Publications

265 Publications visible to you, out of a total of 265

Abstract (Expand)

Genetics of gene expression (eQTLs or expression QTLs) has proved an indispensable tool for understanding biological pathways and pathomechanisms of trait-associated SNPs. However, power of most genome-wide eQTL studies is still limited. We performed a large eQTL study in peripheral blood mononuclear cells of 2112 individuals increasing the power to detect trans-effects genome-wide. Going beyond univariate SNP-transcript associations, we analyse relations of eQTLs to biological pathways, polygenetic effects of expression regulation, trans-clusters and enrichment of co-localized functional elements. We found eQTLs for about 85% of analysed genes, and 18% of genes were trans-regulated. Local eSNPs were enriched up to a distance of 5 Mb to the transcript challenging typically implemented ranges of cis-regulations. Pathway enrichment within regulated genes of GWAS-related eSNPs supported functional relevance of identified eQTLs. We demonstrate that nearest genes of GWAS-SNPs might frequently be misleading functional candidates. We identified novel trans-clusters of potential functional relevance for GWAS-SNPs of several phenotypes including obesity-related traits, HDL-cholesterol levels and haematological phenotypes. We used chromatin immunoprecipitation data for demonstrating biological effects. Yet, we show for strongly heritable transcripts that still little trans-chromosomal heritability is explained by all identified trans-eSNPs; however, our data suggest that most cis-heritability of these transcripts seems explained. Dissection of co-localized functional elements indicated a prominent role of SNPs in loci of pseudogenes and non-coding RNAs for the regulation of coding genes. In summary, our study substantially increases the catalogue of human eQTLs and improves our understanding of the complex genetic regulation of gene expression, pathways and disease-related processes.

Authors: H. Kirsten, H. Al-Hasani, L. Holdt, A. Gross, F. Beutner, K. Krohn, K. Horn, P. Ahnert, R. Burkhardt, K. Reiche, J. Hackermuller, M. Loffler, D. Teupser, J. Thiery, M. Scholz

Date Published: 15th Aug 2015

Publication Type: Journal article

Abstract (Expand)

The Three-Factor-Eating-Questionnaire (TFEQ) is an established instrument to assess eating behaviour. Analysis of the TFEQ-factor structure was based on selected, convenient and clinical samples so far. Aims of this study were (I) to analyse the factor structure of the German version of the TFEQ and (II)--based on the refined factor structure--to examine the association between eating behaviour and the body mass index (BMI) in a general population sample of 3,144 middle-aged and older participants (40-79 years) of the ongoing population based cohort study of the Leipzig Research Center for Civilization Diseases (LIFE Health Study). The factor structure was examined in a split-half analysis with both explorative and confirmatory factor analysis. Associations between TFEQ-scores and BMI values were tested with multiple regression analyses controlled for age, gender, and education. We found a three factor solution for the TFEQ with an 'uncontrolled eating', a 'cognitive restraint' and an 'emotional eating' domain including 29 of the original 51 TFEQ-items. Scores of the 'uncontrolled eating domain' showed the strongest correlation with BMI values (partial r = 0.26). Subjects with scores above the median in both 'uncontrolled eating' and 'emotional eating' showed the highest BMI values (mean = 29.41 kg/m(2)), subjects with scores below the median in all three domains showed the lowest BMI values (mean = 25.68 kg/m(2); F = 72.074, p<0.001). Our findings suggest that the TFEQ is suitable to identify subjects with specific patterns of eating behaviour that are associated with higher BMI values. Such information may help health care professionals to develop and implement more tailored interventions for overweight and obese individuals.

Authors: A. Loffler, T. Luck, F. S. Then, C. Sikorski, P. Kovacs, Y. Bottcher, J. Breitfeld, A. Tonjes, A. Horstmann, M. Loffler, C. Engel, J. Thiery, A. Villringer, M. Stumvoll, S. G. Riedel-Heller

Date Published: 1st Aug 2015

Publication Type: Not specified

Abstract (Expand)

BACKGROUND: Adhering to the Mediterranean diet (MeDi) is known to be beneficial with regard to many age-associated diseases including cardiovascular diseases and type 2 diabetes. Recent studies also suggest an impact on cognition and brain structure, and increasing effort is made to track effects down to single nutrients. AIMS: We aimed to review whether two MeDi components, i.e., long-chain omega-3 fatty acids (LC-n3-FA) derived from sea-fish, and plant polyphenols including resveratrol (RSV), exert positive effects on brain health in aging. CONTENT: We summarized health benefits associated with the MeDi and evaluated available studies on the effect of (1) fish-consumption and LC-n3-FA supplementation as well as (2) diet-derived or supplementary polyphenols such as RSV, on cognitive performance and brain structure in animal models and human studies. Also, we discussed possible underlying mechanisms. CONCLUSION: A majority of available studies suggest that consumption of LC-n3-FA with fish or fishoil-supplements exerts positive effects on brain health and cognition in older humans. However, more large-scale randomized controlled trials are needed to draw definite recommendations. Considering polyphenols and RSV, only few controlled studies are available to date, yet the evidence based on animal research and first interventional human trials is promising and warrants further investigation. In addition, the concept of food synergy within the MeDi encourages future trials that evaluate the impact of comprehensive lifestyle patterns to help maintaining cognitive functions into old age.

Authors: S. Huhn, S. Kharabian Masouleh, M. Stumvoll, A. Villringer, A. V. Witte

Date Published: 29th Jul 2015

Publication Type: Not specified

Human Diseases: cardiovascular system disease, diabetes mellitus

Abstract (Expand)

BACKGROUND: The LIFE-Adult-Study is a population-based cohort study, which has recently completed the baseline examination of 10,000 randomly selected participants from Leipzig, a major city with 550,000 inhabitants in the east of Germany. It is the first study of this kind and size in an urban population in the eastern part of Germany. The study is conducted by the Leipzig Research Centre for Civilization Diseases (LIFE). Our objective is to investigate prevalences, early onset markers, genetic predispositions, and the role of lifestyle factors of major civilization diseases, with primary focus on metabolic and vascular diseases, heart function, cognitive impairment, brain function, depression, sleep disorders and vigilance dysregulation, retinal and optic nerve degeneration, and allergies. METHODS/DESIGN: The study covers a main age range from 40-79 years with particular deep phenotyping in elderly participants above the age of 60. The baseline examination was conducted from August 2011 to November 2014. All participants underwent an extensive core assessment programme (5-6 h) including structured interviews, questionnaires, physical examinations, and biospecimen collection. Participants over 60 underwent two additional assessment programmes (3-4 h each) on two separate visits including deeper cognitive testing, brain magnetic resonance imaging, diagnostic interviews for depression, and electroencephalography. DISCUSSION: The participation rate was 33 %. The assessment programme was accepted well and completely passed by almost all participants. Biomarker analyses have already been performed in all participants. Genotype, transcriptome and metabolome analyses have been conducted in subgroups. The first follow-up examination will commence in 2016.

Authors: M. Loeffler, C. Engel, P. Ahnert, D. Alfermann, K. Arelin, R. Baber, F. Beutner, H. Binder, E. Brahler, R. Burkhardt, U. Ceglarek, C. Enzenbach, M. Fuchs, H. Glaesmer, F. Girlich, A. Hagendorff, M. Hantzsch, U. Hegerl, S. Henger, T. Hensch, A. Hinz, V. Holzendorf, D. Husser, A. Kersting, A. Kiel, T. Kirsten, J. Kratzsch, K. Krohn, T. Luck, S. Melzer, J. Netto, M. Nuchter, M. Raschpichler, F. G. Rauscher, S. G. Riedel-Heller, C. Sander, M. Scholz, P. Schonknecht, M. L. Schroeter, J. C. Simon, R. Speer, J. Staker, R. Stein, Y. Stobel-Richter, M. Stumvoll, A. Tarnok, A. Teren, D. Teupser, F. S. Then, A. Tonjes, R. Treudler, A. Villringer, A. Weissgerber, P. Wiedemann, S. Zachariae, K. Wirkner, J. Thiery

Date Published: 22nd Jul 2015

Publication Type: Not specified

Human Diseases: disease of mental health, mental depression, vascular disease, allergic hypersensitivity disease, sleep disorder, retinal degeneration

Abstract (Expand)

BACKGROUND: Genotype imputation is a common technique in genetic research. Genetic similarity between target population and reference dataset is crucial for high-quality results. Although several reference panels are available, it is often not clear which is the most optimal for a particular target dataset to be imputed. Maximizing genetic similarity between study sample and intended reference panels may be the straight forward method for selecting the genetically best-matched reference. However, the impact of genetic similarity on imputation accuracy has not yet been studied in detail. RESULTS: We performed a simulation study in 20 ethnic groups obtained from POPRES. High-quality SNPs were masked and re-imputed with MaCH, MaCH-minimac and IMPUTE2 using four different HapMap reference panels (CEU, CHB-JPT, MEX and YRI). Imputation accuracy was assessed by different statistics. Genetic similarity between ethnic groups and reference populations were measured by F -statistics (F(ST)) originally proposed by Wright and G -statistics (G(ST)) introduced by Nei and others. To assess the predictive power of these measures regarding imputation accuracy, we analysed relations between them and corresponding imputation accuracy scores. We found that population genetic distances between homogeneous reference and target populations were strongly linearly correlated with resulting imputation accuracies irrespective of considered distance measure, imputation accuracy measure, missingness and imputation software used. Possible exception was African population. CONCLUSION: Usage of G(ST) or F(ST)-related measures for predicting the optimal reference panel for imputation frameworks relying on a specific reference is highly recommended. A cut-off of G(ST) < 0.01 is recommended to achieve good imputation results for high-frequency variants and small data sets. The linear relationship is less pronounced for low-frequency variants for which we also observed a dependence of imputation accuracy on the number of polymorphic sites in the reference. We also show that the software specific measures MaCH-Rsq and IMPUTE-info must be interpreted with caution if the genetic distance of target and reference population is high.

Authors: N. R. Roshyara, M. Scholz

Date Published: 22nd Jul 2015

Publication Type: Not specified

Abstract (Expand)

The genetic hallmark of Burkitt lymphoma is the translocation t(8;14)(q24;q32), or one of its light chain variants, resulting in IG-MYC juxtaposition. However, these translocations alone are insufficient to drive lymphomagenesis, which requires additional genetic changes for malignant transformation. Recent studies of Burkitt lymphoma using next generation sequencing approaches have identified various recurrently mutated genes including ID3, TCF3, CCND3, and TP53. Here, by using similar approaches, we show that PCBP1 is a recurrently mutated gene in Burkitt lymphoma. By whole-genome sequencing, we identified somatic mutations in PCBP1 in 3/17 (18%) Burkitt lymphomas. We confirmed the recurrence of PCBP1 mutations by Sanger sequencing in an independent validation cohort, finding mutations in 3/28 (11%) Burkitt lymphomas and in 6/16 (38%) Burkitt lymphoma cell lines. PCBP1 is an intron-less gene encoding the 356 amino acid poly(rC) binding protein 1, which contains three K-Homology (KH) domains and two nuclear localization signals. The mutations predominantly (10/12, 83%) affect the KH III domain, either by complete domain loss or amino acid changes. Thus, these changes are predicted to alter the various functions of PCBP1, including nuclear trafficking and pre-mRNA splicing. Remarkably, all six primary Burkitt lymphomas with a PCBP1 mutation expressed MUM1/IRF4, which is otherwise detected in around 20-40% of Burkitt lymphomas. We conclude that PCBP1 mutations are recurrent in Burkitt lymphomas and might contribute, in cooperation with other mutations, to its pathogenesis.

Authors: R. Wagener, S. M. Aukema, M. Schlesner, A. Haake, B. Burkhardt, A. Claviez, H. G. Drexler, M. Hummel, M. Kreuz, M. Loeffler, M. Rosolowski, C. Lopez, P. Moller, J. Richter, M. Rohde, M. J. Betts, R. B. Russell, S. H. Bernhart, S. Hoffmann, P. Rosenstiel, M. Schilhabel, M. Szczepanowski, L. Trumper, W. Klapper, R. Siebert

Date Published: 16th Jul 2015

Publication Type: Not specified

Human Diseases: lymphoma

Abstract (Expand)

Genome-wide association studies have identified SNPs near ZNF365 at 10q21.2 that are associated with both breast cancer risk and mammographic density. To identify the most likely causal SNPs, we fine mapped the association signal by genotyping 428 SNPs across the region in 89,050 European and 12,893 Asian case and control subjects from the Breast Cancer Association Consortium. We identified four independent sets of correlated, highly trait-associated variants (iCHAVs), three of which were located within ZNF365. The most strongly risk-associated SNP, rs10995201 in iCHAV1, showed clear evidence of association with both estrogen receptor (ER)-positive (OR = 0.85 [0.82-0.88]) and ER-negative (OR = 0.87 [0.82-0.91]) disease, and was also the SNP most strongly associated with percent mammographic density. iCHAV2 (lead SNP, chr10: 64,258,684:D) and iCHAV3 (lead SNP, rs7922449) were also associated with ER-positive (OR = 0.93 [0.91-0.95] and OR = 1.06 [1.03-1.09]) and ER-negative (OR = 0.95 [0.91-0.98] and OR = 1.08 [1.04-1.13]) disease. There was weaker evidence for iCHAV4, located 5’ of ADO, associated only with ER-positive breast cancer (OR = 0.93 [0.90-0.96]). We found 12, 17, 18, and 2 candidate causal SNPs for breast cancer in iCHAVs 1-4, respectively. Chromosome conformation capture analysis showed that iCHAV2 interacts with the ZNF365 and NRBF2 (more than 600 kb away) promoters in normal and cancerous breast epithelial cells. Luciferase assays did not identify SNPs that affect transactivation of ZNF365, but identified a protective haplotype in iCHAV2, associated with silencing of the NRBF2 promoter, implicating this gene in the etiology of breast cancer.

Authors: Hatef Darabi, Karen McCue, Jonathan Beesley, Kyriaki Michailidou, Silje Nord, Siddhartha Kar, Keith Humphreys, Deborah Thompson, Maya Ghoussaini, Manjeet K. Bolla, Joe Dennis, Qin Wang, Sander Canisius, Christopher G. Scott, Carmel Apicella, John L. Hopper, Melissa C. Southey, Jennifer Stone, Annegien Broeks, Marjanka K. Schmidt, Rodney J. Scott, Artitaya Lophatananon, Kenneth Muir, Matthias W. Beckmann, Arif B. Ekici, Peter A. Fasching, Katharina Heusinger, Isabel Dos-Santos-Silva, Julian Peto, Ian Tomlinson, Elinor J. Sawyer, Barbara Burwinkel, Frederik Marme, Pascal Guénel, Thérèse Truong, Stig E. Bojesen, Henrik Flyger, Javier Benitez, Anna González-Neira, Hoda Anton-Culver, Susan L. Neuhausen, Volker Arndt, Hermann Brenner, Christoph Engel, Alfons Meindl, Rita K. Schmutzler, Norbert Arnold, Hiltrud Brauch, Ute Hamann, Jenny Chang-Claude, Sofia Khan, Heli Nevanlinna, Hidemi Ito, Keitaro Matsuo, Natalia V. Bogdanova, Thilo Dörk, Annika Lindblom, Sara Margolin, Veli-Matti Kosma, Arto Mannermaa, Chiu-Chen Tseng, Anna H. Wu, Giuseppe Floris, Diether Lambrechts, Anja Rudolph, Paolo Peterlongo, Paolo Radice, Fergus J. Couch, Celine Vachon, Graham G. Giles, Catriona McLean, Roger L. Milne, Pierre-Antoine Dugué, Christopher A. Haiman, Gertraud Maskarinec, Christy Woolcott, Brian E. Henderson, Mark S. Goldberg, Jacques Simard, Soo H. Teo, Shivaani Mariapun, Åslaug Helland, Vilde Haakensen, Wei Zheng, Alicia Beeghly-Fadiel, Rulla Tamimi, Arja Jukkola-Vuorinen, Robert Winqvist, Irene L. Andrulis, Julia A. Knight, Peter Devilee, Robert A. E. M. Tollenaar, Jonine Figueroa, Montserrat García-Closas, Kamila Czene, Maartje J. Hooning, Madeleine Tilanus-Linthorst, Jingmei Li, Yu-Tang Gao, Xiao-Ou Shu, Angela Cox, Simon S. Cross, Robert Luben, Kay-Tee Khaw, Ji-Yeob Choi, Daehee Kang, Mikael Hartman, Wei Yen Lim, Maria Kabisch, Diana Torres, Anna Jakubowska, Jan Lubinski, James McKay, Suleeporn Sangrajrang, Amanda E. Toland, Drakoulis Yannoukakos, Chen-Yang Shen, Jyh-Cherng Yu, Argyrios Ziogas, Minouk J. Schoemaker, Anthony Swerdlow, Anne-Lise Borresen-Dale, Vessela Kristensen, Juliet D. French, Stacey L. Edwards, Alison M. Dunning, Douglas F. Easton, Per Hall, Georgia Chenevix-Trench

Date Published: 1st Jul 2015

Publication Type: Journal article

Human Diseases: hereditary breast ovarian cancer syndrome

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