Experimental periodontitis promotes transient vascular inflammation and endothelial dysfunction

Bidirectional Association between Periodontitis and Thyroid Disease: A Scoping Review

Periodontitis is a chronic inflammatory disease of the tissues surrounding and supporting the teeth. Due to the development of chronic inflammation, periodontitis can contribute to the development of several systemic diseases, including thyroid disease. Thyroid pathology includes benign, malignant, and autoimmune conditions leading to hypothyroidism, hyperthyroidism, or euthyroidism. Alterations in thyroid hormones, especially hypothyroidism, can reveal significant oral manifestations, including periodontitis. This scoping review aims to explore the probable causal relationship between periodontitis and thyroid disease, in terms of epidemiology, pathogenesis, and treatment. The search strategy follows the PRISMA-ScR guidelines. PubMed, Scopus, Web of Science, and Cochrane were searched from January 2014 to January 2024, entering the MESH terms "periodontitis" and "thyroid". Of 153 initial records, 20 articles were selected and discussed. There is a high prevalence of periodontitis among patients with thyroid disease, including thyroid cancer. The causes at the basis of this association are genetic factors, the oral microbiome, and proinflammatory cytokines. Periodontal treatment, specifically scaling and root planning, can ameliorate thyroid parameters. Although there are a few randomized controlled studies in the literature, this review lays the foundation for a bidirectional relationship between periodontitis and thyroid disease, the link to which is, once again, systemic inflammation.

Relationship between Carotid Intima-Media Thickness, Periodontal Disease, and Systemic Inflammation Biomarkers in an Adult Population

A positive relationship has been reported between advanced periodontitis and carotid intima-media thickness (cIMT) measurement. The aim of this study was to investigate this relationship with parameters for periodontitis, such as PISA and systemic inflammation biomarkers. An observational descriptive cross-sectional study was conducted. A blood sample was collected from 75 subjects to analyze glucose, total cholesterol, HDL, LDL, and cytokine values. Increased cIMT was found in 32% of the patients with fewer teeth. Patients with periodontitis had a larger periodontal inflamed surface area (PISA) (p = 0.000) and had a 1.42-times-higher risk of having increased cIMT values compared to periodontally healthy individuals, though without a statistically significant association. Higher values in the left cIMT, IL-8, and TNF-α were found in men than in women with significant differences. In the multivariate analysis involving cytokines, age continues to be linked to increased cIMT values. INF-γ showed a trend towards a protective effect; as the IMT-M decreases, there is an increase in the expression of INF-γ, and a higher proportion of subjects with elevated INF-γ concentrations demonstrated normal IMT-C. This study did not find a statistically significant association between cIMT and periodontal disease, but the risk of having increased cIMT is 1.42-times higher for individuals with periodontitis.

Effects of Coriander on the Repair Process of Experimentally-induced Periodontitis in Rats

The aim of this study was to evaluate the effects of Coriandrum sativum L. (CSL) seed extract on gingival levels of antioxidant enzymes, pro-inflammatory cytokines and on alveolar bone and attachment levels after experimental periodontitis induction in rats and compare it with low-dose doxycycline (LDD). Forty adult male Wistar Albino rats were divided randomly into 5 groups as follows: 1 = periodontally healthy (control); 2 = periodontitis; 3 = periodontitis + CSL (32 mg/kg); 4 = periodontitis + CSL (200 mg/kg); and 5 = periodontitis + LDD (6 mg/kg). Gingival superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) levels were evaluated by enzyme-linked immunosorbent assay. The presence of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1βeta (IL-1β) immunoreactivity was detected immunohistochemically. Alveolar bone area in the furcation space (ABA), alveolar bone loss (ABL), and attachment loss (AL) were evaluated histomorphometrically. The SOD level was lower in group 5 than in groups 2, 3, and 4. The IL-1β level was highest in group 4. The TNF-α level was statistically higher in groups 2 and 4 than in groups 1, 3, and 5. The IL-6 level was highest in group 4. Its level was higher in groups 2 and 3 than in group 5. ABA was less in groups 2, 3, and 4 compared to groups 1 and 5. ABL was less in group 5 than in groups 2, 3, and 4. AL was greater in group 4 than in group 5. The use of 200 mg/kg CSL showed a pro-inflammatory effect and IL-1β and TNF-α levels decreased after 32 mg/kg CSL application in the treatment of periodontitis.

Yunvjian decoction attenuates lipopolysaccharide-induced periodontitis by suppressing NFκB/NLRP3/IL-1β pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Yunvjian decoction (YNJ) is a traditional Chinese herbal prescription that has been used in the clinical treatment of periodontitis. However, the underlying molecular mechanism of YNJ in the periodontitis treatment is not well understood.

AIM OF THE STUDY

The purpose of this study was to evaluate the therapeutic effects of YNJ against periodontitis and its underlying molecular mechanisms.

MATERIALS AND METHODS

Orthodontic ligation and lipopolysaccharide (LPS)-induced periodontitis rat model was established. YNJ groups were gavaged with YNJ decoction (5 g/kg/d or 10 g/kg/d) for four months. The rats in positive control group were gavaged with metronidazole (MDZ, 100 mg/kg/d) for four months. The maxilla was scanned by micro-computed tomography. The chemical compositions of YNJ were identified using ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry. The molecular mechanism of YNJ were predicted using network pharmacological analysis and validated using immune-staining and Western blot.

RESULTS

YNJ treatment decreased the distance between cementoenamel junction and alveolar bone crest on the sagittal slide of the periodontitis rats. Western blot showed YNJ downregulated the protein levels of the bone resorption marker (receptor activator of nuclear factor-κB ligand), while upregulated the levels of the bone formation markers (bone morphogenetic protein 2, runt-related transcription factor 2, alkaline phosphatase, and osteoprotegerin) in alveolar bone of the periodontitis rats. Hematoxylin and eosin, immunohistochemical staining, and Western blot analysis indicated that YNJ attenuated the inflammation and decreased the levels of interleukin-6 and tumor necrosis factor-α in the alveolar bone. In addition, a total of 61 compounds were identified from YNJ. Network pharmacology indicated that the nucleotide binding oligomerization domain-like receptor signaling pathway was the main pathway for YNJ in the treatment of periodontitis. The experiments confirmed that YNJ administration inhibited LPS induced-pyroptosis in alveolar bone through suppressing the phosphorylation of nuclear factor κB, reduced expression of NOD-like receptor family pyrin domain containing 3, and Caspase-1, subsequently suppressing the interleukin-1β secretion.

CONCLUSION

YNJ is an effective therapeutic strategy for periodontitis and acts by inhibiting pyroptosis and NFκB/NLRP3/IL-1β pathway in alveolar bone.

Effect of experimental periodontitis on cardiac functions: a comprehensive study using echocardiography, hemodynamic analysis, and histopathological evaluation in a rat model

Introduction

Periodontitis is a prevalent and severe dental condition characterized by the gradual degradation of the bone surrounding the teeth. Over the past two decades, numerous epidemiological investigations have suggested a potential link between periodontitis and cardiovascular disease. However, the complex mechanistic relationship between oral health issues and cardiovascular disorders remains unclear.

Aim

This study aimed to explore comprehensively the cardiac function through various methods, including conventional echocardiography, intraventricular pressure gradient (IVPG) analysis, speckle tracking echocardiography (STE), and hemodynamics analysis.

Methods

Ligature-induced periodontitis was established in a group of rats while the second group served as sham. The successful establishment of the periodontitis model was confirmed through staining and radiographic examination of the affected mandibles.

Results

X-ray films and methylene blue staining revealed alveolar bone resorption in the affected first molar in the model rats, confirming the successful induction of periodontitis. The rats with periodontitis displayed a decrease in ejection fraction compared to the sham group, accompanied by a decrease in mid-to-apical IVPG and mid IVPG. Lower values of strain rate were recorded in the apical segment of the septum, the middle segment of the septum, and the basal segment of the lateral free wall in the periodontitis group, which was associated with histopathological examination showing some degree of myocardial tissue damage. Conversely, rats with periodontitis showed an increase in heart rate, end-systolic volume, and arterial elastance when compared to the sham rats. However, they also exhibited a decrease in stroke work, stroke volume, cardiac output, and end-systolic pressure.

Conclusion

This study suggests that experimental periodontitis may lead to cardiac dysfunction especially compromised systolic function and myocardial relaxation, potentially indicating an increased risk of cardiovascular events in clinical periodontitis cases. The comprehensive assessment of cardiac function, hemodynamics, and histopathological evaluation underscores the profound impact of periodontitis on heart functions within this specific experimental model.

Aerobic exercise 3 times per week in adult rats did not influence the progression of periodontal disease

Introduction

Physical exercise has proven efficacy in the prevention and treatment of chronic diseases, and its anti-inflammatory effect has been evaluated as a potential preventive factor in the progression of periodontal disease, in addition to improving physiological parameters.

Methods

To test this hypothesis regarding its preventive factor, we evaluated the effects of aerobic training on the progression of periodontal disease in 8-month-old Wistar rats (n = 44). The animals underwent a swimming protocol lasting six weeks, with periodontal disease induced by ligature in the fifth week, totaling fourteen days of ligature placement. Anthropometric parameters were measured for subsequent calculations of BMI and Lee's Index. Interleukin-1β testing was performed to measure serum inflammatory parameters, and alveolar bone loss was measured using images to calculate the area of loss.

Results

The trained animals showed no significant differences compared to the non-trained animals in terms of anthropometric measures. Regarding the area of bone loss, although there were significant differences between the groups with and without periodontal disease, exercise did not demonstrate an impact on rats with the disease. IL-1β analysis did not detect any measurable values in the samples in either group.

Discussion

These findings indicate that the applied exercise protocol was not sufficient to attenuate the progression of periodontal disease. This study did not find an effective impact of physical exercise on the analyzed parameters; however, the results are important in highlighting that the experimental animal model for inducing periodontal disease is efficient, which may encourage further investigations to determine factors that can attenuate its progression. Similarly, the application or development of new exercise protocols that can benefit and enrich the discussion on its positive effects in this disease is important, as there is already evidence suggesting an effective relationship between exercise and disease progression.

Neutrophils' Contribution to Periodontitis and Periodontitis-Associated Cardiovascular Diseases

Neutrophils represent the primary defense against microbial threats playing a pivotal role in maintaining tissue homeostasis. This review examines the multifaceted involvement of neutrophils in periodontitis, a chronic inflammatory condition affecting the supporting structures of teeth summarizing the contribution of neutrophil dysfunction in periodontitis and periodontal-related comorbidities. Periodontitis, a pathological condition promoted by dysbiosis of the oral microbiota, is characterized by the chronic inflammation of the gingiva and subsequent tissue destruction. Neutrophils are among the first immune cells recruited to the site of infection, releasing antimicrobial peptides, enzymes, and reactive oxygen species to eliminate pathogens. The persistent inflammatory state in periodontitis can lead to aberrant neutrophil activation and a sustained release of proinflammatory mediators, finally resulting in tissue damage, bone resorption, and disease progression. Growing evidence now points to the correlation between periodontitis and systemic comorbidities. Indeed, the release of inflammatory mediators, immune complexes, and oxidative stress by neutrophils, bridge the gap between local and systemic immunity, thus highlighting neutrophils as key players in linking periodontal inflammation to chronic conditions, including cardiovascular diseases, diabetes mellitus, and rheumatoid arthritis. This review underscores the crucial role of neutrophils in the pathogenesis of periodontitis and the complex link between neutrophil dysfunction, local inflammation, and systemic comorbidities. A comprehensive understanding of neutrophil contribution to periodontitis development and their impact on periodontal comorbidities holds significant implications for the management of oral health. Furthermore, it highlights the need for the development of novel approaches aimed at limiting the persistent recruitment and activation of neutrophils, also reducing the impact of periodontal inflammation on broader health contexts, offering promising avenues for improved disease management and patient care.

Oral microbiome mediated inflammation, a potential inductor of vascular diseases: a comprehensive review

The dysbiosis of the oral microbiome and vascular translocation of the periodontopathic microorganism to peripheral blood can cause local and systemic extra-oral inflammation. Microorganisms associated with the subgingival biofilm are readily translocated to the peripheral circulation, generating bacteremia and endotoxemia, increasing the inflammation in the vascular endothelium and resulting in endothelial dysfunction. This review aimed to demonstrate how the dysbiosis of the oral microbiome and the translocation of oral pathogen-induced inflammation to peripheral blood may be linked to cardiovascular diseases (CVDs). The dysbiosis of the oral microbiome can regulate blood pressure and activate endothelial dysfunction. Similarly, the passage of periodontal microorganisms into the peripheral circulation and their virulence factors have been associated with a vascular compartment with a great capacity to activate endothelial cells, monocytes, macrophages, and plaquettes and increase interleukin and chemokine secretion, as well as oxidative stress. This inflammatory process is related to atherosclerosis, hypertension, thrombosis, and stroke. Therefore, oral diseases could be involved in CVDs via inflammation. The preclinic and clinical evidence suggests that periodontal disease increases the proinflammatory markers associated with endothelial dysfunction. Likewise, the evidence from clinical studies of periodontal treatment in the long term evidenced the reduction of these markers and improved overall health in patients with CVDs.

Unraveling the Link Between Periodontal Disease and High Cholesterol: A Cross-Sectional Study

OBJECTIVE

This cross-sectional study aimed to investigate the association between high cholesterol levels and the prevalence of periodontal disease among patients in the United States, utilizing data from the National Health and Nutrition Examination Survey (NHANES) conducted between 2017 and 2020. We hypothesize that patients with high cholesterol levels will have a high prevalence of periodontal disease.

METHODS

The study utilized a cross-sectional design, analyzing data from NHANES 2017-March 2020 pre-pandemic survey, a nationally representative survey. The sub-sample consisted of 7,042 participants aged 30 years and older who underwent the NHANES survey questionnaire. Information on high cholesterol levels and periodontal disease was obtained through self-reported data. Statistical analyses, using SAS 9.4 (SAS Institute Inc., Cary, NC), were performed to assess the association between high cholesterol levels and periodontal disease prevalence while controlling the potential confounding variables. Descriptive statistics and multivariable logistic regression were used.  Results: The study included a total of 7,042 participants. The mean age (SD) of the participants was 60.2 (13.7); 54% were females and 46% were males. Out of the total, 23% (1636) of the samples had periodontal disease and 52% (3669) of the participants had high cholesterol levels. Findings indicated a significant association between high cholesterol and periodontal disease (odds ratio, OR = 1.21, 95% confidence interval, CI = 1.06-1.40). Socioeconomic factors such as poverty and education, and other factors such as age, gender, race, smoking, physical activity, BMI, diabetes, hypertension, sugar intake, cholesterol intake, saturated fatty acids intake, and oral hygiene were identified as potential confounders.

CONCLUSION

This large-scale cross-sectional study investigated the association between high cholesterol and periodontal disease while comprehensively controlling for potential confounding factors. After adjusting for the relevant confounders, we found a weak positive association between high cholesterol and periodontal disease. While these findings provide valuable insights into the interplay between systemic health and oral health, the cross-sectional nature of the study limits the establishment of causality.

The association of periodontal disease and oral health with hypertension, NHANES 2009-2018

BACKGROUND

Hypertension is a worldwide public health problem. We sought to explore the interaction of oral health and smoking on hypertension, and periodontal disease and smoking on hypertension.

METHODS

We included 21,800 participants aged ≧ 30 years from the National Health and Nutrition Examination Survey (NHANES) 2009-2018. Information of oral health and periodontal disease were self-reported. Blood pressure was taken by trained personnel and/or physicians at mobile testing center. Multiple logistic regression was used to estimate the association between oral health, periodontal disease and the prevalence of hypertension. The effects of oral health and periodontal disease on hypertension under smoking status and age were analyzed by stratified and interaction analysis.

RESULTS

A total of 21,800 participants were investigated, including 11,017 (50.54%) in hypertensive group and 10,783 (49.46%) in non-hypertensive group. Compared with the excellent/very good of oral health, the multivariable-adjusted OR of good, fair, and poor were 1.13 (95% CI, 1.02-1.27), 1.30 (95% CI, 1.15-1.47), and 1.48 (95% CI, 1.22-1.79) (p for trend < 0.001) for hypertension, respectively. Compared without periodontal disease group, the multivariable-adjusted OR of periodontal disease for hypertension was 1.21 (95% CI ,1.09-1.35) (p for trend < 0.001). Furthermore, we found the interactions between periodontal disease and smoking, oral health and smoking, periodontal disease and age, oral health and age were p < 0.001.

CONCLUSIONS

An association between oral health and periodontal disease with the prevalence of hypertension was identified. There exists interactive effect of periodontal disease and smoking, oral health and smoking, periodontal disease and age, oral health and age on hypertension in American population over 30 years of age and older.

The impact of periodontitis on vascular endothelial dysfunction

Periodontitis, an oral inflammatory disease, originates from periodontal microbiota dysbiosis which is associated with the dysregulation of host immunoinflammatory response. This chronic infection is not only harmful to oral health but is also a risk factor for the onset and progress of various vascular diseases, such as hypertension, atherosclerosis, and coronary arterial disease. Vascular endothelial dysfunction is the initial key pathological feature of vascular diseases. Clarifying the association between periodontitis and vascular endothelial dysfunction is undoubtedly a key breakthrough for understanding the potential relationship between periodontitis and vascular diseases. However, there is currently a lack of an updated review of their relationship. Therefore, we aim to focus on the implications of periodontitis in vascular endothelial dysfunction in this review.

Cardiovascular Diseases and Periodontitis

Periodontitis is a chronic inflammatory disease of the tooth-supporting connective tissue and alveolar bone that is initiated by a bacterial biofilm in periodontal pockets. It affects about half of adults in the Western world, and is associated with a range of systemic comorbidities, e.g., cardiovascular disease (CVD), diabetes and rheumatoid arthritis, and these diseases share overlapping systemic and target tissue inflammatory mechanisms. Indeed, mounting evidence has indicated that their association is causal and built on the presence of systemic low-grade inflammation (LGI). Prior research linking periodontitis to CVD has mainly been derived from experimental studies, observational data, and small interventional trials with surrogate markers of CVD, e.g., endothelial dysfunction. However, recent data from randomised studies have demonstrated that intensive treatment of periodontitis can reduce blood pressure in patients with hypertension in conjunction with reduction of systemic inflammatory markers. Furthermore, targeted anti-inflammatory therapy has been shown to reduce recurrent events in patients with established CVD and LGI. Along this line, the concept of residual inflammatory risk has emerged as an independent new risk factor for atherothrombotic CVD. The present review summarizes translational evidence indicating that periodontitis is a risk factor for CVD dependent on LGI, and we conclude that treatment of periodontitis is likely to contribute importantly to reduction of residual inflammatory risk.

Effects of periodontitis and periodontal treatment on systemic inflammatory markers and metabolic profile in obese and non-obese rats

BACKGROUND

Little is known about a synergistic effect of periodontitis and obesity on systemic biomarkers and a possible effect periodontal treatment may exert. This study aimed to evaluate the impact of periodontitis and periodontal treatment on systemic inflammation and metabolic profile in obese and non-obese rats.

METHODS

60 male Wistar rats were randomly divided in six groups differentiated by diet and periodontal status: no periodontitis (G1 and G4), untreated ligature-induced periodontitis (G2 and G5) and treated ligature-induced periodontitis (G3 and G6). Groups G4, G5 and G6 were exposed to cafeteria diet to induce obesity. Periodontitis was induced by silk ligatures over 4 weeks (G2, G3, G5, G6). Rats in G3 and G6 received scaling and root planning and were followed for additional 4 weeks. After sacrifice, serum levels of C-reactive protein (CRP), interleukin (IL)-1β, IL-6, IL-10, IL-17a, tumor necrosis factor alfa (TNF-α), glucose, triglycerides, and total cholesterol (TC) were compared between groups.

RESULTS

CRP was significantly higher in obese rats with than without periodontitis (G5 = 10.15μg/L vs. G4 = 4.47μg/L, p = 0.01). No beneficial effects of periodontal treatment were observed for CRP levels, IL-6, IL-1β, IL-17a, TNF-α, glucose and triglycerides. Treated periodontitis (G6) exhibited significantly lower TC than the periodontitis group (G5) in obese rats.

CONCLUSION

Periodontitis increased serum CRP in obese rats, indicating a synergistic role of periodontitis in the systemic inflammatory burden triggered by obesity. The treatment of induced periodontitis reduced TC levels in obese rats. This article is protected by copyright. All rights reserved.

Association between metabolic syndrome and periodontitis: The role of lipids, inflammatory cytokines, altered host response, and the microbiome

Periodontitis has been associated with many systemic diseases and conditions, including metabolic syndrome. Metabolic syndrome is a cluster of conditions that occur concomitantly and together they increase the risk of cardiovascular disease and double the risk of type 2 diabetes. In this review, we focus on the association between metabolic syndrome and periodontitis; however, we also include information on diabetes mellitus and cardiovascular disease, since these two conditions are significantly intertwined with metabolic syndrome. With regard to periodontitis and metabolic syndrome, to date, the vast majority of studies point to an association between these two conditions and also demonstrate that periodontitis can contribute to the development of, or can worsen, metabolic syndrome. Evaluating the effect of metabolic syndrome on the salivary microbiome, data presented herein support the hypothesis that the salivary bacterial profile is altered in metabolic syndrome patients compared with healthy patients. Considering periodontitis and these three conditions, the vast majority of human and animal studies point to an association between periodontitis and metabolic syndrome, diabetes, and cardiovascular disease. Moreover, there is evidence to suggest that metabolic syndrome and diabetes can alter the oral microbiome. However, more studies are needed to fully understand the influence these conditions have on each other.

The effect of ellagic acid on the repair process of periodontal defects related to experimental periodontitis in rats

Objective

This study aims to evaluate the effect of ellagic acid (EA) by measuring the levels of alveolar bone resorption and inflammatory and oxidative stress markers in the periodontal tissues and serum on the periodontal repair process related to experimental periodontitis in rats.

Methodology

Forty Wistar rats were divided into four study groups as follows: Group 1=healthy control (n=10); Group 2=EA control (15 mg/kg)(n=10); Group 3=periodontitis (n=10); Group 4=periodontitis+EA (15 mg/kg) (n=10). The periodontitis model was established by ligating bilateral mandibular first molars for 14 days. Then, rats were given normal saline or EA for another 14 days by gavage administration. Serum and gingiva myeloperoxidase (MPO) activity, 8-hydroxydeoxyguanosine(8-OHdG), and glutathione (GSH) levels were analyzed by ELISA. İmmunohistochemical analysis was used to detect Interleukin (IL)-6, IL-10, and tumor necrosis factor-alpha (TNF-α) immunoreactivities in the periodontal tissues. Alveolar bone loss (ABL) and attachment loss (AL) was evaluated by histomorphometry analysis.

Results

ABL and AL were statistically higher in group 3 than in groups 1, 2 and 4 and in group 4 than in groups 1 and 2 (p<0.05). MPO activities in gingival tissue and serum were significantly increased in group 3 compared to groups 1 and 2 (p<0.05). Significantly higher serum GSH levels, lower gingiva, and serum 8-OHdG levels, and MPO activity were observed in group 4 compared to group 3 (p<0.05). Rats with periodontitis (group 3) expressed significantly higher immunoreactivities of IL-6 and TNF-α and lower IL-10 immunoreactivity compared to those other groups (p<0.05). IL-6 and TNF-α immunoreactivities significantly decreased and IL-10 immunoreactivity increased in group 4 after the use of EA compared to group 3 (p<0.001).

Conclusions

Our findings showed that EA provides significant improvements on gingival oxidative stress and inflammatory markers and alveolar bone resorption in the repair process associated with experimental periodontitis. Therefore, EA may have a therapeutic potential on periodontitis.

Experimental Periodontal Disease Triggers Coronary Endothelial Dysfunction in Middle-Aged Rats: Preventive Effect of a Prebiotic β-Glucan

This study was aimed to verify the hypothesis that periodontal disease contributes to endothelial dysfunction in the coronary arteries of middle-aged rats. Besides we evaluated the effects of a prebiotic (β-glucan isolated from Saccharomyces cerevisiae) in preventing vascular dysfunction. The sample comprised young (sham and induced to periodontal disease) and middle-aged rats (sham, periodontal disease, sham-treated and periodontal disease-treated), at 12 and 57 weeks, respectively. The treated-groups received daily doses of β-glucan (50 mg/kg) orally (gavage) for 4 weeks, and periodontal disease was induced in the last 2 weeks by ligature. A myograph system assessed vascular reactivity. The expression of endothelial nitric oxide synthase (eNOS), cyclooxygenase 1 (COX-1), COX-2, p47phox, gp91phox, NF-KB p65, p53, p21, and p16 was quantified by western blotting. Serum hydroperoxide production was measured by the ferrous oxidation-xylenol orange (FOX-2) assay method. Interleukin-1 beta (IL-1β), IL-10, and tumor necrosis factor-alpha (TNF-α) levels were evaluated by spectroscopic ultraviolet-visible analysis. Periodontal disease in middle-aged rats was associated with reduced acetylcholine-induced relaxations of coronary artery rings affecting the endothelium-dependent hyperpolarization- and the nitric oxide-mediated relaxations. The endothelial dysfunction was related to eNOS downregulation, pronounced impairment of the EDH-mediated relaxation, increased IL-1β and TNF-α proinflammatory cytokines, and also upregulation of NADPH oxidase and COXs, starting accumulate aging markers such as p53/p21 and the p16. Treatment with β-glucan effectively reduced bone loss in periodontal disease and delayed endothelial dysfunction in the coronary artery. Our data show that yeast β-glucan ingestion prevented oxidative stress and synthesis of proinflammatory marker and prevented eNOS reduction induced by periodontal disease in middle-aged rats. These results suggest that β-glucan has a beneficial effect on the coronary vascular bed.

Role of experimental periodontitis in inducing pulmonary inflammation in mice

OBJECTIVE

The aim of the study was to explore the potential role of experimental periodontitis in pulmonary inflammation in mice.

MATERIALS AND METHODS

Mice were divided into control, ligature-induced periodontitis (L) and ligature plus Porphyromonas gingivalis (P. gingivalis)-induced periodontitis (LPG) groups. Alveolar bone resorption, pulmonary function, lung tissue histology and cytokine expression were examined at 2, 4 and 8 weeks. Then cytokines and neutrophils in the peripheral blood and lung tissue were further assessed at 8 weeks to determine the role of cytokines induced by LPG periodontitis, and the effect of P. gingivalis was evaluated using P. gingivalis-IgG and P. gingivalis gingipain.

RESULTS

Alveolar bone resorption was more severe in the L and LPG groups. However, pulmonary inflammation was observed only in the LPG group at 8 weeks when cytokines and neutrophils in the peripheral blood and lung tissue were the most significant elevation, along with higher levels of P. gingivalis-IgG and P. gingivalis gingipain. Cytokine levels were also increased in the gingival tissue, peripheral blood and lung tissue in the L group, accompanied by elevated peripheral blood neutrophils, but not as significantly as that in the LPG group.

CONCLUSIONS

LPG periodontitis can trigger pulmonary inflammation over the long term, in which cytokines and P. gingivalis play an important role.

Effect of vitamin E on periodontitis: Evidence and proposed mechanisms of action

BACKGROUND

Periodontitis is a noncommunicable inflammatory disease of the soft tissue and bone surrounding the teeth in the jaw, which affects susceptible individuals with poor oral hygiene. A growing interest has been seen in the use of dietary supplements and natural products for the treatment and prevention of periodontitis. Vitamin E consists of two major groups, namely tocopherols and tocotrienols, which are botanical lipophilic compounds with excellent anti-inflammatory and antioxidant properties.

HIGHLIGHT

This review aimed to summarize the preclinical and clinical findings on the effects of vitamin E on periodontitis. The current literature suggests that vitamin E could improve the periodontal status by correcting redox status imbalance, reducing inflammatory responses, and promoting wound healing, thus highlighting the potential of vitamin E in the management of periodontitis.

CONCLUSION

Direct evidence for the use of vitamin E supplementation or treatment of periodontitis in humans is still limited. More well-designed and controlled studies are required to ascertain its effectiveness.

Local and systemic mechanisms linking periodontal disease and inflammatory comorbidities

Periodontitis, a major inflammatory disease of the oral mucosa, is epidemiologically associated with other chronic inflammation-driven disorders, including cardio-metabolic, neurodegenerative and autoimmune diseases and cancer. Emerging evidence from interventional studies indicates that local treatment of periodontitis ameliorates surrogate markers of comorbid conditions. The potential causal link between periodontitis and its comorbidities is further strengthened by recent experimental animal studies establishing biologically plausible and clinically consistent mechanisms whereby periodontitis could initiate or aggravate a comorbid condition. This multi-faceted ‘mechanistic causality’ aspect of the link between periodontitis and comorbidities is the focus of this Review. Understanding how certain extra-oral pathologies are affected by disseminated periodontal pathogens and periodontitis-associated systemic inflammation, including adaptation of bone marrow haematopoietic progenitors, may provide new therapeutic options to reduce the risk of periodontitis-associated comorbidities.

Periodontitis has been causally linked to the development of other chronic inflammatory diseases outside the oral mucosa. In this Review, George Hajishengallis and Triantafyllos Chavakis consider the molecular basis of these links.

Increased Anxiety-Like Behavior in the Acute Phase of a Preclinical Model of Periodontal Disease

Periodontal disease (PD) is an infectious-inflammatory oral disease that is highly prevalent among adolescence and adulthood and can lead to chronic orofacial pain and be associated with anxiety, stress and depression. This study aimed to identify anxiety-like behaviors in the ligature-induced murine preclinical model of PD in different phases of the disease (i.e., acute vs. chronic). Also, we investigated orofacial mechanical allodynia thresholds and superficial cortical plasticity along the orofacial motor cortex in both disease phases. To this aim, 25 male Wistar rats were randomly allocated in acute (14 days) or chronic (28 days) ligature-induced-PD groups and further divided into active-PD or sham-PD. Anxiety-like behavior was evaluated using the elevated plus maze, mechanical allodynia assessed using the von Frey filaments test and superficial motor cortex mapping was performed with electrical transdural stimulation. We observed increased anxiety-like behavior in active-PD animals in the acute phase, characterized by decreased number of entries into the open arm extremities [t (1,7) = 2.42, p = 0.04], and reduced time spent in the open arms [t (1,7) = 3.56, p = 0.01] and in the open arm extremities [t (1,7) = 2.75, p = 0.03]. There was also a reduction in the mechanical allodynia threshold in all active-PD animals [Acute: t (1,7) = 8.81, p < 0.001; Chronic: t (1,6) = 60.0, p < 0.001], that was positively correlated with anxiety-like behaviors in the acute group. No differences were observed in motor cortex mapping. Thus, our findings show the presence of anxiety-like behaviors in the acute phase of PD making this a suitable model to study the impact of anxiety in treatment response and treatment efficacy.

The Concept of Sustainable Development of Modern Dentistry

This paper concerns the assessment of the current state of dentistry in the world and the prospects of its sustainable development. A traditional Chinese censer was adopted as the pattern, with a strong and stable support on three legs. The dominant diseases of the oral cavity are caries and periodontal diseases, with the inevitable consequence of toothlessness. From the caries 3.5–5 billion people suffer. Moreover, each of these diseases has a wide influence on the development of systemic complications. The territorial range of these diseases and their significant differentiation in severity in different countries and their impact on disability-adjusted life years index are presented (DALY). Edentulousness has a significant impact on the oral health-related quality of life (OHRQoL). The etiology of these diseases is presented, as well as the preventive and therapeutic strategies undertaken as a result of modifying the Deming circle through the fives’ rules idea. The state of development of Dentistry 4.0 is an element of the current stage of the industrial revolution Industry 4.0 and the great achievements of modern dental engineering. Dental treatment examples from the authors’ own clinical practice are given. The systemic safety of a huge number of dentists in the world is discussed, in place of the passive strategy of using more and more advanced personal protective equipment (PPE), introducing our own strategy for the active prevention of the spread of pathogenic microorganisms, including SARS-CoV-2. The ethical aspects of dentists’ activity towards their own patients and the ethical obligations of the dentist community towards society are discussed in detail. This paper is a polemic arguing against the view presented by a group of eminent specialists in the middle of last year in The Lancet. It is impossible to disagree with these views when it comes to waiting for egalitarianism in dental care, increasing the scope of prevention and eliminating discrimination in this area on the basis of scarcity and poverty. The views on the discrimination of dentistry in relation to other branches of medicine are far more debatable. Therefore, relevant world statistics for other branches of medicine are presented. The authors of this paper do not agree with the thesis that interventional dental treatment can be replaced with properly implemented prophylaxis. The final remarks, therefore, present a discussion of the prospects for the development of dentistry based on three pillars, analogous to the traditional Chinese censer obtaining a stable balance thanks to its three legs. The Dentistry Sustainable Development (DSD) > 2020 model, consisting of Global Dental Prevention (GDP), Advanced Interventionist Dentistry 4.0 (AID 4.0), and Dentistry Safety System (DSS), is presented.

Porphyromonas gingivalis infection alters Nrf2-phase II enzymes and nitric oxide in primary human aortic endothelial cells

BACKGROUND

Periodontal disease (PD) is known to be associated with endothelial dysfunction in patients with coronary artery and/or cardiovascular disease. In our study, we sought to explore the virulence of P. gingivalis (Pg) affecting glycogen synthase kinase 3 beta (GSK-3β)/nuclear factor (erythroid-derived 2)-like 2 (Nrf2)/tetrahydrobiopterin (BH₄ )/ nitric oxide synthase (NOS) expression in primary human aortic endothelial cells (pHAECs).

METHODS

pHAECs were infected for 48 hours with Pg in vitro using the Human oxygen-Bacteria anaerobic coculture technique. Cell viability was determined, and target gene expression changes were evaluated by quantitative real-time polymerase chain reaction at the end of each incubation period.

RESULTS

Pg impaired pHAEC viability 24 hours post-infection. Pg infection reduced mRNA expression levels of endothelial NOS (eNOS), Nrf2, and Phase II enzymes (heme oxygenase-1, catalase, superoxide dismutase-1) in a time-dependent manner. Significant (P <0.05) increase in the inflammatory markers (interleukin [IL]-1β, IL-6, and tumor necrosis factor-α) were observed in the medium as well as in the infected cells. Interestingly, inducible NOS mRNA levels showed a significant (P <0.05) increase at 12 hours and 24 hours and were reduced at later time points. BH₄ (cofactor of eNOS) biosynthesis enzyme dihydrofolate reductase (DHFR, salvage pathway) mRNA levels showed a significant (P <0.05) decrease, while mRNA levels of GSK-3β were elevated.

CONCLUSIONS

These results suggest that periodontal bacterial infection may cause significant changes in the endothelial GSK-3β/BH₄ /eNOS/Nrf2 pathways, which may lead to impaired vascular relaxation. Greater understanding of the factors that adversely affect endothelial cell function could contribute to the development of new therapeutic compounds to treat PD-induced vascular diseases.

Periodontitis and vascular inflammatory biomarkers: an experimental in vivo study in rats

The objective of this preclinical in vivo study was to determine changes in vascular inflammatory biomarkers in systemic circulation after injection of lipopolysaccharide (LPS) from Porphyromonas gingivalis (Pg) in rats. Experimental periodontitis was induced by injections of Pg-LPS. Gingival soft and hard tissues changes were analysed by means of magnetic resonance imaging and micro computed tomography. Serum levels of interleukin (IL)-6, IL-10, pentraxin (PTX) 3, and soluble fragment of tumor necrosis factor-like weak inducer of apoptosis (sTWEAK) were determined at baseline and 24 h, 7, 14, and 21 days after periodontal induction. Significant periodontal inflammation and alveolar bone loss were evident at the end of periodontal induction. Experimental periodontitis posed an acute systemic inflammatory response with increased serum levels of IL-6 and PTX3 at 24 h post-induction, followed by a significant overexpression of sTWEAK at 7 days. This inflammatory state was maintained until the end of the experiment (21 days). As expected, IL-10 serum levels were significantly lower during the follow-up compared to baseline concentrations. In the present animal model, experimental periodontitis is associated with increased systemic inflammation. Further studies are needed to confirm whether PTX3 and sTWEAK could be useful biomarkers to investigate potential mechanisms underlying the relationship between periodontitis and atherosclerotic vascular diseases.

Updated Evidence of Association Between Periodontal Disease and Incident Erectile Dysfunction

INTRODUCTION

The relationship between periodontal disease (PD) and erectile dysfunction (ED) is still conflicting.

AIM

To investigate whether a link between PD and ED exists, and if so, the degree to which it is significant.

METHODS

The search strategy included using electronic databases and hand searching works published up to June 2018. MEDLINE via PubMed, EMBASE, Proceedings Web of Science, and Current Contents Connect were searched by 2 independent reviewers. Case-control, cohort, or cross-sectional studies including patients with measures of periodontitis and ED were included in the analysis. Quality assessments and sensitivity analysis of selected studies were performed.

MAIN OUTCOME MEASURE

The strength of the association between PD and the prevalence of ED was evaluated.

RESULTS

5 case-control studies with 213,076 participants met the eligibility criteria and were included in the meta-analysis. Patients with PD were 2.85-fold more likely to be diagnosed with ED (OR = 2.85, 95% CI = [1.83, 4.46]). Asian men were reported to be 3.07 times more likely to be at greater risk for the prevalence of ED. Moreover, studies with high quality and case-control design showed 2 times higher risk for ED in PD (OR = 2.44, 95% CI = [1.44, 4.14]). However, the present evidence was not robust enough owing to the high heterogeneity and instability in sensitivity analysis.

CLINICAL IMPLICATIONS

Patients with PD may have increased risk of ED, suggesting that dental hygiene should be of concern to clinicians when managing patients with ED.

STRENGTH & LIMITATIONS

This article includes a large literature search to confirm the evidence that PD increases the occurrence of ED. However, there are several confounders, such as age and the type of ED, that failed to be adjusted and that generate bias and affect the correlation between the incidence of ED and PD.

CONCLUSION

This system review and meta-analysis strengthens the evidence that PD might have important clinical implications for risk stratification of ED. Zhou X, Cao F, Lin Z. Updated evidence of association between periodontal disease and incident erectile dysfunction. J Sex Med 2019;16:61-69.

Periodontitis and Tooth Loss Have Negative Systemic Impact on Circulating Progenitor Cell Levels: A Clinical Study

The aim of the present study was to investigate the association and impact of periodontitis and tooth loss on a subtype of endothelial progenitor cell (EPC) levels (CD133+/KDR+). Furthermore, the objective was to determine if the periodontal status influenced CD133+/KDR+ levels. In all, 88 patients with periodontitis and 79 healthy controls (HCs) were enrolled in the study. Enrolled patients were examined and characterized by clinical and blood sample analysis. Spearman's correlation test was applied in order to assess the interdependence between CD133+/KDR+ levels and all periodontal parameters. In order to estimate a statistically significant trend (p-trend) for ordered CD133++/KDR+ quartiles, the Jonckheere-Terpstra test was applied for all variables. Patients in the periodontitis group presented significantly lower CD133+/KDR+ levels (66.4 (45.5-269.6 cells/µL)) compared to the HC group (76.7 (24.3-313.2 cells/µL), p < 0.001). Lower CD133+/KDR+ levels negatively correlated with C-reactive protein (CRP), with the number of teeth, and with all periodontal parameters (p < 0.001). Moreover, there was a proportional increase in CD133+/KDR+ levels with a progressive increase in number of teeth (p-trend < 0.001), while there was a proportional decrease in CD133+/KDR+ levels with a proportional increase in clinical attachment level (CAL, p-trend = 0.003), probing depth (PD, p-trend = 0.007), and bleeding sites (bleeding on probing (BOP), p-trend < 0.001) as an extent measure of periodontitis. This study demonstrated that patients with periodontitis presented significantly lower CD133+/KDR+ levels compared to HCs. Moreover, all patients presented an increase in the CD133+/KDR+ EPC levels with an extended level of periodontitis and tooth loss.

Distal Consequences of Oral Inflammation

Periodontitis is an incredibly prevalent chronic inflammatory disease, which results in the destruction of tooth supporting structures. However, in addition to causing tooth and alveolar bone loss, this oral inflammatory disease has been shown to contribute to disease states and inflammatory pathology at sites distant from the oral cavity. Epidemiological and experimental studies have linked periodontitis to the development and/or exacerbation of a plethora of other chronic diseases ranging from rheumatoid arthritis to Alzheimer's disease. Such studies highlight how the inflammatory status of the oral cavity can have a profound impact on systemic health. In this review we discuss the disease states impacted by periodontitis and explore potential mechanisms whereby oral inflammation could promote loss of homeostasis at distant sites.

Periodontal Disease: A Risk Factor for Diabetes and Cardiovascular Disease

Periodontitis is a chronic inflammatory disease, initiated by the presence of a bacterial biofilm, called dental plaque, which affects both the periodontal ligaments and bone surrounding teeth. In the last decades, several lines of evidence have supported the existence of a relationship between periodontitis and systemic health. For instance, as periodontitis acts within the same chronic inflammatory model seen in cardiovascular disease (CVD), or other disorders, such as diabetes, several studies have suggested the existence of a bi-directional link between periodontal health and these pathologies. For instance, people with diabetes are more susceptible to infections and are more likely to suffer from periodontitis than people without this syndrome. Analogously, it is now evident that cardiac disorders are worsened by periodontitis, both experimentally and in humans. For all these reasons, it is very plausible that preventing periodontitis has an impact on the onset or progression of CVD and diabetes. On these grounds, in this review, we have provided an updated account on the current knowledge concerning periodontal disease and the adverse effects exerted on the cardiovascular system health and diabetes, informing readers on the most recent preclinical studies and epidemiological evidence.

Interrelation of Cardiovascular Diseases with Anaerobic Bacteria of Subgingival Biofilm

Aims:

The aim of this study is to study the colonization of subgingival biofilm (SGB) with periodontopathogenic bacteria species and endothelium-dependent vasodilation in patients with coronary heart disease and concomitant periodontitis.

Subjects and Methods:

Forty-five patients with cardiovascular diseases (CVDs) were examined – 28 women (62%) and 17 men (38%) aged 53–76 years, including 15 patients with acute myocardial infarction (AMI), 15 patients with exertional angina (pectoris), and 15 patients with chronic periodontitis (CP) without CVD. Dental and cardiological health conditions were determined, a biochemical blood test was conducted, endothelium-dependent vasodilation in the brachial artery was measured, and DNA of periodontopathogenic bacteria in SGB was detected.

Results:

A reliable interrelation between the colonization of SGB with periodontopathogenic bacteria and development of AMI was established. In AMI patients, the frequency of Porphyromonas gingivalis, Tannerella forsythia, and Aggregatibacter actinomycetemcomitans detection was significantly higher than in the group of participants without cardiovascular disease. The presence of P. gingivalis and A. actinomycetemcomitans in patients with CP directly correlated with severity of periodontal tissue destruction. Endothelium-dependent vasodilation in the brachial artery moderately correlated with patient's cardiological condition (r = 0.3284), biochemical markers of atherosclerosis development (r = 0.6465), and frequency of P. intermedia detection in periodontal pockets (r = 0.3828).

Conclusions:

Periodontal status in patients with AMI is characterized by unsatisfactory and poor hygiene, increased indices of bleeding on probing, and periodontal pocket depth in comparison to groups of patients with angina pectoris and CP without cardiovascular pathology.

Physical Exercise Improves Glycemic and Inflammatory Profile and Attenuates Progression of Periodontitis in Diabetic Rats (HFD/STZ)

The authors aimed to evaluate the effects of physical exercise on the metabolism and progression of periodontal disease (PD), induced by ligature in diabetic rats induced by high fat diet and streptozotocin (HFD/STZ). Diabetes Mellitus (DM) was induced by four weeks of a hyperlipidic diet associated with a single low-dose of streptozotocin (35 mg/kg/animal). The exercise groups swam for 60 min/day for eight weeks (five times/week). In the last two weeks of exercise, a ligature was placed around the right and left mandibular first molars. The authors determined alveolar bone loss by morphometry. Blood biochemical profile and serum levels of IL-10 and TNF-α were evaluated by colorimetric and enzyme-linked immunosorbent assays (ELISA), respectively. The diabetic animals subjected to exercise showed decreased alveolar bone loss, lower glycemia, triacylglycerols and glycosylated hemoglobin levels than the controls. Total cholesterol and its fractions (High density lipoprotein—HDL-c, Low density lipoprotein—LDL-c and Very low density lipoprotein—VLDL-c) remained similar among the groups. Animals with PD showed higher levels of TNF-α and lower levels of IL-10, when compared to animals without PD. In diabetic animals with PD, physical exercise decreased TNF-α levels and increased IL-10 levels as well as the IL10/TNF-α ratio. In conclusion, eight weeks of physical exercise improved glycemic control and systemic inflammatory profile, and attenuated alveolar bone loss in rats with DM and PD.

The role of potassium channels in the endothelial dysfunction induced by periodontitis

OBJECTIVE

Periodontitis is associated with endothelial dysfunction, which is clinically characterized by a reduction in endothelium-dependent relaxation. However, we have previously shown that impairment in endothelium-dependent relaxation is transient. Therefore, we evaluated which mediators are involved in endothelium-dependent relaxation recovery.

MATERIAL AND METHODS

Rats were subjected to ligature-induced experimental periodontitis. Twenty-one days after the procedure, the animals were prepared for blood pressure recording, and the responses to acetylcholine or sodium nitroprusside were obtained before and 30 minutes after injection of a nitric oxide synthase inhibitor (L-NAME), cyclooxygenase inhibitor (Indomethacin, SC-550 and NS- 398), or calcium-dependent potassium channel blockers (apamin plus TRAM- 34). The maxilla and mandible were removed for bone loss analysis. Blood and gingivae were obtained for C-reactive protein (CRP) and myeloperoxidase (MPO) measurement, respectively.

RESULTS

Experimental periodontitis induces bone loss and an increase in the gingival MPO and plasmatic CRP. Periodontitis also reduced endothelium-dependent vasodilation, a hallmark of endothelial dysfunction, 14 days after the procedure. However, the response was restored at day 21. We found that endothelium-dependent vasodilation at day 21 in ligature animals was mediated, at least in part, by the activation of endothelial calcium-activated potassium channels.

CONCLUSIONS

Periodontitis induces impairment in endothelial-dependent relaxation; this impairment recovers, even in the presence of periodontitis. The recovery is mediated by the activation of endothelial calcium-activated potassium channels in ligature animals. Although important for maintenance of vascular homeostasis, this effect could mask the lack of NO, which has other beneficial properties.

Development and Evaluation of Minocycline Hydrochloride-Loaded In Situ Cubic Liquid Crystal for Intra-Periodontal Pocket Administration

In the present study, an injectable in situ liquid crystal formulation was developed for local delivery of minocycline hydrochloride (MH) for chronic periodontitis treatment. The physicochemical properties, phase structures, in vitro drug release and pharmacodynamics of in situ liquid crystals were investigated. The optimal formulation (phytantriol (PT)/propylene glycol (PG)/water, 63/27/10, w/w/w) loaded with 20 mg/g MH was proved to be injectable. The precursor formulation can form a cubic phase gel in excess water in 6.97 ± 0.10 s. The results of in vitro drug release suggested the MH presented a sustained release for 4 days. Liquid crystal precursor formulation significantly reduced gingival index, probing depth and alveolar bone loss compared to the model group (p < 0.01). Besides, the pathological characteristics of model rats were improved. The results suggested that MH-loaded in situ cubic liquid crystal possessed of sustained release ability and periodontal clinical symptoms improvement. The developed in situ cubic liquid crystal may be a potentially carrier in the local delivery of MH for periodontal diseases.

Antioxidant effects of melatonin in heart tissue after induction of experimental periodontitis in rats

The aim of this study was to evaluate the effects of melatonin on the oxidative stress in heart tissues after induction of experimental periodontitis in rats. Thirty Wistar Albino male rats were divided into four groups as follows: healthy + saline solution (Hs, n = 7), healthy + melatonin (Hm, n = 7), periodontitis + saline solution (Ps, n = 8), and periodontitis + melatonin (Pm, n = 8). Experimental periodontitis was induced using a ligature placed at the gingival margin of the maxillary second molars. Melatonin was applied intraperitoneally (10 mg/kg) every day for 2 weeks. After sacrificing the rats, serum levels of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) levels, and melatonin levels were evaluated. The Pm group exhibited lower alveolar bone loss than the Ps group. Melatonin levels increased in the periodontitis groups, and the Pm group had lower MDA levels and higher GSH-Px levels than the Ps group. These findings suggest that melatonin administration reduces MDA and increases GSH-Px levels in heart tissue, and these effects may be due to its antioxidant properties. Further studies are needed to understand the effects of melatonin on the association between periodontitis and cardiovascular disease.

Transplantation of hematopoietic stem cells: intra-arterial versus intravenous administration impacts stroke outcomes in a murine model

Based on results of hematopoietic stem cell transplantation in animal models of stroke, clinical trials with hematopoietic stem cells administered intra-arterially or intravenously have been initiated in patients. Although intra-arterial injection is expected to deliver transplanted cells more directly to the ischemic tissue, the optimal route for enhancing clinical outcomes has not been identified in the setting of stroke. In this study, we compared the therapeutic potential of intra-arterial versus intravenous injection of bone marrow derived-mononuclear cells (BM-MNCs) and CD133-positive (CD133(+)) cells in a murine stroke model. We have found that intra-arterial injection of BM-MNCs exaggerates inflammation with accompanying loss of microvascular structures in poststroke brain and no improvement in cortical function. In contrast, intravenous injection of BM-MNCs did not similarly enhance inflammation and improved cortical function. Our results indicate that the optimal route of cell transplantation can vary with different cell populations and highlight possible issues that might arise with intra-arterial cell administration for acute ischemic cerebrovascular disease.

Intermittent local periodontal inflammation causes endothelial dysfunction of the systemic artery via increased levels of hydrogen peroxide concomitantly with overexpression of superoxide dismutase

BACKGROUND

The present study was designed to examine whether the intermittent local periodontal inflammation induces endothelial dysfunction of the systemic artery caused by oxidative stress and if increased levels of hydrogen peroxide coexisted with overexpression of superoxide dismutase (SOD) as well as NADPH oxidase contribute to the oxidative stress.

METHODS

The rats in lipopolysaccharides (LPS) group received 1500μg LPS injection to bilateral gingiva of the lower jaw a week interval from eight- to eleven-week-old. Isolated mandibles or aortas were subjected to the evaluation of histopathological changes, isometric force recordings, reactive oxygen species using 2',7'-dichlorofluorescin diacetate (10(-5)mol/L) and protein expression of NADPH oxidase subunits and SOD, respectively.

RESULTS

Mandible sections demonstrated the periodontal inflammation only in the LPS group at three days, but not seven days, after the LSP injection. Acetylcholine (10(-9) to 10(-5)mol/L)-induced relaxation was reduced only in aortas from the LPS group. Gp91ds-tat and PEG-catalase restored the impaired dilation in arteries from the LPS group. Levels of reactive oxygen species were enhanced in aortas from the LPS group, whereas the increment was abolished by the treatment with gp91-ds-tat or PEG-catalase. Expression of a NADPH oxidase subunit p47phox and CuZn-SOD increased in the LPS group.

CONCLUSIONS

The intermittent local periodontal inflammation induces systemic endothelial dysfunction caused by overproduction of reactive oxygen species in the systemic artery of rats and that overexpression of CuZn-SOD as well as a NADPH oxidase cytosolic subunit contributes to increased levels of hydrogen peroxide in blood vessels of this animal model.

Nonsurgical periodontal treatment reduced aortic inflammation in ApoE(-/-) mice with periodontitis

Background

Although the correlation between periodontal infection and atherosclerotic lesions has been well recognized, whether and how the nonsurgical periodontal treatment (NSPT) can improve the vascular inflammation has not been investigated clearly.

Methods

Thirty-two apolipoprotein E^−/− (apoE^−/−) mice were randomly divided into four groups: (1) Con group: no treatment, blank control group; (2) Lig group: ligature-induced-periodontitis group; (3) Lig-N group: ligatures were removed on the 7th day; (4) Lig-SRP group: ligatures were removed on the 7th day, and scaling and root planing (SRP) were performed on the 9th day. All the animals were euthanized on the 30th day. Alveolar bone loss (ABL) was assessed under microcomputed tomography. Systemic inflammatory status and lipid contents in the plasma were detected. Expression of several surrogate markers for vascular inflammation was evaluated by immunohistology and quantitative real time PCR.

Results

NSPT reduced ABL, improved lipid profile, and inhibited systemic inflammation with reduced plasma interleukin-6 (IL-6) level in apoE^−/− mice; in addition, reduced inflammation in arterial wall was observed in NSPT treated mice, showing less vascular cell adhesion molecule-1 expression and less macrophage adhesion; furthermore, NSPT improved elastic fiber fragmentation disorder in the aortic wall, thus preserved elasticity of aortic artery.

Conclusion

Ligature-induced periodontitis can lead to inflammatory response in the vascular wall and NSPT has beneficial effect on the early stage of atherosclerosis process in the articular wall by reducing systemic inflammation and improving lipid profile.

Endothelial dysfunction in rats with ligature-induced periodontitis: Participation of nitric oxide and cycloxygenase-2-derived products

OBJECTIVES

Considering the evident relationship between periodontitis and cardiovascular diseases in humans, we aimed to study the in vitro vascular reactivity of aorta rings prepared from rats with ligature-induced periodontitis.

METHODS

Seven days after the induction of unilateral periodontitis, the animals were euthanised; rings were prepared from the descending abdominal aortas and mounted in tissue baths for the in vitro measurement of the isometric force responses to norepinephrine (NE) and acetylcholine (ACh), as well as in the presence of inhibitors of nitric oxide synthase (NOS) and cycloxygenase (COX) isoenzymes. Aortic COX and NOS gene expressions were analysed by RT-PCR, as well as protein COX-2 expression by Western blot.

RESULTS

Periodontitis resulted in significant alveolar bone loss and did not affect arterial pressure. However, both NE-induced contraction and ACh-induced relaxation were significantly decreased and related to the presence of endothelium. Diminished eNOS and augmented COX-2 and iNOS expressions were found in the aortas from rats with periodontitis, and the pharmacological inhibition of COX-2 or iNOS improved the observed vasomotor deficiencies.

CONCLUSIONS

We can thus conclude that periodontitis induces significant endothelial dysfunction in rat aorta which is characterized by decreased eNOS expression and mediated by upregulated iNOS and COX-2 products.

Resolvin E1 (RvE1) Attenuates Atherosclerotic Plaque Formation in Diet and Inflammation-Induced Atherogenesis

OBJECTIVE

Epidemiological and recent clinical studies implicate periodontitis as an independent risk factor for cardiovascular disease. Previously, we demonstrated that rabbits with experimental periodontitis and cholesterol diet exhibit more aortic plaque compared with diet alone. We also showed that a proresolution mediator, Resolvin E1 (RvE1), reverses the experimental periodontitis. Here, we determined whether oral/topical application of RvE1 attenuates aortic atherosclerosis induced by both diet and periodontal inflammation.

APPROACH AND RESULTS

Thirty-nine rabbits on a 13-week regimen of 0.5% cholesterol diet were included. Periodontitis was induced by Porphyromonas gingivalis in 24 rabbits and 15 rabbits were placed in no-periodontitis groups. Interventions were no-treatment, vehicle, and RvE1 treatment (4 μg/site or 0.4 μg/site) topically applied 3× per week. At 13 weeks, both periodontitis and atherosclerosis were quantified. Atherosclerotic plaques were assessed by Sudan IV staining, histology, and ex vivo MRI. Serum levels of C-reactive protein were evaluated as a measure of systemic inflammation. RvE1, used as an oral/topical agent, significantly diminished atherogenesis and prevented periodontitis (P<0.05). In the absence of periodontal inflammation, oral/topical application of RvE1 resulted in significantly less arterial plaque, a lower intima/media ratio, and decreased inflammatory cell infiltration compared with no-treatment (P<0.001). Local oral RvE1 application significantly reduced systemic levels of C-reactive protein (P<0.05).

CONCLUSIONS

The results suggest that oral/topical RvE1 attenuates enhanced atherogenesis induced by periodontitis and prevents vascular inflammation and atherogenesis in the absence of periodontitis. The inhibition of vascular inflammation with endogenous mediators of resolution of inflammation provides a novel approach in the prevention of atherogenic events.

Effect of Cimetidine on Nitro-Oxidative Stress in a Rat Model of Periodontitis

Background and aims

Periodontitis is a chronic inflammation that involves nitro-oxidative stress with damaging periodontal structural effects. We aimed to evaluate the consequences of low-dose cimetidine on nitro-oxidative stress in periodontitis.

Methods

A rat model of ligature-induced periodontitis was used. After two weeks, the periodontitis groups were treated with cimetidine, aminoguanidine, N-nitro-L-arginine methyl ester and trolox for one week. On day 21, blood was drawn and the serum analyzed for measurement of total nitrites and nitrates, total oxidative status, total antioxidant response, and oxidative stress index.

Results

Cimetidine had an inhibitory effect on the synthesis of nitric oxide (p=0.001), total oxidative status (p=0.01) and oxidative stress index (p=0.01). Total antioxidant reactivity was increased by cimetidine (p=0.01). The effects of cimetidine were almost like those of aminoguanidine, NG-nitro-L-arginine methyl ester, and trolox.

Conclusions

Low-dose cimetidine can be used as adjunctive host modulatory therapy in chronic periodontitis because it reduces nitro-oxidative stress.

Periodontitis-activated monocytes/macrophages cause aortic inflammation

A relationship between periodontal disease and atherosclerosis has been suggested by epidemiological studies. Ligature-induced experimental periodontitis is an adequate model for clinical periodontitis, which starts from plaque accumulation, followed by inflammation in the periodontal tissue. Here we have demonstrated using a ligature-induced periodontitis model that periodontitis activates monocytes/macrophages, which subsequently circulate in the blood and adhere to vascular endothelial cells without altering the serum TNF-α concentration. Adherent monocytes/macrophages induced NF-κB activation and VCAM-1 expression in the endothelium and increased the expression of the TNF-α signaling cascade in the aorta. Peripheral blood-derived mononuclear cells from rats with experimental periodontitis showed enhanced adhesion and increased NF-κB/VCAM-1 in cultured vascular endothelial cells. Our results suggest that periodontitis triggers the initial pathogenesis of atherosclerosis, inflammation of the vasculature, through activating monocytes/macrophages.

Association between hypertension and periodontitis: possible mechanisms

This review is to examine the current literatures on the relationship between periodontitis and hypertension as well as to explore the possible biological pathways underlying the linkage between these health conditions. Hypertension is one of the major risk factors for cardiovascular diseases. Oxidative stress and endothelial dysfunction are among the critical components in the development of hypertension. Inflammation has received much attention recently and may contribute to a pivotal role in hypertension. Periodontitis, a chronic low-grade inflammation of gingival tissue, has been linked to endothelial dysfunction, with blood pressure elevation and increased mortality risk in hypertensive patients. Inflammatory biomarkers are increased in hypertensive patients with periodontitis. Over the years, various researches have been performed to evaluate the involvement of periodontitis in the initiation and progression of hypertension. Many cross-sectional studies documented an association between hypertension and periodontitis. However, more well-designed prospective population trials need to be carried out to ascertain the role of periodontitis in hypertension.