Cytomegalovirus infection and atherosclerosis risk: A meta-analysis

Memory inflation: Beyond the acute phase of viral infection

Memory inflation is confirmed as the most commonly dysregulation of host immunity with antigen-independent manner in mammals after viral infection. By generating large numbers of effector/memory and terminal differentiated effector memory CD8+ T cells with diminished naïve subsets, memory inflation is believed to play critical roles in connecting the viral infection and the onset of multiple diseases. Here, we reviewed the current understanding of memory inflated CD8+ T cells in their distinct phenotypic features that different from exhausted subsets; the intrinsic and extrinsic roles in regulating the formation of memory inflation; and the key proteins in maintaining the expansion and proliferation of inflationary populations. More importantly, based on the evidences from both clinic and animal models, we summarized the potential mechanisms of memory inflation to trigger autoimmune neuropathies, such as Guillain-Barré syndrome and multiple sclerosis; the correlations of memory inflation between tumorigenesis and resistance of tumour immunotherapies; as well as the effects of memory inflation to facilitate vascular disease progression. To sum up, better understanding of memory inflation could provide us an opportunity to beyond the acute phase of viral infection, and shed a light on the long-term influences of CD8+ T cell heterogeneity in dampen host immune homeostasis.

Virus-induced diabetes mellitus: revisiting infection etiology in light of SARS-CoV-2

Diabetes mellitus (DM) is comprised of two predominant subtypes: type 1 diabetes mellitus (T1DM), accounting for approximately 5 % of cases worldwide and resulting from autoimmune destruction of insulin-producing β-cells, and type 2 (T2DM), accounting for approximately 95 % of cases globally and characterized by the inability of pancreatic β-cells to meet the demand for insulin due to a relative β-cell deficit in the setting of peripheral insulin resistance. Both types of DM involve derangement of glucose metabolism and are metabolic diseases generally considered to be initiated by a combination of genetic and environmental factors. Viruses have been reported to play a role as infectious etiological factors in the initiation of both types of DM in predisposed individuals. Among the reported viral infections causing DM in humans, the most studied include coxsackie B virus, cytomegalovirus and hepatitis C virus. The recent COVID-19 pandemic has highlighted the diabetogenic potential of SARS-CoV-2, rekindling interest in the field of virus-induced diabetes (VID). This review discusses the reported mechanisms of viral-induced DM, addressing emerging concepts in VID, as well as highlighting areas where knowledge is lacking, and further investigation is warranted.

Human cytomegalovirus and neonatal infection

Human cytomegalovirus is an ancient virus that has co-evolved with humans. It establishes a life-long infection in suspectable individuals for which there is no vaccination or cure. The virus can be transmitted to a developing fetus in seropositive pregnant women, and it is the leading cause of congenital infectious disease. While the majority of infected infants remain asymptomatic at birth, congenital cytomegalovirus infection can lead to substantial long-term neurodevelopmental impairments in survivors, resulting in considerable economic and social hardships. Recent discoveries regarding cytomegalovirus pathophysiology and viral replication cycles might enable the development of innovative diagnostics and therapeutics, including an effective vaccine. This Review will detail our understanding of human cytomegalovirus infection, with an in-depth discussion regarding the viral genome and transcriptome that contributes to its pathophysiology. The neonate's clinical course will also be highlighted, including maternal and neonatal testing, treatment recommendations, and long-term outcomes.

Virus-Associated CD8+ T-Cells Are Not Activated Through Antigen-Mediated Interaction Inside Atherosclerotic Lesions

INTRODUCTION

Viral infections have been associated with the progression of atherosclerosis and CD8+ T-cells directed against common viruses, such as influenza, Epstein-Barr virus, and cytomegalovirus, have been detected inside human atherosclerotic lesions. These virus-specific CD8+ T-cells have been hypothesized to contribute to the development of atherosclerosis; however, whether they affect disease progression directly remains unclear. In this study, we aimed to characterize the activation status of virus-specific CD8+ T-cells in the atherosclerotic lesion.

METHODS

The presence, clonality, tissue enrichment, and phenotype of virus-associated CD8+ T-cells in atherosclerotic lesions were assessed by exploiting bulk T-cell receptor-β sequencing and single-cell T-cell receptor (α and β) sequencing datasets on human endarterectomy samples and patient-matched blood samples. To investigate if virus-specific CD8+ T-cells can be activated through T-cell receptor stimulation in the atherosclerotic lesion, the immunopeptidome of human plaques was determined.

RESULTS

Virus-associated CD8+ T-cells accumulated more in the atherosclerotic lesion (mean=2.0%), compared with patient-matched blood samples (mean=1.4%; P=0.05), and were more clonally expanded and tissue enriched in the atherosclerotic lesion in comparison with nonassociated CD8+ T-cells from the lesion. Single-cell T-cell receptor sequencing and flow cytometry revealed that these virus-associated CD8+ T-cells were phenotypically highly similar to other CD8+ T-cells in the lesion and that both exhibited a more activated phenotype compared with circulating T-cells. Interestingly, virus-associated CD8+ T-cells are unlikely to be activated through antigen-specific interactions in the atherosclerotic lesion, as no virus-derived peptides were detected on HLA-I in the lesion.

CONCLUSIONS

This study suggests that virus-specific CD8+ T-cells are tissue enriched in atherosclerotic lesions; however, their potential contribution to inflammation may involve antigen-independent mechanisms.

Fatal attractions that trigger inflammation and drive atherosclerotic disease

BACKGROUND

Atherosclerosis is the salient, underlying cause of cardiovascular diseases, such as arrhythmia, coronary artery disease, cardiomyopathy, pulmonary embolism and myocardial infarction. In recent years, atherosclerosis pathophysiology has evolved from a lipid-based to an inflammation-centric ideology.

METHODS

This narrative review is comprised of review and original articles that were found through the PubMed search engine. The following search terms or amalgamation of terms were used: "cardiovascular disease," "atherosclerosis," "inflammation," "GRP78," "Hsp60," "oxidative low-density lipoproteins," "aldehyde dehydrogenase," "β2-glycoprotein," "lipoprotein lipase A," "human cytomegalovirus." "SARS-CoV-2," "chlamydia pneumonia," "autophagy," "thrombosis" and "therapeutics."

RESULTS

Emerging evidence supports the concept that atherosclerosis is associated with the interaction between cell surface expression of stress response chaperones, including GRP78 and Hsp60, and their respective autoantibodies. Moreover, various other autoantigens and their autoantibodies have displayed a compelling connection with the development of atherosclerosis, including oxidative low-density lipoproteins, aldehyde dehydrogenase, β2-glycoprotein and lipoprotein lipase A. Atherosclerosis progression is also concurrent with viral and bacterial activators of various diseases. This narrative review will focus on the contributions of human cytomegalovirus as well as SARS-CoV-2 and chlamydia pneumonia in atherosclerosis development. Notably, the interaction of an autoantigen with their respective autoantibodies or the presence of a foreign antigen can enhance inflammation development, which leads to atherosclerotic lesion progression.

CONCLUSION

We will highlight and discuss the complex role of the interaction between autoantigens and autoantibodies, and the presence of foreign antigens in the development of atherosclerotic lesions in relationship to pro-inflammatory responses.

UCHL1 deficiency upon HCMV infection induces vascular endothelial inflammatory injury mediated by mitochondrial iron overload

Human cytomeglovirus (HCMV) infection predisposes blood vessels to atherosclerosis (AS) and post-transplantation restenosis, but the underlying molecular basis remains elusive. Here, we found that HCMV infection activates AIM2 inflammasome and pyroptosis in vascular endothelial cells by inducing mitochondrial iron overload. Mechanistically, under normal conditions, ubiquitin carboxyl terminal hydrolase-L1 (UCHL1) was identified as a DUB enzyme that interacts with, deubiquitylates, and stabilizes ferredoxin reductase (FDXR), an important mitochondrial protein that regulates mitochondral iron homeostasis. However, HCMV infection induces the aberrantly elevated m6A modification and R-loops, the three-stranded DNA-DNA:RNA hybrid structures. The expression of UCHL1 was remarkably reduced by m6A modification-mediated mRNA decay and R-loop-dependent transcriptional termination after HCMV infection. Deficiency of UCHL1 causes ubiquitination and degradation of FDXR. Loss of FDXR induces the mitochondrial iron overload, which consequently leads to AIM2 inflammasome activation and endothelial injury. Moreover, both downregulation expression of UCHL1 and related inflammatory injury in vascular endothelium was observed in MCMV-infected mice. Notably, STM2457, a METTL3 specific inhibitor, restores the expression of UCHL1 upon HCMV infection, thereby inhibiting the inflammatory injury of vascular endothelial cells. Our findings delineate a novel mechnism involved in HCMV-induced inflammatory injury to vascular endothelium and implicate the role of METTL3 inhibitor as a potential therapeutic approach.

Associations between human cytomegalovirus infection and type 2 diabetes mellitus: a systematic review and meta-analysis

OBJECTIVE

Multiple studies have reported a potential contribution of human cytomegalovirus (HCMV) to the pathogenesis of type 1 diabetes and post-transplantation diabetes. However, the association between HCMV and type 2 diabetes mellitus (T2DM) remains unclear. In this paper, we employ the meta-analysis approach to investigate the potential correlation between HCMV infection and T2DM.

METHOD

The data of our study were collected from PubMed, Embase, Web of Science, Cochrane Library, China National Knowledge Infrastructure and WAN FANG databases from inception to November 2022. Using the Review Manager V.5.4 software, the meta-analysis was performed.

RESULTS

A total of 18 139 patients from 22 studies were included in our analysis. In the Asian subgroup, the patients with T2DM group had a significantly higher frequency of HCMV infection and older age compared with the healthy group. In the European, the frequency of HCMV infection in the T2DM was lower than the healthy group, although this difference was not statistically significant. After adjusting for demographic factors, the adjusted OR of T2DM for risk of by HCMV status was not found to be significant (adjusted OR=1.19, 95% CI=0.88 to 1.62, p>0.05). Additionally, T2DM with vasculopathy had a significantly higher rate of HCMV infection compared with those without vasculopathy (OR=1.87, 95% CI=1.24 to 2.83, p<0.05). Among T2DM with HCMV infection, there were significant increases in fasting blood glucose levels and the proportion of CD8+ T lymphocytes. Conversely, fasting blood insulin levels, the proportion of CD4+ T lymphocyte and the CD4+/CD8+ ratio were significantly decreased compared with the healthy group.

CONCLUSION

At present, the available evidence does not provide a clear understanding of whether there is a significant association between T2DM and HCMV infection. Additionally, T2DM with HCMV infection exhibited significantly worse blood glucose regulation and immune markers, as well as a higher frequency of vasculopathy.

PROSPERO REGISTRATION NUMBER

CRD42022342066.

Cytomegalovirus and Cardiovascular Disease: A Hypothetical Role for Viral G-Protein-Coupled Receptors in Hypertension

Cytomegalovirus (CMV) is a member of the β-herpesviruses and is ubiquitous, infecting 50%-99% of the human population depending on ethnic and socioeconomic conditions. CMV establishes lifelong, latent infections in their host. Spontaneous reactivation of CMV is usually asymptomatic, but reactivation events in immunocompromised or immunosuppressed individuals can lead to severe morbidity and mortality. Moreover, herpesvirus infections have been associated with several cardiovascular and post-transplant diseases (stroke, atherosclerosis, post-transplant vasculopathy, and hypertension). Herpesviruses, including CMV, encode viral G-protein-coupled receptors (vGPCRs) that alter the host cell by hijacking signaling pathways that play important roles in the viral life cycle and these cardiovascular diseases. In this brief review, we discuss the pharmacology and signaling properties of these vGPCRs, and their contribution to hypertension. Overall, these vGPCRs can be considered attractive targets moving forward in the development of novel hypertensive therapies.

Targeting the Host Mitochondria as a Novel Human Cytomegalovirus Antiviral Strategy

Human cytomegalovirus (HCMV) exploits host mitochondrial function to promote viral replication. HCMV gene products have been described to directly interact and alter functional or structural aspects of host mitochondria. Current antivirals against HCMV, such as ganciclovir and letermovir, are designed against viral targets. Concerns with the current antivirals include toxicity and viral resistance. Targeting host mitochondrial function is a promising alternative or complimentary antiviral approach as (1) drugs targeting host mitochondrial function interact with host targets, minimizing viral resistance, and (2) host mitochondrial metabolism plays key roles in HCMV replication. This review describes how HCMV alters mitochondrial function and highlights pharmacological targets that can be exploited for novel antiviral development.

Human Cytomegalovirus Infection and Cardiovascular Disease: Current Perspectives

Infections with human cytomegalovirus (HCMV) are often asymptomatic in healthy adults but can be severe in people with a compromised immune system. While several studies have demonstrated associations between cardiovascular disease in older adults and HCMV seropositivity, the underlying mechanisms are unclear. We review evidence published within the last 5 years establishing how HCMV can contribute directly and indirectly to the development and progression of atherosclerotic plaques. We also discuss associations between HCMV infection and cardiovascular outcomes in populations with a high or very high burden of HCMV, including patients with renal or autoimmune disease, transplant recipients, and people living with HIV.

Indirect effects of cytomegalovirus infection: Implications for vaccine development

Development of a cytomegalovirus (CMV) vaccine is a high priority due to its significant global impact-contributing to mortality in immunosuppressed individuals, neurodevelopmental delay in infected neonates and non-genetic sensorineural hearing loss. The impact of CMV on the general population has been less well studied; however, a wide range of evidence indicates that CMV may increase the risk of atherosclerosis, cancer, immunosenescence, and progression of tuberculosis (TB) and human immunodeficiency virus. Due to the high seroprevalence of CMV worldwide, any modulation of risk by CMV is likely to have a significant impact on the epidemiology of these diseases. This review will evaluate how CMV may cause morbidity and mortality outside of the neonatal and immunosuppressed populations and consider the potential impact of a CMV vaccine on these outcomes.

Long-Term Associations between Human Cytomegalovirus Antibody Levels with All-Cause Mortality and Cardiovascular Outcomes in an Australian Community-Based Cohort

Human cytomegalovirus (HCMV) infection has been shown to increase the risk of cardiovascular events and all-cause death among individuals with clinically apparent cardiovascular disease (CVD). Whether this association exists in individuals with no history of CVD remains unclear. Serum levels of HCMV IgG antibody were measured using an ELISA in 2050 participants aged 40-80 years from the 1994/1995 Busselton Health Survey who did not have CVD at baseline. Outcomes were all-cause death, cardiovascular death, acute coronary syndrome (ACS) and major adverse coronary and cerebrovascular events (MACCE, composite of all-cause death, ACS, stroke and coronary artery revascularisation procedures). Cox proportional hazards regression analysis was used to investigate HCMV antibody levels as a predictor of death and cardiovascular outcomes during follow-up periods of 5, 10 and 20 years. At baseline, participants had a mean age of 56 years and 57% were female. During the 20-year follow-up, there were 448 (21.9%) deaths (including 152 from CVD), 139 (6.8%) participants had ACS and 575 (28.0%) had MACCE. In the fully adjusted model, levels of HCMV antibody at 20 years was associated with all-cause death (HR 1.04; 95% CI 1.00, 1.07, p = 0.037) but not with CVD death, ACS or MACCE. Levels of HCMV antibody are associated with all-cause death but not with cardiovascular outcomes in adults without pre-existing CVD.

The Role of CMV Infection in Primary Lesions, Development and Clinical Expression of Atherosclerosis

The number of deaths related to cardiovascular disease is increasing every year, despite all available therapies and the aggressive campaigns for lifestyle modification and prevention of risk factors. Atherosclerosis is a complex process underlying cardiovascular disease. Cytomegalovirus (CMV) is often associated to atherosclerosis and its clinical expression such as coronary heart disease, stroke, or peripheral artery disease. CMV infection may promote acute atherosis within placentas from women with preeclampsia and it may also accelerate atherosclerosis in HIV-infected and organ-transplanted patients. This review focuses on the current scientific evidence for the role of CMV infection in the development of acute atherosis and atherosclerosis from placentation throughout life.

Antibodies to Human Herpesviruses and Rate of Incident Cardiovascular Events and All-Cause Mortality in the UK Biobank Infectious Disease Pilot Study

Background

Associations between human herpesviruses (HHVs) and cardiovascular disease/mortality have been reported, but evidence is inconsistent. We investigated associations between 3 common herpesviruses and (1) incident stroke or myocardial infarction (MI) and (2) all-cause mortality.

Methods

We included participants from the UK Biobank Infectious Disease pilot study with valid serum antibody (IgG) measurements taken at cohort entry (2006-2010) for herpes simplex virus type 1 (HSV1), varicella zoster virus (VZV), and cytomegalovirus (CMV). Linked hospital and mortality records up to December 30 2019 provided information on rates of (1) incident first stroke or MI and (2) all-cause mortality. Hazard ratios (HRs) from Cox proportional hazards regression models were used to assess relationships between (1) HHV seropositivity, (2) HHV titer and incident stroke/MI, and death outcomes. Fully adjusted models accounted for sociodemographic information (age, sex, ethnicity, education, deprivation quintile, birthplace, population density), baseline comorbidities (including diabetes and hypertension), smoking status, body mass index, and serum cholesterol.

Results

Of 9429 study participants (56% female, 95% White, median age 58 years), 41% were seropositive for all 3 HHVs. Human herpesvirus seropositivity was not associated with stroke/MI (fully adjusted HRs and 95% confidence intervals [CIs]: HSV1 = 0.93 [CI, 0.72-1.22], VZV = 0.78 [CI, 0.51-1.20], CMV = 0.91 [CI, 0.71-1.16]) or all-cause mortality (HSV1 = 1.21 [CI, 1.00-1.47], VZV = 0.79 [CI, 0.58-1.07], CMV = 0.90 [CI, 0.76-1.06]). Human herpesvirus titers were not associated with outcomes.

Conclusions

In this mostly White UK Biobank subset, neither HHV seropositivity nor titers were associated with stroke/MI or all-cause mortality.

Role of cytomegalovirus infection after kidney transplantation on the subsequent risk of atherosclerotic and thrombotic events

Background and aims

Whether cytomegalovirus (CMV) infection increases the risk of cardiovascular complications after kidney transplantation (KT) through different indirect effects remains controversial.

Methods

We analyzed the incidence of post-transplant atherosclerotic (PAEs) and thrombotic events (PTEs) in 465 KT recipients according to the previous exposure to any level or high-level (≥1,000 IU/mL) CMV viremia (either asymptomatic or clinical disease) by means of landmark analysis beyond days 30, 180 and 360 after transplantation. Proportional hazards models were constructed with death and graft loss as competing risks.

Results

After a median of 722 days, the cumulative incidences of PAE and PTE were 6.0% each. Most PAEs (53.6%) occurred beyond post-transplant day 360, whereas most PTEs (60.7%) were diagnosed between days 30-180.The incidence of PAE beyond day 180 was higher among patients with previous CMV viremia compared to those without (two-year rates: 4.7% versus 0.4%; P-value = 0.035). This difference was more pronounced in recipients developing high-level viremia (6.3% versus 0.7%, respectively; P-value = 0.013). After multivariate adjustment for age, pre-transplant cardiovascular risk, antiplatelet and statin therapy and graft function, however, associations were not maintained either for any-level (hazard ratio [HR]: 1.84; 95% confidence interval [CI]: 0.48-7.05) or high-level CMV viremia (HR: 2.84; 95% CI: 0.78-10.36). No significant differences were found in the remaining landmark analyses (days 30 or 360) or for the outcome of PTE either.

Conclusions

Our study does not support that CMV infection independently contributes to the risk of PAE or PTE after KT.

Vitamin D3 Suppresses Human Cytomegalovirus-Induced Vascular Endothelial Apoptosis via Rectification of Paradoxical m6A Modification of Mitochondrial Calcium Uniporter mRNA, Which Is Regulated by METTL3 and YTHDF3

Human cytomegalovirus (HCMV) infection can induce apoptosis of vascular endothelial cells, which may be the most important element of development and progression of reported atherosclerosis caused by HCMV. As there are no specific drugs to clear HCMV infection, exploration of relevant drugs and mechanisms that can intervene in HCMV-induced atherosclerosis is urgently needed. The present study confirmed that vitamin D3 protected vascular endothelial cells from HCMV-induced apoptosis by inhibiting endoplasmic reticulum (ER) and mitochondrial apoptosis pathway. Mechanistically, HCMV infection could induce aberrantly elevated m6A modification, especially the increases of methyltransferases-“writers” (METTL3) and m6A binding proteins-“readers” (YTHDF3). METTL3 methylates mitochondrial calcium uniporter (MCU), the main contributor to HCMV-induced apoptosis of vascular endothelial cells, at three m6A residues in the 3′-UTR, which promotes the association of the YTHDF3 with methylated MCU mRNA and subsequently increases the translation and expression of MCU. Further analysis shows that ALKBH5 is the demethylases-“eraser” of MCU mRNA, which can negatively regulate the m6A modification process of MCU. Conversely, vitamin D3 downregulated the METTL3 by inhibiting the activation of AMPK, thereby inhibiting the m6A modification of MCU and cell apoptosis. Our findings extend the understanding of m6A driven machinery in virus-induced vascular endothelium damage and highlight the significance of vitamin D3 in the intervention of HCMV-induced atherosclerosis.

Viruses, periodontitis, and comorbidities

Seminal studies published in the 1990s and 2000s explored connections between periodontal diseases and systemic conditions, revealing potential contributions of periodontal diseases in the initiation or worsening of systemic conditions. The resulting field of periodontal medicine led to the publication of studies indicating that periodontal diseases can influence the risk of systemic conditions, including adverse pregnancy outcomes, cardiovascular and respiratory diseases, as well as Alzheimer disease and cancers. In general, these studies hypothesized that the periodontal bacterial insult and/or the associated proinflammatory cascade could contribute to the pathogenesis of these systemic diseases. While investigations of the biological basis of the connections between periodontal diseases and systemic conditions generally emphasized the bacteriome, it is also biologically plausible, under an analogous hypothesis, that other types of organisms may have a similar role. Human viruses would be logical "suspects" in this role, given their ubiquity in the oral cavity, association with periodontal diseases, and ability to elicit strong inflammatory response, compromise immune responses, and synergize with bacteria in favor of a more pathogenic microbial consortium. In this review, the current knowledge of the role of viruses in connecting periodontal diseases and systemic conditions is examined. We will also delve into the mechanistic basis for such connections and highlight the importance of those relationships in the management and treatment of patients.

Validation of Preamplification to Improve Quantification of Cytomegalovirus DNA Using Droplet Digital Polymerase Chain Reaction

Subclinical cytomegalovirus (CMV) replication is associated with strong cellular immune response and chronic inflammation, which could contribute to aging-related conditions such as cardiovascular disease and frailty. However, because of very low levels of CMV DNA present in people with chronic CMV infection, it has been difficult to explore the virologic and immunologic mechanisms of chronic low-level CMV infection and a sensitive method to monitor CMV replication is needed. Droplet digital PCR (ddPCR) has been shown to have higher precision and reproducibility than real-time quantitative PCR (qPCR) in quantifying low levels of CMV DNA, but it is not always sensitive enough for this purpose. Through rigorous validation experiments, we demonstrated that sensitivity and precision of quantification of very low levels of CMV DNA by ddPCR can be significantly increased by preamplification of samples with 10-20 cycles of conventional PCR, especially when testing CMV DNA in the presence of cellular DNA. With preamplification, we could reliably quantify down to two copies of CMV DNA, as opposed to five copies without preamplification. Further studies are needed to determine if ddPCR with preamplification can facilitate mechanistic studies of the characteristics and consequences of chronic CMV infection in aging adults.

Curcumin inhibits the formation of atherosclerosis in ApoE-/- mice by suppressing cytomegalovirus activity in endothelial cells

BACKGROUND

Curcumin (Cur) is a hydrophobic polyphenol compound derived from the rhizome of the herb Curcuma longa. Cur has a wide spectrum of biological and pharmacological activities. It has been shown that human cytomegalovirus (HCMV) infection was an important risk factor for atherosclerosis (AS) and Cur exhibited an outstanding anti-HCMV effect. However, anti-AS effects of Cur remain unclear when HCMV infected endothelial cells.

AIMS

This study will investigate the anti-AS activities and mechanism of Cur,when HCMV infected in vivo and in vitro.

MATERIALS AND METHODS

Cur (0.5, 1, and 2 μM) was used to explore the anti-AS activities and mechanism after HCMV infected endothelial cells in vitro. ApoE^-/- mice were fed a high fat and cholesterol diet (HD) and given 4000,000 copies/mouse MCMV infection by intraperitoneal and treated with ganciclovir (5 mg/kg/d), Cur (25, 15 mg/kg/d) for 10 weeks in vivo.

KEY FINDINGS

As our results showed that Cur inhibited CMV replication and proliferation, reduced the intracellular ROS overproduction, decreased the release of inflammatory cytokines, down-regulated the level of HMGB1-TLRS-NF-κB signaling pathway-related proteins in vitro experiments. Cur reduced the serum levels of LDL-C, TC and TG, significantly decreased the formation of atherosclerotic plaque in the aorta, reduced the lipid deposition in liver and inflammatory damage in heart, lung and kidney in vivo experiments.

SIGNIFICANCE

This study showed that Cur prevent AS progression by inhibiting CMV activity and CMV-induced HMGB1-TLRS-NF-κB signaling pathway.

Human cytomegalovirus infection is correlated with atherosclerotic plaque vulnerability in carotid artery

BACKGROUND

Several studies have suggested that human cytomegalovirus (CMV) infection is closely related to the pathogenesis of atherosclerosis. The present study aimed to investigate the association between human CMV infection and carotid atherosclerotic plaque vulnerability in a Chinese population.

METHODS

In total, 42 patients with carotid atherosclerosis (observation group) and 30 healthy volunteers (control group) were recruited in our study from October 2016 to January 2018. Statistical analysis was carried out to calculate the infection rate of CMV in subjects. Spearman's rank analysis was performed to evaluate the correlation between CMV infection and atherosclerotic plaque vulnerability.

RESULTS

The positive rate of CMV was significantly higher in the observation group compared to the control group, and matrix metalloproteinase 9 (MMP-9), tumor necrosis factor-α (TNF-α) and lectin-like oxidized low density lipoprotein receptor-1 (LOX-1) expression levels were also elevated in the observation group compared to those in the control group. In carotid atherosclerotic patients, the detection rate of unstable plaques and the Crouse scores in vulnerable plaque were significantly higher in the CMV-positive group compared to those in the CMV-negative group. As revealed by correlation analysis, CMV infection was significantly positively correlated with plaque vulnerability and expression levels of MMP-9, TNF-α and LOX-1 in carotid atherosclerotic patients.

CONCLUSIONS

Human CMV infection might be a potential risk factor for increased plaque vulnerability in patients with carotid atherosclerosis.

The role of human cytomegalovirus in atherosclerosis: a systematic review

Atherosclerosis is a progressive vascular disease with increasing morbidity and mortality year by year in modern society. Human cytomegalovirus (HCMV) infection is closely associated with the development of atherosclerosis. HCMV infection may accelerate graft atherosclerosis and the development of transplant vasculopathy in organ transplantation. However, our current understanding of HCMV-associated atherosclerosis remains limited and is mainly based on clinical observations. The underlying mechanism of the involvement of HCMV infection in atherogenesis remains unclear. Here, we summarized current knowledge regarding the multiple influences of HCMV on a diverse range of infected cells, including vascular endothelial cells, vascular smooth muscle cells, monocytes, macrophages, and T cells. In addition, we described potential HCMV-induced molecular mechanisms, such as oxidative stress, endoplasmic reticulum stress, autophagy, lipid metabolism, and miRNA regulation, which are involved in the development of HCMV-associated atherogenesis. Gaining an improved understanding of these mechanisms will facilitate the development of novel and effective therapeutic strategies for the treatment of HCMV-related cardiovascular disease.

Anti-Glycan Autoantibodies Induced by Helicobacter pylori as a Potential Risk Factor for Myocardial Infarction

A number of epidemiological studies have evaluated the potential association between H. pylori and cardiovascular disease, but with contrasting results. We have previously shown that Helicobacter pylori infection is able to induce in mice and humans autoantibodies cross-reacting with histo–blood group Lewis antigens, expressed in different organs and in plasma glycoproteins and glycolipids. The aim of this study was to assess whether immunization of animals with H. pylori might induce myocardial histopathological changes. We have retrospectively examined, in detail, the histology of archived organs from mice and rabbits immunized with H. pylori in our previous studies. Human sera and cross-reacting monoclonal antibodies were also tested against bacterial preparations and tissue sections. Areas of myocardial necrosis, associated with coronary thrombotic occlusion, were found in 5 of 20 mice and 2 of 5 rabbits previously immunized with suspensions of H. pylori. No similar lesions were found in control animals, suggesting a causal link with H. pylori immunization. The animals bearing myocardial lesions had not been infected but only immunized months earlier with parenteral injections of dead H. pylori cells. This strongly suggests that immunization, by itself, might play a causative role. We propose that the cross-reactive autoimmune response induced by H. pylori could promote thrombotic occlusion through direct endothelial damage or by perturbing the coagulation process.

Productive Cytomegalovirus Infection Is Associated With Impaired Endothelial Function in ST-Elevation Myocardial Infarction

BACKGROUND

An association between productive cytomegalovirus infection and atherosclerosis was shown recently in several trials, including a previous study of ours. However, the mechanism involved in this association is still under investigation. Here, we addressed the interaction between productive cytomegalovirus infection and endothelial function in patients with ST-elevation myocardial infarction (STEMI).

METHODS

We analyzed the presence of cytomegaloviral DNA in plasma and endothelial function in 33 patients with STEMI and 33 volunteers without cardiovascular diseases, using real-time polymerase chain reaction (PCR) and a noninvasive test of flow-mediated dilation.

RESULTS

Both the frequency of presence and the load of cytomegaloviral DNA were higher in plasma of patients with STEMI than those in controls. This difference was independent of other cardiovascular risk factors (7.38 [1.36-40.07]; P = 0.02). The results of the flow-mediated dilation test were lower in patients in STEMI than in controls (5.0% [2.65%-3.09%] vs 12. %5 [7.5%-15.15%]; P = 0.004) and correlated negatively with the cytomegaloviral DNA load (Spearman R = -0.407; P = 0.019) independently of other cardiovascular risk factors.

CONCLUSIONS

Productive cytomegalovirus infection in patients with STEMI correlated negatively with endothelial function independently of other cardiovascular risk factors. The impact of cytomegalovirus on endothelial function may explain the role of cytomegalovirus in cardiovascular prognosis.

Human Vascular Pericytes and Cytomegalovirus Pathobiology

Pericytes are multipotent cells of the vascular system with cytoplasmic extensions proximal to endothelial cells that occur along the abluminal surface of the endothelium. The interactions between endothelial cells and pericytes are essential for proper microvascular formation, development, stabilization, and maintenance. Pericytes are essential for the regulation of paracellular flow between cells, transendothelial fluid transport, angiogenesis, and vascular immunosurveillance. They also influence the chemical composition of the surrounding microenvironment to protect endothelial cells from potential harm. Dysregulation or loss of pericyte function can result in microvascular instability and pathological consequences. Human pericytes have been shown to be targets for human cytomegalovirus (HCMV) infection and lytic replication that likely contribute to vascular inflammation. This review focuses on human vascular pericytes and their permissiveness for HCMV infection. It also discusses their implication in pathogenesis in the blood⁻brain barrier (BBB), the inner blood⁻retinal barrier (IBRB), the placenta⁻blood barrier, and the renal glomerulus as well as their potential role in subclinical vascular disease.

Mechanisms of human cytomegalovirus infection with a focus on epidermal growth factor receptor interactions

Human cytomegalovirus (HCMV) is a widespread opportunistic herpesvirus that causes severe diseases in immunocompromised individuals. It has a high prevalence worldwide that is linked with socioeconomic factors. Similar to other herpesviruses, HCMV has the ability to establish lifelong persistence and latent infection following primary exposure. HCMV infects a broad range of cell types. This broad tropism suggests that it may use multiple receptors for host cell entry. The identification of receptors used by HCMV is essential for understanding viral pathogenesis, because these receptors mediate the early events necessary for infection. Many cell surface components have been identified as virus receptors, such as epidermal growth factor receptor (EGFR), which is characterized by tyrosine kinase activity and plays a crucial role in the control of key cellular transduction pathways. EGFR is essential for HCMV binding, signaling, and host cell entry. This review focuses on HCMV infection via EGFR on different cell types and its implications for the cellular environment, viral persistence, and infection.