Re-evaluation of neuronal P2X7 expression using novel mouse models and a P2X7-specific nanobody
Karina Kaczmarek-Hajek,
Jiong Zhang,
Robin Kopp,
Antje Grosche,
Björn Rissiek,
Anika Saul,
Santina Bruzzone,
Tobias Engel,
Tina Jooss,
Anna Krautloher,
Stefanie Schuster,
Tim Magnus,
Christine Stadelmann,
Swetlana Sirko,
Friedrich Koch-Nolte,
Volker Eulenburg,
Annette Nicke
Affiliations
Karina Kaczmarek-Hajek
Department of Molecular Biology of Neuronal Signals, Max Planck Institute for Experimental Medicine, Göttingen, Germany
Jiong Zhang
Department of Molecular Biology of Neuronal Signals, Max Planck Institute for Experimental Medicine, Göttingen, Germany; Walther Straub Institute for Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, Munich, Germany
Walther Straub Institute for Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, Munich, Germany
Antje Grosche
Institute for Human Genetics, University of Regensburg, Regensburg, Germany; Department of Physiological Genomics, Ludwig-Maximilians-Universität München, München, Germany
Department of Physiological Genomics, Ludwig-Maximilians-Universität München, München, Germany; Institute of Stem Cell Research, Helmholtz Center Munich, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
Friedrich Koch-Nolte
Department of Immunology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
Institute of Biochemistry, University Erlangen-Nürnberg, Erlangen, Germany; Department of Anaesthesiology and Intensive Care Therapy, University of Leipzig, Leipzig, Germany
Department of Molecular Biology of Neuronal Signals, Max Planck Institute for Experimental Medicine, Göttingen, Germany; Walther Straub Institute for Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, Munich, Germany
The P2X7 channel is involved in the pathogenesis of various CNS diseases. An increasing number of studies suggest its presence in neurons where its putative functions remain controversial for more than a decade. To resolve this issue and to provide a model for analysis of P2X7 functions, we generated P2X7 BAC transgenic mice that allow visualization of functional EGFP-tagged P2X7 receptors in vivo. Extensive characterization of these mice revealed dominant P2X7-EGFP protein expression in microglia, Bergmann glia, and oligodendrocytes, but not in neurons. These findings were further validated by microglia- and oligodendrocyte-specific P2X7 deletion and a novel P2X7-specific nanobody. In addition to the first quantitative analysis of P2X7 protein expression in the CNS, we show potential consequences of its overexpression in ischemic retina and post-traumatic cerebral cortex grey matter. This novel mouse model overcomes previous limitations in P2X7 research and will help to determine its physiological roles and contribution to diseases.
