Promoter polymorphism in the CD14 gene and concentration of soluble CD14 in patients with in-stent restenosis after elective coronary stenting

Pathogenesis and Clinical Significance of In-Stent Restenosis in Patients with Diabetes

Diabetes mellitus (DM) is a strong risk factor for the development of cardiovascular diseases such as coronary heart disease, cerebrovascular disease, and peripheral arterial disease (PAD). In the population of people living with DM, PAD is characterised by multi-level atherosclerotic lesions as well as greater involvement of the arteries below the knee. DM is also a factor that significantly increases the risk of lower limb amputation. Percutaneous balloon angioplasty with or without stent implantation is an important method of the treatment for atherosclerotic cardiovascular diseases, but restenosis is a factor limiting its long-term effectiveness. The pathogenesis of atherosclerosis in the course of DM differs slightly from that in the general population. In the population of people living with DM, more attention is drawn to such factors as inflammation, endothelial dysfunction, platelet dysfunction, blood rheological properties, hypercoagulability, and additional factors stimulating vascular smooth muscle cell proliferation. DM is a risk factor for restenosis. The purpose of this paper is to provide a review of the literature and to present the most important information on the current state of knowledge on mechanisms and the clinical significance of restenosis and in-stent restenosis in patients with DM, especially in association with the endovascular treatment of PAD. The role of such processes as inflammation, neointimal hyperplasia and neoatherosclerosis, allergy, resistance to antimitotic drugs used for coating stents and balloons, genetic factors, and technical and mechanical factors are discussed. The information on restenosis collected in this publication may be helpful in planning further research in this field, which may contribute to the formulation of more and more precise recommendations for the clinical practice.

Genetic risk factors for restenosis after percutaneous coronary intervention in Kazakh population

BACKGROUND

After coronary stenting, the risk of developing restenosis is from 20 to 35 %. The aim of the present study is to investigate the association of genetic variation in candidate genes in patients diagnosed with restenosis in the Kazakh population.

METHODS

Four hundred fifty-nine patients were recruited to the study; 91 patients were also diagnosed with diabetes and were excluded from the sampling. DNA was extracted with the salting-out method. The patients were genotyped for 53 single-nucleotide polymorphisms. Genotyping was performed on the QuantStudio 12K Flex (Life Technologies). Differences in distribution of BMI score among different genotype groups were compared by analysis of variance (ANOVA). Also, statistical analysis was performed using R and PLINK v.1.07. Haplotype frequencies and LD measures were estimated by using the software Haploview 4.2.

RESULTS

A logistic regression analysis found a significant difference in restenosis rates for different genotypes. FGB (rs1800790) is significantly associated with restenosis after stenting (OR = 2.924, P = 2.3E-06, additive model) in the Kazakh population. CD14 (rs2569190) showed a significant association in the additive (OR = 0.08033, P = 2.11E-09) and dominant models (OR = 0.05359, P = 4.15E-11). NOS3 (rs1799983) was also highly associated with development of restenosis after stenting in additive (OR = 20.05, P = 2.74 E-12) and recessive models (OR = 22.24, P = 6.811E-10).

CONCLUSIONS

Our results indicate that FGB (rs1800790), CD14 (rs2569190), and NOS3 (rs1799983) SNPs could be genetic markers for development of restenosis in Kazakh population. Adjustment for potential confounder factor BMI gave almost the same results.

Genetics of coronary artery disease and myocardial infarction

Atherosclerotic coronary artery disease (CAD) comprises a broad spectrum of clinical entities that include asymptomatic subclinical atherosclerosis and its clinical complications, such as angina pectoris, myocardial infarction (MI) and sudden cardiac death. CAD continues to be the leading cause of death in industrialized society. The long-recognized familial clustering of CAD suggests that genetics plays a central role in its development, with the heritability of CAD and MI estimated at approximately 50% to 60%. Understanding the genetic architecture of CAD and MI has proven to be difficult and costly due to the heterogeneity of clinical CAD and the underlying multi-decade complex pathophysiological processes that involve both genetic and environmental interactions. This review describes the clinical heterogeneity of CAD and MI to clarify the disease spectrum in genetic studies, provides a brief overview of the historical understanding and estimation of the heritability of CAD and MI, recounts major gene discoveries of potential causal mutations in familial CAD and MI, summarizes CAD and MI-associated genetic variants identified using candidate gene approaches and genome-wide association studies (GWAS), and summarizes the current status of the construction and validations of genetic risk scores for lifetime risk prediction and guidance for preventive strategies. Potential protective genetic factors against the development of CAD and MI are also discussed. Finally, GWAS have identified multiple genetic factors associated with an increased risk of in-stent restenosis following stent placement for obstructive CAD. This review will also address genetic factors associated with in-stent restenosis, which may ultimately guide clinical decision-making regarding revascularization strategies for patients with CAD and MI.

Risk of Atherosclerosis and Helicobacter pylori Infection according to CD14 Promotor Polymorphism in Healthy Korean Population

Background and Aim. We aim to elucidate the association of risk factors for atherosclerosis and H. pylori infection according to the promotor polymorphism of the CD14 gene in healthy Korean population. Methods. The patients who visited our hospital for routine health examinations and 266 healthy adults (170 males and 96 females) were enrolled in this study. The promotor polymorphism at -159C/T of the CD14 gene was determined by PCR-restriction fragment length polymorphism analysis. According to genetic polymorphism and H. pylori infection, we analyzed the risk of atherosclerosis. Results. The genotype frequencies were CC 7.9%, CT 45.1%, and TT 47.0%, respectively. There were no differences between specific genotypes of CD14 gene and H. pylori infection rate. As for HDL cholesterol level, there were significant differences among the three genotypes (P < 0.01). In subjects with H. pylori infection, no significant differences were observed between specific genotypes of CD14 gene and the risk factors of atherosclerosis. Conclusion. The promotor polymorphism at -159C/T of the CD14 gene was associated with the risk factor of atherosclerosis in healthy Korean population. However, it was not associated with the rate of H. pylori infection and H. pylori induced atherosclerotic risk.

Systematic testing of literature reported genetic variation associated with coronary restenosis: results of the GENDER Study

Background

Coronary restenosis after percutaneous coronary intervention still remains a significant problem, despite all medical advances. Unraveling the mechanisms leading to restenosis development remains challenging. Many studies have identified genetic markers associated with restenosis, but consistent replication of the reported markers is scarce. The aim of the current study was to analyze the joined effect of previously in literature reported candidate genes for restenosis in the GENetic DEterminants of Restenosis (GENDER) databank.

Methodology/Principal Findings

Candidate genes were selected using a MEDLINE search including the terms ‘genetic polymorphism’ and ‘coronary restenosis’. The final set included 36 genes. Subsequently, all single nucleotide polymorphisms (SNPs) in the genomic region of these genes were analyzed in GENDER using set-based analysis in PLINK. The GENDER databank contains genotypic data of 2,571,586 SNPs of 295 cases with restenosis and 571 matched controls. The set, including all 36 literature reported genes, was, indeed, significantly associated with restenosis, p = 0.024 in the GENDER study. Subsequent analyses of the individual genes demonstrated that the observed association of the complete set was determined by 6 of the 36 genes.

Conclusion

Despite overt inconsistencies in literature, with regard to individual candidate gene studies, this is the first study demonstrating that the joint effect of all these genes together, indeed, is associated with restenosis.

Lipopolysaccharide, CD14 and Toll-like receptors: an emerging link between innate immunity and atherosclerotic disease

Atherosclerosis and its clinical complications are now understood to be an inflammatory syndrome in which an ongoing systemic inflammatory response is combined with the accumulation of immune cells in the atherosclerotic plaque. Both arms of the immune system, innate and adaptive, have been implicated in contributing to essentially all stages of atherosclerosis, from initiation to progression and, ultimately, atherothrombotic complications. Innate immunity is the first line of defense against invading microorganisms. The recognition units of the innate immune system are designed to respond to molecular patterns shared by a variety of infectious microorganisms, such as bacterial lipopolysaccharide. Numerous basic and clinical studies have provided evidence that responsiveness to lipopolysaccharide may be correlated to the risk of atherosclerotic disease. The molecular basis of this connection appears to lie in Toll-like receptors that are expressed on cells of the innate immune system, bind to lipopolysaccharide, and thus determine the strength of antibacterial immune responses in the host. Variations in the function of Toll-like receptors and their signaling pathways are now suspected to play a critical role in determining the risk of atherosclerosis. This review summarizes recent research advances exploring the role of innate immunity, particularly lipopolysaccharide, CD14 and Toll-like receptors, in the initiation and development of atherosclerotic disease.

Pro-inflammatory genetic background and zinc status in old atherosclerotic subjects

Inflammation and genetics are prominent mechanisms in the pathogenesis of atherosclerosis (AT) and its complications. In this review we discuss the possible impact on AT development of several genetic determinants involved in inflammation, oxidative stress and cytoprotection (IL-6, TNF-alpha, IL-10, CD14, TLR4, MT, HSP70). Genetic polymorphisms of these genes may affect a differential inflammatory response predisposing to AT. However, allelic polymorphisms of genes which increase the risk of AT frequently occur in the general population but, only adequate gene-environment-polymorphism interactions promote the onset of the disease. Zinc deficiency has been suggested as an environmental risk factor for AT. With advancing age, the incidence of zinc deficiency increases for several reasons. Among them, dietary intake, malabsorption and genetic background of inflammatory markers may be involved. A crucial contribution may also be played by increased oxidative stress which may lead to the appearance of dysfunctional proteins, including metallothioneins (MT) that are in turn involved in zinc homeostasis. The detection of candidate genes related to inflammation and promoting AT and their reciprocal influence/interaction with zinc status might allow earlier appropriate dietary interventions in genetically susceptible subjects.

CD14 C (-260)T polymorphism, atherosclerosis, elderly: Role of cytokines and metallothioneins

BACKGROUND

CD14 receptor is a mediator of the inflammatory response to bacterial products. A functional polymorphism in the promoter of the CD14 gene (CD14 C-260T) was associated with coronary heart disease and atherosclerosis albeit with conflicting data.

METHODS

To better clarify the role of CD14 in atherosclerosis, we typed CD14 C-260T polymorphism in old Italian (Central of Italy) atherosclerotic patients with carotid stenosis related to lipid assessment, inflammation (soluble CD14, IL-6 serum levels) and IL-6, TNF-alpha, IL-10, Metallothioneins (MT) gene expressions in carotid plaques.

RESULTS

There was an increased frequency of TT homozygotes in patients when compared to controls [26% vs. 13.5%, odds ratio=2.25 (95% C.I., 1.23-4.09, p=0.0082) (Fisher's Exact test)]. Subjects with TT genotype showed a significant increase of soluble CD14 and enhanced MT2A, IL-6, TNF-alpha and decreased IL-10 gene expressions within the carotid plaques. On the basis of lipid assessment, hypercholesterolemic -260TT CD14 patients displayed lower HDL cholesterol and higher triglyceride than did CT and CC carriers. Using Pearson's correlation, a high MT2A expression was associated with high IL-6, TNF-alpha, sCD14 and thereby with severe chronic inflammation.

CONCLUSIONS

These data provide insight into the pathogenetic role of the CD14 C-260T polymorphism in atherosclerosis as -260TT genotype may favour increased inflammation in atheroma promoting possible worsening atherosclerosis, at least in Central of Italy elderly population. Further studies are in progress in cohorts from different European geographic area (Zincage project).

Short-term dexamethasone treatment inhibits vein graft thickening in hypercholesterolemic ApoE3Leiden transgenic mice

OBJECTIVE

The aim of this study was to assess whether the anti-inflammatory agent dexamethasone can inhibit vein graft thickening without the occurrence of serious side effects.

METHODS

Venous interposition grafting was performed in the common carotid artery of hypercholesterolemic ApoE3Leiden transgenic mice. Mice were treated with dexamethasone (0.15 mg.kg(-1).d(-1) orally), and after 28 days, vein graft thickening was quantified.

RESULTS

Treatment with dexamethasone resulted in a significant 43% reduction in lesion area without changes in lesion composition when compared with nontreated controls. However, dexamethasone, when administered for a prolonged period of time, is known for its potentially serious side effects. To overcome these potential side effects of prolonged dexamethasone treatment, the effect of a short-term 7-day dexamethasone treatment was studied. This short dexamethasone treatment resulted in a 49% decrease of vein graft thickening at 28 days. Furthermore, it was demonstrated that dexamethasone treatment led to reduced local expression of several proinflammatory cytokines and factors in the vein grafts 24 hours after surgery. Finally, observations in mice were verified in human saphenous organ cultures. Exposure to dexamethasone for either 7 or 28 days significantly reduced intimal hyperplasia formation on cultured saphenous vein segments.

CONCLUSIONS

Short-term anti-inflammatory treatment with dexamethasone leads to a significant reduction in vein graft thickening over an extended period, possibly by the reduction of early expression of proinflammatory cytokines. This 7-day treatment minimizes the risk of unwanted side effects of long-term dexamethasone treatment and may be a new approach to prevent graft failure.

Genetic inflammatory factors predict restenosis after percutaneous coronary interventions

BACKGROUND

Restenosis is a negative effect of percutaneous coronary intervention (PCI). No clinical factors are available that allow good risk stratification. However, evidence exists that genetic factors are important in the restenotic process as well as in the process of inflammation, a pivotal factor in restenosis. Association studies have identified genes that may predispose to restenosis, but confirmation by large prospective studies is lacking. Our aim was to identify polymorphisms and haplotypes in genes involved in inflammatory pathways that predispose to restenosis.

METHODS AND RESULTS

The GENetic DEterminants of Restenosis (GENDER) project is a multicenter prospective study, including 3104 consecutive patients after successful PCI. Forty-eight polymorphisms in 34 genes in pathways possibly involved in the inflammatory process were analyzed. The 16Gly variant of the beta2-adrenergic receptor gave an increased risk of target vessel revascularization (TVR). The rare alleles of the CD14 gene (-260T/T), colony-stimulating factor 2 gene (117Thr/Thr), and eotaxin gene (-1328A/A) were associated with decreased risk of TVR. However, through the use of multiple testing corrections with permutation analysis, the probability of finding 4 significant markers by chance was 12%.

CONCLUSIONS

Polymorphisms in 4 genes considered involved in the inflammatory reaction showed an association with TVR after PCI. Our results may contribute to the unraveling of the restenotic process. Given the explorative nature of this analysis, our results need to be replicated in other studies.

Helicobacter pylori infection and the CD14 C(−260)T gene polymorphism in ischemic stroke

INTRODUCTION

There is increasing evidence that infective pathogens such as Helicobacter pylori is linked to atherosclerosis of cerebral vessels. As an independent contributing factor, the CD14 receptor-lipopolysaccharide complex plays an important role in activating inflammatory reactions. In particular, the C(-260)T polymorphism in the CD14 receptor may be implicated in atherosclerotic disease. In this study, we investigated a possible association between H. pylori infection and the polymorphism of CD14, and ischemic stroke.

MATERIALS AND METHODS

A total of 125 patients with ischemic stroke and 125 age- and sex-matched controls were included in the study. The stroke subtype of each of the patients was characterized based on the underlying etiology. H. pylori serologic status and the CD14 genotype were determined in both patients and controls.

RESULTS

H. pylori seropositivity was more common in the stroke patients than in the controls (80.0% vs. 60.0%, P=0.001). Moreover, H. pylori seropositivity was more common in the stroke subtype of large artery disease (87.7%, P<0.001). The distribution of CD14 genotypes was as follows: patients, T/T 21.6%, C/T 63.2%, C/C 15.2%; controls, T/T 19.2%, C/T 57.6%, C/C 23.2%. There was no significant difference between these two CD14 genotype distributions.

CONCLUSIONS

These results suggest that H. pylori infection is a risk factor for ischemic stroke and that CD14 polymorphism is not.

Common promoter polymorphism in monocyte differentiation antigen CD14 is associated with serum triglyceride levels and body mass index in non-diabetic individuals

AIMS

Growing evidence supports the hypothesis that chronic low-grade inflammation related to innate immunity may play an important role in the pathophysiology of Type 2 diabetes mellitus (T2DM). The monocyte differentiation antigen CD14 gene (CD14) acts as the receptor for lipopolysaccharide (LPS) and augments monocyte/macrophage inflammatory responses.

METHODS

We have sequenced the gene, including all exons, exon/intron boundaries, and the -1.5 kb of the 5' flanking region. Two common loci (minor allele frequency > 0.05) were genotyped in 775 T2DM patients and 316 control subjects recruited in the Korean T2DM Study.

RESULTS

Eight polymorphisms, including four non-synonymous forms, were identified in CD14. No polymorphisms were found in association with T2DM. However, one common promoter SNP (-260T>C) was significantly associated with both the serum triglyceride level (TG) and body mass index (BMI) in non-diabetic control subjects. Individuals who carried the minor allele (C) had higher TG levels (1.65 +/- 0.81 vs. 1.46 +/- 0.80 mmol/l; P = 0.0007) and BMI (23.96 +/- 3.00 vs. 23.28 +/- 3.22 kg/m(2); P = 0.04) as compared with subjects carrying T/T genotypes.

CONCLUSION

Our data suggest that lipid metabolism and obesity, important pathophysiological elements of T2DM and the metabolic syndrome, are regulated by complex mechanisms that include the CD14 gene polymorphism-mediated genetic propensity to non-specific inflammatory responses.