University of Fribourg

18 articles published in JoVE

• Bioengineering

  
  Cultivating a Three-dimensional Reconstructed Human Epidermis at a Large Scale Irini M. Dijkhoff¹, Benedetta Petracca^1,2, Roxane Prieux³, Giuseppe Valacchi^3,4, Barbara Rothen-Rutishauser¹, Marc Eeman^{2 1}Adolphe Merkle Institute, University of Fribourg, ²Dow Silicones Belgium SRL, ³Department of Biomedical and Specialist Surgical Sciences, University of Ferrara, ⁴Department of Animal Sciences, Plants for Human Health Institute, North Carolina State University This protocol describes a straightforward method to cultivate three-dimensional reconstituted human epidermis in a reproducible and robust manner. Additionally, it characterizes the structure-function relationship of the epidermal barrier model. The biological responses of the reconstituted human epidermis upon proinflammatory stimuli are also presented.

• Biology

  
  Multicellular Human Alveolar Model Composed of Epithelial Cells and Primary Immune Cells for Hazard Assessment Hana Barosova*¹, Barbara Drasler*¹, Alke Petri-Fink¹, Barbara Rothen-Rutishauser^{1 1}Adolphe Merkle Institute, University of Fribourg Presented here is a protocol for primary human blood monocyte isolation as well as their differentiation into macrophages and dendritic cells and assembly with epithelial cells into a multicellular human lung model. Biological responses of cocultures composed of immune cells differentiated from either freshly isolated or thawed monocytes, upon exposure to proinflammatory stimuli, are compared.

• Biology

  
  Intrathoracic Injection for the Study of Adult Zebrafish Heart Thomas Bise¹, Anna Jaźwińska^{1 1}Department of Biology, University of Fribourg This method relies on the injection of 0.5−3 μL of solution into the thorax of adult zebrafish. The procedure efficiently delivers proteins and chemical compounds into the proximity of the zebrafish heart without damaging the organ. The approach is suitable for testing effects of exogenous factors on various tissues of the heart.

• Immunology and Infection

  
  Evaluation of Extracellular Vesicle Function During Malaria Infection María Andrea Hernández-Castañeda*¹, Smart Mbagwu*¹, Kehinde Adebayo Babatunde*¹, Michael Walch¹, Luis Filgueira¹, Pierre-Yves Mantel^{1 1}Department of Medicine, University of Fribourg In this work, we describe protocols to investigate the role of extracellular vesicles (EVs) released by Plasmodium falciparum infected erythrocytes. In particular, we focus on the interactions of EVs with endothelial cells.

• Medicine

  
  The Rabbit Model of Accelerated Atherosclerosis: A Methodological Perspective of the Iliac Artery Balloon Injury Manish Jain*¹, Aurélien Frobert*¹, Jérémy Valentin¹, Stéphane Cook¹, Marie-Noëlle Giraud^{1 1}Cardiology, Department of Medicine, University of Fribourg Animal models of atherosclerosis are essential to understand the mechanism and to investigate newer approaches to prevent plaque development or rupture, a leading cause of death in the industrialized world. This protocol uses a combination of balloon injury and cholesterol rich diet to induce atherosclerotic plaques in rabbit iliac artery.

• Behavior

  
  Intracortical Inhibition Within the Primary Motor Cortex Can Be Modulated by Changing the Focus of Attention Yves-Alain Kuhn¹, Martin Keller¹, Jan Ruffieux¹, Wolfgang Taube^{1 1}Department of Medicine, Movement and Sport Sciences, University of Fribourg Using two different transcranial magnetic stimulation (TMS) protocols, this manuscript describes how to measure and compare cortical inhibition within the primary motor cortex when adopting different attentional foci.

• Neuroscience

  
  Non-invasive Assessment of Changes in Corticomotoneuronal Transmission in Humans Wolfgang Taube¹, Christian Leukel^1,2, Jens Bo Nielsen^3,4, Jesper Lundbye-Jensen^{3,4 1}Department of Medicine, Movement and Sport Science, University of Fribourg (Switzerland), ²Department of Sport Science, University of Freiburg (Germany), ³Department of Neuroscience and Pharmacology, University of Copenhagen, ⁴Department of Nutrition, Exercise and Sports, University of Copenhagen The aim of the present study was to assess changes in transmission at the corticomotoneuronal synapses in humans after repetitive transcranial magnetic stimulation. For this purpose, an electrophysiological method is introduced that allows assessment of pathway specific corticospinal transmission, i.e. differentiation of fast, direct corticospinal pathways from polysynaptic connections.

• Medicine

  
  Histological Quantification of Chronic Myocardial Infarct in Rats Jérémy Valentin¹, Aurélien Frobert¹, Guillaume Ajalbert¹, Stéphane Cook¹, Marie-Noëlle Giraud^{1 1}Cardiology, Department of Medicine, University of Fribourg The post-mortem assessment of myocardial infarction (MI) in rodents is based on quantification of the infarct on stained heart sections. We describe an accurate method to quantify the infarct size using systematic sampling of harvested rat hearts from base to apex and image analyses of trichrome-stained histological sections.

• Behavior

  
  Force and Position Control in Humans - The Role of Augmented Feedback Benedikt Lauber^1,2, Martin Keller², Christian Leukel^1,3, Albert Gollhofer¹, Wolfgang Taube^{2 1}Department of Sport Science, University of Freiburg, ²Department of Medicine, Movement and Sport Science, University of Fribourg, ³Bernsteincenter Freiburg Controlling an identical movement with position or force feedback results in different neural activation and motor behavior. This protocol describes how to investigate behavioral changes by looking at neuromuscular fatigue and how to evaluate motor cortical (inhibitory) activity using subthreshold TMS with respect to the interpretation of augmented feedback.

• Biology

  
  En Face Detection of Nitric Oxide and Superoxide in Endothelial Layer of Intact Arteries Yi Yu^1,2, Yuyan Xiong^1,2, Jean-Pierre Montani^2,3, Zhihong Yang^1,2, Xiu-Fen Ming^{1,2 1}Cardiovascular and Aging Research, Department of Medicine, Division of Physiology, Faculty of Science, University of Fribourg, ²Kidney Control of Homeostasis, Swiss National Centre of Competence in Research, ³System Physiology, Department of Medicine, Division of Physiology, Faculty of Science, University of Fribourg In this article we describe an adapted relatively easy method using the fluorescence dye diaminofluorescein-2 diacetate (DAF-2DA) and dihydroethidium (DHE) for en face simultaneous detection and visualization of intracellular nitric oxide (NO) and superoxide anion (O2^.−) respectively, in freshly isolated intact aortas of an obesity mouse model.

• Behavior

  
  Simple and Computer-assisted Olfactory Testing for Mice Emanuele Brai¹, Lavinia Alberi^{1 1}Unit of Anatomy, Department of Medicine, University of Fribourg We present a simple and unbiased olfactory test in mice. With this protocol olfactory discrimination, preference, avoidance and sensitivity to a novel odor as compared to water can be assessed in single behavioral sessions. This method is indicated for a single experimenter and analysis is based on computer-assisted video processing.

• Biology

  
  A High Yield and Cost-efficient Expression System of Human Granzymes in Mammalian Cells Farokh Dotiwala¹, Isabelle Fellay², Luis Filgueira², Denis Martinvalet³, Judy Lieberman¹, Michael Walch^{2 1} We describe here a cost-efficient granzyme expression system using HEK293T cells that produces high yields of pure, fully glycosylated and enzymatically active protease.

• Biology

  
  Methylnitrosourea (MNU)-induced Retinal Degeneration and Regeneration in the Zebrafish: Histological and Functional Characteristics Ellinor Maurer¹, Markus Tschopp^1,2, Christoph Tappeiner¹, Pauline Sallin³, Anna Jazwinska³, Volker Enzmann^{1 1}Department of Ophthalmology, Inselspital, University of Bern, ²Department of Ophthalmology, University Hospital of Basel, ³Department of Biology, University of Fribourg Herein we demonstrate quantification of retinal de- and regeneration and its impact on visual function using N-methyl-N-nitrosourea in the adult zebrafish. Loss of visual acuity and decreased photoreceptor numbers were followed by proliferation in the inner nuclear layer. Complete morphological and functional regeneration occurred 30 days after the initial treatment.

• Bioengineering

  
  Cell-based Therapy for Heart Failure in Rat: Double Thoracotomy for Myocardial Infarction and Epicardial Implantation of Cells and Biomatrix Aurélien Frobert¹, Jérémy Valentin¹, Stéphane Cook¹, Justine Lopes-Vicente¹, Marie-Noëlle Giraud^{1 1}Cardiology, Department of Medicine, University of Fribourg Implantation of a biograft to treat myocardial infarction induced by LAD ligation in a rodent model has conventionally required two open-heart surgeries. In order to reduce mortality and provide optimal conditions for fixation of solid and gelatinous biomatrices associated with cells, minimally invasive procedures have been developed.

• Neuroscience

  
  Light Preference Assay to Study Innate and Circadian Regulated Photobehavior in Drosophila Larvae Abud J. Farca Luna¹, Alina M. H. J. von Essen¹, Yves F. Widmer¹, Simon G. Sprecher^{1 1}Department of Biology, Institute of Cell and Developmental Biology, University of Fribourg Here we describe a light-dark preference test for Drosophila larva. This assay provides information about innate and circadian regulation of light sensing and processing photobehavior.

• Neuroscience

  
  Appetitive Associative Olfactory Learning in Drosophila Larvae Anthi A. Apostolopoulou¹, Annekathrin Widmann¹, Astrid Rohwedder^1,2, Johanna E. Pfitzenmaier¹, Andreas S. Thum^{1,2 1}Department of Biology, University of Konstanz, ²Department of Biology, University of Fribourg Drosophila larvae are able to associate odor stimuli with gustatory reward. Here we describe a simple behavioral paradigm that allows the analysis of appetitive associative olfactory learning.

• Medicine

  
  Induction of Myocardial Infarction in Adult Zebrafish Using Cryoinjury Fabian Chablais¹, Anna Jaźwińska^{1 1}Department of Biology, Unit of Zoology, University of Fribourg, Fribourg, Switzerland Zebrafish represents a valuable model to study the mechanisms of heart regeneration in vertebrates. Here, we present a protocol for induction of a heart infarct in adult zebrafish using cryoinjury. This method results in massive cell death within 20% of the ventricular wall, similar to that observed in mammalian infarcts.

• Neuroscience

  
  Behavioral Assessment of Manual Dexterity in Non-Human Primates Eric Schmidlin*¹, Mélanie Kaeser*¹, Anne- Dominique Gindrat¹, Julie Savidan¹, Pauline Chatagny¹, Simon Badoud¹, Adjia Hamadjida¹, Marie-Laure Beaud¹, Thierry Wannier¹, Abderraouf Belhaj-Saif¹, Eric M. Rouiller^{1 1}Department of Medicine, University of Fribourg As manual dexterity is a prerogative mainly of primates, behavioral tasks have been developed in macaque monkeys. Four reach and grasp prehension tasks, measuring hand manipulation ability and force, allow to establish functional recovery after a lesion of the central nervous system and to test the effect of a treatment.