CCR2 and coronary artery disease: a woscops substudy

A Common Variant at the 3'untranslated Region of the CCL7 Gene (rs17735770) Is Associated With Decreased Susceptibility to Coronary Heart Disease

Monocytes participate in the development of atherosclerosis through the action of cytokines and other inflammatory mediators. Among them, CCR2 and its ligands, CCL2 and CCL7 play an important role, so the main objective of this work was to determine whether genetic variants affecting their activity were associated with cardiovascular disease. A cohort of 519 patients that have suffered coronary events was analyzed under a propensity score-matching protocol selecting a homogeneous set of cases and controls, according to age, sex, smoking status, dyslipidemia, arterial hypertension and type 2 diabetes as risk factors. While dyslipidemia and arterial hypertension were more prevalent among patients with angina pectoris, current smoking status and elevated inflammatory markers, including total leukocyte and monocyte counts, were more likely associated with acute coronary events. Propensity score matching analysis, performed to eliminate the influence of these risk factors and highlight genetic modifiers, revealed that a single nucleotide variant, rs17735770 at the 3'untranslated region of the CCL7 gene transcript, was associated with decreased cardiovascular risk in a group represented mostly by men, with an average age of 57, and without significant differences in traditional risk factors. Furthermore, the presence of this variant altered the local mRNA structure encompassing a binding site for miR-23ab, resulting in increased translation of a reporter gene in a miR23 independent fashion. The rs17735770 genetic variant led to increased expression of CCL7, a potential antagonist of CCR2 at inflammatory sites, where it could play a meaningful role during the evolution of atherosclerosis.

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.

Optimized dosing of a CCR2 antagonist for amplification of vaccine immunity

We have recently discovered that inflammatory monocytes recruited to lymph nodes in response to vaccine-induced inflammation can function as potent negative regulators of both humoral and cell-mediated immune responses to vaccination. Monocyte depletion or migration blockade can significantly amplify both antibody titers and cellular immune responses to vaccination with several different antigens in mouse models. Thus, we hypothesized that the use of small molecule CCR2 inhibitors to block monocyte migration into lymph nodes may represent a broadly effective means of amplifying vaccine immunity. To address this question, the role of CCR2 in monocyte recruitment to vaccine draining lymph nodes was initially explored in CCR2-/- mice. Next, a small molecule antagonist of CCR2 (RS102895) was evaluated in mouse vaccination models. Initial studies revealed that a single intraperitoneal dose of RS102895 failed to effectively block monocyte recruitment following vaccination. Pharmacokinetic analysis of RS102895 revealed a short half-life (approximately 1h), and suggested that a multi-dose treatment regimen would be more effective. We found that administration of RS102895 every 6 h resulted in consistent plasma levels of 20 ng/ml or greater, which effectively blocked monocyte migration to lymph nodes following vaccination. Moreover, administration of RS102895 with concurrent vaccination markedly enhanced vaccine responses following immunization against the influenza antigen HA1. We concluded that administration of small molecule CCR2 antagonists such as RS102895 in the immediate post-vaccine period could be used as a novel means of significantly enhancing vaccine immunity.

Genetics in arterial calcification: pieces of a puzzle and cogs in a wheel

Artery calcification reflects an admixture of factors such as ectopic osteochondral differentiation with primary host pathological conditions. We review how genetic factors, as identified by human genome-wide association studies, and incomplete correlations with various mouse studies, including knockout and strain analyses, fit into "pieces of the puzzle" in intimal calcification in human atherosclerosis, and artery tunica media calcification in aging, diabetes mellitus, and chronic kidney disease. We also describe in sharp contrast how ENPP1, CD73, and ABCC6 serve as "cogs in a wheel" of arterial calcification. Specifically, each is a minor component in the function of a much larger network of factors that exert balanced effects to promote and suppress arterial calcification. For the network to normally suppress spontaneous arterial calcification, the "cogs" ENPP1, CD73, and ABCC6 must be present and in working order. Monogenic ENPP1, CD73, and ABCC6 deficiencies each drive a molecular pathophysiology of closely related but phenotypically different diseases (generalized arterial calcification of infancy (GACI), pseudoxanthoma elasticum (PXE) and arterial calcification caused by CD73 deficiency (ACDC)), in which premature onset arterial calcification is a prominent but not the sole feature.

Genetic variants of the monocyte chemoattractant protein-1 gene and its receptor CCR2 and risk of coronary artery disease: a meta-analysis

OBJECTIVE

Monocyte chemoattractant protein-1 (MCP-1) and its receptor chemokine (C-C motif) receptor 2 (CCR2) are implicated in promoting atherosclerosis. Many studies have searched the association between variants of the MCP-1 gene or CCR2 gene and risk of coronary artery disease (CAD), but the results are inconsistent.

METHODS

We conducted a meta-analysis of 20 publications including 24 studies on 2 genetic variants [A-2518G in the MCP-1 and V64I in the CCR2] published before January 2011, including a total of 9844 patients with CAD and 11,821 controls. Publication bias and heterogeneity among studies were explored.

RESULTS

In a combined analysis, the pooled OR for CAD of the -2518G allele was 1.42 (95%CI: 1.06-1.92) compared to wild-type A allele under a recessive model in Caucasian group, but there is an indication of publication bias and heterogeneity among the 9 studies. When the analyses were restricted to 2 large studies (n≥500 cases), the pooled OR was 1.08 (95%CI: 0.85-1.37). Our analyses detected a possibility of publication bias with an overestimate of the true association by smaller studies. A meta-analysis of studies on the CCR2 V64I variant showed no significant association with CAD, the pooled OR of 64I was 1.27 (95%CI: 0.81-1.99) in recessive model and 1.06 (95%CI: 0.95-1.19) in dominant model, respectively.

CONCLUSIONS

The results indicate that MCP-1-2518G allele had probably increased risk of CAD in Caucasian but this is likely to be due to publication bias and insufficient sample size. The CCR2 V64I has not been found any association with CAD.