Large Scale Association Analysis of Novel Genetic Loci for Coronary Artery Disease

Background-Combined analysis of 2 genome-wide association studies in cases enriched for family history recently identified 7 loci (on 1p13.3, 1q41, 2q36.3, 6q25.1, 9p21, 10q11.21, and 15q22.33) that may affect risk of coronary artery disease (CAD). Apart from the 9p21 locus, the other loci await substantive replication. Furthermore, the effect of these loci on CAD risk in a broader range of individuals remains to be determined.Methods and Results-We undertook association analysis of single nucleotide polymorphisms at each locus with CAD risk in 11 550 cases and 11 205 controls from 9 European studies. The 9p21.3 locus showed unequivocal association (rs1333049, combined odds ratio [OR]=1.20, 95% CI [1.16 to 1.25], probability value=2.81x10(-21)). We also confirmed association signals at 1p13.3 (rs599839, OR=1.13 [1.08 to 1.19], P=1.44x10(-7)), 1q41 (rs3008621, OR=1.10 [1.04 to 1.17], P=1.02x10(-3)), and 10q11.21 (rs501120, OR=1.11 [1.05 to 1.18], P=4.34x10(-4)). The associations with 6q25.1 (rs6922269, P=0.020) and 2q36.3 (rs2943634, P=0.032) were borderline and not statistically significant after correction for multiple testing. The 15q22.33 locus did not replicate. The 10q11.21 locus showed a possible sex interaction (P = 0.015), with a significant effect in women (OR=1.29 [1.15 to 1.45], P=1.86x10(-5)) but not men (OR=1.03 [0.96 to 1.11], P=0.387). There were no other strong interactions of any of the loci with other traditional risk factors. The loci at 9p21, 1p13.3, 2q36.3, and 10q11.21 acted independently and cumulatively increased CAD risk by 15% (12% to 18%), per additional risk allele. ConclusionsThe findings provide strong evidence for association between at least 4 genetic loci and CAD risk. Cumulatively, these novel loci have a significant impact on risk of CAD at least in European populations. (Arterioscler Thromb Vasc Biol. 2009; 29: 774-780.

Genome-wide association study identifies six new loci influencing pulse pressure and mean arterial pressure.

Numerous genetic loci have been associated with systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Europeans. We now report genome-wide association studies of pulse pressure (PP) and mean arterial pressure (MAP). In discovery (N = 74,064) and follow-up studies (N = 48,607), we identified at genome-wide significance (P = 2.7 × 10(-8) to P = 2.3 × 10(-13)) four new PP loci (at 4q12 near CHIC2, 7q22.3 near PIK3CG, 8q24.12 in NOV and 11q24.3 near ADAMTS8), two new MAP loci (3p21.31 in MAP4 and 10q25.3 near ADRB1) and one locus associated with both of these traits (2q24.3 near FIGN) that has also recently been associated with SBP in east Asians. For three of the new PP loci, the estimated effect for SBP was opposite of that for DBP, in contrast to the majority of common SBP- and DBP-associated variants, which show concordant effects on both traits. These findings suggest new genetic pathways underlying blood pressure variation, some of which may differentially influence SBP and DBP

Genetic variants in novel pathways influence blood pressure and cardiovascular disease risk.

Blood pressure is a heritable trait influenced by several biological pathways and responsive to environmental stimuli. Over one billion people worldwide have hypertension (≥140 mm Hg systolic blood pressure or  ≥90 mm Hg diastolic blood pressure). Even small increments in blood pressure are associated with an increased risk of cardiovascular events. This genome-wide association study of systolic and diastolic blood pressure, which used a multi-stage design in 200,000 individuals of European descent, identified sixteen novel loci: six of these loci contain genes previously known or suspected to regulate blood pressure (GUCY1A3-GUCY1B3, NPR3-C5orf23, ADM, FURIN-FES, GOSR2, GNAS-EDN3); the other ten provide new clues to blood pressure physiology. A genetic risk score based on 29 genome-wide significant variants was associated with hypertension, left ventricular wall thickness, stroke and coronary artery disease, but not kidney disease or kidney function. We also observed associations with blood pressure in East Asian, South Asian and African ancestry individuals. Our findings provide new insights into the genetics and biology of blood pressure, and suggest potential novel therapeutic pathways for cardiovascular disease prevention

Genetic associations at 53 loci highlight cell types and biological pathways relevant for kidney function.

Reduced glomerular filtration rate defines chronic kidney disease and is associated with cardiovascular and all-cause mortality. We conducted a meta-analysis of genome-wide association studies for estimated glomerular filtration rate (eGFR), combining data across 133,413 individuals with replication in up to 42,166 individuals. We identify 24 new and confirm 29 previously identified loci. Of these 53 loci, 19 associate with eGFR among individuals with diabetes. Using bioinformatics, we show that identified genes at eGFR loci are enriched for expression in kidney tissues and in pathways relevant for kidney development and transmembrane transporter activity, kidney structure, and regulation of glucose metabolism. Chromatin state mapping and DNase I hypersensitivity analyses across adult tissues demonstrate preferential mapping of associated variants to regulatory regions in kidney but not extra-renal tissues. These findings suggest that genetic determinants of eGFR are mediated largely through direct effects within the kidney and highlight important cell types and biological pathways

Intratumoral expression of programmed death ligand 1 (PD-L1) in patients with clear cell renal cell carcinoma (ccRCC)

The immunological checkpoints of programmed death 1 and its ligand (PD-L1) are currently in focus as novel therapeutic targets in renal cell carcinoma (RCC). The aim of this study was to evaluate the prognostic association of PD-L1 expression in clear cell (cc) RCC with clinical parameters, tumor aggressiveness and overall survival (OS). Patients who underwent renal surgery due to RCC between 1994 and 2003 were retrospectively evaluated. Tumor specimens were analyzed for PD-L1 expression by immunohistochemistry. One hundred and seventy-seven ccRCC patients were eligible for analysis, in which 140 (79.1 %) were negative and 37 (20.9 %) were positive for PD-L1 expression. PD-L1 positivity was associated with female gender (p = 0.001), lymph node metastasis (p = 0.004), distant metastasis (p = 0.002), higher AJCC stage (p = 0.004), as well as advanced disease (pT3/4 and/or N+ and/or M1) (p < 0.001). Kaplan-Meier analysis revealed a significantly diminished 5- and 10-year overall survival of 46.7 and 28.3 % for PD-L1(+) compared to PD-L1(-) tumors with 66 and 53.4 % (p = 0.005), respectively. Univariate analysis showed a significant negative association of OS with PD-L1 positivity [p = 0.005; HR: 2 (95 % CI 1.2-3.3)], even though PD-L1 positivity only tends to predict independently the OS using multivariate analyses [p = 0.066; HR: 1.6 (95 % CI 0.98-2.7)]. PD-L1 expression in ccRCC is associated with parameters of aggressiveness, as well as with poor OS, even though PD-L1 status was not identified as a significant independent prognostic parameter. However, further studies in larger cohorts are warranted

Pacemaker current inhibition in experimental human cardiac sympathetic activation: a double-blind, randomized, crossover study

Item does not contain fulltextHyperpolarization-activated, cyclic nucleotide-gated 4 (HCN4) channels comprise the final pathway for autonomic heart rate (HR) regulation. We hypothesized that HCN4 inhibition could reverse autonomic imbalance in a human model of cardiac sympathetic activation. Nineteen healthy men ingested oral metoprolol+reboxetine, ivabradine+reboxetine, or placebo+reboxetine in a double-blind, randomized, crossover fashion. We assessed HR, blood pressure (BP), stroke volume, and cardiac output during rest and profound orthostatic stress. HR variability, BP variability, and baroreflex sensitivity were analyzed. Metoprolol, but not ivabradine, decreased resting HR and BP. Ivabradine attenuated the HR increase to orthostatic stress, albeit to a lesser extent than metoprolol. Stroke volume and cardiac output at a given HR were significantly lower with metoprolol. Unlike metoprolol, ivabradine did not affect HR variability, BP variability, or baroreflex sensitivity. Ivabradine attenuates sympathetic influences on HR at the sinus node level, leaving myocardial sympathetic activation unopposed. Reversal of parasympathetic dysfunction by ivabradine appears limited

Influences of Experimental Air Pollution on Human Sympathetic Nerve Traffic and Norepinephrine Metabolism: A Double Blind, Randomized, Twofold Crossover Study

Background Much of the evidence linking air pollutant exposure with changes in human cardiovascular autonomic regulation relied on epidemiological studies, exposure estimates, and indirect autonomic nervous system measurements. We tested the hypothesis that in healthy older individuals, experimental exposure to fine particles increases sympathetic nervous system activity and more so with addition of ozone. Material and Methods Eighteen healthy participants (age >50 years) completed all study visits and were included in the final analysis. Participants were exposed to clean air (‘placebo’), ultrafine particles (UFP, 50μg/m3), and combination of UFP+ozone (250 ppb) for 3 hours combined with intermittent bicycle ergometer training in a randomized, three‐period, cross‐over, double‐blind fashion. Three hours following exposure, respiration, ECG, blood pressure, and muscle sympathetic nerve activity (MSNA) were continuously recorded at supine rest, during deep breathing, and during a Valsalva maneuver. Venous blood samples for plasma catecholamine measurements were taken at baseline. Induced sputum was obtained at the end of each study day. Results Combined exposure to ozone and UFP but not UFP alone caused a significant increase in sputum neutrophils and circulating leucocytes. We did not detect significant effects on blood pressure or heart rate. Resting MSNA was 47±12 with clean air, 47±14 with UFP, and 45±14 bursts/min with UFP+ozone. Maximum MSNA during Valsalva phase IIb was similar. Yet, with UFP+ozone plasma norepinephrine concentrations were significantly increased with concomitant reduction in the dihydroxyphenylglycol (DHPG)/norepinephrine ratio. Respiratory sinus arrhythmia and Valsalva ratio were unaffected by experimental air pollution. Conclusion Exposure to ultrafine particles with or without ozone does not elicit clinically relevant changes in central sympathetic or parasympathetic activity in healthy older subjects. The paradoxical norepinephrine increase with UFP+ozone may be explained by reduced peripheral norepinephrine uptake and metabolism

Do programmed death 1 (PD-1) and its ligand (PD-L1) play a role in patients with non-clear cell renal cell carcinoma?

Clinical trials targeting programmed death 1 (PD-1) and its ligand PD-L1 (PD-L1) for metastatic renal cell cancer (RCC) are ongoing. The aim of this study is to validate their roles as prognostic markers in non-clear cell (non-cc) RCC. Sixty-four non-cc RCC tissue specimens were collected from patients undergoing renal tumor surgery. Expressions of biomarkers were assessed using immunohistochemistry and compared with clinical characteristics. Survival analyses were performed with a median follow-up of 77.5 (range: 0-176) months. No significant correlations were found for PD-1(+) tumor-infiltrating mononuclear cells (TIMC) or PD-L1(+) expression and clinical attributes in patients with non-cc RCC. Kaplan-Meier analysis revealed no differences in 5- and 10-year cancer-specific survival (CSS) for PD-1-TIMC compared to PD-1(+) TIMC (71.4 and 63 % versus 72.2 and 61.9 %; p = 0.88). Intratumoral expression of PD-L1 did not appear to influence the 5-and 10-year CSS significantly, even though a trend was identified (68 and 53.6 % versus 80.1 and 75.7 %; p = 0.08). In multivariate analysis, neither PD-1(+) TIMC nor intratumoral PD-L1(+) expression proved to be independent predictors of CSS (p = 0.99 and p = 0.68, respectively). Our study demonstrates that PD-1(+) TIMC and intratumoral PD-L1(+) expression did not significantly impact tumor aggressiveness or clinical outcome in non-ccRCC specimens. Due to rare incidence of non-cc RCC in particular according to PD-L1 expression, further analyzes are warranted