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

Background

Acute coronary syndrome (ACS) is the most severe clinical manifestation of coronary heart disease and the leading cause of death worldwide.

Purpose

To perform an epigenome-wide analysis in circulating CD4+ and CD8+ T cells of ACS patients and healthy subjects (HS) enrolled in the DIANA clinical trial (NCT04371809) in order to identify differentially methylated genes (DMGs).

Methods

Genomic DNA was extracted from CD4+ and CD8+ T cells of all subjects and sequenced by the reduced representation bisulfite sequencing (RRBS) platform. Functional pathway analysis was performed and significant DMGs were selected for gene expression validation by qRT-PCR in ACS patients and HS. GeneMANIA was used to built a prediction gene network. Correlation analyses between molecular data and clinical variables were performed.

Results

In CD4+ T cells we identified 61 differentially methylated regions (DMRs) associated to 57 annotated genes of which 53% (n=32) were hyper- and 47% (n=29) were hypo-methylated in ACS patients vs HS. In CD8+ T cells we identified 613 DMRs associated to 569 annotated genes of which 28% (n=173) were hyper- and 72% (n=440) were hypo-methylated between two groups. In both cell type of ACS patients, 175 DMRs were associated to 157 annotated genes of which 41% (n=72) were hyper- and 59% (n=103) were hypo-methylated. From functional analysis, we selected the top 5 DMGs in the prevalent pathways with the highest differential of methylation values. Specifically, we considered 6 hub genes: NFATC1, TCF7, PDGFA, PRKCB, PRKCZ and ABCA1 and determined their respective expression levels by q-RT-PCR. We found a significant up-regulation of the selected genes in ACS patients vs HS (P<0.001 for all comparisons). Correlation analysis showed both common and cell specific correlation patterns. In CD4+ T cells, PDGFA promoter methylation was negatively correlated with CK-MB concentrations (r=−0.79, P=0.018). ABCA1, TCF7, PDGFA and PRKCZ gene expression was positively associated to CK-MB 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).

Conlusions

This study is the first single-base resolution map of DNA methylome by RRBS in CD4+ and CD8+ T cells, providing specific methylation signatures that could help to clarify the role of aberrant methylation in ACS pathogenesis, and provide the basis for the search of novel epigenetic-sensitive biomarkers in the prevention and early diagnosis of this pathology.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Italian Ministry of Health;Italian Ministry of Research and University

A new cryptic host defense peptide identified in human 11-hydroxysteroid dehydrogenase-1 β-like: from in silico identification to experimental evidence

BACKGROUND

Host defence peptides (HDPs) are evolutionarily conserved components of innate immunity. Human HDPs, produced by a variety of immune cells of hematopoietic and epithelial origin, are generally grouped into two families: beta structured defensins and variably-structured cathelicidins. We report the characterization of a very promising cryptic human HDP, here called GVF27, identified in 11-hydroxysteroid dehydrogenase-1 β-like protein.

METHODS

Conformational analysis of GVF27 and its propensity to bind endotoxins were performed by NMR, Circular Dichroism, Fluorescence and Dynamic Light Scattering experiments. Crystal violet and WST-1 assays, ATP leakage measurement and colony counting procedures were used to investigate antimicrobial, anti-biofilm, cytotoxicity and hemolytic activities. Anti-inflammatory properties were evaluated by ELISA.

RESULTS

GVF27 possesses significant antibacterial properties on planktonic cells and sessile bacteria forming biofilm, as well as promising dose dependent abilities to inhibit attachment or eradicate existing mature biofilm. It is unstructured in aqueous buffer, whereas it tends to assume a helical conformation in mimic membrane environments as well as it is able to bind lipopolysaccharide (LPS) and lipoteichoic acid (LTA). Notably it is not toxic towards human and murine cell lines and triggers a significant innate immune response by attenuating expression levels of pro-inflammatory interleukins and release of nitric oxide in LPS induced macrophages.

CONCLUSION

Human GVF27 may offer significant advantages as leads for the design of human-specific therapeutics.

GENERAL SIGNIFICANCE

Human cryptic host defence peptides are naturally no immunogenic and for this they are a real alternative for solving the lack of effective antibiotics to control bacterial infections.