title: mTOR regulates brain morphogenesis by mediating GSK3 signaling.
abstract: Balanced control of neural progenitor maintenance and neuron production is crucial in establishing functional neural circuits during brain development, and abnormalities in this process are implicated in many neurological diseases. However, the regulatory mechanisms of neural progenitor homeostasis remain poorly understood. Here, we show that mammalian target of rapamycin (mTOR) is required for maintaining neural progenitor pools and plays a key role in mediating glycogen synthase kinase 3 (GSK3) signaling during brain development. First, we generated and characterized conditional mutant mice exhibiting deletion of mTOR in neural progenitors and neurons in the developing brain using Nestin-cre and Nex-cre lines, respectively. The elimination of mTOR resulted in abnormal cell cycle progression of neural progenitors in the developing brain and thereby disruption of progenitor self-renewal. Accordingly, production of intermediate progenitors and postmitotic neurons were markedly suppressed. Next, we discovered that GSK3, a master regulator of neural progenitors, interacts with mTOR and controls its activity in cortical progenitors. Finally, we found that inactivation of mTOR activity suppresses the abnormal proliferation of neural progenitors induced by GSK3 deletion. Our findings reveal that the interaction between mTOR and GSK3 signaling plays an essential role in dynamic homeostasis of neural progenitors during brain development.
authors.affiliation: Developmental Neuroscience, Munroe-Meyer Institute, University of Nebraska Medical Center, Omaha, NE 68198, USA.
authors.forename: Minhan
authors.initials: M
authors.lastname: Ka
authors.affiliation: Humanitas Clinical and Research Center, University of Milan, Rozzano, Milan, Italy.
authors.forename: Gianluigi
authors.initials: G
authors.lastname: Condorelli
authors.affiliation: Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto M5G 1X5, Canada.
authors.forename: James R
authors.initials: JR
authors.lastname: Woodgett
authors.affiliation: Developmental Neuroscience, Munroe-Meyer Institute, University of Nebraska Medical Center, Omaha, NE 68198, USA wooyang.kim@unmc.edu.
authors.forename: Woo-Yang
authors.initials: WY
authors.lastname: Kim
mesh_terms: D000818:Animals; D001921:Brain / Q000166:cytology / Q000196:embryology* / Q000378:metabolism*; D002453:Cell Cycle / Q000235:genetics / Q000502:physiology; D002478:Cells, Cultured; D005260:Female; D038362:Glycogen Synthase Kinase 3 / Q000235:genetics / Q000378:metabolism*; D007150:Immunohistochemistry; D051379:Mice; D011247:Pregnancy; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology; D058570:TOR Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*
chemical_list: C546843:mTOR protein, mouse; D058570:TOR Serine-Threonine Kinases; D038362:Glycogen Synthase Kinase 3
keywords: GSK3; Mouse; Neural progenitor; Neurogenesis; Neuron positioning; mTOR