Dataset Information

Direct neuronal reprogramming by temporal identity factors

ABSTRACT: Temporal identity factors are sufficient to reprogram developmental competence of neural progenitors and shift cell fate output, but whether they can also reprogram the identity of terminally differentiated cells is unknown. To address this question, we designed a conditional gene expression system that allows rapid screening of potential reprogramming factors in mouse retinal glial cells combined with genetic lineage tracing. Using this assay, we found that co-expression of the early temporal identity transcription factors Ikzf1 and Ikzf4 is sufficient to directly convert Müller glial cells into cells that translocate to the outer nuclear layer (ONL), where photoreceptor cells normally reside. We name these “induced ONL (iONL)” cells. Using genetic lineage tracing, histological, immunohistochemical, and single-cell transcriptome and multiome analyses, we show that expression of Ikzf1/4 in Müller glia in vivo, without retinal injury, mostly generate iONL cells that share molecular characteristics with bipolar cells, although a fraction of them stain for Rxrg, a cone photoreceptor marker. Furthermore, we show that co-expression of Ikzf1 and Ikzf4 can reprogram mouse embryonic fibroblasts to induced neurons (iN) in culture by rapidly remodeling chromatin and activating a neuronal gene expression program. This work uncovers general neuronal reprogramming properties for temporal identity factors in terminally differentiated cells.

ORGANISM(S): Mus musculus

PROVIDER: GSE169519 | GEO | 2023/05/04

REPOSITORIES: GEO

ACCESS DATA

Similar Datasets

Project description:Loss of neurons in the neural retina is a leading cause of vision loss. Retinal regeneration in zebrafish is attributed to Müller glia, which are activated, adopt a stem cell-like state, proliferate, and generate new neurons. Despite the same endogenous Müller glia being present in all vertebrates including humans, Müller glia activation in mammals leads to glial scarring instead of neurogenesis. Therefore, understanding Müller glia cellular states and molecular processes during zebrafish regeneration may allow us to improve mammalian regeneration. Since only a subset of Müller glia activate following neuron loss, we asked whether a specialised subset of Müller glia might be genetically primed for activation. Single-cell RNA sequencing (sc-RNAseq) from integrated zebrafish Müller glia samples reveals heterogeneity of gene expression across the quiescent Müller glia pool with 4 main clusters emerging, two of which are genetically similar. Labelling for key differentially expressed markers identified that these main clusters correlated with glia spatially distributed across dorsal, central and ventral retina. Using a genetically driven, chemically induced nitroreductase approach, three distinct photoreceptor types were ablated: the long (Lws2), short wavelength-sensitive (Sws2) and rod (Xops) photoreceptors, which also differ in their abundance. As expected, histological analysis of the three injuries and sc-RNAseq data for the two cone photoreceptor ablations identified common genetic program involved in the transition of Müller glia quiescence to activation, and differential responses to injury related to either injury extent or subtype of photoreceptor targeted. Interestingly, despite differences in the distributed across the retina, biased activation of Müller glia was observed in dorsal and central regions. Gene ontology analysis revealed that these injury-responsive dorsal and central Müller glia express genes related to dorsal/ventral pattern formation, growth factor activity, and regulation of developmental process. Müller glia upregulated genes related to homeostasis as well as certain AP-1 and injury-responsive transcription factors, followed by expression of genes involved in cell cycle, chromatin remodeling, and microtubule organisation. Prior to cell cycle entry, Müller glia show a transient upregulation of genes involved in gliogenesis, and Notch signalling. These findings enhance our understanding of heterogeneous states of quiescent Müller glia, and how these differences relate to activation and regeneration potential following neural ablation. A comparison of the distinct quiescent Müller glia with glia states in mammals will reveal key molecular pathways that could be targeted for improved mammalian neural regeneration.

Dataset Information

Direct neuronal reprogramming by temporal identity factors

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure