Effect of cigarette smoke on monocyte procoagulant activity: Focus on platelet-derived brain-derived neurotrophic factor (BDNF)

<p>Cigarette smoke (CS) activates platelets, promotes vascular dysfunction, and enhances Tissue Factor (TF) expression in blood monocytes favoring pro-thrombotic states. Brain-derived neurotrophic factor (BDNF), a member of the family of neurotrophins involved in survival, growth, and maturation of neurons, is released by activated platelets (APLTs) and plays a role in the cardiovascular system. The effect of CS on circulating levels of BDNF is controversial and the function of circulating BDNF in atherothrombosis is not fully understood. Here, we have shown that human platelets, treated with an aqueous extract of CS (CSE), released BDNF in a dose-dependent manner. In addition, incubation of human monocytes with BDNF or with the supernatant of platelets activated with CSE increased TF activity by a Tropomyosin receptor kinase B (TrkB)-dependent mechanism. Finally, comparing serum and plasma samples of 12 male never smokers (NS) and 29 male active smokers (AS) we observed a significant increase in microparticle-associated TF activity (MP-TF) as well as BDNF in AS, while in serum, BDNF behaved oppositely. Taken together these findings suggest that platelet-derived BDNF is involved in the regulation of TF activity and that CS plays a role in this pathway by favoring a pro-atherothrombotic state.</p

Analysis of the Role of Interleukin 6 Receptor Haplotypes in the Regulation of Circulating Levels of Inflammatory Biomarkers and Risk of Coronary Heart Disease

<div><p>Variants at the interleukin 6 receptor (<i>IL6R</i>) gene regulate inflammation and are associated with risk of coronary heart disease (CHD). The aim of the present study was to investigate the effects of <i>IL6R</i> haplotypes on circulating levels of inflammatory biomarkers and risk of CHD. We performed a discovery analysis in SHEEP, a myocardial infarction (MI) case control study (n = 2,774) and replicated our results in two large, independent European populations, PROCARDIS, a CHD case control study (n = 7,998), and IMPROVE (n = 3,711) a prospective cardiovascular cohort study. Two major haplotype blocks (rs12083537A/G and rs4075015A/T—block 1; and rs8192282G/A, rs4553185T/C, rs8192284A/C, rs4240872T/C and rs7514452T/C—block 2) were identified in the <i>IL6R</i> gene. <i>IL6R</i> haplotype associations with C-reactive protein (CRP), fibrinogen, IL6, soluble IL6R (sIL6R), IL6, IL8 and TNF-α in SHEEP, CRP and fibrinogen in PROCARDIS and CRP in IMPROVE as well as association with risk of MI and CHD, were analyzed by THESIAS. Haplotypes in block 1 were associated neither with circulating inflammatory biomarkers nor with the MI/CHD risk. Haplotypes in block 2 were associated with circulating levels of CRP, in all three study populations, with fibrinogen in SHEEP and PROCARDIS, with IL8 and sIL6Rin SHEEP and with a modest, non significant, increase (7%) in MI/CHD risk in the three populations studied. Our results indicate that <i>IL6R</i> haplotypes regulate the circulating levels of inflammatory biomarkers. Lack of association with the risk of CHD may be explained by the combined effect of SNPs with opposite effect on the CHD risk, the sample size as well as by structural changes affecting sIL6R stability in the circulation.</p></div

Association of <i>IL6R</i> haplotypes in blocks 1 and 2 with difference in serum sIL6R levels in controls from the SHEEP compared to the reference haplotype where mean sIL6R (95%CI) are shown.

<p>Data represent the mean and relative 95%CI of the difference in serum sIL6R levels (ng/ml) observed in the presence of one copy of each haplotype configurations as compared to the reference haplotype.</p><p>Association of <i>IL6R</i> haplotypes in blocks 1 and 2 with difference in serum sIL6R levels in controls from the SHEEP compared to the reference haplotype where mean sIL6R (95%CI) are shown.</p

Association of <i>IL6R</i> haplotypes in block 1 and block 2 with differences in serum CRP levels (compared to the reference haplotype where mean CRP (95%CI) are shown) in controls from the SHEEP and PROCARDIS and in block 2 from the IMPROVE study.

<p>Data represent the mean and relative 95%CI of the difference in serum CRP levels (mg/L) observed in the presence of one copy of each haplotype configurations as compared to the reference haplotype. Genotype data from only three SNPs in block 2 were available in the IMPROVE study (rs7553796 C/A (pairwise LD with rs4553185T/C, r2 = 0.96) rs8192284A/C and rs4072391T/C (pairwise LD with rs7514452T/C r2 = 0.98).</p><p>Association of <i>IL6R</i> haplotypes in block 1 and block 2 with differences in serum CRP levels (compared to the reference haplotype where mean CRP (95%CI) are shown) in controls from the SHEEP and PROCARDIS and in block 2 from the IMPROVE study.</p

<i>IL6R</i> haplotype frequencies in cases and controls and risk of MI in SHEEP and of CHD in the PROCARDIS and IMPROVE studies associated with <i>IL6R</i> haplotypes.

<p>Only diplotypes and haplotypes with a frequency>1% are reported in the table. The most common diplotype in block 1 and the most common haplotype in block 2 are taken as reference categories.</p><p>Data from only three tag SNPs were available in the IMPROVE study (rs7553796 C/A (pairwise LD with rs4553185T/C, r2 = 0.96) rs8192284A/C and rs4072391T/C (pairwise LD with rs7514452T/C r2 = 0.98). Haplotype-21–1 represents both 12111 and 12121.</p><p><i>IL6R</i> haplotype frequencies in cases and controls and risk of MI in SHEEP and of CHD in the PROCARDIS and IMPROVE studies associated with <i>IL6R</i> haplotypes.</p

IL6R haplotypes selectively regulate inflammatory biomarkers.

<p><b>In particular, changes in CRP and fibrinogen are mirrored by inverse changes in sIL6R serum levels.</b><i>Mutations around the shedding site may affect the shedding/alternative splicing and therefore the relative amount of sIL6R in the circulation</i>. <i>The sIL6R</i>, <i>once released participates in the IL6 transignalling in cells not expressing IL6R (i.e</i>. <i>endothelial and smooth muscle cells) and the complex IL6/sIL6R is buffered in the circulation by its natural antagonist</i>, <i>sgp130</i>. <i>It is possible that the final effect of IL6R haplotypes on the CHD risk depends on the average effect of the association of different SNPs with the CHD risk present in the same haplotype and/or it may reflect changes in the secondary and tertiary structure of the IL6R and sIL6R that may affect the IL6/sIL6R interaction with its downstream mediators</i>.</p

Demographic characteristics of the study participants in the three study populations.

<p>Hyperchol: hypercholesterolemia.</p><p>SHEEP: hypertension defined as blood pressure >140/90 mmHg and/or self-reported and/or antihypertensive drug treatment; diabetes defined as glucose levels>6.7mmol/L and/or insulin or hypoglycemic drugs; smoking defined as current smoking in the past two years; hypercholestesterolemia defined as serum level of total cholesterol ≥6.46 mmol/L and/or treatment with lipid lowering drugs; obesity defined as body mass index>30kg/m2.</p><p>PROCARDIS: hypertension defined as blood pressure >140/90 mmHg and/or self-reported and/or antihypertensive drug treatment; diabetes defined as self-reported, glucose levels>7.0mmol/L and/or insulin or hypoglycemic drugs; hypercholestesterolemia defined as serum level of total cholesterol ≥6.46 mmol/L and/or treatment with lipid lowering drugs; obesity defined as body mass index>30kg/m2.</p><p>IMPROVE: hypertension and hypercholesterolemia were self-reported at the time of enrollment; diabetes defined as self reported and/or glucose levels>7.0mmol/L and/or insulin or hypoglycemic drugs; smoking defined as current smokers; obesity defined as body mass index>30kg/m2</p><p>Demographic characteristics of the study participants in the three study populations.</p

Increased Levels of Circulating Fatty Acids Are Associated with Protective Effects against Future Cardiovascular Events in Nondiabetics

Cardiovascular disease (CVD) is a major cause of morbidity and mortality worldwide, particularly in individuals with diabetes. The current study objective was to determine the circulating metabolite profiles associated with the risk of future cardiovascular events, with emphasis on diabetes status. Nontargeted metabolomics analysis was performed by LC–HRMS in combination with targeted quantification of eicosanoids and endocannabinoids. Plasma from 375 individuals from the IMPROVE pan-European cohort was included in a case-control study design. Following data processing, the three metabolite data sets were concatenated to produce a single data set of 267 identified metabolites. Factor analysis identified six factors that described 26.6% of the variability in the given set of predictors. An association with cardiovascular events was only observed for one factor following adjustment (<i>p</i> = 0.026). From this factor, we identified a free fatty acid signature (<i>n</i> = 10 lipids, including saturated, monounsaturated, and polyunsaturated fatty acids) that was associated with lower risk of future cardiovascular events in nondiabetics only (OR = 0.65, 0.27–0.80 95% CI, <i>p</i> = 0.030), whereas no association was observed among diabetic individuals. These observations support the hypothesis that increased levels of circulating omega-6 and omega-3 fatty acids are associated with protective effects against future cardiovascular events. However, these effects were only observed in the nondiabetic population, further highlighting the need for patient stratification in clinical investigations

SNPs showing significant associations with different IMT measurements.

<p>Chr: chromosome, A1: coded allele, P: p-value for association with IMT, CC-IMT_mean: average IMT of the common carotid in a segment excluding the first cm proximal to the bifurcation, CC-IMT_max: maximum IMT of the common carotid in a segment excluding the first cm proximal to the bifurcation, ICA-IMT_mean: average IMT of the internal carotid, ICA-IMT_max: maximum IMT of the internal carotid, Bif-IMT_mean: average IMT of the bifurcation, Bif-IMT_max: maximum IMT of the bifurcation, IMT_mean: average IMT composite value considering the whole carotid tree derived from the segment-specific measurements, IMT_max: Maximum IMT measure considering the whole carotid tree derived from the segment-specific measurements, IMT_mean-max: average of the IMT_max values for the whole carotid tree derived from the segment-specific measurements. rs4888378 was used as proxy SNP for rs2865531.</p

Information of the 26 lung function-associated SNPs selected in the present study [13], [14], [15], [16].

<p>Columns 1 to 9 refer to frequencies, beta and p values for the association of SNPs with lung function fenotypes as found in the literature. Columns 10 to 15 refer to the frequencies and total sample sizes of the same or proxy-SNPs that were looked up in IMPROVE.</p><p>SNP ID: rs number for the SNPs selected from literature. Chr: chromosome, A1: coded allele, A1 freq: frequency of the coded allele, Measure reported: phenotype for which the SNP reached genome-wide significant association, SE: standard error, P: p-value for association with measure reported, proxy LD: linkage disequilibrium between SNP ID from literature (column 1) and the proxy used for replication in IMPROVE (column 11), proxy SNP: rs number for the proxy SNPs used for replication in IMPROVE, n: number of individuals tested in IMPROVE.</p