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Stark D, Denzinger M, Ebert L, Brandl R, Knorr C. Therapeutic approaches of diametaphyseal radius fractures in children. Arch Orthop Trauma Surg 2024; 144:1179-1188. [PMID: 38231205 DOI: 10.1007/s00402-023-05118-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 10/28/2023] [Indexed: 01/18/2024]
Abstract
BACKGROUND There are clear standards for when to operate on both distal epiphyseal and diaphyseal forearm fractures in children. However, paediatric surgeons are often faced with fractures in the transition zone between metaphysis and diaphysis. This aim of the study is to compare different treatment approaches for diametaphyseal forearm fractures, to classify different types of these fractures, and to define further assessment parameters and treatment recommendations. METHODS This retrospective study included all patients with diametaphyseal radial fractures who were seen at a paediatric surgery clinic between 01.01.2010 and 31.12.2013. Patients were treated either non-surgically (C) or surgically using bicortical Kirschner wire (BC-KW), intramedullary K-wire (IM-KW), elastic stable intramedullary nailing (ESIN), or combined bicortical and intramedullary K-wire (BCIM-KW). RESULTS During the study period, 547 patients presented with forearm fractures of which 88 patients (16%) had a fracture in the diametaphyseal region. The majority of diametaphyseal fractures were greenstick fractures (54.4%) followed by transverse fractures (44.3%). Distal fractures were predominantly treated with bicortical K-wiring (BC-KW, 40.5%) or non-surgically (C, 26.2%). Proximal fractures were treated by ESIN osteosynthesis (50%), followed by IM-KW (30%). Intermediate fractures were just as likely to be treated with one out of the 5 above-mentioned techniques. The ulna was involved in 64 of 88 cases. Depending on the type of fracture, it was treated either by ESIN osteosynthesis or non-surgically. No superior operative technique was identified. CONCLUSIONS The description of diametaphyseal fractures as a separate entity is important, because the therapy of these fractures is heterogeneous and challenging. A classification into proximal, intermediate, and distal may be useful in clinical decision-making. Despite the retrospective nature of this study, our data suggest that the use of a K-wire or combined technique BCIM-KW-technique, whenever technically feasible, achieves better radiological results without secondary dislocation. Further prospective studies are needed to provide better guidance to trauma surgeons.
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Affiliation(s)
- D Stark
- Klinik für Kinderchirurgie, Klinik St. Hedwig, Krankenhaus der Barmherzigen Brüder, Steinmetzstr. 1-3, 93047, Regensburg, Germany.
| | - M Denzinger
- Klinik für Kinderchirurgie, Klinik St. Hedwig, Krankenhaus der Barmherzigen Brüder, Steinmetzstr. 1-3, 93047, Regensburg, Germany
| | - L Ebert
- Klinik für Kinderchirurgie, Klinik St. Hedwig, Krankenhaus der Barmherzigen Brüder, Steinmetzstr. 1-3, 93047, Regensburg, Germany
| | - R Brandl
- Klinik für Radiologie, Krankenhaus der Barmherzigen Brüder, Regensburg, Germany
| | - C Knorr
- Klinik für Kinderchirurgie, Klinik St. Hedwig, Krankenhaus der Barmherzigen Brüder, Steinmetzstr. 1-3, 93047, Regensburg, Germany
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2
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Egea V, Megens RTA, Santovito D, Wantha S, Brandl R, Siess W, Khani S, Soehnlein O, Bartelt A, Weber C, Ries C. Properties and fate of human mesenchymal stem cells upon miRNA let-7f-promoted recruitment to atherosclerotic plaques. Cardiovasc Res 2023; 119:155-166. [PMID: 35238350 PMCID: PMC10022860 DOI: 10.1093/cvr/cvac022] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 02/28/2022] [Indexed: 11/12/2022] Open
Abstract
AIMS Atherosclerosis is a chronic inflammatory disease of the arteries leading to the formation of atheromatous plaques. Human mesenchymal stem cells (hMSCs) are recruited from the circulation into plaques where in response to their environment they adopt a phenotype with immunomodulatory properties. However, the mechanisms underlying hMSC function in these processes are unclear. Recently, we described that miRNA let-7f controls hMSC invasion guided by inflammatory cytokines and chemokines. Here, we investigated the role of let-7f in hMSC tropism to human atheromas and the effects of the plaque microenvironment on cell fate and release of soluble factors. METHODS AND RESULTS Incubation of hMSCs with LL-37, an antimicrobial peptide abundantly found in plaques, increased biosynthesis of let-7f and N-formyl peptide receptor 2 (FPR2), enabling chemotactic invasion of the cells towards LL-37, as determined by qRT-PCR, flow cytometry, and cell invasion assay analysis. In an Apoe-/- mouse model of atherosclerosis, circulating hMSCs preferentially adhered to athero-prone endothelium. This property was facilitated by elevated levels of let-7f in the hMSCs, as assayed by ex vivo artery perfusion and two-photon laser scanning microscopy. Exposure of hMSCs to homogenized human atheromatous plaque material considerably induced the production of various cytokines, chemokines, matrix metalloproteinases, and tissue inhibitors of metalloproteinases, as studied by PCR array and western blot analysis. Moreover, exposure to human plaque extracts elicited differentiation of hMSCs into cells of the myogenic lineage, suggesting a potentially plaque-stabilizing effect. CONCLUSIONS Our findings indicate that let-7f promotes hMSC tropism towards atheromas through the LL-37/FPR2 axis and demonstrate that hMSCs upon contact with human plaque environment develop a potentially athero-protective signature impacting the pathophysiology of atherosclerosis.
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Affiliation(s)
- Virginia Egea
- Corresponding authors. Tel: +49-89-4400-55310, E-mail: (C.R.); Tel: +49-89-4400-43902, E-mail: (V.E.)
| | - Remco Theodorus Adrianus Megens
- Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-University of Munich, Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, Munich, Germany
- Department of Biomedical Engineering, Cardiovascular Research Institute Maastricht, University of Maastricht, Maastricht, The Netherlands
| | - Donato Santovito
- Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-University of Munich, Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, Munich, Germany
- Institute for Genetic and Biomedical Research (IRGB), UoS of Milan, National Research Council (CNR), Milan, Italy
| | - Sarawuth Wantha
- Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Richard Brandl
- St. Mary’s Square Institute for Vascular Surgery and Phlebology, Munich, Germany
| | - Wolfgang Siess
- Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Sajjad Khani
- Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Oliver Soehnlein
- Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-University of Munich, Munich, Germany
- Department of Physiology and Pharmacology (FyFa), Karolinska Institutet, Stockholm, Sweden
- Institute for Experimental Pathology (ExPat), Center for Molecular Biology of Inflammation (ZMBE), Westfaelische Wilhelms-University of Muenster, Muenster, Germany
| | - Alexander Bartelt
- Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-University of Munich, Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, Munich, Germany
- Institute for Diabetes and Cancer (IDC), Helmholtz Center Munich, Neuherberg, Germany
- Department of Molecular Metabolism, Sabri Ülker Center for Metabolic Research, Harvard T.H. Chan School of Public Health, 665 Huntington Avenue, Boston, MA 02115, USA
| | - Christian Weber
- Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-University of Munich, Munich, Germany
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, University of Maastricht, Maastricht, The Netherlands
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Christian Ries
- Corresponding authors. Tel: +49-89-4400-55310, E-mail: (C.R.); Tel: +49-89-4400-43902, E-mail: (V.E.)
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Leberzammer J, Agten SM, Blanchet X, Duan R, Ippel H, Megens RT, Schulz C, Aslani M, Duchene J, Döring Y, Jooss NJ, Zhang P, Brandl R, Stark K, Siess W, Jurk K, Heemskerk JW, Hackeng TM, Mayo KH, Weber C, von Hundelshausen P. Targeting platelet-derived CXCL12 impedes arterial thrombosis. Blood 2022; 139:2691-2705. [PMID: 35313337 PMCID: PMC11022931 DOI: 10.1182/blood.2020010140] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 03/07/2022] [Indexed: 12/14/2022] Open
Abstract
The prevention and treatment of arterial thrombosis continue to be clinically challenging, and understanding the relevant molecular mechanisms in detail may facilitate the quest to identify novel targets and therapeutic approaches that improve protection from ischemic and bleeding events. The chemokine CXCL12 augments collagen-induced platelet aggregation by activating its receptor CXCR4. Here we show that inhibition of CXCR4 attenuates platelet aggregation induced by collagen or human plaque homogenate under static and arterial flow conditions by antagonizing the action of platelet-secreted CXCL12. We further show that platelet-specific CXCL12 deficiency in mice limits arterial thrombosis by affecting thrombus growth and stability without increasing tail bleeding time. Accordingly, neointimal lesion formation after carotid artery injury was attenuated in these mice. Mechanistically, CXCL12 activated via CXCR4 a signaling cascade involving Bruton's tyrosine kinase (Btk) that led to integrin αIIbβ3 activation, platelet aggregation, and granule release. The heterodimeric interaction between CXCL12 and CCL5 can inhibit CXCL12-mediated effects as mimicked by CCL5-derived peptides such as [VREY]4. An improved variant of this peptide, i[VREY]4, binds to CXCL12 in a complex with CXCR4 on the surface of activated platelets, thereby inhibiting Btk activation and preventing platelet CXCL12-dependent arterial thrombosis. In contrast to standard antiplatelet therapies such as aspirin or P2Y12 inhibition, i[VREY]4 reduced CXCL12-induced platelet aggregation and yet did not prolong in vitro bleeding time. We provide evidence that platelet-derived CXCL12 is involved in arterial thrombosis and can be specifically targeted by peptides that harbor potential therapeutic value against atherothrombosis.
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Affiliation(s)
- Julian Leberzammer
- Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-University, Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, Munich, Germany
| | - Stijn M. Agten
- Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Xavier Blanchet
- Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-University, Munich, Germany
| | - Rundan Duan
- Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-University, Munich, Germany
| | - Hans Ippel
- Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Remco T.A. Megens
- Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-University, Munich, Germany
- Department of Biomedical Engineering, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Christian Schulz
- German Center for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, Munich, Germany
- Medizinische Klinik und Poliklinik I, Ludwig-Maximilians-Universität, Munich, Germany
| | - Maria Aslani
- Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-University, Munich, Germany
| | - Johan Duchene
- Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-University, Munich, Germany
| | - Yvonne Döring
- Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-University, Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, Munich, Germany
- Department of Angiology, Swiss Cardiovascular Center, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Natalie J. Jooss
- Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Pengyu Zhang
- Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
- Center for Thrombosis and Hemostasis (CTH), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
- Leibniz Institut für Analytische Wissenschaften–ISAS-e.V., Dortmund, Germany
| | - Richard Brandl
- Institute for Vascular Surgery and Phlebology am Marienplatz, Munich, Germany
| | - Konstantin Stark
- German Center for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, Munich, Germany
- Medizinische Klinik und Poliklinik I, Ludwig-Maximilians-Universität, Munich, Germany
| | - Wolfgang Siess
- Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-University, Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, Munich, Germany
| | - Kerstin Jurk
- Center for Thrombosis and Hemostasis (CTH), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Johan W.M. Heemskerk
- Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
- Synapse Research Institute, Maastricht, The Netherlands
| | - Tilman M. Hackeng
- Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Kevin H. Mayo
- Department of Biochemistry, Molecular Biology & Biophysics, University of Minnesota Health Sciences Center, Minneapolis, MN
| | - Christian Weber
- Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-University, Munich, Germany
- Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Philipp von Hundelshausen
- Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-University, Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, Munich, Germany
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4
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Duan R, Goldmann L, Brandl R, Spannagl M, Weber C, Siess W, von Hundelshausen P. Effects of the Btk-Inhibitors Remibrutinib (LOU064) and Rilzabrutinib (PRN1008) With Varying Btk Selectivity Over Tec on Platelet Aggregation and in vitro Bleeding Time. Front Cardiovasc Med 2021; 8:749022. [PMID: 34631841 PMCID: PMC8498029 DOI: 10.3389/fcvm.2021.749022] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 08/31/2021] [Indexed: 12/02/2022] Open
Abstract
Background: Bruton tyrosine kinase inhibitors (BTKi) are used in B-cell malignancies and in development against various autoimmune diseases. Since Btk is also involved in specific pathways of platelet activation, BTKi might be considered to target platelet GPVI/GPIb-mediated atherothrombosis and platelet FcγRIIA-dependent immune disorders. However, BTKi treatment of patients with B-cell malignancies is frequently associated with mild bleeding events caused possibly by off-target inhibition of Tec. Here, we compared the platelet effects of two novel BTKi that exhibit a high (remibrutinib) or low (rilzabrutinib) selectivity for Btk over Tec. Methods and Results: Remibrutinib and rilzabrutinib were pre-incubated with anticoagulated blood. Platelet aggregation and in vitro bleeding time (closure time) were studied by multiple electrode aggregometry (MEA) and platelet-function analyzer-200 (PFA-200), respectively. Both BTKi inhibited atherosclerotic plaque-stimulated GPVI-mediated platelet aggregation, remibrutinib being more potent (IC50 = 0.03 μM) than rilzabrutinib (IC50 = 0.16 μM). Concentrations of remibrutinib (0.1 μM) and rilzabrutinib (0.5 μM), >80% inhibitory for plaque-induced aggregation, also significantly suppressed (>90%) the Btk-dependent pathways of platelet aggregation upon GPVI, von Willebrand factor/GPIb and FcγRIIA activation stimulated by low collagen concentrations, ristocetin and antibody cross-linking, respectively. Both BTKi did not inhibit aggregation stimulated by ADP, TRAP-6 or arachidonic acid. Remibrutinib (0.1 μM) only slightly prolonged closure time and significantly less than rilzabrutinib (0.5 μM). Conclusion: Remibrutinib and rilzabrutinib inhibit Btk-dependent pathways of platelet aggregation upon GPVI, VWF/GPIb, and FcγRIIA activation. Remibrutinib being more potent and showing a better profile of inhibition of Btk-dependent platelet activation vs. hemostatic impairment than rilzabrutinib may be considered for further development as an antiplatelet drug.
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Affiliation(s)
- Rundan Duan
- Institute for Cardiovascular Prevention, Ludwig-Maximilians-University, Munich, Germany
| | - Luise Goldmann
- Institute for Cardiovascular Prevention, Ludwig-Maximilians-University, Munich, Germany
| | - Richard Brandl
- Institute for Vascular Surgery and Phlebology am Marienplatz, Munich, Germany
| | - Michael Spannagl
- Department of Transfusion Medicine, Cell Therapeutics and Hemostaseology, Ludwig-Maximilians University, Munich, Germany
| | - Christian Weber
- Institute for Cardiovascular Prevention, Ludwig-Maximilians-University, Munich, Germany.,German Centre for Cardiovascular Research, Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK), Partner Site Munich Heart Alliance, Munich, Germany.,Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, Netherlands
| | - Wolfgang Siess
- Institute for Cardiovascular Prevention, Ludwig-Maximilians-University, Munich, Germany.,German Centre for Cardiovascular Research, Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK), Partner Site Munich Heart Alliance, Munich, Germany
| | - Philipp von Hundelshausen
- Institute for Cardiovascular Prevention, Ludwig-Maximilians-University, Munich, Germany.,German Centre for Cardiovascular Research, Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK), Partner Site Munich Heart Alliance, Munich, Germany
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5
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Petzold T, Thienel M, Dannenberg L, Mourikis P, Helten C, Ayhan A, M'Pembele R, Achilles A, Trojovky K, Zhang Z, Regenauer R, Pircher J, Ehrlich A, Lüsebrink E, Nicolai L, Stocker TJ, Brandl R, Röschenthaler F, Strecker J, Saleh I, Spannagl M, Mayr CH, Schiller HB, Jung C, Gerdes N, Hoffmann T, Levkau B, Hohlfeld T, Zeus T, Schulz C, Kelm M, Polzin A. Response by Petzold et al to Letter Regarding Article, "Rivaroxaban Reduces Arterial Thrombosis by Inhibition of FXa-Driven Platelet Activation via Protease Activated Receptor-1". Circ Res 2020; 126:e54-e55. [PMID: 32271680 DOI: 10.1161/circresaha.120.316786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Tobias Petzold
- German Centre for Cardiovascular Research, Partner Site Munich Heart Alliance, Germany (T.P., M.T., J.P., A.E., E.L., L.N., T.J.S., C.S.).,Medizinische Klinik und Poliklinik I, Klinikum der Universität München (T.P., M.T., Z.Z., R.R., J.P., A.E., E.L., L.N., T.J.S., J.S., I.S., C.S.), Ludwig-Maximilians-University, Munich, Germany
| | - Manuela Thienel
- German Centre for Cardiovascular Research, Partner Site Munich Heart Alliance, Germany (T.P., M.T., J.P., A.E., E.L., L.N., T.J.S., C.S.).,Medizinische Klinik und Poliklinik I, Klinikum der Universität München (T.P., M.T., Z.Z., R.R., J.P., A.E., E.L., L.N., T.J.S., J.S., I.S., C.S.), Ludwig-Maximilians-University, Munich, Germany
| | - Lisa Dannenberg
- From the Department of Cardiology, Pulmonology and Vascular Medicine (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., C.J., N.G., T.Z., M.K., A.P.), Medical Faculty of the Heinrich Heine University Düsseldorf, Germany.,Cardiovascular Research Institute Düsseldorf, Germany (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., C.J., N.G., T.Z., M.K., A.P.)
| | - Philipp Mourikis
- From the Department of Cardiology, Pulmonology and Vascular Medicine (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., C.J., N.G., T.Z., M.K., A.P.), Medical Faculty of the Heinrich Heine University Düsseldorf, Germany.,Cardiovascular Research Institute Düsseldorf, Germany (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., C.J., N.G., T.Z., M.K., A.P.)
| | - Carolin Helten
- From the Department of Cardiology, Pulmonology and Vascular Medicine (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., C.J., N.G., T.Z., M.K., A.P.), Medical Faculty of the Heinrich Heine University Düsseldorf, Germany.,Cardiovascular Research Institute Düsseldorf, Germany (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., C.J., N.G., T.Z., M.K., A.P.)
| | - Aysel Ayhan
- From the Department of Cardiology, Pulmonology and Vascular Medicine (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., C.J., N.G., T.Z., M.K., A.P.), Medical Faculty of the Heinrich Heine University Düsseldorf, Germany.,Cardiovascular Research Institute Düsseldorf, Germany (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., C.J., N.G., T.Z., M.K., A.P.)
| | - René M'Pembele
- From the Department of Cardiology, Pulmonology and Vascular Medicine (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., C.J., N.G., T.Z., M.K., A.P.), Medical Faculty of the Heinrich Heine University Düsseldorf, Germany.,Cardiovascular Research Institute Düsseldorf, Germany (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., C.J., N.G., T.Z., M.K., A.P.)
| | - Alina Achilles
- From the Department of Cardiology, Pulmonology and Vascular Medicine (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., C.J., N.G., T.Z., M.K., A.P.), Medical Faculty of the Heinrich Heine University Düsseldorf, Germany.,Cardiovascular Research Institute Düsseldorf, Germany (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., C.J., N.G., T.Z., M.K., A.P.)
| | - Kajetan Trojovky
- From the Department of Cardiology, Pulmonology and Vascular Medicine (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., C.J., N.G., T.Z., M.K., A.P.), Medical Faculty of the Heinrich Heine University Düsseldorf, Germany.,Cardiovascular Research Institute Düsseldorf, Germany (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., C.J., N.G., T.Z., M.K., A.P.)
| | - Zhe Zhang
- Medizinische Klinik und Poliklinik I, Klinikum der Universität München (T.P., M.T., Z.Z., R.R., J.P., A.E., E.L., L.N., T.J.S., J.S., I.S., C.S.), Ludwig-Maximilians-University, Munich, Germany
| | - Ron Regenauer
- Medizinische Klinik und Poliklinik I, Klinikum der Universität München (T.P., M.T., Z.Z., R.R., J.P., A.E., E.L., L.N., T.J.S., J.S., I.S., C.S.), Ludwig-Maximilians-University, Munich, Germany
| | - Joachim Pircher
- German Centre for Cardiovascular Research, Partner Site Munich Heart Alliance, Germany (T.P., M.T., J.P., A.E., E.L., L.N., T.J.S., C.S.).,Medizinische Klinik und Poliklinik I, Klinikum der Universität München (T.P., M.T., Z.Z., R.R., J.P., A.E., E.L., L.N., T.J.S., J.S., I.S., C.S.), Ludwig-Maximilians-University, Munich, Germany
| | - Andreas Ehrlich
- German Centre for Cardiovascular Research, Partner Site Munich Heart Alliance, Germany (T.P., M.T., J.P., A.E., E.L., L.N., T.J.S., C.S.).,Medizinische Klinik und Poliklinik I, Klinikum der Universität München (T.P., M.T., Z.Z., R.R., J.P., A.E., E.L., L.N., T.J.S., J.S., I.S., C.S.), Ludwig-Maximilians-University, Munich, Germany
| | - Enzo Lüsebrink
- German Centre for Cardiovascular Research, Partner Site Munich Heart Alliance, Germany (T.P., M.T., J.P., A.E., E.L., L.N., T.J.S., C.S.).,Medizinische Klinik und Poliklinik I, Klinikum der Universität München (T.P., M.T., Z.Z., R.R., J.P., A.E., E.L., L.N., T.J.S., J.S., I.S., C.S.), Ludwig-Maximilians-University, Munich, Germany
| | - Leo Nicolai
- German Centre for Cardiovascular Research, Partner Site Munich Heart Alliance, Germany (T.P., M.T., J.P., A.E., E.L., L.N., T.J.S., C.S.).,Medizinische Klinik und Poliklinik I, Klinikum der Universität München (T.P., M.T., Z.Z., R.R., J.P., A.E., E.L., L.N., T.J.S., J.S., I.S., C.S.), Ludwig-Maximilians-University, Munich, Germany
| | - Thomas J Stocker
- German Centre for Cardiovascular Research, Partner Site Munich Heart Alliance, Germany (T.P., M.T., J.P., A.E., E.L., L.N., T.J.S., C.S.).,Medizinische Klinik und Poliklinik I, Klinikum der Universität München (T.P., M.T., Z.Z., R.R., J.P., A.E., E.L., L.N., T.J.S., J.S., I.S., C.S.), Ludwig-Maximilians-University, Munich, Germany
| | - Richard Brandl
- St. Mary's Square Institute for Vascular Surgery and Phlebology, Munich, Germany (R.B.)
| | - Franz Röschenthaler
- German Heart Center, Institute for Laboratory Medicine, Technical University Munich (F.R.)
| | - Jan Strecker
- Medizinische Klinik und Poliklinik I, Klinikum der Universität München (T.P., M.T., Z.Z., R.R., J.P., A.E., E.L., L.N., T.J.S., J.S., I.S., C.S.), Ludwig-Maximilians-University, Munich, Germany
| | - Inas Saleh
- Medizinische Klinik und Poliklinik I, Klinikum der Universität München (T.P., M.T., Z.Z., R.R., J.P., A.E., E.L., L.N., T.J.S., J.S., I.S., C.S.), Ludwig-Maximilians-University, Munich, Germany
| | - Michael Spannagl
- Department of Anesthesiology, Cell Therapeutics and Hemostaseology (M.S.), Ludwig-Maximilians-University, Munich, Germany.,Department of Transfusion Medicine, Cell Therapeutics and Hemostaseology (M.S.), Ludwig-Maximilians-University, Munich, Germany
| | - Christoph H Mayr
- Helmholtz Zentrum München, Institute of Lung Biology and Disease, Group Systems Medicine of Chronic Lung Disease, Member of the German Center for Lung Research, Munich, Germany (C.H.M., H.B.S.)
| | - Herbert B Schiller
- Helmholtz Zentrum München, Institute of Lung Biology and Disease, Group Systems Medicine of Chronic Lung Disease, Member of the German Center for Lung Research, Munich, Germany (C.H.M., H.B.S.)
| | - Christian Jung
- From the Department of Cardiology, Pulmonology and Vascular Medicine (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., C.J., N.G., T.Z., M.K., A.P.), Medical Faculty of the Heinrich Heine University Düsseldorf, Germany.,Cardiovascular Research Institute Düsseldorf, Germany (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., C.J., N.G., T.Z., M.K., A.P.)
| | - Norbert Gerdes
- From the Department of Cardiology, Pulmonology and Vascular Medicine (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., C.J., N.G., T.Z., M.K., A.P.), Medical Faculty of the Heinrich Heine University Düsseldorf, Germany.,Cardiovascular Research Institute Düsseldorf, Germany (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., C.J., N.G., T.Z., M.K., A.P.)
| | - Till Hoffmann
- Institute of Transplantation Diagnostics and Cell Therapeutics, Heinrich Heine University Medical Center Düsseldorf, Germany (T. Hoffmann)
| | - Bodo Levkau
- Institute of Pathophysiology, West German Heart and Vascular Center, University Hospital Essen, University of Duisburg-Essen, Germany (B.L.)
| | - Thomas Hohlfeld
- Institute of Pharmacology and Clinical Pharmacology (T. Hohlfeld), Medical Faculty of the Heinrich Heine University Düsseldorf, Germany
| | - Tobias Zeus
- Cardiovascular Research Institute Düsseldorf, Germany (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., C.J., N.G., T.Z., M.K., A.P.)
| | - Christian Schulz
- German Centre for Cardiovascular Research, Partner Site Munich Heart Alliance, Germany (T.P., M.T., J.P., A.E., E.L., L.N., T.J.S., C.S.).,Medizinische Klinik und Poliklinik I, Klinikum der Universität München (T.P., M.T., Z.Z., R.R., J.P., A.E., E.L., L.N., T.J.S., J.S., I.S., C.S.), Ludwig-Maximilians-University, Munich, Germany
| | - Malte Kelm
- From the Department of Cardiology, Pulmonology and Vascular Medicine (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., C.J., N.G., T.Z., M.K., A.P.), Medical Faculty of the Heinrich Heine University Düsseldorf, Germany.,Cardiovascular Research Institute Düsseldorf, Germany (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., C.J., N.G., T.Z., M.K., A.P.)
| | - Amin Polzin
- From the Department of Cardiology, Pulmonology and Vascular Medicine (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., C.J., N.G., T.Z., M.K., A.P.), Medical Faculty of the Heinrich Heine University Düsseldorf, Germany.,Cardiovascular Research Institute Düsseldorf, Germany (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., C.J., N.G., T.Z., M.K., A.P.)
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6
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Petzold T, Thienel M, Dannenberg L, Mourikis P, Helten C, Ayhan A, M'Pembele R, Achilles A, Trojovky K, Konsek D, Zhang Z, Regenauer R, Pircher J, Ehrlich A, Lüsebrink E, Nicolai L, Stocker TJ, Brandl R, Röschenthaler F, Strecker J, Saleh I, Spannagl M, Mayr CH, Schiller HB, Jung C, Gerdes N, Hoffmann T, Levkau B, Hohlfeld T, Zeus T, Schulz C, Kelm M, Polzin A. Rivaroxaban Reduces Arterial Thrombosis by Inhibition of FXa-Driven Platelet Activation via Protease Activated Receptor-1. Circ Res 2019; 126:486-500. [PMID: 31859592 DOI: 10.1161/circresaha.119.315099] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
RATIONALE A reduced rate of myocardial infarction has been reported in patients with atrial fibrillation treated with FXa (factor Xa) inhibitors including rivaroxaban compared with vitamin K antagonists. At the same time, low-dose rivaroxaban has been shown to reduce mortality and atherothrombotic events in patients with coronary artery disease. Yet, the mechanisms underlying this reduction remain unknown. OBJECTIVE In this study, we hypothesized that rivaroxaban's antithrombotic potential is linked to a hitherto unknown rivaroxaban effect that impacts on platelet reactivity and arterial thrombosis. METHODS AND RESULTS In this study, we identified FXa as potent, direct agonist of the PAR-1 (protease-activated receptor 1), leading to platelet activation and thrombus formation, which can be inhibited by rivaroxaban. We found that rivaroxaban reduced arterial thrombus stability in a mouse model of arterial thrombosis using intravital microscopy. For in vitro studies, atrial fibrillation patients on permanent rivaroxaban treatment for stroke prevention, respective controls, and patients with new-onset atrial fibrillation before and after first intake of rivaroxaban (time series analysis) were recruited. Platelet aggregation responses, as well as thrombus formation under arterial flow conditions on collagen and atherosclerotic plaque material, were attenuated by rivaroxaban. We show that rivaroxaban's antiplatelet effect is plasma dependent but independent of thrombin and rivaroxaban's anticoagulatory capacity. CONCLUSIONS Here, we identified FXa as potent platelet agonist that acts through PAR-1. Therefore, rivaroxaban exerts an antiplatelet effect that together with its well-known potent anticoagulatory capacity might lead to reduced frequency of atherothrombotic events and improved outcome in patients.
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Affiliation(s)
- Tobias Petzold
- From the Medizinische Klinik und Poliklinik I, Klinikum der Universität München (T.P., M.T., Z.Z., R.R., J.P., A.E., E.L., L.N., T.J.S., J.S., I.S., C.S.), Ludwig-Maximilians-University Munich, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Germany (T.P., M.T., J.P., A.E., E.L., L.N., T.J.S., C.S.)
| | - Manuela Thienel
- From the Medizinische Klinik und Poliklinik I, Klinikum der Universität München (T.P., M.T., Z.Z., R.R., J.P., A.E., E.L., L.N., T.J.S., J.S., I.S., C.S.), Ludwig-Maximilians-University Munich, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Germany (T.P., M.T., J.P., A.E., E.L., L.N., T.J.S., C.S.)
| | - Lisa Dannenberg
- Cardiology, Pulmonology and Vascular Medicine, Medical Faculty of the Heinrich Heine University Düsseldorf, Düsseldorf (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., D.K., C.J., N.G., T.Z., M.K., A.P.)
| | - Philipp Mourikis
- Cardiology, Pulmonology and Vascular Medicine, Medical Faculty of the Heinrich Heine University Düsseldorf, Düsseldorf (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., D.K., C.J., N.G., T.Z., M.K., A.P.)
| | - Carolin Helten
- Cardiology, Pulmonology and Vascular Medicine, Medical Faculty of the Heinrich Heine University Düsseldorf, Düsseldorf (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., D.K., C.J., N.G., T.Z., M.K., A.P.)
| | - Aysel Ayhan
- Cardiology, Pulmonology and Vascular Medicine, Medical Faculty of the Heinrich Heine University Düsseldorf, Düsseldorf (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., D.K., C.J., N.G., T.Z., M.K., A.P.)
| | - René M'Pembele
- Cardiology, Pulmonology and Vascular Medicine, Medical Faculty of the Heinrich Heine University Düsseldorf, Düsseldorf (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., D.K., C.J., N.G., T.Z., M.K., A.P.)
| | - Alina Achilles
- Cardiology, Pulmonology and Vascular Medicine, Medical Faculty of the Heinrich Heine University Düsseldorf, Düsseldorf (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., D.K., C.J., N.G., T.Z., M.K., A.P.)
| | - Kajetan Trojovky
- Cardiology, Pulmonology and Vascular Medicine, Medical Faculty of the Heinrich Heine University Düsseldorf, Düsseldorf (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., D.K., C.J., N.G., T.Z., M.K., A.P.)
| | - Daniel Konsek
- Cardiology, Pulmonology and Vascular Medicine, Medical Faculty of the Heinrich Heine University Düsseldorf, Düsseldorf (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., D.K., C.J., N.G., T.Z., M.K., A.P.)
| | - Zhe Zhang
- From the Medizinische Klinik und Poliklinik I, Klinikum der Universität München (T.P., M.T., Z.Z., R.R., J.P., A.E., E.L., L.N., T.J.S., J.S., I.S., C.S.), Ludwig-Maximilians-University Munich, Germany
| | - Ron Regenauer
- From the Medizinische Klinik und Poliklinik I, Klinikum der Universität München (T.P., M.T., Z.Z., R.R., J.P., A.E., E.L., L.N., T.J.S., J.S., I.S., C.S.), Ludwig-Maximilians-University Munich, Germany
| | - Joachim Pircher
- From the Medizinische Klinik und Poliklinik I, Klinikum der Universität München (T.P., M.T., Z.Z., R.R., J.P., A.E., E.L., L.N., T.J.S., J.S., I.S., C.S.), Ludwig-Maximilians-University Munich, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Germany (T.P., M.T., J.P., A.E., E.L., L.N., T.J.S., C.S.)
| | - Andreas Ehrlich
- From the Medizinische Klinik und Poliklinik I, Klinikum der Universität München (T.P., M.T., Z.Z., R.R., J.P., A.E., E.L., L.N., T.J.S., J.S., I.S., C.S.), Ludwig-Maximilians-University Munich, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Germany (T.P., M.T., J.P., A.E., E.L., L.N., T.J.S., C.S.)
| | - Enzo Lüsebrink
- From the Medizinische Klinik und Poliklinik I, Klinikum der Universität München (T.P., M.T., Z.Z., R.R., J.P., A.E., E.L., L.N., T.J.S., J.S., I.S., C.S.), Ludwig-Maximilians-University Munich, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Germany (T.P., M.T., J.P., A.E., E.L., L.N., T.J.S., C.S.)
| | - Leo Nicolai
- From the Medizinische Klinik und Poliklinik I, Klinikum der Universität München (T.P., M.T., Z.Z., R.R., J.P., A.E., E.L., L.N., T.J.S., J.S., I.S., C.S.), Ludwig-Maximilians-University Munich, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Germany (T.P., M.T., J.P., A.E., E.L., L.N., T.J.S., C.S.)
| | - Thomas J Stocker
- From the Medizinische Klinik und Poliklinik I, Klinikum der Universität München (T.P., M.T., Z.Z., R.R., J.P., A.E., E.L., L.N., T.J.S., J.S., I.S., C.S.), Ludwig-Maximilians-University Munich, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Germany (T.P., M.T., J.P., A.E., E.L., L.N., T.J.S., C.S.)
| | - Richard Brandl
- St Mary's Square Institute for Vascular Surgery and Phlebology, Munich (R.B.)
| | - Franz Röschenthaler
- German Heart Center, Institute for Laboratory Medicine, Technical University Munich (F.R.)
| | - Jan Strecker
- From the Medizinische Klinik und Poliklinik I, Klinikum der Universität München (T.P., M.T., Z.Z., R.R., J.P., A.E., E.L., L.N., T.J.S., J.S., I.S., C.S.), Ludwig-Maximilians-University Munich, Germany
| | - Inas Saleh
- From the Medizinische Klinik und Poliklinik I, Klinikum der Universität München (T.P., M.T., Z.Z., R.R., J.P., A.E., E.L., L.N., T.J.S., J.S., I.S., C.S.), Ludwig-Maximilians-University Munich, Germany
| | - Michael Spannagl
- Anesthesiology and Transfusion Medicine, Cell Therapeutics and Hemostaseology (M.S.), Ludwig-Maximilians-University Munich, Germany
| | - Christoph H Mayr
- Helmholtz Zentrum München, Institute of Lung Biology and Disease, Group Systems Medicine of Chronic Lung Disease, Munich, Germany, Member of the German Center for Lung Research (DZL) (C.H.M., H.B.S.)
| | - Herbert B Schiller
- Helmholtz Zentrum München, Institute of Lung Biology and Disease, Group Systems Medicine of Chronic Lung Disease, Munich, Germany, Member of the German Center for Lung Research (DZL) (C.H.M., H.B.S.)
| | - Christian Jung
- Cardiology, Pulmonology and Vascular Medicine, Medical Faculty of the Heinrich Heine University Düsseldorf, Düsseldorf (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., D.K., C.J., N.G., T.Z., M.K., A.P.)
| | - Norbert Gerdes
- Cardiology, Pulmonology and Vascular Medicine, Medical Faculty of the Heinrich Heine University Düsseldorf, Düsseldorf (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., D.K., C.J., N.G., T.Z., M.K., A.P.)
| | - Till Hoffmann
- Institute of Transplantation Diagnostics and Cell Therapeutics, Heinrich Heine University Medical Center Düsseldorf (T. Hoffmann)
| | - Bodo Levkau
- Institute of Pathophysiology, West German Heart and Vascular Center, University Hospital Essen, University of Duisburg-Essen (B.L.)
| | - Thomas Hohlfeld
- Cardiovascular Research Institute Düsseldorf (CARID), Institute of Pharmacology and Clinical Pharmacology, Medical Faculty of the Heinrich Heine University Düsseldorf (T. Hohlfeld)
| | - Tobias Zeus
- Cardiology, Pulmonology and Vascular Medicine, Medical Faculty of the Heinrich Heine University Düsseldorf, Düsseldorf (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., D.K., C.J., N.G., T.Z., M.K., A.P.)
| | - Christian Schulz
- From the Medizinische Klinik und Poliklinik I, Klinikum der Universität München (T.P., M.T., Z.Z., R.R., J.P., A.E., E.L., L.N., T.J.S., J.S., I.S., C.S.), Ludwig-Maximilians-University Munich, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Germany (T.P., M.T., J.P., A.E., E.L., L.N., T.J.S., C.S.)
| | - Malte Kelm
- Cardiology, Pulmonology and Vascular Medicine, Medical Faculty of the Heinrich Heine University Düsseldorf, Düsseldorf (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., D.K., C.J., N.G., T.Z., M.K., A.P.)
| | - Amin Polzin
- Cardiology, Pulmonology and Vascular Medicine, Medical Faculty of the Heinrich Heine University Düsseldorf, Düsseldorf (L.D., P.M., C.H., A. Ayhan, R.M., A. Achilles, K.T., D.K., C.J., N.G., T.Z., M.K., A.P.)
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Affiliation(s)
- Richard Brandl
- *Practice for Vascular Surgery and Venous Medicine am Marienplatz München
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8
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Heer K, Behringer D, Piermattei A, Bässler C, Brandl R, Fady B, Jehl H, Liepelt S, Lorch S, Piotti A, Vendramin G, Weller M, Ziegenhagen B, Büntgen U, Opgenoorth L. Linking dendroecology and association genetics in natural populations: Stress responses archived in tree rings associate with SNP genotypes in silver fir (Abies albaMill.). Mol Ecol 2018; 27:1428-1438. [DOI: 10.1111/mec.14538] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 02/08/2018] [Indexed: 01/07/2023]
Affiliation(s)
- K. Heer
- Faculty of Biology, Conservation Biology; Philipps-University Marburg; Marburg Germany
- Department of Ecology; Faculty of Biology; Philipps-University Marburg; Marburg Germany
| | - D. Behringer
- Faculty of Biology, Conservation Biology; Philipps-University Marburg; Marburg Germany
| | - A. Piermattei
- Department of Geography; University of Cambridge; Cambridge UK
- Department of Agricultural, Food and Environmental Sciences; Marche Polytechnic University; Ancona Italy
- Dendro Science; Swiss Federal Research Institute WSL; Birmensdorf Switzerland
| | - C. Bässler
- Bavarian Forest National Park; Grafenau Germany
| | - R. Brandl
- Department of Ecology; Faculty of Biology; Philipps-University Marburg; Marburg Germany
| | - B. Fady
- INRA; UR Ecologie des Forêts Méditerranéennes; Avignon France
| | - H. Jehl
- Bavarian Forest National Park; Grafenau Germany
| | - S. Liepelt
- Faculty of Biology, Conservation Biology; Philipps-University Marburg; Marburg Germany
| | - S. Lorch
- Department of Ecology; Faculty of Biology; Philipps-University Marburg; Marburg Germany
| | - A. Piotti
- National Research Council; Institute of Biosciences and Bioresources; Firenze Italy
| | - G.G. Vendramin
- National Research Council; Institute of Biosciences and Bioresources; Firenze Italy
| | - M. Weller
- Department of Ecology; Faculty of Biology; Philipps-University Marburg; Marburg Germany
| | - B. Ziegenhagen
- Faculty of Biology, Conservation Biology; Philipps-University Marburg; Marburg Germany
| | - U. Büntgen
- Department of Geography; University of Cambridge; Cambridge UK
- Dendro Science; Swiss Federal Research Institute WSL; Birmensdorf Switzerland
- CzechGlobe, Global Change Research Institute CAS and Masaryk University; Brno Czech Republic
| | - L. Opgenoorth
- Department of Ecology; Faculty of Biology; Philipps-University Marburg; Marburg Germany
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9
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Ebrahim M, Jamasbi J, Adler K, Megens R, M'Bengue Y, Blanchet X, Uhland K, Ungerer M, Brandl R, Weber C, Elia N, Lorenz R, Münch G, Siess W. Dimeric Glycoprotein VI Binds to Collagen but Not to Fibrin. Thromb Haemost 2018; 118:351-361. [DOI: 10.1160/th17-04-0302] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
AbstractPlatelet glycoprotein VI (GPVI) acts as a decisive collagen receptor in atherothrombosis. Besides collagen, injured atherosclerotic plaques expose tissue factor (TF) that triggers fibrin formation. Two recent studies reported that platelet GPVI also functions as fibrin receptor, which would importantly widen the mode of action of GPVI-targeted antithrombotic drugs. We studied the binding of two GPVI fusion proteins to fibrin under static and arterial flow conditions. Fibrin was prepared from purified fibrinogen or generated more physiologically from endogenous fibrinogen by coagulating plasma with thrombin. Fibrin formation was also triggered by exposing TF-coated surfaces or human atherosclerotic plaque slices to arterially flowing blood. By binding studies and advanced optical imaging, we found that recombinant dimeric GPVI-Fc fusion proteins with Fc from either IgG1 (GPVI-Fc1) or IgG2 (GPVI-Fc2) bound to collagen fibres, but neither to fibrin prepared from purified fibrinogen obtained from three suppliers, nor to physiological fibrin formed by thrombin in plasma or triggered by exposing TF or atherosclerotic plaque slices to arterially flowing blood. Our findings do not support a role of dimeric platelet GPVI as receptor for fibrin. This is important for the understanding of plaque-triggered platelet thrombus formation and is clinically relevant for future GPVI-targeting therapies with recombinant GPVI-Fc and anti-GPVI antibodies.
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Mojica Muñoz AK, Jamasbi J, Uhland K, Degen H, Münch G, Ungerer M, Brandl R, Megens R, Weber C, Lorenz R, Siess W. Recombinant GPVI-Fc added to single or dual antiplatelet therapy in vitro prevents plaque-induced platelet thrombus formation. Thromb Haemost 2017; 117:1651-1659. [DOI: 10.1160/th16-11-0856] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 05/04/2017] [Indexed: 11/05/2022]
Abstract
SummaryThe efficiency of current dual antiplatelet therapy might be further improved by its combination with a glycoprotein (GP) VI-targeting strategy without increasing bleeding. GPVI-Fc, a recombinant dimeric fusion protein binding to plaque collagen and concealing binding sites for platelet GPVI, acts as a lesion-focused antiplatelet drug, and does not increase bleeding in vivo. We investigated, whether GPVI-Fc added in vitro on top of acetylsalicylic acid (ASA), the P2Y12 antagonist ticagrelor, and the fibrinogen receptor antagonist abciximab alone or in combination would increase inhibition of platelet activation by atherosclerotic plaque. Under static conditions, GPVI-Fc inhibited plaque-induced platelet aggregation by 53%, and increased platelet inhibition by ASA (51%) and ticagrelor (64%) to 66% and 80%, respectively. Under arterial flow, GPVI-Fc inhibited plaque-induced platelet aggregation by 57%, and significantly increased platelet inhibition by ASA (28%) and ticagrelor (47%) to about 81% each. The triple combination of GPVI-Fc, ASA and ticagrelor achieved almost complete inhibition of plaque-induced platelet aggregation (93%). GPVI-Fc alone or in combination with ASA or ticagrelor did not increase closure time measured by the platelet function analyzer (PFA)-200. GPVI-Fc added on top of abciximab, a clinically used anti-fibrinogen receptor antibody which blocks platelet aggregation, strongly inhibited total (81%) and stable (89%) platelet adhesion. We conclude that GPVI-Fc added on top of single or dual antiplatelet therapy with ASA and/or a P2Y12 antagonist is likely to improve anti-atherothrombotic protection without increasing bleeding risk. In contrast, the strong inhibition of platelet adhesion by GPVI-Fc in combination with GPIIb/IIIa inhibitors could be harmful.Note: The review process for this manuscript was fully handled by Gregory Y. H. Lip, Editor in Chief.Supplementary Material to this article is available at www.thrombosis-online.com.
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11
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Degen H, Borst O, Ziegler M, Mojica Munoz AK, Jamasbi J, Walker B, Göbel S, Fassbender J, Adler K, Brandl R, Münch G, Lorenz R, Siess W, Gawaz M, Ungerer M. ADPase CD39 Fused to Glycoprotein VI-Fc Boosts Local Antithrombotic Effects at Vascular Lesions. J Am Heart Assoc 2017; 6:JAHA.117.005991. [PMID: 28751543 PMCID: PMC5586441 DOI: 10.1161/jaha.117.005991] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND GPVI (Glycoprotein VI) is the essential platelet collagen receptor in atherothrombosis. Dimeric GPVI-Fc (Revacept) binds to GPVI binding sites on plaque collagen. As expected, it did not increase bleeding in clinical studies. GPVI-Fc is a potent inhibitor of atherosclerotic plaque-induced platelet aggregation at high shear flow, but its inhibition at low shear flow is limited. We sought to increase the platelet inhibitory potential by fusing GPVI-Fc to the ectonucleotidase CD39 (fusion protein GPVI-CD39), which inhibits local ADP accumulation at vascular plaques, and thus to create a lesion-directed dual antiplatelet therapy that is expected to lack systemic bleeding risks. METHODS AND RESULTS GPVI-CD39 effectively stimulated local ADP degradation and, compared with GPVI-Fc alone, led to significantly increased inhibition of ADP-, collagen-, and human plaque-induced platelet aggregation in Multiplate aggregometry and plaque-induced platelet thrombus formation under arterial flow conditions. GPVI-CD39 did not increase bleeding time in an in vitro assay simulating primary hemostasis. In a mouse model of ferric chloride-induced arterial thrombosis, GPVI-CD39 effectively delayed vascular thrombosis but did not increase tail bleeding time in vivo. CONCLUSIONS GPVI-CD39 is a novel approach to increase local antithrombotic activity at sites of atherosclerotic plaque rupture or injury. It enhances GPVI-Fc-mediated platelet inhibition and presents a potentially effective and safe molecule for the treatment of acute atherothrombotic events, with a favorable risk-benefit ratio.
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Affiliation(s)
| | - Oliver Borst
- Medical Clinic III, University of Tübingen, Germany
| | | | | | - Janina Jamasbi
- IPEK - Institute for Prevention of Cardiovascular Diseases, University of Munich, Germany
| | | | | | | | | | - Richard Brandl
- St. Mary's Square Institute for Vascular Surgery and Phlebology, Munich, Germany
| | - Götz Münch
- advanceCOR - Procorde, Martinsried, Germany
| | - Reinhard Lorenz
- IPEK - Institute for Prevention of Cardiovascular Diseases, University of Munich, Germany
| | - Wolfgang Siess
- IPEK - Institute for Prevention of Cardiovascular Diseases, University of Munich, Germany.,DZHK (German Centre for Cardiovascular Research) partner site Munich Heart Alliance, Munich, Germany
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Petzold T, Thienel M, Konrad I, Schubert I, Regenauer R, Hoppe B, Lorenz M, Eckart A, Chandraratne S, Lennerz C, Kolb C, Braun D, Jamasbi J, Brandl R, Braun S, Siess W, Schulz C, Massberg S. Oral thrombin inhibitor aggravates platelet adhesion and aggregation during arterial thrombosis. Sci Transl Med 2016; 8:367ra168. [DOI: 10.1126/scitranslmed.aad6712] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 08/31/2016] [Indexed: 12/13/2022]
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Silva Gracia M, Brandl R, Haen E. Comparison of the pharmacokinetic interaction of antipsychotics and beta-blockers. Pharmacopsychiatry 2016. [DOI: 10.1055/s-0036-1582048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Jamasbi J, Megens RTA, Bianchini M, Uhland K, Münch G, Ungerer M, Sherman S, Faussner A, Brandl R, John C, Buchner J, Weber C, Lorenz R, Elia N, Siess W. Cross-Linking GPVI-Fc by Anti-Fc Antibodies Potentiates Its Inhibition of Atherosclerotic Plaque- and Collagen-Induced Platelet Activation. JACC Basic Transl Sci 2016; 1:131-142.. [PMID: 27766315 PMCID: PMC5063538 DOI: 10.1016/j.jacbts.2016.03.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 03/08/2016] [Indexed: 10/26/2022]
Abstract
To enhance the antithrombotic properties of recombinant glycoprotein VI fragment crystallizable (GPVI-Fc), the authors incubated GPVI-Fc with anti-human Fc antibodies to cross-link the Fc tails of GPVI-Fc. Cross-linking potentiated the inhibition of human plaque- and collagen-induced platelet aggregation by GPVI-Fc under static and flow conditions without increasing bleeding time in vitro. Cross-linking with anti-human-Fc Fab2 was even superior to anti-human-Fc immunoglobulin G (IgG). Advanced optical imaging revealed a continuous sheath-like coverage of collagen fibers by cross-linked GPVI-Fc complexes. Cross-linking of GPVI into oligomeric complexes provides a new, highly effective, and probably safe antithrombotic treatment as it suppresses platelet GPVI-plaque interaction selectively at the site of acute atherothrombosis.
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Affiliation(s)
- Janina Jamasbi
- Institute for the Prevention of Cardiovascular Diseases, University of Munich (LMU Munich), Munich, Germany
| | - Remco T A Megens
- Institute for the Prevention of Cardiovascular Diseases, University of Munich (LMU Munich), Munich, Germany; Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, the Netherlands
| | - Mariaelvy Bianchini
- Institute for the Prevention of Cardiovascular Diseases, University of Munich (LMU Munich), Munich, Germany
| | | | | | | | - Shachar Sherman
- Department of Life Sciences, Ben Gurion University, Beer-Sheva, Israel
| | - Alexander Faussner
- Institute for the Prevention of Cardiovascular Diseases, University of Munich (LMU Munich), Munich, Germany
| | - Richard Brandl
- St. Mary's Square Institute for Vascular Surgery and Phlebology, Munich, Germany
| | - Christine John
- Department of Biotechnology, Technical University of Munich, Garching, Germany
| | - Johannes Buchner
- Department of Biotechnology, Technical University of Munich, Garching, Germany
| | - Christian Weber
- Institute for the Prevention of Cardiovascular Diseases, University of Munich (LMU Munich), Munich, Germany; Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, the Netherlands; DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany
| | - Reinhard Lorenz
- Institute for the Prevention of Cardiovascular Diseases, University of Munich (LMU Munich), Munich, Germany
| | - Natalie Elia
- Department of Life Sciences, Ben Gurion University, Beer-Sheva, Israel
| | - Wolfgang Siess
- Institute for the Prevention of Cardiovascular Diseases, University of Munich (LMU Munich), Munich, Germany; DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany
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Steckel J, Penrith M, Henschel J, Brandl R, Meyer J. A preliminary molecular phylogeny of the Namib Desert darkling beetles (Tenebrionidae). African Zoology 2015. [DOI: 10.1080/15627020.2010.11657259] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Jamasbi J, Megens RTA, Bianchini M, Münch G, Ungerer M, Faussner A, Sherman S, Walker A, Goyal P, Jung S, Brandl R, Weber C, Lorenz R, Farndale R, Elia N, Siess W. Differential Inhibition of Human Atherosclerotic Plaque-Induced Platelet Activation by Dimeric GPVI-Fc and Anti-GPVI Antibodies: Functional and Imaging Studies. J Am Coll Cardiol 2015; 65:2404-15. [PMID: 26046734 PMCID: PMC4452546 DOI: 10.1016/j.jacc.2015.03.573] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 03/25/2015] [Accepted: 03/31/2015] [Indexed: 12/20/2022]
Abstract
Background Glycoprotein VI (GPVI) is the essential platelet collagen receptor in atherothrombosis, but its inhibition causes only a mild bleeding tendency. Thus, targeting this receptor has selective antithrombotic potential. Objectives This study sought to compare compounds interfering with platelet GPVI–atherosclerotic plaque interaction to improve current antiatherothrombotic therapy. Methods Human atherosclerotic plaque–induced platelet aggregation was measured in anticoagulated blood under static and arterial flow conditions (550/s, 1,100/s, and 1,500/s). Inhibition by dimeric GPVI fragment crystallizable region of IgG (Fc) masking GPVI binding sites on collagen was compared with that of 3 anti-GPVI antibodies: BLO8-1, a human domain antibody; 5C4, a fragment antigen-binding (Fab fragment) of monoclonal rat immunoglobulin G; and m-Fab-F, a human recombinant sFab against GPVI dimers. Results GPVI-Fc reduced plaque-triggered platelet aggregation in static blood by 51%, BLO8-1 by 88%, and 5C4 by 93%. Under arterial flow conditions, BLO8-1 and 5C4 almost completely inhibited platelet aggregation while preserving platelet adhesion on plaque. Inhibition by GPVI-Fc, even at high concentrations, was less marked but increased with shear rate. Advanced optical imaging revealed rapid persistent GPVI-Fc binding to collagen under low and high shear flow, upstream and downstream of plaque fragments. At low shear particularly, platelets adhered in plaque flow niches to GPVI-Fc–free segments of collagen fibers and recruited other platelets onto aggregates via ADP and TxA2 release. Conclusions Anti-GPVI antibodies inhibit atherosclerotic plaque-induced platelet aggregation under static and flow conditions more effectively than GPVI-Fc. However, potent platelet inhibition by GPVI-Fc at a higher shear rate (1,500/s) suggests localized antithrombotic efficacy at denuded or fissured stenotic high-risk lesions without systemic bleeding. The compound-specific differences have relevance for clinical trials targeting GPVI-collagen interaction combined with established antiplatelet therapies in patients with spontaneous plaque rupture or intervention-associated plaque injury.
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Affiliation(s)
- Janina Jamasbi
- Institute for the Prevention of Cardiovascular Diseases, University of Munich, Munich, Germany
| | - Remco T A Megens
- Institute for the Prevention of Cardiovascular Diseases, University of Munich, Munich, Germany; Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, the Netherlands
| | - Mariaelvy Bianchini
- Institute for the Prevention of Cardiovascular Diseases, University of Munich, Munich, Germany
| | | | | | - Alexander Faussner
- Institute for the Prevention of Cardiovascular Diseases, University of Munich, Munich, Germany
| | - Shachar Sherman
- Department of Life Sciences, Ben Gurion University, Beer-Sheva, Israel
| | - Adam Walker
- GlaxoSmithKline Research & Development, Brentford, Middlesex, United Kingdom
| | - Pankaj Goyal
- Department of Biotechnology, The Central University of Rajasthan, Rajasthan, India
| | - Stephanie Jung
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Richard Brandl
- St. Mary's Square Institute for Vascular Surgery and Phlebology, Munich, Germany
| | - Christian Weber
- Institute for the Prevention of Cardiovascular Diseases, University of Munich, Munich, Germany; Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, the Netherlands; DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany
| | - Reinhard Lorenz
- Institute for the Prevention of Cardiovascular Diseases, University of Munich, Munich, Germany
| | - Richard Farndale
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Natalie Elia
- Department of Life Sciences, Ben Gurion University, Beer-Sheva, Israel
| | - Wolfgang Siess
- Institute for the Prevention of Cardiovascular Diseases, University of Munich, Munich, Germany; DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany.
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Affiliation(s)
- Richard Brandl
- Praxis für Gefäßchirurgie und Venenmedizin am Marienplatz, München
| | - Hubert Stiegler
- Klinik für Medizinische Angiologie, Klinikum München-Schwabing
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Wenzel-Seifert K, Brandl R, Hiemke C, Haen E. Influence of concomitant medications on the total clearance and the risk for supra-therapeutic plasma concentrations of Citalopram. A population-based cohort study. Pharmacopsychiatry 2014; 47:239-44. [PMID: 25372890 DOI: 10.1055/s-0034-1390477] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
INTRODUCTION The main objective of this study was to investigate the influence of the use of multiple medications and other risk factors on citalopram plasma concentrations. METHODS A retrospective cohort study with a naturalistic population of 957 patients for whom routine therapeutic drug monitoring (TDM) of citalopram had been requested between 2006 and 2013 was conducted. RESULTS Concomitant drugs inhibiting at least 2 different CYP subtypes involved in the metabolism of citalopram decreased statistically significantly the total clearance (Clt). Compared to younger patients over 64-year-old patients had on average a 4.5 times higher risk rate of supra-therapeutic plasma concentrations. However, binary logistic regression showed that age, sex and co-medication accounted only for 26% of the inter-individual variability of citalopram plasma concentrations. DISCUSSION Due to pharmacokinetic interactions, citalopram plasma concentrations are often higher than expected with a given dose. Especially in geriatric and often multimorbid patients who are usually prescribed high numbers of concomitant drugs and are at higher risk for adverse drug reactions (ADR), restriction of the maximal dose of citalopram is not sufficient to prevent supra-therapeutic plasma concentrations.
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Affiliation(s)
- K Wenzel-Seifert
- Department of Psychiatry and Psychotherapy, Clinical Psychopharmacology, University of Regensburg, Regensburg, Germany
| | - R Brandl
- Department of Psychiatry and Psychotherapy, Clinical Psychopharmacology, University of Regensburg, Regensburg, Germany
| | - C Hiemke
- Department of Psychiatry and Psychotherapy, University Medical Center Mainz, Mainz, Germany
| | - E Haen
- Department of Psychiatry and Psychotherapy, Clinical Psychopharmacology, University of Regensburg, Regensburg, Germany
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Rösner S, Brandl R, Segelbacher G, Lorenc T, Müller J. Noninvasive genetic sampling allows estimation of capercaillie numbers and population structure in the Bohemian Forest. EUR J WILDLIFE RES 2014. [DOI: 10.1007/s10344-014-0848-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Brandl R, Stiegler H. Das diabetische Fußsyndrom – Pathophysiologie, Diagnostik und Therapie. DIABETOL STOFFWECHS 2013. [DOI: 10.1055/s-0033-1356293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- R. Brandl
- Praxis für Gefäßchirurgie und Venenmedizin am Marienplatz, München
| | - H. Stiegler
- Praxis für Gefäßchirurgie und Venenmedizin am Marienplatz, München
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Ng'endo R, Osiemo Z, Brandl R. DNA barcodes for species identification in the hyperdiverse ant genus Pheidole (Formicidae: Myrmicinae). J Insect Sci 2013; 13:27. [PMID: 23902257 PMCID: PMC3735075 DOI: 10.1673/031.013.2701] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/10/2011] [Accepted: 11/03/2012] [Indexed: 06/02/2023]
Abstract
DNA sequencing is increasingly being used to assist in species identification in order to overcome taxonomic impediment. However, few studies attempt to compare the results of these molecular studies with a more traditional species delineation approach based on morphological characters. Mitochondrial DNA Cytochrome oxidase subunit 1 (CO1) gene was sequenced, measuring 636 base pairs, from 47 ants of the genus Pheidole (Formicidae: Myrmicinae) collected in the Brazilian Atlantic Forest to test whether the morphology-based assignment of individuals into species is supported by DNA-based species delimitation. Twenty morphospecies were identified, whereas the barcoding analysis identified 19 Molecular Operational Taxonomic Units (MOTUs). Fifteen out of the 19 DNA-based clusters allocated, using sequence divergence thresholds of 2% and 3%, matched with morphospecies. Both thresholds yielded the same number of MOTUs. Only one MOTU was successfully identified to species level using the CO1 sequences of Pheidole species already in the Genbank. The average pairwise sequence divergence for all 47 sequences was 19%, ranging between 0-25%. In some cases, however, morphology and molecular based methods differed in their assignment of individuals to morphospecies or MOTUs. The occurrence of distinct mitochondrial lineages within morphological species highlights groups for further detailed genetic and morphological studies, and therefore a pluralistic approach using several methods to understand the taxonomy of difficult lineages is advocated.
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Affiliation(s)
- R.N. Ng'endo
- Department of Ecology, Animal Ecology Faculty of Biology Philipps-Universitaet Marburg, Karl-von-Frisch-Strasse 8 D-35032 Marburg, Germany
| | - Z.B. Osiemo
- Department of Zoology Faculty of Science Jomo Kenyatta University of Agriculture and Technology P.O BOX 62000-00200 Nairobi, Kenya
| | - R. Brandl
- Department of Ecology, Animal Ecology Faculty of Biology Philipps-Universitaet Marburg, Karl-von-Frisch-Strasse 8 D-35032 Marburg, Germany
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Stiegler H, Hosie S, Burdach S, Hahn H, Saleh A, Brandl R, Lauen J. [Congenital vascular malformations]. MMW Fortschr Med 2012; 154:51-56. [PMID: 23156876 DOI: 10.1007/s15006-012-1280-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Affiliation(s)
- Hubert Stiegler
- Klinik für Angiologie, Stadtisches Klinikum München, Klinikum München-Schwabing.
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Brandl R, Köber R, Jahner T, Outlaw EM, Wenzel-Seifert K, Wittmann K, Haen E. Enzyme assay to study the metabolism of quetiapine and the influence of psychotropic comedication on the concentration of quetiapine. Pharmacopsychiatry 2012. [DOI: 10.1055/s-0032-1326748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Bampalis VG, Dwivedi S, Shai E, Brandl R, Varon D, Siess W. Effect of 5-HT2A receptor antagonists on human platelet activation in blood exposed to physiologic stimuli and atherosclerotic plaque. J Thromb Haemost 2011; 9:2112-5. [PMID: 21848639 DOI: 10.1111/j.1538-7836.2011.04476.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Haen E, Köstlbacher A, Bader W, Greiner C, Hader A, Köber R, Wenzel-Seifert K, Wittmann M, Dörfelt A, Melchner D, Outlaw E, Brandl R. The dose-related reference range – a new tool for therapeutic drug monitoring (TDM). Pharmacopsychiatry 2011. [DOI: 10.1055/s-0031-1292489] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Brandl R, Köber R, Jahner T, Dörfelt A, Haen E. Enzyme assay to study the influence of citalopram on the concentration of psychotropic comedication. Pharmacopsychiatry 2011. [DOI: 10.1055/s-0031-1292291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Brandl R, Koeber R, Jahner T, Outlaw E, Wittmann M, Haen E. Enzyme assay to study the metabolism of quetiapine and the influence of psychotropic comedication on the concentration of quetiapine. Pharmacopsychiatry 2011. [DOI: 10.1055/s-0031-1292451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Vierling KT, Bässler C, Brandl R, Vierling LA, Weiss I, Müller J. Spinning a laser web: predicting spider distributions using LiDAR. Ecol Appl 2011; 21:577-588. [PMID: 21563587 DOI: 10.1890/09-2155.1] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
LiDAR remote sensing has been used to examine relationships between vertebrate diversity and environmental characteristics, but its application to invertebrates has been limited. Our objectives were to determine whether LiDAR-derived variables could be used to accurately describe single-species distributions and community characteristics of spiders in remote forested and mountainous terrain. We collected over 5300 spiders across multiple transects in the Bavarian National Park (Germany) using pitfall traps. We examined spider community characteristics (species richness, the Shannon index, the Simpson index, community composition, mean body size, and abundance) and single-species distribution and abundance with LiDAR variables and ground-based measurements. We used the R2 and partial R2 provided by variance partitioning to evaluate the predictive power of LiDAR-derived variables compared to ground measurements for each of the community characteristics. The total adjusted R2 for species richness, the Shannon index, community species composition, and body size had a range of 25-57%. LiDAR variables and ground measurements both contributed >80% to the total predictive power. For species composition, the explained variance was approximately 32%, which was significantly greater than expected by chance. The predictive power of LiDAR-derived variables was comparable or superior to that of the ground-based variables for examinations of single-species distributions, and it explained up to 55% of the variance. The predictability of species distributions was higher for species that had strong associations with shade in open-forest habitats, and this niche position has been well documented across the European continent for spider species. The similar statistical performance between LiDAR and ground-based measures at our field sites indicated that deriving spider community and species distribution information using LiDAR data can provide not only high predictive power at relatively low cost, but may also allow unprecedented mapping of community- and species-level spider information at scales ranging from stands to landscapes. Therefore, LiDAR is a viable tool to assist species-specific conservation as well as broader biodiversity planning efforts not only for a growing list of vertebrates, but for invertebrates as well.
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Affiliation(s)
- K T Vierling
- Department of Fish and Wildlife Resources, University of Idaho, Box 441136, Moscow, Idaho 83844-1136, USA.
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Khandoga AL, Pandey D, Welsch U, Brandl R, Siess W. GPR92/LPA₅ lysophosphatidate receptor mediates megakaryocytic cell shape change induced by human atherosclerotic plaques. Cardiovasc Res 2010; 90:157-64. [PMID: 21106562 PMCID: PMC3058733 DOI: 10.1093/cvr/cvq369] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Aims Oxidative processes and vascular inflammation underlying atherosclerosis lead to an accumulation of lysophosphatidic acid (LPA) molecules in the atheromatous intima. LPA, a platelet-activating component of human atherosclerotic plaques, possibly contributes to atherothrombus formation after plaque rupture. Human platelets express mRNA for the G protein-coupled receptors LPA1–7 that derive from megakaryocytes. The aim of our study was to identify the functional LPA receptor(s) in human platelets by silencing individual LPA receptors in megakaryocytic (MK) cells. Methods and results We studied shape change of two human MK cell lines (Meg-01, Dami) by turbidometry, phase-contrast and scanning electron microscopy. They showed upon LPA stimulation a rapid, Rho-kinase-mediated shape change similar to that of human platelets. By qRT–PCR analysis we found expression of LPA1–7 in both cell lines; LPA4 and LPA5 were the most abundant receptor transcripts. In both Meg-01 and Dami cells, the rank order of activation by LPA species was similar to that found in platelets: alkyl-LPA 18:1 > alkyl-LPA 16:0 > acyl-LPA 18:1 >> alkyl-LPA 18:0. Knock-down of individual LPA receptors by siRNA showed that LPA-mediated activation of MK cells was mediated by LPA5, but not by LPA1–4,6,7. Importantly, we found that human atherosclerotic plaque and lipid-rich core induced shape change of Dami cells, and that this effect was inhibited after LPA5 silencing. Conclusions Our findings indicate that LPA5 mediates LPA-induced shape change of MK cells and support its involvement in atherosclerotic plaque and lipid-rich core-mediated platelet activation. This receptor could be an attractive novel target for antithrombotic therapy.
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Affiliation(s)
- Anna L Khandoga
- Institute for Prevention of Cardiovascular Diseases, University of Munich, Munich, Germany
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Demetz G, Seitz I, Stein A, Steppich B, Groha P, Brandl R, Schömig A, Ott I. Tissue Factor-Factor VIIa complex induces cytokine expression in coronary artery smooth muscle cells. Atherosclerosis 2010; 212:466-71. [PMID: 20708733 DOI: 10.1016/j.atherosclerosis.2010.07.017] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Revised: 06/26/2010] [Accepted: 07/15/2010] [Indexed: 10/19/2022]
Abstract
OBJECTIVE Within atherosclerotic lesions Tissue Factor (TF)-Factor VIIa (FVIIa) not only contributes to thrombotic events but also alters vascular remodeling through enhancement of migration. Moreover, the TF-FVIIa-FXa complex activates protease-activated receptors (PAR). TF/FVIIa/PAR-2 signaling has also been shown to promote proliferation and metastasis of tumor cells. Since coagulation factors promote inflammation which plays a major role during atherosclerosis as well as tumor metastasis this study sought to investigate the effects of FVIIa on the inflammatory response in vascular cells. METHODS/RESULTS FVIIa induces interleukin-8 (IL-8) and IL-6 in primary smooth muscle cells (SMC), which was correlated to the expression of TF and PAR-2 as shown by immunoassay and qRT-PCR. The effect was dose-dependent and required TF, the proteolytic activity of FVIIa and PAR-2. Secondary effects of downstream coagulation factors were excluded. No proinflammatory FVIIa effect was observed in endothelial cells (EC) and mononuclear cells (MNC), expressing either TF or PAR-2. In atherosclerotic lesions mRNA expression of PAR-1, PAR-2 and IL-8 was elevated compared to healthy vessels indicating a role for PAR-1 and PAR-2 signaling in atherosclerosis. CONCLUSION In addition to the procoagulant and promigratory role of the TF-FVIIa complex we identify a proinflammatory role of FVIIa in human SMC dependent on expression of TF and PAR-2 that provides yet another link between coagulation and inflammation.
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Affiliation(s)
- G Demetz
- Deutsches Herzzentrum und 1. Medizinische Klinik, Technische Universität München, Lazarettstr. 36, 80636 Munich, Germany
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Reininger AJ, Bernlochner I, Penz SM, Ravanat C, Smethurst P, Farndale RW, Gachet C, Brandl R, Siess W. A 2-Step Mechanism of Arterial Thrombus Formation Induced by Human Atherosclerotic Plaques. J Am Coll Cardiol 2010; 55:1147-58. [DOI: 10.1016/j.jacc.2009.11.051] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2009] [Revised: 11/09/2009] [Accepted: 11/18/2009] [Indexed: 11/16/2022]
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Hänfling B, Dümpelmann C, Bogutskaya NG, Brandl R, Brändle M. Shallow phylogeographic structuring of Vimba vimba across Europe suggests two distinct refugia during the last glaciation. J Fish Biol 2009; 75:2269-2286. [PMID: 20738686 DOI: 10.1111/j.1095-8649.2009.02415.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Genetic variation and geographical structuring of vimba Vimba vimba were analysed across 26 sites (80 individuals) by means of mtDNA sequences (cyt b gene, mitochondrial control region) to localize hypothesized glacial refugia and to reconstruct postglacial recoloniation routes. Although genetic diversity among sequenced individuals was low, a combined analysis of the two sequenced fragments revealed a western (central and northern Europe: Danube, Elbe and lakes of Sweden) and an eastern clade (eastern Europe: Dnieper-South Bug, Don, Neman). Furthermore, a number of divergent ancestral haplotypes distributed around the Black and Caspian Seas became apparent. Mismatch analyses supported a sudden expansion model for the populations of the western clade between 50 and 10 000 bp. Overall, the study provides strong evidence for a northward and westward expansion of V. vimba from two refugial regions located in the Danubian drainage and the northern Pontic regions respectively.
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Affiliation(s)
- B Hänfling
- Department of Biological Sciences, University of Hull, Cottingham Road, Hull HU6 7RX, UK
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Affiliation(s)
- H Stiegler
- Klinik für Angiologie, Klinikum München Schwabing, Kölner Platz 1, 80804 München
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Brandl R, Stiegler H. Therapieresistente Wunden der unteren Extremität. DIABETOL STOFFWECHS 2008. [DOI: 10.1055/s-0028-1098743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Stein A, Montens HP, Steppich B, Busch G, Brandl R, Ott I. Circulating endothelial progenitor cells decrease in patients after endarterectomy. J Vasc Surg 2008; 48:1217-22. [DOI: 10.1016/j.jvs.2008.06.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2008] [Revised: 05/30/2008] [Accepted: 06/04/2008] [Indexed: 10/21/2022]
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Stiegler H, Brandl R. [The acute extremity pain]. MMW Fortschr Med 2008; 150:30-33. [PMID: 18575366 DOI: 10.1007/bf03365492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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Schulz C, Penz S, Hoffmann C, Langer H, Gillitzer A, Schneider S, Brandl R, Seidl S, Massberg S, Pichler B, Kremmer E, Stellos K, Schönberger T, Siess W, Gawaz M. Platelet GPVI binds to collagenous structures in the core region of human atheromatous plaque and is critical for atheroprogression in vivo. Basic Res Cardiol 2008; 103:356-67. [DOI: 10.1007/s00395-008-0722-3] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2008] [Accepted: 02/25/2008] [Indexed: 12/27/2022]
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Meyer J, Raudnitschka D, Steinhauser J, Jeltsch F, Brandl R. Biology and ecology of Thallomys nigricauda (Rodentia, Muridae) in the Thornveld savannah of South Africa. Mamm Biol 2008. [DOI: 10.1016/j.mambio.2006.11.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Brandl R, Hyodo F, Korff-Schmising MV, Maekawa K, Miura T, Takematsu Y, Matsumoto T, Abe T, Bagine R, Kaib M. Divergence times in the termite genus Macrotermes (Isoptera: Termitidae). Mol Phylogenet Evol 2007; 45:239-50. [PMID: 17714956 DOI: 10.1016/j.ympev.2007.07.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2006] [Revised: 07/10/2007] [Accepted: 07/10/2007] [Indexed: 11/19/2022]
Abstract
The evolution of fungus-growing termites is supposed to have started in the African rain forests with multiple invasions of semi-arid habitats as well as multiple invasions of the Oriental region. We used sequences of the mitochondrial COII gene and Bayesian dating to investigate the time frame of the evolution of Macrotermes, an important genus of fungus-growing termites. We found that the genus Macrotermes consists of at least 6 distantly related clades. Furthermore, the COII sequences suggested some cryptic diversity within the analysed African Macrotermes species. The dates calculated with the COII data using a fossilized termite mound to calibrate the clock were in good agreement with dates calculated with COI sequences using the split between Locusta and Chortippus as calibration point which supports the consistency of the calibration points. The clades from the Oriental region dated back to the early Tertiary. These estimates of divergence times suggested that Macrotermes invaded Asia during periods with humid climates. For Africa, many speciation events predated the Pleistocene and fall in range of 6-23 million years ago. These estimates suggest that savannah-adapted African clades radiated with the spread of the semi-arid ecosystems during the Miocene. Apparently, events during the Pleistocene were of little importance for speciation within the genus Macrotermes. However, further investigations are necessary to increase the number of taxa for phylogenetic analysis.
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Affiliation(s)
- R Brandl
- Department of Animal Ecology, University of Marburg, Karl-von-Frisch-Strasse, D-35032 Marburg, Germany.
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Penz S, Reininger A, Tóth O, Deckmyn H, Brandl R, Siess W. EFFECT OF ANTI-PLATELET DRUGS ON PLATELET AGGREGATION AND THROMBUS FORMATION INDUCED BY HUMAN ATHEROSCLEROTIC PLAQUES. J Thromb Haemost 2007. [DOI: 10.1111/j.1538-7836.2007.tb01051.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Brandl R, Stiegler H. [Therapy-resistant sores of the lower extremities]. Dtsch Med Wochenschr 2007; 132:1103-16; quiz 1117-20. [PMID: 17492570 DOI: 10.1055/s-2007-979387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- R Brandl
- Klinik für Gefässchirurgie, Gefässzentrum des Klinikums München-Schwabing.
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45
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Penz SM, Reininger AJ, Toth O, Deckmyn H, Brandl R, Siess W. Glycoprotein Ibalpha inhibition and ADP receptor antagonists, but not aspirin, reduce platelet thrombus formation in flowing blood exposed to atherosclerotic plaques. Thromb Haemost 2007; 97:435-43. [PMID: 17334511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Anti-platelet drugs are used to prevent intra-arterial thrombus formation after rupture of atherosclerotic plaques. Until now, the inhibitory effect of present and future anti-platelet drugs such as aspirin, ADP receptor P2Y(1)/P2Y(12) antagonists and glycoprotein (GP) Ibalpha inhibitors on the interaction of platelets with human plaques is not known. To study those effects we obtained human atherosclerotic plaques by surgical endarterectomy. Plaques induced maximal platelet aggregation in hirudinized platelet-rich plasma (PRP) and blood that was effectively inhibited by aspirin, the P2Y(1) antagonist MRS2179 and the P2Y(12) antagonist AR-C69931MX, but not by GPIbalpha blockade with the mAB 6B4. Inhibition of platelet aggregation by MRS2179 was 74 +/- 37% and 68 +/- 20%, by AR-C69931MX 94 +/- 7% and 80 +/- 6%, and by aspirin 88 +/- 19% and 64 +/- 28%, in PRP and blood, respectively (mean +/- SD; n = 6-12 with plaques from 6 patients). The combination of both ADP receptor antagonists completely inhibited plaque-induced platelet aggregation in hirudinized PRP and blood. Under arterial flow conditions (1,500s(-1)), blockade of platelet GPIbalpha resulted in a strong decrease of plaque-stimulated platelet adhesion/aggregate formation of 77 +/- 5% (mean +/- SD; n = 4). Furthermore, MRS2179, AR-C69931MX and their combination reduced plaque-dependent platelet aggregate formation by 35 +/- 14%, 32 +/- 13% and 58 +/- 12% (mean +/- SD; n = 5), respectively. Aspirin was without significant effect. In conclusion, a GPIbalpha-blocking antibody, as well as P2Y(1) and P2Y(12) receptor antagonists, alone or in combination, reduce in contrast to aspirin human plaque-induced platelet thrombus formation under arterial flow. Although these new anti-platelet agents inhibit platelet thrombus formation after plaque rupture, more efficient platelet blockers are required.
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Affiliation(s)
- Sandra M Penz
- Institute for Prevention of Cardiovascular Diseases, University of Munich, Munich, Germany
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Seitz I, Hess S, Schulz H, Eckl R, Busch G, Montens HP, Brandl R, Seidl S, Schömig A, Ott I. Membrane-type serine protease-1/matriptase induces interleukin-6 and -8 in endothelial cells by activation of protease-activated receptor-2: potential implications in atherosclerosis. Arterioscler Thromb Vasc Biol 2007; 27:769-75. [PMID: 17255532 DOI: 10.1161/01.atv.0000258862.61067.14] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE The serine protease MT-SP1/matriptase plays an important role in cell migration and matrix degradation. Hepatocyte growth factor (HGF), urokinase-type plasminogen activator (uPA), and protease-activated receptor 2 (PAR-2) have been identified as in vitro substrates of MT-SP1/matriptase. Because PAR-2 is expressed in endothelial cells and contributes to inflammatory processes, we sought to investigate the effects of MT-SP1/matriptase on endothelial cytokine expression and analyzed MT-SP1/matriptase expression in vascular cells and atherosclerotic lesions. METHODS AND RESULTS In endothelial cells, recombinant MT-SP1/matriptase dose-dependently induced interleukin (IL)-8 and IL-6 mRNA and protein expression dependent on its proteolytic activity. MT-SP1/matriptase time-dependently induced phosphorylation of p38 MAPK and p42/44 MAPK. Inhibitor experiments revealed that p38 MAPK and PKCalpha were necessary for IL-8 induction. PAR-2 downregulation abolished and PAR-2 overexpression augmented MT-SP1/matriptase-induced IL-8 expression as evidence for PAR-2 signaling. In human atherectomies, MT-SP1/matriptase was expressed in blood cells adherent to the endothelium. Concordantly, basal MT-SP1/matriptase expression was detected in isolated monocytes. Coincubation of monocytes and endothelial cells resulted in an increased IL-8 release, which was reduced after downregulation of endothelial PAR-2 and monocytic MT-SP1/matriptase. CONCLUSION MT-SP1/matriptase induces release of proinflammatory cytokines in endothelial cells through activation of PAR-2. MT-SP1/matriptase is expressed in monocytes, thus, interaction of monocytic MT-SP1/matriptase with endothelial PAR-2 may contribute to atherosclerosis.
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Affiliation(s)
- Isabell Seitz
- Deutsches Herzzentrum und 1. Medizinische Klinik, Technische Universität München, 80636 München, Germany
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Bikou O, Penz S, Pandey D, Brandl R, Siess W. Mo-W10:6 The atherosclerotic plaque components lysophosphatidic acid and collagen synergistically activate platelets. ATHEROSCLEROSIS SUPP 2006. [DOI: 10.1016/s1567-5688(06)80087-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Weinmeister P, Lukowski R, Linder S, Erl W, Brandl R, Feil S, Hofmann F, Feil R. Regulation of vascular smooth muscle growth by cyclic nucleotides and cGMP-dependent protein kinase. BMC Pharmacol 2005. [DOI: 10.1186/1471-2210-5-s1-p62] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Penz S, Reininger AJ, Brandl R, Goyal P, Rabie T, Bernlochner I, Rother E, Goetz C, Engelmann B, Smethurst PA, Ouwehand WH, Farndale R, Nieswandt B, Siess W. Human atheromatous plaques stimulate thrombus formation by activating platelet glycoprotein VI. FASEB J 2005; 19:898-909. [PMID: 15923400 DOI: 10.1096/fj.04-2748com] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Lipid-rich atherosclerotic plaques are vulnerable, and their rupture can cause the formation of a platelet- and fibrin-rich thrombus leading to myocardial infarction and ischemic stroke. Although the role of plaque-based tissue factor as stimulator of blood coagulation has been recognized, it is not known whether plaques can cause thrombus formation through direct activation of platelets. We isolated lipid-rich atheromatous plaques from 60 patients with carotid stenosis and identified morphologically diverse collagen type I- and type III-positive structures in the plaques that directly stimulated adhesion, dense granule secretion, and aggregation of platelets in buffer, plasma, and blood. This material also elicited platelet-monocyte aggregation and platelet-dependent blood coagulation. Plaques exposed to flowing blood at arterial wall shear rate induced platelets to adhere to and spread on the collagenous structures, triggering subsequent thrombus formation. Plaque-induced platelet thrombus formation was observed in fully anticoagulated blood (i.e., in the absence of tissue factor-mediated coagulation). Mice platelets lacking glycoprotein VI (GPVI) were unable to adhere to atheromatous plaque or form thrombi. Human platelet thrombus formation onto plaques in flowing blood was completely blocked by GPVI inhibition with the antibody 10B12 but not affected by integrin alpha2beta1 inhibition with 6F1 mAb. Moreover, the initial platelet response, shape change, induced by plaque was blocked by GPVI inhibition but not with alpha2beta1 antagonists (6F1 mAb or GFOGER-GPP peptide). Pretreatment of plaques with collagenase or anti-collagen type I and anti-collagen type III antibodies abolished plaque-induced platelet activation. Our results indicate that morphologically diverse collagen type I- and collagen type III-containing structures in lipid-rich atherosclerotic plaques stimulate thrombus formation by activating platelet GPVI. This platelet collagen receptor, essential for plaque-induced thrombus formation, presents a promising new anti-thrombotic target for the prevention of ischemic cardiovascular diseases.
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Affiliation(s)
- Sandra Penz
- Institute for Prevention of Cardiovascular Diseases, University of Munich, Munich, Germany
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Abstract
Relatedness increases the likelihood of cooperation within colonies of social insects. Polygyny, the coexistence of numerous reproductive females (queens) in a colony, is common in mature colonies of the termite Macrotermes michaelseni. In this species, polygyny results from pleometrosis and from several female alates that jointly found a new colony. To explain this phenomenon, it was suggested that only related females cooperate and survive during maturation of colonies. Using multilocus fingerprints as well as microsatellites, we showed that nestmate queens in mature colonies are unrelated. Furthermore, we found that all nestmate queens contributed to the production of steriles. Even in mature colonies, several matrilines of steriles coexist within a colony. Although genetic diversity within colonies may increase the likelihood of conflicts, high genetic diversity may be important for foraging, colony growth, and resistance to disease and parasites.
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Affiliation(s)
- M Hacker
- Department of Animal Physiology, University of Bayreuth, 95440 Bayreuth, Germany
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