Prospective identification of functionally distinct stem cells and neurosphere-initiating cells in adult mouse forebrain
John K Mich,
Robert AJ Signer,
Daisuke Nakada,
André Pineda,
Rebecca J Burgess,
Tou Yia Vue,
Jane E Johnson,
Sean J Morrison
Affiliations
John K Mich
Department of Pediatrics, Children's Research Institute, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
Robert AJ Signer
Department of Pediatrics, Children's Research Institute, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
Daisuke Nakada
Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States
André Pineda
Department of Pediatrics, Children's Research Institute, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
Rebecca J Burgess
Department of Pediatrics, Children's Research Institute, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
Tou Yia Vue
Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, United States
Jane E Johnson
Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, United States
Sean J Morrison
Department of Pediatrics, Children's Research Institute, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
Neurosphere formation is commonly used as a surrogate for neural stem cell (NSC) function but the relationship between neurosphere-initiating cells (NICs) and NSCs remains unclear. We prospectively identified, and isolated by flow cytometry, adult mouse lateral ventricle subventricular zone (SVZ) NICs as GlastmidEGFRhighPlexinB2highCD24−/lowO4/PSA-NCAM−/lowTer119/CD45− (GEPCOT) cells. They were highly mitotic and short-lived in vivo based on fate-mapping with Ascl1CreERT2 and Dlx1CreERT2. In contrast, pre-GEPCOT cells were quiescent, expressed higher Glast, and lower EGFR and PlexinB2. Pre-GEPCOT cells could not form neurospheres but expressed the stem cell markers Slc1a3-CreERT, GFAP-CreERT2, Sox2CreERT2, and Gli1CreERT2 and were long-lived in vivo. While GEPCOT NICs were ablated by temozolomide, pre-GEPCOT cells survived and repopulated the SVZ. Conditional deletion of the Bmi-1 polycomb protein depleted pre-GEPCOT and GEPCOT cells, though pre-GEPCOT cells were more dependent upon Bmi-1 for Cdkn2a (p16Ink4a) repression. Our data distinguish quiescent NSCs from NICs and make it possible to study their properties in vivo.
