Human cytomegalovirus induces MMP-1 and MMP-3 expression in aortic smooth muscle cells

Comprehensive bioinformatics analysis of human cytomegalovirus pathway genes in pan-cancer

BACKGROUND

Human cytomegalovirus (HCMV) is a herpesvirus that can infect various cell types and modulate host gene expression and immune response. It has been associated with the pathogenesis of various cancers, but its molecular mechanisms remain elusive.

METHODS

We comprehensively analyzed the expression of HCMV pathway genes across 26 cancer types using the Cancer Genome Atlas (TCGA) and The Genotype-Tissue Expression (GTEx) databases. We also used bioinformatics tools to study immune invasion and tumor microenvironment in pan-cancer. Cox regression and machine learning were used to analyze prognostic genes and their relationship with drug sensitivity.

RESULTS

We found that HCMV pathway genes are widely expressed in various cancers. Immune infiltration and the tumor microenvironment revealed that HCMV is involved in complex immune processes. We obtained prognostic genes for 25 cancers and significantly found 23 key genes in the HCMV pathway, which are significantly enriched in cellular chemotaxis and synaptic function and may be involved in disease progression. Notably, CaM family genes were up-regulated and AC family genes were down-regulated in most tumors. These hub genes correlate with sensitivity or resistance to various drugs, suggesting their potential as therapeutic targets.

CONCLUSIONS

Our study has revealed the role of the HCMV pathway in various cancers and provided insights into its molecular mechanism and therapeutic significance. It is worth noting that the key genes of the HCMV pathway may open up new doors for cancer prevention and treatment.

HCMV-IE2 promotes atherosclerosis by inhibiting vascular smooth muscle cells' pyroptosis

Atherosclerosis is still the main cause of death in developed and developing countries. Vascular smooth muscle cells (VSMCs) death disorder is a key pathogens of atherosclerosis. During the early stage of human cytomegalovirus (HCMV) infection, immediate early protein 2 (IE2) is critical in regulating its host cell death to ensure HCMV replication. Abnormal cell death induced by HCMV infection contributes to the development of numerous diseases, including atherosclerosis. Hitherto, the underlying mechanism of HCMV involved in the progression of atherosclerosis is still unclear. In this study, the infection models in vitro and in vivo were constructed to explore the pathogenesis of HCMV-related atherosclerosis. Our results indicated that HCMV could contribute to the progression of atherosclerosis by enhancing the proliferation, invasion, and inhibiting the pyroptosis of VSMCs under inflammatory conditions. Meanwhile, IE2 played a key role in these events. Our present research revealed a novel pathogenesis of HCMV-related atherosclerosis, which might help develop new therapeutic strategies.

The Viral G-Protein-Coupled Receptor Homologs M33 and US28 Promote Cardiac Dysfunction during Murine Cytomegalovirus Infection

Human cytomegalovirus (HCMV) is a ubiquitous pathogen that infects the majority of the world population and causes lifelong latent infection. HCMV has been shown to exacerbate cardiovascular diseases, including myocarditis, vascular sclerosis, and transplant vasculopathy. Recently, we have shown that murine CMV (MCMV) recapitulates the cardiovascular dysfunction observed in patients with HCMV-induced myocarditis. To understand the viral mechanisms involved in CMV-induced heart dysfunction, we further characterized cardiac function in response to MCMV and examined virally encoded G-protein-coupled receptor homologs (vGPCRs) US28 and M33 as potential factors that promote infection in the heart. We hypothesized that the CMV-encoded vGPCRs could exacerbate cardiovascular damage and dysfunction. Three viruses were used to evaluate the role of vGPCRs in cardiac dysfunction: wild-type MCMV, a M33-deficient virus (∆M33), and a virus with the M33 open reading frame (ORF) replaced with US28, an HCMV vGPCR (i.e., US28+). Our in vivo studies revealed that M33 plays a role in promoting cardiac dysfunction by increasing viral load and heart rate during acute infection. During latency, ΔM33-infected mice demonstrated reduced calcification, altered cellular gene expression, and less cardiac hypertrophy compared with wild-type MCMV-infected mice. Ex vivo viral reactivation from hearts was less efficient in ΔM33-infected animals. HCMV protein US28 expression restored the ability of the M33-deficient virus to reactivate from the heart. US28+ MCMV infection caused damage to the heart comparable with wild-type MCMV infection, suggesting that the US28 protein is sufficient to complement the function of M33 in the heart. Altogether, these data suggest a role for vGPCRs in viral pathogenesis in the heart and thus suggest that vGPCRs promote long-term cardiac damage and dysfunction.

Neurotrophic factor levels in the serum and cerebrospinal fluid of neonates infected with human cytomegalovirus

Human cytomegalovirus (HCMV) is most likely to damage the central nervous system (CNS) during early embryonic development; however, the early neurodevelopmental abnormalities caused by HCMV infection and the regulation of cytokines remain unclear. Therefore, we investigated neuronal factors in the serum and cerebrospinal fluid (CSF) of newborns infected with HCMV using protein microarray technology with a view to elucidating the changes in specific neuronal factors for use in the development of a reliable index for predicting CNS injury caused by HCMV infection. Serum and CSF were collected from four newborns with HCMV infection and CNS injury (HCMV-infected group) and from four newborns without CNS infection (control group). A protein microarray containing 29 kinds of CNS-related cytokines was used to identify differentially expressed neuronal factors in the serum and CSF of the HCMV-infected and control groups. The levels of the differentially expressed proteins were verified further in 30 CSF samples from an HCMV-infected group using enzyme-linkedimmunosorbent assay (ELISA). Between newborns in the HCMV-infected and control groups, the protein microarray analysis identified three differentially expressed neurotrophic factors in the CSF samples: Acrp30, MMP-3, and interleukin-1 alpha (IL-1α). No differential cytokine expression was seen in the serum. ELISA showed significantly higher expression levels of Acrp30 and MMP-3 in the CSF of the 30 newborns with HCMV infection and CNS injury than in those in the control group, whereas the expression of IL-1α was significantly lower. Our results demonstrate that changes in the expression levels of Acrp30, MMP-3, and IL-1α in the CSF of newborns infected with HCMV may be related to the pathogenesis of CNS infection.

Apoptosis Disorder, a Key Pathogenesis of HCMV-Related Diseases

Human cytomegalovirus (HCMV) belongs to the β-herpesvirus family, which is transmitted in almost every part of the world and is carried by more than 90% of the general population. Increasing evidence indicates that HCMV infection triggers numerous diseases by disrupting the normal physiological activity of host cells, particularly apoptosis. Apoptosis disorder plays a key role in the initiation and development of multiple diseases. However, the relationship and molecular mechanism of HCMV-related diseases and apoptosis have not yet been systematically summarized. This review aims to summarize the role of apoptosis in HCMV-related diseases and provide an insight into the molecular mechanism of apoptosis induced by HCMV infection. We summarize the literature on HCMV-related diseases and suggest novel strategies for HCMV treatment by regulating apoptosis.

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.

Periodontal bacterial invasion and infection: contribution to atherosclerotic pathology

OBJECTIVE

The objective of this review was to perform a systematic evaluation of the literature reporting current scientific evidence for periodontal bacteria as contributors to atherosclerosis.

METHODS

Literature from epidemiological, clinical and experimental studies concerning periodontal bacteria and atherosclerosis were reviewed. Gathered data were categorized into seven "proofs" of evidence that periodontal bacteria: 1) disseminate from the oral cavity and reach systemic vascular tissues; 2) can be found in the affected tissues; 3) live within the affected site; 4) invade affected cell types in vitro; 5) induce atherosclerosis in animal models of disease; 6) non-invasive mutants of periodontal bacteria cause significantly reduced pathology in vitro and in vivo; and 7) periodontal isolates from human atheromas can cause disease in animal models of infection.

RESULTS

Substantial evidence for proofs 1 to 6 was found. However, proof 7 has not yet been fulfilled.

CONCLUSIONS

Despite the lack of evidence that periodontal bacteria obtained from human atheromas can cause atherosclerosis in animal models of infection, attainment of proofs 1 to 6 provides support that periodontal pathogens can contribute to atherosclerosis.

Periodontal bacterial invasion and infection: contribution to atherosclerotic pathology

OBJECTIVE

The objective of this review was to perform a systematic evaluation of the literature reporting current scientific evidence for periodontal bacteria as contributors to atherosclerosis.

METHODS

Literature from epidemiological, clinical and experimental studies concerning periodontal bacteria and atherosclerosis were reviewed. Gathered data were categorized into seven "proofs" of evidence that periodontal bacteria: 1) disseminate from the oral cavity and reach systemic vascular tissues; 2) can be found in the affected tissues; 3) live within the affected site; 4) invade affected cell types in vitro; 5) induce atherosclerosis in animal models of disease; 6) non-invasive mutants of periodontal bacteria cause significantly reduced pathology in vitro and in vivo; and 7) periodontal isolates from human atheromas can cause disease in animal models of infection.

RESULTS

Substantial evidence for proofs 1 to 6 was found. However, proof 7 has not yet been fulfilled.

CONCLUSIONS

Despite the lack of evidence that periodontal bacteria obtained from human atheromas can cause atherosclerosis in animal models of infection, attainment proofs 1 to 6 provides support that periodontal pathogens can contribute to atherosclerosis.

Periodontal associations in cardiovascular diseases: The latest evidence and understanding

Periodontal and cardiovascular diseases (CVD) are inflammatory diseases. Recent epidemiological studies have associated the effect of periodontitis on CVD progression. Findings of oral pathogens in carotid atheromas provided a plausible relationship between these two diseases. One possible mechanism is the infiltration of oral/periodontal pathogens through inflamed and ulcerated gingival epithelium. This results in translocation of oral pathogens throughout the systemic circulation affecting vascular tissues, and initiating a cascade of inflammatory reactions detrimental to the cardiovascular system. In addition, leakage of pro-inflammatory cytokines/chemokines from the ulcerated periodontium into the bloodstream may cause the production of hepatic acute-phase proteins. Moreover, as chronic bacteremia occurs, the adaptive immune system is activated. Antibodies produced in response to periodontal pathogens trigger a cross-reaction between endothelial cells and modified low-density lipoprotein to enhance the movement of lipids into cells within the vessel wall. Some antibodies and inflammatory cytokines promote the Th1 response, thereby further activating macrophages within the atheroma. These plausible mechanisms are contributing factors in initiating and propagating atherogenesis. This review discusses the current understanding of CVD pathology/periodontitis, potential underlying mechanisms regarding this association, and general guidelines for treating patients with CVD risks.

Retinal pericytes and cytomegalovirus infectivity: implications for HCMV-induced retinopathy and congenital ocular disease

Background

Human cytomegalovirus (HCMV) is the leading infectious cause of vision loss among congenitally infected children. Retinal pericytes play an essential role in maintaining retinal vascular and endothelial cell proliferation. However, the role of retinal pericytes in ocular HCMV pathogenesis is unknown.

Methods

Retinal pericytes were exposed to clinical (SBCMV) and lab strains of HCMV; infectivity was analyzed by microscopy, immunofluorescence and qRT-PCR (reverse transcription polymerase chain reaction). Cytokine expression was examined by Luminex assay. Recombinant HCMV-GPF was used to examine viral replication kinetics. A Tricell culture model of the inner blood-retinal barrier (IBRB) was examined for cell type infectivity using immunohistochemistry.

Results

Retinal pericytes expressed the biomarker neuron-glial antigen 2. Antigenic expression profiles for several cytoskeletal, cell adhesion and inflammatory proteins were shared by both retinal and brain pericytes. Infected pericytes showed cytomegalic cytopathology and expressed mRNAs for the major immediate protein (MIE) and HCMV phosphorylated envelop protein 65. qRT-PCR analysis showed full lytic replication of HCMV in retinal pericytes. Pericytes exposed to SBCMV for 9 days expressed higher levels of vascular endothelial cell growth factor mRNA compared to controls. Luminex analysis of supernatants from SBCMV-infected retinal pericytes had increased levels of macrophage inflammatory protein-1α, beta-2 microglobulin (B2-m), matrix metalloproteinase-3 and -9 (MMP3/9), and lower levels of IL-6 and IL-8 compared to controls. At 24 hours post infection, pericytes expressed higher levels of IL-8, TIMP-1 (tissue inhibitor of metalloproteinase-1), and RANTES (regulated upon activation normal T cell-expressed and presumably secreted) but lower levels of MMP9. Time course analysis showed that both brain and retinal pericytes were more permissive for HCMV infection than other cellular components of the BBB (blood-brain barrier) and IBRB. Using a Tricell culture model of the IBRB (retinal endothelial, pericytes, Müller cells), retinal pericytes were most permissive for SBCMV infection. SBCMV infection of this IBRB Tricell mixture for 96 hours resulted in increased levels of IL-6, MMP9, and stem cell factor with a concomitant decrease in granulocyte-macrophage colony-stimulating factor and TNF-alpha.

Conclusion

In retinal pericytes, HCMV induces proinflammatory and angiogenic cytokines. In the IBRB, pericytes likely serve as an amplification reservoir which contributes to retinal inflammation and angiogenesis.