Genomic correlates of glatiramer acetate adverse cardiovascular effects lead to a novel locus mediating coronary risk

Glatiramer acetate is used therapeutically in multiple sclerosis but also known for adverse effects including elevated coronary artery disease (CAD) risk. The mechanisms underlying the cardiovascular side effects of the medication are unclear. Here, we made use of the chromosomal variation in the genes that are known to be affected by glatiramer treatment. Focusing on genes and gene products reported by drug-gene interaction database to interact with glatiramer acetate we explored a large meta-analysis on CAD genome-wide association studies aiming firstly, to investigate whether variants in these genes also affect cardiovascular risk and secondly, to identify new CAD risk genes. We traced association signals in a 200-kb region around genomic positions of genes interacting with glatiramer in up to 60 801 CAD cases and 123 504 controls. We validated the identified association in additional 21 934 CAD cases and 76 087 controls. We identified three new CAD risk alleles within the TGFB1 region on chromosome 19 that independently affect CAD risk. The lead SNP rs12459996 was genome-wide significantly associated with CAD in the extended meta-analysis (odds ratio 1.09, p = 1.58×10-12). The other two SNPs at the locus were not in linkage disequilibrium with the lead SNP and by a conditional analysis showed p-values of 4.05 × 10-10 and 2.21 × 10-6. Thus, studying genes reported to interact with glatiramer acetate we identified genetic variants that concordantly with the drug increase the risk of CAD. Of these, TGFB1 displayed signal for association. Indeed, the gene has been associated with CAD previously in both in vivo and in vitro studies. Here we establish genome-wide significant association with CAD in large human samples.This work was supported by grants from the Fondation Leducq (CADgenomics: Understanding CAD Genes, 12CVD02), the German Federal Ministry of Education and Research (BMBF) within the framework of the e:Med research and funding concept (e:AtheroSysMed, grant 01ZX1313A-2014 and SysInflame, grant 01ZX1306A), and the European Union Seventh Framework Programme FP7/2007-2013 under grant agreement no HEALTH-F2-2013-601456 (CVgenes-at-target). Further grants were received from the DFG as part of the Sonderforschungsbereich CRC 1123 (B2). T.K. was supported by a DZHK Rotation Grant. I.B. was supported by the Deutsche Forschungsgemeinschaft (DFG) cluster of excellence ‘Inflammation at Interfaces’. F.W.A. is supported by a Dekker scholarship-Junior Staff Member 2014T001 - Netherlands Heart Foundation and UCL Hospitals NIHR Biomedical Research Centre

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

During the evolution of land plants the anion channel SLAC1 became a part of the ABA signaling pathway

Die ersten Landpflanzen standen vor der Herausforderung sich mit der wechselnden Verfügbarkeit von Wasser an Land arrangieren zu müssen. Daraus ergab sich die Notwendigkeit den Wasserverlust zu minimieren und dennoch ausreichend CO2 für die Photosynthese aufzunehmen (Raven, 2002). Im Laufe der Evolution der Pflanzen entstanden mehrere Anpassungen an diese neuen Gegebenheiten, die schließlich auch zur Entstehung von regulierbaren Öffnungen, den Stomata, in der Blattepidermis führte. Zwei Schließzellen umschließen das Stoma und regulieren über die Aufnahme oder Abgabe von osmotisch-aktiven Teilchen ihren Turgordruck und damit die Öffnungsweite des Stomas. Das Kation Kalium und die Anionen Chlorid und Nitrat repräsentieren die Hauptosmotika, die je nach Bedarf durch Transportproteine über die Plasmamembran der Schließzellen geschleust werden. In den Samenpflanzen wie zum Beispiel der Modellpflanze Arabidopsis thaliana, ist der Signalweg in Schließzellen, der bei Trockenheit zu einem schnellen Schluss des Stomas führt bereits sehr gut untersucht. Bei Wassermangel synthetisiert die Pflanze das Trockenstresshormon ABA (Abscisinsäure). Das Hormon wird durch ABA-Rezeptoren erkannt und resultiert schließlich in der Aktivität der Proteinkinase OST1. Daraufhin reguliert diese Kinase zum einen die Transkription ABA-abhängiger Gene, die der Pflanze eine langfristige Adaptation an Trockenheit und Austrocknungstoleranz verleiht. Zum anderen, phosphoryliert OST1 den Anionenkanal SLAC1 und aktiviert ihn so. Die Aktivität des Kanals initiiert schließlich den Stomaschluss durch einen Ausstrom von Anionen aus den Schließzellen, der mit einer Depolarisation der Schließzellmembran einhergeht. Der ABA-Signalweg, der zur transkriptionellen Regulation von Genen und der damit verbunden Trockentoleranz führt ist ein sehr stark konservierter und evolutiv sehr alter Signalweg, der in allen Geweben von Pflanzen bei Trockenheit beschritten wird. Der schnelle ABA-Signalweg, der die Aktivität der SLAC1 Anionenkanäle reguliert, ist auf Schließzellen begrenzt. Da sich Schließzellen aber erst spät in der Evolution von Landpflanzen etablierten, erhob sich die Frage, wann in der Evolution geriet SLAC1 unter die Kontrolle das ABA-Signalwegs? Geht diese Regulation von SLAC1 mit der Entstehung von Schließzellen einher oder bestand dieser Regulationsmechanismus bereits in Pflanzen, die keine Schließzellen besitzen. Zur Beantwortung dieser Frage untersuchte ich die einzelnen Komponenten des Signalwegs und ihre Beziehungen zu einander im heterologen Expressionssystem der Xenopus laevis Oozyten. Im Laufe dieser Arbeit wurden Schlüsselelemente des ABA-Signalwegs aus sechs verschiedenen Versuchspflanzen kloniert und in Oozyten charakterisiert. Für die Untersuchung der Evolution des schnellen ABA-Signalwegs wurden die sechs Versuchspflanzen aus je einem rezenten Vertreter der Grünalgen (Klebsormidium nitens), der Lebermoose (Marchantia polymorpha), der Laubmoose (Physcomitrella patens), der Lycophyten (Selaginella moellendorffii) und der Farne (Ceratopteris richardii) ausgewählt und mit der Samenpflanze Arabidopsis thaliana verglichen. Die sechs Pflanzengruppen spalteten sich an unterschiedlichen Zeitpunkten im Laufe der pflanzlichen Evolution von der Entwicklung der restlichen Pflanzen ab und erlauben so einen bestmöglichen Einblick in den jeweiligen Entwicklungsstand der Landpflanzen während der Entstehung der einzelnen Pflanzenfamilien. Obwohl sich die ersten Stomata erst in den Laubmoosen entwickelten, besitzen schon die Grünalgen OST1-Kinasen und SLAC1-Kanäle. Interessanterweise konnte wir zeigen, dass schon die frühen OST1-Kinasen aus Algen und Moosen dazu in der Lage sind, in den höher entwickelten Samenpflanzen die Rolle in der Regulation der ABA-abhängigen Expression von Genen zu übernehmen. Außerdem zeigte sich im Laufe meiner biophysikalischen Untersuchungen, dass alle dreizehn getesteten OST1-Kinasen aus den sechs unterschiedlichen Versuchspflanzenarten in Lage sind, den Anionenkanal SLAC1 aus Arabidopsis in Xenopus Oozyten zu aktivieren. Diese Austauschbarkeit von den AtSLAC1-aktivierenden Kinasen deutet auf eine sehr starke Konservierung der Struktur und Funktion von OST1 hin. Anders verhielt es sich bei der funktionellen Analyse der Anionenkanäle aus den verschiedenen Versuchspflanzen: Hier bildete nur der evolutionär gesehen jüngsten SLAC-Kanal AtSLAC1 aus Arabidopsis ein funktionelles Pärchen mit OST1. Die SLAC1 Kanäle aus der Grünalge, dem Lebermoos, den Lycophyten und dem Farn blieben ohne messbare Aktivität bei einer Co-expression mit den verschiedenen OST1 Kinasen. Nur beim Laubmoos (Physcomitrella patens) konnte noch ein funktionelles Kinase-Anionenkanal Pärchen gefunden werden. Struktur-Funktionsuntersuchungen erlaubten mir schließlich zu zeigen, dass bestimmte funktionelle Domänen sowohl im N-terminus als auch im C-terminus von SLAC1 erforderlich sind, um eine Aktivierung des Kanals durch OST1 Kinasen sicherzustellen.Since the beginnings of the colonization of the land, plants had to overcome numerous obstacles. In this new environment the major challenge was the preservation of water supply despite the severe changes in the availability of water. Due to these new requirements plants had to balance water loss and the necessary uptake of CO2 for photosynthesis. Along the evolution of land plants they evolved numerous adaptations to the new environment like the cuticle and adjustable stomata. The stomata are small pores embedded in the epidermis of the leaves. A pair of guard cells regulates the aperture of the pore (stoma) via their turgor pressure. Potassium and the counter ions chloride and nitrate are the major osmolytes driving the opening and closing of the stoma. Specialized transport proteins regulate the ion fluxes across the plasma membrane of guard cells. In seed plants like the model plant Arabidopsis thaliana, the control of guard cells under drought stress conditions is well understood. Upon water shortage the plants produce the phytohormone ABA (abscisic acid). Following the perception of ABA by its receptors, the phytohormone activates the protein kinase OST1. The activated kinase on the one hand controls the expression of ABA dependent genes that lead to drought-adaptation and tolerance. On the other hand, the OST1 kinase phosphorylates and activates SLAC1-type anion channels. In turn, the activation of SLAC1 leads to the release of anions, thereby initiating guard cell depolarization which leads to the release of anions together with potassium. This depolarization step represents the initiation of ABA-dependent stomatal closure. The transcriptional ABA signaling pathway that regulates gene expression and the adaptation to drought stress is a very ancient and conserved pathway. It can be found in all plant tissues during periods of water shortage. In contrast, the ABA pathway leading to the activation of SLAC1 is restricted to guard cells only. Guard cells evolved rather late during the evolution of land plants. Therefore, the question arises, when did the ancient ABA signaling pathway co-opt SLAC1? Did the control of SLAC1 activity through the ABA-signaling pathway already exist before the stomata appeared in early land plants or did it co-evolve with stomata rather recently? To answer these questions, we investigated the relationship between the single components of the signaling cascade in the heterologous expression system of Xenopus laevis oocytes. To investigate the evolution of fast ABA signaling, we cloned the key players of the signaling cascade from six different model plants and functionally characterized the ABA-signaling components in oocytes. The model plants were chosen from green algae (Klebsormidium nitens), liverworts (Marchantia polymorpha), mosses (Physcomitrella patens), lycophytes (Selaginella moellendorffii) and ferns (Ceratopteris richardii) and their ABA-signaling components were compared to those of the seed plant Arabidopsis thaliana. These plant families diverged during evolution of land plants at distinct evolutionary steps. Thus these plant species should allow us insights into the evolution of land plants. Although the first stomata were found in mosses, already the green algae Klebsormidium nitens expressed SLAC1-type anion channels and the OST1 kinase. Gene expression studies with Arabidopsis protoplasts revealed that already the OST1 kinase of green algae is able to regulate ABA-dependent gene expression in seed plants. This indicates that the substrate specificity of OST1 kinases remained highly conserved during evolution. This notion was reinforced by biophysical investigations in the oocyte system. All thirteen tested OST1 kinases originating from the six model plants were capable to activate the evolutionary youngest SLAC channel AtSLAC1 from Arabidopsis in the heterologous expression system. Thus the structure and function of OST1 kinases is highly conserved during the evolution of land plants. In contrast, SLAC1 channels originating from ferns, lycophytes, liverworts and algae could not be activated by any of the OST1 kinases. Only the SLAC1 channel and the OST1 kinase of the seed plant Arabidopsis thaliana formed a functional anion channel/kinase-pair. Apart from Arabidopsis SLAC1, only the moss (Physcomitrella patens) PpSLAC1 could be activated by the Arabidopsis and one of the moss OST1 kinases. Subsequent detailed structure-function analysis revealed several essential domains in the anion channel’s N-terminus and C-terminus which are important for the functional interaction between SLACs and OSTs

Proton exchange by the vacuolar nitrate transporter CLCa is required for plant growth and nitrogen use efficiency

International audienceNitrate is a major nutrient and osmoticum for plants. To deal with fluctuating nitrate availability in soils, plants store this nutrient in their vacuoles. Chloride channel a (CLCa), a 2NO À 3 /1H + exchanger localized to the vacuole in Arabidopsis (Arabidopsis thaliana), ensures this storage process. CLCa belongs to the CLC family, which includes anion/proton exchangers and anion channels. A mutation in a glutamate residue conserved across CLC exchangers is likely responsible for the conversion of exchangers to channels. Here, we show that CLCa with a mutation in glutamate 203 (E203) behaves as an anion channel in its native membrane. We introduced the CLCa E203A point mutation to investigate its physiological importance into the Arabidopsis clca knockout mutant. These CLCa E203A mutants displayed a growth deficit linked to the disruption of water homeostasis. Additionally, CLCa E203A expression failed to complement the defect in nitrate accumulation of clca and favored higher N-assimilation at the vegetative stage. Further analyses at the post-flowering stages indicated that CLCa E203A expression results in an increase in N uptake allocation to seeds, leading to a higher nitrogen use efficiency compared to the wild-type. Altogether, these results point to the critical function of the CLCa exchanger on the vacuole for plant metabolism and development

Measurement of charged particle spectra in minimum-bias events from proton-proton collisions at root s =13 TeV

Pseudorapidity, transverse momentum, and multiplicity distributions are measured in the pseudorapidity range vertical bar eta vertical bar 0.5 GeV in proton-proton collisions at a center-of-mass energy of root s = 13 TeV. Measurements are presented in three different event categories. The most inclusive of the categories corresponds to an inelastic pp data set, while the other two categories are exclusive subsets of the inelastic sample that are either enhanced or depleted in single diffractive dissociation events. The measurements are compared to predictions from Monte Carlo event generators used to describe high-energy hadronic interactions in collider and cosmic-ray physics.Peer reviewe

Large-scale association analysis identifies new risk loci for coronary artery disease

Coronary artery disease (CAD) is the commonest cause of death. Here, we report an association analysis in 63,746 CAD cases and 130,681 controls identifying 15 loci reaching genome-wide significance, taking the number of susceptibility loci for CAD to 46, and a further 104 independent variants (r(2) < 0.2) strongly associated with CAD at a 5% false discovery rate (FDR). Together, these variants explain approximately 10.6% of CAD heritability. Of the 46 genome-wide significant lead SNPs, 12 show a significant association with a lipid trait, and 5 show a significant association with blood pressure, but none is significantly associated with diabetes. Network analysis with 233 candidate genes (loci at 10% FDR) generated 5 interaction networks comprising 85% of these putative genes involved in CAD. The four most significant pathways mapping to these networks are linked to lipid metabolism and inflammation, underscoring the causal role of these activities in the genetic etiology of CAD. Our study provides insights into the genetic basis of CAD and identifies key biological pathways.Merck British Heart Foundation (BHF) Centre of Research Excellenc