Structural plasticity of perisynaptic astrocyte processes involves ezrin and metabotropic glutamate receptors
| Autor: | Monique Arpin, Georg Aumann, Monique Lavialle, Felicitas Pröls, Amin Derouiche, Enrico Anlauf |
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| Přispěvatelé: | Laboratoire de nutrition et sécurité alimentaire, Institut National de la Recherche Agronomique (INRA), Technische Universität Dresden = Dresden University of Technology (TU Dresden), Universitaetsklinikum Hamburg-Eppendorf = University Medical Center Hamburg-Eppendorf [Hamburg] (UKE), Institut Curie [Paris], Institute for Anatomy and Cell Biology, Universität Ulm - Ulm University [Ulm, Allemagne], Institute of Cellular Neurosciences, Rheinische Friedrich-Wilhelms-Universität Bonn, Goethe-Universität Frankfurt am Main |
| Rok vydání: | 2011 |
| Předmět: |
Male
actin cytoskeleton [SDV]Life Sciences [q-bio] Receptors Metabotropic Glutamate Hippocampus Rats Sprague-Dawley Synapse 0302 clinical medicine Ezrin Pregnancy Postsynaptic potential Cricetinae Pseudopodia Microscopy Immunoelectron Cells Cultured 0303 health sciences Neuronal Plasticity Multidisciplinary Glial fibrillary acidic protein Glutamate receptor Biological Sciences Immunohistochemistry Cell biology medicine.anatomical_structure Female RNA Interference Filopodia noyau suprachiasmatique Astrocyte Receptor Metabotropic Glutamate 5 Green Fluorescent Proteins ERM proteins suprachiasmatic nucleus circadian regulation deconvolution Glutamic Acid macromolecular substances Biology 03 medical and health sciences Glial Fibrillary Acidic Protein medicine Animals variation circadienne 030304 developmental biology Mesocricetus Rats Cytosquelette d'actine (MreB) Cytoskeletal Proteins Microscopy Fluorescence nervous system Metabotropic glutamate receptor Astrocytes Synapses biology.protein 030217 neurology & neurosurgery |
| Zdroj: | Proceedings of the National Academy of Sciences of the United States of America Proceedings of the National Academy of Sciences of the United States of America, National Academy of Sciences, 2011, 108 (31), pp.12915-12919. ⟨10.1073/pnas.1100957108⟩ Proceedings of the National Academy of Sciences of the United States of America 31 (108), 12915-12919. (2011) |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.1100957108 |
| Popis: | The peripheral astrocyte process (PAP) preferentially associates with the synapse. The PAP, which is not found around every synapse, extends to or withdraws from it in an activity-dependent manner. Although the pre- and postsynaptic elements have been described in great molecular detail, relatively little is known about the PAP because of its difficult access for electrophysiology or light microscopy, as they are smaller than microscopic resolution. We investigated possible stimuli and mechanisms of PAP plasticity. Immunocytochemistry on rat brain sections demonstrates that the actin-binding protein ezrin and the metabotropic glutamate receptors (mGluRs) 3 and 5 are compartmentalized to the PAP but not to the GFAP-containing stem process. Further experiments applying ezrin siRNA or dominant-negative ezrin in primary astrocytes indicate that filopodia formation and motility require ezrin in the membrane/cytoskeleton bound (i.e., T567-phosphorylated) form. Glial processes around synapses in situ consistently display this ezrin form. Possible motility stimuli of perisynaptic glial processes were studied in culture, based on their similarity with filopodia. Glutamate and glutamate analogues reveal that rapid (5 min), glutamate-induced filopodia motility is mediated by mGluRs 3 and 5. Ultrastructurally, these mGluR subtypes were also localized in astrocytes in the rat hippocampus, preferentially in their fine PAPs. In vivo, changes in glutamatergic circadian activity in the hamster suprachiasmatic nucleus are accompanied by changes of ezrin immunoreactivity in the suprachiasmatic nucleus, in line with transmitter-induced perisynaptic glial motility. The data suggest that ( i ) ezrin is required for the structural plasticity of PAPs and ( ii ) mGluRs can stimulate PAP plasticity. |
| Databáze: | OpenAIRE |
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