Beclin1 Regulates Adult Hippocampal Neurogenesis

Abstract

Adult neurogenesis is a process that produces neurons in the adult brain and garners potential for the development of novel therapeutic interventions to combat neurodegenerative and other brain related diseases. With the hope of increasing neurogenesis, active investigations are defining the cellular and molecular mechanisms that regulate adult neural precursor cell (NPC) survival, and thus maintain neurogenesis. Recently, autophagy, an intracellular recycling pathway, has been implicated in regulating adult NPCs in embryonic knockout mice models. Whether autophagy has a similar effect within the adult and how autophagy regulates development of adult NPC remains unknown. Here, we investigate the role of Beclin1, a gene responsible for autophagy induction, in adult hippocampal NPC function in mice. Retroviral-mediated removal of Beclin1 from proliferating adult NPCs in vivo led to a reduction in the survival of adult-born neurons. In addition, Beclin1 was removed specifically from nestin-expressing adult neural stem- and progenitor-cells through the development of a Beclin1 nestin-inducible knockout mouse. Beclin1 nKO mice had a reduction in NPC proliferation and development, and overall fewer adult-generated neurons. Together, these findings reveal Beclin1 is required for adult hippocampal neurogenesis through regulating the proliferation and survival of the NPCs, in the absence of changing NPC fate.