title: Ascl1a/Dkk/beta-catenin signaling pathway is necessary and glycogen synthase kinase-3beta inhibition is sufficient for zebrafish retina regeneration.
abstract: Key to successful retina regeneration in zebrafish are Müller glia (MG) that respond to retinal injury by dedifferentiating into a cycling population of retinal progenitors. Although recent studies have identified several genes involved in retina regeneration, the signaling mechanisms underlying injury-dependent MG proliferation have remained elusive. Here we report that canonical Wnt signaling controls the proliferation of MG-derived retinal progenitors. We found that injury-dependent induction of Ascl1a suppressed expression of the Wnt signaling inhibitor, Dkk, and induced expression of the Wnt ligand, Wnt4a. Genetic and pharmacological inhibition of Wnt signaling suppressed injury-dependent proliferation of MG-derived progenitors. Remarkably, in the uninjured retina, glycogen synthase kinase-3β (GSK-3β) inhibition was sufficient to stimulate MG dedifferentiation and the formation of multipotent retinal progenitors that were capable of differentiating into all major retinal cell types. Importantly, Ascl1a expression was found to contribute to the multipotential character of these progenitors. Our data suggest that Wnt signaling and GSK-3β inhibition, in particular, are crucial for successful retina regeneration.
authors.affiliation: Molecular and Behavioral Neuroscience Institute and Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Ramachandran
authors.forename: Xiao-Feng
authors.initials: XF
authors.lastname: Zhao
authors.forename: Daniel
authors.initials: D
authors.lastname: Goldman
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D054337:Cell Dedifferentiation / Q000187:drug effects / Q000235:genetics; D049109:Cell Proliferation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D020869:Gene Expression Profiling; D055785:Gene Knockdown Techniques; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D017403:In Situ Hybridization; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D008856:Microscopy, Fluorescence; D009457:Neuroglia / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D012038:Regeneration; D012160:Retina / Q000378:metabolism / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D013234:Stem Cells / Q000187:drug effects / Q000378:metabolism; D014157:Transcription Factors; D060528:Wnt4 Protein / Q000235:genetics / Q000378:metabolism; D015027:Zebrafish / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D029961:Zebrafish Proteins / Q000235:genetics* / Q000378:metabolism; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D004791:Enzyme Inhibitors; D038362:Glycogen Synthase Kinase 3; D000071679:Glycogen Synthase Kinase 3 beta; D049452:Green Fluorescent Proteins; D036341:Intercellular Signaling Peptides and Proteins; D014157:Transcription Factors; D060528:Wnt4 Protein; D029961:Zebrafish Proteins; D051176:beta Catenin; C468127:Ascl1a protein, zebrafish; C501128:dkk1b protein, zebrafish