Chemokine receptor 5 (CCR5) deletion polymorphism in North Indian patients with coronary artery disease

Identification of necroptosis-related diagnostic biomarkers in coronary heart disease

Background

The implication of necroptosis in cardiovascular disease was already recognized. However, the molecular mechanism of necroptosis has not been extensively studied in coronary heart disease (CHD).

Methods

The differentially expressed genes (DEGs) between CHD and control samples were acquired in the GSE20681 dataset downloaded from the GEO database. Key necroptosis-related DEGs were captured and ascertained by bioinformatics analysis techniques, including weighted gene co-expression network analysis (WGCNA) and two machine learning algorithms, while single-gene gene set enrichment analysis (GSEA) revealed their molecular mechanisms. The diagnostic biomarkers were selected via receiver operating characteristic (ROC) analysis. Moreover, an analysis of immune elements infiltration degree was carried out. Authentication of pivotal gene expression at the mRNA level was investigated in vitro utilizing quantitative real-time PCR (qRT-PCR).

Results

A total of 94 DE-NRGs were recognized here, among which, FAM166B, NEFL, POLDIP3, PRSS37, and ZNF594 were authenticated as necroptosis-related biomarkers, and the linear regression model based on them presented an acceptable ability to different sample types. Following regulatory analysis, the ascertained biomarkers were markedly abundant in functions pertinent to blood circulation, calcium ion homeostasis, and the MAPK/cAMP/Ras signaling pathway. Single-sample GSEA exhibited that APC co-stimulation and CCR were more abundant, and aDCs and B cells were relatively scarce in CHD patients. Consistent findings from bioinformatics and qRT-PCR analyses confirmed the upregulation of NEFL and the downregulation of FAM166B, POLDIP3, and PRSS37 in CHD.

Conclusion

Our current investigation identified 5 necroptosis-related genes that could be diagnostic markers for CHD and brought a novel comprehension of the latent molecular mechanisms of necroptosis in CHD.

Chemokine Receptor 5, a Double-Edged Sword in Metabolic Syndrome and Cardiovascular Disease

The key characteristic of cardiovascular disease (CVD) is endothelial dysfunction, which is likely the consequence of inflammation. It is well demonstrated that chemokines and their receptors play a crucial role in regulating inflammatory responses, and recently, much attention has been paid to chemokine receptor 5 (CCR5) and its ligands. For example, CCR5 aggravates the inflammatory response in adipose tissue by regulating macrophage recruitment and M1/M2 phenotype switch, thus causing insulin resistance and obesity. Inhibition of CCR5 expression reduces the aggregation of pro-atherogenic cytokines to the site of arterial injury. However, targeting CCR5 is not always effective, and emerging evidence has shown that CCR5 facilitates progenitor cell recruitment and promotes vascular endothelial cell repair. In this paper, we provide recent insights into the role of CCR5 and its ligands in metabolic syndrome as related to cardiovascular disease and the opportunities and roadblocks in targeting CCR5 and its ligands.

Metabolomics as an Approach to Characterise the Contrasting Roles of CCR5 in the Presence and Absence of Disease

Chemokine receptors such as C-C chemokine receptor 5 (CCR5) are activated through interaction with their ligands and are well known for their role in chemotaxis and signal transduction. While serving these roles, cellular responses are effected, hence the immune function of these molecules is established. Given the role of CCR5 in immune function and that the immune and metabolic systems are interlinked, subsequent immune-directed changes should be measurable at a metabolic level. Numerous investigations have reported on metabolic changes associated with CCR5 status in the presence of disease, so as to understand whether specific CCR5 genotypes, frequency and/or levels offer protection to the host or not. However, these metabolic changes were recorded using older conventional techniques. Depending on certain factors such as the disease model, the geography of the samples and/or the ethnic group under study, the role of CCR5 in disease differs. In addition, little is known about CCR5’s role in the absence of an enhanced inflammatory state, such as when infection persists. Metabolomics is defined as the study of metabolites and informs on metabolic changes within living organisms as induced by various stimuli, such as the interaction of CCR5 with its ligand. Since metabolomics reflects the underlying biochemical activity and state of cells/tissues, this review proposes it as a tool to clarify the contrasting roles of CCR5.

Immunobiology of Atherosclerosis: A Complex Net of Interactions

Cardiovascular disease is the leading cause of mortality worldwide, and atherosclerosis the principal factor underlying cardiovascular events. Atherosclerosis is a chronic inflammatory disease characterized by endothelial dysfunction, intimal lipid deposition, smooth muscle cell proliferation, cell apoptosis and necrosis, and local and systemic inflammation, involving key contributions to from innate and adaptive immunity. The balance between proatherogenic inflammatory and atheroprotective anti-inflammatory responses is modulated by a complex network of interactions among vascular components and immune cells, including monocytes, macrophages, dendritic cells, and T, B, and foam cells; these interactions modulate the further progression and stability of the atherosclerotic lesion. In this review, we take a global perspective on existing knowledge about the pathogenesis of immune responses in the atherosclerotic microenvironment and the interplay between the major innate and adaptive immune factors in atherosclerosis. Studies such as this are the basis for the development of new therapies against atherosclerosis.

Emerging role of chemokine CC motif ligand 4 related mechanisms in diabetes mellitus and cardiovascular disease: friends or foes?

Chemokines are critical components in pathology. The roles of chemokine CC motif ligand 4 (CCL4) and its receptor are associated with diabetes mellitus (DM) and atherosclerosis cardiovascular diseases. However, due to the complexity of these diseases, the specific effects of CCL4 remain unclear, although recent reports have suggested that multiple pathways are related to CCL4. In this review, we provide an overview of the role and potential mechanisms of CCL4 and one of its major receptors, fifth CC chemokine receptor (CCR5), in DM and cardiovascular diseases. CCL4-related mechanisms, including CCL4 and CCR5, might provide potential therapeutic targets in DM and/or atherosclerosis cardiovascular diseases.

Genetic epidemiology of coronary artery disease: an Asian Indian perspective

Coronary artery disease (CAD) has emerged as a major cause of morbidity and mortality worldwide. Recent findings on the role of genetic factors in the aetiopathology of CAD have implicated novel genes and variants in addition to those involved in lipid and lipoprotein metabolism. However, our present knowledge is limited due to lack of clarity on their exact identity and the quantum of impact on disease susceptibility, and incident risk. It is a matter of great interest to understand the role of genetic factors in ethnic populations that have a strong underlying predisposition to CAD such as the South Asian populations, particularly among Asian Indians living in India and abroad. Although, a number of isolated studies do implicate certain gene polymorphisms towards enhanced disease susceptibility, the available data remains scanty and inconclusive as they have not been validated in large, prospective cohorts. The present review aims to consolidate the available literature on the genetics of CAD in Asian Indians and seeks to provide insights on the concerns that need to be addressed in future studies to generate information having clinical value.

Relationship of Genetic Polymorphisms of the Chemokine, CCL5, and Its Receptor, CCR5, with Coronary Artery Disease in Taiwan

The chemokine receptor CCR5 polymorphism, which confers resistance to HIV infection, has been associated with reduced risk of cardiovascular disease. However, the association of the chemokine, CCL5, and its receptor, CCR5, polymorphism and coronary artery disease (CAD) in the Taiwanese has not been studied. In this study, 483 subjects who received elective coronary angiography were recruited from Chung Shan Medical University Hospital. CCL5-403 and CCR5-59029 were determined by polymerase chain reaction-restriction fragment length polymorphism. We found that CCL5-403 with TT genotype frequencies was significantly associated with the risk of CAD group (odds ratio = 3.063 and p = 0.012). Moreover, the frequencies of CCR5-59029 with GG or GA genotype were higher than AA genotype in acute coronary syndrome individuals (odds ratio = 1.853, CI = 1.176–2.921, p = 0.008). In conclusion, we found that CCL5-403 polymorphism may increase genetic susceptibility of CAD. CCL5-403 or CCR5-59029 single nucleotide polymorphism may include genotype score and it may predict cardiovascular event.

Selective and Dual Targeting of CCR2 and CCR5 Receptors: A Current Overview

The chemokine receptor 2 (CCR2) and chemokine receptor 5 (CCR5) are important mediators of leukocyte trafficking in inflammatory processes. The emerging evidence for a role of CCR2 and CCR5 receptors in human inflammatory diseases led to a growing interest in CCR2- and CCR5-selective antagonists. In this review, we focus on the recent development of selective CCR2/CCR5 receptor ligands and dual antagonists. Several compounds targeting CCR2, e.g., INCB8761 and MK0812, were developed as promising candidates for clinical trials, but failed to show clinical efficacy as presumed from preclinical models. The role of CCR5 receptors as the second co-receptor for the HIV-host cell fusion led to the development of various CCR5-selective ligands. Maraviroc is the first CCR5-targeting drug for the treatment of HIV-1 infections on the market. The role of CCR5 receptors in the progression of inflammatory processes fueled the use of CCR5 antagonists for the treatment of rheumatoid arthritis. Unfortunately, the use of maraviroc for the treatment of rheumatoid arthritis failed due to its inefficacy. Some of the ligands, e.g., TAK-779 and TAK-652, were also found to be dual antagonists of CCR2 and CCR5 receptors. The fact that CCR2 and CCR5 receptor antagonists contribute to the treatment of inflammatory diseases renders the development of dual antagonists as promising novel therapeutic strategy.

Determination of the CCR5∆32 frequency in Emiratis and Tunisians and the screening of the CCR5 gene for novel alleles in Emiratis

BACKGROUND

The chemokine receptor components play crucial roles in the immune system and some of them serve as co-receptors for the HIV virus. Several studies have documented that variants in chemokine receptors are correlated with susceptibility and resistance to infection with HIV virus. For example, mutations in the chemokine receptor 5 gene (CCR5) resulting in loss-of-function (such as the homozygous CCR5∆32) confer high degree of resistance to HIV infection. Heterozygotes for these variants exhibit slow progression to AIDS. The prevalence of CCR5 polymorphisms varies among ethnic and geographical groups. For example, the CCR5∆32 variant is present in 10-15% of north Europeans but is rarely encountered among Africans. This study aims to identify the prevalence of some CCR5 variants in two geographically distant Arab populations (namely Emiratis and Tunisians).

METHODOLOGY

The prevalence of CCR5 gene variants including CCR5∆32, FS299, C101X, A29S and C178R has been determined using PCR and direct DNA sequencing. A total of 403 unrelated healthy individuals (253 Emiratis and 150 Tunisians) were genotyped for the CCR5∆32 variant using PCR amplification and gel electrophoresis. In addition, 200 Emiratis have been screened for other SNPs using Sanger DNA sequencing.

RESULTS

Among Emiratis, the allele frequency of the CCR5∆32 variant has been found to be 0.002. In addition, two variants L55Q and A159 were found at a frequency of 0.002. Moreover, the prevalence of the CCR5∆32 variant in Tunisians was estimated to be 0.013 which is relatively higher than its frequency in Emiratis but lower than Europeans.

CONCLUSION

We conclude that the allele frequency of the most critical CCR5 polymorphism (∆32) is extremely low among Emiratis compared to other Arabs and North Europeans. In addition, very low allele frequencies of other CCR5 polymorphisms have been detected among Emiratis.

Association of the CCR5Δ32 polymorphism and its ligand RANTES-403G/A polymorphism with coronary artery disease: a meta-analysis

INTRODUCTION

To explore the relationship between polymorphisms in the RANTES and CCR5 genes and the risk of coronary artery disease (CAD).

MATERIALS AND METHODS

We conducted a meta-analysis on two genetic variants (RANTES-403G/A and CCR5Δ32). Publication bias was tested by the Egger's regression test and Begg's test. Sensitivity analysis and subgroup analyses were performed to explore the heterogeneity among studies.

RESULTS

No significant association of RANTES-403G/A polymorphism and CAD risk was observed (dominant model: RR=1.02, 95%CI=0.90-1.06; recessive model: RR=1.27, 95%CI=0.90-1.80). However, after excluding the study conducted by Yangsoo et al., the pooled relative ratio (RR) in the dominant model suggested that the RANTES-403G/A polymorphism was positively associated with CAD risk. The subgroup analyses found that a positive relationship between the polymorphism and CAD risk was restricted to the Caucasian population. A meta-analysis of studies on the CCR5Δ32 polymorphism showed no significant association with CAD risk both in dominant (RR=1.05, 95%CI=0.92-1.21) and recessive (RR=1.27, 95%CI=0.90-1.80) models. Moreover, no association was identified in the subgroup analyses.

CONCLUSIONS

The RANTES-403G/A polymorphism is not associated with CAD risk, but does most likely increase CAD risk in Caucasians. Moreover, no relationship between the CCR5∆32 polymorphism and risk of CAD was found.

Polymorphisms in the CC-chemokine receptor-2 (CCR2) and -5 (CCR5) genes and risk of myocardial infarction among Tunisian male patients

OBJECTIVES

The aim of the present study was to investigate the association between CCR2-Val64Ile and CCR5-Δ32 variants and the estimation of haplotypes with MI in a sample of the Tunisian population.

DESIGN AND METHODS

A total of 290 unrelated MI patients and 282 healthy controls were studied. The CCR2-Val64Ile and CCR5-Δ32 variants were analyzed by PCR-RFLP.

RESULTS

Subjects carrying at least one copy of the CCR5-deletion allele were significantly more common in the control group, suggesting an atheroprotective effect (adjusted OR=0.44, 95% CI=0.28-0.72, p=0.001). Haplotype analysis showed that MI patients had significantly less 64Val-Del haplotype (9.9% vs. 21.3%, OR=0.30, 95% CI=0.21-0.43, p<0.001) and 64Ile-Ins haplotype (12.3% vs. 16.7%, OR=0.58, 95% CI=0.42-0.80, p<0.001).

CONCLUSION

A protective effect of the CCR5-Δ32 polymorphism against MI in the Tunisian population was found.

Chemokine receptor CCR5: from AIDS to atherosclerosis

There is increasing recognition of an important contribution of chemokines and their receptors in the pathology of atherosclerosis and related cardiovascular disease. The chemokine receptor CCR5 was initially known for its role as a co-receptor for HIV infection of macrophages and is the target of the recently approved CCR5 antagonist maraviroc. However, evidence is now emerging supporting a role for CCR5 and its ligands CCL3 (MIP-1α), CCL4 (MIP-1β) and CCL5 (RANTES) in the initiation and progression of atherosclerosis. Specifically, the CCR5 deletion polymorphism CCR5delta32, which confers resistance to HIV infection, has been associated with a reduced risk of cardiovascular disease and both CCR5 antagonism and gene deletion reduce atherosclerosis in mouse models of the disease. Antagonism of CCL5 has also been shown to reduce atherosclerotic burden in these animal models. Crucially, CCR5 and its ligands CCL3, CCL4 and CCL5 have been identified in human and mouse vasculature and have been detected in human atherosclerotic plaque. Not unexpectedly, CC chemokines have also been linked to saphenous vein graft disease, which shares similarity to native vessel atherosclerosis. Distinct roles for chemokine-receptor systems in atherogenesis have been proposed, with CCR5 likely to be critical in recruitment of monocytes to developing plaques. With an increased burden of cardiovascular disease observed in HIV-infected individuals, the potential cardiovascular-protective effects of drugs that target the CCR5 receptor warrant greater attention. The availability of clinically validated antagonists such as maraviroc currently provides an advantage for targeting of CCR5 over other chemokine receptors.

Polymorphism in chemokine receptor genes and risk of acute myocardial infarction in North Indian population

Chemokines regulates the trafficking of leukocytes to the site of inflammation hence may be implicated in cardiac events. Currently no consistent effects have been revealed their role in acute myocardial infarction (MI). The aim of current study was to investigate the impact of human chemokine receptor genetic variants, CCR5-Δ32 insertion/deletion, CCR5-59029-A/G, CX3CR1-V249I and CX3CR1-T280 M on acute MI. 230 acute MI and 300 controls were examined. Patients carrying CCR5-Δ32 genotype were at three times higher risk of developing MI odds ratio (OR, 3.24, CI 1.127-9.356, P = 0.04). Significant association was found with risk of acute MI in recipients who possessed homozygous 59029-A allele (OR 1.47, CI 1.03-2.09, P = 0.03). While CX3CR1-I249 and M280 were found to be protective in MI patients with OR 0.46, CI 0.32-0.66, P < 0.0001 and OR 0.36, CI 0.24-0.55, P < 0.0001, respectively. It might be possible that risk of acute MI is associated with genetic variation in chemokine receptors, i.e., CCR5 and CX3CR1.

The Consequence of a Founder Effect: CCR5-∆32, CCR2-64I and SDF1-3'A Polymorphism in Vlach Gypsy Population in Hungary

Frequencies of genetic polymorphisms of the three most frequent HIV-1 resistance-conferring alleles playing an important role in HIV-1 pathogenesis were analysed in Vlach Gypsy populations living in Hungary, as the largest minority. Mutations in the encoding genes, such as CCR5-∆32, CCR2-64I and SDF1-3'A are shown to result in protective effects against HIV-1 infection and disease progression. 560 samples collected from Vlach Gypsy individuals living in 6 North-East Hungarian settlements were genotyped by PCR-RFLP method. Overall allele frequencies of CCR5-∆32, CCR2-64I and SDF1-3'A were found as 0.122, 0.186 and 0.115 respectively. All the observed genotype frequencies were in accordance with Hardy-Weinberg equilibrium . In regions, however, Vlach Gypsies live in majority and in ethnically homogenous communities, a higher CCR5-∆32 mutations were found, with allele frequencies of 0.148 and 0.140 respectively, which are remarkably higher than those in general Hungarian people, and ten times higher than in regions of North-Western India from where present day Hungarian Gypsies originated in the Middle Ages. In the background of this higher CCR5-∆32 allele frequency in the population analysed in our study a genetic founder effect could be assumed. Allele frequency of CCR2-64I was found to be among the highest in Europe. SDF1-3'A allele frequency in Vlach Gypsies was significantly lower than in ethnic Hungarians. 63% of the total 560 individuals tested carried at least one of the mutations studied. These results could partially explain the low incidence of HIV/AIDS among Vlach Gypsies in Hungary.

Genetic association of the CCR5 region with lipid levels in at-risk cardiovascular patients

BACKGROUND

There is mounting evidence to suggest that chemokine receptor 5 (CCR5) plays an important role in the development and progression of atherosclerosis. A naturally occurring variant of the CCR5 gene CCR532, exists at allele frequencies of typically 10% in European populations and results in a nonfunctional CCR5 receptor.

METHODS AND RESULTS

The CCR5Delta32 deletion and 26 other variants within the chemokine receptor 2-CCR5-chemokine receptor-like protein 2 (CCRL2) gene cluster spanning 59 kilobases of chromosome 3 were genotyped in 5748 subjects from the Treating to New Targets atorvastatin trial to determine whether genetic associations could be identified with circulating lipid values and cardiovascular disease. Our results demonstrate an association between the CCR5Delta32 deletion and increased plasma high-density lipoprotein cholesterol and decreased plasma triglycerides, both of which are beneficial from a cardiovascular perspective. Three single-nucleotide polymorphisms (rs1154428, rs6808835, and rs6791599) in CCRL2 in linkage disequilibrium (r(2)> or =0.65) with CCR5Delta32 and located up to 45 kilobases distal to it were associated with high-density lipoprotein cholesterol. The high-density lipoprotein cholesterol and triglycerides findings were replicated in an additional set of >6000 individuals from the Incremental Decrease in Endpoints through Aggressive Lipid Lowering atorvastatin trial.

CONCLUSIONS

Our study provides evidence that a locus within the region of the genome encompassing the CCR5-CCRL2 region is associated with lipid levels and suggests that chemokine activity influences lipid levels in populations with preexisting cardiovascular disease. CLINICAL TRIAL REGISTRATION- clinicaltrials.gov. Identifier: TNT, NCT00327691; IDEAL, NCT00159835.

The Latitude Wise Prevalence of the CCR5-Δ32-HIV Resistance Allele in India

The chemokine receptor CCR5 plays a crucial role during CD4-mediated entry of HIV-1 in macrophages and a 32 bp deletion in the CCR5 gene (CCR5-Δ32) confers protection against HIV infection and AIDS progression. To evaluate the contribution of this host genetic factor in aggravating India's HIV/AIDS problem, we exclusively examined the frequency of CCR5-Δ32 in 43 different ethnic endogamous Indian populations comprising 1,882 individuals and its latitude-wise distribution in India. This is the first report of prevalence and latitude-wise distribution of CCR5-Δ32 in such large scale in India, which indicates that most of the Indian populations lack the CCR5-Δ32 mutation. This mutation was exhibited in only 13 out of the 43 ethnic populations of India studied with allelic frequency 0.62 - 5%. Southward decreasing cline was observed for frequencies of CCR5-Δ32 (0.79% to 5.0% in North vs. 0.62% to 1.4% South). These results are in accordance with HIV/AIDS prevalence in India, and suggest that absence of CCR5-Δ32 mutation may be one of the important factors for HIV/AIDS incidence in India.

Association of chemokines receptor (CCR5 Delta32) in idiopathic recurrent miscarriages among north Indians

PURPOSE

Human reproduction is a complex process involving multiple factors for the success of pregnancy. Chemokines are one of the immunomodulators which may determine pregnancy outcome. In the present study, we have tested genetic association between CCR5 Delta32 polymorphism and idiopathic recurrent miscarriages (IRM) among north Indians.

METHODS

Two hundred patients and 300 age, sex and ethnically matched controls were genotyped for CCR5 Delta32 polymorphism, genotype and allele frequencies were compared in both the groups.

RESULTS

IRM patients had a three times higher (5.5 vs. 1.7%) frequency of heterozygote genotype (P = 0.0335, OR = 3.43; 95% CI = 1.17-10.04). Allele frequency in IRM patients was 3.7 and 0.83% among controls and the differences were statistically significant (P = 0.0349, OR = 3.37; 95% CI = 1.16-9.76).

CONCLUSIONS

Our results demonstrated that it had a higher frequency of CCR5 Delta32 at allelic level suggesting a possible susceptibility trend (OR = 3.43) and CCR5 Delta32 may be a potential genetic risk factor for IRM.

CCR5 Delta32 polymorphism: associated with gallbladder cancer susceptibility

Inflammation of gallbladder is an established risk factor for gallbladder cancer (GBC) pathogenesis. Chemokine receptors play crucial role in antitumour immunity and are involved in inflammation and pathogenesis of cancers. Present study was aimed to examine the role of CCR5 Delta32 polymorphism in conferring genetic susceptibility to GBC. Present case-control study included 144 proven GBC patients and 210 healthy controls. Genotyping was done by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Statistically significant difference was observed in distribution of CCR5+/Delta32 genotype (P = 0.028) [odds ratio (OR) = 2.850; 95% confidence interval (CI) = 1.1-7.2] and CCR5 Delta32 allele (P = 0.012) (OR = 3.145, 95% CI = 1.2-7.7) in GBC patients which was conferring high risk. Stratification of GBC patients showed significant association of CCR5+/Delta32 genotype and CCR5 Delta32 allele with GBC patients with and without gallstones. Analysis based on age of onset and gender suggested significant association of CCR5 Delta32 allele with early onset (<50 years) of the disease but only marginal influence of gender in CCR5 Delta32-mediated risk of cancer. Risk was further modulated by tobacco usage and significantly increased risk was observed in tobacco users with CCR5+/Delta32 genotype. In conclusion, CCR5+/Delta32 genotype and CCR5 Delta32 allele confer significant risk for GBC particularly in patients with early onset and tobacco usage. Role of CCR5+/Delta32 polymorphism in GBC susceptibility is independent of gallstone formation.