Polymorphisms in the CC-chemokine receptor-2 (CCR2) and -5 (CCR5) genes and risk of coronary heart disease among US women

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.

CCR5 deficiency: Decreased neuronal resilience to oxidative stress and increased risk of vascular dementia

INTRODUCTION

As the chemokine receptor5 (CCR5) may play a role in ischemia, we studied the links between CCR5 deficiency, the sensitivity of neurons to oxidative stress, and the development of dementia.

METHODS

Logistic regression models with CCR5/apolipoprotein E (ApoE) polymorphisms were applied on a sample of 205 cognitively normal individuals and 189 dementia patients from Geneva. The impact of oxidative stress on Ccr5 expression and cell death was assessed in mice neurons.

RESULTS

CCR5-Δ32 allele synergized with ApoEε4 as risk factor for dementia and specifically for dementia with a vascular component. We confirmed these results in an independent cohort from Italy (157 cognitively normal and 620 dementia). Carriers of the ApoEε4/CCR5-Δ32 genotype aged ≥80 years have an 11-fold greater risk of vascular-and-mixed dementia. Oxidative stress-induced cell death in Ccr5-/- mice neurons.

DISCUSSION

We propose the vulnerability of CCR5-deficient neurons in response to oxidative stress as possible mechanisms contributing to dementia.

Contribution of immune cells to intervertebral disc degeneration and the potential of immunotherapy

Substantial evidence supports that chronic low back pain is associated with intervertebral disc degeneration (IDD), which is accompanied by decreased cell activity and matrix degradation. The role of immune cells, especially macrophages, in a variety of diseases has been extensively studied; therefore, their role in IDD has naturally attracted widespread scholarly interest. The IVD is considered to be an immunologically-privileged site given the presence of physical and biological barriers that include an avascular microenvironment, a high proteoglycan concentration, high physical pressure, the presence of apoptosis inducers such as Fas ligand, and the presence of notochordal cells. However, during IDD, immune cells with distinct characteristics appear in the IVD. Some of these immune cells release factors that promote the inflammatory response and angiogenesis in the disc and are, therefore, important drivers of IDD. Although some studies have elucidated the role of immune cells, no specific strategies related to systemic immunotherapy have been proposed. Herein, we summarize current knowledge of the presence and role of immune cells in IDD and consider that immunotherapy targeting immune cells may be a novel strategy for alleviating IDD symptoms.

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.

Chemokines in human obesity

Obesity and type 2 diabetes have been shown to be associated with chronic inflammation. Despite extensive evidence for inflammatory mediators in the obese patients and multiple clinical trials, the outcome has been disappointing. In murine models recruitment of immune cells during inflammation has been shown to contribute to the chronic inflammation. Clearcut evidence for the differential expression of chemokines that mediate this recruitment is not available. In this short review we discuss the observations on CCL2 and CCL5 in human obesity.

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.

Variety matters: Diverse functions of monocyte subtypes in vascular inflammation and atherogenesis

Monocytes are important mediators of the innate immunity by recognizing and attacking especially bacterial pathogens but also play crucial roles in various inflammatory diseases, including vascular inflammation and atherosclerosis. Maturation, differentiation and function of monocytes have been intensively explored for a long time in innumerable experimental and clinical studies. Monocytes do not represent a uniform cell type but could be further subdivided into subpopulations with distinct features and functions. Those subpopulations have been identified in experimental mouse models as well as in humans, albeit distinguished by different cell surface markers. While Ly6C is used for subpopulation differentiation in mice, corresponding human subsets are differentiated by CD14 and CD16. In this review, we specifically focused on new experimental insights from recent years mainly in regard to murine monocyte subpopulations and their roles in vascular inflammation und atherogenesis.

Up-regulated expression of CD86 on circulating intermediate monocytes correlated with disease severity in psoriasis

BACKGROUND

The number of intermediate monocytes (CD14⁺⁺CD16⁺) increases in many inflammatory conditions. However, it is not yet known which functional markers expressed by these populations are linked to the pathogenesis of psoriasis.

OBJECTIVES

We evaluated the expression of functional markers on circulating intermediate monocytes. Our goal was to correlate specific populations and their markers with the clinical severity of psoriasis.

METHODS

A cohort of 43 psoriatic patients was subjected to analysis. The proportion of intermediate monocytes with CD86 expression was evaluated by flow cytometry. Serum beta defensin-2 levels were measured by ELISA. Immunofluorescent staining was performed in order to identify the presence of CD14⁺CD16⁺ cells that co-expressed CD86 in affected skin tissues.

RESULTS

Upregulated expression of CD86 on the intermediate subset (but not the number of intermediate monocytes) correlated with clinical severity as measured by PASI scores and serum beta defensin-2 levels. Immunostaining also showed the presence of CD86⁺CD14⁺CD16⁺ cells in the epidermis and dermis of psoriatic plaques, which was associated with increased epidermal proliferation.

CONCLUSION

These results suggest that the expression of CD86 on circulating intermediate monocytes could be used as an index in clinical practice and provide novel insights into how these cells join a complex immune network under the pathological conditions of psoriasis.

Impact of CD14++CD16+ monocytes on plaque vulnerability in diabetic and non-diabetic patients with asymptomatic coronary artery disease: a cross-sectional study

Background

Previously, we have reported that daily glucose fluctuations could affect coronary plaque vulnerability, but the underlying mechanisms remained unclear. This study sought to investigate the impact of CD14⁺⁺CD16⁺ monocytes on plaque vulnerability, as assessed by virtual histology intravascular ultrasound (VH-IVUS), as well as their relationship to fluctuating glucose levels in patients with asymptomatic coronary artery disease (CAD).

Methods

Fifty-one patients with asymptomatic CAD, who were undergoing lipid-lowering therapy and underwent VH-IVUS evaluation for angiographically mild to moderate lesions, were enrolled in the study. Standard VH-IVUS parameters, including the percentage volume of the necrotic core (%NC) within the plaque and the presence of a virtual histology thin-cap fibroatheroma (VH-TCFA), were then evaluated. Additionally, monocyte subsets were assessed by flow cytometry, and daily glucose fluctuations were analyzed by measuring the mean amplitude of glycemic excursion (MAGE).

Results

Among 82 plaques from 22 diabetes mellitus (DM) patients and 29 non-DM patients, 15 VH-TCFAs were identified. CD14⁺⁺CD16⁺ monocyte counts significantly correlated with both  %NC and the presence of VH-TCFA (%NC: r = 0.339, p = 0.002; VH-TCFA: p = 0.003). Multivariate logistic regression analysis revealed that CD14⁺⁺CD16⁺ monocyte counts were independently associated with VH-TCFA (odds ratio = 1.029, p = 0.004). Furthermore, CD14⁺⁺CD16⁺ monocyte counts were significantly correlated with the MAGE score in the non-DM patients (r = 0.544, p = 0.005).

Conclusions

CD14⁺⁺CD16⁺ monocyte levels are associated with coronary plaque vulnerability and can serve as a biomarker for VH-TCFA in patients with CAD undergoing lipid-lowering therapy. In patients without DM, glucose fluctuations may alter the balance of monocyte subsets.

Trial registration UMIN Registry number: UMIN000021228

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-017-0577-8) contains supplementary material, which is available to authorized users.

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.

Chemokine genetic polymorphism in human health and disease

Chemokine receptor-ligand interaction regulates transmigration of lymphocytes and monocytes from circulation to the inflammatory sites. CC chemokine receptors, chemokine receptor 2(CCR2) and 5 (CCR5) are important in recruitment of immune cells as well as non-immune cells under pathological condition. CCR2, CCR5 and their ligands (CCL2 and CCL5) are major contributor to the autoimmune and inflammatory diseases and cancer. Currently studies are being done to explore genetic variations in chemokine genes and their involvement in diseases that could make clear disease severity and deaths. Conflicting results of studies in different populations and diseases promoted to investigate chemokines genetic polymorphisms in miscellaneous diseases. This study is aimed to evaluate the influence of chemokines genetic polymorphisms in pathogenesis and outcome of prevalent non infectious diseases. Present study demonstrates the likely role played by genetic variations in drug response and evolution. Moreover this study highlights chemokine as therapeutic target and diagnostic biomarker in pathological condition.

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.

The Role of Different Monocyte Subsets in the Pathogenesis of Atherosclerosis and Acute Coronary Syndromes

The inflammation underlying both atherosclerosis and acute coronary syndromes is strongly related to monocyte-related actions. However, different monocyte subsets can play differential roles in the formation and destabilization of atherosclerotic plaque as well as healing of damaged myocardial tissue. Monocytes are currently being divided into three functionally distinct subsets with different levels of CD14 (cluster of differentiation 14) and CD16 expression. Thus, there are classical CD14++CD16-, intermediate CD14++CD16+ and non-classical CD14+CD16++ monocytes. Here, we summarize the current knowledge on complex activities of different monocyte subsets in atherosclerosis and acute coronary syndromes. Moreover, we discuss which monocyte subsets can serve either as predictive biomarkers of cardiovascular risk or as potential targets used in atherosclerosis and its complications.

The impact of CCR5-Δ32 deletion on C-reactive protein levels and cardiovascular disease: Results from the Danish Blood Donor Study

BACKGROUND AND PURPOSE

The C-C chemokine receptor 5-Δ32 deletion (CCR5-Δ32) has been associated with lower levels of C-reactive protein (CRP), but the effect on cardiovascular diseases is uncertain. This study addresses the impact of CCR5-Δ32 on the risk of low-grade inflammation and hospitalization with cardiovascular diseases in a large cohort of blood donors.

METHODS

Genotyping of 15,206 healthy participants from The Danish Blood Donor Study for CCR5-Δ32 was performed and combined with CRP measurements and questionnaire data. Cardiovascular disease diagnoses were identified by ICD-10 codes in the Danish National Patient Registry.

RESULTS

CCR5-Δ32-carriers had a higher risk of hospitalization for cardiovascular diseases when compared with wild-type homozygotes (hazard ratio = 1.35, 95%-confidence interval: 1.00-1.87). CRP levels were unaffected by the CCR5-Δ32 deletion.

CONCLUSION

In this cohort, carriers of the CCR5-Δ32 deletion had normal CRP levels but a borderline significant increased risk of cardiovascular diseases.

Association of serum uric acid and coronary artery disease in premenopausal women

Objective

To date, no study in the published literature has investigated the role of various serum uric acid (SUA) concentrations in the development of angiographically-proven coronary artery disease (CAD) in premenopausal women. Therefore, the aim of this study was to investigate the role SUA levels may play in the prevalence, severity, and prognosis of CAD in premenopausal women.

Methods

This cross-sectional retrospective study included 607 premenopausal women who had undergone coronary angiography. The CAD diagnosis was based upon stenosis affecting ≥50% of the luminal diameter. Association of the SUA levels with CAD prevalence, severity, and clinical outcomes were assessed by statistical analysis.

Results

In total, 369 (60.8%) of the patients were diagnosed with CAD. The CAD patients had significantly higher SUA levels than those without CAD (5.3±1.9 vs. 4.8±1.7 mg/dL, P = 0.001). The SUA levels were found to be significantly associated with CAD prevalence (P = 0.013). Patients with higher levels of SUA also showed increased rates of multivessel disease and composite end-points, such as major adverse cardiac events. Furthermore, multivariate analysis identified abnormally high levels of uric acid (hyperuricemia) as an independent risk factor for CAD (OR 1.51 (1.11–2.53), P<0.05).

Conclusions

The SUA levels are significantly associated with the prevalence of CAD. The SUA levels may be a predictor for incidence of major cardiovascular events in premenopausal women.

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.

The CCR5 chemokine receptor mediates vasoconstriction and stimulates intimal hyperplasia in human vessels in vitro

AIMS

The chemokine receptor CCR5 and its inflammatory ligands have been linked to atherosclerosis, an accelerated form of which occurs in saphenous vein graft disease. We investigated the function of vascular smooth muscle CCR5 in human coronary artery and saphenous vein, vascular tissues susceptible to atherosclerosis, and vasospasm.

METHODS AND RESULTS

CCR5 ligands were vasoconstrictors in saphenous vein and coronary artery. In vein, constrictor responses to CCL4 were completely blocked by CCR5 antagonists, including maraviroc. CCR5 antagonists prevented the development of a neointima after 14 days in cultured saphenous vein. CCR5 and its ligands were expressed in normal and diseased coronary artery and saphenous vein and localized to medial and intimal smooth muscle, endothelial, and inflammatory cells. [(125)I]-CCL4 bound to venous smooth muscle with KD = 1.15 ± 0.26 nmol/L and density of 22 ± 9 fmol mg(-1) protein.

CONCLUSIONS

Our data support a potential role for CCR5 in vasoconstriction and neointimal formation in vitro and imply that CCR5 chemokines may contribute to vascular remodelling and augmented vascular tone in human coronary artery and vein graft disease. The repurposing of maraviroc for the treatment of cardiovascular disease warrants further investigation.

C-C chemokine receptor type five (CCR5): An emerging target for the control of HIV infection

When HIV was initially discovered as the causative agent of AIDS, many expected to find a vaccine within a few years. This has however proven to be elusive; it has been approximately 30 years since HIV was first discovered, and a suitable vaccine is still not in effect. In 2009, a paper published by Hutter et al. reported on a bone marrow transplant performed on an HIV positive individual using stem cells that were derived from a donor who was homozygous for a mutation in the CCR5 gene known as CCR5 delta-32 (Δ32) (Hütter et al., 2009). The HIV positive individual became HIV negative and remained free of viral detection after transplantation despite having halted anti-retroviral (ARV) treatment. This review will focus on CCR5 as a key component in HIV immunity and will discuss the role of CCR5 in the control of HIV infection.

Expression and relationship of proinflammatory chemokine RANTES/CCL5 and cytokine IL-1β in painful human intervertebral discs

STUDY DESIGN

Laboratory study.

OBJECTIVE

To evaluate expression of chemokine regulated and normal T cell expressed and secreted (RANTES)/C-C motif ligand 5 (CCL5) and interleukins in intervertebral discs (IVDs) specimens from patients with discogram-proven painful degeneration.

SUMMARY OF BACKGROUND DATA

Discogenic back pain results in tremendous costs related to treatment and lost productivity. The relationship between inflammation, degeneration (IVD), and cytokine upregulation is well established, but other mediators of the inflammatory cascade are not well characterized.

METHODS

Painful IVDs were taken from 18 patients undergoing surgery for discogenic pain with positive preoperative discogram. Painless control tissue was taken at autopsy from patients without back pain/spinal pathology or spinal levels with negative discograms resected for deformity.Quantitative real time polymerase chain reaction (qRT-PCR) was performed to evaluate RANTES, IL-1β, IL-6, and IL-8 expression in painful and control discs. RANTES and interleukin expression were analyzed on the basis of Pfirrmann grade.Disc cells were cultured in alginate beads using 2 groups: an untreated group and a group treated with 10 ng/mL IL-1β, 10 ng/mL TNF-α, and 1% fetal bovine serum to induce a degenerative phenotype.

RESULTS

Nine painless IVD specimens and 7 painful IVD specimens were collected. RANTES expression demonstrated a 3.60-fold increase in painful discs versus painless discs, a significant difference (P = 0.049). IL-1β expression demonstrated significantly higher expression in painful discs (P = 0.03). RANTES expression data demonstrated significant upregulation with increasing Pfirrmann grade (P = 0.045). RANTES expression correlated significantly with IL-1β expression (ρ = 0.67, P < 0.0001). RANTES expression increased more than 200-fold in the alginate culture model in cells treated with IL-1β/TNF-α, 1% fetal bovine serum (P < 0.001).

CONCLUSION

RANTES and IL-1β expression was significantly elevated in painful IVDs after careful selection of painless versus painful IVD tissue. RANTES expression was found to correlate significantly with expression of IL-1β. RANTES was upregulated by IL-1β/TNF-α/1% fetal bovine serum an in vitro treatment to induce a degenerative phenotype.

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.

CD14++CD16+ monocytes independently predict cardiovascular events: a cohort study of 951 patients referred for elective coronary angiography

OBJECTIVES

The aim of this study was to analyze the yet ill-defined relationship of distinct human monocyte subsets with cardiovascular outcomes in a broad patient population at cardiovascular risk.

BACKGROUND

Monocytes, the most abundant immune cell type found in atherosclerotic plaques, are crucial promoters of atherogenesis. Three distinct human monocyte subsets exist: classical CD14++CD16-, intermediate CD14++CD16+, and nonclassical CD14+CD16++ monocytes. Immunomodulation of distinct monocyte subsets has recently been discussed as a new therapeutic avenue in atherosclerosis.

METHODS

Cardiovascular events in 951 subjects referred for elective coronary angiography were prospectively analyzed. Monocyte subset analysis was performed using flow cytometry, blinded to patients' clinical characteristics, and patients were categorized according to quartiles of total monocyte and monocyte subset counts. The primary endpoint was defined a priori as the first occurrence of cardiovascular death, acute myocardial infarction, or nonhemorrhagic stroke. Endpoint adjudication was done blinded to monocyte subset distribution.

RESULTS

During a mean follow-up period of 2.6 ± 1.0 years, 93 patients experienced the primary endpoint. In univariate Kaplan-Meier analysis, counts of total (p = 0.010), classical CD14++CD16- (p = 0.024), and intermediate CD14++CD16+ (p < 0.001) monocytes predicted the primary endpoint, whereas nonclassical monocytes did not (p = 0.158). After full adjustment for confounders, CD14++CD16+ monocytes remained the only monocyte subset independently related to cardiovascular events (fourth vs. first quartile: hazard ratio: 3.019; 95% confidence interval: 1.315 to 6.928; p = 0.009).

CONCLUSIONS

CD14++CD16+ monocytes independently predicted cardiovascular events in subjects referred for elective coronary angiography. Future studies will be needed to elucidate whether CD14++CD16+ monocytes may become a target cell population for new therapeutic strategies in atherosclerosis.

Genetic markers of cardiovascular disease in rheumatoid arthritis

Cardiovascular (CV) disease is the most common cause of premature mortality in patients with rheumatoid arthritis (RA). It is the result of an accelerated atherosclerotic process. Both RA and atherosclerosis are complex polygenic diseases. Besides traditional CV risk factors and chronic inflammation, a number of studies have confirmed the role of genetic factors in the development of the atherogenesis observed in RA. In this regard, besides a strong association between the HLA-DRB1∗04 shared epitope alleles and both endothelial dysfunction, an early step in the atherosclerotic process, and clinically evident CV disease, other polymorphisms belonging to genes implicated in inflammatory and metabolic pathways, located inside and outside the HLA region, such as the 308 variant (G > A, rs1800629) of the TNFA locus, the rs1801131 polymorphism (A > C; position + 1298) of the MTHFR locus, or a deletion of 32 base pairs on the CCR5 gene, seem to be associated with the risk of CV disease in patients with RA. Despite considerable effort to decipher the genetic basis of CV disease in RA, further studies are required to better establish the genetic influence in the increased risk of CV events observed in patients with RA.

CCR5Δ32 genotype leads to a Th2 type directed immune response in ESRD patients

Background

In patients with end stage renal disease (ESRD) we observed protection from inflammation-associated mortality in CCR5Δ32 carriers, leading to CCR5 deficiency, suggesting impact of CCR5Δ32 on inflammatory processes. Animal studies have shown that CCR5 deficiency is associated with a more pronounced Th2 type immune response, suggesting that in human CCR5Δ32 carriers the immune response may be more Th2 type directed. So, in the present study we determined the Th1-Th2 type directed immune response in ESRD patients carrying and not carrying the CCR5Δ32 genetic variant after stimulation.

Methodology/Principal Findings

We tested this hypothesis by determining the levels of IFN-γ and IL-4 and the distribution of Th1, Th2 and Th17 directed circulating CD4+ and CD8+ T cells and regulatory T cells (Tregs) after stimulation in ESRD patients with (n = 10) and without (n = 9) the CCR5Δ32 genotype. The extracellular levels of IFN-γ and IL-4 did not differ between CCR5Δ32 carriers and non carriers. However, based on their intracellular cytokine profile the percentages IL-4 secreting CD4+ and CD8+ T cells carrying the CCR5Δ32 genotype were significantly increased (p = 0.02, respectively p = 0.02) compared to non carriers, indicating a more Th2 type directed response. Based on their intracellular cytokine profile the percentages IFN-γ and IL-17 secreting T cells did not differ between carriers and non-carriers nor did the percentage Tregs, indicating that the Th1, Th17 and T regulatory response was not affected by the CCR5Δ32 genotype.

Conclusions/Significance

This first, functional human study shows a more pronounced Th2 type immune response in CCR5Δ32 carriers compared to non carriers. These differences may be involved in the previously observed protection from inflammation-associated mortality in ESRD patients carrying CCR5Δ32.

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.

Using a genetic, observational study as a strategy to estimate the potential cost-effectiveness of pharmacological CCR5 blockade in dialysis patients

BACKGROUND AND OBJECTIVE

Randomized clinical trials are expensive and time consuming. Therefore, strategies are needed to prioritise tracks for drug development. Genetic association studies may provide such a strategy by considering the differences between genotypes as a proxy for a natural, lifelong, randomized at conception, clinical trial. Previously an association with better survival was found in dialysis patients with systemic inflammation carrying a deletion variant of the CC-chemokine receptor 5 (CCR5). We hypothesized that in an analogous manner, pharmacological CCR5 blockade could protect against inflammation-driven mortality and estimated if such a treatment would be cost-effective.

METHODS

A genetic screen and treat strategy was modelled using a decision-analytic Markov model, in which patients were screened for the CCR5 deletion 32 polymorphism and those with the wild type and systemic inflammation were treated with pharmacological CCR5 blockers. Kidney transplantation and mortality rates were calculated using patient level data. Extensive sensitivity analyses were performed.

RESULTS

The cost-effectiveness of the genetic screen and treat strategy was &OV0556;18 557 per life year gained and &OV0556;21 896 per quality-adjusted life years gained. Concordance between the genetic association and pharmacological effectiveness was a main driver of cost-effectiveness. Sensitivity analyses showed that even a modest effectiveness of pharmacological CCR5 blockade would result in a treatment strategy that is good value for money.

CONCLUSION

Pharmacological blockade of the CCR5 receptor in inflamed dialysis patients can be incorporated in a potentially cost-effective screen and treat programme. These findings provide formal rationale for clinical studies. This study illustrates the potential of genetic association studies for drug development, as a source of Mendelian randomized evidence from an observational setting.

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.

Polymorphisms in serine hydroxymethyltransferase 1 and methylenetetrahydrofolate reductase interact to increase cardiovascular disease risk in humans

The enzymes serine hydroxymethyltransferase 1 (gene name SHMT1) and methylenetetrahydrofolate reductase (gene name MTHFR) regulate key reactions in folate-mediated one-carbon metabolism. Common genetic variants with the potential to influence disease risk exist in both genes. A prior report from the Normative Aging Study indicated no association of the SHMT1 rs1979277 SNP with cardiovascular disease (CVD), but a strong gene-gene interaction was detected with MTHFR rs1801133. We investigated the effect of the SHMT1 rs1979277 SNP and the SHMT1 rs1979277-MTHFR rs1801133 interaction in 2 epidemiologic cohort studies. In the Nurses' Health Study (NHS), the MTHFR rs1801133 variant genotypes were associated with an increased CVD risk and there was an interaction between SHMT1 and MTHFR such that the association of the MTHFR rs1801133 CT genotype (vs. CC; the TT genotype could not be evaluated) was stronger in the presence of the SHMT1 rs1979277 TT genotype (OR = 4.34, 95% CI = 1.2, 16.2; P = 0.049). In the Health Professionals Follow-Up Study, the MTHFR rs1801133 genotype was not associated with CVD risk, nor was there an interaction with SHMT1 rs1979277. The association of genetic variation in the SHMT1 gene, alone and in interaction with MTHFR, in relation to CVD risk is relatively understudied at the population level and results in the NHS confirmed a past report of gene-gene interaction, which is consistent with mechanisms suggested by basic science studies.

The Role of the CCR2 Gene Polymorphism in Abdominal Aortic Aneurysms

Objective: Chronic inflammation play an important role on abdominal aortic aneurysms (AAA) formation. Chemokine receptor-2 (CCR2) is involved in regulation of the inflammatory response. However, relation between CCR2 polymorphism and AAA formation in human has not yet been investigated. In this study, we aimed to investigate the relationship between AAA and CCR2-V64I gene polymorphism. Methods: In this study, 100 consecutive patients with AAA and 138 individuals with normal aortic diameter were included. CCR2-V64I gene polymorphism were analyzed by PCR-RFLP technique. Genotype distribution and allele frequencies of CCR2-V64I gene polymorphism in patients with AAA and healthy subjects were compared. Results: CCR2 heterozygote V64I polymorphism and allele frequency were more frequently observed in the AAA group (p = 0.01, p = 0.004). Significant relationship was observed between CCR2 V64I polymorphism (OR:2.31, 95% CI:1.19-4.46, p = 0.01) and presence of AAA in multivariate regression analysis. Conclusion: The present study, showed us a relationship between CCR2-V64I polymorphism and AAA.

Chemokine (CCR) and fractalkine (CX3CR) receptors and end stage renal disease

OBJECTIVE AND DESIGN

Genetic polymorphisms of chemokines and their receptors were reported to be independent risk factors for inflammation associated disease. We explored the role of CCR5-Δ32, CCR5-G59029A, CX3CR1 V249I and T280M gene polymorphisms as susceptibility for end stage renal disease (ESRD).

SUBJECTS AND METHODS

We genotyped 258 ESRD and 569 healthy controls by sequence-specific primers and RFLP and examined their association.

RESULTS

There was significant difference in genotype frequencies of CCR5-G59029A (p = 0.005), and CX3CR1 V249I (p < 0.0001) between ESRD and controls. No homozygous individuals were observed for CCR5-Δ32. The haplotype analysis of all four studied genes reveled that haplotype +/A/T/I was more significant in patients and associated with higher risk (OR = 2.95) of ESRD. Further, the haplotype of CX3CR1 (T280M, V249I) gene showed 3.6-fold higher in an individual carrying T/I haplotype. No risk was seen for CCR5 haplotypes.

CONCLUSIONS

These results highlight the role of CCR5 and CX3CR1 in ESRD.

CD14++CD16+ monocytes and cardiovascular outcome in patients with chronic kidney disease

AIMS

Patients with chronic kidney disease (CKD) pose a worldwide growing burden to health care systems due to accelerated atherosclerosis and subsequent high cardiovascular (CV) morbidity. Atherogenesis is prominently driven by monocytes and monocyte-derived macrophages. The expression of CD14 and CD16 characterizes three monocyte subsets: CD14(++)CD16(-), CD14(++)CD16(+), and CD14((+))CD16(+) cells; the latter two are often denoted as 'proinflammatory' CD16(+) monocytes. Despite an association between CD16(+) monocyte counts and higher CV risk in cross-sectional cohorts, the prognostic impact of elevated CD16(+) monocyte counts is poorly understood.

METHODS AND RESULTS

We assessed monocyte heterogeneity using flow cytometry in 119 patients with non-dialysis CKD, who were prospectively followed for a median of 4.9 (inter-quartile range 4.8-5.0) years for the occurrence of CV events. In addition, we assessed expression of chemokine receptors on monocyte subsets. CD14(++)CD16(+) monocyte were independently associated with CV events [hazard ratio (for an increase of 10 cells/μL) 1.26 (confidence interval: 1.04-1.52; P = 0.018)] after adjustment for variables that significantly affected CD14(++)CD16(+) cell counts at baseline. Across the spectrum of CKD, CD14(++)CD16(+) monocytes selectively expressed CCR5.

CONCLUSION

We found that CD14(++)CD16(+) monocytes were independently associated with CV events in non-dialysis CKD patients. Our results support the notion that CD16(+) monocytes rather than CD16(-) monocytes are involved in human atherosclerosis.

TNF-α levels are not increased in inflamed patients carrying the CCR5 deletion 32

BACKGROUND AND AIMS

Recently we reported on a genetically predisposed protection from C-reactive protein (CRP) related mortality in dialysis patients carrying the functional CC-chemokine receptor 5 deletion 32 allele (CCR5Δ32) mutation. Since CCR5Δ32 is associated with a less pro-inflammatory immune response in mice, we hypothesized that the observed protection is (in part) due to a less pro-inflammatory cytokine profile.

METHODS

Cross-sectional observational study including 263 incident dialysis patients aged 18-70years, without clinical signs of infection and/or acute vasculitis. TNF-α, IL-6, IL-10 and hsCRP levels were determined and studied in relation to the CCR5 genotype.

RESULTS

In the presence of elevated hsCRP, IL-6 concentration was higher irrespective of the CCR5 genotype. However, in patients with the CCR5 deletion, TNF-α did not differ in the presence/absence of elevated hsCRP and was not correlated with hsCRP levels in carriers of the CCR5Δ32 polymorphism.

CONCLUSIONS

A possible underlying mechanism of the impact of CCR5Δ32 genotype on inflammation driven mortality in dialysis patients could be a reduced Th1 immune response as represented by decreased TNF-α levels.

Persistent inflammation as a catalyst for other risk factors in chronic kidney disease: a hypothesis proposal

Because inflammation by now is a "traditional" finding that predicts poor outcome and cardiovascular events in the vast majority of patients with ESRD, it could be argued that inflammatory biomarkers should not longer be considered "novel" risk factors. In this review, we forward the hypothesis that, in addition to putative direct proatherogenic effects, persistent inflammation may serve as a catalyst and, in the toxic uremic milieu, modulate the effects of other concurrent vascular and nutritional risk factors. We discuss some recent observational studies, suggesting that the presence of persistent inflammation magnifies the risk for poor outcome via mechanisms related to self-enhancement of the inflammatory cascade and exacerbation of both the wasting and the vascular calcification processes. Because persistent inflammation may be the silent culprit of other commonly observed pathophysiologic alterations in chronic kidney disease, it is imperative that inflammatory markers be regularly monitored and therapeutic attempts be made to target persistent low-grade inflammation in this patient group.

Effect of genetic variants of chemokine receptors on the development of myocardial infarction in Turkish population

Inflammation is a crucial component of coronary atherosclerosis and myocardial infarction (MI). Chemokine receptors are important modulators of inflammation. Polymorphisms in genes coding for chemokine receptors, CCR2 and CCR5, have been studied as genetic markers of coronary artery disease. In the present study, we investigated whether genetic variants of CCR2-V64I and CCR5-delta32 chemokine receptors have any effect on the development of myocardial infarction. A total of 146 MI patients and 202 control subjects were genotyped for CCR2 and CCR5. CCR2-V64I genotypes were not significantly different between patients with MI and controls (P > 0.05). CCR5-delta32 genotype distribution in cases was significantly different from that of controls (P = 0.042). The CCR5-delta32 wt/deletion genotype frequencies for controls and cases were 0.10 and 0.19, respectively and individuals with CCR5-delta32 wt/deletion genotype had a 2.13-fold increased risk of myocardial infarction (P = 0.0013). Individuals carrying the CCR5-delta32 heterozygote or homozygous variant genotype (deletion/deletion + wt/deletion) had a 1.96-fold increased risk of myocardial infarction compared with the wild-type genotype (wt/wt) (p: 0.016). In conclusion, our data have suggested that genetic variant of CCR5 might be associated with the development of MI. Further larger sample size studies are required to confirm our findings.

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.

Common CCR 5 polymorphism in stroke: the CCR 5 delta32 polymorphism differentiates cardioembolism from other aetiologies of ischaemic cerebrovascular diseases

Inflammation is involved in the development of atherosclerosis. The CC chemokine receptor 5 (CCR5) initiates chemotaxis and modulates the inflammation secondary to atherosclerosis and related vascular diseases. The CCR5 Delta32 polymorphism influences the expression of CCR5 on the cell surface. The purpose of this study was to examine the effect of the Delta32 polymorphism in ischaemic cerebrovascular disease (ICVD). The CCR5 Delta32 polymorphism was genotyped in 1462 individuals: 562 ischaemic stroke (IS), 97 transient ischaemic attack (TIA) and in 803 healthy controls. All 659 ICVD patients were categorized according to the Trial of Org 10172 in Acute Stroke Treatment aetiological classification. The investigated subtypes were large artery atherosclerosis (LAA), cardioembolism (CE), small artery occlusion (SAO) and cryptogenic disease (CRYPT). Genotyping was performed with the TaqMan polymerase chain reaction. The Delta32 allele was less frequent in CE patients compared with LAA (OR, 0.4; 95% CI, 0.24-0.79; P = 0.008), SAO (OR, 0.5; 95% CI, 0.29-0.84; P = 0.01), CRYPT (OR, 0.5; 95% CI, 0.28-0.82; P = 0.008) and controls (OR, 0.5; 95% CI, 0.36-0.82; P = 0.002). Multiple logistic regression analysis showed that the Delta32 allele is associated with a lower risk for cardioembolic ICVD (OR 0.5; 95% CI, 0.28-0.75; P = 0.002) when compared with ICVD of other causes. The Delta32 polymorphism of CCR5 may differentiate cardioembolism from the remaining causes of ICVD.

CCR5Delta32 genotype is associated with outcome in type 2 diabetes mellitus

AIMS

To test whether the genetic variant CCR5Delta32 in the CC-chemokine receptor 5, which is known to lead to CCR5 deficiency, is associated with mortality in type 2 diabetes patients.

METHODS

We examined the effect of presence or absence of the CCR5Delta32 on overall and cardiovascular mortality risk in the Zwolle Outpatient Diabetes project Integrating Available Care (ZODIAC) cohort, a type 2 diabetes patient cohort.

RESULTS

We studied 756 patients with a mean duration of follow-up of 5.4 (+/- 1.4) years. 194 patients died during follow up of which 83 were cardiovascular deaths. 144 subjects (19%) carried the CCR5Delta32 deletion. CCR5Delta32 carriers had an adjusted hazard ratio of 0.62 (95%CI: 0.40-0.96; p=0.03) for all-cause mortality and 0.63 (95%CI: 0.33-1.19; p=0.16) for cardiovascular mortality.

CONCLUSIONS

The presence of CCR5Delta32 is associated with better survival in type 2 diabetes patients. These data suggest that it is worthwhile to explore the protective potential of pharmacological blockade of CCR5 in type 2 diabetic patients.

CCR5 deletion protects against inflammation-associated mortality in dialysis patients

The CC-chemokine receptor 5 (CCR5) is a receptor for various proinflammatory chemokines, and a deletion variant of the CCR5 gene (CCR5 Delta 32) leads to deficiency of the receptor. We hypothesized that CCR5 Delta 32 modulates inflammation-driven mortality in patients with ESRD. We studied the interaction between CCR5 genotype and levels of high-sensitivity C-reactive protein (hsCRP) in 603 incident dialysis patients from the multicenter, prospective NEtherlands COoperative Study on the Adequacy of Dialysis (NECOSAD) cohort. CCR5 genotype and hsCRP levels were both available for 413 patients. During 5 yr of follow-up, 170 patients died; 87 from cardiovascular causes. Compared with the reference group of patients who had the wild-type CCR5 genotype and hsCRP <or= 10 mg/L (n = 225), those carrying the deletion allele with hsCRP <or= 10 mg/L (n = 55) had similar mortality, and those carrying the wild-type genotype with hsCRP > 10 mg/L (n = 108) had an increased risk for mortality (HR: 1.82; 95% CI: 1.29 to 2.58). However, those carrying the deletion allele with hsCRP > 10 mg/L (n = 25) had a mortality rate similar to the reference group; this seemingly protective effect of the CCR5 deletion was even more pronounced for cardiovascular mortality. We replicated these findings in an independent Swedish cohort of 302 ESRD patients. In conclusion, the CCR5 Delta 32 polymorphism attenuates the adverse effects of inflammation on overall and cardiovascular mortality in ESRD.

Common CCR5-del32 frameshift mutation associated with serum levels of inflammatory markers and cardiovascular disease risk in the Bruneck population

BACKGROUND AND PURPOSE

Atherosclerosis is a progressive inflammatory disease and can develop in large arteries such as carotid and femoral arteries or medium-sized muscular arteries of the heart. Previous predominantly experimental studies suggested an important role of chemokines in the development of atherosclerosis. The main aim of this study was to examine potential effect of the CCR5-del32 mutation on systemic inflammation, intima-media thickness in carotid and femoral arteries, and on the indices of cardiovascular disease.

METHODS

In the present study, we have examined the association of a common functional 32-bp frameshift deletion mutation in a chemokine receptor (CCR5) in relation to inflammation and atherosclerosis. CCR5 is a G protein-coupled receptor involved in inflammatory response and regulation of leukocytes activation and migration. Genetic screening of this mutation was carried out on a well-known and previously described cohort of Bruneck (n=826) using polymerase chain reaction.

RESULTS

Screening was successful in 810 subjects of whom 7 were homozygous, 102 were heterozygous, and 701 were normal. The mutation was associated with significantly lower levels of C-reactive protein in a dose-dependent manner. Moreover, CCR5-del32 was associated with a significantly lower carotid intima-media thickness in the common carotid artery (del32/del32, 837+/-8 microm; wt/del32, 909+/-21 microm; wt/wt, 958+/-8 microm; P=0.007 after multivariable adjustment). Furthermore, incident cardiovascular disease (1995 to 2005) was markedly reduced in del32 homozygotes and heterozygotes subjects compared with wild-type homozygotes (del32/del32=0%, wt/del32=7.8%, wt/wt=14.8%, P=0.020). Findings equally applied to coronary artery and cerebrovascular disease.

CONCLUSIONS

The chemokine receptor CCR5-del32 frameshift mutation is associated with low levels of C-reactive protein, decreased intima-media thickness, and cardiovascular disease risk. These findings are consistent with the hypothesis that the chemokine receptor CCR5 is involved in the mediation of low-grade systemic inflammation and may play a role in human atherosclerosis and cardiovascular disease.

Association of CCR2 polymorphisms with the number of closed coronary artery vessels in coronary artery disease

Coronary artery disease (CAD) is one of the most common forms of heart disease. It has been demonstrated that chemokine-mediated inflammation is associated with the development of CAD. In this study, in order to determine the role of CCR2, a receptor for MCP-1, in the development of CAD, we initially sequenced and identified the genetic variants of CCR2 using 24 unrelated Korean individuals' DNA samples. A total of 13 genetic variants, including 1 deletion and 12 SNPs, were identified in the Korean population. Although we could not detect any association of CCR2 polymorphic markers with CAD, several SNP markers of CCR2 gene showed highly significant signals with the number of arteries with significant coronary artery stenosis in the CAD male patients. The most significant signal was detected at the SNP located at exon 2 (+780T>C, Asn260Asn) CI: 1.19-1.87, P=0.0005 (odds ratio: 1.49, 95% CI: 1.19-1.87, p=0.0005) (Table 3). This result indicates that CCR2 can play a role in the pathogenesis of CAD, especially to the number of vessels in CAD.

CCR5 receptor: biologic and genetic implications in age-related diseases

The CC chemokine receptor 5 (CCR5) is a member of CC-chemokine receptor family. CCR5 has the characteristic structure of a seven transmembrane G protein-coupled receptor (GPCR), which regulates trafficking and effector functions of memory/effector Th1 cells, macrophages, NK cells, and immature dendritic cells. CCR5 and its ligands are important molecules in viral pathogenesis. CCR5 represents the co-receptor for macrophage (M) and dual (T cell and M)-tropic immunodeficiency viruses. Recent evidence has also demonstrated the role of CCR5 in a variety of human diseases, ranging from infectious and inflammatory diseases to cancer. In this article, we describe the involvement of CCR5 in two age-related diseases, atherosclerosis and Alzheimer's disease, suggesting a possible role of chemokine system on these diseases' pathophysiology. Finally, we review the data on the probable association between CCR5Delta32 deletion and cardiovascular diseases and Alzheimer's disease.

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

BACKGROUND

Polymorphisms in genes coding for chemokine receptors, CCR2 and CCR5 have been studied as genetic markers of coronary artery disease (CAD). V64Ile polymorphism in CCR2 has been implicated in the manifestation of myocardial infarction in different populations, but data on association of the CCR5 deletion variant in etiology of CAD are conflicting. In the present study we tested genetic association between CCR5 Delta32 polymorphism and CAD among North Indians (Uttar Pradesh).

METHODS

Two hundred angiographically proven patients with coronary artery disease and two hundred age, sex and ethnically matched controls were genotyped for CCR5 Delta32 polymorphism by polymerase chain reaction. Genotype/allele frequencies were compared in patients and controls using the chi-square test.

RESULTS

The frequency of the heterozygote genotype in the population, including both patient and control group, was 3% and the frequency of the mutant allele Delta32 was 1.5%. CAD patients had a three times higher (4.6% vs. 1.5%) frequency of heterozygote genotype but the differences were statistically not significant. Association analysis did not achieve statistical significance, though odds ratio of 3.13 was observed for heterozygote genotype.

CONCLUSIONS

The allele frequency of the CCR5 Delta32 polymorphism in CAD patients is 2.25% and 0.75% among controls but the differences were not significant. Overall this fits well with the pattern of CCR5 Delta32 allele frequency in Indian subcontinent where it varies from 1 to 3%. The heterozygote (+/ Delta32) genotype does not seem to have any protective role against development of CAD in this population. In fact, North Indian CAD had a higher frequency of CCR5 Delta32 allele suggesting a possible susceptibility trend (odds ratio 3.08, CI 0.83-11.46, chi-square 2.167, NS).