RRC ID 65578
Author Ueda Y, Shimizu Y, Shimizu N, Ishitani T, Ohshima T.
Title Involvement of sonic hedgehog and notch signaling in regenerative neurogenesis in adult zebrafish optic tectum after stab injury.
Journal 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 and suppresses their differentiation into neurons after stab injury. In contrast, Notch signaling was down-regulated after stab injury, indicated by the decrease in the 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.
Volume 526(15)
Pages 2360-2372
Published 2018-10-15
DOI 10.1002/cne.24489
PMID 30014463
MeSH 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*
IF 2.801
Zebrafish RIKEN WT Tg(8xGliBS-miniP: dEGFP)