Cell-specific Studies Through Novel Mouse Model Reveal the Transcriptomic Response of Retinal Müller Glia to Acute and Chronic Stress [Aging]

ABSTRACT: Epigenetic regulation of the genome through DNA modifications, mainly methylcytosine (mC) and hydroxymethylcytosine (hmC), alters DNA accessibility, genomic organization and gene expression and is thought to be altered during neurodegenerative diseases, such as  age-related macular degeneration (AMD). Analysis of retina epigenetic and transcriptomic signatures at the cell-type specific level is crucial to understanding the pathophysiology of retinal degeneration. We have discovered that Aldh1l1 is specifically expressed in the major macroglia of the retina, the Müller glia, and, unlike the brain, is not expressed in retinal astrocytes. This allows a novel model to study paired epigenetic and transcriptomic signatures in Müller glia using Nuclear Tagging and Translating Ribosome Affinity Purification (NuTRAP) for temporally controlled labeling and isolation of Müller glial DNA and RNA. As validated through a variety of approaches, the Aldh1l1cre/ERT2-NuTRAP model provides Müller glia specific translatome and epigenome profiles. Application of this approach to models of acute injury (optic nerve crush) and chronic stress (aging) uncovered common Müller glia-specific transcriptome changes in inflammatory pathways, as well as differential signatures for each stimulus. The expression of components of the IL1b signalling axis, complement system, and markers of gliosis was enhanced in Müller glia in response to optic nerve crush but not in response to aging. The expression of components of the purinergic receptor and focal adhesion signalling pathways changed uniquely in response to aging but not with optic nerve crush. The Aldh1l1cre/ERT2-NuTRAP model allows focusing molecular analyses to a single, minority cell type within the retina, providing more substantial effect sizes than whole tissue analyses. The NuTRAP model, nucleic acid isolation, and ­validation approaches presented here can be applied to any retina cell type for which a cell type-specific cre is available.

ORGANISM(S): Mus musculus

PROVIDER: GSE197481 | GEO | 2022/11/15

REPOSITORIES: GEO