Potential infectious etiologies of atherosclerosis: a multifactorial perspective

Human herpesvirus reactivation and its potential role in the pathogenesis of post-acute sequelae of SARS-CoV-2 infection

The emergence of SARS-CoV-2 has precipitated a global pandemic with substantial long-term health implications, including the condition known as post-acute sequelae of SARS-CoV-2 infection (PASC), commonly referred to as Long COVID. PASC is marked by persistent symptoms such as fatigue, neurological issues, and autonomic dysfunction that persist for months beyond the acute phase of COVID-19. This review examines the potential role of herpesvirus reactivation, specifically Epstein-Barr virus (EBV) and cytomegalovirus (CMV), in the pathogenesis of PASC. Elevated antibody titers and specific T cell responses suggest recent herpesvirus reactivation in some PASC patients, although viremia is not consistently detected. SARS-CoV-2 exhibits endothelial trophism, directly affecting the vascular endothelium and contributing to microvascular pathologies. These pathologies are significant in PASC, where microvascular dysfunction may underlie various chronic symptoms. Similarly, herpesviruses like CMV also exhibit endothelial trophism, which may exacerbate endothelial damage when reactivated. Evidence suggests that EBV and CMV reactivation could indirectly contribute to the immune dysregulation, immunosenescence, and autoimmune responses observed in PASC. Additionally, EBV may play a role in the genesis of neurological symptoms through creating mitochondrial dysfunction, though direct confirmation remains elusive. The reviewed evidence suggests that while herpesviruses may not play a direct role in the pathogenesis of PASC, their potential indirect effects, especially in the context of endothelial involvement, warrant further investigation.

CAIP-Induced ROS Production Contributes to Sustaining Atherosclerotic Process Associated with Helicobacter cinaedi Infection through Macrophages and Endothelial Cells Activation

Several lines of evidence have linked the intestinal bacterium Helicobacter cinaedi with the pathogenesis of atherosclerosis, identifying the Cinaedi Antigen Inflammatory Protein (CAIP) as a key virulence factor. Oxidative stress and inflammation are crucial in sustaining the atherosclerotic process and oxidized LDL (oxLDL) uptake. Primary human macrophages and endothelial cells were pre-incubated with 10 µM diphenyl iodonium salt (DPI) and stimulated with 20 µg/mL CAIP. Lectin-like oxLDL receptor (LOX-1) expression was evaluated by FACS analysis, reactive oxygen species (ROS) production was measured using the fluorescent probe H2DCF-DA, and cytokine release was quantified by ELISA assay. Foam cells formation was assessed by Oil Red-O staining, and phosphorylation of p38 and ERK1/2 MAP kinases and NF-κB pathway activation were determined by Western blot. This study demonstrated that CAIP triggered LOX-1 over-expression and increased ROS production in both macrophages and endothelial cells. Blocking ROS abrogated LOX-1 expression and reduced LDL uptake and foam cells formation. Additionally, CAIP-mediated pro-inflammatory cytokine release was significantly affected by ROS inhibition. The signaling pathway induced by CAIP-induced oxidative stress led to p38 MAP kinase phosphorylation and NF-κB activation. These findings elucidate the mechanism of action of CAIP, which heightens oxidative stress and contributes to the atherosclerotic process in H. cinaedi-infected patients.

The oral microbiota in patients undergoing coronary artery bypass graft surgery

The oral cavity houses a diverse community of microorganisms which play an important role in maintaining the health of the individual. The coexistence of periodontal infections with coronary artery disease (CAD) has been shown in many studies. We investigated the presence and abundance of periodontitis-causing bacteria in patients with CAD. The oral microbiome of five patients admitted for coronary artery bypass graft (CABG) surgery was analysed by metagenomic sequencing of 16 s ribosomal ribonucleic acid (rRNA) gene amplicons. Two samples of oral mouthwash were collected 48-72 h apart when the patients were in the intensive care unit. Abundance and diversity of oral bacterial flora were analysed. The most abundant phyla were Firmicutes and Bacteroidetes. Less than 5% of the taxa in this group of patients belonged to the phylum Proteobacteria. Though there were variations in the abundance of the bacterial species in the immediate postoperative period, there was no major change in the overall diversity. High counts of periodontal pathogens such as Tannerella forsythia, Campylobacter rectus, Fusobacterium nucleatum, Prevotella intermedia, and Treponema denticola were seen in most of the patients.

Mathematical model of aging in COVID-19

Background

The aim was examination of the intimamedia thickness of carotid arteries in COVID-19 infection.

Methods

In 50 patients, the thickness of the intimomedial complex (IMT) in the common carotid arteries was measured. The values were compared with the control group in 2006-9. The condition of the lungs was assessed by ultrasound score (It score) (0-42) as mild (0-14) or mediumsevere (15-28) Covid. IMT thickening risk factors and the value of fibrinogen, IL-6 and CRP were recorded. Two IMT prediction models were formed. The socio-epidemiological model predicts the development of IMT based on epidemiological factors. Apart from these factors, the second model also includes the values of the mentioned biomarkers.

Results

It score 20±6, IMT values right: median 0.99 mm, p25=0.89, p75=1.14; left: 1±0.22 mm. Control: IMTright: median 0.7 mm, p25=0.68 mm; p75=0-9 mm; left: median=0.75 mm, p25=0.6 mm, p75=1.0 mm. The group/control difference is highly significant. Epide mio - logical model: logit (IMT)= 4.463+(2.021+value for GEN)+(0.055x AGE value)+(-3.419x RF value)+(-4.447x SM value)+(5.115x HTA value)+(3.56x DM value)+ (22.389x LIP value)+(24.206x CVD value)+(1.449x other value)+(-0.138x It score value)+(0.19xBMI value). Epidemiological-inflammatory model: logit (IMT)=5.204+ (2.545x GEN value)+(0.076x AGE value)+(-6.132x RF value)+(-7.583x SM value)+(8.744x HTA value)+(6.838x DM value)+(25.446x LIP value)+(28.825x CVD value)+ (2.487x other value)+(-0.218xIt score value)+(0.649x BMI value) +(-0.194x fibrinogen value)+(0.894x IL-6 value)+(0.659x CRP value). Values for both models Exp(B)=4.882; P of sample=0.83; logit=-0.19; OR= 23.84; model accuracy for the first model 87% and for the second 88%; Omnibus test of the first model c2=34.324; p=0.000; reliability coefficient -2LogLH=56.854; Omnibus test of the second model c2=39.774; p=0.000; and -2LogLH=51.403.

Conclusions

The ageing of blood vessels in COVID-19 can be predicted.

Association between influenza vaccination and risk of stroke in Alberta, Canada: a population-based study

BACKGROUND

Respiratory infection can be an immediate precursor to stroke and myocardial infarction. Influenza vaccination is associated with reduced risk of myocardial infarction and hospitalisation for cardiac disease, and influenza vaccination is strongly recommended for patients with heart disease. Evidence on whether the same protective association exists for stroke, and whether this potential effect is consistent across age and risk groups, is conflicting. We aimed to assess the risk of stroke after influenza vaccination in adults.

METHODS

We obtained administrative data from the Alberta Health Care Insurance Plan (which covers all residents of Alberta, Canada) beginning on Sept 30, 2009, or May 15 of the year in which residents were recorded as being 18 years of age. Individuals were censored at the earliest of three events: death, recorded outmigration, or Dec 31, 2018. The outcome of interest was any stroke event, comprising acute ischaemic stroke, intracerebral haemorrhage, subarachnoid haemorrhage, and transient ischaemic attack. We used Andersen-Gill Cox models to analyse the hazard of any stroke event for individuals with recent (<182 days) influenza vaccination compared with those without recent influenza vaccination, with adjustment for age, sex, anticoagulant use, atrial fibrillation, chronic obstructive pulmonary disease, diabetes, hypertension, income quintile, and rural or urban home location. Two-way interaction terms between each individual covariate and vaccination status were used to assess for effect modification by risk factor. The association between vaccination and risk of each type of stroke was also modelled, adjusting for baseline covariates.

FINDINGS

The study sample consisted of 4 141 209 adults (29 687 899 person-years of observation time) registered under the provincial health-care system between Sept 30, 2009, and Dec 31, 2018. 1 769 565 (42·73%) individuals received at least one vaccination during the study period, and 38 126 stroke events were recorded. Adjusted for demographics and comorbidities, recent influenza vaccination significantly reduced the hazard of stroke (hazard ratio 0·775 [95% CI 0·757-0·793]). This association persisted across all stroke types. We found effect modification by each covariate examined except for home location; however, vaccination was associated with a reduced risk of stroke overall across all ages and risk profiles with the exception of individuals without hypertension.

INTERPRETATION

The risk of stroke is reduced among people who have recently been vaccinated against influenza compared with those who have not. This association extended to the entire adult population and was not limited to individuals with a baseline high risk of stroke. Further studies in a variety of settings are needed to evaluate whether influenza vaccination could be used as a public health strategy to prevent stroke.

FUNDING

None.

Bacterial Infections and Atherosclerosis – A Mini Review

Atherosclerosis is the most challenging subsets of coronary artery disease in humans, in which risk factors emerge from childhood, and its prevalence increases with age. Experimental research demonstrates that infections due to bacteria stimulate atherogenic events. Atherosclerosis has complex pathophysiology that is linked with several bacterial infections by damaging the inner arterial wall and heart muscles directly and indirectly by provoking a systemic pro-inflammation and acute-phase protein. Repeated bacterial infections trigger an inflammatory cascade that triggers immunological responses that negatively impact cardiovascular biomarkers includes triglycerides, high-density lipoprotein, C-reactive protein, heat shock proteins, cytokines, fibrinogen, and leukocyte count. Herein, we intended to share the role of bacterial infection in atherosclerosis and evaluate existing evidence of animal and human trials on the association between bacterial infections and atherosclerosis on update.

MicroRNAs and Sepsis-Induced Cardiac Dysfunction: A Systematic Review

Sepsis is a severe condition characterized by systemic inflammation. One of the most involved organs in sepsis is the heart. On the other hand, heart failure and dysfunction are some of the most leading causes of death in septic patients. miRNAs are short single-strand non-coding ribonucleic acids involved in the regulation of gene expression on a post-transcriptional phase, which means they are a part of the epigenetic process. Recently, researchers have found that miRNA expression in tissues and blood differs depending on different conditions. Because of this property, their use as serum sepsis biomarkers has also been explored. A narrative review is carried out to gather and summarize what is known about miRNAs' influence on cardiac dysfunction during sepsis. When reviewing the literature, we found at least 77 miRNAs involved in cardiac inflammation and dysfunction during sepsis. In the future, miRNAs may be used as early sepsis-induced cardiac dysfunction biomarkers or as new drug targets. This could help clinicians to early detect, prevent, and treat cardiac damage. The potential role of miRNAs as new diagnostic tools and therapeutic strategies worth deepening the complex network between non-coding RNA and biological pathways. Additional studies are needed to further investigate their role in sepsis-induced myocardium injury.

[Detection of Antigens of Cardiotropic Viruses in Atherosclerotic Plaques in Patients with Fatal Myocardial Infarction]

AIM

To assess the frequency of detection of cardiotropic virus antigens in coronary artery atherosclerotic plaques in patients with fatal myocardial infarction (MI).

MATERIALS AND METHODS

We examined fragments of coronary plaques of 12 patients with fatal type 1 MI. Immunohistochemistry (IHC) of plaques was performed with the paraffin blocks using antibodies to Herpes simplex virus (HSV)-1, HSV-2, HSV-6, cytomegalovirus (CMV), parvovirus B19, adenovirus, Epstein-Barr virus and enteroviruses.

RESULTS

According to the IHC all patients had virus antigens. The most common virus agents in fragments of coronary plaques were HSV-6 (10 patients) and enteroviruses (5 patients). Antigens of CMV, parvovirus B19, adenovirus, Epstein-Barr virus were not detected in any case.

CONCLUSIONS

In this study viral antigens in coronary artery atherosclerotic plaques were found in all victims of fatal MI. There was no difference in the frequency of detection and type of viral agents between plaques in culprit arteries and uncomplicated atherosclerotic plaques.

Oolong Tea Extract and Citrus Peel Polymethoxyflavones Reduce Transformation of l-Carnitine to Trimethylamine-N-Oxide and Decrease Vascular Inflammation in l-Carnitine Feeding Mice

Carnitine, a dietary quaternary amine mainly from red meat, is metabolized to trimethylamine (TMA) by gut microbiota and subsequently oxidized to trimethylamine-N-oxide (TMAO) by host hepatic enzymes, flavin monooxygenases (FMOs). The objective of this study aims to investigate the effects of flavonoids from oolong tea and citrus peels on reducing TMAO formation and protecting vascular inflammation in carnitine-feeding mice. The results showed that mice treated with 1.3% carnitine in drinking water significantly (p < 0.05) increased the plasma levels of TMAO compared to control group, whereas the plasma TMAO was remarkedly reduced by flavonoids used. Meanwhile, these dietary phenolic compounds significantly (p < 0.05) decreased hepatic FMO3 mRNA levels compared to carnitine only group. Additionally, oolong tea extract decreased mRNA levels of vascular inflammatory markers such as tissue necrosis factor-alpha (TNF-α), vascular cell adhesion molecule-1 (VCAM-1) and E-selectin. Polymethoxyflavones significantly lowered the expression of VCAM-1 and showed a decreasing trend in TNF-α and E-selectin mRNA expression compared to the carnitine group. Genus-level analysis of the gut microbiota in the cecum showed that these dietary phenolic compounds induced an increase in the relative abundances of Bacteroides. Oolong tea extract-treated group up-regulated Lactobacillus genus, compared to the carnitine only group. Administration of polymethoxyflavones increased Akkermansia in mice.

Prevalence of Porphyromonas gingivalis fimbriae A genotypes II and IV in patients with chronic periodontitis and atherosclerosis

Background

Atherosclerosis is known as one of the chronic diseases with high prevalence in the human species. Many studies have elucidated the relationship between this disease and chronic periodontitis caused by Porphyromonas gingivalis (P.g). The aim of this study was to investigate the prevalence of P.g fimbriae A (fimA) genotypes II and IV in patients with periodontitis and atherosclerosis.

Methods

This cross-sectional study investigated the frequency of P.g II and IV genotypes in the subgingival plaque specimens of 42 subjects in three experimental groups: periodontitis (A), atherosclerosis (B), periodontitis + atherosclerosis (C) and aortic wall specimens obtained from 30 patients (groups B and C) by the PCR technique.

Results

P.g bacterium was seen in 46.6% of patients with chronic periodontitis. The same bacterium was not found in aortic wall specimens of patients with chronic periodontitis (group C) and there was only one P.g-positive aortic wall specimen (7.7%) among the patients with healthy periodontium (group B). Genotypes II and IV were not observed in any specimen.

Conclusion

The results of statistical analysis showed no significant correlation between the prevalence of P.g and genotypes II and IV in the subgingival plaques and the incidence and severity of atherosclerosis.

Childhood infections and common carotid intima media thickness in adolescence

Atherosclerotic changes can be measured as changes in common carotid intima media thickness (CIMT). It is hypothesised that repeated infection-associated inflammatory responses in childhood contribute to the atherosclerotic process. We set out to determine whether the frequency of infectious diseases in childhood is associated with CIMT in adolescence. The study is part of the Prevention and Incidence of Asthma and Mite Allergy (PIAMA) population-based birth cohort. At age 16 years, common CIMT was measured. We collected general practitioner (GP) diagnosed infections and prescribed antibiotics. Parent-reported infections were retrieved from annual questionnaires. Linear regression analysis assessed the association between number of infections during the first 4 years of life and common CIMT. Common CIMT measurement, GP and questionnaire data were available for 221 participants. No association was observed between the infection measures and CIMT. In a subgroup analysis, significant positive associations with CIMT were observed in participants with low parental education for 2-3 or ⩾7 GP diagnosed infections (+26.4 µm, 95% CI 0.4-52.4 and +26.8 µm, 95% CI 3.6-49.9, respectively) and ⩾3 antibiotic prescriptions (+35.5 µm, 95%CI 15.8-55.3). Overall, early childhood infections were not associated with common CIMT in adolescence. However, a higher number of childhood infections might contribute to the inflammatory process of atherosclerosis in subgroups with low education, this needs to be confirmed in future studies.

Viral infection and atherosclerosis

Several risk factors have been described for the pathogenesis of atherosclerosis. Infectious diseases are suggested to be a causative factor, and some viruses have been studied for their relation with atherosclerotic diseases. Studies report two hypotheses, direct and indirect effects, for the role of viral infections in atherogenesis. Viruses are able to initiate atherosclerosis by two different pathways. They can exert their direct effects on atherogenesis by infecting vascular cells and then inducing inflammation in the endothelium and smooth muscle cells. Alternatively, they can also apply indirect effects by infecting non-vascular cells and inducing systemic inflammation. In this review, we consider the available data about the effects and correlations of DNA and RNA viruses on atherosclerosis.

Chlamydia Pneumoniae in Asymptomatic Carotid Atherosclerosis

We evaluated, in 415 patients with asymptomatic carotid atherosclerosis: (i) the prevalence of C. pneumoniae DNA in atherosclerotic carotid plaques and peripheral blood mononuclear cells (PBMC); (ii) the distribution of C. pneumoniae in atherosclerotic carotid plaques and PBMC from the same patients; (iii) the correlation between circulating anti-chlamydial antibodies and the presence of C. pneumoniae DNA. Overall, 160 atherosclerotic carotid plaques and 174 PBMC specimens from patients with asymptomatic carotid atherosclerosis were examined by ompA nested touchdown PCR for presence of C. pneumoniae. In addition, C. pneumoniae DNA was detected in 81 specimens of atherosclerotic carotid plaque and PBMC obtained from the same patients. C. pneumoniae DNA was found in 36.9% of atherosclerotic carotid plaques and in 40.2% of PBMC specimens examined (P=NS). With regard to 81 patients, C. pneumoniae DNA was detected in 27.2% of atherosclerotic carotid plaques and in 44.4% of PBMC specimens (P=0.05). In 18 patients, the presence of C. pneumoniae DNA in PBMC specimens and atherosclerotic carotid plaques coincided (P=0.005). No statistically significant association was found between anti-C pneumoniae antibodies (IgG and IgA) and positive PCR results. In conclusion, our results suggest that the detection of C. pneumoniae DNA in PBMC specimens seems to be a first-choice method to identify the patients at risk for endovascular chlamydial infection.

Wild Lonicera caerulea berry polyphenol extract reduces cholesterol accumulation and enhances antioxidant capacity in vitro and in vivo

The hypocholesterolemic effect of Lonicera caerulea berry extract rich in polyphenols (LCBP) on high cholesterol-induced hypercholesterolemia and lipoprotein metabolite changes was examined in Caco-2 cells and rats. Cyanidin-3-glucoside, catechin, and chlorogenic acid are the major phenolic components of LCBP. The cholesterol-reducing effect and antioxidant capacity of these components were compared in Caco-2 cells. LCBP (80 μg/mL) and cyanidin-3-glucoside, catechin, and chlorogenic acid (50 μM) were found to be effective (p < 0.05). Rats were fed a high cholesterol diet (HCD) with or without LCBP supplementation (75, 150, and 300 mg/kg body weight intragastrically once daily) for 12 weeks. Compared with the HCD control group, LCBP supplementation at 150 and 300 mg/kg decreased the levels of TC, TG, and LDL-C, but increased that of HDL-C. LCBP treatment promoted greater neutral and acidic sterol excretion (p < 0.05) and improved the antioxidant capacity of the colon tissue, colon contents, and blood. Moreover, trimethylamine N-oxide (TMAO) levels were decreased in serum (p < 0.05). NPC1L1, ACAT2, and MTP mRNA and protein expression were reduced and ABCG5/8 expression was increased (p < 0.05) after LCBP treatment. Our results suggest that LCBP could be used as a functional food for the prevention and treatment of diseases related to excessive cholesterol accumulation.

Evaluation of Lipid Profile Changes in Pediatric Patients with Acute Mononucleosis

BACKGROUND

Acute Epstein-Barr virus (EBV) infection could lead to atherogenic lipid profile changes in adults; while there is no evidence about the children with Infectious mononucleosis (IM). The aim of this study was to evaluate the lipid profile of the children in acute phase of mononucleosis and two months after the recovery.

MATERIALS AND METHODS

From 2010 through 2012, 36 children with IM aged 1-10 years were enrolled in a prospective cross-sectional study. Fasting serum total cholesterol, high density lipoprotein (HDL), low density lipoprotein (LDL), and triglyceride level were measured during acute phase of the disease and after 2 months of the recovery.

RESULTS

From 36 patients enrolled, 25 (69.4%) cases were male and the mean age of the patients was 4.1 ± 2.0 years. The mean of the total cholesterol level in the acute phase and 2 months after the recovery were149.5 ± 35.3 mg/dL and 145.7±30.6, respectively (P = 0.38). However, the serum level of HDL cholesterol in patients after 2 months of recovery was significantly increased (37.9 ± 9.3 mg/dL vs. 28.5 ± 10.6 mg/dL, P < 0.001). The mean value of serum LDL cholesterol was significantly reduced, two months after recovery (81.4 ± 19.5 mg/dL, vs. 92.6 ± 28.8 mg/dL, P = 0.009). Furthermore, the serum triglyceride level was significantly reduced after the recovery (108.7 ± 36.9 mg/dL) compared with the acute phase (163.8 ± 114.3 mg/dL) (P = 0.004).

CONCLUSION

EBV infection in children could change lipid profile which is partially restored 2 months after the recovery.

The Helicobacter cinaedi antigen CAIP participates in atherosclerotic inflammation by promoting the differentiation of macrophages in foam cells

Recent studies have shown that certain specific microbial infections participate in atherosclerosis by inducing inflammation and immune reactions, but how the pathogens implicated in this pathology trigger the host responses remains unknown. In this study we show that Helicobacter cinaedi (Hc) is a human pathogen linked to atherosclerosis development since at least 27% of sera from atherosclerotic patients specifically recognize a protein of the Hc proteome, that we named Cinaedi Atherosclerosis Inflammatory Protein (CAIP) (n = 71). CAIP appears to be implicated in this pathology because atheromatous plaques isolated from atherosclerotic patients are enriched in CAIP-specific T cells (10%) which, in turn, we show to drive a Th1 inflammation, an immunopathological response typically associated to atherosclerosis. Recombinant CAIP promotes the differentiation and maintenance of the pro-inflammatory profile of human macrophages and triggers the formation of foam cells, which are a hallmark of atherosclerosis. This study identifies CAIP as a relevant factor in atherosclerosis inflammation linked to Hc infection and suggests that preventing and eradicating Hc infection could reduce the incidence of atherosclerosis.

Trained immunity: A smart way to enhance innate immune defence

The innate arm of the immune system is generally viewed as primitive and non-specific and - in contrast to the adaptive immune arm - not to possess memory. However in plants and invertebrate animals that lack adaptive immunity, innate immunity will exhibit a prolonged enhanced functional state after adequate priming. A similar enhancement of function of the innate immunity has occasionally been described in vertebrates, including humans. Over the past few years we have studied this phenomenon in greater detail and we have coined the term 'Trained (innate) immunity' (TI). TI can be induced by a variety of stimuli, of which we have studied BCG and β-glucan in greater detail. The non-specific protective effects of BCG that have been observed in vaccination studies in the literature are probably due to TI. Monocytes and macrophages are among the main cells of the innate immune arm that can be trained. We have discovered that both BCG (via NOD2 signalling) and β-glucan (via dectin-1) induce epigenetic reprogramming, in particular stable changes in histone trimethylation at H3K4. These epigenetic changes lead to cellular activation, enhanced cytokine production and a change in the metabolic state of the cell with a shift from oxidative phosphorylation to aerobic glycolysis. TI is not only important for host defence and vaccine responses, but most probably also for diseases like atherosclerosis. Modulation of TI is a promising area for new treatments.

Infection and Atherosclerosis Development

Atherosclerosis is a chronic disease hallmarked by chronic inflammation, endothelial dysfunction and lipid accumulation in the vasculature. Although lipid modification and deposition are thought to be a major source of the continuous inflammatory stimulus, a large body of evidence suggests that infectious agents may contribute to atherosclerotic processes. This could occur by either direct effects through infection of vascular cells and/or through indirect effects by induction of cytokine and acute phase reactant proteins by infection at other sites. Multiple bacterial and viral pathogens have been associated with atherosclerosis by seroepidemiological studies, identification of the infectious agent in human atherosclerotic tissue, and experimental studies demonstrating an acceleration of atherosclerosis following infection in animal models of atherosclerosis. This review will focus on those infectious agents for which biological plausibility has been demonstrated in animal models and on the challenges of proving a role of infection in human atherosclerotic disease.

The Infection Hypothesis Revisited: Oral Infection and Cardiovascular Disease

Background. The pathophysiology of cardiovascular disease (CVD) includes inflammation in the development of atherosclerosis and thrombosis. Increasing evidence supports oral infections, and in particular the common periodontal disease, to be associated with CVD development. Periodontal infection is present in populations worldwide and in the moderate to mild form in about 35% of populations according to the World Health Organization. Objective. This review of the literature aims to present cross evidence from medical research disciplines that explore how oral infections can contribute to increase the risk for CVDs and how treatment of oral infections can reduce the risk for CVDs. Design. Review article. Results. Long-term exposure to active nontreated infections of the oral cavity presents an opportunity for bacteria, bacterial products, and viruses to enter the circulation. Toxic bacterial products enter the circulation, affecting atherosclerosis, causing platelet adhesiveness that results in clot formation, and establishing cardiac vegetation. Pathological observations have identified oral bacteria in heart valves, aortic aneurysms, and arterial walls. Clinical intervention studies on periodontal disease reduce the risk level of serological predictors for CVDs. Conclusions. This paper presents evidence across medical research disciplines for oral infections to be considered as one of the risk factors for CVDs.

Role of PON2 in innate immune response in an acute infection model

N-(3-oxododecanoyl)-l-homoserine lactone (3OC(12)-HSL) is a quorum-sensing molecule produced by gram-negative microbial pathogens such as Pseudomonas aeruginosa (PAO1). 3OC(12)-HSL is involved in the regulation of bacterial virulence factors and also alters the function of the host immune cells. Others and we have previously shown that paraoxonase 2 (PON2), a member of the paraoxonase gene family expressed in immune cells, hydrolyzes 3OC(12)-HSL. In this study, we examined i) whether macrophage PON2 participates in 3OC(12)-HSL hydrolysis, ii) the effect of PON2 deficiency in acute PAO1 infection in mice and iii) the effect of 3OC(12)-HSL on PON2 deficient (PON2-def) macrophages. When compared to wild type macrophages, both intact cells and membrane-enriched protein lysates obtained from PON2-def macrophages show a marked impairment in their ability to hydrolyze 3OC(12)-HSL. PON2 expression (message and protein) is not altered in response to 3OC(12)-HSL in macrophages. 3OC(12)-HSL treated PON2-def macrophages showed i) an increase in ER stress and oxidative stress, ii) defective phosphatidylinositol 3-kinase (PI3 kinase)/AKT activation, and iii) reduced phagocytosis function. Moreover, the nitration to phosphorylation ratio of Tyr458 in p85 protein, the regulatory subunit of PI3-kinase that has been correlated with the phagocytosis function of macrophages, was increased in PON2-def macrophages. Antioxidant treatment reversed the effects of PON2 deficiency in macrophage phagocytosis function. Furthermore, following administration of 1.6 × 10(7) CFU of PAO1, bacterial clearance was significantly reduced in the lungs (5.7 fold), liver (2.5 fold), and spleen (14.8 fold) of PON2-def mice when compared to wild type mice. Our results suggest that PON2 plays an important role in innate immune defense against PAO1 infection.

Correlation between the severity of periodontitis and coronary artery stenosis in a Chinese population

BACKGROUND

The aim of this study was to evaluate the relationship between the severity of periodontitis and the extent and degree of coronary artery stenosis in a Chinese population.

METHODS

Patients (n = 853) with coronary artery stenosis confirmed by coronary angiography were eligible to take part in the study. Only subjects that were ≥60 years old, had ≥50% stenosis in at least one coronary artery, and did not have diabetes or a history of smoking were included (n = 115). After periodontal examination, including bleeding index, probing depth calculus index, plaque index and periodontal attachment loss, four groups were defined based on the severity of periodontitis: no periodontitis/gingivitis (M0, n = 19); mild periodontitis (M1, n = 27); moderate periodontitis (M2, n = 31); and severe periodontitis (M3, n = 38). The extent and degree of coronary artery stenosis was obtained by calculating the Gensini score (GS).

RESULTS

The GS was significantly greater in the M3 group compared with the M0 group. Multiple linear regression analysis revealed that probing depth and plaque index were significantly correlated with the GS.

CONCLUSIONS

The extent and severity of coronary artery stenosis in Chinese patients ≥60 years old is positively correlated with the severity of periodontitis.

Oral health status of CHD and non-CHD adults of Lahore, Pakistan

BACKGROUND

Evidence on association of oral health and coronary heart diseases (CHD) is mounting in the literature. This study was designed to observe an association between status of oral health and cardiac diseases in Pakistani adults.

MATERIALS AND METHODS

A case-control study was conducted on CHD and non-CHD adults aged >30 years. Age-gender matched individuals without CHD, fulfilling the inclusion criteria as for CHD patients were selected for comparison. Bleeding on probing (BOP), periodontal pocket depth (PPD) and tooth loss were noted as oral health parameters.

RESULTS

45 CHD patients and 35 non-CHD individuals were examined. 53.75% were males and 46.25% females, 37.5% subjects were uneducated, 65% belonged to lower income group, 58.75% subjects were ≥obese and 88.75% were non-smokers. Mean of percent sites of BOP (P =0.007), PPD (P =0.031) and tooth loss (P =0.021) were significantly higher in study group. In stepwise logistic regression analysis, BOP and tooth loss showed a significant positive association with CHD; however, association of PPD was not significant.

CONCLUSION

Oral health parameters were significantly higher in CHD patients. Bleeding on probing and tooth loss was positively associated with CHD after adjusting for other socio-demographic variables.

Chronic oral infection with Porphyromonas gingivalis accelerates atheroma formation by shifting the lipid profile

Background

Recent studies have suggested that periodontal disease increases the risk of atherothrombotic disease. Atherosclerosis has been characterized as a chronic inflammatory response to cholesterol deposition in the arteries. Although several studies have suggested that certain periodontopathic bacteria accelerate atherogenesis in apolipoprotein E-deficient mice, the mechanistic link between cholesterol accumulation and periodontal infection-induced inflammation is largely unknown.

Methodology/Principal Findings

We orally infected C57BL/6 and C57BL/6.KOR-Apoe^shl (B6.Apoeshl) mice with Porphyromonas gingivalis, which is a representative periodontopathic bacterium, and evaluated atherogenesis, gene expression in the aorta and liver and systemic inflammatory and lipid profiles in the blood. Furthermore, the effect of lipopolysaccharide (LPS) from P. gingivalis on cholesterol transport and the related gene expression was examined in peritoneal macrophages. Alveolar bone resorption and elevation of systemic inflammatory responses were induced in both strains. Despite early changes in the expression of key genes involved in cholesterol turnover, such as liver X receptor and ATP-binding cassette A1, serum lipid profiles did not change with short-term infection. Long-term infection was associated with a reduction in serum high-density lipoprotein (HDL) cholesterol but not with the development of atherosclerotic lesions in wild-type mice. In B6.Apoeshl mice, long-term infection resulted in the elevation of very low-density lipoprotein (VLDL), LDL and total cholesterols in addition to the reduction of HDL cholesterol. This shift in the lipid profile was concomitant with a significant increase in atherosclerotic lesions. Stimulation with P. gingivalis LPS induced the change of cholesterol transport via targeting the expression of LDL receptor-related genes and resulted in the disturbance of regulatory mechanisms of the cholesterol level in macrophages.

Conclusions/Significance

Periodontal infection itself does not cause atherosclerosis, but it accelerates it by inducing systemic inflammation and deteriorating lipid metabolism, particularly when underlying hyperlidemia or susceptibility to hyperlipidemia exists, and it may contribute to the development of coronary heart disease.

Periodontitis and coronary artery disease: a questioned association between periodontal and vascular plaques

Periodontitis is a bacterially-induced, localized chronic inflammatory disease destroying both the connective tissue and the supporting bone of the teeth. In the general population, severe forms of the disease demonstrate a prevalence of almost 5%, whereas initial epidemiological evidence suggests an association between periodontitis and coronary artery disease (CAD). Both the infectious nature of periodontitis and the yet etiologically unconfirmed infectious hypothesis of CAD, question their potential association. Ephemeral bacteremia, systemic inflammation and immune-pathological reactions constitute a triad of mechanisms supporting a cross-talk between periodontal and vascular damage. To which extent each of these periodontitis-mediated components contribute to vascular damage still remains uncertain. More than twenty years from the initial epidemiological association, the positive weight of evidence remains still alive but rather debated, because of both the presence of many uncontrolled confounding factors and the different assessment of periodontal disease. From the clinical point of view, advising periodontal prevention or treatment targeting on the prevention of CAD it is unjustified. By contrast, oral hygiene including periodontal health might contribute to the overall well-being and healthy lifestyle and hence as might at least partially contribute to cardiovascular prevention.

Detection of human herpesvirus 6 DNA but not human herpesvirus 7 or 8 DNA in atherosclerotic and nonatherosclerotic vascular tissues

INTRODUCTION

Various viral infections are thought to play a role in the development of atherosclerosis. A number of studies suggest that certain viruses from the Herpesviridae family in particular may lead to atherosclerosis.

METHODS

We investigated the presence of human herpesvirus 6 (HHV-6), human herpesvirus 7 (HHV-7), and human herpesvirus 8 (HHV-8) DNA in carotid, iliac, and coronary artery specimens obtained from a group of adult autopsy cases by means of polymerase chain reaction (PCR) analysis and nested PCR techniques. A 28-subject study group with at least type IV atherosclerosis and a 25-subject control group with no visible atherosclerosis were enrolled.

RESULTS

HHV-6 DNA was found in the carotid artery specimen of 1 subject with atherosclerosis, in an iliac artery specimen of another subject, and in the iliac artery specimen of one of the control subjects. HHV-7 or HHV-8 DNA was not found in either the atherosclerosis or control cases.

CONCLUSIONS

This study is the first to demonstrate the presence of HHV-6 in atherosclerotic vascular tissues. HHV-7 and HHV-8 were not found in atherosclerotic tissues; however, further research on broader study groups and with different protocols is needed to determine whether these viruses play a role in the formation of atherosclerosis.

HBV or HCV coinfections and risk of myocardial infarction in HIV-infected individuals: the D:A:D Cohort Study

BACKGROUND

Data on a link between HCV or HBV infection and the development of cardiovascular disease among HIV-negative and HIV-positive individuals are conflicting. We sought to investigate the association between HBV or HCV infection and myocardial infarction in HIV-infected individuals.

METHODS

The prospective observational database of the D:A:D collaboration of 11 cohorts of HIV-infected individuals, including 212 clinics in Europe, the United States and Australia was used. Multivariate Poisson regression was used to assess the effect of HCV or HBV infection on the development of myocardial infarction after adjustment for potential confounders, including cardiovascular risk factors, diabetes mellitus and exposure to antiretroviral therapy.

RESULTS

Of 33,347 individuals, 517 developed a myocardial infarction over 157,912 person-years, with an event rate of 3.3 events/1,000 person-years (95% confidence interval [CI] 3.0-3.6). Event rates (95% CIs) per 1,000 person-years in those who were HCV-seronegative and HCV-seropositive were 3.3 (3.0-3.7) and 2.7 (2.2-3.3), respectively, and for those who were HBV-seronegative, had inactive infection or had active infection were 3.2 (2.8-3.5), 4.2 (3.1-5.2) and 2.8 (1.8-3.9), respectively. After adjustment, there was no association between HCV seropositivity (rate ratio 0.86 [95% CI 0.62-1.19]), inactive HBV infection (rate ratio 1.07 [95% CI 0.79-1.43]) or active HBV infection (rate ratio 0.78 [95% CI 0.52-1.15]) and the development of myocardial infarction.

CONCLUSIONS

We found no association between HBV or HCV coinfection and the development of myocardial infarction among HIV-infected individuals.

Vitamin E dose-dependently reduces aortic fatty lesion formation in orchidectomized aged rats

BACKGROUND AND AIMS

Although the cardioprotective effects of supplemental doses of vitamin E have been investigated in several conditions, its role in gonadectomy- induced fatty lesion formation is unclear. The present study was designed to examine the efficacy of vitamin E in a dose-dependent manner on indices of oxidative stress and in preventing the formation of aortic fatty lesions in orchidectomized (Orx) aged rats.

METHODS

Forty 12-month old male Sprague-Dawley rats were either sham-operated (Sham) or Orx and fed a semi-purified control diet for 120 days. Thereafter, rats were assigned to four treatment groups (n=10): Sham and one Orx group received 75 IU vitamin E and served as controls, and the other two Orx groups received either 250 or 500 IU vitamin E per kg diet for 90 days.

RESULTS

Vitamin E at the highest dose (500 IU) was able to lower serum total cholesterol by 16% and significantly increase superoxide dismutase by 9% compared to Orx controls. Similarly, this dose was able to significantly reduce the development of atherosclerotic lesion formation and aortic fatty streak area by 93% compared to Orx controls.

CONCLUSIONS

The findings of this study suggest that dietary vitamin E supplementation in Orx aged rats provide anti-atherogenic effects, in part, due to vitamin E's antioxidative properties. Clinical studies are needed to confirm whether supplemental doses of vitamin E can prevent the development of atherosclerosis in older men particularly with low testosterone level.

Receptor for advanced glycation endproducts mediates pro-atherogenic responses to periodontal infection in vascular endothelial cells

OBJECTIVE

A link between periodontal infections and an increased risk for vascular disease has been demonstrated. Porphyromonas gingivalis, a major periodontal pathogen, localizes in human atherosclerotic plaques, accelerates atherosclerosis in animal models and modulates vascular cell function. The receptor for advanced glycation endproducts (RAGE) regulates vascular inflammation and atherogenesis. We hypothesized that RAGE is involved in P. gingivalis's contribution to pro-atherogenic responses in vascular endothelial cells.

METHODS AND RESULTS

Murine aortic endothelial cells (MAEC) were isolated from wild-type C57BL/6 or RAGE-/- mice and were infected with P. gingivalis strain 381. P. gingivalis 381 infection significantly enhanced expression of RAGE in wild-type MAEC. Levels of pro-atherogenic advanced glycation endproducts (AGEs) and monocyte chemoattractant protein 1 (MCP-1) were significantly increased in wild-type MAEC following P. gingivalis 381 infection, but were unaffected in MAEC from RAGE-/- mice or in MAEC infected with DPG3, a fimbriae-deficient mutant of P. gingivalis 381. Consistent with a role for oxidative stress and an AGE-dependent activation of RAGE in this setting, both antioxidant treatment and AGE blockade significantly suppressed RAGE gene expression and RAGE and MCP-1 protein levels in P. gingivalis 381-infected human aortic endothelial cells (HAEC).

CONCLUSION

The present findings implicate for the first time the AGE-RAGE axis in the amplification of pro-atherogenic responses triggered by P. gingivalis in vascular endothelial cells.

Toll-like receptors and atherosclerosis: oxidized LDL as an endogenous Toll-like receptor ligand

The oxidation hypothesis of atherosclerosis suggests that oxidative modification of low-density lipoprotein (LDL) is a prerequisite for LDL atherogenicity. Recent studies demonstrate that upon oxidative modification, LDL becomes enriched with pathogen-associated molecular patterns recognized by natural (inborn) antibodies and innate immune receptors. This review focuses on recent findings showing that Toll-like receptors (TLRs)--which sense microbial pathogens and initiate immediate inflammatory responses--are potentially involved in the pathogenesis of atherosclerosis. In addition to the data that bacterial agonists of TLR4 and TLR2 accelerate atherosclerosis, new evidence suggests that minimally oxidized LDL and specific oxidized phospholipids signal via TLRs to induce cytoskeletal changes and inflammatory cytokine secretion by macrophages and endothelial cells. Identifying the signaling mechanisms by which oxidized LDL induces chronic inflammation in atherosclerotic lesions may lead to novel therapeutic targets for the treatment of atherosclerotic cardiovascular disease.

Prevalence of Chlamydophila pneumoniae is higher in aorta and coronary artery than in carotid artery of coronary artery disease patients

Coronary artery disease (CAD) is a public health problem accounting for an estimated one-third of deaths overall. A potential link between infectious agents and atherosclerosis has been suggested. Data obtained from several seroepidemiological studies have suggested that infection with Chlamydophila pneumoniae, Helicobacter pylori, cytomegalovirus and herpes simplex virus-1 can initiate or maintain the atherosclerotic process. However, there is no single study in which multiple infectious agents have been detected together in different vascular locations in the same population. This would help in determining if there is any leading pathogen in atheromatous plaques of CAD patients. Hence, we screened for C. pneumoniae, H. pylori, CMV and HSV-1 in different vascular locations of CAD patients using quantitative real-time (RT) PCR. We performed multiplex RT-PCR for detecting pathogens, viz. C. pneumoniae, H. pylori, CMV and HSV-1 in different vascular locations of CAD patients. Percent positivity scores for C. pneumoniae, H. pylori, CMV and HSV-1 in different vascular locations were as follows: aorta (64.7, 35.3, 11.7 and 11.7 respectively); carotid (27.2, 27.2, 9 and 0 respectively); coronary artery (58.3, 33.3, 16.6 and 8.3 respectively). Combined positivity for C. pneumoniae (C. pneumoniae IgA and RT-PCR for C. pneumoniae) was the highest compared with all other groups. Aorta and coronary artery were more susceptible to these pathogens as compared with carotid artery. Moreover, CAD patients' characteristics were associated with C. pneumoniae positivity (C. pneumoniae IgA and RT-PCR), suggesting thereby that C. pneumoniae may have caused chronic persistent infection in CAD.

Atherosclerosis, inflammation and Chlamydia pneumoniae

Coronary heart disease is the single most common cause of illness and death in the developed world. Coronary atherosclerosis is by far the most frequent cause of ischemic heart disease, and plaque disruption with superimposed thrombosis is the main cause of the acute coronary syndromes of unstable angina, myocardial infarction, and sudden death. Atherosclerosis is the result of a complex interaction between blood elements, disturbed flow, and vessel wall abnormality, involving several pathological processes: inflammation, with increased endothelial permeability, endothelial activation, and monocyte recruitment; growth, with smooth muscle cell proliferation, migration, and matrix synthesis; degeneration, with lipid accumulation; necrosis, possibly related to the cytotoxic effect of oxidized lipid; calcification/ossification, which may represent an active rather than a dystrophic process; and thrombosis, with platelet recruitment and fibrin formation. In this review we discuss these processes and the possible pathological effects of Chlamydia infection and the ensuing phlogosis.

Mycoplasma pneumoniae and/or Chlamydophila pneumoniae inoculation causing different aggravations in cholesterol-induced atherosclerosis in apoE KO male mice

BACKGROUND

Chamydophila pneumoniae (CP) and/or Mycoplasma pneumoniae (MP) are two bacteria detected in vulnerable atheromas. In this study we aimed to analyze whether CP and/or MP aggravates atherosclerosis induced by cholesterol-enriched diet in C57BL/6 apoE KO male mice. Thirty male apoE KO mice aged eight weeks fed by a diet containing 1% cholesterol until 32 weeks of age were divided into four groups: the first was inoculated with CP (n = 7), the second with MP (n = 12), the third with both CP + MP (n = 5), and the fourth with saline (sham n = 6). The animals were re-inoculated at 36 weeks of age, and sacrificed at 40 weeks of age. Two ascending aorta and one aortic arch segments were sampled. In the most severely obstructed segment, vessel diameter, plaque height, percentage of luminal obstruction and the degree of adventitial inflammation were analyzed. The plaque area/intimal surface ratio was obtained by measuring all three segments. The adventitial inflammation was semiquantified (0 absent, 1 mild, 2 moderate, and 3 diffuse).

RESULTS

The mean and standard deviation of plaque height, % luminal obstruction, external diameter, the plaque area/intimal surface ratio and the adventitial inflammation values are the following for each group: MP (0.20 +/- 0.12 mm, 69 +/- 26%, 0.38 +/- 0.11 mm, 0.04 +/- 0.04 and 0.22 +/- 0.67), CP (0.23 +/- 0.08 mm, 90 +/- 26%, 0.37 +/- 0.08 mm, 0.04 +/- 0.03, and 0.44 +/- 0.53), MP + CP (18 +/- 0.08 mm, 84 +/- 4.0%, 0.35 +/- 0.25 mm, 0.03 +/- 0.03 and 1.33 +/- 0.82) and sham (0.08 +/- 0.09 mm, 42 +/- 46%, 0.30 +/- 0.10 mm, 0.02 +/- 0.03 and 0.71 +/- 0.76). A wider area of plaque/intimal surface was observed in MP + CP inoculated groups (p = 0.07 and 0.06) as well as an increased plaque height in CP (p = 0.01) in comparison with sham group. There was also an increased luminal obstruction (p = 0.047) in CP inoculated group in comparison to sham group. Adventitial inflammation in MP + CP inoculated group was higher than MP, CP and the sham groups (p = 0.02).

CONCLUSION

Inoculation of CP, MP or both agents in C57BL/6 apoE KO male mice caused aggravation of experimental atherosclerosis induced by cholesterol-enriched diet, with distinct characteristics. CP inoculation increased the plaque height with positive vessel remodeling and co-inoculation of MP + CP caused the highest adventitial inflammation measures.

Inflammation and infection do not promote arterial aging and cardiovascular disease risk factors among lean horticulturalists

Background

Arterial aging is well characterized in industrial populations, but scantly described in populations with little access to modern medicine. Here we characterize health and aging among the Tsimane, Amazonian forager-horticulturalists with short life expectancy, high infectious loads and inflammation, but low adiposity and robust physical fitness. Inflammation has been implicated in all stages of arterial aging, atherogenesis and hypertension, and so we test whether greater inflammation associates with atherosclerosis and CVD risk. In contrast, moderate to vigorous daily activity, minimal obesity, and low fat intake predict minimal CVD risk among older Tsimane.

Methods and Findings

Peripheral arterial disease (PAD), based on the Ankle-Brachial Index (ABI), and hypertension were measured in Tsimane adults, and compared with rates from industrialized populations. No cases of PAD were found among Tsimane and hypertension was comparatively low (prevalence: 3.5%, 40+; 23%, 70+). Markers of infection and inflammation were much higher among Tsimane than among U.S. adults, whereas HDL was substantially lower. Regression models examine associations of ABI and BP with biomarkers of energy balance and metabolism and of inflammation and infection. Among Tsimane, obesity, blood lipids, and disease history were not significantly associated with ABI. Unlike the Tsimane case, higher cholesterol, C-reactive protein, leukocytes, cigarette smoking and systolic pressure among North Americans are all significantly associated with lower ABI.

Conclusions

Inflammation may not always be a risk factor for arterial degeneration and CVD, but instead may be offset by other factors: healthy metabolism, active lifestyle, favorable body mass, lean diet, low blood lipids and cardiorespiratory health. Other possibilities, including genetic susceptibility and the role of helminth infections, are discussed. The absence of PAD and CVD among Tsimane parallels anecdotal reports from other small-scale subsistence populations and suggests that chronic vascular disease had little impact on adult mortality throughout most of human evolutionary history.

Emerging and reemerging diseases: a historical perspective

Summary: Between mid‐century and 1992, there was a consensus that the battle against infectious diseases had been won, and the Surgeon General announced that it was time to close the book. Experience with human immunodeficiency virus/acquired immunodeficiency syndrome, the return of cholera to the Americas in 1991, the plague outbreak in India in 1994, and the emergence of Ebola in Zaire in 1995 created awareness of a new vulnerability to epidemics due to population growth, unplanned urbanization, antimicrobial resistance, poverty, societal change, and rapid mass movement of people. The increasing virulence of dengue fever with dengue hemorrhagic fever and dengue shock syndrome disproved the theory of the evolution toward commensalism, and the discovery of the microbial origins of peptic ulcer demonstrated the reach of infectious diseases. The Institute of Medicine coined the term ‘emerging and reemerging diseases’ to explain that the world had entered an era in which the vulnerability to epidemics in the United States and globally was greater than ever. The United States and the World Health Organization took devised rapid response systems to monitor and contain disease outbreaks and to develop new weapons against microbes. These mechanisms were tested by severe acute respiratory syndrome in 2003, and a series of practical and conceptual blind spots in preparedness were revealed.

HIV type 1 infection, and not short-term HAART, induces endothelial dysfunction

OBJECTIVE

Ischemic cardiovascular events increasingly occur during long-lasting HIV infection and are attributed either to the infection itself or to the use of HAART. Endothelial dysfunction and platelet activation are markers of atherosclerosis. Our aim was to assess whether patients with chronic HIV infection present endothelial dysfunction and whether this is the consequence of infection or of HAART.

DESIGN

Fifty-six HIV-infected patients were studied in a retrospective cohort study before and 3, 6, 12 and 24 months after starting HAART with protease inhibitors (n = 28) or nonnucleoside reverse transcriptase inhibitors (n = 28), and compared with 28 age-matched and sex-matched healthy controls, and with 10 naive HIV-infected patients studied at diagnosis and after 12 months of untreated infection.

METHODS

Soluble endothelial and platelet activation markers were measured in plasma by flow cytometry.

RESULTS

Soluble P-selectin, soluble vascular cell adhesion molecule-1, monocyte chemoattractant protein-1 and von Willebrand factor were significantly higher in HIV-infected patients than in healthy controls, whereas soluble CD40 ligand and tissue type plasminogen activator were within normal range. During follow-up, soluble vascular cell adhesion molecule-1, monocyte chemoattractant protein-1 and von Willebrand factor but not soluble P-selectin decreased progressively, without significant differences between protease inhibitors and nonnucleoside reverse transcriptase inhibitors treatment. In naive, untreated patients, increased plasma markers of endothelial dysfunction were confirmed at diagnosis, with no changes upon follow-up.

CONCLUSION

Chronic HIV infection, and not its pharmacological treatment, induces alterations of markers of endothelial function. Short-term treatment with HAART reduces some markers of endothelial dysfunction, with no differences between protease inhibitors and nonnucleoside reverse transcriptase inhibitors.

Effects of wheat antioxidants on oxygen diffusion-concentration products in liposomes and mRNA levels of HMG-CoA reductase and cholesterol 7alpha-hydroxylase in primary rat hepatocytes

Three wheat antioxidant fractions were investigated for their potential effects on oxygen diffusion-concentration products in liposomes prepared with egg yolk phosphatidycholine (yolk PC) and rat liver PC (liver PC), using the electron spin resonance (ESR) oximetry method with 2,2'-azobis(2-aminopropane) dihydrochloride (AAPH) and 2,2'-azobis(2,4-dimethylvaleronitrile) (AMVN) as radical generators. Both water-soluble wheat antioxidant (WWA) and the second lipophilic antioxidant (LWA2) fractions were able to inhibit oxygen diffusion-concentration product induced by either AAPH or AMVN. The first lipophilic wheat antioxidant (LWA1) fraction only showed antioxidant activity in yolk PC liposomes with AAPH as the radical initiator but had pro-oxidant activity under other testing conditions. Both liposome composition and radical initiator altered the antioxidative properties of WWA, LWA1, and LWA2. WWA also showed the strongest DPPH(*) scavenging capacity on a per grain weight basis. HPLC analysis showed that WWA had a much higher level of total phenolic acids, which may partially explain their antioxidant properties. In addition, wheat antioxidants significantly down-regulated the mRNA of HMG-CoA reductase, the key enzyme for cholesterol biosynthesis, and up-regulated the mRNA of cholesterol 7alpha-hydroxylase (CYP7A1), the key enzyme for cholesterol metabolism, in primary rat hepatocytes. These data indicated the potential of wheat antioxidants in reducing the risk of atherosclerosis through multimechanisms.

Respiratory infection recurrence and passive smoking in early atherosclerosis in children and adolescents with type 1 diabetes

BACKGROUND

Optimal glucose control in juvenile type 1 diabetes mellitus is necessary but not sufficient to reduce the burden of cardiovascular events in later life. This emphasizes the importance of searching for other possible risk factors associated with diabetes. We investigated whether recurrent episodes of acute respiratory infections and exposure to tobacco smoke could influence vascular phenotypes for early atherosclerosis in children and adolescents with type 1 diabetes.

MATERIALS AND METHODS

Common carotid artery elasticity and intima-media thickness along with circulating markers of lipid, inflammatory and glycaemic profiles were investigated in up to 98 children and adolescents with type 1 diabetes. The number of clinically manifest acute respiratory tract infections (RTI) during the past year, and the degree of exposure to environmental tobacco smoke (ETS), were assessed by separate questionnaires.

RESULTS

Carotid artery compliance (CAC) was decreased in patients with high (>or= 4/year; n = 22) recurrence of RTI compared to the remaining patients (n = 40; P < 0.05). In a multivariate analysis, the number of RTI during the past year and HbA(1C) were independently associated with decreased CAC (P < 0.05 for both). The inverse relationship between RTI recurrence and CAC was strengthened by frequent exposure to ETS.

CONCLUSIONS

High recurrence of respiratory infections in young type 1 diabetics is associated with increased stiffening of the carotid artery particularly in those often exposed to tobacco smoke.

Human cytomegalovirus latent infection of myeloid cells directs monocyte migration by up-regulating monocyte chemotactic protein-1

Following primary infection, human cytomegalovirus (HCMV) establishes a latent infection in hematopoietic cells from which it reactivates to cause serious disease in immunosuppressed patients such as allograft recipients. HCMV is a common cause of disease in newborns and transplant patients and has also been linked with vascular diseases such as primary and post-transplant arteriosclerosis. A major factor in the pathogenesis of vascular disease is the CC chemokine MCP-1. In this study, we demonstrate that granulocyte macrophage progenitors (GMPs) latently infected with HCMV significantly increased expression of MCP-1 and that this phenotype was dependent on infection with viable virus. Inhibitors of a subset of G(alpha) proteins and PI3K inhibited the up-regulation of MCP-1 in latently infected cultures, suggesting that the mechanism underlying this phenotype involves signaling through a G-protein coupled receptor. In GMPs infected with the low passage viral strain Toledo, up-regulated MCP-1 was restricted to a subset of myeloid progenitor cells expressing CD33, HLA-DR, and CD14 but not CD1a, CD15, or CD16, and the increase in MCP-1 was sufficient to enhance migration of CD14(+) monocytes to latently infected cells. Latent HCMV-mediated up-regulation of MCP-1 provides a mechanism by which HCMV may contribute to vascular disease during the latent phase of infection or facilitate dissemination of virus upon reactivation from latency.

Enterovirus in arteriosclerosis: A pilot study

BACKGROUND

Various pathogens have been suspected to play a role in the initiation or amplification of the atherosclerotic lesions. Both experimental and epidemiological arguments plead for a possible role of enterovirus in this process.

OBJECTIVE

To determine the prevalence of enterovirus genome in atherosclerotic plaques, in comparison with Chlamydia pneumoniae, human cytomegalovirus (hCMV) and herpes simplex virus.

STUDY DESIGN

Pilot study on 18 patients who underwent artery resection. Five artery samples were tested for each patient and each pathogen by using PCR techniques whose sensitivity was evaluated for this kind of specimen. The quality of the extraction step was assessed by amplification of a fragment of the human aldolase A gene.

RESULTS

The genome of at least one infectious agent was detected in artery samples from 7 of the 18 patients (38.9%). In all cases, only one of the five aliquots was found positive; a confirmation was done by sequencing the PCR product. With regards to enterovirus, four patients (22.2%) were detected positive (one of them being also positive for hCMV).

CONCLUSIONS

These results suggest that small amounts of enterovirus genome are commonly found in lesions of patients with advanced arteriosclerosis. Further studies are needed to evaluate the clinical significance of this association.

No detectable Chlamydia pneumoniae and cytomegalovirus DNA in leukocytes in subjects with echolucent and echogenic carotid artery plaques

BACKGROUND

Controversy exists whether persistent Chlamydia pneumoniae or cytomegalovirus infections cause initiation or progression of atherosclerosis. C. pneumoniae DNA in peripheral blood mononuclear cells (PBMC) has been proposed to be a more reliable marker of cardiovascular risk than are C. pneumoniae antibodies. Reported prevalences of C. pneumoniae DNA among cardiovascular patients vary greatly, indicating methodological limitations. There is an increasing concern that published results may have been biased by extensive use of less specific polymerase chain reaction (PCR) technology.

METHODS

C. pneumoniae DNA and cytomegalovirus DNA were determined by probe-based real-time PCR technology in PBMCs among subjects with echolucent (n=29) or echogenic (n=28) carotid artery plaques, and in controls without carotid plaques (n=38), all recruited from a population-based study. Samples were examined in multiple repeats with PCR assays targeting two different sequences of the genome for both microorganisms.

RESULTS AND CONCLUSION

IgG seropositivity was frequent in all three groups, confirming previous exposure, but C. pneumoniae DNA or cytomegalovirus DNA was not detected in a single PBMC sample by means of probe-based, highly sensitive, and specific real-time PCR assays. Our results indicate that persistent C. pneumoniae or CMV infection is not a common phenomenon in subjects with carotid atherosclerosis.

Periodontal infections and cardiovascular disease: the heart of the matter

BACKGROUND

Oral infection models have emerged as useful tools to study the hypothesis that infection is a cardiovascular disease (CVD) risk factor. Periodontal infections are a leading culprit, with studies reporting associations between periodontal disease and CVD. The results, however, have varied, and it often is unclear what conclusions can be drawn from these data.

SUMMARY

An association exists between periodontal disease and CVD. It is unknown, however, whether this relationship is causal or coincidental. Early studies predominantly used nonspecific clinical and radiographic definitions of periodontal disease as surrogates for infectious exposure. While most studies demonstrated positive associations between periodontal disease and CVD, not all studies were positive, and substantial variations in results were evident. More recent studies have enhanced the specificity of infectious exposure definitions by measuring systemic antibodies to selected periodontal pathogens or by directly measuring and quantifying oral microbiota from subgingival dental plaque. Results from these studies have shown positive associations between periodontal disease and CVD.

CONCLUSIONS

Evidence continues to support an association among periodontal infections, atherosclerosis and vascular disease. Ongoing observational and focused pilot intervention studies may inform the design of large-scale clinical intervention studies. Recommending periodontal treatment for the prevention of atherosclerotic CVD is not warranted based on scientific evidence. Periodontal treatment must be recommended on the basis of the value of its benefits for the oral health of patients, recognizing that patients are not healthy without good oral health. However, the emergence of periodontal infections as a potential risk factor for CVD is leading to a convergence in oral and medical care that can only benefit the patients and public health.

A role for archaeal organisms in development of atherosclerotic vulnerable plaques and myxoid matrices

PURPOSE

Vulnerable plaques are characterized by a myxoid matrix, necrotic lipidic core, reactive oxygen species, and high levels of microorganisms. Aerobic microbes such as Chlamydophila pneumoniae and Mycoplasma pneumoniae usually do not survive in oxidative stress media. Archaea are anaerobic microbes with powerful anti-oxidative enzymes that allow detoxification of free radicals whose presence might favor the survival of aerobic microorganisms. We searched for archaeal organisms in vulnerable plaques, and possible associations with myxoid matrix, chlamydia, and mycoplasma bodies.

METHODS

Twenty-nine tissue samples from 13 coronary artherectomies from large excentric ostial or bifurcational lesions were studied using optical and electron microscopy. Infectious agents compatible with archaea, chlamydia, and mycoplasma were semiquantified using electron micrographs and correlated with the amounts of fibromuscular tissue, myxoid matrix, and foam cells, as determined from semi-thin sections. Six of the cases were also submitted to polymerase chain reaction with archaeal primers.

RESULTS

All 13 specimens showed archaeal-compatible structures and chlamydial and mycoplasmal bodies in at least 1 sample. There was a positive correlation between extent of the of myxoid matrix and archaeal bodies (r = 0.44, P = 0.02); between archaeal and mycoplasmal bodies (r = 0.41, P = 0.03), and between chlamydial bodies and foam cells (r = 0.42; P = 0.03). The PCR test was positive for archaeal DNA in 4 of the 6 fragments.

DISCUSSION

DNA and forms suggestive of archaea are present in vulnerable plaques and may have a fundamental role in the proliferation of mycoplasma and chlamydia. This seems to be the first description of apparently pathogenic archaea in human internal organ lesions.

Infectious Agents, Inflammation, and Growth Factors: How Do They Interact in the Progression or Stabilization of Mild Human Atherosclerotic Lesions?

Advanced complicated atherosclerotic lesions have been related to many factors, including inflammation, infectious agents, and growth factors. Mycoplasma pneumoniae (MP) and Chlamydia pneumoniae (CP), inflammation, and growth factors have been associated with severe atherosclerotic lesions in necropsy material in recent work at our lab. The present study intends to clarify the pathogenesis of atherosclerosis, analyzing which of these elements (macrophages, MP, CP, lymphocytes, and growth factors) are associated with initial development of atherosclerotic lesions, discriminating elements related to stabilization of the plaque versus those related to subendothelial active accumulation of macrophages in living patients. Surgical ascending aorta fragments presenting mild atherosclerotic lesions from 30 coronary atherosclerotic patients were immunohistochemically quantified regarding CP, MP, T cells (CD4, CD8), B cells (CD20), macrophages (CD68), and growth factors [platelet-derived growth factor A (PDGF-A), PDGF-B, transforming growth factor-beta (TGF-beta), granulocyte-macrophage colony-stimulating factor (GM-CSF)]. Cases were grouped according to the presence or not of active accumulation of macrophages at the subendothelium that indicates atheroma in development: group I (GI) fragments with <4 CD68+ cells/x400 field, in normal distribution (mean 1.8 +/- 1) representing stable atherosclerotic mild lesion, and GII fragments presenting >or=4 CD68+ cells/x400 field, in a non-normal distribution, mean (8.9 +/- 4.8, atheromas in progress), which was followed by increased number of lymphocytes. The median number in GI was significantly lower than that in GII: CD4 T (2.5 vs. 7.7), CD8 T (1.0 vs. 5.5), and CD20 B (1.5 vs. 5.5) cells/x400 field, p < 0.001. Percentage area positive for CP antigens was significantly lower in GI than in GII: 1.0 vs. 9.2, p < 0.001. There was a higher percentage area occupied by MP than CP in both GI and GII (7.8 vs. 13.8). There was no difference regarding mean number of growth factor-positive cells/x400 field: PDGF-A, 1.4 vs. 3.9; PDGF-B, 3.4 vs. 5.7; TGF-beta, 0.9 vs. 2.2; and GM-CSF, 2.0 vs. 2.2. Considering all cases, a positive correlation was seen between inflammatory cells and CP+ cells (r > 0.5 and p < 0.01). Growth factors did not correlate with inflammatory cells, CP, or MP and were usually seen in smooth muscle cell and fibrotic areas. Study of initial atherosclerotic lesions showed that MP is present in both kinds of lesion: stable and active subendothelial accumulation of macrophages. Stabilization was related to proportional increase of both infectious agents, which were also related to increased amount of PDGF-A and PDGF-B. Active macrophage accumulation lesions were related to higher elevation in CP concentration at subendothelial regions, in association with B cells, but not of MP and growth factors. MP and CP, inflammation, and growth factors, which were already described in severe atherosclerotic lesions in necropsy material, are also present in mild lesions in living patients, strongly favoring a pathogenetic role for these bacteria in the pathogenesis of atherosclerosis. Predominance of CP in relation to MP may favor progression of the plaque, which is associated with increased B-cell proliferation. PDGF-A and PDGF-B are associated with plaque stability, at least in arterial segments not prone for development of complicated lesions.