Elevated Methylation of FOXP3 (Forkhead Box P3)-TSDR (Regulatory T-Cell-Specific Demethylated Region) Is Associated With Increased Risk for Adverse Outcomes in Patients With Acute Coronary Syndrome

Identification of Hub Genes and Immune Infiltration in Coronary Artery Disease: A Risk Prediction Model

Purpose

Our study aimed to establish a prediction model for coronary artery disease (CAD) that integrates immune infiltration and a gene expression signature.

Methods

613 differentially expressed genes (DEGs) and 12 hub genes were screened via the GSE113079 dataset. The pathway enrichment analysis indicated that these genes (613 DEGs and 12 hub genes) were closely associated with the inflammatory and immune responses. Based on the differentially expressed miRNA (DEmiRNA)-DEG regulatory network and immune cell infiltration, the Lasso algorithm constructed a CAD risk prediction model containing the risk score and immune score. Then, ROC-AUC and polymerase chain reaction (PCR) were performed for validation.

Results

Six hub genes (PTGER1, PIK3R1, ADRA2A, CORT, CXCL12, and S1PR5) had a high distinguishing capability (AUC > 0.90). In addition, the miRNAs targeting 12 hub genes were predicted and intersected with the DEmiRNAs, and the DEmiRNA-DEG regulatory network was then constructed. Two LASSO models and a novel CAD risk prediction model were constructed through LASSO regression analysis, and they both accurately obtained the risk of CAD. The CAD risk prediction model shows good performance (AUC = 0.988). We also constructed a valid nomogram, and PCR results verified three downregulation hub genes and one upregulation gene in the CAD risk model.

Conclusion

We demonstrated the molecular mechanism of the hub genes in CAD and provided a valuable tool for predicting the risk of CAD.

Regulatory T Cells in Pathological Cardiac Hypertrophy: Mechanisms and Therapeutic Potential

BACKGROUND

Pathological cardiac hypertrophy is linked to immune-inflammatory injury, and regulatory T cells (Tregs) play a crucial role in suppressing immune-inflammatory responses. However, the precise role of Tregs in pathological cardiac hypertrophy remains unclear.

OBJECTIVE

To summarize the current knowledge on the role and mechanisms of Tregs in pathological cardiac hypertrophy and explore their perspectives and challenges as a new therapeutic approach.

RESULTS

Treg cells may play an important protective role in pressure overload (hypertension, aortic stenosis), myocardial infarction, metabolic disorders (diabetes, obesity), acute myocarditis, cardiomyopathy (hypertrophic cardiomyopathy, storage diseases), and chronic obstructive pulmonary disease-related pathological cardiac hypertrophy. Although some challenges remain, the safety and efficacy of Treg-based therapies have been confirmed in some clinical trials, and engineered antigen-specific Treg cells may have better clinical application prospects due to stronger immunosuppressive function and stability.

CONCLUSION

Targeting the immune-inflammatory response via Treg-based therapies might provide a promising and novel future approach to the prevention and treatment of pathological cardiac hypertrophy.

Epigenetic modification of CD4+ T cells into Tregs by 5-azacytidine as cellular therapeutic for atherosclerosis treatment

Recent research has explored the potential of the demethylating drug 5-azacytidine (Aza) as therapy for a range of diseases. However, the therapeutic efficacy of Aza for patients of atherosclerosis remains unclear. This study investigates the therapeutic application of Aza to atherosclerosis in order to elucidate the underlying mechanisms. We generated induced Tregs (iTregs) from CD4+ T cells by using Aza in vitro, and this was followed by the intravenous infusion of iTregs for the treatment of atherosclerosis. The adoptive transfer of Aza-iTreg significantly increased peripheral blood Treg cells, suppressed inflammation, and attenuated atherosclerosis in ApoE-/- mice. Furthermore, we observed a notable demethylation of the Forkhead box P3 (Foxp3)-regulatory T cell-specific demethylated region (TSDR) and an upregulation of Foxp3 expression in the CD4+ T cells in the spleen of the ApoE-/- mice following the transfer of Aza- iTregs. We also demonstrated that Aza converted naive CD4+ T cells into Tregs by DNA methyltransferase 1 (Dnmt1)-mediated Foxp3-TSDR demethylation and the upregulation of Foxp3 expression. Conversely, the overexpression of Dnmt1 in the CD4+ T cells attenuated the Aza-induced Foxp3-TSDR demethylation and upregulation of Foxp3 expression. Our results reveal that Aza converts naive CD4+ T cells into functional Tregs by inhibiting Dnmt1, and the transfer of Aza-iTregs suppresses atherosclerosis in mice.

DNA methyltransferase isoforms regulate endothelial cell exosome proteome composition

Extrinsic and intrinsic pathological stimuli in vascular disorders induce DNA methylation based epigenetic reprogramming in endothelial cells, which leads to perturbed gene expression and subsequently results in endothelial dysfunction (ED). ED is also characterized by release of exosomes with altered proteome leading to paracrine interactions in vasculature and subsequently contributing to manifestation, progression and severity of vascular complications. However, epigenetic regulation of exosome proteome is not known. Hence, our present study aimed to understand influence of DNA methylation on exosome proteome composition and their influence on endothelial cell (EC) function. DNMT isoforms (DNMT1, DNMT3A, and DNMT3B) were overexpressed using lentivirus in ECs. Exosomes were isolated and characterized from ECs overexpressing DNMT isoforms and C57BL/6 mice plasma treated with 5-aza-2'-deoxycytidine. 3D spheroid assay was performed to understand the influence of exosomes derived from cells overexpressing DNMTs on EC functions. Further, the exosomes were subjected to TMT labelled proteomics analysis followed by validation. 3D spheroid assay showed increase in the pro-angiogenic activity in response to exosomes derived from DNMT overexpressing cells which was impeded by inclusion of 5-aza-2'-deoxycytidine. Our results showed that exosome proteome and PTMs were significantly modulated and were associated with dysregulation of vascular homeostasis, metabolism, inflammation and endothelial cell functions. In vitro and in vivo validation showed elevated DNMT1 and TGF-β1 exosome proteins due to DNMT1 and DNMT3A overexpression, but not DNMT3B which was mitigated by 5-aza-2'-deoxycytidine indicating epigenetic regulation. Further, exosomes induced ED as evidenced by reduced expression of phospho-eNOSser1177. Our study unveils epigenetically regulated exosome proteins, aiding management of vascular complications.

Role of Treg cell subsets in cardiovascular disease pathogenesis and potential therapeutic targets

In the genesis and progression of cardiovascular diseases involving both innate and adaptive immune responses, inflammation plays a pivotal and dual role. Studies in experimental animals indicate that certain immune responses are protective, while others exacerbate the disease. T-helper (Th) 1 cell immune responses are recognized as key drivers of inflammatory progression in cardiovascular diseases. Consequently, the CD4+CD25+FOXP3+ regulatory T cells (Tregs) are gaining increasing attention for their roles in inflammation and immune regulation. Given the critical role of Tregs in maintaining immune-inflammatory balance and homeostasis, abnormalities in their generation or function might lead to aberrant immune responses, thereby initiating pathological changes. Numerous preclinical studies and clinical trials have unveiled the central role of Tregs in cardiovascular diseases, such as atherosclerosis. Here, we review the roles and mechanisms of Treg subsets in cardiovascular conditions like atherosclerosis, hypertension, myocardial infarction and remodeling, myocarditis, dilated cardiomyopathy, and heart failure. While the precise molecular mechanisms of Tregs in cardiac protection remain elusive, therapeutic strategies targeting Tregs present a promising new direction for the prevention and treatment of cardiovascular diseases.

Ginkgo biloba Extract Attenuates the Disruption of Pro- and Anti-inflammatory Balance of Peripheral Blood in Arsenism Patients by Decreasing Hypermethylation of the Foxp3 Promoter Region

Coal-burning type of arsenism, a chronic arsenism caused by environmental arsenic pollution, found firstly at Guizhou Province of China, manifested as the disruption of pro- and anti-inflammatory T cell balance and multiple organ damage, while no specific treatment for the arsenism patients. The effect of methylation of the forkhead box P3 (Foxp3) promoter region on arsenic-induced disruption of pro- and anti-inflammatory T cell balance was first evaluated in this study, between the control and arsenism groups. The results show that arsenic can induce the hypermethylation of 6 sites in the Foxp3 promoter by upregulating the expression of recombinant DNA Methyltransferase 1 (Dnmt1) mRNA, leading to the downregulation of Foxp3 mRNA, Tregs, and interleukin 10 (IL-10, anti-inflammatory cytokine) levels, and increased the levels of interleukin 17 (IL-17, pro-inflammatory cytokine) in the peripheral blood of patients with arsenic poisoning. Further randomized controlled double-blind experiments (including the placebo control groups and the Ginkgo biloba extract (GBE) intervention groups) showed that compared to the placebo control group or before GBE intervention, the levels of Dnmt1 mRNA, Foxp3 methylation, and IL-17 in the peripheral blood of the GBE intervention group were significantly decreased after intervention (P < 0.05), but the levels of regulatory T cells (Tregs) and IL-10 were significantly increased (P < 0.05). Our study provides some limited evidence that GBE can attenuate the disruption of pro- and anti-inflammatory balance of peripheral blood in arsenism patients by decreasing hypermethylation of the Foxp3 promoter region. This study provides scientific basis for further understanding a possible natural medicinal plant, GBE, as a more effective measure to prevent and control the disruption of pro- and anti-inflammatory balance caused by coal-burning type of arsenism.

Theories and Molecular Basis of Vascular Aging: A Review of the Literature from VascAgeNet Group on Pathophysiological Mechanisms of Vascular Aging

Vascular aging, characterized by structural and functional alterations of the vascular wall, is a hallmark of aging and is tightly related to the development of cardiovascular mortality and age-associated vascular pathologies. Over the last years, extensive and ongoing research has highlighted several sophisticated molecular mechanisms that are involved in the pathophysiology of vascular aging. A more thorough understanding of these mechanisms could help to provide a new insight into the complex biology of this non-reversible vascular process and direct future interventions to improve longevity. In this review, we discuss the role of the most important molecular pathways involved in vascular ageing including oxidative stress, vascular inflammation, extracellular matrix metalloproteinases activity, epigenetic regulation, telomere shortening, senescence and autophagy.

Matrine inhibits advanced glycation end products-induced macrophage M1 polarization by reducing DNMT3a/b-mediated DNA methylation of GPX1 promoter

Advanced glycation end products (AGEs) are characterized diabetic metabolites inducing macrophage M1 polarization which is crucial in diabetes-exacerbated atherosclerosis. Matrine was proved anti-atherosclerotic. The current study was aimed to investigate the inhibitory effects of matrine on AGEs- induced macrophage M1 polarization and underlying molecular mechanisms. Primary mouse macrophages were exposed to AGEs. Receptor for AGEs (RAGE) and toll-like receptor 4 (TLR4) were over-expressed by vectors. Matrine was used to treat these cells. Inducible nitric oxide synthase (iNOS) expression and pro-inflammatory cytokine production were used to evaluate macrophage M1 polarization. Oxidative stress was assessed by intracellular reactive oxygen species (ROS) generation, total antioxidant capacity (TAC) and malondialdehyde (MDA) contents. Relative mRNA expression level was determined by real-time PCR. Western blotting was used to evaluate protein and protein phosphorylation levels. Bisulfite sequencing PCR (BSP) was used to evaluate DNA methylation. Matrine reduced AGEs exposure-elevated expressions of DNA methyltransferase (DNA MTase, DNMT)3a and DNMT3b in macrophages which were not affected by RAGE or TLR4 over expressions. DNA methylation rate of GPX1 promoter was reduced from 97.22% to 66.67% in AGEs- exposed macrophages treated by matrine. GPX1 expression was up-regulated by matrine, which further suppressed AGEs/RAGE-mediated oxidative stress. Thus, the activation of down-stream TLR4/STAT1 signaling pathway was inhibited by matrine treatment which eventually suppressed AGEs- induced macrophage M1 polarization. However, these effects of matrine were impaired by RAGE and TLR4 overexpression. Results from this study suggested that matrine inhibited AGEs- induced macrophage M1 polarization by suppressing RAGE-induced oxidative stress-mediated TLR4/STAT1 signaling pathway. Matrine exerted anti-oxidant effects via increasing GPX1 expression by inhibiting DNMT3a/b-induced GPX1 promoter DNA methylation.

DNA Methyltransferase 3b Accelerates the Process of Atherosclerosis

Background

DNA methylation plays a key role in establishing cell type-specific gene expression profiles and patterns in atherosclerosis. The underlying mechanism remains unclear. Previous studies have shown that DNA methyltransferase 3b (DNMT3b) may play an important role in atherosclerosis. This study aimed to establish the regulatory role of DNMT3b in the development of atherosclerosis.

Methods

We constructed a viral vector carrying Dnmt3b shRNA to transduce ApoE-/- mice. Meanwhile, healthy human peripheral blood Treg cells were treated with inhibitor of DNMT3b (AZA and EGCG) or transduced with DNMT3b shRNA.

Results

It showed that Dnmt3b silencing attenuated atherosclerosis, including decreased lesion size and macrophage content and increased collagen and smooth muscle cells content in ApoE-/- mice. To further investigate the possible mechanisms, combined with previous studies by our group, we showed that Foxp3-TSDR methylation level was significantly reduced Foxp3 expression and peripheral blood Treg levels were significantly increased by Dnmt3b shRNA vector transduction in animals committed to western diet for 12 and 18 weeks. Consistently, inhibition of DNMT3b (AZA and EGCG) decreased the expression levels of DNMT3b, which can increase the expression levels of FOXP3, and increase the levels of TGF-β and IL-10 and decrease the levels of IL-β and IFN-γ. After transduction with DNMT3b shRNA, the effect was more obvious.

Conclusions

DNMT3b accelerated atherosclerosis, and may be associated with FOXP3 hypermethylation status in regulatory T cells.

Rivaroxaban Suppresses Atherosclerosis by Inhibiting FXa-Induced Macrophage M1 Polarization-Mediated Phenotypic Conversion of Vascular Smooth Muscle Cells

Background: Factor Xa (FXa) is a mediator initiating and accelerating atherosclerosis (AS). Both macrophage and vascular smooth muscle cells (VSMCs) participate in AS progression. This study was aimed to investigate the mechanisms underlying the effects of the FXa inhibitor rivaroxaban on AS.

Methods: Rivaroxaban was administered to AS mice. Primary macrophages were exposed to FXa, treated with rivaroxaban, and transfected with siRNA silencing protease-activated receptor 2 (PAR2), hypoxia-inducible factor 1α (HIF1α), delta-like receptor 4 (Dll4), and Akt. Interaction between macrophages and VSMCs was assessed by co-culturing systems. Atherosclerotic lesions were evaluated by oil red O stain. Fluorescent staining was used to determine the cell phenotypes. Secretions of inflammatory cytokines and collagen were assessed by ELISA and Sircol assays. Western blotting was used to evaluate the protein expression and phosphorylation levels.

Results: Rivaroxaban reduced lesion area, accumulation of M1 macrophages, and contractile-synthetic phenotypic conversion of VSMCs in atherosclerotic plaques. FXa exposure induced polarization of macrophages toward M1 and Dll4 high expression, which were inhibited by PAR2, Akt1, and HIF1α silencing. Rivaroxaban treatment inhibited PAR2/Akt/HIF1α signaling activation and Dll4 expression in FXa-exposed macrophages. By cell-to-cell contact, M1 macrophages induced Notch signaling activation in VSMCs which committed contractile-synthetic conversion. Rivaroxaban treatment and Dll4 silencing incapacitated macrophage in inducing phenotypic conversion of VSMCs upon cell-to-cell contact.

Conclusion: Rivaroxaban suppresses AS by inhibiting FXa-induced PAR2/Akt/HIF1α signaling activation-mediated macrophage M1 polarization and high Dll4 expression. These macrophages facilitated VSMCs to perform contractile-synthetic phenotypic conversion upon macrophage-VSMCs cell-to-cell contact.

Roles and Mechanisms of DNA Methylation in Vascular Aging and Related Diseases

Vascular aging is a pivotal risk factor promoting vascular dysfunction, the development and progression of vascular aging-related diseases. The structure and function of endothelial cells (ECs), vascular smooth muscle cells (VSMCs), fibroblasts, and macrophages are disrupted during the aging process, causing vascular cell senescence as well as vascular dysfunction. DNA methylation, an epigenetic mechanism, involves the alteration of gene transcription without changing the DNA sequence. It is a dynamically reversible process modulated by methyltransferases and demethyltransferases. Emerging evidence reveals that DNA methylation is implicated in the vascular aging process and plays a central role in regulating vascular aging-related diseases. In this review, we seek to clarify the mechanisms of DNA methylation in modulating ECs, VSMCs, fibroblasts, and macrophages functions and primarily focus on the connection between DNA methylation and vascular aging-related diseases. Therefore, we represent many vascular aging-related genes which are modulated by DNA methylation. Besides, we concentrate on the potential clinical application of DNA methylation to serve as a reliable diagnostic tool and DNA methylation-based therapeutic drugs for vascular aging-related diseases.

ABCA1, TCF7, NFATC1, PRKCZ, and PDGFA DNA methylation as potential epigenetic-sensitive targets in acute coronary syndrome via network analysis

Acute coronary syndrome (ACS) is the most severe clinical manifestation of coronary heart disease.We performed an epigenome-wide analysis of circulating CD4⁺ and CD8⁺ T cells isolated from ACS patients and healthy subjects (HS), enrolled in the DIANA clinical trial, by reduced-representation bisulphite sequencing (RRBS). In CD4⁺ T cells, we identified 61 differentially methylated regions (DMRs) associated with 57 annotated genes (53% hyper- and 47% hypo-methylated) by comparing ACS patients vs HS. In CD8⁺ T cells, we identified 613 DMRs associated with 569 annotated genes (28% hyper- and 72% hypo-methylated) in ACS patients as compared to HS. In CD4⁺ vs CD8⁺ T cells of ACS patients we identified 175 statistically significant DMRs associated with 157 annotated genes (41% hyper- and 59% hypo-methylated). From pathway analyses, we selected six differentially methylated hub genes (NFATC1, TCF7, PDGFA, PRKCB, PRKCZ, ABCA1) and assessed their expression levels by q-RT-PCR. We found an up-regulation of selected genes in ACS patients vs HS (P < 0.001). ABCA1, TCF7, PDGFA, and PRKCZ gene expression was positively associated with CK-MB serum concentrations (r = 0.75, P = 0.03; r = 0.760, P = 0.029; r = 0.72, P = 0.044; r = 0.74, P = 0.035, respectively).This pilot study is the first single-base resolution map of DNA methylome by RRBS in CD4⁺ and CD8⁺ T cells and provides specific methylation signatures to clarify the role of aberrant methylation in ACS pathogenesis, thus supporting future research for novel epigenetic-sensitive biomarkers in the prevention and early diagnosis of this pathology.

Contribution of Regulatory T Cell Methylation Modifications to the Pathogenesis of Allergic Airway Diseases

Regulatory T (Treg) cells are a subtype of CD4⁺ T cells that play a significant role in the protection from autoimmunity and the maintenance of immune tolerance via immune regulation. Epigenetic modifications of Treg cells (i.e., cytosine methylation at the promoter region of the transcription factor, Forkhead Box P3) have been found to be closely associated with allergic diseases, including allergic rhinitis, asthma, and food allergies. In this study, we highlighted the recent evidence on the contribution of epigenetic modifications in Treg cells to the pathogenesis of allergic diseases. Moreover, we also discussed directions for future clinical treatment approaches, with a particular emphasis on Treg cell-targeted therapies for allergic disorders.

Epigenetic Changes Associated With Interleukin-10

IL-10 is a regulator of inflammation and immunosuppression. IL-10 regulates a variety of immune cells to limit and stop the inflammatory response, and thus plays an important role in autoimmune diseases, inflammatory diseases and cancer. IL-10 is closely related to epigenetic modification, in which changes in DNA methylation of IL-10 gene can affect mRNA and protein levels of IL-10. In addition, changes in histone modifications, especially histone acetylation, can also lead to abnormal expression of IL-10 mRNA. At the same time, a handful of IL-10 related microRNAs (miRNAs) are found to be aberrantly expressed in multiple diseases. Besides, long non-coding RNA (lncRNA) growth arrest specific transcript 5 (GAS5) also inhibits IL-10 expression. Here, we reviewed the epigenetic changes related to IL-10 in various diseases, as well as the regulation of IL-10 gene expression in various diseases by epigenetic modifications such as DNA methylation, histone modification, miRNA, and lncRNA.

A male-specific association between AGTR1 hypermethylation and coronary heart disease

The AGTR1 gene encodes angiotensin II receptor type 1, which is involved in cardiovascular diseases such as coronary heart disease (CHD). In the current study, we analyzed AGTR1 promoter methylation level in a Han Chinese population by SYBR green-based quantitative methylation-specific PCR (qMSP). We collected blood samples from 761 CHD patients and 398 non-CHD controls at the Ningbo First Hospital. A data mining analysis was also performed to explore the association between AGTR1 methylation and AGTR1 gene expression, using datasets from the cBioPortal for Cancer Genomics and the Gene Expression Omnibus (GEO) database. Our results showed a significantly higher percentage of methylated reference (PMR) of AGTR1 in male CHD patients compared with male non-CHD controls (median PMR: 2.12% vs. 0.59%, p = 0.037). The data mining analysis showed that AGTR1 expression was significantly increased in human hepatoma HepG2 cells treated with the demethylation agent 5-aza-2’-deoxycytidine (fold = 3.12, p = 0.009). Further data mining analysis using the cholangiocarcinoma (TCGA, PanCancer Atlas) data indicated an inverse association between AGTR1 methylation and AGTR1 expression (r = -0.595, p = 1.29E-04). Overall, our results suggest that AGTR1 methylation is involved in the regulation of AGTR1 gene expression and that AGTR1 hypermethylation is associated with CHD in males. These findings may provide new clues about the pathogenesis of CHD.