A nuclear role for miR-9 and Argonaute proteins in balancing quiescent and activated neural stem cell states
journal contributionposted on 2020-08-12, 13:27 authored by Shauna Katz, Delphine Cussigh, Noelia Urban, Isabelle Blomfield, Francois Guillemot, Laure Bally-Cuif, Marion Coolen
Throughout life, adult neural stem cells (NSCs) produce new neurons and glia that contribute to crucial brain functions. Quiescence is an essential protective feature of adult NSCs; however, the establishment and maintenance of this state remain poorly understood. We demonstrate that in the adult zebrafish pallium, the brain-enriched miR-9 is expressed exclusively in a subset of quiescent NSCs, highlighting a heterogeneity within these cells, and is necessary to maintain NSC quiescence. Strikingly, miR-9, along with Argonaute proteins (Agos), is localized to the nucleus of quiescent NSCs, and manipulating their nuclear/cytoplasmic ratio impacts quiescence. Mechanistically, miR-9 permits efficient Notch signaling to promote quiescence, and we identify the RISC protein TNRC6 as a mediator of miR-9/Agos nuclear localization in vivo. We propose a conserved non-canonical role for nuclear miR-9/Agos in controlling the balance between NSC quiescence and activation, a key step in maintaining adult germinal pools.
ArgonauteNotchadult neurogenesismiR-9neural stem cellquiescenceradial gliatelencephalonzebrafishAgingAnimalsArgonaute ProteinsCell CycleCell NucleusGene Expression RegulationMiceMicroRNAsModels, BiologicalNeural Stem CellsNeurogliaReceptors, NotchSignal TransductionTelencephalonZebrafishGuillemot FC0010890601 Biochemistry and Cell Biology