Cell Reports (Aug 2020)

Local Translation in Perisynaptic Astrocytic Processes Is Specific and Changes after Fear Conditioning

  • Noémie Mazaré,
  • Marc Oudart,
  • Julien Moulard,
  • Giselle Cheung,
  • Romain Tortuyaux,
  • Philippe Mailly,
  • David Mazaud,
  • Alexis-Pierre Bemelmans,
  • Anne-Cécile Boulay,
  • Corinne Blugeon,
  • Laurent Jourdren,
  • Stéphane Le Crom,
  • Nathalie Rouach,
  • Martine Cohen-Salmon

Journal volume & issue
Vol. 32, no. 8
p. 108076

Abstract

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Summary: Local translation is a conserved mechanism conferring cells the ability to quickly respond to local stimuli. In the brain, it has been recently reported in astrocytes, whose fine processes contact blood vessels and synapses. Yet the specificity and regulation of astrocyte local translation remain unknown. We study hippocampal perisynaptic astrocytic processes (PAPs) and show that they contain the machinery for translation. Using a refined immunoprecipitation technique, we characterize the entire pool of ribosome-bound mRNAs in PAPs and compare it with the one expressed in the whole astrocyte. We find that a specific pool of mRNAs is highly polarized at the synaptic interface. These transcripts encode an unexpected molecular repertoire, composed of proteins involved in iron homeostasis, translation, cell cycle, and cytoskeleton. Remarkably, we observe alterations in global RNA distribution and ribosome-bound status of some PAP-enriched transcripts after fear conditioning, indicating the role of astrocytic local translation in memory and learning.

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