Prospective Identification and Purification of Quiescent Adult Neural Stem Cells from Their In Vivo Niche

Highlights

• CD133 is expressed by qNSCs and activated adult neural stem cells

• qNSCs are largely dormant and neurogenic in vivo but rarely form colonies in vitro

• qNSCs are Nestin negative and upregulate Nestin on activation

• GPCR ligands actively maintain the quiescent state of qNSCs

Summary

Adult neurogenic niches harbor quiescent neural stem cells; however, their in vivo identity has been elusive. Here, we prospectively isolate GFAP⁺CD133⁺ (quiescent neural stem cells [qNSCs]) and GFAP⁺CD133⁺EGFR⁺ (activated neural stem cells [aNSCs]) from the adult ventricular-subventricular zone. aNSCs are rapidly cycling, highly neurogenic in vivo, and enriched in colony-forming cells in vitro. In contrast, qNSCs are largely dormant in vivo, generate olfactory bulb interneurons with slower kinetics, and only rarely form colonies in vitro. Moreover, qNSCs are Nestin negative, a marker widely used for neural stem cells. Upon activation, qNSCs upregulate Nestin and EGFR and become highly proliferative. Notably, qNSCs and aNSCs can interconvert in vitro. Transcriptome analysis reveals that qNSCs share features with quiescent stem cells from other organs. Finally, small-molecule screening identified the GPCR ligands, S1P and PGD₂, as factors that actively maintain the quiescent state of qNSCs.