German Centre for Cardiovascular Research (DZHK) 13 articles published in JoVE Medicine Implantation of Combined Telemetric ECG and Blood Pressure Transmitters to Determine Spontaneous Baroreflex Sensitivity in Conscious Mice René D. Rötzer1, Verena F. Brox1, Konstantin Hennis1, Stefan B. Thalhammer1, Martin Biel1,2, Christian Wahl-Schott3, Stefanie Fenske1,2 1Center for Integrated Protein Science (CIPS-M) and Center for Drug Research, Department of Pharmacy, Ludwig-Maximilians-Universität München, 2German Center for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, 3Hannover Medical School, Institute for Neurophysiology The baroreflex is a heart-rate regulation mechanism by the autonomic nervous system in response to blood-pressure changes. We describe a surgical technique to implant telemetry transmitters for continuous and simultaneous measurement of electrocardiogram and blood pressure in mice. This can determine spontaneous baroreflex sensitivity, an important prognostic marker for cardiovascular disease. Medicine Implantation of hiPSC-derived Cardiac-muscle Patches after Myocardial Injury in a Guinea Pig Model Liesa Castro1,2, Birgit Geertz3, Marina Reinsch2,3, Bülent Aksehirlioglu3, Arne Hansen2,3, Thomas Eschenhagen2,3, Hermann Reichenspurner1,2, Florian Weinberger*2,3, Simon Pecha*1,2 1Department of Cardiovascular Surgery, University Heart Center Hamburg, 2partner site Hamburg/Kiel/Lübeck, German Centre for Cardiovascular Research (DZHK), 3Department of Experimental Pharmacology and Toxicology, Cardiovascular ResearchCenter, University Medical Center Hamburg-Eppendorf Here we present a protocol for the induction of left ventricular cryoinjury followed by the implantation of a cardiac muscle patch, derived from human iPS-cell cardiomyocytes in a guinea pig model. Behavior Visualization of Intensity Levels to Reduce the Gap Between Self-Reported and Directly Measured Physical Activity Lisa Voigt1,4, Antje Ullrich1,4, Ulrike Siewert-Markus1,2,4, Marcus Dörr3,4, Ulrich John1,4, Sabina Ulbricht1,4 1Institute of Social Medicine and Prevention, University Medicine Greifswald, 2Institute for Medical Psychology, University Medicine Greifswald, 3Department of Internal Medicine B, University Medicine Greifswald, 4partner site Greifswald, DZHK (German Centre for Cardiovascular Research) This protocol describes a randomized controlled trial as a method to test the effect of a video demonstration on the intra-individual difference between self-reported and accelerometer-based moderate-to-vigorous physical activity. Biochemistry Identification of Functional Protein Regions Through Chimeric Protein Construction Juan M. Adrian-Segarra1, Holger Lörchner1,2, Thomas Braun1,2, Jochen Pöling1,2 1Department of Cardiac Development and Remodelling, Max Planck Institute for Heart and Lung Research, 2Partner site Rhein-Main, German Centre for Cardiovascular Research (DZHK) Structurally related proteins frequently exert distinct biological functions. The exchange of equivalent regions of these proteins in order to create chimeric proteins constitutes an innovative approach to identify critical protein regions that are responsible for their functional divergence. Biology Subtype-specific Optical Action Potential Recordings in Human Induced Pluripotent Stem Cell-derived Ventricular Cardiomyocytes Alexander Goedel*1,2, Dorota M. Zawada*1, Fangfang Zhang1, Zhifen Chen3, Alessandra Moretti1,2, Daniel Sinnecker1,2 1Medical Department I, University Hospital Klinikum rechts der Isar, Technical University of Munich, 2German Centre for Cardiovascular Research (DZHK), Munich Heart Alliance, 3Beth Israel Deaconess Medical Center, Harvard Medical School Here we present a method to optically image action potentials, specifically in ventricular-like induced pluripotent stem cell-derived cardiomyocytes. The method is based on the promoter-driven expression of a voltage-sensitive fluorescent protein. Medicine Isolation of Atrial Cardiomyocytes from a Rat Model of Metabolic Syndrome-related Heart Failure with Preserved Ejection Fraction David Bode1,2, Tim Guthof1, Burkert M. Pieske1,2, Frank R. Heinzel1,2, Felix Hohendanner1,2 1Department of Internal Medicine and Cardiology, Charité University Medicine, 2German Center for Cardiovascular Research (DZHK) Here, we describe an optimized, Langendorff-based procedure for the isolation of single-cell atrial cardiomyocytes from a rat model of metabolic syndrome-related heart failure with preserved ejection fraction. A manual regulation of intraluminal pressure of cardiac cavities is implemented to yield functionally intact myocytes suitable for excitation-contraction-coupling studies. Medicine Impact of Intracardiac Neurons on Cardiac Electrophysiology and Arrhythmogenesis in an Ex Vivo Langendorff System Christiane Jungen1,2, Katharina Scherschel1,2, Nadja I. Bork2,3, Pawel Kuklik1, Christian Eickholt1, Helge Kniep1, Niklas Klatt1,2, Stephan Willems1,2, Viacheslav O. Nikolaev2,3, Christian Meyer1,2 1Department of Cardiology-Electrophysiology, cNEP (cardiac Neuro- and Electrophysiology research group), University Heart Center, University Hospital Hamburg-Eppendorf, 2DZHK (German Center for Cardiovascular Research), 3Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf Here, we present a protocol for the modulation of the intracardiac autonomic nervous system and the assessment of its influence on basic electrophysiology, arrhythmogenesis, and cAMP dynamics using an ex vivo Langendorff setup. Medicine Balloon-based Injury to Induce Myointimal Hyperplasia in the Mouse Abdominal Aorta Grigol Tediashvili1,2,3, Dong Wang1,2,3,4, Hermann Reichenspurner4, Tobias Deuse1,2,3,4, Sonja Schrepfer1,2,3,4 1Transplant and Stem Cell Immunobiology Lab, University Heart Center, 2Department of Surgery, Transplant and Stem Cell Immunobiology Lab, University of California San Francisco (UCSF), 3Cardiovascular Research Center (CVRC) and DZHK German Center for Cardiovascular Research, 4Cardiovascular Surgery, University Heart Center This article demonstrates a murine model to study the development of myointimal hyperplasia (MH) after aortic balloon injury. Immunology and Infection Visualizing Leukocyte Rolling and Adhesion in Angiotensin II-Infused Mice: Techniques and Pitfalls Jeremy Lagrange1, Sabine Kossmann1,2, Klytaimnistra Kiouptsi1, Philip Wenzel1,2,3 1Center for Thrombosis and Hemostasis Mainz, University Medical Center Mainz, 2Center for Cardiology, University Medical Center Mainz, 3German Center for Cardiovascular Research (DZHK) This manuscript describes the use of transgenic reporter mice and different administration routes of fluorescent dyes in angiotensin II-induced hypertension using intravital video microscopy of blood vessels to evaluate the activation of immune cells and their ability to roll and adhere to the endothelium. Developmental Biology Processing of Human Cardiac Tissue Toward Extracellular Matrix Self-assembling Hydrogel for In Vitro and In Vivo Applications Matthias Becker1,2, Janita A. Maring1,2, Barbara Oberwallner2, Benjamin Kappler2, Oliver Klein1,2, Volkmar Falk2,3,4,5, Christof Stamm2,3,4 1Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 2Berlin-Brandenburg Center for Regenerative Therapies (BCRT), 3German Center for Cardiovascular Research (DZHK), 4Deutsches Herzzentrum Berlin (DHZB), 5Department of Cardiovascular Surgery, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health This protocol describes the complete decellularization of human myocardium while preserving its extracellular matrix components. Further processing of the extracellular matrix results in the production of microparticles and a cytoprotective self-assembling hydrogel. Bioengineering Automated Contraction Analysis of Human Engineered Heart Tissue for Cardiac Drug Safety Screening Ingra Mannhardt1, Umber Saleem1, Anika Benzin1, Thomas Schulze1, Birgit Klampe1, Thomas Eschenhagen1, Arne Hansen1 1Department of Experimental Pharmacology and Toxicology, Cardiovascular Research Center, University Medical Center Hamburg-Eppendorf and DZHK (German Center for Cardiovascular Research) Here, we show the generation of human engineered heart tissue from induced pluripotent stem cells (hiPSC)-derived cardiomyocytes. We present a method to analyze contraction force and exemplary alteration of contraction pattern by the hERG channel inhibitor E-4031. This method shows high level of robustness and suitability for cardiac drug screening. Medicine Vein Interposition Model: A Suitable Model to Study Bypass Graft Patency Dong Wang1,2,3,4, Grigol Tediashvili1,2,3, Simon Pecha4, Hermann Reichenspurner4, Tobias Deuse1,2,3,4, Sonja Schrepfer1,2,3,4 1Transplant and Stem Cell Immunobiology Lab, University Heart Center Hamburg, 2Department of Surgery, Transplant and Stem Cell Immunobiology Lab, University of California San Francisco (UCSF), 3Cardiovascular Research Center (CVRC) and DZHK German Center for Cardiovascular Research), partner site Hamburg/Kiel/Luebeck, 4Cardiovascular Surgery, University Heart Center Hamburg This video demonstrates a model to study the development of myointimal hyperplasia after venous interposition surgery in rats. Bioengineering Analysis of Tubular Membrane Networks in Cardiac Myocytes from Atria and Ventricles Eva Wagner*1,2,3, Sören Brandenburg*1,2, Tobias Kohl1,2, Stephan E. Lehnart1,2,3,4 1Heart Research Center Goettingen, 2Clinic of Cardiology & Pulmonology, University Medical Center Goettingen, 3German Center for Cardiovascular Research (DZHK) partner site Goettingen, 4BioMET, Center for Biomedical Engineering & Technology, University of Maryland School of Medicine In cardiac myocytes, tubular membrane structures form intracellular networks. We describe optimized protocols for i) isolation of myocytes from mouse heart including quality control, ii) live cell staining for state-of-the-art fluorescence microscopy, and iii) direct image analysis to quantify the component complexity and the plasticity of intracellular membrane networks.