Reawakening the lost regenerative power of Müller glia: Epigenetic locks and immune gates in retinal repair

Neuronal regeneration in the adult central nervous system remains one of the most formidable challenges in neuroscience. Among glial cell populations, Müller glia of the retina embodies a striking paradox: in lower vertebrates, they readily dedifferentiate, proliferate, and regenerate all neuronal subtypes after injury, whereas in mammals, they enter a state of reactive gliosis, an initially protective but ultimately maladaptive response that amplifies inflammation and scarring. Comparative and mechanistic studies now trace this evolutionary trade-off to two intertwined barriers: a restrictive epigenetic landscape and a persistently pro-inflammatory microenvironment. Here, we synthesize emerging evidence on the epigenetic, transcriptional, and post-transcriptional programs that govern Müller glia reprogramming, with a focus on the crosstalk among chromatin accessibility, microRNA networks, and immune signaling. We also discuss combinatorial strategies, such as epigenetic modulators, transcription factor cocktails, and immune rebalancing, designed to unlock the neurogenic potential of mammalian Müller glia. Understanding and manipulating these multi-layered controls could not only enable functional retinal repair but also provide a conceptual framework for glia-to-neuron conversion across the central nervous system.