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Fischer T.H.,University of Gottingen | Eiringhaus J.,University of Gottingen | Dybkova N.,University of Gottingen | Forster A.,University of Gottingen | And 12 more authors.
European Journal of Heart Failure | Year: 2014

Methods and results Western blots showed a significantly increased expression (by 54 ± 9%) and autophosphorylation at Thr286 (by 129 ± 29%, P < 0.05 each) of CaMKII in HF compared with healthy myocardium. However, no significant difference could be detected in ICM compared with DCM as to the expression and autophosphorylation of CaMKII nor the phosphorylation of the target sites ryanodine receptor 2 (RyR2)-S2809, RyR2-S2815, and phospholamban-Thr17. Isolated human cardiomyocytes (CMs) of patients with DCM and ICM showed a similar frequency of diastolic Ca2+ sparks (confocal microscopy) as well as of major arrhythmic events (Ca2+ waves, spontaneous Ca2+ transients). Despite a slightly smaller size of Ca2+ sparks in DCM (P < 0.01), the calculated SR Ca2+ leak [Ca2+ spark frequecy (CaSpF) × amplitude × width × duration] did not differ between CMs of ICM vs. DCM. Importantly, CaMKII inhibition by autocamide-2-related inhibitory peptide (AIP, 1 μmol/L) reduced the SR Ca2+ leak by 80% in both aetiologies (P < 0.05 each) and effectively decreased the ratio of arrhythmic cells (P < 0.05). Conclusion Functional and molecular measures of the SR Ca2+ leak are comparable in human ICM and DCM. CaMKII is equally responsible for the induction of the 'RyR2 leakiness' in both pathologies. Thus, CaMKII inhibition as a therapeutic measure may not be restricted to patients suffering from DCM but rather may be beneficial for the majority of HF patients.Aims The sarcoplasmic reticulum (SR) Ca2+ leak is an important pathomechanism in heart failure (HF). It has been suggested that Ca2+/calmodulin-dependent protein kinase II (CaMKII) is only relevant for the induction of the SR Ca2+ leak in non-ischaemic but not in ischaemic HF. Therefore, we investigated CaMKII and its targets as well as the functional effects of CaMKII inhibition in human ischaemic cardiomyopathy (ICM, n = 37) and dilated cardiomyopathy (DCM, n = 40). © 2014 The Authors. European Journal of Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.


Tsaprouni L.G.,Wellcome Trust Sanger Institute | Tsaprouni L.G.,University of Bedfordshire | Yang T.-P.,Wellcome Trust Sanger Institute | Yang T.-P.,University of Cambridge | And 27 more authors.
Epigenetics | Year: 2014

Smoking is a major risk factor in many diseases. Genome wide association studies have linked genes for nicotine dependence and smoking behavior to increased risk of cardiovascular, pulmonary, and malignant diseases. We conducted an epigenome wide association study in peripheral-blood DNA in 464 individuals (22 current smokers and 263 ex-smokers), using the Human Methylation 450 K array. Upon replication in an independent sample of 356 twins (41 current and 104 ex-smokers), we identified 30 probes in 15 distinct loci, all of which reached genome-wide significance in the combined analysis P < 5 × 10−8. All but one probe (cg17024919) remained significant after adjusting for blood cell counts. We replicated all 9 known loci and found an independent signal at CPOX near GPR15. In addition, we found 6 new loci at PRSS23, AVPR1B,PSEN2, LINC00299, RPS6KA2, and KIAA0087. Most of the lead probes (13 out of 15) associated with cigarette smoking, overlapped regions of open chromatin (FAIRE and DNaseI hypersensitive sites) or / and H3K27Ac peaks (ENCODE data set), which mark regulatory elements. The effect of smoking on DNA methylation was partially reversible upon smoking cessation for longer than 3 months. We report the first statistically significant interaction between a SNP (rs2697768) and cigarette smoking on DNA methylation (cg03329539). We provide evidence that the metSNP for cg03329539 regulates expression of the CHRND gene located circa 95 Kb downstream of the methylation site. Our findings suggest the existence of dynamic, reversible site-specific methylation changes in response to cigarette smoking, which may contribute to the extended health risks associated with cigarette smoking. © 2014 Taylor & Francis Group, LLC.


Dichgans M.,Ludwig Maximilians University of Munich | Dichgans M.,Synergy Systems | Malik R.,Ludwig Maximilians University of Munich | Konig I.R.,Institute For Medizinische Biometrie Und Statistik | And 43 more authors.
Stroke | Year: 2014

Background and Purpose-Ischemic stroke (IS) and coronary artery disease (CAD) share several risk factors and each has a substantial heritability. We conducted a genome-wide analysis to evaluate the extent of shared genetic determination of the two diseases. Methods-Genome-wide association data were obtained from the METASTROKE, Coronary Artery Disease Genomewide Replication and Meta-analysis (CARDIoGRAM), and Coronary Artery Disease (C4D) Genetics consortia. We first analyzed common variants reaching a nominal threshold of significance (P<0.01) for CAD for their association with IS and vice versa. We then examined specific overlap across phenotypes for variants that reached a high threshold of significance. Finally, we conducted a joint meta-analysis on the combined phenotype of IS or CAD. Corresponding analyses were performed restricted to the 2167 individuals with the ischemic large artery stroke (LAS) subtype. Results-Common variants associated with CAD at P<0.01 were associated with a significant excess risk for IS and for LAS and vice versa. Among the 42 known genome-wide significant loci for CAD, 3 and 5 loci were significantly associated with IS and LAS, respectively. In the joint meta-analyses, 15 loci passed genome-wide significance (P<5×10-8) for the combined phenotype of IS or CAD and 17 loci passed genome-wide significance for LAS or CAD. Because these loci had prior evidence for genome-wide significance for CAD, we specifically analyzed the respective signals for IS and LAS and found evidence for association at chr12q24/SH2B3 (PIS=1.62×10-7) and ABO (PIS=2.6×10-4), as well as at HDAC9 (PLAS=2.32×10-12), 9p21 (PLAS=3.70×10-6), RAI1-PEMT-RASD1 (PLAS=2.69×10-5), EDNRA (PLAS=7.29×10-4), and CYP17A1-CNNM2-NT5C2 (PLAS=4.9×10-4). Conclusions-Our results demonstrate substantial overlap in the genetic risk of IS and particularly the LAS subtype with CAD. © 2013 American Heart Association, Inc.


Boraska V.,Wellcome Trust Sanger Institute | Boraska V.,University of Split | Jeroncic A.,University of Split | Colonna V.,Wellcome Trust Sanger Institute | And 157 more authors.
Human Molecular Genetics | Year: 2012

The male-to-female sex ratio at birth is constant across world populations with an average of 1.06 (106 male to 100 female live births) for populations of European descent. The sex ratio is considered to be affected by numerous biological and environmental factors and to have a heritable component. The aim of this study was to investigate the presence of common allele modest effects at autosomal and chromosome X variants that could explain the observed sex ratio at birth. We conducted a large-scale genome-wide association scan (GWAS) meta-analysis across 51 studies, comprising overall 114 863 individuals (61 094 women and 53 769 men) of European ancestry and 2 623 828 common (minor allele frequency >0.05) single-nucleotide polymorphisms (SNPs). Allele frequencies were compared between men and women for directly-typed and imputed variants within each study. Forward-time simulations for unlinked, neutral, autosomal, common loci were performed under the demographic model for European populations with a fixed sex ratio and a random mating scheme to assess the probability of detecting significant allele frequency differences. We do not detect any genome-wide significant (P < 5 × 10-8) common SNP differences between men and women in this well-powered meta-analysis. The simulated data provided results entirely consistent with these findings. This large-scale investigation across ~115 000 individuals shows no detectable contribution from common genetic variants to the observed skew in the sex ratio. The absence of sex-specific differences is useful in guiding genetic association study design, for example when using mixed controls for sex-biased traits. © The Author 2012. Published by Oxford University Press.


Schunkert H.,University of Lubeck | Konig I.R.,University of Lubeck | Kathiresan S.,Massachusetts General Hospital | Kathiresan S.,The Broad Institute of MIT and Harvard | And 191 more authors.
Nature Genetics | Year: 2011

We performed a meta-analysis of 14 genome-wide association studies of coronary artery disease (CAD) comprising 22,233 individuals with CAD (cases) and 64,762 controls of European descent followed by genotyping of top association signals in 56,682 additional individuals. This analysis identified 13 loci newly associated with CAD at P < 5 - 10'8 and confirmed the association of 10 of 12 previously reported CAD loci. The 13 new loci showed risk allele frequencies ranging from 0.13 to 0.91 and were associated with a 6% to 17% increase in the risk of CAD per allele. Notably, only three of the new loci showed significant association with traditional CAD risk factors and the majority lie in gene regions not previously implicated in the pathogenesis of CAD. Finally, five of the new CAD risk loci appear to have pleiotropic effects, showing strong association with various other human diseases or traits. © 2011 Nature America, Inc. All rights reserved.

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