FGF Signaling Potentiates Müller Glia for Mammalian Retinal Regeneration

Area of Science:

• Neuroscience
• Ophthalmology
• Regenerative Medicine

Background:

• Müller glia have latent regenerative potential for retinal repair.
• The role of fibroblast growth factor (FGF) signaling in mammalian retinal regeneration is not well understood.

Purpose of the Study:

• To investigate the function of FGF signaling in Müller glial reprogramming and retinal regeneration.
• To determine the molecular mechanisms by which FGF signaling regulates Müller glial regenerative capacity.

Main Methods:

• Genetic manipulation (conditional deletion of FGFR1/2 in Müller glia).
• Pharmacological inhibition and activation of signaling pathways (MEK/ERK, STAT3/5).
• Single-cell RNA sequencing (scRNA-seq) to analyze gene expression changes.
• Retinal injury models in mice.

Main Results:

• FGF signaling is essential for regenerative responses in Müller glia, as its deletion abolished regeneration induced by various pathways.
• Loss of FGF signaling impaired sustained ERK/MAPK activation post-injury.
• Constitutive MEK activation promoted limited Müller glial proliferation without injury.
• FGF signaling suppresses anti-regenerative programs like Hes1, S1pr1, p27, and NF-κB.

Conclusions:

• FGF signaling acts as a critical permissive regulator of mammalian retinal regeneration.
• It potentiates Müller glia by sustaining ERK activation and suppressing transcriptional barriers.
• Harnessing FGF signaling may offer therapeutic strategies for retinal neurodegeneration.