Toll-like receptor-2 has a critical role in periodontal pathogen-induced myocardial fibrosis in the pressure-overloaded murine hearts

Akkermansia muciniphila participates in the host protection against helminth-induced cardiac fibrosis via TLR2

Helminth Trichinella spiralis (Ts) is one of the major pathogens of human infective myocarditis that can lead to cardiac fibrosis (CF). The gut microbiota involved in this pathology are of interest. Here, we use mice infected with Ts as a model to examine the interactions between gut microbes and host protection to CF. Infected mice show enhanced CF severity. We find that antibiotics treatment to deplete the microbiota aggravates the disease phenotype. Attempts to restore microbiota using fecal microbiota transplantation ameliorates helminth-induced CF. 16S rRNA gene sequencing and metagenomics sequencing reveal a higher abundance of Akkermansia muciniphila in gut microbiomes of Ts-infected mice. Oral supplementation with alive or pasteurized A. muciniphila improves CF via TLR2. This work represents a substantial advance toward our understanding of causative rather than correlative relationships between the gut microbiota and CF.

Effects of Oral Inflammatory Diseases and Oral Hygiene on Atrial Fibrillation: A Systematic Review

Objective. Research evidence suggests a link between periodontitis (PD) and atrial fibrillation, but the nature of this link is unclear. This study aimed to systematically review and evaluate the association between PD, other oral diseases, and atrial fibrillation and the role of oral hygiene in preventing atrial fibrillation. Methods. We searched the Medline, Embase, Cochrane Library, and Web of Science databases for the clinical study of oral health and atrial fibrillation from inception to November 2022. Oral health conditions included PD and other oral inflammatory diseases, regular oral hygiene, and tooth brushing. The primary outcomes were the risk of new-onset atrial fibrillation in patients with oral disease, the effect of regular oral care on preventing atrial fibrillation, the effect of frequent tooth brushing on preventing atrial fibrillation, and the incidence of atrial fibrillation in PD patients. Results. Eight clinical trials with a total of 4,328,355 patients were included. The result of the research showed that PD and other impaired oral health may be associated with new-onset atrial fibrillation, and its severity was dose-responsive to the risk of atrial fibrillation. The incidence of atrial fibrillation in patients with severe PD was about 16.3%. Moreover, PD may increase the risk of long-term arrhythmia in patients with atrial fibrillation. Regular oral care and frequent tooth brushing can reduce the incidence of atrial fibrillation. Conclusion. Regular and moderate oral hygiene, frequent tooth brushing, and prevention of PD and other oral inflammatory diseases could reduce the occurrence of atrial fibrillation. It is recommended to strengthen the popularization of oral health knowledge in the publicity related to atrial fibrillation.

Periodontal Disease Associated With Interstitial Myocardial Fibrosis: The Multiethnic Study of Atherosclerosis

Background Periodontitis is a chronic inflammatory disease common among adults. It has been suggested that periodontal disease (PD) may be a contributing risk factor for cardiovascular disease; however, pathways underlying such a relationship require further investigation. Methods and Results A total of 665 men (mean age 68±9 years) and 611 women (mean age 67±9 years) enrolled in the MESA (Multiethnic Study of Atherosclerosis) underwent PD assessment using a 2-item questionnaire at baseline (2000-2002) and had cardiovascular magnetic resonance 10 years later. PD was defined when participants reported either a history of periodontitis or gum disease or lost teeth caused by periodontitis or gum disease. Multivariable linear regression models were constructed to assess the associations of baseline self-reported PD with cardiovascular magnetic resonance-obtained measures of interstitial myocardial fibrosis (IMF), including extracellular volume and native T1 time. Men with a self-reported history of PD had greater extracellular volume percent (ß=0.6%±0.2, P=0.01). This association was independent of age, left ventricular mass, traditional cardiovascular risk factors, and history of myocardial infarction. In a subsequent model, substituting myocardial infarction for coronary artery calcium score, the association of PD with IMF remained significant (ß=0.6%±0.3, P=0.03). In women, a self-reported history of PD was not linked to higher IMF. Importantly, a self-reported history of PD was not found to be associated with myocardial scar independent of sex (odds ratio, 1.01 [95% CI, 0.62-1.65]; P=0.9). Conclusions In a community-based setting, men but not women with a self-reported PD history at baseline were found to be associated with increased measures of IMF. These findings support a plausible link between PD, a proinflammatory condition, and subclinical IMF.

A common oral pathogen Porphyromonas gingivalis induces myocarditis in rats

AIM

To evaluate whether Porphyromonas gingivalis (P. gingivalis) inoculation could induce cardiac remodelling in rats.

MATERIALS AND METHODS

The study was conducted on 33 Wistar rats, which were distributed in the following experimental groups: not inoculated; inoculated with 1 × 10⁸ CFU/ml of bacteria; inoculated with 3 × 10⁸ CFU/ml of bacteria. The animals were inoculated at baseline and on the 15th day of follow-up. Blood collection was performed at baseline and 60 min after each inoculation. At 29 days, the animals were subjected to echocardiography and at 30 days to haemodynamic studies before sacrificing them.

RESULTS

Impact of the bacteria was more evident in rats that received higher P. gingivalis concentration. Thus, 3 × 10⁸ CFU/ml of bacteria increased the rectal temperature and water content in the lung as well as myocardial necrosis and fibrosis. P. gingivalis induced the intensification of DNA fragmentation and increased the levels of malondialdehyde, oxidized proteins, and macrophage expression in the myocardium. These findings were associated with lower LV isovolumetric relaxation time, +dP/dt, -dP/dt, and higher end-diastolic pressure.

CONCLUSIONS

P. gingivalis bacteraemia is significantly associated with adverse cardiac remodelling and may play a biological role in the genesis of heart failure.

Short-term effect of ligature-induced periodontitis on cardiovascular variability and inflammatory response in spontaneously hypertensive rats

BACKGROUND

We previously reported that periodontal disease (PD) induces high arterial pressure variability (APV) consistent with sympathetic overactivity and elicits myocardial inflammation in Balb/c mice. However, it is unknown whether PD can change APV and heart rate variability (HRV) in spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats. This study aimed to evaluate the hemodynamic level, HRV, and APV associating with myocardial inflammation and plasma concentrations of oxide nitric (NO) in SHR and WKY rats with PD.

METHODS

Three weeks after bilateral ligation of the first mandibular molar, or Sham operation, the rats received catheters into the femoral artery and had their arterial pressure (AP) recorded the following day. Subsequently, plasma, heart, and jaw were collected. The NO was quantified by the chemiluminescence method in plasma, and the myocardial IL-1β concentrations were evaluated by ELISA. In the jaw was evaluated linear alveolar bone loss induced by PD.

RESULTS

The linear alveolar bone loss in jaws of SHR with PD was higher than in all other groups. AP and heart rate were higher in SHR than in their WKY counterparts. SHR with PD showed lower AP than control SHR. HRV and APV were different between SHR and WKY rats; however, no differences in these parameters were found between the animals with PD and their control counterparts. Plasma NO and myocardial IL-1β concentrations were higher in SHR with PD as compared to control WKY. A significant correlation was found between linear alveolar bone loss and plasma NO and myocardial IL-1β concentrations.

CONCLUSION

Our results demonstrated that short-term PD lowered the AP in SHR, which might be due to the higher levels of plasma NO. Even though PD did not affect either HRV or APV, it did induce myocardial inflammation, which can determine cardiovascular dysfunction in long-term PD.

Cardiovascular and Autonomic Dysfunction in Murine Ligature-Induced Periodontitis

The present study examined the hemodynamics [arterial pressure (AP), AP variability (APV), heart rate (HR), and heart rate variability (HRV)], cardiac function (echocardiographycally), and myocardial inflammation in Balb/c mice submitted to Periodontitis, through the ligation of the left first molar, or Sham surgical procedure. The first protocol indicated that the AP was similar (136 ± 2 vs. 132 ± 3 mmHg in Sham), while the HR was higher in mice with Periodontitis (475 ± 20 vs. 412 ± 18 bpm in Sham), compared to their Sham counterparts. The APV was higher in mice with Periodontitis when evaluated in the time domain (4.5 ± 0.3 vs. 3.4 ± 0.2 mmHg in Sham), frequency domain (power of the LF band of systolic AP), or through symbolic analysis (patterns 0V + 1V), indicating a sympathetic overactivity. The HRV was similar in the mice with Periodontitis, as compared to their Sham counterparts. In the second protocol, the mice with Periodontitis showed decreased cardiac output (10 ± 0.8 vs. 15 ± 1.4 mL/min in Sham) and ejection fraction (37 ± 3 vs. 47 ± 2% in Sham) associated with increased myocardial cytokines (Interleukin-17, Interleukin-6, and Interleukin-4). This study shows that experimental Periodontitis caused cardiac dysfunction, increased heart cytokines, and sympathetic overactivity, in line with epidemiological studies indicating an increased risk of cardiovascular events in clinical Periodontitis.

Leukocytic toll-like receptor 2 knockout protects against diabetes-induced cardiac dysfunction

Diabetic cardiomyopathy is characterized by the deterioration of the myocardial function. Emerging evidences have indicated that leukocytic toll-like receptor 2 (TLR2) played an important role in the development of diabetic cardiomyopathy. Our study aimed to investigate whether TLR2 knockout (KO) exerted a cardioprotective effect in vivo. The establishment of diabetes model was set up in mice via intraperitoneal injection of streptozotocin (STZ). Results demonstrated that blocking of TLR2 significantly suppressed the enhanced left ventricular end-diastolic dimension (LVEDD), left ventricular end systolic diameter (LVESD) and the reduced the heart rate in diabetic cardiomyopathy mice. The decreased resting cell length, PS, TPS and + dL/dt while increased TR90 and - dL/dt caused by diabetic cardiomyopathy were remarkably inhibited by TLR2 KO. Besides that, the alleviated ΔFFI (360/380), decreased SERCA2a and p-NFATc3 expressions, extended Ca²⁺ decay time and elevated Calcineurin A induced by diabetic cardiomyopathy were vastly repressed by TLR2 KO in cardiocytes. Moreover, TLR2 gene silence could ameliorate oxidative stress-induced apoptosis, evidences were the up-regulated superoxide generation and Bax/Bcl-2 expression while restrained GSH/GSSG ratio caused by diabetic cardiomyopathy were tremendously repressed in TLR2 KO mice. Furthermore, blocking of TLR2 remarkably attenuated the augmented fibrosis areas of heart tissues in mice with diabetic cardiomyopathy. The result of the enhanced α-SMA and collagenⅠ caused by diabetic cardiomyopathy were suppressed in heart tissues of TLR2 KO mice further validate it. All in all, our study demonstrated that diabetes-induced cardiac dysfunction could be attenuated by TLR2 KO.

Increased Oral Porphyromonas gingivalis Prevalence in Cardiovascular Patients with Uncontrolled Diabetes Mellitus

The aim of this study was to determine the correlation between periodontopathic bacteria and diabetes mellitus (DM) status in cardiovascular disease (CVD) subjects.DM is associated with the progression of periodontitis. Several epidemiological studies have suggested that periodontitis may be a risk factor for CVD. However, no study has compared the periodontal condition between well-controlled and poorly-controlled DM patients with CVD.The subjects were well-controlled (n = 73) or poorly-controlled (n = 39) DM patients with CVD. Blood examinations and dental clinical measurements, including number of teeth, probing pocket depth, bleeding on probing (BOP), and clinical attachment level (CAL) were performed. Periodontopathic bacterial existence was evaluated.Worsened CAL and BOP rate were detected in the uncontrolled DM group compared to the controlled group. We found increased salivary Porphyromonas gingivalis counts in the uncontrolled DM group compared to well-controlled DM subjects.Specific periodontopathic bacterial infection may affect DM condition in CVD patients.

Mechanisms contributing to cardiac remodelling

Cardiac remodelling is classified as physiological (in response to growth, exercise and pregnancy) or pathological (in response to inflammation, ischaemia, ischaemia/reperfusion (I/R) injury, biomechanical stress, excess neurohormonal activation and excess afterload). Physiological remodelling of the heart is characterized by a fine-tuned and orchestrated process of beneficial adaptations. Pathological cardiac remodelling is the process of structural and functional changes in the left ventricle (LV) in response to internal or external cardiovascular damage or influence by pathogenic risk factors, and is a precursor of clinical heart failure (HF). Pathological remodelling is associated with fibrosis, inflammation and cellular dysfunction (e.g. abnormal cardiomyocyte/non-cardiomyocyte interactions, oxidative stress, endoplasmic reticulum (ER) stress, autophagy alterations, impairment of metabolism and signalling pathways), leading to HF. This review describes the key molecular and cellular responses involved in pathological cardiac remodelling.