Multiple intrinsic factors act in concert with Lhx2 to direct retinal gliogenesis.
Müller glia (MG) are the principal glial cell type in the vertebrate retina. Recent work has identified the LIM homeodomain factor encoding gene Lhx2 as necessary for both Notch signaling and MG differentiation in late-stage retinal progenitor cells (RPCs). However, the extent to which Lhx2 interacts with other intrinsic regulators of MG differentiation is unclear. We investigated this question by investigating the effects of overexpression of multiple transcriptional regulators that are either known or hypothesized to control MG formation, in both wildtype and Lhx2-deficient RPCs. We observe that constitutively elevated Notch signaling, induced by N1ICD electroporation, inhibited gliogenesis in wildtype animals, but rescued MG development in Lhx2-deficient retinas. Electroporation of Nfia promoted the formation of cells with MG-like radial morphology, but did not drive expression of MG molecular markers. Plagl1 and Sox9 did not induce gliogenesis in wildtype animals, but nonetheless activated expression of the Müller marker P27(Kip1) in Lhx2-deficient cells. Finally, Sox2, Sox8, and Sox9 promoted amacrine cell formation in Lhx2-deficient cells, but not in wildtype retinas. These findings demonstrate that overexpression of individual gliogenic factors typically regulates only a subset of characteristic MG markers, and that these effects are differentially modulated by Lhx2.
Johns Hopkins University School of Medicine, Solomon H. Snyder Department of Neuroscience, Baltimore, 21205, USA.
Jimmy
J
de Melo
Johns Hopkins University School of Medicine, Solomon H. Snyder Department of Neuroscience, Baltimore, 21205, USA.
Brian S
BS
Clark
Johns Hopkins University School of Medicine, Solomon H. Snyder Department of Neuroscience, Baltimore, 21205, USA.|Johns Hopkins University School of Medicine, Department of Ophthalmology, Baltimore, 21205, USA.|Johns Hopkins University School of Medicine, Department of Neurology, Baltimore, 21205, USA.|Johns Hopkins University School of Medicine, Center for Human Systems Biology, Baltimore, 21205, USA.|Johns Hopkins University School of Medicine, Institute for Cell Engineering, Baltimore, 21205, USA.
Seth
S
Blackshaw
D000818:Animals; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics; D018274:Electroporation; D005136:Eye Proteins / Q000235:genetics / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D016147:Genes, Tumor Suppressor; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D060850:LIM-Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008815:Mice, Inbred Strains; D018345:Mice, Knockout; D051839:NFI Transcription Factors / Q000235:genetics / Q000378:metabolism; D046569:Neuroepithelial Cells / Q000502:physiology; D009457:Neuroglia / Q000166:cytology / Q000502:physiology*; D012160:Retina / Q000166:cytology* / Q000378:metabolism; D055747:SOX Transcription Factors / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D018797:Cell Cycle Proteins; D005136:Eye Proteins; D018398:Homeodomain Proteins; D060850:LIM-Homeodomain Proteins; C489784:Lhx2 protein, mouse; D051839:NFI Transcription Factors; C497646:Nfia protein, mouse; C498423:Plagl1 protein, mouse; C105441:Rax protein, mouse; D055747:SOX Transcription Factors; D014157:Transcription Factors