title: Stat3 defines three populations of Müller glia and is required for initiating maximal müller glia proliferation in the regenerating zebrafish retina.
abstract: We analyzed the role of Stat3, Ascl1a, and Lin28a in Müller glia reentry into the cell cycle following damage to the zebrafish retina. Immunohistochemical analysis was employed to determine the temporal and spatial expression of Stat3 and Ascl1a proteins following rod and cone photoreceptor cell apoptosis. Stat3 expression was observed in all Müller glia, whereas Ascl1a expression was restricted to only the mitotic Müller glia. Knockdown of Stat3 protein expression did not affect photoreceptor apoptosis, but significantly reduced, without abolishing, the number of proliferating Ascl1a-positive Müller glia. Knockdown of Ascl1a protein also did not change the extent of photoreceptor apoptosis, but did yield significantly fewer Müller glia that reentered the cell cycle relative to the stat3 morphant and significantly decreased the number and intensity of Stat3-expressing Müller glia. Finally, introduction of lin28a morpholinos resulted in decreased Müller glia expression of Stat3 and Ascl1a, significantly reducing the number of proliferating Müller glia. Thus, there are three populations of Müller glia in the light-damaged zebrafish retina: 1) Stat3-expressing Ascl1a-nonexpressing nonproliferating (quiescent) Müller glia; 2) Stat3-dependent Ascl1a-dependent proliferating Müller glia; and 3) Stat3-independent Ascl1a-dependent proliferating Müller glia. Whereas Ascl1a and Lin28a are required for Müller glia proliferation, Stat3 is necessary for the maximal number of Müller glia to proliferate during regeneration of the damaged zebrafish retina.
authors.affiliation: Department of Biological Sciences and the Center for Zebrafish Research, Galvin Life Science Building, University of Notre Dame, Notre Dame, Indiana 46556, USA.
authors.forename: Craig M
authors.initials: CM
authors.lastname: Nelson
authors.forename: Ryne A
authors.initials: RA
authors.lastname: Gorsuch
authors.forename: Travis J
authors.initials: TJ
authors.lastname: Bailey
authors.forename: Kristin M
authors.initials: KM
authors.lastname: Ackerman
authors.forename: Sean C
authors.initials: SC
authors.lastname: Kassen
authors.forename: David R
authors.initials: DR
authors.lastname: Hyde
mesh_terms: D000199:Actins / Q000235:genetics / Q000378:metabolism; D000221:Adaptation, Ocular; D000818:Animals; D030801:Animals, Genetically Modified; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D002452:Cell Count; D049109:Cell Proliferation; D005786:Gene Expression Regulation / Q000528:radiation effects; D005904:Glial Fibrillary Acidic Protein / Q000235:genetics; D049452:Green Fluorescent Proteins / Q000235:genetics; D008027:Light / Q000009:adverse effects; D055495:Neurogenesis / Q000502:physiology*; D009457:Neuroglia / Q000145:classification / Q000378:metabolism*; D018809:Proliferating Cell Nuclear Antigen / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012160:Retina / Q000473:pathology*; D012164:Retinal Diseases / Q000209:etiology / Q000473:pathology*; D050796:STAT3 Transcription Factor / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D000199:Actins; D051792:Basic Helix-Loop-Helix Proteins; D005904:Glial Fibrillary Acidic Protein; D049452:Green Fluorescent Proteins; D018809:Proliferating Cell Nuclear Antigen; D012333:RNA, Messenger; D050796:STAT3 Transcription Factor; D014157:Transcription Factors; D029961:Zebrafish Proteins; C468127:Ascl1a protein, zebrafish; C485184:enhanced green fluorescent protein