ASCL1 reprograms mouse Muller glia into neurogenic retinal progenitors

Area of Science:

• Neuroscience
• Developmental Biology
• Ophthalmology

Background:

• Mammalian Müller glia (MG) exhibit limited retinal regeneration compared to non-mammalian vertebrates.
• This regenerative failure is linked to the inability of mammalian MG to upregulate the proneural gene Achaete-scute homolog 1 (Ascl1) following injury.

Purpose of the Study:

• To investigate if overexpressing Ascl1 can restore the neurogenic potential of mammalian MG.
• To determine if Ascl1 can reprogram mature MG into neural progenitor cells capable of neuronal differentiation.

Main Methods:

• Overexpression of ASCL1 in cultured mouse MG and intact retinal explants.
• Analysis of gene expression changes, including upregulation of progenitor genes and downregulation of glial genes.
• Chromatin remodeling assessment to evaluate changes in gene accessibility.

Main Results:

• ASCL1 overexpression reprogrammed MG, leading to the upregulation of retinal progenitor-specific genes.
• Infected MG downregulated glial markers and exhibited chromatin remodeling towards an active configuration at target genes.
• MG-derived progenitors differentiated into cells with neuronal morphologies, expressed neuronal markers, and showed physiological responses.

Conclusions:

• A single transcription factor, ASCL1, is sufficient to induce a neurogenic state in mature mammalian MG.
• This finding highlights the potential of Ascl1 as a therapeutic target for retinal regeneration in mammals.