Canonical Wnt signaling regulates NG2 glia fate and plasticity in healthy and ischemic cortex

Abstract NG2 glia, also known as oligodendrocyte precursor cells, display unexpected plasticity in the adult brain after injury, yet the molecular cues guiding their fate remain unclear. The Wnt signaling pathway contributes to post-stroke responses, but its role in glial remodeling is not well defined. Here, we show that Wnt/β-catenin signaling regulates NG2 glial fate after focal cerebral ischemia. Using genetic mouse models combined with single-cell RNA sequencing, histology, and electrophysiology, we identify twelve transcriptionally distinct oligodendroglial subpopulations, including astrocyte-like cells. Wnt hyperactivation shifts the balance from oligodendrocyte differentiation toward expansion of astrocyte-like cells derived from NG2-expressing cells and maintenance of a progenitor-like state, likely through Notch signaling. Notably, Wnt hyperactivation induces the emergence of cholinergic neuron-like cells from NG2-expressing cells in the somatosensory cortex, which display voltage-dependent sodium conductance and action potentials. These findings demonstrate that NG2 glial plasticity after stroke is regulated by Wnt signaling and suggest that its modulation may enable directed lineage reprogramming in the injured adult brain.