CANONICAL WNT SIGNALING ALTERS NG2 GLIA PLASTICITY AFTER ISCHEMIC STROKE

NG2 glia, also known as oligodendrocyte precursor cells, play an important role after focal cerebral ischemia (FCI) due to their plasticity. However, understanding the signaling mechanisms regulating their post-injury fate remains lacking. Given the involvement of Wnt signaling in tissue response to ischemic stroke, we investigated how canonical Wnt pathway modulation shapes NG2 glial responses in FCI. Using transgenic NG2CreER^TM BAC:Rosa26-tdTomato reporter mice combined with genetic modulation of Wnt/β-catenin signaling, we analyzed NG2 expressing cells and their progeny following middle cerebral artery occlusion. Single-cell RNA sequencing, immunohistochemistry, and electrophysiological recordings were used to assess transcriptional identity, cell fate, and functional properties. We identified 12 transcriptionally distinct subpopulations within the oligodendroglial lineage, encompassing basal and proliferative NG2 glia, astrocyte-like and perivascular-like NG2-expressing cells, and oligodendrocytes at different maturation stages. Wnt hyperactivation shifted lineage progression toward proliferative and astrocyte-like states while impairing oligodendrocyte maturation. Disruption of intrinsic Wnt signaling altered NG2 glial contribution to glial scar formation. Strikingly, Wnt hyperactivation induced the emergence of neuron-like cells from NG2 cells in the cortex. These cells expressed NeuN and exhibited electrophysiological properties consistent with neurons. These findings demonstrate that regulation of NG2 glia fate after FCI is sensitive to Wnt signaling and highlight its modulations as a potential approach to conduct reparative or neurogenic treatment in the injured adult brain.
This research is funded by the Czech Science Foundation (No. 24-10912S), Czech Academy of Sciences, Strategy AV21 (No. VP29), and Ministry of Education, Youth and Sports, ELIXIR CZ (No. LM2023055, LM2023050, CZ.02.1.01/0.0/0.0/18_046/0016045, and CZ.02.01.01/00/23_015/0008205).