CD14 C(-260)T promoter polymorphism and prevalence of acute coronary syndromes

Investigating intestinal permeability and gut microbiota roles in acute coronary syndrome patients

Background:

Methods:

Results:

Conclusions:

Genetic polymorphisms in the CD14 gene are associated with monocyte activation and carotid intima-media thickness in HIV-infected patients on antiretroviral therapy

HIV-infected individuals on antiretroviral therapy (ART) are at increased risk of cardiovascular disease (CVD). Given the relationship between innate immune activation and CVD, we investigated the association of single-nucleotide polymorphisms (SNPs) in TLR4 and CD14 and carotid intima-media thickness (cIMT), a surrogate measurement for CVD, in HIV-infected individuals on ART and HIV-uninfected controls as a cross-sectional, case-control study. We quantified the frequency of monocyte subsets (CD14, CD16), markers of monocyte activation (CD38, HLA-DR), and endothelial adhesion (CCR2, CX3CR1, CD11b) by flow cytometry. Plasma levels of lipopolysaccharide, sCD163, sCD14, sCX3CL1, and sCCL2, were measured by ELISA. Genotyping of TLR4 and CD14 SNPs was also performed. The TT genotype for CD14/-260SNP but not the CC/CT genotype was associated with elevated plasma sCD14, and increased frequency of CD11b+CD14+ monocytes in HIV-infected individuals. The TT genotype was associated with lower cIMT in HIV-infected patients (n = 47) but not in HIV-uninfected controls (n = 37). The AG genotype for TLR4/+896 was associated with increased CX3CR1 expression on total monocytes among HIV-infected individuals and increased sCCL2 and fibrinogen levels in HIV-uninfected controls. SNPs in CD14/-260 and TLR4/+896 were significantly associated with different markers of systemic and monocyte activation and cIMT that differed between HIV-infected participants on ART and HIV-uninfected controls. Further investigation on the relationship of these SNPs with a clinical endpoint of CVD is warranted in HIV-infected patients on ART.

The CD14 C-260T single nucleotide polymorphism (SNP) modulates monocyte/macrophage activation in treated HIV-infected individuals

Background

HIV-infected individuals have an increased risk of cardiovascular disease (CVD). T-allele carriers of the CD14 C-260T single-nucleotide polymorphism (SNP) have reported increased expression of the LPS-binding receptor, CD14 and inflammation in the general population. Our aim was to explore the relationship of this SNP with monocyte/macrophage activation and inflammation and its association with sub-clinical atherosclerosis in HIV-infected individuals.

Methods

Patients with no pre-existing CVD risk factors on suppressive antiretroviral therapy were recruited from University Malaya Medical Centre, Malaysia (n = 84). The CD14 C-260T and TLR4 SNPs, Asp299Gly and Thr399Ile were genotyped and soluble(s) CD14 and sCD163 and high-sensitivity C-reactive protein, hsCRP were measured in plasma. Subclinical atherosclerosis was assessed by measuring carotid intima media thickness (cIMT). The association between CD14 C-260T SNP carriage and cIMT was assessed in a multivariable quantile regression model where a p-value of <0.05 was considered significant.

Results

We found the CD14 C-260T T-allele in 56% of the cohort and evidence of subclinical atherosclerosis in 27%. TT genotype was associated with higher sCD163 (p = 0.009) but only marginally higher sCD14 (p = 0.209) and no difference in hsCRP (p = 0.296) compared to CC/CT. In multivariable analysis, only Framingham risk score was independently associated with higher cIMT while lower sCD163 was trending towards significance. No association was found in TT-genotype carriers and cIMT measurements.

Conclusion

The CD14 C-260T SNP was associated with increased monocyte activation but not systemic inflammation or cIMT in this HIV-infected cohort with low CVD risk profile.

The association between CD14 gene C-260T polymorphism and coronary heart disease risk: a meta-analysis

Monocyte differentiation antigen CD14 is considered an important cell-activating mediator of inflammatory responses that may result in atherosclerosis, coronary heart disease (CHD), thrombus formation, and myocardial infarction (MI). A common C-260T polymorphism in the promoter of the CD14 gene, the trans-membrane receptor of lipopolysaccharides, has been inconsistently associated with CHD. To investigate this inconsistency, we performed a meta-analysis of 28 studies involving a total of 13,335 CHD cases and 7,979 controls for C-260T of the CD14 gene to evaluate the effect of CD14 on genetic susceptibility for CHD. An overall random effects odds ratio of 1.24 (95 % CI: 1.12-1.36, P < 10(-5)) was found for T allele. Significant results were also observed using dominant (OR = 1.34, 95 % CI: 1.17-1.54, P < 10(-4)) or recessive genetic model (OR = 1.25, 95 % CI: 1.10-1.41, P = 0.0004). There was strong evidence of heterogeneity (P < 10(-5)), which largely disappeared after stratification by ethnicity. After stratified by ethnicity, significant results were found in East Asians; whereas no significant associations were found among Caucasians and other ethnic populations in all genetic models. In the stratified analysis according to sample size, CHD endpoints, and HWE status, significantly increased risks for the polymorphism were found in all genetic models. In conclusion, our results indicate that the CD14 C-260T polymorphism is a risk factor of CHD, especially in East Asians. However, additional very large-scale studies are warranted to confirm our results.

CRP and CD14 polymorphisms correlate with coronary plaque volume in patients with coronary artery disease--IVUS substudy of the ENCORE trials

BACKGROUND

Several proinflammatory single-nucleotide polymorphisms (SNPs) have been linked to the progression of atherosclerosis and coronary artery disease (CAD). Plaque size and its destabilization by inflammatory processes are major determinants of ischemia and acute coronary syndromes. Intravascular ultrasound (IVUS) allows for quantification of plaque size in vivo. We therefore investigated the relation of plaque size with mutations of proinflammatory genes in patients with CAD.

METHODS

In 196 patients with stable CAD enrolled in the ENCORE trials coronary plaque and vessel volume was assessed by IVUS. 173 patients were successfully genotyped for polymorphisms of proinflammatory genes CD14 C(-260)T and CRP C(+1444)T using the single-nucleotide polymorphism polymerase chain reaction (SNP PCR) approach.

RESULTS

Baseline characteristics were comparable for all genotype groups. Higher ratios of plaque volume/vessel volume were observed in patients with the CRP 1444TT (n=11) and CD14 260TT (n=33) genotypes (p=0.016 and p=0.026, respectively).

CONCLUSION

In patients with stable coronary artery disease the CRP 1444TT and CD14 260TT variants are associated with larger coronary plaque volume independently of concomitant cardiovascular risk factors.

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.

CD14 C-260T gene polymorphism and ischemic heart disease susceptibility: a HuGE review and meta-analysis

The CD14 gene C-260T polymorphism has been reported to be associated with ischemic heart disease, but results were conflicting. To evaluate the role of the CD14 C-260T polymorphism in ischemic heart disease, we performed meta-analyses of all available data. Comprehensive searches for studies on the association between the genotypes (CC, CT, TT) distributions and ischemic heart disease risk were performed. Patients with acute coronary syndrome, prior myocardial infarction, stable angina pectoris, or angiographic coronary artery stenosis were included. Potential sources of heterogeneity were explored by meta-regression. Analyses were performed under European, East Asian, and Indian studies, respectively. Data were available for 19 studies involving 11,813 cases and 6,196 controls. The summary odds ratio under the recessive model was 1.53 (95% confidence interval: 1.20-1.96) for East Asian studies published in English language journals on overall ischemic heart disease. Pooled odds ratios under the codominant model were about 1.81 (95% confidence interval: 1.36-2.40) and 1.70 (95% confidence interval: 1.26-2.29) for Chinese studies on overall ischemic heart disease and other ischemic heart disease (angina pectoris and angiographic coronary artery stenosis), respectively. No significant association was found in a European population, an Indian population, or the vulnerable plaque ischemic heart disease (acute coronary syndrome and prior myocardial infarction) subgroup of an East Asian population. It is probable that T allele and TT genotype are associated with ischemic heart disease in the East Asian population but not in the European or Indian populations. Further studies are warranted to assess these associations in greater details, especially in East Asian and Indian populations.

Monocytes in acute coronary syndromes

The aim of this overview is to summarize the available data on the involvement of monocytes in the pathological processes related to the development of acute coronary syndromes and the recovery of damaged areas, the prevention of excessive inflammatory and procoagulant response, and the restoration of microcirculation (angiogenesis).

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.

Angiotensin-converting enzyme 2 A1075G polymorphism is associated with survival in an acute coronary syndromes cohort

BACKGROUND

Polymorphisms of the angiotensin-converting enzyme 2 (ACE2) gene, which is located on the X chromosome, have been associated with hypertension and left ventricular hypertrophy in previous studies. We tested the hypothesis that the rare allele of an ACE2 gene polymorphism was associated with risk factors for and adverse outcome after acute coronary syndrome (ACS) events.

METHODS

Patients (n = 1,042) were recruited after admission for an ACS event and were genotyped for the A1075G polymorphism of the angiotensin-converting enzyme 2 gene. This genetic marker was tested for association with baseline measurements, echocardiographic measurements, and clinical outcome, over a median 2.19 years follow-up. As the ACE2 gene is X-linked, analyses were performed separately for males and females. Patients were predominantly of European ethnicity (90.1%).

RESULTS

The A1075 allele was significantly associated with covariate-adjusted mortality in male patients (hazard ratio 1.95, 95% CI 1.10-3.46, P = .047) but not unadjusted (hazard ratio 1.14, 95% CI 0.736-1.76, P = .56). The G1075 (P < .035) allele was more frequent in patients of Maori compared to European ancestry. E/E', an echocardiographic index of left ventricular diastolic function and filling pressure, was higher in males in the A1075 group (G allele group 10.5 [95% CI 10.0-11.0], A allele group 11.4 [95% CI 10.8-12.1], P = .024). A1075 genotype was significantly associated with male survival in the absence of (mortality: A 12.8%, n = 39; G 29.2%, n = 48; P = .037) but not in the presence of beta-blocker treatment (mortality: A 13.5% n = 273; G 8.2% n = 304, P = nonsignificant).

CONCLUSIONS

The A1075 allele was associated with covariate-adjusted mortality in male patients.

Review: variability of host-pathogen interaction

The course of every infection is different. The same pathogen can lead to subclinical, mild, severe or lethal infections in individuals. But is this just chance or determined by individual differences--on the side of the host as well as on the side of the pathogen? If so, we might need to consider these variations for treatment decisions. Indeed, we now understand that genetic polymorphisms and health status represent inborn and acquired risk factors. Similarly, pathogens impress with an increasing number of already identified virulence factors and host response modifiers. The emerging, more complex, view of the factors determining course and outcome of infections promises to enable more tailored and thus, hopefully, more effective treatment decisions.

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).

Molecular cloning, mapping, and tissue expression of the porcine cluster of differentiation 14 (CD14) gene

CD14 plays an important role in initiating the innate response to lipopolysaccharide from Gram-negative bacteria. The gene and corresponding cDNA of porcine CD14 were sequenced and characterized. The porcine CD14 gene consists of two exons and a short intron (80 bp) located immediately after the ATG translation start codon. This structure is very similar to the CD14 gene of human, rat, mouse, rabbit, horse, and cow. The sequence of the porcine CD14 protein is 59-76% identical to that of rat, mouse, rabbit, human, horse, and cow CD14 protein. A highly conserved structure of the CD14 protein with respect to the leucine-rich repeats domain and the N-glycosylation sites was observed between species. Porcine CD14 was assigned to porcine chromosome 2q21 by a radiation hybrid panel. Using RT-PCR analysis, porcine CD14 transcripts were detected in liver, spleen, thymus, white matter, and skeletal muscle.

Influence of the CD14 C260T promoter polymorphism on C-reactive protein levels in patients with coronary artery disease

The CD14 receptor is an important mediator of inflammatory reactions, and its expression is under genetic control. The allelic variant of the C260T polymorphism located in the promoter region of the CD14 gene is associated with receptor expression and ischemic risk. To date, most studies assessing the functional implications of the C260T polymorphism have been performed under proinflammatory conditions (e.g., acute coronary syndromes), and whether gene sequence variations of the CD14 receptor have any functional effect on systemic inflammation in patients in a stable phase of their atherosclerotic disease process is unknown. Eighty-two patients with stable coronary artery disease were studied. High-sensitivity C-reactive protein (hs-CRP) was used as a measurement of systemic inflammation. The genotype distribution of the C260T polymorphism of the CD14 gene was as follows: CC in 18 of 82 patients (22%), TC in 48 of 82 patients (58.5%), and TT in 16 of 82 patients (19.5%). TT subjects had increased hs-CRP levels compared with carriers of the C allele (p = 0.04). A higher percentage of T allele homozygotes had hs-CRP levels >0.3 mg/dl (p = 0.01). Homozygosis status of the T allele was independently associated with hs-CRP levels >0.3 mg/dl (p = 0.004). In conclusion, these observations may support the findings in large-scale studies that T homozygotes of this functional polymorphism are at increased ischemic risk.

Genetic polymorphisms of inflammatory cytokines and myocardial infarction in the elderly

Cardiovascular diseases (CVD), such as myocardial infarction (MI), are major causes of disability and mortality in the elderly. The increasing burden of CVD in ageing industrialized populations requires intensive research in order to improve preventive and therapeutic strategies especially in old people and if possible slow the processes of cardiovascular disease generation and progression. Ageing is accompanied by an age-dependent up-regulation of the inflammatory response, due to chronic antigenic stress stimulation, which potentially triggers the onset of inflammatory diseases, especially CVD. However, the exact mechanisms are still poorly understood. Since CVD are caused by interactions between genetic and environmental factors, a possible approach to their prevention is to identify the potential genetic component of inflammatory cardiovascular risk factors, providing the basis for personalized lifestyle modification and improved pharmacological therapy. Some common gene polymorphisms associated with high production of inflammatory molecules have been associated with atherosclerosis. Therefore, controlling inflammation might play a protective role against CVD, especially in ageing. Although a large number of studies of pro- and anti-inflammatory gene variants in association with CVD and MI exists, the emerging data are quite conflicting and do not provide definitive evidence for a role of these polymorphisms in the pathogenesis of MI. In this paper we review the evidence for a possible role of genetic polymorphisms of the most important inflammatory cytokines (IL-6, TNF-alpha, IL-10) and immune receptors (CD14 receptor and TLR-4) in modulating the incidence or the prognosis of MI, with a special focus in ageing population.