@article{CouchWangMcGuffogetal.2013, author = {Couch, Fergus J. and Wang, Xianshu and McGuffog, Lesley and Lee, Andrew and Olswold, Curtis and Kuchenbaecker, Karoline B. and Soucy, Penny and Fredericksen, Zachary and Barrowdale, Daniel and Dennis, Joe and Gaudet, Mia M. and Dicks, Ed and Kosel, Matthew and Healey, Sue and Sinilnikova, Olga M. and Lee, Adam and Bacot, Fran{\c{c}}ios and Vincent, Daniel and Hogervorst, Frans B. L. and Peock, Susan and Stoppa-Lyonnet, Dominique and Jakubowska, Anna and Radice, Paolo and Schmutzler, Rita Katharina and Domchek, Susan M. and Piedmonte, Marion and Singer, Christian F. and Friedman, Eitan and Thomassen, Mads and Hansen, Thomas V. O. and Neuhausen, Susan L. and Szabo, Csilla I. and Blanco, Ingnacio and Greene, Mark H. and Karlan, Beth Y. and Garber, Judy and Phelan, Catherine M. and Weitzel, Jeffrey N. and Montagna, Marco and Olah, Edith and Andrulis, Irene L. and Godwin, Andrew K. and Yannoukakos, Drakoulis and Goldgar, David E. and Caldes, Trinidad and Nevanlinna, Heli and Osorio, Ana and Terry, Mary Beth and Daly, Mary B. and van Rensburg, Elisabeth J. and Hamann, Ute and Ramus, Susan J. and Toland, Amanda Ewart and Caligo, Maria A. and Olopade, Olufunmilayo I. and Tung, Nadine and Claes, Kathleen and Beattie, Mary S. and Southey, Melissa C. and Imyanitov, Evgeny N. and Tischkowitz, Marc and Janavicius, Ramunas and John, Esther M. and Kwong, Ava and Diez, Orland and Kwong, Ava and Balma{\~n}a, Judith and Barkardottir, Rosa B. and Arun, Banu K. and Rennert, Gad and Teo, Soo-Hwang and Ganz, Patricia A. and Campbell, Ian and van der Hout, Annemarie H. and van Deurzen, Carolien H. M. and Seynaeve, Caroline and Garcia, Encarna B. G{\´o}mez and van Leeuwen, Flora E. and Meijers-Heijboer, Hanne E. J. and Gille, Johannes J. P. and Ausems, Magreet G. E. M. and Blok, Marinus J. and Ligtenberg, Marjolinjin J. L. and Rookus, Matti A. and Devilee, Peter and Verhoef, Senno and van Os, Theo A. M. and Wijnen, Juul T. and Frost, Debra and Ellis, Steve and Fineberg, Elena and Platte, Radke and Evans, D. Gareth and Izatt, Luise and Eeles, Rosalind A. and Adlard, Julian and Eccles, Diana M. and Cook, Jackie and Brewer, Carole and Douglas, Fiona and Hodgson, Shirley and Morrison, Patrick J. and Side, Lucy E. and Donaldson, Alan and Houghton, Catherine and Rogers, Mark T. and Dorkins, Huw and Eason, Jacqueline and Gregory, Helen and McCann, Emma and Murray, Alex and Calender, Alain and Hardouin, Agn{\`e}s and Berthet, Pascaline and Delnatte, Capucine and Nogues, Catherine and Lasset, Christine and Houdayer, Claude and Leroux,, Dominique and Rouleau, Etienne and Prieur, Fabienne and Damiola, Francesca and Sobol, Hagay and Coupier, Isabelle and Venat-Bouvet, Laurence and Castera, Laurent and Gauthier-Villars, Marion and L{\´e}on{\´e}, M{\´e}lanie and Pujol, Pascal and Mazoyer, Sylvie and Bignon, Yves-Jean and Zlowocka-Perlowska, Elzbieta and Gronwald, Jacek and Lubinski,, Jan and Durda, Katarzyna and Jaworska, Katarzyna and Huzarski, Tomasz and Spurdle, Amanda B. and Viel, Alessandra and Peissel, Bernhard and Bonanni, Bernardo and Melloni, Guilia and Ottini, Laura and Papi, Laura and Varesco, Liliana and Tibiletti, Maria Grazia and Peterlongo, Paolo and Volorio, Sara and Manoukian, Siranoush and Pensotti, Valeria and Arnold, Norbert and Engel, Christoph and Deissler, Helmut and Gadzicki, Dorothea and Gehrig, Andrea and Kast, Karin and Rhiem, Kerstin and Meindl, Alfons and Niederacher, Dieter and Ditsch, Nina and Plendl, Hansjoerg and Preisler-Adams, Sabine and Engert, Stefanie and Sutter, Christian and Varon-Mateeva, Raymenda and Wappenschmidt, Barbara and Weber, Bernhard H. F. and Arver, Brita and Stenmark-Askmalm, Marie and Loman, Niklas and Rosenquist, Richard and Einbeigi, Zakaria and Nathanson, Katherine L. and Rebbeck, Timothy R. and Blank, Stephanie V. and Cohn, David E. and Rodriguez, Gustavo C. and Small, Laurie and Friedlander, Michael and Bae-Jump, Victoria L. and Fink-Retter, Anneliese and Rappaport, Christine and Gschwantler-Kaulich, Daphne and Pfeiler, Georg and Tea, Muy-Kheng and Lindor, Noralane M. and Kaufman, Bella and Paluch, Shani Shimon and Laitman, Yael and Skytte, Anne-Bine and Gerdes, Anne-Marie and Pedersen, Inge Sokilde and Moeller, Sanne Traasdahl and Kruse, Torben A. and Jensen, Uffe Birk and Vijai, Joseph and Sarrel, Kara and Robson, Mark and Kauff, Noah and Mulligan, Anna Marie and Glendon, Gord and Ozcelik, Hilmi and Ejlertsen, Bent and Nielsen, Finn C. and J{\o}nson, Lars and Andersen, Mette K. and Ding, Yuan Chun and Steele, Linda and Foretova, Lenka and Teul{\´e}, Alex and Lazaro, Conxi and Brunet, Joan and Pujana, Miquel Angel and Mai, Phuong L. and Loud, Jennifer T. and Walsh, Christine and Lester, Jenny and Orsulic, Sandra and Narod, Steven A. and Herzog, Josef and Sand, Sharon R. and Tognazzo, Silvia and Agata, Simona and Vaszko, Tibor and Weaver, Joellen and Stravropoulou, Alexandra V. and Buys, Saundra S. and Romero, Atocha and de la Hoya, Miguel and Aittom{\"a}ki, Kristiina and Muranen, Taru A. and Duran, Mercedes and Chung, Wendy K. and Lasa, Adriana and Dorfling, Cecilia M. and Miron, Alexander and Benitez, Javier and Senter, Leigha and Huo, Dezheng and Chan, Salina B. and Sokolenko, Anna P. and Chiquette, Jocelyne and Tihomirova, Laima and Friebel, Tara M. and Agnarsson, Bjarne A. and Lu, Karen H. and Lejbkowicz, Flavio and James, Paul A. and Hall, Per and Dunning, Alison M. and Tessier, Daniel and Cunningham, Julie and Slager, Susan L. and Chen, Wang and Hart, Steven and Stevens, Kristen and Simard, Jacques and Pastinen, Tomi and Pankratz, Vernon S. and Offit, Kenneth and Easton, Douglas F. and Chenevix-Trench, Georgia and Antoniou, Antonis C.}, title = {Genome-Wide Association Study in BRCA1 Mutation Carriers Identifies Novel Loci Associated with Breast and Ovarian Cancer Risk}, series = {PLOS Genetics}, volume = {9}, journal = {PLOS Genetics}, number = {3}, issn = {1553-7404}, doi = {10.1371/journal.pgen.1003212}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-127947}, pages = {e1003212}, year = {2013}, abstract = {BRCA1-associated breast and ovarian cancer risks can be modified by common genetic variants. To identify further cancer risk-modifying loci, we performed a multi-stage GWAS of 11,705 BRCA1 carriers (of whom 5,920 were diagnosed with breast and 1,839 were diagnosed with ovarian cancer), with a further replication in an additional sample of 2,646 BRCA1 carriers. We identified a novel breast cancer risk modifier locus at 1q32 for BRCA1 carriers (rs2290854, P = 2.7 x 10(-8), HR = 1.14, 95\% CI: 1.09-1.20). In addition, we identified two novel ovarian cancer risk modifier loci: 17q21.31 (rs17631303, P = 1.4 x 10(-8), HR = 1.27, 95\% CI: 1.17-1.38) and 4q32.3 (rs4691139, P = 3.4 x 10(-8), HR = 1.20, 95\% CI: 1.17-1.38). The 4q32.3 locus was not associated with ovarian cancer risk in the general population or BRCA2 carriers, suggesting a BRCA1-specific association. The 17q21.31 locus was also associated with ovarian cancer risk in 8,211 BRCA2 carriers (P = 2 x 10(-4)). These loci may lead to an improved understanding of the etiology of breast and ovarian tumors in BRCA1 carriers. Based on the joint distribution of the known BRCA1 breast cancer risk-modifying loci, we estimated that the breast cancer lifetime risks for the 5\% of BRCA1 carriers at lowest risk are 28\%-50\% compared to 81\%-100\% for the 5\% at highest risk. Similarly, based on the known ovarian cancer risk-modifying loci, the 5\% of BRCA1 carriers at lowest risk have an estimated lifetime risk of developing ovarian cancer of 28\% or lower, whereas the 5\% at highest risk will have a risk of 63\% or higher. Such differences in risk may have important implications for risk prediction and clinical management for BRCA1 carriers.}, language = {en} } @article{CarstenAGorskiLietal.2011, author = {Carsten A., B{\"o}ger and Gorski, Mathias and Li, Man and Hoffmann, Michael M. and Huang, Chunmei and Yang, Qiong and Teumer, Alexander and Krane, Vera and O'Seaghdha, Conall M. and Kutalik, Zolt{\´a}n and Wichmann, H.-Erich and Haak, Thomas and Boes, Eva and Coassin, Stefan and Coresh, Josef and Kollerits, Barbara and Haun, Margot and Paulweber, Bernhard and K{\"o}ttgen, Anna and Li, Guo and Shlipak, Michael G. and Powe, Neil and Hwang, Shih-Jen and Dehghan, Abbas and Rivadeneira, Fernando and Uitterlinden, Andr{\´e} and Hofman, Albert and Beckmann, Jacques S. and Kr{\"a}mer, Bernhard K. and Witteman, Jacqueline and Bochud, Murielle and Siscovick, David and Rettig, Rainer and Kronenberg, Florian and Wanner, Christoph and Thadhani, Ravi I. and Heid, Iris M. and Fox, Caroline S. and Kao, W.H.}, title = {Association of eGFR-Related Loci Identified by GWAS with Incident CKD and ESRD}, series = {PLoS Genetics}, volume = {7}, journal = {PLoS Genetics}, number = {9}, doi = {10.1371/journal.pgen.1002292}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-133758}, pages = {e1002292}, year = {2011}, abstract = {Family studies suggest a genetic component to the etiology of chronic kidney disease (CKD) and end stage renal disease (ESRD). Previously, we identified 16 loci for eGFR in genome-wide association studies, but the associations of these single nucleotide polymorphisms (SNPs) for incident CKD or ESRD are unknown. We thus investigated the association of these loci with incident CKD in 26,308 individuals of European ancestry free of CKD at baseline drawn from eight population-based cohorts followed for a median of 7.2 years (including 2,122 incident CKD cases defined as eGFR < 60ml/min/1.73m(2) at follow-up) and with ESRD in four case-control studies in subjects of European ancestry (3,775 cases, 4,577 controls). SNPs at 11 of the 16 loci (UMOD, PRKAG2, ANXA9, DAB2, SHROOM3, DACH1, STC1, SLC34A1, ALMS1/NAT8, UBE2Q2, and GCKR) were associated with incident CKD; p-values ranged from p = 4.1e-9 in UMOD to p = 0.03 in GCKR. After adjusting for baseline eGFR, six of these loci remained significantly associated with incident CKD (UMOD, PRKAG2, ANXA9, DAB2, DACH1, and STC1). SNPs in UMOD (OR = 0.92, p = 0.04) and GCKR (OR = 0.93, p = 0.03) were nominally associated with ESRD. In summary, the majority of eGFR-related loci are either associated or show a strong trend towards association with incident CKD, but have modest associations with ESRD in individuals of European descent. Additional work is required to characterize the association of genetic determinants of CKD and ESRD at different stages of disease progression.}, language = {en} } @article{NagyvanGeffenStegneretal.2019, author = {Nagy, Magdolna and van Geffen, Johanna P. and Stegner, David and Adams, David J. and Braun, Attila and de Witt, Susanne M. and Elvers, Margitta and Geer, Mitchell J. and Kuijpers, Marijke J. E. and Kunzelmann, Karl and Mori, Jun and Oury, C{\´e}cile and Pircher, Joachim and Pleines, Irina and Poole, Alastair W. and Senis, Yotis A. and Verdoold, Remco and Weber, Christian and Nieswandt, Bernhard and Heemskerk, Johan W. M. and Baaten, Constance C. F. M. J.}, title = {Comparative Analysis of Microfluidics Thrombus Formation in Multiple Genetically Modified Mice: Link to Thrombosis and Hemostasis}, series = {Frontiers in Cardiovascular Medicine}, volume = {6}, journal = {Frontiers in Cardiovascular Medicine}, doi = {10.3389/fcvm.2019.00099}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-232194}, year = {2019}, abstract = {Genetically modified mice are indispensable for establishing the roles of platelets in arterial thrombosis and hemostasis. Microfluidics assays using anticoagulated whole blood are commonly used as integrative proxy tests for platelet function in mice. In the present study, we quantified the changes in collagen-dependent thrombus formation for 38 different strains of (genetically) modified mice, all measured with the same microfluidics chamber. The mice included were deficient in platelet receptors, protein kinases or phosphatases, small GTPases or other signaling or scaffold proteins. By standardized re-analysis of high-resolution microscopic images, detailed information was obtained on altered platelet adhesion, aggregation and/or activation. For a subset of 11 mouse strains, these platelet functions were further evaluated in rhodocytin- and laminin-dependent thrombus formation, thus allowing a comparison of glycoprotein VI (GPVI), C-type lectin-like receptor 2 (CLEC2) and integrin α6β1 pathways. High homogeneity was found between wild-type mice datasets concerning adhesion and aggregation parameters. Quantitative comparison for the 38 modified mouse strains resulted in a matrix visualizing the impact of the respective (genetic) deficiency on thrombus formation with detailed insight into the type and extent of altered thrombus signatures. Network analysis revealed strong clusters of genes involved in GPVI signaling and Ca2+ homeostasis. The majority of mice demonstrating an antithrombotic phenotype in vivo displayed with a larger or smaller reduction in multi-parameter analysis of collagen-dependent thrombus formation in vitro. Remarkably, in only approximately half of the mouse strains that displayed reduced arterial thrombosis in vivo, this was accompanied by impaired hemostasis. This was also reflected by comparing in vitro thrombus formation (by microfluidics) with alterations in in vivo bleeding time. In conclusion, the presently developed multi-parameter analysis of thrombus formation using microfluidics can be used to: (i) determine the severity of platelet abnormalities; (ii) distinguish between altered platelet adhesion, aggregation and activation; and (iii) elucidate both collagen and non-collagen dependent alterations of thrombus formation. This approach may thereby aid in the better understanding and better assessment of genetic variation that affect in vivo arterial thrombosis and hemostasis.}, language = {en} } @article{DrubeWeberLoschinskietal.2015, author = {Drube, Sebastian and Weber, Franziska and Loschinski, Romy and Beyer, Mandy and Rothe, Mandy and Rabenhorst, Anja and G{\"o}pfert, Christiane and Meininger, Isabel and Diamanti, Michaela A. and Stegner, David and H{\"a}fner, Norman and B{\"o}ttcher, Martin and Reinecke, Kirstin and Herdegen, Thomas and Greten, Florian R. and Nieswandt, Bernhard and Hartmann, Karin and Kr{\"a}mer, Oliver H. and Kamradt, Thomas}, title = {Subthreshold IKK activation modulates the effector functions of primary mast cells and allows specific targeting of transformed mast cells}, series = {Oncotarget}, volume = {6}, journal = {Oncotarget}, number = {7}, doi = {10.18632/oncotarget.3022}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-143681}, pages = {5354-5368}, year = {2015}, abstract = {Mast cell differentiation and proliferation depends on IL-3. IL-3 induces the activation of MAP-kinases and STATs and consequently induces proliferation and survival. Dysregulation of IL-3 signaling pathways also contribute to inflammation and tumorigenesis. We show here that IL-3 induces a SFK- and Ca2\(^{+}\)-dependent activation of the inhibitor of κB kinases 2 (IKK2) which results in mast cell proliferation and survival but does not induce IκBα-degradation and NFκB activation. Therefore we propose the term "subthreshold IKK activation". This subthreshold IKK activation also primes mast cells for enhanced responsiveness to IL-33R signaling. Consequently, co-stimulation with IL-3 and IL-33 increases IKK activation and massively enhances cytokine production induced by IL-33. We further reveal that in neoplastic mast cells expressing constitutively active Ras, subthreshold IKK activation is associated with uncontrolled proliferation. Consequently, pharmacological IKK inhibition reduces tumor growth selectively by inducing apoptosis in vivo. Together, subthreshold IKK activation is crucial to mediate the full IL-33-induced effector functions in primary mast cells and to mediate uncontrolled proliferation of neoplastic mast cells. Thus, IKK2 is a new molecularly defined target structure.}, language = {en} } @article{PollittPoulterGitzetal.2014, author = {Pollitt, Alice Y. and Poulter, Natalie S. and Gitz, Eelo and Navarro-Nu{\~n}ez, Leyre and Wang, Ying-Jie and Hughes, Craig E. and Thomas, Steven G. and Nieswandt, Bernhard and Douglas, Michael R. and Owen, Dylan M. and Jackson, David G. and Dustin, Michael L. and Watson, Steve P.}, title = {Syk and Src Family Kinases Regulate C-type Lectin Receptor 2 (CLEC-2)-mediated Clustering of Podoplanin and Platelet Adhesion to Lymphatic Endothelial Cells*}, series = {The Journal of Biological Chemistry}, volume = {289}, journal = {The Journal of Biological Chemistry}, number = {52}, doi = {10.1074/jbc.M114.584284}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-120770}, pages = {35695-710}, year = {2014}, abstract = {The interaction of CLEC-2 on platelets with Podoplanin on lymphatic endothelial cells initiates platelet signalling events that are necessary for prevention of blood-lymph mixing during development. In the present study, we show that CLEC-2 signalling via Src family and Syk tyrosine kinases promotes platelet adhesion to primary mouse lymphatic endothelial cells at low shear. Using supported lipid bilayers containing mobile Podoplanin, we further show that activation of Src and Syk in platelets promotes clustering of CLEC-2 and Podoplanin. Clusters of CLEC-2-bound Podoplanin migrate rapidly to the centre of the platelet to form a single structure. Fluorescence life-time imaging demonstrates that molecules within these clusters are within 10 nm of one another and that the clusters are disrupted by inhibition of Src and Syk family kinases. CLEC-2 clusters are also seen in platelets adhered to immobilised Podoplanin using direct stochastic optical reconstruction microscopy (dSTORM). These findings provide mechanistic insight by which CLEC-2 signalling promotes adhesion to Podoplanin and regulation of Podoplanin signalling thereby contributing to lymphatic vasculature development.}, language = {en} } @article{PoppThielmanNieswandtetal.2015, author = {Popp, Michael and Thielman, Ina and Nieswandt, Bernhard and Stegner, David}, title = {Normal Platelet Integrin Function in Mice Lacking Hydrogen Peroxide-Induced Clone-5 (Hic-5)}, series = {PLoS One}, volume = {10}, journal = {PLoS One}, number = {7}, doi = {10.1371/journal.pone.0133429}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125724}, pages = {e0133429}, year = {2015}, abstract = {Integrin αIIbβ3 plays a central role in the adhesion and aggregation of platelets and thus is essential for hemostasis and thrombosis. Integrin activation requires the transmission of a signal from the small cytoplasmic tails of the α or β subunit to the large extracellular domains resulting in conformational changes of the extracellular domains to enable ligand binding. Hydrogen peroxide-inducible clone-5 (Hic-5), a member of the paxillin family, serves as a focal adhesion adaptor protein associated with αIIbβ3 at its cytoplasmic tails. Previous studies suggested Hic-5 as a novel regulator of integrin αIIbβ3 activation and platelet aggregation in mice. To assess this in more detail, we generated Hic-5-null mice and analyzed activation and aggregation of their platelets in vitro and in vivo. Surprisingly, lack of Hic-5 had no detectable effect on platelet integrin activation and function in vitro and in vivo under all tested conditions. These results indicate that Hic-5 is dispensable for integrin αIIbβ3 activation and consequently for arterial thrombosis and hemostasis in mice.}, language = {en} } @article{AmmarThahoulyHanaueretal.2015, author = {Ammar, Mohamed Raafet and Thahouly, Tamou and Hanauer, Andr{\´e} and Stegner, David and Nieswandt, Bernhard and Vitale, Nicolas}, title = {PLD1 participates in BDNF-induced signalling in cortical neurons}, series = {Scientific Reports}, volume = {5}, journal = {Scientific Reports}, number = {14778}, doi = {10.1038/srep14778}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-139962}, year = {2015}, abstract = {The brain-derived neurotrophic factor BDNF plays a critical role in neuronal development and the induction of L-LTP at glutamatergic synapses in several brain regions. However, the cellular and molecular mechanisms underlying these BDNF effects have not been firmly established. Using in vitro cultures of cortical neurons from knockout mice for Pld1 and Rsk2, BDNF was observed to induce a rapid RSK2-dependent activation of PLD and to stimulate BDNF ERK1/2-CREB and mTor-S6K signalling pathways, but these effects were greatly reduced in Pld1\(^{-/-}\) neurons. Furthermore, phospho-CREB did not accumulate in the nucleus, whereas overexpression of PLD1 amplified the BDNF-dependent nuclear recruitment of phospho-ERK1/2 and phospho-CREB. This BDNF retrograde signalling was prevented in cells silenced for the scaffolding protein PEA15, a protein which complexes with PLD1, ERK1/2, and RSK2 after BDNF treatment. Finally PLD1, ERK1/2, and RSK2 partially colocalized on endosomal structures, suggesting that these proteins are part of the molecular module responsible for BDNF signalling in cortical neurons.}, language = {en} } @article{ManchiaAdliAkulaetal.2013, author = {Manchia, Mirko and Adli, Mazda and Akula, Nirmala and Arda, Raffaella and Aubry, Jean-Michel and Backlund, Lena and Banzato, Claudio E. M. and Baune, Bernhard T. and Bellivier, Frank and Bengesser, Susanne and Biernacka, Joanna M. and Brichant-Petitjean, Clara and Bui, Elise and Calkin, Cynthia V. and Cheng, Andrew Tai Ann and Chillotti, Caterina and Cichon, Sven and Clark, Scott and Czerski, Piotr M. and Dantas, Clarissa and Del Zompo, Maria and DePaulo, J. Raymond and Detera-Wadleigh, Sevilla D. and Etain, Bruno and Falkai, Peter and Fris{\´e}n, Louise and Frye, Mark A. and Fullerton, Jan and Gard, S{\´e}bastien and Garnham, Julie and Goes, Fernando S. and Grof, Paul and Gruber, Oliver and Hashimoto, Ryota and Hauser, Joanna and Heilbronner, Urs and Hoban, Rebecca and Hou, Liping and Jamain, St{\´e}phane and Kahn, Jean-Pierre and Kassem, Layla and Kato, Tadafumi and Kelsoe, John R. and Kittel-Schneider, Sarah and Kliwicki, Sebastian and Kuo, Po-Hsiu and Kusumi, Ichiro and Laje, Gonzalo and Lavebratt, Catharina and Leboyer, Marion and Leckband, Susan G. and L{\´o}pez Jaramillo, Carlos A. and Maj, Mario and Malafosse, Alain and Martinsson, Lina and Masui, Takuya and Mitchell, Philip B. and Mondimore, Frank and Monteleone, Palmiero and Nallet, Audrey and Neuner, Maria and Nov{\´a}k, Tom{\´a}s and O'Donovan, Claire and {\"O}sby, Urban and Ozaki, Norio and Perlis, Roy H. and Pfennig, Andrea and Potash, James B. and Reich-Erkelenz, Daniela and Reif, Andreas and Reininghaus, Eva and Richardson, Sara and Rouleau, Guy A. and Rybakowski, Janusz K. and Schalling, Martin and Schofield, Peter R. and Schubert, Oliver K. and Schweizer, Barbara and Seem{\"u}ller, Florian and Grigoroiu-Serbanescu, Maria and Severino, Giovanni and Seymour, Lisa R. and Slaney, Claire and Smoller, Jordan W. and Squassina, Alessio and Stamm, Thomas and Steele, Jo and Stopkova, Pavla and Tighe, Sarah K. and Tortorella, Alfonso and Turecki, Gustavo and Wray, Naomi R. and Wright, Adam and Zandi, Peter P. and Zilles, David and Bauer, Michael and Rietschel, Marcella and McMahon, Francis J. and Schulze, Thomas G. and Alda, Martin}, title = {Assessment of Response to Lithium Maintenance Treatment in Bipolar Disorder: A Consortium on Lithium Genetics (ConLiGen) Report}, series = {PLoS ONE}, volume = {8}, journal = {PLoS ONE}, number = {6}, doi = {10.1371/journal.pone.0065636}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130938}, pages = {e65636}, year = {2013}, abstract = {Objective: The assessment of response to lithium maintenance treatment in bipolar disorder (BD) is complicated by variable length of treatment, unpredictable clinical course, and often inconsistent compliance. Prospective and retrospective methods of assessment of lithium response have been proposed in the literature. In this study we report the key phenotypic measures of the "Retrospective Criteria of Long-Term Treatment Response in Research Subjects with Bipolar Disorder" scale currently used in the Consortium on Lithium Genetics (ConLiGen) study. Materials and Methods: Twenty-nine ConLiGen sites took part in a two-stage case-vignette rating procedure to examine inter-rater agreement [Kappa (\(\kappa\))] and reliability [intra-class correlation coefficient (ICC)] of lithium response. Annotated first-round vignettes and rating guidelines were circulated to expert research clinicians for training purposes between the two stages. Further, we analyzed the distributional properties of the treatment response scores available for 1,308 patients using mixture modeling. Results: Substantial and moderate agreement was shown across sites in the first and second sets of vignettes (\(\kappa\) = 0.66 and \(\kappa\) = 0.54, respectively), without significant improvement from training. However, definition of response using the A score as a quantitative trait and selecting cases with B criteria of 4 or less showed an improvement between the two stages (\(ICC_1 = 0.71\) and \(ICC_2 = 0.75\), respectively). Mixture modeling of score distribution indicated three subpopulations (full responders, partial responders, non responders). Conclusions: We identified two definitions of lithium response, one dichotomous and the other continuous, with moderate to substantial inter-rater agreement and reliability. Accurate phenotypic measurement of lithium response is crucial for the ongoing ConLiGen pharmacogenomic study.}, language = {en} } @article{BreezeVaissiereBommarcoetal.2014, author = {Breeze, Tom D. and Vaissiere, Bernhard E. and Bommarco, Riccardo and Petanidou, Theodora and Seraphides, Nicos and Kozak, Lajos and Scheper, Jeroen and Biesmeijer, Jacobus C. and Kleijn, David and Gyldenk{\ae}rne, Steen and Moretti, Marco and Holzschuh, Andrea and Steffan-Dewenter, Ingolf and Stout, Jane C. and P{\"a}rtel, Meelis and Zobel, Martin and Potts, Simon G.}, title = {Agricultural Policies Exacerbate Honeybee Pollination Service Supply-Demand Mismatches Across Europe}, series = {PLOS ONE}, volume = {9}, journal = {PLOS ONE}, number = {1}, issn = {1932-6203}, doi = {10.1371/journal.pone.0082996}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117692}, pages = {e82996}, year = {2014}, abstract = {Declines in insect pollinators across Europe have raised concerns about the supply of pollination services to agriculture. Simultaneously, EU agricultural and biofuel policies have encouraged substantial growth in the cultivated area of insect pollinated crops across the continent. Using data from 41 European countries, this study demonstrates that the recommended number of honeybees required to provide crop pollination across Europe has risen 4.9 times as fast as honeybee stocks between 2005 and 2010. Consequently, honeybee stocks were insufficient to supply >90\% of demands in 22 countries studied. These findings raise concerns about the capacity of many countries to cope with major losses of wild pollinators and highlight numerous critical gaps in current understanding of pollination service supplies and demands, pointing to a pressing need for further research into this issue.}, language = {en} } @article{PrelogAlmanzarEberleetal.2013, author = {Prelog, Martina and Almanzar, Giovanni and Eberle, Gernot and Lassacher, Andrea and Specht, Christian and Koppelstaetter, Christian and Heinz-Erian, Peter and Traw{\"o}ger, Rudolf and Bernhard, David}, title = {Maternal cigarette smoking and its effect on neonatal lymphocyte subpopulations and replication}, series = {BMC Pediatrics}, journal = {BMC Pediatrics}, doi = {10.1186/1471-2431-13-57}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96435}, year = {2013}, abstract = {Background Significant immunomodulatory effects have been described as result of cigarette smoking in adults and pregnant women. However, the effect of cigarette smoking during pregnancy on the lymphocyte subpopulations in newborns has been discussed, controversially. Methods In a prospective birth cohort, we analyzed the peripheral lymphocyte subpopulations of smoking (SM) and non-smoking mothers (NSM) and their newborns and the replicative history of neonatal, mostly naive CD4 + CD45RA + T cells by measurements of T-cell-receptor-excision-circles (TRECs), relative telomere lengths (RTL) and the serum cytokine concentrations. Results SM had higher lymphocyte counts than NSM. Comparing SM and NSM and SM newborns with NSM newborns, no significant differences in proportions of lymphocyte subpopulations were seen. Regardless of their smoking habits, mothers had significantly lower naive T cells and higher memory and effector T cells than newborns. NSM had significantly lower percentages of CD4 + CD25++ T cells compared to their newborns, which was not significant in SM. There were no differences regarding cytokine concentrations in newborns of SM and NSM. However, NSM had significantly higher Interleukin-7 concentrations than their newborns. Regardless of smoking habits of mothers, newborns had significantly longer telomeres and higher TRECs than their mothers. Newborns of SM had significantly longer telomeres than newborns of NSM. Conclusions Apart from higher lymphocyte counts in SM, our results did not reveal differences between lymphocyte subpopulations of SM and NSM and their newborns, respectively. Our finding of significantly longer RTL in newborns of SM may reflect potential harm on lymphocytes, such as cytogenetic damage induced by smoking.}, language = {en} } @article{NeagoeGardinerStegneretal.2022, author = {Neagoe, Raluca A. I. and Gardiner, Elizabeth E. and Stegner, David and Nieswandt, Bernhard and Watson, Steve P. and Poulter, Natalie S.}, title = {Rac inhibition causes impaired GPVI signalling in human platelets through GPVI shedding and reduction in PLCγ2 phosphorylation}, series = {International Journal of Molecular Sciences}, volume = {23}, journal = {International Journal of Molecular Sciences}, number = {7}, issn = {1422-0067}, doi = {10.3390/ijms23073746}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-284350}, year = {2022}, abstract = {Rac1 is a small Rho GTPase that is activated in platelets upon stimulation with various ligands, including collagen and thrombin, which are ligands for the glycoprotein VI (GPVI) receptor and the protease-activated receptors, respectively. Rac1-deficient murine platelets have impaired lamellipodia formation, aggregation, and reduced PLCγ2 activation, but not phosphorylation. The objective of our study is to investigate the role of Rac1 in GPVI-dependent human platelet activation and downstream signalling. Therefore, we used human platelets stimulated using GPVI agonists (collagen and collagen-related peptide) in the presence of the Rac1-specific inhibitor EHT1864 and analysed platelet activation, aggregation, spreading, protein phosphorylation, and GPVI clustering and shedding. We observed that in human platelets, the inhibition of Rac1 by EHT1864 had no significant effect on GPVI clustering on collagen fibres but decreased the ability of platelets to spread or aggregate in response to GPVI agonists. Additionally, in contrast to what was observed in murine Rac1-deficient platelets, EHT1864 enhanced GPVI shedding in platelets and reduced the phosphorylation levels of PLCγ2 following GPVI activation. In conclusion, Rac1 activity is required for both human and murine platelet activation in response to GPVI-ligands, but Rac1's mode of action differs between the two species.}, language = {en} } @article{BieberSchuhmannBellutetal.2022, author = {Bieber, Michael and Schuhmann, Michael K. and Bellut, Maximilian and Stegner, David and Heinze, Katrin G. and Pham, Mirko and Nieswandt, Bernhard and Stoll, Guido}, title = {Blockade of platelet glycoprotein Ibα augments neuroprotection in Orai2-deficient mice during middle cerebral artery occlusion}, series = {International Journal of Molecular Sciences}, volume = {23}, journal = {International Journal of Molecular Sciences}, number = {16}, issn = {1422-0067}, doi = {10.3390/ijms23169496}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-286038}, year = {2022}, abstract = {During ischemic stroke, infarct growth before recanalization diminishes functional outcome. Hence, adjunct treatment options to protect the ischemic penumbra before recanalization are eagerly awaited. In experimental stroke targeting two different pathways conferred protection from penumbral tissue loss: (1) enhancement of hypoxic tolerance of neurons by deletion of the calcium channel subunit Orai2 and (2) blocking of detrimental lymphocyte-platelet responses. However, until now, no preclinical stroke study has assessed the potential of combining neuroprotective with anti-thrombo-inflammatory interventions to augment therapeutic effects. We induced focal cerebral ischemia in Orai2-deficient (Orai2\(^{-/-}\)) mice by middle cerebral artery occlusion (MCAO). Animals were treated with anti-glycoprotein Ib alpha (GPIbα) Fab fragments (p0p/B Fab) blocking GPIbα-von Willebrand factor (vWF) interactions. Rat immunoglobulin G (IgG) Fab was used as the control treatment. The extent of infarct growth before recanalization was assessed at 4 h after MCAO. Moreover, infarct volumes were determined 6 h after recanalization (occlusion time: 4 h). Orai2 deficiency significantly halted cerebral infarct progression under occlusion. Inhibition of platelet GPIbα further reduced primary infarct growth in Orai2\(^{-/-}\) mice. During ischemia-reperfusion, upon recanalization, mice were likewise protected. All in all, we show that neuroprotection in Orai2\(^{-/-}\) mice can be augmented by targeting thrombo-inflammation. This supports the clinical development of combined neuroprotective/anti-platelet strategies in hyper-acute stroke.}, language = {en} } @article{AscheidBaumannFunkeetal.2023, author = {Ascheid, David and Baumann, Magdalena and Funke, Caroline and Volz, Julia and Pinnecker, J{\"u}rgen and Friedrich, Mike and H{\"o}hn, Marie and Nandigama, Rajender and Erg{\"u}n, S{\"u}leyman and Nieswandt, Bernhard and Heinze, Katrin G. and Henke, Erik}, title = {Image-based modeling of vascular organization to evaluate anti-angiogenic therapy}, series = {Biology Direct}, volume = {18}, journal = {Biology Direct}, doi = {10.1186/s13062-023-00365-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-357242}, year = {2023}, abstract = {In tumor therapy anti-angiogenic approaches have the potential to increase the efficacy of a wide variety of subsequently or co-administered agents, possibly by improving or normalizing the defective tumor vasculature. Successful implementation of the concept of vascular normalization under anti-angiogenic therapy, however, mandates a detailed understanding of key characteristics and a respective scoring metric that defines an improved vasculature and thus a successful attempt. Here, we show that beyond commonly used parameters such as vessel patency and maturation, anti-angiogenic approaches largely benefit if the complex vascular network with its vessel interconnections is both qualitatively and quantitatively assessed. To gain such deeper insight the organization of vascular networks, we introduce a multi-parametric evaluation of high-resolution angiographic images based on light-sheet fluorescence microscopy images of tumors. We first could pinpoint key correlations between vessel length, straightness and diameter to describe the regular, functional and organized structure observed under physiological conditions. We found that vascular networks from experimental tumors diverted from those in healthy organs, demonstrating the dysfunctionality of the tumor vasculature not only on the level of the individual vessel but also in terms of inadequate organization into larger structures. These parameters proofed effective in scoring the degree of disorganization in different tumor entities, and more importantly in grading a potential reversal under treatment with therapeutic agents. The presented vascular network analysis will support vascular normalization assessment and future optimization of anti-angiogenic therapy.}, language = {en} } @article{NavarroStarkeHeemskerketal.2022, author = {Navarro, Stefano and Starke, Andreas and Heemskerk, Johan W. M. and Kuijpers, Marijke J. E. and Stegner, David and Nieswandt, Bernhard}, title = {Targeting of a conserved epitope in mouse and human GPVI differently affects receptor function}, series = {International Journal of Molecular Sciences}, volume = {23}, journal = {International Journal of Molecular Sciences}, number = {15}, issn = {1422-0067}, doi = {10.3390/ijms23158610}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-286227}, year = {2022}, abstract = {Glycoprotein (GP) VI is the major platelet collagen receptor and a promising anti-thrombotic target. This was first demonstrated in mice using the rat monoclonal antibody JAQ1, which completely blocks the Collagen-Related Peptide (CRP)-binding site on mouse GPVI and efficiently inhibits mouse platelet adhesion, activation and aggregation on collagen. Here, we show for the first time that JAQ1 cross-reacts with human GPVI (huGPVI), but not with GPVI in other tested species, including rat, rabbit, guinea pig, swine, and dog. We further demonstrate that JAQ1 differently modulates mouse and human GPVI function. Similar to its effects on mouse GPVI (mGPVI), JAQ1 inhibits CRP-induced activation in human platelets, whereas, in stark contrast to mouse GPVI, it does not inhibit the adhesion, activation or aggregate formation of human platelets on collagen, but causes instead an increased response. This effect was also seen with platelets from newly generated human GPVI knockin mice (hGP6\(^{tg/tg\)). These results indicate that the binding of JAQ1 to a structurally conserved epitope in GPVI differently affects its function in human and mouse platelets.}, language = {en} } @article{PetruskiIvlevaKucharskaNewtonPaltaetal.2017, author = {Petruski-Ivleva, Natalia and Kucharska-Newton, Anna and Palta, Priya and Couper, David and Meyer, Katie and Graff, Misa and Haring, Bernhard and Sharrett, Richey and Heiss, Gerardo}, title = {Milk intake at midlife and cognitive decline over 20 years. The Atherosclerosis risk in communities (ARIC) study}, series = {Nutrients}, volume = {9}, journal = {Nutrients}, number = {10}, doi = {10.3390/nu9101134}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-173909}, year = {2017}, abstract = {Background: Faster rates of cognitive decline are likely to result in earlier onset of cognitive impairment and dementia. d-galactose, a derivative of lactose, is used in animal studies to induce neurodegeneration. Milk is the primary source of lactose in the human diet, and its effects on cognitive decline have not been fully evaluated. Objective: Assess the association of milk intake with change in cognitive function over 20 years. Methods: A total of 13,751 participants of the Atherosclerosis Risk in Communities (ARIC) cohort completed a food frequency questionnaire and three neurocognitive evaluations from 1990 through 2013. Two single nucleotide polymorphisms (SNPs) were used to determine lactase persistence (LCT-13910 C/T for Whites and LCT-14010 G/C for Blacks). Mixed-effects models were used to study the association of milk intake with cognitive change. Multiple imputations by chained equations were used to account for attrition. Results: Milk intake greater than 1 glass/day was associated with greater decline in the global z-score over a 20-year period. The difference in decline was 0.10 (95\% CI: 0.16, 0.03) z-scores, or an additional 10\% decline, relative to the group reporting "almost never" consuming milk. Conclusions: Replication of these results is warranted in diverse populations with greater milk intake and higher variability of lactase persistence genotype.}, language = {en} } @article{HolzmannLittigStadlerPoppetal.2023, author = {Holzmann-Littig, Christopher and Stadler, David and Popp, Maria and Kranke, Peter and Fichtner, Falk and Schmaderer, Christoph and Renders, Lutz and Braunisch, Matthias Christoph and Assali, Tarek and Platen, Louise and Wijnen-Meijer, Marjo and L{\"u}hnen, Julia and Steckelberg, Anke and Pfadenhauer, Lisa and Haller, Bernhard and Fuetterer, Cornelia and Seeber, Christian and Schaaf, Christian}, title = {Locating medical information during an infodemic: information seeking behavior and strategies of health-care workers in Germany}, series = {Healthcare}, volume = {11}, journal = {Healthcare}, number = {11}, issn = {2227-9032}, doi = {10.3390/healthcare11111602}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-319306}, year = {2023}, abstract = {Background: The COVID-19 pandemic has led to a flood of — often contradictory — evidence. HCWs had to develop strategies to locate information that supported their work. We investigated the information-seeking of different HCW groups in Germany. Methods: In December 2020, we conducted online surveys on COVID-19 information sources, strategies, assigned trustworthiness, and barriers — and in February 2021, on COVID-19 vaccination information sources. Results were analyzed descriptively; group comparisons were performed using χ\(^2\)-tests. Results: For general COVID-19-related medical information (413 participants), non-physicians most often selected official websites (57\%), TV (57\%), and e-mail/newsletters (46\%) as preferred information sources — physicians chose official websites (63\%), e-mail/newsletters (56\%), and professional journals (55\%). Non-physician HCWs used Facebook/YouTube more frequently. The main barriers were insufficient time and access issues. Non-physicians chose abstracts (66\%), videos (45\%), and webinars (40\%) as preferred information strategy; physicians: overviews with algorithms (66\%), abstracts (62\%), webinars (48\%). Information seeking on COVID-19 vaccination (2700 participants) was quite similar, however, with newspapers being more often used by non-physicians (63\%) vs. physician HCWs (70\%). Conclusion: Non-physician HCWs more often consulted public information sources. Employers/institutions should ensure the supply of professional, targeted COVID-19 information for different HCW groups.}, language = {en} } @article{VieraElMerahbiNieswandtetal.2016, author = {Viera, Jonathan Trujillo and El-Merahbi, Rabih and Nieswandt, Bernhard and Stegner, David and Sumara, Grzegorz}, title = {Phospholipases D1 and D2 Suppress Appetite and Protect against Overweight}, series = {PLoS ONE}, volume = {11}, journal = {PLoS ONE}, number = {6}, doi = {10.1371/journal.pone.0157607}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-179729}, year = {2016}, abstract = {Obesity is a major risk factor predisposing to the development of peripheral insulin resistance and type 2 diabetes (T2D). Elevated food intake and/or decreased energy expenditure promotes body weight gain and acquisition of adipose tissue. Number of studies implicated phospholipase D (PLD) enzymes and their product, phosphatidic acid (PA), in regulation of signaling cascades controlling energy intake, energy dissipation and metabolic homeostasis. However, the impact of PLD enzymes on regulation of metabolism has not been directly determined so far. In this study we utilized mice deficient for two major PLD isoforms, PLD1 and PLD2, to assess the impact of these enzymes on regulation of metabolic homeostasis. We showed that mice lacking PLD1 or PLD2 consume more food than corresponding control animals. Moreover, mice deficient for PLD2, but not PLD1, present reduced energy expenditure. In addition, deletion of either of the PLD enzymes resulted in development of elevated body weight and increased adipose tissue content in aged animals. Consistent with the fact that elevated content of adipose tissue predisposes to the development of hyperlipidemia and insulin resistance, characteristic for the pre-diabetic state, we observed that Pld1\(^{-/-}\) and Pld2\(^{-/-}\) mice present elevated free fatty acids (FFA) levels and are insulin as well as glucose intolerant. In conclusion, our data suggest that deficiency of PLD1 or PLD2 activity promotes development of overweight and diabetes.}, language = {en} } @article{DumontWeberLassalleJolyBeauparlantetal.2022, author = {Dumont, Martine and Weber-Lassalle, Nana and Joly-Beauparlant, Charles and Ernst, Corinna and Droit, Arnaud and Feng, Bing-Jian and Dubois, St{\´e}phane and Collin-Deschesnes, Annie-Claude and Soucy, Penny and Vall{\´e}e, Maxime and Fournier, Fr{\´e}d{\´e}ric and Lema{\c{c}}on, Audrey and Adank, Muriel A. and Allen, Jamie and Altm{\"u}ller, Janine and Arnold, Norbert and Ausems, Margreet G. E. M. and Berutti, Riccardo and Bolla, Manjeet K. and Bull, Shelley and Carvalho, Sara and Cornelissen, Sten and Dufault, Michael R. and Dunning, Alison M. and Engel, Christoph and Gehrig, Andrea and Geurts-Giele, Willemina R. R. and Gieger, Christian and Green, Jessica and Hackmann, Karl and Helmy, Mohamed and Hentschel, Julia and Hogervorst, Frans B. L. and Hollestelle, Antoinette and Hooning, Maartje J. and Horv{\´a}th, Judit and Ikram, M. Arfan and Kaulfuß, Silke and Keeman, Renske and Kuang, Da and Luccarini, Craig and Maier, Wolfgang and Martens, John W. M. and Niederacher, Dieter and N{\"u}rnberg, Peter and Ott, Claus-Eric and Peters, Annette and Pharoah, Paul D. P. and Ramirez, Alfredo and Ramser, Juliane and Riedel-Heller, Steffi and Schmidt, Gunnar and Shah, Mitul and Scherer, Martin and St{\"a}bler, Antje and Strom, Tim M. and Sutter, Christian and Thiele, Holger and van Asperen, Christi J. and van der Kolk, Lizet and van der Luijt, Rob B. and Volk, Alexander E. and Wagner, Michael and Waisfisz, Quinten and Wang, Qin and Wang-Gohrke, Shan and Weber, Bernhard H. F. and Devilee, Peter and Tavtigian, Sean and Bader, Gary D. and Meindl, Alfons and Goldgar, David E. and Andrulis, Irene L. and Schmutzler, Rita K. and Easton, Douglas F. and Schmidt, Marjanka K. and Hahnen, Eric and Simard, Jacques}, title = {Uncovering the contribution of moderate-penetrance susceptibility genes to breast cancer by whole-exome sequencing and targeted enrichment sequencing of candidate genes in women of European ancestry}, series = {Cancers}, volume = {14}, journal = {Cancers}, number = {14}, issn = {2072-6694}, doi = {10.3390/cancers14143363}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-281768}, year = {2022}, abstract = {Rare variants in at least 10 genes, including BRCA1, BRCA2, PALB2, ATM, and CHEK2, are associated with increased risk of breast cancer; however, these variants, in combination with common variants identified through genome-wide association studies, explain only a fraction of the familial aggregation of the disease. To identify further susceptibility genes, we performed a two-stage whole-exome sequencing study. In the discovery stage, samples from 1528 breast cancer cases enriched for breast cancer susceptibility and 3733 geographically matched unaffected controls were sequenced. Using five different filtering and gene prioritization strategies, 198 genes were selected for further validation. These genes, and a panel of 32 known or suspected breast cancer susceptibility genes, were assessed in a validation set of 6211 cases and 6019 controls for their association with risk of breast cancer overall, and by estrogen receptor (ER) disease subtypes, using gene burden tests applied to loss-of-function and rare missense variants. Twenty genes showed nominal evidence of association (p-value < 0.05) with either overall or subtype-specific breast cancer. Our study had the statistical power to detect susceptibility genes with effect sizes similar to ATM, CHEK2, and PALB2, however, it was underpowered to identify genes in which susceptibility variants are rarer or confer smaller effect sizes. Larger sample sizes would be required in order to identify such genes.}, language = {en} } @article{NavarroStegnerNieswandtetal.2021, author = {Navarro, Stefano and Stegner, David and Nieswandt, Bernhard and Heemskerk, Johan W. M. and Kuijpers, Marijke J. E.}, title = {Temporal roles of platelet and coagulation pathways in collagen- and tissue factor-induced thrombus formation}, series = {International Journal of Molecular Sciences}, volume = {23}, journal = {International Journal of Molecular Sciences}, number = {1}, issn = {1422-0067}, doi = {10.3390/ijms23010358}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-284219}, year = {2021}, abstract = {In hemostasis and thrombosis, the complex process of thrombus formation involves different molecular pathways of platelet and coagulation activation. These pathways are considered as operating together at the same time, but this has not been investigated. The objective of our study was to elucidate the time-dependency of key pathways of thrombus and clot formation, initiated by collagen and tissue factor surfaces, where coagulation is triggered via the extrinsic route. Therefore, we adapted a microfluidics whole-blood assay with the Maastricht flow chamber to acutely block molecular pathways by pharmacological intervention at desired time points. Application of the technique revealed crucial roles of glycoprotein VI (GPVI)-induced platelet signaling via Syk kinase as well as factor VIIa-induced thrombin generation, which were confined to the first minutes of thrombus buildup. A novel anti-GPVI Fab EMF-1 was used for this purpose. In addition, platelet activation with the protease-activating receptors 1/4 (PAR1/4) and integrin αIIbβ3 appeared to be prolongedly active and extended to later stages of thrombus and clot formation. This work thereby revealed a more persistent contribution of thrombin receptor-induced platelet activation than of collagen receptor-induced platelet activation to the thrombotic process.}, language = {en} } @article{SchuhmannKraftBieberetal.2019, author = {Schuhmann, Michael K. and Kraft, Peter and Bieber, Michael and Kollikowski, Alexander M. and Schulze, Harald and Nieswandt, Bernhard and Pham, Mirko and Stegner, David and Stoll, Guido}, title = {Targeting platelet GPVI plus rt-PA administration but not α2β1-mediated collagen binding protects against ischemic brain damage in mice}, series = {International Journal of Molecular Science}, volume = {20}, journal = {International Journal of Molecular Science}, number = {8}, issn = {1422-0067}, doi = {10.3390/ijms20082019}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201700}, year = {2019}, abstract = {Platelet collagen interactions at sites of vascular injuries predominantly involve glycoprotein VI (GPVI) and the integrin α2β1. Both proteins are primarily expressed on platelets and megakaryocytes whereas GPVI expression is also shown on endothelial and integrin α2β1 expression on epithelial cells. We recently showed that depletion of GPVI improves stroke outcome without increasing the risk of cerebral hemorrhage. Genetic variants associated with higher platelet surface integrin α2 (ITGA2) receptor levels have frequently been found to correlate with an increased risk of ischemic stroke in patients. However until now, no preclinical stroke study has addressed whether platelet integrin α2β1 contributes to the pathophysiology of ischemia/reperfusion (I/R) injury. Focal cerebral ischemia was induced in C57BL/6 and Itga2\(^{-/-}\) mice by a 60 min transient middle cerebral artery occlusion (tMCAO). Additionally, wild-type animals were pretreated with anti-GPVI antibody (JAQ1) or Fab fragments of a function blocking antibody against integrin α2β1 (LEN/B). In anti-GPVI treated animals, intravenous (IV) recombinant tissue plasminogen activator (rt-PA) treatment was applied immediately prior to reperfusion. Stroke outcome, including infarct size and neurological scoring was determined on day 1 after tMCAO. We demonstrate that targeting the integrin α2β1 (pharmacologic; genetic) did neither reduce stroke size nor improve functional outcome on day 1 after tMCAO. In contrast, depletion of platelet GPVI prior to stroke was safe and effective, even when combined with rt-PA treatment. Our results underscore that GPVI, but not ITGA2, is a promising and safe target in the setting of ischemic stroke.}, language = {en} } @article{StegnerKlausNieswandt2019, author = {Stegner, David and Klaus, Vanessa and Nieswandt, Bernhard}, title = {Platelets as modulators of cerebral ischemia/reperfusion injury}, series = {Frontiers in Immunology}, volume = {10}, journal = {Frontiers in Immunology}, number = {2505}, issn = {1664-3224}, doi = {10.3389/fimmu.2019.02505}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-195748}, year = {2019}, abstract = {Ischemic stroke is among the leading causes of disability and death worldwide. In acute ischemic stroke, the rapid recanalization of occluded cranial vessels is the primary therapeutic aim. However, experimental data (obtained using mostly the transient middle cerebral artery occlusion model) indicates that progressive stroke can still develop despite successful recanalization, a process termed "reperfusion injury." Mounting experimental evidence suggests that platelets and T cells contribute to cerebral ischemia/reperfusion injury, and ischemic stroke is increasingly considered a thrombo-inflammatory disease. The interaction of von Willebrand factor and its receptor on the platelet surface, glycoprotein Ib, as well as many activatory platelet receptors and platelet degranulation contribute to secondary infarct growth in this setting. In contrast, interference with GPIIb/IIIa-dependent platelet aggregation and thrombus formation does not improve the outcome of acute brain ischemia but dramatically increases the susceptibility to intracranial hemorrhage. Here, we summarize the current understanding of the mechanisms and the potential translational impact of platelet contributions to cerebral ischemia/reperfusion injury.}, language = {en} } @article{DuettingGaitsIacovoniStegneretal.2017, author = {D{\"u}tting, Sebastian and Gaits-Iacovoni, Frederique and Stegner, David and Popp, Michael and Antkowiak, Adrien and van Eeuwijk, Judith M.M. and Nurden, Paquita and Stritt, Simon and Heib, Tobias and Aurbach, Katja and Angay, Oguzhan and Cherpokova, Deya and Heinz, Niels and Baig, Ayesha A. and Gorelashvili, Maximilian G. and Gerner, Frank and Heinze, Katrin G. and Ware, Jerry and Krohne, Georg and Ruggeri, Zaverio M. and Nurden, Alan T. and Schulze, Harald and Modlich, Ute and Pleines, Irina and Brakebusch, Cord and Nieswandt, Bernhard}, title = {A Cdc42/RhoA regulatory circuit downstream of glycoprotein Ib guides transendothelial platelet biogenesis}, series = {Nature Communications}, volume = {8}, journal = {Nature Communications}, number = {15838}, doi = {10.1038/ncomms15838}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170797}, year = {2017}, abstract = {Blood platelets are produced by large bone marrow (BM) precursor cells, megakaryocytes (MKs), which extend cytoplasmic protrusions (proplatelets) into BM sinusoids. The molecular cues that control MK polarization towards sinusoids and limit transendothelial crossing to proplatelets remain unknown. Here, we show that the small GTPases Cdc42 and RhoA act as a regulatory circuit downstream of the MK-specific mechanoreceptor GPIb to coordinate polarized transendothelial platelet biogenesis. Functional deficiency of either GPIb or Cdc42 impairs transendothelial proplatelet formation. In the absence of RhoA, increased Cdc42 activity and MK hyperpolarization triggers GPIb-dependent transmigration of entire MKs into BM sinusoids. These findings position Cdc42 (go-signal) and RhoA (stop-signal) at the centre of a molecular checkpoint downstream of GPIb that controls transendothelial platelet biogenesis. Our results may open new avenues for the treatment of platelet production disorders and help to explain the thrombocytopenia in patients with Bernard-Soulier syndrome, a bleeding disorder caused by defects in GPIb-IX-V.}, language = {en} } @article{StegnervanEeuwijkAngayetal.2017, author = {Stegner, David and van Eeuwijk, Judith M.M. and Angay, Oğuzhan and Gorelashvili, Maximilian G. and Semeniak, Daniela and Pinnecker, J{\"u}rgen and Schmithausen, Patrick and Meyer, Imke and Friedrich, Mike and D{\"u}tting, Sebastian and Brede, Christian and Beilhack, Andreas and Schulze, Harald and Nieswandt, Bernhard and Heinze, Katrin G.}, title = {Thrombopoiesis is spatially regulated by the bone marrow vasculature}, series = {Nature Communications}, volume = {8}, journal = {Nature Communications}, number = {127}, doi = {10.1038/s41467-017-00201-7}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170591}, year = {2017}, abstract = {In mammals, megakaryocytes (MKs) in the bone marrow (BM) produce blood platelets, required for hemostasis and thrombosis. MKs originate from hematopoietic stem cells and are thought to migrate from an endosteal niche towards the vascular sinusoids during their maturation. Through imaging of MKs in the intact BM, here we show that MKs can be found within the entire BM, without a bias towards bone-distant regions. By combining in vivo two-photon microscopy and in situ light-sheet fluorescence microscopy with computational simulations, we reveal surprisingly slow MK migration, limited intervascular space, and a vessel-biased MK pool. These data challenge the current thrombopoiesis model of MK migration and support a modified model, where MKs at sinusoids are replenished by sinusoidal precursors rather than cells from a distant periostic niche. As MKs do not need to migrate to reach the vessel, therapies to increase MK numbers might be sufficient to raise platelet counts.}, language = {en} } @article{GoebVollZimmermannetal.2021, author = {G{\"o}b, Vanessa and Voll, Maximilian G. and Zimmermann, Lena and Hemmen, Katharina and Stoll, Guido and Nieswandt, Bernhard and Schuhmann, Michael K. and Heinze, Katrin G. and Stegner, David}, title = {Infarct growth precedes cerebral thrombosis following experimental stroke in mice}, series = {Scientific Reports}, volume = {11}, journal = {Scientific Reports}, number = {1}, doi = {10.1038/s41598-021-02360-6}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265791}, year = {2021}, abstract = {Ischemic stroke is among the leading causes of disability and death worldwide. In acute ischemic stroke, successful recanalization of occluded vessels is the primary therapeutic aim, but even if it is achieved, not all patients benefit. Although blockade of platelet aggregation did not prevent infarct progression, cerebral thrombosis as cause of secondary infarct growth has remained a matter of debate. As cerebral thrombi are frequently observed after experimental stroke, a thrombus-induced impairment of the brain microcirculation is considered to contribute to tissue damage. Here, we combine the model of transient middle cerebral artery occlusion (tMCAO) with light sheet fluorescence microscopy and immunohistochemistry of brain slices to investigate the kinetics of thrombus formation and infarct progression. Our data reveal that tissue damage already peaks after 8 h of reperfusion following 60 min MCAO, while cerebral thrombi are only observed at later time points. Thus, cerebral thrombosis is not causative for secondary infarct growth during ischemic stroke.}, language = {en} } @article{BeckStegnerLorochetal.2021, author = {Beck, Sarah and Stegner, David and Loroch, Stefan and Baig, Ayesha A. and G{\"o}b, Vanessa and Schumbutzki, Cornelia and Eilers, Eva and Sickmann, Albert and May, Frauke and Nolte, Marc W. and Panousis, Con and Nieswandt, Bernhard}, title = {Generation of a humanized FXII knock-in mouse-A powerful model system to test novel anti-thrombotic agents}, series = {Journal of Thrombosis and Haemostasis}, volume = {19}, journal = {Journal of Thrombosis and Haemostasis}, number = {11}, doi = {10.1111/jth.15488}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-259567}, pages = {2835-2840}, year = {2021}, abstract = {Background Effective inhibition of thrombosis without generating bleeding risks is a major challenge in medicine. Accumulating evidence suggests that this can be achieved by inhibition of coagulation factor XII (FXII), as either its knock-out or inhibition in animal models efficiently reduced thrombosis without affecting normal hemostasis. Based on these findings, highly specific inhibitors for human FXII(a) are under development. However, currently, in vivo studies on their efficacy and safety are impeded by the lack of an optimized animal model expressing the specific target, that is, human FXII. Objective The primary objective of this study is to develop and functionally characterize a humanized FXII mouse model. Methods A humanized FXII mouse model was generated by replacing the murine with the human F12 gene (genetic knock-in) and tested it in in vitro coagulation assays and in in vivo thrombosis models. Results These hF12\(^{KI}\) mice were indistinguishable from wild-type mice in all tested assays of coagulation and platelet function in vitro and in vivo, except for reduced expression levels of hFXII compared to human plasma. Targeting FXII by the anti-human FXIIa antibody 3F7 increased activated partial thromboplastin time dose-dependently and protected hF12\(^{KI}\) mice in an arterial thrombosis model without affecting bleeding times. Conclusion These data establish the newly generated hF12\(^{KI}\) mouse as a powerful and unique model system for in vivo studies on anti-FXII(a) biologics, supporting the development of efficient and safe human FXII(a) inhibitors.}, language = {en} } @article{SchuhmannBieberFrankeetal.2021, author = {Schuhmann, Michael K. and Bieber, Michael and Franke, Maximilian and Kollikowski, Alexander M. and Stegner, David and Heinze, Katrin G. and Nieswandt, Bernhard and Pham, Mirko and Stoll, Guido}, title = {Platelets and lymphocytes drive progressive penumbral tissue loss during middle cerebral artery occlusion in mice}, series = {Journal of Neuroinflammation}, volume = {18}, journal = {Journal of Neuroinflammation}, number = {1}, doi = {10.1186/s12974-021-02095-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-259172}, pages = {46}, year = {2021}, abstract = {Background In acute ischemic stroke, cessation of blood flow causes immediate tissue necrosis within the center of the ischemic brain region accompanied by functional failure in the surrounding brain tissue designated the penumbra. The penumbra can be salvaged by timely thrombolysis/thrombectomy, the only available acute stroke treatment to date, but is progressively destroyed by the expansion of infarction. The underlying mechanisms of progressive infarction are not fully understood. Methods To address mechanisms, mice underwent filament occlusion of the middle cerebral artery (MCAO) for up to 4 h. Infarct development was compared between mice treated with antigen-binding fragments (Fab) against the platelet surface molecules GPIb (p0p/B Fab) or rat immunoglobulin G (IgG) Fab as control treatment. Moreover, Rag1\(^{-/-}\) mice lacking T-cells underwent the same procedures. Infarct volumes as well as the local inflammatory response were determined during vessel occlusion. Results We show that blocking of the platelet adhesion receptor, glycoprotein (GP) Ibα in mice, delays cerebral infarct progression already during occlusion and thus before recanalization/reperfusion. This therapeutic effect was accompanied by decreased T-cell infiltration, particularly at the infarct border zone, which during occlusion is supplied by collateral blood flow. Accordingly, mice lacking T-cells were likewise protected from infarct progression under occlusion. Conclusions Progressive brain infarction can be delayed by blocking detrimental lymphocyte/platelet responses already during occlusion paving the way for ultra-early treatment strategies in hyper-acute stroke before recanalization.}, language = {en} }