A self-renewing division of zebrafish Müller glial cells generates neuronal progenitors that require N-cadherin to regenerate retinal neurons

Abstract

Müller glia function as retinal stem cells in adult zebrafish. In response to loss of retinal neurons, Müller glia partially dedifferentiate, re-express neuroepithelial markers and re-enter the cell cycle. We show that the immunoglobulin superfamily adhesion molecule Alcama is a novel marker of multipotent retinal stem cells, including injury-induced Müller glia, and that each Müller glial cell divides asymmetrically only once to produce an Alcama-negative, proliferating retinal progenitor. The initial mitotic division of Müller glia involves interkinetic nuclear migration, but mitosis of retinal progenitors occurs in situ. Rapidly dividing retinal progenitors form neurogenic clusters tightly associated with Alcama/N-cadherinlabeled Müller glial radial processes. Genetic suppression of Ncadherin function interferes with basal migration of retinal progenitors and subsequent regeneration of HuC/D + inner retinal neurons.

The bHLH Transcription Factor NeuroD Governs Photoreceptor Genesis and Regeneration Through Delta-Notch Signaling

“…Within 24 to 48 hours after light onset (hpl), a subset of Müller glia divides once, each producing a mitotic daughter cell that subsequently divides multiple times to produce a cluster of neurogenic progenitors. 30 Therefore, in the present study, 48 hpl was the earliest time point analyzed for progenitor markers. In situ hybridization and immunohistochemistry showed that the progenitor cell marker pax6a and the photoreceptor lineage marker nr2e3 are expressed in proliferating cell nuclear antigenpositive (PCNAþ) cells by 56 hpl (Fig.…”

Interkinetic Nuclear Migration in the Regenerating Retina

“…Recently, Müller glia nuclei were observed to translocate from their typical basal inner nuclear layer (INL) position to the ONL, where they colabel with the mitotic marker phospho-histone-3 (pH3). The subsequent return of the arising NPCs to the basal INL gave the first evidence that INM also occurs in the light-damaged zebrafish retina (Lahne & Hyde, unpublished data; Nagashima et al 2013). Interestingly, ablation of ganglion cells and INL neurons by ouabain, also induced Müller glia nuclei to migrate apically; however, most of these Müller glia remained in the apical INL and those that passed into the ONL did not attach to the outer limiting membrane (Nagashima et al 2013).…”

“…The subsequent return of the arising NPCs to the basal INL gave the first evidence that INM also occurs in the light-damaged zebrafish retina (Lahne & Hyde, unpublished data; Nagashima et al 2013). Interestingly, ablation of ganglion cells and INL neurons by ouabain, also induced Müller glia nuclei to migrate apically; however, most of these Müller glia remained in the apical INL and those that passed into the ONL did not attach to the outer limiting membrane (Nagashima et al 2013). This raises the question as to the signal(s) that impose(s) the directionality of this nuclear migration specifically towards the apical site of the retina.…”

“…Recently, an additional event, interkinetic nuclear migration (INM) of Mül-ler glia nuclei, was observed in the regenerating light-damaged retina ( Fig. 78.1, (Nagashima et al 2013)). INM is the movement of nuclei between the apical and basal limits of epithelia in phase with the cell cycle and has been studied in the developing retina, brain and neural tube (Pearson et al 2005;Baye and Link 2007;Del Bene et al 2008;Norden et al 2009;Lee and Norden 2013).…”

Characterization of a Spontaneously Immortalized Murine Müller Glial Cell Line QMMuC-1

“…For instance, in response to acute retinal damage, Müller glia from fish and adult birds may re-enter the mitotic cycle, proliferate, and de-differentiate into neurons. 8,9 In mammals, they can proliferate and express genes that are associated with retinal stem cells, [10][11][12] but do not appear to function as retinal progenitors in vivo. 13 Müller glial cultures have made a significant contribution for understanding retinal pathophysiology, especially in the context of retinal degenerative diseases.…”