# Transcriptional regulation of retinal cell differentiation and function

> **NIH NIH R01** · JOHNS HOPKINS UNIVERSITY · 2021 · $397,093

## Abstract

Project Summary
 Müller glia, which closely resemble retinal progenitor cells (RPCs) in their morphology and gene
expression profile, are the last cell type generated in the developing retina. Mammalian Müller glia, however,
rapidly lose the ability to proliferate and generate neurons following specification. The molecular mechanisms
that allow RPCs to become gliogenic, and lead Müller glia to lose neurogenic competence remain poorly
understood. We have recently identified the LIM homeodomain factor Lhx2 as a central regulator of MG
differentiation and function, and now seek to characterize its mechanism of action. Based on our preliminary
findings, we hypothesize that Lhx2 cooperates with NFI and SoxE factors to initiate gliogenesis. We propose
that NFI and SoxE factors bind to target sequences that control expression of gliogenic and glial-specific genes
in late-stage RPCs, which then exposes binding site for Lhx2. Lhx2 then induces chromatin opening at these
sites, which in turn leads to stable activation of these genes. In postmitotic glial precursors, in contrast, rising
levels of Rnf12 inhibit Ldb1/Lhx2-dependent transcriptional activation of neurogenic bHLH genes, eventually
leading to a permanent loss of neurogenic competence in mature Müller glia. We aim to determine how NFI,
SoxE, and Lhx2 act to drive glial differentiation and restrict neurogenic competence. We will first determine
whether NFI factors promote gliogenic competence and glial differentiation in retina. We will next test whether
NFI and SoxE directly regulate expression of gliogenic and glial-specific genes, and determine whether
selective loss of Lhx2 in differentiating glia reduces chromatin accessibility at cis-regulatory elements that
control glial-specific genes. We will also test whether NFI and SoxE direct target site selection by Lhx2 in late-
stage RPCs and glial precursors. In addition to these studies of how glial differentiation is controlled, we intend
to determine how Lhx2-dependent neurogenic competence is lost in differentiating Müller glia. We will
determine whether Rnf12 acts in an Lhx2-dependent manner to drive loss of neurogenic competence in
differentiating and mature Müller glia. Finally, we will identify molecules that mediate Lhx2-dependent
transcriptional repression in postnatal retina. We anticipate that a full understanding of the mechanism by
which Lhx2 regulates gliogenesis will identify key targets for drug and gene-based therapies aimed at restoring
vision through controlled dedifferentiation of Müller glia.

## Key facts

- **NIH application ID:** 10113622
- **Project number:** 5R01EY020560-11
- **Recipient organization:** JOHNS HOPKINS UNIVERSITY
- **Principal Investigator:** Seth Blackshaw
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $397,093
- **Award type:** 5
- **Project period:** 2010-12-01 → 2022-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10113622

## Citation

> US National Institutes of Health, RePORTER application 10113622, Transcriptional regulation of retinal cell differentiation and function (5R01EY020560-11). Retrieved via AI Analytics 2026-05-21 from https://api.ai-analytics.org/grant/nih/10113622. Licensed CC0.

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