recognized as controversial, and randomized, controlled trials are required to evaluate the outcome of periodontal or gut bacteria modification (through diet, prebiotics, and probiotics) or eradication (using antibiotics) in hard and surrogate cardiovascular endpoints.

Periodontal innate immune mechanisms relevant to atherosclerosis

Atherosclerosis is a common cardiovascular disease in the USA where it is a leading cause of illness and death. Atherosclerosis is the most common cause for heart attack and stroke. Most commonly, people develop atherosclerosis as a result of diabetes, genetic risk factors, high blood pressure, a high-fat diet, obesity, high blood cholesterol levels, and smoking. However, a sizable number of patients suffering from atherosclerosis do not harbor the classical risk factors. Ongoing infections have been suggested to play a role in this process. Periodontal disease is perhaps the most common chronic infection in adults with a wide range of clinical variability and severity. Research in the past decade has shed substantial light on both the initiating infectious agents and host immunological responses in periodontal disease. Up to 46% of the general population harbors the microorganism(s) associated with periodontal disease, although many are able to limit the progression of periodontal disease or even clear the organism(s) if infected. In the last decade, several epidemiological studies have found an association between periodontal infection and atherosclerosis. This review focuses on exploring the molecular consequences of infection by pathogens that exacerbate atherosclerosis, with the focus on infections by the periodontal bacterium Porphyromonas gingivalis as a running example.

Antibiotic susceptibility of 33 Prevotella strains isolated from Romanian patients with abscesses in head and neck spaces

The purpose of this study was to investigate the susceptibility of a series of 33 Prevotella strains isolated from patients with abscesses in the head and neck spaces, presented to one Romanian hospital. The Etest was applied to determine the value of the minimum inhibitory concentrations for: penicillin G, ampicillin, amoxicillin-clavulanate, metronidazole and clindamycin. In addition, the beta-lactamase activity was detected by the chromogenic cephalosporin disc method. The results indicated that 11 isolates were resistant to both penicillin G and ampicillin due to the beta-lactamase production. All the 33 Prevotella strains were susceptible to the other 3 antimicrobial agents tested, except for only one penicillin G - ampicillin resistant isolate of Prevotella buccae (MIC > 32 and MIC = 12 mg/L, respectively), which showed high resistance to clindamycin (MIC > 256 mg/L) too. Our data underline the necessity for antimicrobial testing including monitoring of beta-lactamase production in cases of oro-maxillo-facial mixed anaerobic infections where antimicrobial treatment is required in addition to the surgical drainage. The results of the study indicated that amoxicillin-clavulanate, like metronidazole, was fully active against the tested Prevotella strains. However, local and multicentre surveys on drug resistance among the clinically significant anaerobic isolates should be carried out periodically.