title: Expression and function of orphan nuclear receptor TLX in adult neural stem cells.
abstract: The finding of neurogenesis in the adult brain led to the discovery of adult neural stem cells. TLX was initially identified as an orphan nuclear receptor expressed in vertebrate forebrains and is highly expressed in the adult brain. The brains of TLX-null mice have been reported to have no obvious defects during embryogenesis; however, mature mice suffer from retinopathies, severe limbic defects, aggressiveness, reduced copulation and progressively violent behaviour. Here we show that TLX maintains adult neural stem cells in an undifferentiated, proliferative state. We show that TLX-expressing cells isolated by fluorescence-activated cell sorting (FACS) from adult brains can proliferate, self-renew and differentiate into all neural cell types in vitro. By contrast, TLX-null cells isolated from adult mutant brains fail to proliferate. Reintroducing TLX into FACS-sorted TLX-null cells rescues their ability to proliferate and to self-renew. In vivo, TLX mutant mice show a loss of cell proliferation and reduced labelling of nestin in neurogenic areas in the adult brain. TLX can silence glia-specific expression of the astrocyte marker GFAP in neural stem cells, suggesting that transcriptional repression may be crucial in maintaining the undifferentiated state of these cells.
authors.affiliation: Gene Expression Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, USA.
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Shi
authors.forename: D
authors.initials: D
authors.lastname: Chichung Lie
authors.forename: Philippe
authors.initials: P
authors.lastname: Taupin
authors.forename: Kinichi
authors.initials: K
authors.lastname: Nakashima
authors.forename: Jasodhara
authors.initials: J
authors.lastname: Ray
authors.forename: Ruth T
authors.initials: RT
authors.lastname: Yu
authors.forename: Fred H
authors.initials: FH
authors.lastname: Gage
authors.forename: Ronald M
authors.initials: RM
authors.lastname: Evans
mesh_terms: D000375:Aging; D000818:Animals; D001973:Bromodeoxyuridine / Q000378:metabolism; D002454:Cell Differentiation; D002455:Cell Division; D002460:Cell Line; D002999:Clone Cells / Q000166:cytology / Q000378:metabolism; D017353:Gene Deletion; D018507:Gene Expression Regulation, Developmental; D020868:Gene Silencing; D007381:Intermediate Filament Proteins / Q000378:metabolism; D051379:Mice; D039902:Multipotent Stem Cells / Q000166:cytology / Q000378:metabolism; D009419:Nerve Tissue Proteins; D064231:Nestin; D009457:Neuroglia / Q000166:cytology / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D016548:Prosencephalon / Q000166:cytology* / Q000378:metabolism*; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism*; D012097:Repressor Proteins / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*
chemical_list: D007381:Intermediate Filament Proteins; D009419:Nerve Tissue Proteins; C577485:Nes protein, mouse; D064231:Nestin; C490258:Nr2e1 protein, mouse; D018160:Receptors, Cytoplasmic and Nuclear; D012097:Repressor Proteins; D001973:Bromodeoxyuridine