The role of infection in restenosis and atherosclerosis: focus on cytomegalovirus

Gut Microbiota Modulation as a Novel Therapeutic Strategy in Cardiometabolic Diseases

The human gut harbors microbial ecology that is in a symbiotic relationship with its host and has a vital function in keeping host homeostasis. Inimical alterations in the composition of gut microbiota, known as gut dysbiosis, have been associated with cardiometabolic diseases. Studies have revealed the variation in gut microbiota composition in healthy individuals as compared to the composition of those with cardiometabolic diseases. Perturbation of host-microbial interaction attenuates physiological processes and may incite several cardiometabolic disease pathways. This imbalance contributes to cardiometabolic diseases via metabolism-independent and metabolite-dependent pathways. The aim of this review was to elucidate studies that have demonstrated the complex relationship between the intestinal microbiota as well as their metabolites and the development/progression of cardiometabolic diseases. Furthermore, we systematically itemized the potential therapeutic approaches for cardiometabolic diseases that target gut microbiota and/or their metabolites by following the pathophysiological pathways of disease development. These approaches include the use of diet, prebiotics, and probiotics. With the exposition of the link between gut microbiota and cardiometabolic diseases, the human gut microbiota therefore becomes a potential therapeutic target in the development of novel cardiometabolic agents.

Gut Microbiota and Cardiovascular Disease

Fecal microbial community changes are associated with numerous disease states, including cardiovascular disease (CVD). However, such data are merely associative. A causal contribution for gut microbiota in CVD has been further supported by a multitude of more direct experimental evidence. Indeed, gut microbiota transplantation studies, specific gut microbiota-dependent pathways, and downstream metabolites have all been shown to influence host metabolism and CVD, sometimes through specific identified host receptors. Multiple metaorganismal pathways (involving both microbe and host) both impact CVD in animal models and show striking clinical associations in human studies. For example, trimethylamine N-oxide and, more recently, phenylacetylglutamine are gut microbiota-dependent metabolites whose blood levels are associated with incident CVD risks in large-scale clinical studies. Importantly, a causal link to CVD for these and other specific gut microbial metabolites/pathways has been shown through numerous mechanistic animal model studies. Phenylacetylglutamine, for example, was recently shown to promote adverse cardiovascular phenotypes in the host via interaction with multiple ARs (adrenergic receptors)-a class of key receptors that regulate cardiovascular homeostasis. In this review, we summarize recent advances of microbiome research in CVD and related cardiometabolic phenotypes that have helped to move the field forward from associative to causative results. We focus on microbiota and metaorganismal compounds/pathways, with specific attention paid to short-chain fatty acids, secondary bile acids, trimethylamine N-oxide, and phenylacetylglutamine. We also discuss novel therapeutic strategies for directly targeting the gut microbiome to improve cardiovascular outcomes.

Antiviral anticoagulation

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel envelope virus that causes coronavirus disease 2019 (COVID-19). Hallmarks of COVID-19 are a puzzling form of thrombophilia that has elevated D-dimer but only modest effects on other parameters of coagulopathy. This is combined with severe inflammation, often leading to acute respiratory distress and possible lethality. Coagulopathy and inflammation are interconnected by the transmembrane receptor, tissue factor (TF), which initiates blood clotting as a cofactor for factor VIIa (FVIIa)-mediated factor Xa (FXa) generation. TF also functions from within the nascent TF/FVIIa/FXa complex to trigger profound changes via protease-activated receptors (PARs) in many cell types, including SARS-CoV-2-trophic cells. Therefore, aberrant expression of TF may be the underlying basis of COVID-19 symptoms. Evidence suggests a correlation between infection with many virus types and development of clotting-related symptoms, ranging from heart disease to bleeding, depending on the virus. Since numerous cell types express TF and can act as sites for virus replication, a model envelope virus, herpes simplex virus type 1 (HSV1), has been used to investigate the uptake of TF into the envelope. Indeed, HSV1 and other viruses harbor surface TF antigen, which retains clotting and PAR signaling function. Strikingly, envelope TF is essential for HSV1 infection in mice, and the FXa-directed oral anticoagulant apixaban had remarkable antiviral efficacy. SARS-CoV-2 replicates in TF-bearing epithelial and endothelial cells and may stimulate and integrate host cell TF, like HSV1 and other known coagulopathic viruses. Combined with this possibility, the features of COVID-19 suggest that it is a TFopathy, and the TF/FVIIa/FXa complex is a feasible therapeutic target.

Venous Thrombosis Secondary to Acute Cytomegalovirus Infection in an Immunocompetent Host: Consideration for New Screening Guidelines

Serious thrombotic complications associated with an acute cytomegalovirus (CMV) infection in immunocompromised and immunocompetent patients are becoming increasingly recognized. While typically asymptomatic and self-limiting, an acute CMV infection appears to demonstrate a rare propensity for a vascular thrombosis, such as deep vein thrombosis (DVT), thrombophlebitis, and pulmonary embolism (PE). It remains unclear whether other predisposing factors play a role in its pathogenesis. We report the case of a young, immunocompetent male with extensive lower extremity DVT who was coincidentally found to be CMV-immunoglobulin M (IgM) seropositive. In light of the increasing prevalence of CMV-associated thrombotic events, we reviewed the current literature on its incidence, pathophysiology, clinical features, and thrombophilia screening to consider the possibility of CMV seropositivity as an independent risk factor for vascular events. This may have repercussions for screening guidelines and preventive strategies in those with active CMV infection.

Cytomegalovirus and HIV: A Dangerous Pas de Deux

Human immunodeficiency virus (HIV)-infected adults who take stable antiretroviral therapy (ART) are at risk for early onset of age-related diseases. This is likely due to a complex interaction between traditional risk factors, HIV infection itself, and other factors, such as underlying immune dysfunction and persistent inflammation. HIV disrupts the balance between the host and coinfecting microbes, worsening control of these potential pathogens. For example, HIV-infected adults are more likely than the general population to have subclinical bursts of cytomegalovirus (CMV) replication at mucosal sites. Production of antigens can activate the immune system and stimulate HIV replication, and it could contribute to the pathogenesis of adverse outcomes of aging, like cardiovascular disease and neurocognitive impairment. Further investigation of the relationships between CMV, immune dysfunction, and unsuccessful aging during chronic HIV infection is warranted.

Cytomegalovirus infection in immunosuppressed patients after kidney transplantation

The first kidney transplantation was performed in 1951 and ever since then living donor transplantation became a more and more important solution for patients with end-stage renal disease (ESRD).

Renal transplantation is a life-saving procedure. Morbidity and mortality on waiting-lists are strongly correlated with the time of dialysis and end-stage renal disease is one of the most important causes of death; this is the reason why transplantation has to be performed as soon as possible in order to reduce the time of dialysis.

Once the transplantation is performed, a number of complications may occur in post-transplant evolution, the most important of which is rejection.

The rejection may appear through several mechanisms, but one of the most frequent causes of rejection is cytomegalovirus (CMV) infection. It is very important to have a precocious and fast diagnosis of CMV infection in order to maintain the functionality and survival of the graft. PP65 CMV antigenemia has proven its effectiveness in detecting and monitoring the CMV infection in transplanted patients.

In the laboratory of the Clinical Institute of Urology and Renal Transplantation (ICUTR) of Cluj Napoca the CMV infection is evidenced by two methods: PP65antigenemia and IgM antibody identification by chemiluminiscence.

Toll-like receptors mediating vascular malfunction: Lessons from receptor subtypes

Toll-like receptors (TLR) are a subfamily of pattern recognition receptors (PRR) implicated in a variety of vascular abnormalities. However, the pathophysiological role and the interplay between different TLR-mediated innate and adaptive immune responses during the development of vascular diseases remain largely unspecified. TLR are widely distributed in both immune and nonimmune cells in the blood vessel wall. The expressions and locations of TLR are dynamically regulated in response to distinct molecular patterns derived from pathogens or damaged host cells. As a result, the outcome of TLR signaling is agonist- and cell type-dependent. A better understanding of discrete TLR signaling pathways in the vasculature will provide unprecedented opportunities for the discovery of novel therapies in many inflammatory vascular diseases. The present brief review discusses the role of individual TLR in controlling cellular functions of the vascular system, by focusing on the inflammatory responses within the blood vessel wall which contribute to the development of hypertension and atherosclerosis.

The probable role of cytomegalovirus in acute myocardial infarction

BACKGROUND

Coronary artery disease (CAD) is the most common cause of death worldwide and many studies have been performed on reduction of its prevalence.

OBJECTIVES

This case control study was designed to investigate the presence of Cytomegaloviruses, Chlamydia pneumoniae and Helicobacter pylori in atherosclerotic plaques of cadaveric coronary endothelium of patients with and without acute myocardial infarction.

PATIENTS AND METHODS

Sixty cadavers in two equal groups were analyzed. Acute myocardial infarction group included cadavers with acute myocardial infarction and atherosclerotic plaque. The non- acute myocardial infarction group included those with innocent atherosclerotic plaques in autopsy, expired due to other causes. Specimens from coronary vessels' atherosclerotic plaque were taken and studied by polymerase chain reaction for Cytomegaloviruses, C. pneumoniae and H. pylori.

RESULTS

Cadavers of 26 males and 34 females underwent autopsy procedures. Their mean age at the time of death was 48.17 ± 18.74 years. Unknown causes (20%), hanging (20%), head trauma (16.7%) and multiple traumas (13.3%) were the most common causes of death in the non- acute myocardial infarction group. PCR test results were negative for C. pneumoniae and H. pylori in all cadavers of both groups. Nine cadavers from the acute myocardial infarction group and one from the non- acute myocardial infarction group showed positive PCR results for Cytomegaloviruses (30% and 3.33%, respectively). There was a significant difference between the two groups regarding Cytomegaloviruses positivity in coronary artery plaques (P < 0.01, odd ratio: 12.42, 95% CI: 10.46 to 15.73).

CONCLUSIONS

A significant proportion of coronary atherosclerotic plaques in cadavers with confirmed acute myocardial infarction were detected to be infected with Cytomegaloviruses while no infections of C. pneumoniae and H. pylori were detected.Coronary artery disease (CAD) is the most common cause of death worldwide and many studies have been performed on reduction of its prevalence.

Sirolimus and cardiovascular disease risk in liver transplantation

BACKGROUND

Two adverse effects of sirolimus are hypertriglyceridemia and hypercholesterolemia. These elevated levels often lead clinicians to discontinue the sirolimus from concerns of an increased cardiovascular disease (CVD) risk; however, evidence suggests that sirolimus might be cardioprotective. There are no published reports of sirolimus CVD in liver transplantation.

METHODS

We reviewed all 1812 liver recipients who underwent transplantation from 1998 to 2010, identifying a cohort using sirolimus as part of the initial immunosuppression (SRL Cohort) and a control group of the remaining patients from this period where SRL was never given (Non-SRL Control). A prospectively maintained database identified all episodes of myocardial infarction (MI), congestive heart failure (CHF), abdominal aortic aneurysm (AAA), and cerebrovascular accident and tracked triglyceride, high-density and low-density lipoproteins, and total cholesterol levels. A Framingham Risk Model calculated the predicted 10-year risk of CVD for both groups.

RESULTS

The SRL Cohort (n=406) is older, more predominantly male, with more pretransplantation hypertension and diabetes and posttransplantation hypertension compared to Non-SRL Controls (n=1005). The SRL Cohort has significantly higher triglyceride, low-density lipoprotein, and cholesterol levels at 6 months and 1 year. There is no difference in MI incidence in the SRL Cohort (1.0% vs. 1.2%) and no difference in AAA, cerebrovascular accident, and CHF. The Framingham Risk Model predicts that the SRL Cohort should have almost double the 10-year risk of CVD compared to the Non-SRL Control (11% vs. 6%).

CONCLUSIONS

Sirolimus causes hypertriglyceridemia and hypercholesterolemia, but it does not increase the incidence of MI or other CVDs. Considering the SRL Cohort has more cardiac risk factors and nearly double 10-year predicted CVD risk, the fact that the CVD incidence is similar suggests that sirolimus is in fact cardioprotective.

The gut microbiota, environment and diseases of modern society

The human gut microbiota is a complex community that provides important metabolic functions to the host. Consequently, alterations in the gut microbiota have been associated with the pathogenesis of several human diseases associated with a disturbance in metabolism, particularly those that have been increasing in incidence over the last several decades including obesity, diabetes and atherosclerosis. In this review, we explore how advances in deep DNA sequencing technology have provided us a greater understanding of the factors that influence that composition of the gut microbiota and its possible links to the pathogenesis of these diseases.

Human cytomegalovirus-specific T-cell immune reconstitution in preemptively treated heart transplant recipients identifies subjects at critical risk for infection

Human cytomegalovirus (CMV) infection represents a major threat for heart transplant recipients (HTXs). CMV-specific T cells effectively control virus infection, and thus, assessment of antiviral immune recovery may have clinical utility in identifying HTXs at risk of infection. In this study, 10 CMV-seropositive (R(+)) pretransplant patients and 48 preemptively treated R(+) HTXs were examined before and after 100 days posttransplant. Preemptive treatment is supposed to favor the immune recovery. CMV DNAemia and gamma interferon enzyme-linked immunosorbent spot (ELISPOT) assay were employed to assess the viremia and immune reconstitution. HTXs could be categorized into three groups characterized by high (>100), medium (50 to 100), and low (<50) spot levels. Early-identified high responders efficiently controlled the infection and also maintained high immunity levels after 100 days after transplant. No episodes of grade ≥2R rejection occurred in the high responders. Midresponders were identified as a group with heterogeneous trends of immune reconstitution. Low responders were 41% and 21% of HTXs before and after 100 days posttransplant, respectively. Low responders were associated with a higher incidence of infection. The effect of viremia on immune recovery was investigated: a statistically significant inverse correlation between magnitude of viremia and immune recovery emerged; in particular, each 10-fold increase in viremia (>4 log(10) DNAemia/ml) was associated with a 36% decrease of the ELISPOT assay spot levels. All episodes of high viremia (>4 log(10) DNAemia/ml) occurred from 1 to 60 days after transplant. Thus, the concomitant evaluation of viremia and CMV immune reconstitution has clinical utility in identifying HTXs at risk of infection and may represent a helpful guide in making therapeutic choices.

Intestinal microbiota determine severity of myocardial infarction in rats

Signals from the intestinal microbiota are important for normal host physiology; alteration of the microbiota (dysbiosis) is associated with multiple disease states. We determined the effect of antibiotic-induced intestinal dysbiosis on circulating cytokine levels and severity of ischemia/reperfusion injury in the heart. Treatment of Dahl S rats with a minimally absorbed antibiotic vancomycin, in the drinking water, decreased circulating leptin levels by 38%, resulted in smaller myocardial infarcts (27% reduction), and improved recovery of postischemic mechanical function (35%) as compared with untreated controls. Vancomycin altered the abundance of intestinal bacteria and fungi, measured by 16S and 18S ribosomal DNA quantity. Pretreatment with leptin (0.12 μg/kg i.v.) 24 h before ischemia/reperfusion abolished cardioprotection produced by vancomycin treatment. Dahl S rats fed the commercially available probiotic product Goodbelly, which contains the leptin-suppressing bacteria Lactobacillus plantarum 299v, also resulted in decreased circulating leptin levels by 41%, smaller myocardial infarcts (29% reduction), and greater recovery of postischemic mechanical function (23%). Pretreatment with leptin (0.12 μg/kg i.v.) abolished cardioprotection produced by Goodbelly. This proof-of-concept study is the first to identify a mechanistic link between changes in intestinal microbiota and myocardial infarction and demonstrates that a probiotic supplement can reduce myocardial infarct size.

Gut flora metabolism of phosphatidylcholine promotes cardiovascular disease

Metabolomics studies hold promise for discovery of pathways linked to disease processes. Cardiovascular disease (CVD) represents the leading cause of death and morbidity worldwide. A metabolomics approach was used to generate unbiased small molecule metabolic profiles in plasma that predict risk for CVD. Three metabolites of the dietary lipid phosphatidylcholine, namely choline, trimethylamine N-oxide (TMAO), and betaine, were identified and then shown to predict risk for CVD in an independent large clinical cohort. Dietary supplementation of mice with choline, TMAO or betaine promoted up-regulation of multiple macrophage scavenger receptors linked to atherosclerosis, and supplementation with choline or TMAO promoted atherosclerosis. Studies using germ-free mice confirmed a critical role for dietary choline and gut flora in TMAO production, augmented macrophage cholesterol accumulation and foam cell formation. Suppression of intestinal microflora in atherosclerosis-prone mice inhibited dietary choline-enhanced atherosclerosis. Genetic variations controlling expression of flavin monooxygenases (FMOs), an enzymatic source of TMAO, segregated with atherosclerosis in hyperlipidemic mice. Discovery of a relationship between gut flora-dependent metabolism of dietary phosphatidylcholine and CVD pathogenesis provides opportunities for development of both novel diagnostic tests and therapeutic approaches for atherosclerotic heart disease.

Research on Psychoneuroimmunology: Does Stress Influence Immunity and Cause Coronary Artery Disease?

This review addresses the importance of psychoneuroimmunology (PNI) studies in understanding the role of acute and chronic psychological stressors on the immune system and development of coronary artery disease (CAD). Firstly, it illustrates how psychological stressors change endothelial function and lead to chemotaxis. Secondly, acute psychological stressors lead to leukocytosis, increased natural killer cell cytotoxicity and reduced proliferative response to mitogens while chronic psychological stressors may lead to adverse health effects. This will result in changes in cardiovascular function and development of CAD. Thirdly, acute and chronic psychological stressors will increase haemostatic factors and acute phase proteins, possibly leading to thrombus formation and myocardial infarction. The evidence for the effects of acute and chronic psychological stress on the onset and progression of CAD is consistent and convincing. This paper also highlights potential research areas and implications of early detection of immunological changes and cardiovascular risk in people under high psychological stress. Key words: Cardiovascular, Inflammation, Psychoneuroimmunology, Stress

Antitreponemal antibodies leading to autoantibody production and protection from atherosclerosis in Kitavans from Papua New Guinea

The objective of our study was to determine the prevalence of anti-infectious agent antibodies and autoantibodies in a unique non-Westernized population from Kitava, Papua New Guinea (PNG), compared to Western populations. We matched 120 serum samples from Kitavans with 437 samples from four healthy control groups. Sera were tested for the presence of anti-infectious agent antibodies (treponema, toxoplsmosis, Epstein-Barr virus, cytomegalovirus, rubella) and autoantiobodies [anti-double-stranded (ds)DNA, anti-chromatin, anti-ribonucleoprotein (RNP), anti-SSB, anti-SSA, anti-Scl-70, anti-Smith, anti-centromer, anti-SmRNP, anti-Jo-1, and anti-ribosomal-P] using the Bio-Rad BioPlex 2200. Antitreponemal antibodies were detected in 87% of PNG sera versus 0-6% of controls (P < 0.0001). Anti-dsDNA antibodies were detected in 31% of PNG samples, which was significantly higher than in three of the control groups (<10%). The outstanding high rate of antitreponemal antibodies detected in Kitavans possibly represents prior yaws disease. A low prevalence of cardiovascular disease was previously documented in Kitavans and has been attributed, in addition to their diet, to the high prevalence of natural cardioprotective autoantibodies (the IgM-antiphosphorylcholine antibodies) in this population. Treponemal infection has been shown to induce the appearance of antiphosphorylcholine antibodies. These protective autoantibodies may cross-react with the pathogenic anti-dsDNA antibodies. Thus, it is suggested that infection with treponema is associated with the presence of protective as well as pathogenic autoantibodies.

Highly quantitative serological detection of anti-cytomegalovirus (CMV) antibodies

Background

Human cytomegalovirus infection is associated with a variety of pathological conditions including retinitis, pneumonia, hepatitis and encephalitis that may be transmitted congenitally, horizontally and parenterally and occurs both as a primary infection and as reactivation in immunocompromised individuals. Currently, there is a need for improved quantitative serological tests to document seropositivity with high sensitivity and specificity.

Methods

Here we investigated whether luciferase immunoprecipitation systems (LIPS) would provide a more quantitative and sensitive method for detecting anti-CMV antibodies. Four protein fragments of immunodominant regions of CMV antigens pp150 and pp65 were generated as Renilla luciferase (Ruc) fusion proteins and used in LIPS with two cohorts of CMV positive and negative sera samples previously tested by ELISA.

Results

Analysis of the antibody responses to two of these antigen fragments, pp150-d1 and pp150-d2, revealed geometric mean antibody titers in the first cohort that were 100–1000 fold higher in the CMV positive sera compared to the CMV negative samples (p < 0.0001) and infection status exactly matched the ELISA results for the 46 samples of the first cohort (100% sensitivity and 100% specificity). Two additional antigen fragments, pp65-d1 and pp65-d2 also showed robust antibody titers in some CMV-infected sera and yielded 50% and 96% sensitivity, respectively. Analysis of a second cohort of 70 samples using a mixture of the 4 antigens, which simplifies data collection and analysis, yielded values which correlated well with the sum of the values from the 4 separate tests (r_s = 0.93, p < 0.00001). While comparison of the LIPS results from this second cohort with ELISA showed 100% sensitivity, LIPS detected six additional CMV positive samples that were not detected by ELISA. Heat map analysis revealed that several of the LIPS positive/ELISA negative samples had positive LIPS immunoreactivity with 3–4 of the CMV antigens.

Conclusion

These results suggest that LIPS provides a highly robust and quantitative method for studying anti-CMV antibodies and has the potential to more accurately document CMV infection than standard ELISA.

Aspects of human cytomegalovirus latency and reactivation

Primary infection of healthy individuals with human cytomegalovirus (HCMV) is usually asymptomatic and results in the establishment of a lifelong latent infection of the host. Although no overt HCMV disease is observed in healthy carriers, due to effective immune control, severe clinical symptoms associated with HCMV reactivation are observed in immunocompromised transplant patients and HIV sufferers. Work from a number of laboratories has identified the myeloid lineage as one important site for HCMV latency and reactivation and thus has been the subject of extensive study. Attempts to elucidate the mechanisms controlling viral latency have shown that cellular transcription factors and histone proteins influence HCMV gene expression profoundly and that the type of cellular environment virus encounters upon infection may have a critical role in determining a lytic or latent infection and subsequent reactivation from latency. Furthermore, the identification of a number of viral gene products expressed during latent infection suggests a more active role for HCMV during latency. Defining the role of these viral proteins in latently infected cells will be important for our full understanding of HCMV latency and reactivation in vivo.

The endothelium as a target for infections

The endothelial cells lining vascular and lymphatic vessels are targets of several infectious agents, including viruses and bacteria, that lead to dramatic changes in their functions. Understanding the pathophysiological mechanisms that cause the clinical manifestations of those infections has been advanced through the use of animal models and in vitro systems; however, there are also abundant studies that explore the consequences of endothelial infection in vitro without supporting evidence that endothelial cells are actual in vivo targets of infection in human diseases. This article defines criteria for considering an infection as truly endothelium-targeted and reviews the literature that offers insights into the pathogenesis of human endothelial-target infections.

Inflammation as a risk factor for carotid intimal-medial thickening, a measure of subclinical atherosclerosis in haemodialysis patients: the role of chlamydia and cytomegalovirus infection

OBJECTIVES

Atherosclerotic vascular disease is the most frequent complication seen in haemodialysis (HD) patients. Evidence suggests that inflammation may play a role in the pathogenesis and progression of atherosclerosis. Our aim was to evaluate the causative role of inflammation in atherosclerosis among HD patients.

METHODS

Intima-media thickness (IMT) in carotid arteries was determined in 54 HD patients and 52 controls. Plasma levels of lipids, glucose, albumin and several acute phase proteins, and immunoglobulin G titres against chlamydia and cytomegalovirus were measured in all subjects.

RESULTS

Mean carotid IMT was significantly greater in HD patients than in controls (0.75 mm vs 0.56 mm, P < 0.005). While plasma levels of C-reactive protein (CRP), serum amyloid A (SAA), lipoprotein (a) Lp(a), fibrinogen and ferritin were higher in HD patients, albumin levels were lower. In HD patients, carotid IMT was correlated positively with CRP (R = 0.29, P = 0.019), SAA (R = 0.69, P < 0.001), Lp(a) (R = 0.42, P = 0.001), fibrinogen (R = 0.57, P < 0.001) and chlamydia pneumonia immunoglobulin G titres (R = 0.50, P < 0.001), and negatively with albumin levels (R = -0.33, P = 0.02); there was no relationship between carotid IMT and hypertension, plasma lipid levels and cytomegalovirus. In multivariate regression analysis, these variables still showed a significant relationship with IMT (R(2) = 0.694 and P < 0.001).

CONCLUSION

We conclude that atherosclerotic changes are more common in HD patients than in controls, and that inflammatory processes may play a role in the pathogenesis of atherosclerosis.

The human cytomegalovirus virion possesses an activated casein kinase II that allows for the rapid phosphorylation of the inhibitor of NF-kappaB, IkappaBalpha

We documented that the NF-kappaB signaling pathway was rapidly induced following human cytomegalovirus (HCMV) infection of human fibroblasts and that this induced NF-kappaB activity promoted efficient transactivation of the major immediate-early promoter (MIEP). Previously, we showed that the major HCMV envelope glycoproteins, gB and gH, initiated this NF-kappaB signaling event. However, we also hypothesized that there were additional mechanisms utilized by the virus to rapidly upregulate NF-kappaB. In this light, we specifically hypothesized that the HCMV virion contained IkappaBalpha kinase activity, allowing for direct phosphorylation of IkappaBalpha following virion entry into infected cells. In vitro kinase assays performed on purified HCMV virion extract identified bona fide IkappaBalpha kinase activity in the virion. The enzyme responsible for this kinase activity was identified as casein kinase II (CKII), a cellular serine-threonine protein kinase. CKII activity was necessary for efficient transactivation of the MIEP and IE gene expression. CKII is generally considered to be a constitutively active kinase. We suggest that this molecular characteristic of CKII represents the biologic rationale for the viral capture and utilization of this kinase early after infection. The packaging of CKII into the HCMV virion identifies that diverse molecular mechanisms are utilized by HCMV for rapid NF-kappaB activation. We propose that HCMV possesses multiple pathways to increase NF-kappaB activity to ensure that the correct temporal regulation of NF-kappaB occurs following infection and that sufficient threshold levels of NF-kappaB are reached in the diverse array of cells, including monocytes and endothelial cells, infected in vivo.

Latency and reactivation of human cytomegalovirus

Human cytomegalovirus (HCMV) persists as a subclinical, lifelong infection in the normal human host, maintained at least in part by its carriage in the absence of detectable infectious virus – the hallmark of latent infection. Reactivation from latency in immunocompromised individuals, in contrast, often results in serious disease. Latency and reactivation are defining characteristics of the herpesviruses and key to understanding their biology. However, the precise cellular sites in which HCMV is carried and the mechanisms regulating its latency and reactivation during natural infection remain poorly understood. This review will detail our current knowledge of where HCMV is carried in healthy individuals, which viral genes are expressed upon carriage of the virus and what effect this has on cellular gene expression. It will also address the accumulating evidence suggesting that reactivation of HCMV from latency appears to be linked intrinsically to the differentiation status of the myeloid cell, and how the cellular mechanisms that normally control host gene expression play a critical role in the differential regulation of viral gene expression during latency and reactivation.

In stent restenosis: bane of the stent era

The long term outcome of stent implantation is affected by a process called in stent restenosis (ISR). Multiple contributory factors have been identified, but clear understanding of the overall underlying mechanism remains an enigma. ISR progresses through several different phases and involves numerous cellular and molecular constituents. Platelets and macrophages play a central role via vascular smooth muscle cell migration and proliferation in the intima to produce neointimal hyperplasia, which is pathognomic of ISR. Increased extracellular matrix formation appears to form the bulk of the neointimal hyperplasia tissue. Emerging evidence of the role of inflammatory cytokines and suppressors of cytokine signalling make this an exciting and novel field of antirestenosis research. Activation of Akt pathway triggered by mechanical stretch may also be a contributory factor to ISR formation. Prevention of ISR appears to be a multipronged attack as no therapeutic "magic bullet" exists to block all the processes in one go.

Immune activation following cytomegalovirus infection: More important than direct viral effects in cardiovascular disease?

BACKGROUND

Over the last 30 years multiple micro-organisms have been associated with different types of vascular disease, like atherosclerosis, restenosis or transplant arteriosclerosis. Nonetheless, it is still ambiguous which molecular mechanisms are exactly involved in the exacerbating effect of microbes in these disorders.

OBJECTIVES AND STUDY DESIGN

The present review summarizes sero-epidemiological, in vitro and animal data supporting the role of cytomegalovirus, a member of the herpes virus family, in vascular disease. Additionally, various ways by which the virus can potentially affect the disease will be discussed.

RESULTS

Rodent models as well as in vitro studies suggested that CMV might enhance lesion formation in various ways, like augmentation of the oxLDL uptake, altering monocyte adhesion or increasing the production of pro-inflammatory cytokines. Nevertheless, recent data from our lab and others suggest that alternative mechanisms also may contribute to CMV induced. Inspired by this, we will hypothesise alternative mechanisms by which CMV might affect atherosclerosis.

CONCLUSIONS

Although researchers have tried for many years to unravel the tactics by which micro-organisms, like CMV, aggravate atherosclerosis, so far most suggested mechanisms failed to fully explain both experimental and clinical observations. Therefore, new means to elucidate the observed effects are required.

Acute myocardial infarction and rescue percutaneous transluminal coronary angioplasty in a young HIV-infected patient

We report a case of acute myocardial infarction in an HIV-infected patient without significant coronary artery disease (CAD) risk factors. The patient underwent rescue percutaneous transluminal coronary angioplasty (PTCA), with a successful outcome. We presume a possible pathogenetic role of anti-retroviral therapy and/or direct viral action on ischaemic heart disease progression. We propose that the current approach to management of AIDS-affected patients needs close monitoring for CAD risk factors and symptoms, to improve prognosis and life expectancy.

Cytomegalovirus aggravates intimal hyperplasia in rats by stimulating smooth muscle cell proliferation

Epidemiological and animal studies suggest a role for cytomegalovirus (CMV) in restenosis. Previously, we demonstrated that proliferating smooth muscle cells (SMCs) in the injured arterial wall are particularly susceptible to CMV-induced effects. Therefore, we hypothesised that, depending on the time point of infection after vascular injury, CMV infection may affect cell proliferation either in the media or in the neointima, thereby aggravating the process of restenosis. In the present study, we focused on the individual layers of the arterial wall by evaluating, besides the neointima-to-media ratio, the medial and neointimal area and cellularity in the rat femoral artery. Vascular injury was photochemically induced in rat femoral arteries. Immediately or 14 days thereafter, rats were infected with rat CMV (RCMV) or mock infected. The presence of RCMV in the vascular wall was determined at 3, 5, 14 and 35 days after infection by quantitative real-time PCR. When rats were infected immediately after injury, a significant increase was seen only in the medial but not in the neointimal cross-sectional area. On the other hand, when rats were infected 14 days after the initial injury, a significant increase was only seen in the neointimal area, thereby confirming our hypothesis that RCMV infection primary affects proliferating SMCs. As the mean number of SMCs per microm2 in both cell layers was unchanged despite an increase in cross-sectional area, this implies that RCMV stimulated SMC proliferation. Furthermore, these vascular effects were observed without the virus being abundantly present in the vascular wall, suggesting that inflammatory and immune-mediated responses to RCMV infection are more important in aggravating the response to vascular injury than the virus itself.

The pathogenesis of atherosclerosis

Worldwide, more people die of the complications of atherosclerosis than of any other cause. It is not surprising, therefore, that enormous resources have been devoted to studying the pathogenesis of this condition. This article attempts to summarize present knowledge on the events that take place within the arterial wall during atherogenesis. Classical risk factors are not dealt with as they are the subjects of other parts of this book. First, we deal with the role of endothelial dysfunction and infection in initiating the atherosclerotic lesion. Then we describe the development of the lesion itself, with particular emphasis on the cell types involved and the interactions between them. The next section of the chapter deals with the events leading to thrombotic occlusion of the atherosclerotic vessel, the cause of heart attack and stroke. Finally, we describe the advantages--and limitations--of current animal models as they contribute to our understanding of atherosclerosis and its complications.

CC and CX3C chemokines differentially interact with the N terminus of the human cytomegalovirus-encoded US28 receptor

Human cytomegalovirus (HCMV) is the causative agent of life-threatening systemic diseases in immunocompromised patients as well as a risk factor for vascular pathologies, like atherosclerosis, in immunocompetent individuals. HCMV encodes a G-protein-coupled receptor (GPCR), referred to as US28, that displays homology to the human chemokine receptor CCR1 and binds several chemokines of the CC family as well as the CX3C chemokine fractalkine with high affinity. Most importantly, following HCMV infection, US28 activates several intracellular pathways, either constitutively or in a chemokine-dependent manner. In this study, our goal was to understand the molecular interactions between chemokines and the HCMV-encoded US28 receptor. To achieve this goal, a double approach has been used, consisting in the analysis of both receptor and ligand mutants. This approach has led us to identify several amino acids located in the N terminus of US28 that differentially contribute to the high affinity binding of CC versus CX3C chemokines. Additionally, our results highlight the importance of secondary modifications occurring at US28, such as sulfation, for ligand recognition. Finally, the effects of chemokine dimerization and interaction with glycosaminoglycans (GAGs) on chemokine binding and activation of US28 were investigated as well using CCL4 as model ligand. In line with the two-state model describing chemokine/receptor interaction, we show that an aromatic residue in the N-loop region of CCL4 promotes tight binding to US28, whereas receptor activation depends on the presence of the N terminus of CCL4, as shown previously for CCR5.

Cytomegalovirus and Chlamydia pneumoniae as predictors for adverse events and angina pectoris after percutaneous coronary intervention

BACKGROUND

The aim of our study was to investigate the influence of prior cytomegalovirus (CMV) or Chlamydia pneumoniae (CP) infection on prognosis after percutaneous coronary intervention (PCI).

METHODS

Using the enzyme-linked immunosorbent assay technique preprocedural anti-CMV immunoglobulin G and anti-CP immunoglobulin A (CP IgA), immunoglobulin M, and immunoglobulin G antibodies were measured. Repeat anginal complaints and major adverse clinical events (MACE), including PCI, coronary artery bypass grafting, myocardial infarction, and death, were recorded at 8-month follow-up.

RESULTS

Six hundred consecutive patients were included after successful PCI. Sixty-four percent of the patients were stented. The mean age was 61.6 years, and 68.9% were male. The rate of seropositivity for CP IgA in patients with MACE as compared with patients without MACE was 50.9% versus 35.4% (P =.0276). In patients with repeat anginal complaints, CP IgA seropositivity was 41.6% versus 34.6% in patients without repeat angina (P =.1057). The negative effect of CP on prognosis was confirmed after calculating the odds ratios for MACE (1.9, 95% CI 1.1-3.3). The rates of seropositivity for anti-CMV immunoglobulin G were not significantly different between both groups, although we found an association between infectious burden and repeat angina pectoris (odds ratio 1.8, 95% CI 1.1-3.0).

CONCLUSIONS

We conclude that preprocedural seropositivity of CP IgA is a risk factor for MACE and angina pectoris after PCI. Although no such relation was found for CMV alone, the cumulative infectious burden was also related to these clinical manifestations of restenosis.

Enhanced cytomegalovirus infection in atherosclerotic human blood vessels

Human cytomegalovirus (CMV) is a possible co-factor in atherogenesis and vascular occlusion, but its ability to actively infect medium and large blood vessels is unclear. A vascular explant model was adapted to investigate CMV infection in human coronary artery, internal mammary artery (IMA), and saphenous vein (SV). Vascular explants were inoculated with CMV Towne or low-passage clinical isolate and examined in situ for CMV cytopathic effect and immediate-early and early antigens, as indicators of active infection. At 5 to 7 days after inoculation, we found that CMV Towne actively infected eight of eight different atherosclerotic blood vessel explants (coronary artery, n = 4; SV and IMA grafts, n = 4), whereas it only infected 2 of 14 nonatherosclerotic blood vessel explants (SV, n = 10; IMA, n = 4) (P = 0.001). The CMV clinical isolate actively infected none of six sets of nonatherosclerotic SV explants at 5 to 7 days after inoculation. The active CMV infections involved adventitial and, less frequently, intimal cells. A small subset of infected cells in atherosclerotic tissue expresses the endothelial cell marker CD31. Smooth muscle cells residing in both atherosclerotic and nonatherosclerotic blood vessels were free of active CMV infections even after all vascular tissue layers were exposed to the virus. In contrast, active CMV Towne infection was evident at 2 days after inoculation in smooth muscle cells and endothelial cells previously isolated from the SV tissues. We conclude that active CMV infection is enhanced in atherosclerotic blood vessels compared to atherosclerosis-free vascular equivalents, and this viral activity is restricted to subpopulations of intimal and adventitial cells.

Functional profiling of a human cytomegalovirus genome

Human cytomegalovirus (HCMV), a ubiquitous herpesvirus, causes a lifelong subclinical infection in healthy adults but leads to significant morbidity and mortality in neonates and immunocompromised individuals. Its ability to grow in different cell types is responsible for HCMV-associated diseases, including mental retardation and retinitis, and vascular disorders. To globally assess viral gene function for replication in cells, we determined the genomic sequence of a bacterial artificial chromosome (BAC)-based clone of HCMV Towne strain and used this information to delete each of its 162 unique ORFs and generate a collection of viral mutants. The growth of these mutants in different cultured cells was examined to systematically investigate the necessity of each ORF for replication. Our results showed that 45 ORFs are essential for viral replication in fibroblasts and 117 are nonessential. Some genes were found to be required for viral replication in retinal pigment epithelial cells and microvascular endothelial cells, but not in fibroblasts, indicating their role as tropism factors. Interestingly, several viral mutants grew 10- to 500-fold better than the parental strain in different cell types, suggesting that the deleted ORFs encode replication temperance or repressing functions. Thus, HCMV encodes supportive and suppressive growth regulators for optimizing its replication in human fibroblasts, epithelial, and endothelial cells. Suppression of viral replication by virus-encoded temperance factors represents a novel mechanism for regulating the growth of an animal virus, and may contribute to HCMV's optimal infection of different tissues and successful proliferation among the human population.

Acute cytomegalovirus infection and transient carotid intimal-medial thickening in a young, otherwise healthy woman

Carotid intimal-medial thickening was observed in a 23-year-old woman with acute cytomegalovirus (CMV) infection. The thickening disappeared after her recovery from the infection. As endothelial cells are common targets of CMV, this thickening suggests that CMV infection causes vascular lesions, even in otherwise healthy individuals.

Acute-phase response of human hepatocytes after infection with Chlamydia pneumoniae and cytomegalovirus

BACKGROUND

There is increasing evidence that chronic inflammation plays a pivotal role in the development of atherosclerosis. Whether inflammation is the cause or consequence of vascular damage is unclear. Also, the source of inflammation is unknown, but may well be infection by Cytomegalovirus (CMV) or Chlamydia pneumoniae (C. pneumoniae). Infection of the liver by CMV or C. pneumoniae may induce a general inflammatory reaction contributing to accelerated atherogenesis. In this study we investigated the production of interleukin-6 (IL-6), fibrinogen and plasminogen activator inhibitor-1 (PAI-1) by hepatocytes after infection with CMV or C. pneumoniae.

METHODS

HepG2 cell monolayers were grown to confluence in 48-well tissue culture plates. Hepatocytes were infected with 50 microL or 100 microL of suspension of CMV (10(2.70) TCID50 mL(-1)) and C. pneumoniae (10(4.75) TCID50 mL(-1)). The medium of the inoculated cells was collected every 24 h, from day 1 to day 4, for determination of IL-6, PAI-1 and fibrinogen concentrations.

RESULTS

Fibrinogen production was increased significantly in a dose-dependent manner after infection with CMV (50 microL: P=0.022 and 100 microL: P<0.001) and C. pneumoniae (P=0.012). Cytomegalovirus infection resulted in an increase of IL-6 production compared with uninfected cells (P=0.048). Cytomegalovirus and C. pneumoniae infection did not result in a significantly increase of PAI-1 production by hepatocytes.

CONCLUSION

We conclude that in addition to direct vascular wall infection by C. pneumoniae and CMV, virus-related development of atherosclerosis might also be initiated by chronic liver infection and subsequent production of inflammatory and procoagulant mediators released in the circulation. This may be another pathophysiological link for the observed relation between infections and the development of atherosclerosis.

Is periodontitis associated with an increased risk of coronary heart disease and preterm and/or low birth weight births?

The objective of this systematic review was to determine whether periodontal disease is associated with an increased risk for coronary heart disease (CHD) and preterm and/or low birth weight deliveries (PLBW). A literature search was performed to identify cross-sectional, case-control, and cohort studies as well as clinical trials addressing different aspects of periodontal disease (clinical, microbial, immunological) and clinical outcomes of CHD or PLBW. The periodontitis-CHD association was evaluated in eight cohort, four case-control- and four cross-sectional studies. Meta-analysis was not performed due to the extensive heterogeneity of the studies, particularly with regard to periodontitis measures, which varied from full mouth probing assessments to questionnaires. Percentage-wise, 50% of the cohort studies (4/8), 75% of the case-control studies (3/4) and 50% of the cross-sectional studies (2/4) reported a significant association between clinical measures of periodontitis and CHD (excess risk ranged from 0 to 3.3-fold). The periodontitis-PLBW association was evaluated in one cohort and two case-control studies. The cohort study as well as one of the two case-control studies reported a significant association between periodontitis and PLBW (odds ratios 4.4-7.9). From two additional case-control studies microbiological data could be extracted. Bacteroides forsythus was found to be associated with PLBW in both studies. In conclusion, the evidence linking periodontitis with an increased risk for CHD and PLBW is limited. There is a clear need for new, well designed observational and intervention studies to confirm the thus far observed associations, explore the validity of the associations in diverse populations, establish whether they are causal in nature and determine potential benefits of periodontal intervention in reducing the risk for these conditions.

Vascular thrombosis and acute cytomegalovirus infection in immunocompetent patients: report of 2 cases and literature review

Acute cytomegalovirus (CMV) infection in immunocompetent patients is common worldwide, with seroprevalence rates of 40%-100%, depending on the country, socioeconomic conditions, and the patient's age. Infection is most often asymptomatic, but acute cytomegalovirus infection is occasionally revealed by prolonged fever, cervical lymphadenitis, and arthralgia, and it is more rarely revealed by pneumonia, myocarditis, pericarditis, colitis, and hemolytic anemia. Here, we report 2 cases of acute CMV infection in nonimmunocompromised adults that were complicated by venous thrombosis with pulmonary embolism. We also review previously reported cases of vascular thrombosis and discuss the propensity of CMV to induce vascular damage with associated thrombosis.

Role of IgG-seropositivity to Chlamydia pneumoniae in early thrombotic events after coronary stent placement

AIMS

Since infection of endothelial or smooth muscle cells with Chlamydia pneumoniae increased expression of tissue factor and plasminogen activator inhibitor I (PAI-1), C. pneumoniae might be involved in triggering acute thrombotic events in patients with coronary artery disease. Therefore, we explored a potential relationship between IgG-seropositivity to C. pneumoniae and early thrombotic events after coronary stent placement.

METHODS AND RESULTS

In a prospective randomized placebo-controlled study 1010 patients with successful coronary stent placement received roxithromycin or placebo for 4 weeks after coronary stent placement, which showed no effect of roxithromycin on early thrombotic events, as expected. Venous blood samples were collected from patients immediately before treatment. Plasma was analyzed for C. pneumoniae-specific IgG antibody levels by microimmuno-fluorescence. Thrombotic events were defined as death, non-fatal myocardial infarction, or urgent target vessel reintervention within 30 days after stent placement. We found no significant difference concerning the frequency of early thrombotic events in patients positive or negative for C. pneumoniae-specific antibodies. If patients were stratified according to their antibody levels, again no significant difference in the frequency of thrombotic events was observed.

CONCLUSION

Our findings do not suggest a role of C. pneumoniae in the development of early complications after stent placement.

[Secondary prevention of coronary artery disease. Flu vaccinations and new evidence of the role of infection in acute coronary syndromes]

Recent reports have detected an increase in the number of patients with acute coronary syndromes during the flu season. More recently, case-control studies of patients with prior infarction have shown that flu vaccination significantly reduces the risk of myocardial necrosis and strokes. The World Health Organization recommended flu vaccination for the Southern Hemisphere in the winter of 2001. We evaluated the preventive impact of flu vaccination on subsequent ischemic events in myocardial infarction patients and in subjects undergoing scheduled percutaneous coronary angioplasty. In the first study we included 200 myocardial infarction patients admitted in the first 72 hours and 100 patients scheduled for angioplasty/stent (PCI) without unstable coronary artery disease, prior bypass surgery, angioplasty or tissue necrosis, were included in a prospective, multicenter registry, during the winter season. Infarction patients received standard therapy, and then were randomly allocated in a single-blind manner as a unique intramuscular Influenza vaccination or as controls. Similarly, PCI patients were allocated to either vaccination or control. The first primary outcome -cardiovascular death- occurred within 6 months in 2% of the patients in the vaccinnated group vs 8% of controls (RR: 0.25; 95% CI, 0.07-0.86; p = 0.01). The triple composite end point occurred in 11% of the patients in the vaccinnated group vs 23% of controls (p = 0.009) at 6 months. Although our study is the first to demonstrate lower rates of cardiovascular ischemic events in patients vaccinated against Influenza during the flu season, the modification of flu vaccination recommendations in patients admitted for cardiovascular events merits further study before being considered.

Genetic control of innate immune responses against cytomegalovirus: MCMV meets its match

Cytomegalovirus (CMV) is a widespread pathogen that is responsible for severe disease in immunocompromised individuals and probably, associated with vascular disease in the general population. There is increasing evidence that cells of the innate immune system play a key role in controlling this important pathogen. This is particularly evident in the experimental murine CMV (MCMV) model of infection which has revealed an important role for natural killer (NK) cells in controlling early viral replication after infection with MCMV. In this model, different strains of inbred mice exhibit striking differences in their level of susceptibility to MCMV infection. Genetic studies, performed almost 10 years ago, revealed that this pattern of susceptibility/resistance can be attributed to a single genetic locus termed Cmv1 and recently several groups that have been working on the mapping and identification of Cmv1 have met with success. Interestingly, Cmv1 is allelic to a member of the Ly49 gene family, which encode activating or inhibitory transmembrane receptors present on the surface of NK cells. All Ly49 receptors characterized to date interact with MHC class I molecules on potential target cells, resulting in the accumulation of signals to the NK to either 'kill' or 'ignore' the cell based upon the repertoire of MHC class I molecules expressed. The identification of Cmv1 as Ly49H, a stimulatory member of the Ly49 family, adds an interesting twist to the Ly49 story. Although the ligand of Ly49H is not yet known, there is already compelling evidence that the ligand is upregulated on virally infected cells, resulting in specific activation of Ly49H-expressing NK cells. This review provides an historical perspective of the MCMV infection model from its inception to the discovery of the gene responsible for the phenotype and provides a basis for further experiments aimed at understanding the role of NK cells, in general, and Ly49H, in particular, in mediating resistance to cytomegalovirus.

Has cytomegalovirus infection any role in the development of atherosclerosis?

An interesting aspect of infection with several infectious agents is the possible association with some diseases apparently not associated with infections. One of the most exciting examples of this is the association of cardiovascular diseases with infection involving several different infectious agents. Cytomegalovirus (CMV) is one of the chief candidates that have been studied. Several epidemiologic reports indicate a possible association of various forms of vascular disease with the presence and titer of viral antibodies. Other studies show the presence of virus, viral antigens or nucleic acid in atherosclerotic lesions. Studies in animal models and cell-culture studies present attractive mechanisms by which the virus may play a role in the etiology of these diseases. However, negative results have also been reported, and more research is needed before the final verdict on this exciting question is presented.

Thrombosis associated with cytomegalovirus infection in patients with ANCA-positive vasculitis

Three cases of venous thrombosis with pulmonary embolism in two patients associated with underlying antineutrophil cytoplasmic autoantibody (ANCA)-positive vasculitis and reactivated cytomegalovirus (CMV) infection are described. In vitro studies previously have shown that infection of endothelium with CMV increases the release of procoagulant factors and stimulates the expression of adhesion molecules. Because the endothelial cell plays a pivotal role in maintaining the equilibrium between procoagulant and anticoagulant states, injury by ANCA-positive vasculitis and additional infection with CMV may ignite a local thrombosis easily. Although venous thrombosis is uncommon in CMV infection (eg, in the immunosuppressed state after organ transplantation), the combination of vasculitis and reactivated CMV infection may have contributed to injury of the vessel wall with subsequent development of thrombosis. A better awareness of this association could improve morbidity and may lead to prevention of potentially life-threatening pulmonary embolism. Patients with ANCA-positive vasculitis and CMV infection may profit from prophylactic anticoagulant therapy with heparin or low-molecular-weight heparin.

Inhibition of intimal hyperplasia after balloon injury in rat carotid artery model using cis-element 'decoy' of nuclear factor-kappaB binding site as a novel molecular strategy

The transcription factor, NFkB, plays a pivotal role in the coordinated transactivation of cytokine and adhesion molecule genes involved in atherosclerosis and lesion formation after vascular injury. We hypothesized that synthetic double-stranded DNA with high affinity for NFkB may be introduced as a 'decoy' cis element to bind the transcription factor, and block gene activation, resulting in an effective therapeutic agent for treating intimal hyperplasia. In vivo transfection of NFkB decoy oligodeoxynucleotides (ODN) into balloon-injured rat carotid artery resulted in the inhibition of neointimal formation at 14 days after injury as compared with vessels transfected with scrambled ODN (P < 0.01). It is of importance to note that in the vessels transfected with NFkB decoy ODN, the expression of p53, a pro-apoptotic gene, was upregulated in neointimal area, followed by increased apoptosis at 14 days. In addition, gene expression of ICAM-1 and VCAM-1 was markedly decreased in blood vessels transfected with NFkB decoy ODN compared with scrambled ODN, whereas balloon injury induced ICAM and VCAM expression in the neointimal area. More importantly, the migration of macrophages and T-lymphocytes into the neointima and media was significantly inhibited by NFkB decoy ODN as compared with scrambled ODN. Here, we demonstrated that in vivo transfer of NFkB decoy ODN successfully inhibited neointimal formation after balloon injury, accompanied by (1) induction of apoptosis through p53 upregulation, and (2) inhibition of local inflammatory actions through the downregulation of adhesion molecules. These results suggest that decoy treatment against NFkB provides a new therapeutic strategy to inhibit neointimal hyperplasia after angioplasty.

Role of human cytomegalovirus immediate-early proteins in cell growth control

Human cytomegalovirus (HCMV) is a ubiquitous herpesvirus that has been implicated in several disorders, including an association between HCMV reactivation and the overproliferation of arterial smooth muscle cells observed in restenosis. Although HCMV can mediate a growth-arrest phenotype in infected cells, the virus can also promote an environment conducive to proliferation. Here, we present evidence that the HCMV immediate-early (IE) proteins, IE1-72 and IE2-86, may be responsible for inducing this proliferative environment by altering cell cycle control. We find that expression of either of these IE proteins can alter the cell cycle distribution of randomly cycling cells towards S and G(2)/M phases. Additionally, we find that expression of IE2-86, but not IE1-72, induces quiescent cells into S phase and delays cell cycle exit. In the absence of p53, IE1-72 expression can induce S phase and delay cell cycle exit. We also demonstrate that p53 protein levels increase in fibroblasts following the expression of IE1-72. The observed accumulation of p53 protein in IE1-72-expressing cells may account for the inability of IE1-72 to induce S phase and delay cell cycle exit. Our data suggest that expression of HCMV IE1-72 and IE2-86 is sufficient to alter the cell cycle to generate an environment conducive to proliferation.

Inflammation, depressive symptomtology, and coronary artery disease

OBJECTIVE

Many patients feel exhausted or depressed before the onset of an acute coronary event, but little is known about the origin of these feelings. We tested the hypothesis that the depressive symptomatology is associated with a reactivation of latent viruses and inflammation of a coronary vessel.

METHODS

A blood sample was drawn and a biopsy sample was obtained from the coronary lesion of 15 exhausted and 15 nonexhausted patients treated with directional coronary angioplasty because of severe angina. Blood samples were analyzed to measure antibody titers against Chlamydia pneumoniae, cytomegalovirus, and the cytokines interleukin (IL)-1beta, IL-6, and tumor necrosis factor (TNF)-alpha. The biopsy sample was analyzed for the presence of IL-1beta and TNF-alpha.

RESULTS

Exhausted/depressed patients had higher antibody titers against cytomegalovirus, higher levels of C. pneumoniae immunoglobulin G, and higher levels of IL-1beta and TNF-alpha. No associations between the mental state of a patient and cytokine mRNA in the biopsy sample were found.

CONCLUSIONS

The findings indicate that the mental state of angioplasty patients is positively associated with serological markers of inflammation. It remains to be seen whether the inflammation causes feelings of exhaustion, whether exhaustion and depression set the stage for inflammation, or whether existing feelings of exhaustion are amplified by the inflammation.

Effect of prior exposure to Chlamydia pneumoniae, Helicobacter pylori, or cytomegalovirus on the degree of inflammation and one-year prognosis of patients with unstable angina pectoris or non-Q-wave acute myocardial infarction

Inflammation and chronic infections may be important features in the pathogenesis of acute coronary syndromes. We describe 6 systemic markers of inflammation in patients with unstable angina or non-Q-wave myocardial infarction and the relations between these markers, seropositivity to chronic infections, and prognosis. C-reactive protein (CRP), serum amyloid A protein (SAA), fibrinogen, interleukin-6 (IL-6), neopterin, procalcitonin, and serum antibody levels to Chlamydia pneumoniae, Helicobacter pylori, and cytomegalovirus were measured on admission and 48 hours later. One-year clinical follow-up was performed. Plasma levels of acute phase reactants were all elevated on admission and increased further at 48 hours: CRP from 10.1 +/- 2.1 mg/L at baseline to 26.6 +/- 5.1 mg/L at 48 hours (p <0.001); SAA from 27.3 +/- 8.5 to 93.1 +/- 23.2 mg/dl (p <0.005); fibrinogen from 3.2 +/- 0.1 to 3.8 +/- 0.1 g/L (p <0.0001); whereas initial high levels of IL-6 tended also to increase from 9.8 +/- 2 to 15.3 +/- 3.1 pg/ml (p = NS). In contrast, neopterin and procalcitonin remained unchanged. We found no association between levels of each inflammatory marker and the serologic status. Furthermore, levels of inflammatory proteins in patients seronegative to all 3 agents were comparable to those of patients seropositive to 2 or 3 infectious agents. The composite end points of death, myocardial infarction, recurrent angina, or revascularization at 1-year follow-up did not differ according to the serologic status. Thus, in patients with acute coronary syndromes, the acute phase proteins increased over the first 2 days of hospitalization. This initial inflammatory reaction as well as the 1-year clinical outcome did not differ according to the initial serologic status of Chlamydia pneumoniae, Helicobacter pylori, or cytomegalovirus.