Anna Jazwinska Müller
Injuries to human organs, such as the limbs and the heart, result in persistent pathologic conditions. By contrast, zebrafish can completely reconstitute parts of their fins, hearts, retinas and spinal cords. Regeneration in zebrafish predominantly relies on the intrinsic plasticity of mature tissues. This property involves activation of the remaining tissue at the site of injury to promote cell division, cell migration and replacement of the missing structures. Which biological mechanisms guide the mature cells through the regeneration process? How do systemic factors modulate this process? Do regenerative programs of different organs rely on conserved mechanisms? In our research, we address these questions focusing on heart and fin regeneration in zebrafish. Our methods rely on pharmacological approaches and transgenic animals.
Adult zebrafish can regenerate their hearts within 1 to 2 months after damage. Several years ago, our laboratory established a cryoinjury-induced myocardial infarction model in zebrafish, whereby a freezing-thawing procedure destroys approx. 20% of the ventricle. We have since identified several signaling pathways that are required for heart restoration. We also found specific extracellular matrix components that are beneficial for regeneration. Our experiments revealed that the myocardium adjacent to the injury undergoes dedifferentiation, during which embryonic cardiac programs become reactivated to give rise to new tissue. We also reported that the natural power of heart regeneration in zebrafish can be suppressed by a daily hour of stress, such as crowding. By contrast, preconditioning, the application of a small remote noxious stimulus before injury, boosts heart regeneration. We are currently investigating the regenerative capacity of specific cardiac cell populations and comparing the restorative programs of different fish species.
The zebrafish fin is a multi-tissue appendage, the correct pattern and size of which can be restablished within 3 weeks after amputation. First, the fin margin is covered by a wound epithelium, and next a proliferative blastema arises by dedifferentiation of stump tissues near the amputation. Our laboratory identified signalling pathways that orchestrate proliferation, migration and patterning of different tissues in the regenerating fin. Furthermore, we identified that chromatin modification is critical for redifferentiation of blastema cells. Regarding extracellular matrix, we characterized the dynamics and regulation of the regeneration of actinotrichia, which are fin-specific skeletal structures. Our fate mapping experiments demonstrated that the activated mesenchyme of the stump gives rise to the blastema. We are currently investigating which adhesion mechanisms organize the different cells types during fin regeneration.
The lab of Anna Jazwinska investigates the biological processes of organ regeneration in zebrafish. Her lab established the cryoinjury model system for inducing myocardial infarction in adult fish. Her research identified the preconditioning phenomenon in the zebrafish heart. The focus of her studies includes the coordination of wound repair and functional regeneration of tissues in fish. Her work combines cell and molecular biology, genetics, microscopy, imaging and statistics. Ultimate goal is an improved understanding of the cellular plasticity of mature functional organs in vertebrates.
Nationality: Swiss and Polish
1990 – 1995 Study of biology at the University of Warsaw, Poland
1995 – 1996 Study of biology at the King’s College London England
June 1996 Master’s degree in biology at the University of Warsaw, Poland
1996 – 2000 work for PhD in the lab of Prof. Siegried Roth at the Max-Planck Institut für Entwicklungsbiologie in Tübingen, Germany
June, 2000 PhD degree in developmental biology at the University of Cologne, Germany
“The role of brinker during embryogenesis and patterning of imaginal discs in Drosophila”
2000 – 2003 Postdoctoral fellow in the lab of Markus Affolter at the Biozentrum of the University Basel, Switzerland
2004 – 2005 Postdoctoral fellow in Mark T. Keating’s lab at Children’s Hospital Boston, Harvard Medical School, Boston, USA
2005 – 2007 Instructor at the Department of Pediatrics, Harvard Medical School and Associate Researcherat the Department of Cardiology, Children’s Hospital Boston, USA
2008 – 2010 Lecturer at the Department of Medicine, University of Fribourg, Switzerland
Since 08/2010 Associate Professor at the Department of Biology at the University of Fribourg
2017 – 2021 Chair of the Swiss Stem Cell Network, organization of the SSCN website
2019 – 2022 Scientific Delegate of Switzerland to the council of European Molecular Biology Organization (EMBO)
2019 – 2022 Scientific Delegate of Switzerland to the council of European Molecular Biology Laboratory (EMBL)
Since 2019 Representative of the University of Fribourg in the Strategic Board of the Swss Animal Facilities Network (SAFN)