Identification of a novel immune infiltration-related gene signature, MCEMP1, for coronary artery disease

Background

This study aims to identify a novel gene signature for coronary artery disease (CAD), explore the role of immune cell infiltration in CAD pathogenesis, and assess the cell function of mast cell-expressed membrane protein 1 (MCEMP1) in human umbilical vein endothelial cells (HUVECs) treated with oxidized low-density lipoprotein (ox-LDL).

Methods

To identify differentially expressed genes (DEGs) of CAD, datasets GSE24519 and GSE61145 were downloaded from the Gene Expression Omnibus (GEO) database using the R "limma" package with p < 0.05 and |log2 FC| > 1. Gene ontology (GO) and pathway analyses were conducted to determine the biological functions of DEGs. Hub genes were identified using support vector machine-recursive feature elimination (SVM-RFE) and least absolute shrinkage and selection operator (LASSO). The expression levels of these hub genes in CAD were validated using the GSE113079 dataset. CIBERSORT program was used to quantify the proportion of immune cell infiltration. Western blot assay and qRT-PCR were used to detect the expression of hub genes in ox-LDL-treated HUVECs to validate the bioinformatics results. Knockdown interference sequences for MCEMP1 were synthesized, and cell proliferation and apoptosis were examined using a CCK8 kit and Muse® Cell Analyzer, respectively. The concentrations of IL-1β, IL-6, and TNF-α were measured with respective enzyme-linked immunosorbent assay (ELISA) kits.

Results

A total of 73 DEGs (four down-regulated genes and 69 up-regulated genes) were identified in the metadata (GSE24519 and GSE61145) cohort. GO and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis results indicated that these DEGs might be associated with the regulation of platelet aggregation, defense response or response to bacterium, NF-kappa B signaling pathway, and lipid and atherosclerosis. Using SVM-RFE and LASSO, seven hub genes were obtained from the metadata. The upregulated expression of DIRC2 and MCEMP1 in CAD was confirmed in the GSE113079 dataset and in ox-LDL-treated HUVECs. The associations between the two hub genes (DIRC2 and MCEMP1) and the 22 types of immune cell infiltrates in CAD were found. MCEMP1 knockdown accelerated cell proliferation and suppressed cell apoptosis for ox-LDL-treated HUVECs. Additionally, MCEMP1 knockdown appeared to decrease the expression of inflammatory factors IL-1β, IL-6, and TNF-α.

Conclusions

The results of this study indicate that MCEMP1 may play an important role in CAD pathophysiology.

Major Adverse Cardiovascular Events: The Importance of Serum Levels and Haplotypes of the Anti-Inflammatory Cytokine Interleukin 10

BACKGROUND

Cardiovascular diseases (CVDs) represent major medical and socio-economic challenges worldwide. There is substantial evidence that CVD is closely linked to inflammatory changes triggered by a complex cytokine network. In this context, interleukin 10 (IL-10) plays an important role as a pleiotropic cytokine with an anti-inflammatory capacity. In this study (a substudy of ClinTrials.gov, identifier: NCT01045070), the prognostic relevance of IL-10 levels and IL-10 haplotypes (rs1800896/rs1800871/rs1800872) was assessed regarding adverse cardiovascular outcomes (combined endpoint: myocardial infarction, stroke/transient ischemic attack, cardiac death and death according to stroke) within a 10-year follow-up.

PATIENTS AND METHODS

At baseline, 1002 in-patients with CVD were enrolled. Serum levels of IL-10 were evaluated utilizing flow cytometry (BD™ Cytometric Bead Array). Haplotype analyses were carried out by polymerase chain reactions with sequence-specific primers (PCR-SSP).

RESULTS

In a survival analysis, IL-10 haplotypes were not proven to be cardiovascular prognostic factors in a 10-year follow-up (Breslow test: p = 0.423). However, a higher IL-10 level was associated with adverse cardiovascular outcomes (Breslow test: p = 0.047). A survival analysis considering adjusted hazard ratios (HRs) could not confirm this correlation (Cox regression: adjusted HR = 1.26, p = 0.168).

CONCLUSION

In the present study, an elevated IL-10 level but not IL-10 haplotypes was linked to adverse cardiovascular outcomes (10-year follow-up) in a cohort of CVD patients.

Interleukin-10 -1082 G/A polymorphism and its association with early or severe presentation of coronary artery disease: A systematic review and meta-analysis

INTRODUCTION

Interleukin-10 (IL-10) is an anti-inflammatory cytokine with potent deactivating properties on macrophages and T cells; and plays an important role in atherosclerotic plaque maturation and rupture. A guanine (G) to adenine (A) substitution in the IL-10 gene at -1082 bp (rs1800896) has been associated with reduced in IL-10 production in vitro. Against this background, we tested the association of IL-10 -1082G/A with early or severe presentation of coronary artery disease (CAD) using a systematic review and updated meta-analysis of published association studies.

MATERIALS AND METHODS

Relevant studies were identified following a comprehensive online search on PubMed, EMBASE, MEDLINE, Scopus, Cochrane library and Web of Science databases and stratified into two subgroups based on mode of CAD presentation: early or severe and non-severe. Study level odds ratios (ORs) and their 95% confidence intervals (CI) were pooled using random effects employing a Z test.

RESULTS

A total of 24 studies were included for quantitative synthesis with a cumulative sample of 19,135 (11,143 cases / 7,992 controls). A significant association was derived for IL-10 -1082G/A and early or severe CAD via dominant, recessive, and allelic genetic model comparisons [OR 1.24 (95 % CI 1.02, 1.50), p = 0.03; OR 1.32 (95 % CI 1.03, 1.69), p = 0.03 and OR 1.18 (95 % CI 1.02, 1.36), p = 0.02 respectively]. In contrast, no significant association was seen for the pooled group or non-severe CAD subgroup (p = NS). Sensitivity analysis showed consistent results.

CONCLUSIONS

IL-10 -1082G/A appears to be associated with early or severe presentation of CAD. Further studies are warranted to confirm this association.

Genotyping of interleukins-18 promoters and their correlation with coronary artery stenosis in Saudi population

BACKGROUND

Complex coronary atherosclerotic lesions often lead to coronary occlusion, clinically represented as a single-vessel disease (SVD) and multivessel disease (MVD). These occlusions could hinder the blood flow in coronary arteries that affects appropriate management of the CVD. The current study intended to genotype interleukin (IL)-18 promoter's hotspots (rs187238, rs1946518, and rs1946519) and their possible association with coronary artery stenosis.

MATERIAL AND METHODS

The IL-18 promoter genotyping was performed by the Sanger method along with the examination of biochemical parameters in 125 study subjects categorized into three groups, viz. controls, SVD and MVD.

RESULTS

The current study observed a significant association of diabetes, hypertension, and dyslipidemia between the studied group's viz. healthy controls, SVD, and MVD. Fasting blood sugar and glycosylated hemoglobin (HBA1C) were also significantly enhanced from 4.82 vs. 8.01 and 4.33 vs. 8.27, in SVD, and MVD respectively. Despite the visible differences in the pattern of genotypic and allelic expressions, the current study did not show any statistically significant correlation with IL-18 promoter polymorphism at its hotspots with controls, SVD, and MVD subjects. The only exception of the above results was the distribution of allelic frequency at the rs1946519 hotspot, where a significant change (P < 0.05) was observed.

CONCLUSION

This study is of additional value to our previous reports, revealing the pattern of genotypes and allelic frequency of IL-18 promoters in a small cohort of Saudi ethnicity. Further investigations on larger sample size are recommended to envisage the presence of functional mutations in the IL-18 gene that could establish or rule out the possible association of IL-18 polymorphism with SVD and MVD.

Polymorphisms and haplotypes of IL2RA, IL10, IFNG, IRF5, and CCR2 are associated with Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis in children

OBJECTIVE

Cytokine storms are central to the development of Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH). Previous studies have shown that single-nucleotide polymorphisms (SNPs) of cytokine genes may be associated with the development of EBV-HLH in children. As such, we investigated the association between susceptibility to EBV-HLH in children and SNPs and haplotypes of genes encoding interleukin-2 receptor subunit alpha (IL2RA), interleukin-10 (IL10), interferon gamma (IFNG), interferon regulatory factor 5 (IRF5), and C-C chemokine receptor 2 (CCR2).

METHODS

Sixty-six children with EBV-HLH and 58 healthy EBV-seropositive controls were enrolled in this study. SNPs of IL2RA rs2104286, rs12722489, and rs11594656; IL10 rs1800896, rs1800871, and rs1800872; IFNG rs2430561, IRF5 rs2004640, and CCR2 rs1799864 were assayed and genotyped using the SNaPshot technique.

RESULTS

Frequencies of the A allele of IL2RA rs2104286 and IL10 rs1800896, and C allele of IL-10 rs1800872 were significantly higher in the EBV-HLH group than in the control group. The AA genotype of IL2RA rs2104286 and IL10 rs1800896, and the CC genotype of IL10 rs1800872 might be associated with a significantly high risk of EBV-HLH. However, the frequencies of genotypes and alleles of IL2RA rs2104286, IL10 rs1800871, IFNG rs2430561, IRF5 rs2004640, and CCR2 rs1799864 were similar in both groups. Additionally, IL2RA AGT (rs2104286-rs12722489-rs11594656) and IL10 ACC (rs1800896-rs1800871-rs1800872) haplotypes were also associated with an increased risk of EBV-HLH.

CONCLUSIONS

SNPs of IL2RA rs2104286, IL10 rs1800896 and rs1800872 and the haplotypes of IL2RA AGT and IL10 ACC were highly associated with susceptibility to EBV-HLH in children.

Associations between interleukin 18 gene polymorphisms and susceptibility to vasculitis: A meta-analysis

Interleukin 18 (IL18), a pro-inflammatory cytokine, affects the development and progress of vasculitis. The production, expression, and function of this cytokine are affected by polymorphisms of promoter region of the IL18 gene. In this study, a meta-analysis of the associations between several IL18 polymorphisms and susceptibility to vasculitis was performed. Published literature from PubMed and Embase were retrieved. In total, nine studies comprising 1006 patients with vasculitis and 1499 controls combined, and the investigating the rs187238, rs194618, and rs360719 polymorphisms of the promoter region of the IL18 gene, were included in the meta-analysis. Pooled odds ratios (OR) and 95% confidence intervals (CI) were estimated with fixed-effects model or random-effects model. The recessive model of the rs194618 polymorphism was found to be significantly associated with a high susceptibility to vasculitis (OR = 1.54, 95% CI = 1.02–2.33, P = 0.04), especially in the Mongoloid race, where the A allele of rs194618 was associated with a low risk of the disease (OR = 0.77, 95% CI = 0.62–0.95, P = 0.01). By contrast, the rs187238 and rs360719 polymorphisms were not associated with this inflammatory condition. This meta-analysis showed that some IL18 polymorphisms are associated with susceptibility to vasculitis. (Sarcoidosis Vasc Diffuse Lung Dis 2020; 37 (2): 203-211)