ZFIN ID: ZDB-PUB-180718-6
Involvement of Sonic hedgehog and Notch signaling in regenerative neurogenesis in adult zebrafish optic tectum after stab injury
Ueda, Y., Shimizu, Y., Shimizu, N., Ishitani, T., Ohshima, T.
Date: 2018
Source: The Journal of comparative neurology   526(15): 2360-2372 (Journal)
Registered Authors: Ishitani, Tohru, Ohshima, Toshio, Shimizu, Nobuyuki, Shimizu, Yuki, Ueda, Yuto
Keywords: Notch signal, RRID: AB_10000325, RRID: AB_143165, RRID: AB_2160651, RRID: AB_221448, RRID: AB_2534069, RRID: AB_2534079, RRID: AB_2534083, RRID: AB_2534091, RRID: AB_2536183, RRID: AB_302659, RRID: AB_591823, Sonic hedgehog signal, neurogenesis, regeneration, zebrafish
MeSH Terms:
  • Animals
  • Animals, Genetically Modified
  • Anti-Inflammatory Agents/pharmacology
  • Cell Count
  • Cell Differentiation
  • Cell Proliferation
  • DNA/biosynthesis
  • DNA/genetics
  • Dexamethasone/pharmacology
  • Hedgehog Proteins*
  • Immunohistochemistry
  • Nerve Regeneration*
  • Neuroglia
  • Receptors, Notch*
  • Signal Transduction*
  • Superior Colliculi/growth & development*
  • Superior Colliculi/injuries*
  • Superior Colliculi/pathology
  • Wounds, Stab/pathology*
  • Zebrafish Proteins*
PubMed: 30014463 Full text @ J. Comp. Neurol.
ABSTRACT
Unlike humans and other mammals, adult zebrafish have the superior capability to recover from central nervous system (CNS) injury. We previously found that proliferation of radial glia (RG) is induced in response to stab injury in optic tectum and that new neurons are generated from RG after stab injury. However, molecular mechanisms which regulate proliferation and differentiation of RG are not well known. In the present study, we investigated Shh and Notch signaling as potential mechanisms regulating regeneration in the optic tectum of adult zebrafish. We used Shh reporter fish and confirmed that canonical Shh signaling is activated specifically in RG after stab injury. Moreover, we have shown that Shh signaling promotes RG proliferation suppresses their differentiation into neurons after stab injury. In contrast, Notch signaling was down-regulated after stab injury, indicated by the decrease in expression level of her4 and her6, a target gene of Notch signaling. We also found that inhibition of Notch signaling after stab injury, induced more proliferative RG, but that inhibition of Notch signaling inhibited generation of newborn neurons from RG after stab injury. These results suggest that high level of Notch signaling keeps RG quiescent and that appropriate level of Notch signaling is required for generation of newborn neurons from RG. Under physiological condition, activation of Shh signaling or inhibition of Notch signaling also induced RG proliferation. In adult optic tectum of zebrafish, canonical Shh signaling and Notch signaling play important roles in proliferation and differentiation of RG in physiological and regenerative conditions. This article is protected by copyright. All rights reserved.
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