title: Aging brain microenvironment decreases hippocampal neurogenesis through Wnt-mediated survivin signaling.
abstract: Accumulating evidence suggests that adult hippocampal neurogenesis relies on the controlled and continued proliferation of neural progenitor cells (NPCs). With age, neurogenesis decreases through mechanisms that remain unclear but are believed to involve changes in the NPC microenvironment. Here, we provide evidence that NPC proliferation in the adult brain is in part regulated by astrocytes via Wnt signaling and that this cellular cross-talk is modified in the aging brain, leading to decreased proliferation of NPCs. Furthermore, we show that astrocytes regulate the NPC cell cycle by acting on the expression levels of survivin, a known mitotic regulator. Among cell cycle genes found down-regulated in aged NPCs, survivin was the only one that restored NPC proliferation in the aged brain. Our results provide a mechanism for the gradual loss of neurogenesis in the brain associated with aging and suggest that targeted modulation of survivin expression directly or through Wnt signaling could be used to stimulate adult neurogenesis.
authors.affiliation: Center for Gene Therapy, Nationwide Children's Hospital Research Institute, Columbus, OH 43205, USA.
authors.forename: Carlos J
authors.initials: CJ
authors.lastname: Miranda
authors.forename: Lyndsey
authors.initials: L
authors.lastname: Braun
authors.forename: Yuying
authors.initials: Y
authors.lastname: Jiang
authors.forename: Mark E
authors.initials: ME
authors.lastname: Hester
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.forename: Matthew
authors.initials: M
authors.lastname: Riolo
authors.forename: Haijuan
authors.initials: H
authors.lastname: Wang
authors.forename: Meghan
authors.initials: M
authors.lastname: Rao
authors.forename: Rachel A
authors.initials: RA
authors.lastname: Altura
authors.forename: Brian K
authors.initials: BK
authors.lastname: Kaspar
mesh_terms: D000375:Aging / Q000502:physiology; D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology; D048708:Cell Growth Processes / Q000502:physiology; D006624:Hippocampus / Q000166:cytology* / Q000378:metabolism; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins / Q000378:metabolism*; D051379:Mice; D058953:Neural Stem Cells / Q000166:cytology* / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism*; D015398:Signal Transduction; D000077022:Survivin; D051153:Wnt Proteins / Q000378:metabolism*; D060449:Wnt Signaling Pathway
chemical_list: C107489:BIRC5 protein, human; C117749:Birc5 protein, mouse; D051034:Inhibitor of Apoptosis Proteins; D012097:Repressor Proteins; D000077022:Survivin; D051153:Wnt Proteins