Redox-Dependent Igfbp2 Signaling Controls Brca1 DNA Damage Response to Govern Neural Stem Cell Fate

Neural stem cell (NSC) maintenance and functions are regulated by reactive oxygen species (ROS). However, the mechanisms by which ROS control NSC behavior remain unclear. Here we report that ROS-dependent Igfbp2 signaling controls DNA repair pathways which balance NSC self-renewal and lineage commitment. Ncf1 or Igfbp2 deficiency constrained NSCs to a self-renewing state and prevented neurosphere formation due to absent Igfbp2 cysteine-43 oxidation. Ncf1-dependent oxidation of Igfbp2 promoted neurogenesis by NSCs in vitro and in vivo, while repressing Brca1 DNA damage response genes and inducing DNA double-strand breaks (DDSBs). By contrast, Ncf1–/– and Igfbp2–/– NSCs favored the formation of oligodendrocytes in vitro and in vivo. Notably, transient repression of Brca1 DNA repair pathway genes induced DDSBs and was sufficient to rescue the ability of Ncf1–/– and Igfbp2–/– NSCs to lineage-commit to form neurospheres and neurons. Our study highlights the role of DNA damage/repair in orchestrating NSC fate decisions downstream of redox-regulated Igfbp2. NCF1KO, NCF1KO+IGFBP2, and WT neurospheres were subjected to RNAseq analysis